[S390] Randomize PIEs

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

Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

1 files changed, 11 insertions, 0 deletions

diff --git a/arch/s390/kernel/process.c b/arch/s390/kernel/process.c
index 26d48fe72999..a895e69379f7 100644
--- a/arch/s390/kernel/process.c
+++ b/arch/s390/kernel/process.c
@@ -359,3 +359,14 @@ unsigned long arch_randomize_brk(struct mm_struct *mm)
 		return mm->brk;
 	return ret;
 }
+
+unsigned long randomize_et_dyn(unsigned long base)
+{
+	unsigned long ret = PAGE_ALIGN(base + brk_rnd());
+
+	if (!(current->flags & PF_RANDOMIZE))
+		return base;
+	if (ret < base)
+		return base;
+	return ret;
+}