[PATCH] arm64: define BUG() instruction without CONFIG_BUG

[arnd@arndb.de (Arnd Bergmann)]

This mirrors commit e9c38ceba8d9 ("ARM: 8455/1: define __BUG as
asm(BUG_INSTR) without CONFIG_BUG") to make the behavior of
arm64 consistent with arm and x86, and avoids lots of warnings in
randconfig builds, such as:

kernel/seccomp.c: In function '__seccomp_filter':
kernel/seccomp.c:666:1: error: no return statement in function returning non-void [-Werror=return-type]

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
---
 arch/arm64/include/asm/bug.h | 11 ++++++++++-
 1 file changed, 10 insertions(+), 1 deletion(-)

diff --git a/arch/arm64/include/asm/bug.h b/arch/arm64/include/asm/bug.h
index 561190d15881..461751429fc3 100644
--- a/arch/arm64/include/asm/bug.h
+++ b/arch/arm64/include/asm/bug.h
@@ -20,9 +20,10 @@
 
 #include <asm/brk-imm.h>
 
-#ifdef CONFIG_GENERIC_BUG
 #define HAVE_ARCH_BUG
 
+#ifdef CONFIG_GENERIC_BUG
+
 #ifdef CONFIG_DEBUG_BUGVERBOSE
 #define _BUGVERBOSE_LOCATION(file, line) __BUGVERBOSE_LOCATION(file, line)
 #define __BUGVERBOSE_LOCATION(file, line)				\
@@ -57,6 +58,14 @@ _BUGVERBOSE_LOCATION(__FILE__, __LINE__)		\
 
 #define __WARN_TAINT(taint) _BUG_FLAGS(BUGFLAG_TAINT(taint))
 
+#else
+
+#define BUG() do {					\
+	asm volatile("brk %[imm]"			\
+		     :: [imm] "i" (BUG_BRK_IMM));	\
+	unreachable();					\
+} while (0)
+
 #endif /* ! CONFIG_GENERIC_BUG */
 
 #include <asm-generic/bug.h>
-- 
2.9.0