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| author | Mauro Carvalho Chehab <mchehab@infradead.org> | 2008-07-27 12:33:36 -0300 |
|---|---|---|
| committer | Mauro Carvalho Chehab <mchehab@infradead.org> | 2008-07-27 12:33:36 -0300 |
| commit | 983693ce340ad9713179eaac6359a5cac52ce858 (patch) | |
| tree | 89d106ebc19819462722310a2d7ef1c1a1e7f9be /linux/drivers/media/video/pvrusb2/pvrusb2-ioread.c | |
| parent | b758fc01ef8bdaa9a7380ef01c1e27cf6a96e256 (diff) | |
| download | mediapointer-dvb-s2-983693ce340ad9713179eaac6359a5cac52ce858.tar.gz mediapointer-dvb-s2-983693ce340ad9713179eaac6359a5cac52ce858.tar.bz2 | |
backport commit 27ac792ca0b0a1e7e65f20342260650516c95864
From: Mauro Carvalho Chehab <mchehab@infradead.org>
kernel-sync:
Author: Andrea Righi <righi.andrea@gmail.com>
Date: Wed Jul 23 21:28:13 2008 -0700
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: Mauro Carvalho Chehab <mchehab@infradead.org>
Diffstat (limited to 'linux/drivers/media/video/pvrusb2/pvrusb2-ioread.c')
| -rw-r--r-- | linux/drivers/media/video/pvrusb2/pvrusb2-ioread.c | 1 |
1 files changed, 1 insertions, 0 deletions
diff --git a/linux/drivers/media/video/pvrusb2/pvrusb2-ioread.c b/linux/drivers/media/video/pvrusb2/pvrusb2-ioread.c index fa599a1bf..987e71142 100644 --- a/linux/drivers/media/video/pvrusb2/pvrusb2-ioread.c +++ b/linux/drivers/media/video/pvrusb2/pvrusb2-ioread.c @@ -22,6 +22,7 @@ #include "pvrusb2-debug.h" #include <linux/errno.h> #include <linux/string.h> +#include <linux/mm.h> #include <linux/slab.h> #include <linux/mutex.h> #include <asm/uaccess.h> |