linux-stable.git/tools/perf/builtin-script.c, branch linux-4.4.y

perf tools: Fix snprint warnings for gcc 8

2020-07-31T14:43:17+00:00

commit 77f18153c080855e1c3fb520ca31a4e61530121d upstream.

[Add an additional sprintf replacement in tools/perf/builtin-script.c]

With gcc 8 we get new set of snprintf() warnings that breaks the
compilation, one example:

  tests/mem.c: In function ‘check’:
  tests/mem.c:19:48: error: ‘%s’ directive output may be truncated writing \
        up to 99 bytes into a region of size 89 [-Werror=format-truncation=]
    snprintf(failure, sizeof failure, "unexpected %s", out);

The gcc docs says:

 To avoid the warning either use a bigger buffer or handle the
 function's return value which indicates whether or not its output
 has been truncated.

Given that all these warnings are harmless, because the code either
properly fails due to uncomplete file path or we don't care for
truncated output at all, I'm changing all those snprintf() calls to
scnprintf(), which actually 'checks' for the snprint return value so the
gcc stays silent.

Signed-off-by: Jiri Olsa 
Cc: Alexander Shishkin 
Cc: David Ahern 
Cc: Josh Poimboeuf 
Cc: Namhyung Kim 
Cc: Peter Zijlstra 
Cc: Sergey Senozhatsky 
Link: http://lkml.kernel.org/r/20180319082902.4518-1-jolsa@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo 
Signed-off-by: Greg Kroah-Hartman

perf script: Use readdir() instead of deprecated readdir_r()

2017-07-15T09:57:48+00:00

commit a5e8e825bd1704c488bf6a46936aaf3b9f203d6a upstream.

The readdir() function is thread safe as long as just one thread uses a
DIR, which is the case in 'perf script', so, to avoid breaking the build
with glibc-2.23.90 (upcoming 2.24), use it instead of readdir_r().

See: http://man7.org/linux/man-pages/man3/readdir.3.html

"However, in modern implementations (including the glibc implementation),
concurrent calls to readdir() that specify different directory streams
are thread-safe.  In cases where multiple threads must read from the
same directory stream, using readdir() with external synchronization is
still preferable to the use of the deprecated readdir_r(3) function."

Noticed while building on a Fedora Rawhide docker container.

Cc: Adrian Hunter 
Cc: David Ahern 
Cc: Jiri Olsa 
Cc: Namhyung Kim 
Cc: Wang Nan 
Link: http://lkml.kernel.org/n/tip-mt3xz7n2hl49ni2vx7kuq74g@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo 
Signed-off-by: Greg Kroah-Hartman

perf script: Enable printing of branch stack

2015-10-29T20:16:20+00:00

This patch improves perf script by enabling printing of the
branch stack via the 'brstack' and 'brstacksym' arguments to
the field selection option -F. The option is off by default
and operates only if the perf.data file has branch stack content.

The branches are printed in to/from pairs. The most recent branch
is printed first. The number of branch entries vary based on the
underlying hardware and filtering used.

The brstack prints FROM/TO addresses in raw hexadecimal format.
The brstacksym prints FROM/TO addresses in symbolic form wherever
possible.

 $ perf script -F ip,brstack
  5d3000 0x401aa0/0x5d2000/M/-/-/-/0 ...

 $ perf script -F ip,brstacksym
  4011e0 noploop+0x0/noploop+0x0/P/-/-/0

The notation F/T/M/X/A/C describes the attributes of the branch.
F=from, T=to, M/P=misprediction/prediction, X=TSX, A=TSX abort, C=cycles (SKL)

Signed-off-by: Stephane Eranian 
Cc: Adrian Hunter 
Cc: Andi Kleen 
Cc: David Ahern 
Cc: Jiri Olsa 
Cc: Kan Liang 
Cc: Namhyung Kim 
Cc: Peter Zijlstra 
Cc: Yuanfang Chen 
Link: http://lkml.kernel.org/r/1441039273-16260-5-git-send-email-eranian@google.com
Signed-off-by: Arnaldo Carvalho de Melo

perf tools: Introduce usage_with_options_msg()

2015-10-27T12:28:44+00:00

Now usage_with_options() setup a pager before printing message so normal
printf() or pr_err() will not be shown.  The usage_with_options_msg()
can be used to print some help message before usage strings.

Signed-off-by: Namhyung Kim 
Acked-by: Masami Hiramatsu 
Cc: David Ahern 
Cc: Jiri Olsa 
Cc: Peter Zijlstra 
Link: http://lkml.kernel.org/r/1445701767-12731-4-git-send-email-namhyung@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo

perf script: Check output fields only for samples

2015-10-19T21:05:59+00:00

There's no need to check sampling output fields for events without
perf_event_attr::sample_type field set.

Signed-off-by: Jiri Olsa 
Tested-by: Kan Liang 
Cc: David Ahern 
Cc: Namhyung Kim 
Cc: Peter Zijlstra 
Link: http://lkml.kernel.org/r/1444992092-17897-51-git-send-email-jolsa@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo

perf script: Make scripting_max_stack value allow for synthesized callchains

2015-09-28T20:09:41+00:00

perf script has a setting to set the maximum stack depth when processing
callchains.  The setting defaults to the hard-coded maximum definition
PERF_MAX_STACK_DEPTH which is 127.

It is possible, when processing instruction traces, to synthesize
callchains.  Synthesized callchains do not have the kernel size
limitation and are whatever size the user requests, although validation
presently prevents the user requested a value greater that 1024.  The
default value is 16.

To allow for synthesized callchains, make the scripting_max_stack value
at least the same size as the synthesized callchain size.

Signed-off-by: Adrian Hunter 
Cc: Jiri Olsa 
Link: http://lkml.kernel.org/r/1443186956-18718-21-git-send-email-adrian.hunter@intel.com
Signed-off-by: Arnaldo Carvalho de Melo

perf scripting python: Allow for max_stack greater than PERF_MAX_STACK_DEPTH

2015-09-28T20:09:12+00:00

Use the scripting_max_stack value to allow for values greater than
PERF_MAX_STACK_DEPTH.

Signed-off-by: Adrian Hunter 
Cc: Jiri Olsa 
Link: http://lkml.kernel.org/r/1443186956-18718-20-git-send-email-adrian.hunter@intel.com
Signed-off-by: Arnaldo Carvalho de Melo

perf script: Add a setting for maximum stack depth

2015-09-28T20:08:48+00:00

Add a setting for maximum stack depth in preparation for allowing for
synthesized callchains.

Signed-off-by: Adrian Hunter 
Cc: Jiri Olsa 
Link: http://lkml.kernel.org/r/1443186956-18718-19-git-send-email-adrian.hunter@intel.com
Signed-off-by: Arnaldo Carvalho de Melo

perf script: Allow time to be displayed in nanoseconds

2015-09-28T19:46:05+00:00

Add option --ns to display time to 9 decimal places.  That is useful in
some cases, for example when using Intel PT cycle accurate mode.

Signed-off-by: Adrian Hunter 
Cc: Jiri Olsa 
Link: http://lkml.kernel.org/r/1443186956-18718-6-git-send-email-adrian.hunter@intel.com
Signed-off-by: Arnaldo Carvalho de Melo

perf tools: Fix use of wrong event when processing exit events

2015-09-02T20:46:26+00:00

In a couple of cases the 'comm' member of 'union event' has been used
instead of the correct member ('fork') when processing exit events.

In the cases where it has been used incorrectly, only the 'pid' and
'tid' are affected.  The 'pid' value would be correct anyway because it
is in the same position in 'comm' and 'fork' events, but the 'tid' would
have been incorrectly assigned from 'ppid'.

However, for exit events, the kernel puts the current task in the 'ppid'
and 'ttid' which is the same as the exiting task.  That is 'ppid' ==
'pid' and if the task is not multi-threaded, 'pid' == 'tid' i.e. the
data goes wrong only when tracing multi-threaded programs.

It is hard to find an example of how this would produce an error in
practice.  There are 3 occurences of the fix:

1. perf script is only affected if !sample_id_all which only happens on
  old kernels.

2. intel_pt is only affected when decoding without timestamps
   and would probably still decode correctly - the exit event is
   only used to flush out data which anyway gets flushed at the
   end of the session

3. intel_bts also uses the exit event to flush data which
   would probably not cause errors as it would get flushed at
   the end of the session instead

Signed-off-by: Adrian Hunter 
Cc: Jiri Olsa 
Link: http://lkml.kernel.org/r/1439888825-27708-1-git-send-email-adrian.hunter@intel.com
Signed-off-by: Arnaldo Carvalho de Melo