When building the files in the tracefs file system, do not by default set
any permissions for OTH (other). This will make it easier for admins who
want to define a group for accessing tracefs and not having to first
disable all the permission bits for "other" in the file system.
As tracing can leak sensitive information, it should never by default
allowing all users access. An admin can still set the permission bits for
others to have access, which may be useful for creating a honeypot and
seeing who takes advantage of it and roots the machine.
Link: https://lkml.kernel.org/r/20210818153038.864149276@goodmis.org
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
When the trace_pid_list was created, the default pid max was 32768.
Creating a bitmask that can hold one bit for all 32768 took up 4096 (one
page). Having a one page bitmask was not much of a problem, and that was
used for mapping pids. But today, systems are bigger and can run more
tasks, and now the default pid_max is usually set to 4194304. Which means
to handle that many pids requires 524288 bytes. Worse yet, the pid_max can
be set to 2^30 (1073741824 or 1G) which would take 134217728 (128M) of
memory to store this array.
Since the pid_list array is very sparsely populated, it is a huge waste of
memory to store all possible bits for each pid when most will not be set.
Instead, use a page table scheme to store the array, and allow this to
handle up to 30 bit pids.
The pid_mask will start out with 256 entries for the first 8 MSB bits.
This will cost 1K for 32 bit architectures and 2K for 64 bit. Each of
these will have a 256 array to store the next 8 bits of the pid (another
1 or 2K). These will hold an 2K byte bitmask (which will cover the LSB
14 bits or 16384 pids).
When the trace_pid_list is allocated, it will have the 1/2K upper bits
allocated, and then it will allocate a cache for the next upper chunks and
the lower chunks (default 6 of each). Then when a bit is "set", these
chunks will be pulled from the free list and added to the array. If the
free list gets down to a lever (default 2), it will trigger an irqwork
that will refill the cache back up.
On clearing a bit, if the clear causes the bitmask to be zero, that chunk
will then be placed back into the free cache for later use, keeping the
need to allocate more down to a minimum.
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Instead of having the logic that does trace_pid_list open coded, wrap it in
abstract functions. This will allow a rewrite of the logic that implements
the trace_pid_list without affecting the users.
Note, this causes a change in behavior. Every time a pid is written into
the set_*_pid file, it creates a new list and uses RCU to update it. If
pid_max is lowered, but there was a pid currently in the list that was
higher than pid_max, those pids will now be removed on updating the list.
The old behavior kept that from happening.
The rewrite of the pid_list logic will no longer depend on pid_max,
and will return the old behavior.
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Daniel Borkmann says:
====================
bpf-next 2021-10-02
We've added 85 non-merge commits during the last 15 day(s) which contain
a total of 132 files changed, 13779 insertions(+), 6724 deletions(-).
The main changes are:
1) Massive update on test_bpf.ko coverage for JITs as preparatory work for
an upcoming MIPS eBPF JIT, from Johan Almbladh.
2) Add a batched interface for RX buffer allocation in AF_XDP buffer pool,
with driver support for i40e and ice from Magnus Karlsson.
3) Add legacy uprobe support to libbpf to complement recently merged legacy
kprobe support, from Andrii Nakryiko.
4) Add bpf_trace_vprintk() as variadic printk helper, from Dave Marchevsky.
5) Support saving the register state in verifier when spilling <8byte bounded
scalar to the stack, from Martin Lau.
6) Add libbpf opt-in for stricter BPF program section name handling as part
of libbpf 1.0 effort, from Andrii Nakryiko.
7) Add a document to help clarifying BPF licensing, from Alexei Starovoitov.
8) Fix skel_internal.h to propagate errno if the loader indicates an internal
error, from Kumar Kartikeya Dwivedi.
9) Fix build warnings with -Wcast-function-type so that the option can later
be enabled by default for the kernel, from Kees Cook.
10) Fix libbpf to ignore STT_SECTION symbols in legacy map definitions as it
otherwise errors out when encountering them, from Toke Høiland-Jørgensen.
11) Teach libbpf to recognize specialized maps (such as for perf RB) and
internally remove BTF type IDs when creating them, from Hengqi Chen.
12) Various fixes and improvements to BPF selftests.
====================
Link: https://lore.kernel.org/r/20211002001327.15169-1-daniel@iogearbox.net
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
MAX_SNPRINTF_VARARGS and MAX_SEQ_PRINTF_VARARGS are used by bpf helpers
bpf_snprintf and bpf_seq_printf to limit their varargs. Both call into
bpf_bprintf_prepare for print formatting logic and have convenience
macros in libbpf (BPF_SNPRINTF, BPF_SEQ_PRINTF) which use the same
helper macros to convert varargs to a byte array.
Changing shared functionality to support more varargs for either bpf
helper would affect the other as well, so let's combine the _VARARGS
macros to make this more obvious.
Signed-off-by: Dave Marchevsky <davemarchevsky@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20210917182911.2426606-2-davemarchevsky@fb.com
Alexei Starovoitov says:
====================
pull-request: bpf-next 2021-09-17
We've added 63 non-merge commits during the last 12 day(s) which contain
a total of 65 files changed, 2653 insertions(+), 751 deletions(-).
The main changes are:
1) Streamline internal BPF program sections handling and
bpf_program__set_attach_target() in libbpf, from Andrii.
2) Add support for new btf kind BTF_KIND_TAG, from Yonghong.
3) Introduce bpf_get_branch_snapshot() to capture LBR, from Song.
4) IMUL optimization for x86-64 JIT, from Jie.
5) xsk selftest improvements, from Magnus.
6) Introduce legacy kprobe events support in libbpf, from Rafael.
7) Access hw timestamp through BPF's __sk_buff, from Vadim.
* https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next: (63 commits)
selftests/bpf: Fix a few compiler warnings
libbpf: Constify all high-level program attach APIs
libbpf: Schedule open_opts.attach_prog_fd deprecation since v0.7
selftests/bpf: Switch fexit_bpf2bpf selftest to set_attach_target() API
libbpf: Allow skipping attach_func_name in bpf_program__set_attach_target()
libbpf: Deprecated bpf_object_open_opts.relaxed_core_relocs
selftests/bpf: Stop using relaxed_core_relocs which has no effect
libbpf: Use pre-setup sec_def in libbpf_find_attach_btf_id()
bpf: Update bpf_get_smp_processor_id() documentation
libbpf: Add sphinx code documentation comments
selftests/bpf: Skip btf_tag test if btf_tag attribute not supported
docs/bpf: Add documentation for BTF_KIND_TAG
selftests/bpf: Add a test with a bpf program with btf_tag attributes
selftests/bpf: Test BTF_KIND_TAG for deduplication
selftests/bpf: Add BTF_KIND_TAG unit tests
selftests/bpf: Change NAME_NTH/IS_NAME_NTH for BTF_KIND_TAG format
selftests/bpf: Test libbpf API function btf__add_tag()
bpftool: Add support for BTF_KIND_TAG
libbpf: Add support for BTF_KIND_TAG
libbpf: Rename btf_{hash,equal}_int to btf_{hash,equal}_int_tag
...
====================
Link: https://lore.kernel.org/r/20210917173738.3397064-1-ast@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Introduce bpf_get_branch_snapshot(), which allows tracing pogram to get
branch trace from hardware (e.g. Intel LBR). To use the feature, the
user need to create perf_event with proper branch_record filtering
on each cpu, and then calls bpf_get_branch_snapshot in the bpf function.
On Intel CPUs, VLBR event (raw event 0x1b00) can be use for this.
Signed-off-by: Song Liu <songliubraving@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: John Fastabend <john.fastabend@gmail.com>
Acked-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20210910183352.3151445-3-songliubraving@fb.com
Pull tracing fixes from Steven Rostedt:
"Minor fixes to the processing of the bootconfig tree"
* tag 'trace-v5.15-3' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace:
bootconfig: Rename xbc_node_find_child() to xbc_node_find_subkey()
tracing/boot: Fix to check the histogram control param is a leaf node
tracing/boot: Fix trace_boot_hist_add_array() to check array is value
Rename xbc_node_find_child() to xbc_node_find_subkey() for
clarifying that function returns a key node (no value node).
Since there are xbc_node_for_each_child() (loop on all child
nodes) and xbc_node_for_each_subkey() (loop on only subkey
nodes), this name distinction is necessary to avoid confusing
users.
Link: https://lkml.kernel.org/r/163119459826.161018.11200274779483115300.stgit@devnote2
Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
trace_boot_hist_add_array() uses the combination of
xbc_node_find_child() and xbc_node_get_child() to get the
child node of the key node. But since it missed to check
the child node is data node or not, user can pass the
subkey node for the array node (anode).
To avoid this issue, check the array node is a data node.
Actually, there is xbc_node_find_value(node, key, vnode),
which ensures the @vnode is a value node, so use it in
trace_boot_hist_add_array() to fix this issue.
Link: https://lkml.kernel.org/r/163119458308.161018.1516455973625940212.stgit@devnote2
Fixes: e66ed86ca6 ("tracing/boot: Add per-event histogram action options")
Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Pull more tracing updates from Steven Rostedt:
- Add migrate-disable counter to tracing header
- Fix error handling in event probes
- Fix missed unlock in osnoise in error path
- Fix merge issue with tools/bootconfig
- Clean up bootconfig data when init memory is removed
- Fix bootconfig to loop only on subkeys
- Have kernel command lines override bootconfig options
- Increase field counts for synthetic events
- Have histograms dynamic allocate event elements to save space
- Fixes in testing and documentation
* tag 'trace-v5.15-2' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace:
tracing/boot: Fix to loop on only subkeys
selftests/ftrace: Exclude "(fault)" in testing add/remove eprobe events
tracing: Dynamically allocate the per-elt hist_elt_data array
tracing: synth events: increase max fields count
tools/bootconfig: Show whole test command for each test case
bootconfig: Fix missing return check of xbc_node_compose_key function
tools/bootconfig: Fix tracing_on option checking in ftrace2bconf.sh
docs: bootconfig: Add how to use bootconfig for kernel parameters
init/bootconfig: Reorder init parameter from bootconfig and cmdline
init: bootconfig: Remove all bootconfig data when the init memory is removed
tracing/osnoise: Fix missed cpus_read_unlock() in start_per_cpu_kthreads()
tracing: Fix some alloc_event_probe() error handling bugs
tracing: Add migrate-disabled counter to tracing output.
Since the commit e5efaeb8a8 ("bootconfig: Support mixing
a value and subkeys under a key") allows to co-exist a value
node and key nodes under a node, xbc_node_for_each_child()
is not only returning key node but also a value node.
In the boot-time tracing using xbc_node_for_each_child() to
iterate the events, groups and instances, but those must be
key nodes. Thus it must use xbc_node_for_each_subkey().
Link: https://lkml.kernel.org/r/163112988361.74896.2267026262061819145.stgit@devnote2
Fixes: e5efaeb8a8 ("bootconfig: Support mixing a value and subkeys under a key")
Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Setting the hist_elt_data.field_var_str[] array unconditionally to a
size of SYNTH_FIELD_MAX elements wastes space unnecessarily. The
actual number of elements needed can be calculated at run-time
instead.
In most cases, this will save a lot of space since it's a per-elt
array which isn't normally close to being full. It also allows us to
increase SYNTH_FIELD_MAX without worrying about even more wastage when
we do that.
Link: https://lkml.kernel.org/r/d52ae0ad5e1b59af7c4f54faf3fc098461fd82b3.camel@kernel.org
Signed-off-by: Tom Zanussi <zanussi@kernel.org>
Tested-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
There are two bugs in this code. First, if the kzalloc() fails it leads
to a NULL dereference of "ep" on the next line. Second, if the
alloc_event_probe() function returns an error then it leads to an
error pointer dereference in the caller.
Link: https://lkml.kernel.org/r/20210824115150.GI31143@kili
Fixes: 7491e2c442 ("tracing: Add a probe that attaches to trace events")
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Pull kgdb updates from Daniel Thompson:
"Changes for kgdb/kdb this cycle are dominated by a change from Sumit
that removes as small (256K) private heap from kdb. This is change
I've hoped for ever since I discovered how few users of this heap
remained in the kernel, so many thanks to Sumit for hunting these
down.
The other change is an incremental step towards SPDX headers"
* tag 'kgdb-5.15-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/danielt/linux:
kernel: debug: Convert to SPDX identifier
kdb: Rename members of struct kdbtab_t
kdb: Simplify kdb_defcmd macro logic
kdb: Get rid of redundant kdb_register_flags()
kdb: Rename struct defcmd_set to struct kdb_macro
kdb: Get rid of custom debug heap allocator
Pull tracing updates from Steven Rostedt:
- simplify the Kconfig use of FTRACE and TRACE_IRQFLAGS_SUPPORT
- bootconfig can now start histograms
- bootconfig supports group/all enabling
- histograms now can put values in linear size buckets
- execnames can be passed to synthetic events
- introduce "event probes" that attach to other events and can retrieve
data from pointers of fields, or record fields as different types (a
pointer to a string as a string instead of just a hex number)
- various fixes and clean ups
* tag 'trace-v5.15' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace: (35 commits)
tracing/doc: Fix table format in histogram code
selftests/ftrace: Add selftest for testing duplicate eprobes and kprobes
selftests/ftrace: Add selftest for testing eprobe events on synthetic events
selftests/ftrace: Add test case to test adding and removing of event probe
selftests/ftrace: Fix requirement check of README file
selftests/ftrace: Add clear_dynamic_events() to test cases
tracing: Add a probe that attaches to trace events
tracing/probes: Reject events which have the same name of existing one
tracing/probes: Have process_fetch_insn() take a void * instead of pt_regs
tracing/probe: Change traceprobe_set_print_fmt() to take a type
tracing/probes: Use struct_size() instead of defining custom macros
tracing/probes: Allow for dot delimiter as well as slash for system names
tracing/probe: Have traceprobe_parse_probe_arg() take a const arg
tracing: Have dynamic events have a ref counter
tracing: Add DYNAMIC flag for dynamic events
tracing: Replace deprecated CPU-hotplug functions.
MAINTAINERS: Add an entry for os noise/latency
tracepoint: Fix kerneldoc comments
bootconfig/tracing/ktest: Update ktest example for boot-time tracing
tools/bootconfig: Use per-group/all enable option in ftrace2bconf script
...
migrate_disable() forbids task migration to another CPU. It is available
since v5.11 and has already users such as highmem or BPF. It is useful
to observe this task state in tracing which already has other states
like the preemption counter.
Instead of adding the migrate disable counter as a new entry to struct
trace_entry, which would extend the whole struct by four bytes, it is
squashed into the preempt-disable counter. The lower four bits represent
the preemption counter, the upper four bits represent the migrate
disable counter. Both counter shouldn't exceed 15 but if they do, there
is a safety net which caps the value at 15.
Add the migrate-disable counter to the trace entry so it shows up in the
trace. Due to the users mentioned above, it is already possible to
observe it:
| bash-1108 [000] ...21 73.950578: rss_stat: mm_id=2213312838 curr=0 type=MM_ANONPAGES size=8192B
| bash-1108 [000] d..31 73.951222: irq_disable: caller=flush_tlb_mm_range+0x115/0x130 parent=ptep_clear_flush+0x42/0x50
| bash-1108 [000] d..31 73.951222: tlb_flush: pages:1 reason:local mm shootdown (3)
The last value is the migrate-disable counter.
Things that popped up:
- trace_print_lat_context() does not print the migrate counter. Not sure
if it should. It is used in "verbose" mode and uses 8 digits and I'm
not sure ther is something processing the value.
- trace_define_common_fields() now defines a different variable. This
probably breaks things. No ide what to do in order to preserve the old
behaviour. Since this is used as a filter it should be split somehow
to be able to match both nibbles here.
Link: https://lkml.kernel.org/r/20210810132625.ylssabmsrkygokuv@linutronix.de
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
[bigeasy: patch description.]
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
[ SDR: Removed change to common_preempt_count field name ]
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Pull printk updates from Petr Mladek:
- Optionally, provide an index of possible printk messages via
<debugfs>/printk/index/. It can be used when monitoring important
kernel messages on a farm of various hosts. The monitor has to be
updated when some messages has changed or are not longer available by
a newly deployed kernel.
- Add printk.console_no_auto_verbose boot parameter. It allows to
generate crash dump even with slow consoles in a reasonable time
frame.
- Remove printk_safe buffers. The messages are always stored directly
to the main logbuffer, even in NMI or recursive context. Also it
allows to serialize syslog operations by a mutex instead of a spin
lock.
- Misc clean up and build fixes.
* tag 'printk-for-5.15' of git://git.kernel.org/pub/scm/linux/kernel/git/printk/linux:
printk/index: Fix -Wunused-function warning
lib/nmi_backtrace: Serialize even messages about idle CPUs
printk: Add printk.console_no_auto_verbose boot parameter
printk: Remove console_silent()
lib/test_scanf: Handle n_bits == 0 in random tests
printk: syslog: close window between wait and read
printk: convert @syslog_lock to mutex
printk: remove NMI tracking
printk: remove safe buffers
printk: track/limit recursion
lib/nmi_backtrace: explicitly serialize banner and regs
printk: Move the printk() kerneldoc comment to its new home
printk/index: Fix warning about missing prototypes
MIPS/asm/printk: Fix build failure caused by printk
printk: index: Add indexing support to dev_printk
printk: Userspace format indexing support
printk: Rework parse_prefix into printk_parse_prefix
printk: Straighten out log_flags into printk_info_flags
string_helpers: Escape double quotes in escape_special
printk/console: Check consistent sequence number when handling race in console_unlock()
Pull networking updates from Jakub Kicinski:
"Core:
- Enable memcg accounting for various networking objects.
BPF:
- Introduce bpf timers.
- Add perf link and opaque bpf_cookie which the program can read out
again, to be used in libbpf-based USDT library.
- Add bpf_task_pt_regs() helper to access user space pt_regs in
kprobes, to help user space stack unwinding.
- Add support for UNIX sockets for BPF sockmap.
- Extend BPF iterator support for UNIX domain sockets.
- Allow BPF TCP congestion control progs and bpf iterators to call
bpf_setsockopt(), e.g. to switch to another congestion control
algorithm.
Protocols:
- Support IOAM Pre-allocated Trace with IPv6.
- Support Management Component Transport Protocol.
- bridge: multicast: add vlan support.
- netfilter: add hooks for the SRv6 lightweight tunnel driver.
- tcp:
- enable mid-stream window clamping (by user space or BPF)
- allow data-less, empty-cookie SYN with TFO_SERVER_COOKIE_NOT_REQD
- more accurate DSACK processing for RACK-TLP
- mptcp:
- add full mesh path manager option
- add partial support for MP_FAIL
- improve use of backup subflows
- optimize option processing
- af_unix: add OOB notification support.
- ipv6: add IFLA_INET6_RA_MTU to expose MTU value advertised by the
router.
- mac80211: Target Wake Time support in AP mode.
- can: j1939: extend UAPI to notify about RX status.
Driver APIs:
- Add page frag support in page pool API.
- Many improvements to the DSA (distributed switch) APIs.
- ethtool: extend IRQ coalesce uAPI with timer reset modes.
- devlink: control which auxiliary devices are created.
- Support CAN PHYs via the generic PHY subsystem.
- Proper cross-chip support for tag_8021q.
- Allow TX forwarding for the software bridge data path to be
offloaded to capable devices.
Drivers:
- veth: more flexible channels number configuration.
- openvswitch: introduce per-cpu upcall dispatch.
- Add internet mix (IMIX) mode to pktgen.
- Transparently handle XDP operations in the bonding driver.
- Add LiteETH network driver.
- Renesas (ravb):
- support Gigabit Ethernet IP
- NXP Ethernet switch (sja1105):
- fast aging support
- support for "H" switch topologies
- traffic termination for ports under VLAN-aware bridge
- Intel 1G Ethernet
- support getcrosststamp() with PCIe PTM (Precision Time
Measurement) for better time sync
- support Credit-Based Shaper (CBS) offload, enabling HW traffic
prioritization and bandwidth reservation
- Broadcom Ethernet (bnxt)
- support pulse-per-second output
- support larger Rx rings
- Mellanox Ethernet (mlx5)
- support ethtool RSS contexts and MQPRIO channel mode
- support LAG offload with bridging
- support devlink rate limit API
- support packet sampling on tunnels
- Huawei Ethernet (hns3):
- basic devlink support
- add extended IRQ coalescing support
- report extended link state
- Netronome Ethernet (nfp):
- add conntrack offload support
- Broadcom WiFi (brcmfmac):
- add WPA3 Personal with FT to supported cipher suites
- support 43752 SDIO device
- Intel WiFi (iwlwifi):
- support scanning hidden 6GHz networks
- support for a new hardware family (Bz)
- Xen pv driver:
- harden netfront against malicious backends
- Qualcomm mobile
- ipa: refactor power management and enable automatic suspend
- mhi: move MBIM to WWAN subsystem interfaces
Refactor:
- Ambient BPF run context and cgroup storage cleanup.
- Compat rework for ndo_ioctl.
Old code removal:
- prism54 remove the obsoleted driver, deprecated by the p54 driver.
- wan: remove sbni/granch driver"
* tag 'net-next-5.15' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next: (1715 commits)
net: Add depends on OF_NET for LiteX's LiteETH
ipv6: seg6: remove duplicated include
net: hns3: remove unnecessary spaces
net: hns3: add some required spaces
net: hns3: clean up a type mismatch warning
net: hns3: refine function hns3_set_default_feature()
ipv6: remove duplicated 'net/lwtunnel.h' include
net: w5100: check return value after calling platform_get_resource()
net/mlxbf_gige: Make use of devm_platform_ioremap_resourcexxx()
net: mdio: mscc-miim: Make use of the helper function devm_platform_ioremap_resource()
net: mdio-ipq4019: Make use of devm_platform_ioremap_resource()
fou: remove sparse errors
ipv4: fix endianness issue in inet_rtm_getroute_build_skb()
octeontx2-af: Set proper errorcode for IPv4 checksum errors
octeontx2-af: Fix static code analyzer reported issues
octeontx2-af: Fix mailbox errors in nix_rss_flowkey_cfg
octeontx2-af: Fix loop in free and unmap counter
af_unix: fix potential NULL deref in unix_dgram_connect()
dpaa2-eth: Replace strlcpy with strscpy
octeontx2-af: Use NDC TX for transmit packet data
...
Daniel Borkmann says:
====================
bpf-next 2021-08-31
We've added 116 non-merge commits during the last 17 day(s) which contain
a total of 126 files changed, 6813 insertions(+), 4027 deletions(-).
The main changes are:
1) Add opaque bpf_cookie to perf link which the program can read out again,
to be used in libbpf-based USDT library, from Andrii Nakryiko.
2) Add bpf_task_pt_regs() helper to access userspace pt_regs, from Daniel Xu.
3) Add support for UNIX stream type sockets for BPF sockmap, from Jiang Wang.
4) Allow BPF TCP congestion control progs to call bpf_setsockopt() e.g. to switch
to another congestion control algorithm during init, from Martin KaFai Lau.
5) Extend BPF iterator support for UNIX domain sockets, from Kuniyuki Iwashima.
6) Allow bpf_{set,get}sockopt() calls from setsockopt progs, from Prankur Gupta.
7) Add bpf_get_netns_cookie() helper for BPF_PROG_TYPE_{SOCK_OPS,CGROUP_SOCKOPT}
progs, from Xu Liu and Stanislav Fomichev.
8) Support for __weak typed ksyms in libbpf, from Hao Luo.
9) Shrink struct cgroup_bpf by 504 bytes through refactoring, from Dave Marchevsky.
10) Fix a smatch complaint in verifier's narrow load handling, from Andrey Ignatov.
11) Fix BPF interpreter's tail call count limit, from Daniel Borkmann.
12) Big batch of improvements to BPF selftests, from Magnus Karlsson, Li Zhijian,
Yucong Sun, Yonghong Song, Ilya Leoshkevich, Jussi Maki, Ilya Leoshkevich, others.
13) Another big batch to revamp XDP samples in order to give them consistent look
and feel, from Kumar Kartikeya Dwivedi.
* https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next: (116 commits)
MAINTAINERS: Remove self from powerpc BPF JIT
selftests/bpf: Fix potential unreleased lock
samples: bpf: Fix uninitialized variable in xdp_redirect_cpu
selftests/bpf: Reduce more flakyness in sockmap_listen
bpf: Fix bpf-next builds without CONFIG_BPF_EVENTS
bpf: selftests: Add dctcp fallback test
bpf: selftests: Add connect_to_fd_opts to network_helpers
bpf: selftests: Add sk_state to bpf_tcp_helpers.h
bpf: tcp: Allow bpf-tcp-cc to call bpf_(get|set)sockopt
selftests: xsk: Preface options with opt
selftests: xsk: Make enums lower case
selftests: xsk: Generate packets from specification
selftests: xsk: Generate packet directly in umem
selftests: xsk: Simplify cleanup of ifobjects
selftests: xsk: Decrease sending speed
selftests: xsk: Validate tx stats on tx thread
selftests: xsk: Simplify packet validation in xsk tests
selftests: xsk: Rename worker_* functions that are not thread entry points
selftests: xsk: Disassociate umem size with packets sent
selftests: xsk: Remove end-of-test packet
...
====================
Link: https://lore.kernel.org/r/20210830225618.11634-1-daniel@iogearbox.net
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Pull s390 updates from Heiko Carstens:
- Improve ftrace code patching so that stop_machine is not required
anymore. This requires a small common code patch acked by Steven
Rostedt:
https://lore.kernel.org/linux-s390/20210730220741.4da6fdf6@oasis.local.home/
- Enable KCSAN for s390. This comes with a small common code change to
fix a compile warning. Acked by Marco Elver:
https://lore.kernel.org/r/20210729142811.1309391-1-hca@linux.ibm.com
- Add KFENCE support for s390. This also comes with a minimal x86 patch
from Marco Elver who said also this can be carried via the s390 tree:
https://lore.kernel.org/linux-s390/YQJdarx6XSUQ1tFZ@elver.google.com/
- More changes to prepare the decompressor for relocation.
- Enable DAT also for CPU restart path.
- Final set of register asm removal patches; leaving only three
locations where needed and sane.
- Add NNPA, Vector-Packed-Decimal-Enhancement Facility 2, PCI MIO
support to hwcaps flags.
- Cleanup hwcaps implementation.
- Add new instructions to in-kernel disassembler.
- Various QDIO cleanups.
- Add SCLP debug feature.
- Various other cleanups and improvements all over the place.
* tag 's390-5.15-1' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux: (105 commits)
s390: remove SCHED_CORE from defconfigs
s390/smp: do not use nodat_stack for secondary CPU start
s390/smp: enable DAT before CPU restart callback is called
s390: update defconfigs
s390/ap: fix state machine hang after failure to enable irq
KVM: s390: generate kvm hypercall functions
s390/sclp: add tracing of SCLP interactions
s390/debug: add early tracing support
s390/debug: fix debug area life cycle
s390/debug: keep debug data on resize
s390/diag: make restart_part2 a local label
s390/mm,pageattr: fix walk_pte_level() early exit
s390: fix typo in linker script
s390: remove do_signal() prototype and do_notify_resume() function
s390/crypto: fix all kernel-doc warnings in vfio_ap_ops.c
s390/pci: improve DMA translation init and exit
s390/pci: simplify CLP List PCI handling
s390/pci: handle FH state mismatch only on disable
s390/pci: fix misleading rc in clp_set_pci_fn()
s390/boot: factor out offset_vmlinux_info() function
...
The motivation behind this helper is to access userspace pt_regs in a
kprobe handler.
uprobe's ctx is the userspace pt_regs. kprobe's ctx is the kernelspace
pt_regs. bpf_task_pt_regs() allows accessing userspace pt_regs in a
kprobe handler. The final case (kernelspace pt_regs in uprobe) is
pretty rare (usermode helper) so I think that can be solved later if
necessary.
More concretely, this helper is useful in doing BPF-based DWARF stack
unwinding. Currently the kernel can only do framepointer based stack
unwinds for userspace code. This is because the DWARF state machines are
too fragile to be computed in kernelspace [0]. The idea behind
DWARF-based stack unwinds w/ BPF is to copy a chunk of the userspace
stack (while in prog context) and send it up to userspace for unwinding
(probably with libunwind) [1]. This would effectively enable profiling
applications with -fomit-frame-pointer using kprobes and uprobes.
[0]: https://lkml.org/lkml/2012/2/10/356
[1]: https://github.com/danobi/bpf-dwarf-walk
Signed-off-by: Daniel Xu <dxu@dxuuu.xyz>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/e2718ced2d51ef4268590ab8562962438ab82815.1629772842.git.dxu@dxuuu.xyz
A new dynamic event is introduced: event probe. The event is attached
to an existing tracepoint and uses its fields as arguments. The user
can specify custom format string of the new event, select what tracepoint
arguments will be printed and how to print them.
An event probe is created by writing configuration string in
'dynamic_events' ftrace file:
e[:[SNAME/]ENAME] SYSTEM/EVENT [FETCHARGS] - Set an event probe
-:SNAME/ENAME - Delete an event probe
Where:
SNAME - System name, if omitted 'eprobes' is used.
ENAME - Name of the new event in SNAME, if omitted the SYSTEM_EVENT is used.
SYSTEM - Name of the system, where the tracepoint is defined, mandatory.
EVENT - Name of the tracepoint event in SYSTEM, mandatory.
FETCHARGS - Arguments:
<name>=$<field>[:TYPE] - Fetch given filed of the tracepoint and print
it as given TYPE with given name. Supported
types are:
(u8/u16/u32/u64/s8/s16/s32/s64), basic type
(x8/x16/x32/x64), hexadecimal types
"string", "ustring" and bitfield.
Example, attach an event probe on openat system call and print name of the
file that will be opened:
echo "e:esys/eopen syscalls/sys_enter_openat file=\$filename:string" >> dynamic_events
A new dynamic event is created in events/esys/eopen/ directory. It
can be deleted with:
echo "-:esys/eopen" >> dynamic_events
Filters, triggers and histograms can be attached to the new event, it can
be matched in synthetic events. There is one limitation - an event probe
can not be attached to kprobe, uprobe or another event probe.
Link: https://lkml.kernel.org/r/20210812145805.2292326-1-tz.stoyanov@gmail.com
Link: https://lkml.kernel.org/r/20210819152825.142428383@goodmis.org
Acked-by: Masami Hiramatsu <mhiramat@kernel.org>
Co-developed-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Signed-off-by: Tzvetomir Stoyanov (VMware) <tz.stoyanov@gmail.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Since kprobe_events and uprobe_events only check whether the
other same-type probe event has the same name or not, if the
user gives the same name of the existing tracepoint event (or
the other type of probe events), it silently fails to create
the tracefs entry (but registered.) as below.
/sys/kernel/tracing # ls events/task/task_rename
enable filter format hist id trigger
/sys/kernel/tracing # echo p:task/task_rename vfs_read >> kprobe_events
[ 113.048508] Could not create tracefs 'task_rename' directory
/sys/kernel/tracing # cat kprobe_events
p:task/task_rename vfs_read
To fix this issue, check whether the existing events have the
same name or not in trace_probe_register_event_call(). If exists,
it rejects to register the new event.
Link: https://lkml.kernel.org/r/162936876189.187130.17558311387542061930.stgit@devnote2
Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
In preparation to allow event probes to use the process_fetch_insn()
callback in trace_probe_tmpl.h, change the data passed to it from a
pointer to pt_regs, as the event probe will not be using regs, and make it
a void pointer instead.
Update the process_fetch_insn() callers for kprobe and uprobe events to
have the regs defined in the function and just typecast the void pointer
parameter.
Link: https://lkml.kernel.org/r/20210819041842.291622924@goodmis.org
Acked-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Instead of a boolean "is_return" have traceprobe_set_print_fmt() take a
type (currently just PROBE_PRINT_NORMAL and PROBE_PRINT_RETURN). This will
simplify adding different types. For example, the development of the
event_probe, will need its own type as it prints an event, and not an IP.
Link: https://lkml.kernel.org/r/20210819041842.104626301@goodmis.org
Acked-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Kprobe and uprobe events can add a "system" to the events that are created
via the kprobe_events and uprobe_events files respectively. If they do not
include a "system" in the name, then the default "kprobes" or "uprobes" is
used. The current notation to specify a system for one of these probe
events is to add a '/' delimiter in the name, where the content before the
'/' will be the system to use, and the content after will be the event
name.
echo 'p:my_system/my_event' > kprobe_events
But this is inconsistent with the way histogram triggers separate their
system / event names. The histogram triggers use a '.' delimiter, which
can be confusing.
To allow this to be more consistent, as well as keep backward
compatibility, allow the kprobe and uprobe events to denote a system name
with either a '/' or a '.'.
That is:
echo 'p:my_system/my_event' > kprobe_events
is equivalent to:
echo 'p:my_system.my_event' > kprobe_events
Link: https://lore.kernel.org/linux-trace-devel/20210813004448.51c7de69ce432d338f4d226b@kernel.org/
Link: https://lkml.kernel.org/r/20210817035027.580493202@goodmis.org
Suggested-by: Masami Hiramatsu <mhiramat@kernel.org>
Acked-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
The two places that call traceprobe_parse_probe_arg() allocate a temporary
buffer to copy the argv[i] into, because argv[i] is constant and the
traceprobe_parse_probe_arg() will modify it to do the parsing. These two
places allocate this buffer and then free it right after calling this
function, leaving the onus of this allocation to the caller.
As there's about to be a third user of this function that will have to do
the same thing, instead of having the caller allocate the temporary
buffer, simply move that allocation into the traceprobe_parse_probe_arg()
itself, which will simplify the code of the callers.
Link: https://lkml.kernel.org/r/20210817035027.385422828@goodmis.org
Acked-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
