[PATCH 04/13] perf tools libunwind: Check for mmaps also in MAP__VARIABLE tree

[Jiri Olsa <jolsa@kernel.org>]

We've seen cases (softice) where DWARF unwinder went
through non executable mmaps, which we need to lookup
in MAP__VARIABLE tree.

Reported-by: Noel Grandin <noelgrandin@gmail.com>
Tested-by: Noel Grandin <noelgrandin@gmail.com>
Link: http://lkml.kernel.org/n/tip-@git.kernel.org
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
---
 tools/perf/util/unwind-libunwind.c | 9 +++++++++
 1 file changed, 9 insertions(+)

diff --git a/tools/perf/util/unwind-libunwind.c b/tools/perf/util/unwind-libunwind.c
index f37859c04317..ee7e372297e5 100644
--- a/tools/perf/util/unwind-libunwind.c
+++ b/tools/perf/util/unwind-libunwind.c
@@ -319,6 +319,15 @@ static struct map *find_map(unw_word_t ip, struct unwind_info *ui)
 
 	thread__find_addr_map(ui->thread, PERF_RECORD_MISC_USER,
 			      MAP__FUNCTION, ip, &al);
+	if (!al.map) {
+		/*
+		 * We've seen cases (softice) where DWARF unwinder went
+		 * through non executable mmaps, which we need to lookup
+		 * in MAP__VARIABLE tree.
+		 */
+		thread__find_addr_map(ui->thread, PERF_RECORD_MISC_USER,
+				      MAP__VARIABLE, ip, &al);
+	}
 	return al.map;
 }
 
-- 
2.4.3