[PATCH] kernel.h: Include <linux/bug.h> to avoid build breakage with ARRAY_SIZE()

[Fabio Estevam]

Building imx_v6_v7_defconfig generated the following build error:

arch/arm/mach-imx/cpu_op-mx51.c: In function 'mx51_get_cpu_op':
arch/arm/mach-imx/cpu_op-mx51.c:27: error: implicit declaration of function 'BUILD_BUG_ON_ZERO'

commit 6f863554 (kernel.h: doesn't explicitly use bug.h, so don't include it.)
has removed asm/debug.h from linux/kernel.h.

Quoting Russell King (http://www.spinics.net/lists/arm-kernel/msg161916.html)

"linux/kernel.h _does_ use bug stuff - in ARRAY_SIZE().

ARRAY_SIZE() uses __must_be_array(), which is defined in linux/compiler-gcc.h,
which is obtained via linux/compiler.h and linux/linkage.h.

linux/compiler-gcc.h defines __must_be_array() to be:
#define __must_be_array(a) BUILD_BUG_ON_ZERO(__same_type((a), &(a)[0]))

and BUILD_BUG_ON_ZERO used to be in linux/kernel.h but got moved to
linux/bug.h.

Hence why people are seeing build breakage with ARRAY_SIZE()."

Signed-off-by: Fabio Estevam <fabio.estevam@xxxxxxxxxxxxx>
---
 include/linux/kernel.h |    1 +
 1 files changed, 1 insertions(+), 0 deletions(-)

diff --git a/include/linux/kernel.h b/include/linux/kernel.h
index ed9f92e..9c0a86b 100644
--- a/include/linux/kernel.h
+++ b/include/linux/kernel.h
@@ -21,6 +21,7 @@
 #include <linux/typecheck.h>
 #include <linux/printk.h>
 #include <linux/dynamic_debug.h>
+#include <linux/bug.h>
 #include <asm/byteorder.h>
 
 #define USHRT_MAX	((u16)(~0U))
-- 
1.7.1


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