From 941091024ef0f2f7e09eb81201d293ac18833cc8 Mon Sep 17 00:00:00 2001
From: Franck Bui-Huu <fbuihuu@gmail.com>
Date: Thu, 19 Jul 2007 14:04:21 +0200
Subject: [MIPS] User stack pointer randomisation

Signed-off-by: Franck Bui-Huu <fbuihuu@gmail.com>
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
---
 arch/mips/kernel/process.c | 14 ++++++++++++++
 1 file changed, 14 insertions(+)

(limited to 'arch/mips/kernel')

diff --git a/arch/mips/kernel/process.c b/arch/mips/kernel/process.c
index 8f4cf27c715..bd05f5a927e 100644
--- a/arch/mips/kernel/process.c
+++ b/arch/mips/kernel/process.c
@@ -25,7 +25,9 @@
 #include <linux/init.h>
 #include <linux/completion.h>
 #include <linux/kallsyms.h>
+#include <linux/random.h>
 
+#include <asm/asm.h>
 #include <asm/bootinfo.h>
 #include <asm/cpu.h>
 #include <asm/dsp.h>
@@ -460,3 +462,15 @@ unsigned long get_wchan(struct task_struct *task)
 out:
 	return pc;
 }
+
+/*
+ * Don't forget that the stack pointer must be aligned on a 8 bytes
+ * boundary for 32-bits ABI and 16 bytes for 64-bits ABI.
+ */
+unsigned long arch_align_stack(unsigned long sp)
+{
+	if (!(current->personality & ADDR_NO_RANDOMIZE) && randomize_va_space)
+		sp -= get_random_int() & ~PAGE_MASK;
+
+	return sp & ALMASK;
+}
-- 
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