From 1a1e0a80ceb766852e8abd5d4c3d9475611a7d85 Mon Sep 17 00:00:00 2001 From: Arnd Bergmann Date: Thu, 2 Jan 2014 13:07:50 +0100 Subject: [PATCH] sound: oss: dmasound: kill SLEEP() macro to avoid race The use of interruptible_sleep_on_timeout in the dmasound driver is questionable and we want to kill off all sleep_on variants. This replaces the calls with wait_event_interruptible_timeout where possible, to wait for a particular event instead of blocking in a racy way. In the sq_write function, the easiest solution is an open-coded prepare_to_wait loop. Signed-off-by: Arnd Bergmann Signed-off-by: Takashi Iwai --- sound/oss/dmasound/dmasound.h | 1 - sound/oss/dmasound/dmasound_core.c | 28 +++++++++++++++++++--------- 2 files changed, 19 insertions(+), 10 deletions(-) diff --git a/sound/oss/dmasound/dmasound.h b/sound/oss/dmasound/dmasound.h index 1308d8d34186..01019f06fa91 100644 --- a/sound/oss/dmasound/dmasound.h +++ b/sound/oss/dmasound/dmasound.h @@ -239,7 +239,6 @@ struct sound_queue { int busy, syncing, xruns, died; }; -#define SLEEP(queue) interruptible_sleep_on_timeout(&queue, HZ) #define WAKE_UP(queue) (wake_up_interruptible(&queue)) extern struct sound_queue dmasound_write_sq; diff --git a/sound/oss/dmasound/dmasound_core.c b/sound/oss/dmasound/dmasound_core.c index bac43b5b6e95..f4ee85a4c42f 100644 --- a/sound/oss/dmasound/dmasound_core.c +++ b/sound/oss/dmasound/dmasound_core.c @@ -619,15 +619,27 @@ static ssize_t sq_write(struct file *file, const char __user *src, size_t uLeft, } while (uLeft) { + DEFINE_WAIT(wait); + while (write_sq.count >= write_sq.max_active) { + prepare_to_wait(&write_sq.action_queue, &wait, TASK_INTERRUPTIBLE); sq_play(); - if (write_sq.non_blocking) + if (write_sq.non_blocking) { + finish_wait(&write_sq.action_queue, &wait); return uWritten > 0 ? uWritten : -EAGAIN; - SLEEP(write_sq.action_queue); - if (signal_pending(current)) + } + if (write_sq.count < write_sq.max_active) + break; + + schedule_timeout(HZ); + if (signal_pending(current)) { + finish_wait(&write_sq.action_queue, &wait); return uWritten > 0 ? uWritten : -EINTR; + } } + finish_wait(&write_sq.action_queue, &wait); + /* Here, we can avoid disabling the interrupt by first * copying and translating the data, and then updating * the write_sq variables. Until this is done, the interrupt @@ -707,11 +719,8 @@ static int sq_open2(struct sound_queue *sq, struct file *file, fmode_t mode, if (file->f_flags & O_NONBLOCK) return rc; rc = -EINTR; - while (sq->busy) { - SLEEP(sq->open_queue); - if (signal_pending(current)) - return rc; - } + if (wait_event_interruptible(sq->open_queue, !sq->busy)) + return rc; rc = 0; #else /* OSS manual says we will return EBUSY regardless @@ -844,7 +853,8 @@ static int sq_fsync(void) sq_play(); /* there may be an incomplete frame waiting */ while (write_sq.active) { - SLEEP(write_sq.sync_queue); + wait_event_interruptible_timeout(write_sq.sync_queue, + !write_sq.active, HZ); if (signal_pending(current)) { /* While waiting for audio output to drain, an * interrupt occurred. Stop audio output immediately -- 2.34.1