[PATCH v2 21/21] dma-mapping: Disallow .map_sg operations from returning zero on error
From: Logan Gunthorpe <logang@deltatee.com>
Date: 2021-07-23 17:50:35
Also in:
linux-alpha, linux-iommu, linux-mips, linux-s390, linuxppc-dev, lkml, sparclinux, xen-devel
Subsystem:
dma mapping helpers, the rest · Maintainers:
Marek Szyprowski, Linus Torvalds
Now that all the .map_sg operations have been converted to returning proper error codes, drop the code to handle a zero return value, add a warning if a zero is returned and update the comment for the map_sg operation. Signed-off-by: Logan Gunthorpe <logang@deltatee.com> --- kernel/dma/mapping.c | 7 ++++--- 1 file changed, 4 insertions(+), 3 deletions(-)
diff --git a/kernel/dma/mapping.c b/kernel/dma/mapping.c
index b8dc8b1cb402..86a8a421344a 100644
--- a/kernel/dma/mapping.c
+++ b/kernel/dma/mapping.c@@ -194,6 +194,9 @@ static int __dma_map_sg_attrs(struct device *dev, struct scatterlist *sg, else ents = ops->map_sg(dev, sg, nents, dir, attrs); + if (WARN_ON_ONCE(ents == 0)) + return -EIO; + if (ents > 0) debug_dma_map_sg(dev, sg, nents, ents, dir);
@@ -259,9 +262,7 @@ int dma_map_sgtable(struct device *dev, struct sg_table *sgt, int nents; nents = __dma_map_sg_attrs(dev, sgt->sgl, sgt->orig_nents, dir, attrs); - if (nents == 0) - return -EIO; - else if (nents < 0) { + if (nents < 0) { if (WARN_ON_ONCE(nents != -EINVAL && nents != -ENOMEM && nents != -EIO)) return -EIO;
--
2.20.1
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