From 8c87df457cb58fe75b9b893007917cf8095660a0 Mon Sep 17 00:00:00 2001
From: Jan Beulich <JBeulich@novell.com>
Date: Tue, 22 Sep 2009 16:43:52 -0700
Subject: BUILD_BUG_ON(): fix it and a couple of bogus uses of it

gcc permitting variable length arrays makes the current construct used for
BUILD_BUG_ON() useless, as that doesn't produce any diagnostic if the
controlling expression isn't really constant.  Instead, this patch makes
it so that a bit field gets used here.  Consequently, those uses where the
condition isn't really constant now also need fixing.

Note that in the gfp.h, kmemcheck.h, and virtio_config.h cases
MAYBE_BUILD_BUG_ON() really just serves documentation purposes - even if
the expression is compile time constant (__builtin_constant_p() yields
true), the array is still deemed of variable length by gcc, and hence the
whole expression doesn't have the intended effect.

[akpm@linux-foundation.org: make arch/sparc/include/asm/vio.h compile]
[akpm@linux-foundation.org: more nonsensical assertions in tpm.c..]
Signed-off-by: Jan Beulich <jbeulich@novell.com>
Cc: Andi Kleen <andi@firstfloor.org>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Rajiv Andrade <srajiv@linux.vnet.ibm.com>
Cc: Mimi Zohar <zohar@us.ibm.com>
Cc: James Morris <jmorris@namei.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
---
 arch/sparc/include/asm/vio.h | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

(limited to 'arch/sparc/include')

diff --git a/arch/sparc/include/asm/vio.h b/arch/sparc/include/asm/vio.h
index d4de32f0f8af..6cdbf7e7351d 100644
--- a/arch/sparc/include/asm/vio.h
+++ b/arch/sparc/include/asm/vio.h
@@ -258,7 +258,7 @@ static inline void *vio_dring_entry(struct vio_dring_state *dr,
 static inline u32 vio_dring_avail(struct vio_dring_state *dr,
 				  unsigned int ring_size)
 {
-	BUILD_BUG_ON(!is_power_of_2(ring_size));
+	MAYBE_BUILD_BUG_ON(!is_power_of_2(ring_size));
 
 	return (dr->pending -
 		((dr->prod - dr->cons) & (ring_size - 1)));
-- 
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