perf symbols: Fix ppc64 SEGV in dso__load_sym with debuginfo files

64bit PowerPC debuginfo files have an empty function descriptor section.
I hit a SEGV when perf tried to use this section for symbol resolution.

To fix this we need to check the section is valid and we can do this by
checking for type SHT_PROGBITS.

Cc: <stable@kernel.org>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Eric B Munson <emunson@mgebm.net>
Link: http://lkml.kernel.org/r/20110824065242.895239970@samba.org
Signed-off-by: Anton Blanchard <anton@samba.org>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

diff --git a/tools/perf/util/symbol.c b/tools/perf/util/symbol.c
index 469c0264ed298d138698d93206419b87fbb3dd99..bb5d32f38af2f4fbde3eda4bf71820c25fb79302 100644 (file)
--- a/tools/perf/util/symbol.c
+++ b/tools/perf/util/symbol.c
@@ -1111,6 +1111,8 @@ static int dso__load_sym(struct dso *dso, struct map *map, const char *name,
        }
 
        opdsec = elf_section_by_name(elf, &ehdr, &opdshdr, ".opd", &opdidx);
+       if (opdshdr.sh_type != SHT_PROGBITS)
+               opdsec = NULL;
        if (opdsec)
                opddata = elf_rawdata(opdsec, NULL);