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authorLinus Torvalds <torvalds@woody.osdl.org>2006-11-26 19:05:22 -0800
committerLinus Torvalds <torvalds@woody.osdl.org>2006-11-26 19:05:22 -0800
commit2ea5814472c3c910aed5c5b60f1f3b1000e353f1 (patch)
treee8c8bf721cc917c8842c4a007ad4b3f68eb7aa1e
parentc9c3b86f2ab79f7f6e87eb735f9cc4508b73fc48 (diff)
Fix 'ALIGN()' macro, take 2
You wouldn't think that doing an ALIGN() macro that aligns something up to a power-of-two boundary would be likely to have bugs, would you? But hey, in the wonderful world of mixing integer types, you have to be careful. This just makes sure that the alignment is interpreted in the same type as the thing to be aligned. Thanks to Roland Dreier, who noticed that the amso1100 driver got broken by the previous fix (that just extended the mask to "unsigned long", but was still broken in "unsigned long long" - it just happened to be the same on 64-bit architectures). See commit 4c8bd7eeee4c8f157fb61fb64b57500990b42e0e for the history of bugs here... Acked-by: Roland Dreier <rdreier@cisco.com> Cc: Andrew Morton <akpm@osdl.org> Cc: David Miller <davem@davemloft.net> Cc: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
-rw-r--r--include/linux/kernel.h4
1 files changed, 3 insertions, 1 deletions
diff --git a/include/linux/kernel.h b/include/linux/kernel.h
index 24b611147adb..b9b5e4ba166a 100644
--- a/include/linux/kernel.h
+++ b/include/linux/kernel.h
@@ -30,8 +30,10 @@ extern const char linux_banner[];
#define STACK_MAGIC 0xdeadbeef
+#define ALIGN(x,a) __ALIGN_MASK(x,(typeof(x))(a)-1)
+#define __ALIGN_MASK(x,mask) (((x)+(mask))&~(mask))
+
#define ARRAY_SIZE(x) (sizeof(x) / sizeof((x)[0]))
-#define ALIGN(x,a) (((x)+(a)-1UL)&~((a)-1UL))
#define FIELD_SIZEOF(t, f) (sizeof(((t*)0)->f))
#define DIV_ROUND_UP(n,d) (((n) + (d) - 1) / (d))
#define roundup(x, y) ((((x) + ((y) - 1)) / (y)) * (y))