The commit b3aa14f02254 ("iommu: remove the mapping_error dma_map_ops
method") incorrectly changed the checking from dma_ops_alloc_iova() in
map_sg() causes a crash under memory pressure as dma_ops_alloc_iova()
never return DMA_MAPPING_ERROR on failure but 0, so the error handling
is all wrong.
kernel BUG at drivers/iommu/iova.c:801!
Workqueue: kblockd blk_mq_run_work_fn
RIP: 0010:iova_magazine_free_pfns+0x7d/0xc0
Call Trace:
free_cpu_cached_iovas+0xbd/0x150
alloc_iova_fast+0x8c/0xba
dma_ops_alloc_iova.isra.6+0x65/0xa0
map_sg+0x8c/0x2a0
scsi_dma_map+0xc6/0x160
pqi_aio_submit_io+0x1f6/0x440 [smartpqi]
pqi_scsi_queue_command+0x90c/0xdd0 [smartpqi]
scsi_queue_rq+0x79c/0x1200
blk_mq_dispatch_rq_list+0x4dc/0xb70
blk_mq_sched_dispatch_requests+0x249/0x310
__blk_mq_run_hw_queue+0x128/0x200
blk_mq_run_work_fn+0x27/0x30
process_one_work+0x522/0xa10
worker_thread+0x63/0x5b0
kthread+0x1d2/0x1f0
ret_from_fork+0x22/0x40
Fixes: b3aa14f02254 ("iommu: remove the mapping_error dma_map_ops method")
Signed-off-by: Qian Cai <[email protected]>
---
v2: Fix the offensive commit directly.
drivers/iommu/amd_iommu.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/iommu/amd_iommu.c b/drivers/iommu/amd_iommu.c
index 73740b969e62..b607a92791d3 100644
--- a/drivers/iommu/amd_iommu.c
+++ b/drivers/iommu/amd_iommu.c
@@ -2533,7 +2533,7 @@ static int map_sg(struct device *dev, struct scatterlist *sglist,
npages = sg_num_pages(dev, sglist, nelems);
address = dma_ops_alloc_iova(dev, dma_dom, npages, dma_mask);
- if (address == DMA_MAPPING_ERROR)
+ if (!address)
goto out_err;
prot = dir2prot(direction);
--
1.8.3.1
On Thu, Jul 11, 2019 at 9:18 AM Qian Cai <[email protected]> wrote:
>
> The commit b3aa14f02254 ("iommu: remove the mapping_error dma_map_ops
> method") incorrectly changed the checking from dma_ops_alloc_iova() in
> map_sg() causes a crash under memory pressure as dma_ops_alloc_iova()
> never return DMA_MAPPING_ERROR on failure but 0, so the error handling
> is all wrong.
This one seems to have fallen through the cracks.
Applied directly.
Maybe it's hiding in some fixes tree that I haven't gotten a pull
request for yet?
Linus
Hi Linus,
On Sun, Jul 21, 2019 at 09:58:04AM -0700, Linus Torvalds wrote:
> This one seems to have fallen through the cracks.
>
> Applied directly.
Thanks!
> Maybe it's hiding in some fixes tree that I haven't gotten a pull
> request for yet?
No, I havn't had it applied anywhere yet. I usually don't pay close
attention to patches sent to me during the merge window, as I won't
update my tree anyway before -rc1.
I only take care of important fixes, but this one seems to have
fallen through my heuristic. Thanks for applying it directly.
Regards,
Joerg