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authorArnd Bergmann <arnd@arndb.de>2019-06-17 15:28:43 +0200
committerKonrad Rzeszutek Wilk <konrad.wilk@oracle.com>2019-06-19 16:28:54 +0200
commit9c106119f6538f65bdddb7948a157d90625effa7 (patch)
tree1728ec5ac2c790191d37fe3e6b724fa1b5180732 /kernel
parentxen/swiotlb: don't initialize swiotlb twice on arm64 (diff)
downloadlinux-9c106119f6538f65bdddb7948a157d90625effa7.tar.xz
linux-9c106119f6538f65bdddb7948a157d90625effa7.zip
swiotlb: fix phys_addr_t overflow warning
On architectures that have a larger dma_addr_t than phys_addr_t, the swiotlb_tbl_map_single() function truncates its return code in the failure path, making it impossible to identify the error later, as we compare to the original value: kernel/dma/swiotlb.c:551:9: error: implicit conversion from 'dma_addr_t' (aka 'unsigned long long') to 'phys_addr_t' (aka 'unsigned int') changes value from 18446744073709551615 to 4294967295 [-Werror,-Wconstant-conversion] return DMA_MAPPING_ERROR; Use an explicit typecast here to convert it to the narrower type, and use the same expression in the error handling later. Fixes: b907e20508d0 ("swiotlb: remove SWIOTLB_MAP_ERROR") Acked-by: Stefano Stabellini <sstabellini@kernel.org> Signed-off-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Diffstat (limited to 'kernel')
-rw-r--r--kernel/dma/swiotlb.c4
1 files changed, 2 insertions, 2 deletions
diff --git a/kernel/dma/swiotlb.c b/kernel/dma/swiotlb.c
index 38d57218809c..48e7488e3482 100644
--- a/kernel/dma/swiotlb.c
+++ b/kernel/dma/swiotlb.c
@@ -538,7 +538,7 @@ not_found:
if (!(attrs & DMA_ATTR_NO_WARN) && printk_ratelimit())
dev_warn(hwdev, "swiotlb buffer is full (sz: %zd bytes), total %lu (slots), used %lu (slots)\n",
size, io_tlb_nslabs, tmp_io_tlb_used);
- return DMA_MAPPING_ERROR;
+ return (phys_addr_t)DMA_MAPPING_ERROR;
found:
io_tlb_used += nslots;
spin_unlock_irqrestore(&io_tlb_lock, flags);
@@ -656,7 +656,7 @@ bool swiotlb_map(struct device *dev, phys_addr_t *phys, dma_addr_t *dma_addr,
/* Oh well, have to allocate and map a bounce buffer. */
*phys = swiotlb_tbl_map_single(dev, __phys_to_dma(dev, io_tlb_start),
*phys, size, dir, attrs);
- if (*phys == DMA_MAPPING_ERROR)
+ if (*phys == (phys_addr_t)DMA_MAPPING_ERROR)
return false;
/* Ensure that the address returned is DMA'ble */