[PATCH V2 3/3] perf symbols: debuglink should take symfs option into account

[Victor Kamensky]

Currently code that tries to read corresponding debug symbol
file from .gnu_debuglink section (DSO_BINARY_TYPE__DEBUGLINK)
does not take in account symfs option, so filename__read_debuglink
function cannot open ELF file, if symfs option is used.

Fix is to add proper handling of symfs as it is done in other
places: use __symbol__join_symfs function to get real file name
of target ELF file.

Signed-off-by: Victor Kamensky <victor.kamensky at linaro.org>
Cc: Peter Zijlstra <a.p.zijlstra at chello.nl>
Cc: Paul Mackerras <paulus at samba.org>
Cc: Ingo Molnar <mingo at redhat.com>
Cc: Arnaldo Carvalho de Melo <acme at kernel.org>
Cc: Jiri Olsa <jolsa at kernel.org>
Cc: Namhyung Kim <namhyung at kernel.org>
Cc: Adrian Hunter <adrian.hunter at intel.com>
Cc: Waiman Long <Waiman.Long at hp.com>
Cc: David Ahern <dsahern at gmail.com>
Acked-and-tested-by: David Ahern <dsahern at gmail.com>
---
 tools/perf/util/dso.c | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/tools/perf/util/dso.c b/tools/perf/util/dso.c
index 45be944..ca8d8d5 100644
--- a/tools/perf/util/dso.c
+++ b/tools/perf/util/dso.c
@@ -45,13 +45,13 @@ int dso__read_binary_type_filename(const struct dso *dso,
 	case DSO_BINARY_TYPE__DEBUGLINK: {
 		char *debuglink;
 
-		strncpy(filename, dso->long_name, size);
-		debuglink = filename + dso->long_name_len;
+		len = __symbol__join_symfs(filename, size, dso->long_name);
+		debuglink = filename + len;
 		while (debuglink != filename && *debuglink != '/')
 			debuglink--;
 		if (*debuglink == '/')
 			debuglink++;
-		ret = filename__read_debuglink(dso->long_name, debuglink,
+		ret = filename__read_debuglink(filename, debuglink,
 					       size - (debuglink - filename));
 		}
 		break;
-- 
1.9.3