It simplifies the code a bit, because we dump the callchain
Link: http://lkml.kernel.org/n/tip-uqp7qd6aif47g39glnbu95yl@git.kernel.org
even if it's empty. With 'empty' callchain we can remove
all the NULL-checking code paths.
Original-patch-from: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Link: http://lkml.kernel.org/r/20180107160356.28203-7-jolsa@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
And move it to core.c, because there's no caller of this function other
than the one in core.c
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/20180107160356.28203-6-jolsa@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Currently we use perf_event_context::task_ctx_data to save and restore
the LBR status when the task is scheduled out and in.
We don't allocate it for child contexts, which results in shorter task's
LBR stack, because we don't save the history from previous run and start
over every time we schedule the task in.
I made a test to generate samples with LBR call stack and got higher
numbers on bigger chain depths:
before: after:
LBR call chain: nr: 1 60561 498127
LBR call chain: nr: 2 0 0
LBR call chain: nr: 3 107030 2172
LBR call chain: nr: 4 466685 62758
LBR call chain: nr: 5 2307319 878046
LBR call chain: nr: 6 48713 495218
LBR call chain: nr: 7 1040 4551
LBR call chain: nr: 8 481 172
LBR call chain: nr: 9 878 120
LBR call chain: nr: 10 2377 6698
LBR call chain: nr: 11 28830 151487
LBR call chain: nr: 12 29347 339867
LBR call chain: nr: 13 4 22
LBR call chain: nr: 14 3 53
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Fixes: 4af57ef28c ("perf: Add pmu specific data for perf task context")
Link: http://lkml.kernel.org/r/20180107160356.28203-4-jolsa@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Pull RCU updates from Paul E. McKenney:
- Updates to use cond_resched() instead of cond_resched_rcu_qs()
where feasible (currently everywhere except in kernel/rcu and
in kernel/torture.c). Also a couple of fixes to avoid sending
IPIs to offline CPUs.
- Updates to simplify RCU's dyntick-idle handling.
- Updates to remove almost all uses of smp_read_barrier_depends()
and read_barrier_depends().
- Miscellaneous fixes.
- Torture-test updates.
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Export perf_event_update_userpage() so that PMU driver using them,
can be built as modules.
Acked-by: Peter Zilstra <peterz@infradead.org>
Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Daniel Borkmann says:
====================
pull-request: bpf-next 2017-12-18
The following pull-request contains BPF updates for your *net-next* tree.
The main changes are:
1) Allow arbitrary function calls from one BPF function to another BPF function.
As of today when writing BPF programs, __always_inline had to be used in
the BPF C programs for all functions, unnecessarily causing LLVM to inflate
code size. Handle this more naturally with support for BPF to BPF calls
such that this __always_inline restriction can be overcome. As a result,
it allows for better optimized code and finally enables to introduce core
BPF libraries in the future that can be reused out of different projects.
x86 and arm64 JIT support was added as well, from Alexei.
2) Add infrastructure for tagging functions as error injectable and allow for
BPF to return arbitrary error values when BPF is attached via kprobes on
those. This way of injecting errors generically eases testing and debugging
without having to recompile or restart the kernel. Tags for opting-in for
this facility are added with BPF_ALLOW_ERROR_INJECTION(), from Josef.
3) For BPF offload via nfp JIT, add support for bpf_xdp_adjust_head() helper
call for XDP programs. First part of this work adds handling of BPF
capabilities included in the firmware, and the later patches add support
to the nfp verifier part and JIT as well as some small optimizations,
from Jakub.
4) The bpftool now also gets support for basic cgroup BPF operations such
as attaching, detaching and listing current BPF programs. As a requirement
for the attach part, bpftool can now also load object files through
'bpftool prog load'. This reuses libbpf which we have in the kernel tree
as well. bpftool-cgroup man page is added along with it, from Roman.
5) Back then commit e87c6bc385 ("bpf: permit multiple bpf attachments for
a single perf event") added support for attaching multiple BPF programs
to a single perf event. Given they are configured through perf's ioctl()
interface, the interface has been extended with a PERF_EVENT_IOC_QUERY_BPF
command in this work in order to return an array of one or multiple BPF
prog ids that are currently attached, from Yonghong.
6) Various minor fixes and cleanups to the bpftool's Makefile as well
as a new 'uninstall' and 'doc-uninstall' target for removing bpftool
itself or prior installed documentation related to it, from Quentin.
7) Add CONFIG_CGROUP_BPF=y to the BPF kernel selftest config file which is
required for the test_dev_cgroup test case to run, from Naresh.
8) Fix reporting of XDP prog_flags for nfp driver, from Jakub.
9) Fix libbpf's exit code from the Makefile when libelf was not found in
the system, also from Jakub.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>
Commit f371b304f1 ("bpf/tracing: allow user space to
query prog array on the same tp") introduced a perf
ioctl command to query prog array attached to the
same perf tracepoint. The commit introduced a
compilation error under certain config conditions, e.g.,
(1). CONFIG_BPF_SYSCALL is not defined, or
(2). CONFIG_TRACING is defined but neither CONFIG_UPROBE_EVENTS
nor CONFIG_KPROBE_EVENTS is defined.
Error message:
kernel/events/core.o: In function `perf_ioctl':
core.c:(.text+0x98c4): undefined reference to `bpf_event_query_prog_array'
This patch fixed this error by guarding the real definition under
CONFIG_BPF_EVENTS and provided static inline dummy function
if CONFIG_BPF_EVENTS was not defined.
It renamed the function from bpf_event_query_prog_array to
perf_event_query_prog_array and moved the definition from linux/bpf.h
to linux/trace_events.h so the definition is in proximity to
other prog_array related functions.
Fixes: f371b304f1 ("bpf/tracing: allow user space to query prog array on the same tp")
Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Yonghong Song <yhs@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Error injection is sloppy and very ad-hoc. BPF could fill this niche
perfectly with it's kprobe functionality. We could make sure errors are
only triggered in specific call chains that we care about with very
specific situations. Accomplish this with the bpf_override_funciton
helper. This will modify the probe'd callers return value to the
specified value and set the PC to an override function that simply
returns, bypassing the originally probed function. This gives us a nice
clean way to implement systematic error injection for all of our code
paths.
Acked-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Josef Bacik <jbacik@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Commit e87c6bc385 ("bpf: permit multiple bpf attachments
for a single perf event") added support to attach multiple
bpf programs to a single perf event.
Although this provides flexibility, users may want to know
what other bpf programs attached to the same tp interface.
Besides getting visibility for the underlying bpf system,
such information may also help consolidate multiple bpf programs,
understand potential performance issues due to a large array,
and debug (e.g., one bpf program which overwrites return code
may impact subsequent program results).
Commit 2541517c32 ("tracing, perf: Implement BPF programs
attached to kprobes") utilized the existing perf ioctl
interface and added the command PERF_EVENT_IOC_SET_BPF
to attach a bpf program to a tracepoint. This patch adds a new
ioctl command, given a perf event fd, to query the bpf program
array attached to the same perf tracepoint event.
The new uapi ioctl command:
PERF_EVENT_IOC_QUERY_BPF
The new uapi/linux/perf_event.h structure:
struct perf_event_query_bpf {
__u32 ids_len;
__u32 prog_cnt;
__u32 ids[0];
};
User space provides buffer "ids" for kernel to copy to.
When returning from the kernel, the number of available
programs in the array is set in "prog_cnt".
The usage:
struct perf_event_query_bpf *query =
malloc(sizeof(*query) + sizeof(u32) * ids_len);
query.ids_len = ids_len;
err = ioctl(pmu_efd, PERF_EVENT_IOC_QUERY_BPF, query);
if (err == 0) {
/* query.prog_cnt is the number of available progs,
* number of progs in ids: (ids_len == 0) ? 0 : query.prog_cnt
*/
} else if (errno == ENOSPC) {
/* query.ids_len number of progs copied,
* query.prog_cnt is the number of available progs
*/
} else {
/* other errors */
}
Signed-off-by: Yonghong Song <yhs@fb.com>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Pull networking fixes from David Miller:
1) CAN fixes from Martin Kelly (cancel URBs properly in all the CAN usb
drivers).
2) Revert returning -EEXIST from __dev_alloc_name() as this propagates
to userspace and broke some apps. From Johannes Berg.
3) Fix conn memory leaks and crashes in TIPC, from Jon Malloc and Cong
Wang.
4) Gianfar MAC can't do EEE so don't advertise it by default, from
Claudiu Manoil.
5) Relax strict netlink attribute validation, but emit a warning. From
David Ahern.
6) Fix regression in checksum offload of thunderx driver, from Florian
Westphal.
7) Fix UAPI bpf issues on s390, from Hendrik Brueckner.
8) New card support in iwlwifi, from Ihab Zhaika.
9) BBR congestion control bug fixes from Neal Cardwell.
10) Fix port stats in nfp driver, from Pieter Jansen van Vuuren.
11) Fix leaks in qualcomm rmnet, from Subash Abhinov Kasiviswanathan.
12) Fix DMA API handling in sh_eth driver, from Thomas Petazzoni.
13) Fix spurious netpoll warnings in bnxt_en, from Calvin Owens.
* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net: (67 commits)
net: mvpp2: fix the RSS table entry offset
tcp: evaluate packet losses upon RTT change
tcp: fix off-by-one bug in RACK
tcp: always evaluate losses in RACK upon undo
tcp: correctly test congestion state in RACK
bnxt_en: Fix sources of spurious netpoll warnings
tcp_bbr: reset long-term bandwidth sampling on loss recovery undo
tcp_bbr: reset full pipe detection on loss recovery undo
tcp_bbr: record "full bw reached" decision in new full_bw_reached bit
sfc: pass valid pointers from efx_enqueue_unwind
gianfar: Disable EEE autoneg by default
tcp: invalidate rate samples during SACK reneging
can: peak/pcie_fd: fix potential bug in restarting tx queue
can: usb_8dev: cancel urb on -EPIPE and -EPROTO
can: kvaser_usb: cancel urb on -EPIPE and -EPROTO
can: esd_usb2: cancel urb on -EPIPE and -EPROTO
can: ems_usb: cancel urb on -EPIPE and -EPROTO
can: mcba_usb: cancel urb on -EPROTO
usbnet: fix alignment for frames with no ethernet header
tcp: use current time in tcp_rcv_space_adjust()
...
Commit 0515e5999a ("bpf: introduce BPF_PROG_TYPE_PERF_EVENT
program type") introduced the bpf_perf_event_data structure which
exports the pt_regs structure. This is OK for multiple architectures
but fail for s390 and arm64 which do not export pt_regs. Programs
using them, for example, the bpf selftest fail to compile on these
architectures.
For s390, exporting the pt_regs is not an option because s390 wants
to allow changes to it. For arm64, there is a user_pt_regs structure
that covers parts of the pt_regs structure for use by user space.
To solve the broken uapi for s390 and arm64, introduce an abstract
type for pt_regs and add an asm/bpf_perf_event.h file that concretes
the type. An asm-generic header file covers the architectures that
export pt_regs today.
The arch-specific enablement for s390 and arm64 follows in separate
commits.
Reported-by: Thomas Richter <tmricht@linux.vnet.ibm.com>
Fixes: 0515e5999a ("bpf: introduce BPF_PROG_TYPE_PERF_EVENT program type")
Signed-off-by: Hendrik Brueckner <brueckner@linux.vnet.ibm.com>
Reviewed-and-tested-by: Thomas Richter <tmricht@linux.vnet.ibm.com>
Acked-by: Alexei Starovoitov <ast@kernel.org>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Now that READ_ONCE() implies smp_read_barrier_depends(), the
get_xol_area() and get_trampoline_vaddr() no longer need their
smp_read_barrier_depends() calls, which this commit removes.
While we are here, convert the corresponding smp_wmb() to an
smp_store_release().
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Pull perf tooling fixes from Arnaldo Carvalho de Melo:
"- Fix window dimensions change handling in 'perf top' (Jiri Olsa)
- Fix 'perf record -c/-F' options for CPU event aliases (Andi Kleen)
- Generate PERF_RECORD_{MMAP,COMM,EXEC} with 'perf record --delay'
fixing symbol resolution for processes created, maps put in place
while --delay happens (Arnaldo Carvalho de Melo)
- Fix up leftover perf_evsel_stat usage via evsel->priv, plugging
a SEGV when using event groups as in:
$ perf stat -e '{cpu-clock,instructions}' workload
- Fix 'perf script --per-event-dump' for auxtrace synth evsels (Arnaldo Carvalho de Melo)
- Ignore kptr_restrict when not sampling the kernel (Arnaldo Carvalho de Melo)
- Synchronize kernel ABI headers wrt SPDX tags and ABI changes,
taking minimal action to handle new syscall args and silencing
perf build warnings (Arnaldo Carvalho de Melo, Ingo Molnar)
- Fix header.size for namespace events (Jiri Olsa)
- Fix a bug during strstart() conversion in 'perf help' (Namhyung Kim)
- Do not truncate instruction names at 6 chars in 'perf annotate', there
are really long instruction names in PPC (Ravi Bangoria)
- Fixup discontiguous/sparse numa nodes in 'perf bench numa' (Satheesh Rajendran)
- Fix an exit code of trace__symbols_init in 'perf trace' (Andrei Vagin)
- Fix 'perf test' entries on s/390 (Thomas Richter)
- Bring instruction decoder files used by Intel PT into line with the kernel,
silencing build warning (Adrian Hunter)"
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Reset header size for namespace events, otherwise it only gets bigger in
ctx iterations.
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Fixes: e422267322 ("perf: Add PERF_RECORD_NAMESPACES to include namespaces related info")
Link: http://lkml.kernel.org/n/tip-nlo4gonz9d4guyb8153ukzt0@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Pull perf fixes from Ingo Molnar:
"Misc fixes: two PMU driver fixes and a memory leak fix"
* 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
perf/core: Fix memory leak triggered by perf --namespace
perf/x86/intel/uncore: Add event constraint for BDX PCU
perf/x86/intel: Hide TSX events when RTM is not supported
- Now allow module init functions to be traced
- Clean up some unused or not used by config events (saves space)
- Clean up of trace histogram code
- Add support for preempt and interrupt enabled/disable events
- Other various clean ups
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Merge tag 'trace-v4.15' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace
Pull tracing updates from
- allow module init functions to be traced
- clean up some unused or not used by config events (saves space)
- clean up of trace histogram code
- add support for preempt and interrupt enabled/disable events
- other various clean ups
* tag 'trace-v4.15' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace: (30 commits)
tracing, thermal: Hide cpu cooling trace events when not in use
tracing, thermal: Hide devfreq trace events when not in use
ftrace: Kill FTRACE_OPS_FL_PER_CPU
perf/ftrace: Small cleanup
perf/ftrace: Fix function trace events
perf/ftrace: Revert ("perf/ftrace: Fix double traces of perf on ftrace:function")
tracing, dma-buf: Remove unused trace event dma_fence_annotate_wait_on
tracing, memcg, vmscan: Hide trace events when not in use
tracing/xen: Hide events that are not used when X86_PAE is not defined
tracing: mark trace_test_buffer as __maybe_unused
printk: Remove superfluous memory barriers from printk_safe
ftrace: Clear hashes of stale ips of init memory
tracing: Add support for preempt and irq enable/disable events
tracing: Prepare to add preempt and irq trace events
ftrace/kallsyms: Have /proc/kallsyms show saved mod init functions
ftrace: Add freeing algorithm to free ftrace_mod_maps
ftrace: Save module init functions kallsyms symbols for tracing
ftrace: Allow module init functions to be traced
ftrace: Add a ftrace_free_mem() function for modules to use
tracing: Reimplement log2
...
Pull networking updates from David Miller:
"Highlights:
1) Maintain the TCP retransmit queue using an rbtree, with 1GB
windows at 100Gb this really has become necessary. From Eric
Dumazet.
2) Multi-program support for cgroup+bpf, from Alexei Starovoitov.
3) Perform broadcast flooding in hardware in mv88e6xxx, from Andrew
Lunn.
4) Add meter action support to openvswitch, from Andy Zhou.
5) Add a data meta pointer for BPF accessible packets, from Daniel
Borkmann.
6) Namespace-ify almost all TCP sysctl knobs, from Eric Dumazet.
7) Turn on Broadcom Tags in b53 driver, from Florian Fainelli.
8) More work to move the RTNL mutex down, from Florian Westphal.
9) Add 'bpftool' utility, to help with bpf program introspection.
From Jakub Kicinski.
10) Add new 'cpumap' type for XDP_REDIRECT action, from Jesper
Dangaard Brouer.
11) Support 'blocks' of transformations in the packet scheduler which
can span multiple network devices, from Jiri Pirko.
12) TC flower offload support in cxgb4, from Kumar Sanghvi.
13) Priority based stream scheduler for SCTP, from Marcelo Ricardo
Leitner.
14) Thunderbolt networking driver, from Amir Levy and Mika Westerberg.
15) Add RED qdisc offloadability, and use it in mlxsw driver. From
Nogah Frankel.
16) eBPF based device controller for cgroup v2, from Roman Gushchin.
17) Add some fundamental tracepoints for TCP, from Song Liu.
18) Remove garbage collection from ipv6 route layer, this is a
significant accomplishment. From Wei Wang.
19) Add multicast route offload support to mlxsw, from Yotam Gigi"
* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next: (2177 commits)
tcp: highest_sack fix
geneve: fix fill_info when link down
bpf: fix lockdep splat
net: cdc_ncm: GetNtbFormat endian fix
openvswitch: meter: fix NULL pointer dereference in ovs_meter_cmd_reply_start
netem: remove unnecessary 64 bit modulus
netem: use 64 bit divide by rate
tcp: Namespace-ify sysctl_tcp_default_congestion_control
net: Protect iterations over net::fib_notifier_ops in fib_seq_sum()
ipv6: set all.accept_dad to 0 by default
uapi: fix linux/tls.h userspace compilation error
usbnet: ipheth: prevent TX queue timeouts when device not ready
vhost_net: conditionally enable tx polling
uapi: fix linux/rxrpc.h userspace compilation errors
net: stmmac: fix LPI transitioning for dwmac4
atm: horizon: Fix irq release error
net-sysfs: trigger netlink notification on ifalias change via sysfs
openvswitch: Using kfree_rcu() to simplify the code
openvswitch: Make local function ovs_nsh_key_attr_size() static
openvswitch: Fix return value check in ovs_meter_cmd_features()
...
Plenty of acronym soup here:
- Initial support for the Scalable Vector Extension (SVE)
- Improved handling for SError interrupts (required to handle RAS events)
- Enable GCC support for 128-bit integer types
- Remove kernel text addresses from backtraces and register dumps
- Use of WFE to implement long delay()s
- ACPI IORT updates from Lorenzo Pieralisi
- Perf PMU driver for the Statistical Profiling Extension (SPE)
- Perf PMU driver for Hisilicon's system PMUs
- Misc cleanups and non-critical fixes
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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:
"The big highlight is support for the Scalable Vector Extension (SVE)
which required extensive ABI work to ensure we don't break existing
applications by blowing away their signal stack with the rather large
new vector context (<= 2 kbit per vector register). There's further
work to be done optimising things like exception return, but the ABI
is solid now.
Much of the line count comes from some new PMU drivers we have, but
they're pretty self-contained and I suspect we'll have more of them in
future.
Plenty of acronym soup here:
- initial support for the Scalable Vector Extension (SVE)
- improved handling for SError interrupts (required to handle RAS
events)
- enable GCC support for 128-bit integer types
- remove kernel text addresses from backtraces and register dumps
- use of WFE to implement long delay()s
- ACPI IORT updates from Lorenzo Pieralisi
- perf PMU driver for the Statistical Profiling Extension (SPE)
- perf PMU driver for Hisilicon's system PMUs
- misc cleanups and non-critical fixes"
* tag 'arm64-upstream' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux: (97 commits)
arm64: Make ARMV8_DEPRECATED depend on SYSCTL
arm64: Implement __lshrti3 library function
arm64: support __int128 on gcc 5+
arm64/sve: Add documentation
arm64/sve: Detect SVE and activate runtime support
arm64/sve: KVM: Hide SVE from CPU features exposed to guests
arm64/sve: KVM: Treat guest SVE use as undefined instruction execution
arm64/sve: KVM: Prevent guests from using SVE
arm64/sve: Add sysctl to set the default vector length for new processes
arm64/sve: Add prctl controls for userspace vector length management
arm64/sve: ptrace and ELF coredump support
arm64/sve: Preserve SVE registers around EFI runtime service calls
arm64/sve: Preserve SVE registers around kernel-mode NEON use
arm64/sve: Probe SVE capabilities and usable vector lengths
arm64: cpufeature: Move sys_caps_initialised declarations
arm64/sve: Backend logic for setting the vector length
arm64/sve: Signal handling support
arm64/sve: Support vector length resetting for new processes
arm64/sve: Core task context handling
arm64/sve: Low-level CPU setup
...
perf with --namespace key leaks various memory objects including namespaces
4.14.0+
pid_namespace 1 12 2568 12 8
user_namespace 1 39 824 39 8
net_namespace 1 5 6272 5 8
This happen because perf_fill_ns_link_info() struct patch ns_path:
during initialization ns_path incremented counters on related mnt and dentry,
but without lost path_put nobody decremented them back.
Leaked dentry is name of related namespace,
and its leak does not allow to free unused namespace.
Signed-off-by: Vasily Averin <vvs@virtuozzo.com>
Acked-by: Peter Zijlstra <peterz@infradead.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: Hari Bathini <hbathini@linux.vnet.ibm.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Fixes: commit e422267322 ("perf: Add PERF_RECORD_NAMESPACES to include namespaces related info")
Link: http://lkml.kernel.org/r/c510711b-3904-e5e1-d296-61273d21118d@virtuozzo.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
perf with --namespace key leaks various memory objects including namespaces
4.14.0+
pid_namespace 1 12 2568 12 8
user_namespace 1 39 824 39 8
net_namespace 1 5 6272 5 8
This happen because perf_fill_ns_link_info() struct patch ns_path:
during initialization ns_path incremented counters on related mnt and dentry,
but without lost path_put nobody decremented them back.
Leaked dentry is name of related namespace,
and its leak does not allow to free unused namespace.
Signed-off-by: Vasily Averin <vvs@virtuozzo.com>
Acked-by: Peter Zijlstra <peterz@infradead.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: Hari Bathini <hbathini@linux.vnet.ibm.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Fixes: commit e422267322 ("perf: Add PERF_RECORD_NAMESPACES to include namespaces related info")
Link: http://lkml.kernel.org/r/c510711b-3904-e5e1-d296-61273d21118d@virtuozzo.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Pull perf updates from Ingo Molnar:
"The main changes in this cycle were:
Kernel:
- kprobes updates: use better W^X patterns for code modifications,
improve optprobes, remove jprobes. (Masami Hiramatsu, Kees Cook)
- core fixes: event timekeeping (enabled/running times statistics)
fixes, perf_event_read() locking fixes and cleanups, etc. (Peter
Zijlstra)
- Extend x86 Intel free-running PEBS support and support x86
user-register sampling in perf record and perf script. (Andi Kleen)
Tooling:
- Completely rework the way inline frames are handled. Instead of
querying for the inline nodes on-demand in the individual tools, we
now create proper callchain nodes for inlined frames. (Milian
Wolff)
- 'perf trace' updates (Arnaldo Carvalho de Melo)
- Implement a way to print formatted output to per-event files in
'perf script' to facilitate generate flamegraphs, elliminating the
need to write scripts to do that separation (yuzhoujian, Arnaldo
Carvalho de Melo)
- Update vendor events JSON metrics for Intel's Broadwell, Broadwell
Server, Haswell, Haswell Server, IvyBridge, IvyTown, JakeTown,
Sandy Bridge, Skylake, SkyLake Server - and Goldmont Plus V1 (Andi
Kleen, Kan Liang)
- Multithread the synthesizing of PERF_RECORD_ events for
pre-existing threads in 'perf top', speeding up that phase, greatly
improving the user experience in systems such as Intel's Knights
Mill (Kan Liang)
- Introduce the concept of weak groups in 'perf stat': try to set up
a group, but if it's not schedulable fallback to not using a group.
That gives us the best of both worlds: groups if they work, but
still a usable fallback if they don't. E.g: (Andi Kleen)
- perf sched timehist enhancements (David Ahern)
- ... various other enhancements, updates, cleanups and fixes"
* 'perf-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (139 commits)
kprobes: Don't spam the build log with deprecation warnings
arm/kprobes: Remove jprobe test case
arm/kprobes: Fix kretprobe test to check correct counter
perf srcline: Show correct function name for srcline of callchains
perf srcline: Fix memory leak in addr2inlines()
perf trace beauty kcmp: Beautify arguments
perf trace beauty: Implement pid_fd beautifier
tools include uapi: Grab a copy of linux/kcmp.h
perf callchain: Fix double mapping al->addr for children without self period
perf stat: Make --per-thread update shadow stats to show metrics
perf stat: Move the shadow stats scale computation in perf_stat__update_shadow_stats
perf tools: Add perf_data_file__write function
perf tools: Add struct perf_data_file
perf tools: Rename struct perf_data_file to perf_data
perf script: Print information about per-event-dump files
perf trace beauty prctl: Generate 'option' string table from kernel headers
tools include uapi: Grab a copy of linux/prctl.h
perf script: Allow creating per-event dump files
perf evsel: Restore evsel->priv as a tool private area
perf script: Use event_format__fprintf()
...
Error injection is sloppy and very ad-hoc. BPF could fill this niche
perfectly with it's kprobe functionality. We could make sure errors are
only triggered in specific call chains that we care about with very
specific situations. Accomplish this with the bpf_override_funciton
helper. This will modify the probe'd callers return value to the
specified value and set the PC to an override function that simply
returns, bypassing the originally probed function. This gives us a nice
clean way to implement systematic error injection for all of our code
paths.
Acked-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Josef Bacik <jbacik@fb.com>
Acked-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
Simple cases of overlapping changes in the packet scheduler.
Must easier to resolve this time.
Which probably means that I screwed it up somehow.
Signed-off-by: David S. Miller <davem@davemloft.net>
Use lockdep to check that IRQs are enabled or disabled as expected. This
way the sanity check only shows overhead when concurrency correctness
debug code is enabled.
Signed-off-by: Frederic Weisbecker <frederic@kernel.org>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
Cc: David S . Miller <davem@davemloft.net>
Cc: Lai Jiangshan <jiangshanlai@gmail.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Tejun Heo <tj@kernel.org>
Link: http://lkml.kernel.org/r/1509980490-4285-9-git-send-email-frederic@kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Files removed in 'net-next' had their license header updated
in 'net'. We take the remove from 'net-next'.
Signed-off-by: David S. Miller <davem@davemloft.net>
Many source files in the tree are missing licensing information, which
makes it harder for compliance tools to determine the correct license.
By default all files without license information are under the default
license of the kernel, which is GPL version 2.
Update the files which contain no license information with the 'GPL-2.0'
SPDX license identifier. The SPDX identifier is a legally binding
shorthand, which can be used instead of the full boiler plate text.
This patch is based on work done by Thomas Gleixner and Kate Stewart and
Philippe Ombredanne.
How this work was done:
Patches were generated and checked against linux-4.14-rc6 for a subset of
the use cases:
- file had no licensing information it it.
- file was a */uapi/* one with no licensing information in it,
- file was a */uapi/* one with existing licensing information,
Further patches will be generated in subsequent months to fix up cases
where non-standard license headers were used, and references to license
had to be inferred by heuristics based on keywords.
The analysis to determine which SPDX License Identifier to be applied to
a file was done in a spreadsheet of side by side results from of the
output of two independent scanners (ScanCode & Windriver) producing SPDX
tag:value files created by Philippe Ombredanne. Philippe prepared the
base worksheet, and did an initial spot review of a few 1000 files.
The 4.13 kernel was the starting point of the analysis with 60,537 files
assessed. Kate Stewart did a file by file comparison of the scanner
results in the spreadsheet to determine which SPDX license identifier(s)
to be applied to the file. She confirmed any determination that was not
immediately clear with lawyers working with the Linux Foundation.
Criteria used to select files for SPDX license identifier tagging was:
- Files considered eligible had to be source code files.
- Make and config files were included as candidates if they contained >5
lines of source
- File already had some variant of a license header in it (even if <5
lines).
All documentation files were explicitly excluded.
The following heuristics were used to determine which SPDX license
identifiers to apply.
- when both scanners couldn't find any license traces, file was
considered to have no license information in it, and the top level
COPYING file license applied.
For non */uapi/* files that summary was:
SPDX license identifier # files
---------------------------------------------------|-------
GPL-2.0 11139
and resulted in the first patch in this series.
If that file was a */uapi/* path one, it was "GPL-2.0 WITH
Linux-syscall-note" otherwise it was "GPL-2.0". Results of that was:
SPDX license identifier # files
---------------------------------------------------|-------
GPL-2.0 WITH Linux-syscall-note 930
and resulted in the second patch in this series.
- if a file had some form of licensing information in it, and was one
of the */uapi/* ones, it was denoted with the Linux-syscall-note if
any GPL family license was found in the file or had no licensing in
it (per prior point). Results summary:
SPDX license identifier # files
---------------------------------------------------|------
GPL-2.0 WITH Linux-syscall-note 270
GPL-2.0+ WITH Linux-syscall-note 169
((GPL-2.0 WITH Linux-syscall-note) OR BSD-2-Clause) 21
((GPL-2.0 WITH Linux-syscall-note) OR BSD-3-Clause) 17
LGPL-2.1+ WITH Linux-syscall-note 15
GPL-1.0+ WITH Linux-syscall-note 14
((GPL-2.0+ WITH Linux-syscall-note) OR BSD-3-Clause) 5
LGPL-2.0+ WITH Linux-syscall-note 4
LGPL-2.1 WITH Linux-syscall-note 3
((GPL-2.0 WITH Linux-syscall-note) OR MIT) 3
((GPL-2.0 WITH Linux-syscall-note) AND MIT) 1
and that resulted in the third patch in this series.
- when the two scanners agreed on the detected license(s), that became
the concluded license(s).
- when there was disagreement between the two scanners (one detected a
license but the other didn't, or they both detected different
licenses) a manual inspection of the file occurred.
- In most cases a manual inspection of the information in the file
resulted in a clear resolution of the license that should apply (and
which scanner probably needed to revisit its heuristics).
- When it was not immediately clear, the license identifier was
confirmed with lawyers working with the Linux Foundation.
- If there was any question as to the appropriate license identifier,
the file was flagged for further research and to be revisited later
in time.
In total, over 70 hours of logged manual review was done on the
spreadsheet to determine the SPDX license identifiers to apply to the
source files by Kate, Philippe, Thomas and, in some cases, confirmation
by lawyers working with the Linux Foundation.
Kate also obtained a third independent scan of the 4.13 code base from
FOSSology, and compared selected files where the other two scanners
disagreed against that SPDX file, to see if there was new insights. The
Windriver scanner is based on an older version of FOSSology in part, so
they are related.
Thomas did random spot checks in about 500 files from the spreadsheets
for the uapi headers and agreed with SPDX license identifier in the
files he inspected. For the non-uapi files Thomas did random spot checks
in about 15000 files.
In initial set of patches against 4.14-rc6, 3 files were found to have
copy/paste license identifier errors, and have been fixed to reflect the
correct identifier.
Additionally Philippe spent 10 hours this week doing a detailed manual
inspection and review of the 12,461 patched files from the initial patch
version early this week with:
- a full scancode scan run, collecting the matched texts, detected
license ids and scores
- reviewing anything where there was a license detected (about 500+
files) to ensure that the applied SPDX license was correct
- reviewing anything where there was no detection but the patch license
was not GPL-2.0 WITH Linux-syscall-note to ensure that the applied
SPDX license was correct
This produced a worksheet with 20 files needing minor correction. This
worksheet was then exported into 3 different .csv files for the
different types of files to be modified.
These .csv files were then reviewed by Greg. Thomas wrote a script to
parse the csv files and add the proper SPDX tag to the file, in the
format that the file expected. This script was further refined by Greg
based on the output to detect more types of files automatically and to
distinguish between header and source .c files (which need different
comment types.) Finally Greg ran the script using the .csv files to
generate the patches.
Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org>
Reviewed-by: Philippe Ombredanne <pombredanne@nexb.com>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The following commit:
864c2357ca ("perf/core: Do not set cpuctx->cgrp for unscheduled cgroups")
made list_update_cgroup_event() skip setting cpuctx->cgrp if no cgroup event
targets %current's cgroup.
This breaks perf_event's hierarchical support because events which target one
of the ancestors get ignored.
Fix it by using cgroup_is_descendant() test instead of equality.
Signed-off-by: Tejun Heo <tj@kernel.org>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: David Carrillo-Cisneros <davidcc@google.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: kernel-team@fb.com
Cc: stable@vger.kernel.org # v4.9+
Fixes: 864c2357ca ("perf/core: Do not set cpuctx->cgrp for unscheduled cgroups")
Link: http://lkml.kernel.org/r/20171028164237.GA972780@devbig577.frc2.facebook.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
The current even timekeeping, which computes enabled and running
times, uses 3 distinct timestamps to reflect the various event states:
OFF (stopped), INACTIVE (enabled) and ACTIVE (running).
Furthermore, the update rules are such that even INACTIVE events need
their timestamps updated. This is undesirable because we'd like to not
touch INACTIVE events if at all possible, this makes event scheduling
(much) more expensive than needed.
Rewrite the timekeeping to directly use event->state, this greatly
simplifies the code and results in only having to update things when
we change state, or an up-to-date value is requested (read).
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
perf_event_read() has a number of issues regarding the timekeeping bits.
- The IPI didn't update group times when it found INACTIVE
- The direct call would not re-check ->state after taking ctx->lock
which can result in ->count and timestamps getting out of sync.
And we can make use of the ordering introduced for perf_event_stop()
to make it more accurate for ACTIVE.
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
The barrier and comment make no sense:
- if what the barrier says is true, it should be wmb() but that
should then be part of the arch driver, not the generic code.
- if it is an SMP barrier, there must be a matching barrier, and
there isn't one.
So kill it.
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Its a weird name, active is one of the states, it should not be part
of the name, also, its too long.
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
We should make sure to update ctx time before we use it to update
event times.
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Event timestamps are serialized using ctx->lock, make sure to hold it
over reading all values.
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
We should make sure the ctx time is updated before we detach events;
which will want to update event times.
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
perf_event_read_value() is an external accessor, just like
perf_event_{en,dis}able() and should thus use perf_event_ctx_lock().
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Fixes: f63a8daa58 ("perf: Fix event->ctx locking")
Signed-off-by: Ingo Molnar <mingo@kernel.org>
eBPF programs would like access to the (perf) event enabled and
running times along with the event value, such that they can deal with
event multiplexing (among other things).
This patch extends the interface; a future eBPF patch will utilize
the new functionality.
[ Note, there's a same-content commit with a poor changelog and a meaningless
title in the networking tree as well - but we need this change for subsequent
perf work, so apply it here as well, with a proper changelog. Hopefully Git
will be able to sort out this somewhat messy workflow, if there are no other,
conflicting changes to these files. ]
Signed-off-by: Yonghong Song <yhs@fb.com>
[ Rewrote the changelog. ]
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: <ast@fb.com>
Cc: <daniel@iogearbox.net>
Cc: <rostedt@goodmis.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: David S. Miller <davem@davemloft.net>
Link: http://lkml.kernel.org/r/20171005161923.332790-2-yhs@fb.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Please do not apply this to mainline directly, instead please re-run the
coccinelle script shown below and apply its output.
For several reasons, it is desirable to use {READ,WRITE}_ONCE() in
preference to ACCESS_ONCE(), and new code is expected to use one of the
former. So far, there's been no reason to change most existing uses of
ACCESS_ONCE(), as these aren't harmful, and changing them results in
churn.
However, for some features, the read/write distinction is critical to
correct operation. To distinguish these cases, separate read/write
accessors must be used. This patch migrates (most) remaining
ACCESS_ONCE() instances to {READ,WRITE}_ONCE(), using the following
coccinelle script:
----
// Convert trivial ACCESS_ONCE() uses to equivalent READ_ONCE() and
// WRITE_ONCE()
// $ make coccicheck COCCI=/home/mark/once.cocci SPFLAGS="--include-headers" MODE=patch
virtual patch
@ depends on patch @
expression E1, E2;
@@
- ACCESS_ONCE(E1) = E2
+ WRITE_ONCE(E1, E2)
@ depends on patch @
expression E;
@@
- ACCESS_ONCE(E)
+ READ_ONCE(E)
----
Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: davem@davemloft.net
Cc: linux-arch@vger.kernel.org
Cc: mpe@ellerman.id.au
Cc: shuah@kernel.org
Cc: snitzer@redhat.com
Cc: thor.thayer@linux.intel.com
Cc: tj@kernel.org
Cc: viro@zeniv.linux.org.uk
Cc: will.deacon@arm.com
Link: http://lkml.kernel.org/r/1508792849-3115-19-git-send-email-paulmck@linux.vnet.ibm.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
This patch enables multiple bpf attachments for a
kprobe/uprobe/tracepoint single trace event.
Each trace_event keeps a list of attached perf events.
When an event happens, all attached bpf programs will
be executed based on the order of attachment.
A global bpf_event_mutex lock is introduced to protect
prog_array attaching and detaching. An alternative will
be introduce a mutex lock in every trace_event_call
structure, but it takes a lot of extra memory.
So a global bpf_event_mutex lock is a good compromise.
The bpf prog detachment involves allocation of memory.
If the allocation fails, a dummy do-nothing program
will replace to-be-detached program in-place.
Signed-off-by: Yonghong Song <yhs@fb.com>
Acked-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Martin KaFai Lau <kafai@fb.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This is a cleanup such that doing the same check in
perf_event_free_bpf_prog as we already do in
perf_event_set_bpf_prog step.
Signed-off-by: Yonghong Song <yhs@fb.com>
Acked-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Martin KaFai Lau <kafai@fb.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
READ_ONCE() now has an implicit smp_read_barrier_depends() call, so it
can be used instead of lockless_dereference() without any change in
semantics.
Signed-off-by: Will Deacon <will.deacon@arm.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/1508840570-22169-4-git-send-email-will.deacon@arm.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
There were quite a few overlapping sets of changes here.
Daniel's bug fix for off-by-ones in the new BPF branch instructions,
along with the added allowances for "data_end > ptr + x" forms
collided with the metadata additions.
Along with those three changes came veritifer test cases, which in
their final form I tried to group together properly. If I had just
trimmed GIT's conflict tags as-is, this would have split up the
meta tests unnecessarily.
In the socketmap code, a set of preemption disabling changes
overlapped with the rename of bpf_compute_data_end() to
bpf_compute_data_pointers().
Changes were made to the mv88e6060.c driver set addr method
which got removed in net-next.
The hyperv transport socket layer had a locking change in 'net'
which overlapped with a change of socket state macro usage
in 'net-next'.
Signed-off-by: David S. Miller <davem@davemloft.net>
Perf PMU drivers using AUX buffers cannot be built as modules unless
the AUX helpers are exported.
This patch exports perf_aux_output_{begin,end,skip} and perf_get_aux to
modules.
Cc: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Revert commit:
75e8387685 ("perf/ftrace: Fix double traces of perf on ftrace:function")
The reason I instantly stumbled on that patch is that it only addresses the
ftrace situation and doesn't mention the other _5_ places that use this
interface. It doesn't explain why those don't have the problem and if not, why
their solution doesn't work for ftrace.
It doesn't, but this is just putting more duct tape on.
Link: http://lkml.kernel.org/r/20171011080224.200565770@infradead.org
Cc: Zhou Chengming <zhouchengming1@huawei.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Since commit:
1fd7e41699 ("perf/core: Remove perf_cpu_context::unique_pmu")
... when a PMU is unregistered then its associated ->pmu_cpu_context is
unconditionally freed. Whilst this is fine for dynamically allocated
context types (i.e. those registered using perf_invalid_context), this
causes a problem for sharing of static contexts such as
perf_{sw,hw}_context, which are used by multiple built-in PMUs and
effectively have a global lifetime.
Whilst testing the ARM SPE driver, which must use perf_sw_context to
support per-task AUX tracing, unregistering the driver as a result of a
module unload resulted in:
Unable to handle kernel NULL pointer dereference at virtual address 00000038
Internal error: Oops: 96000004 [#1] PREEMPT SMP
Modules linked in: [last unloaded: arm_spe_pmu]
PC is at ctx_resched+0x38/0xe8
LR is at perf_event_exec+0x20c/0x278
[...]
ctx_resched+0x38/0xe8
perf_event_exec+0x20c/0x278
setup_new_exec+0x88/0x118
load_elf_binary+0x26c/0x109c
search_binary_handler+0x90/0x298
do_execveat_common.isra.14+0x540/0x618
SyS_execve+0x38/0x48
since the software context has been freed and the ctx.pmu->pmu_disable_count
field has been set to NULL.
This patch fixes the problem by avoiding the freeing of static PMU contexts
altogether. Whilst the sharing of dynamic contexts is questionable, this
actually requires the caller to share their context pointer explicitly
and so the burden is on them to manage the object lifetime.
Reported-by: Kim Phillips <kim.phillips@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Mark Rutland <mark.rutland@arm.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Fixes: 1fd7e41699 ("perf/core: Remove perf_cpu_context::unique_pmu")
Link: http://lkml.kernel.org/r/1507040450-7730-1-git-send-email-will.deacon@arm.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
This patch does not impact existing functionalities.
It contains the changes in perf event area needed for
subsequent bpf_perf_event_read_value and
bpf_perf_prog_read_value helpers.
Signed-off-by: Yonghong Song <yhs@fb.com>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
To clarify why atomic_inc_return(&perf_sched_events) is not sufficient and
a mutex is needed to order static branch enabling vs the atomic counter
increment, this adds a comment with a short explanation.
Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/20170829140103.6563-1-alexander.shishkin@linux.intel.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
The following commit:
d9a50b0256 ("perf/aux: Ensure aux_wakeup represents most recent wakeup index")
changed the AUX wakeup position calculation to rounddown(), which causes
a division-by-zero in AUX overwrite mode (aka "snapshot mode").
The zero denominator results from the fact that perf record doesn't set
aux_watermark to anything, in which case the kernel will set it to half
the AUX buffer size, but only for non-overwrite mode. In the overwrite
mode aux_watermark stays zero.
The good news is that, AUX overwrite mode, wakeups don't happen and
related bookkeeping is not relevant, so we can simply forego the whole
wakeup updates.
Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: will.deacon@arm.com
Link: http://lkml.kernel.org/r/20170906160811.16510-1-alexander.shishkin@linux.intel.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
This patch fixes a bug exhibited by the following scenario:
1. fd1 = perf_event_open with attr.config = ID1
2. attach bpf program prog1 to fd1
3. fd2 = perf_event_open with attr.config = ID1
<this will be successful>
4. user program closes fd2 and prog1 is detached from the tracepoint.
5. user program with fd1 does not work properly as tracepoint
no output any more.
The issue happens at step 4. Multiple perf_event_open can be called
successfully, but only one bpf prog pointer in the tp_event. In the
current logic, any fd release for the same tp_event will free
the tp_event->prog.
The fix is to free tp_event->prog only when the closing fd
corresponds to the one which registered the program.
Signed-off-by: Yonghong Song <yhs@fb.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Pull cgroup updates from Tejun Heo:
"Several notable changes this cycle:
- Thread mode was merged. This will be used for cgroup2 support for
CPU and possibly other controllers. Unfortunately, CPU controller
cgroup2 support didn't make this pull request but most contentions
have been resolved and the support is likely to be merged before
the next merge window.
- cgroup.stat now shows the number of descendant cgroups.
- cpuset now can enable the easier-to-configure v2 behavior on v1
hierarchy"
* 'for-4.14' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup: (21 commits)
cpuset: Allow v2 behavior in v1 cgroup
cgroup: Add mount flag to enable cpuset to use v2 behavior in v1 cgroup
cgroup: remove unneeded checks
cgroup: misc changes
cgroup: short-circuit cset_cgroup_from_root() on the default hierarchy
cgroup: re-use the parent pointer in cgroup_destroy_locked()
cgroup: add cgroup.stat interface with basic hierarchy stats
cgroup: implement hierarchy limits
cgroup: keep track of number of descent cgroups
cgroup: add comment to cgroup_enable_threaded()
cgroup: remove unnecessary empty check when enabling threaded mode
cgroup: update debug controller to print out thread mode information
cgroup: implement cgroup v2 thread support
cgroup: implement CSS_TASK_ITER_THREADED
cgroup: introduce cgroup->dom_cgrp and threaded css_set handling
cgroup: add @flags to css_task_iter_start() and implement CSS_TASK_ITER_PROCS
cgroup: reorganize cgroup.procs / task write path
cgroup: replace css_set walking populated test with testing cgrp->nr_populated_csets
cgroup: distinguish local and children populated states
cgroup: remove now unused list_head @pending in cgroup_apply_cftypes()
...
Pull networking updates from David Miller:
1) Support ipv6 checksum offload in sunvnet driver, from Shannon
Nelson.
2) Move to RB-tree instead of custom AVL code in inetpeer, from Eric
Dumazet.
3) Allow generic XDP to work on virtual devices, from John Fastabend.
4) Add bpf device maps and XDP_REDIRECT, which can be used to build
arbitrary switching frameworks using XDP. From John Fastabend.
5) Remove UFO offloads from the tree, gave us little other than bugs.
6) Remove the IPSEC flow cache, from Florian Westphal.
7) Support ipv6 route offload in mlxsw driver.
8) Support VF representors in bnxt_en, from Sathya Perla.
9) Add support for forward error correction modes to ethtool, from
Vidya Sagar Ravipati.
10) Add time filter for packet scheduler action dumping, from Jamal Hadi
Salim.
11) Extend the zerocopy sendmsg() used by virtio and tap to regular
sockets via MSG_ZEROCOPY. From Willem de Bruijn.
12) Significantly rework value tracking in the BPF verifier, from Edward
Cree.
13) Add new jump instructions to eBPF, from Daniel Borkmann.
14) Rework rtnetlink plumbing so that operations can be run without
taking the RTNL semaphore. From Florian Westphal.
15) Support XDP in tap driver, from Jason Wang.
16) Add 32-bit eBPF JIT for ARM, from Shubham Bansal.
17) Add Huawei hinic ethernet driver.
18) Allow to report MD5 keys in TCP inet_diag dumps, from Ivan
Delalande.
* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next: (1780 commits)
i40e: point wb_desc at the nvm_wb_desc during i40e_read_nvm_aq
i40e: avoid NVM acquire deadlock during NVM update
drivers: net: xgene: Remove return statement from void function
drivers: net: xgene: Configure tx/rx delay for ACPI
drivers: net: xgene: Read tx/rx delay for ACPI
rocker: fix kcalloc parameter order
rds: Fix non-atomic operation on shared flag variable
net: sched: don't use GFP_KERNEL under spin lock
vhost_net: correctly check tx avail during rx busy polling
net: mdio-mux: add mdio_mux parameter to mdio_mux_init()
rxrpc: Make service connection lookup always check for retry
net: stmmac: Delete dead code for MDIO registration
gianfar: Fix Tx flow control deactivation
cxgb4: Ignore MPS_TX_INT_CAUSE[Bubble] for T6
cxgb4: Fix pause frame count in t4_get_port_stats
cxgb4: fix memory leak
tun: rename generic_xdp to skb_xdp
tun: reserve extra headroom only when XDP is set
net: dsa: bcm_sf2: Configure IMP port TC2QOS mapping
net: dsa: bcm_sf2: Advertise number of egress queues
...
Pull x86 cache quality monitoring update from Thomas Gleixner:
"This update provides a complete rewrite of the Cache Quality
Monitoring (CQM) facility.
The existing CQM support was duct taped into perf with a lot of issues
and the attempts to fix those turned out to be incomplete and
horrible.
After lengthy discussions it was decided to integrate the CQM support
into the Resource Director Technology (RDT) facility, which is the
obvious choise as in hardware CQM is part of RDT. This allowed to add
Memory Bandwidth Monitoring support on top.
As a result the mechanisms for allocating cache/memory bandwidth and
the corresponding monitoring mechanisms are integrated into a single
management facility with a consistent user interface"
* 'x86-cache-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (37 commits)
x86/intel_rdt: Turn off most RDT features on Skylake
x86/intel_rdt: Add command line options for resource director technology
x86/intel_rdt: Move special case code for Haswell to a quirk function
x86/intel_rdt: Remove redundant ternary operator on return
x86/intel_rdt/cqm: Improve limbo list processing
x86/intel_rdt/mbm: Fix MBM overflow handler during CPU hotplug
x86/intel_rdt: Modify the intel_pqr_state for better performance
x86/intel_rdt/cqm: Clear the default RMID during hotcpu
x86/intel_rdt: Show bitmask of shareable resource with other executing units
x86/intel_rdt/mbm: Handle counter overflow
x86/intel_rdt/mbm: Add mbm counter initialization
x86/intel_rdt/mbm: Basic counting of MBM events (total and local)
x86/intel_rdt/cqm: Add CPU hotplug support
x86/intel_rdt/cqm: Add sched_in support
x86/intel_rdt: Introduce rdt_enable_key for scheduling
x86/intel_rdt/cqm: Add mount,umount support
x86/intel_rdt/cqm: Add rmdir support
x86/intel_rdt: Separate the ctrl bits from rmdir
x86/intel_rdt/cqm: Add mon_data
x86/intel_rdt: Prepare for RDT monitor data support
...
Pull perf updates from Ingo Molnar:
"Kernel side changes:
- Add branch type profiling/tracing support. (Jin Yao)
- Add the PERF_SAMPLE_PHYS_ADDR ABI to allow the tracing/profiling of
physical memory addresses, where the PMU supports it. (Kan Liang)
- Export some PMU capability details in the new
/sys/bus/event_source/devices/cpu/caps/ sysfs directory. (Andi
Kleen)
- Aux data fixes and updates (Will Deacon)
- kprobes fixes and updates (Masami Hiramatsu)
- AMD uncore PMU driver fixes and updates (Janakarajan Natarajan)
On the tooling side, here's a (limited!) list of highlights - there
were many other changes that I could not list, see the shortlog and
git history for details:
UI improvements:
- Implement a visual marker for fused x86 instructions in the
annotate TUI browser, available now in 'perf report', more work
needed to have it available as well in 'perf top' (Jin Yao)
Further explanation from one of Jin's patches:
│ ┌──cmpl $0x0,argp_program_version_hook
81.93 │ ├──je 20
│ │ lock cmpxchg %esi,0x38a9a4(%rip)
│ │↓ jne 29
│ │↓ jmp 43
11.47 │20:└─→cmpxch %esi,0x38a999(%rip)
That means the cmpl+je is a fused instruction pair and they should
be considered together.
- Record the branch type and then show statistics and info about in
callchain entries (Jin Yao)
Example from one of Jin's patches:
# perf record -g -j any,save_type
# perf report --branch-history --stdio --no-children
38.50% div.c:45 [.] main div
|
---main div.c:42 (RET CROSS_2M cycles:2)
compute_flag div.c:28 (cycles:2)
compute_flag div.c:27 (RET CROSS_2M cycles:1)
rand rand.c:28 (cycles:1)
rand rand.c:28 (RET CROSS_2M cycles:1)
__random random.c:298 (cycles:1)
__random random.c:297 (COND_BWD CROSS_2M cycles:1)
__random random.c:295 (cycles:1)
__random random.c:295 (COND_BWD CROSS_2M cycles:1)
__random random.c:295 (cycles:1)
__random random.c:295 (RET CROSS_2M cycles:9)
namespaces support:
- Add initial support for namespaces, using setns to access files in
namespaces, grabbing their build-ids, etc. (Krister Johansen)
perf trace enhancements:
- Beautify pkey_{alloc,free,mprotect} arguments in 'perf trace'
(Arnaldo Carvalho de Melo)
- Add initial 'clone' syscall args beautifier in 'perf trace'
(Arnaldo Carvalho de Melo)
- Ignore 'fd' and 'offset' args for MAP_ANONYMOUS in 'perf trace'
(Arnaldo Carvalho de Melo)
- Beautifiers for the 'cmd' arg of several ioctl types, including:
sound, DRM, KVM, vhost virtio and perf_events. (Arnaldo Carvalho de
Melo)
- Add PERF_SAMPLE_CALLCHAIN and PERF_RECORD_MMAP[2] to 'perf data'
CTF conversion, allowing CTF trace visualization tools to show
callchains and to resolve symbols (Geneviève Bastien)
- Beautify the fcntl syscall, which is an interesting one in the
sense that infrastructure had to be put in place to change the
formatters of some arguments according to the value in a previous
one, i.e. cmd dictates how arg and the syscall return will be
formatted. (Arnaldo Carvalho de Melo
perf stat enhancements:
- Use group read for event groups in 'perf stat', reducing overhead
when groups are defined in the event specification, i.e. when using
{} to enclose a list of events, asking them to be read at the same
time, e.g.: "perf stat -e '{cycles,instructions}'" (Jiri Olsa)
pipe mode improvements:
- Process tracing data in 'perf annotate' pipe mode (David
Carrillo-Cisneros)
- Add header record types to pipe-mode, now this command:
$ perf record -o - -e cycles sleep 1 | perf report --stdio --header
Will show the same as in non-pipe mode, i.e. involving a perf.data
file (David Carrillo-Cisneros)
Vendor specific hardware event support updates/enhancements:
- Update POWER9 vendor events tables (Sukadev Bhattiprolu)
- Add POWER9 PMU events Sukadev (Bhattiprolu)
- Support additional POWER8+ PVR in PMU mapfile (Shriya)
- Add Skylake server uncore JSON vendor events (Andi Kleen)
- Support exporting Intel PT data to sqlite3 with python perf
scripts, this is in addition to the postgresql support that was
already there (Adrian Hunter)"
* 'perf-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (253 commits)
perf symbols: Fix plt entry calculation for ARM and AARCH64
perf probe: Fix kprobe blacklist checking condition
perf/x86: Fix caps/ for !Intel
perf/core, x86: Add PERF_SAMPLE_PHYS_ADDR
perf/core, pt, bts: Get rid of itrace_started
perf trace beauty: Beautify pkey_{alloc,free,mprotect} arguments
tools headers: Sync cpu features kernel ABI headers with tooling headers
perf tools: Pass full path of FEATURES_DUMP
perf tools: Robustify detection of clang binary
tools lib: Allow external definition of CC, AR and LD
perf tools: Allow external definition of flex and bison binary names
tools build tests: Don't hardcode gcc name
perf report: Group stat values on global event id
perf values: Zero value buffers
perf values: Fix allocation check
perf values: Fix thread index bug
perf report: Add dump_read function
perf record: Set read_format for inherit_stat
perf c2c: Fix remote HITM detection for Skylake
perf tools: Fix static build with newer toolchains
...
Pull perf fixes from Thomas Gleixner:
- Prevent a potential inconistency in the perf user space access which
might lead to evading sanity checks.
- Prevent perf recording function trace entries twice
* 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
perf/ftrace: Fix double traces of perf on ftrace:function
perf/core: Fix potential double-fetch bug
Commit 7c05126793 ("mm, fork: make dup_mmap wait for mmap_sem for
write killable") made it possible to kill a forking task while it is
waiting to acquire its ->mmap_sem for write, in dup_mmap().
However, it was overlooked that this introduced an new error path before
the new mm_struct's ->uprobes_state.xol_area has been set to NULL after
being copied from the old mm_struct by the memcpy in dup_mm(). For a
task that has previously hit a uprobe tracepoint, this resulted in the
'struct xol_area' being freed multiple times if the task was killed at
just the right time while forking.
Fix it by setting ->uprobes_state.xol_area to NULL in mm_init() rather
than in uprobe_dup_mmap().
With CONFIG_UPROBE_EVENTS=y, the bug can be reproduced by the same C
program given by commit 2b7e8665b4 ("fork: fix incorrect fput of
->exe_file causing use-after-free"), provided that a uprobe tracepoint
has been set on the fork_thread() function. For example:
$ gcc reproducer.c -o reproducer -lpthread
$ nm reproducer | grep fork_thread
0000000000400719 t fork_thread
$ echo "p $PWD/reproducer:0x719" > /sys/kernel/debug/tracing/uprobe_events
$ echo 1 > /sys/kernel/debug/tracing/events/uprobes/enable
$ ./reproducer
Here is the use-after-free reported by KASAN:
BUG: KASAN: use-after-free in uprobe_clear_state+0x1c4/0x200
Read of size 8 at addr ffff8800320a8b88 by task reproducer/198
CPU: 1 PID: 198 Comm: reproducer Not tainted 4.13.0-rc7-00015-g36fde05f3fb5 #255
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.10.2-20170228_101828-anatol 04/01/2014
Call Trace:
dump_stack+0xdb/0x185
print_address_description+0x7e/0x290
kasan_report+0x23b/0x350
__asan_report_load8_noabort+0x19/0x20
uprobe_clear_state+0x1c4/0x200
mmput+0xd6/0x360
do_exit+0x740/0x1670
do_group_exit+0x13f/0x380
get_signal+0x597/0x17d0
do_signal+0x99/0x1df0
exit_to_usermode_loop+0x166/0x1e0
syscall_return_slowpath+0x258/0x2c0
entry_SYSCALL_64_fastpath+0xbc/0xbe
...
Allocated by task 199:
save_stack_trace+0x1b/0x20
kasan_kmalloc+0xfc/0x180
kmem_cache_alloc_trace+0xf3/0x330
__create_xol_area+0x10f/0x780
uprobe_notify_resume+0x1674/0x2210
exit_to_usermode_loop+0x150/0x1e0
prepare_exit_to_usermode+0x14b/0x180
retint_user+0x8/0x20
Freed by task 199:
save_stack_trace+0x1b/0x20
kasan_slab_free+0xa8/0x1a0
kfree+0xba/0x210
uprobe_clear_state+0x151/0x200
mmput+0xd6/0x360
copy_process.part.8+0x605f/0x65d0
_do_fork+0x1a5/0xbd0
SyS_clone+0x19/0x20
do_syscall_64+0x22f/0x660
return_from_SYSCALL_64+0x0/0x7a
Note: without KASAN, you may instead see a "Bad page state" message, or
simply a general protection fault.
Link: http://lkml.kernel.org/r/20170830033303.17927-1-ebiggers3@gmail.com
Fixes: 7c05126793 ("mm, fork: make dup_mmap wait for mmap_sem for write killable")
Signed-off-by: Eric Biggers <ebiggers@google.com>
Reported-by: Oleg Nesterov <oleg@redhat.com>
Acked-by: Oleg Nesterov <oleg@redhat.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Konstantin Khlebnikov <koct9i@gmail.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: <stable@vger.kernel.org> [4.7+]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
For understanding how the workload maps to memory channels and hardware
behavior, it's very important to collect address maps with physical
addresses. For example, 3D XPoint access can only be found by filtering
the physical address.
Add a new sample type for physical address.
perf already has a facility to collect data virtual address. This patch
introduces a function to convert the virtual address to physical address.
The function is quite generic and can be extended to any architecture as
long as a virtual address is provided.
- For kernel direct mapping addresses, virt_to_phys is used to convert
the virtual addresses to physical address.
- For user virtual addresses, __get_user_pages_fast is used to walk the
pages tables for user physical address.
- This does not work for vmalloc addresses right now. These are not
resolved, but code to do that could be added.
The new sample type requires collecting the virtual address. The
virtual address will not be output unless SAMPLE_ADDR is applied.
For security, the physical address can only be exposed to root or
privileged user.
Tested-by: Madhavan Srinivasan <maddy@linux.vnet.ibm.com>
Signed-off-by: Kan Liang <kan.liang@intel.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vince Weaver <vincent.weaver@maine.edu>
Cc: acme@kernel.org
Cc: mpe@ellerman.id.au
Link: http://lkml.kernel.org/r/1503967969-48278-1-git-send-email-kan.liang@intel.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
I just noticed that hw.itrace_started and hw.config are aliased to the
same location. Now, the PT driver happens to use both, which works out
fine by sheer luck:
- STORE(hw.itrace_start) is ordered before STORE(hw.config), in the
program order, although there are no compiler barriers to ensure that,
- to the perf_log_itrace_start() hw.itrace_start looks set at the same
time as when it is intended to be set because both stores happen in the
same path,
- hw.config is never reset to zero in the PT driver.
Now, the use of hw.config by the PT driver makes more sense (it being a
HW PMU) than messing around with itrace_started, which is an awkward API
to begin with.
This patch replaces hw.itrace_started with an attach_state bit and an
API call for the PMU drivers to use to communicate the condition.
Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Arnaldo Carvalho de Melo <acme@infradead.org>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vince Weaver <vincent.weaver@maine.edu>
Cc: vince@deater.net
Link: http://lkml.kernel.org/r/20170330153956.25994-1-alexander.shishkin@linux.intel.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
When running perf on the ftrace:function tracepoint, there is a bug
which can be reproduced by:
perf record -e ftrace:function -a sleep 20 &
perf record -e ftrace:function ls
perf script
ls 10304 [005] 171.853235: ftrace:function:
perf_output_begin
ls 10304 [005] 171.853237: ftrace:function:
perf_output_begin
ls 10304 [005] 171.853239: ftrace:function:
task_tgid_nr_ns
ls 10304 [005] 171.853240: ftrace:function:
task_tgid_nr_ns
ls 10304 [005] 171.853242: ftrace:function:
__task_pid_nr_ns
ls 10304 [005] 171.853244: ftrace:function:
__task_pid_nr_ns
We can see that all the function traces are doubled.
The problem is caused by the inconsistency of the register
function perf_ftrace_event_register() with the probe function
perf_ftrace_function_call(). The former registers one probe
for every perf_event. And the latter handles all perf_events
on the current cpu. So when two perf_events on the current cpu,
the traces of them will be doubled.
So this patch adds an extra parameter "event" for perf_tp_event,
only send sample data to this event when it's not NULL.
Signed-off-by: Zhou Chengming <zhouchengming1@huawei.com>
Reviewed-by: Jiri Olsa <jolsa@kernel.org>
Acked-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: acme@kernel.org
Cc: alexander.shishkin@linux.intel.com
Cc: huawei.libin@huawei.com
Link: http://lkml.kernel.org/r/1503668977-12526-1-git-send-email-zhouchengming1@huawei.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
While examining the kernel source code, I found a dangerous operation that
could turn into a double-fetch situation (a race condition bug) where the same
userspace memory region are fetched twice into kernel with sanity checks after
the first fetch while missing checks after the second fetch.
1. The first fetch happens in line 9573 get_user(size, &uattr->size).
2. Subsequently the 'size' variable undergoes a few sanity checks and
transformations (line 9577 to 9584).
3. The second fetch happens in line 9610 copy_from_user(attr, uattr, size)
4. Given that 'uattr' can be fully controlled in userspace, an attacker can
race condition to override 'uattr->size' to arbitrary value (say, 0xFFFFFFFF)
after the first fetch but before the second fetch. The changed value will be
copied to 'attr->size'.
5. There is no further checks on 'attr->size' until the end of this function,
and once the function returns, we lose the context to verify that 'attr->size'
conforms to the sanity checks performed in step 2 (line 9577 to 9584).
6. My manual analysis shows that 'attr->size' is not used elsewhere later,
so, there is no working exploit against it right now. However, this could
easily turns to an exploitable one if careless developers start to use
'attr->size' later.
To fix this, override 'attr->size' from the second fetch to the one from the
first fetch, regardless of what is actually copied in.
In this way, it is assured that 'attr->size' is consistent with the checks
performed after the first fetch.
Signed-off-by: Meng Xu <mengxu.gatech@gmail.com>
Acked-by: Peter Zijlstra <peterz@infradead.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: acme@kernel.org
Cc: alexander.shishkin@linux.intel.com
Cc: meng.xu@gatech.edu
Cc: sanidhya@gatech.edu
Cc: taesoo@gatech.edu
Link: http://lkml.kernel.org/r/1503522470-35531-1-git-send-email-meng.xu@gatech.edu
Signed-off-by: Ingo Molnar <mingo@kernel.org>
In an XDP redirect applications using tracepoint xdp:xdp_redirect to
diagnose TX overrun, I noticed perf_swevent_get_recursion_context()
was consuming 2% CPU. This was reduced to 1.85% with this simple
change.
Looking at the annotated asm code, it was clear that the unlikely case
in_nmi() test was chosen (by the compiler) as the most likely
event/branch. This small adjustment makes the compiler (GCC version
7.1.1 20170622 (Red Hat 7.1.1-3)) put in_nmi() as an unlikely branch.
Signed-off-by: Jesper Dangaard Brouer <brouer@redhat.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/150342256382.16595.986861478681783732.stgit@firesoul
Signed-off-by: Ingo Molnar <mingo@kernel.org>
The exiting/dead task has no PIDs and in this case perf_event_pid/tid()
return zero, change them to return -1 to distinguish this case from
idle threads.
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Arnaldo Carvalho <acme@kernel.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/20170822155928.GA6892@redhat.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
The aux_watermark member of struct ring_buffer represents the period (in
terms of bytes) at which wakeup events should be generated when data is
written to the aux buffer in non-snapshot mode. On hardware that cannot
generate an interrupt when the aux_head reaches an arbitrary wakeup index
(such as ARM SPE), the aux_head sampled from handle->head in
perf_aux_output_{skip,end} may in fact be past the wakeup index. This
can lead to wakeup slowly falling behind the head. For example, consider
the case where hardware can only generate an interrupt on a page-boundary
and the aux buffer is initialised as follows:
// Buffer size is 2 * PAGE_SIZE
rb->aux_head = rb->aux_wakeup = 0
rb->aux_watermark = PAGE_SIZE / 2
following the first perf_aux_output_begin call, the handle is
initialised with:
handle->head = 0
handle->size = 2 * PAGE_SIZE
handle->wakeup = PAGE_SIZE / 2
and the hardware will be programmed to generate an interrupt at
PAGE_SIZE.
When the interrupt is raised, the hardware head will be at PAGE_SIZE,
so calling perf_aux_output_end(handle, PAGE_SIZE) puts the ring buffer
into the following state:
rb->aux_head = PAGE_SIZE
rb->aux_wakeup = PAGE_SIZE / 2
rb->aux_watermark = PAGE_SIZE / 2
and then the next call to perf_aux_output_begin will result in:
handle->head = handle->wakeup = PAGE_SIZE
for which the semantics are unclear and, for a smaller aux_watermark
(e.g. PAGE_SIZE / 4), then the wakeup would in fact be behind head at
this point.
This patch fixes the problem by rounding down the aux_head (as sampled
from the handle) to the nearest aux_watermark boundary when updating
rb->aux_wakeup, therefore taking into account any overruns by the
hardware.
Reported-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-arm-kernel@lists.infradead.org
Link: http://lkml.kernel.org/r/1502900297-21839-2-git-send-email-will.deacon@arm.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
The aux_head and aux_wakeup members of struct ring_buffer are defined
using the local_t type, despite the fact that they are only accessed via
the perf_aux_output_*() functions, which cannot race with each other for a
given ring buffer.
This patch changes the type of the members to long, so we can avoid
using the local_*() API where it isn't needed.
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-arm-kernel@lists.infradead.org
Link: http://lkml.kernel.org/r/1502900297-21839-1-git-send-email-will.deacon@arm.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Regardless of which events form a group, it does not make sense for the
events to target different tasks and/or CPUs, as this leaves the group
inconsistent and impossible to schedule. The core perf code assumes that
these are consistent across (successfully intialised) groups.
Core perf code only verifies this when moving SW events into a HW
context. Thus, we can violate this requirement for pure SW groups and
pure HW groups, unless the relevant PMU driver happens to perform this
verification itself. These mismatched groups subsequently wreak havoc
elsewhere.
For example, we handle watchpoints as SW events, and reserve watchpoint
HW on a per-CPU basis at pmu::event_init() time to ensure that any event
that is initialised is guaranteed to have a slot at pmu::add() time.
However, the core code only checks the group leader's cpu filter (via
event_filter_match()), and can thus install follower events onto CPUs
violating thier (mismatched) CPU filters, potentially installing them
into a CPU without sufficient reserved slots.
This can be triggered with the below test case, resulting in warnings
from arch backends.
#define _GNU_SOURCE
#include <linux/hw_breakpoint.h>
#include <linux/perf_event.h>
#include <sched.h>
#include <stdio.h>
#include <sys/prctl.h>
#include <sys/syscall.h>
#include <unistd.h>
static int perf_event_open(struct perf_event_attr *attr, pid_t pid, int cpu,
int group_fd, unsigned long flags)
{
return syscall(__NR_perf_event_open, attr, pid, cpu, group_fd, flags);
}
char watched_char;
struct perf_event_attr wp_attr = {
.type = PERF_TYPE_BREAKPOINT,
.bp_type = HW_BREAKPOINT_RW,
.bp_addr = (unsigned long)&watched_char,
.bp_len = 1,
.size = sizeof(wp_attr),
};
int main(int argc, char *argv[])
{
int leader, ret;
cpu_set_t cpus;
/*
* Force use of CPU0 to ensure our CPU0-bound events get scheduled.
*/
CPU_ZERO(&cpus);
CPU_SET(0, &cpus);
ret = sched_setaffinity(0, sizeof(cpus), &cpus);
if (ret) {
printf("Unable to set cpu affinity\n");
return 1;
}
/* open leader event, bound to this task, CPU0 only */
leader = perf_event_open(&wp_attr, 0, 0, -1, 0);
if (leader < 0) {
printf("Couldn't open leader: %d\n", leader);
return 1;
}
/*
* Open a follower event that is bound to the same task, but a
* different CPU. This means that the group should never be possible to
* schedule.
*/
ret = perf_event_open(&wp_attr, 0, 1, leader, 0);
if (ret < 0) {
printf("Couldn't open mismatched follower: %d\n", ret);
return 1;
} else {
printf("Opened leader/follower with mismastched CPUs\n");
}
/*
* Open as many independent events as we can, all bound to the same
* task, CPU0 only.
*/
do {
ret = perf_event_open(&wp_attr, 0, 0, -1, 0);
} while (ret >= 0);
/*
* Force enable/disble all events to trigger the erronoeous
* installation of the follower event.
*/
printf("Opened all events. Toggling..\n");
for (;;) {
prctl(PR_TASK_PERF_EVENTS_DISABLE, 0, 0, 0, 0);
prctl(PR_TASK_PERF_EVENTS_ENABLE, 0, 0, 0, 0);
}
return 0;
}
Fix this by validating this requirement regardless of whether we're
moving events.
Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Zhou Chengming <zhouchengming1@huawei.com>
Cc: stable@vger.kernel.org
Link: http://lkml.kernel.org/r/1498142498-15758-1-git-send-email-mark.rutland@arm.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Vince reported that when we do IOC_ENABLE/IOC_DISABLE while the task
is SIGSTOP'ed state the timestamps go wobbly.
It turns out we indeed fail to correctly account time while in 'OFF'
state and doing IOC_ENABLE without getting scheduled in exposes the
problem.
Further thinking about this problem, it occurred to me that we can
suffer a similar fate when we migrate an uncore event between CPUs.
The perf_event_install() on the 'new' CPU will do add_event_to_ctx()
which will reset all the time stamp, resulting in a subsequent
update_event_times() to overwrite the total_time_* fields with smaller
values.
Reported-by: Vince Weaver <vincent.weaver@maine.edu>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Vince reported the following rdpmc() testcase failure:
> Failing test case:
>
> fd=perf_event_open();
> addr=mmap(fd);
> exec() // without closing or unmapping the event
> fd=perf_event_open();
> addr=mmap(fd);
> rdpmc() // GPFs due to rdpmc being disabled
The problem is of course that exec() plays tricks with what is
current->mm, only destroying the old mappings after having
installed the new mm.
Fix this confusion by passing along vma->vm_mm instead of relying on
current->mm.
Reported-by: Vince Weaver <vincent.weaver@maine.edu>
Tested-by: Vince Weaver <vincent.weaver@maine.edu>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Andy Lutomirski <luto@kernel.org>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@gmail.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: stable@vger.kernel.org
Fixes: 1e0fb9ec67 ("perf: Add pmu callbacks to track event mapping and unmapping")
Link: http://lkml.kernel.org/r/20170802173930.cstykcqefmqt7jau@hirez.programming.kicks-ass.net
[ Minor cleanups. ]
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Currently, bpf programs cannot be attached to sys_enter_* and sys_exit_*
style tracepoints. The iovisor/bcc issue #748
(https://github.com/iovisor/bcc/issues/748) documents this issue.
For example, if you try to attach a bpf program to tracepoints
syscalls/sys_enter_newfstat, you will get the following error:
# ./tools/trace.py t:syscalls:sys_enter_newfstat
Ioctl(PERF_EVENT_IOC_SET_BPF): Invalid argument
Failed to attach BPF to tracepoint
The main reason is that syscalls/sys_enter_* and syscalls/sys_exit_*
tracepoints are treated differently from other tracepoints and there
is no bpf hook to it.
This patch adds bpf support for these syscalls tracepoints by
. permitting bpf attachment in ioctl PERF_EVENT_IOC_SET_BPF
. calling bpf programs in perf_syscall_enter and perf_syscall_exit
The legality of bpf program ctx access is also checked.
Function trace_event_get_offsets returns correct max offset for each
specific syscall tracepoint, which is compared against the maximum offset
access in bpf program.
Signed-off-by: Yonghong Song <yhs@fb.com>
Acked-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
'perf cqm' never worked due to the incompatibility between perf
infrastructure and cqm hardware support. The hardware uses RMIDs to
track the llc occupancy of tasks and these RMIDs are per package. This
makes monitoring a hierarchy like cgroup along with monitoring of tasks
separately difficult and several patches sent to lkml to fix them were
NACKed. Further more, the following issues in the current perf cqm make
it almost unusable:
1. No support to monitor the same group of tasks for which we do
allocation using resctrl.
2. It gives random and inaccurate data (mostly 0s) once we run out
of RMIDs due to issues in Recycling.
3. Recycling results in inaccuracy of data because we cannot
guarantee that the RMID was stolen from a task when it was not
pulling data into cache or even when it pulled the least data. Also
for monitoring llc_occupancy, if we stop using an RMID_x and then
start using an RMID_y after we reclaim an RMID from an other event,
we miss accounting all the occupancy that was tagged to RMID_x at a
later perf_count.
2. Recycling code makes the monitoring code complex including
scheduling because the event can lose RMID any time. Since MBM
counters count bandwidth for a period of time by taking snap shot of
total bytes at two different times, recycling complicates the way we
count MBM in a hierarchy. Also we need a spin lock while we do the
processing to account for MBM counter overflow. We also currently
use a spin lock in scheduling to prevent the RMID from being taken
away.
4. Lack of support when we run different kind of event like task,
system-wide and cgroup events together. Data mostly prints 0s. This
is also because we can have only one RMID tied to a cpu as defined
by the cqm hardware but a perf can at the same time tie multiple
events during one sched_in.
5. No support of monitoring a group of tasks. There is partial support
for cgroup but it does not work once there is a hierarchy of cgroups
or if we want to monitor a task in a cgroup and the cgroup itself.
6. No support for monitoring tasks for the lifetime without perf
overhead.
7. It reported the aggregate cache occupancy or memory bandwidth over
all sockets. But most cloud and VMM based use cases want to know the
individual per-socket usage.
Signed-off-by: Vikas Shivappa <vikas.shivappa@linux.intel.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: ravi.v.shankar@intel.com
Cc: tony.luck@intel.com
Cc: fenghua.yu@intel.com
Cc: peterz@infradead.org
Cc: eranian@google.com
Cc: vikas.shivappa@intel.com
Cc: ak@linux.intel.com
Cc: davidcc@google.com
Cc: reinette.chatre@intel.com
Link: http://lkml.kernel.org/r/1501017287-28083-2-git-send-email-vikas.shivappa@linux.intel.com
Pull perf fixes from Ingo Molnar:
"Two hw-enablement patches, two race fixes, three fixes for regressions
of semantics, plus a number of tooling fixes"
* 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
perf/x86/intel: Add proper condition to run sched_task callbacks
perf/core: Fix locking for children siblings group read
perf/core: Fix scheduling regression of pinned groups
perf/x86/intel: Fix debug_store reset field for freq events
perf/x86/intel: Add Goldmont Plus CPU PMU support
perf/x86/intel: Enable C-state residency events for Apollo Lake
perf symbols: Accept zero as the kernel base address
Revert "perf/core: Drop kernel samples even though :u is specified"
perf annotate: Fix broken arrow at row 0 connecting jmp instruction to its target
perf evsel: State in the default event name if attr.exclude_kernel is set
perf evsel: Fix attr.exclude_kernel setting for default cycles:p
This patch implements cgroup v2 thread support. The goal of the
thread mode is supporting hierarchical accounting and control at
thread granularity while staying inside the resource domain model
which allows coordination across different resource controllers and
handling of anonymous resource consumptions.
A cgroup is always created as a domain and can be made threaded by
writing to the "cgroup.type" file. When a cgroup becomes threaded, it
becomes a member of a threaded subtree which is anchored at the
closest ancestor which isn't threaded.
The threads of the processes which are in a threaded subtree can be
placed anywhere without being restricted by process granularity or
no-internal-process constraint. Note that the threads aren't allowed
to escape to a different threaded subtree. To be used inside a
threaded subtree, a controller should explicitly support threaded mode
and be able to handle internal competition in the way which is
appropriate for the resource.
The root of a threaded subtree, the nearest ancestor which isn't
threaded, is called the threaded domain and serves as the resource
domain for the whole subtree. This is the last cgroup where domain
controllers are operational and where all the domain-level resource
consumptions in the subtree are accounted. This allows threaded
controllers to operate at thread granularity when requested while
staying inside the scope of system-level resource distribution.
As the root cgroup is exempt from the no-internal-process constraint,
it can serve as both a threaded domain and a parent to normal cgroups,
so, unlike non-root cgroups, the root cgroup can have both domain and
threaded children.
Internally, in a threaded subtree, each css_set has its ->dom_cset
pointing to a matching css_set which belongs to the threaded domain.
This ensures that thread root level cgroup_subsys_state for all
threaded controllers are readily accessible for domain-level
operations.
This patch enables threaded mode for the pids and perf_events
controllers. Neither has to worry about domain-level resource
consumptions and it's enough to simply set the flag.
For more details on the interface and behavior of the thread mode,
please refer to the section 2-2-2 in Documentation/cgroup-v2.txt added
by this patch.
v5: - Dropped silly no-op ->dom_cgrp init from cgroup_create().
Spotted by Waiman.
- Documentation updated as suggested by Waiman.
- cgroup.type content slightly reformatted.
- Mark the debug controller threaded.
v4: - Updated to the general idea of marking specific cgroups
domain/threaded as suggested by PeterZ.
v3: - Dropped "join" and always make mixed children join the parent's
threaded subtree.
v2: - After discussions with Waiman, support for mixed thread mode is
added. This should address the issue that Peter pointed out
where any nesting should be avoided for thread subtrees while
coexisting with other domain cgroups.
- Enabling / disabling thread mode now piggy backs on the existing
control mask update mechanism.
- Bug fixes and cleanup.
Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Waiman Long <longman@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
We're missing ctx lock when iterating children siblings
within the perf_read path for group reading. Following
race and crash can happen:
User space doing read syscall on event group leader:
T1:
perf_read
lock event->ctx->mutex
perf_read_group
lock leader->child_mutex
__perf_read_group_add(child)
list_for_each_entry(sub, &leader->sibling_list, group_entry)
----> sub might be invalid at this point, because it could
get removed via perf_event_exit_task_context in T2
Child exiting and cleaning up its events:
T2:
perf_event_exit_task_context
lock ctx->mutex
list_for_each_entry_safe(child_event, next, &child_ctx->event_list,...
perf_event_exit_event(child)
lock ctx->lock
perf_group_detach(child)
unlock ctx->lock
----> child is removed from sibling_list without any sync
with T1 path above
...
free_event(child)
Before the child is removed from the leader's child_list,
(and thus is omitted from perf_read_group processing), we
need to ensure that perf_read_group touches child's
siblings under its ctx->lock.
Peter further notes:
| One additional note; this bug got exposed by commit:
|
| ba5213ae6b ("perf/core: Correct event creation with PERF_FORMAT_GROUP")
|
| which made it possible to actually trigger this code-path.
Tested-by: Andi Kleen <ak@linux.intel.com>
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Fixes: ba5213ae6b ("perf/core: Correct event creation with PERF_FORMAT_GROUP")
Link: http://lkml.kernel.org/r/20170720141455.2106-1-jolsa@kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Vince Weaver reported:
> I was tracking down some regressions in my perf_event_test testsuite.
> Some of the tests broke in the 4.11-rc1 timeframe.
>
> I've bisected one of them, this report is about
> tests/overflow/simul_oneshot_group_overflow
> This test creates an event group containing two sampling events, set
> to overflow to a signal handler (which disables and then refreshes the
> event).
>
> On a good kernel you get the following:
> Event perf::instructions with period 1000000
> Event perf::instructions with period 2000000
> fd 3 overflows: 946 (perf::instructions/1000000)
> fd 4 overflows: 473 (perf::instructions/2000000)
> Ending counts:
> Count 0: 946379875
> Count 1: 946365218
>
> With the broken kernels you get:
> Event perf::instructions with period 1000000
> Event perf::instructions with period 2000000
> fd 3 overflows: 938 (perf::instructions/1000000)
> fd 4 overflows: 318 (perf::instructions/2000000)
> Ending counts:
> Count 0: 946373080
> Count 1: 653373058
The root cause of the bug is that the following commit:
487f05e18a ("perf/core: Optimize event rescheduling on active contexts")
erronously assumed that event's 'pinned' setting determines whether the
event belongs to a pinned group or not, but in fact, it's the group
leader's pinned state that matters.
This was discovered by Vince in the test case described above, where two instruction
counters are grouped, the group leader is pinned, but the other event is not;
in the regressed case the counters were off by 33% (the difference between events'
periods), but should be the same within the error margin.
Fix the problem by looking at the group leader's pinning.
Reported-by: Vince Weaver <vincent.weaver@maine.edu>
Tested-by: Vince Weaver <vincent.weaver@maine.edu>
Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@gmail.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: stable@vger.kernel.org
Fixes: 487f05e18a ("perf/core: Optimize event rescheduling on active contexts")
Link: http://lkml.kernel.org/r/87lgnmvw7h.fsf@ashishki-desk.ger.corp.intel.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
This reverts commit cc1582c231.
This commit introduced a regression that broke rr-project, which uses sampling
events to receive a signal on overflow (but does not care about the contents
of the sample). These signals are critical to the correct operation of rr.
There's been some back and forth about how to fix it - but to not keep
applications in limbo queue up a revert.
Reported-by: Kyle Huey <me@kylehuey.com>
Acked-by: Kyle Huey <me@kylehuey.com>
Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Jin Yao <yao.jin@linux.intel.com>
Cc: Vince Weaver <vincent.weaver@maine.edu>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Stephane Eranian <eranian@google.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: <stable@vger.kernel.org>
Link: http://lkml.kernel.org/r/20170628105600.GC5981@leverpostej
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Pull networking updates from David Miller:
"Reasonably busy this cycle, but perhaps not as busy as in the 4.12
merge window:
1) Several optimizations for UDP processing under high load from
Paolo Abeni.
2) Support pacing internally in TCP when using the sch_fq packet
scheduler for this is not practical. From Eric Dumazet.
3) Support mutliple filter chains per qdisc, from Jiri Pirko.
4) Move to 1ms TCP timestamp clock, from Eric Dumazet.
5) Add batch dequeueing to vhost_net, from Jason Wang.
6) Flesh out more completely SCTP checksum offload support, from
Davide Caratti.
7) More plumbing of extended netlink ACKs, from David Ahern, Pablo
Neira Ayuso, and Matthias Schiffer.
8) Add devlink support to nfp driver, from Simon Horman.
9) Add RTM_F_FIB_MATCH flag to RTM_GETROUTE queries, from Roopa
Prabhu.
10) Add stack depth tracking to BPF verifier and use this information
in the various eBPF JITs. From Alexei Starovoitov.
11) Support XDP on qed device VFs, from Yuval Mintz.
12) Introduce BPF PROG ID for better introspection of installed BPF
programs. From Martin KaFai Lau.
13) Add bpf_set_hash helper for TC bpf programs, from Daniel Borkmann.
14) For loads, allow narrower accesses in bpf verifier checking, from
Yonghong Song.
15) Support MIPS in the BPF selftests and samples infrastructure, the
MIPS eBPF JIT will be merged in via the MIPS GIT tree. From David
Daney.
16) Support kernel based TLS, from Dave Watson and others.
17) Remove completely DST garbage collection, from Wei Wang.
18) Allow installing TCP MD5 rules using prefixes, from Ivan
Delalande.
19) Add XDP support to Intel i40e driver, from Björn Töpel
20) Add support for TC flower offload in nfp driver, from Simon
Horman, Pieter Jansen van Vuuren, Benjamin LaHaise, Jakub
Kicinski, and Bert van Leeuwen.
21) IPSEC offloading support in mlx5, from Ilan Tayari.
22) Add HW PTP support to macb driver, from Rafal Ozieblo.
23) Networking refcount_t conversions, From Elena Reshetova.
24) Add sock_ops support to BPF, from Lawrence Brako. This is useful
for tuning the TCP sockopt settings of a group of applications,
currently via CGROUPs"
* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next: (1899 commits)
net: phy: dp83867: add workaround for incorrect RX_CTRL pin strap
dt-bindings: phy: dp83867: provide a workaround for incorrect RX_CTRL pin strap
cxgb4: Support for get_ts_info ethtool method
cxgb4: Add PTP Hardware Clock (PHC) support
cxgb4: time stamping interface for PTP
nfp: default to chained metadata prepend format
nfp: remove legacy MAC address lookup
nfp: improve order of interfaces in breakout mode
net: macb: remove extraneous return when MACB_EXT_DESC is defined
bpf: add missing break in for the TCP_BPF_SNDCWND_CLAMP case
bpf: fix return in load_bpf_file
mpls: fix rtm policy in mpls_getroute
net, ax25: convert ax25_cb.refcount from atomic_t to refcount_t
net, ax25: convert ax25_route.refcount from atomic_t to refcount_t
net, ax25: convert ax25_uid_assoc.refcount from atomic_t to refcount_t
net, sctp: convert sctp_ep_common.refcnt from atomic_t to refcount_t
net, sctp: convert sctp_transport.refcnt from atomic_t to refcount_t
net, sctp: convert sctp_chunk.refcnt from atomic_t to refcount_t
net, sctp: convert sctp_datamsg.refcnt from atomic_t to refcount_t
net, sctp: convert sctp_auth_bytes.refcnt from atomic_t to refcount_t
...
Pull SMP hotplug updates from Thomas Gleixner:
"This update is primarily a cleanup of the CPU hotplug locking code.
The hotplug locking mechanism is an open coded RWSEM, which allows
recursive locking. The main problem with that is the recursive nature
as it evades the full lockdep coverage and hides potential deadlocks.
The rework replaces the open coded RWSEM with a percpu RWSEM and
establishes full lockdep coverage that way.
The bulk of the changes fix up recursive locking issues and address
the now fully reported potential deadlocks all over the place. Some of
these deadlocks have been observed in the RT tree, but on mainline the
probability was low enough to hide them away."
* 'smp-hotplug-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (37 commits)
cpu/hotplug: Constify attribute_group structures
powerpc: Only obtain cpu_hotplug_lock if called by rtasd
ARM/hw_breakpoint: Fix possible recursive locking for arch_hw_breakpoint_init
cpu/hotplug: Remove unused check_for_tasks() function
perf/core: Don't release cred_guard_mutex if not taken
cpuhotplug: Link lock stacks for hotplug callbacks
acpi/processor: Prevent cpu hotplug deadlock
sched: Provide is_percpu_thread() helper
cpu/hotplug: Convert hotplug locking to percpu rwsem
s390: Prevent hotplug rwsem recursion
arm: Prevent hotplug rwsem recursion
arm64: Prevent cpu hotplug rwsem recursion
kprobes: Cure hotplug lock ordering issues
jump_label: Reorder hotplug lock and jump_label_lock
perf/tracing/cpuhotplug: Fix locking order
ACPI/processor: Use cpu_hotplug_disable() instead of get_online_cpus()
PCI: Replace the racy recursion prevention
PCI: Use cpu_hotplug_disable() instead of get_online_cpus()
perf/x86/intel: Drop get_online_cpus() in intel_snb_check_microcode()
x86/perf: Drop EXPORT of perf_check_microcode
...
Pull perf updates from Ingo Molnar:
"Most of the changes are for tooling, the main changes in this cycle were:
- Improve Intel-PT hardware tracing support, both on the kernel and
on the tooling side: PTWRITE instruction support, power events for
C-state tracing, etc. (Adrian Hunter)
- Add support to measure SMI cost to the x86 architecture, with
tooling support in 'perf stat' (Kan Liang)
- Support function filtering in 'perf ftrace', plus related
improvements (Namhyung Kim)
- Allow adding and removing fields to the default 'perf script'
columns, using + or - as field prefixes to do so (Andi Kleen)
- Allow resolving the DSO name with 'perf script -F brstack{sym,off},dso'
(Mark Santaniello)
- Add perf tooling unwind support for PowerPC (Paolo Bonzini)
- ... and various other improvements as well"
* 'perf-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (84 commits)
perf auxtrace: Add CPU filter support
perf intel-pt: Do not use TSC packets for calculating CPU cycles to TSC
perf intel-pt: Update documentation to include new ptwrite and power events
perf intel-pt: Add example script for power events and PTWRITE
perf intel-pt: Synthesize new power and "ptwrite" events
perf intel-pt: Move code in intel_pt_synth_events() to simplify attr setting
perf intel-pt: Factor out intel_pt_set_event_name()
perf intel-pt: Tidy messages into called function intel_pt_synth_event()
perf intel-pt: Tidy Intel PT evsel lookup into separate function
perf intel-pt: Join needlessly wrapped lines
perf intel-pt: Remove unused instructions_sample_period
perf intel-pt: Factor out common code synthesizing event samples
perf script: Add synthesized Intel PT power and ptwrite events
perf/x86/intel: Constify the 'lbr_desc[]' array and make a function static
perf script: Add 'synth' field for synthesized event payloads
perf auxtrace: Add itrace option to output power events
perf auxtrace: Add itrace option to output ptwrite events
tools include: Add byte-swapping macros to kernel.h
perf script: Add 'synth' event type for synthesized events
x86/insn: perf tools: Add new ptwrite instruction
...
If the event for which an AUX area is about to be allocated, does
not support setting up an AUX area, rb_alloc_aux() return -ENOTSUPP.
This error condition is being returned unfiltered to the user space,
and, for example, the perf tools fails with:
failed to mmap with 524 (INTERNAL ERROR: strerror_r(524, 0x3fff497a1c8, 512)=22)
This error can be easily seen with "perf record -m 128,256 -e cpu-clock".
The 524 error code maps to -ENOTSUPP (in rb_alloc_aux()). The -ENOTSUPP
error code shall be only used within the kernel. So the correct error
code would then be -EOPNOTSUPP.
With this commit, the perf tool then reports:
failed to mmap with 95 (Operation not supported)
which is more clear.
Signed-off-by: Hendrik Brueckner <brueckner@linux.vnet.ibm.com>
Acked-by: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Pu Hou <bjhoupu@linux.vnet.ibm.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Thomas-Mich Richter <tmricht@linux.vnet.ibm.com>
Cc: acme@kernel.org
Cc: linux-s390@vger.kernel.org
Link: http://lkml.kernel.org/r/1497954399-6355-1-git-send-email-brueckner@linux.vnet.ibm.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
The function was added by commit e5d1367f17 ("perf: Add cgroup
support") in 2011 and hasn't been used since then. Removing it fixes the
following warning when building with Clang:
kernel/events/core.c:696:19: error: unused function 'perf_cgroup_event_cgrp_time' [-Werror,-Wunused-function]
Signed-off-by: Matthias Kaehlcke <mka@chromium.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: Douglas Anderson <dianders@chromium.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/20170523215132.189049-1-mka@chromium.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Andi was asking about PERF_FORMAT_GROUP vs inherited events, which led
to the discovery of a bug from commit:
3dab77fb1b ("perf: Rework/fix the whole read vs group stuff")
- PERF_SAMPLE_GROUP = 1U << 4,
+ PERF_SAMPLE_READ = 1U << 4,
- if (attr->inherit && (attr->sample_type & PERF_SAMPLE_GROUP))
+ if (attr->inherit && (attr->read_format & PERF_FORMAT_GROUP))
is a clear fail :/
While this changes user visible behaviour; it was previously possible
to create an inherited event with PERF_SAMPLE_READ; this is deemed
acceptible because its results were always incorrect.
Reported-by: Andi Kleen <ak@linux.intel.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vince Weaver <vince@deater.net>
Fixes: 3dab77fb1b ("perf: Rework/fix the whole read vs group stuff")
Link: http://lkml.kernel.org/r/20170530094512.dy2nljns2uq7qa3j@hirez.programming.kicks-ass.net
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Allow BPF_PROG_TYPE_PERF_EVENT program types to attach to all
perf_event types, including HW_CACHE, RAW, and dynamic pmu events.
Only tracepoint/kprobe events are treated differently which require
BPF_PROG_TYPE_TRACEPOINT/BPF_PROG_TYPE_KPROBE program types accordingly.
Also add support for reading all event counters using
bpf_perf_event_read() helper.
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
perf, tracing, kprobes and jump_labels have a gazillion of ways to create
dependency lock chains. Some of those involve nested invocations of
get_online_cpus().
The conversion of the hotplug locking to a percpu rwsem requires to avoid
such nested calls. sys_perf_event_open() protects most of the syscall logic
against cpu hotplug. This causes nested calls and lock inversions versus
ftrace and kprobes in various interesting ways.
It's impossible to move the hotplug locking to the outer end of all call
chains in the involved facilities, so the hotplug protection in
sys_perf_event_open() needs to be solved differently.
Introduce 'pmus_mutex' which protects a perf private online cpumask. This
mutex is taken when the mask is updated in the cpu hotplug callbacks and
can be taken in sys_perf_event_open() to protect the swhash setup/teardown
code and when the final judgement about a valid event has to be made.
[ tglx: Produced changelog and fixed the swhash interaction ]
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Ingo Molnar <mingo@kernel.org>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Sebastian Siewior <bigeasy@linutronix.de>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Link: http://lkml.kernel.org/r/20170524081548.930941109@linutronix.de
We don't set an error code here which means that perf_event_alloc()
returns ERR_PTR(0) (in other words NULL). The callers are not expecting
that and would Oops.
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vince Weaver <vincent.weaver@maine.edu>
Fixes: 375637bc52 ("perf/core: Introduce address range filtering")
Link: http://lkml.kernel.org/r/20170522090418.hvs6icgpdo53wkn5@mwanda
Signed-off-by: Ingo Molnar <mingo@kernel.org>
