lkml.org 
[lkml]   [2016]   [Oct]   [20]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    Patch in this message
    /
    Date
    From
    Subject[PATCH] perf c2c report: Properly check data presence in rb_tree loop
    On Thu, Oct 20, 2016 at 06:02:24PM -0500, Kim Phillips wrote:

    SNIP

    > (gdb) bt
    > #0 c2c_browser__update_nr_entries (hb=<optimized out>, hb=<optimized out>) at builtin-c2c.c:2142
    > #1 perf_c2c__hists_browse (hists=0x8b2d90 <c2c+240>) at builtin-c2c.c:2287
    > #2 perf_c2c_display (session=0x205b1a0) at builtin-c2c.c:2316
    > #3 perf_c2c__report (argv=<optimized out>, argc=<optimized out>) at builtin-c2c.c:2621
    > #4 cmd_c2c (argc=<optimized out>, argv=<optimized out>, prefix=<optimized out>) at builtin-c2c.c:2748
    > #5 0x000000000048df61 in run_builtin (p=p@entry=0x8be168 <commands+72>, argc=argc@entry=2, argv=argv@entry=0x7fffffffddb0)
    > at perf.c:358
    > #6 0x00000000004249b6 in handle_internal_command (argv=0x7fffffffddb0, argc=2) at perf.c:420
    > #7 run_argv (argv=0x7fffffffdb40, argcp=0x7fffffffdb4c) at perf.c:466
    > #8 main (argc=2, argv=0x7fffffffddb0) at perf.c:610
    > (gdb)
    >
    > All the above work fine when run under sudo.

    ugh, stupid mistake.. attached patch fixes that for me

    thanks,
    jirka


    ---
    Kim reported crash when there's no data stored. In this case
    the TUI code crashes in c2c_browser__update_nr_entries, because
    we dont check the initial rb_tree node for NULL.

    Adding the missing check.

    Reported-by: Kim Phillips <kim.phillips@arm.com>
    Signed-off-by: Jiri Olsa <jolsa@kernel.org>
    ---
    tools/perf/builtin-c2c.c | 4 ++--
    1 file changed, 2 insertions(+), 2 deletions(-)

    diff --git a/tools/perf/builtin-c2c.c b/tools/perf/builtin-c2c.c
    index dc4f0636dfa1..c6d0dda594d9 100644
    --- a/tools/perf/builtin-c2c.c
    +++ b/tools/perf/builtin-c2c.c
    @@ -2135,14 +2135,14 @@ static void c2c_browser__update_nr_entries(struct hist_browser *hb)
    u64 nr_entries = 0;
    struct rb_node *nd = rb_first(&hb->hists->entries);

    - do {
    + while (nd) {
    struct hist_entry *he = rb_entry(nd, struct hist_entry, rb_node);

    if (!he->filtered)
    nr_entries++;

    nd = rb_next(nd);
    - } while (nd);
    + }

    hb->nr_non_filtered_entries = nr_entries;
    }
    --
    2.7.4
    \
     
     \ /
      Last update: 2016-10-21 02:20    [W:2.851 / U:0.052 seconds]
    ©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site