| Message ID | 1404959313-15198-1-git-send-email-haojian.zhuang@linaro.org |
|---|---|
| State | Rejected |
| Headers | show |
On Thu, Jul 10, 2014 at 03:28:33AM +0100, Haojian Zhuang wrote: > The issue of boundary checking on bitmaps is introduced by this commit > in below. > > commit 4d852ef8c2544ce21ae41414099a7504c61164a0 > Author: Andreas Herrmann <andreas.herrmann@calxeda.com> > Date: Tue Feb 25 13:09:53 2014 +0100 > > arm: dma-mapping: Add support to extend DMA IOMMU mappings > > Multiple bitmaps were introduced as extension. If it needs to extend > a bitmap, it still check whether the allocation exceeding the total > size, not current bitmap size. So change the condition from > mapping->bits to PAGE_SIZE. > > Signed-off-by: Haojian Zhuang <haojian.zhuang@linaro.org> > --- > arch/arm/mm/dma-mapping.c | 8 ++++---- > 1 file changed, 4 insertions(+), 4 deletions(-) > > diff --git a/arch/arm/mm/dma-mapping.c b/arch/arm/mm/dma-mapping.c > index 4c88935..d7da5c3 100644 > --- a/arch/arm/mm/dma-mapping.c > +++ b/arch/arm/mm/dma-mapping.c > @@ -1089,9 +1089,9 @@ static inline dma_addr_t __alloc_iova(struct dma_iommu_mapping *mapping, > spin_lock_irqsave(&mapping->lock, flags); > for (i = 0; i < mapping->nr_bitmaps; i++) { > start = bitmap_find_next_zero_area(mapping->bitmaps[i], > - mapping->bits, 0, count, align); > + PAGE_SIZE, 0, count, align); I'm probably just missing something, but what guarantees that the bitmap is PAGE_SIZE? It looks to me like we could easily go off the end of the bitmap if arm_iommu_create_mapping is called with a small size parameter. Will -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
Hello, On 2014-07-10 04:28, Haojian Zhuang wrote: > The issue of boundary checking on bitmaps is introduced by this commit > in below. > > commit 4d852ef8c2544ce21ae41414099a7504c61164a0 > Author: Andreas Herrmann <andreas.herrmann@calxeda.com> > Date: Tue Feb 25 13:09:53 2014 +0100 > > arm: dma-mapping: Add support to extend DMA IOMMU mappings > > Multiple bitmaps were introduced as extension. If it needs to extend > a bitmap, it still check whether the allocation exceeding the total > size, not current bitmap size. So change the condition from > mapping->bits to PAGE_SIZE. > > Signed-off-by: Haojian Zhuang <haojian.zhuang@linaro.org> NACK, this patch is not correct. mapping->bits contains the correct size of a single bitmap, see the beginning of arm_iommu_create_mapping() function. > --- > arch/arm/mm/dma-mapping.c | 8 ++++---- > 1 file changed, 4 insertions(+), 4 deletions(-) > > diff --git a/arch/arm/mm/dma-mapping.c b/arch/arm/mm/dma-mapping.c > index 4c88935..d7da5c3 100644 > --- a/arch/arm/mm/dma-mapping.c > +++ b/arch/arm/mm/dma-mapping.c > @@ -1089,9 +1089,9 @@ static inline dma_addr_t __alloc_iova(struct dma_iommu_mapping *mapping, > spin_lock_irqsave(&mapping->lock, flags); > for (i = 0; i < mapping->nr_bitmaps; i++) { > start = bitmap_find_next_zero_area(mapping->bitmaps[i], > - mapping->bits, 0, count, align); > + PAGE_SIZE, 0, count, align); > > - if (start > mapping->bits) > + if (start > PAGE_SIZE) > continue; > > bitmap_set(mapping->bitmaps[i], start, count); > @@ -1110,9 +1110,9 @@ static inline dma_addr_t __alloc_iova(struct dma_iommu_mapping *mapping, > } > > start = bitmap_find_next_zero_area(mapping->bitmaps[i], > - mapping->bits, 0, count, align); > + PAGE_SIZE, 0, count, align); > > - if (start > mapping->bits) { > + if (start > PAGE_SIZE) { > spin_unlock_irqrestore(&mapping->lock, flags); > return DMA_ERROR_CODE; > } Best regards
diff --git a/arch/arm/mm/dma-mapping.c b/arch/arm/mm/dma-mapping.c index 4c88935..d7da5c3 100644 --- a/arch/arm/mm/dma-mapping.c +++ b/arch/arm/mm/dma-mapping.c @@ -1089,9 +1089,9 @@ static inline dma_addr_t __alloc_iova(struct dma_iommu_mapping *mapping, spin_lock_irqsave(&mapping->lock, flags); for (i = 0; i < mapping->nr_bitmaps; i++) { start = bitmap_find_next_zero_area(mapping->bitmaps[i], - mapping->bits, 0, count, align); + PAGE_SIZE, 0, count, align); - if (start > mapping->bits) + if (start > PAGE_SIZE) continue; bitmap_set(mapping->bitmaps[i], start, count); @@ -1110,9 +1110,9 @@ static inline dma_addr_t __alloc_iova(struct dma_iommu_mapping *mapping, } start = bitmap_find_next_zero_area(mapping->bitmaps[i], - mapping->bits, 0, count, align); + PAGE_SIZE, 0, count, align); - if (start > mapping->bits) { + if (start > PAGE_SIZE) { spin_unlock_irqrestore(&mapping->lock, flags); return DMA_ERROR_CODE; }
The issue of boundary checking on bitmaps is introduced by this commit in below. commit 4d852ef8c2544ce21ae41414099a7504c61164a0 Author: Andreas Herrmann <andreas.herrmann@calxeda.com> Date: Tue Feb 25 13:09:53 2014 +0100 arm: dma-mapping: Add support to extend DMA IOMMU mappings Multiple bitmaps were introduced as extension. If it needs to extend a bitmap, it still check whether the allocation exceeding the total size, not current bitmap size. So change the condition from mapping->bits to PAGE_SIZE. Signed-off-by: Haojian Zhuang <haojian.zhuang@linaro.org> --- arch/arm/mm/dma-mapping.c | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-)