svn commit: r212886 - head/sbin/growfs

[Bruce Evans]

On Tue, 21 Sep 2010, Brian Somers wrote:

> On Mon, 20 Sep 2010 16:55:57 +1000 (EST) Bruce Evans <brde at 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
>> ...
>
> 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?

Just because of WARNS.

The `caddr_t iobuf;' in newfs is really old and should be fixed someday.  It
is the only caddr_t remaining in newfs.  In Lite2, newfs also uses caddr_t
for its now-dead mfs parts, including for its replacements for the malloc()
family which were errors in theory even at the time of Lite2 and which are
now errors in practice.

Bruce