perf: Remove superfluous allocation error check

commit bfb3d7b8b906b66551424d7636182126e1d134c8 upstream.

If the get_callchain_buffers fails to allocate the buffer it will
decrease the nr_callchain_events right away.

There's no point of checking the allocation error for
nr_callchain_events > 1. Removing that check.

Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Andi Kleen <andi@firstfloor.org>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: syzkaller-bugs@googlegroups.com
Cc: x86@kernel.org
Link: http://lkml.kernel.org/r/20180415092352.12403-3-jolsa@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/kernel/events/callchain.c b/kernel/events/callchain.c
index fa4f47a..b23294e 100644 (file)
--- a/kernel/events/callchain.c
+++ b/kernel/events/callchain.c
@@ -131,14 +131,8 @@ int get_callchain_buffers(int event_max_stack)
                goto exit;
        }
 
-       if (count > 1) {
-               /* If the allocation failed, give up */
-               if (!callchain_cpus_entries)
-                       err = -ENOMEM;
-               goto exit;
-       }
-
-       err = alloc_callchain_buffers();
+       if (count == 1)
+               err = alloc_callchain_buffers();
 exit:
        if (err)
                atomic_dec(&nr_callchain_events);