linux-toradex.git/tools/perf/util/probe-event.h, branch v6.15

perf probe: Replace unacceptable characters when generating event name

2024-12-10T18:41:10+00:00

Replace unacceptable characters with '_' when generating event name from
the probing function name.

This is not for a C program. For the a C program, it will continue to
remove suffixes.

Note that this language checking depends on the debuginfo. So without
the debuginfo, perf probe will always replaces unacceptable characters
with '_'.

For example.

  $ ./perf probe -x cro3 -D \"cro3::cmd::servo::run_show\"
  p:probe_cro3/cro3_cmd_servo_run_show /work/cro3/target/x86_64-unknown-linux-gnu/debug/cro3:0x197530

  $ ./perf probe -x /work/go/example/outyet/main -D 'main.(*Server).poll'
  p:probe_main/main_Server_poll /work/go/example/outyet/main:0x353040

Signed-off-by: Masami Hiramatsu 
Cc: Alexander Lobakin 
Cc: Dima Kogan 
Cc: Ian Rogers 
Cc: Ingo Molnar 
Cc: Namhyung Kim 
Cc: Peter Zijlstra 
Cc: Przemek Kitszel 
Link: https://lore.kernel.org/r/173145728160.2747044.18089011235495186810.stgit@mhiramat.roam.corp.google.com
[ Removed some extra tabs in the new struct fields ]
Signed-off-by: Arnaldo Carvalho de Melo

perf: Remove unused del_perf_probe_events()

2024-11-16T20:07:31+00:00

del_perf_probe_events() last use was removed by commit 3d6dfae889174340
("perf parse-events: Remove BPF event support")

Remove it.

It was the last user of probe_file__del_events(), so remove it as well.

Signed-off-by: Dr. David Alan Gilbert 
Cc: Adrian Hunter 
Cc: Alexander Shishkin 
Cc: Ian Rogers 
Cc: Ingo Molnar 
Cc: Jiri Olsa 
Cc: Kan Liang 
Cc: Mark Rutland 
Cc: Namhyung Kim 
Cc: Peter Zijlstra 
Link: https://lore.kernel.org/r/20241022002940.302946-1-linux@treblig.org
Signed-off-by: Arnaldo Carvalho de Melo

perf probe: Remove unused add_perf_probe_events

2024-10-09T17:52:08+00:00

add_perf_probe_events has been unused since 2015's commit
b02137cc6550 ("perf probe: Move print logic into cmd_probe()")
which confusingly now uses perf_add_probe_events.

Remove it.

Signed-off-by: Dr. David Alan Gilbert 
Cc: Masami Hiramatsu 
Link: https://lore.kernel.org/r/20240929010659.430208-1-linux@treblig.org
Signed-off-by: Namhyung Kim

perf probe: Make synthesize_perf_probe_point() private to probe-event.c

2023-08-07T19:40:29+00:00

Not used in any other place, so just make it static.

Cc: Adrian Hunter 
Cc: Ian Rogers 
Cc: Jiri Olsa 
Cc: Masami Hiramatsu 
Cc: Namhyung Kim 
Link: https://lore.kernel.org/lkml/ZM0pjfOe6R4X%2Fcql@kernel.org/
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: 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: Trace a magic number if variable is not found

2019-11-18T22:09:23+00:00

Trace a magic number as immediate value if the target variable is not
found at some probe points which is based on one probe event.

This feature is good for the case if you trace a source code line with
some local variables, which is compiled into several instructions and
some of the variables are optimized out on some instructions.

Even if so, with this feature, perf probe trace a magic number instead
of such disappeared variables and fold those probes on one event.

E.g. without this patch:

  # perf probe -D "pud_page_vaddr pud"
  Failed to find 'pud' in this function.
  Failed to find 'pud' in this function.
  Failed to find 'pud' in this function.
  Failed to find 'pud' in this function.
  Failed to find 'pud' in this function.
  Failed to find 'pud' in this function.
  Failed to find 'pud' in this function.
  Failed to find 'pud' in this function.
  Failed to find 'pud' in this function.
  Failed to find 'pud' in this function.
  Failed to find 'pud' in this function.
  Failed to find 'pud' in this function.
  Failed to find 'pud' in this function.
  Failed to find 'pud' in this function.
  Failed to find 'pud' in this function.
  Failed to find 'pud' in this function.
  p:probe/pud_page_vaddr _text+23480787 pud=%ax:x64
  p:probe/pud_page_vaddr _text+23808453 pud=%bp:x64
  p:probe/pud_page_vaddr _text+23558082 pud=%ax:x64
  p:probe/pud_page_vaddr _text+328373 pud=%r8:x64
  p:probe/pud_page_vaddr _text+348448 pud=%bx:x64
  p:probe/pud_page_vaddr _text+23816818 pud=%bx:x64

With this patch:

  # perf probe -D "pud_page_vaddr pud" | head
  spurious_kernel_fault is blacklisted function, skip it.
  vmalloc_fault is blacklisted function, skip it.
  p:probe/pud_page_vaddr _text+23480787 pud=%ax:x64
  p:probe/pud_page_vaddr _text+149051 pud=\deade12d:x64
  p:probe/pud_page_vaddr _text+23808453 pud=%bp:x64
  p:probe/pud_page_vaddr _text+315926 pud=\deade12d:x64
  p:probe/pud_page_vaddr _text+23807209 pud=\deade12d:x64
  p:probe/pud_page_vaddr _text+23557365 pud=%ax:x64
  p:probe/pud_page_vaddr _text+314097 pud=%di:x64
  p:probe/pud_page_vaddr _text+314015 pud=\deade12d:x64
  p:probe/pud_page_vaddr _text+313893 pud=\deade12d:x64
  p:probe/pud_page_vaddr _text+324083 pud=\deade12d:x64

Signed-off-by: Masami Hiramatsu 
Cc: Namhyung Kim 
Cc: Ravi Bangoria 
Cc: Steven Rostedt (VMware) 
Cc: Tom Zanussi 
Link: http://lore.kernel.org/lkml/157406476931.24476.6261475888681844285.stgit@devnote2
Signed-off-by: Arnaldo Carvalho de Melo

perf-probe: Add user memory access attribute support

2019-05-26T03:04:42+00:00

Add user memory access attribute for kprobe event arguments.
If a given 'local variable' is in user-space, User can
specify memory access method by '@user' suffix. This is
not only for string but also for data structure.

If we access a field of data structure in user memory from
kernel on some arch, it will fail. e.g.

 perf probe -a "sched_setscheduler param->sched_priority"

This will fail to access the "param->sched_priority" because
the param is __user pointer. Instead, we can now specify
@user suffix for such argument.

 perf probe -a "sched_setscheduler param->sched_priority@user"

Note that kernel memory access with "@user" must always fail
on any arch.

Link: http://lkml.kernel.org/r/155789874562.26965.10836126971405890891.stgit@devnote2

Acked-by: Ingo Molnar 
Signed-off-by: Masami Hiramatsu 
Signed-off-by: Steven Rostedt (VMware)

perf namespaces: Remove namespaces.h from .h headers

2019-01-25T14:12:09+00:00

There we need just forward declarations, so remove it and add it just on
the .c files that actually touch the struct definitions.

Cc: Adrian Hunter 
Cc: Jiri Olsa 
Cc: Namhyung Kim 
Link: https://lkml.kernel.org/n/tip-wsjxzt99p83jubt6hu0med0f@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo

perf probe: Support SDT markers having reference counter (semaphore)

2018-09-24T08:44:54+00:00

With this, perf buildid-cache will save SDT markers with reference
counter in probe cache. Perf probe will be able to probe markers
having reference counter. Ex,

  # readelf -n /tmp/tick | grep -A1 loop2
    Name: loop2
    ... Semaphore: 0x0000000010020036

  # ./perf buildid-cache --add /tmp/tick
  # ./perf probe sdt_tick:loop2
  # ./perf stat -e sdt_tick:loop2 /tmp/tick
    hi: 0
    hi: 1
    hi: 2
    ^C
     Performance counter stats for '/tmp/tick':
                 3      sdt_tick:loop2
       2.561851452 seconds time elapsed

Link: http://lkml.kernel.org/r/20180820044250.11659-5-ravi.bangoria@linux.ibm.com

Acked-by: Arnaldo Carvalho de Melo 
Acked-by: Masami Hiramatsu 
Acked-by: Srikar Dronamraju 
Reviewed-by: Song Liu 
Tested-by: Song Liu 
Signed-off-by: Ravi Bangoria 
Signed-off-by: Steven Rostedt (VMware)