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-rw-r--r--arch/x86/include/asm/elf.h2
-rw-r--r--arch/x86/mm/mmap.c17
2 files changed, 17 insertions, 2 deletions
diff --git a/arch/x86/include/asm/elf.h b/arch/x86/include/asm/elf.h
index 83c1bc8d2e8a..456a304b8172 100644
--- a/arch/x86/include/asm/elf.h
+++ b/arch/x86/include/asm/elf.h
@@ -299,6 +299,8 @@ do { \
#ifdef CONFIG_X86_32
+#define STACK_RND_MASK (0x7ff)
+
#define VDSO_HIGH_BASE (__fix_to_virt(FIX_VDSO))
#define ARCH_DLINFO ARCH_DLINFO_IA32(vdso_enabled)
diff --git a/arch/x86/mm/mmap.c b/arch/x86/mm/mmap.c
index 165829600566..c8191defc38a 100644
--- a/arch/x86/mm/mmap.c
+++ b/arch/x86/mm/mmap.c
@@ -29,13 +29,26 @@
#include <linux/random.h>
#include <linux/limits.h>
#include <linux/sched.h>
+#include <asm/elf.h>
+
+static unsigned int stack_maxrandom_size(void)
+{
+ unsigned int max = 0;
+ if ((current->flags & PF_RANDOMIZE) &&
+ !(current->personality & ADDR_NO_RANDOMIZE)) {
+ max = ((-1U) & STACK_RND_MASK) << PAGE_SHIFT;
+ }
+
+ return max;
+}
+
/*
* Top of mmap area (just below the process stack).
*
- * Leave an at least ~128 MB hole.
+ * Leave an at least ~128 MB hole with possible stack randomization.
*/
-#define MIN_GAP (128*1024*1024)
+#define MIN_GAP (128*1024*1024UL + stack_maxrandom_size())
#define MAX_GAP (TASK_SIZE/6*5)
/*