Re: [PATCH] tools: Change asprintf return code check

[Bartosz Golaszewski <brgl@xxxxxxxx>]

On Tue, Sep 13, 2022 at 10:30 PM Catalin Petrescu
<catalin.petrescu@xxxxxxxxx> wrote:
>
> On Tue, 2022-09-13 at 16:47 +0200, Bartosz Golaszewski wrote:
> > On Thu, Sep 8, 2022 at 4:03 PM Catalin Petrescu
> > <catalin.petrescu@xxxxxxxxx> wrote:
> > >
> > > Hi there,
> > >
> > > I found a small error (IMHO) in libgpiod.
> > > The issue is that asprintf may return -1 if it fails to allocate
> > > memory, and if that happens, chip_open_by_number will pass a NULL
> > > pointer to gpiod_chip_open.
> > >
> > > I hope this helps.
> > >
> > > Thanks,
> > >
> > > Catalin.
> >
> > Hey Catalin,
> >
> > Please next time send the patch inline using git's send-email
> > command.
> >
> > You're right about the error code check but it should actually be ret
> > < 0 as per asprintf's documentation.
> >
> > Bart
>
> Hi Bart,
>
> I'll use git send-email next time. I was not aware of its existence.
> And I still need to figure out how to pass the gmail SMTP
> authentication.
>
> You're right, when asprintf returns zero, technically, that's not an
> error.
> My thought was that if asprintf ever returns zero, that means that the
> path is a zero-length string.
> So, the next call to gpiod_chip_open(path) will likely fail. But I
> guess, the right thing to do is to let gpiod_chip_open() deal with it.
>
> Thanks,
>
> Catalin.
>
>

Yes and also next thing we do is use strerror() which will return
"Success" for 0.

Bart