shinys000114/linux
1
0
Fork 0
mirror of https://github.com/hardkernel/linux.git synced 2026-06-07 03:15:31 +09:00
Code Issues Packages Projects Releases Wiki Activity

ALSA: seq: Fix regression by incorrect ioctl_mutex usages

Browse Source 
This is the revised backport of the upstream commit
b3defb791b

We had another backport (e.g. 623e5c8ae3 in 4.4.115), but it applies
the new mutex also to the code paths that are invoked via faked
kernel-to-kernel ioctls.  As reported recently, this leads to a
deadlock at suspend (or other scenarios triggering the kernel
sequencer client).

This patch addresses the issue by taking the mutex only in the code
paths invoked by user-space, just like the original fix patch does.

Reported-and-tested-by: Andres Bertens <abertensu@yahoo.com>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Takashi Iwai
2018-02-19 17:16:01 +01:00
committed by Greg Kroah-Hartman
parent 7f5cb8e97b
commit 5ff8af891d
1 changed files with 7 additions and 8 deletions
Download Patch File Download Diff File Expand all files Collapse all files

15
sound/core/seq/seq_clientmgr.c
View File

@@ -2196,7 +2196,6 @@ static int snd_seq_do_ioctl(struct snd_seq_client *client, unsigned int cmd,
void __user *arg)
{
struct seq_ioctl_table *p;
int ret;
switch (cmd) {
case SNDRV_SEQ_IOCTL_PVERSION:
@@ -2210,12 +2209,8 @@ static int snd_seq_do_ioctl(struct snd_seq_client *client, unsigned int cmd,
if (! arg)
return -EFAULT;
for (p = ioctl_tables; p->cmd; p++) {
if (p->cmd == cmd) {
mutex_lock(&client->ioctl_mutex);
ret = p->func(client, arg);
mutex_unlock(&client->ioctl_mutex);
return ret;
}
if (p->cmd == cmd)
return p->func(client, arg);
}
pr_debug("ALSA: seq unknown ioctl() 0x%x (type='%c', number=0x%02x)\n",
cmd, _IOC_TYPE(cmd), _IOC_NR(cmd));
@@ -2226,11 +2221,15 @@ static int snd_seq_do_ioctl(struct snd_seq_client *client, unsigned int cmd,
static long snd_seq_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
{
struct snd_seq_client *client = file->private_data;
long ret;
if (snd_BUG_ON(!client))
return -ENXIO;
return snd_seq_do_ioctl(client, cmd, (void __user *) arg);
mutex_lock(&client->ioctl_mutex);
ret = snd_seq_do_ioctl(client, cmd, (void __user *) arg);
mutex_unlock(&client->ioctl_mutex);
return ret;
}
#ifdef CONFIG_COMPAT