sound: oss: msnd_pinnacle: avoid interruptible_sleep_on_timeout

We want to remove all sleep_on variants from the kernel because they are
racy. In case of the pinnacle driver, we can replace
interruptible_sleep_on_timeout with wait_event_interruptible_timeout
by changing the meaning of a few flags used in the driver so they
are cleared at wakeup time, which is a somewhat more appropriate
way to do the same, although probably still racy.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Takashi Iwai <tiwai@suse.de>

diff --git a/sound/oss/msnd_pinnacle.c b/sound/oss/msnd_pinnacle.c
index 11ff7c5..c23f9f9 100644 (file)
--- a/sound/oss/msnd_pinnacle.c
+++ b/sound/oss/msnd_pinnacle.c
@@ -664,12 +664,15 @@ static long dev_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
 
 static void dsp_write_flush(void)
 {
+       int timeout = get_play_delay_jiffies(dev.DAPF.len);
+
        if (!(dev.mode & FMODE_WRITE) || !test_bit(F_WRITING, &dev.flags))
                return;
        set_bit(F_WRITEFLUSH, &dev.flags);
-       interruptible_sleep_on_timeout(
-               &dev.writeflush,
-               get_play_delay_jiffies(dev.DAPF.len));
+       wait_event_interruptible_timeout(
+               dev.writeflush,
+               !test_bit(F_WRITEFLUSH, &dev.flags),
+               timeout);
        clear_bit(F_WRITEFLUSH, &dev.flags);
        if (!signal_pending(current)) {
                current->state = TASK_INTERRUPTIBLE;
@@ -897,6 +900,7 @@ static int dsp_read(char __user *buf, size_t len)
 {
        int count = len;
        char *page = (char *)__get_free_page(GFP_KERNEL);
+       int timeout = get_rec_delay_jiffies(DAR_BUFF_SIZE);
 
        if (!page)
                return -ENOMEM;
@@ -936,11 +940,11 @@ static int dsp_read(char __user *buf, size_t len)
 
                if (count > 0) {
                        set_bit(F_READBLOCK, &dev.flags);
-                       if (!interruptible_sleep_on_timeout(
-                               &dev.readblock,
-                               get_rec_delay_jiffies(DAR_BUFF_SIZE)))
+                       if (wait_event_interruptible_timeout(
+                                       dev.readblock,
+                                       test_bit(F_READBLOCK, &dev.flags),
+                                       timeout) <= 0)
                                clear_bit(F_READING, &dev.flags);
-                       clear_bit(F_READBLOCK, &dev.flags);
                        if (signal_pending(current)) {
                                free_page((unsigned long)page);
                                return -EINTR;
@@ -955,6 +959,7 @@ static int dsp_write(const char __user *buf, size_t len)
 {
        int count = len;
        char *page = (char *)__get_free_page(GFP_KERNEL);
+       int timeout = get_play_delay_jiffies(DAP_BUFF_SIZE);
 
        if (!page)
                return -ENOMEM;
@@ -995,10 +1000,10 @@ static int dsp_write(const char __user *buf, size_t len)
 
                if (count > 0) {
                        set_bit(F_WRITEBLOCK, &dev.flags);
-                       interruptible_sleep_on_timeout(
-                               &dev.writeblock,
-                               get_play_delay_jiffies(DAP_BUFF_SIZE));
-                       clear_bit(F_WRITEBLOCK, &dev.flags);
+                       wait_event_interruptible_timeout(
+                               dev.writeblock,
+                               test_bit(F_WRITEBLOCK, &dev.flags),
+                               timeout);
                        if (signal_pending(current)) {
                                free_page((unsigned long)page);
                                return -EINTR;
@@ -1044,7 +1049,7 @@ static __inline__ void eval_dsp_msg(register WORD wMessage)
                        clear_bit(F_WRITING, &dev.flags);
                }
 
-               if (test_bit(F_WRITEBLOCK, &dev.flags))
+               if (test_and_clear_bit(F_WRITEBLOCK, &dev.flags))
                        wake_up_interruptible(&dev.writeblock);
                break;
 
@@ -1055,7 +1060,7 @@ static __inline__ void eval_dsp_msg(register WORD wMessage)
 
                pack_DARQ_to_DARF(dev.last_recbank);
 
-               if (test_bit(F_READBLOCK, &dev.flags))
+               if (test_and_clear_bit(F_READBLOCK, &dev.flags))
                        wake_up_interruptible(&dev.readblock);
                break;