Based on commit 1091458d09e1a (mmap randomization)
For 32-bit address spaces randomize within a
16MB space, for 64-bit within a 256MB space.
Signed-off-by: Prem Karat <pkarat@xxxxxxxxxx>
---
arch/mips/kernel/vdso.c | 15 ++++++++++++++-
1 file changed, 14 insertions(+), 1 deletion(-)
diff --git a/arch/mips/kernel/vdso.c b/arch/mips/kernel/vdso.c
index 0f1af58..b49c705 100644
--- a/arch/mips/kernel/vdso.c
+++ b/arch/mips/kernel/vdso.c
@@ -16,9 +16,11 @@
#include <linux/elf.h>
#include <linux/vmalloc.h>
#include <linux/unistd.h>
+#include <linux/random.h>
#include <asm/vdso.h>
#include <asm/uasm.h>
+#include <asm/processor.h>
/*
* Including <asm/unistd.h> would give use the 64-bit syscall numbers ...
@@ -67,7 +69,18 @@ subsys_initcall(init_vdso);
static unsigned long vdso_addr(unsigned long start)
{
- return STACK_TOP;
+ unsigned long offset = 0UL;
+
+ if (current->flags & PF_RANDOMIZE) {
+ offset = get_random_int();
+ offset = offset << PAGE_SHIFT;
+ if (TASK_IS_32BIT_ADDR)
+ offset &= 0xfffffful;
+ else
+ offset &= 0xffffffful;
+ }
+
+ return (STACK_TOP + offset);
}
int arch_setup_additional_pages(struct linux_binprm *bprm, int uses_interp)
--
1.7.9.5
