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

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>
Cc: <stable@vger.kernel.org>
Signed-off-by: Takashi Iwai <tiwai@suse.de>

diff --git a/sound/core/rawmidi.c b/sound/core/rawmidi.c
index a7759846fbaadff0c9493760ce7b14eff7ca8ad9..f75d1656272c87c35780dfb7017bf239aa29c331 100644 (file)
--- a/sound/core/rawmidi.c
+++ b/sound/core/rawmidi.c
@@ -1178,7 +1178,7 @@ 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;