diff options
| author | Qian Cai <cai@lca.pw> | 2019-07-11 12:17:45 -0400 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2019-07-21 09:57:13 -0700 |
| commit | 8cf66504210d308a35cca35fe9c310b1241f9fa7 (patch) | |
| tree | 989d4a1798e25562c918cb72c8254a0a5c3f7f1d /drivers | |
| parent | 618381f09cc15592bf3afe846c6a94e9bfcd9ce4 (diff) | |
| download | lwn-8cf66504210d308a35cca35fe9c310b1241f9fa7.tar.gz lwn-8cf66504210d308a35cca35fe9c310b1241f9fa7.zip | |
iommu/amd: fix a crash in iova_magazine_free_pfns
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 <cai@lca.pw>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'drivers')
| -rw-r--r-- | drivers/iommu/amd_iommu.c | 2 |
1 files changed, 1 insertions, 1 deletions
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); |