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authorArnd Bergmann <arnd@arndb.de>2014-01-02 13:07:49 +0100
committerTakashi Iwai <tiwai@suse.de>2014-01-14 16:01:27 +0100
commit7bd6972a921e148beea54919a00aa7b0bf046ff1 (patch)
tree37e0f74ceba884d3a2af13b8bf7e8d2a412619c9 /sound
parent1a21576562507b2b10b9aa53555857868fe51c94 (diff)
downloadlwn-7bd6972a921e148beea54919a00aa7b0bf046ff1.tar.gz
lwn-7bd6972a921e148beea54919a00aa7b0bf046ff1.zip
sound: oss: vwsnd: avoid interruptible_sleep_on
Interruptible_sleep_on is racy and we want to remove it. This replaces the use in the vwsnd driver with an open-coded prepare_to_wait loop that fixes the race between concurrent open() and close() calls, and also drops the global mutex while waiting here, which restores the original behavior that was changed during the BKL removal. Signed-off-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Takashi Iwai <tiwai@suse.de>
Diffstat (limited to 'sound')
-rw-r--r--sound/oss/vwsnd.c14
1 files changed, 10 insertions, 4 deletions
diff --git a/sound/oss/vwsnd.c b/sound/oss/vwsnd.c
index 4bbcc0fcd4eb..a077e9c69a5e 100644
--- a/sound/oss/vwsnd.c
+++ b/sound/oss/vwsnd.c
@@ -2921,6 +2921,7 @@ static int vwsnd_audio_open(struct inode *inode, struct file *file)
vwsnd_dev_t *devc;
int minor = iminor(inode);
int sw_samplefmt;
+ DEFINE_WAIT(wait);
DBGE("(inode=0x%p, file=0x%p)\n", inode, file);
@@ -2937,21 +2938,26 @@ static int vwsnd_audio_open(struct inode *inode, struct file *file)
}
mutex_lock(&devc->open_mutex);
- while (devc->open_mode & file->f_mode) {
+ while (1) {
+ prepare_to_wait(&devc->open_wait, &wait, TASK_INTERRUPTIBLE);
+ if (!(devc->open_mode & file->f_mode))
+ break;
+
mutex_unlock(&devc->open_mutex);
+ mutex_unlock(&vwsnd_mutex);
if (file->f_flags & O_NONBLOCK) {
DEC_USE_COUNT;
- mutex_unlock(&vwsnd_mutex);
return -EBUSY;
}
- interruptible_sleep_on(&devc->open_wait);
+ schedule();
if (signal_pending(current)) {
DEC_USE_COUNT;
- mutex_unlock(&vwsnd_mutex);
return -ERESTARTSYS;
}
+ mutex_lock(&vwsnd_mutex);
mutex_lock(&devc->open_mutex);
}
+ finish_wait(&devc->open_wait, &wait);
devc->open_mode |= file->f_mode & (FMODE_READ | FMODE_WRITE);
mutex_unlock(&devc->open_mutex);