linux.git/tools/perf/util, branch v4.4-rc4

perf probe: Clear probe_trace_event when add_probe_trace_event() fails

2015-11-13T15:28:09+00:00

When probing with a glob, errors in add_probe_trace_event() won't be
passed to debuginfo__find_trace_events() because it would be modified by
probe_point_search_cb(). It causes a segfault if perf fails to find an
argument for a probe point matched by the glob. For example:

  # ./perf probe -v -n 'SyS_dup? oldfd'
  probe-definition(0): SyS_dup? oldfd
  symbol:SyS_dup? file:(null) line:0 offset:0 return:0 lazy:(null)
  parsing arg: oldfd into oldfd
  1 arguments
  Looking at the vmlinux_path (7 entries long)
  Using /lib/modules/4.3.0-rc4+/build/vmlinux for symbols
  Open Debuginfo file: /lib/modules/4.3.0-rc4+/build/vmlinux
  Try to find probe point from debuginfo.
  Matched function: SyS_dup3
  found inline addr: 0xffffffff812095c0
  Probe point found: SyS_dup3+0
  Searching 'oldfd' variable in context.
  Converting variable oldfd into trace event.
  oldfd type is long int.
  found inline addr: 0xffffffff812096d4
  Probe point found: SyS_dup2+36
  Searching 'oldfd' variable in context.
  Failed to find 'oldfd' in this function.
  Matched function: SyS_dup3
  Probe point found: SyS_dup3+0
  Searching 'oldfd' variable in context.
  Converting variable oldfd into trace event.
  oldfd type is long int.
  Matched function: SyS_dup2
  Probe point found: SyS_dup2+0
  Searching 'oldfd' variable in context.
  Converting variable oldfd into trace event.
  oldfd type is long int.
  Found 4 probe_trace_events.
  Opening /sys/kernel/debug/tracing//kprobe_events write=1
  Writing event: p:probe/SyS_dup3 _text+2135488 oldfd=%di:s64
  Segmentation fault (core dumped)
  #

This patch ensures that add_probe_trace_event() doesn't touches
tf->ntevs and tf->tevs if those functions fail.

After the patch:

  # perf probe  'SyS_dup? oldfd'
  Failed to find 'oldfd' in this function.
  Added new events:
    probe:SyS_dup3       (on SyS_dup? with oldfd)
    probe:SyS_dup3_1     (on SyS_dup? with oldfd)
    probe:SyS_dup2       (on SyS_dup? with oldfd)

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

	perf record -e probe:SyS_dup2 -aR sleep 1

Signed-off-by: Wang Nan 
Tested-by: Arnaldo Carvalho de Melo 
Cc: Alexei Starovoitov 
Cc: Masami Hiramatsu 
Cc: Zefan Li 
Cc: pi3orama@163.com
Link: http://lkml.kernel.org/r/1447417761-156094-3-git-send-email-wangnan0@huawei.com
Signed-off-by: Arnaldo Carvalho de Melo

perf probe: Fix memory leaking on failure by clearing all probe_trace_events

2015-11-13T15:24:32+00:00

Fix memory leaking on the debuginfo__find_trace_events() failure path
which frees an array of probe_trace_events but doesn't clears all the
allocated sub-structures and strings.

So, before doing zfree(tevs), clear all the array elements which may
have allocated resources.

Reported-by: Wang Nan 
Signed-off-by: Masami Hiramatsu 
Cc: Alexei Starovoitov 
Cc: Zefan Li 
Cc: pi3orama@163.com
Link: http://lkml.kernel.org/r/1447417761-156094-2-git-send-email-wangnan0@huawei.com
Signed-off-by: Arnaldo Carvalho de Melo

perf buildid-list: Requires ordered events

2015-11-13T15:22:04+00:00

'perf buildid-list' processes events to determine hits (i.e. with-hits
option).  That may not work if events are not sorted in order. i.e. MMAP
events must be processed before the samples that depend on them so that
sample processing can 'hit' the DSO to which the MMAP refers.

Signed-off-by: Adrian Hunter 
Cc: Jiri Olsa 
Link: http://lkml.kernel.org/r/1447408112-1920-3-git-send-email-adrian.hunter@intel.com
Signed-off-by: Arnaldo Carvalho de Melo

perf symbols: Fix dso lookup by long name and missing buildids

2015-11-13T14:14:36+00:00

Commit 4598a0a6d22f ("perf symbols: Improve DSO long names lookup speed
with rbtree") Added a tree to lookup dsos by long name.  That tree gets
corrupted whenever a dso long name is changed because the tree is not
updated.

One effect of that is buildid-list does not work with the 'with-hits'
option because dso lookup fails and results in two structs for the same
dso.  The first has the buildid but no hits, the second has hits but no
buildid. e.g.

Before:

  $ tools/perf/perf record ls
  arch     certs    CREDITS  Documentation  firmware  include
  ipc      Kconfig  lib      Makefile       net       REPORTING-BUGS
  scripts  sound    usr      block          COPYING   crypto
  drivers  fs       init     Kbuild         kernel    MAINTAINERS
  mm       README   samples  security       tools     virt
  [ perf record: Woken up 1 times to write data ]
  [ perf record: Captured and wrote 0.012 MB perf.data (11 samples) ]
  $ tools/perf/perf buildid-list
  574da826c66538a8d9060d393a8866289bd06005 [kernel.kallsyms]
  30c94dc66a1fe95180c3d68d2b89e576d5ae213c /lib/x86_64-linux-gnu/libc-2.19.so
  $ tools/perf/perf buildid-list -H
  574da826c66538a8d9060d393a8866289bd06005 [kernel.kallsyms]
  0000000000000000000000000000000000000000 /lib/x86_64-linux-gnu/libc-2.19.so

After:

  $ tools/perf/perf buildid-list -H
  574da826c66538a8d9060d393a8866289bd06005 [kernel.kallsyms]
  30c94dc66a1fe95180c3d68d2b89e576d5ae213c /lib/x86_64-linux-gnu/libc-2.19.so

The fix is to record the root of the tree on the dso so that
dso__set_long_name() can update the tree when the long name changes.

Signed-off-by: Adrian Hunter 
Tested-by: Arnaldo Carvalho de Melo 
Cc: Adrian Hunter 
Cc: Don Zickus 
Cc: Douglas Hatch 
Cc: Jiri Olsa 
Cc: Namhyung Kim 
Cc: Peter Zijlstra 
Cc: Scott J Norton 
Cc: Waiman Long 
Fixes: 4598a0a6d22f ("perf symbols: Improve DSO long names lookup speed with rbtree")
Link: http://lkml.kernel.org/r/1447408112-1920-2-git-send-email-adrian.hunter@intel.com
Signed-off-by: Arnaldo Carvalho de Melo

perf symbols: Allow forcing reading of non-root owned files by root

2015-11-12T21:58:18+00:00

When the root user tries to read a file owned by some other user we get:

  # ls -la perf.data
  -rw-------. 1 acme acme 20032 Nov 12 15:50 perf.data
  # perf report
  File perf.data not owned by current user or root (use -f to override)
  # perf report -f | grep -v ^# | head -2
    30.96%  ls       [kernel.vmlinux]  [k] do_set_pte
    28.24%  ls       libc-2.20.so      [.] intel_check_word
  #

That wasn't happening when the symbol code tried to read a JIT map,
where the same check was done but no forcing was possible, fix it.

Reported-by: Brendan Gregg 
Tested-by: Brendan Gregg 
Cc: Adrian Hunter 
Cc: David Ahern 
Cc: Jiri Olsa 
Cc: Namhyung Kim 
Cc: Wang Nan 
Link: http://permalink.gmane.org/gmane.linux.kernel.perf.user/2380
Signed-off-by: Arnaldo Carvalho de Melo

perf symbols: Rebuild rbtree when adjusting symbols for kcore

2015-11-12T21:58:17+00:00

Normally symbols are read from the DSO and adjusted, if need be, so that
the symbol start matches the file offset in the DSO file (we want the
file offset because that is what we know from MMAP events). That is done
by dso__load_sym() which inserts the symbols *after* adjusting them.

In the case of kcore, the symbols have been read from kallsyms and the
symbol start is the memory address. The symbols have to be adjusted to
match the kcore file offsets. dso__split_kallsyms_for_kcore() does that,
but now the adjustment is being done *after* the symbols have been
inserted. It appears dso__split_kallsyms_for_kcore() was assuming that
changing the symbol start would not change the order in the rbtree -
which is, of course, not guaranteed.

Signed-off-by: Adrian Hunter 
Tested-by: Wang Nan 
Cc: Jiri Olsa 
Cc: Masami Hiramatsu 
Cc: Namhyung Kim 
Cc: Zefan Li 
Cc: pi3orama@163.com
Link: http://lkml.kernel.org/r/563CB241.2090701@intel.com
Signed-off-by: Arnaldo Carvalho de Melo

perf probe: Verify parameters in two functions

2015-11-11T21:41:32+00:00

On kernel with only one out of CONFIG_KPROBE_EVENTS and
CONFIG_UPROBE_EVENTS enabled, 'perf probe -d' causes a segfault because
perf_del_probe_events() calls probe_file__get_events() with a negative
fd.

This patch fixes it by adding parameter validation at the entry of
probe_file__get_events() and probe_file__get_rawlist(). Since they are
both non-static public functions (in .h file), parameter verifying is
required.

v1 -> v2: Verify fd at the head of probe_file__get_rawlist() instead of
          checking at call site (suggested by Masami and Arnaldo at [1,2]).

[1] http://lkml.kernel.org/r/50399556C9727B4D88A595C8584AAB37526048E3@GSjpTKYDCembx32.service.hitachi.net
[2] http://lkml.kernel.org/r/20151105155830.GV13236@kernel.org

Signed-off-by: Wang Nan 
Acked-by: Masami Hiramatsu 
Cc: Jiri Olsa 
Cc: Namhyung Kim 
Cc: Zefan Li 
Cc: pi3orama@163.com
Link: http://lkml.kernel.org/r/1446803415-83382-1-git-send-email-wangnan0@huawei.com
Signed-off-by: Arnaldo Carvalho de Melo

perf session: Add missing newlines to some pr_err() calls

2015-11-11T21:41:31+00:00

Before:

  [acme@zoo linux]$ perf evlist
  WARNING: The perf.data file's data size field is 0 which is unexpected.
  Was the 'perf record' command properly terminated?
  non matching sample_type[acme@zoo linux]$

After:

  [acme@zoo linux]$ perf evlist
  WARNING: The perf.data file's data size field is 0 which is unexpected.
  Was the 'perf record' command properly terminated?
  non matching sample_type
  [acme@zoo linux]$

Cc: Adrian Hunter 
Cc: David Ahern 
Cc: Jiri Olsa 
Cc: Namhyung Kim 
Cc: Wang Nan 
Link: http://lkml.kernel.org/n/tip-wscok3a2s7yrj8156oc2r6qe@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo

perf annotate: Support full source file paths for srcline fix

2015-11-11T21:41:30+00:00

The --full-paths option did not show the full source file paths in the 'perf
annotate' tool, because the value of the option was not propagated into the
related functions.

With this patch the value of the --full-paths option is known to the function
that composes the srcline string, so it prints the full path when necessary.

Committer Note:

This affects annotate when the --print-line option is used:

  # perf annotate -h 2>&1 | grep print-line
      -l, --print-line      print matching source lines (may be slow)

Looking just at the lines that should be affected by this change:

Before:

  # perf annotate --print-line --full-paths --stdio fput | grep '\.[ch]:[0-9]\+'
     94.44 atomic64_64.h:114
      5.56 file_table.c:265
   file_table.c:265    5.56 :	  ffffffff81219a00:       callq  ffffffff81769360 <__fentry__>
   atomic64_64.h:114   94.44 :	  ffffffff81219a05:       lock decq 0x38(%rdi)

After:

  # perf annotate --print-line --full-paths --stdio fput | grep '\.[ch]:[0-9]\+'
     94.44 /home/git/linux/arch/x86/include/asm/atomic64_64.h:114
      5.56 /home/git/linux/fs/file_table.c:265
   /home/git/linux/fs/file_table.c:265    5.56 :	  ffffffff81219a00:       callq  ffffffff81769360 <__fentry__>
   /home/git/linux/arch/x86/include/asm/atomic64_64.h:114   94.44 :	  ffffffff81219a05:       lock decq 0x38(%rdi)
  #

Signed-off-by: Michael Petlan 
Tested-by: Arnaldo Carvalho de Melo 
Link: http://permalink.gmane.org/gmane.linux.kernel.perf.user/2365
Signed-off-by: Arnaldo Carvalho de Melo

perf test: Add 'perf test BPF'

2015-11-06T20:50:03+00:00

This patch adds BPF testcase for testing BPF event filtering.

By utilizing the result of 'perf test LLVM', this patch compiles the
eBPF sample program then test its ability. The BPF script in 'perf test
LLVM' lets only 50% samples generated by epoll_pwait() to be captured.
This patch runs that system call for 111 times, so the result should
contain 56 samples.

Signed-off-by: Wang Nan 
Tested-by: Arnaldo Carvalho de Melo 
Cc: Alexei Starovoitov 
Cc: Jiri Olsa 
Cc: Namhyung Kim 
Cc: Zefan Li 
Cc: pi3orama@163.com
Link: http://lkml.kernel.org/r/1446817783-86722-8-git-send-email-wangnan0@huawei.com
Signed-off-by: Arnaldo Carvalho de Melo