From: Jan Beulich Date: Tue, 5 Aug 2008 20:01:31 +0000 (-0700) Subject: dma: fix order calculation in dma_mark_declared_memory_occupied() X-Git-Url: https://git.stricted.de/?a=commitdiff_plain;h=d2dc1f4adb4b5b02d87e49e115e5107f4da790c0;p=GitHub%2Fmoto-9609%2Fandroid_kernel_motorola_exynos9610.git dma: fix order calculation in dma_mark_declared_memory_occupied() get_order() takes byte-sized input, not a page-granular one. Irrespective of this fix I'm inclined to believe that this doesn't work right anyway - bitmap_allocate_region() has an implicit assumption of 'pos' being suitable for 'order', which this function doesn't seem to enforce (and since it's being called with a byte-granular value there's no reason to believe that the callers would make sure device_addr is passed accordingly - it's also not documented that way). Signed-off-by: Jan Beulich Cc: James E.J. Bottomley Cc: Ingo Molnar Cc: Dmitry Baryshkov Cc: Jesse Barnes Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- diff --git a/kernel/dma-coherent.c b/kernel/dma-coherent.c index 7517115a8cce..91e96950cd52 100644 --- a/kernel/dma-coherent.c +++ b/kernel/dma-coherent.c @@ -77,15 +77,14 @@ void *dma_mark_declared_memory_occupied(struct device *dev, { struct dma_coherent_mem *mem = dev->dma_mem; int pos, err; - int pages = (size + (device_addr & ~PAGE_MASK) + PAGE_SIZE - 1); - pages >>= PAGE_SHIFT; + size += device_addr & ~PAGE_MASK; if (!mem) return ERR_PTR(-EINVAL); pos = (device_addr - mem->device_base) >> PAGE_SHIFT; - err = bitmap_allocate_region(mem->bitmap, pos, get_order(pages)); + err = bitmap_allocate_region(mem->bitmap, pos, get_order(size)); if (err != 0) return ERR_PTR(err); return mem->virt_base + (pos << PAGE_SHIFT);