8 files changed, 44 insertions, 6 deletions
diff --git a/arch/arc/include/asm/bug.h b/arch/arc/include/asm/bug.h
index ea022d47896c..21ec82466d62 100644
--- a/arch/arc/include/asm/bug.h
+++ b/arch/arc/include/asm/bug.h
@@ -23,7 +23,8 @@ void die(const char *str, struct pt_regs *regs, unsigned long address);
 
 #define BUG()	do {								\
 	pr_warn("BUG: failure at %s:%d/%s()!\n", __FILE__, __LINE__, __func__); \
-	dump_stack();								\
+	barrier_before_unreachable();						\
+	__builtin_trap();							\
 } while (0)
 
 #define HAVE_ARCH_BUG
diff --git a/arch/cris/include/arch-v10/arch/bug.h b/arch/cris/include/arch-v10/arch/bug.h
index 905afeacfedf..06da9d49152a 100644
--- a/arch/cris/include/arch-v10/arch/bug.h
+++ b/arch/cris/include/arch-v10/arch/bug.h
@@ -44,18 +44,25 @@ struct bug_frame {
  * not be used like this with newer versions of gcc.
  */
 #define BUG()								\
+do {									\
 	__asm__ __volatile__ ("clear.d [" __stringify(BUG_MAGIC) "]\n\t"\
 			      "movu.w " __stringify(__LINE__) ",$r0\n\t"\
 			      "jump 0f\n\t"				\
 			      ".section .rodata\n"			\
 			      "0:\t.string \"" __FILE__ "\"\n\t"	\
-			      ".previous")
+			      ".previous");				\
+	unreachable();							\
+} while (0)
 #endif
 
 #else
 
 /* This just causes an oops. */
-#define BUG() (*(int *)0 = 0)
+#define BUG()								\
+do {									\
+	barrier_before_unreachable();					\
+	__builtin_trap();						\
+} while (0)
 
 #endif
 
diff --git a/arch/ia64/include/asm/bug.h b/arch/ia64/include/asm/bug.h
index bd3eeb8d1cfa..66b37a532765 100644
--- a/arch/ia64/include/asm/bug.h
+++ b/arch/ia64/include/asm/bug.h
@@ -4,7 +4,11 @@
 
 #ifdef CONFIG_BUG
 #define ia64_abort()	__builtin_trap()
-#define BUG() do { printk("kernel BUG at %s:%d!\n", __FILE__, __LINE__); ia64_abort(); } while (0)
+#define BUG() do {						\
+	printk("kernel BUG at %s:%d!\n", __FILE__, __LINE__);	\
+	barrier_before_unreachable();				\
+	ia64_abort();						\
+} while (0)
 
 /* should this BUG be made generic? */
 #define HAVE_ARCH_BUG
diff --git a/arch/m68k/include/asm/bug.h b/arch/m68k/include/asm/bug.h
index b7e2bf1ba4a6..275dca1435bf 100644
--- a/arch/m68k/include/asm/bug.h
+++ b/arch/m68k/include/asm/bug.h
@@ -8,16 +8,19 @@
 #ifndef CONFIG_SUN3
 #define BUG() do { \
 	pr_crit("kernel BUG at %s:%d!\n", __FILE__, __LINE__); \
+	barrier_before_unreachable(); \
 	__builtin_trap(); \
 } while (0)
 #else
 #define BUG() do { \
 	pr_crit("kernel BUG at %s:%d!\n", __FILE__, __LINE__); \
+	barrier_before_unreachable(); \
 	panic("BUG!"); \
 } while (0)
 #endif
 #else
 #define BUG() do { \
+	barrier_before_unreachable(); \
 	__builtin_trap(); \
 } while (0)
 #endif
diff --git a/arch/sparc/include/asm/bug.h b/arch/sparc/include/asm/bug.h
index 6f17528356b2..ea53e418f6c0 100644
--- a/arch/sparc/include/asm/bug.h
+++ b/arch/sparc/include/asm/bug.h
@@ -9,10 +9,14 @@
 void do_BUG(const char *file, int line);
 #define BUG() do {					\
 	do_BUG(__FILE__, __LINE__);			\
+	barrier_before_unreachable();			\
 	__builtin_trap();				\
 } while (0)
 #else
-#define BUG()		__builtin_trap()
+#define BUG() do {					\
+	barrier_before_unreachable();			\
+	__builtin_trap();				\
+} while (0)
 #endif
 
 #define HAVE_ARCH_BUG
diff --git a/include/asm-generic/bug.h b/include/asm-generic/bug.h
index 963b755d19b0..a7613e1b0c87 100644
--- a/include/asm-generic/bug.h
+++ b/include/asm-generic/bug.h
@@ -52,6 +52,7 @@ struct bug_entry {
 #ifndef HAVE_ARCH_BUG
 #define BUG() do { \
 	printk("BUG: failure at %s:%d/%s()!\n", __FILE__, __LINE__, __func__); \
+	barrier_before_unreachable(); \
 	panic("BUG!"); \
 } while (0)
 #endif
diff --git a/include/linux/compiler-gcc.h b/include/linux/compiler-gcc.h
index 73bc63e0a1c4..901c1ccb3374 100644
--- a/include/linux/compiler-gcc.h
+++ b/include/linux/compiler-gcc.h
@@ -208,6 +208,15 @@
 #endif
 
 /*
+ * calling noreturn functions, __builtin_unreachable() and __builtin_trap()
+ * confuse the stack allocation in gcc, leading to overly large stack
+ * frames, see https://gcc.gnu.org/bugzilla/show_bug.cgi?id=82365
+ *
+ * Adding an empty inline assembly before it works around the problem
+ */
+#define barrier_before_unreachable() asm volatile("")
+
+/*
  * Mark a position in code as unreachable.  This can be used to
  * suppress control flow warnings after asm blocks that transfer
  * control elsewhere.
@@ -217,7 +226,11 @@
  * unreleased.  Really, we need to have autoconf for the kernel.
  */
 #define unreachable() \
-	do { annotate_unreachable(); __builtin_unreachable(); } while (0)
+	do {					\
+		annotate_unreachable();		\
+		barrier_before_unreachable();	\
+		__builtin_unreachable();	\
+	} while (0)
 
 /* Mark a function definition as prohibited from being cloned. */
 #define __noclone	__attribute__((__noclone__, __optimize__("no-tracer")))
diff --git a/include/linux/compiler.h b/include/linux/compiler.h
index e835fc0423ec..ab4711c63601 100644
--- a/include/linux/compiler.h
+++ b/include/linux/compiler.h
@@ -86,6 +86,11 @@ void ftrace_likely_update(struct ftrace_likely_data *f, int val,
 # define barrier_data(ptr) barrier()
 #endif
 
+/* workaround for GCC PR82365 if needed */
+#ifndef barrier_before_unreachable
+# define barrier_before_unreachable() do { } while (0)
+#endif
+
 /* Unreachable code */
 #ifdef CONFIG_STACK_VALIDATION
 /*