linux-toradex.git/tools/perf/util/probe-event.c, branch v6.3-rc3

perf probe: Update the exit error codes in function try_to_find_probe_trace_event

2023-02-06T18:00:05+00:00

try_to_find_probe_trace_events() uses return error code as ENOENT in two
places.

First place is after open_debuginfo() when opening debuginfo fails and
secondly, after when not finding the probe point.

This function is invoked during BPF load and there are other exit points
in this code path which returns ENOENT. This makes it difficult to
understand the exact reason for exit.

Patches changes the exit code from ENOENT to:

- ENODATA when it fails to find debuginfo

- ENODEV when it fails to find probe point

Signed-off-by: Athira Rajeev 
Cc: Andi Kleen 
Cc: Disha Goel 
Cc: Ian Rogers 
Cc: James Clark 
Cc: Jiri Olsa 
Cc: Kajol Jain 
Cc: Madhavan Srinivasan 
Cc: Michael Ellerman 
Cc: Nageswara R Sastry 
Cc: Namhyung Kim 
Cc: linuxppc-dev@lists.ozlabs.org
Link: https://lore.kernel.org/r/20230105121742.92249-1-atrajeev@linux.vnet.ibm.com
Signed-off-by: Arnaldo Carvalho de Melo

perf dso: Hold lock when accessing nsinfo

2022-10-04T11:55:20+00:00

There may be threads racing to update dso->nsinfo:

  https://lore.kernel.org/linux-perf-users/CAP-5=fWZH20L4kv-BwVtGLwR=Em3AOOT+Q4QGivvQuYn5AsPRg@mail.gmail.com/

Holding the dso->lock avoids use-after-free, memory leaks and other such
bugs. Apply the fix in:

  https://lore.kernel.org/linux-perf-users/20211118193714.2293728-1-irogers@google.com/

of there being a missing nsinfo__put now that the accesses are data race
free. Fixes test "Lookup mmap thread" when compiled with address
sanitizer.

Signed-off-by: Ian Rogers 
Reviewed-by: Adrian Hunter 
Cc: Alexander Shishkin 
Cc: Alexandre Truong 
Cc: Alexey Bayduraev 
Cc: Andi Kleen 
Cc: Andres Freund 
Cc: Andrii Nakryiko 
Cc: André Almeida 
Cc: Athira Jajeev 
Cc: Christophe JAILLET 
Cc: Colin Ian King 
Cc: Dario Petrillo 
Cc: Darren Hart 
Cc: Dave Marchevsky 
Cc: Davidlohr Bueso 
Cc: Fangrui Song 
Cc: Hewenliang 
Cc: Ingo Molnar 
Cc: James Clark 
Cc: Jason Wang 
Cc: Jiri Olsa 
Cc: Kajol Jain 
Cc: Kim Phillips 
Cc: Leo Yan 
Cc: Mark Rutland 
Cc: Martin Liška 
Cc: Masami Hiramatsu 
Cc: Nathan Chancellor 
Cc: Nick Desaulniers 
Cc: Pavithra Gurushankar 
Cc: Peter Zijlstra 
Cc: Quentin Monnet 
Cc: Ravi Bangoria 
Cc: Remi Bernon 
Cc: Riccardo Mancini 
Cc: Song Liu 
Cc: Stephane Eranian 
Cc: Thomas Gleixner 
Cc: Thomas Richter 
Cc: Tom Rix 
Cc: Weiguo Li 
Cc: Wenyu Liu 
Cc: William Cohen 
Cc: Zechuan Chen 
Cc: bpf@vger.kernel.org
Cc: llvm@lists.linux.dev
Cc: yaowenbin 
Link: https://lore.kernel.org/r/20220826164242.43412-15-irogers@google.com
Signed-off-by: Arnaldo Carvalho de Melo

perf probe: Fix an error handling path in 'parse_perf_probe_command()'

2022-08-10T13:44:02+00:00

If a memory allocation fail, we should branch to the error handling path
in order to free some resources allocated a few lines above.

Fixes: 15354d54698648e2 ("perf probe: Generate event name with line number")
Signed-off-by: Christophe JAILLET 
Acked-by: Masami Hiramatsu 
Cc: Alexander Shishkin 
Cc: Ingo Molnar 
Cc: Jiri Olsa 
Cc: kernel-janitors@vger.kernel.org
Cc: Mark Rutland 
Cc: Namhyung Kim 
Cc: Peter Zijlstra 
Link: https://lore.kernel.org/r/b71bcb01fa0c7b9778647235c3ab490f699ba278.1659797452.git.christophe.jaillet@wanadoo.fr
Signed-off-by: Arnaldo Carvalho de Melo

perf probe: Fix duplicated 'the' in comment

2022-07-20T14:09:11+00:00

The double `the' is duplicated in the comment, remove one.

Signed-off-by: Jason Wang 
Cc: Alexander Shishkin 
Cc: Ian Rogers 
Cc: Jiri Olsa 
Cc: Mark Rutland 
Cc: Masami Hiramatsu 
Cc: Namhyung Kim 
Cc: Peter Zijlstra 
Cc: Yang Jihong 
Cc: Zechuan Chen 
Link: http://lore.kernel.org/lkml/20220716043957.42829-1-wangborong@cdjrlc.com
Signed-off-by: Arnaldo Carvalho de Melo

perf maps: Use a pointer for kmaps

2022-02-14T19:47:13+00:00

struct maps is reference counted, using a pointer is more idiomatic.

Committer notes:

Delay:

   maps = machine__kernel_maps(&vmlinux);

To after:

  machine__init(&vmlinux, "", HOST_KERNEL_ID);

To avoid this on f34:

  In file included from /var/home/acme/git/perf/tools/perf/util/build-id.h:10,
                   from /var/home/acme/git/perf/tools/perf/util/dso.h:13,
                   from tests/vmlinux-kallsyms.c:8:
  In function ‘machine__kernel_maps’,
      inlined from ‘test__vmlinux_matches_kallsyms’ at tests/vmlinux-kallsyms.c:122:22:
  /var/home/acme/git/perf/tools/perf/util/machine.h:86:23: error: ‘vmlinux.kmaps’ is used uninitialized [-Werror=uninitialized]
     86 |         return machine->kmaps;
        |                ~~~~~~~^~~~~~~
  tests/vmlinux-kallsyms.c: In function ‘test__vmlinux_matches_kallsyms’:
  tests/vmlinux-kallsyms.c:121:34: note: ‘vmlinux’ declared here
    121 |         struct machine kallsyms, vmlinux;
        |                                  ^~~~~~~
  cc1: all warnings being treated as errors

Signed-off-by: Ian Rogers 
Cc: Adrian Hunter 
Cc: Alexander Shishkin 
Cc: Alexey Bayduraev 
Cc: Andi Kleen 
Cc: Andrew Morton 
Cc: André Almeida 
Cc: Andy Shevchenko 
Cc: Darren Hart 
Cc: Davidlohr Bueso 
Cc: Dmitriy Vyukov 
Cc: Eric Dumazet 
Cc: German Gomez 
Cc: Hao Luo 
Cc: James Clark 
Cc: Jin Yao 
Cc: Jiri Olsa 
Cc: John Garry 
Cc: Kajol Jain 
Cc: Kan Liang 
Cc: Leo Yan 
Cc: Madhavan Srinivasan 
Cc: Mark Rutland 
Cc: Masami Hiramatsu 
Cc: Miaoqian Lin 
Cc: Namhyung Kim 
Cc: Peter Zijlstra 
Cc: Riccardo Mancini 
Cc: Shunsuke Nakamura 
Cc: Song Liu 
Cc: Stephane Eranian 
Cc: Stephen Brennan 
Cc: Steven Rostedt (VMware) 
Cc: Thomas Gleixner 
Cc: Thomas Richter 
Cc: Yury Norov 
Link: http://lore.kernel.org/lkml/20220211103415.2737789-6-irogers@google.com
Signed-off-by: Arnaldo Carvalho de Melo

perf probe: Fix ppc64 'perf probe add events failed' case

2022-01-18T12:24:58+00:00

Because of commit bf794bf52a80c627 ("powerpc/kprobes: Fix kallsyms
lookup across powerpc ABIv1 and ABIv2"), in ppc64 ABIv1, our perf
command eliminates the need to use the prefix "." at the symbol name.

But when the command "perf probe -a schedule" is executed on ppc64
ABIv1, it obtains two symbol address information through /proc/kallsyms,
for example:

  cat /proc/kallsyms | grep -w schedule
  c000000000657020 T .schedule
  c000000000d4fdb8 D schedule

The symbol "D schedule" is not a function symbol, and perf will print:
"p:probe/schedule _text+13958584"Failed to write event: Invalid argument

Therefore, when searching symbols from map and adding probe point for
them, a symbol type check is added. If the type of symbol is not a
function, skip it.

Fixes: bf794bf52a80c627 ("powerpc/kprobes: Fix kallsyms lookup across powerpc ABIv1 and ABIv2")
Signed-off-by: Zechuan Chen 
Acked-by: Masami Hiramatsu 
Cc: Alexander Shishkin 
Cc: Ingo Molnar 
Cc: Jianlin Lv 
Cc: Jin Yao 
Cc: Jiri Olsa 
Cc: Mark Rutland 
Cc: Michael Ellerman 
Cc: Namhyung Kim 
Cc: Naveen N. Rao 
Cc: Peter Zijlstra 
Cc: Ravi Bangoria 
Cc: Yang Jihong 
Link: https://lore.kernel.org/r/20211228111338.218602-1-chenzechuan1@huawei.com
Signed-off-by: Arnaldo Carvalho de Melo

perf probe: Fix add event failure when running 32-bit perf in a 64-bit kernel

2021-07-18T12:31:15+00:00

The "address" member of "struct probe_trace_point" uses long data type.
If kernel is 64-bit and perf program is 32-bit, size of "address"
variable is 32 bits.

As a result, upper 32 bits of address read from kernel are truncated, an
error occurs during address comparison in kprobe_warn_out_range().

Before:

  # perf probe -a schedule
  schedule is out of .text, skip it.
    Error: Failed to add events.

Solution:
  Change data type of "address" variable to u64 and change corresponding
address printing and value assignment.

After:

  # perf.new.new probe -a schedule
  Added new event:
    probe:schedule       (on schedule)

  You can now use it in all perf tools, such as:

          perf record -e probe:schedule -aR sleep 1

  # perf probe -l
    probe:schedule       (on schedule@kernel/sched/core.c)
  # perf record -e probe:schedule -aR sleep 1
  [ perf record: Woken up 1 times to write data ]
  [ perf record: Captured and wrote 0.156 MB perf.data (1366 samples) ]
  # perf report --stdio
  # To display the perf.data header info, please use --header/--header-only options.
  #
  #
  # Total Lost Samples: 0
  #
  # Samples: 1K of event 'probe:schedule'
  # Event count (approx.): 1366
  #
  # Overhead  Command          Shared Object      Symbol
  # ........  ...............  .................  ............
  #
       6.22%  migration/0      [kernel.kallsyms]  [k] schedule
       6.22%  migration/1      [kernel.kallsyms]  [k] schedule
       6.22%  migration/2      [kernel.kallsyms]  [k] schedule
       6.22%  migration/3      [kernel.kallsyms]  [k] schedule
       6.15%  migration/10     [kernel.kallsyms]  [k] schedule
       6.15%  migration/11     [kernel.kallsyms]  [k] schedule
       6.15%  migration/12     [kernel.kallsyms]  [k] schedule
       6.15%  migration/13     [kernel.kallsyms]  [k] schedule
       6.15%  migration/14     [kernel.kallsyms]  [k] schedule
       6.15%  migration/15     [kernel.kallsyms]  [k] schedule
       6.15%  migration/4      [kernel.kallsyms]  [k] schedule
       6.15%  migration/5      [kernel.kallsyms]  [k] schedule
       6.15%  migration/6      [kernel.kallsyms]  [k] schedule
       6.15%  migration/7      [kernel.kallsyms]  [k] schedule
       6.15%  migration/8      [kernel.kallsyms]  [k] schedule
       6.15%  migration/9      [kernel.kallsyms]  [k] schedule
       0.22%  rcu_sched        [kernel.kallsyms]  [k] schedule
  ...
  #
  # (Cannot load tips.txt file, please install perf!)
  #

Signed-off-by: Yang Jihong 
Acked-by: Masami Hiramatsu 
Cc: Alexander Shishkin 
Cc: Frank Ch. Eigler 
Cc: Ian Rogers 
Cc: Jianlin Lv 
Cc: Jin Yao 
Cc: Jiri Olsa 
Cc: Li Huafei 
Cc: Mark Rutland 
Cc: Namhyung Kim 
Cc: Peter Zijlstra 
Cc: Ravi Bangoria 
Cc: Srikar Dronamraju 
Link: http://lore.kernel.org/lkml/20210715063723.11926-1-yangjihong1@huawei.com
Signed-off-by: Arnaldo Carvalho de Melo

perf probe: Fix dso->nsinfo refcounting

2021-07-15T20:25:28+00:00

ASan reports a memory leak of nsinfo during the execution of:

 # perf test "31: Lookup mmap thread".

The leak is caused by a refcounted variable being replaced without
dropping the refcount.

This patch makes sure that the refcnt of nsinfo is decreased whenever
a refcounted variable is replaced with a new value.

Signed-off-by: Riccardo Mancini 
Fixes: 544abd44c7064c8a ("perf probe: Allow placing uprobes in alternate namespaces.")
Cc: Ian Rogers 
Cc: Jiri Olsa 
Cc: Krister Johansen 
Cc: Mark Rutland 
Cc: Namhyung Kim 
Cc: Peter Zijlstra 
Link: http://lore.kernel.org/lkml/55223bc8821b34ccb01f92ef1401c02b6a32e61f.1626343282.git.rickyman7@gmail.com
[ Split from a larger patch ]
Signed-off-by: Arnaldo Carvalho de Melo

perf probe: Add --bootconfig to output definition in bootconfig format

2021-06-18T16:50:05+00:00

Now the boot-time tracing supports kprobes events and that must be
written in bootconfig file in the following format.

  ftrace.event.kprobes..probes = 

'perf probe' already supports --definition (-D) action to show probe
definitions, but the format is for tracefs:

  [p|r][:EVENT_NAME] 

This patch adds the --bootconfig option for -D action so that it outputs
the probe definitions in bootconfig format. E.g.

  $ perf probe --bootconfig -D "path_lookupat:7 err:s32 s:string"
  ftrace.event.kprobes.path_lookupat_L7.probe = 'path_lookupat.isra.0+309 err_s32=%ax:s32 s_string=+0(%r13):string'

Signed-off-by: Masami Hiramatsu 
Cc: Alexander Shishkin 
Cc: Jiri Olsa 
Cc: Mark Rutland 
Cc: Namhyung Kim 
Cc: Peter Zijlstra 
Link: http://lore.kernel.org/lkml/162282412351.452340.14871995440005640114.stgit@devnote2
Signed-off-by: Arnaldo Carvalho de Melo

perf probe: Cleanup synthesize_probe_trace_command()

2021-06-18T16:50:05+00:00

Cleanup synthesize_probe_trace_command() to simplify the code path.

Signed-off-by: Masami Hiramatsu 
Cc: Alexander Shishkin 
Cc: Jiri Olsa 
Cc: Mark Rutland 
Cc: Namhyung Kim 
Cc: Peter Zijlstra 
Link: http://lore.kernel.org/lkml/162282411361.452340.16886399333622147122.stgit@devnote2
Signed-off-by: Arnaldo Carvalho de Melo