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authorStefano Panella <stefano.panella@citrix.com>2013-12-10 14:20:28 +0000
committerTakashi Iwai <tiwai@suse.de>2013-12-10 15:30:46 +0100
commit932e9dec380c67ec15ac3eb073bb55797d8b4801 (patch)
treeb949c0b86510f230f28ffe53687b3b2f4d7403db
parent0dfb9809e93b60946d1915b554138eb93595860c (diff)
ALSA: memalloc.h - fix wrong truncation of dma_addr_t
When running a 32bit kernel the hda_intel driver is still reporting a 64bit dma_mask if the HW supports it. From sound/pci/hda/hda_intel.c: /* allow 64bit DMA address if supported by H/W */ if ((gcap & ICH6_GCAP_64OK) && !pci_set_dma_mask(pci, DMA_BIT_MASK(64))) pci_set_consistent_dma_mask(pci, DMA_BIT_MASK(64)); else { pci_set_dma_mask(pci, DMA_BIT_MASK(32)); pci_set_consistent_dma_mask(pci, DMA_BIT_MASK(32)); } which means when there is a call to dma_alloc_coherent from snd_malloc_dev_pages a machine address bigger than 32bit can be returned. This can be true in particular if running the 32bit kernel as a pv dom0 under the Xen Hypervisor or PAE on bare metal. The problem is that when calling setup_bdle to program the BLE the dma_addr_t returned from the dma_alloc_coherent is wrongly truncated from snd_sgbuf_get_addr if running a 32bit kernel: static inline dma_addr_t snd_sgbuf_get_addr(struct snd_dma_buffer *dmab, size_t offset) { struct snd_sg_buf *sgbuf = dmab->private_data; dma_addr_t addr = sgbuf->table[offset >> PAGE_SHIFT].addr; addr &= PAGE_MASK; return addr + offset % PAGE_SIZE; } where PAGE_MASK in a 32bit kernel is zeroing the upper 32bit af addr. Without this patch the HW will fetch the 32bit truncated address, which is not the one obtained from dma_alloc_coherent and will result to a non working audio but can corrupt host memory at a random location. The current patch apply to v3.13-rc3-74-g6c843f5 Signed-off-by: Stefano Panella <stefano.panella@citrix.com> Reviewed-by: Frediano Ziglio <frediano.ziglio@citrix.com> Cc: <stable@vger.kernel.org> Signed-off-by: Takashi Iwai <tiwai@suse.de>
-rw-r--r--include/sound/memalloc.h2
1 files changed, 1 insertions, 1 deletions
diff --git a/include/sound/memalloc.h b/include/sound/memalloc.h
index af9983970417..5f73785f5977 100644
--- a/include/sound/memalloc.h
+++ b/include/sound/memalloc.h
@@ -108,7 +108,7 @@ static inline dma_addr_t snd_sgbuf_get_addr(struct snd_dma_buffer *dmab,
{
struct snd_sg_buf *sgbuf = dmab->private_data;
dma_addr_t addr = sgbuf->table[offset >> PAGE_SHIFT].addr;
- addr &= PAGE_MASK;
+ addr &= ~((dma_addr_t)PAGE_SIZE - 1);
return addr + offset % PAGE_SIZE;
}