Messages in this thread |  | | | Date | Mon, 2 Jan 2012 10:54:46 -0800 | | Subject | Re: Circular dependency between <linux/kernel.h> and <asm/bug.h> on ARM | | From | Simon Glass <> |
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Hi Ben, Olof,
On Sun, Jan 1, 2012 at 11:01 PM, Olof Johansson <olof@lixom.net> wrote: > On Sun, Jan 1, 2012 at 6:44 PM, Ben Hutchings <ben@decadent.org.uk> wrote: >> Commit 87e040b6456fd3416a1f6831c1eedaef5c0a94ff ("ARM: 7017/1: Use >> generic BUG() handler") makes BUG() use BUILD_BUG_ON(). However, >> BUILD_BUG_ON() is not defined in <linux/bug.h> but in <linux/kernel.h>. >> >> arch/include/asm/bug.h does not include <linux/kernel.h> and *cannot* do >> so because the latter already includes <asm/bug.h>. > > Sure it can, but it's not ideal. Since the BUILD_BUG_ON is only used > in bug.h in a #define, it will be resolved below the includes of > either so there should be no ordering issue between the two. > > I coincidentally posted a patch earlier to do just that, I didn't see > your email until later. > >> Maybe BUILD_BUG_ON() should be moved out to a header of its own, or else >> this particular use should be moved to some other file. This needs to >> be fixed somehow, as it obviously leads to build failures, e.g.: >> >> https://buildd.debian.org/status/fetch.php?pkg=linux-2.6&arch=armel&ver=3.2~rc7-1~experimental.1&stamp=1325142904 > > Or perhaps moving BUILD_BUG_ON to include/linux/bug.h? > > The quickest fix for now might be to take out the BUILD_BUG_ON(), > especially so close to 3.2-final.
Yes I like that idea as the check isn't funtional. Perhaps ultimately the BUILD_BUG_ON check for sizeof(struct bug_entry) should really go in lib/bug.c. Something like, in the header:
#define GENERIC_BUG_ENTRY_SIZE 12
and then in lib/bug.c:
#ifdef GENERIC_BUG_ENTRY_SIZE BUILD_BUG_ON(GENERIC_BUG_ENTRY_SIZE != sizeof(struct bug_entry)) #endif
The other more fragile option might be to make sure all files include <linux/kernel.h>?
Regards, Simon
> > > -Olof -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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