4.9-stable review patch. If anyone has any objections, please let me know.
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From: Jiri Olsa jolsa@kernel.org
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
--- kernel/events/callchain.c | 10 ++-------- 1 file changed, 2 insertions(+), 8 deletions(-)
--- a/kernel/events/callchain.c +++ b/kernel/events/callchain.c @@ -129,14 +129,8 @@ int get_callchain_buffers(int event_max_ 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);