Hello.
On 19-04-2014 13:33, Prem Karat wrote:
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>
[...]
@@ -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;
Why not:
offset <<= PAGE_SHIFT;
+ if (TASK_IS_32BIT_ADDR)
+ offset &= 0xfffffful;
+ else
+ offset &= 0xffffffful;
+ }
+
+ return (STACK_TOP + offset);
Parens not needed.
WBR, Sergei
