From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
From: Leo Sandoval <lsandova@redhat.com>
Date: Fri, 1 Aug 2025 11:56:53 -0600
Subject: [PATCH] Add __stack_chk_fail function for non-EFI archs

This function allows to include '-fstack-protector-strong' compiler
flag for non-EFI archs. Also fixes a configure.ac condition where only
disables stack protection when stack protector is not possible.

Signed-off-by: Leo Sandoval <lsandova@redhat.com>
---
 configure.ac          | 4 +---
 grub-core/kern/main.c | 8 ++++++++
 include/grub/misc.h   | 4 ++++
 3 files changed, 13 insertions(+), 3 deletions(-)

diff --git a/configure.ac b/configure.ac
index a6a6957fbd..a803d21a3e 100644
--- a/configure.ac
+++ b/configure.ac
@@ -1466,9 +1466,7 @@ AC_ARG_ENABLE([stack-protector],
 	      [],
 	      [enable_stack_protector=no])
 if test "x$enable_stack_protector" = xno; then
-  if test "x$ssp_possible" = xyes; then
-    # Need that, because some distributions ship compilers that include
-    # `-fstack-protector' in the default specs.
+  if test "x$ssp_possible" != xyes; then
     TARGET_CFLAGS="$TARGET_CFLAGS -fno-stack-protector"
   fi
 elif test "x$platform" != xefi; then
diff --git a/grub-core/kern/main.c b/grub-core/kern/main.c
index 2e6b79ee3d..aeafbbff9c 100644
--- a/grub-core/kern/main.c
+++ b/grub-core/kern/main.c
@@ -39,6 +39,14 @@
 static bool cli_disabled = false;
 static bool cli_need_auth = false;
 
+#ifndef GRUB_MACHINE_EFI
+void __attribute__ ((noreturn))
+__stack_chk_fail (void)
+{
+  grub_abort();
+}
+#endif
+
 grub_addr_t
 grub_modules_get_end (void)
 {
diff --git a/include/grub/misc.h b/include/grub/misc.h
index 0429339ef3..751eb992ca 100644
--- a/include/grub/misc.h
+++ b/include/grub/misc.h
@@ -446,6 +446,10 @@ extern bool EXPORT_FUNC(grub_is_cli_disabled) (void);
 extern bool EXPORT_FUNC(grub_is_cli_need_auth) (void);
 extern void EXPORT_FUNC(grub_cli_set_auth_needed) (void);
 
+#ifndef GRUB_MACHINE_EFI
+extern void __attribute__ ((noreturn)) EXPORT_FUNC (__stack_chk_fail) (void);
+#endif
+
 /* Must match softdiv group in gentpl.py.  */
 #if !defined(GRUB_MACHINE_EMU) && (defined(__arm__) || defined(__ia64__) || \
     (defined(__riscv) && (__riscv_xlen == 32)))