diff options
Diffstat (limited to 'arch/s390/mm')
-rw-r--r-- | arch/s390/mm/mmap.c | 41 |
1 files changed, 19 insertions, 22 deletions
diff --git a/arch/s390/mm/mmap.c b/arch/s390/mm/mmap.c index 179a2c2..bb3367c 100644 --- a/arch/s390/mm/mmap.c +++ b/arch/s390/mm/mmap.c @@ -60,22 +60,20 @@ static inline int mmap_is_legacy(void) return sysctl_legacy_va_layout; } -static unsigned long mmap_rnd(void) +unsigned long arch_mmap_rnd(void) { - if (!(current->flags & PF_RANDOMIZE)) - return 0; if (is_32bit_task()) return (get_random_int() & 0x7ff) << PAGE_SHIFT; else return (get_random_int() & mmap_rnd_mask) << PAGE_SHIFT; } -static unsigned long mmap_base_legacy(void) +static unsigned long mmap_base_legacy(unsigned long rnd) { - return TASK_UNMAPPED_BASE + mmap_rnd(); + return TASK_UNMAPPED_BASE + rnd; } -static inline unsigned long mmap_base(void) +static inline unsigned long mmap_base(unsigned long rnd) { unsigned long gap = rlimit(RLIMIT_STACK); @@ -84,7 +82,7 @@ static inline unsigned long mmap_base(void) else if (gap > MAX_GAP) gap = MAX_GAP; gap &= PAGE_MASK; - return STACK_TOP - stack_maxrandom_size() - mmap_rnd() - gap; + return STACK_TOP - stack_maxrandom_size() - rnd - gap; } unsigned long @@ -179,17 +177,6 @@ arch_get_unmapped_area_topdown(struct file *filp, const unsigned long addr0, return addr; } -unsigned long randomize_et_dyn(void) -{ - unsigned long base; - - base = STACK_TOP / 3 * 2; - if (!is_32bit_task()) - /* Align to 4GB */ - base &= ~((1UL << 32) - 1); - return base + mmap_rnd(); -} - #ifndef CONFIG_64BIT /* @@ -198,15 +185,20 @@ unsigned long randomize_et_dyn(void) */ void arch_pick_mmap_layout(struct mm_struct *mm) { + unsigned long random_factor = 0UL; + + if (current->flags & PF_RANDOMIZE) + random_factor = arch_mmap_rnd(); + /* * Fall back to the standard layout if the personality * bit is set, or if the expected stack growth is unlimited: */ if (mmap_is_legacy()) { - mm->mmap_base = mmap_base_legacy(); + mm->mmap_base = mmap_base_legacy(random_factor); mm->get_unmapped_area = arch_get_unmapped_area; } else { - mm->mmap_base = mmap_base(); + mm->mmap_base = mmap_base(random_factor); mm->get_unmapped_area = arch_get_unmapped_area_topdown; } } @@ -273,15 +265,20 @@ s390_get_unmapped_area_topdown(struct file *filp, const unsigned long addr, */ void arch_pick_mmap_layout(struct mm_struct *mm) { + unsigned long random_factor = 0UL; + + if (current->flags & PF_RANDOMIZE) + random_factor = arch_mmap_rnd(); + /* * Fall back to the standard layout if the personality * bit is set, or if the expected stack growth is unlimited: */ if (mmap_is_legacy()) { - mm->mmap_base = mmap_base_legacy(); + mm->mmap_base = mmap_base_legacy(random_factor); mm->get_unmapped_area = s390_get_unmapped_area; } else { - mm->mmap_base = mmap_base(); + mm->mmap_base = mmap_base(random_factor); mm->get_unmapped_area = s390_get_unmapped_area_topdown; } } |