| Message ID | 20201028174301.15033-1-mike.leach@linaro.org (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | coresight: Fix uninitialised pointer bug in etm_setup_aux() | expand |
On Wed, Oct 28, 2020 at 05:43:01PM +0000, Mike Leach wrote: > Commit [bb1860efc817] changed the sink handling code introducing an > uninitialised pointer bug. This results in the default sink selection > failing. > > Prior to commit: > > static void etm_setup_aux(...) > > <snip> > struct coresight_device *sink; > <snip> > > /* First get the selected sink from user space. */ > if (event->attr.config2) { > id = (u32)event->attr.config2; > sink = coresight_get_sink_by_id(id); > } else { > sink = coresight_get_enabled_sink(true); > } > <ctd> > > *sink always initialised - possibly to NULL which triggers the > automatic sink selection. > > After commit: > > static void etm_setup_aux(...) > > <snip> > struct coresight_device *sink; > <snip> > > /* First get the selected sink from user space. */ > if (event->attr.config2) { > id = (u32)event->attr.config2; > sink = coresight_get_sink_by_id(id); > } > <ctd> > > *sink pointer uninitialised when not providing a sink on the perf command > line. This breaks later checks to enable automatic sink selection. > > Fixes [bb1860efc817] ("coresight: etm: perf: Sink selection using sysfs is deprecated") > Signed-off-by: Mike Leach <mike.leach@linaro.org> > --- > drivers/hwtracing/coresight/coresight-etm-perf.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/drivers/hwtracing/coresight/coresight-etm-perf.c b/drivers/hwtracing/coresight/coresight-etm-perf.c > index c2c9b127d074..bdc34ca449f7 100644 > --- a/drivers/hwtracing/coresight/coresight-etm-perf.c > +++ b/drivers/hwtracing/coresight/coresight-etm-perf.c > @@ -210,7 +210,7 @@ static void *etm_setup_aux(struct perf_event *event, void **pages, > u32 id; > int cpu = event->cpu; > cpumask_t *mask; > - struct coresight_device *sink; > + struct coresight_device *sink = NULL; Yes, obviously - thanks for catching that. As checkpatch has complained about, the Fixes line you added isn't correct. It should have been: Fixes: bb1860efc817 ("coresight: etm: perf: Sink selection using sysfs is deprecated") I made the modification and applied to my tree. Thanks, Mathieu > struct etm_event_data *event_data = NULL; > > event_data = alloc_event_data(cpu); > -- > 2.17.1 >
diff --git a/drivers/hwtracing/coresight/coresight-etm-perf.c b/drivers/hwtracing/coresight/coresight-etm-perf.c index c2c9b127d074..bdc34ca449f7 100644 --- a/drivers/hwtracing/coresight/coresight-etm-perf.c +++ b/drivers/hwtracing/coresight/coresight-etm-perf.c @@ -210,7 +210,7 @@ static void *etm_setup_aux(struct perf_event *event, void **pages, u32 id; int cpu = event->cpu; cpumask_t *mask; - struct coresight_device *sink; + struct coresight_device *sink = NULL; struct etm_event_data *event_data = NULL; event_data = alloc_event_data(cpu);
Commit [bb1860efc817] changed the sink handling code introducing an uninitialised pointer bug. This results in the default sink selection failing. Prior to commit: static void etm_setup_aux(...) <snip> struct coresight_device *sink; <snip> /* First get the selected sink from user space. */ if (event->attr.config2) { id = (u32)event->attr.config2; sink = coresight_get_sink_by_id(id); } else { sink = coresight_get_enabled_sink(true); } <ctd> *sink always initialised - possibly to NULL which triggers the automatic sink selection. After commit: static void etm_setup_aux(...) <snip> struct coresight_device *sink; <snip> /* First get the selected sink from user space. */ if (event->attr.config2) { id = (u32)event->attr.config2; sink = coresight_get_sink_by_id(id); } <ctd> *sink pointer uninitialised when not providing a sink on the perf command line. This breaks later checks to enable automatic sink selection. Fixes [bb1860efc817] ("coresight: etm: perf: Sink selection using sysfs is deprecated") Signed-off-by: Mike Leach <mike.leach@linaro.org> --- drivers/hwtracing/coresight/coresight-etm-perf.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)