[tip:perf/core] perf/core: Fix error handling in perf_event_alloc()

[tip-bot for Dan Carpenter <tipbot@zytor.com>]

Commit-ID:  36cc2b9222b5106de34085c4dd8635ac67ef5cba
Gitweb:     http://git.kernel.org/tip/36cc2b9222b5106de34085c4dd8635ac67ef5cba
Author:     Dan Carpenter <dan.carpenter@oracle.com>
AuthorDate: Mon, 22 May 2017 12:04:18 +0300
Committer:  Ingo Molnar <mingo@kernel.org>
CommitDate: Tue, 23 May 2017 09:50:05 +0200

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>
---
 kernel/events/core.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/kernel/events/core.c b/kernel/events/core.c
index 0028efa..f8c27d3 100644
--- 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;