[PATCH 4.9 021/241] perf sort: Fix segfault with basic block cycles sort dimension

[Greg Kroah-Hartman]

4.9-stable review patch.  If anyone has any objections, please let me know.

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

From: Changbin Du <changbin.du@xxxxxxxxx>


[ Upstream commit 4b0b3aa6a2756e6115fdf275c521e4552a7082f3 ]

Skip the sample which doesn't have branch_info to avoid segmentation
fault:

The fault can be reproduced by:

  perf record -a
  perf report -F cycles

Signed-off-by: Changbin Du <changbin.du@xxxxxxxxx>
Tested-by: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx>
Cc: Andi Kleen <ak@xxxxxxxxxxxxxxx>
Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
Fixes: 0e332f033a82 ("perf tools: Add support for cycles, weight branch_info field")
Link: http://lkml.kernel.org/r/20170313083148.23568-1-changbin.du@xxxxxxxxx
Signed-off-by: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx>
Signed-off-by: Sasha Levin <alexander.levin@xxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
 tools/perf/util/sort.c |    5 +++++
 1 file changed, 5 insertions(+)

--- a/tools/perf/util/sort.c
+++ b/tools/perf/util/sort.c
@@ -846,6 +846,9 @@ static int hist_entry__mispredict_snprin
 static int64_t
 sort__cycles_cmp(struct hist_entry *left, struct hist_entry *right)
 {
+	if (!left->branch_info || !right->branch_info)
+		return cmp_null(left->branch_info, right->branch_info);
+
 	return left->branch_info->flags.cycles -
 		right->branch_info->flags.cycles;
 }
@@ -853,6 +856,8 @@ sort__cycles_cmp(struct hist_entry *left
 static int hist_entry__cycles_snprintf(struct hist_entry *he, char *bf,
 				    size_t size, unsigned int width)
 {
+	if (!he->branch_info)
+		return scnprintf(bf, size, "%-.*s", width, "N/A");
 	if (he->branch_info->flags.cycles == 0)
 		return repsep_snprintf(bf, size, "%-*s", width, "-");
 	return repsep_snprintf(bf, size, "%-*hd", width,