From 32a932332c8bad842804842eaf9651ad6268e637 Mon Sep 17 00:00:00 2001 From: Ingo Molnar Date: Wed, 6 Feb 2008 22:39:44 +0100 Subject: brk randomization: introduce CONFIG_COMPAT_BRK based on similar patch from: Pavel Machek Introduce CONFIG_COMPAT_BRK. If disabled then the kernel is free (but not obliged to) randomize the brk area. Heap randomization breaks ancient binaries, so we keep COMPAT_BRK enabled by default. Signed-off-by: Ingo Molnar --- mm/memory.c | 13 ++++++++++++- 1 file changed, 12 insertions(+), 1 deletion(-) (limited to 'mm') diff --git a/mm/memory.c b/mm/memory.c index 7bb7072..9d073fa 100644 --- a/mm/memory.c +++ b/mm/memory.c @@ -82,7 +82,18 @@ void * high_memory; EXPORT_SYMBOL(num_physpages); EXPORT_SYMBOL(high_memory); -int randomize_va_space __read_mostly = 1; +/* + * Randomize the address space (stacks, mmaps, brk, etc.). + * + * ( When CONFIG_COMPAT_BRK=y we exclude brk from randomization, + * as ancient (libc5 based) binaries can segfault. ) + */ +int randomize_va_space __read_mostly = +#ifdef CONFIG_COMPAT_BRK + 1; +#else + 2; +#endif static int __init disable_randmaps(char *s) { -- cgit v1.1