Date: Tue, 21 Sep 2010 03:09:16 -0700 From: Brian Somers <brian@Awfulhak.org> To: Bruce Evans <brde@optusnet.com.au> Cc: svn-src-head@FreeBSD.org, svn-src-all@FreeBSD.org, Marcel Moolenaar <marcel@FreeBSD.org>, src-committers@FreeBSD.org Subject: Re: svn commit: r212886 - head/sbin/growfs Message-ID: <20100921030916.3ee375c6@dev.lan.Awfulhak.org> In-Reply-To: <20100920163758.A788@besplex.bde.org> References: <201009200420.o8K4KtKn026514@svn.freebsd.org> <20100920163758.A788@besplex.bde.org>
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On Mon, 20 Sep 2010 16:55:57 +1000 (EST) Bruce Evans <brde@optusnet.com.au> wrote:
> On Mon, 20 Sep 2010, Marcel Moolenaar wrote:
>
> > Log:
> > Unbreak the build on strong-aligned architectures (arm, ia64).
> > Casting from (char *) to (struct ufs1_dinode *) changes the
> > alignment requirement of the pointer and GCC does not know that
> > the pointer is adequately aligned (due to malloc(3)), and warns
> > about it. Cast to (void *) first to by-pass the check.
>
> A previous version in which the pointer (iobuf) the correct type to
> begin with was better. It used to have type void *, but now has type
> caddr_t (whose existence is a bug), in order to abuse caddr_t by
> assuming that it is char * to do pointer arithmetic on it in 1 place
> (iobuf + sblock.fs_cgsize). The 7 other places where iobuf is used
> only assume that caddr_t is a pointer (or perhaps a [u]intptr_t).
>
> growfs has no other instances of caddr_t.
Maybe iobuf ought to go back to being a void * with casting where the
arithmetic happens. If it's changed, newfs/mkfs.c should probably change
too.
Is there some subtle difference that makes the casting ok in newfs/mkfs.c:
dp1 = (struct ufs1_dinode *)(&iobuf[start]);
and not ok in growfs/growfs.c r212885:
dp1 = (struct ufs1_dinode *)iobuf;
or is it just ignored because WARNS is 3 for newfs and is defaulted to 6 for growfs?
--
Brian Somers <brian@Awfulhak.org>
Don't _EVER_ lose your sense of humour ! <brian@FreeBSD.org>
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