linux.git/tools/lib, branch v5.15-rc2

libperf evsel: Make use of FD robust.

2021-09-18T20:43:06+00:00

FD uses xyarray__entry that may return NULL if an index is out of
bounds. If NULL is returned then a segv happens as FD unconditionally
dereferences the pointer. This was happening in a case of with perf
iostat as shown below. The fix is to make FD an "int*" rather than an
int and handle the NULL case as either invalid input or a closed fd.

  $ sudo gdb --args perf stat --iostat  list
  ...
  Breakpoint 1, perf_evsel__alloc_fd (evsel=0x5555560951a0, ncpus=1, nthreads=1) at evsel.c:50
  50      {
  (gdb) bt
   #0  perf_evsel__alloc_fd (evsel=0x5555560951a0, ncpus=1, nthreads=1) at evsel.c:50
   #1  0x000055555585c188 in evsel__open_cpu (evsel=0x5555560951a0, cpus=0x555556093410,
      threads=0x555556086fb0, start_cpu=0, end_cpu=1) at util/evsel.c:1792
   #2  0x000055555585cfb2 in evsel__open (evsel=0x5555560951a0, cpus=0x0, threads=0x555556086fb0)
      at util/evsel.c:2045
   #3  0x000055555585d0db in evsel__open_per_thread (evsel=0x5555560951a0, threads=0x555556086fb0)
      at util/evsel.c:2065
   #4  0x00005555558ece64 in create_perf_stat_counter (evsel=0x5555560951a0,
      config=0x555555c34700 , target=0x555555c2f1c0 , cpu=0) at util/stat.c:590
   #5  0x000055555578e927 in __run_perf_stat (argc=1, argv=0x7fffffffe4a0, run_idx=0)
      at builtin-stat.c:833
   #6  0x000055555578f3c6 in run_perf_stat (argc=1, argv=0x7fffffffe4a0, run_idx=0)
      at builtin-stat.c:1048
   #7  0x0000555555792ee5 in cmd_stat (argc=1, argv=0x7fffffffe4a0) at builtin-stat.c:2534
   #8  0x0000555555835ed3 in run_builtin (p=0x555555c3f540 , argc=3,
      argv=0x7fffffffe4a0) at perf.c:313
   #9  0x0000555555836154 in handle_internal_command (argc=3, argv=0x7fffffffe4a0) at perf.c:365
   #10 0x000055555583629f in run_argv (argcp=0x7fffffffe2ec, argv=0x7fffffffe2e0) at perf.c:409
   #11 0x0000555555836692 in main (argc=3, argv=0x7fffffffe4a0) at perf.c:539
  ...
  (gdb) c
  Continuing.
  Error:
  The sys_perf_event_open() syscall returned with 22 (Invalid argument) for event (uncore_iio_0/event=0x83,umask=0x04,ch_mask=0xF,fc_mask=0x07/).
  /bin/dmesg | grep -i perf may provide additional information.

  Program received signal SIGSEGV, Segmentation fault.
  0x00005555559b03ea in perf_evsel__close_fd_cpu (evsel=0x5555560951a0, cpu=1) at evsel.c:166
  166                     if (FD(evsel, cpu, thread) >= 0)

v3. fixes a bug in perf_evsel__run_ioctl where the sense of a branch was
    backward.

Signed-off-by: Ian Rogers 
Acked-by: Jiri Olsa 
Cc: Alexander Shishkin 
Cc: Mark Rutland 
Cc: Namhyung Kim 
Cc: Peter Zijlstra 
Cc: Stephane Eranian 
Link: http://lore.kernel.org/lkml/20210918054440.2350466-1-irogers@google.com
Signed-off-by: Arnaldo Carvalho de Melo

Merge tag 'perf-tools-for-v5.15-2021-09-04' of git://git.kernel.org/pub/scm/linux/kernel/git/acme/linux

2021-09-05T18:56:18+00:00

Pull perf tool updates from Arnaldo Carvalho de Melo:
"New features:

- Improvements for the flamegraph python script, including:
- Display perf.data header
- Display PIDs of user stacks
- Added option to change color scheme
- Default to blue/green color scheme to improve accessibility
- Correctly identify kernel stacks when debuginfo is available

- Improvements for 'perf bench futex':
- Add --mlockall parameter
- Add --broadcast and --pi to the 'requeue' sub benchmark

- Add support for PMU aliases.

- Introduce an ARM Coresight ETE decoder.

- Add a 'perf bench' entry for evlist open/close operations, to help
quantify improvements with multithreading 'perf record'.

- Allow reporting the [un]throttle PERF_RECORD_ meta event in 'perf
script's python scripting.

- Add a 'perf test' entry for PMU aliases.

- Add a 'perf test' entry for 'perf record/perf report/perf script'
pipe mode.

Fixes:

- perf script dlfilter (API for filtering via dynamically loaded
shared object introduced in v5.14) fixes and a 'perf test' entry
for it.

- Fix get_current_dir_name() compilation on Android.

- Fix issues with asciidoc and double dashes uses.

- Fix memory leaks in the BTF handling code.

- Fix leftover problems in the Documentation from the infrastructure
originally lifted from the git codebase.

- Fix *probe_vfs_getname.sh 'perf test' failures.

- Handle fd gaps in 'perf test's test__dso_data_reopen().

- Make sure to show disasembly warnings for 'perf annotate --stdio'.

- Fix output from pipe to file and vice-versa in 'perf
record/report/script'.

- Correct 'perf data -h' output.

- Fix wrong comm in system-wide mode with 'perf record --delay'.

- Do not allow --for-each-cgroup without cpu in 'perf stat'

- Make 'perf test --skip' work on shell tests.

- Fix libperf's verbose printing.

Misc improvements:

- Preparatory patches for multithreading various 'perf record' phases
(synthesizing, opening, recording, etc).

- Add sparse context/locking annotations in compiler-types.h, also to
help with the multithreading effort.

- Optimize the generation of the arch specific erno tables used in
'perf trace'.

- Optimize libperf's perf_cpu_map__max().

- Improve ARM's CoreSight warnings.

- Report collisions in AUX records.

- Improve warnings for the LLVM 'perf test' entry.

- Improve the PMU events 'perf test' codebase.

- perf test: Do not compare overheads in the zstd comp test

- Better support annotation on ARM.

- Update 'perf trace's cmd string table to decode sys_bpf() first
arg.

Vendor events:

- Add JSON events and metrics for Intel's Ice Lake, Tiger Lake and
Elhart Lake.

- Update JSON eventsand metrics for Intel's Cascade Lake and Sky Lake
servers.

Hardware tracing:

- Improvements for the ARM hardware tracing auxtrace support"

* tag 'perf-tools-for-v5.15-2021-09-04' of git://git.kernel.org/pub/scm/linux/kernel/git/acme/linux: (130 commits)
perf tests: Add test for PMU aliases
perf pmu: Add PMU alias support
perf session: Report collisions in AUX records
perf script python: Allow reporting the [un]throttle PERF_RECORD_ meta event
perf build: Report failure for testing feature libopencsd
perf cs-etm: Show a warning for an unknown magic number
perf cs-etm: Print the decoder name
perf cs-etm: Create ETE decoder
perf cs-etm: Update OpenCSD decoder for ETE
perf cs-etm: Fix typo
perf cs-etm: Save TRCDEVARCH register
perf cs-etm: Refactor out ETMv4 header saving
perf cs-etm: Initialise architecture based on TRCIDR1
perf cs-etm: Refactor initialisation of decoder params.
tools build: Fix feature detect clean for out of source builds
perf evlist: Add evlist__for_each_entry_from() macro
perf evsel: Handle precise_ip fallback in evsel__open_cpu()
perf evsel: Move bpf_counter__install_pe() to success path in evsel__open_cpu()
perf evsel: Move test_attr__open() to success path in evsel__open_cpu()
perf evsel: Move ignore_missing_thread() to fallback code
...

libperf cpumap: Take into advantage it is sorted to optimize perf_cpu_map__max()

2021-08-31T19:17:02+00:00

From commit 7074674e7338863e ("perf cpumap: Maintain cpumaps ordered and
without dups"), perf_cpu_map elements are sorted in ascending order.

This patch improves the perf_cpu_map__max function by returning the last
element.

Committer notes:

Do it as a ternary to keep it in just one return line, add a comment
explaining it is sorted and what functions does it.

Signed-off-by: Riccardo Mancini 
Cc: Ian Rogers 
Cc: Jiri Olsa 
Cc: Mark Rutland 
Cc: Namhyung Kim 
Cc: Peter Zijlstra 
Link: http://lore.kernel.org/lkml/fb79f02e7b86ea8044d563adb1e9890c906f982f.1629490974.git.rickyman7@gmail.com
Signed-off-by: Arnaldo Carvalho de Melo

libsubcmd: add OPT_UINTEGER_OPTARG option type

2021-08-31T18:44:05+00:00

This patch adds OPT_UINTEGER_OPTARG, which is the same as OPT_UINTEGER,
but also makes it possible to use the option without any value, setting
the variable to a default value, d.

Signed-off-by: Riccardo Mancini 
Cc: Ian Rogers 
Cc: Jiri Olsa 
Cc: Mark Rutland 
Cc: Namhyung Kim 
Cc: Peter Zijlstra 
Link: http://lore.kernel.org/lkml/c46749b3dff796729078352ff164d363457a3587.1629490974.git.rickyman7@gmail.com
Signed-off-by: Arnaldo Carvalho de Melo

Merge remote-tracking branch 'torvalds/master' into perf/core

2021-08-30T13:05:46+00:00

To pick up fixes.

Signed-off-by: Arnaldo Carvalho de Melo

libperf tests: Fix verbose printing

2021-08-24T18:05:35+00:00

libperf's verbose printing checks the -v option every time the macro _T_ START
is called.

Since there are currently four libperf tests registered, the macro _T_ START is
called four times, but verbose printing after the second time is not output.

Resets the index of the element processed by getopt() and fix verbose printing
so that it prints in all tests.

Signed-off-by: Shunsuke Nakamura 
Acked-by: Rob Herring 
Cc: Alexander Shishkin 
Cc: Jiri Olsa 
Cc: Mark Rutland 
Cc: Namhyung Kim 
Cc: Peter Zijlstra 
Link: http://lore.kernel.org/lkml/20210820093908.734503-3-nakamura.shun@fujitsu.com
Signed-off-by: Arnaldo Carvalho de Melo

libbpf: Add uprobe ref counter offset support for USDT semaphores

2021-08-16T22:45:08+00:00

When attaching to uprobes through perf subsystem, it's possible to specify
offset of a so-called USDT semaphore, which is just a reference counted u16,
used by kernel to keep track of how many tracers are attached to a given
location. Support for this feature was added in [0], so just wire this through
uprobe_opts. This is important to enable implementing USDT attachment and
tracing through libbpf's bpf_program__attach_uprobe_opts() API.

  [0] a6ca88b241d5 ("trace_uprobe: support reference counter in fd-based uprobe")

Signed-off-by: Andrii Nakryiko 
Signed-off-by: Daniel Borkmann 
Link: https://lore.kernel.org/bpf/20210815070609.987780-16-andrii@kernel.org

libbpf: Add bpf_cookie to perf_event, kprobe, uprobe, and tp attach APIs

2021-08-16T22:45:08+00:00

Wire through bpf_cookie for all attach APIs that use perf_event_open under the
hood:
  - for kprobes, extend existing bpf_kprobe_opts with bpf_cookie field;
  - for perf_event, uprobe, and tracepoint APIs, add their _opts variants and
    pass bpf_cookie through opts.

For kernel that don't support BPF_LINK_CREATE for perf_events, and thus
bpf_cookie is not supported either, return error and log warning for user.

Signed-off-by: Andrii Nakryiko 
Signed-off-by: Daniel Borkmann 
Link: https://lore.kernel.org/bpf/20210815070609.987780-12-andrii@kernel.org

libbpf: Add bpf_cookie support to bpf_link_create() API

2021-08-16T22:45:08+00:00

Add ability to specify bpf_cookie value when creating BPF perf link with
bpf_link_create() low-level API.

Given BPF_LINK_CREATE command is growing and keeps getting new fields that are
specific to the type of BPF_LINK, extend libbpf side of bpf_link_create() API
and corresponding OPTS struct to accomodate such changes. Add extra checks to
prevent using incompatible/unexpected combinations of fields.

Signed-off-by: Andrii Nakryiko 
Signed-off-by: Daniel Borkmann 
Link: https://lore.kernel.org/bpf/20210815070609.987780-11-andrii@kernel.org

libbpf: Use BPF perf link when supported by kernel

2021-08-16T22:45:08+00:00

Detect kernel support for BPF perf link and prefer it when attaching to
perf_event, tracepoint, kprobe/uprobe. Underlying perf_event FD will be kept
open until BPF link is destroyed, at which point both perf_event FD and BPF
link FD will be closed.

This preserves current behavior in which perf_event FD is open for the
duration of bpf_link's lifetime and user is able to "disconnect" bpf_link from
underlying FD (with bpf_link__disconnect()), so that bpf_link__destroy()
doesn't close underlying perf_event FD.When BPF perf link is used, disconnect
will keep both perf_event and bpf_link FDs open, so it will be up to
(advanced) user to close them. This approach is demonstrated in bpf_cookie.c
selftests, added in this patch set.

Signed-off-by: Andrii Nakryiko 
Signed-off-by: Daniel Borkmann 
Link: https://lore.kernel.org/bpf/20210815070609.987780-10-andrii@kernel.org