Commit Graph

133 Commits

Author SHA1 Message Date
He Kuang
f19e80c640 perf probe: Fix segfault when probe with lazy_line to file
The first argument passed to find_probe_point_lazy() should be CU die,
which will be passed to die_walk_lines() when lazy_line matches.
Currently, when we probe with lazy_line pattern to file without function
name, NULL pointer is passed and causes a segment fault.

Can be reproduced as following:

  $ perf probe -k vmlinux --add='fs/super.c;s->s_count=1;'
  [ 1958.984658] perf[1020]: segfault at 10 ip 00007fc6e10d8c71 sp
  00007ffcbfaaf900 error 4 in libdw-0.161.so[7fc6e10ce000+34000]
  Segmentation fault

After this patch:

  $ perf probe -k vmlinux --add='fs/super.c;s->s_count=1;'
  Added new event:
  probe:_stext         (on @fs/super.c)

  You can now use it in all perf tools, such as:
    perf record -e probe:_stext -aR sleep 1

Signed-off-by: He Kuang <hekuang@huawei.com>
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Acked-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Wang Nan <wangnan0@huawei.com>
Link: http://lkml.kernel.org/r/1428925290-5623-3-git-send-email-hekuang@huawei.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2015-04-13 20:12:21 -03:00
Naohiro Aota
09ed8975c4 perf probe: Find compilation directory path for lazy matching
If we use lazy matching, it failed to open a souce file if perf command
is invoked outside of compilation directory:

$ perf probe -a '__schedule;clear_*'
Failed to open kernel/sched/core.c: No such file or directory
  Error: Failed to add events. (-2)

OTOH, other commands like "probe -L" can solve the souce directory by
themselves. Let's make it possible for lazy matching too!

Signed-off-by: Naohiro Aota <naota@elisp.net>
Acked-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Cc: He Kuang <hekuang@huawei.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/1426223923-1493-1-git-send-email-naota@elisp.net
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2015-04-13 20:11:05 -03:00
Masami Hiramatsu
c72738355b perf probe: Fix to track down unnamed union/structure members
Fix 'perf probe' to track down unnamed union/structure members.

perf probe did not track down the tree of unnamed union/structure
members, since it just failed to find given "name" in a parent
structure/union.  To solve this issue, I've introduced 2 changes.

- Fix die_find_member() to track down the type-DIE if it is
  unnamed, and if it contains the specified member, returns the
  unnamed member.
  (note that we don't return found member, since unnamed member
   has the offset in the parent structure)
- Fix convert_variable_fields() to track down the unnamed union/
  structure (one-by-one).

With this patch, perf probe can access unnamed fields:
  -----
  #./perf probe -nfx ./perf lock__delete ops 'locked_ops=ops->locked.ops'
  Added new event:
    probe_perf:lock__delete (on lock__delete in /home/mhiramat/ksrc/linux-3/tools/perf/perf with ops locked_ops=ops->locked.ops)

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

          perf record -e probe_perf:lock__delete -aR sleep 1
  -----

Reported-by: Arnaldo Carvalho de Melo <acme@kernel.org>
Report-Link: https://lkml.org/lkml/2015/3/5/431
Signed-off-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/20150402073312.14482.37942.stgit@localhost.localdomain
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2015-04-02 13:18:44 -03:00
Masami Hiramatsu
0104fe69e0 perf probe: Remove bias offset to find probe point by address
Remove bias offset to find probe point by address.

Without this patch, probe points on kernel and executables are shown
correctly, but do not work with libraries:

  # ./perf probe -l
    probe:do_fork        (on do_fork@kernel/fork.c)
    probe_libc:malloc    (on malloc in /usr/lib64/libc-2.17.so)
    probe_perf:strlist__new (on strlist__new@util/strlist.c in /home/mhiramat/ksrc/linux-3/tools/perf/perf)

Removing bias allows it to show it as real place:

  # ./perf probe -l
    probe:do_fork        (on do_fork@kernel/fork.c)
    probe_libc:malloc    (on __libc_malloc@malloc/malloc.c in /usr/lib64/libc-2.17.so)
    probe_perf:strlist__new (on strlist__new@util/strlist.c in /home/mhiramat/ksrc/linux-3/tools/perf/perf)

Signed-off-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Naohiro Aota <naota@elisp.net>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/20150302124946.9191.64085.stgit@localhost.localdomain
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2015-03-02 12:34:38 -03:00
Masami Hiramatsu
e1ecbbc3fa perf probe: Fix to handle optimized not-inlined functions
Fix to handle optimized no-inline functions which have only function
definition but no actual instance at that point.

To fix this problem, we need to find actual instance of the function.

Without this patch:
  ----
  # perf probe -a __up
  Failed to get entry address of __up.
    Error: Failed to add events.
  # perf probe -L __up
  Specified source line is not found.
    Error: Failed to show lines.
  ----

With this patch:
  ----
  # perf probe -a __up
  Added new event:
    probe:__up           (on __up)

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

          perf record -e probe:__up -aR sleep 1

  # perf probe -L __up
  <__up@/home/fedora/ksrc/linux-3/kernel/locking/semaphore.c:0>
        0  static noinline void __sched __up(struct semaphore *sem)
           {
                  struct semaphore_waiter *waiter = list_first_entry(&sem->wait_
                                                          struct semaphore_waite
        4         list_del(&waiter->list);
        5         waiter->up = true;
        6         wake_up_process(waiter->task);
        7  }
  ----

Signed-off-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/20150130093744.30575.43290.stgit@localhost.localdomain
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2015-02-06 11:46:36 +01:00
Namhyung Kim
4093325f82 perf probe: Fix crash in dwarf_getcfi_elf
David reported that perf can segfault when adding an uprobe event like
this:

  $ perf probe -x /lib64/libc-2.14.90.so -a 'malloc  size=%di'

  (gdb) bt
  #0  parse_eh_frame_hdr (hdr=0x0, hdr_size=2596, hdr_vaddr=71788,
      ehdr=0x7fffffffd390, eh_frame_vaddr=
      0x7fffffffd378, table_entries=0x8808d8, table_encoding=0x8808e0 "") at
      dwarf_getcfi_elf.c:79
  #1  0x000000385f81615a in getcfi_scn_eh_frame (hdr_vaddr=71788,
      hdr_scn=0x8839b0, shdr=0x7fffffffd2f0, scn=<optimized out>,
      ehdr=0x7fffffffd390, elf=0x882b30) at dwarf_getcfi_elf.c:231
  #2  getcfi_shdr (ehdr=0x7fffffffd390, elf=0x882b30) at dwarf_getcfi_elf.c:283
  #3  dwarf_getcfi_elf (elf=0x882b30) at dwarf_getcfi_elf.c:309
  #4  0x00000000004d5bac in debuginfo__find_probes (pf=0x7fffffffd4f0,
      dbg=Unhandled dwarf expression opcode 0xfa) at util/probe-finder.c:993
  #5  0x00000000004d634a in debuginfo__find_trace_events (dbg=0x880840,
      pev=<optimized out>, tevs=0x880f88, max_tevs=<optimized out>) at
      util/probe-finder.c:1200
  #6  0x00000000004aed6b in try_to_find_probe_trace_events (target=0x881b20
      "/lib64/libpthread-2.14.90.so",
      max_tevs=128, tevs=0x880f88, pev=0x859b30) at util/probe-event.c:482
  #7  convert_to_probe_trace_events (target=0x881b20
      "/lib64/libpthread-2.14.90.so", max_tevs=128, tevs=0x880f88,
      pev=0x859b30) at util/probe-event.c:2356
  #8  add_perf_probe_events (pevs=<optimized out>, npevs=1, max_tevs=128,
      target=0x881b20 "/lib64/libpthread-2.14.90.so", force_add=false) at
      util/probe-event.c:2391
  #9  0x000000000044014f in __cmd_probe (argc=<optimized out>,
      argv=0x7fffffffe2f0, prefix=Unhandled dwarf expression opcode 0xfa) at
      at builtin-probe.c:488
  #10 0x0000000000440313 in cmd_probe (argc=5, argv=0x7fffffffe2f0,
      prefix=<optimized out>) at builtin-probe.c:506
  #11 0x000000000041d133 in run_builtin (p=0x805680, argc=5,
      argv=0x7fffffffe2f0) at perf.c:341
  #12 0x000000000041c8b2 in handle_internal_command (argv=<optimized out>,
      argc=<optimized out>) at perf.c:400
  #13 run_argv (argv=<optimized out>, argcp=<optimized out>) at perf.c:444
  #14 main (argc=5, argv=0x7fffffffe2f0) at perf.c:559

And I found a related commit (5704c8c4fa71 "getcfi_scn_eh_frame: Don't
crash and burn when .eh_frame bits aren't there.") in elfutils that can
lead to a unexpected crash like this.  To safely use the function, it
needs to check the .eh_frame section is a PROGBITS type.

Reported-by: David Ahern <dsahern@gmail.com>
Tested-by: David Ahern <dsahern@gmail.com>
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Acked-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Mark Wielaard <mjw@redhat.com>
Cc: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Link: http://lkml.kernel.org/r/20141230090533.GH6081@sejong
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2015-01-02 12:44:01 -03:00
Masami Hiramatsu
664fee3dc3 perf probe: Do not use dwfl_module_addrsym if dwarf_diename finds symbol name
Do not use dwfl_module_addrsym if dwarf_diename can find the symbol
name, since dwfl_module_addrsym can be failed on shared libraries.

Without this patch
  ----
  $ perf probe -x ../lib/traceevent/libtraceevent.so -V create_arg_op
  Failed to find symbol at 0x11df1
  Failed to find the address of create_arg_op
    Error: Failed to show vars.
  ----
With this patch
  ----
  $ perf probe -x ../lib/traceevent/libtraceevent.so -V create_arg_op
  Available variables at create_arg_op
          @<create_arg_op+0>
                  enum filter_op_type     btype
                  struct filter_arg*      arg
  ----

This bug was reported on linux-perf-users@vger.kernel.org.

Reported-by: david lerner <dlernerdroid@gmail.com>
Signed-off-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Cc: david lerner <dlernerdroid@gmail.com>
Cc: linux-perf-user@vger.kernel.org
Cc: yrl.pp-manager.tt@hitachi.com
Link: http://permalink.gmane.org/gmane.linux.kernel.perf.user/1691
Link: http://lkml.kernel.org/r/20140917084101.3722.25299.stgit@kbuild-f20.novalocal
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2014-09-17 18:01:43 -03:00
Masami Hiramatsu
5f03cba415 perf probe: Make error messages thread-safe
To make error messages thread-safe, this replaces strerror with
strerror_r for warnings, and just shows the return value instead of
using strerror for debug messages.

Signed-off-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Naohiro Aota <naota@elisp.net>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/20140814022234.3545.22199.stgit@kbuild-fedora.novalocal
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2014-08-15 10:56:53 -03:00
Jiri Olsa
ff527bccd4 perf tools: Remove needless getopt.h includes
We don't use getopt.h interfaces.

Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Cc: Corey Ashford <cjashfor@linux.vnet.ibm.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/1405374411-29012-6-git-send-email-jolsa@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2014-07-17 12:59:00 -03:00
Masami Hiramatsu
69e96eaa4f perf probe: Improve an error message of perf probe --vars mode
Fix an error message when failed to find given address in --vars
mode.

Without this fix, perf probe -V doesn't show the final "Error"
message if it fails to find given source line. Moreover, it
tells it fails to find "variables" instead of the source line.
  -----
  # perf probe -V foo@bar
  Failed to find variables at foo@bar (0)
  -----
The result also shows mysterious error code. Actually the error
returns 0 or -ENOENT means that it just fails to find the address
of given source line. (0 means there is no matching address,
and -ENOENT means there is an entry(DIE) but it has no instance,
e.g. an empty inlined function)

This fixes it to show what happened and the final error message
as below.
  -----
  # perf probe -V foo@bar
  Failed to find the address of foo@bar
    Error: Failed to show vars.
  -----

Signed-off-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/20140606071359.6788.84716.stgit@kbuild-fedora.novalocal
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2014-06-09 14:35:58 -03:00
Masami Hiramatsu
36d789a4d7 perf probe: Improve error message for unknown member of data structure
Improve the error message if we can not find given member in the given
structure. Currently perf probe shows a wrong error message as below.

  -----
  # perf probe getname_flags:65 "result->BOGUS"
  result(type:filename) has no member BOGUS.
  Failed to find 'result' in this function.
    Error: Failed to add events. (-22)
  -----

The first message is correct, but the second one is not, since we didn't
fail to find a variable but fails to find the member of given variable.

  -----
  # perf probe getname_flags:65 "result->BOGUS"
  result(type:filename) has no member BOGUS.
    Error: Failed to add events. (-22)
  -----

With this patch, the error message shows only the first one.  And if we
really failed to find given variable, it tells us so.

  -----
  # perf probe getname_flags:65 "BOGUS"
  Failed to find 'BOGUS' in this function.
    Error: Failed to add events. (-2)
  -----

Reported-by: Arnaldo Carvalho de Melo <acme@kernel.org>
Signed-off-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/20140606071345.6788.23744.stgit@kbuild-fedora.novalocal
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2014-06-09 12:15:07 -03:00
Masami Hiramatsu
0c188a07b6 perf probe: Fix a segfault if asked for variable it doesn't find
Fix a segfault bug by asking for variable it doesn't find.
Since the convert_variable() didn't handle error code returned
from convert_variable_location(), it just passed an incomplete
variable field and then a segfault was occurred when formatting
the field.

This fixes that bug by handling success code correctly in
convert_variable(). Other callers of convert_variable_location()
are correctly checking the return code.

This bug was introduced by following commit. But another hidden
erroneous error handling has been there previously (-ENOMEM case).

 commit 3d918a12a1

Signed-off-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Reported-by: Arnaldo Carvalho de Melo <acme@kernel.org>
Tested-by: Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Link: http://lkml.kernel.org/r/20140529105232.28251.30447.stgit@ltc230.yrl.intra.hitachi.co.jp
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
2014-06-04 14:48:03 +02:00
Namhyung Kim
03d8941298 perf probe: Use dwarf_getcfi_elf() instead of dwarf_getcfi()
The dwarf_getcfi() only checks .debug_frame section for CFI, but as
most binaries only have .eh_frame it'd return NULL and it makes
some variables inaccessible.

Using dwarf_getcfi_elf (along with dwarf_getelf()) allows to show and
add probe to more variables.

Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Acked-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Cc: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Link: http://lkml.kernel.org/r/1396854348-9296-1-git-send-email-namhyung@kernel.org
Signed-off-by: Jiri Olsa <jolsa@redhat.com>
2014-04-14 12:55:40 +02:00
Masami Hiramatsu
182c228ebc perf probe: Fix to handle errors in line_range searching
As Namhyung reported(https://lkml.org/lkml/2014/4/1/89),
current perf-probe -L option doesn't handle errors in line-range
searching correctly. It causes a SEGV if an error occured in the
line-range searching.

  ----
  $ perf probe -x ./perf -v -L map__load
  Open Debuginfo file: /home/namhyung/project/linux/tools/perf/perf
  fname: util/map.c, lineno:153
  New line range: 153 to 2147483647
  path: (null)
  Segmentation fault (core dumped)
  ----

This is because line_range_inline_cb() ignores errors
from find_line_range_by_line() which means that lr->path is
already freed on the error path in find_line_range_by_line().
As a result, get_real_path() accesses the lr->path and it
causes a NULL pointer exception.

This fixes line_range_inline_cb() to handle the error correctly,
and report it to the caller.

Anyway, this just fixes a possible SEGV bug, Namhyung's patch
is also required.

Reported-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Acked-by: Namhyung Kim <namhyung@kernel.org>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Namhyung Kim <namhyung.kim@lge.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/20140402054831.19080.27006.stgit@ltc230.yrl.intra.hitachi.co.jp
Signed-off-by: Jiri Olsa <jolsa@redhat.com>
2014-04-14 12:55:39 +02:00
Namhyung Kim
202c7c123c perf probe: Fix --line option behavior
The commit 5a62257a3d ("perf probe: Replace line_list with
intlist") replaced line_list to intlist but it has a problem that if a
same line was added again, it'd return -EEXIST rather than 1.

Since line_range_walk_cb() only checks the result being negative, it
resulted in failure or segfault sometimes.

Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Acked-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Cc: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Link: http://lkml.kernel.org/r/1396327677-3657-1-git-send-email-namhyung@kernel.org
Signed-off-by: Jiri Olsa <jolsa@redhat.com>
2014-04-14 12:55:39 +02:00
Masami Hiramatsu
a15ad2f536 perf probe: Support distro-style debuginfo for uprobe
Support distro-style debuginfo supported by dso for setting uprobes.
Note that this tries to find a debuginfo file based on the real path of
the target binary. If the debuginfo is not correctly installed on the
system, this can not find it.

Signed-off-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: "David A. Long" <dave.long@linaro.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: yrl.pp-manager.tt@hitachi.com
Link: http://lkml.kernel.org/r/20140206053227.29635.54434.stgit@kbuild-fedora.yrl.intra.hitachi.co.jp
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2014-02-18 09:38:44 -03:00
Masami Hiramatsu
f90acac757 perf probe: Find given address from offline dwarf
Find the given address from offline dwarfs instead of online kernel
dwarfs.

On the KASLR enabled kernel, the kernel text section is loaded with
random offset, and the debuginfo__new_online_kernel can't handle it. So
let's move to the offline dwarf loader instead of using the online dwarf
loader.

As a result, since we don't need debuginfo__new_online_kernel any more,
this also removes the functions related to that.

Without this change;

  # ./perf probe -l
    probe:t_show         (on _stext+901288 with m v)
    probe:t_show_1       (on _stext+939624 with m v t)
    probe:t_show_2       (on _stext+980296 with m v fmt)
    probe:t_show_3       (on _stext+1014392 with m v file)

With this change;

  # ./perf probe -l
    probe:t_show         (on t_show@linux-3/kernel/trace/ftrace.c with m v)
    probe:t_show_1       (on t_show@linux-3/kernel/trace/trace.c with m v t)
    probe:t_show_2       (on t_show@kernel/trace/trace_printk.c with m v fmt)
    probe:t_show_3       (on t_show@kernel/trace/trace_events.c with m v file)

Changes from v2:
 - Instead of retrying, directly opens offline dwarf.
 - Remove debuginfo__new_online_kernel and related functions.
 - Refer map->reloc to get the correct address of a symbol.
 - Add a special case for handling ref_reloc_sym based address.

Signed-off-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: "David A. Long" <dave.long@linaro.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: yrl.pp-manager.tt@hitachi.com
Link: http://lkml.kernel.org/r/20140206053218.29635.74821.stgit@kbuild-fedora.yrl.intra.hitachi.co.jp
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2014-02-18 09:34:51 -03:00
Masami Hiramatsu
5a62257a3d perf probe: Replace line_list with intlist
Replace line_list (struct line_node) with intlist for reducing similar
codes.

Signed-off-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Acked-by: Namhyung Kim <namhyung@kernel.org>
Cc: David Ahern <dsahern@gmail.com>
Cc: "David A. Long" <dave.long@linaro.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: yrl.pp-manager.tt@hitachi.com
Link: http://lkml.kernel.org/r/20140206053209.29635.81043.stgit@kbuild-fedora.yrl.intra.hitachi.co.jp
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2014-02-18 09:34:50 -03:00
Arnaldo Carvalho de Melo
74cf249d5c perf tools: Use zfree to help detect use after free bugs
Several areas already used this technique, so do some audit to
consistently use it elsewhere.

Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Link: http://lkml.kernel.org/n/tip-9sbere0kkplwe45ak6rk4a1f@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2013-12-27 17:08:19 -03:00
Arnaldo Carvalho de Melo
046625231a perf tools: Introduce zfree
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 <adrian.hunter@intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Link: http://lkml.kernel.org/n/tip-pfw02ezuab37kha18wlut7ir@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2013-12-27 15:17:00 -03:00
Arnaldo Carvalho de Melo
f5385650c0 perf tools: No need to test against NULL before calling free()
Its perfectly fine to call free(NULL), so no need to clutter the source
code with all those superfluous testing.

Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Link: http://lkml.kernel.org/n/tip-uux5wpvevlerd42gqer13e7n@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2013-12-26 15:58:52 -03:00
Masami Hiramatsu
fb7345bbf7 perf probe: Support basic dwarf-based operations on uprobe events
Support basic dwarf(debuginfo) based operations for uprobe events.  With
this change, perf probe can analyze debuginfo of user application binary
to set up new uprobe event.

This allows perf-probe --add(with local variables, line numbers) and
--line works with -x option.  (Actually, --vars has already accepted -x
option)

For example, the following command shows the probe-able lines of a given
user space function. Something that so far was only available in the
'perf probe' tool for kernel space functions:

  # ./perf probe -x perf --line map__load
  <map__load@/home/fedora/ksrc/linux-2.6/tools/perf/util/map.c:0>
        0  int map__load(struct map *map, symbol_filter_t filter)
        1  {
        2         const char *name = map->dso->long_name;
                  int nr;

        5         if (dso__loaded(map->dso, map->type))
        6                 return 0;

        8         nr = dso__load(map->dso, map, filter);
        9         if (nr < 0) {
       10                 if (map->dso->has_build_id) {

And this shows the available variables at the given line of the
function.

  # ./perf probe -x perf --vars map__load:8
  Available variables at map__load:8
          @<map__load+96>
                  char*   name
                  struct map*     map
                  symbol_filter_t filter
          @<map__find_symbol+112>
                  char*   name
                  symbol_filter_t filter
          @<map__find_symbol_by_name+136>
                  char*   name
                  symbol_filter_t filter
          @<map_groups__find_symbol_by_name+176>
                  char*   name
                  struct map*     map
                  symbol_filter_t filter

And lastly, we can now define probe(s) with all available
variables on the given line:

  # ./perf probe -x perf --add 'map__load:8 $vars'

  Added new events:
    probe_perf:map__load (on map__load:8 with $vars)
    probe_perf:map__load_1 (on map__load:8 with $vars)
    probe_perf:map__load_2 (on map__load:8 with $vars)
    probe_perf:map__load_3 (on map__load:8 with $vars)

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

          perf record -e probe_perf:map__load_3 -aR sleep 1

  Changes from previous version:
   - Add examples in the patch description.
   - Use .text section start address and dwarf symbol address
     for calculating the offset of given symbol, instead of
     searching the symbol in symtab again.
     With this change, we can safely handle multiple local
     function instances (e.g. scnprintf in perf).

Signed-off-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: David A. Long <dave.long@linaro.org>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: systemtap@sourceware.org
Cc: yrl.pp-manager.tt@hitachi.com
Link: http://lkml.kernel.org/r/20131226054152.22364.47021.stgit@kbuild-fedora.novalocal
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2013-12-26 11:22:01 -03:00
Arnaldo Carvalho de Melo
316c7136f8 perf tools: Finish the removal of 'self' arguments
They convey no information, perhaps I was bitten by some snake at some
point, complete the detox by naming the last of those arguments more
sensibly.

Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Link: http://lkml.kernel.org/n/tip-u1r0dnjoro08dgztiy2g3t2q@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2013-11-05 15:32:36 -03:00
Arnaldo Carvalho de Melo
9ef0438a95 perf probe: Fix typo
s/tyep/type/g.

Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Link: http://lkml.kernel.org/n/tip-cznw5tnruonyoisxu8be11bv@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2013-11-04 10:48:02 -03:00
Ingo Molnar
aac898548d Merge branch 'perf/urgent' into perf/core
Conflicts:
	tools/perf/builtin-record.c
	tools/perf/builtin-top.c
	tools/perf/util/hist.h
2013-10-29 11:23:32 +01:00
Masami Hiramatsu
3d918a12a1 perf probe: Find fentry mcount fuzzed parameter location
At this point, --fentry (mcount function entry) option for gcc fuzzes
the debuginfo variable locations by skipping the mcount instruction
offset (on x86, this is a 5 byte call instruction).

This makes variable searching fail at the entry of functions which
are mcount'ed.

e.g.)
Available variables at vfs_read
        @<vfs_read+0>
                (No matched variables)

This patch adds additional location search at the function entry point
to solve this issue, which tries to find the earliest address for the
variable location.

Note that this only works with function parameters (formal parameters)
because any local variables should not exist on the function entry
address (those are not initialized yet).

With this patch, perf probe shows correct parameters if possible;
 # perf probe --vars vfs_read
 Available variables at vfs_read
         @<vfs_read+0>
                 char*   buf
                 loff_t* pos
                 size_t  count
                 struct file*    file

Signed-off-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/20131011071025.15557.13275.stgit@udc4-manage.rcp.hitachi.co.jp
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2013-10-23 09:55:37 -03:00
Masami Hiramatsu
7969ec7728 perf probe: Support "$vars" meta argument syntax for local variables
Support "$vars" meta argument syntax for tracing all local variables at
probe point.

Now you can trace all available local variables (including function
parameters) at the probe point by passing $vars.

 # perf probe --add foo $vars

This automatically finds all local variables at foo() and adds it as
probe arguments.

Signed-off-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/20131011071023.15557.51770.stgit@udc4-manage.rcp.hitachi.co.jp
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2013-10-23 09:55:37 -03:00
Masami Hiramatsu
1b286bdd5b perf probe: Fix to initialize fname always before use it
Fix perf probe --list to initialize fname local var always before
use it. This may cause a SEGV if there is a probe which is in
the function body but not in any inline function.

Problem introduced in:

	commit e08cfd4bda
	Author: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
	Date:   Mon Sep 30 18:21:44 2013 +0900

	    perf probe: Fix to find line information for probe list

Signed-off-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/20131011122317.9662.29736.stgit@kbuild-fedora.novalocal
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2013-10-15 14:37:38 -03:00
Masami Hiramatsu
e08cfd4bda perf probe: Fix to find line information for probe list
Fix to find the correct (as much as possible) line information for
listing probes. Without this fix, perf probe --list action will show
incorrect line information as below;

  probe:getname_flags  (on getname_flags@ksrc/linux-3/fs/namei.c)
  probe:getname_flags_1 (on getname:-89@x86/include/asm/current.h)
  probe:getname_flags_2 (on user_path_at_empty:-2054@x86/include/asm/current.h)

The minus line number is obviously wrong, and current.h is not related
to the probe point. Deeper investigation discovered that there were 2
issues related to this bug, and minor typos too.

The 1st issue is the rack of considering about nested inlined functions,
which causes the wrong (relative) line number.

The 2nd issue is that the dwarf line info is not correct at those
points. It points 14th line of current.h.

Since it seems that the line info includes somewhat unreliable
information, this fixes perf to try to find correct line information
from both of debuginfo and line info as below.

1) Probe address is the entry of a function instance

  In this case, the line is set as the function declared line.

2) Probe address is the entry of an expanded inline function block

  In this case, the line is set as the function call-site line.
  This means that the line number is relative from the entry line
  of caller function (which can be an inlined function if nested)

3) Probe address is inside a function instance or an expanded
   inline function block

  In this case, perf probe queries the line number from lineinfo
  and verify the function declared file is same as the file name
  queried from lineinfo.

  If the file name is different, it is a failure case. The probe
  address is shown as symbol+offset.

4) Probe address is not in the any function instance

  This is a failure case, the probe address is shown as
  symbol+offset.

With this fix, perf probe -l shows correct probe lines as below;

  probe:getname_flags  (on getname_flags@ksrc/linux-3/fs/namei.c)
  probe:getname_flags_1 (on getname:2@ksrc/linux-3/fs/namei.c)
  probe:getname_flags_2 (on user_path_at_empty:4@ksrc/linux-3/fs/namei.c)

Changes at v2:
 - Fix typos in the function comments. (Thanks to Namhyung Kim)
 - Use die_find_top_inlinefunc instead of die_find_inlinefunc_next.

Signed-off-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/20130930092144.1693.11058.stgit@udc4-manage.rcp.hitachi.co.jp
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2013-10-04 15:16:05 -03:00
Masami Hiramatsu
576b523721 perf probe: Fix probing symbols with optimization suffix
Fix perf probe to probe on some symbols which have some optimzation
suffixes, e.g. ".part", ".isra", and ".constprop".

To fix this issue, instead of using the DIE name, perf probe uses the
symbol name found by dwfl_module_addrsym().

This also involves a perf probe --vars operation update which now shows
the symbol name instead of the DIE name.

Without this patch, putting a probe on an inlined function which was
compiled with a suffixed symbol will fail like this:

  $ perf probe -v getname_flags
  probe-definition(0): getname_flags
  symbol:getname_flags file:(null) line:0 offset:0 return:0 lazy:(null)
  0 arguments
  Looking at the vmlinux_path (6 entries long)
  Using /lib/modules/3.11.0+/build/vmlinux for symbols
  found inline addr: 0xffffffff8119bb70
  Probe point found: getname_flags+0
  found inline addr: 0xffffffff8119bcb6
  Probe point found: getname+6
  found inline addr: 0xffffffff811a06a6
  Probe point found: user_path_at_empty+6
  find 3 probe_trace_events.
  Opening /sys/kernel/debug//tracing/kprobe_events write=1
  Added new events:
  Writing event: p:probe/getname_flags getname_flags+0
  Failed to write event: No such file or directory
    Error: Failed to add events. (-1)

Because the debuginfo knows only the original (non suffix) symbol name,
it uses the original symbol for probe address but the kernel (kallsyms)
knows only suffixed symbol.  Then, the kernel rejects that original
symbol.

This patch uses dwfl_module_addrsym() to get the correct (suffixed)
symbol from symtab when a probe point is found.

Reported-by: Arnaldo Carvalho de Melo <acme@ghostprotocols.net>
Signed-off-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/20130925131616.31632.46658.stgit@udc4-manage.rcp.hitachi.co.jp
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2013-09-25 12:27:31 -03:00
Masami Hiramatsu
0dbb1cac1d perf probe: Fix finder to find lines of given function
The commit ba28c59bc9 fixed a declaration
entry bug in probe_point_search_cb().  There are same bugs in line
finder and call_probe_finder().  This introduces a new dwarf utility
function to determine given DIE is a function definition, not
declaration.

Signed-off-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Cc: Ananth N Mavinakayanahalli <ananth@in.ibm.com>
Cc: Prashanth Nageshappa <prashanth@linux.vnet.ibm.com>
Cc: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: yrl.pp-manager.tt@hitachi.com
Link: http://lkml.kernel.org/r/20120423032435.8737.80064.stgit@localhost.localdomain
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2013-09-19 11:35:05 -03:00
Hyeoncheol Lee
7ce28b5b5b perf probe: Allow of casting an array of char to string
Before casting a type of a variable to string, convert_variable_type()
confirms that the type is a pointer or an array. then if it is a pointer
to char, it is casted to string.  but in case of an array of char, it
isn't

Signed-off-by: H.C. Lee <hyc.lee@gmail.com>
Acked-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Link: http://lkml.kernel.org/r/CANFS6bb75e8a_UtyAD9yF73hfXDy0N8tSjDz=a+Vna=Y8ORMHg@mail.gmail.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2013-01-24 16:40:20 -03:00
Hyeoncheol Lee
7b0295b3db perf probe: Add union member access support
Union members can be accessed with '.' or '->' like data structure
member access

Signed-off-by: Hyunchul Lee <hyc.lee@gmail.com>
Acked-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Cc: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Cc: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Link: http://lkml.kernel.org/r/CANFS6baeuSBxPGQ8SUZWZErJ2bWs-Nojg+FSo138E1QK8bJJig@mail.gmail.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2012-09-14 15:48:08 -03:00
Irina Tirdea
1d037ca164 perf tools: Use __maybe_used for unused variables
perf defines both __used and __unused variables to use for marking
unused variables. The variable __used is defined to
__attribute__((__unused__)), which contradicts the kernel definition to
__attribute__((__used__)) for new gcc versions. On Android, __used is
also defined in system headers and this leads to warnings like: warning:
'__used__' attribute ignored

__unused is not defined in the kernel and is not a standard definition.
If __unused is included everywhere instead of __used, this leads to
conflicts with glibc headers, since glibc has a variables with this name
in its headers.

The best approach is to use __maybe_unused, the definition used in the
kernel for __attribute__((unused)). In this way there is only one
definition in perf sources (instead of 2 definitions that point to the
same thing: __used and __unused) and it works on both Linux and Android.
This patch simply replaces all instances of __used and __unused with
__maybe_unused.

Signed-off-by: Irina Tirdea <irina.tirdea@intel.com>
Acked-by: Pekka Enberg <penberg@kernel.org>
Cc: David Ahern <dsahern@gmail.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Namhyung Kim <namhyung.kim@lge.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Steven Rostedt <rostedt@goodmis.org>
Link: http://lkml.kernel.org/r/1347315303-29906-7-git-send-email-irina.tirdea@intel.com
[ committer note: fixed up conflict with a116e05 in builtin-sched.c ]
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2012-09-11 12:19:15 -03:00
Prashanth Nageshappa
ba28c59bc9 perf probe: Finder fails to resolve function name to address
If DIE entries corresponding to declarations appear before definition
entry, probe finder returns error instead of continuing to look further
for a definition entry.

This patch ensures we reach to the DIE entry corresponding to the
definition and get the function address.

V2: A simpler solution based on Masami's suggestion.

Signed-off-by: Prashanth Nageshappa <prashanth@linux.vnet.ibm.com>
Acked-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Cc: Ananth N Mavinakayanahalli <ananth@in.ibm.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Cc: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Link: http://lkml.kernel.org/r/4F703FB9.9020407@linux.vnet.ibm.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2012-03-28 11:56:49 -03:00
Ingo Molnar
737f24bda7 Merge branch 'perf/urgent' into perf/core
Conflicts:
	tools/perf/builtin-record.c
	tools/perf/builtin-top.c
	tools/perf/perf.h
	tools/perf/util/top.h

Merge reason: resolve these cherry-picking conflicts.

Signed-off-by: Ingo Molnar <mingo@elte.hu>
2012-03-05 09:20:08 +01:00
Prashanth Nageshappa
26b7952494 perf probe: Ensure offset provided is not greater than function length
The perf probe command allows kprobe to be inserted at any offset from a
function start, which results in adding kprobes to unintended location.

Example: perf probe do_fork+10000 is allowed even though size of do_fork
is ~904.

This patch will ensure probe addition fails when the offset specified is
greater than size of the function.

Acked-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Cc: Ananth N Mavinakayanahalli <ananth@in.ibm.com>
Cc: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Jason Baron <jbaron@redhat.com>
Cc: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Link: http://lkml.kernel.org/r/4F473F33.4060409@linux.vnet.ibm.com
Signed-off-by: Prashanth Nageshappa <prashanth@linux.vnet.ibm.com>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2012-02-29 18:29:45 -03:00
Namhyung Kim
d30d4a080d perf tools: Remove unnecessary ctype.h inclusion
There are unnecessary #include <ctype.h> out there, and they might cause
a nasty build failure in some environment. As we already have most of
ctype macros in util.h, just get rid of them.

A few of exceptions are util/symbol.c which needs isupper() macro util.h
doesn't provide and perl scripting support code which includes ctype.h
internally.

Suggested-by: Ingo Molnar <mingo@elte.hu>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/1327827356-8786-4-git-send-email-namhyung@gmail.com
Signed-off-by: Namhyung Kim <namhyung@gmail.com>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2012-01-30 18:37:35 -02:00
Masami Hiramatsu
f66fedcb72 perf probe: Fix regression of variable finder
Fix to call convert_variable() if previous call does not fail.

To call convert_variable, it ensures "ret" is 0. However, since
"ret" has the return value of synthesize_perf_probe_arg() which
always returns positive value if it succeeded, perf probe doesn't
call convert_variable(). This will cause a SEGV when we add an
event with arguments.

This has to be fixed as it ensures "ret" is greater than 0
(or not negative).

This regression has been introduced by my previous patch, f182e3e1.

Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: yrl.pp-manager.tt@hitachi.com
Link: http://lkml.kernel.org/r/20110820053922.3286.65805.stgit@fedora15
Signed-off-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2011-09-23 14:33:19 -03:00
Masami Hiramatsu
db0d2c6420 perf probe: Search concrete out-of-line instances
gcc 4.6 generates a concrete out-of-line instance when there is a
function which is implicitly inlined somewhere but also has its own
instance. The concrete out-of-line instance means that it has an
abstract origin of the function which is referred by not only
inlined-subroutines but also a concrete subprogram.

Since current dwarf_func_inline_instances() can find only instances of
inlined-subroutines, this introduces new die_walk_instances() to find
both of subprogram and inlined-subroutines.

e.g. without this,
Available variables at sched_group_rt_period
        @<cpu_rt_period_read_uint+9>
                struct task_group*      tg

perf probe failed to find actual subprogram instance of
sched_group_rt_period().

With this,

Available variables at sched_group_rt_period
        @<cpu_rt_period_read_uint+9>
                struct task_group*      tg
        @<sched_group_rt_period+0>
                struct task_group*      tg

Now it found the sched_group_rt_period() itself.

Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: yrl.pp-manager.tt@hitachi.com
Link: http://lkml.kernel.org/r/20110811110311.19900.63997.stgit@fedora15
Signed-off-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2011-08-12 09:32:10 -03:00
Masami Hiramatsu
f182e3e13c perf probe: Avoid searching variables in intermediate scopes
Fix variable searching logic to search one in inner than local scope or
global(CU) scope. In the other words, skip searching in intermediate
scopes.

e.g., in the following code,

int var1;

void inline infunc(int i)
{
    i++;   <--- [A]
}

void func(void)
{
   int var1, var2;
   infunc(var2);
}

At [A], "var1" should point the global variable "var1", however, if user
mis-typed as "var2", variable search should be failed. However, current
logic searches variable infunc() scope, global scope, and then func()
scope. Thus, it can find "var2" variable in func() scope. This may not
be what user expects.

So, it would better not search outer scopes except outermost (compile
unit) scope which contains only global variables, when it failed to find
given variable in local scope.

E.g.

Without this:
$ perf probe -V pre_schedule --externs > without.vars

With this:
$ perf probe -V pre_schedule --externs > with.vars

Check the diff:
$ diff without.vars with.vars
88d87
<               int     cpu
133d131
<               long unsigned int*      switch_count

These vars are actually in the scope of schedule(), the caller of
pre_schedule().

Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: yrl.pp-manager.tt@hitachi.com
Link: http://lkml.kernel.org/r/20110811110305.19900.94374.stgit@fedora15
Signed-off-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2011-08-12 09:29:34 -03:00
Masami Hiramatsu
221d061182 perf probe: Fix to search local variables in appropriate scope
Fix perf probe to search local variables in appropriate local inlined
function scope. For example, pre_schedule() has only 2 local variables,
as below;

$ perf probe -L pre_schedule
<pre_schedule@/home/mhiramat/ksrc/linux-2.6/kernel/sched.c:0>
      0  static inline void pre_schedule(struct rq *rq, struct task_struct *prev)
         {
      2         if (prev->sched_class->pre_schedule)
      3                 prev->sched_class->pre_schedule(rq, prev);
         }

However, current perf probe shows 4 local variables on pre_schedule(),
because it searches variables in the caller(schedule()) scope.

$ perf probe -V pre_schedule
Available variables at pre_schedule
        @<schedule+445>
                int     cpu
                long unsigned int*      switch_count
                struct rq*      rq
                struct task_struct*     prev

This patch fixes this issue by searching variables in the local scope of
the instance of inlined function. Here is the result.

$ perf probe -V pre_schedule
Available variables at pre_schedule
        @<schedule+445>
                struct rq*      rq
                struct task_struct*     prev

Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: yrl.pp-manager.tt@hitachi.com
Link: http://lkml.kernel.org/r/20110811110259.19900.85664.stgit@fedora15
Signed-off-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2011-08-12 09:28:45 -03:00
Masami Hiramatsu
36c0c588b9 perf probe: Fix to walk all inline instances
Fix line-range collector to walk all instances of inlined function,
because some execution paths can be optimized out depending on the
function argument of instances.

E.g.)
inline_func (arg) {
	if (arg)
		do_something;
	else
		do_another;
}

func_A() {
	inline_func(1)
}

func_B() {
	inline_func(0)
}

In this case, func_A may have only do_something code and func_B may have
only do_another.

Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Masami Hiramatsu <masami.hiramatsu@gmail.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: yrl.pp-manager.tt@hitachi.com
Link: http://lkml.kernel.org/r/20110811110247.19900.93702.stgit@fedora15
Signed-off-by: Masami Hiramatsu <masami.hiramatsu@gmail.com>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2011-08-12 09:25:38 -03:00
Masami Hiramatsu
8afa2a707d perf probe: Fix a memory leak for scopes array
Fix a memory leak for scopes array when it finds a variable in the
global scope.

Reviewed-by: Pekka Enberg <penberg@kernel.org>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: yrl.pp-manager.tt@hitachi.com
Link: http://lkml.kernel.org/r/20110811110229.19900.63019.stgit@fedora15
Signed-off-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2011-08-12 09:21:15 -03:00
Masami Hiramatsu
ff74178350 perf probe: Introduce debuginfo to encapsulate dwarf information
Introduce debuginfo to encapsulate dwarf information.
This new object allows us to reuse and expand debuginfo easily.

Signed-off-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Arnaldo Carvalho de Melo <acme@ghostprotocols.net>
Link: http://lkml.kernel.org/r/20110627072739.6528.12438.stgit@fedora15
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2011-07-15 16:14:19 -04:00
Masami Hiramatsu
e0d153c690 perf-probe: Move dwarf library routines to dwarf-aux.{c, h}
Move dwarf library related routines to dwarf-aux.{c,h}.
This includes several minor changes.
- Add simple documents for each API.
- Rename die_find_real_subprogram() to die_find_realfunc()
- Rename line_walk_handler_t to line_walk_callback_t.
- Minor cleanups.

Signed-off-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Arnaldo Carvalho de Melo <acme@ghostprotocols.net>
Link: http://lkml.kernel.org/r/20110627072727.6528.57647.stgit@fedora15
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2011-07-15 16:10:17 -04:00
Masami Hiramatsu
bcfc082150 perf probe: Remove redundant dwarf functions
Since there are dwarf_bitsize, dwarf_bitoffset and dwarf_bytesize
defined in libdw, we don't need die_get_bit_size, die_get_bit_offset
and die_get_byte_size anymore.

Signed-off-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Arnaldo Carvalho de Melo <acme@ghostprotocols.net>
Link: http://lkml.kernel.org/r/20110627072721.6528.2747.stgit@fedora15
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2011-07-15 16:04:47 -04:00
Masami Hiramatsu
bad03ae476 perf probe: Move strtailcmp to string.c
Since strtailcmp() is enough generic, it should be defined in string.c.

Signed-off-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Arnaldo Carvalho de Melo <acme@ghostprotocols.net>
Link: http://lkml.kernel.org/r/20110627072715.6528.10677.stgit@fedora15
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2011-07-15 16:00:47 -04:00
Masami Hiramatsu
baad2d3e69 perf probe: Rename DIE_FIND_CB_FOUND to DIE_FIND_CB_END
Since die_find/walk* callbacks use DIE_FIND_CB_FOUND for
both of failed and found cases, it should be "END"
instead "FOUND" for avoiding confusion.

Signed-off-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Reported-by: Arnaldo Carvalho de Melo <acme@ghostprotocols.net>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Ingo Molnar <mingo@elte.hu>
Link: http://lkml.kernel.org/r/20110627072709.6528.45706.stgit@fedora15
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2011-07-15 15:55:57 -04:00
Lin Ming
2b348a7798 perf probe: Fix the missed parameter initialization
pubname_callback_param::found should be initialized to 0 in
fastpath lookup, the structure is on the stack and
uninitialized otherwise.

Signed-off-by: Lin Ming <ming.m.lin@intel.com>
Cc: Arnaldo Carvalho de Melo <acme@infradead.org>
Link: http://lkml.kernel.org/r/1304066518-30420-2-git-send-email-ming.m.lin@intel.com
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-05-10 17:06:23 +02:00