#include <string.h>
-#include <inttypes.h>
-#include <elf.h>
+#include <stdint.h>
#include "pthread_impl.h"
-#include "atomic.h"
uintptr_t __stack_chk_guard;
void __init_ssp(void *entropy)
{
- pthread_t self = __pthread_self_init();
- uintptr_t canary;
- if (entropy) memcpy(&canary, entropy, sizeof canary);
- else canary = (uintptr_t)&canary * 1103515245;
- a_cas_l(&__stack_chk_guard, 0, canary);
- self->canary = __stack_chk_guard;
+ if (entropy) memcpy(&__stack_chk_guard, entropy, sizeof(uintptr_t));
+ else __stack_chk_guard = (uintptr_t)&__stack_chk_guard * 1103515245;
+
+#if UINTPTR_MAX >= 0xffffffffffffffff
+ /* Sacrifice 8 bits of entropy on 64bit to prevent leaking/
+ * overwriting the canary via string-manipulation functions.
+ * The NULL byte is on the second byte so that off-by-ones can
+ * still be detected. Endianness is taken care of
+ * automatically. */
+ ((char *)&__stack_chk_guard)[1] = 0;
+#endif
+
+ __pthread_self()->canary = __stack_chk_guard;
}
void __stack_chk_fail(void)
{
a_crash();
}
+
+hidden void __stack_chk_fail_local(void);
+
+weak_alias(__stack_chk_fail, __stack_chk_fail_local);