ALSA: seq: More protection for concurrent write and ioctl races

[pandora-kernel.git] / sound / core / seq / seq_fifo.c

diff --git a/sound/core/seq/seq_fifo.c b/sound/core/seq/seq_fifo.c
index 3a94ed0..9d429bc 100644 (file)
--- a/sound/core/seq/seq_fifo.c
+++ b/sound/core/seq/seq_fifo.c
@@ -65,11 +65,16 @@ void snd_seq_fifo_delete(struct snd_seq_fifo **fifo)
 {
        struct snd_seq_fifo *f;
 
-       snd_assert(fifo != NULL, return);
+       if (snd_BUG_ON(!fifo))
+               return;
        f = *fifo;
-       snd_assert(f != NULL, return);
+       if (snd_BUG_ON(!f))
+               return;
        *fifo = NULL;
 
+       if (f->pool)
+               snd_seq_pool_mark_closing(f->pool);
+
        snd_seq_fifo_clear(f);
 
        /* wake up clients if any */
@@ -116,12 +121,13 @@ int snd_seq_fifo_event_in(struct snd_seq_fifo *f,
        unsigned long flags;
        int err;
 
-       snd_assert(f != NULL, return -EINVAL);
+       if (snd_BUG_ON(!f))
+               return -EINVAL;
 
        snd_use_lock_use(&f->use_lock);
-       err = snd_seq_event_dup(f->pool, event, &cell, 1, NULL); /* always non-blocking */
+       err = snd_seq_event_dup(f->pool, event, &cell, 1, NULL, NULL); /* always non-blocking */
        if (err < 0) {
-               if (err == -ENOMEM)
+               if ((err == -ENOMEM) || (err == -EAGAIN))
                        atomic_inc(&f->overflow);
                snd_use_lock_free(&f->use_lock);
                return err;
@@ -134,6 +140,7 @@ int snd_seq_fifo_event_in(struct snd_seq_fifo *f,
        f->tail = cell;
        if (f->head == NULL)
                f->head = cell;
+       cell->next = NULL;
        f->cells++;
        spin_unlock_irqrestore(&f->lock, flags);
 
@@ -174,7 +181,8 @@ int snd_seq_fifo_cell_out(struct snd_seq_fifo *f,
        unsigned long flags;
        wait_queue_t wait;
 
-       snd_assert(f != NULL, return -EINVAL);
+       if (snd_BUG_ON(!f))
+               return -EINVAL;
 
        *cellp = NULL;
        init_waitqueue_entry(&wait, current);
@@ -212,6 +220,8 @@ void snd_seq_fifo_cell_putback(struct snd_seq_fifo *f,
                spin_lock_irqsave(&f->lock, flags);
                cell->next = f->head;
                f->head = cell;
+               if (!f->tail)
+                       f->tail = cell;
                f->cells++;
                spin_unlock_irqrestore(&f->lock, flags);
        }
@@ -233,7 +243,8 @@ int snd_seq_fifo_resize(struct snd_seq_fifo *f, int poolsize)
        struct snd_seq_pool *newpool, *oldpool;
        struct snd_seq_event_cell *cell, *next, *oldhead;
 
-       snd_assert(f != NULL && f->pool != NULL, return -EINVAL);
+       if (snd_BUG_ON(!f || !f->pool))
+               return -EINVAL;
 
        /* allocate new pool */
        newpool = snd_seq_pool_new(poolsize);
@@ -256,6 +267,10 @@ int snd_seq_fifo_resize(struct snd_seq_fifo *f, int poolsize)
        /* NOTE: overflow flag is not cleared */
        spin_unlock_irqrestore(&f->lock, flags);
 
+       /* close the old pool and wait until all users are gone */
+       snd_seq_pool_mark_closing(oldpool);
+       snd_use_lock_sync(&f->use_lock);
+
        /* release cells in old pool */
        for (cell = oldhead; cell; cell = next) {
                next = cell->next;