Messages in this thread Patch in this message | | | From | Jiri Olsa <> | Subject | [PATCH] perf unwind: Do not fail due to missing unwind support | Date | Tue, 4 Jul 2017 15:11:31 +0200 |
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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.
Cc: Hekuang <hekuang@huawei.com> Link: http://lkml.kernel.org/n/tip-cm8sdv60vroypck9n65rsmo4@git.kernel.org Signed-off-by: Jiri Olsa <jolsa@kernel.org> --- 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
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