diff options
| -rw-r--r-- | arch/powerpc/mm/mmap_64.c | 14 | ||||
| -rw-r--r-- | arch/sparc/kernel/sys_sparc_64.c | 6 |
2 files changed, 6 insertions, 14 deletions
diff --git a/arch/powerpc/mm/mmap_64.c b/arch/powerpc/mm/mmap_64.c index 5a783d8e8e8e..67a42ed0d2fc 100644 --- a/arch/powerpc/mm/mmap_64.c +++ b/arch/powerpc/mm/mmap_64.c @@ -53,14 +53,6 @@ static inline int mmap_is_legacy(void) return sysctl_legacy_va_layout; } -/* - * Since get_random_int() returns the same value within a 1 jiffy window, - * we will almost always get the same randomisation for the stack and mmap - * region. This will mean the relative distance between stack and mmap will - * be the same. - * - * To avoid this we can shift the randomness by 1 bit. - */ static unsigned long mmap_rnd(void) { unsigned long rnd = 0; @@ -68,11 +60,11 @@ static unsigned long mmap_rnd(void) if (current->flags & PF_RANDOMIZE) { /* 8MB for 32bit, 1GB for 64bit */ if (is_32bit_task()) - rnd = (long)(get_random_int() % (1<<(22-PAGE_SHIFT))); + rnd = (long)(get_random_int() % (1<<(23-PAGE_SHIFT))); else - rnd = (long)(get_random_int() % (1<<(29-PAGE_SHIFT))); + rnd = (long)(get_random_int() % (1<<(30-PAGE_SHIFT))); } - return (rnd << PAGE_SHIFT) * 2; + return rnd << PAGE_SHIFT; } static inline unsigned long mmap_base(void) diff --git a/arch/sparc/kernel/sys_sparc_64.c b/arch/sparc/kernel/sys_sparc_64.c index 441521ad8a3f..232df9949530 100644 --- a/arch/sparc/kernel/sys_sparc_64.c +++ b/arch/sparc/kernel/sys_sparc_64.c @@ -368,11 +368,11 @@ static unsigned long mmap_rnd(void) if (current->flags & PF_RANDOMIZE) { unsigned long val = get_random_int(); if (test_thread_flag(TIF_32BIT)) - rnd = (val % (1UL << (22UL-PAGE_SHIFT))); + rnd = (val % (1UL << (23UL-PAGE_SHIFT))); else - rnd = (val % (1UL << (29UL-PAGE_SHIFT))); + rnd = (val % (1UL << (30UL-PAGE_SHIFT))); } - return (rnd << PAGE_SHIFT) * 2; + return rnd << PAGE_SHIFT; } void arch_pick_mmap_layout(struct mm_struct *mm) |