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authorIngo Molnar <mingo@elte.hu>2009-06-21 13:58:51 +0200
committerIngo Molnar <mingo@elte.hu>2009-06-21 13:58:51 +0200
commitc1f47b454ce759d7b13604137a233cad4617e1e8 (patch)
tree109fc21410332c47d31cf507508c3369d8ac1477 /tools/perf
parentd9f2a5ecb2846d0fd368fb4c45182e43f38e4471 (diff)
perf_counter tools: Fix vmlinux fallback when running on a different kernel
Lucas De Marchi reported that perf report and perf annotate displays mismatching profile if a perf.data is analyzed on an older kernel - even if the correct vmlinux is specified via the -k option. The reason is the fallback path in util/symbol.c:dso__load_kernel(): int dso__load_kernel(struct dso *self, const char *vmlinux, symbol_filter_t filter, int verbose) { int err = -1; if (vmlinux) err = dso__load_vmlinux(self, vmlinux, filter, verbose); if (err) err = dso__load_kallsyms(self, filter, verbose); return err; } dso__load_vmlinux() returns negative on error, but on success it returns the number of symbols loaded - which confuses the function to load the kallsyms. This is normally harmless, as reporting is usually performed on the same kernel that is analyzed - but if there's a mismatch then we load the wrong kallsyms and create a non-sensical symbol tree. The fix is to only fall back to kallsyms on errors. Reported-by: Lucas De Marchi <lucas.de.marchi@gmail.com> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Mike Galbraith <efault@gmx.de> Cc: Paul Mackerras <paulus@samba.org> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> LKML-Reference: <new-submission> Signed-off-by: Ingo Molnar <mingo@elte.hu>
Diffstat (limited to 'tools/perf')
-rw-r--r--tools/perf/util/symbol.c2
1 files changed, 1 insertions, 1 deletions
diff --git a/tools/perf/util/symbol.c b/tools/perf/util/symbol.c
index 86e14375e74..01b62fa0399 100644
--- a/tools/perf/util/symbol.c
+++ b/tools/perf/util/symbol.c
@@ -629,7 +629,7 @@ int dso__load_kernel(struct dso *self, const char *vmlinux,
if (vmlinux)
err = dso__load_vmlinux(self, vmlinux, filter, verbose);
- if (err)
+ if (err < 0)
err = dso__load_kallsyms(self, filter, verbose);
return err;