commit 9046e401e752dba784805a7818f99cc45a39cbff
author Heiko Carstens <heiko.carstens@de.ibm.com> Wed Jan 12 09:55:22 2011 +0100
committer Martin Schwidefsky <sky@mschwide.boeblingen.de.ibm.com> Wed Jan 12 09:55:24 2011 +0100
tree 0f05676ac01a7892b7fddf4e9f3a7e335c1f78d1
parent 7a63fa1a85d75756368d9c86fff5c1b193de991c

[S390] mmap: consider stack address randomization

Consider stack address randomization when calulating mmap_base for
flexible mmap layout . Because of address randomization the stack
address can be up to 8MB lower than STACK_TOP.
When calculating mmap_base this isn't taken into account, which could
lead to the case that the gap between the real stack top and mmap_base
is lower than what ulimit specifies for the maximum stack size.

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

arch/s390/include/asm/elf.h

diff --git a/arch/s390/include/asm/elf.h b/arch/s390/include/asm/elf.h
index 354d426..9dbd3e7 100644
--- a/arch/s390/include/asm/elf.h
+++ b/arch/s390/include/asm/elf.h
@@ -206,6 +206,8 @@
 	current->mm->context.noexec == 0;		\
 })
 
+#define STACK_RND_MASK	0x7ffUL
+
 #define ARCH_DLINFO							    \
 do {									    \
 	if (vdso_enabled)						    \