Re: [PATCH] xfs: Replace strncpy with strscpy

[Marcelo Moreira]

Em dom., 20 de jul. de 2025 às 10:35, Carlos Maiolino <cem@xxxxxxxxxx> escreveu:
>
> On Fri, Jul 18, 2025 at 04:10:39PM -0300, Marcelo Moreira wrote:
> > Em sex., 18 de jul. de 2025 às 08:16, Dave Chinner
> > <david@xxxxxxxxxxxxx> escreveu:
> > >
> > > On Thu, Jul 17, 2025 at 02:34:25PM -0300, Marcelo Moreira wrote:
> > > > Given that the original `strncpy()` is safe and correctly implemented
> > > > for this context, and understanding that `memcpy()` would be the
> > > > correct replacement if a change were deemed necessary for
> > > > non-NUL-terminated raw data, I have a question:
> > > >
> > > > Do you still think a replacement is necessary here, or would you
> > > > prefer to keep the existing `strncpy()` given its correct and safe
> > > > usage in this context? If a replacement is preferred, I will resubmit
> > > > a V2 using `memcpy()` instead.
> > >
> > > IMO: if it isn't broken, don't try to fix it. Hence I -personally-
> > > wouldn't change it.
> > >
> > > However, modernisation and cleaning up of the code base to be
> > > consistent is a useful endeavour. So from this perspective replacing
> > > strncpy with memcpy() would be something I'd consider an acceptible
> > > change.
> > >
> > > Largely it is up to the maintainer to decide.....
> >
> > Hmm ok, thanks for the teaching :)
> >
> > So, I'll prepare v2 replacing `strncpy` with `memcpy` aiming for that
> > modernization and cleanup you mentioned, but it's clear that the
> > intention is to focus on changes that cause real bugs.
> > Thanks!
> >
>
> I'm ok with cleanups, code refactoring, etc, when they are
> aiming to improve something.
>
> I'm not against the strncpy -> memcpy change itself, but my biggest
> concern is that I'm almost sure you are not testing it. I really do
> wish to be wrong here though, so...
> Did you test this patch before sending?
>
> I'm not talking about build and boot. Even for a 'small' change like
> this, you should at least be running xfstests and ensure no tests are
> failing because of this change, otherwise you are essentially sending
> to the list an untested patch.
>
> Even experienced developers falls into the "I'm sure this patch is
> correct", just to get caught by some testing system - just to emphasize
> how important it's to test the patches you craft.


I actually only tested build and boot, sorry. I wasn't aware of
xfstests, thanks for letting me know. I'll research how to use
xfstests. Thanks, Carlos :)

-- 
Cheers,
Marcelo Moreira