x86: Fix mmap random address range
authorLudwig Nussel <ludwig.nussel@suse.de>
Tue, 15 Nov 2011 22:46:46 +0000 (14:46 -0800)
committerIngo Molnar <mingo@elte.hu>
Mon, 5 Dec 2011 16:07:23 +0000 (17:07 +0100)
commit9af0c7a6fa860698d080481f24a342ba74b68982
tree51d5b388fc86379193bcdbba16fa6cd44dcb16ec
parent176239153049a023d060ce95b05f7ef31667e362
x86: Fix mmap random address range

On x86_32 casting the unsigned int result of get_random_int() to
long may result in a negative value.  On x86_32 the range of
mmap_rnd() therefore was -255 to 255.  The 32bit mode on x86_64
used 0 to 255 as intended.

The bug was introduced by 675a081 ("x86: unify mmap_{32|64}.c")
in January 2008.

Signed-off-by: Ludwig Nussel <ludwig.nussel@suse.de>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: harvey.harrison@gmail.com
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Harvey Harrison <harvey.harrison@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Link: http://lkml.kernel.org/r/201111152246.pAFMklOB028527@wpaz5.hot.corp.google.com
Signed-off-by: Ingo Molnar <mingo@elte.hu>
arch/x86/mm/mmap.c