s390/mm: limit STACK_RND_MASK for compat tasks

Martin Schwidefsky · Martin Schwidefsky · commit e143fa93c286 · 2015-03-13T12:15:45.000+01:00
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 &lt;schwidefsky@de.ibm.com&gt;
diff --git 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 {									    \
