svn commit: r334814 - head/sbin/dump

[John Baldwin]

On 6/8/18 10:27 AM, Justin Hibbits wrote:
> On Fri, Jun 8, 2018 at 10:08 AM, Ed Maste <emaste at freebsd.org> wrote:
>> On 7 June 2018 at 16:49, Kirk McKusick <mckusick at freebsd.org> wrote:
>>> Author: mckusick
>>> Date: Thu Jun  7 20:49:01 2018
>>> New Revision: 334814
>>> URL: https://svnweb.freebsd.org/changeset/base/334814
>>>
>>> Log:
>>>   Ensure proper initialization of superblock.
>>>
>> ...
>>> --- head/sbin/dump/main.c       Thu Jun  7 19:57:55 2018        (r334813)
>>> +++ head/sbin/dump/main.c       Thu Jun  7 20:49:01 2018        (r334814)
>>> @@ -433,6 +433,7 @@ main(int argc, char *argv[])
>>>                 msgtail("to %s\n", tape);
>>>
>>>         sync();
>>> +       sblock = NULL;
>>>         if ((ret = sbget(diskfd, &sblock, -1)) != 0) {
>>
>> sblock is initialized to NULL at the beginning of ffs_sbget, so I'm
>> not really sure what's happening here.
>>
> 
> Diane just found possibly the real cause of the problem.  dump.h is
> included by almost every .c file, but defines variables, doesn't just
> declare them.  I think the real solution would be to  define them in
> main.c, or somewhere else, and just declare them in dump.h.  Or if
> they're truly only needed on a per-file basis, not as globals, they
> could be marked static so there is no chance of conflict, and they're
> pre-initialized to 0.  The linker "might" merge them into the common
> section, or might not, resulting in bizarre conflicts like what she's
> seeing.  Though, I'm surprised we're not seeing a linker error or
> warning anyway.

Is this in fact fallout from lld vs ld.bfd then?

-- 
John Baldwin