Re: [PATCH 2/2] vfs: Add KUnit tests for fdtable

[Jann Horn]

On Tue, Aug 11, 2026 at 2:16 AM Kees Cook <kees@xxxxxxxxxx> wrote:
> On Mon, Aug 10, 2026 at 08:41:13PM +0000, Bill Wendling wrote:
> > +static void fdtable_test_alloc(struct kunit *test)
> > +{
> > +     struct fdtable *fdt;
> > +     unsigned int slots = 64;
> > +
> > +     fdt = alloc_fdtable(slots);
> > +     KUNIT_ASSERT_NOT_ERR_OR_NULL(test, fdt);
> > +
> > +     /* Check that max_fds is set correctly and is >= slots */
> > +     KUNIT_EXPECT_GE(test, fdt->max_fds, slots);
> > +
> > +     /* Check that fd is allocated */
> > +     KUNIT_EXPECT_NOT_ERR_OR_NULL(test, fdt->fd);
>
> Nice to add these tests! Can you add one for each of the conditionals
> in alloc_fdtable (e.g. ENOMEM, EMFILE, and the power-of-two rounding-up
> logic, etc)?

Wouldn't tests for stuff like the rounding-up logic get into
implementation details too much, and break if implementation choices
change?