This is a note to let you know that I've just added the patch titled
iommu/dma: Fix incorrect error return on iommu deferred attach
to the 5.15-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
iommu-dma-fix-incorrect-error-return-on-iommu-deferr.patch
and it can be found in the queue-5.15 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit d866af7e8606fcf4befe2dffaf7df255a39a9f03
Author: Logan Gunthorpe <logang@xxxxxxxxxxxx>
Date: Wed Oct 27 11:47:57 2021 -0600
iommu/dma: Fix incorrect error return on iommu deferred attach
[ Upstream commit ac315f96b3bd6f6b8f18f387816c7c2cc6b32e02 ]
scsi_dma_map() was reporting a failure during boot on an AMD machine
with the IOMMU enabled.
scsi_dma_map failed: request for 36 bytes!
The issue was tracked down to a mistake in logic: should not return
an error if iommu_deferred_attach() returns zero.
Reported-by: Marshall Midden <marshallmidden@xxxxxxxxx>
Fixes: dabb16f67215 ("iommu/dma: return error code from iommu_dma_map_sg()")
Link: https://lore.kernel.org/all/CAD2CkAWjS8=kKwEEN4cgVNjyFORUibzEiCUA-X+SMtbo0JoMmA@xxxxxxxxxxxxxx
Signed-off-by: Logan Gunthorpe <logang@xxxxxxxxxxxx>
Cc: Joerg Roedel <joro@xxxxxxxxxx>
Cc: Will Deacon <will@xxxxxxxxxx>
Link: https://lore.kernel.org/r/20211027174757.119755-1-logang@xxxxxxxxxxxx
Signed-off-by: Joerg Roedel <jroedel@xxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/drivers/iommu/dma-iommu.c b/drivers/iommu/dma-iommu.c
index 19bebacbf1780..2d60216440009 100644
--- a/drivers/iommu/dma-iommu.c
+++ b/drivers/iommu/dma-iommu.c
@@ -1007,7 +1007,8 @@ static int iommu_dma_map_sg(struct device *dev, struct scatterlist *sg,
if (static_branch_unlikely(&iommu_deferred_attach_enabled)) {
ret = iommu_deferred_attach(dev, domain);
- goto out;
+ if (ret)
+ goto out;
}
if (dev_is_untrusted(dev))
