Merge branch 'for-linus' of git://git390.marist.edu/pub/scm/linux-2.6

* 'for-linus' of git://git390.marist.edu/pub/scm/linux-2.6:
  [S390] MAINTAINERS: Update zcrypt driver entry
  [S390] Randomize PIEs
  [S390] Randomise the brk region
  [S390] Add is_32bit_task() helper function
  [S390] Randomize lower bits of stack address
  [S390] Randomize mmap start address
  [S390] Rearrange mmap.c
  [S390] Enable flexible mmap layout for 64 bit processes
  [S390] vdso: dont map at mmap_base
  [S390] reduce miminum gap between stack and mmap_base
  [S390] mmap: consider stack address randomization
  [S390] Update default configuration
  [S390] cio: path_event overindication after resume

1 files changed, 38 insertions, 0 deletions

diff --git a/arch/s390/kernel/process.c b/arch/s390/kernel/process.c
index 6ba42222b542..a895e69379f7 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 +334,39 @@ 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;
+}
+
+static inline unsigned long brk_rnd(void)
+{
+	/* 8MB for 32bit, 1GB for 64bit */
+	if (is_32bit_task())
+		return (get_random_int() & 0x7ffUL) << PAGE_SHIFT;
+	else
+		return (get_random_int() & 0x3ffffUL) << PAGE_SHIFT;
+}
+
+unsigned long arch_randomize_brk(struct mm_struct *mm)
+{
+	unsigned long ret = PAGE_ALIGN(mm->brk + brk_rnd());
+
+	if (ret < mm->brk)
+		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;
+}