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| author | Breno Leitao <leitao@debian.org> | 2018-08-21 15:44:48 -0300 |
|---|---|---|
| committer | Michael Ellerman <mpe@ellerman.id.au> | 2018-09-19 21:58:09 +1000 |
| commit | 984ecdd68de0fa1f63ce205d6c19ef5a7bc67b40 (patch) | |
| tree | 4eb2bb5bf308d08eb4791b8cd5b34f4863019cb2 /arch/powerpc/kernel/iommu.c | |
| parent | 8ac9e5bfd8cf41ef106ac97267117e5209627c74 (diff) | |
| download | lwn-984ecdd68de0fa1f63ce205d6c19ef5a7bc67b40.tar.gz lwn-984ecdd68de0fa1f63ce205d6c19ef5a7bc67b40.zip | |
powerpc/iommu: Avoid derefence before pointer check
The tbl pointer is being derefenced by IOMMU_PAGE_SIZE prior the check
if it is not NULL.
Just moving the dereference code to after the check, where there will
be guarantee that 'tbl' will not be NULL.
Signed-off-by: Breno Leitao <leitao@debian.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Diffstat (limited to 'arch/powerpc/kernel/iommu.c')
| -rw-r--r-- | arch/powerpc/kernel/iommu.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/arch/powerpc/kernel/iommu.c b/arch/powerpc/kernel/iommu.c index af7a20dc6e09..80b6caaa9b92 100644 --- a/arch/powerpc/kernel/iommu.c +++ b/arch/powerpc/kernel/iommu.c @@ -785,9 +785,9 @@ dma_addr_t iommu_map_page(struct device *dev, struct iommu_table *tbl, vaddr = page_address(page) + offset; uaddr = (unsigned long)vaddr; - npages = iommu_num_pages(uaddr, size, IOMMU_PAGE_SIZE(tbl)); if (tbl) { + npages = iommu_num_pages(uaddr, size, IOMMU_PAGE_SIZE(tbl)); align = 0; if (tbl->it_page_shift < PAGE_SHIFT && size >= PAGE_SIZE && ((unsigned long)vaddr & ~PAGE_MASK) == 0) |