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author | Andrea Righi <righi.andrea@gmail.com> | 2008-07-23 21:28:13 -0700 |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2008-07-24 10:47:21 -0700 |
commit | 27ac792ca0b0a1e7e65f20342260650516c95864 (patch) | |
tree | 8e0bc93612da0803fe12303ccb75c837cd633c83 /drivers/ieee1394/iso.c | |
parent | d92bc318547507a944a22e7ef936793dc0fe167f (diff) | |
download | linux-27ac792ca0b0a1e7e65f20342260650516c95864.tar.gz |
PAGE_ALIGN(): correctly handle 64-bit values on 32-bit architectures
On 32-bit architectures PAGE_ALIGN() truncates 64-bit values to the 32-bit boundary. For example: u64 val = PAGE_ALIGN(size); always returns a value < 4GB even if size is greater than 4GB. The problem resides in PAGE_MASK definition (from include/asm-x86/page.h for example): #define PAGE_SHIFT 12 #define PAGE_SIZE (_AC(1,UL) << PAGE_SHIFT) #define PAGE_MASK (~(PAGE_SIZE-1)) ... #define PAGE_ALIGN(addr) (((addr)+PAGE_SIZE-1)&PAGE_MASK) The "~" is performed on a 32-bit value, so everything in "and" with PAGE_MASK greater than 4GB will be truncated to the 32-bit boundary. Using the ALIGN() macro seems to be the right way, because it uses typeof(addr) for the mask. Also move the PAGE_ALIGN() definitions out of include/asm-*/page.h in include/linux/mm.h. See also lkml discussion: http://lkml.org/lkml/2008/6/11/237 [akpm@linux-foundation.org: fix drivers/media/video/uvc/uvc_queue.c] [akpm@linux-foundation.org: fix v850] [akpm@linux-foundation.org: fix powerpc] [akpm@linux-foundation.org: fix arm] [akpm@linux-foundation.org: fix mips] [akpm@linux-foundation.org: fix drivers/media/video/pvrusb2/pvrusb2-dvb.c] [akpm@linux-foundation.org: fix drivers/mtd/maps/uclinux.c] [akpm@linux-foundation.org: fix powerpc] Signed-off-by: Andrea Righi <righi.andrea@gmail.com> Cc: <linux-arch@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'drivers/ieee1394/iso.c')
-rw-r--r-- | drivers/ieee1394/iso.c | 1 |
1 files changed, 1 insertions, 0 deletions
diff --git a/drivers/ieee1394/iso.c b/drivers/ieee1394/iso.c index 07ca35c98f96..1cf6487b65ba 100644 --- a/drivers/ieee1394/iso.c +++ b/drivers/ieee1394/iso.c @@ -11,6 +11,7 @@ #include <linux/pci.h> #include <linux/sched.h> +#include <linux/mm.h> #include <linux/slab.h> #include "hosts.h" |