s390/mm: limit STACK_RND_MASK for compat tasks

For compat tasks the mmap randomization does not use the maximum
randomization value from mmap_rnd_mask but the fixed value of 0x7ff.
This needs to be respected in the definition of STACK_RND_MASK as
well.

Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

diff --git a/arch/s390/include/asm/elf.h b/arch/s390/include/asm/elf.h
index c9df40b5c0ac1915eac7d6a794b25f7f9d6173b5..c9c875d9ed318cc75f7123a8d999b464201a4fd5 100644 (file)
--- a/arch/s390/include/asm/elf.h
+++ b/arch/s390/include/asm/elf.h
@@ -211,7 +211,7 @@ do {                                                                \
 
 extern unsigned long mmap_rnd_mask;
 
-#define STACK_RND_MASK (mmap_rnd_mask)
+#define STACK_RND_MASK (test_thread_flag(TIF_31BIT) ? 0x7ff : mmap_rnd_mask)
 
 #define ARCH_DLINFO                                                        \
 do {                                                                       \