Commit 984ecdd6 authored Aug 21, 2018 by Breno Leitao Committed by Michael Ellerman Sep 19, 2018

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>

parent 8ac9e5bf

arch/powerpc/kernel/iommu.c

+1 −1

Original line number	Diff line number	Diff line
		@@ -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)

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