lkml.org 
[lkml]   [2018]   [Mar]   [19]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    Patch in this message
    /
    From
    Subject[PATCH 4.4 071/134] perf inject: Copy events when reordering events in pipe mode
    Date
    4.4-stable review patch.  If anyone has any objections, please let me know.

    ------------------

    From: David Carrillo-Cisneros <davidcc@google.com>


    [ Upstream commit 1e0d4f0200e4dbdfc38d818f329d8a0955f7c6f5 ]

    __perf_session__process_pipe_events reuses the same memory buffer to
    process all events in the pipe.

    When reordering is needed (e.g. -b option), events are not immediately
    flushed, but kept around until reordering is possible, causing
    memory corruption.

    The problem is usually observed by a "Unknown sample error" output. It
    can easily be reproduced by:

    perf record -o - noploop | perf inject -b > output

    Committer testing:

    Before:

    $ perf record -o - stress -t 2 -c 2 | perf inject -b > /dev/null
    stress: info: [8297] dispatching hogs: 2 cpu, 0 io, 0 vm, 0 hdd
    stress: info: [8297] successful run completed in 2s
    [ perf record: Woken up 3 times to write data ]
    [ perf record: Captured and wrote 0.000 MB - ]
    Warning:
    Found 1 unknown events!

    Is this an older tool processing a perf.data file generated by a more recent tool?

    If that is not the case, consider reporting to linux-kernel@vger.kernel.org.

    $

    After:

    $ perf record -o - stress -t 2 -c 2 | perf inject -b > /dev/null
    stress: info: [9027] dispatching hogs: 2 cpu, 0 io, 0 vm, 0 hdd
    stress: info: [9027] successful run completed in 2s
    [ perf record: Woken up 3 times to write data ]
    [ perf record: Captured and wrote 0.000 MB - ]
    no symbols found in /usr/bin/stress, maybe install a debug package?
    no symbols found in /usr/bin/stress, maybe install a debug package?
    $

    Signed-off-by: David Carrillo-Cisneros <davidcc@google.com>
    Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
    Acked-by: Jiri Olsa <jolsa@kernel.org>
    Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
    Cc: Andi Kleen <ak@linux.intel.com>
    Cc: He Kuang <hekuang@huawei.com>
    Cc: Masami Hiramatsu <mhiramat@kernel.org>
    Cc: Paul Turner <pjt@google.com>
    Cc: Peter Zijlstra <peterz@infradead.org>
    Cc: Simon Que <sque@chromium.org>
    Cc: Stephane Eranian <eranian@google.com>
    Cc: Wang Nan <wangnan0@huawei.com>
    Link: http://lkml.kernel.org/r/20170410201432.24807-3-davidcc@google.com
    Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
    Signed-off-by: Sasha Levin <alexander.levin@microsoft.com>
    Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
    ---
    tools/perf/util/ordered-events.c | 3 ++-
    tools/perf/util/session.c | 1 +
    2 files changed, 3 insertions(+), 1 deletion(-)

    --- a/tools/perf/util/ordered-events.c
    +++ b/tools/perf/util/ordered-events.c
    @@ -79,7 +79,7 @@ static union perf_event *dup_event(struc

    static void free_dup_event(struct ordered_events *oe, union perf_event *event)
    {
    - if (oe->copy_on_queue) {
    + if (event && oe->copy_on_queue) {
    oe->cur_alloc_size -= event->header.size;
    free(event);
    }
    @@ -150,6 +150,7 @@ void ordered_events__delete(struct order
    list_move(&event->list, &oe->cache);
    oe->nr_events--;
    free_dup_event(oe, event->event);
    + event->event = NULL;
    }

    int ordered_events__queue(struct ordered_events *oe, union perf_event *event,
    --- a/tools/perf/util/session.c
    +++ b/tools/perf/util/session.c
    @@ -1437,6 +1437,7 @@ static int __perf_session__process_pipe_
    buf = malloc(cur_size);
    if (!buf)
    return -errno;
    + ordered_events__set_copy_on_queue(oe, true);
    more:
    event = buf;
    err = readn(fd, event, sizeof(struct perf_event_header));

    \
     
     \ /
      Last update: 2018-03-19 21:10    [W:3.213 / U:0.132 seconds]
    ©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site