From: Mike Leach mike.leach@linaro.org
commit 39a7661dcf655c8198fd5d72412f5030a8e58444 upstream.
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 Signed-off-by: Mathieu Poirier mathieu.poirier@linaro.org Link: https://lore.kernel.org/r/20201029164559.1268531-3-mathieu.poirier@linaro.or... Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org Reported-by: kernel test robot lkp@intel.com --- 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 75379184f391..9a8d03e62a75 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);