[PATCH 5/7] perf tools: Fix report -F symbol_from for data without branch info

[Jiri Olsa <jolsa@kernel.org>]

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 symbol_from
  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 | 16 +++++++++++++---
 1 file changed, 13 insertions(+), 3 deletions(-)

diff --git a/tools/perf/util/sort.c b/tools/perf/util/sort.c
index 134633c474a0..d64c020acac5 100644
--- a/tools/perf/util/sort.c
+++ b/tools/perf/util/sort.c
@@ -404,6 +404,12 @@ sort__sym_from_cmp(struct hist_entry *left, struct hist_entry *right)
 	struct addr_map_symbol *from_l = &left->branch_info->from;
 	struct addr_map_symbol *from_r = &right->branch_info->from;
 
+	if (!left->branch_info || !right->branch_info)
+		return 0;
+
+	from_l = &left->branch_info->from;
+	from_r = &right->branch_info->from;
+
 	if (!from_l->sym && !from_r->sym)
 		return _sort__addr_cmp(from_l->addr, from_r->addr);
 
@@ -430,10 +436,14 @@ sort__sym_to_cmp(struct hist_entry *left, struct hist_entry *right)
 static int hist_entry__sym_from_snprintf(struct hist_entry *he, char *bf,
 					 size_t size, unsigned int width)
 {
-	struct addr_map_symbol *from = &he->branch_info->from;
-	return _hist_entry__sym_snprintf(from->map, from->sym, from->addr,
-					 he->level, bf, size, width);
+	if (he->branch_info) {
+		struct addr_map_symbol *from = &he->branch_info->from;
 
+		return _hist_entry__sym_snprintf(from->map, from->sym, from->addr,
+						 he->level, bf, size, width);
+	}
+
+	return repsep_snprintf(bf, size, "%-*.*s", width, width, "N/A");
 }
 
 static int hist_entry__sym_to_snprintf(struct hist_entry *he, char *bf,
-- 
1.9.3