From: Linus Torvalds Date: Mon, 27 Nov 2006 03:05:22 +0000 (-0800) Subject: Fix 'ALIGN()' macro, take 2 X-Git-Tag: v2.6.19~16 X-Git-Url: http://pilppa.com/gitweb/?a=commitdiff_plain;h=2ea5814472c3c910aed5c5b60f1f3b1000e353f1;p=linux-2.6-omap-h63xx.git 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 Cc: Andrew Morton Cc: David Miller Cc: Al Viro Signed-off-by: Linus Torvalds --- diff --git a/include/linux/kernel.h b/include/linux/kernel.h index 24b611147ad..b9b5e4ba166 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))