[PATCH 5.14 035/172] ALSA: rawmidi: introduce SNDRV_RAWMIDI_IOCTL_USER_PVERSION

Greg Kroah-Hartman
2021-10-04T13:29:59Z

From: Jaroslav Kysela <perex@perex.cz>

commit 09d23174402da0f10e98da2c61bb5ac8e7d79fdd upstream.

The new framing mode causes the user space regression, because
the alsa-lib code does not initialize the reserved space in
the params structure when the device is opened.

This change adds SNDRV_RAWMIDI_IOCTL_USER_PVERSION like we
do for the PCM interface for the protocol acknowledgment.

Cc: David Henningsson <coding@diwic.se>
Cc: <stable@vger.kernel.org>
Fixes: 08fdced60ca0 ("ALSA: rawmidi: Add framing mode")
BugLink: https://github.com/alsa-project/alsa-lib/issues/178
Signed-off-by: Jaroslav Kysela <perex@perex.cz>
Link: https://lore.kernel.org/r/20210920171850.154186-1-perex@perex.cz
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
include/sound/rawmidi.h | 1 +
include/uapi/sound/asound.h | 1 +
sound/core/rawmidi.c | 9 +++++++++
3 files changed, 11 insertions(+)

--- a/include/sound/rawmidi.h
+++ b/include/sound/rawmidi.h
@@ -98,6 +98,7 @@ struct snd_rawmidi_file {
struct snd_rawmidi *rmidi;
struct snd_rawmidi_substream *input;
struct snd_rawmidi_substream *output;
+ unsigned int user_pversion; /* supported protocol version */
};

struct snd_rawmidi_str {
--- a/include/uapi/sound/asound.h
+++ b/include/uapi/sound/asound.h
@@ -783,6 +783,7 @@ struct snd_rawmidi_status {

#define SNDRV_RAWMIDI_IOCTL_PVERSION _IOR('W', 0x00, int)
#define SNDRV_RAWMIDI_IOCTL_INFO _IOR('W', 0x01, struct snd_rawmidi_info)
+#define SNDRV_RAWMIDI_IOCTL_USER_PVERSION _IOW('W', 0x02, int)
#define SNDRV_RAWMIDI_IOCTL_PARAMS _IOWR('W', 0x10, struct snd_rawmidi_params)
#define SNDRV_RAWMIDI_IOCTL_STATUS _IOWR('W', 0x20, struct snd_rawmidi_status)
#define SNDRV_RAWMIDI_IOCTL_DROP _IOW('W', 0x30, int)
--- a/sound/core/rawmidi.c
+++ b/sound/core/rawmidi.c
@@ -873,12 +873,21 @@ static long snd_rawmidi_ioctl(struct fil
return -EINVAL;
}
}
+ case SNDRV_RAWMIDI_IOCTL_USER_PVERSION:
+ if (get_user(rfile->user_pversion, (unsigned int __user *)arg))
+ return -EFAULT;
+ return 0;
+
case SNDRV_RAWMIDI_IOCTL_PARAMS:
{
struct snd_rawmidi_params params;

if (copy_from_user(&params, argp, sizeof(struct snd_rawmidi_params)))
return -EFAULT;
+ if (rfile->user_pversion < SNDRV_PROTOCOL_VERSION(2, 0, 2)) {
+ params.mode = 0;
+ memset(params.reserved, 0, sizeof(params.reserved));
+ }
switch (params.stream) {
case SNDRV_RAWMIDI_STREAM_OUTPUT:
if (rfile->output == NULL)