From a65cb4b9f8a777a715371c63c0525408048cea3e Mon Sep 17 00:00:00 2001 From: Jiri Olsa Date: Wed, 2 Oct 2013 15:46:39 +0200 Subject: perf evlist: Fix perf_evlist__mmap_read event overflow The perf_evlist__mmap_read used 'union perf_event' as a placeholder for event crossing the mmap boundary. This is ok for sample shorter than ~PATH_MAX. However we could grow up to the maximum sample size which is 16 bits max. I hit this overflow issue when using 'perf top -G dwarf' which produces sample with the size around 8192 bytes. We could configure any valid sample size here using: '-G dwarf,size'. Using array with sample max size instead for the event placeholder. Also adding another safe check for the dynamic size of the user stack. TODO: The 'struct perf_mmap' is quite big now, maybe we could use some lazy allocation for event_copy size. Signed-off-by: Jiri Olsa Acked-by: David Ahern Cc: Corey Ashford Cc: David Ahern Cc: Frederic Weisbecker Cc: Ingo Molnar Cc: Namhyung Kim Cc: Paul Mackerras Cc: Peter Zijlstra Link: http://lkml.kernel.org/r/1380721599-24285-1-git-send-email-jolsa@redhat.com Signed-off-by: Arnaldo Carvalho de Melo --- tools/perf/util/event.h | 3 +++ 1 file changed, 3 insertions(+) (limited to 'tools/perf/util/event.h') diff --git a/tools/perf/util/event.h b/tools/perf/util/event.h index 9b7d4d333111..752709ccfb00 100644 --- a/tools/perf/util/event.h +++ b/tools/perf/util/event.h @@ -75,6 +75,9 @@ struct throttle_event { PERF_SAMPLE_CPU | PERF_SAMPLE_PERIOD | \ PERF_SAMPLE_IDENTIFIER) +/* perf sample has 16 bits size limit */ +#define PERF_SAMPLE_MAX_SIZE (1 << 16) + struct sample_event { struct perf_event_header header; u64 array[]; -- cgit v1.2.3