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Andrea Righi 27ac792ca0 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>
2008-07-24 10:47:21 -07:00
..
alpha bootmem: replace node_boot_start in struct bootmem_data 2008-07-24 10:47:20 -07:00
arm PAGE_ALIGN(): correctly handle 64-bit values on 32-bit architectures 2008-07-24 10:47:21 -07:00
avr32 PAGE_ALIGN(): correctly handle 64-bit values on 32-bit architectures 2008-07-24 10:47:21 -07:00
blackfin remove mention of CONFIG_KMOD from documentation 2008-07-22 19:24:29 +10:00
cris mm: drop unneeded pgdat argument from free_area_init_node() 2008-07-24 10:47:16 -07:00
frv PCI: remove unused arch pcibios_update_resource() functions 2008-06-27 13:14:01 -07:00
h8300 PAGE_ALIGN(): correctly handle 64-bit values on 32-bit architectures 2008-07-24 10:47:21 -07:00
ia64 bootmem: replace node_boot_start in struct bootmem_data 2008-07-24 10:47:20 -07:00
m32r bootmem: replace node_boot_start in struct bootmem_data 2008-07-24 10:47:20 -07:00
m68k PAGE_ALIGN(): correctly handle 64-bit values on 32-bit architectures 2008-07-24 10:47:21 -07:00
m68knommu PAGE_ALIGN(): correctly handle 64-bit values on 32-bit architectures 2008-07-24 10:47:21 -07:00
mips PAGE_ALIGN(): correctly handle 64-bit values on 32-bit architectures 2008-07-24 10:47:21 -07:00
mn10300 bootmem: replace node_boot_start in struct bootmem_data 2008-07-24 10:47:20 -07:00
parisc mm: drop unneeded pgdat argument from free_area_init_node() 2008-07-24 10:47:16 -07:00
powerpc PAGE_ALIGN(): correctly handle 64-bit values on 32-bit architectures 2008-07-24 10:47:21 -07:00
s390 hugetlb: introduce pud_huge 2008-07-24 10:47:18 -07:00
sh bootmem: replace node_boot_start in struct bootmem_data 2008-07-24 10:47:20 -07:00
sparc mm: drop unneeded pgdat argument from free_area_init_node() 2008-07-24 10:47:16 -07:00
sparc64 PAGE_ALIGN(): correctly handle 64-bit values on 32-bit architectures 2008-07-24 10:47:21 -07:00
um UML - Fix boot crash 2008-07-23 09:36:56 -07:00
v850 mm: drop unneeded pgdat argument from free_area_init_node() 2008-07-24 10:47:16 -07:00
x86 PAGE_ALIGN(): correctly handle 64-bit values on 32-bit architectures 2008-07-24 10:47:21 -07:00
xtensa PAGE_ALIGN(): correctly handle 64-bit values on 32-bit architectures 2008-07-24 10:47:21 -07:00
.gitignore
Kconfig access_process_vm device memory infrastructure 2008-07-24 10:47:15 -07:00