lib/dma-debug.c: fix incorrect pfn calculation
dma-debug reports the following warning: WARNING: CPU: 3 PID: 298 at kernel-4.4/lib/dma-debug.c:604 debug _dma_assert_idle+0x1a8/0x230() DMA-API: cpu touching an active dma mapped cacheline [cln=0x00000882300] CPU: 3 PID: 298 Comm: vold Tainted: G W O 4.4.22+ #1 Hardware name: MT6739 (DT) Call trace: debug_dma_assert_idle+0x1a8/0x230 wp_page_copy.isra.96+0x118/0x520 do_wp_page+0x4fc/0x534 handle_mm_fault+0xd4c/0x1310 do_page_fault+0x1c8/0x394 do_mem_abort+0x50/0xec I found that debug_dma_alloc_coherent() and debug_dma_free_coherent() assume that dma_alloc_coherent() always returns a linear address. However it's possible that dma_alloc_coherent() returns a non-linear address. In this case, page_to_pfn(virt_to_page(virt)) will return an incorrect pfn. If the pfn is valid and mapped as a COW page, we will hit the warning when doing wp_page_copy(). Fix this by calculating pfn for linear and non-linear addresses. [miles.chen@mediatek.com: v4] Link: http://lkml.kernel.org/r/1510872972-23919-1-git-send-email-miles.chen@mediatek.com Link: http://lkml.kernel.org/r/1506484087-1177-1-git-send-email-miles.chen@mediatek.com Signed-off-by: Miles Chen <miles.chen@mediatek.com> Reviewed-by: Robin Murphy <robin.murphy@arm.com> Cc: Christoph Hellwig <hch@lst.de> Cc: Marek Szyprowski <m.szyprowski@samsung.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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@ -1495,14 +1495,22 @@ void debug_dma_alloc_coherent(struct device *dev, size_t size,
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if (!entry)
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if (!entry)
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return;
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return;
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/* handle vmalloc and linear addresses */
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if (!is_vmalloc_addr(virt) && !virt_to_page(virt))
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return;
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entry->type = dma_debug_coherent;
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entry->type = dma_debug_coherent;
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entry->dev = dev;
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entry->dev = dev;
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entry->pfn = page_to_pfn(virt_to_page(virt));
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entry->offset = offset_in_page(virt);
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entry->offset = offset_in_page(virt);
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entry->size = size;
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entry->size = size;
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entry->dev_addr = dma_addr;
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entry->dev_addr = dma_addr;
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entry->direction = DMA_BIDIRECTIONAL;
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entry->direction = DMA_BIDIRECTIONAL;
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if (is_vmalloc_addr(virt))
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entry->pfn = vmalloc_to_pfn(virt);
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else
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entry->pfn = page_to_pfn(virt_to_page(virt));
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add_dma_entry(entry);
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add_dma_entry(entry);
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}
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}
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EXPORT_SYMBOL(debug_dma_alloc_coherent);
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EXPORT_SYMBOL(debug_dma_alloc_coherent);
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@ -1513,13 +1521,21 @@ void debug_dma_free_coherent(struct device *dev, size_t size,
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struct dma_debug_entry ref = {
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struct dma_debug_entry ref = {
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.type = dma_debug_coherent,
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.type = dma_debug_coherent,
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.dev = dev,
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.dev = dev,
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.pfn = page_to_pfn(virt_to_page(virt)),
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.offset = offset_in_page(virt),
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.offset = offset_in_page(virt),
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.dev_addr = addr,
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.dev_addr = addr,
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.size = size,
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.size = size,
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.direction = DMA_BIDIRECTIONAL,
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.direction = DMA_BIDIRECTIONAL,
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};
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};
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/* handle vmalloc and linear addresses */
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if (!is_vmalloc_addr(virt) && !virt_to_page(virt))
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return;
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if (is_vmalloc_addr(virt))
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ref.pfn = vmalloc_to_pfn(virt);
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else
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ref.pfn = page_to_pfn(virt_to_page(virt));
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if (unlikely(dma_debug_disabled()))
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if (unlikely(dma_debug_disabled()))
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return;
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return;
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