From: serge@hallyn.com (Serge E. Hallyn) To: linux-security-module@vger.kernel.org Subject: [PATCH V3 02/10] capabilities: intuitive names for cap gain status Date: Fri, 25 Aug 2017 13:47:51 -0500 [thread overview] Message-ID: <20170825184751.GA26620@mail.hallyn.com> (raw) In-Reply-To: <CALCETrUC4hjsCyOeT8R-L8KL5k5BCAfxQQC-XqMWhKMW8ZtvSQ@mail.gmail.com> Quoting Andy Lutomirski (luto at kernel.org): > On Wed, Aug 23, 2017 at 3:12 AM, Richard Guy Briggs <rgb@redhat.com> wrote: > > Introduce macros cap_gained, cap_grew, cap_full to make the use of the > > negation of is_subset() easier to read and analyse. > > > > Signed-off-by: Richard Guy Briggs <rgb@redhat.com> > > --- > > security/commoncap.c | 16 ++++++++++------ > > 1 files changed, 10 insertions(+), 6 deletions(-) > > > > diff --git a/security/commoncap.c b/security/commoncap.c > > index b7fbf77..6f05ec0 100644 > > --- a/security/commoncap.c > > +++ b/security/commoncap.c > > @@ -513,6 +513,12 @@ void handle_privileged_root(struct linux_binprm *bprm, bool has_cap, bool *effec > > *effective = true; > > } > > > > +#define cap_gained(field, target, source) \ > > + !cap_issubset(target->cap_##field, source->cap_##field) > > +#define cap_grew(target, source, cred) \ > > + !cap_issubset(cred->cap_##target, cred->cap_##source) > > +#define cap_full(field, cred) \ > > + cap_issubset(CAP_FULL_SET, cred->cap_##field) > > I read this several times and I can't figure out what "gain" means, > what "grew" means, and why it's more intuitive that they signify weird gain means the new set has bits which the old didn't. It's clearer precisely because it describes the intent rather than the mechanism. > permutations of the parameters. I also don't know what "source" and > "target" mean in this context. Source and target might be better named 'old' and 'new' or something like that, though I didn't found source and target to be confusing. > Can you clearly articulate how this is better than the status quo? Yes, it describes what we're checking for, making the code more self-documenting. -- To unsubscribe from this list: send the line "unsubscribe linux-security-module" in the body of a message to majordomo at vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
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From: "Serge E. Hallyn" <serge@hallyn.com> To: Andy Lutomirski <luto@kernel.org> Cc: Richard Guy Briggs <rgb@redhat.com>, LSM List <linux-security-module@vger.kernel.org>, linux-audit@redhat.com, "Serge E. Hallyn" <serge.hallyn@ubuntu.com>, Kees Cook <keescook@chromium.org>, James Morris <james.l.morris@oracle.com>, Eric Paris <eparis@redhat.com>, Paul Moore <pmoore@redhat.com>, Steve Grubb <sgrubb@redhat.com> Subject: Re: [PATCH V3 02/10] capabilities: intuitive names for cap gain status Date: Fri, 25 Aug 2017 13:47:51 -0500 [thread overview] Message-ID: <20170825184751.GA26620@mail.hallyn.com> (raw) In-Reply-To: <CALCETrUC4hjsCyOeT8R-L8KL5k5BCAfxQQC-XqMWhKMW8ZtvSQ@mail.gmail.com> Quoting Andy Lutomirski (luto@kernel.org): > On Wed, Aug 23, 2017 at 3:12 AM, Richard Guy Briggs <rgb@redhat.com> wrote: > > Introduce macros cap_gained, cap_grew, cap_full to make the use of the > > negation of is_subset() easier to read and analyse. > > > > Signed-off-by: Richard Guy Briggs <rgb@redhat.com> > > --- > > security/commoncap.c | 16 ++++++++++------ > > 1 files changed, 10 insertions(+), 6 deletions(-) > > > > diff --git a/security/commoncap.c b/security/commoncap.c > > index b7fbf77..6f05ec0 100644 > > --- a/security/commoncap.c > > +++ b/security/commoncap.c > > @@ -513,6 +513,12 @@ void handle_privileged_root(struct linux_binprm *bprm, bool has_cap, bool *effec > > *effective = true; > > } > > > > +#define cap_gained(field, target, source) \ > > + !cap_issubset(target->cap_##field, source->cap_##field) > > +#define cap_grew(target, source, cred) \ > > + !cap_issubset(cred->cap_##target, cred->cap_##source) > > +#define cap_full(field, cred) \ > > + cap_issubset(CAP_FULL_SET, cred->cap_##field) > > I read this several times and I can't figure out what "gain" means, > what "grew" means, and why it's more intuitive that they signify weird gain means the new set has bits which the old didn't. It's clearer precisely because it describes the intent rather than the mechanism. > permutations of the parameters. I also don't know what "source" and > "target" mean in this context. Source and target might be better named 'old' and 'new' or something like that, though I didn't found source and target to be confusing. > Can you clearly articulate how this is better than the status quo? Yes, it describes what we're checking for, making the code more self-documenting.
next prev parent reply other threads:[~2017-08-25 18:47 UTC|newest] Thread overview: 114+ messages / expand[flat|nested] mbox.gz Atom feed top 2017-08-23 10:12 [PATCH V3 00/10] capabilities: do not audit log BPRM_FCAPS on set*id Richard Guy Briggs 2017-08-23 10:12 ` Richard Guy Briggs 2017-08-23 10:12 ` [PATCH V3 01/10] capabilities: factor out cap_bprm_set_creds privileged root Richard Guy Briggs 2017-08-23 10:12 ` Richard Guy Briggs 2017-08-24 15:42 ` Serge E. Hallyn 2017-08-24 15:42 ` Serge E. Hallyn 2017-08-25 5:55 ` James Morris 2017-08-25 5:55 ` James Morris 2017-08-25 10:49 ` Richard Guy Briggs 2017-08-25 10:49 ` Richard Guy Briggs 2017-08-23 10:12 ` [PATCH V3 02/10] capabilities: intuitive names for cap gain status Richard Guy Briggs 2017-08-23 10:12 ` Richard Guy Briggs 2017-08-24 16:03 ` Serge E. Hallyn 2017-08-24 16:03 ` Serge E. Hallyn 2017-08-24 16:19 ` Richard Guy Briggs 2017-08-24 16:19 ` Richard Guy Briggs 2017-08-24 16:37 ` Serge E. Hallyn 2017-08-24 16:37 ` Serge E. Hallyn 2017-08-24 19:06 ` Kees Cook 2017-08-24 19:06 ` Kees Cook 2017-08-24 21:17 ` Paul Moore 2017-08-24 21:17 ` Paul Moore 2017-08-28 9:19 ` Richard Guy Briggs 2017-08-28 9:19 ` Richard Guy Briggs 2017-08-28 11:08 ` Richard Guy Briggs 2017-08-28 11:08 ` Richard Guy Briggs 2017-09-01 10:18 ` Richard Guy Briggs 2017-09-01 10:18 ` Richard Guy Briggs 2017-09-02 5:37 ` Serge E. Hallyn 2017-09-02 5:37 ` Serge E. Hallyn 2017-09-04 6:57 ` Richard Guy Briggs 2017-09-04 6:57 ` Richard Guy Briggs 2017-09-05 6:45 ` Richard Guy Briggs 2017-09-05 6:45 ` Richard Guy Briggs 2017-08-25 5:56 ` James Morris 2017-08-25 5:56 ` James Morris 2017-08-25 15:08 ` Andy Lutomirski 2017-08-25 15:08 ` Andy Lutomirski 2017-08-25 18:47 ` Serge E. Hallyn [this message] 2017-08-25 18:47 ` Serge E. Hallyn 2017-08-23 10:12 ` [PATCH V3 03/10] capabilities: rename has_cap to has_fcap Richard Guy Briggs 2017-08-23 10:12 ` Richard Guy Briggs 2017-08-24 16:10 ` Serge E. Hallyn 2017-08-24 16:10 ` Serge E. Hallyn 2017-08-25 5:56 ` James Morris 2017-08-25 5:56 ` James Morris 2017-08-23 10:12 ` [PATCH V3 04/10] capabilities: use root_priveleged inline to clarify logic Richard Guy Briggs 2017-08-23 10:12 ` Richard Guy Briggs 2017-08-24 16:14 ` Serge E. Hallyn 2017-08-24 16:14 ` Serge E. Hallyn 2017-08-25 5:58 ` James Morris 2017-08-25 5:58 ` James Morris 2017-08-28 12:03 ` Richard Guy Briggs 2017-08-28 12:03 ` Richard Guy Briggs 2017-08-31 14:49 ` Serge E. Hallyn 2017-08-31 14:49 ` Serge E. Hallyn 2017-08-23 10:12 ` [PATCH V3 05/10] capabilities: use intuitive names for id changes Richard Guy Briggs 2017-08-23 10:12 ` Richard Guy Briggs 2017-08-24 16:17 ` Serge E. Hallyn 2017-08-24 16:17 ` Serge E. Hallyn 2017-08-25 5:59 ` James Morris 2017-08-25 5:59 ` James Morris 2017-08-25 15:06 ` Andy Lutomirski 2017-08-25 15:06 ` Andy Lutomirski 2017-08-25 18:51 ` Serge E. Hallyn 2017-08-25 18:51 ` Serge E. Hallyn 2017-08-25 19:45 ` Andy Lutomirski 2017-08-25 19:45 ` Andy Lutomirski 2017-08-25 20:06 ` Serge E. Hallyn 2017-08-25 20:06 ` Serge E. Hallyn 2017-08-28 1:32 ` James Morris 2017-08-28 1:32 ` James Morris 2017-08-28 9:12 ` Richard Guy Briggs 2017-08-28 9:12 ` Richard Guy Briggs 2017-08-28 20:12 ` Andy Lutomirski 2017-08-28 20:12 ` Andy Lutomirski 2017-08-23 10:12 ` [PATCH V3 06/10] capabilities: move audit log decision to function Richard Guy Briggs 2017-08-23 10:12 ` Richard Guy Briggs 2017-08-24 16:18 ` Serge E. Hallyn 2017-08-24 16:18 ` Serge E. Hallyn 2017-08-25 6:01 ` James Morris 2017-08-25 6:01 ` James Morris 2017-08-23 10:12 ` [PATCH V3 07/10] capabilities: remove a layer of conditional logic Richard Guy Briggs 2017-08-23 10:12 ` Richard Guy Briggs 2017-08-24 16:20 ` Serge E. Hallyn 2017-08-24 16:20 ` Serge E. Hallyn 2017-08-25 5:47 ` James Morris 2017-08-25 5:47 ` James Morris 2017-08-25 15:11 ` Andy Lutomirski 2017-08-25 15:11 ` Andy Lutomirski 2017-08-25 18:53 ` Serge E. Hallyn 2017-08-25 18:53 ` Serge E. Hallyn 2017-08-23 10:12 ` [PATCH V3 08/10] capabilities: invert logic for clarity Richard Guy Briggs 2017-08-23 10:12 ` Richard Guy Briggs 2017-08-24 16:23 ` Serge E. Hallyn 2017-08-24 16:23 ` Serge E. Hallyn 2017-08-25 5:47 ` James Morris 2017-08-25 5:47 ` James Morris 2017-08-23 10:13 ` [PATCH V3 09/10] capabilities: fix logic for effective root or real root Richard Guy Briggs 2017-08-23 10:13 ` Richard Guy Briggs 2017-08-24 16:29 ` Serge E. Hallyn 2017-08-24 16:29 ` Serge E. Hallyn 2017-08-24 16:44 ` Richard Guy Briggs 2017-08-24 16:44 ` Richard Guy Briggs 2017-08-24 16:47 ` Serge E. Hallyn 2017-08-24 16:47 ` Serge E. Hallyn 2017-08-25 5:48 ` James Morris 2017-08-25 5:48 ` James Morris 2017-08-23 10:13 ` [PATCH V3 10/10] capabilities: audit log other surprising conditions Richard Guy Briggs 2017-08-23 10:13 ` Richard Guy Briggs 2017-08-24 16:35 ` Serge E. Hallyn 2017-08-24 16:35 ` Serge E. Hallyn 2017-08-25 5:50 ` James Morris 2017-08-25 5:50 ` James Morris
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