[RFC PATCH 09/29] lsm: cleanup and normalize the LSM enabled functions

[Paul Moore]

On Thu, Apr 10, 2025 at 9:50 PM Paul Moore <paul at paul-moore.com> wrote:
> On Wed, Apr 9, 2025 at 8:11 PM Kees Cook <kees at kernel.org> wrote:
> > On Wed, Apr 09, 2025 at 02:49:54PM -0400, Paul Moore wrote:

...

> > > -/* Append an LSM to the list of ordered LSMs to initialize. */
> > > -static int last_lsm __initdata;
> > > -static void __init append_ordered_lsm(struct lsm_info *lsm, const char *from)
> > > +/**
> > > + * lsm_order_append - Append a LSM to the ordered list
> > > + * @lsm: LSM definition
> > > + * @src: source of the addition
> > > + */
> > > +static void __init lsm_order_append(struct lsm_info *lsm, const char *src)
> > >  {
> > >       /* Ignore duplicate selections. */
> > > -     if (exists_ordered_lsm(lsm))
> > > +     if (lsm_order_exists(lsm))
> > >               return;
> > >
> > > -     if (WARN(last_lsm == MAX_LSM_COUNT, "%s: out of LSM static calls!?\n", from))
> > > -             return;
> > > +     /* Skip explicitly disabled LSMs. */
> > > +     if (lsm->enabled && !lsm_is_enabled(lsm)) {
> > > +             if (WARN(lsm_count == MAX_LSM_COUNT,
> > > +                      "%s: out of LSM static calls!?\n", src))
> > > +                     return;
> > > +             lsm_enabled_set(lsm, true);
> > > +             lsm_order[lsm_count] = lsm;
> > > +             lsm_idlist[lsm_count++] = lsm->id;
> > > +     }
> > >
> > > -     /* Enable this LSM, if it is not already set. */
> > > -     if (!lsm->enabled)
> > > -             lsm->enabled = &lsm_enabled_true;
> > > -     lsm_order[last_lsm] = lsm;
> > > -     lsm_idlist[last_lsm++] = lsm->id;
> >
> > I don't understand the logic change here. I may be missing something (it
> > feels like a lot of logic changes mixed together again), but this logic:
> >
> >      /* Enable this LSM, if it is not already set. */
> >      if (!lsm->enabled)
> >              lsm->enabled = &lsm_enabled_true;
> >
> > seems like it has gone missing now?
>
> It's a little confusing as lsm_order_append() gets heavily reworked a
> couple of patches later in "lsm: cleanup the LSM ordered parsing",
> which is essentially this function's end state from a logic
> perspective.  I think the best thing to do might be to squash those
> two patches ... lemme see how ugly that ends up ...

Yeah, it looks *way* better now with those two patches squashed.

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