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

[David Laight <David.Laight@ACULAB.COM>]

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!)

	David

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