diff options
| -rw-r--r-- | arch/powerpc/mm/mmap.c | 17 |
1 files changed, 16 insertions, 1 deletions
diff --git a/arch/powerpc/mm/mmap.c b/arch/powerpc/mm/mmap.c index 8ff5757af0d..f7376dbb653 100644 --- a/arch/powerpc/mm/mmap.c +++ b/arch/powerpc/mm/mmap.c @@ -24,6 +24,7 @@ #include <linux/personality.h> #include <linux/mm.h> +#include <linux/random.h> #include <linux/sched.h> /* @@ -45,6 +46,20 @@ static inline int mmap_is_legacy(void) return sysctl_legacy_va_layout; } +static unsigned long mmap_rnd(void) +{ + unsigned long rnd = 0; + + if (current->flags & PF_RANDOMIZE) { + /* 8MB for 32bit, 1GB for 64bit */ + if (is_32bit_task()) + rnd = (long)(get_random_int() % (1<<(23-PAGE_SHIFT))); + else + rnd = (long)(get_random_int() % (1<<(30-PAGE_SHIFT))); + } + return rnd << PAGE_SHIFT; +} + static inline unsigned long mmap_base(void) { unsigned long gap = current->signal->rlim[RLIMIT_STACK].rlim_cur; @@ -54,7 +69,7 @@ static inline unsigned long mmap_base(void) else if (gap > MAX_GAP) gap = MAX_GAP; - return TASK_SIZE - (gap & PAGE_MASK); + return PAGE_ALIGN(TASK_SIZE - gap - mmap_rnd()); } /* |