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From:   =?UTF-8?Q?Christian_G=C3=B6ttsche?= <cgzones@googlemail.com>
Date:   Tue, 8 Mar 2022 16:57:52 +0100
Message-ID: <CAJ2a_DfpYp_n8F7rg5yRAK9S8r0GcTQFHfB=d6cwRSHwMUjCyA@mail.gmail.com>
Subject: Re: [PATCH 3/5] selinux: use consistent pointer types for boolean arrays
To:     Paul Moore <paul@paul-moore.com>
Cc:     SElinux list <selinux@vger.kernel.org>,
        Stephen Smalley <stephen.smalley.work@gmail.com>,
        Eric Paris <eparis@parisplace.org>,
        Nathan Chancellor <nathan@kernel.org>,
        Nick Desaulniers <ndesaulniers@google.com>,
        Ondrej Mosnacek <omosnace@redhat.com>,
        James Morris <jamorris@linux.microsoft.com>,
        Austin Kim <austin.kim@lge.com>,
        Casey Schaufler <casey@schaufler-ca.com>,
        Jiapeng Chong <jiapeng.chong@linux.alibaba.com>,
        Yang Li <yang.lee@linux.alibaba.com>,
        Linux kernel mailing list <linux-kernel@vger.kernel.org>,
        llvm@lists.linux.dev
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On Fri, 18 Feb 2022 at 17:01, Paul Moore <paul@paul-moore.com> wrote:
>
> On Thu, Feb 17, 2022 at 9:21 AM Christian G=C3=B6ttsche
> <cgzones@googlemail.com> wrote:
> >
> > Use a consistent type of unsigned int* for boolean arrays, instead of
> > using implicit casts to and from int*.
> >
> > Reported by sparse:
> >
> >     security/selinux/selinuxfs.c:1481:30: warning: incorrect type in as=
signment (different signedness)
> >     security/selinux/selinuxfs.c:1481:30:    expected unsigned int *
> >     security/selinux/selinuxfs.c:1481:30:    got int *[addressable] val=
ues
> >     security/selinux/selinuxfs.c:1398:48: warning: incorrect type in ar=
gument 3 (different signedness)
> >     security/selinux/selinuxfs.c:1398:48:    expected int *values
> >     security/selinux/selinuxfs.c:1398:48:    got unsigned int *bool_pen=
ding_values
> >
> > Signed-off-by: Christian G=C3=B6ttsche <cgzones@googlemail.com>
> >
> > ---
> > A more invasive change would be to change all boolean arrays to bool*.
>
> I think that might be a worthwhile change, although that can happen at
> a later date.
>
> A quick general comment: please try to stick to 80-char long lines.  I
> realize Linus/checkpatch.pl has started to allow longer lines but I
> would still like SELinux to try and keep to 80-chars or under.
>
> > diff --git a/security/selinux/ss/services.c b/security/selinux/ss/servi=
ces.c
> > index 6901dc07680d..7865926962ab 100644
> > --- a/security/selinux/ss/services.c
> > +++ b/security/selinux/ss/services.c
> > @@ -3175,7 +3175,8 @@ int security_get_bool_value(struct selinux_state =
*state,
> >  static int security_preserve_bools(struct selinux_policy *oldpolicy,
> >                                 struct selinux_policy *newpolicy)
> >  {
> > -       int rc, *bvalues =3D NULL;
> > +       int rc;
> > +       unsigned int *bvalues =3D NULL;
>
> Doesn't this cause a type mismatch (unsigned int vs int) when an entry
> from bvalues[] is assigned to cond_bool_datum::state later in the
> security_preserve_bools() function?

Yes, but those variables *should* only hold the values 0 or 1.
But probably it's better to re-spin for 5.19 with all arrays and
cond_bool_datum::state converted to literal bool type.

>
> --
> paul-moore.com