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Subject[PATCH 3/7] perf tools: Fix report -F mispredict for data without branch info
Date
The branch field sorting code assumes hist_entry::branch_info
is allocated, which is wrong and following perf session ends
up with report segfault.

$ perf record ls
$ perf report -F mispredict
perf: Segmentation fault

Checking that hist_entry::branch_info is valid and display
"N/A" string in snprint callback if it's not.

Cc: Andi Kleen <ak@linux.intel.com>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Corey Ashford <cjashfor@linux.vnet.ibm.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
---
tools/perf/util/sort.c | 20 ++++++++++++--------
1 file changed, 12 insertions(+), 8 deletions(-)

diff --git a/tools/perf/util/sort.c b/tools/perf/util/sort.c
index 9bcdb57076b8..0c68af83e7dd 100644
--- a/tools/perf/util/sort.c
+++ b/tools/perf/util/sort.c
@@ -471,11 +471,13 @@ struct sort_entry sort_sym_to = {
static int64_t
sort__mispredict_cmp(struct hist_entry *left, struct hist_entry *right)
{
- const unsigned char mp = left->branch_info->flags.mispred !=
- right->branch_info->flags.mispred;
- const unsigned char p = left->branch_info->flags.predicted !=
- right->branch_info->flags.predicted;
+ unsigned char mp, p;

+ if (!left->branch_info || !right->branch_info)
+ return cmp_null(left->branch_info, right->branch_info);
+
+ mp = left->branch_info->flags.mispred != right->branch_info->flags.mispred;
+ p = left->branch_info->flags.predicted != right->branch_info->flags.predicted;
return mp || p;
}

@@ -483,10 +485,12 @@ static int hist_entry__mispredict_snprintf(struct hist_entry *he, char *bf,
size_t size, unsigned int width){
static const char *out = "N/A";

- if (he->branch_info->flags.predicted)
- out = "N";
- else if (he->branch_info->flags.mispred)
- out = "Y";
+ if (he->branch_info) {
+ if (he->branch_info->flags.predicted)
+ out = "N";
+ else if (he->branch_info->flags.mispred)
+ out = "Y";
+ }

return repsep_snprintf(bf, size, "%-*.*s", width, width, out);
}
--
1.9.3


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