From: Jiri Olsa <jo...@kernel.org>
We currently fail the MMAP event processing if we don't have the MMAP
event's specific arch unwind support compiled in.
That's wrong and can lead to unresolved mmaps in report output for 32bit
binaries on 64bit server, like in this example on x86_64 server:
$ cat ex.c
int main(int argc, char **argv)
{
while (1) {}
}
$ gcc -o ex -m32 ex.c
$ perf record ./ex
^C[ perf record: Woken up 2 times to write data ]
[ perf record: Captured and wrote 0.371 MB perf.data (9322 samples) ]
Before:
$ perf report --stdio
SNIP
# Overhead Command Shared Object Symbol
# ........ ....... ................ ......................
#
100.00% ex [unknown] [.] 0x00000000080483de
0.00% ex [unknown] [.] 0x00000000f76dba4f
0.00% ex [unknown] [.] 0x00000000f76e4c11
0.00% ex [unknown] [.] 0x00000000f76daa30
After:
$ perf report --stdio
SNIP
# Overhead Command Shared Object Symbol
# ........ ....... ............. ...............
#
100.00% ex ex [.] main
0.00% ex ld-2.24.so [.] _dl_start
0.00% ex ld-2.24.so [.] do_lookup_x
0.00% ex ld-2.24.so [.] _start
The fix is not to fail, just warn if there's not unwind support compiled
in.
Reported-by: Michael Lyle <ml...@lyle.org>
Signed-off-by: Jiri Olsa <jo...@kernel.org>
Tested-by: Arnaldo Carvalho de Melo <a...@redhat.com>
Cc: David Ahern <dsah...@gmail.com>
Cc: He Kuang <heku...@huawei.com>
Cc: Namhyung Kim <namhy...@kernel.org>
Cc: Peter Zijlstra <a.p.zijls...@chello.nl>
Link: http://lkml.kernel.org/r/20170704131131.27508-1-jo...@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <a...@redhat.com>
---
tools/perf/util/unwind-libunwind.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/tools/perf/util/unwind-libunwind.c
b/tools/perf/util/unwind-libunwind.c
index 6d542a4e0648..8aef572d0889 100644
--- a/tools/perf/util/unwind-libunwind.c
+++ b/tools/perf/util/unwind-libunwind.c
@@ -50,7 +50,7 @@ int unwind__prepare_access(struct thread *thread, struct map
*map,
if (!ops) {
pr_err("unwind: target platform=%s is not supported\n", arch);
- return -1;
+ return 0;
}
out_register:
unwind__register_ops(thread, ops);
--
2.9.4
