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-rw-r--r--arch/powerpc/mm/mmap.c17
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());
}
/*