linux-stable.git/tools/perf/util/thread_map.c, branch linux-4.1.y

perf thread_map: Correctly size buffer used with dirent->dt_name

2017-07-31T17:37:53+00:00

[ Upstream commit bdf23a9a190d7ecea092fd5c4aabb7d4bd0a9980 ]

The size of dirent->dt_name is NAME_MAX + 1, but the size for the 'path'
buffer is hard coded at 256, which may truncate it because we also
prepend "/proc/", so that all that into account and thank gcc 7 for this
warning:

  /git/linux/tools/perf/util/thread_map.c: In function 'thread_map__new_by_uid':
  /git/linux/tools/perf/util/thread_map.c:119:39: error: '%s' directive output may be truncated writing up to 255 bytes into a region of size 250 [-Werror=format-truncation=]
     snprintf(path, sizeof(path), "/proc/%s", dirent->d_name);
                                         ^~
  In file included from /usr/include/stdio.h:939:0,
                   from /git/linux/tools/perf/util/thread_map.c:5:
  /usr/include/bits/stdio2.h:64:10: note: '__builtin___snprintf_chk' output between 7 and 262 bytes into a destination of size 256
     return __builtin___snprintf_chk (__s, __n, __USE_FORTIFY_LEVEL - 1,
            ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
          __bos (__s), __fmt, __va_arg_pack ());
          ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

Cc: Adrian Hunter 
Cc: David Ahern 
Cc: Jiri Olsa 
Cc: Namhyung Kim 
Cc: Wang Nan 
Link: http://lkml.kernel.org/n/tip-csy0r8zrvz5efccgd4k12c82@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo 
Signed-off-by: Sasha Levin

perf thread_map: Create dummy constructor out of open coded equivalent

2014-10-14T20:32:52+00:00

Create a dummy thread_map, one that has just one entry and it is -1,
meaning 'all threads', as this ends up going down to perf_event_open().

Cc: Adrian Hunter 
Cc: Borislav Petkov 
Cc: David Ahern 
Cc: Don Zickus 
Cc: Frederic Weisbecker 
Cc: Jean Pihet 
Cc: Jiri Olsa 
Cc: Mike Galbraith 
Cc: Namhyung Kim 
Cc: Paul Mackerras 
Cc: Peter Zijlstra 
Cc: Stephane Eranian 
Link: http://lkml.kernel.org/n/tip-8av26cz8uxmbnihl5mmrygp9@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo

perf tools: Use zfree to help detect use after free bugs

2013-12-27T20:08:19+00:00

Several areas already used this technique, so do some audit to
consistently use it elsewhere.

Cc: Adrian Hunter 
Cc: David Ahern 
Cc: Frederic Weisbecker 
Cc: Jiri Olsa 
Cc: Mike Galbraith 
Cc: Namhyung Kim 
Cc: Paul Mackerras 
Cc: Peter Zijlstra 
Cc: Stephane Eranian 
Link: http://lkml.kernel.org/n/tip-9sbere0kkplwe45ak6rk4a1f@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo

perf tools: Introduce zfree

2013-12-27T18:17:00+00:00

For the frequent idiom of:

   free(ptr);
   ptr = NULL;

Make it expect a pointer to the pointer being freed, so that it becomes
clear at first sight that the variable being freed is being modified.

Cc: Adrian Hunter 
Cc: David Ahern 
Cc: Frederic Weisbecker 
Cc: Jiri Olsa 
Cc: Mike Galbraith 
Cc: Namhyung Kim 
Cc: Paul Mackerras 
Cc: Peter Zijlstra 
Cc: Stephane Eranian 
Link: http://lkml.kernel.org/n/tip-pfw02ezuab37kha18wlut7ir@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo

perf tools: fix thread_map__new_by_pid_str() memory leak in error path

2012-05-25T14:40:59+00:00

The namelist array (including its content) was not freed if we fail to
realloc a new 'threads' structure.

Signed-off-by: Franck Bui-Huu 
Cc: David Ahern 
Link: http://lkml.kernel.org/r/1337952109-31995-1-git-send-email-fbuihuu@gmail.com
Signed-off-by: Arnaldo Carvalho de Melo

perf tools: fix broken perf record -a mode

2012-02-21T17:05:43+00:00

The following commit:
b52956c perf tools: Allow multiple threads or processes in record, stat, top

introduced a bug in the thread_map code which caused perf record -a to
not setup system-wide monitoring properly.

$ taskset -c 1 noploop 1000 &
$ perf record -a -C 1 sleep 10
$ perf report -D | tail -20
cycles stats:
           TOTAL events:       4413
            MMAP events:       4025
            COMM events:        340
          SAMPLE events:         48

Here I was expecting about 10,000 samples and not 48.

In system-wide mode, the PID passed to perf_event_open() must be -1 and
it was 0. That caused the kernel to setup a per-process event on PID:0.
Consequently, the number of samples captured does not correspond to the
requested measurement.

The following one-liner fixes the problem for me with or without -C.

I would also suggest to change the malloc() to something that matches
the struct definition. thread_map->map[] is declared as int map[] and
not pid_t map[]. If map[] can only contain pids, then change the struct
definition.

Acked-by: David Ahern 
Cc: David Ahern 
Cc: Eric Dumazet 
Cc: Ingo Molnar 
Cc: Peter Zijlstra 
Link: http://lkml.kernel.org/r/20120221145424.GA6757@quad
Signed-off-by: Stephane Eranian 
Signed-off-by: Arnaldo Carvalho de Melo

perf tools: Allow multiple threads or processes in record, stat, top

2012-02-14T00:54:11+00:00

Allow a user to collect events for multiple threads or processes
using a comma separated list.

e.g., collect data on a VM and its vhost thread:
  perf top -p 21483,21485
  perf stat -p 21483,21485 -ddd
  perf record -p 21483,21485

or monitoring vcpu threads
  perf top -t 21488,21489
  perf stat -t 21488,21489 -ddd
  perf record -t 21488,21489

Cc: Frederic Weisbecker 
Cc: Ingo Molnar 
Cc: Paul Mackerras 
Cc: Peter Zijlstra 
Cc: Thomas Gleixner 
Link: http://lkml.kernel.org/r/1328718772-16688-1-git-send-email-dsahern@gmail.com
Signed-off-by: David Ahern 
Signed-off-by: Arnaldo Carvalho de Melo

perf tools: Introduce per user view

2012-01-24T21:47:37+00:00

The new --uid command line option will show only the tasks for a given
user, using the proc interface to figure out the existing tasks.

Kernel work is needed to close races at startup, but this should already
be useful in many use cases.

Cc: David Ahern 
Cc: Frederic Weisbecker 
Cc: Mike Galbraith 
Cc: Paul Mackerras 
Cc: Peter Zijlstra 
Cc: Stephane Eranian 
Link: http://lkml.kernel.org/n/tip-bdnspm000gw2l984a2t53o8z@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo

perf tools: Add fprintf methods for thread_map and cpu_map classes

2012-01-24T21:46:48+00:00

For helping with debugging.

Cc: David Ahern 
Cc: Frederic Weisbecker 
Cc: Mike Galbraith 
Cc: Paul Mackerras 
Cc: Peter Zijlstra 
Cc: Stephane Eranian 
Link: http://lkml.kernel.org/n/tip-m06n4rp7pwr6dlzwoq89cl69@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo

perf threads: Move thread_map to separate file

2011-01-24T12:59:00+00:00

To untangle it from struct thread handling, that is tied to symbols, etc.

Right now in the python bindings I'm working on I need just a subset of
the util/ files, untangling it allows me to do that.

Cc: Frederic Weisbecker 
Cc: Ingo Molnar 
Cc: Mike Galbraith 
Cc: Paul Mackerras 
Cc: Peter Zijlstra 
Cc: Stephane Eranian 
Cc: Tom Zanussi 
LKML-Reference: 
Signed-off-by: Arnaldo Carvalho de Melo