From: Takashi Iwai <tiwai@suse.de>
Date: Mon, 1 Feb 2016 11:04:55 +0000 (+0100)
Subject: ALSA: rawmidi: Remove kernel WARNING for NULL user-space buffer check
X-Git-Tag: v4.3.6~93
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=5b68916055c08c0ec26117e708a955dfb15f49b1;p=thirdparty%2Fkernel%2Fstable.git

ALSA: rawmidi: Remove kernel WARNING for NULL user-space buffer check

commit cc85f7a634cfaf9f0713c6aa06d08817424db37a upstream.

NULL user-space buffer can be passed even in a normal path, thus it's
not good to spew a kernel warning with stack trace at each time.
Just drop snd_BUG_ON() macro usage there.

BugLink: http://lkml.kernel.org/r/CACT4Y+YfVJ3L+q0i-4vyQVyyPD7V=OMX0PWPi29x9Bo3QaBLdw@mail.gmail.com
Reported-by: Dmitry Vyukov <dvyukov@google.com>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---

diff --git a/sound/core/rawmidi.c b/sound/core/rawmidi.c
index c7dfa571875f7..26ca022488857 100644
--- a/sound/core/rawmidi.c
+++ b/sound/core/rawmidi.c
@@ -1224,7 +1224,7 @@ static long snd_rawmidi_kernel_write1(struct snd_rawmidi_substream *substream,
 	long count1, result;
 	struct snd_rawmidi_runtime *runtime = substream->runtime;
 
-	if (snd_BUG_ON(!kernelbuf && !userbuf))
+	if (!kernelbuf && !userbuf)
 		return -EINVAL;
 	if (snd_BUG_ON(!runtime->buffer))
 		return -EINVAL;