From d2731d77eac37510db9024caa6519caddbfd1808 Mon Sep 17 00:00:00 2001
From: Heiko Carstens <heiko.carstens@de.ibm.com>
Date: Wed, 12 Jan 2011 09:55:30 +0100
Subject: [PATCH] --- yaml --- r: 230973 b: refs/heads/master c:
 3351918282fd664e918a3175ddfae9b15656122e h: refs/heads/master i:   230971:
 a9510b6067aee6e346a8613f33f78f3b65559d63 v: v3

---
 [refs]                            |  2 +-
 trunk/arch/s390/include/asm/elf.h |  3 +++
 trunk/arch/s390/kernel/process.c  | 18 ++++++++++++++++++
 3 files changed, 22 insertions(+), 1 deletion(-)

diff --git a/[refs] b/[refs]
index 130285e7a00a..7cff00bce6fe 100644
--- a/[refs]
+++ b/[refs]
@@ -1,2 +1,2 @@
 ---
-refs/heads/master: a05c90f1948baacedd0c3e7e3250225be4cae727
+refs/heads/master: 3351918282fd664e918a3175ddfae9b15656122e
diff --git a/trunk/arch/s390/include/asm/elf.h b/trunk/arch/s390/include/asm/elf.h
index 9dbd3e7a3bc3..457fb7c16236 100644
--- a/trunk/arch/s390/include/asm/elf.h
+++ b/trunk/arch/s390/include/asm/elf.h
@@ -220,4 +220,7 @@ struct linux_binprm;
 #define ARCH_HAS_SETUP_ADDITIONAL_PAGES 1
 int arch_setup_additional_pages(struct linux_binprm *, int);
 
+extern unsigned long arch_randomize_brk(struct mm_struct *mm);
+#define arch_randomize_brk arch_randomize_brk
+
 #endif
diff --git a/trunk/arch/s390/kernel/process.c b/trunk/arch/s390/kernel/process.c
index 38ff69e562c8..26d48fe72999 100644
--- a/trunk/arch/s390/kernel/process.c
+++ b/trunk/arch/s390/kernel/process.c
@@ -341,3 +341,21 @@ unsigned long arch_align_stack(unsigned long sp)
 		sp -= get_random_int() & ~PAGE_MASK;
 	return sp & ~0xf;
 }
+
+static inline unsigned long brk_rnd(void)
+{
+	/* 8MB for 32bit, 1GB for 64bit */
+	if (is_32bit_task())
+		return (get_random_int() & 0x7ffUL) << PAGE_SHIFT;
+	else
+		return (get_random_int() & 0x3ffffUL) << PAGE_SHIFT;
+}
+
+unsigned long arch_randomize_brk(struct mm_struct *mm)
+{
+	unsigned long ret = PAGE_ALIGN(mm->brk + brk_rnd());
+
+	if (ret < mm->brk)
+		return mm->brk;
+	return ret;
+}