| From | Greg Kroah-Hartman <> | Subject | [PATCH 3.14 60/70] dma-debug: Fix dma_debug_entry offset calculation | Date | Tue, 23 Feb 2016 19:34:09 -0800 |
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3.14-stable review patch. If anyone has any objections, please let me know.
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From: Daniel Mentz <danielmentz@google.com>
commit 0354aec19ce3d355c6213b0434064efc25c9b22c upstream.
dma-debug uses struct dma_debug_entry to keep track of dma coherent memory allocation requests. The virtual address is converted into a pfn and an offset. Previously, the offset was calculated using an incorrect bit mask. As a result, we saw incorrect error messages from dma-debug like the following:
"DMA-API: exceeded 7 overlapping mappings of cacheline 0x03e00000"
Cacheline 0x03e00000 does not exist on our platform.
Fixes: 0abdd7a81b7e ("dma-debug: introduce debug_dma_assert_idle()") Signed-off-by: Daniel Mentz <danielmentz@google.com> Signed-off-by: Dan Williams <dan.j.williams@intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
--- lib/dma-debug.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-)
--- a/lib/dma-debug.c +++ b/lib/dma-debug.c @@ -1440,7 +1440,7 @@ void debug_dma_alloc_coherent(struct dev entry->type = dma_debug_coherent; entry->dev = dev; entry->pfn = page_to_pfn(virt_to_page(virt)); - entry->offset = (size_t) virt & PAGE_MASK; + entry->offset = (size_t) virt & ~PAGE_MASK; entry->size = size; entry->dev_addr = dma_addr; entry->direction = DMA_BIDIRECTIONAL; @@ -1456,7 +1456,7 @@ void debug_dma_free_coherent(struct devi .type = dma_debug_coherent, .dev = dev, .pfn = page_to_pfn(virt_to_page(virt)), - .offset = (size_t) virt & PAGE_MASK, + .offset = (size_t) virt & ~PAGE_MASK, .dev_addr = addr, .size = size, .direction = DMA_BIDIRECTIONAL,
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