From 3e906035cc7295812516c3d5de516786cd839e68 Mon Sep 17 00:00:00 2001
From: Anton Blanchard <anton@samba.org>
Date: Sun, 22 Feb 2009 01:50:01 +0000
Subject: [PATCH] --- yaml --- r: 138491 b: refs/heads/master c:
 9f14c42d7582bf33bbe1e133d897a6942ceae08e h: refs/heads/master i:   138489:
 3f7ff8daeb07c08ab5f8deded05e5c650ce8210d   138487:
 4d127648ea01e2ef2e6070661b89fb8389d27f17 v: v3

---
 [refs]                       |  2 +-
 trunk/arch/powerpc/mm/mmap.c | 17 ++++++++++++++++-
 2 files changed, 17 insertions(+), 2 deletions(-)

diff --git a/[refs] b/[refs]
index 719c4fcb3872..76d6009129c2 100644
--- a/[refs]
+++ b/[refs]
@@ -1,2 +1,2 @@
 ---
-refs/heads/master: 13a2cb3694d7237e6cc3e94fcb311b81908ccd06
+refs/heads/master: 9f14c42d7582bf33bbe1e133d897a6942ceae08e
diff --git a/trunk/arch/powerpc/mm/mmap.c b/trunk/arch/powerpc/mm/mmap.c
index 8ff5757af0d7..f7376dbb653b 100644
--- a/trunk/arch/powerpc/mm/mmap.c
+++ b/trunk/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());
 }
 
 /*