glibc/sysdeps/i386/stackguard-macros.h
Carlos O'Donell c61b4d41c9 BZ #15754: CVE-2013-4788
The pointer guard used for pointer mangling was not initialized for
static applications resulting in the security feature being disabled.
The pointer guard is now correctly initialized to a random value for
static applications. Existing static applications need to be
recompiled to take advantage of the fix.

The test tst-ptrguard1-static and tst-ptrguard1 add regression
coverage to ensure the pointer guards are sufficiently random
and initialized to a default value.
2013-09-23 00:52:09 -04:00

13 lines
293 B
C

#include <stdint.h>
#define STACK_CHK_GUARD \
({ uintptr_t x; asm ("movl %%gs:0x14, %0" : "=r" (x)); x; })
#define POINTER_CHK_GUARD \
({ \
uintptr_t x; \
asm ("movl %%gs:%c1, %0" : "=r" (x) \
: "i" (offsetof (tcbhead_t, pointer_guard))); \
x; \
})