perf unwind: Check for mmaps also in MAP__VARIABLE tree

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

Reported-and-Tested-by: Noel Grandin <noelgrandin@gmail.com>
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/1452158050-28061-5-git-send-email-jolsa@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

1 files changed, 9 insertions, 0 deletions

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;
 }