perf/core: Fix error handling in perf_event_alloc()

We don't set an error code here which means that perf_event_alloc()
returns ERR_PTR(0) (in other words NULL).  The callers are not expecting
that and would Oops.

Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vince Weaver <vincent.weaver@maine.edu>
Fixes: 375637bc5249 ("perf/core: Introduce address range filtering")
Link: http://lkml.kernel.org/r/20170522090418.hvs6icgpdo53wkn5@mwanda
Signed-off-by: Ingo Molnar <mingo@kernel.org>

diff --git a/kernel/events/core.c b/kernel/events/core.c
index 0028efa0abc304931314f91932da3e4a8f4a042e..f8c27d3ef3a1309a39b7d1c2798d8c8882aa4481 100644 (file)
--- a/kernel/events/core.c
+++ b/kernel/events/core.c
@@ -9469,8 +9469,10 @@ perf_event_alloc(struct perf_event_attr *attr, int cpu,
                event->addr_filters_offs = kcalloc(pmu->nr_addr_filters,
                                                   sizeof(unsigned long),
                                                   GFP_KERNEL);
-               if (!event->addr_filters_offs)
+               if (!event->addr_filters_offs) {
+                       err = -ENOMEM;
                        goto err_per_task;
+               }
 
                /* force hw sync on the address filters */
                event->addr_filters_gen = 1;