[PATCH 3.18 14/31] perf unwind: Unwind with libdw doesnt take symfs into account

[Greg Kroah-Hartman]

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

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

[ Upstream commit 3d20c6246690219881786de10d2dda93f616d0ac ]

Path passed to libdw for unwinding doesn't include symfs path
if specified, so unwinding fails because ELF file is not found.

Similar to unwinding with libunwind, pass symsrc_filename instead
of long_name. If there is no symsrc_filename, fallback to long_name.

Signed-off-by: Martin Vuille <jpmv27@xxxxxxx>
Cc: Adrian Hunter <adrian.hunter@xxxxxxxxx>
Cc: David Ahern <dsahern@xxxxxxxxx>
Cc: Jiri Olsa <jolsa@xxxxxxxxxx>
Cc: Namhyung Kim <namhyung@xxxxxxxxxx>
Cc: Wang Nan <wangnan0@xxxxxxxxxx>
Link: http://lkml.kernel.org/r/20180211212420.18388-1-jpmv27@xxxxxxx
Signed-off-by: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
 tools/perf/util/unwind-libdw.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

--- a/tools/perf/util/unwind-libdw.c
+++ b/tools/perf/util/unwind-libdw.c
@@ -47,7 +47,7 @@ static int __report_module(struct addr_l
 
 	if (!mod)
 		mod = dwfl_report_elf(ui->dwfl, dso->short_name,
-				      dso->long_name, -1, al->map->start,
+				      (dso->symsrc_filename ? dso->symsrc_filename : dso->long_name), -1, al->map->start,
 				      false);
 
 	return mod && dwfl_addrmodule(ui->dwfl, ip) == mod ? 0 : -1;