[PATCH 6/7] ALSA: memalloc: don't pass bogus GFP_ flags to dma_alloc_*

Christoph Hellwig
2022-11-13T16:36:44Z

dma_alloc_coherent/dma_alloc_wc is an opaque allocator that only uses
the GFP_ flags for allocation context control. Don't pass __GFP_COMP
which makes no sense for an allocation that can't in any way be
converted to a page pointer.

Note that for dma_alloc_noncoherent and dma_alloc_noncontigous in
combination with the DMA mmap helpers __GFP_COMP looks sketchy as well,
so I would suggest to drop that as well after a careful audit.

Signed-off-by: Christoph Hellwig <hch@lst.de>
---
sound/core/memalloc.c | 5 ++---
1 file changed, 2 insertions(+), 3 deletions(-)

diff --git a/sound/core/memalloc.c b/sound/core/memalloc.c
index 03cffe7713667..fe03cf796e8bb 100644
--- a/sound/core/memalloc.c
+++ b/sound/core/memalloc.c
@@ -20,7 +20,6 @@

#define DEFAULT_GFP \
(GFP_KERNEL | \
- __GFP_COMP | /* compound page lets parts be mapped */ \
__GFP_RETRY_MAYFAIL | /* don't trigger OOM-killer */ \
__GFP_NOWARN) /* no stack trace print - this call is non-critical */

@@ -542,7 +541,7 @@ static void *snd_dma_noncontig_alloc(struct snd_dma_buffer *dmab, size_t size)
void *p;

sgt = dma_alloc_noncontiguous(dmab->dev.dev, size, dmab->dev.dir,
- DEFAULT_GFP, 0);
+ DEFAULT_GFP | __GFP_COMP, 0);
if (!sgt) {
#ifdef CONFIG_SND_DMA_SGBUF
if (dmab->dev.type == SNDRV_DMA_TYPE_DEV_WC_SG)
@@ -810,7 +809,7 @@ static void *snd_dma_noncoherent_alloc(struct snd_dma_buffer *dmab, size_t size)
void *p;

p = dma_alloc_noncoherent(dmab->dev.dev, size, &dmab->addr,
- dmab->dev.dir, DEFAULT_GFP);
+ dmab->dev.dir, DEFAULT_GFP | __GFP_COMP);
if (p)
dmab->dev.need_sync = dma_need_sync(dmab->dev.dev, dmab->addr);
return p;
--
2.30.2