[PATCH] include/linux/kernel.h: Make might_fault to be a nop for !MMU

[Axel Lin <axel.lin@ingics.com>]

No fault if !MUU, thus make might_fault to be a nop for !MMU.

This fixes below build error if
!CONFIG_MMU && (CONFIG_PROVE_LOCKING=y || CONFIG_DEBUG_ATOMIC_SLEEP=y):

arch/arm/kernel/built-in.o: In function `arch_ptrace':
arch/arm/kernel/ptrace.c:852: undefined reference to `might_fault'
arch/arm/kernel/built-in.o: In function `restore_sigframe':
arch/arm/kernel/signal.c:173: undefined reference to `might_fault'
arch/arm/kernel/signal.c:174: undefined reference to `might_fault'
arch/arm/kernel/signal.c:175: undefined reference to `might_fault'
arch/arm/kernel/signal.c:176: undefined reference to `might_fault'
arch/arm/kernel/built-in.o:arch/arm/kernel/signal.c:177: more undefined references to `might_fault' follow
make: *** [vmlinux] Error 1

Signed-off-by: Axel Lin <axel.lin@ingics.com>
Cc: Michael S. Tsirkin <mst@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
---
 include/linux/kernel.h | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/include/linux/kernel.h b/include/linux/kernel.h
index 2ac0277..8b0ad48 100644
--- a/include/linux/kernel.h
+++ b/include/linux/kernel.h
@@ -193,7 +193,8 @@ extern int _cond_resched(void);
 		(__x < 0) ? -__x : __x;		\
 	})
 
-#if defined(CONFIG_PROVE_LOCKING) || defined(CONFIG_DEBUG_ATOMIC_SLEEP)
+#if defined(CONFIG_MMU) && \
+	(defined(CONFIG_PROVE_LOCKING) || defined(CONFIG_DEBUG_ATOMIC_SLEEP))
 void might_fault(void);
 #else
 static inline void might_fault(void) { }
-- 
1.8.1.2