Messages in this thread | | | Date | Mon, 7 Dec 2015 10:28:59 +0100 | From | Jiri Olsa <> | Subject | Re: [PATCH] perf/x86: fix filter_events() bug with event mappings |
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On Sun, Dec 06, 2015 at 10:35:06PM +0100, Stephane Eranian wrote:
SNIP
> > This problem was introduced into commit 8300daa26. > > Fixes: 8300daa26 ("perf/x86: Filter out undefined events from sysfs events attribute") > > Patch is relative to tip.git commit 03b6b9f. > > Signed-off-by: Stephane Eranian <eranian@google.com> > --- > arch/x86/kernel/cpu/perf_event.c | 12 +++++++++++- > 1 file changed, 11 insertions(+), 1 deletion(-) > > diff --git a/arch/x86/kernel/cpu/perf_event.c b/arch/x86/kernel/cpu/perf_event.c > index e7e63a9..70e16c7 100644 > --- a/arch/x86/kernel/cpu/perf_event.c > +++ b/arch/x86/kernel/cpu/perf_event.c > @@ -1534,6 +1534,7 @@ static void __init filter_events(struct attribute **attrs) > { > struct device_attribute *d; > struct perf_pmu_events_attr *pmu_attr; > + int offset = 0; > int i, j; > > for (i = 0; attrs[i]; i++) { > @@ -1542,14 +1543,23 @@ static void __init filter_events(struct attribute **attrs) > /* str trumps id */ > if (pmu_attr->event_str) > continue; > - if (x86_pmu.event_map(i)) > + if (x86_pmu.event_map(i + offset)) > continue; > > for (j = i; attrs[j]; j++) > attrs[j] = attrs[j + 1]; > + attrs[j] = NULL;
hum.. the loop above quits when attrs[j] == NULL, so I dont think u need to assign it again after
the NULL should get shifted in the last iteration of the loop above
> > /* Check the shifted attr. */ > i--; > + > + /* > + * event_map() is index based, the attrs array is organized > + * by increasing event index. If we shift the events, then > + * we need to compensate for the event_map(), otherwise > + * we are looking up the wrong event in the map > + */ > + offset++;
ouch, thanks for fixing this
I tested the patch and it fixes the issue
jirka
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