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authorHeiko Carstens <heiko.carstens@de.ibm.com>2011-01-12 09:55:28 +0100
committerMartin Schwidefsky <sky@mschwide.boeblingen.de.ibm.com>2011-01-12 09:55:25 +0100
commit9887a1fcddef1386d3387edf6497d08670460edb (patch)
treec586ef2f1053acbb71c837ed5b46cbfe32bf7263 /arch/s390
parentdf1ca53cba34b1d40a4ed47907d71397e4ee72c2 (diff)
downloadlinux-linaro-android-9887a1fcddef1386d3387edf6497d08670460edb.tar.gz
[S390] Randomize lower bits of stack address
Randomize the lower bits of the stack address like x86 and powerpc. Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Diffstat (limited to 'arch/s390')
-rw-r--r--arch/s390/include/asm/system.h2
-rw-r--r--arch/s390/kernel/process.c9
2 files changed, 10 insertions, 1 deletions
diff --git a/arch/s390/include/asm/system.h b/arch/s390/include/asm/system.h
index 6710b0eac16..8f8d759f6a7 100644
--- a/arch/s390/include/asm/system.h
+++ b/arch/s390/include/asm/system.h
@@ -449,7 +449,7 @@ extern void (*_machine_restart)(char *command);
extern void (*_machine_halt)(void);
extern void (*_machine_power_off)(void);
-#define arch_align_stack(x) (x)
+extern unsigned long arch_align_stack(unsigned long sp);
static inline int tprot(unsigned long addr)
{
diff --git a/arch/s390/kernel/process.c b/arch/s390/kernel/process.c
index 6ba42222b54..38ff69e562c 100644
--- a/arch/s390/kernel/process.c
+++ b/arch/s390/kernel/process.c
@@ -30,9 +30,11 @@
#include <linux/tick.h>
#include <linux/elfcore.h>
#include <linux/kernel_stat.h>
+#include <linux/personality.h>
#include <linux/syscalls.h>
#include <linux/compat.h>
#include <linux/kprobes.h>
+#include <linux/random.h>
#include <asm/compat.h>
#include <asm/uaccess.h>
#include <asm/pgtable.h>
@@ -332,3 +334,10 @@ unsigned long get_wchan(struct task_struct *p)
}
return 0;
}
+
+unsigned long arch_align_stack(unsigned long sp)
+{
+ if (!(current->personality & ADDR_NO_RANDOMIZE) && randomize_va_space)
+ sp -= get_random_int() & ~PAGE_MASK;
+ return sp & ~0xf;
+}