Re: [PATCH 2/6] selinux: dump statistics for more hash tables

[Paul Moore]

On Wed, Sep 13, 2023 at 2:03 PM Stephen Smalley
<stephen.smalley.work@xxxxxxxxx> wrote:
> On Wed, Sep 13, 2023 at 12:12 PM Paul Moore <paul@xxxxxxxxxxxxxx> wrote:
> > On Thu, Sep 7, 2023 at 1:42 PM Stephen Smalley
> > <stephen.smalley.work@xxxxxxxxx> wrote:
> > > On Fri, Aug 18, 2023 at 11:12 AM Christian Göttsche
> > > <cgzones@xxxxxxxxxxxxxx> wrote:
> > > >
> > > > Dump in the SELinux debug configuration the statistics for the
> > > > conditional rules avtab, the role transition, and class and common
> > > > permission hash tables.
> > > >
> > > > Signed-off-by: Christian Göttsche <cgzones@xxxxxxxxxxxxxx>
> > > > ---
> > >
> > > > diff --git a/security/selinux/ss/policydb.c b/security/selinux/ss/policydb.c
> > > > index 84f02d4f8093..932e383bcad6 100644
> > > > --- a/security/selinux/ss/policydb.c
> > > > +++ b/security/selinux/ss/policydb.c
> > > > @@ -1158,6 +1158,8 @@ static int common_read(struct policydb *p, struct symtab *s, void *fp)
> > > >                         goto bad;
> > > >         }
> > > >
> > > > +       hash_eval(&comdatum->permissions.table, "common_permissions");
> > > > +
> > > >         rc = symtab_insert(s, key, comdatum);
> > > >         if (rc)
> > > >                 goto bad;
> > > > @@ -1339,6 +1341,8 @@ static int class_read(struct policydb *p, struct symtab *s, void *fp)
> > > >                         goto bad;
> > > >         }
> > > >
> > > > +       hash_eval(&cladatum->permissions.table, "class_permissions");
> > > > +
> > > >         rc = read_cons_helper(p, &cladatum->constraints, ncons, 0, fp);
> > > >         if (rc)
> > > >                 goto bad;
> > >
> > > Do we want to embed the actual common and class keys in the output to
> > > distinguish among the multiple common and class permissions tables?
> >
> > That seems reasonable, were you thinking of just adding it to the
> > hash_eval()'s hash name string, e.g. "common_permissions[XXX]"?
>
> Yes, otherwise you get a bunch of common_permissions and
> class_permissions lines with no way to correlate.

Agreed, I was asking more to determine how you envisioned the keys in
the output.

Christian, instead of creating the combined string in the caller I
would suggest adding a third parameter to the hash_eval() function and
having hash_eval() add the extra info (if present, NULL should be
acceptable) to the output.  This should ensure no extra work is done
when debug is disabled.

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