powerpc: Randomise PIEs

Randomise ELF_ET_DYN_BASE, which is used when loading position independent
executables.

Signed-off-by: Anton Blanchard <anton@samba.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>

1 files changed, 10 insertions, 0 deletions

diff --git a/arch/powerpc/kernel/process.c b/arch/powerpc/kernel/process.c
index 30b149ce759..eac06494878 100644
--- a/arch/powerpc/kernel/process.c
+++ b/arch/powerpc/kernel/process.c
@@ -1170,3 +1170,13 @@ unsigned long arch_randomize_brk(struct mm_struct *mm)
 
 	return ret;
 }
+
+unsigned long randomize_et_dyn(unsigned long base)
+{
+	unsigned long ret = PAGE_ALIGN(base + brk_rnd());
+
+	if (ret < base)
+		return base;
+
+	return ret;
+}