[PATCH] windows: Add _stack_chk_guard/_stack_chk_fail symbols for Windows 64-bit target

[Daniel Kiper]

Otherwise the GRUB cannot start when stack protector is enabled on EFI 
platforms.

Signed-off-by: Daniel Kiper <daniel.kiper@oracle.com>
---
 include/grub/stack_protector.h | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/include/grub/stack_protector.h b/include/grub/stack_protector.h
index c88dc00b5..13d2657d9 100644
--- a/include/grub/stack_protector.h
+++ b/include/grub/stack_protector.h
@@ -25,6 +25,10 @@
 #ifdef GRUB_STACK_PROTECTOR
 extern grub_addr_t EXPORT_VAR (__stack_chk_guard);
 extern void __attribute__ ((noreturn)) EXPORT_FUNC (__stack_chk_fail) (void);
+#if defined(_WIN64) && !defined(__CYGWIN__) /* MinGW, Windows 64-bit target. */
+static grub_addr_t __attribute__ ((weakref("__stack_chk_guard"))) EXPORT_VAR 
(_stack_chk_guard);
+static void __attribute__ ((noreturn, weakref("__stack_chk_fail"))) 
EXPORT_FUNC (_stack_chk_fail) (void);
+#endif
 #endif
 
 #endif /* GRUB_STACK_PROTECTOR_H */
-- 
2.11.0