lisa/android_kernel_xiaomi_sm8350
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

Revert "ALSA: pcm: Fix potential data race at PCM memory allocation helpers"

Browse Source 
This reverts commit 7e1d1456c8 which is
commit bd55842ed998a622ba6611fe59b3358c9f76773d upstream.

It breaks the Android abi.  If it is required in the future, it can
come back in an abi-safe way.

Bug: 161946584
Change-Id: I1ef898f3ecf95e31f03d37785cebb5d773e0f577
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>
This commit is contained in:
Greg Kroah-Hartman 2023-08-31 13:44:36 +00:00
parent cebc239dda
commit bd7fae9e3e
1 changed files with 8 additions and 36 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

44
sound/core/pcm_memory.c
View File

@ -31,40 +31,14 @@ static unsigned long max_alloc_per_card = 32UL * 1024UL * 1024UL;
module_param(max_alloc_per_card, ulong, 0644);
MODULE_PARM_DESC(max_alloc_per_card, "Max total allocation bytes per card.");
static void __update_allocated_size(struct snd_card *card, ssize_t bytes)
{
card->total_pcm_alloc_bytes += bytes;
}
static void update_allocated_size(struct snd_card *card, ssize_t bytes)
{
mutex_lock(&card->memory_mutex);
__update_allocated_size(card, bytes);
mutex_unlock(&card->memory_mutex);
}
static void decrease_allocated_size(struct snd_card *card, size_t bytes)
{
mutex_lock(&card->memory_mutex);
WARN_ON(card->total_pcm_alloc_bytes < bytes);
__update_allocated_size(card, -(ssize_t)bytes);
mutex_unlock(&card->memory_mutex);
}
static int do_alloc_pages(struct snd_card *card, int type, struct device *dev,
size_t size, struct snd_dma_buffer *dmab)
{
int err;
/* check and reserve the requested size */
mutex_lock(&card->memory_mutex);
if (max_alloc_per_card &&
card->total_pcm_alloc_bytes + size > max_alloc_per_card) {
mutex_unlock(&card->memory_mutex);
card->total_pcm_alloc_bytes + size > max_alloc_per_card)
return -ENOMEM;
}
__update_allocated_size(card, size);
mutex_unlock(&card->memory_mutex);
if (IS_ENABLED(CONFIG_SND_DMA_SGBUF) &&
(type == SNDRV_DMA_TYPE_DEV_SG || type == SNDRV_DMA_TYPE_DEV_UC_SG) &&
@ -79,14 +53,9 @@ static int do_alloc_pages(struct snd_card *card, int type, struct device *dev,
err = snd_dma_alloc_pages(type, dev, size, dmab);
if (!err) {
/* the actual allocation size might be bigger than requested,
* and we need to correct the account
*/
if (dmab->bytes != size)
update_allocated_size(card, dmab->bytes - size);
} else {
/* take back on allocation failure */
decrease_allocated_size(card, size);
mutex_lock(&card->memory_mutex);
card->total_pcm_alloc_bytes += dmab->bytes;
mutex_unlock(&card->memory_mutex);
}
return err;
}
@ -95,7 +64,10 @@ static void do_free_pages(struct snd_card *card, struct snd_dma_buffer *dmab)
{
if (!dmab->area)
return;
decrease_allocated_size(card, dmab->bytes);
mutex_lock(&card->memory_mutex);
WARN_ON(card->total_pcm_alloc_bytes < dmab->bytes);
card->total_pcm_alloc_bytes -= dmab->bytes;
mutex_unlock(&card->memory_mutex);
snd_dma_free_pages(dmab);
dmab->area = NULL;
}