Switch to using AT_RANDOM for the stack guards.
Bug: 7959813
Change-Id: I8db4b8912ba649bfe668c6f22aa44690ddd401a2
diff --git a/libc/private/bionic_ssp.h b/libc/private/bionic_ssp.h
index 697216c..d34b6ab 100644
--- a/libc/private/bionic_ssp.h
+++ b/libc/private/bionic_ssp.h
@@ -29,48 +29,14 @@
#ifndef _PRIVATE_SSP_H
#define _PRIVATE_SSP_H
-#include <errno.h>
-#include <sys/cdefs.h>
-
__BEGIN_DECLS
-/** WARNING WARNING WARNING
- **
- ** This header file is *NOT* part of the public Bionic ABI/API
- ** and should not be used/included by user-serviceable parts of
- ** the system (e.g. applications).
- **/
-
-/* GCC uses this on ARM and MIPS. */
-extern void* __stack_chk_guard;
+/* GCC uses this on ARM and MIPS; we use it on x86 to set the guard in TLS. */
+extern uintptr_t __stack_chk_guard;
/* GCC calls this if a stack guard check fails. */
extern void __stack_chk_fail();
-__inline__ static void* __attribute__((always_inline)) __generate_stack_chk_guard(void) {
- union {
- uintptr_t value;
- char bytes[sizeof(uintptr_t)];
- } u;
-
- /* Try pulling random bytes from /dev/urandom. */
- int fd = TEMP_FAILURE_RETRY(open("/dev/urandom", O_RDONLY));
- if (fd != -1) {
- ssize_t byte_count = TEMP_FAILURE_RETRY(read(fd, &u.bytes, sizeof(u)));
- close(fd);
- if (byte_count == sizeof(u)) {
- return (void*) u.value;
- }
- }
-
- /* If that failed, switch to 'terminator canary'. */
- u.bytes[0] = 0;
- u.bytes[1] = 0;
- u.bytes[2] = '\n';
- u.bytes[3] = 255;
- return (void*) u.value;
-}
-
__END_DECLS
#endif