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  1. 18 Mar, 2013 6 commits
    • Masami Hiramatsu's avatar
      kprobes/x86: Check Interrupt Flag modifier when registering probe · 9a556ab9
      Masami Hiramatsu authored 
      Currently kprobes check whether the copied instruction modifies
IF (interrupt flag) on each probe hit. This results not only in
introducing overhead but also involving
inat_get_opcode_attribute into the kprobes hot path, and it can
cause an infinite recursive call (and kernel panic in the end).

Actually, since the copied instruction itself can never be modified
on the buffer, it is needless to analyze the instruction on every
probe hit.

To fix this issue, we check it only once when registering probe
and store the result on ainsn->if_modifier.
Reported-by: default avatarTimo Juhani Lindfors <timo.lindfors@iki.fi>
Signed-off-by: default avatarMasami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Acked-by: default avatarAnanth N Mavinakayanahalli <ananth@in.ibm.com>
Cc: yrl.pp-manager.tt@hitachi.com
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: David S. Miller <davem@davemloft.net>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Link: http://lkml.kernel.org/r/20130314115242.19690.33573.stgit@mhiramat-M0-7522Signed-off-by: default avatarIngo Molnar <mingo@kernel.org>
      9a556ab9
    • Masami Hiramatsu's avatar
      kprobes: Make hash_64() as always inlined · 65c10553
      Masami Hiramatsu authored 
      Because hash_64() is called from the get_kprobe() inside
int3 handler, kernel causes int3 recursion and crashes if
kprobes user puts a probe on it.

Usually hash_64() is inlined into caller function, but in
some cases, it has instances by gcc's interprocedural
constant propagation.

This patch uses __always_inline instead of inline to
prevent gcc from doing such things.
Reported-by: default avatarTimo Juhani Lindfors <timo.lindfors@iki.fi>
Signed-off-by: default avatarMasami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Acked-by: default avatarAnanth N Mavinakayanahalli <ananth@in.ibm.com>
Cc: Pavel Emelyanov <xemul@parallels.com>
Cc: Jiri Kosina <jkosina@suse.cz>
Cc: Nadia Yvette Chambers <nyc@holomorphy.com>
Cc: yrl.pp-manager.tt@hitachi.com
Cc: David S. Miller <davem@davemloft.net>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Link: http://lkml.kernel.org/r/20130314115230.19690.39387.stgit@mhiramat-M0-7522Signed-off-by: default avatarIngo Molnar <mingo@kernel.org>
      65c10553
    • Ingo Molnar's avatar
      Merge tag 'perf-urgent-for-mingo' of... · a0bf225d
      Ingo Molnar authored 
      Merge tag 'perf-urgent-for-mingo' of git://git.kernel.org/pub/scm/linux/kernel/git/acme/linux into perf/urgent

Pull perf/urgent fixes from Arnaldo Carvalho de Melo:

. perf probe: Fix segfault due to testing the wrong pointer for NULL,
  from Ananth N Mavinakayanahalli.

. libtraceevent: Remove hard coded include to /usr/local/include in
  Makefile, which causes cross builds to include host header files,
  fix from Jack Mitchell.

. perf record: Use the right target interface for synthesizing
  threads when --cpu/-C option is used, fix from Jiri Olsa.

. Check if -DFORTIFY_SOURCE=2 is allowed, as gcc 4.7.2 defines
  it and then the build is broken when it is redefined in perf,
  fix from Marcin Slusarz.

. Fix build with NO_NEWT=1, that can happen explicitely or when
  the newt-devel package is not installed, from Michael Ellerman.

. perf/POWER7: Create a sysfs format entry for Power7 events, missing
  patch from a patchseries already merged, from Sukadev Bhattiprolu.

. Fix LIBNUMA build with glibc 2.12 and older, from Vinson Lee.
Signed-off-by: default avatarArnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: default avatarIngo Molnar <mingo@kernel.org>
      a0bf225d
    • Ingo Molnar's avatar
      Merge branch 'tip/perf/urgent-2' of... · 1f1b3967
      Ingo Molnar authored 
      Merge branch 'tip/perf/urgent-2' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace into perf/urgent

Pull tracing fixes from Steven Rostedt.
Signed-off-by: default avatarIngo Molnar <mingo@kernel.org>
      1f1b3967
    • Namhyung Kim's avatar
      perf: Generate EXIT event only once per task context · d610d98b
      Namhyung Kim authored 
      perf_event_task_event() iterates pmu list and generate events
for each eligible pmu context.  But if task_event has task_ctx
like in EXIT it'll generate events even though the pmu doesn't
have an eligible one. Fix it by moving the code to proper
places.

Before this patch:

  $ perf record -n true
  [ perf record: Woken up 1 times to write data ]
  [ perf record: Captured and wrote 0.006 MB perf.data (~248 samples) ]

  $ perf report -D | tail
  Aggregated stats:
             TOTAL events:         73
              MMAP events:         67
              COMM events:          2
              EXIT events:          4
  cycles stats:
             TOTAL events:         73
              MMAP events:         67
              COMM events:          2
              EXIT events:          4

After this patch:

  $ perf report -D | tail
  Aggregated stats:
             TOTAL events:         70
              MMAP events:         67
              COMM events:          2
              EXIT events:          1
  cycles stats:
             TOTAL events:         70
              MMAP events:         67
              COMM events:          2
              EXIT events:          1
Signed-off-by: default avatarNamhyung Kim <namhyung@kernel.org>
Cc: Arnaldo Carvalho de Melo <acme@ghostprotocols.net>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Namhyung Kim <namhyung.kim@lge.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/1363332433-7637-1-git-send-email-namhyung@kernel.orgSigned-off-by: default avatarIngo Molnar <mingo@kernel.org>
      d610d98b
    • Namhyung Kim's avatar
      perf: Reset hwc->last_period on sw clock events · 778141e3
      Namhyung Kim authored 
      When cpu/task clock events are initialized, their sampling
frequencies are converted to have a fixed value.  However it
missed to update the hwc->last_period which was set to 1 for
initial sampling frequency calibration.

Because this hwc->last_period value is used as a period in
perf_swevent_ hrtime(), every recorded sample will have an
incorrected period of 1.

  $ perf record -e task-clock noploop 1
  [ perf record: Woken up 1 times to write data ]
  [ perf record: Captured and wrote 0.158 MB perf.data (~6919 samples) ]

  $ perf report -n --show-total-period  --stdio
  # Samples: 4K of event 'task-clock'
  # Event count (approx.): 4000
  #
  # Overhead       Samples        Period  Command  Shared Object              Symbol
  # ........  ............  ............  .......  .............  ..................
  #
      99.95%          3998          3998  noploop  noploop        [.] main
       0.03%             1             1  noploop  libc-2.15.so   [.] init_cacheinfo
       0.03%             1             1  noploop  ld-2.15.so     [.] open_verify

Note that it doesn't affect the non-sampling event so that the
perf stat still gets correct value with or without this patch.

  $ perf stat -e task-clock noploop 1

   Performance counter stats for 'noploop 1':

         1000.272525 task-clock                #    1.000 CPUs utilized

         1.000560605 seconds time elapsed
Signed-off-by: default avatarNamhyung Kim <namhyung@kernel.org>
Cc: Arnaldo Carvalho de Melo <acme@ghostprotocols.net>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Namhyung Kim <namhyung.kim@lge.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/1363574507-18808-1-git-send-email-namhyung@kernel.orgSigned-off-by: default avatarIngo Molnar <mingo@kernel.org>
      778141e3
  3. 15 Mar, 2013 2 commits
  5. 14 Mar, 2013 3 commits
  7. 13 Mar, 2013 29 commits
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