glibc/sysdeps/x86_64/stackguard-macros.h

#include <stdint.h>

#define STACK_CHK_GUARD \
  ({ uintptr_t x;						\
     asm ("mov %%fs:%c1, %0" : "=r" (x)				\
	  : "i" (offsetof (tcbhead_t, stack_guard))); x; })

#define POINTER_CHK_GUARD \
  ({ uintptr_t x;						\
     asm ("mov %%fs:%c1, %0" : "=r" (x)				\
	  : "i" (offsetof (tcbhead_t, pointer_guard))); x; })
Split up stackguard-macros.h into sysdeps directories. 2012-05-15 23:34:30 +00:00			`#include <stdint.h>`

			`#define STACK_CHK_GUARD \`
			`({ uintptr_t x; \`
			`asm ("mov %%fs:%c1, %0" : "=r" (x) \`
			`: "i" (offsetof (tcbhead_t, stack_guard))); x; })`
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
			`#define POINTER_CHK_GUARD \`
			`({ uintptr_t x; \`
			`asm ("mov %%fs:%c1, %0" : "=r" (x) \`
			`: "i" (offsetof (tcbhead_t, pointer_guard))); x; })`