Make sure compiler won't do weird things with limits. Fetching them
twice may return 2 different values after writable limits are
implemented.
We can either use rlimit helpers added in
3e10e716ab or ACCESS_ONCE if not
applicable; this patch uses the helpers.
Signed-off-by: Jiri Slaby <jslaby@suse.cz>
LKML-Reference: <1264609942-24621-1-git-send-email-jslaby@suse.cz>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
Currently we are not including randomized stack size when calculating
mmap_base address in arch_pick_mmap_layout for topdown case. This might
cause that mmap_base starts in the stack reserved area because stack is
randomized by 1GB for 64b (8MB for 32b) and the minimum gap is 128MB.
If the stack really grows down to mmap_base then we can get silent mmap
region overwrite by the stack values.
Let's include maximum stack randomization size into MIN_GAP which is
used as the low bound for the gap in mmap.
Signed-off-by: Michal Hocko <mhocko@suse.cz>
LKML-Reference: <1252400515-6866-1-git-send-email-mhocko@suse.cz>
Acked-by: Jiri Kosina <jkosina@suse.cz>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
Cc: Stable Team <stable@kernel.org>
mmap_is_ia32 always true for X86_32, or while emulating IA32 on X86_64
Randomization not supported on X86_32 in legacy layout. Both layouts allow
randomization on X86_64.
Signed-off-by: Harvey Harrison <harvey.harrison@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
