Commit Graph

277 Commits

Author SHA1 Message Date
Namhyung Kim bb963e1650 perf utils: Check verbose flag properly
It now can have negative value to suppress the message entirely.  So it
needs to check it being positive.

Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: kernel-team@lge.com
Link: http://lkml.kernel.org/r/20170217081742.17417-3-namhyung@kernel.org
[ Adjust fuzz on tools/perf/util/pmu.c, add > 0 checks in many other places ]
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2017-02-20 11:35:54 -03:00
Arnaldo Carvalho de Melo 8a2efd6dd5 perf probe: Avoid accessing uninitialized 'map' variable
Genuine problem detected with clang, the warnings are spot on:

  util/probe-event.c:2079:7: error: variable 'map' is used uninitialized whenever 'if' condition is false [-Werror,-Wsometimes-uninitialized]
                  if (addr) {
                      ^~~~
  util/probe-event.c:2094:6: note: uninitialized use occurs here
          if (map && !is_kprobe) {
              ^~~
  util/probe-event.c:2079:3: note: remove the 'if' if its condition is always true
                  if (addr) {
                  ^~~~~~~~~~
  util/probe-event.c:2075:8: error: variable 'map' is used uninitialized whenever 'if' condition is true [-Werror,-Wsometimes-uninitialized]
                          if (kernel_get_symbol_address_by_name(tp->symbol,
                              ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
  util/probe-event.c:2094:6: note: uninitialized use occurs here
          if (map && !is_kprobe) {
              ^~~
  util/probe-event.c:2075:4: note: remove the 'if' if its condition is always false
                          if (kernel_get_symbol_address_by_name(tp->symbol,
                          ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
  util/probe-event.c:2064:17: note: initialize the variable 'map' to silence this warning
          struct map *map;
                         ^
                          = NULL

Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Wang Nan <wangnan0@huawei.com>
Link: http://lkml.kernel.org/n/tip-m3501el55i10hctfbmi2qxzr@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2017-02-14 15:28:41 -03:00
Ingo Molnar e2cf00c257 New features:
- Introduce 'perf ftrace' a perf front end to the kernel's ftrace
   function and function_graph tracer, defaulting to the "function_graph"
   tracer, more work will be done in reviving this effort, forward porting
   it from its initial patch submission (Namhyung Kim)
 
 - Add 'e' and 'c' hotkeys to expand/collapse call chains for a single
   hist entry in the 'perf report' and 'perf top' TUI (Jiri Olsa)
 
 Fixes:
 
 - Fix wrong register name for arm64, used in 'perf probe' (He Kuang)
 
 - Fix map offsets in relocation in libbpf (Joe Stringer)
 
 - Fix looking up dwarf unwind stack info (Matija Glavinic Pecotic)
 
 Infrastructure:
 
 - libbpf prog functions sync with what is exported via uapi (Joe Stringer)
 
 Trivial:
 
 - Remove unnecessary checks and assignments in 'perf probe's
   try_to_find_absolute_address() (Markus Elfring)
 
 Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
 -----BEGIN PGP SIGNATURE-----
 Version: GnuPG v2
 
 iQIcBAABCAAGBQJYig7UAAoJENZQFvNTUqpAhJQP/iI0T7A8TNekPGLv7j20c302
 89N9+9TAFtVqjgr1hIzqQgGOqbOdAW1tU3VTPW92nNDBn9JV5qwuF9YWEiDaAVv2
 0bmV5hLnrNlymddm3pdg/PbD1TVlwk2NFxtrkPxuf/vx0ZhEGqsSrRUCR/xGXbtQ
 TcMg3rQquspV9JNv4HzFdQC9nsG1CGNotZKsE1avRw70pWAqCtF81B0m8teb6OWo
 5qnN+AMJlYcC+OGffROemUksuehkMvi5L8v1e/6RO/lU1qt9Jrc/2sT9cqvjVFNR
 k4c76cUgWOCYzDEotENMpU4bc6e/24DE2ydFeovihdXw8Qs4ajEA9LXKM4yW+ZoE
 MZE3GS153a8n+CvTfkB9Ow1QJ8rgmR/L0BuhmGb6bYW/MtuTRTShhSduZwOrIyap
 9KckHYti4p3oN3CKFYGO9PN3DRUdx+Xqg/miwrgjkPo09QFp+lzfFFOk0P2/Zqw2
 yfvdWeHxkkrwoWQIyMHVKp/E9jQPuyYqwnKdp68LCN+DgNiFpPpSA8id5e47RQDE
 otqrK8U/82ktakfrBijSPBI6EEqFg7ltip2KT/xlDMfnP9HtxgFhzrk52dyi6pM/
 jkBhJaTQhVZTyaFvUXuaLmBSdPpcaaGM4KJ+2iAayA2r0KLiDj6IdzD5ROCRFOvJ
 SFA472mIxNxUjpQEUTtc
 =tYKN
 -----END PGP SIGNATURE-----

Merge tag 'perf-core-for-mingo-4.11-20170126' of git://git.kernel.org/pub/scm/linux/kernel/git/acme/linux into perf/core

Pull the latest perf/core updates from Arnaldo Carvalho de Melo:

New features:

 - Introduce 'perf ftrace' a perf front end to the kernel's ftrace
   function and function_graph tracer, defaulting to the "function_graph"
   tracer, more work will be done in reviving this effort, forward porting
   it from its initial patch submission (Namhyung Kim)

 - Add 'e' and 'c' hotkeys to expand/collapse call chains for a single
   hist entry in the 'perf report' and 'perf top' TUI (Jiri Olsa)

Fixes:

 - Fix wrong register name for arm64, used in 'perf probe' (He Kuang)

 - Fix map offsets in relocation in libbpf (Joe Stringer)

 - Fix looking up dwarf unwind stack info (Matija Glavinic Pecotic)

Infrastructure changes:

 - libbpf prog functions sync with what is exported via uapi (Joe Stringer)

Trivial changes:

 - Remove unnecessary checks and assignments in 'perf probe's
   try_to_find_absolute_address() (Markus Elfring)

Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-01-26 16:20:59 +01:00
Markus Elfring d1d0e29cb7 perf probe: Delete an unnecessary assignment in try_to_find_absolute_address()
Remove an error code assignment which is redundant in an if branch for
the handling of a memory allocation failure because the same value was
set for the local variable "err" before.

Signed-off-by: Markus Elfring <elfring@users.sourceforge.net>
Acked-by: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: He Kuang <hekuang@huawei.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Milian Wolff <milian.wolff@kdab.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Ravi Bangoria <ravi.bangoria@linux.vnet.ibm.com>
Cc: Wang Nan <wangnan0@huawei.com>
Cc: kernel-janitors@vger.kernel.org
Link: http://lkml.kernel.org/r/0ede09ec-79b6-c8bd-5b20-02c63ed98aab@users.sourceforge.net
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2017-01-26 11:42:56 -03:00
Markus Elfring 42e233cacc perf probe: Delete an unnecessary check in try_to_find_absolute_address()
Remove a condition check which is unnecessary at the end
because this source code place should usually only be reached
with a non-zero pointer.

Signed-off-by: Markus Elfring <elfring@users.sourceforge.net>
Acked-by: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: He Kuang <hekuang@huawei.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Milian Wolff <milian.wolff@kdab.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Ravi Bangoria <ravi.bangoria@linux.vnet.ibm.com>
Cc: Wang Nan <wangnan0@huawei.com>
Cc: kernel-janitors@vger.kernel.org
Link: http://lkml.kernel.org/r/a3f2473b-6383-a326-bce0-b826423608b8@users.sourceforge.net
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2017-01-26 11:42:55 -03:00
Masami Hiramatsu 613f050d68 perf probe: Fix to probe on gcc generated functions in modules
Fix to probe on gcc generated functions on modules. Since
probing on a module is based on its symbol name, it should
be adjusted on actual symbols.

E.g. without this fix, perf probe shows probe definition
on non-exist symbol as below.

  $ perf probe -m build-x86_64/net/netfilter/nf_nat.ko -F in_range*
  in_range.isra.12
  $ perf probe -m build-x86_64/net/netfilter/nf_nat.ko -D in_range
  p:probe/in_range nf_nat:in_range+0

With this fix, perf probe correctly shows a probe on
gcc-generated symbol.

  $ perf probe -m build-x86_64/net/netfilter/nf_nat.ko -D in_range
  p:probe/in_range nf_nat:in_range.isra.12+0

This also fixes same problem on online module as below.

  $ perf probe -m i915 -D assert_plane
  p:probe/assert_plane i915:assert_plane.constprop.134+0

Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.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/148411450673.9978.14905987549651656075.stgit@devbox
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2017-01-16 15:43:04 -03:00
Masami Hiramatsu 3e96dac7c9 perf probe: Add error checks to offline probe post-processing
Add error check codes on post processing and improve it for offline
probe events as:

 - post processing fails if no matched symbol found in map(-ENOENT)
   or strdup() failed(-ENOMEM).

 - Even if the symbol name is the same, it updates symbol address
   and offset.

Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/148411443738.9978.4617979132625405545.stgit@devbox
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2017-01-16 15:35:25 -03:00
Masami Hiramatsu 8a937a25a7 perf probe: Fix to probe on gcc generated symbols for offline kernel
Fix perf-probe to show probe definition on gcc generated symbols for
offline kernel (including cross-arch kernel image).

gcc sometimes optimizes functions and generate new symbols with suffixes
such as ".constprop.N" or ".isra.N" etc. Since those symbol names are
not recorded in DWARF, we have to find correct generated symbols from
offline ELF binary to probe on it (kallsyms doesn't correct it).  For
online kernel or uprobes we don't need it because those are rebased on
_text, or a section relative address.

E.g. Without this:

  $ perf probe -k build-arm/vmlinux -F __slab_alloc*
  __slab_alloc.constprop.9
  $ perf probe -k build-arm/vmlinux -D __slab_alloc
  p:probe/__slab_alloc __slab_alloc+0

If you put above definition on target machine, it should fail
because there is no __slab_alloc in kallsyms.

With this fix, perf probe shows correct probe definition on
__slab_alloc.constprop.9:

  $ perf probe -k build-arm/vmlinux -D __slab_alloc
  p:probe/__slab_alloc __slab_alloc.constprop.9+0

Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/148350060434.19001.11864836288580083501.stgit@devbox
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2017-01-04 11:44:22 -03:00
Masami Hiramatsu eebc509b20 perf probe: Fix --funcs to show correct symbols for offline module
Fix --funcs (-F) option to show correct symbols for offline module.
Since previous perf-probe uses machine__findnew_module_map() for offline
module, even if user passes a module file (with full path) which is for
other architecture, perf-probe always tries to load symbol map for
current kernel module.

This fix uses dso__new_map() to load the map from given binary as same
as a map for user applications.

Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/148350053478.19001.15435255244512631545.stgit@devbox
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2017-01-04 11:15:09 -03:00
Masami Hiramatsu 1f2ed153b9 perf probe: Fix to get correct modname from elf header
Since 'perf probe' supports cross-arch probes, it is possible to analyze
different arch kernel image which has different bits-per-long.

In that case, it fails to get the module name because it uses the
MOD_NAME_OFFSET macro based on the host machine bits-per-long, instead
of the target arch bits-per-long.

This fixes above issue by changing modname-offset based on the target
archs bit width. This is ok because linux kernel uses LP64 model on
64bit arch.

E.g. without this (on x86_64, and target module is arm32):

  $ perf probe -m build-arm/fs/configfs/configfs.ko -D configfs_lookup
  p:probe/configfs_lookup :configfs_lookup+0
                          ^-Here is an empty module name.

With this fix, you can see correct module name:

  $ perf probe -m build-arm/fs/configfs/configfs.ko -D configfs_lookup
  p:probe/configfs_lookup configfs:configfs_lookup+0

Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/148337043836.6752.383495516397005695.stgit@devbox
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2017-01-02 14:09:17 -03:00
Colin Ian King ead1a57457 perf probe: Check if *ptr2 is zero and not ptr2
Static anaylsis with cppcheck[1] detected an incorrect comparison:
[tools/perf/util/probe-event.c:216]: (warning) Char literal compared
with pointer 'ptr2'. Did you intend to dereference it?

Dereference ptr2 for the comparison to fix this.

1: https://sourceforge.net/p/cppcheck/wiki/Home/

Signed-off-by: Colin King <colin.king@canonical.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Ravi Bangoria <ravi.bangoria@linux.vnet.ibm.com>
Cc: Wang Nan <wangnan0@huawei.com>
Fixes: 35726d3a4c ("perf probe: Fix to cut off incompatible chars from group name")
Link: http://lkml.kernel.org/r/20161003103431.18534-1-colin.king@canonical.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2016-10-03 11:24:12 -03:00
Masami Hiramatsu 35726d3a4c perf probe: Fix to cut off incompatible chars from group name
Cut off the characters which can not use for group name of uprobes
when making it based on executable filename.

For example, if the exec name is libstdc++.so, without this fix
perf probe generates "probe_libstdc++" as the group name, but
it is failed to set because '+' can not be used for group name.

With this fix perf accepts only alphabet, number or '_' for group
name, thus perf generates "probe_libstdc" as the group name.

E.g. with this fix, you can see the event name has no "+".
  ----
  $ ./perf probe -x /usr/lib64/libstdc++.so.6 -D is_open
  p:probe_libstdc/is_open /usr/lib64/libstdc++.so.6.0.22:0x8ca80
  p:probe_libstdc/is_open_1 /usr/lib64/libstdc++.so.6.0.22:0x8ca70
  p:probe_libstdc/is_open_2 /usr/lib64/libstdc++.so.6.0.22:0x8ca60
  p:probe_libstdc/is_open_3 /usr/lib64/libstdc++.so.6.0.22:0xb0ad0
  p:probe_libstdc/is_open_4 /usr/lib64/libstdc++.so.6.0.22:0xecca9
  ----

Committer note:

Before this fix:

  # perf probe -x /usr/lib64/libstdc++.so.6 is_open
  Failed to write event: Invalid argument
    Error: Failed to add events.
  #

After the fix:

  # perf probe -x /usr/lib64/libstdc++.so.6 is_open
  Added new events:
    probe_libstdc:is_open (on is_open in /usr/lib64/libstdc++.so.6.0.22)
    probe_libstdc:is_open_1 (on is_open in /usr/lib64/libstdc++.so.6.0.22)
    probe_libstdc:is_open_2 (on is_open in /usr/lib64/libstdc++.so.6.0.22)
    probe_libstdc:is_open_3 (on is_open in /usr/lib64/libstdc++.so.6.0.22)
    probe_libstdc:is_open_4 (on is_open in /usr/lib64/libstdc++.so.6.0.22)

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

	  perf record -e probe_libstdc:is_open_4 -aR sleep 1

  # perf probe -l probe_libstdc:*
    probe_libstdc:is_open (on is_open@libstdc++-v3/include/fstream in /usr/lib64/libstdc++.so.6.0.22)
    probe_libstdc:is_open_1 (on is_open@libstdc++-v3/include/fstream in /usr/lib64/libstdc++.so.6.0.22)
    probe_libstdc:is_open_2 (on is_open@libstdc++-v3/include/fstream in /usr/lib64/libstdc++.so.6.0.22)
    probe_libstdc:is_open_3 (on is_open@src/c++98/basic_file.cc in /usr/lib64/libstdc++.so.6.0.22)
    probe_libstdc:is_open_4 (on stdio_filebuf:5@include/ext/stdio_filebuf.h in /usr/lib64/libstdc++.so.6.0.22)
  #

Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Tested-by: Jiri Olsa <jolsa@kernel.org>
Cc: David Ahern <dsahern@gmail.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/147464491667.29804.9553638175441827970.stgit@devbox
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2016-09-29 11:17:08 -03:00
Arnaldo Carvalho de Melo be39db9f29 perf symbols: Remove symbol_filter_t machinery
We're not using it anymore, few users were, but we really could do
without it, simplify lots of functions by removing it.

Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Wang Nan <wangnan0@huawei.com>
Link: http://lkml.kernel.org/n/tip-1zng8wdznn00iiz08bb7q3vn@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2016-09-05 11:14:50 -03:00
Ravi Bangoria b3f33f9306 perf probe: Add helper function to check if probe with variable
Introduce helper function instead of inline code and replace hardcoded
strings "$vars" and "$params" with their corresponding macros.

perf_probe_with_var() is not declared as static since it will be called
from different file in subsequent patch.

Signed-off-by: Ravi Bangoria <ravi.bangoria@linux.vnet.ibm.com>
Acked-by: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Hemant Kumar <hemant@linux.vnet.ibm.com>
Cc: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Wang Nan <wangnan0@huawei.com>
Link: http://lkml.kernel.org/r/1470214725-5023-1-git-send-email-ravi.bangoria@linux.vnet.ibm.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2016-09-01 12:42:25 -03:00
Masami Hiramatsu 428aff82e9 perf probe: Ignore vmlinux buildid if offline kernel is given
Ignore the buildid of running kernel when both of --definition and
--vmlinux is given because that kernel should be off-line.

This also skips post-processing of kprobe event for relocating symbol
and checking blacklist, because it can not be done on off-line kernel.

E.g. without this fix perf shows an error as below
  ----
  $ perf probe --vmlinux=./vmlinux-arm --definition do_sys_open
  ./vmlinux-arm with build id 7a1f76dd56e9c4da707cd3d6333f50748141434b not found, continuing without symbols
  Failed to find symbol do_sys_open in kernel
    Error: Failed to add events.
  ----
with this fix, we can get the definition
  ----
  $ perf probe --vmlinux=./vmlinux-arm --definition do_sys_open
  p:probe/do_sys_open do_sys_open+0
  ----

Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/147214228193.23638.12581984840822162131.stgit@devbox
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2016-09-01 09:44:14 -03:00
Masami Hiramatsu 1c20b1d154 perf probe: Show trace event definition
Add --definition/-D option for showing the trace-event definition in
stdout. This can be useful in debugging or combined with a shell script.

e.g.
  ----
  # perf probe --definition 'do_sys_open $params'
  p:probe/do_sys_open _text+2261728 dfd=%di:s32 filename=%si:u64 flags=%dx:s32 mode=%cx:u16
  ----

Suggested-and-Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/147214226712.23638.2240534040014013658.stgit@devbox
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2016-09-01 09:44:13 -03:00
Arnaldo Carvalho de Melo fd2275984d perf probe: Do not use map_load filters for function
It is simpler to just do the loop, no need for globals and the last user
of such facility disappears.

Testing:

  # perf probe -F [a-z]*recvmsg
  aead_recvmsg
  compat_SyS_recvmsg
  compat_sys_recvmsg
  hash_recvmsg
  inet_recvmsg
  kernel_recvmsg
  netlink_recvmsg
  packet_recvmsg
  ping_recvmsg
  raw_recvmsg
  rawv6_recvmsg
  rng_recvmsg
  security_socket_recvmsg
  selinux_socket_recvmsg
  skcipher_recvmsg
  sock_common_recvmsg
  sock_no_recvmsg
  sock_recvmsg
  sys_recvmsg
  tcp_recvmsg
  udp_recvmsg
  udpv6_recvmsg
  unix_dgram_recvmsg
  unix_seqpacket_recvmsg
  unix_stream_recvmsg
  #

Without filters:

  # perf probe -F | tail -5
  zswap_pool_create
  zswap_pool_current
  zswap_update_total_size
  zswap_writeback_entry
  zswap_zpool_param_set
  #
  # perf probe -F | wc -l
  33311
  #

Acked-by: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Wang Nan <wangnan0@huawei.com>
Link: http://lkml.kernel.org/r/20160831130427.GA13095@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2016-09-01 09:43:57 -03:00
Ravi Bangoria 99e608b595 perf probe ppc64le: Fix probe location when using DWARF
Powerpc has Global Entry Point and Local Entry Point for functions.  LEP
catches call from both the GEP and the LEP. Symbol table of ELF contains
GEP and Offset from which we can calculate LEP, but debuginfo does not
have LEP info.

Currently, perf prioritize symbol table over dwarf to probe on LEP for
ppc64le. But when user tries to probe with function parameter, we fall
back to using dwarf(i.e. GEP) and when function called via LEP, probe
will never hit.

For example:

  $ objdump -d vmlinux
    ...
    do_sys_open():
    c0000000002eb4a0:       e8 00 4c 3c     addis   r2,r12,232
    c0000000002eb4a4:       60 00 42 38     addi    r2,r2,96
    c0000000002eb4a8:       a6 02 08 7c     mflr    r0
    c0000000002eb4ac:       d0 ff 41 fb     std     r26,-48(r1)

  $ sudo ./perf probe do_sys_open
  $ sudo cat /sys/kernel/debug/tracing/kprobe_events
    p:probe/do_sys_open _text+3060904

  $ sudo ./perf probe 'do_sys_open filename:string'
  $ sudo cat /sys/kernel/debug/tracing/kprobe_events
    p:probe/do_sys_open _text+3060896 filename_string=+0(%gpr4):string

For second case, perf probed on GEP. So when function will be called via
LEP, probe won't hit.

  $ sudo ./perf record -a -e probe:do_sys_open ls
    [ perf record: Woken up 1 times to write data ]
    [ perf record: Captured and wrote 0.195 MB perf.data ]

To resolve this issue, let's not prioritize symbol table, let perf
decide what it wants to use. Perf is already converting GEP to LEP when
it uses symbol table. When perf uses debuginfo, let it find LEP offset
form symbol table. This way we fall back to probe on LEP for all cases.

After patch:

  $ sudo ./perf probe 'do_sys_open filename:string'
  $ sudo cat /sys/kernel/debug/tracing/kprobe_events
    p:probe/do_sys_open _text+3060904 filename_string=+0(%gpr4):string

  $ sudo ./perf record -a -e probe:do_sys_open ls
    [ perf record: Woken up 1 times to write data ]
    [ perf record: Captured and wrote 0.197 MB perf.data (11 samples) ]

Signed-off-by: Ravi Bangoria <ravi.bangoria@linux.vnet.ibm.com>
Acked-by: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Ananth N Mavinakayanahalli <ananth@in.ibm.com>
Cc: Balbir Singh <bsingharora@gmail.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Wang Nan <wangnan0@huawei.com>
Link: http://lkml.kernel.org/r/1470723805-5081-2-git-send-email-ravi.bangoria@linux.vnet.ibm.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2016-08-09 12:14:29 -03:00
Ravi Bangoria d820456dc7 perf probe: Add function to post process kernel trace events
Instead of inline code, introduce function to post process kernel
probe trace events.

Signed-off-by: Ravi Bangoria <ravi.bangoria@linux.vnet.ibm.com>
Acked-by: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Ananth N Mavinakayanahalli <ananth@in.ibm.com>
Cc: Balbir Singh <bsingharora@gmail.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Wang Nan <wangnan0@huawei.com>
Link: http://lkml.kernel.org/r/1470723805-5081-1-git-send-email-ravi.bangoria@linux.vnet.ibm.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2016-08-09 12:09:59 -03:00
Konstantin Khlebnikov cb3f3378cd perf probe: Fix module name matching
If module is "module" then dso->short_name is "[module]".  Substring
comparing is't enough: "raid10" matches to "[raid1]".  This patch also
checks terminating zero in module name.

Signed-off-by: Konstantin Khlebnikov <khlebnikov@yandex-team.ru>
Acked-by: Masami Hiramatsu <mhiramat@kernel.org>
Link: http://lkml.kernel.org/r/147039975648.715620.12985971832789032159.stgit@buzz
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2016-08-09 10:48:09 -03:00
Masami Hiramatsu 8e34189b34 perf probe: Adjust map->reloc offset when finding kernel symbol from map
Adjust map->reloc offset for the unmapped address when finding
alternative symbol address from map, because KASLR can relocate the
kernel symbol address.

The same adjustment has been done when finding appropriate kernel symbol
address from map which was introduced by commit f90acac757 ("perf
probe: Find given address from offline dwarf")

Reported-by: Arnaldo Carvalho de Melo <acme@kernel.org>
Signed-off-by: Masami Hiramatsu <masami.hiramatsu@linaro.org>
Cc: Alexei Starovoitov <alexei.starovoitov@gmail.com>
Cc: Wang Nan <wangnan0@huawei.com>
Link: http://lkml.kernel.org/r/20160806192948.e366f3fbc4b194de600f8326@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2016-08-09 10:47:43 -03:00
Masami Hiramatsu e70493429b perf probe: Warn unmatched function filter correctly
Warn unmatched function filter correctly instead of warning
"symbol-loading error", since that can be a filter issue.

From the technical point of view, this adds a filter chech in map__load
and if there is a filter, it returns -2 (filter-out), instead of -1
(error), and perf-probe checks it and change message.

E.g. without this fix:

  # perf probe -F rt_sp*
  no symbols found in [kernel.kallsyms], maybe install a debug package?
  Failed to load symbols in kernel

With this fix:

  # perf probe -F rt_sp*
  no symbols passed the given filter.
  Failed to find symbols matched to "rt_sp*"
    Error: Failed to show functions.

Reported-and-Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/146885835596.16106.2293540792775552481.stgit@devbox
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2016-07-18 19:46:34 -03:00
Masami Hiramatsu 7e9fca51fb perf probe: Support a special SDT probe format
Support a special SDT probe format which can omit the '%' prefix only if
the SDT group name starts with "sdt_". So, for example both of
"%sdt_libc:setjump" and "sdt_libc:setjump" are acceptable for perf probe
--add.

E.g. without this:

  # perf probe -a sdt_libc:setjmp
  Semantic error :There is non-digit char in line number.
  ...

With this:

  # perf probe -a sdt_libc:setjmp
  Added new event:
    sdt_libc:setjmp      (on %setjmp in /usr/lib64/libc-2.20.so)

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

  	perf record -e sdt_libc:setjmp -aR sleep 1

Suggested-by: Brendan Gregg <brendan.d.gregg@gmail.com>
Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Ananth N Mavinakayanahalli <ananth@linux.vnet.ibm.com>
Cc: Brendan Gregg <brendan.d.gregg@gmail.com>
Cc: Hemant Kumar <hemant@linux.vnet.ibm.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/146831794674.17065.13359473252168740430.stgit@devbox
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2016-07-13 23:09:09 -03:00
Masami Hiramatsu a598180aa1 perf probe: Support @BUILDID or @FILE suffix for SDT events
Support @BUILDID or @FILE suffix for SDT events. This allows perf to add
probes on SDTs/pre-cached events on given FILE or the file which has
given BUILDID (also, this complements BUILDID.)

For example, both gcc and libstdc++ has same SDTs as below.  If you
would like to add a probe on sdt_libstdcxx:catch on gcc, you can do as
below.

  ----
  # perf list sdt | tail -n 6
    sdt_libstdcxx:catch@/usr/bin/gcc(0cc207fc4b27)     [SDT event]
    sdt_libstdcxx:catch@/usr/lib64/libstdc++.so.6.0.20(91c7a88fdf49)
    sdt_libstdcxx:rethrow@/usr/bin/gcc(0cc207fc4b27)   [SDT event]
    sdt_libstdcxx:rethrow@/usr/lib64/libstdc++.so.6.0.20(91c7a88fdf49)
    sdt_libstdcxx:throw@/usr/bin/gcc(0cc207fc4b27)     [SDT event]
    sdt_libstdcxx:throw@/usr/lib64/libstdc++.so.6.0.20(91c7a88fdf49)
  # perf probe -a %sdt_libstdcxx:catch@0cc
  Added new event:
    sdt_libstdcxx:catch  (on %catch in /usr/bin/gcc)

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

  	perf record -e sdt_libstdcxx:catch -aR sleep 1
  ----

Committer note:

Doing the full sequence of steps to get the results above:

With a clean build-id cache:

  [root@jouet ~]# rm -rf ~/.debug/
  [root@jouet ~]# perf list sdt

  List of pre-defined events (to be used in -e):

  [root@jouet ~]#

No events whatsoever, then, we can add all events in gcc to the build-id
cache, doing a --add + --dry-run:

  [root@jouet ~]# perf probe --dry-run --cache -x /usr/bin/gcc --add %sdt_libstdcxx:\*
  Added new events:
    sdt_libstdcxx:throw  (on %* in /usr/bin/gcc)
    sdt_libstdcxx:rethrow (on %* in /usr/bin/gcc)
    sdt_libstdcxx:catch  (on %* in /usr/bin/gcc)

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

	perf record -e sdt_libstdcxx:catch -aR sleep 1

  [root@jouet ~]#

It really didn't add any events, it just cached them:

  [root@jouet ~]# perf probe -l
  [root@jouet ~]#

We can see that it was cached as:

  [root@jouet ~]# ls -la ~/.debug/usr/bin/gcc/9a0730e2bcc6d2a2003d21ac46807e8ee6bcb7c2/
  total 976
  drwxr-xr-x. 2 root root   4096 Jul 13 21:47 .
  drwxr-xr-x. 3 root root   4096 Jul 13 21:47 ..
  -rwxr-xr-x. 4 root root 985912 Jun 22 18:52 elf
  -rw-r--r--. 1 root root    303 Jul 13 21:47 probes
  [root@jouet ~]# file ~/.debug/usr/bin/gcc/9a0730e2bcc6d2a2003d21ac46807e8ee6bcb7c2/elf
  /root/.debug/usr/bin/gcc/9a0730e2bcc6d2a2003d21ac46807e8ee6bcb7c2/elf: ELF 64-bit LSB executable, x86-64, version 1 (SYSV), dynamically linked, interpreter /lib64/ld-linux-x86-64.so.2, for GNU/Linux 2.6.32, BuildID[sha1]=9a0730e2bcc6d2a2003d21ac46807e8ee6bcb7c2, stripped
  [root@jouet ~]# cat ~/.debug/usr/bin/gcc/9a0730e2bcc6d2a2003d21ac46807e8ee6bcb7c2/probes
  %sdt_libstdcxx:throw=throw
  p:sdt_libstdcxx/throw /usr/bin/gcc:0x71ffd
  %sdt_libstdcxx:rethrow=rethrow
  p:sdt_libstdcxx/rethrow /usr/bin/gcc:0x720b8
  %sdt_libstdcxx:catch=catch
  p:sdt_libstdcxx/catch /usr/bin/gcc:0x7307f
  %sdt_libgcc:unwind=unwind
  p:sdt_libgcc/unwind /usr/bin/gcc:0x7eec0
  #sdt_libstdcxx:*=%*
  [root@jouet ~]#

Ok, now we can use 'perf probe' to refer to those cached entries as:

  Humm, nope, doing as above we end up with:

  [root@jouet ~]# perf probe -a %sdt_libstdcxx:catch
  Semantic error :* is bad for event name -it must follow C symbol-naming rule.
    Error: Failed to add events.
  [root@jouet ~]#

But it worked at some point, lets try not using --dry-run:

Resetting everything:

  # rm -rf ~/.debug/
  # perf probe -d *:*
  # perf probe -l
  # perf list sdt

    List of pre-defined events (to be used in -e):

  #

Ok, now it cached everything, even things we haven't asked it to
(sdt_libgcc:unwind):

  [root@jouet ~]# perf probe -x /usr/bin/gcc --add %sdt_libstdcxx:\*
  Added new events:
    sdt_libstdcxx:throw  (on %* in /usr/bin/gcc)
    sdt_libstdcxx:rethrow (on %* in /usr/bin/gcc)
    sdt_libstdcxx:catch  (on %* in /usr/bin/gcc)

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

	perf record -e sdt_libstdcxx:catch -aR sleep 1

  [root@jouet ~]# perf list sdt

  List of pre-defined events (to be used in -e):

    sdt_libgcc:unwind                                  [SDT event]
    sdt_libstdcxx:catch                                [SDT event]
    sdt_libstdcxx:rethrow                              [SDT event]
    sdt_libstdcxx:throw                                [SDT event]
  [root@jouet ~]#

And we have the events in place:

  [root@jouet ~]# perf probe -l
    sdt_libstdcxx:catch  (on execute_cfa_program+1551@../../../libgcc/unwind-dw2.c in /usr/bin/gcc)
    sdt_libstdcxx:rethrow (on d_print_subexpr+280@libsupc++/cp-demangle.c in /usr/bin/gcc)
    sdt_libstdcxx:throw  (on d_print_subexpr+93@libsupc++/cp-demangle.c in /usr/bin/gcc)
  [root@jouet ~]#

And trying to use them at least has 'perf trace --event sdt*:*' working.

Then, if we try to add the ones in libstdc++:

  [root@jouet ~]# perf probe -x /usr/lib64/libstdc++.so.6 -a %sdt_libstdcxx:\*
  Error: event "catch" already exists.
   Hint: Remove existing event by 'perf probe -d'
         or force duplicates by 'perf probe -f'
         or set 'force=yes' in BPF source.
    Error: Failed to add events.
  [root@jouet ~]#

Doesn't work, dups, but at least this served to, unbeknownst to the user, add
the SDT probes in /usr/lib64/libstdc++.so.6!

  [root@jouet ~]# perf list sdt

  List of pre-defined events (to be used in -e):

    sdt_libgcc:unwind                                  [SDT event]
    sdt_libstdcxx:catch@/usr/bin/gcc(9a0730e2bcc6)     [SDT event]
    sdt_libstdcxx:catch@/usr/lib64/libstdc++.so.6.0.22(ef2b7066559a) [SDT event]
    sdt_libstdcxx:rethrow@/usr/bin/gcc(9a0730e2bcc6)   [SDT event]
    sdt_libstdcxx:rethrow@/usr/lib64/libstdc++.so.6.0.22(ef2b7066559a) [SDT event]
    sdt_libstdcxx:throw@/usr/bin/gcc(9a0730e2bcc6)     [SDT event]
    sdt_libstdcxx:throw@/usr/lib64/libstdc++.so.6.0.22(ef2b7066559a) [SDT event]
  [root@jouet ~]#

Now we should be able to get to the original cset comment, if we remove all
SDTs events in place, not from the cache, from the kernel, where it was set up as:

  [root@jouet ~]# ls -la /sys/kernel/debug/tracing/events/sdt_libstdcxx/
  total 0
  drwxr-xr-x.  5 root root 0 Jul 13 22:00 .
  drwxr-xr-x. 80 root root 0 Jul 13 21:56 ..
  drwxr-xr-x.  2 root root 0 Jul 13 22:00 catch
  -rw-r--r--.  1 root root 0 Jul 13 22:00 enable
  -rw-r--r--.  1 root root 0 Jul 13 22:00 filter
  drwxr-xr-x.  2 root root 0 Jul 13 22:00 rethrow
  drwxr-xr-x.  2 root root 0 Jul 13 22:00 throw
  [root@jouet ~]#

  [root@jouet ~]# head -2 /sys/kernel/debug/tracing/events/sdt_libstdcxx/throw/format
  name: throw
  ID: 2059
  [root@jouet ~]#

Now to remove it:

  [root@jouet ~]# perf probe -d sdt_libstdc*:*
  Removed event: sdt_libstdcxx:catch
  Removed event: sdt_libstdcxx:rethrow
  Removed event: sdt_libstdcxx:throw
  [root@jouet ~]#

Which caused:

  [root@jouet ~]# ls -la /sys/kernel/debug/tracing/events/sdt_libstdcxx/
  ls: cannot access '/sys/kernel/debug/tracing/events/sdt_libstdcxx/': No such file or directory
  [root@jouet ~]#

Ok, now we can do:

  [root@jouet ~]# perf list sdt_libstdcxx:catch

  List of pre-defined events (to be used in -e):

    sdt_libstdcxx:catch@/usr/bin/gcc(9a0730e2bcc6)     [SDT event]
    sdt_libstdcxx:catch@/usr/lib64/libstdc++.so.6.0.22(ef2b7066559a) [SDT event]
  [root@jouet ~]#

So, these are not really 'pre-defined events', i.e. we can't use them with
'perf record --event':

  [root@jouet ~]# perf record --event sdt_libstdcxx:catch*
  event syntax error: 'sdt_libstdcxx:catch*'
                       \___ unknown tracepoint

  Error:	File /sys/kernel/debug/tracing/events/sdt_libstdcxx/catch* not found.
  Hint:	Perhaps this kernel misses some CONFIG_ setting to enable this feature?.
<SNIP>
  [root@jouet ~]#

To have it really pre-defined we must use perf probe to get its definition from
the cache and set it up in the kernel, creating the tracepoint to _then_ use it
with 'perf record --event':

  [root@jouet ~]# perf probe -a sdt_libstdcxx:catch
  Semantic error :There is non-digit char in line number.
  <SNIP>

Oops, there is another gotcha here, we need that pesky '%' character:

  [root@jouet ~]# perf probe -a %sdt_libstdcxx:catch
  Added new events:
    sdt_libstdcxx:catch  (on %catch in /usr/bin/gcc)
    sdt_libstdcxx:catch_1 (on %catch in /usr/lib64/libstdc++.so.6.0.22)

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

	perf record -e sdt_libstdcxx:catch_1 -aR sleep 1

  [root@jouet ~]#

But then we added _two_ events, one with the name we expected, the other one
with a _ added, when doing the analysis we need to pay attention to who maps to
who.

And here is where we get to the point of this patch, which is to be able to
disambiguate those definitions for 'catch' in the build-id cache, but first we need
remove those events we just added:

[root@jouet ~]# perf probe -d %sdt_libstdcxx:catch

Oops, that didn't remove anything, we need to _remove_ that % char in this case:

  [root@jouet ~]# perf probe -d sdt_libstdcxx:catch
  Removed event: sdt_libstdcxx:catch

And we need to remove the other event added, i.e. I forgot to add a * at the end:

  [root@jouet ~]# perf probe -d sdt_libstdcxx:catch*
  Removed event: sdt_libstdcxx:catch_1
  [root@jouet ~]#

Ok, disambiguating it using what is in this patch:

  [root@jouet ~]# perf list sdt_libstdcxx:catch

  List of pre-defined events (to be used in -e):

    sdt_libstdcxx:catch@/usr/bin/gcc(9a0730e2bcc6)     [SDT event]
    sdt_libstdcxx:catch@/usr/lib64/libstdc++.so.6.0.22(ef2b7066559a) [SDT event]
  [root@jouet ~]#
  [root@jouet ~]# perf probe -a %sdt_libstdcxx:catch@9a07
  Added new event:
    sdt_libstdcxx:catch  (on %catch in /usr/bin/gcc)

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

	perf record -e sdt_libstdcxx:catch -aR sleep 1

  [root@jouet ~]# perf probe -l
    sdt_libstdcxx:catch  (on execute_cfa_program+1551@../../../libgcc/unwind-dw2.c in /usr/bin/gcc)
  [root@jouet ~]#

Yeah, it works! But we need to try and simplify this :-)

Update: Some aspects of this simplification take place in the following
        patches.

Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Ananth N Mavinakayanahalli <ananth@linux.vnet.ibm.com>
Cc: Brendan Gregg <brendan.d.gregg@gmail.com>
Cc: Hemant Kumar <hemant@linux.vnet.ibm.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/146831793746.17065.13065062753978236612.stgit@devbox
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2016-07-13 23:09:08 -03:00
Masami Hiramatsu 1de7b8bf72 perf probe: Search SDT/cached event from all probe caches
Search SDT/cached event from all probe caches if user doesn't pass any
binary. With this, we don't have to specify target binary for SDT and
named cached events (which start with %).

E.g. without this, a target binary must be passed with -x.

  # perf probe -x /usr/lib64/libc-2.20.so -a %sdt_libc:\*

With this change, we don't need it anymore.

  # perf probe -a %sdt_libc:\*

Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Ananth N Mavinakayanahalli <ananth@linux.vnet.ibm.com>
Cc: Brendan Gregg <brendan.d.gregg@gmail.com>
Cc: Hemant Kumar <hemant@linux.vnet.ibm.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/146831792812.17065.2353705982669445313.stgit@devbox
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2016-07-13 23:09:07 -03:00
Masami Hiramatsu 42bba263eb perf probe: Allow wildcard for cached events
Allo glob wildcard for reusing cached/SDT events. E.g.

  # perf probe -x /usr/lib64/libc-2.20.so -a %sdt_libc:\*

This example adds probes for all SDT in libc.
Note that the SDTs must have been scanned by perf buildid-cache.

Committer note:

Using it to check what of those SDT probes would take place when doing
a cargo run (rust):

  # trace --no-sys --event sdt_libc:* cargo run
     0.000 sdt_libc:setjmp:(7f326b69c4d1))
    28.423 sdt_libc:setjmp:(7f4b0a5364d1))
    29.000 sdt_libc:setjmp:(7f4b0a5364d1))
    88.597 sdt_libc:setjmp:(7fc01fd414d1))
    89.220 sdt_libc:setjmp:(7fc01fd414d1))
    95.501 sdt_libc:setjmp:(7f326b69c4d1))
     Running `target/debug/hello_world`
    97.110 sdt_libc:setjmp:(7f95e09234d1))
  Hello, world!
  #

Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Ananth N Mavinakayanahalli <ananth@linux.vnet.ibm.com>
Cc: Brendan Gregg <brendan.d.gregg@gmail.com>
Cc: Hemant Kumar <hemant@linux.vnet.ibm.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/146831791813.17065.17846564230840594888.stgit@devbox
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2016-07-13 23:09:07 -03:00
Masami Hiramatsu 36a009fe07 perf probe: Accept %sdt and %cached event name
To improve usability, support %[PROVIDER:]SDTEVENT format to add new
probes on SDT and cached events.

e.g.
  ----
  # perf probe -x /lib/libc-2.17.so  %lll_lock_wait_private
  Added new event:
    sdt_libc:lll_lock_wait_private (on %lll_lock_wait_private in /usr/lib/libc-2.17.so)

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

          perf record -e sdt_libc:lll_lock_wait_private -aR sleep 1

  # perf probe -l | more
    sdt_libc:lll_lock_wait_private (on __lll_lock_wait_private+21 in /usr/lib/libc-2.17.so)
  ----

Note that this is not only for SDT events, but also normal
events with event-name.

e.g. define "myevent" on cache (-n doesn't add the real probe)
  ----
  # perf probe -x ./perf --cache -n --add 'myevent=dso__load $params'
  ----
  Reuse the "myevent" from cache as below.
  ----
  # perf probe -x ./perf %myevent
  ----

Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Ananth N Mavinakayanahalli <ananth@linux.vnet.ibm.com>
Cc: Brendan Gregg <brendan.d.gregg@gmail.com>
Cc: Hemant Kumar <hemant@linux.vnet.ibm.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/146831788372.17065.3645054540325909346.stgit@devbox
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2016-07-13 23:09:05 -03:00
Masami Hiramatsu f6eb0518f3 perf probe: Fix to show correct error message for $vars and $params
Fix to show correct error messages for $vars and $params because
those special variables requires debug information to find the
real variables or function parameters.

E.g. without this fix;
  ----
  # perf probe -x /lib64/libc-2.23.so getaddrinfo \$params
  Failed to write event: Invalid argument
  Please upgrade your kernel to at least 3.14 to have access to feature $params
    Error: Failed to add events.
  ----

Perf ends up with an error, but the message is not correct.  With this
fix, perf shows correct error message as below.

  ----
  # perf probe -x /lib64/libc-2.23.so getaddrinfo \$params
  The /usr/lib64/libc-2.23.so file has no debug information.
  Rebuild with -g, or install an appropriate debuginfo package.
    Error: Failed to add events.
  ----

Reported-and-Tested-by: Arnaldo Carvalho de Melo <acme@kernel.org>
Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Ananth N Mavinakayanahalli <ananth@linux.vnet.ibm.com>
Cc: Brendan Gregg <brendan.d.gregg@gmail.com>
Cc: Hemant Kumar <hemant@linux.vnet.ibm.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/146831787438.17065.6152436996780110699.stgit@devbox
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2016-07-13 23:09:04 -03:00
Arnaldo Carvalho de Melo c8b5f2c96d tools: Introduce str_error_r()
The tools so far have been using the strerror_r() GNU variant, that
returns a string, be it the buffer passed or something else.

But that, besides being tricky in cases where we expect that the
function using strerror_r() returns the error formatted in a provided
buffer (we have to check if it returned something else and copy that
instead), breaks the build on systems not using glibc, like Alpine
Linux, where musl libc is used.

So, introduce yet another wrapper, str_error_r(), that has the GNU
interface, but uses the portable XSI variant of strerror_r(), so that
users rest asured that the provided buffer is used and it is what is
returned.

Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Wang Nan <wangnan0@huawei.com>
Link: http://lkml.kernel.org/n/tip-d4t42fnf48ytlk8rjxs822tf@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2016-07-12 15:19:47 -03:00
Masami Hiramatsu 8d993d9690 perf probe: Add group name support
Allow user to set group name for adding new event.  Note that user must
ensure that the group name doesn't conflict with existing group name
carefully.

E.g. Existing group name can conflict with other events.  Especially,
using the group name reserved for kernel modules can hide kernel
embedded events when loading modules.

Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Cc: Ananth N Mavinakayanahalli <ananth@linux.vnet.ibm.com>
Cc: Brendan Gregg <brendan.d.gregg@gmail.com>
Cc: Hemant Kumar <hemant@linux.vnet.ibm.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/146736024091.27797.9471545190066268995.stgit@devbox
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2016-07-04 19:39:00 -03:00
Masami Hiramatsu 1f3736c9c8 perf probe: Show all cached probes
perf probe --list shows all cached probes when --cache is given. Each
caches are shown with on which binary that probed. E.g.:

  -----
  # perf probe --cache vfs_read \$params
  # perf probe --cache -x /lib64/libc-2.17.so getaddrinfo \$params
  # perf probe --cache --list
  [kernel.kallsyms] (1466a0a250b5d0070c6d0f03c5fed30b237970a1):
  vfs_read $params
  /usr/lib64/libc-2.17.so (c31ffe7942bfd77b2fca8f9bd5709d387a86d3bc):
  getaddrinfo $params
  -----

Note that $params requires debuginfo.

Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Ananth N Mavinakayanahalli <ananth@linux.vnet.ibm.com>
Cc: Brendan Gregg <brendan.d.gregg@gmail.com>
Cc: Hemant Kumar <hemant@linux.vnet.ibm.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/146736020674.27797.13488316780383460180.stgit@devbox
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2016-07-01 11:34:57 -03:00
Masami Hiramatsu bc0622302f perf probe: Use cache entry if possible
Before analyzing debuginfo, try to find a corresponding entry from probe
cache always. This does not depend on --cache, the --cache enables to
store/update cache, but looking up the cache is always enabled.

Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Cc: Ananth N Mavinakayanahalli <ananth@linux.vnet.ibm.com>
Cc: Brendan Gregg <brendan.d.gregg@gmail.com>
Cc: Hemant Kumar <hemant@linux.vnet.ibm.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/146736019226.27797.16366402884098398857.stgit@devbox
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2016-07-01 11:34:57 -03:00
Arnaldo Carvalho de Melo 10daf4d01b perf intlist: Rename for_each() macros to for_each_entry()
To match the semantics for list.h in the kernel, that are the
interface we use in them.

Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Milian Wolff <milian.wolff@kdab.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Taeung Song <treeze.taeung@gmail.com>
Cc: Wang Nan <wangnan0@huawei.com>
Link: http://lkml.kernel.org/n/tip-mdp1heu9xjjc12zebh91232l@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2016-06-23 11:39:19 -03:00
Arnaldo Carvalho de Melo 602a1f4daa perf tools: Rename strlist_for_each() macros to for_each_entry()
To match the semantics for list.h in the kernel, that are the
interface we use in them.

Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Milian Wolff <milian.wolff@kdab.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Taeung Song <treeze.taeung@gmail.com>
Cc: Wang Nan <wangnan0@huawei.com>
Link: http://lkml.kernel.org/n/tip-0b5i2ki9c3di6706fxpticsb@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2016-06-23 11:35:01 -03:00
Arnaldo Carvalho de Melo 32ca678dcd perf machine: Destructors should accept NULL
And do nothing, just like free(), to avoid having to test it in callers,
usually in error paths.

Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Wang Nan <wangnan0@huawei.com>
Link: http://lkml.kernel.org/n/tip-q42gj3b3znhho9z1mrbo4jce@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2016-06-22 10:19:11 -03:00
Masami Hiramatsu 2fd457a345 perf probe: Add --cache option to cache the probe definitions
Add --cache option to cache the probe definitions. This just saves the
result of the dwarf analysis to probe cache.

Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Cc: Ananth N Mavinakayanahalli <ananth@linux.vnet.ibm.com>
Cc: Brendan Gregg <brendan.d.gregg@gmail.com>
Cc: Hemant Kumar <hemant@linux.vnet.ibm.com>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/20160615032840.31330.44412.stgit@devbox
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2016-06-15 14:34:42 -03:00
Masami Hiramatsu c4ff49209b perf probe: Uncomment and export synthesize_perf_probe_point()
Uncomment and export synthesize_perf_probe_point() which had once
introduced but has been disabled for a long time. This renews the code
and re-enable it.

Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Ananth N Mavinakayanahalli <ananth@linux.vnet.ibm.com>
Cc: Brendan Gregg <brendan.d.gregg@gmail.com>
Cc: Hemant Kumar <hemant@linux.vnet.ibm.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/20160608092949.3116.21958.stgit@devbox
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2016-06-14 09:29:54 -03:00
Masami Hiramatsu 0542bb9c8d perf probe: Add perf_probe_event__copy()
Add perf_probe_event__copy() to copy perf_probe_event data structure and
sub data structures under given source perf_probe_event.

Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Ananth N Mavinakayanahalli <ananth@linux.vnet.ibm.com>
Cc: Brendan Gregg <brendan.d.gregg@gmail.com>
Cc: Hemant Kumar <hemant@linux.vnet.ibm.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/20160608092940.3116.18034.stgit@devbox
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2016-06-14 09:29:54 -03:00
Masami Hiramatsu 844faa4bcd perf probe: Fix to add NULL check for strndup
Fix to add a NULL check for strndup when parsing probe trace command.

Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Ananth N Mavinakayanahalli <ananth@linux.vnet.ibm.com>
Cc: Brendan Gregg <brendan.d.gregg@gmail.com>
Cc: Hemant Kumar <hemant@linux.vnet.ibm.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/20160608092920.3116.63319.stgit@devbox
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2016-06-14 09:29:54 -03:00
Masami Hiramatsu bf4d5f25c9 perf probe: Check the return value of strbuf APIs
Check the return value of strbuf APIs in perf-probe
related code, so that it can handle errors in strbuf.

Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/20160510054707.6158.69861.stgit@devbox
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2016-05-10 11:53:34 -03:00
Naveen N. Rao 0b3c2264ae perf symbols: Fix kallsyms perf test on ppc64le
ppc64le functions have a Global Entry Point (GEP) and a Local Entry
Point (LEP). While placing a probe, we always prefer the LEP since it
catches function calls through both the GEP and the LEP. In order to do
this, we fixup the function entry points during elf symbol table lookup
to point to the LEPs. This works, but breaks 'perf test kallsyms' since
the symbols loaded from the symbol table (pointing to the LEP) do not
match the symbols in kallsyms.

To fix this, we do not adjust all the symbols during symbol table load.
Instead, we note down st_other in a newly introduced arch-specific
member of perf symbol structure, and later use this to adjust the probe
trace point.

Reported-by: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
Acked-by: Ananth N Mavinakayanahalli <ananth@in.ibm.com>
Acked-by: Balbir Singh <bsingharora@gmail.com>
Cc: Mark Wielaard <mjw@redhat.com>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Thiago Jung Bauermann <bauerman@linux.vnet.ibm.com>
Cc: linuxppc-dev@lists.ozlabs.org
Link: http://lkml.kernel.org/r/6be7c2b17e370100c2f79dd444509df7929bdd3e.1460451721.git.naveen.n.rao@linux.vnet.ibm.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2016-05-05 21:04:03 -03:00
Masami Hiramatsu 909b0360ae perf probe: Use strbuf for making strings
Replace many fixed-length char array with strbuf to stringify
perf_probe_event and probe_trace_event etc.

Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Cc: Ananth N Mavinakayanahalli <ananth@linux.vnet.ibm.com>
Cc: Hemant Kumar <hemant@linux.vnet.ibm.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/20160427183713.23446.97377.stgit@devbox
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2016-04-28 09:58:58 -03:00
Ravi Bangoria c61fb959df perf probe: Fix module probe issue if no dwarf support
Perf is not able to register probe in kernel module when dwarf supprt
is not there(and so it goes for symtab). Perf passes full path of
module where only module name is required which is causing the problem.
This patch fixes this issue.

Before applying patch:

  $ dpkg -s libdw-dev
  dpkg-query: package 'libdw-dev' is not installed and no information is...

  $ sudo ./perf probe -m /linux/samples/kprobes/kprobe_example.ko kprobe_init
  Added new event:
    probe:kprobe_init (on kprobe_init in /linux/samples/kprobes/kprobe_example.ko)

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

  perf record -e probe:kprobe_init -aR sleep 1

  $ sudo cat /sys/kernel/debug/tracing/kprobe_events
  p:probe/kprobe_init /linux/samples/kprobes/kprobe_example.ko:kprobe_init

  $ sudo ./perf record -a -e probe:kprobe_init
  [ perf record: Woken up 1 times to write data ]
  [ perf record: Captured and wrote 0.105 MB perf.data ]

  $ sudo ./perf script 	# No output here

After applying patch:

  $ sudo ./perf probe -m /linux/samples/kprobes/kprobe_example.ko kprobe_init
  Added new event:
    probe:kprobe_init    (on kprobe_init in kprobe_example)

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

  perf record -e probe:kprobe_init -aR sleep 1

  $ sudo cat /sys/kernel/debug/tracing/kprobe_events
  p:probe/kprobe_init kprobe_example:kprobe_init

  $ sudo ./perf record -a -e probe:kprobe_init
  [ perf record: Woken up 1 times to write data ]
  [ perf record: Captured and wrote 0.105 MB perf.data (2 samples) ]

  $ sudo ./perf script
  insmod 13990 [002]  5961.216833: probe:kprobe_init: ...
  insmod 13995 [002]  5962.889384: probe:kprobe_init: ...

Signed-off-by: Ravi Bangoria <ravi.bangoria@linux.vnet.ibm.com>
Acked-by: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Cc: Wang Nan <wangnan0@huawei.com>
Link: http://lkml.kernel.org/r/1461680741-12517-1-git-send-email-ravi.bangoria@linux.vnet.ibm.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2016-04-26 13:15:01 -03:00
Ravi Bangoria 63a29613d7 perf probe: Fix offline module name missmatch issue
Perf can add a probe on kernel module which has not been loaded yet.

The current implementation finds the module name from path. But if the
filename is different from the actual module name then perf fails to
register a probe while loading module because of mismatch in the names.

For example, samples/kobject/kobject-example.ko is loaded as
kobject_example.

Before applying patch:

  $ sudo ./perf probe -m /linux/samples/kobject/kobject-example.ko foo_show
    Added new event:
      probe:foo_show       (on foo_show in kobject-example)

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

    perf record -e probe:foo_show -aR sleep 1

  $ cat /sys/kernel/debug/tracing/kprobe_events
    p:probe/foo_show kobject-example:foo_show

  $ insmod kobject-example.ko

  $ lsmod
    Module                  Size  Used by
    kobject_example        16384  0

  Generate read to /sys/kernel/kobject_example/foo while recording data
  with below command
  $ sudo ./perf record -e probe:foo_show -a
    [ perf record: Woken up 1 times to write data ]
    [ perf record: Captured and wrote 0.093 MB perf.data ]

  $./perf report --stdio -F overhead,comm,dso,sym
    Error:
    The perf.data.old file has no samples!

After applying patch:

  $ sudo ./perf probe -m /linux/samples/kobject/kobject-example.ko foo_show
    Added new event:
      probe:foo_show       (on foo_show in kobject_example)

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

    perf record -e probe:foo_show -aR sleep 1

  $ sudo cat /sys/kernel/debug/tracing/kprobe_events
    p:probe/foo_show kobject_example:foo_show

  $ insmod kobject-example.ko

  $ lsmod
    Module                  Size  Used by
    kobject_example        16384  0

  Generate read to /sys/kernel/kobject_example/foo while recording data
  with below command
  $ sudo ./perf record -e probe:foo_show -a
    [ perf record: Woken up 1 times to write data ]
    [ perf record: Captured and wrote 0.097 MB perf.data (8 samples) ]

  $ sudo ./perf report  --stdio -F overhead,comm,dso,sym
    ...
    # Samples: 8  of event 'probe:foo_show'
    # Event count (approx.): 8
    #
    # Overhead  Command  Shared Object      Symbol
    # ........  .......  .................  ............
    #
       100.00%  cat      [kobject_example]  [k] foo_show

Signed-off-by: Ravi Bangoria <ravi.bangoria@linux.vnet.ibm.com>
Acked-by: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Cc: Wang Nan <wangnan0@huawei.com>
Link: http://lkml.kernel.org/r/1461680741-12517-2-git-send-email-ravi.bangoria@linux.vnet.ibm.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2016-04-26 13:15:01 -03:00
Masami Hiramatsu 2a12ec13cc perf probe: Set default kprobe group name if it is not given
Set kprobe group name as "probe" if it is not given.

Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Cc: Ananth N Mavinakayanahalli <ananth@linux.vnet.ibm.com>
Cc: Hemant Kumar <hemant@linux.vnet.ibm.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/20160426090413.11891.95640.stgit@devbox
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2016-04-26 13:14:58 -03:00
Masami Hiramatsu 062d6c2aec perf probe: Close target file on error path
Fix a bug to close target elf file in get_text_start_address().

Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/20160426064737.1443.44093.stgit@devbox
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2016-04-26 10:56:08 -03:00
Arnaldo Carvalho de Melo 88fd633cdf perf probe: No need to use formatting strbuf method
We have addch() for chars, add() for fixed size data, and addstr() for
variable length strings, use them.

Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Wang Nan <wangnan0@huawei.com>
Link: http://lkml.kernel.org/n/tip-0ap02fn2xtvpduj2j6b2o1j4@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2016-03-23 16:53:05 -03:00
Wang Nan 03e01f5687 perf bpf: Allow BPF program config probing options
By extending the syntax of BPF object section names, this patch allows users to
config probing options like what they can do in 'perf probe'.

The error message in 'perf probe' is also updated.

Test result:

For following BPF file test_probe_glob.c:

  # cat test_probe_glob.c
  __attribute__((section("inlines=no;func=SyS_dup?"), used))

  int func(void *ctx)
  {
	  return 1;
  }

  char _license[] __attribute__((section("license"), used)) = "GPL";
  int _version __attribute__((section("version"), used)) = 0x40300;
  #
  # ./perf record  -e ./test_probe_glob.c ls /
  ...
  [ perf record: Woken up 1 times to write data ]
  [ perf record: Captured and wrote 0.013 MB perf.data ]
  # ./perf evlist
  perf_bpf_probe:func_1
  perf_bpf_probe:func

After changing "inlines=no" to "inlines=yes":

  # ./perf record  -e ./test_probe_glob.c ls /
  ...
  [ perf record: Woken up 2 times to write data ]
  [ perf record: Captured and wrote 0.013 MB perf.data ]
  # ./perf evlist
  perf_bpf_probe:func_3
  perf_bpf_probe:func_2
  perf_bpf_probe:func_1
  perf_bpf_probe:func

Then test 'force':

Use following program:

  # cat test_probe_force.c
  __attribute__((section("func=sys_write"), used))

  int funca(void *ctx)
  {
	  return 1;
  }

  __attribute__((section("force=yes;func=sys_write"), used))

  int funcb(void *ctx)
  {
  	return 1;
  }

  char _license[] __attribute__((section("license"), used)) = "GPL";
  int _version __attribute__((section("version"), used)) = 0x40300;
  #

  # perf record -e ./test_probe_force.c usleep 1
  Error: event "func" already exists.
   Hint: Remove existing event by 'perf probe -d'
       or force duplicates by 'perf probe -f'
       or set 'force=yes' in BPF source.
  event syntax error: './test_probe_force.c'
                       \___ Probe point exist. Try 'perf probe -d "*"' and set 'force=yes'

  (add -v to see detail)
  ...

Then replace 'force=no' to 'force=yes':

  # vim test_probe_force.c
  # perf record -e ./test_probe_force.c usleep 1
  [ perf record: Woken up 1 times to write data ]
  [ perf record: Captured and wrote 0.017 MB perf.data ]
  # perf evlist
  perf_bpf_probe:func_1
  perf_bpf_probe:func
  #

Signed-off-by: Wang Nan <wangnan0@huawei.com>
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Alexei Starovoitov <ast@kernel.org>
Cc: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Cc: Zefan Li <lizefan@huawei.com>
Cc: pi3orama@163.com
Link: http://lkml.kernel.org/r/1447675815-166222-7-git-send-email-wangnan0@huawei.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2015-11-18 17:51:04 -03:00
Masami Hiramatsu 0a62f6869f perf probe: Cleanup find_perf_probe_point_from_map to reduce redundancy
In find_perf_probe_point_from_map(), the 'ret' variable is initialized
with -ENOENT but overwritten by the return code of
kernel_get_symbol_address_by_name(), and after that it is re-initialized
with -ENOENT again.

Setting ret=-ENOENT twice looks a bit redundant. This avoids the
overwriting and just returns -ENOENT if some error happens to simplify
the code.

Signed-off-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Wang Nan <wangnan0@huawei.com>
Cc: Zefan Li <lizefan@huawei.com>
Link: http://lkml.kernel.org/n/tip-ufp1zgbktzmttcputozneomd@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2015-11-06 10:47:33 -03:00
Wang Nan 98d3b258ed perf tools: Fix find_perf_probe_point_from_map() which incorrectly returns success
It is possible that find_perf_probe_point_from_map() fails to find a
symbol but still returns 0 because of an small error when coding:
find_perf_probe_point_from_map() set 'ret' to error code at first, but
also use it to hold return value of kernel_get_symbol_address_by_name().

This patch resets 'ret' to error even kernel_get_symbol_address_by_name()
success, so if !sym, the whole function returns error correctly.

Signed-off-by: Wang Nan <wangnan0@huawei.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Zefan Li <lizefan@huawei.com>
Cc: pi3orama@163.com
Link: http://lkml.kernel.org/r/1446729565-27592-3-git-send-email-wangnan0@huawei.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2015-11-05 12:47:52 -03:00