Commit Graph

41788 Commits

Author SHA1 Message Date
Linus Torvalds
cec24b8b6b Char/Misc drivers for 6.4-rc1
Here is the "big" set of char/misc and other driver subsystems for
 6.4-rc1.
 
 It's pretty big, but due to the removal of pcmcia drivers, almost breaks
 even for number of lines added vs. removed, a nice change.
 
 Included in here are:
   - removal of unused PCMCIA drivers (finally!)
   - Interconnect driver updates and additions
   - Lots of IIO driver updates and additions
   - MHI driver updates
   - Coresight driver updates
   - NVMEM driver updates, which required some OF updates
   - W1 driver updates and a new maintainer to manage the subsystem
   - FPGA driver updates
   - New driver subsystem, CDX, for AMD systems
   - lots of other small driver updates and additions
 
 All of these have been in linux-next for a while with no reported
 issues.
 
 Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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Merge tag 'char-misc-6.4-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc

Pull char/misc drivers updates from Greg KH:
 "Here is the "big" set of char/misc and other driver subsystems for
  6.4-rc1.

  It's pretty big, but due to the removal of pcmcia drivers, almost
  breaks even for number of lines added vs. removed, a nice change.

  Included in here are:

   - removal of unused PCMCIA drivers (finally!)

   - Interconnect driver updates and additions

   - Lots of IIO driver updates and additions

   - MHI driver updates

   - Coresight driver updates

   - NVMEM driver updates, which required some OF updates

   - W1 driver updates and a new maintainer to manage the subsystem

   - FPGA driver updates

   - New driver subsystem, CDX, for AMD systems

   - lots of other small driver updates and additions

  All of these have been in linux-next for a while with no reported
  issues"

* tag 'char-misc-6.4-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc: (196 commits)
  mcb-lpc: Reallocate memory region to avoid memory overlapping
  mcb-pci: Reallocate memory region to avoid memory overlapping
  mcb: Return actual parsed size when reading chameleon table
  kernel/configs: Drop Android config fragments
  virt: acrn: Replace obsolete memalign() with posix_memalign()
  spmi: Add a check for remove callback when removing a SPMI driver
  spmi: fix W=1 kernel-doc warnings
  spmi: mtk-pmif: Drop of_match_ptr for ID table
  spmi: pmic-arb: Convert to platform remove callback returning void
  spmi: mtk-pmif: Convert to platform remove callback returning void
  spmi: hisi-spmi-controller: Convert to platform remove callback returning void
  w1: gpio: remove unnecessary ENOMEM messages
  w1: omap-hdq: remove unnecessary ENOMEM messages
  w1: omap-hdq: add SPDX tag
  w1: omap-hdq: allow compile testing
  w1: matrox: remove unnecessary ENOMEM messages
  w1: matrox: use inline over __inline__
  w1: matrox: switch from asm to linux header
  w1: ds2482: do not use assignment in if condition
  w1: ds2482: drop unnecessary header
  ...
2023-04-27 12:07:50 -07:00
Linus Torvalds
556eb8b791 Driver core changes for 6.4-rc1
Here is the large set of driver core changes for 6.4-rc1.
 
 Once again, a busy development cycle, with lots of changes happening in
 the driver core in the quest to be able to move "struct bus" and "struct
 class" into read-only memory, a task now complete with these changes.
 
 This will make the future rust interactions with the driver core more
 "provably correct" as well as providing more obvious lifetime rules for
 all busses and classes in the kernel.
 
 The changes required for this did touch many individual classes and
 busses as many callbacks were changed to take const * parameters
 instead.  All of these changes have been submitted to the various
 subsystem maintainers, giving them plenty of time to review, and most of
 them actually did so.
 
 Other than those changes, included in here are a small set of other
 things:
   - kobject logging improvements
   - cacheinfo improvements and updates
   - obligatory fw_devlink updates and fixes
   - documentation updates
   - device property cleanups and const * changes
   - firwmare loader dependency fixes.
 
 All of these have been in linux-next for a while with no reported
 problems.
 
 Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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Merge tag 'driver-core-6.4-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core

Pull driver core updates from Greg KH:
 "Here is the large set of driver core changes for 6.4-rc1.

  Once again, a busy development cycle, with lots of changes happening
  in the driver core in the quest to be able to move "struct bus" and
  "struct class" into read-only memory, a task now complete with these
  changes.

  This will make the future rust interactions with the driver core more
  "provably correct" as well as providing more obvious lifetime rules
  for all busses and classes in the kernel.

  The changes required for this did touch many individual classes and
  busses as many callbacks were changed to take const * parameters
  instead. All of these changes have been submitted to the various
  subsystem maintainers, giving them plenty of time to review, and most
  of them actually did so.

  Other than those changes, included in here are a small set of other
  things:

   - kobject logging improvements

   - cacheinfo improvements and updates

   - obligatory fw_devlink updates and fixes

   - documentation updates

   - device property cleanups and const * changes

   - firwmare loader dependency fixes.

  All of these have been in linux-next for a while with no reported
  problems"

* tag 'driver-core-6.4-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core: (120 commits)
  device property: make device_property functions take const device *
  driver core: update comments in device_rename()
  driver core: Don't require dynamic_debug for initcall_debug probe timing
  firmware_loader: rework crypto dependencies
  firmware_loader: Strip off \n from customized path
  zram: fix up permission for the hot_add sysfs file
  cacheinfo: Add use_arch[|_cache]_info field/function
  arch_topology: Remove early cacheinfo error message if -ENOENT
  cacheinfo: Check cache properties are present in DT
  cacheinfo: Check sib_leaf in cache_leaves_are_shared()
  cacheinfo: Allow early level detection when DT/ACPI info is missing/broken
  cacheinfo: Add arm64 early level initializer implementation
  cacheinfo: Add arch specific early level initializer
  tty: make tty_class a static const structure
  driver core: class: remove struct class_interface * from callbacks
  driver core: class: mark the struct class in struct class_interface constant
  driver core: class: make class_register() take a const *
  driver core: class: mark class_release() as taking a const *
  driver core: remove incorrect comment for device_create*
  MIPS: vpe-cmp: remove module owner pointer from struct class usage.
  ...
2023-04-27 11:53:57 -07:00
Chen Yu
5904de0d73 PM: hibernate: Do not get block device exclusively in test_resume mode
The system refused to do a test_resume because it found that the
swap device has already been taken by someone else. Specifically,
the swsusp_check()->blkdev_get_by_dev(FMODE_EXCL) is supposed to
do this check.

Steps to reproduce:
 dd if=/dev/zero of=/swapfile bs=$(cat /proc/meminfo |
       awk '/MemTotal/ {print $2}') count=1024 conv=notrunc
 mkswap /swapfile
 swapon /swapfile
 swap-offset /swapfile
 echo 34816 > /sys/power/resume_offset
 echo test_resume > /sys/power/disk
 echo disk > /sys/power/state

 PM: Using 3 thread(s) for compression
 PM: Compressing and saving image data (293150 pages)...
 PM: Image saving progress:   0%
 PM: Image saving progress:  10%
 ata1: SATA link up 1.5 Gbps (SStatus 113 SControl 300)
 ata1.00: configured for UDMA/100
 ata2: SATA link down (SStatus 0 SControl 300)
 ata5: SATA link down (SStatus 0 SControl 300)
 ata6: SATA link down (SStatus 0 SControl 300)
 ata3: SATA link down (SStatus 0 SControl 300)
 ata4: SATA link down (SStatus 0 SControl 300)
 PM: Image saving progress:  20%
 PM: Image saving progress:  30%
 PM: Image saving progress:  40%
 PM: Image saving progress:  50%
 pcieport 0000:00:02.5: pciehp: Slot(0-5): No device found
 PM: Image saving progress:  60%
 PM: Image saving progress:  70%
 PM: Image saving progress:  80%
 PM: Image saving progress:  90%
 PM: Image saving done
 PM: hibernation: Wrote 1172600 kbytes in 2.70 seconds (434.29 MB/s)
 PM: S|
 PM: hibernation: Basic memory bitmaps freed
 PM: Image not found (code -16)

This is because when using the swapfile as the hibernation storage,
the block device where the swapfile is located has already been mounted
by the OS distribution(usually mounted as the rootfs). This is not
an issue for normal hibernation, because software_resume()->swsusp_check()
happens before the block device(rootfs) mount. But it is a problem for the
test_resume mode. Because when test_resume happens, the block device has
been mounted already.

Thus remove the FMODE_EXCL for test_resume mode. This would not be a
problem because in test_resume stage, the processes have already been
frozen, and the race condition described in
Commit 39fbef4b0f ("PM: hibernate: Get block device exclusively in swsusp_check()")
is unlikely to happen.

Fixes: 39fbef4b0f ("PM: hibernate: Get block device exclusively in swsusp_check()")
Reported-by: Yifan Li <yifan2.li@intel.com>
Suggested-by: Pavankumar Kondeti <quic_pkondeti@quicinc.com>
Tested-by: Pavankumar Kondeti <quic_pkondeti@quicinc.com>
Tested-by: Wendy Wang <wendy.wang@intel.com>
Signed-off-by: Chen Yu <yu.c.chen@intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2023-04-27 19:00:28 +02:00
Chen Yu
08169a162f PM: hibernate: Turn snapshot_test into global variable
There is need to check snapshot_test and open block device
in different mode, so as to avoid the race condition.

No functional changes intended.

Suggested-by: Pavankumar Kondeti <quic_pkondeti@quicinc.com>
Signed-off-by: Chen Yu <yu.c.chen@intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2023-04-27 19:00:28 +02:00
Linus Torvalds
6e98b09da9 Networking changes for 6.4.
Core
 ----
 
  - Introduce a config option to tweak MAX_SKB_FRAGS. Increasing the
    default value allows for better BIG TCP performances.
 
  - Reduce compound page head access for zero-copy data transfers.
 
  - RPS/RFS improvements, avoiding unneeded NET_RX_SOFTIRQ when possible.
 
  - Threaded NAPI improvements, adding defer skb free support and unneeded
    softirq avoidance.
 
  - Address dst_entry reference count scalability issues, via false
    sharing avoidance and optimize refcount tracking.
 
  - Add lockless accesses annotation to sk_err[_soft].
 
  - Optimize again the skb struct layout.
 
  - Extends the skb drop reasons to make it usable by multiple
    subsystems.
 
  - Better const qualifier awareness for socket casts.
 
 BPF
 ---
 
  - Add skb and XDP typed dynptrs which allow BPF programs for more
    ergonomic and less brittle iteration through data and variable-sized
    accesses.
 
  - Add a new BPF netfilter program type and minimal support to hook
    BPF programs to netfilter hooks such as prerouting or forward.
 
  - Add more precise memory usage reporting for all BPF map types.
 
  - Adds support for using {FOU,GUE} encap with an ipip device operating
    in collect_md mode and add a set of BPF kfuncs for controlling encap
    params.
 
  - Allow BPF programs to detect at load time whether a particular kfunc
    exists or not, and also add support for this in light skeleton.
 
  - Bigger batch of BPF verifier improvements to prepare for upcoming BPF
    open-coded iterators allowing for less restrictive looping capabilities.
 
  - Rework RCU enforcement in the verifier, add kptr_rcu and enforce BPF
    programs to NULL-check before passing such pointers into kfunc.
 
  - Add support for kptrs in percpu hashmaps, percpu LRU hashmaps and in
    local storage maps.
 
  - Enable RCU semantics for task BPF kptrs and allow referenced kptr
    tasks to be stored in BPF maps.
 
  - Add support for refcounted local kptrs to the verifier for allowing
    shared ownership, useful for adding a node to both the BPF list and
    rbtree.
 
  - Add BPF verifier support for ST instructions in convert_ctx_access()
    which will help new -mcpu=v4 clang flag to start emitting them.
 
  - Add ARM32 USDT support to libbpf.
 
  - Improve bpftool's visual program dump which produces the control
    flow graph in a DOT format by adding C source inline annotations.
 
 Protocols
 ---------
 
  - IPv4: Allow adding to IPv4 address a 'protocol' tag. Such value
    indicates the provenance of the IP address.
 
  - IPv6: optimize route lookup, dropping unneeded R/W lock acquisition.
 
  - Add the handshake upcall mechanism, allowing the user-space
    to implement generic TLS handshake on kernel's behalf.
 
  - Bridge: support per-{Port, VLAN} neighbor suppression, increasing
    resilience to nodes failures.
 
  - SCTP: add support for Fair Capacity and Weighted Fair Queueing
    schedulers.
 
  - MPTCP: delay first subflow allocation up to its first usage. This
    will allow for later better LSM interaction.
 
  - xfrm: Remove inner/outer modes from input/output path. These are
    not needed anymore.
 
  - WiFi:
    - reduced neighbor report (RNR) handling for AP mode
    - HW timestamping support
    - support for randomized auth/deauth TA for PASN privacy
    - per-link debugfs for multi-link
    - TC offload support for mac80211 drivers
    - mac80211 mesh fast-xmit and fast-rx support
    - enable Wi-Fi 7 (EHT) mesh support
 
 Netfilter
 ---------
 
  - Add nf_tables 'brouting' support, to force a packet to be routed
    instead of being bridged.
 
  - Update bridge netfilter and ovs conntrack helpers to handle
    IPv6 Jumbo packets properly, i.e. fetch the packet length
    from hop-by-hop extension header. This is needed for BIT TCP
    support.
 
  - The iptables 32bit compat interface isn't compiled in by default
    anymore.
 
  - Move ip(6)tables builtin icmp matches to the udptcp one.
    This has the advantage that icmp/icmpv6 match doesn't load the
    iptables/ip6tables modules anymore when iptables-nft is used.
 
  - Extended netlink error report for netdevice in flowtables and
    netdev/chains. Allow for incrementally add/delete devices to netdev
    basechain. Allow to create netdev chain without device.
 
 Driver API
 ----------
 
  - Remove redundant Device Control Error Reporting Enable, as PCI core
    has already error reporting enabled at enumeration time.
 
  - Move Multicast DB netlink handlers to core, allowing devices other
    then bridge to use them.
 
  - Allow the page_pool to directly recycle the pages from safely
    localized NAPI.
 
  - Implement lockless TX queue stop/wake combo macros, allowing for
    further code de-duplication and sanitization.
 
  - Add YNL support for user headers and struct attrs.
 
  - Add partial YNL specification for devlink.
 
  - Add partial YNL specification for ethtool.
 
  - Add tc-mqprio and tc-taprio support for preemptible traffic classes.
 
  - Add tx push buf len param to ethtool, specifies the maximum number
    of bytes of a transmitted packet a driver can push directly to the
    underlying device.
 
  - Add basic LED support for switch/phy.
 
  - Add NAPI documentation, stop relaying on external links.
 
  - Convert dsa_master_ioctl() to netdev notifier. This is a preparatory
    work to make the hardware timestamping layer selectable by user
    space.
 
  - Add transceiver support and improve the error messages for CAN-FD
    controllers.
 
 New hardware / drivers
 ----------------------
 
  - Ethernet:
    - AMD/Pensando core device support
    - MediaTek MT7981 SoC
    - MediaTek MT7988 SoC
    - Broadcom BCM53134 embedded switch
    - Texas Instruments CPSW9G ethernet switch
    - Qualcomm EMAC3 DWMAC ethernet
    - StarFive JH7110 SoC
    - NXP CBTX ethernet PHY
 
  - WiFi:
    - Apple M1 Pro/Max devices
    - RealTek rtl8710bu/rtl8188gu
    - RealTek rtl8822bs, rtl8822cs and rtl8821cs SDIO chipset
 
  - Bluetooth:
    - Realtek RTL8821CS, RTL8851B, RTL8852BS
    - Mediatek MT7663, MT7922
    - NXP w8997
    - Actions Semi ATS2851
    - QTI WCN6855
    - Marvell 88W8997
 
  - Can:
    - STMicroelectronics bxcan stm32f429
 
 Drivers
 -------
  - Ethernet NICs:
    - Intel (1G, icg):
      - add tracking and reporting of QBV config errors.
      - add support for configuring max SDU for each Tx queue.
    - Intel (100G, ice):
      - refactor mailbox overflow detection to support Scalable IOV
      - GNSS interface optimization
    - Intel (i40e):
      - support XDP multi-buffer
    - nVidia/Mellanox:
      - add the support for linux bridge multicast offload
      - enable TC offload for egress and engress MACVLAN over bond
      - add support for VxLAN GBP encap/decap flows offload
      - extend packet offload to fully support libreswan
      - support tunnel mode in mlx5 IPsec packet offload
      - extend XDP multi-buffer support
      - support MACsec VLAN offload
      - add support for dynamic msix vectors allocation
      - drop RX page_cache and fully use page_pool
      - implement thermal zone to report NIC temperature
    - Netronome/Corigine:
      - add support for multi-zone conntrack offload
    - Solarflare/Xilinx:
      - support offloading TC VLAN push/pop actions to the MAE
      - support TC decap rules
      - support unicast PTP
 
  - Other NICs:
    - Broadcom (bnxt): enforce software based freq adjustments only
 		on shared PHC NIC
    - RealTek (r8169): refactor to addess ASPM issues during NAPI poll.
    - Micrel (lan8841): add support for PTP_PF_PEROUT
    - Cadence (macb): enable PTP unicast
    - Engleder (tsnep): add XDP socket zero-copy support
    - virtio-net: implement exact header length guest feature
    - veth: add page_pool support for page recycling
    - vxlan: add MDB data path support
    - gve: add XDP support for GQI-QPL format
    - geneve: accept every ethertype
    - macvlan: allow some packets to bypass broadcast queue
    - mana: add support for jumbo frame
 
  - Ethernet high-speed switches:
    - Microchip (sparx5): Add support for TC flower templates.
 
  - Ethernet embedded switches:
    - Broadcom (b54):
      - configure 6318 and 63268 RGMII ports
    - Marvell (mv88e6xxx):
      - faster C45 bus scan
    - Microchip:
      - lan966x:
        - add support for IS1 VCAP
        - better TX/RX from/to CPU performances
      - ksz9477: add ETS Qdisc support
      - ksz8: enhance static MAC table operations and error handling
      - sama7g5: add PTP capability
    - NXP (ocelot):
      - add support for external ports
      - add support for preemptible traffic classes
    - Texas Instruments:
      - add CPSWxG SGMII support for J7200 and J721E
 
  - Intel WiFi (iwlwifi):
    - preparation for Wi-Fi 7 EHT and multi-link support
    - EHT (Wi-Fi 7) sniffer support
    - hardware timestamping support for some devices/firwmares
    - TX beacon protection on newer hardware
 
  - Qualcomm 802.11ax WiFi (ath11k):
    - MU-MIMO parameters support
    - ack signal support for management packets
 
  - RealTek WiFi (rtw88):
    - SDIO bus support
    - better support for some SDIO devices
      (e.g. MAC address from efuse)
 
  - RealTek WiFi (rtw89):
    - HW scan support for 8852b
    - better support for 6 GHz scanning
    - support for various newer firmware APIs
    - framework firmware backwards compatibility
 
  - MediaTek WiFi (mt76):
    - P2P support
    - mesh A-MSDU support
    - EHT (Wi-Fi 7) support
    - coredump support
 
 Signed-off-by: Paolo Abeni <pabeni@redhat.com>
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Merge tag 'net-next-6.4' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next

Pull networking updates from Paolo Abeni:
 "Core:

   - Introduce a config option to tweak MAX_SKB_FRAGS. Increasing the
     default value allows for better BIG TCP performances

   - Reduce compound page head access for zero-copy data transfers

   - RPS/RFS improvements, avoiding unneeded NET_RX_SOFTIRQ when
     possible

   - Threaded NAPI improvements, adding defer skb free support and
     unneeded softirq avoidance

   - Address dst_entry reference count scalability issues, via false
     sharing avoidance and optimize refcount tracking

   - Add lockless accesses annotation to sk_err[_soft]

   - Optimize again the skb struct layout

   - Extends the skb drop reasons to make it usable by multiple
     subsystems

   - Better const qualifier awareness for socket casts

  BPF:

   - Add skb and XDP typed dynptrs which allow BPF programs for more
     ergonomic and less brittle iteration through data and
     variable-sized accesses

   - Add a new BPF netfilter program type and minimal support to hook
     BPF programs to netfilter hooks such as prerouting or forward

   - Add more precise memory usage reporting for all BPF map types

   - Adds support for using {FOU,GUE} encap with an ipip device
     operating in collect_md mode and add a set of BPF kfuncs for
     controlling encap params

   - Allow BPF programs to detect at load time whether a particular
     kfunc exists or not, and also add support for this in light
     skeleton

   - Bigger batch of BPF verifier improvements to prepare for upcoming
     BPF open-coded iterators allowing for less restrictive looping
     capabilities

   - Rework RCU enforcement in the verifier, add kptr_rcu and enforce
     BPF programs to NULL-check before passing such pointers into kfunc

   - Add support for kptrs in percpu hashmaps, percpu LRU hashmaps and
     in local storage maps

   - Enable RCU semantics for task BPF kptrs and allow referenced kptr
     tasks to be stored in BPF maps

   - Add support for refcounted local kptrs to the verifier for allowing
     shared ownership, useful for adding a node to both the BPF list and
     rbtree

   - Add BPF verifier support for ST instructions in
     convert_ctx_access() which will help new -mcpu=v4 clang flag to
     start emitting them

   - Add ARM32 USDT support to libbpf

   - Improve bpftool's visual program dump which produces the control
     flow graph in a DOT format by adding C source inline annotations

  Protocols:

   - IPv4: Allow adding to IPv4 address a 'protocol' tag. Such value
     indicates the provenance of the IP address

   - IPv6: optimize route lookup, dropping unneeded R/W lock acquisition

   - Add the handshake upcall mechanism, allowing the user-space to
     implement generic TLS handshake on kernel's behalf

   - Bridge: support per-{Port, VLAN} neighbor suppression, increasing
     resilience to nodes failures

   - SCTP: add support for Fair Capacity and Weighted Fair Queueing
     schedulers

   - MPTCP: delay first subflow allocation up to its first usage. This
     will allow for later better LSM interaction

   - xfrm: Remove inner/outer modes from input/output path. These are
     not needed anymore

   - WiFi:
      - reduced neighbor report (RNR) handling for AP mode
      - HW timestamping support
      - support for randomized auth/deauth TA for PASN privacy
      - per-link debugfs for multi-link
      - TC offload support for mac80211 drivers
      - mac80211 mesh fast-xmit and fast-rx support
      - enable Wi-Fi 7 (EHT) mesh support

  Netfilter:

   - Add nf_tables 'brouting' support, to force a packet to be routed
     instead of being bridged

   - Update bridge netfilter and ovs conntrack helpers to handle IPv6
     Jumbo packets properly, i.e. fetch the packet length from
     hop-by-hop extension header. This is needed for BIT TCP support

   - The iptables 32bit compat interface isn't compiled in by default
     anymore

   - Move ip(6)tables builtin icmp matches to the udptcp one. This has
     the advantage that icmp/icmpv6 match doesn't load the
     iptables/ip6tables modules anymore when iptables-nft is used

   - Extended netlink error report for netdevice in flowtables and
     netdev/chains. Allow for incrementally add/delete devices to netdev
     basechain. Allow to create netdev chain without device

  Driver API:

   - Remove redundant Device Control Error Reporting Enable, as PCI core
     has already error reporting enabled at enumeration time

   - Move Multicast DB netlink handlers to core, allowing devices other
     then bridge to use them

   - Allow the page_pool to directly recycle the pages from safely
     localized NAPI

   - Implement lockless TX queue stop/wake combo macros, allowing for
     further code de-duplication and sanitization

   - Add YNL support for user headers and struct attrs

   - Add partial YNL specification for devlink

   - Add partial YNL specification for ethtool

   - Add tc-mqprio and tc-taprio support for preemptible traffic classes

   - Add tx push buf len param to ethtool, specifies the maximum number
     of bytes of a transmitted packet a driver can push directly to the
     underlying device

   - Add basic LED support for switch/phy

   - Add NAPI documentation, stop relaying on external links

   - Convert dsa_master_ioctl() to netdev notifier. This is a
     preparatory work to make the hardware timestamping layer selectable
     by user space

   - Add transceiver support and improve the error messages for CAN-FD
     controllers

  New hardware / drivers:

   - Ethernet:
      - AMD/Pensando core device support
      - MediaTek MT7981 SoC
      - MediaTek MT7988 SoC
      - Broadcom BCM53134 embedded switch
      - Texas Instruments CPSW9G ethernet switch
      - Qualcomm EMAC3 DWMAC ethernet
      - StarFive JH7110 SoC
      - NXP CBTX ethernet PHY

   - WiFi:
      - Apple M1 Pro/Max devices
      - RealTek rtl8710bu/rtl8188gu
      - RealTek rtl8822bs, rtl8822cs and rtl8821cs SDIO chipset

   - Bluetooth:
      - Realtek RTL8821CS, RTL8851B, RTL8852BS
      - Mediatek MT7663, MT7922
      - NXP w8997
      - Actions Semi ATS2851
      - QTI WCN6855
      - Marvell 88W8997

   - Can:
      - STMicroelectronics bxcan stm32f429

  Drivers:

   - Ethernet NICs:
      - Intel (1G, icg):
         - add tracking and reporting of QBV config errors
         - add support for configuring max SDU for each Tx queue
      - Intel (100G, ice):
         - refactor mailbox overflow detection to support Scalable IOV
         - GNSS interface optimization
      - Intel (i40e):
         - support XDP multi-buffer
      - nVidia/Mellanox:
         - add the support for linux bridge multicast offload
         - enable TC offload for egress and engress MACVLAN over bond
         - add support for VxLAN GBP encap/decap flows offload
         - extend packet offload to fully support libreswan
         - support tunnel mode in mlx5 IPsec packet offload
         - extend XDP multi-buffer support
         - support MACsec VLAN offload
         - add support for dynamic msix vectors allocation
         - drop RX page_cache and fully use page_pool
         - implement thermal zone to report NIC temperature
      - Netronome/Corigine:
         - add support for multi-zone conntrack offload
      - Solarflare/Xilinx:
         - support offloading TC VLAN push/pop actions to the MAE
         - support TC decap rules
         - support unicast PTP

   - Other NICs:
      - Broadcom (bnxt): enforce software based freq adjustments only on
        shared PHC NIC
      - RealTek (r8169): refactor to addess ASPM issues during NAPI poll
      - Micrel (lan8841): add support for PTP_PF_PEROUT
      - Cadence (macb): enable PTP unicast
      - Engleder (tsnep): add XDP socket zero-copy support
      - virtio-net: implement exact header length guest feature
      - veth: add page_pool support for page recycling
      - vxlan: add MDB data path support
      - gve: add XDP support for GQI-QPL format
      - geneve: accept every ethertype
      - macvlan: allow some packets to bypass broadcast queue
      - mana: add support for jumbo frame

   - Ethernet high-speed switches:
      - Microchip (sparx5): Add support for TC flower templates

   - Ethernet embedded switches:
      - Broadcom (b54):
         - configure 6318 and 63268 RGMII ports
      - Marvell (mv88e6xxx):
         - faster C45 bus scan
      - Microchip:
         - lan966x:
            - add support for IS1 VCAP
            - better TX/RX from/to CPU performances
         - ksz9477: add ETS Qdisc support
         - ksz8: enhance static MAC table operations and error handling
         - sama7g5: add PTP capability
      - NXP (ocelot):
         - add support for external ports
         - add support for preemptible traffic classes
      - Texas Instruments:
         - add CPSWxG SGMII support for J7200 and J721E

   - Intel WiFi (iwlwifi):
      - preparation for Wi-Fi 7 EHT and multi-link support
      - EHT (Wi-Fi 7) sniffer support
      - hardware timestamping support for some devices/firwmares
      - TX beacon protection on newer hardware

   - Qualcomm 802.11ax WiFi (ath11k):
      - MU-MIMO parameters support
      - ack signal support for management packets

   - RealTek WiFi (rtw88):
      - SDIO bus support
      - better support for some SDIO devices (e.g. MAC address from
        efuse)

   - RealTek WiFi (rtw89):
      - HW scan support for 8852b
      - better support for 6 GHz scanning
      - support for various newer firmware APIs
      - framework firmware backwards compatibility

   - MediaTek WiFi (mt76):
      - P2P support
      - mesh A-MSDU support
      - EHT (Wi-Fi 7) support
      - coredump support"

* tag 'net-next-6.4' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next: (2078 commits)
  net: phy: hide the PHYLIB_LEDS knob
  net: phy: marvell-88x2222: remove unnecessary (void*) conversions
  tcp/udp: Fix memleaks of sk and zerocopy skbs with TX timestamp.
  net: amd: Fix link leak when verifying config failed
  net: phy: marvell: Fix inconsistent indenting in led_blink_set
  lan966x: Don't use xdp_frame when action is XDP_TX
  tsnep: Add XDP socket zero-copy TX support
  tsnep: Add XDP socket zero-copy RX support
  tsnep: Move skb receive action to separate function
  tsnep: Add functions for queue enable/disable
  tsnep: Rework TX/RX queue initialization
  tsnep: Replace modulo operation with mask
  net: phy: dp83867: Add led_brightness_set support
  net: phy: Fix reading LED reg property
  drivers: nfc: nfcsim: remove return value check of `dev_dir`
  net: phy: dp83867: Remove unnecessary (void*) conversions
  net: ethtool: coalesce: try to make user settings stick twice
  net: mana: Check if netdev/napi_alloc_frag returns single page
  net: mana: Rename mana_refill_rxoob and remove some empty lines
  net: veth: add page_pool stats
  ...
2023-04-26 16:07:23 -07:00
Geert Uytterhoeven
158009f1b4 timekeeping: Fix references to nonexistent ktime_get_fast_ns()
There was never a function named ktime_get_fast_ns().
Presumably these should refer to ktime_get_mono_fast_ns() instead.

Fixes: c1ce406e80 ("timekeeping: Fix up function documentation for the NMI safe accessors")
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: John Stultz <jstultz@google.com>
Link: https://lore.kernel.org/r/06df7b3cbd94f016403bbf6cd2b38e4368e7468f.1682516546.git.geert+renesas@glider.be
2023-04-26 23:43:16 +02:00
Linus Torvalds
733f7e9c18 This update includes the following changes:
API:
 
 - Total usage stats now include all that returned error (instead of some).
 - Remove maximum hash statesize limit.
 - Add cloning support for hmac and unkeyed hashes.
 - Demote BUG_ON in crypto_unregister_alg to a WARN_ON.
 
 Algorithms:
 
 - Use RIP-relative addressing on x86 to prepare for PIE build.
 - Add accelerated AES/GCM stitched implementation on powerpc P10.
 - Add some test vectors for cmac(camellia).
 - Remove failure case where jent is unavailable outside of FIPS mode in drbg.
 - Add permanent and intermittent health error checks in jitter RNG.
 
 Drivers:
 
 - Add support for 402xx devices in qat.
 - Add support for HiSTB TRNG.
 - Fix hash concurrency issues in stm32.
 - Add OP-TEE firmware support in caam.
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Merge tag 'v6.4-p1' of git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6

Pull crypto updates from Herbert Xu:
 "API:
   - Total usage stats now include all that returned errors (instead of
     just some)
   - Remove maximum hash statesize limit
   - Add cloning support for hmac and unkeyed hashes
   - Demote BUG_ON in crypto_unregister_alg to a WARN_ON

  Algorithms:
   - Use RIP-relative addressing on x86 to prepare for PIE build
   - Add accelerated AES/GCM stitched implementation on powerpc P10
   - Add some test vectors for cmac(camellia)
   - Remove failure case where jent is unavailable outside of FIPS mode
     in drbg
   - Add permanent and intermittent health error checks in jitter RNG

  Drivers:
   - Add support for 402xx devices in qat
   - Add support for HiSTB TRNG
   - Fix hash concurrency issues in stm32
   - Add OP-TEE firmware support in caam"

* tag 'v6.4-p1' of git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6: (139 commits)
  i2c: designware: Add doorbell support for Mendocino
  i2c: designware: Use PCI PSP driver for communication
  powerpc: Move Power10 feature PPC_MODULE_FEATURE_P10
  crypto: p10-aes-gcm - Remove POWER10_CPU dependency
  crypto: testmgr - Add some test vectors for cmac(camellia)
  crypto: cryptd - Add support for cloning hashes
  crypto: cryptd - Convert hash to use modern init_tfm/exit_tfm
  crypto: hmac - Add support for cloning
  crypto: hash - Add crypto_clone_ahash/shash
  crypto: api - Add crypto_clone_tfm
  crypto: api - Add crypto_tfm_get
  crypto: x86/sha - Use local .L symbols for code
  crypto: x86/crc32 - Use local .L symbols for code
  crypto: x86/aesni - Use local .L symbols for code
  crypto: x86/sha256 - Use RIP-relative addressing
  crypto: x86/ghash - Use RIP-relative addressing
  crypto: x86/des3 - Use RIP-relative addressing
  crypto: x86/crc32c - Use RIP-relative addressing
  crypto: x86/cast6 - Use RIP-relative addressing
  crypto: x86/cast5 - Use RIP-relative addressing
  ...
2023-04-26 08:32:52 -07:00
Ken Lin
adace44082 tracing: Add missing spaces in trace_print_hex_seq()
If the buffer length is larger than 16 and concatenate is set to false,
there would be missing spaces every 16 bytes.
Example:
  Before: c5 11 10 50 05 4d 31 40 00 40 00 40 00 4d 31 4000 40 00
  After:  c5 11 10 50 05 4d 31 40 00 40 00 40 00 4d 31 40 00 40 00

Link: https://lore.kernel.org/linux-trace-kernel/20230426032257.3157247-1-lyenting@google.com

Signed-off-by: Ken Lin <lyenting@google.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2023-04-26 09:10:02 -04:00
Tze-nan Wu
7c339fb4d8 ring-buffer: Ensure proper resetting of atomic variables in ring_buffer_reset_online_cpus
In ring_buffer_reset_online_cpus, the buffer_size_kb write operation
may permanently fail if the cpu_online_mask changes between two
for_each_online_buffer_cpu loops. The number of increases and decreases
on both cpu_buffer->resize_disabled and cpu_buffer->record_disabled may be
inconsistent, causing some CPUs to have non-zero values for these atomic
variables after the function returns.

This issue can be reproduced by "echo 0 > trace" while hotplugging cpu.
After reproducing success, we can find out buffer_size_kb will not be
functional anymore.

To prevent leaving 'resize_disabled' and 'record_disabled' non-zero after
ring_buffer_reset_online_cpus returns, we ensure that each atomic variable
has been set up before atomic_sub() to it.

Link: https://lore.kernel.org/linux-trace-kernel/20230426062027.17451-1-Tze-nan.Wu@mediatek.com

Cc: stable@vger.kernel.org
Cc: <mhiramat@kernel.org>
Cc: npiggin@gmail.com
Fixes: b23d7a5f4a ("ring-buffer: speed up buffer resets by avoiding synchronize_rcu for each CPU")
Reviewed-by: Cheng-Jui Wang <cheng-jui.wang@mediatek.com>
Signed-off-by: Tze-nan Wu <Tze-nan.Wu@mediatek.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2023-04-26 09:08:53 -04:00
Linus Torvalds
0cfd8703e7 Power management updates for 6.4-rc1
- Fix the frequency unit in cpufreq_verify_current_freq checks()
    (Sanjay Chandrashekara).
 
  - Make mode_state_machine in amd-pstate static (Tom Rix).
 
  - Make the cpufreq core require drivers with target_index() to set
    freq_table (Viresh Kumar).
 
  - Fix typo in the ARM_BRCMSTB_AVS_CPUFREQ Kconfig entry (Jingyu Wang).
 
  - Use of_property_read_bool() for boolean properties in the pmac32
    cpufreq driver (Rob Herring).
 
  - Make the cpufreq sysfs interface return proper error codes on
    obviously invalid input (qinyu).
 
  - Add guided autonomous mode support to the AMD P-state driver (Wyes
    Karny).
 
  - Make the Intel P-state driver enable HWP IO boost on all server
    platforms (Srinivas Pandruvada).
 
  - Add opp and bandwidth support to tegra194 cpufreq driver (Sumit
    Gupta).
 
  - Use of_property_present() for testing DT property presence (Rob
    Herring).
 
  - Remove MODULE_LICENSE in non-modules (Nick Alcock).
 
  - Add SM7225 to cpufreq-dt-platdev blocklist (Luca Weiss).
 
  - Optimizations and fixes for qcom-cpufreq-hw driver (Krzysztof
    Kozlowski, Konrad Dybcio, and Bjorn Andersson).
 
  - DT binding updates for qcom-cpufreq-hw driver (Konrad Dybcio and
    Bartosz Golaszewski).
 
  - Updates and fixes for mediatek driver (Jia-Wei Chang and
    AngeloGioacchino Del Regno).
 
  - Use of_property_present() for testing DT property presence in the
    cpuidle code (Rob Herring).
 
  - Drop unnecessary (void *) conversions from the PM core (Li zeming).
 
  - Add sysfs files to represent time spent in a platform sleep state
    during suspend-to-idle and make AMD and Intel PMC drivers use them
    (Mario Limonciello).
 
  - Use of_property_present() for testing DT property presence (Rob
    Herring).
 
  - Add set_required_opps() callback to the 'struct opp_table', to make
    the code paths cleaner (Viresh Kumar).
 
  - Update the pm-graph siute of utilities to v5.11 with the following
    changes:
    * New script which allows users to install the latest pm-graph
      from the upstream github repo.
    * Update all the dmesg suspend/resume PM print formats to be able to
      process recent timelines using dmesg only.
    * Add ethtool output to the log for the system's ethernet device if
      ethtool exists.
    * Make the tool more robustly handle events where mangled dmesg or
      ftrace outputs do not include all the requisite data.
 
  - Make the sleepgraph utility recognize "CPU killed" messages (Xueqin
    Luo).
 
  - Remove unneeded SRCU selection in Kconfig because it's always set
    from devfreq core (Paul E. McKenney).
 
  - Drop of_match_ptr() macro from exynos-bus.c because this driver is
    always using the DT table for driver probe (Krzysztof Kozlowski).
 
  - Use the preferred of_property_present() instead of the low-level
    of_get_property() on exynos-bus.c (Rob Herring).
 
  - Use devm_platform_get_and_ioream_resource() in exyno-ppmu.c (Yang Li).
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Merge tag 'pm-6.4-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm

Pull power management updates from Rafael Wysocki:
 "These update several cpufreq drivers and the cpufreq core, add sysfs
  interface for exposing the time really spent in the platform low-power
  state during suspend-to-idle, update devfreq (core and drivers) and
  the pm-graph suite of tools and clean up code.

  Specifics:

   - Fix the frequency unit in cpufreq_verify_current_freq checks()
     Sanjay Chandrashekara)

   - Make mode_state_machine in amd-pstate static (Tom Rix)

   - Make the cpufreq core require drivers with target_index() to set
     freq_table (Viresh Kumar)

   - Fix typo in the ARM_BRCMSTB_AVS_CPUFREQ Kconfig entry (Jingyu Wang)

   - Use of_property_read_bool() for boolean properties in the pmac32
     cpufreq driver (Rob Herring)

   - Make the cpufreq sysfs interface return proper error codes on
     obviously invalid input (qinyu)

   - Add guided autonomous mode support to the AMD P-state driver (Wyes
     Karny)

   - Make the Intel P-state driver enable HWP IO boost on all server
     platforms (Srinivas Pandruvada)

   - Add opp and bandwidth support to tegra194 cpufreq driver (Sumit
     Gupta)

   - Use of_property_present() for testing DT property presence (Rob
     Herring)

   - Remove MODULE_LICENSE in non-modules (Nick Alcock)

   - Add SM7225 to cpufreq-dt-platdev blocklist (Luca Weiss)

   - Optimizations and fixes for qcom-cpufreq-hw driver (Krzysztof
     Kozlowski, Konrad Dybcio, and Bjorn Andersson)

   - DT binding updates for qcom-cpufreq-hw driver (Konrad Dybcio and
     Bartosz Golaszewski)

   - Updates and fixes for mediatek driver (Jia-Wei Chang and
     AngeloGioacchino Del Regno)

   - Use of_property_present() for testing DT property presence in the
     cpuidle code (Rob Herring)

   - Drop unnecessary (void *) conversions from the PM core (Li zeming)

   - Add sysfs files to represent time spent in a platform sleep state
     during suspend-to-idle and make AMD and Intel PMC drivers use them
     Mario Limonciello)

   - Use of_property_present() for testing DT property presence (Rob
     Herring)

   - Add set_required_opps() callback to the 'struct opp_table', to make
     the code paths cleaner (Viresh Kumar)

   - Update the pm-graph siute of utilities to v5.11 with the following
     changes:
       * New script which allows users to install the latest pm-graph
         from the upstream github repo.
       * Update all the dmesg suspend/resume PM print formats to be able
         to process recent timelines using dmesg only.
       * Add ethtool output to the log for the system's ethernet device
         if ethtool exists.
       * Make the tool more robustly handle events where mangled dmesg
         or ftrace outputs do not include all the requisite data.

   - Make the sleepgraph utility recognize "CPU killed" messages (Xueqin
     Luo)

   - Remove unneeded SRCU selection in Kconfig because it's always set
     from devfreq core (Paul E. McKenney)

   - Drop of_match_ptr() macro from exynos-bus.c because this driver is
     always using the DT table for driver probe (Krzysztof Kozlowski)

   - Use the preferred of_property_present() instead of the low-level
     of_get_property() on exynos-bus.c (Rob Herring)

   - Use devm_platform_get_and_ioream_resource() in exyno-ppmu.c (Yang
     Li)"

* tag 'pm-6.4-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm: (44 commits)
  platform/x86/intel/pmc: core: Report duration of time in HW sleep state
  platform/x86/intel/pmc: core: Always capture counters on suspend
  platform/x86/amd: pmc: Report duration of time in hw sleep state
  PM: Add sysfs files to represent time spent in hardware sleep state
  cpufreq: use correct unit when verify cur freq
  cpufreq: tegra194: add OPP support and set bandwidth
  cpufreq: amd-pstate: Make varaiable mode_state_machine static
  PM: core: Remove unnecessary (void *) conversions
  cpufreq: drivers with target_index() must set freq_table
  PM / devfreq: exynos-ppmu: Use devm_platform_get_and_ioremap_resource()
  OPP: Move required opps configuration to specialized callback
  OPP: Handle all genpd cases together in _set_required_opps()
  cpufreq: qcom-cpufreq-hw: Revert adding cpufreq qos
  dt-bindings: cpufreq: cpufreq-qcom-hw: Add QCM2290
  dt-bindings: cpufreq: cpufreq-qcom-hw: Sanitize data per compatible
  dt-bindings: cpufreq: cpufreq-qcom-hw: Allow just 1 frequency domain
  cpufreq: Add SM7225 to cpufreq-dt-platdev blocklist
  cpufreq: qcom-cpufreq-hw: fix double IO unmap and resource release on exit
  cpufreq: mediatek: Raise proc and sram max voltage for MT7622/7623
  cpufreq: mediatek: raise proc/sram max voltage for MT8516
  ...
2023-04-25 18:44:10 -07:00
Beau Belgrave
41d8fba193 tracing/user_events: Limit max fault-in attempts
When event enablement changes, user_events attempts to update a bit in
the user process. If a fault is hit, an attempt to fault-in the page and
the write is retried if the page made it in. While this normally requires
a couple attempts, it is possible a bad user process could attempt to
cause infinite loops.

Ensure fault-in attempts either sync or async are limited to a max of 10
attempts for each update. When the max is hit, return -EFAULT so another
attempt is not made in all cases.

Link: https://lkml.kernel.org/r/20230425225107.8525-5-beaub@linux.microsoft.com

Suggested-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Signed-off-by: Beau Belgrave <beaub@linux.microsoft.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2023-04-25 21:04:45 -04:00
Beau Belgrave
97bbce89bf tracing/user_events: Prevent same address and bit per process
User processes register an address and bit pair for events. If the same
address and bit pair are registered multiple times in the same process,
it can cause undefined behavior when events are enabled/disabled.
When more than one are used, the bit could be turned off by another
event being disabled, while the original event is still enabled.

Prevent undefined behavior by checking the current mm to see if any
event has already been registered for the address and bit pair. Return
EADDRINUSE back to the user process if it's already being used.

Update ftrace self-test to ensure this occurs properly.

Link: https://lkml.kernel.org/r/20230425225107.8525-4-beaub@linux.microsoft.com

Suggested-by: Doug Cook <dcook@linux.microsoft.com>
Signed-off-by: Beau Belgrave <beaub@linux.microsoft.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2023-04-25 21:04:32 -04:00
Beau Belgrave
17b439db21 tracing/user_events: Ensure bit is cleared on unregister
If an event is enabled and a user process unregisters user_events, the
bit is left set. Fix this by always clearing the bit in the user process
if unregister is successful.

Update abi self-test to ensure this occurs properly.

Link: https://lkml.kernel.org/r/20230425225107.8525-3-beaub@linux.microsoft.com

Suggested-by: Doug Cook <dcook@linux.microsoft.com>
Signed-off-by: Beau Belgrave <beaub@linux.microsoft.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2023-04-25 21:04:16 -04:00
Beau Belgrave
cd98c93286 tracing/user_events: Ensure write index cannot be negative
The write index indicates which event the data is for and accesses a
per-file array. The index is passed by user processes during write()
calls as the first 4 bytes. Ensure that it cannot be negative by
returning -EINVAL to prevent out of bounds accesses.

Update ftrace self-test to ensure this occurs properly.

Link: https://lkml.kernel.org/r/20230425225107.8525-2-beaub@linux.microsoft.com

Fixes: 7f5a08c79d ("user_events: Add minimal support for trace_event into ftrace")
Reported-by: Doug Cook <dcook@linux.microsoft.com>
Signed-off-by: Beau Belgrave <beaub@linux.microsoft.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2023-04-25 21:03:46 -04:00
Beau Belgrave
c7bdb07902 tracing: Fix print_fields() for __dyn_loc/__rel_loc
Both print_fields() and print_array() do not handle if dynamic data ends
at the last byte of the payload for both __dyn_loc and __rel_loc field
types. For __rel_loc, the offset was off by 4 bytes, leading to
incorrect strings and data being printed out. In print_array() the
buffer pos was missed from being advanced, which results in the first
payload byte being used as the offset base instead of the field offset.

Advance __rel_loc offset by 4 to ensure correct offset and advance pos
to the field offset to ensure correct data is displayed when printing
arrays. Change >= to > when checking if data is in-bounds, since it's
valid for dynamic data to include the last byte of the payload.

Example outputs for event format:
        field:unsigned short common_type;       offset:0;       size:2; signed:0;
        field:unsigned char common_flags;       offset:2;       size:1; signed:0;
        field:unsigned char common_preempt_count;       offset:3;       size:1; signed:0;
        field:int common_pid;   offset:4;       size:4; signed:1;

        field:__rel_loc char text[];  offset:8;      size:4; signed:1;

Output before:
tp_rel_loc: text=<OVERFLOW>

Output after:
tp_rel_loc: text=Test

Link: https://lkml.kernel.org/r/20230419214140.4158-3-beaub@linux.microsoft.com

Fixes: 80a76994b2 ("tracing: Add "fields" option to show raw trace event fields")
Reported-by: Doug Cook <dcook@linux.microsoft.com>
Signed-off-by: Beau Belgrave <beaub@linux.microsoft.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2023-04-25 20:11:26 -04:00
Beau Belgrave
9872c07b14 tracing/user_events: Set event filter_type from type
Users expect that events can be filtered by the kernel. User events
currently sets all event fields as FILTER_OTHER which limits to binary
filters only. When strings are being used, functionality is reduced.

Use filter_assign_type() to find the most appropriate filter
type for each field in user events to ensure full kernel capabilities.

Link: https://lkml.kernel.org/r/20230419214140.4158-2-beaub@linux.microsoft.com

Signed-off-by: Beau Belgrave <beaub@linux.microsoft.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2023-04-25 20:11:26 -04:00
Zheng Yejian
625ed52717 ring-buffer: Clearly check null ptr returned by rb_set_head_page()
In error case, 'buffer_page' returned by rb_set_head_page() is NULL,
currently check '&buffer_page->list' is equivalent to check 'buffer_page'
due to 'list' is the first member of 'buffer_page', but suppose it is not
some time, 'head_page' would be wild memory while check would be bypassed.

Link: https://lore.kernel.org/linux-trace-kernel/20230414071729.57312-1-zhengyejian1@huawei.com

Cc: <mhiramat@kernel.org>
Signed-off-by: Zheng Yejian <zhengyejian1@huawei.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2023-04-25 20:11:26 -04:00
Colin Ian King
73e053cbd0 rv: Remove redundant assignment to variable retval
Variable retval is being assigned a value that is never read, it is
being re-assigned a new value in both paths of a following if statement.
Remove the assignment.

Cleans up clang-scan warning:
kernel/trace/rv/rv.c:293:2: warning: Value stored to 'retval' is never read [deadcode.DeadStores]
        retval = count;

Link: https://lkml.kernel.org/r/20230418150018.3123753-1-colin.i.king@gmail.com

Cc: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Colin Ian King <colin.i.king@gmail.com>
Acked-by: Daniel Bristot de Oliveira <bristot@kernel.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2023-04-25 19:24:28 -04:00
Linus Torvalds
736b378b29 slab changes for 6.4
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Merge tag 'slab-for-6.4' of git://git.kernel.org/pub/scm/linux/kernel/git/vbabka/slab

Pull slab updates from Vlastimil Babka:
 "The main change is naturally the SLOB removal. Since its deprecation
  in 6.2 I've seen no complaints so hopefully SLUB_(TINY) works well for
  everyone and we can proceed.

  Besides the code cleanup, the main immediate benefit will be allowing
  kfree() family of function to work on kmem_cache_alloc() objects,
  which was incompatible with SLOB. This includes kfree_rcu() which had
  no kmem_cache_free_rcu() counterpart yet and now it shouldn't be
  necessary anymore.

  Besides that, there are several small code and comment improvements
  from Thomas, Thorsten and Vernon"

* tag 'slab-for-6.4' of git://git.kernel.org/pub/scm/linux/kernel/git/vbabka/slab:
  mm/slab: document kfree() as allowed for kmem_cache_alloc() objects
  mm/slob: remove slob.c
  mm/slab: remove CONFIG_SLOB code from slab common code
  mm, pagemap: remove SLOB and SLQB from comments and documentation
  mm, page_flags: remove PG_slob_free
  mm/slob: remove CONFIG_SLOB
  mm/slub: fix help comment of SLUB_DEBUG
  mm: slub: make kobj_type structure constant
  slab: Adjust comment after refactoring of gfp.h
2023-04-25 13:00:41 -07:00
Linus Torvalds
11704531dd Livepatching changes for 6.4
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Merge tag 'livepatching-for-6.4' of git://git.kernel.org/pub/scm/linux/kernel/git/livepatching/livepatching

Pull livepatching updates from Petr Mladek:

 - Code and documentation cleanup

* tag 'livepatching-for-6.4' of git://git.kernel.org/pub/scm/linux/kernel/git/livepatching/livepatching:
  livepatch: Make kobj_type structures constant
  livepatch: fix ELF typos
2023-04-25 12:51:51 -07:00
Linus Torvalds
7ec85f3e08 printk changes for 6.4
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Merge tag 'printk-for-6.4' of git://git.kernel.org/pub/scm/linux/kernel/git/printk/linux

Pull printk updates from Petr Mladek:

 - Code cleanup and dead code removal

* tag 'printk-for-6.4' of git://git.kernel.org/pub/scm/linux/kernel/git/printk/linux:
  printk: Remove obsoleted check for non-existent "user" object
  lib/vsprintf: Use isodigit() for the octal number check
  Remove orphaned CONFIG_PRINTK_SAFE_LOG_BUF_SHIFT
2023-04-25 12:46:48 -07:00
Linus Torvalds
df45da57cb arm64 updates for 6.4
ACPI:
 	* Improve error reporting when failing to manage SDEI on AGDI device
 	  removal
 
 Assembly routines:
 	* Improve register constraints so that the compiler can make use of
 	  the zero register instead of moving an immediate #0 into a GPR
 
 	* Allow the compiler to allocate the registers used for CAS
 	  instructions
 
 CPU features and system registers:
 	* Cleanups to the way in which CPU features are identified from the
 	  ID register fields
 
 	* Extend system register definition generation to handle Enum types
 	  when defining shared register fields
 
 	* Generate definitions for new _EL2 registers and add new fields
 	  for ID_AA64PFR1_EL1
 
 	* Allow SVE to be disabled separately from SME on the kernel
 	  command-line
 
 Tracing:
 	* Support for "direct calls" in ftrace, which enables BPF tracing
 	  for arm64
 
 Kdump:
 	* Don't bother unmapping the crashkernel from the linear mapping,
 	  which then allows us to use huge (block) mappings and reduce
 	  TLB pressure when a crashkernel is loaded.
 
 Memory management:
 	* Try again to remove data cache invalidation from the coherent DMA
 	  allocation path
 
 	* Simplify the fixmap code by mapping at page granularity
 
 	* Allow the kfence pool to be allocated early, preventing the rest
 	  of the linear mapping from being forced to page granularity
 
 Perf and PMU:
 	* Move CPU PMU code out to drivers/perf/ where it can be reused
 	  by the 32-bit ARM architecture when running on ARMv8 CPUs
 
 	* Fix race between CPU PMU probing and pKVM host de-privilege
 
 	* Add support for Apple M2 CPU PMU
 
 	* Adjust the generic PERF_COUNT_HW_BRANCH_INSTRUCTIONS event
 	  dynamically, depending on what the CPU actually supports
 
 	* Minor fixes and cleanups to system PMU drivers
 
 Stack tracing:
 	* Use the XPACLRI instruction to strip PAC from pointers, rather
 	  than rolling our own function in C
 
 	* Remove redundant PAC removal for toolchains that handle this in
 	  their builtins
 
 	* Make backtracing more resilient in the face of instrumentation
 
 Miscellaneous:
 	* Fix single-step with KGDB
 
 	* Remove harmless warning when 'nokaslr' is passed on the kernel
 	  command-line
 
 	* Minor fixes and cleanups across the board
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Merge tag 'arm64-upstream' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux

Pull arm64 updates from Will Deacon:
 "ACPI:

   - Improve error reporting when failing to manage SDEI on AGDI device
     removal

  Assembly routines:

   - Improve register constraints so that the compiler can make use of
     the zero register instead of moving an immediate #0 into a GPR

   - Allow the compiler to allocate the registers used for CAS
     instructions

  CPU features and system registers:

   - Cleanups to the way in which CPU features are identified from the
     ID register fields

   - Extend system register definition generation to handle Enum types
     when defining shared register fields

   - Generate definitions for new _EL2 registers and add new fields for
     ID_AA64PFR1_EL1

   - Allow SVE to be disabled separately from SME on the kernel
     command-line

  Tracing:

   - Support for "direct calls" in ftrace, which enables BPF tracing for
     arm64

  Kdump:

   - Don't bother unmapping the crashkernel from the linear mapping,
     which then allows us to use huge (block) mappings and reduce TLB
     pressure when a crashkernel is loaded.

  Memory management:

   - Try again to remove data cache invalidation from the coherent DMA
     allocation path

   - Simplify the fixmap code by mapping at page granularity

   - Allow the kfence pool to be allocated early, preventing the rest of
     the linear mapping from being forced to page granularity

  Perf and PMU:

   - Move CPU PMU code out to drivers/perf/ where it can be reused by
     the 32-bit ARM architecture when running on ARMv8 CPUs

   - Fix race between CPU PMU probing and pKVM host de-privilege

   - Add support for Apple M2 CPU PMU

   - Adjust the generic PERF_COUNT_HW_BRANCH_INSTRUCTIONS event
     dynamically, depending on what the CPU actually supports

   - Minor fixes and cleanups to system PMU drivers

  Stack tracing:

   - Use the XPACLRI instruction to strip PAC from pointers, rather than
     rolling our own function in C

   - Remove redundant PAC removal for toolchains that handle this in
     their builtins

   - Make backtracing more resilient in the face of instrumentation

  Miscellaneous:

   - Fix single-step with KGDB

   - Remove harmless warning when 'nokaslr' is passed on the kernel
     command-line

   - Minor fixes and cleanups across the board"

* tag 'arm64-upstream' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux: (72 commits)
  KVM: arm64: Ensure CPU PMU probes before pKVM host de-privilege
  arm64: kexec: include reboot.h
  arm64: delete dead code in this_cpu_set_vectors()
  arm64/cpufeature: Use helper macro to specify ID register for capabilites
  drivers/perf: hisi: add NULL check for name
  drivers/perf: hisi: Remove redundant initialized of pmu->name
  arm64/cpufeature: Consistently use symbolic constants for min_field_value
  arm64/cpufeature: Pull out helper for CPUID register definitions
  arm64/sysreg: Convert HFGITR_EL2 to automatic generation
  ACPI: AGDI: Improve error reporting for problems during .remove()
  arm64: kernel: Fix kernel warning when nokaslr is passed to commandline
  perf/arm-cmn: Fix port detection for CMN-700
  arm64: kgdb: Set PSTATE.SS to 1 to re-enable single-step
  arm64: move PAC masks to <asm/pointer_auth.h>
  arm64: use XPACLRI to strip PAC
  arm64: avoid redundant PAC stripping in __builtin_return_address()
  arm64/sme: Fix some comments of ARM SME
  arm64/signal: Alloc tpidr2 sigframe after checking system_supports_tpidr2()
  arm64/signal: Use system_supports_tpidr2() to check TPIDR2
  arm64/idreg: Don't disable SME when disabling SVE
  ...
2023-04-25 12:39:01 -07:00
Linus Torvalds
e7989789c6 Timers and timekeeping updates:
- Improve the VDSO build time checks to cover all dynamic relocations
 
     VDSO does not allow dynamic relcations, but the build time check is
     incomplete and fragile.
 
     It's based on architectures specifying the relocation types to search
     for and does not handle R_*_NONE relocation entries correctly.
     R_*_NONE relocations are injected by some GNU ld variants if they fail
     to determine the exact .rel[a]/dyn_size to cover trailing zeros.
     R_*_NONE relocations must be ignored by dynamic loaders, so they
     should be ignored in the build time check too.
 
     Remove the architecture specific relocation types to check for and
     validate strictly that no other relocations than R_*_NONE end up
     in the VSDO .so file.
 
   - Prefer signal delivery to the current thread for
     CLOCK_PROCESS_CPUTIME_ID based posix-timers
 
     Such timers prefer to deliver the signal to the main thread of a
     process even if the context in which the timer expires is the current
     task. This has the downside that it might wake up an idle thread.
 
     As there is no requirement or guarantee that the signal has to be
     delivered to the main thread, avoid this by preferring the current
     task if it is part of the thread group which shares sighand.
 
     This not only avoids waking idle threads, it also distributes the
     signal delivery in case of multiple timers firing in the context
     of different threads close to each other better.
 
   - Align the tick period properly (again)
 
     For a long time the tick was starting at CLOCK_MONOTONIC zero, which
     allowed users space applications to either align with the tick or to
     place a periodic computation so that it does not interfere with the
     tick. The alignement of the tick period was more by chance than by
     intention as the tick is set up before a high resolution clocksource is
     installed, i.e. timekeeping is still tick based and the tick period
     advances from there.
 
     The early enablement of sched_clock() broke this alignement as the time
     accumulated by sched_clock() is taken into account when timekeeping is
     initialized. So the base value now(CLOCK_MONOTONIC) is not longer a
     multiple of tick periods, which breaks applications which relied on
     that behaviour.
 
     Cure this by aligning the tick starting point to the next multiple of
     tick periods, i.e 1000ms/CONFIG_HZ.
 
  - A set of NOHZ fixes and enhancements
 
    - Cure the concurrent writer race for idle and IO sleeptime statistics
 
      The statitic values which are exposed via /proc/stat are updated from
      the CPU local idle exit and remotely by cpufreq, but that happens
      without any form of serialization. As a consequence sleeptimes can be
      accounted twice or worse.
 
      Prevent this by restricting the accumulation writeback to the CPU
      local idle exit and let the remote access compute the accumulated
      value.
 
    - Protect idle/iowait sleep time with a sequence count
 
      Reading idle/iowait sleep time, e.g. from /proc/stat, can race with
      idle exit updates. As a consequence the readout may result in random
      and potentially going backwards values.
 
      Protect this by a sequence count, which fixes the idle time
      statistics issue, but cannot fix the iowait time problem because
      iowait time accounting races with remote wake ups decrementing the
      remote runqueues nr_iowait counter. The latter is impossible to fix,
      so the only way to deal with that is to document it properly and to
      remove the assertion in the selftest which triggers occasionally due
      to that.
 
    - Restructure struct tick_sched for better cache layout
 
    - Some small cleanups and a better cache layout for struct tick_sched
 
  - Implement the missing timer_wait_running() callback for POSIX CPU timers
 
    For unknown reason the introduction of the timer_wait_running() callback
    missed to fixup posix CPU timers, which went unnoticed for almost four
    years.
 
    While initially only targeted to prevent livelocks between a timer
    deletion and the timer expiry function on PREEMPT_RT enabled kernels, it
    turned out that fixing this for mainline is not as trivial as just
    implementing a stub similar to the hrtimer/timer callbacks.
 
    The reason is that for CONFIG_POSIX_CPU_TIMERS_TASK_WORK enabled systems
    there is a livelock issue independent of RT.
 
    CONFIG_POSIX_CPU_TIMERS_TASK_WORK=y moves the expiry of POSIX CPU timers
    out from hard interrupt context to task work, which is handled before
    returning to user space or to a VM. The expiry mechanism moves the
    expired timers to a stack local list head with sighand lock held. Once
    sighand is dropped the task can be preempted and a task which wants to
    delete a timer will spin-wait until the expiry task is scheduled back
    in. In the worst case this will end up in a livelock when the preempting
    task and the expiry task are pinned on the same CPU.
 
    The timer wheel has a timer_wait_running() mechanism for RT, which uses
    a per CPU timer-base expiry lock which is held by the expiry code and the
    task waiting for the timer function to complete blocks on that lock.
 
    This does not work in the same way for posix CPU timers as there is no
    timer base and expiry for process wide timers can run on any task
    belonging to that process, but the concept of waiting on an expiry lock
    can be used too in a slightly different way.
 
    Add a per task mutex to struct posix_cputimers_work, let the expiry task
    hold it accross the expiry function and let the deleting task which
    waits for the expiry to complete block on the mutex.
 
    In the non-contended case this results in an extra mutex_lock()/unlock()
    pair on both sides.
 
    This avoids spin-waiting on a task which is scheduled out, prevents the
    livelock and cures the problem for RT and !RT systems.
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Merge tag 'timers-core-2023-04-24' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull timers and timekeeping updates from Thomas Gleixner:

 - Improve the VDSO build time checks to cover all dynamic relocations

   VDSO does not allow dynamic relocations, but the build time check is
   incomplete and fragile.

   It's based on architectures specifying the relocation types to search
   for and does not handle R_*_NONE relocation entries correctly.
   R_*_NONE relocations are injected by some GNU ld variants if they
   fail to determine the exact .rel[a]/dyn_size to cover trailing zeros.
   R_*_NONE relocations must be ignored by dynamic loaders, so they
   should be ignored in the build time check too.

   Remove the architecture specific relocation types to check for and
   validate strictly that no other relocations than R_*_NONE end up in
   the VSDO .so file.

 - Prefer signal delivery to the current thread for
   CLOCK_PROCESS_CPUTIME_ID based posix-timers

   Such timers prefer to deliver the signal to the main thread of a
   process even if the context in which the timer expires is the current
   task. This has the downside that it might wake up an idle thread.

   As there is no requirement or guarantee that the signal has to be
   delivered to the main thread, avoid this by preferring the current
   task if it is part of the thread group which shares sighand.

   This not only avoids waking idle threads, it also distributes the
   signal delivery in case of multiple timers firing in the context of
   different threads close to each other better.

 - Align the tick period properly (again)

   For a long time the tick was starting at CLOCK_MONOTONIC zero, which
   allowed users space applications to either align with the tick or to
   place a periodic computation so that it does not interfere with the
   tick. The alignement of the tick period was more by chance than by
   intention as the tick is set up before a high resolution clocksource
   is installed, i.e. timekeeping is still tick based and the tick
   period advances from there.

   The early enablement of sched_clock() broke this alignement as the
   time accumulated by sched_clock() is taken into account when
   timekeeping is initialized. So the base value now(CLOCK_MONOTONIC) is
   not longer a multiple of tick periods, which breaks applications
   which relied on that behaviour.

   Cure this by aligning the tick starting point to the next multiple of
   tick periods, i.e 1000ms/CONFIG_HZ.

 - A set of NOHZ fixes and enhancements:

     * Cure the concurrent writer race for idle and IO sleeptime
       statistics

       The statitic values which are exposed via /proc/stat are updated
       from the CPU local idle exit and remotely by cpufreq, but that
       happens without any form of serialization. As a consequence
       sleeptimes can be accounted twice or worse.

       Prevent this by restricting the accumulation writeback to the CPU
       local idle exit and let the remote access compute the accumulated
       value.

     * Protect idle/iowait sleep time with a sequence count

       Reading idle/iowait sleep time, e.g. from /proc/stat, can race
       with idle exit updates. As a consequence the readout may result
       in random and potentially going backwards values.

       Protect this by a sequence count, which fixes the idle time
       statistics issue, but cannot fix the iowait time problem because
       iowait time accounting races with remote wake ups decrementing
       the remote runqueues nr_iowait counter. The latter is impossible
       to fix, so the only way to deal with that is to document it
       properly and to remove the assertion in the selftest which
       triggers occasionally due to that.

     * Restructure struct tick_sched for better cache layout

     * Some small cleanups and a better cache layout for struct
       tick_sched

 - Implement the missing timer_wait_running() callback for POSIX CPU
   timers

   For unknown reason the introduction of the timer_wait_running()
   callback missed to fixup posix CPU timers, which went unnoticed for
   almost four years.

   While initially only targeted to prevent livelocks between a timer
   deletion and the timer expiry function on PREEMPT_RT enabled kernels,
   it turned out that fixing this for mainline is not as trivial as just
   implementing a stub similar to the hrtimer/timer callbacks.

   The reason is that for CONFIG_POSIX_CPU_TIMERS_TASK_WORK enabled
   systems there is a livelock issue independent of RT.

   CONFIG_POSIX_CPU_TIMERS_TASK_WORK=y moves the expiry of POSIX CPU
   timers out from hard interrupt context to task work, which is handled
   before returning to user space or to a VM. The expiry mechanism moves
   the expired timers to a stack local list head with sighand lock held.
   Once sighand is dropped the task can be preempted and a task which
   wants to delete a timer will spin-wait until the expiry task is
   scheduled back in. In the worst case this will end up in a livelock
   when the preempting task and the expiry task are pinned on the same
   CPU.

   The timer wheel has a timer_wait_running() mechanism for RT, which
   uses a per CPU timer-base expiry lock which is held by the expiry
   code and the task waiting for the timer function to complete blocks
   on that lock.

   This does not work in the same way for posix CPU timers as there is
   no timer base and expiry for process wide timers can run on any task
   belonging to that process, but the concept of waiting on an expiry
   lock can be used too in a slightly different way.

   Add a per task mutex to struct posix_cputimers_work, let the expiry
   task hold it accross the expiry function and let the deleting task
   which waits for the expiry to complete block on the mutex.

   In the non-contended case this results in an extra
   mutex_lock()/unlock() pair on both sides.

   This avoids spin-waiting on a task which is scheduled out, prevents
   the livelock and cures the problem for RT and !RT systems

* tag 'timers-core-2023-04-24' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  posix-cpu-timers: Implement the missing timer_wait_running callback
  selftests/proc: Assert clock_gettime(CLOCK_BOOTTIME) VS /proc/uptime monotonicity
  selftests/proc: Remove idle time monotonicity assertions
  MAINTAINERS: Remove stale email address
  timers/nohz: Remove middle-function __tick_nohz_idle_stop_tick()
  timers/nohz: Add a comment about broken iowait counter update race
  timers/nohz: Protect idle/iowait sleep time under seqcount
  timers/nohz: Only ever update sleeptime from idle exit
  timers/nohz: Restructure and reshuffle struct tick_sched
  tick/common: Align tick period with the HZ tick.
  selftests/timers/posix_timers: Test delivery of signals across threads
  posix-timers: Prefer delivery of signals to the current thread
  vdso: Improve cmd_vdso_check to check all dynamic relocations
2023-04-25 11:22:46 -07:00
Linus Torvalds
3f614ab563 Interrupt core and drivers updates:
- Core:
 
    - Add tracepoints for tasklet callbacks which makes it possible to
      analyze individual tasklet functions instead of guess working
      from the overall duration of tasklet processing
 
    - Ensure that secondary interrupt threads have their affinity adjusted
      correctly.
 
  - Drivers:
 
    - A large rework of the RISC-V IPI management to prepare for a new
      RISC-V interrupt architecture
 
    - Small fixes and enhancements all over the place
 
    - Removal of support for various obsolete hardware platforms and the
      related code
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Merge tag 'irq-core-2023-04-24' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull interrupt updates from Thomas Gleixner:
 "Core:

   - Add tracepoints for tasklet callbacks which makes it possible to
     analyze individual tasklet functions instead of guess working from
     the overall duration of tasklet processing

   - Ensure that secondary interrupt threads have their affinity
     adjusted correctly

  Drivers:

   - A large rework of the RISC-V IPI management to prepare for a new
     RISC-V interrupt architecture

   - Small fixes and enhancements all over the place

   - Removal of support for various obsolete hardware platforms and the
     related code"

* tag 'irq-core-2023-04-24' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (21 commits)
  irqchip/st: Remove stih415/stih416 and stid127 platforms support
  irqchip/gic-v3: Add Rockchip 3588001 erratum workaround
  genirq: Update affinity of secondary threads
  softirq: Add trace points for tasklet entry/exit
  irqchip/loongson-pch-pic: Fix pch_pic_acpi_init calling
  irqchip/loongson-pch-pic: Fix registration of syscore_ops
  irqchip/loongson-eiointc: Fix registration of syscore_ops
  irqchip/loongson-eiointc: Fix incorrect use of acpi_get_vec_parent
  irqchip/loongson-eiointc: Fix returned value on parsing MADT
  irqchip/riscv-intc: Add empty irq_eoi() for chained irq handlers
  RISC-V: Use IPIs for remote icache flush when possible
  RISC-V: Use IPIs for remote TLB flush when possible
  RISC-V: Allow marking IPIs as suitable for remote FENCEs
  RISC-V: Treat IPIs as normal Linux IRQs
  irqchip/riscv-intc: Allow drivers to directly discover INTC hwnode
  RISC-V: Clear SIP bit only when using SBI IPI operations
  irqchip/irq-sifive-plic: Add syscore callbacks for hibernation
  irqchip: Use of_property_read_bool() for boolean properties
  irqchip/bcm-6345-l1: Request memory region
  irqchip/gicv3: Workaround for NVIDIA erratum T241-FABRIC-4
  ...
2023-04-25 11:16:08 -07:00
Linus Torvalds
15bbeec0fe Update for entry and ptrace:
Provide a ptrace set/get interface for syscall user dispatch. The main
   purpose is to enable checkpoint/restore (CRIU) to handle processes which
   utilize syscall user dispatch correctly.
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Merge tag 'core-entry-2023-04-24' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull core entry/ptrace update from Thomas Gleixner:
 "Provide a ptrace set/get interface for syscall user dispatch. The main
  purpose is to enable checkpoint/restore (CRIU) to handle processes
  which utilize syscall user dispatch correctly"

* tag 'core-entry-2023-04-24' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  selftest, ptrace: Add selftest for syscall user dispatch config api
  ptrace: Provide set/get interface for syscall user dispatch
  syscall_user_dispatch: Untag selector address before access_ok()
  syscall_user_dispatch: Split up set_syscall_user_dispatch()
2023-04-25 11:05:04 -07:00
Linus Torvalds
ef36b9afc2 fget() to fdget() conversions
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
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Merge tag 'pull-fd' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs

Pull vfs fget updates from Al Viro:
 "fget() to fdget() conversions"

* tag 'pull-fd' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
  fuse_dev_ioctl(): switch to fdget()
  cgroup_get_from_fd(): switch to fdget_raw()
  bpf: switch to fdget_raw()
  build_mount_idmapped(): switch to fdget()
  kill the last remaining user of proc_ns_fget()
  SVM-SEV: convert the rest of fget() uses to fdget() in there
  convert sgx_set_attribute() to fdget()/fdput()
  convert setns(2) to fdget()/fdput()
2023-04-24 19:14:20 -07:00
Yafang Shao
a0c109dcaf bpf: Add __rcu_read_{lock,unlock} into btf id deny list
The tracing recursion prevention mechanism must be protected by rcu, that
leaves __rcu_read_{lock,unlock} unprotected by this mechanism. If we trace
them, the recursion will happen. Let's add them into the btf id deny list.

When CONFIG_PREEMPT_RCU is enabled, it can be reproduced with a simple bpf
program as such:
  SEC("fentry/__rcu_read_lock")
  int fentry_run()
  {
      return 0;
  }

Signed-off-by: Yafang Shao <laoar.shao@gmail.com>
Link: https://lore.kernel.org/r/20230424161104.3737-2-laoar.shao@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2023-04-24 14:16:01 -07:00
Dave Marchevsky
7deca5eae8 bpf: Disable bpf_refcount_acquire kfunc calls until race conditions are fixed
As reported by Kumar in [0], the shared ownership implementation for BPF
programs has some race conditions which need to be addressed before it
can safely be used. This patch does so in a minimal way instead of
ripping out shared ownership entirely, as proper fixes for the issues
raised will follow ASAP, at which point this patch's commit can be
reverted to re-enable shared ownership.

The patch removes the ability to call bpf_refcount_acquire_impl from BPF
programs. Programs can only bump refcount and obtain a new owning
reference using this kfunc, so removing the ability to call it
effectively disables shared ownership.

Instead of changing success / failure expectations for
bpf_refcount-related selftests, this patch just disables them from
running for now.

  [0]: https://lore.kernel.org/bpf/d7hyspcow5wtjcmw4fugdgyp3fwhljwuscp3xyut5qnwivyeru@ysdq543otzv2/

Reported-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
Signed-off-by: Dave Marchevsky <davemarchevsky@fb.com>
Link: https://lore.kernel.org/r/20230424204321.2680232-1-davemarchevsky@fb.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2023-04-24 14:02:11 -07:00
Linus Torvalds
ec40758b31 v6.4/pidfd.file
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Merge tag 'v6.4/pidfd.file' of git://git.kernel.org/pub/scm/linux/kernel/git/brauner/linux

Pull pidfd updates from Christian Brauner:
 "This adds a new pidfd_prepare() helper which allows the caller to
  reserve a pidfd number and allocates a new pidfd file that stashes the
  provided struct pid.

  It should be avoided installing a file descriptor into a task's file
  descriptor table just to close it again via close_fd() in case an
  error occurs. The fd has been visible to userspace and might already
  be in use. Instead, a file descriptor should be reserved but not
  installed into the caller's file descriptor table.

  If another failure path is hit then the reserved file descriptor and
  file can just be put without any userspace visible side-effects. And
  if all failure paths are cleared the file descriptor and file can be
  installed into the task's file descriptor table.

  This helper is now used in all places that open coded this
  functionality before. For example, this is currently done during
  copy_process() and fanotify used pidfd_create(), which returns a pidfd
  that has already been made visibile in the caller's file descriptor
  table, but then closed it using close_fd().

  In one of the next merge windows there is also new functionality
  coming to unix domain sockets that will have to rely on
  pidfd_prepare()"

* tag 'v6.4/pidfd.file' of git://git.kernel.org/pub/scm/linux/kernel/git/brauner/linux:
  fanotify: use pidfd_prepare()
  fork: use pidfd_prepare()
  pid: add pidfd_prepare()
2023-04-24 13:03:42 -07:00
Linus Torvalds
3323ddce08 v6.4/kernel.user_worker
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Merge tag 'v6.4/kernel.user_worker' of git://git.kernel.org/pub/scm/linux/kernel/git/brauner/linux

Pull user work thread updates from Christian Brauner:
 "This contains the work generalizing the ability to create a kernel
  worker from a userspace process.

  Such user workers will run with the same credentials as the userspace
  process they were created from providing stronger security and
  accounting guarantees than the traditional override_creds() approach
  ever could've hoped for.

  The original work was heavily based and optimzed for the needs of
  io_uring which was the first user. However, as it quickly turned out
  the ability to create user workers inherting properties from a
  userspace process is generally useful.

  The vhost subsystem currently creates workers using the kthread api.
  The consequences of using the kthread api are that RLIMITs don't work
  correctly as they are inherited from khtreadd. This leads to bugs
  where more workers are created than would be allowed by the RLIMITs of
  the userspace process in lieu of which workers are created.

  Problems like this disappear with user workers created from the
  userspace processes for which they perform the work. In addition,
  providing this api allows vhost to remove additional complexity. For
  example, cgroup and mm sharing will just work out of the box with user
  workers based on the relevant userspace process instead of manually
  ensuring the correct cgroup and mm contexts are used.

  So the vhost subsystem should simply be made to use the same mechanism
  as io_uring. To this end the original mechanism used for
  create_io_thread() is generalized into user workers:

   - Introduce PF_USER_WORKER as a generic indicator that a given task
     is a user worker, i.e., a kernel task that was created from a
     userspace process. Now a PF_IO_WORKER thread is just a specialized
     version of PF_USER_WORKER. So io_uring io workers raise both flags.

   - Make copy_process() available to core kernel code

   - Extend struct kernel_clone_args with the following bitfields
     allowing to indicate to copy_process():
       - to create a user worker (raise PF_USER_WORKER)
       - to not inherit any files from the userspace process
       - to ignore signals

  After all generic changes are in place the vhost subsystem implements
  a new dedicated vhost api based on user workers. Finally, vhost is
  switched to rely on the new api moving it off of kthreads.

  Thanks to Mike for sticking it out and making it through this rather
  arduous journey"

* tag 'v6.4/kernel.user_worker' of git://git.kernel.org/pub/scm/linux/kernel/git/brauner/linux:
  vhost: use vhost_tasks for worker threads
  vhost: move worker thread fields to new struct
  vhost_task: Allow vhost layer to use copy_process
  fork: allow kernel code to call copy_process
  fork: Add kernel_clone_args flag to ignore signals
  fork: add kernel_clone_args flag to not dup/clone files
  fork/vm: Move common PF_IO_WORKER behavior to new flag
  kernel: Make io_thread and kthread bit fields
  kthread: Pass in the thread's name during creation
  kernel: Allow a kernel thread's name to be set in copy_process
  csky: Remove kernel_thread declaration
2023-04-24 12:52:35 -07:00
Linus Torvalds
5dfb75e842 RCU Changes for 6.4:
o  MAINTAINERS files additions and changes.
  o  Fix hotplug warning in nohz code.
  o  Tick dependency changes by Zqiang.
  o  Lazy-RCU shrinker fixes by Zqiang.
  o  rcu-tasks stall reporting improvements by Neeraj.
  o  Initial changes for renaming of k[v]free_rcu() to its new k[v]free_rcu_mightsleep()
     name for robustness.
  o  Documentation Updates:
  o  Significant changes to srcu_struct size.
  o  Deadlock detection for srcu_read_lock() vs synchronize_srcu() from Boqun.
  o  rcutorture and rcu-related tool, which are targeted for v6.4 from Boqun's tree.
  o  Other misc changes.
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Merge tag 'rcu.6.4.april5.2023.3' of git://git.kernel.org/pub/scm/linux/kernel/git/jfern/linux

Pull RCU updates from Joel Fernandes:

 - Updates and additions to MAINTAINERS files, with Boqun being added to
   the RCU entry and Zqiang being added as an RCU reviewer.

   I have also transitioned from reviewer to maintainer; however, Paul
   will be taking over sending RCU pull-requests for the next merge
   window.

 - Resolution of hotplug warning in nohz code, achieved by fixing
   cpu_is_hotpluggable() through interaction with the nohz subsystem.

   Tick dependency modifications by Zqiang, focusing on fixing usage of
   the TICK_DEP_BIT_RCU_EXP bitmask.

 - Avoid needless calls to the rcu-lazy shrinker for CONFIG_RCU_LAZY=n
   kernels, fixed by Zqiang.

 - Improvements to rcu-tasks stall reporting by Neeraj.

 - Initial renaming of k[v]free_rcu() to k[v]free_rcu_mightsleep() for
   increased robustness, affecting several components like mac802154,
   drbd, vmw_vmci, tracing, and more.

   A report by Eric Dumazet showed that the API could be unknowingly
   used in an atomic context, so we'd rather make sure they know what
   they're asking for by being explicit:

      https://lore.kernel.org/all/20221202052847.2623997-1-edumazet@google.com/

 - Documentation updates, including corrections to spelling,
   clarifications in comments, and improvements to the srcu_size_state
   comments.

 - Better srcu_struct cache locality for readers, by adjusting the size
   of srcu_struct in support of SRCU usage by Christoph Hellwig.

 - Teach lockdep to detect deadlocks between srcu_read_lock() vs
   synchronize_srcu() contributed by Boqun.

   Previously lockdep could not detect such deadlocks, now it can.

 - Integration of rcutorture and rcu-related tools, targeted for v6.4
   from Boqun's tree, featuring new SRCU deadlock scenarios, test_nmis
   module parameter, and more

 - Miscellaneous changes, various code cleanups and comment improvements

* tag 'rcu.6.4.april5.2023.3' of git://git.kernel.org/pub/scm/linux/kernel/git/jfern/linux: (71 commits)
  checkpatch: Error out if deprecated RCU API used
  mac802154: Rename kfree_rcu() to kvfree_rcu_mightsleep()
  rcuscale: Rename kfree_rcu() to kfree_rcu_mightsleep()
  ext4/super: Rename kfree_rcu() to kfree_rcu_mightsleep()
  net/mlx5: Rename kfree_rcu() to kfree_rcu_mightsleep()
  net/sysctl: Rename kvfree_rcu() to kvfree_rcu_mightsleep()
  lib/test_vmalloc.c: Rename kvfree_rcu() to kvfree_rcu_mightsleep()
  tracing: Rename kvfree_rcu() to kvfree_rcu_mightsleep()
  misc: vmw_vmci: Rename kvfree_rcu() to kvfree_rcu_mightsleep()
  drbd: Rename kvfree_rcu() to kvfree_rcu_mightsleep()
  rcu: Protect rcu_print_task_exp_stall() ->exp_tasks access
  rcu: Avoid stack overflow due to __rcu_irq_enter_check_tick() being kprobe-ed
  rcu-tasks: Report stalls during synchronize_srcu() in rcu_tasks_postscan()
  rcu: Permit start_poll_synchronize_rcu_expedited() to be invoked early
  rcu: Remove never-set needwake assignment from rcu_report_qs_rdp()
  rcu: Register rcu-lazy shrinker only for CONFIG_RCU_LAZY=y kernels
  rcu: Fix missing TICK_DEP_MASK_RCU_EXP dependency check
  rcu: Fix set/clear TICK_DEP_BIT_RCU_EXP bitmask race
  rcu/trace: use strscpy() to instead of strncpy()
  tick/nohz: Fix cpu_is_hotpluggable() by checking with nohz subsystem
  ...
2023-04-24 12:16:14 -07:00
Linus Torvalds
4a4075ada6 locktorture updates for v6.4
This update adds tests for nested locking and also adds support for
 testing raw spinlocks in PREEMPT_RT kernels.
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Merge tag 'locktorture.2023.04.04a' of git://git.kernel.org/pub/scm/linux/kernel/git/paulmck/linux-rcu

Pull locktorture updates from Paul McKenney:
 "This adds tests for nested locking and also adds support for testing
  raw spinlocks in PREEMPT_RT kernels"

* tag 'locktorture.2023.04.04a' of git://git.kernel.org/pub/scm/linux/kernel/git/paulmck/linux-rcu:
  locktorture: Add raw_spinlock* torture tests for PREEMPT_RT kernels
  locktorture: With nested locks, occasionally skip main lock
  locktorture: Add nested locking to rtmutex torture tests
  locktorture: Add nested locking to mutex torture tests
  locktorture: Add nested_[un]lock() hooks and nlocks parameter
2023-04-24 12:05:08 -07:00
Linus Torvalds
022e32094e Kernel concurrency sanitizer (KCSAN) updates for v6.4
This update fixes kernel-doc warnings and also updates instrumentation
 from READ_ONCE() to volatile in order to avoid unaligned load-acquire
 instructions on arm64 in kernels built with LTO.
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Merge tag 'kcsan.2023.04.04a' of git://git.kernel.org/pub/scm/linux/kernel/git/paulmck/linux-rcu

Pull KCSAN updates from Paul McKenney:
 "Kernel concurrency sanitizer (KCSAN) updates for v6.4

  This fixes kernel-doc warnings and also updates instrumentation from
  READ_ONCE() to volatile in order to avoid unaligned load-acquire
  instructions on arm64 in kernels built with LTO"

* tag 'kcsan.2023.04.04a' of git://git.kernel.org/pub/scm/linux/kernel/git/paulmck/linux-rcu:
  kcsan: Avoid READ_ONCE() in read_instrumented_memory()
  instrumented.h: Fix all kernel-doc format warnings
2023-04-24 11:46:53 -07:00
Petr Mladek
c9c8133080 Merge branch 'for-6.4/doc' into for-linus 2023-04-24 16:49:08 +02:00
Jakub Kicinski
9a82cdc28f bpf-next-for-netdev
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Merge tag 'for-netdev' of https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next

Daniel Borkmann says:

====================
pull-request: bpf-next 2023-04-21

We've added 71 non-merge commits during the last 8 day(s) which contain
a total of 116 files changed, 13397 insertions(+), 8896 deletions(-).

The main changes are:

1) Add a new BPF netfilter program type and minimal support to hook
   BPF programs to netfilter hooks such as prerouting or forward,
   from Florian Westphal.

2) Fix race between btf_put and btf_idr walk which caused a deadlock,
   from Alexei Starovoitov.

3) Second big batch to migrate test_verifier unit tests into test_progs
   for ease of readability and debugging, from Eduard Zingerman.

4) Add support for refcounted local kptrs to the verifier for allowing
   shared ownership, useful for adding a node to both the BPF list and
   rbtree, from Dave Marchevsky.

5) Migrate bpf_for(), bpf_for_each() and bpf_repeat() macros from BPF
  selftests into libbpf-provided bpf_helpers.h header and improve
  kfunc handling, from Andrii Nakryiko.

6) Support 64-bit pointers to kfuncs needed for archs like s390x,
   from Ilya Leoshkevich.

7) Support BPF progs under getsockopt with a NULL optval,
   from Stanislav Fomichev.

8) Improve verifier u32 scalar equality checking in order to enable
   LLVM transformations which earlier had to be disabled specifically
   for BPF backend, from Yonghong Song.

9) Extend bpftool's struct_ops object loading to support links,
   from Kui-Feng Lee.

10) Add xsk selftest follow-up fixes for hugepage allocated umem,
    from Magnus Karlsson.

11) Support BPF redirects from tc BPF to ifb devices,
    from Daniel Borkmann.

12) Add BPF support for integer type when accessing variable length
    arrays, from Feng Zhou.

* tag 'for-netdev' of https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next: (71 commits)
  selftests/bpf: verifier/value_ptr_arith converted to inline assembly
  selftests/bpf: verifier/value_illegal_alu converted to inline assembly
  selftests/bpf: verifier/unpriv converted to inline assembly
  selftests/bpf: verifier/subreg converted to inline assembly
  selftests/bpf: verifier/spin_lock converted to inline assembly
  selftests/bpf: verifier/sock converted to inline assembly
  selftests/bpf: verifier/search_pruning converted to inline assembly
  selftests/bpf: verifier/runtime_jit converted to inline assembly
  selftests/bpf: verifier/regalloc converted to inline assembly
  selftests/bpf: verifier/ref_tracking converted to inline assembly
  selftests/bpf: verifier/map_ptr_mixing converted to inline assembly
  selftests/bpf: verifier/map_in_map converted to inline assembly
  selftests/bpf: verifier/lwt converted to inline assembly
  selftests/bpf: verifier/loops1 converted to inline assembly
  selftests/bpf: verifier/jeq_infer_not_null converted to inline assembly
  selftests/bpf: verifier/direct_packet_access converted to inline assembly
  selftests/bpf: verifier/d_path converted to inline assembly
  selftests/bpf: verifier/ctx converted to inline assembly
  selftests/bpf: verifier/btf_ctx_access converted to inline assembly
  selftests/bpf: verifier/bpf_get_stack converted to inline assembly
  ...
====================

Link: https://lore.kernel.org/r/20230421211035.9111-1-daniel@iogearbox.net
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2023-04-21 20:32:37 -07:00
Stefan Roesch
d7597f59d1 mm: add new api to enable ksm per process
Patch series "mm: process/cgroup ksm support", v9.

So far KSM can only be enabled by calling madvise for memory regions.  To
be able to use KSM for more workloads, KSM needs to have the ability to be
enabled / disabled at the process / cgroup level.

Use case 1:
  The madvise call is not available in the programming language.  An
  example for this are programs with forked workloads using a garbage
  collected language without pointers.  In such a language madvise cannot
  be made available.

  In addition the addresses of objects get moved around as they are
  garbage collected.  KSM sharing needs to be enabled "from the outside"
  for these type of workloads.

Use case 2:
  The same interpreter can also be used for workloads where KSM brings
  no benefit or even has overhead.  We'd like to be able to enable KSM on
  a workload by workload basis.

Use case 3:
  With the madvise call sharing opportunities are only enabled for the
  current process: it is a workload-local decision.  A considerable number
  of sharing opportunities may exist across multiple workloads or jobs (if
  they are part of the same security domain).  Only a higler level entity
  like a job scheduler or container can know for certain if its running
  one or more instances of a job.  That job scheduler however doesn't have
  the necessary internal workload knowledge to make targeted madvise
  calls.

Security concerns:

  In previous discussions security concerns have been brought up.  The
  problem is that an individual workload does not have the knowledge about
  what else is running on a machine.  Therefore it has to be very
  conservative in what memory areas can be shared or not.  However, if the
  system is dedicated to running multiple jobs within the same security
  domain, its the job scheduler that has the knowledge that sharing can be
  safely enabled and is even desirable.

Performance:

  Experiments with using UKSM have shown a capacity increase of around 20%.

  Here are the metrics from an instagram workload (taken from a machine
  with 64GB main memory):

   full_scans: 445
   general_profit: 20158298048
   max_page_sharing: 256
   merge_across_nodes: 1
   pages_shared: 129547
   pages_sharing: 5119146
   pages_to_scan: 4000
   pages_unshared: 1760924
   pages_volatile: 10761341
   run: 1
   sleep_millisecs: 20
   stable_node_chains: 167
   stable_node_chains_prune_millisecs: 2000
   stable_node_dups: 2751
   use_zero_pages: 0
   zero_pages_sharing: 0

After the service is running for 30 minutes to an hour, 4 to 5 million
shared pages are common for this workload when using KSM.


Detailed changes:

1. New options for prctl system command
   This patch series adds two new options to the prctl system call. 
   The first one allows to enable KSM at the process level and the second
   one to query the setting.

The setting will be inherited by child processes.

With the above setting, KSM can be enabled for the seed process of a cgroup
and all processes in the cgroup will inherit the setting.

2. Changes to KSM processing
   When KSM is enabled at the process level, the KSM code will iterate
   over all the VMA's and enable KSM for the eligible VMA's.

   When forking a process that has KSM enabled, the setting will be
   inherited by the new child process.

3. Add general_profit metric
   The general_profit metric of KSM is specified in the documentation,
   but not calculated.  This adds the general profit metric to
   /sys/kernel/debug/mm/ksm.

4. Add more metrics to ksm_stat
   This adds the process profit metric to /proc/<pid>/ksm_stat.

5. Add more tests to ksm_tests and ksm_functional_tests
   This adds an option to specify the merge type to the ksm_tests. 
   This allows to test madvise and prctl KSM.

   It also adds a two new tests to ksm_functional_tests: one to test
   the new prctl options and the other one is a fork test to verify that
   the KSM process setting is inherited by client processes.


This patch (of 3):

So far KSM can only be enabled by calling madvise for memory regions.  To
be able to use KSM for more workloads, KSM needs to have the ability to be
enabled / disabled at the process / cgroup level.

1. New options for prctl system command

   This patch series adds two new options to the prctl system call.
   The first one allows to enable KSM at the process level and the second
   one to query the setting.

   The setting will be inherited by child processes.

   With the above setting, KSM can be enabled for the seed process of a
   cgroup and all processes in the cgroup will inherit the setting.

2. Changes to KSM processing

   When KSM is enabled at the process level, the KSM code will iterate
   over all the VMA's and enable KSM for the eligible VMA's.

   When forking a process that has KSM enabled, the setting will be
   inherited by the new child process.

  1) Introduce new MMF_VM_MERGE_ANY flag

     This introduces the new flag MMF_VM_MERGE_ANY flag.  When this flag
     is set, kernel samepage merging (ksm) gets enabled for all vma's of a
     process.

  2) Setting VM_MERGEABLE on VMA creation

     When a VMA is created, if the MMF_VM_MERGE_ANY flag is set, the
     VM_MERGEABLE flag will be set for this VMA.

  3) support disabling of ksm for a process

     This adds the ability to disable ksm for a process if ksm has been
     enabled for the process with prctl.

  4) add new prctl option to get and set ksm for a process

     This adds two new options to the prctl system call
     - enable ksm for all vmas of a process (if the vmas support it).
     - query if ksm has been enabled for a process.

3. Disabling MMF_VM_MERGE_ANY for storage keys in s390

   In the s390 architecture when storage keys are used, the
   MMF_VM_MERGE_ANY will be disabled.

Link: https://lkml.kernel.org/r/20230418051342.1919757-1-shr@devkernel.io
Link: https://lkml.kernel.org/r/20230418051342.1919757-2-shr@devkernel.io
Signed-off-by: Stefan Roesch <shr@devkernel.io>
Acked-by: David Hildenbrand <david@redhat.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Rik van Riel <riel@surriel.com>
Cc: Bagas Sanjaya <bagasdotme@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-04-21 14:52:03 -07:00
Florian Westphal
fd9c663b9a bpf: minimal support for programs hooked into netfilter framework
This adds minimal support for BPF_PROG_TYPE_NETFILTER bpf programs
that will be invoked via the NF_HOOK() points in the ip stack.

Invocation incurs an indirect call.  This is not a necessity: Its
possible to add 'DEFINE_BPF_DISPATCHER(nf_progs)' and handle the
program invocation with the same method already done for xdp progs.

This isn't done here to keep the size of this chunk down.

Verifier restricts verdicts to either DROP or ACCEPT.

Signed-off-by: Florian Westphal <fw@strlen.de>
Link: https://lore.kernel.org/r/20230421170300.24115-3-fw@strlen.de
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2023-04-21 11:34:14 -07:00
Florian Westphal
84601d6ee6 bpf: add bpf_link support for BPF_NETFILTER programs
Add bpf_link support skeleton.  To keep this reviewable, no bpf program
can be invoked yet, if a program is attached only a c-stub is called and
not the actual bpf program.

Defaults to 'y' if both netfilter and bpf syscall are enabled in kconfig.

Uapi example usage:
	union bpf_attr attr = { };

	attr.link_create.prog_fd = progfd;
	attr.link_create.attach_type = 0; /* unused */
	attr.link_create.netfilter.pf = PF_INET;
	attr.link_create.netfilter.hooknum = NF_INET_LOCAL_IN;
	attr.link_create.netfilter.priority = -128;

	err = bpf(BPF_LINK_CREATE, &attr, sizeof(attr));

... this would attach progfd to ipv4:input hook.

Such hook gets removed automatically if the calling program exits.

BPF_NETFILTER program invocation is added in followup change.

NF_HOOK_OP_BPF enum will eventually be read from nfnetlink_hook, it
allows to tell userspace which program is attached at the given hook
when user runs 'nft hook list' command rather than just the priority
and not-very-helpful 'this hook runs a bpf prog but I can't tell which
one'.

Will also be used to disallow registration of two bpf programs with
same priority in a followup patch.

v4: arm32 cmpxchg only supports 32bit operand
    s/prio/priority/
v3: restrict prog attachment to ip/ip6 for now, lets lift restrictions if
    more use cases pop up (arptables, ebtables, netdev ingress/egress etc).

Signed-off-by: Florian Westphal <fw@strlen.de>
Link: https://lore.kernel.org/r/20230421170300.24115-2-fw@strlen.de
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2023-04-21 11:34:14 -07:00
Stanislav Fomichev
00e74ae086 bpf: Don't EFAULT for getsockopt with optval=NULL
Some socket options do getsockopt with optval=NULL to estimate the size
of the final buffer (which is returned via optlen). This breaks BPF
getsockopt assumptions about permitted optval buffer size. Let's enforce
these assumptions only when non-NULL optval is provided.

Fixes: 0d01da6afc ("bpf: implement getsockopt and setsockopt hooks")
Reported-by: Martin KaFai Lau <martin.lau@kernel.org>
Signed-off-by: Stanislav Fomichev <sdf@google.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/ZD7Js4fj5YyI2oLd@google.com/T/#mb68daf700f87a9244a15d01d00c3f0e5b08f49f7
Link: https://lore.kernel.org/bpf/20230418225343.553806-2-sdf@google.com
2023-04-21 17:09:53 +02:00
Dave Marchevsky
4ab07209d5 bpf: Fix bpf_refcount_acquire's refcount_t address calculation
When calculating the address of the refcount_t struct within a local
kptr, bpf_refcount_acquire_impl should add refcount_off bytes to the
address of the local kptr. Due to some missing parens, the function is
incorrectly adding sizeof(refcount_t) * refcount_off bytes. This patch
fixes the calculation.

Due to the incorrect calculation, bpf_refcount_acquire_impl was trying
to refcount_inc some memory well past the end of local kptrs, resulting
in kasan and refcount complaints, as reported in [0]. In that thread,
Florian and Eduard discovered that bpf selftests written in the new
style - with __success and an expected __retval, specifically - were
not actually being run. As a result, selftests added in bpf_refcount
series weren't really exercising this behavior, and thus didn't unearth
the bug.

With this fixed behavior it's safe to revert commit 7c4b96c000
("selftests/bpf: disable program test run for progs/refcounted_kptr.c"),
this patch does so.

  [0] https://lore.kernel.org/bpf/ZEEp+j22imoN6rn9@strlen.de/

Fixes: 7c50b1cb76 ("bpf: Add bpf_refcount_acquire kfunc")
Reported-by: Florian Westphal <fw@strlen.de>
Reported-by: Eduard Zingerman <eddyz87@gmail.com>
Signed-off-by: Dave Marchevsky <davemarchevsky@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Tested-by: Eduard Zingerman <eddyz87@gmail.com>
Link: https://lore.kernel.org/bpf/20230421074431.3548349-1-davemarchevsky@fb.com
2023-04-21 16:31:37 +02:00
Alexei Starovoitov
acf1c3d68e bpf: Fix race between btf_put and btf_idr walk.
Florian and Eduard reported hard dead lock:
[   58.433327]  _raw_spin_lock_irqsave+0x40/0x50
[   58.433334]  btf_put+0x43/0x90
[   58.433338]  bpf_find_btf_id+0x157/0x240
[   58.433353]  btf_parse_fields+0x921/0x11c0

This happens since btf->refcount can be 1 at the time of btf_put() and
btf_put() will call btf_free_id() which will try to grab btf_idr_lock
and will dead lock.
Avoid the issue by doing btf_put() without locking.

Fixes: 3d78417b60 ("bpf: Add bpf_btf_find_by_name_kind() helper.")
Fixes: 1e89106da2 ("bpf: Add bpf_core_add_cands() and wire it into bpf_core_apply_relo_insn().")
Reported-by: Florian Westphal <fw@strlen.de>
Reported-by: Eduard Zingerman <eddyz87@gmail.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Tested-by: Eduard Zingerman <eddyz87@gmail.com>
Link: https://lore.kernel.org/bpf/20230421014901.70908-1-alexei.starovoitov@gmail.com
2023-04-21 16:27:56 +02:00
Thomas Gleixner
f7abf14f00 posix-cpu-timers: Implement the missing timer_wait_running callback
For some unknown reason the introduction of the timer_wait_running callback
missed to fixup posix CPU timers, which went unnoticed for almost four years.
Marco reported recently that the WARN_ON() in timer_wait_running()
triggers with a posix CPU timer test case.

Posix CPU timers have two execution models for expiring timers depending on
CONFIG_POSIX_CPU_TIMERS_TASK_WORK:

1) If not enabled, the expiry happens in hard interrupt context so
   spin waiting on the remote CPU is reasonably time bound.

   Implement an empty stub function for that case.

2) If enabled, the expiry happens in task work before returning to user
   space or guest mode. The expired timers are marked as firing and moved
   from the timer queue to a local list head with sighand lock held. Once
   the timers are moved, sighand lock is dropped and the expiry happens in
   fully preemptible context. That means the expiring task can be scheduled
   out, migrated, interrupted etc. So spin waiting on it is more than
   suboptimal.

   The timer wheel has a timer_wait_running() mechanism for RT, which uses
   a per CPU timer-base expiry lock which is held by the expiry code and the
   task waiting for the timer function to complete blocks on that lock.

   This does not work in the same way for posix CPU timers as there is no
   timer base and expiry for process wide timers can run on any task
   belonging to that process, but the concept of waiting on an expiry lock
   can be used too in a slightly different way:

    - Add a mutex to struct posix_cputimers_work. This struct is per task
      and used to schedule the expiry task work from the timer interrupt.

    - Add a task_struct pointer to struct cpu_timer which is used to store
      a the task which runs the expiry. That's filled in when the task
      moves the expired timers to the local expiry list. That's not
      affecting the size of the k_itimer union as there are bigger union
      members already

    - Let the task take the expiry mutex around the expiry function

    - Let the waiter acquire a task reference with rcu_read_lock() held and
      block on the expiry mutex

   This avoids spin-waiting on a task which might not even be on a CPU and
   works nicely for RT too.

Fixes: ec8f954a40 ("posix-timers: Use a callback for cancel synchronization on PREEMPT_RT")
Reported-by: Marco Elver <elver@google.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Marco Elver <elver@google.com>
Tested-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Reviewed-by: Frederic Weisbecker <frederic@kernel.org>
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/87zg764ojw.ffs@tglx
2023-04-21 15:34:33 +02:00
Aaron Thompson
f31dcb152a sched/clock: Fix local_clock() before sched_clock_init()
Have local_clock() return sched_clock() if sched_clock_init() has not
yet run. sched_clock_cpu() has this check but it was not included in the
new noinstr implementation of local_clock().

The effect can be seen on x86 with CONFIG_PRINTK_TIME enabled, for
instance. scd->clock quickly reaches the value of TICK_NSEC and that
value is returned until sched_clock_init() runs.

dmesg without this patch:

    [    0.000000] kvm-clock: ...
    [    0.000002] kvm-clock: ...
    [    0.000672] clocksource: ...
    [    0.001000] tsc: ...
    [    0.001000] e820: ...
    [    0.001000] e820: ...
     ...
    [    0.001000] ..TIMER: ...
    [    0.001000] clocksource: ...
    [    0.378956] Calibrating delay loop ...
    [    0.379955] pid_max: ...

dmesg with this patch:

    [    0.000000] kvm-clock: ...
    [    0.000001] kvm-clock: ...
    [    0.000675] clocksource: ...
    [    0.002685] tsc: ...
    [    0.003331] e820: ...
    [    0.004190] e820: ...
     ...
    [    0.421939] ..TIMER: ...
    [    0.422842] clocksource: ...
    [    0.424582] Calibrating delay loop ...
    [    0.425580] pid_max: ...

Fixes: 776f22913b ("sched/clock: Make local_clock() noinstr")
Signed-off-by: Aaron Thompson <dev@aaront.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/20230413175012.2201-1-dev@aaront.org
2023-04-21 13:24:21 +02:00
Schspa Shi
feffe5bb27 sched/rt: Fix bad task migration for rt tasks
Commit 95158a89dd ("sched,rt: Use the full cpumask for balancing")
allows find_lock_lowest_rq() to pick a task with migration disabled.
The purpose of the commit is to push the current running task on the
CPU that has the migrate_disable() task away.

However, there is a race which allows a migrate_disable() task to be
migrated. Consider:

  CPU0                                    CPU1
  push_rt_task
    check is_migration_disabled(next_task)

                                          task not running and
                                          migration_disabled == 0

    find_lock_lowest_rq(next_task, rq);
      _double_lock_balance(this_rq, busiest);
        raw_spin_rq_unlock(this_rq);
        double_rq_lock(this_rq, busiest);
          <<wait for busiest rq>>
                                              <wakeup>
                                          task become running
                                          migrate_disable();
                                            <context out>
    deactivate_task(rq, next_task, 0);
    set_task_cpu(next_task, lowest_rq->cpu);
      WARN_ON_ONCE(is_migration_disabled(p));

Fixes: 95158a89dd ("sched,rt: Use the full cpumask for balancing")
Signed-off-by: Schspa Shi <schspa@gmail.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Reviewed-by: Dietmar Eggemann <dietmar.eggemann@arm.com>
Reviewed-by: Valentin Schneider <vschneid@redhat.com>
Tested-by: Dwaine Gonyier <dgonyier@redhat.com>
2023-04-21 13:24:21 +02:00
Mathieu Desnoyers
223baf9d17 sched: Fix performance regression introduced by mm_cid
Introduce per-mm/cpu current concurrency id (mm_cid) to fix a PostgreSQL
sysbench regression reported by Aaron Lu.

Keep track of the currently allocated mm_cid for each mm/cpu rather than
freeing them immediately on context switch. This eliminates most atomic
operations when context switching back and forth between threads
belonging to different memory spaces in multi-threaded scenarios (many
processes, each with many threads). The per-mm/per-cpu mm_cid values are
serialized by their respective runqueue locks.

Thread migration is handled by introducing invocation to
sched_mm_cid_migrate_to() (with destination runqueue lock held) in
activate_task() for migrating tasks. If the destination cpu's mm_cid is
unset, and if the source runqueue is not actively using its mm_cid, then
the source cpu's mm_cid is moved to the destination cpu on migration.

Introduce a task-work executed periodically, similarly to NUMA work,
which delays reclaim of cid values when they are unused for a period of
time.

Keep track of the allocation time for each per-cpu cid, and let the task
work clear them when they are observed to be older than
SCHED_MM_CID_PERIOD_NS and unused. This task work also clears all
mm_cids which are greater or equal to the Hamming weight of the mm
cidmask to keep concurrency ids compact.

Because we want to ensure the mm_cid converges towards the smaller
values as migrations happen, the prior optimization that was done when
context switching between threads belonging to the same mm is removed,
because it could delay the lazy release of the destination runqueue
mm_cid after it has been replaced by a migration. Removing this prior
optimization is not an issue performance-wise because the introduced
per-mm/per-cpu mm_cid tracking also covers this more specific case.

Fixes: af7f588d8f ("sched: Introduce per-memory-map concurrency ID")
Reported-by: Aaron Lu <aaron.lu@intel.com>
Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Tested-by: Aaron Lu <aaron.lu@intel.com>
Link: https://lore.kernel.org/lkml/20230327080502.GA570847@ziqianlu-desk2/
2023-04-21 13:24:20 +02:00
Peter Zijlstra
5a4d3b38ed Linux 6.3-rc7
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Merge branch 'v6.3-rc7'

Sync with the urgent patches; in particular:

a53ce18cac ("sched/fair: Sanitize vruntime of entity being migrated")

Signed-off-by: Peter Zijlstra <peterz@infradead.org>
2023-04-21 13:24:18 +02:00
Al Viro
2f31fa029d cgroup_get_from_fd(): switch to fdget_raw()
Reviewed-by: Christian Brauner <brauner@kernel.org>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2023-04-20 22:55:35 -04:00
Al Viro
1d0027dc9a bpf: switch to fdget_raw()
Reviewed-by: Christian Brauner <brauner@kernel.org>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2023-04-20 22:55:35 -04:00
Al Viro
281117ccb2 convert setns(2) to fdget()/fdput()
Reviewed-by: Christian Brauner <brauner@kernel.org>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2023-04-20 22:55:35 -04:00
Jakub Kicinski
681c5b51dc Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net
Adjacent changes:

net/mptcp/protocol.h
  63740448a3 ("mptcp: fix accept vs worker race")
  2a6a870e44 ("mptcp: stops worker on unaccepted sockets at listener close")
  ddb1a072f8 ("mptcp: move first subflow allocation at mpc access time")

Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2023-04-20 16:29:51 -07:00
Linus Torvalds
23309d600d Networking fixes for 6.3-rc8, including fixes from netfilter and bpf
Current release - regressions:
 
   - sched: clear actions pointer in miss cookie init fail
 
   - mptcp: fix accept vs worker race
 
   - bpf: fix bpf_arch_text_poke() with new_addr == NULL on s390
 
   - eth: bnxt_en: fix a possible NULL pointer dereference in unload path
 
   - eth: veth: take into account peer device for NETDEV_XDP_ACT_NDO_XMIT xdp_features flag
 
 Current release - new code bugs:
 
   - eth: revert "net/mlx5: Enable management PF initialization"
 
 Previous releases - regressions:
 
   - netfilter: fix recent physdev match breakage
 
   - bpf: fix incorrect verifier pruning due to missing register precision taints
 
   - eth: virtio_net: fix overflow inside xdp_linearize_page()
 
   - eth: cxgb4: fix use after free bugs caused by circular dependency problem
 
   - eth: mlxsw: pci: fix possible crash during initialization
 
 Previous releases - always broken:
 
   - sched: sch_qfq: prevent slab-out-of-bounds in qfq_activate_agg
 
   - netfilter: validate catch-all set elements
 
   - bridge: don't notify FDB entries with "master dynamic"
 
   - eth: bonding: fix memory leak when changing bond type to ethernet
 
   - eth: i40e: fix accessing vsi->active_filters without holding lock
 
 Misc:
 
   - Mat is back as MPTCP co-maintainer
 
 Signed-off-by: Paolo Abeni <pabeni@redhat.com>
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Merge tag 'net-6.3-rc8' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net

Pull networking fixes from Paolo Abeni:
 "Including fixes from netfilter and bpf.

  There are a few fixes for new code bugs, including the Mellanox one
  noted in the last networking pull. No known regressions outstanding.

  Current release - regressions:

   - sched: clear actions pointer in miss cookie init fail

   - mptcp: fix accept vs worker race

   - bpf: fix bpf_arch_text_poke() with new_addr == NULL on s390

   - eth: bnxt_en: fix a possible NULL pointer dereference in unload
     path

   - eth: veth: take into account peer device for
     NETDEV_XDP_ACT_NDO_XMIT xdp_features flag

  Current release - new code bugs:

   - eth: revert "net/mlx5: Enable management PF initialization"

  Previous releases - regressions:

   - netfilter: fix recent physdev match breakage

   - bpf: fix incorrect verifier pruning due to missing register
     precision taints

   - eth: virtio_net: fix overflow inside xdp_linearize_page()

   - eth: cxgb4: fix use after free bugs caused by circular dependency
     problem

   - eth: mlxsw: pci: fix possible crash during initialization

  Previous releases - always broken:

   - sched: sch_qfq: prevent slab-out-of-bounds in qfq_activate_agg

   - netfilter: validate catch-all set elements

   - bridge: don't notify FDB entries with "master dynamic"

   - eth: bonding: fix memory leak when changing bond type to ethernet

   - eth: i40e: fix accessing vsi->active_filters without holding lock

  Misc:

   - Mat is back as MPTCP co-maintainer"

* tag 'net-6.3-rc8' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net: (33 commits)
  net: bridge: switchdev: don't notify FDB entries with "master dynamic"
  Revert "net/mlx5: Enable management PF initialization"
  MAINTAINERS: Resume MPTCP co-maintainer role
  mailmap: add entries for Mat Martineau
  e1000e: Disable TSO on i219-LM card to increase speed
  bnxt_en: fix free-runnig PHC mode
  net: dsa: microchip: ksz8795: Correctly handle huge frame configuration
  bpf: Fix incorrect verifier pruning due to missing register precision taints
  hamradio: drop ISA_DMA_API dependency
  mlxsw: pci: Fix possible crash during initialization
  mptcp: fix accept vs worker race
  mptcp: stops worker on unaccepted sockets at listener close
  net: rpl: fix rpl header size calculation
  net: vmxnet3: Fix NULL pointer dereference in vmxnet3_rq_rx_complete()
  bonding: Fix memory leak when changing bond type to Ethernet
  veth: take into account peer device for NETDEV_XDP_ACT_NDO_XMIT xdp_features flag
  mlxfw: fix null-ptr-deref in mlxfw_mfa2_tlv_next()
  bnxt_en: Fix a possible NULL pointer dereference in unload path
  bnxt_en: Do not initialize PTP on older P3/P4 chips
  netfilter: nf_tables: tighten netlink attribute requirements for catch-all elements
  ...
2023-04-20 11:03:51 -07:00
Mario Limonciello
b52124a78a PM: Add sysfs files to represent time spent in hardware sleep state
Userspace can't easily discover how much of a sleep cycle was spent in a
hardware sleep state without using kernel tracing and vendor specific sysfs
or debugfs files.

To make this information more discoverable, introduce 3 new sysfs files:
1) The time spent in a hw sleep state for last cycle.
2) The time spent in a hw sleep state since the kernel booted
3) The maximum time that the hardware can report for a sleep cycle.
All of these files will be present only if the system supports s2idle.

Reviewed-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Mario Limonciello <mario.limonciello@amd.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2023-04-20 19:06:12 +02:00
Petr Tesarik
ec274aff21 swiotlb: Omit total_used and used_hiwater if !CONFIG_DEBUG_FS
The tracking of used_hiwater adds an atomic operation to the hot
path. This is acceptable only when debugging the kernel. To make
sure that the fields can never be used by mistake, do not even
include them in struct io_tlb_mem if CONFIG_DEBUG_FS is not set.

The build fails after doing that. To fix it, it is necessary to
remove all code specific to debugfs and instead provide a stub
implementation of swiotlb_create_debugfs_files(). As a bonus, this
change allows to remove one __maybe_unused attribute.

Signed-off-by: Petr Tesarik <petr.tesarik.ext@huawei.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
2023-04-20 14:51:41 +02:00
John Stultz
4daa669efc kernel/configs: Drop Android config fragments
In the old days where each device had a custom kernel, the
android config fragments were useful to provide the required
and reccomended options expected by userland.

However, these days devices are expected to use the GKI kernel,
so these config fragments no longer needed, and out of date, so
they seem to only cause confusion.

So lets drop them. If folks are curious what configs are
expected by the Android environment, check out the gki_defconfig
file in the latest android common kernel tree.

Cc: Rob Herring <robh@kernel.org>
Cc: Amit Pundir <amit.pundir@linaro.org>
Cc: <kernel-team@android.com>
Signed-off-by: John Stultz <jstultz@google.com>
Link: https://lore.kernel.org/r/20230411180409.1706067-1-jstultz@google.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-04-20 14:23:10 +02:00
Heiko Carstens
491a78663e stackleak: allow to specify arch specific stackleak poison function
Factor out the code that fills the stack with the stackleak poison value
in order to allow architectures to provide a faster implementation.

Acked-by: Vasily Gorbik <gor@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Acked-by: Mark Rutland <mark.rutland@arm.com>
Link: https://lore.kernel.org/r/20230405130841.1350565-2-hca@linux.ibm.com
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2023-04-20 11:36:35 +02:00
Feng Zhou
2569c7b872 bpf: support access variable length array of integer type
After this commit:
bpf: Support variable length array in tracing programs (9c5f8a1008)
Trace programs can access variable length array, but for structure
type. This patch adds support for integer type.

Example:
Hook load_balance
struct sched_domain {
	...
	unsigned long span[];
}

The access: sd->span[0].

Co-developed-by: Chengming Zhou <zhouchengming@bytedance.com>
Signed-off-by: Chengming Zhou <zhouchengming@bytedance.com>
Signed-off-by: Feng Zhou <zhoufeng.zf@bytedance.com>
Link: https://lore.kernel.org/r/20230420032735.27760-2-zhoufeng.zf@bytedance.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2023-04-19 21:29:39 -07:00
Linus Torvalds
cb0856346a 22 hotfixes.
19 are cc:stable and the remainder address issues which were introduced
 during this merge cycle, or aren't considered suitable for -stable
 backporting.
 
 19 are for MM and the remainder are for other subsystems.
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Merge tag 'mm-hotfixes-stable-2023-04-19-16-36' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

Pull misc fixes from Andrew Morton:
 "22 hotfixes.

  19 are cc:stable and the remainder address issues which were
  introduced during this merge cycle, or aren't considered suitable for
  -stable backporting.

  19 are for MM and the remainder are for other subsystems"

* tag 'mm-hotfixes-stable-2023-04-19-16-36' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (22 commits)
  nilfs2: initialize unused bytes in segment summary blocks
  mm: page_alloc: skip regions with hugetlbfs pages when allocating 1G pages
  mm/mmap: regression fix for unmapped_area{_topdown}
  maple_tree: fix mas_empty_area() search
  maple_tree: make maple state reusable after mas_empty_area_rev()
  mm: kmsan: handle alloc failures in kmsan_ioremap_page_range()
  mm: kmsan: handle alloc failures in kmsan_vmap_pages_range_noflush()
  tools/Makefile: do missed s/vm/mm/
  mm: fix memory leak on mm_init error handling
  mm/page_alloc: fix potential deadlock on zonelist_update_seq seqlock
  kernel/sys.c: fix and improve control flow in __sys_setres[ug]id()
  Revert "userfaultfd: don't fail on unrecognized features"
  writeback, cgroup: fix null-ptr-deref write in bdi_split_work_to_wbs
  maple_tree: fix a potential memory leak, OOB access, or other unpredictable bug
  tools/mm/page_owner_sort.c: fix TGID output when cull=tg is used
  mailmap: update jtoppins' entry to reference correct email
  mm/mempolicy: fix use-after-free of VMA iterator
  mm/huge_memory.c: warn with pr_warn_ratelimited instead of VM_WARN_ON_ONCE_FOLIO
  mm/mprotect: fix do_mprotect_pkey() return on error
  mm/khugepaged: check again on anon uffd-wp during isolation
  ...
2023-04-19 17:55:45 -07:00
Luis Chamberlain
8660484ed1 module: add debugging auto-load duplicate module support
The finit_module() system call can in the worst case use up to more than
twice of a module's size in virtual memory. Duplicate finit_module()
system calls are non fatal, however they unnecessarily strain virtual
memory during bootup and in the worst case can cause a system to fail
to boot. This is only known to currently be an issue on systems with
larger number of CPUs.

To help debug this situation we need to consider the different sources for
finit_module(). Requests from the kernel that rely on module auto-loading,
ie, the kernel's *request_module() API, are one source of calls. Although
modprobe checks to see if a module is already loaded prior to calling
finit_module() there is a small race possible allowing userspace to
trigger multiple modprobe calls racing against modprobe and this not
seeing the module yet loaded.

This adds debugging support to the kernel module auto-loader (*request_module()
calls) to easily detect duplicate module requests. To aid with possible bootup
failure issues incurred by this, it will converge duplicates requests to a
single request. This avoids any possible strain on virtual memory during
bootup which could be incurred by duplicate module autoloading requests.

Folks debugging virtual memory abuse on bootup can and should enable
this to see what pr_warn()s come on, to see if module auto-loading is to
blame for their wores. If they see duplicates they can further debug this
by enabling the module.enable_dups_trace kernel parameter or by enabling
CONFIG_MODULE_DEBUG_AUTOLOAD_DUPS_TRACE.

Current evidence seems to point to only a few duplicates for module
auto-loading. And so the source for other duplicates creating heavy
virtual memory pressure due to larger number of CPUs should becoming
from another place (likely udev).

Signed-off-by: Luis Chamberlain <mcgrof@kernel.org>
2023-04-19 17:26:01 -07:00
Daniel Borkmann
71b547f561 bpf: Fix incorrect verifier pruning due to missing register precision taints
Juan Jose et al reported an issue found via fuzzing where the verifier's
pruning logic prematurely marks a program path as safe.

Consider the following program:

   0: (b7) r6 = 1024
   1: (b7) r7 = 0
   2: (b7) r8 = 0
   3: (b7) r9 = -2147483648
   4: (97) r6 %= 1025
   5: (05) goto pc+0
   6: (bd) if r6 <= r9 goto pc+2
   7: (97) r6 %= 1
   8: (b7) r9 = 0
   9: (bd) if r6 <= r9 goto pc+1
  10: (b7) r6 = 0
  11: (b7) r0 = 0
  12: (63) *(u32 *)(r10 -4) = r0
  13: (18) r4 = 0xffff888103693400 // map_ptr(ks=4,vs=48)
  15: (bf) r1 = r4
  16: (bf) r2 = r10
  17: (07) r2 += -4
  18: (85) call bpf_map_lookup_elem#1
  19: (55) if r0 != 0x0 goto pc+1
  20: (95) exit
  21: (77) r6 >>= 10
  22: (27) r6 *= 8192
  23: (bf) r1 = r0
  24: (0f) r0 += r6
  25: (79) r3 = *(u64 *)(r0 +0)
  26: (7b) *(u64 *)(r1 +0) = r3
  27: (95) exit

The verifier treats this as safe, leading to oob read/write access due
to an incorrect verifier conclusion:

  func#0 @0
  0: R1=ctx(off=0,imm=0) R10=fp0
  0: (b7) r6 = 1024                     ; R6_w=1024
  1: (b7) r7 = 0                        ; R7_w=0
  2: (b7) r8 = 0                        ; R8_w=0
  3: (b7) r9 = -2147483648              ; R9_w=-2147483648
  4: (97) r6 %= 1025                    ; R6_w=scalar()
  5: (05) goto pc+0
  6: (bd) if r6 <= r9 goto pc+2         ; R6_w=scalar(umin=18446744071562067969,var_off=(0xffffffff00000000; 0xffffffff)) R9_w=-2147483648
  7: (97) r6 %= 1                       ; R6_w=scalar()
  8: (b7) r9 = 0                        ; R9=0
  9: (bd) if r6 <= r9 goto pc+1         ; R6=scalar(umin=1) R9=0
  10: (b7) r6 = 0                       ; R6_w=0
  11: (b7) r0 = 0                       ; R0_w=0
  12: (63) *(u32 *)(r10 -4) = r0
  last_idx 12 first_idx 9
  regs=1 stack=0 before 11: (b7) r0 = 0
  13: R0_w=0 R10=fp0 fp-8=0000????
  13: (18) r4 = 0xffff8ad3886c2a00      ; R4_w=map_ptr(off=0,ks=4,vs=48,imm=0)
  15: (bf) r1 = r4                      ; R1_w=map_ptr(off=0,ks=4,vs=48,imm=0) R4_w=map_ptr(off=0,ks=4,vs=48,imm=0)
  16: (bf) r2 = r10                     ; R2_w=fp0 R10=fp0
  17: (07) r2 += -4                     ; R2_w=fp-4
  18: (85) call bpf_map_lookup_elem#1   ; R0=map_value_or_null(id=1,off=0,ks=4,vs=48,imm=0)
  19: (55) if r0 != 0x0 goto pc+1       ; R0=0
  20: (95) exit

  from 19 to 21: R0=map_value(off=0,ks=4,vs=48,imm=0) R6=0 R7=0 R8=0 R9=0 R10=fp0 fp-8=mmmm????
  21: (77) r6 >>= 10                    ; R6_w=0
  22: (27) r6 *= 8192                   ; R6_w=0
  23: (bf) r1 = r0                      ; R0=map_value(off=0,ks=4,vs=48,imm=0) R1_w=map_value(off=0,ks=4,vs=48,imm=0)
  24: (0f) r0 += r6
  last_idx 24 first_idx 19
  regs=40 stack=0 before 23: (bf) r1 = r0
  regs=40 stack=0 before 22: (27) r6 *= 8192
  regs=40 stack=0 before 21: (77) r6 >>= 10
  regs=40 stack=0 before 19: (55) if r0 != 0x0 goto pc+1
  parent didn't have regs=40 stack=0 marks: R0_rw=map_value_or_null(id=1,off=0,ks=4,vs=48,imm=0) R6_rw=P0 R7=0 R8=0 R9=0 R10=fp0 fp-8=mmmm????
  last_idx 18 first_idx 9
  regs=40 stack=0 before 18: (85) call bpf_map_lookup_elem#1
  regs=40 stack=0 before 17: (07) r2 += -4
  regs=40 stack=0 before 16: (bf) r2 = r10
  regs=40 stack=0 before 15: (bf) r1 = r4
  regs=40 stack=0 before 13: (18) r4 = 0xffff8ad3886c2a00
  regs=40 stack=0 before 12: (63) *(u32 *)(r10 -4) = r0
  regs=40 stack=0 before 11: (b7) r0 = 0
  regs=40 stack=0 before 10: (b7) r6 = 0
  25: (79) r3 = *(u64 *)(r0 +0)         ; R0_w=map_value(off=0,ks=4,vs=48,imm=0) R3_w=scalar()
  26: (7b) *(u64 *)(r1 +0) = r3         ; R1_w=map_value(off=0,ks=4,vs=48,imm=0) R3_w=scalar()
  27: (95) exit

  from 9 to 11: R1=ctx(off=0,imm=0) R6=0 R7=0 R8=0 R9=0 R10=fp0
  11: (b7) r0 = 0                       ; R0_w=0
  12: (63) *(u32 *)(r10 -4) = r0
  last_idx 12 first_idx 11
  regs=1 stack=0 before 11: (b7) r0 = 0
  13: R0_w=0 R10=fp0 fp-8=0000????
  13: (18) r4 = 0xffff8ad3886c2a00      ; R4_w=map_ptr(off=0,ks=4,vs=48,imm=0)
  15: (bf) r1 = r4                      ; R1_w=map_ptr(off=0,ks=4,vs=48,imm=0) R4_w=map_ptr(off=0,ks=4,vs=48,imm=0)
  16: (bf) r2 = r10                     ; R2_w=fp0 R10=fp0
  17: (07) r2 += -4                     ; R2_w=fp-4
  18: (85) call bpf_map_lookup_elem#1
  frame 0: propagating r6
  last_idx 19 first_idx 11
  regs=40 stack=0 before 18: (85) call bpf_map_lookup_elem#1
  regs=40 stack=0 before 17: (07) r2 += -4
  regs=40 stack=0 before 16: (bf) r2 = r10
  regs=40 stack=0 before 15: (bf) r1 = r4
  regs=40 stack=0 before 13: (18) r4 = 0xffff8ad3886c2a00
  regs=40 stack=0 before 12: (63) *(u32 *)(r10 -4) = r0
  regs=40 stack=0 before 11: (b7) r0 = 0
  parent didn't have regs=40 stack=0 marks: R1=ctx(off=0,imm=0) R6_r=P0 R7=0 R8=0 R9=0 R10=fp0
  last_idx 9 first_idx 9
  regs=40 stack=0 before 9: (bd) if r6 <= r9 goto pc+1
  parent didn't have regs=40 stack=0 marks: R1=ctx(off=0,imm=0) R6_rw=Pscalar() R7_w=0 R8_w=0 R9_rw=0 R10=fp0
  last_idx 8 first_idx 0
  regs=40 stack=0 before 8: (b7) r9 = 0
  regs=40 stack=0 before 7: (97) r6 %= 1
  regs=40 stack=0 before 6: (bd) if r6 <= r9 goto pc+2
  regs=40 stack=0 before 5: (05) goto pc+0
  regs=40 stack=0 before 4: (97) r6 %= 1025
  regs=40 stack=0 before 3: (b7) r9 = -2147483648
  regs=40 stack=0 before 2: (b7) r8 = 0
  regs=40 stack=0 before 1: (b7) r7 = 0
  regs=40 stack=0 before 0: (b7) r6 = 1024
  19: safe
  frame 0: propagating r6
  last_idx 9 first_idx 0
  regs=40 stack=0 before 6: (bd) if r6 <= r9 goto pc+2
  regs=40 stack=0 before 5: (05) goto pc+0
  regs=40 stack=0 before 4: (97) r6 %= 1025
  regs=40 stack=0 before 3: (b7) r9 = -2147483648
  regs=40 stack=0 before 2: (b7) r8 = 0
  regs=40 stack=0 before 1: (b7) r7 = 0
  regs=40 stack=0 before 0: (b7) r6 = 1024

  from 6 to 9: safe
  verification time 110 usec
  stack depth 4
  processed 36 insns (limit 1000000) max_states_per_insn 0 total_states 3 peak_states 3 mark_read 2

The verifier considers this program as safe by mistakenly pruning unsafe
code paths. In the above func#0, code lines 0-10 are of interest. In line
0-3 registers r6 to r9 are initialized with known scalar values. In line 4
the register r6 is reset to an unknown scalar given the verifier does not
track modulo operations. Due to this, the verifier can also not determine
precisely which branches in line 6 and 9 are taken, therefore it needs to
explore them both.

As can be seen, the verifier starts with exploring the false/fall-through
paths first. The 'from 19 to 21' path has both r6=0 and r9=0 and the pointer
arithmetic on r0 += r6 is therefore considered safe. Given the arithmetic,
r6 is correctly marked for precision tracking where backtracking kicks in
where it walks back the current path all the way where r6 was set to 0 in
the fall-through branch.

Next, the pruning logics pops the path 'from 9 to 11' from the stack. Also
here, the state of the registers is the same, that is, r6=0 and r9=0, so
that at line 19 the path can be pruned as it is considered safe. It is
interesting to note that the conditional in line 9 turned r6 into a more
precise state, that is, in the fall-through path at the beginning of line
10, it is R6=scalar(umin=1), and in the branch-taken path (which is analyzed
here) at the beginning of line 11, r6 turned into a known const r6=0 as
r9=0 prior to that and therefore (unsigned) r6 <= 0 concludes that r6 must
be 0 (**):

  [...]                                 ; R6_w=scalar()
  9: (bd) if r6 <= r9 goto pc+1         ; R6=scalar(umin=1) R9=0
  [...]

  from 9 to 11: R1=ctx(off=0,imm=0) R6=0 R7=0 R8=0 R9=0 R10=fp0
  [...]

The next path is 'from 6 to 9'. The verifier considers the old and current
state equivalent, and therefore prunes the search incorrectly. Looking into
the two states which are being compared by the pruning logic at line 9, the
old state consists of R6_rwD=Pscalar() R9_rwD=0 R10=fp0 and the new state
consists of R1=ctx(off=0,imm=0) R6_w=scalar(umax=18446744071562067968)
R7_w=0 R8_w=0 R9_w=-2147483648 R10=fp0. While r6 had the reg->precise flag
correctly set in the old state, r9 did not. Both r6'es are considered as
equivalent given the old one is a superset of the current, more precise one,
however, r9's actual values (0 vs 0x80000000) mismatch. Given the old r9
did not have reg->precise flag set, the verifier does not consider the
register as contributing to the precision state of r6, and therefore it
considered both r9 states as equivalent. However, for this specific pruned
path (which is also the actual path taken at runtime), register r6 will be
0x400 and r9 0x80000000 when reaching line 21, thus oob-accessing the map.

The purpose of precision tracking is to initially mark registers (including
spilled ones) as imprecise to help verifier's pruning logic finding equivalent
states it can then prune if they don't contribute to the program's safety
aspects. For example, if registers are used for pointer arithmetic or to pass
constant length to a helper, then the verifier sets reg->precise flag and
backtracks the BPF program instruction sequence and chain of verifier states
to ensure that the given register or stack slot including their dependencies
are marked as precisely tracked scalar. This also includes any other registers
and slots that contribute to a tracked state of given registers/stack slot.
This backtracking relies on recorded jmp_history and is able to traverse
entire chain of parent states. This process ends only when all the necessary
registers/slots and their transitive dependencies are marked as precise.

The backtrack_insn() is called from the current instruction up to the first
instruction, and its purpose is to compute a bitmask of registers and stack
slots that need precision tracking in the parent's verifier state. For example,
if a current instruction is r6 = r7, then r6 needs precision after this
instruction and r7 needs precision before this instruction, that is, in the
parent state. Hence for the latter r7 is marked and r6 unmarked.

For the class of jmp/jmp32 instructions, backtrack_insn() today only looks
at call and exit instructions and for all other conditionals the masks
remain as-is. However, in the given situation register r6 has a dependency
on r9 (as described above in **), so also that one needs to be marked for
precision tracking. In other words, if an imprecise register influences a
precise one, then the imprecise register should also be marked precise.
Meaning, in the parent state both dest and src register need to be tracked
for precision and therefore the marking must be more conservative by setting
reg->precise flag for both. The precision propagation needs to cover both
for the conditional: if the src reg was marked but not the dst reg and vice
versa.

After the fix the program is correctly rejected:

  func#0 @0
  0: R1=ctx(off=0,imm=0) R10=fp0
  0: (b7) r6 = 1024                     ; R6_w=1024
  1: (b7) r7 = 0                        ; R7_w=0
  2: (b7) r8 = 0                        ; R8_w=0
  3: (b7) r9 = -2147483648              ; R9_w=-2147483648
  4: (97) r6 %= 1025                    ; R6_w=scalar()
  5: (05) goto pc+0
  6: (bd) if r6 <= r9 goto pc+2         ; R6_w=scalar(umin=18446744071562067969,var_off=(0xffffffff80000000; 0x7fffffff),u32_min=-2147483648) R9_w=-2147483648
  7: (97) r6 %= 1                       ; R6_w=scalar()
  8: (b7) r9 = 0                        ; R9=0
  9: (bd) if r6 <= r9 goto pc+1         ; R6=scalar(umin=1) R9=0
  10: (b7) r6 = 0                       ; R6_w=0
  11: (b7) r0 = 0                       ; R0_w=0
  12: (63) *(u32 *)(r10 -4) = r0
  last_idx 12 first_idx 9
  regs=1 stack=0 before 11: (b7) r0 = 0
  13: R0_w=0 R10=fp0 fp-8=0000????
  13: (18) r4 = 0xffff9290dc5bfe00      ; R4_w=map_ptr(off=0,ks=4,vs=48,imm=0)
  15: (bf) r1 = r4                      ; R1_w=map_ptr(off=0,ks=4,vs=48,imm=0) R4_w=map_ptr(off=0,ks=4,vs=48,imm=0)
  16: (bf) r2 = r10                     ; R2_w=fp0 R10=fp0
  17: (07) r2 += -4                     ; R2_w=fp-4
  18: (85) call bpf_map_lookup_elem#1   ; R0=map_value_or_null(id=1,off=0,ks=4,vs=48,imm=0)
  19: (55) if r0 != 0x0 goto pc+1       ; R0=0
  20: (95) exit

  from 19 to 21: R0=map_value(off=0,ks=4,vs=48,imm=0) R6=0 R7=0 R8=0 R9=0 R10=fp0 fp-8=mmmm????
  21: (77) r6 >>= 10                    ; R6_w=0
  22: (27) r6 *= 8192                   ; R6_w=0
  23: (bf) r1 = r0                      ; R0=map_value(off=0,ks=4,vs=48,imm=0) R1_w=map_value(off=0,ks=4,vs=48,imm=0)
  24: (0f) r0 += r6
  last_idx 24 first_idx 19
  regs=40 stack=0 before 23: (bf) r1 = r0
  regs=40 stack=0 before 22: (27) r6 *= 8192
  regs=40 stack=0 before 21: (77) r6 >>= 10
  regs=40 stack=0 before 19: (55) if r0 != 0x0 goto pc+1
  parent didn't have regs=40 stack=0 marks: R0_rw=map_value_or_null(id=1,off=0,ks=4,vs=48,imm=0) R6_rw=P0 R7=0 R8=0 R9=0 R10=fp0 fp-8=mmmm????
  last_idx 18 first_idx 9
  regs=40 stack=0 before 18: (85) call bpf_map_lookup_elem#1
  regs=40 stack=0 before 17: (07) r2 += -4
  regs=40 stack=0 before 16: (bf) r2 = r10
  regs=40 stack=0 before 15: (bf) r1 = r4
  regs=40 stack=0 before 13: (18) r4 = 0xffff9290dc5bfe00
  regs=40 stack=0 before 12: (63) *(u32 *)(r10 -4) = r0
  regs=40 stack=0 before 11: (b7) r0 = 0
  regs=40 stack=0 before 10: (b7) r6 = 0
  25: (79) r3 = *(u64 *)(r0 +0)         ; R0_w=map_value(off=0,ks=4,vs=48,imm=0) R3_w=scalar()
  26: (7b) *(u64 *)(r1 +0) = r3         ; R1_w=map_value(off=0,ks=4,vs=48,imm=0) R3_w=scalar()
  27: (95) exit

  from 9 to 11: R1=ctx(off=0,imm=0) R6=0 R7=0 R8=0 R9=0 R10=fp0
  11: (b7) r0 = 0                       ; R0_w=0
  12: (63) *(u32 *)(r10 -4) = r0
  last_idx 12 first_idx 11
  regs=1 stack=0 before 11: (b7) r0 = 0
  13: R0_w=0 R10=fp0 fp-8=0000????
  13: (18) r4 = 0xffff9290dc5bfe00      ; R4_w=map_ptr(off=0,ks=4,vs=48,imm=0)
  15: (bf) r1 = r4                      ; R1_w=map_ptr(off=0,ks=4,vs=48,imm=0) R4_w=map_ptr(off=0,ks=4,vs=48,imm=0)
  16: (bf) r2 = r10                     ; R2_w=fp0 R10=fp0
  17: (07) r2 += -4                     ; R2_w=fp-4
  18: (85) call bpf_map_lookup_elem#1
  frame 0: propagating r6
  last_idx 19 first_idx 11
  regs=40 stack=0 before 18: (85) call bpf_map_lookup_elem#1
  regs=40 stack=0 before 17: (07) r2 += -4
  regs=40 stack=0 before 16: (bf) r2 = r10
  regs=40 stack=0 before 15: (bf) r1 = r4
  regs=40 stack=0 before 13: (18) r4 = 0xffff9290dc5bfe00
  regs=40 stack=0 before 12: (63) *(u32 *)(r10 -4) = r0
  regs=40 stack=0 before 11: (b7) r0 = 0
  parent didn't have regs=40 stack=0 marks: R1=ctx(off=0,imm=0) R6_r=P0 R7=0 R8=0 R9=0 R10=fp0
  last_idx 9 first_idx 9
  regs=40 stack=0 before 9: (bd) if r6 <= r9 goto pc+1
  parent didn't have regs=240 stack=0 marks: R1=ctx(off=0,imm=0) R6_rw=Pscalar() R7_w=0 R8_w=0 R9_rw=P0 R10=fp0
  last_idx 8 first_idx 0
  regs=240 stack=0 before 8: (b7) r9 = 0
  regs=40 stack=0 before 7: (97) r6 %= 1
  regs=40 stack=0 before 6: (bd) if r6 <= r9 goto pc+2
  regs=240 stack=0 before 5: (05) goto pc+0
  regs=240 stack=0 before 4: (97) r6 %= 1025
  regs=240 stack=0 before 3: (b7) r9 = -2147483648
  regs=40 stack=0 before 2: (b7) r8 = 0
  regs=40 stack=0 before 1: (b7) r7 = 0
  regs=40 stack=0 before 0: (b7) r6 = 1024
  19: safe

  from 6 to 9: R1=ctx(off=0,imm=0) R6_w=scalar(umax=18446744071562067968) R7_w=0 R8_w=0 R9_w=-2147483648 R10=fp0
  9: (bd) if r6 <= r9 goto pc+1
  last_idx 9 first_idx 0
  regs=40 stack=0 before 6: (bd) if r6 <= r9 goto pc+2
  regs=240 stack=0 before 5: (05) goto pc+0
  regs=240 stack=0 before 4: (97) r6 %= 1025
  regs=240 stack=0 before 3: (b7) r9 = -2147483648
  regs=40 stack=0 before 2: (b7) r8 = 0
  regs=40 stack=0 before 1: (b7) r7 = 0
  regs=40 stack=0 before 0: (b7) r6 = 1024
  last_idx 9 first_idx 0
  regs=200 stack=0 before 6: (bd) if r6 <= r9 goto pc+2
  regs=240 stack=0 before 5: (05) goto pc+0
  regs=240 stack=0 before 4: (97) r6 %= 1025
  regs=240 stack=0 before 3: (b7) r9 = -2147483648
  regs=40 stack=0 before 2: (b7) r8 = 0
  regs=40 stack=0 before 1: (b7) r7 = 0
  regs=40 stack=0 before 0: (b7) r6 = 1024
  11: R6=scalar(umax=18446744071562067968) R9=-2147483648
  11: (b7) r0 = 0                       ; R0_w=0
  12: (63) *(u32 *)(r10 -4) = r0
  last_idx 12 first_idx 11
  regs=1 stack=0 before 11: (b7) r0 = 0
  13: R0_w=0 R10=fp0 fp-8=0000????
  13: (18) r4 = 0xffff9290dc5bfe00      ; R4_w=map_ptr(off=0,ks=4,vs=48,imm=0)
  15: (bf) r1 = r4                      ; R1_w=map_ptr(off=0,ks=4,vs=48,imm=0) R4_w=map_ptr(off=0,ks=4,vs=48,imm=0)
  16: (bf) r2 = r10                     ; R2_w=fp0 R10=fp0
  17: (07) r2 += -4                     ; R2_w=fp-4
  18: (85) call bpf_map_lookup_elem#1   ; R0_w=map_value_or_null(id=3,off=0,ks=4,vs=48,imm=0)
  19: (55) if r0 != 0x0 goto pc+1       ; R0_w=0
  20: (95) exit

  from 19 to 21: R0=map_value(off=0,ks=4,vs=48,imm=0) R6=scalar(umax=18446744071562067968) R7=0 R8=0 R9=-2147483648 R10=fp0 fp-8=mmmm????
  21: (77) r6 >>= 10                    ; R6_w=scalar(umax=18014398507384832,var_off=(0x0; 0x3fffffffffffff))
  22: (27) r6 *= 8192                   ; R6_w=scalar(smax=9223372036854767616,umax=18446744073709543424,var_off=(0x0; 0xffffffffffffe000),s32_max=2147475456,u32_max=-8192)
  23: (bf) r1 = r0                      ; R0=map_value(off=0,ks=4,vs=48,imm=0) R1_w=map_value(off=0,ks=4,vs=48,imm=0)
  24: (0f) r0 += r6
  last_idx 24 first_idx 21
  regs=40 stack=0 before 23: (bf) r1 = r0
  regs=40 stack=0 before 22: (27) r6 *= 8192
  regs=40 stack=0 before 21: (77) r6 >>= 10
  parent didn't have regs=40 stack=0 marks: R0_rw=map_value(off=0,ks=4,vs=48,imm=0) R6_r=Pscalar(umax=18446744071562067968) R7=0 R8=0 R9=-2147483648 R10=fp0 fp-8=mmmm????
  last_idx 19 first_idx 11
  regs=40 stack=0 before 19: (55) if r0 != 0x0 goto pc+1
  regs=40 stack=0 before 18: (85) call bpf_map_lookup_elem#1
  regs=40 stack=0 before 17: (07) r2 += -4
  regs=40 stack=0 before 16: (bf) r2 = r10
  regs=40 stack=0 before 15: (bf) r1 = r4
  regs=40 stack=0 before 13: (18) r4 = 0xffff9290dc5bfe00
  regs=40 stack=0 before 12: (63) *(u32 *)(r10 -4) = r0
  regs=40 stack=0 before 11: (b7) r0 = 0
  parent didn't have regs=40 stack=0 marks: R1=ctx(off=0,imm=0) R6_rw=Pscalar(umax=18446744071562067968) R7_w=0 R8_w=0 R9_w=-2147483648 R10=fp0
  last_idx 9 first_idx 0
  regs=40 stack=0 before 9: (bd) if r6 <= r9 goto pc+1
  regs=240 stack=0 before 6: (bd) if r6 <= r9 goto pc+2
  regs=240 stack=0 before 5: (05) goto pc+0
  regs=240 stack=0 before 4: (97) r6 %= 1025
  regs=240 stack=0 before 3: (b7) r9 = -2147483648
  regs=40 stack=0 before 2: (b7) r8 = 0
  regs=40 stack=0 before 1: (b7) r7 = 0
  regs=40 stack=0 before 0: (b7) r6 = 1024
  math between map_value pointer and register with unbounded min value is not allowed
  verification time 886 usec
  stack depth 4
  processed 49 insns (limit 1000000) max_states_per_insn 1 total_states 5 peak_states 5 mark_read 2

Fixes: b5dc0163d8 ("bpf: precise scalar_value tracking")
Reported-by: Juan Jose Lopez Jaimez <jjlopezjaimez@google.com>
Reported-by: Meador Inge <meadori@google.com>
Reported-by: Simon Scannell <simonscannell@google.com>
Reported-by: Nenad Stojanovski <thenenadx@google.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Co-developed-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Reviewed-by: John Fastabend <john.fastabend@gmail.com>
Reviewed-by: Juan Jose Lopez Jaimez <jjlopezjaimez@google.com>
Reviewed-by: Meador Inge <meadori@google.com>
Reviewed-by: Simon Scannell <simonscannell@google.com>
2023-04-19 10:18:18 -07:00
Yang Yang
a3b2aeac9d delayacct: track delays from IRQ/SOFTIRQ
Delay accounting does not track the delay of IRQ/SOFTIRQ.  While
IRQ/SOFTIRQ could have obvious impact on some workloads productivity, such
as when workloads are running on system which is busy handling network
IRQ/SOFTIRQ.

Get the delay of IRQ/SOFTIRQ could help users to reduce such delay.  Such
as setting interrupt affinity or task affinity, using kernel thread for
NAPI etc.  This is inspired by "sched/psi: Add PSI_IRQ to track
IRQ/SOFTIRQ pressure"[1].  Also fix some code indent problems of older
code.

And update tools/accounting/getdelays.c:
    / # ./getdelays -p 156 -di
    print delayacct stats ON
    printing IO accounting
    PID     156

    CPU             count     real total  virtual total    delay total  delay average
                       15       15836008       16218149      275700790         18.380ms
    IO              count    delay total  delay average
                        0              0          0.000ms
    SWAP            count    delay total  delay average
                        0              0          0.000ms
    RECLAIM         count    delay total  delay average
                        0              0          0.000ms
    THRASHING       count    delay total  delay average
                        0              0          0.000ms
    COMPACT         count    delay total  delay average
                        0              0          0.000ms
    WPCOPY          count    delay total  delay average
                       36        7586118          0.211ms
    IRQ             count    delay total  delay average
                       42         929161          0.022ms

[1] commit 52b1364ba0b1("sched/psi: Add PSI_IRQ to track IRQ/SOFTIRQ pressure")

Link: https://lkml.kernel.org/r/202304081728353557233@zte.com.cn
Signed-off-by: Yang Yang <yang.yang29@zte.com.cn>
Cc: Jiang Xuexin <jiang.xuexin@zte.com.cn>
Cc: wangyong <wang.yong12@zte.com.cn>
Cc: junhua huang <huang.junhua@zte.com.cn>
Cc: Balbir Singh <bsingharora@gmail.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Juri Lelli <juri.lelli@redhat.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-04-18 16:39:34 -07:00
Pavankumar Kondeti
1f6ab566cb printk: export console trace point for kcsan/kasan/kfence/kmsan
The console tracepoint is used by kcsan/kasan/kfence/kmsan test modules. 
Since this tracepoint is not exported, these modules iterate over all
available tracepoints to find the console trace point.  Export the trace
point so that it can be directly used.

Link: https://lkml.kernel.org/r/20230413100859.1492323-1-quic_pkondeti@quicinc.com
Signed-off-by: Pavankumar Kondeti <quic_pkondeti@quicinc.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Andrey Konovalov <andreyknvl@gmail.com>
Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: John Ogness <john.ogness@linutronix.de>
Cc: Marco Elver <elver@google.com>
Cc: Petr Mladek <pmladek@suse.com>
Cc: Sergey Senozhatsky <senozhatsky@chromium.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Vincenzo Frascino <vincenzo.frascino@arm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-04-18 16:30:11 -07:00
Josh Triplett
ddc65971bb prctl: add PR_GET_AUXV to copy auxv to userspace
If a library wants to get information from auxv (for instance,
AT_HWCAP/AT_HWCAP2), it has a few options, none of them perfectly reliable
or ideal:

- Be main or the pre-main startup code, and grub through the stack above
  main. Doesn't work for a library.
- Call libc getauxval. Not ideal for libraries that are trying to be
  libc-independent and/or don't otherwise require anything from other
  libraries.
- Open and read /proc/self/auxv. Doesn't work for libraries that may run
  in arbitrarily constrained environments that may not have /proc
  mounted (e.g. libraries that might be used by an init program or a
  container setup tool).
- Assume you're on the main thread and still on the original stack, and
  try to walk the stack upwards, hoping to find auxv. Extremely bad
  idea.
- Ask the caller to pass auxv in for you. Not ideal for a user-friendly
  library, and then your caller may have the same problem.

Add a prctl that copies current->mm->saved_auxv to a userspace buffer.

Link: https://lkml.kernel.org/r/d81864a7f7f43bca6afa2a09fc2e850e4050ab42.1680611394.git.josh@joshtriplett.org
Signed-off-by: Josh Triplett <josh@joshtriplett.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-04-18 16:29:53 -07:00
Yosry Ahmed
8bff9a04ca cgroup: rename cgroup_rstat_flush_"irqsafe" to "atomic"
Patch series "memcg: avoid flushing stats atomically where possible", v3.

rstat flushing is an expensive operation that scales with the number of
cpus and the number of cgroups in the system.  The purpose of this series
is to minimize the contexts where we flush stats atomically.

Patches 1 and 2 are cleanups requested during reviews of prior versions of
this series.

Patch 3 makes sure we never try to flush from within an irq context.

Patches 4 to 7 introduce separate variants of mem_cgroup_flush_stats() for
atomic and non-atomic flushing, and make sure we only flush the stats
atomically when necessary.

Patch 8 is a slightly tangential optimization that limits the work done by
rstat flushing in some scenarios.


This patch (of 8):

cgroup_rstat_flush_irqsafe() can be a confusing name.  It may read as
"irqs are disabled throughout", which is what the current implementation
does (currently under discussion [1]), but is not the intention.  The
intention is that this function is safe to call from atomic contexts. 
Name it as such.

Link: https://lkml.kernel.org/r/20230330191801.1967435-1-yosryahmed@google.com
Link: https://lkml.kernel.org/r/20230330191801.1967435-2-yosryahmed@google.com
Signed-off-by: Yosry Ahmed <yosryahmed@google.com>
Suggested-by: Johannes Weiner <hannes@cmpxchg.org>
Acked-by: Shakeel Butt <shakeelb@google.com>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Josef Bacik <josef@toxicpanda.com>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Michal Koutný <mkoutny@suse.com>
Cc: Muchun Song <muchun.song@linux.dev>
Cc: Roman Gushchin <roman.gushchin@linux.dev>
Cc: Tejun Heo <tj@kernel.org>
Cc: Vasily Averin <vasily.averin@linux.dev>
Cc: Zefan Li <lizefan.x@bytedance.com>
Cc: Michal Hocko <mhocko@suse.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-04-18 16:29:49 -07:00
Andrew Morton
f8f238ffe5 sync mm-stable with mm-hotfixes-stable to pick up depended-upon upstream changes 2023-04-18 14:53:49 -07:00
Mathieu Desnoyers
b20b0368c6 mm: fix memory leak on mm_init error handling
commit f1a7941243 ("mm: convert mm's rss stats into percpu_counter")
introduces a memory leak by missing a call to destroy_context() when a
percpu_counter fails to allocate.

Before introducing the per-cpu counter allocations, init_new_context() was
the last call that could fail in mm_init(), and thus there was no need to
ever invoke destroy_context() in the error paths.  Adding the following
percpu counter allocations adds error paths after init_new_context(),
which means its associated destroy_context() needs to be called when
percpu counters fail to allocate.

Link: https://lkml.kernel.org/r/20230330133822.66271-1-mathieu.desnoyers@efficios.com
Fixes: f1a7941243 ("mm: convert mm's rss stats into percpu_counter")
Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Acked-by: Shakeel Butt <shakeelb@google.com>
Cc: Marek Szyprowski <m.szyprowski@samsung.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-04-18 14:22:12 -07:00
Ondrej Mosnacek
659c0ce1cb kernel/sys.c: fix and improve control flow in __sys_setres[ug]id()
Linux Security Modules (LSMs) that implement the "capable" hook will
usually emit an access denial message to the audit log whenever they
"block" the current task from using the given capability based on their
security policy.

The occurrence of a denial is used as an indication that the given task
has attempted an operation that requires the given access permission, so
the callers of functions that perform LSM permission checks must take care
to avoid calling them too early (before it is decided if the permission is
actually needed to perform the requested operation).

The __sys_setres[ug]id() functions violate this convention by first
calling ns_capable_setid() and only then checking if the operation
requires the capability or not.  It means that any caller that has the
capability granted by DAC (task's capability set) but not by MAC (LSMs)
will generate a "denied" audit record, even if is doing an operation for
which the capability is not required.

Fix this by reordering the checks such that ns_capable_setid() is checked
last and -EPERM is returned immediately if it returns false.

While there, also do two small optimizations:
* move the capability check before prepare_creds() and
* bail out early in case of a no-op.

Link: https://lkml.kernel.org/r/20230217162154.837549-1-omosnace@redhat.com
Fixes: 1da177e4c3 ("Linux-2.6.12-rc2")
Signed-off-by: Ondrej Mosnacek <omosnace@redhat.com>
Cc: Eric W. Biederman <ebiederm@xmission.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-04-18 14:22:12 -07:00
Arnd Bergmann
a81b1fc8ea module: stats: fix invalid_mod_bytes typo
This was caught by randconfig builds but does not show up in
build testing without CONFIG_MODULE_DECOMPRESS:

kernel/module/stats.c: In function 'mod_stat_bump_invalid':
kernel/module/stats.c:229:42: error: 'invalid_mod_byte' undeclared (first use in this function); did you mean 'invalid_mod_bytes'?
  229 |   atomic_long_add(info->compressed_len, &invalid_mod_byte);
      |                                          ^~~~~~~~~~~~~~~~
      |                                          invalid_mod_bytes

Fixes: df3e764d8e ("module: add debug stats to help identify memory pressure")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Randy Dunlap <rdunlap@infradead.org>
Tested-by: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: Luis Chamberlain <mcgrof@kernel.org>
2023-04-18 11:36:41 -07:00
Tom Rix
9f5cab173e module: remove use of uninitialized variable len
clang build reports
kernel/module/stats.c:307:34: error: variable
  'len' is uninitialized when used here [-Werror,-Wuninitialized]
        len = scnprintf(buf + 0, size - len,
                                        ^~~
At the start of this sequence, neither the '+ 0', nor the '- len' are needed.
So remove them and fix using 'len' uninitalized.

Fixes: df3e764d8e ("module: add debug stats to help identify memory pressure")
Signed-off-by: Tom Rix <trix@redhat.com>
Signed-off-by: Luis Chamberlain <mcgrof@kernel.org>
2023-04-18 11:36:24 -07:00
Arnd Bergmann
719ccd803e module: fix building stats for 32-bit targets
The new module statistics code mixes 64-bit types and wordsized 'long'
variables, which leads to build failures on 32-bit architectures:

kernel/module/stats.c: In function 'read_file_mod_stats':
kernel/module/stats.c:291:29: error: passing argument 1 of 'atomic64_read' from incompatible pointer type [-Werror=incompatible-pointer-types]
  291 |  total_size = atomic64_read(&total_mod_size);
x86_64-linux-ld: kernel/module/stats.o: in function `read_file_mod_stats':
stats.c:(.text+0x2b2): undefined reference to `__udivdi3'

To fix this, the code has to use one of the two types consistently.

Change them all to word-size types here.

Fixes: df3e764d8e ("module: add debug stats to help identify memory pressure")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Luis Chamberlain <mcgrof@kernel.org>
2023-04-18 11:36:00 -07:00
Arnd Bergmann
635dc38314 module: stats: include uapi/linux/module.h
MODULE_INIT_COMPRESSED_FILE is defined in the uapi header, which
is not included indirectly from the normal linux/module.h, but
has to be pulled in explicitly:

kernel/module/stats.c: In function 'mod_stat_bump_invalid':
kernel/module/stats.c:227:14: error: 'MODULE_INIT_COMPRESSED_FILE' undeclared (first use in this function)
  227 |  if (flags & MODULE_INIT_COMPRESSED_FILE)
      |              ^~~~~~~~~~~~~~~~~~~~~~~~~~~

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Luis Chamberlain <mcgrof@kernel.org>
2023-04-18 11:35:50 -07:00
Luis Chamberlain
064f4536d1 module: avoid allocation if module is already present and ready
The finit_module() system call can create unnecessary virtual memory
pressure for duplicate modules. This is because load_module() can in
the worse case allocate more than twice the size of a module in virtual
memory. This saves at least a full size of the module in wasted vmalloc
space memory by trying to avoid duplicates as soon as we can validate
the module name in the read module structure.

This can only be an issue if a system is getting hammered with userspace
loading modules. There are two ways to load modules typically on systems,
one is the kernel moduile auto-loading (*request_module*() calls in-kernel)
and the other is things like udev. The auto-loading is in-kernel, but that
pings back to userspace to just call modprobe. We already have a way to
restrict the amount of concurrent kernel auto-loads in a given time, however
that still allows multiple requests for the same module to go through
and force two threads in userspace racing to call modprobe for the same
exact module. Even though libkmod which both modprobe and udev does check
if a module is already loaded prior calling finit_module() races are
still possible and this is clearly evident today when you have multiple
CPUs.

To avoid memory pressure for such stupid cases put a stop gap for them.
The *earliest* we can detect duplicates from the modules side of things
is once we have blessed the module name, sadly after the first vmalloc
allocation. We can check for the module being present *before* a secondary
vmalloc() allocation.

There is a linear relationship between wasted virtual memory bytes and
the number of CPU counts. The reason is that udev ends up racing to call
tons of the same modules for each of the CPUs.

We can see the different linear relationships between wasted virtual
memory and CPU count during after boot in the following graph:

         +----------------------------------------------------------------------------+
    14GB |-+          +            +            +           +           *+          +-|
         |                                                          ****              |
         |                                                       ***                  |
         |                                                     **                     |
    12GB |-+                                                 **                     +-|
         |                                                 **                         |
         |                                               **                           |
         |                                             **                             |
         |                                           **                               |
    10GB |-+                                       **                               +-|
         |                                       **                                   |
         |                                     **                                     |
         |                                   **                                       |
     8GB |-+                               **                                       +-|
waste    |                               **                             ###           |
         |                             **                           ####              |
         |                           **                      #######                  |
     6GB |-+                     ****                    ####                       +-|
         |                      *                    ####                             |
         |                     *                 ####                                 |
         |                *****              ####                                     |
     4GB |-+            **               ####                                       +-|
         |            **             ####                                             |
         |          **           ####                                                 |
         |        **         ####                                                     |
     2GB |-+    **      #####                                                       +-|
         |     *    ####                                                              |
         |    * ####                                                   Before ******* |
         |  **##      +            +            +           +           After ####### |
         +----------------------------------------------------------------------------+
         0            50          100          150         200          250          300
                                          CPUs count

On the y-axis we can see gigabytes of wasted virtual memory during boot
due to duplicate module requests which just end up failing. Trying to
infer the slope this ends up being about ~463 MiB per CPU lost prior
to this patch. After this patch we only loose about ~230 MiB per CPU, for
a total savings of about ~233 MiB per CPU. This is all *just on bootup*!

On a 8vcpu 8 GiB RAM system using kdevops and testing against selftests
kmod.sh -t 0008 I see a saving in the *highest* side of memory
consumption of up to ~ 84 MiB with the Linux kernel selftests kmod
test 0008. With the new stress-ng module test I see a 145 MiB difference
in max memory consumption with 100 ops. The stress-ng module ops tests can be
pretty pathalogical -- it is not realistic, however it was used to
finally successfully reproduce issues which are only reported to happen on
system with over 400 CPUs [0] by just usign 100 ops on a 8vcpu 8 GiB RAM
system. Running out of virtual memory space is no surprise given the
above graph, since at least on x86_64 we're capped at 128 MiB, eventually
we'd hit a series of errors and once can use the above graph to
guestimate when. This of course will vary depending on the features
you have enabled. So for instance, enabling KASAN seems to make this
much worse.

The results with kmod and stress-ng can be observed and visualized below.
The time it takes to run the test is also not affected.

The kmod tests 0008:

The gnuplot is set to a range from 400000 KiB (390 Mib) - 580000 (566 Mib)
given the tests peak around that range.

cat kmod.plot
set term dumb
set output fileout
set yrange [400000:580000]
plot filein with linespoints title "Memory usage (KiB)"

Before:
root@kmod ~ # /data/linux-next/tools/testing/selftests/kmod/kmod.sh -t 0008
root@kmod ~ # free -k -s 1 -c 40 | grep Mem | awk '{print $3}' > log-0008-before.txt ^C
root@kmod ~ # sort -n -r log-0008-before.txt | head -1
528732

So ~516.33 MiB

After:

root@kmod ~ # /data/linux-next/tools/testing/selftests/kmod/kmod.sh -t 0008
root@kmod ~ # free -k -s 1 -c 40 | grep Mem | awk '{print $3}' > log-0008-after.txt ^C

root@kmod ~ # sort -n -r log-0008-after.txt | head -1
442516

So ~432.14 MiB

That's about 84 ~MiB in savings in the worst case. The graphs:

root@kmod ~ # gnuplot -e "filein='log-0008-before.txt'; fileout='graph-0008-before.txt'" kmod.plot
root@kmod ~ # gnuplot -e "filein='log-0008-after.txt';  fileout='graph-0008-after.txt'"  kmod.plot

root@kmod ~ # cat graph-0008-before.txt

  580000 +-----------------------------------------------------------------+
         |       +        +       +       +       +        +       +       |
  560000 |-+                                    Memory usage (KiB) ***A***-|
         |                                                                 |
  540000 |-+                                                             +-|
         |                                                                 |
         |        *A     *AA*AA*A*AA          *A*AA    A*A*A *AA*A*AA*A  A |
  520000 |-+A*A*AA  *AA*A           *A*AA*A*AA     *A*A     A          *A+-|
         |*A                                                               |
  500000 |-+                                                             +-|
         |                                                                 |
  480000 |-+                                                             +-|
         |                                                                 |
  460000 |-+                                                             +-|
         |                                                                 |
         |                                                                 |
  440000 |-+                                                             +-|
         |                                                                 |
  420000 |-+                                                             +-|
         |       +        +       +       +       +        +       +       |
  400000 +-----------------------------------------------------------------+
         0       5        10      15      20      25       30      35      40

root@kmod ~ # cat graph-0008-after.txt

  580000 +-----------------------------------------------------------------+
         |       +        +       +       +       +        +       +       |
  560000 |-+                                    Memory usage (KiB) ***A***-|
         |                                                                 |
  540000 |-+                                                             +-|
         |                                                                 |
         |                                                                 |
  520000 |-+                                                             +-|
         |                                                                 |
  500000 |-+                                                             +-|
         |                                                                 |
  480000 |-+                                                             +-|
         |                                                                 |
  460000 |-+                                                             +-|
         |                                                                 |
         |          *A              *A*A                                   |
  440000 |-+A*A*AA*A  A       A*A*AA    A*A*AA*A*AA*A*AA*A*AA*AA*A*AA*A*AA-|
         |*A           *A*AA*A                                             |
  420000 |-+                                                             +-|
         |       +        +       +       +       +        +       +       |
  400000 +-----------------------------------------------------------------+
         0       5        10      15      20      25       30      35      40

The stress-ng module tests:

This is used to run the test to try to reproduce the vmap issues
reported by David:

  echo 0 > /proc/sys/vm/oom_dump_tasks
  ./stress-ng --module 100 --module-name xfs

Prior to this commit:
root@kmod ~ # free -k -s 1 -c 40 | grep Mem | awk '{print $3}' > baseline-stress-ng.txt
root@kmod ~ # sort -n -r baseline-stress-ng.txt | head -1
5046456

After this commit:
root@kmod ~ # free -k -s 1 -c 40 | grep Mem | awk '{print $3}' > after-stress-ng.txt
root@kmod ~ # sort -n -r after-stress-ng.txt | head -1
4896972

5046456 - 4896972
149484
149484/1024
145.98046875000000000000

So this commit using stress-ng reveals saving about 145 MiB in memory
using 100 ops from stress-ng which reproduced the vmap issue reported.

cat kmod.plot
set term dumb
set output fileout
set yrange [4700000:5070000]
plot filein with linespoints title "Memory usage (KiB)"

root@kmod ~ # gnuplot -e "filein='baseline-stress-ng.txt'; fileout='graph-stress-ng-before.txt'"  kmod-simple-stress-ng.plot
root@kmod ~ # gnuplot -e "filein='after-stress-ng.txt'; fileout='graph-stress-ng-after.txt'"  kmod-simple-stress-ng.plot

root@kmod ~ # cat graph-stress-ng-before.txt

           +---------------------------------------------------------------+
  5.05e+06 |-+     + A     +       +       +       +       +       +     +-|
           |         *                          Memory usage (KiB) ***A*** |
           |         *                             A                       |
     5e+06 |-+      **                            **                     +-|
           |        **                            * *    A                 |
  4.95e+06 |-+      * *                          A  *   A*               +-|
           |        * *      A       A           *  *  *  *             A  |
           |       *  *     * *     * *        *A   *  *  *      A      *  |
   4.9e+06 |-+     *  *     * A*A   * A*AA*A  A      *A    **A   **A*A  *+-|
           |       A  A*A  A    *  A       *  *      A     A *  A    * **  |
           |      *      **      **         * *              *  *    * * * |
  4.85e+06 |-+   A       A       A          **               *  *     ** *-|
           |     *                           *               * *      ** * |
           |     *                           A               * *      *  * |
   4.8e+06 |-+   *                                           * *      A  A-|
           |     *                                           * *           |
  4.75e+06 |-+  *                                            * *         +-|
           |    *                                            **            |
           |    *  +       +       +       +       +       + **    +       |
   4.7e+06 +---------------------------------------------------------------+
           0       5       10      15      20      25      30      35      40

root@kmod ~ # cat graph-stress-ng-after.txt

           +---------------------------------------------------------------+
  5.05e+06 |-+     +       +       +       +       +       +       +     +-|
           |                                    Memory usage (KiB) ***A*** |
           |                                                               |
     5e+06 |-+                                                           +-|
           |                                                               |
  4.95e+06 |-+                                                           +-|
           |                                                               |
           |                                                               |
   4.9e+06 |-+                                      *AA                  +-|
           |  A*AA*A*A  A  A*AA*AA*A*AA*A  A  A  A*A   *AA*A*A  A  A*AA*AA |
           |  *      * **  *            *  *  ** *            ***  *       |
  4.85e+06 |-+*       ***  *            * * * ***             A *  *     +-|
           |  *       A *  *             ** * * A               *  *       |
           |  *         *  *             *  **                  *  *       |
   4.8e+06 |-+*         *  *             A   *                  *  *     +-|
           | *          * *                  A                  * *        |
  4.75e+06 |-*          * *                                     * *      +-|
           | *          * *                                     * *        |
           | *     +    * *+       +       +       +       +    * *+       |
   4.7e+06 +---------------------------------------------------------------+
           0       5       10      15      20      25      30      35      40

[0] https://lkml.kernel.org/r/20221013180518.217405-1-david@redhat.com

Reported-by: David Hildenbrand <david@redhat.com>
Signed-off-by: Luis Chamberlain <mcgrof@kernel.org>
2023-04-18 11:15:24 -07:00
Luis Chamberlain
df3e764d8e module: add debug stats to help identify memory pressure
Loading modules with finit_module() can end up using vmalloc(), vmap()
and vmalloc() again, for a total of up to 3 separate allocations in the
worst case for a single module. We always kernel_read*() the module,
that's a vmalloc(). Then vmap() is used for the module decompression,
and if so the last read buffer is freed as we use the now decompressed
module buffer to stuff data into our copy module. The last allocation is
specific to each architectures but pretty much that's generally a series
of vmalloc() calls or a variation of vmalloc to handle ELF sections with
special permissions.

Evaluation with new stress-ng module support [1] with just 100 ops
is proving that you can end up using GiBs of data easily even with all
care we have in the kernel and userspace today in trying to not load modules
which are already loaded. 100 ops seems to resemble the sort of pressure a
system with about 400 CPUs can create on module loading. Although issues
relating to duplicate module requests due to each CPU inucurring a new
module reuest is silly and some of these are being fixed, we currently lack
proper tooling to help diagnose easily what happened, when it happened
and who likely is to blame -- userspace or kernel module autoloading.

Provide an initial set of stats which use debugfs to let us easily scrape
post-boot information about failed loads. This sort of information can
be used on production worklaods to try to optimize *avoiding* redundant
memory pressure using finit_module().

There's a few examples that can be provided:

A 255 vCPU system without the next patch in this series applied:

Startup finished in 19.143s (kernel) + 7.078s (userspace) = 26.221s
graphical.target reached after 6.988s in userspace

And 13.58 GiB of virtual memory space lost due to failed module loading:

root@big ~ # cat /sys/kernel/debug/modules/stats
         Mods ever loaded       67
     Mods failed on kread       0
Mods failed on decompress       0
  Mods failed on becoming       0
      Mods failed on load       1411
        Total module size       11464704
      Total mod text size       4194304
       Failed kread bytes       0
  Failed decompress bytes       0
    Failed becoming bytes       0
        Failed kmod bytes       14588526272
 Virtual mem wasted bytes       14588526272
         Average mod size       171115
    Average mod text size       62602
  Average fail load bytes       10339140
Duplicate failed modules:
              module-name        How-many-times                    Reason
                kvm_intel                   249                      Load
                      kvm                   249                      Load
                irqbypass                     8                      Load
         crct10dif_pclmul                   128                      Load
      ghash_clmulni_intel                    27                      Load
             sha512_ssse3                    50                      Load
           sha512_generic                   200                      Load
              aesni_intel                   249                      Load
              crypto_simd                    41                      Load
                   cryptd                   131                      Load
                    evdev                     2                      Load
                serio_raw                     1                      Load
               virtio_pci                     3                      Load
                     nvme                     3                      Load
                nvme_core                     3                      Load
    virtio_pci_legacy_dev                     3                      Load
    virtio_pci_modern_dev                     3                      Load
                   t10_pi                     3                      Load
                   virtio                     3                      Load
             crc32_pclmul                     6                      Load
           crc64_rocksoft                     3                      Load
             crc32c_intel                    40                      Load
              virtio_ring                     3                      Load
                    crc64                     3                      Load

The following screen shot, of a simple 8vcpu 8 GiB KVM guest with the
next patch in this series applied, shows 226.53 MiB are wasted in virtual
memory allocations which due to duplicate module requests during boot.
It also shows an average module memory size of 167.10 KiB and an an
average module .text + .init.text size of 61.13 KiB. The end shows all
modules which were detected as duplicate requests and whether or not
they failed early after just the first kernel_read*() call or late after
we've already allocated the private space for the module in
layout_and_allocate(). A system with module decompression would reveal
more wasted virtual memory space.

We should put effort now into identifying the source of these duplicate
module requests and trimming these down as much possible. Larger systems
will obviously show much more wasted virtual memory allocations.

root@kmod ~ # cat /sys/kernel/debug/modules/stats
         Mods ever loaded       67
     Mods failed on kread       0
Mods failed on decompress       0
  Mods failed on becoming       83
      Mods failed on load       16
        Total module size       11464704
      Total mod text size       4194304
       Failed kread bytes       0
  Failed decompress bytes       0
    Failed becoming bytes       228959096
        Failed kmod bytes       8578080
 Virtual mem wasted bytes       237537176
         Average mod size       171115
    Average mod text size       62602
  Avg fail becoming bytes       2758544
  Average fail load bytes       536130
Duplicate failed modules:
              module-name        How-many-times                    Reason
                kvm_intel                     7                  Becoming
                      kvm                     7                  Becoming
                irqbypass                     6           Becoming & Load
         crct10dif_pclmul                     7           Becoming & Load
      ghash_clmulni_intel                     7           Becoming & Load
             sha512_ssse3                     6           Becoming & Load
           sha512_generic                     7           Becoming & Load
              aesni_intel                     7                  Becoming
              crypto_simd                     7           Becoming & Load
                   cryptd                     3           Becoming & Load
                    evdev                     1                  Becoming
                serio_raw                     1                  Becoming
                     nvme                     3                  Becoming
                nvme_core                     3                  Becoming
                   t10_pi                     3                  Becoming
               virtio_pci                     3                  Becoming
             crc32_pclmul                     6           Becoming & Load
           crc64_rocksoft                     3                  Becoming
             crc32c_intel                     3                  Becoming
    virtio_pci_modern_dev                     2                  Becoming
    virtio_pci_legacy_dev                     1                  Becoming
                    crc64                     2                  Becoming
                   virtio                     2                  Becoming
              virtio_ring                     2                  Becoming

[0] https://github.com/ColinIanKing/stress-ng.git
[1] echo 0 > /proc/sys/vm/oom_dump_tasks
    ./stress-ng --module 100 --module-name xfs

Signed-off-by: Luis Chamberlain <mcgrof@kernel.org>
2023-04-18 11:15:24 -07:00
Luis Chamberlain
f71afa6a42 module: extract patient module check into helper
The patient module check inside add_unformed_module() is large
enough as we need it. It is a bit hard to read too, so just
move it to a helper and do the inverse checks first to help
shift the code and make it easier to read. The new helper then
is module_patient_check_exists().

To make this work we need to mvoe the finished_loading() up,
we do that without making any functional changes to that routine.

Reviewed-by: David Hildenbrand <david@redhat.com>
Signed-off-by: Luis Chamberlain <mcgrof@kernel.org>
2023-04-18 11:15:24 -07:00
Luis Chamberlain
25a1b5b518 modules/kmod: replace implementation with a semaphore
Simplify the concurrency delimiter we use for kmod with the semaphore.
I had used the kmod strategy to try to implement a similar concurrency
delimiter for the kernel_read*() calls from the finit_module() path
so to reduce vmalloc() memory pressure. That effort didn't provide yet
conclusive results, but one thing that became clear is we can use
the suggested alternative solution with semaphores which Linus hinted
at instead of using the atomic / wait strategy.

I've stress tested this with kmod test 0008:

time /data/linux-next/tools/testing/selftests/kmod/kmod.sh -t 0008

And I get only a *slight* delay. That delay however is small, a few
seconds for a full test loop run that runs 150 times, for about ~30-40
seconds. The small delay is worth the simplfication IMHO.

Reviewed-by: Davidlohr Bueso <dave@stgolabs.net>
Reviewed-by: Miroslav Benes <mbenes@suse.cz>
Reviewed-by: David Hildenbrand <david@redhat.com>
Signed-off-by: Luis Chamberlain <mcgrof@kernel.org>
2023-04-18 11:15:24 -07:00
Peter Zijlstra
48380368de Change DEFINE_SEMAPHORE() to take a number argument
Fundamentally semaphores are a counted primitive, but
DEFINE_SEMAPHORE() does not expose this and explicitly creates a
binary semaphore.

Change DEFINE_SEMAPHORE() to take a number argument and use that in the
few places that open-coded it using __SEMAPHORE_INITIALIZER().

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
[mcgrof: add some tribal knowledge about why some folks prefer
 binary sempahores over mutexes]
Reviewed-by: Sergey Senozhatsky <senozhatsky@chromium.org>
Reviewed-by: Davidlohr Bueso <dave@stgolabs.net>
Signed-off-by: Luis Chamberlain <mcgrof@kernel.org>
2023-04-18 11:15:24 -07:00
Frederic Weisbecker
289dafed38 timers/nohz: Remove middle-function __tick_nohz_idle_stop_tick()
There is no need for the __tick_nohz_idle_stop_tick() function between
tick_nohz_idle_stop_tick() and its implementation. Remove that
unnecessary step.

Signed-off-by: Frederic Weisbecker <frederic@kernel.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lore.kernel.org/r/20230222144649.624380-6-frederic@kernel.org
2023-04-18 16:35:12 +02:00
Frederic Weisbecker
ead70b7523 timers/nohz: Add a comment about broken iowait counter update race
The per-cpu iowait task counter is incremented locally upon sleeping.
But since the task can be woken to (and by) another CPU, the counter may
then be decremented remotely. This is the source of a race involving
readers VS writer of idle/iowait sleeptime.

The following scenario shows an example where a /proc/stat reader
observes a pending sleep time as IO whereas that pending sleep time
later eventually gets accounted as non-IO.

    CPU 0                       CPU  1                    CPU 2
    -----                       -----                     ------
    //io_schedule() TASK A
    current->in_iowait = 1
    rq(0)->nr_iowait++
    //switch to idle
                        // READ /proc/stat
                        // See nr_iowait_cpu(0) == 1
                        return ts->iowait_sleeptime +
                               ktime_sub(ktime_get(), ts->idle_entrytime)

                                                          //try_to_wake_up(TASK A)
                                                          rq(0)->nr_iowait--
    //idle exit
    // See nr_iowait_cpu(0) == 0
    ts->idle_sleeptime += ktime_sub(ktime_get(), ts->idle_entrytime)

As a result subsequent reads on /proc/stat may expose backward progress.

This is unfortunately hardly fixable. Just add a comment about that
condition.

Signed-off-by: Frederic Weisbecker <frederic@kernel.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lore.kernel.org/r/20230222144649.624380-5-frederic@kernel.org
2023-04-18 16:35:12 +02:00
Frederic Weisbecker
620a30fa0b timers/nohz: Protect idle/iowait sleep time under seqcount
Reading idle/IO sleep time (eg: from /proc/stat) can race with idle exit
updates because the state machine handling the stats is not atomic and
requires a coherent read batch.

As a result reading the sleep time may report irrelevant or backward
values.

Fix this with protecting the simple state machine within a seqcount.
This is expected to be cheap enough not to add measurable performance
impact on the idle path.

Note this only fixes reader VS writer condition partitially. A race
remains that involves remote updates of the CPU iowait task counter. It
can hardly be fixed.

Reported-by: Yu Liao <liaoyu15@huawei.com>
Signed-off-by: Frederic Weisbecker <frederic@kernel.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lore.kernel.org/r/20230222144649.624380-4-frederic@kernel.org
2023-04-18 16:35:12 +02:00
Frederic Weisbecker
07b65a800b timers/nohz: Only ever update sleeptime from idle exit
The idle and IO sleeptime statistics appearing in /proc/stat can be
currently updated from two sites: locally on idle exit and remotely
by cpufreq. However there is no synchronization mechanism protecting
concurrent updates. It is therefore possible to account the sleeptime
twice, among all the other possible broken scenarios.

To prevent from breaking the sleeptime accounting source, restrict the
sleeptime updates to the local idle exit site. If there is a delta to
add since the last update, IO/Idle sleep time readers will now only
compute the delta without actually writing it back to the internal idle
statistic fields.

This fixes a writer VS writer race. Note there are still two known
reader VS writer races to handle. A subsequent patch will fix one.

Reported-by: Yu Liao <liaoyu15@huawei.com>
Signed-off-by: Frederic Weisbecker <frederic@kernel.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lore.kernel.org/r/20230222144649.624380-3-frederic@kernel.org
2023-04-18 16:35:12 +02:00
Frederic Weisbecker
605da849d5 timers/nohz: Restructure and reshuffle struct tick_sched
Restructure and group fields by access in order to optimize cache
layout. While at it, also add missing kernel doc for two fields:
@last_jiffies and @idle_expires.

Reported-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Frederic Weisbecker <frederic@kernel.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lore.kernel.org/r/20230222144649.624380-2-frederic@kernel.org
2023-04-18 16:35:12 +02:00
Sebastian Andrzej Siewior
e9523a0d81 tick/common: Align tick period with the HZ tick.
With HIGHRES enabled tick_sched_timer() is programmed every jiffy to
expire the timer_list timers. This timer is programmed accurate in
respect to CLOCK_MONOTONIC so that 0 seconds and nanoseconds is the
first tick and the next one is 1000/CONFIG_HZ ms later. For HZ=250 it is
every 4 ms and so based on the current time the next tick can be
computed.

This accuracy broke since the commit mentioned below because the jiffy
based clocksource is initialized with higher accuracy in
read_persistent_wall_and_boot_offset(). This higher accuracy is
inherited during the setup in tick_setup_device(). The timer still fires
every 4ms with HZ=250 but timer is no longer aligned with
CLOCK_MONOTONIC with 0 as it origin but has an offset in the us/ns part
of the timestamp. The offset differs with every boot and makes it
impossible for user land to align with the tick.

Align the tick period with CLOCK_MONOTONIC ensuring that it is always a
multiple of 1000/CONFIG_HZ ms.

Fixes: 857baa87b6 ("sched/clock: Enable sched clock early")
Reported-by: Gusenleitner Klaus <gus@keba.com>
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/20230406095735.0_14edn3@linutronix.de
Link: https://lore.kernel.org/r/20230418122639.ikgfvu3f@linutronix.de
2023-04-18 15:06:50 +02:00
Yonghong Song
3be49f7955 bpf: Improve verifier u32 scalar equality checking
In [1], I tried to remove bpf-specific codes to prevent certain
llvm optimizations, and add llvm TTI (target transform info) hooks
to prevent those optimizations. During this process, I found
if I enable llvm SimplifyCFG:shouldFoldTwoEntryPHINode
transformation, I will hit the following verification failure with selftests:

  ...
  8: (18) r1 = 0xffffc900001b2230       ; R1_w=map_value(off=560,ks=4,vs=564,imm=0)
  10: (61) r1 = *(u32 *)(r1 +0)         ; R1_w=scalar(umax=4294967295,var_off=(0x0; 0xffffffff))
  ; if (skb->tstamp == EGRESS_ENDHOST_MAGIC)
  11: (79) r2 = *(u64 *)(r6 +152)       ; R2_w=scalar() R6=ctx(off=0,imm=0)
  ; if (skb->tstamp == EGRESS_ENDHOST_MAGIC)
  12: (55) if r2 != 0xb9fbeef goto pc+10        ; R2_w=195018479
  13: (bc) w2 = w1                      ; R1_w=scalar(umax=4294967295,var_off=(0x0; 0xffffffff)) R2_w=scalar(umax=4294967295,var_off=(0x0; 0xffffffff))
  ; if (test < __NR_TESTS)
  14: (a6) if w1 < 0x9 goto pc+1 16: R0=2 R1_w=scalar(umax=8,var_off=(0x0; 0xf)) R2_w=scalar(umax=4294967295,var_off=(0x0; 0xffffffff)) R6=ctx(off=0,imm=0) R10=fp0
  ;
  16: (27) r2 *= 28                     ; R2_w=scalar(umax=120259084260,var_off=(0x0; 0x1ffffffffc),s32_max=2147483644,u32_max=-4)
  17: (18) r3 = 0xffffc900001b2118      ; R3_w=map_value(off=280,ks=4,vs=564,imm=0)
  19: (0f) r3 += r2                     ; R2_w=scalar(umax=120259084260,var_off=(0x0; 0x1ffffffffc),s32_max=2147483644,u32_max=-4) R3_w=map_value(off=280,ks=4,vs=564,umax=120259084260,var_off=(0x0; 0x1ffffffffc),s32_max=2147483644,u32_max=-4)
  20: (61) r2 = *(u32 *)(r3 +0)
  R3 unbounded memory access, make sure to bounds check any such access
  processed 97 insns (limit 1000000) max_states_per_insn 1 total_states 10 peak_states 10 mark_read 6
  -- END PROG LOAD LOG --
  libbpf: prog 'ingress_fwdns_prio100': failed to load: -13
  libbpf: failed to load object 'test_tc_dtime'
  libbpf: failed to load BPF skeleton 'test_tc_dtime': -13
  ...

At insn 14, with condition 'w1 < 9', register r1 is changed from an arbitrary
u32 value to `scalar(umax=8,var_off=(0x0; 0xf))`. Register r2, however, remains
as an arbitrary u32 value. Current verifier won't claim r1/r2 equality if
the previous mov is alu32 ('w2 = w1').

If r1 upper 32bit value is not 0, we indeed cannot clamin r1/r2 equality
after 'w2 = w1'. But in this particular case, we know r1 upper 32bit value
is 0, so it is safe to claim r1/r2 equality. This patch exactly did this.
For a 32bit subreg mov, if the src register upper 32bit is 0,
it is okay to claim equality between src and dst registers.

With this patch, the above verification sequence becomes

  ...
  8: (18) r1 = 0xffffc9000048e230       ; R1_w=map_value(off=560,ks=4,vs=564,imm=0)
  10: (61) r1 = *(u32 *)(r1 +0)         ; R1_w=scalar(umax=4294967295,var_off=(0x0; 0xffffffff))
  ; if (skb->tstamp == EGRESS_ENDHOST_MAGIC)
  11: (79) r2 = *(u64 *)(r6 +152)       ; R2_w=scalar() R6=ctx(off=0,imm=0)
  ; if (skb->tstamp == EGRESS_ENDHOST_MAGIC)
  12: (55) if r2 != 0xb9fbeef goto pc+10        ; R2_w=195018479
  13: (bc) w2 = w1                      ; R1_w=scalar(id=6,umax=4294967295,var_off=(0x0; 0xffffffff)) R2_w=scalar(id=6,umax=4294967295,var_off=(0x0; 0xffffffff))
  ; if (test < __NR_TESTS)
  14: (a6) if w1 < 0x9 goto pc+1        ; R1_w=scalar(id=6,umin=9,umax=4294967295,var_off=(0x0; 0xffffffff))
  ...
  from 14 to 16: R0=2 R1_w=scalar(id=6,umax=8,var_off=(0x0; 0xf)) R2_w=scalar(id=6,umax=8,var_off=(0x0; 0xf)) R6=ctx(off=0,imm=0) R10=fp0
  16: (27) r2 *= 28                     ; R2_w=scalar(umax=224,var_off=(0x0; 0xfc))
  17: (18) r3 = 0xffffc9000048e118      ; R3_w=map_value(off=280,ks=4,vs=564,imm=0)
  19: (0f) r3 += r2
  20: (61) r2 = *(u32 *)(r3 +0)         ; R2_w=scalar(umax=4294967295,var_off=(0x0; 0xffffffff)) R3_w=map_value(off=280,ks=4,vs=564,umax=224,var_off=(0x0; 0xfc),s32_max=252,u32_max=252)
  ...

and eventually the bpf program can be verified successfully.

  [1] https://reviews.llvm.org/D147968

Signed-off-by: Yonghong Song <yhs@fb.com>
Link: https://lore.kernel.org/r/20230417222134.359714-1-yhs@fb.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2023-04-17 15:50:02 -07:00
Sean Young
69a8c792cd bpf: lirc program type should not require SYS_CAP_ADMIN
Make it possible to load lirc program type with just CAP_BPF. There is
nothing exceptional about lirc programs that means they require
SYS_CAP_ADMIN.

In order to attach or detach a lirc program type you need permission to
open /dev/lirc0; if you have permission to do that, you can alter all
sorts of lirc receiving options. Changing the IR protocol decoder is no
different.

Right now on a typical distribution /dev/lirc devices are only
read/write by root. Ideally we would make them group read/write like
other devices so that local users can use them without becoming root.

Signed-off-by: Sean Young <sean@mess.org>
Link: https://lore.kernel.org/r/ZD0ArKpwnDBJZsrE@gofer.mess.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2023-04-17 13:21:14 -07:00
Michael Kelley
0459ff4873 swiotlb: Remove bounce buffer remapping for Hyper-V
With changes to how Hyper-V guest VMs flip memory between private
(encrypted) and shared (decrypted), creating a second kernel virtual
mapping for shared memory is no longer necessary. Everything needed
for the transition to shared is handled by set_memory_decrypted().

As such, remove swiotlb_unencrypted_base and the associated
code.

Signed-off-by: Michael Kelley <mikelley@microsoft.com>
Acked-by: Christoph Hellwig <hch@lst.de>
Acked-by: Borislav Petkov (AMD) <bp@alien8.de>
Link: https://lore.kernel.org/r/1679838727-87310-8-git-send-email-mikelley@microsoft.com
Signed-off-by: Wei Liu <wei.liu@kernel.org>
2023-04-17 19:19:04 +00:00
Andrew Morton
e492cd61b9 sync mm-stable with mm-hotfixes-stable to pick up depended-upon upstream changes 2023-04-16 12:31:58 -07:00
Linus Torvalds
6c538e1adb - Do not pull tasks to the local scheduling group if its average load is
higher than the average system load
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Merge tag 'sched_urgent_for_v6.3_rc7' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull scheduler fix from Borislav Petkov:

 - Do not pull tasks to the local scheduling group if its average load
   is higher than the average system load

* tag 'sched_urgent_for_v6.3_rc7' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  sched/fair: Fix imbalance overflow
2023-04-16 10:33:43 -07:00
David Vernet
7b4ddf3920 bpf: Remove KF_KPTR_GET kfunc flag
We've managed to improve the UX for kptrs significantly over the last 9
months. All of the existing use cases which previously had KF_KPTR_GET
kfuncs (struct bpf_cpumask *, struct task_struct *, and struct cgroup *)
have all been updated to be synchronized using RCU. In other words,
their KF_KPTR_GET kfuncs have been removed in favor of KF_RCU |
KF_ACQUIRE kfuncs, with the pointers themselves also being readable from
maps in an RCU read region thanks to the types being RCU safe.

While KF_KPTR_GET was a logical starting point for kptrs, it's become
clear that they're not the correct abstraction. KF_KPTR_GET is a flag
that essentially does nothing other than enforcing that the argument to
a function is a pointer to a referenced kptr map value. At first glance,
that's a useful thing to guarantee to a kfunc. It gives kfuncs the
ability to try and acquire a reference on that kptr without requiring
the BPF prog to do something like this:

struct kptr_type *in_map, *new = NULL;

in_map = bpf_kptr_xchg(&map->value, NULL);
if (in_map) {
        new = bpf_kptr_type_acquire(in_map);
        in_map = bpf_kptr_xchg(&map->value, in_map);
        if (in_map)
                bpf_kptr_type_release(in_map);
}

That's clearly a pretty ugly (and racy) UX, and if using KF_KPTR_GET is
the only alternative, it's better than nothing. However, the problem
with any KF_KPTR_GET kfunc lies in the fact that it always requires some
kind of synchronization in order to safely do an opportunistic acquire
of the kptr in the map. This is because a BPF program running on another
CPU could do a bpf_kptr_xchg() on that map value, and free the kptr
after it's been read by the KF_KPTR_GET kfunc. For example, the
now-removed bpf_task_kptr_get() kfunc did the following:

struct task_struct *bpf_task_kptr_get(struct task_struct **pp)
{
            struct task_struct *p;

        rcu_read_lock();
        p = READ_ONCE(*pp);
        /* If p is non-NULL, it could still be freed by another CPU,
         * so we have to do an opportunistic refcount_inc_not_zero()
         * and return NULL if the task will be freed after the
         * current RCU read region.
         */
        |f (p && !refcount_inc_not_zero(&p->rcu_users))
                p = NULL;
        rcu_read_unlock();

        return p;
}

In other words, the kfunc uses RCU to ensure that the task remains valid
after it's been peeked from the map. However, this is completely
redundant with just defining a KF_RCU kfunc that itself does a
refcount_inc_not_zero(), which is exactly what bpf_task_acquire() now
does.

So, the question of whether KF_KPTR_GET is useful is actually, "Are
there any synchronization mechanisms / safety flags that are required by
certain kptrs, but which are not provided by the verifier to kfuncs?"
The answer to that question today is "No", because every kptr we
currently care about is RCU protected.

Even if the answer ever became "yes", the proper way to support that
referenced kptr type would be to add support for whatever
synchronization mechanism it requires in the verifier, rather than
giving kfuncs a flag that says, "Here's a pointer to a referenced kptr
in a map, do whatever you need to do."

With all that said -- so as to allow us to consolidate the kfunc API,
and simplify the verifier a bit, this patch removes KF_KPTR_GET, and all
relevant logic from the verifier.

Signed-off-by: David Vernet <void@manifault.com>
Link: https://lore.kernel.org/r/20230416084928.326135-3-void@manifault.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2023-04-16 08:51:24 -07:00
Gregory Price
3f67987cdc ptrace: Provide set/get interface for syscall user dispatch
The syscall user dispatch configuration can only be set by the task itself,
but lacks a ptrace set/get interface which makes it impossible to implement
checkpoint/restore for it.

Add the required ptrace requests and the get/set functions in the syscall
user dispatch code to make that possible.

Signed-off-by: Gregory Price <gregory.price@memverge.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Oleg Nesterov <oleg@redhat.com>
Link: https://lore.kernel.org/r/20230407171834.3558-4-gregory.price@memverge.com
2023-04-16 14:23:07 +02:00
Gregory Price
463b7715e7 syscall_user_dispatch: Untag selector address before access_ok()
To support checkpoint/restart, ptrace must be able to set the selector
of the tracee.  The selector is a user pointer that may be subject to
memory tagging extensions on some architectures (namely ARM MTE).

access_ok() clears memory tags for tagged addresses if the current task has
memory tagging enabled.

This obviously fails when ptrace modifies the selector of a tracee when
tracer and tracee do not have the same memory tagging enabled state.

Solve this by untagging the selector address before handing it to
access_ok(), like other ptrace functions which modify tracee pointers do.

Obviously a tracer can set an invalid selector address for the tracee, but
that's independent of tagging and a general capability of the tracer.

Suggested-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Gregory Price <gregory.price@memverge.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Acked-by: Oleg Nesterov <oleg@redhat.com>
Link: https://lore.kernel.org/all/ZCWXE04nLZ4pXEtM@arm.com/
Link: https://lore.kernel.org/r/20230407171834.3558-3-gregory.price@memverge.com
2023-04-16 14:23:07 +02:00
Gregory Price
4336068632 syscall_user_dispatch: Split up set_syscall_user_dispatch()
syscall user dispatch configuration is not covered by checkpoint/restore.

To prepare for ptrace access to the syscall user dispatch configuration,
move the inner working of set_syscall_user_dispatch() into a helper
function. Make the helper function task pointer based and let
set_syscall_user_dispatch() invoke it with task=current.

No functional change.

Signed-off-by: Gregory Price <gregory.price@memverge.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Oleg Nesterov <oleg@redhat.com>
Link: https://lore.kernel.org/r/20230407171834.3558-2-gregory.price@memverge.com
2023-04-16 14:23:07 +02:00
Dmitry Vyukov
bcb7ee7902 posix-timers: Prefer delivery of signals to the current thread
POSIX timers using the CLOCK_PROCESS_CPUTIME_ID clock prefer the main
thread of a thread group for signal delivery. However, this has a
significant downside: it requires waking up a potentially idle thread.

Instead, prefer to deliver signals to the current thread (in the same
thread group) if SIGEV_THREAD_ID is not set by the user. This does not
change guaranteed semantics, since POSIX process CPU time timers have
never guaranteed that signal delivery is to a specific thread (without
SIGEV_THREAD_ID set).

The effect is that queueing the signal no longer wakes up potentially idle
threads, and the kernel is no longer biased towards delivering the timer
signal to any particular thread (which better distributes the timer signals
esp. when multiple timers fire concurrently).

Suggested-by: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Dmitry Vyukov <dvyukov@google.com>
Signed-off-by: Marco Elver <elver@google.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Oleg Nesterov <oleg@redhat.com>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lore.kernel.org/r/20230316123028.2890338-1-elver@google.com
2023-04-16 09:00:18 +02:00
Michael Kelley
8b0977ecc8 swiotlb: track and report io_tlb_used high water marks in debugfs
swiotlb currently reports the total number of slabs and the instantaneous
in-use slabs in debugfs. But with increased usage of swiotlb for all I/O
in Confidential Computing (coco) VMs, it has become difficult to know
how much memory to allocate for swiotlb bounce buffers, either via the
automatic algorithm in the kernel or by specifying a value on the
kernel boot line. The current automatic algorithm generously allocates
swiotlb bounce buffer memory, and may be wasting significant memory in
many use cases.

To support better understanding of swiotlb usage, add tracking of the
the high water mark for usage of the default swiotlb bounce buffer memory
pool and any reserved memory pools. Report these high water marks in
debugfs along with the other swiotlb pool metrics.  Allow the high water
marks to be reset to zero at runtime by writing to them.

Signed-off-by: Michael Kelley <mikelley@microsoft.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
2023-04-16 08:25:29 +02:00
Michael Kelley
5499d01c02 swiotlb: fix debugfs reporting of reserved memory pools
For io_tlb_nslabs, the debugfs code reports the correct value for a
specific reserved memory pool.  But for io_tlb_used, the value reported
is always for the default pool, not the specific reserved pool. Fix this.

Fixes: 5c850d3188 ("swiotlb: fix passing local variable to debugfs_create_ulong()")
Signed-off-by: Michael Kelley <mikelley@microsoft.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
2023-04-16 08:23:14 +02:00
Doug Berger
a90922fa25 swiotlb: relocate PageHighMem test away from rmem_swiotlb_setup
The reservedmem_of_init_fn's are invoked very early at boot before the
memory zones have even been defined. This makes it inappropriate to test
whether the page corresponding to a PFN is in ZONE_HIGHMEM from within
one.

Removing the check allows an ARM 32-bit kernel with SPARSEMEM enabled to
boot properly since otherwise we would be de-referencing an
uninitialized sparsemem map to perform pfn_to_page() check.

The arm64 architecture happens to work (and also has no high memory) but
other 32-bit architectures could also be having similar issues.

While it would be nice to provide early feedback about a reserved DMA
pool residing in highmem, it is not possible to do that until the first
time we try to use it, which is where the check is moved to.

Fixes: 0b84e4f8b7 ("swiotlb: Add restricted DMA pool initialization")
Signed-off-by: Doug Berger <opendmb@gmail.com>
Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
2023-04-16 08:23:10 +02:00
Dave Marchevsky
3e81740a90 bpf: Centralize btf_field-specific initialization logic
All btf_fields in an object are 0-initialized by memset in
bpf_obj_init. This might not be a valid initial state for some field
types, in which case kfuncs that use the type will properly initialize
their input if it's been 0-initialized. Some BPF graph collection types
and kfuncs do this: bpf_list_{head,node} and bpf_rb_node.

An earlier patch in this series added the bpf_refcount field, for which
the 0 state indicates that the refcounted object should be free'd.
bpf_obj_init treats this field specially, setting refcount to 1 instead
of relying on scattered "refcount is 0? Must have just been initialized,
let's set to 1" logic in kfuncs.

This patch extends this treatment to list and rbtree field types,
allowing most scattered initialization logic in kfuncs to be removed.

Note that bpf_{list_head,rb_root} may be inside a BPF map, in which case
they'll be 0-initialized without passing through the newly-added logic,
so scattered initialization logic must remain for these collection root
types.

Signed-off-by: Dave Marchevsky <davemarchevsky@fb.com>
Link: https://lore.kernel.org/r/20230415201811.343116-9-davemarchevsky@fb.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2023-04-15 17:36:50 -07:00
Dave Marchevsky
404ad75a36 bpf: Migrate bpf_rbtree_remove to possibly fail
This patch modifies bpf_rbtree_remove to account for possible failure
due to the input rb_node already not being in any collection.
The function can now return NULL, and does when the aforementioned
scenario occurs. As before, on successful removal an owning reference to
the removed node is returned.

Adding KF_RET_NULL to bpf_rbtree_remove's kfunc flags - now KF_RET_NULL |
KF_ACQUIRE - provides the desired verifier semantics:

  * retval must be checked for NULL before use
  * if NULL, retval's ref_obj_id is released
  * retval is a "maybe acquired" owning ref, not a non-owning ref,
    so it will live past end of critical section (bpf_spin_unlock), and
    thus can be checked for NULL after the end of the CS

BPF programs must add checks
============================

This does change bpf_rbtree_remove's verifier behavior. BPF program
writers will need to add NULL checks to their programs, but the
resulting UX looks natural:

  bpf_spin_lock(&glock);

  n = bpf_rbtree_first(&ghead);
  if (!n) { /* ... */}
  res = bpf_rbtree_remove(&ghead, &n->node);

  bpf_spin_unlock(&glock);

  if (!res)  /* Newly-added check after this patch */
    return 1;

  n = container_of(res, /* ... */);
  /* Do something else with n */
  bpf_obj_drop(n);
  return 0;

The "if (!res)" check above is the only addition necessary for the above
program to pass verification after this patch.

bpf_rbtree_remove no longer clobbers non-owning refs
====================================================

An issue arises when bpf_rbtree_remove fails, though. Consider this
example:

  struct node_data {
    long key;
    struct bpf_list_node l;
    struct bpf_rb_node r;
    struct bpf_refcount ref;
  };

  long failed_sum;

  void bpf_prog()
  {
    struct node_data *n = bpf_obj_new(/* ... */);
    struct bpf_rb_node *res;
    n->key = 10;

    bpf_spin_lock(&glock);

    bpf_list_push_back(&some_list, &n->l); /* n is now a non-owning ref */
    res = bpf_rbtree_remove(&some_tree, &n->r, /* ... */);
    if (!res)
      failed_sum += n->key;  /* not possible */

    bpf_spin_unlock(&glock);
    /* if (res) { do something useful and drop } ... */
  }

The bpf_rbtree_remove in this example will always fail. Similarly to
bpf_spin_unlock, bpf_rbtree_remove is a non-owning reference
invalidation point. The verifier clobbers all non-owning refs after a
bpf_rbtree_remove call, so the "failed_sum += n->key" line will fail
verification, and in fact there's no good way to get information about
the node which failed to add after the invalidation. This patch removes
non-owning reference invalidation from bpf_rbtree_remove to allow the
above usecase to pass verification. The logic for why this is now
possible is as follows:

Before this series, bpf_rbtree_add couldn't fail and thus assumed that
its input, a non-owning reference, was in the tree. But it's easy to
construct an example where two non-owning references pointing to the same
underlying memory are acquired and passed to rbtree_remove one after
another (see rbtree_api_release_aliasing in
selftests/bpf/progs/rbtree_fail.c).

So it was necessary to clobber non-owning refs to prevent this
case and, more generally, to enforce "non-owning ref is definitely
in some collection" invariant. This series removes that invariant and
the failure / runtime checking added in this patch provide a clean way
to deal with the aliasing issue - just fail to remove.

Because the aliasing issue prevented by clobbering non-owning refs is no
longer an issue, this patch removes the invalidate_non_owning_refs
call from verifier handling of bpf_rbtree_remove. Note that
bpf_spin_unlock - the other caller of invalidate_non_owning_refs -
clobbers non-owning refs for a different reason, so its clobbering
behavior remains unchanged.

No BPF program changes are necessary for programs to remain valid as a
result of this clobbering change. A valid program before this patch
passed verification with its non-owning refs having shorter (or equal)
lifetimes due to more aggressive clobbering.

Also, update existing tests to check bpf_rbtree_remove retval for NULL
where necessary, and move rbtree_api_release_aliasing from
progs/rbtree_fail.c to progs/rbtree.c since it's now expected to pass
verification.

Signed-off-by: Dave Marchevsky <davemarchevsky@fb.com>
Link: https://lore.kernel.org/r/20230415201811.343116-8-davemarchevsky@fb.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2023-04-15 17:36:50 -07:00
Dave Marchevsky
d2dcc67df9 bpf: Migrate bpf_rbtree_add and bpf_list_push_{front,back} to possibly fail
Consider this code snippet:

  struct node {
    long key;
    bpf_list_node l;
    bpf_rb_node r;
    bpf_refcount ref;
  }

  int some_bpf_prog(void *ctx)
  {
    struct node *n = bpf_obj_new(/*...*/), *m;

    bpf_spin_lock(&glock);

    bpf_rbtree_add(&some_tree, &n->r, /* ... */);
    m = bpf_refcount_acquire(n);
    bpf_rbtree_add(&other_tree, &m->r, /* ... */);

    bpf_spin_unlock(&glock);

    /* ... */
  }

After bpf_refcount_acquire, n and m point to the same underlying memory,
and that node's bpf_rb_node field is being used by the some_tree insert,
so overwriting it as a result of the second insert is an error. In order
to properly support refcounted nodes, the rbtree and list insert
functions must be allowed to fail. This patch adds such support.

The kfuncs bpf_rbtree_add, bpf_list_push_{front,back} are modified to
return an int indicating success/failure, with 0 -> success, nonzero ->
failure.

bpf_obj_drop on failure
=======================

Currently the only reason an insert can fail is the example above: the
bpf_{list,rb}_node is already in use. When such a failure occurs, the
insert kfuncs will bpf_obj_drop the input node. This allows the insert
operations to logically fail without changing their verifier owning ref
behavior, namely the unconditional release_reference of the input
owning ref.

With insert that always succeeds, ownership of the node is always passed
to the collection, since the node always ends up in the collection.

With a possibly-failed insert w/ bpf_obj_drop, ownership of the node
is always passed either to the collection (success), or to bpf_obj_drop
(failure). Regardless, it's correct to continue unconditionally
releasing the input owning ref, as something is always taking ownership
from the calling program on insert.

Keeping owning ref behavior unchanged results in a nice default UX for
insert functions that can fail. If the program's reaction to a failed
insert is "fine, just get rid of this owning ref for me and let me go
on with my business", then there's no reason to check for failure since
that's default behavior. e.g.:

  long important_failures = 0;

  int some_bpf_prog(void *ctx)
  {
    struct node *n, *m, *o; /* all bpf_obj_new'd */

    bpf_spin_lock(&glock);
    bpf_rbtree_add(&some_tree, &n->node, /* ... */);
    bpf_rbtree_add(&some_tree, &m->node, /* ... */);
    if (bpf_rbtree_add(&some_tree, &o->node, /* ... */)) {
      important_failures++;
    }
    bpf_spin_unlock(&glock);
  }

If we instead chose to pass ownership back to the program on failed
insert - by returning NULL on success or an owning ref on failure -
programs would always have to do something with the returned ref on
failure. The most likely action is probably "I'll just get rid of this
owning ref and go about my business", which ideally would look like:

  if (n = bpf_rbtree_add(&some_tree, &n->node, /* ... */))
    bpf_obj_drop(n);

But bpf_obj_drop isn't allowed in a critical section and inserts must
occur within one, so in reality error handling would become a
hard-to-parse mess.

For refcounted nodes, we can replicate the "pass ownership back to
program on failure" logic with this patch's semantics, albeit in an ugly
way:

  struct node *n = bpf_obj_new(/* ... */), *m;

  bpf_spin_lock(&glock);

  m = bpf_refcount_acquire(n);
  if (bpf_rbtree_add(&some_tree, &n->node, /* ... */)) {
    /* Do something with m */
  }

  bpf_spin_unlock(&glock);
  bpf_obj_drop(m);

bpf_refcount_acquire is used to simulate "return owning ref on failure".
This should be an uncommon occurrence, though.

Addition of two verifier-fixup'd args to collection inserts
===========================================================

The actual bpf_obj_drop kfunc is
bpf_obj_drop_impl(void *, struct btf_struct_meta *), with bpf_obj_drop
macro populating the second arg with 0 and the verifier later filling in
the arg during insn fixup.

Because bpf_rbtree_add and bpf_list_push_{front,back} now might do
bpf_obj_drop, these kfuncs need a btf_struct_meta parameter that can be
passed to bpf_obj_drop_impl.

Similarly, because the 'node' param to those insert functions is the
bpf_{list,rb}_node within the node type, and bpf_obj_drop expects a
pointer to the beginning of the node, the insert functions need to be
able to find the beginning of the node struct. A second
verifier-populated param is necessary: the offset of {list,rb}_node within the
node type.

These two new params allow the insert kfuncs to correctly call
__bpf_obj_drop_impl:

  beginning_of_node = bpf_rb_node_ptr - offset
  if (already_inserted)
    __bpf_obj_drop_impl(beginning_of_node, btf_struct_meta->record);

Similarly to other kfuncs with "hidden" verifier-populated params, the
insert functions are renamed with _impl prefix and a macro is provided
for common usage. For example, bpf_rbtree_add kfunc is now
bpf_rbtree_add_impl and bpf_rbtree_add is now a macro which sets
"hidden" args to 0.

Due to the two new args BPF progs will need to be recompiled to work
with the new _impl kfuncs.

This patch also rewrites the "hidden argument" explanation to more
directly say why the BPF program writer doesn't need to populate the
arguments with anything meaningful.

How does this new logic affect non-owning references?
=====================================================

Currently, non-owning refs are valid until the end of the critical
section in which they're created. We can make this guarantee because, if
a non-owning ref exists, the referent was added to some collection. The
collection will drop() its nodes when it goes away, but it can't go away
while our program is accessing it, so that's not a problem. If the
referent is removed from the collection in the same CS that it was added
in, it can't be bpf_obj_drop'd until after CS end. Those are the only
two ways to free the referent's memory and neither can happen until
after the non-owning ref's lifetime ends.

On first glance, having these collection insert functions potentially
bpf_obj_drop their input seems like it breaks the "can't be
bpf_obj_drop'd until after CS end" line of reasoning. But we care about
the memory not being _freed_ until end of CS end, and a previous patch
in the series modified bpf_obj_drop such that it doesn't free refcounted
nodes until refcount == 0. So the statement can be more accurately
rewritten as "can't be free'd until after CS end".

We can prove that this rewritten statement holds for any non-owning
reference produced by collection insert functions:

* If the input to the insert function is _not_ refcounted
  * We have an owning reference to the input, and can conclude it isn't
    in any collection
    * Inserting a node in a collection turns owning refs into
      non-owning, and since our input type isn't refcounted, there's no
      way to obtain additional owning refs to the same underlying
      memory
  * Because our node isn't in any collection, the insert operation
    cannot fail, so bpf_obj_drop will not execute
  * If bpf_obj_drop is guaranteed not to execute, there's no risk of
    memory being free'd

* Otherwise, the input to the insert function is refcounted
  * If the insert operation fails due to the node's list_head or rb_root
    already being in some collection, there was some previous successful
    insert which passed refcount to the collection
  * We have an owning reference to the input, it must have been
    acquired via bpf_refcount_acquire, which bumped the refcount
  * refcount must be >= 2 since there's a valid owning reference and the
    node is already in a collection
  * Insert triggering bpf_obj_drop will decr refcount to >= 1, never
    resulting in a free

So although we may do bpf_obj_drop during the critical section, this
will never result in memory being free'd, and no changes to non-owning
ref logic are needed in this patch.

Signed-off-by: Dave Marchevsky <davemarchevsky@fb.com>
Link: https://lore.kernel.org/r/20230415201811.343116-6-davemarchevsky@fb.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2023-04-15 17:36:50 -07:00
Dave Marchevsky
7c50b1cb76 bpf: Add bpf_refcount_acquire kfunc
Currently, BPF programs can interact with the lifetime of refcounted
local kptrs in the following ways:

  bpf_obj_new  - Initialize refcount to 1 as part of new object creation
  bpf_obj_drop - Decrement refcount and free object if it's 0
  collection add - Pass ownership to the collection. No change to
                   refcount but collection is responsible for
		   bpf_obj_dropping it

In order to be able to add a refcounted local kptr to multiple
collections we need to be able to increment the refcount and acquire a
new owning reference. This patch adds a kfunc, bpf_refcount_acquire,
implementing such an operation.

bpf_refcount_acquire takes a refcounted local kptr and returns a new
owning reference to the same underlying memory as the input. The input
can be either owning or non-owning. To reinforce why this is safe,
consider the following code snippets:

  struct node *n = bpf_obj_new(typeof(*n)); // A
  struct node *m = bpf_refcount_acquire(n); // B

In the above snippet, n will be alive with refcount=1 after (A), and
since nothing changes that state before (B), it's obviously safe. If
n is instead added to some rbtree, we can still safely refcount_acquire
it:

  struct node *n = bpf_obj_new(typeof(*n));
  struct node *m;

  bpf_spin_lock(&glock);
  bpf_rbtree_add(&groot, &n->node, less);   // A
  m = bpf_refcount_acquire(n);              // B
  bpf_spin_unlock(&glock);

In the above snippet, after (A) n is a non-owning reference, and after
(B) m is an owning reference pointing to the same memory as n. Although
n has no ownership of that memory's lifetime, it's guaranteed to be
alive until the end of the critical section, and n would be clobbered if
we were past the end of the critical section, so it's safe to bump
refcount.

Implementation details:

* From verifier's perspective, bpf_refcount_acquire handling is similar
  to bpf_obj_new and bpf_obj_drop. Like the former, it returns a new
  owning reference matching input type, although like the latter, type
  can be inferred from concrete kptr input. Verifier changes in
  {check,fixup}_kfunc_call and check_kfunc_args are largely copied from
  aforementioned functions' verifier changes.

* An exception to the above is the new KF_ARG_PTR_TO_REFCOUNTED_KPTR
  arg, indicated by new "__refcounted_kptr" kfunc arg suffix. This is
  necessary in order to handle both owning and non-owning input without
  adding special-casing to "__alloc" arg handling. Also a convenient
  place to confirm that input type has bpf_refcount field.

* The implemented kfunc is actually bpf_refcount_acquire_impl, with
  'hidden' second arg that the verifier sets to the type's struct_meta
  in fixup_kfunc_call.

Signed-off-by: Dave Marchevsky <davemarchevsky@fb.com>
Link: https://lore.kernel.org/r/20230415201811.343116-5-davemarchevsky@fb.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2023-04-15 17:36:50 -07:00
Dave Marchevsky
1512217c47 bpf: Support refcounted local kptrs in existing semantics
A local kptr is considered 'refcounted' when it is of a type that has a
bpf_refcount field. When such a kptr is created, its refcount should be
initialized to 1; when destroyed, the object should be free'd only if a
refcount decr results in 0 refcount.

Existing logic always frees the underlying memory when destroying a
local kptr, and 0-initializes all btf_record fields. This patch adds
checks for "is local kptr refcounted?" and new logic for that case in
the appropriate places.

This patch focuses on changing existing semantics and thus conspicuously
does _not_ provide a way for BPF programs in increment refcount. That
follows later in the series.

__bpf_obj_drop_impl is modified to do the right thing when it sees a
refcounted type. Container types for graph nodes (list, tree, stashed in
map) are migrated to use __bpf_obj_drop_impl as a destructor for their
nodes instead of each having custom destruction code in their _free
paths. Now that "drop" isn't a synonym for "free" when the type is
refcounted it makes sense to centralize this logic.

Signed-off-by: Dave Marchevsky <davemarchevsky@fb.com>
Link: https://lore.kernel.org/r/20230415201811.343116-4-davemarchevsky@fb.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2023-04-15 17:36:49 -07:00
Dave Marchevsky
d54730b50b bpf: Introduce opaque bpf_refcount struct and add btf_record plumbing
A 'struct bpf_refcount' is added to the set of opaque uapi/bpf.h types
meant for use in BPF programs. Similarly to other opaque types like
bpf_spin_lock and bpf_rbtree_node, the verifier needs to know where in
user-defined struct types a bpf_refcount can be located, so necessary
btf_record plumbing is added to enable this. bpf_refcount is sized to
hold a refcount_t.

Similarly to bpf_spin_lock, the offset of a bpf_refcount is cached in
btf_record as refcount_off in addition to being in the field array.
Caching refcount_off makes sense for this field because further patches
in the series will modify functions that take local kptrs (e.g.
bpf_obj_drop) to change their behavior if the type they're operating on
is refcounted. So enabling fast "is this type refcounted?" checks is
desirable.

No such verifier behavior changes are introduced in this patch, just
logic to recognize 'struct bpf_refcount' in btf_record.

Signed-off-by: Dave Marchevsky <davemarchevsky@fb.com>
Link: https://lore.kernel.org/r/20230415201811.343116-3-davemarchevsky@fb.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2023-04-15 17:36:49 -07:00