Re: [PATCH] kconfig: fix missing fclose() on error paths

[Masahiro Yamada <masahiroy@kernel.org>]

On Fri, Feb 11, 2022 at 8:47 PM David Laight <David.Laight@aculab.com> wrote:
>
> From: Masahiro Yamada
> > Sent: 10 February 2022 00:54
> > >
> > > The file is not closed when ferror() fails.
> > >
> > > Fixes: 00d674cb3536 ("kconfig: refactor conf_write_dep()")
> > > Fixes: 57ddd07c4560 ("kconfig: refactor conf_write_autoconf()")
> > > Reported-by: Ryan Cai <ycaibb@gmail.com>
> > > Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
> > > ---
> >
> >
> > Applied to linux-kbuild/fixes.
> >
> >
> > >
> > >  scripts/kconfig/confdata.c | 12 ++++++------
> > >  1 file changed, 6 insertions(+), 6 deletions(-)
> > >
> > > diff --git a/scripts/kconfig/confdata.c b/scripts/kconfig/confdata.c
> > > index 59717be31210..16897cb8cefd 100644
> > > --- a/scripts/kconfig/confdata.c
> > > +++ b/scripts/kconfig/confdata.c
> > > @@ -979,10 +979,10 @@ static int conf_write_autoconf_cmd(const char *autoconf_name)
> > >
> > >         fprintf(out, "\n$(deps_config): ;\n");
> > >
> > > -       if (ferror(out)) /* error check for all fprintf() calls */
> > > -               return -1;
> > > -
> > > +       ret = ferror(out); /* error check for all fprintf() calls */
> > >         fclose(out);
> > > +       if (ret)
> > > +               return -1;
>
> There's not much point calling ferror() unless you call fflush() first.
>
> Similarly there's about zero point in checking the return from fprintf().
> At least I've never found any distro adding 'must_check' to fprintf().
> ('must_not_check' would be more appropriate!)


Thanks for pointing it out. You are right.

I assume you are not opposed to this patch itself.

I will insert fflush() before ferror()
as a separate patch.





>         David
>
> -
> Registered Address Lakeside, Bramley Road, Mount Farm, Milton Keynes, MK1 1PT, UK
> Registration No: 1397386 (Wales)



-- 
Best Regards
Masahiro Yamada