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author | Ingo Molnar <mingo@elte.hu> | 2009-06-21 13:58:51 +0200 |
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committer | Ingo Molnar <mingo@elte.hu> | 2009-06-21 13:58:51 +0200 |
commit | c1f47b454ce759d7b13604137a233cad4617e1e8 (patch) | |
tree | 109fc21410332c47d31cf507508c3369d8ac1477 /tools/perf/util/strbuf.c | |
parent | d9f2a5ecb2846d0fd368fb4c45182e43f38e4471 (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/util/strbuf.c')
0 files changed, 0 insertions, 0 deletions