powerpc: Randomise the brk region
Randomize the heap.
before:
tundro2:~ # sleep 1 & cat /proc/${!}/maps | grep heap
10017000-10118000 rw-p 10017000 00:00 0 [heap]
10017000-10118000 rw-p 10017000 00:00 0 [heap]
10017000-10118000 rw-p 10017000 00:00 0 [heap]
10017000-10118000 rw-p 10017000 00:00 0 [heap]
10017000-10118000 rw-p 10017000 00:00 0 [heap]
after
tundro2:~ # sleep 1 & cat /proc/${!}/maps | grep heap
19419000-1951a000 rw-p 19419000 00:00 0 [heap]
325ff000-32700000 rw-p 325ff000 00:00 0 [heap]
1a97c000-1aa7d000 rw-p 1a97c000 00:00 0 [heap]
1cc60000-1cd61000 rw-p 1cc60000 00:00 0 [heap]
1afa9000-1b0aa000 rw-p 1afa9000 00:00 0 [heap]
Signed-off-by: Anton Blanchard <anton@samba.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
diff --git a/arch/powerpc/include/asm/elf.h b/arch/powerpc/include/asm/elf.h
index 3f94d8880..968b37f 100644
--- a/arch/powerpc/include/asm/elf.h
+++ b/arch/powerpc/include/asm/elf.h
@@ -276,6 +276,9 @@
(0x7ff >> (PAGE_SHIFT - 12)) : \
(0x3ffff >> (PAGE_SHIFT - 12)))
+extern unsigned long arch_randomize_brk(struct mm_struct *mm);
+#define arch_randomize_brk arch_randomize_brk
+
#endif /* __KERNEL__ */
/*