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From:   Vincent Whitchurch <vincent.whitchurch@axis.com>
To:     Peter Zijlstra <peterz@infradead.org>,
        Ingo Molnar <mingo@redhat.com>,
        Arnaldo Carvalho de Melo <acme@kernel.org>
CC:     <kernel@axis.com>,
        Vincent Whitchurch <vincent.whitchurch@axis.com>,
        Mark Rutland <mark.rutland@arm.com>,
        Alexander Shishkin <alexander.shishkin@linux.intel.com>,
        Jiri Olsa <jolsa@kernel.org>,
        Namhyung Kim <namhyung@kernel.org>,
        <linux-perf-users@vger.kernel.org>, <linux-kernel@vger.kernel.org>
Subject: [PATCH] perf: unwind: Fix symfs with libdw
Date:   Fri, 25 Nov 2022 12:27:42 +0100
Message-ID: <20221125112743.2285759-1-vincent.whitchurch@axis.com>
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Pass the full path including the symfs (if any) to libdw.  Without this
unwinding fails with errors like this when a symfs is used:

  unwind: failed with 'No such file or directory'"

Signed-off-by: Vincent Whitchurch <vincent.whitchurch@axis.com>
---
 tools/perf/util/unwind-libdw.c | 8 ++++++--
 1 file changed, 6 insertions(+), 2 deletions(-)

diff --git a/tools/perf/util/unwind-libdw.c b/tools/perf/util/unwind-libdw.c
index 94aa40f6e348..1915c9769dbe 100644
--- a/tools/perf/util/unwind-libdw.c
+++ b/tools/perf/util/unwind-libdw.c
@@ -66,9 +66,13 @@ static int __report_module(struct addr_location *al, u64 ip,
 			mod = 0;
 	}
 
-	if (!mod)
-		mod = dwfl_report_elf(ui->dwfl, dso->short_name, dso->long_name, -1,
+	if (!mod) {
+		char filename[PATH_MAX];
+
+		__symbol__join_symfs(filename, sizeof(filename), dso->long_name);
+		mod = dwfl_report_elf(ui->dwfl, dso->short_name, filename, -1,
 				      al->map->start - al->map->pgoff, false);
+	}
 	if (!mod) {
 		char filename[PATH_MAX];
 
-- 
2.34.1