linux/arch/xtensa/kernel
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
..
align.S
asm-offsets.c xtensa: use kbuild.h macros instead of defining them in asm-offsets.c 2008-04-29 08:06:29 -07:00
coprocessor.S [XTENSA] Add support for configurable registers and coprocessors 2008-02-13 17:41:43 -08:00
entry.S [XTENSA] Fix register corruption for certain processor configurations 2008-02-13 17:43:54 -08:00
head.S
init_task.c [PATCH] take init_files to fs/file.c 2008-05-16 17:22:20 -04:00
io.c
irq.c
Makefile Generic semaphore implementation 2008-04-17 10:42:34 -04:00
module.c [XTENSA] Fix modules for non-exec processor configurations 2008-02-13 17:23:26 -08:00
pci-dma.c
pci.c
platform.c
process.c [XTENSA] Add support for configurable registers and coprocessors 2008-02-13 17:41:43 -08:00
ptrace.c [XTENSA] Allow debugger to modify the WINDOWBASE register. 2008-02-13 17:45:36 -08:00
setup.c PAGE_ALIGN(): correctly handle 64-bit values on 32-bit architectures 2008-07-24 10:47:21 -07:00
signal.c [XTENSA] Add support for the sa_restorer function 2008-02-13 17:42:31 -08:00
syscall.c
time.c
traps.c [XTENSA] Add support for configurable registers and coprocessors 2008-02-13 17:41:43 -08:00
vectors.S
vmlinux.lds.S [XTENSA] Add missing RELOCATE_ENTRY for debug vector 2008-02-13 17:25:14 -08:00
xtensa_ksyms.c Generic semaphore implementation 2008-04-17 10:42:34 -04:00