On Wed, Aug 14, 2024 at 2:39 PM Jiri Olsa <olsajiri@xxxxxxxxx> wrote:
>
> On Tue, Aug 13, 2024 at 04:02:55PM -0700, Andrii Nakryiko wrote:
> > Factor out the logic to extract bpf_map instances from FD embedded in
> > bpf_insns, adding it to the list of used_maps (unless it's already
> > there, in which case we just reuse map's index). This simplifies the
> > logic in resolve_pseudo_ldimm64(), especially around `struct fd`
> > handling, as all that is now neatly contained in the helper and doesn't
> > leak into a dozen error handling paths.
> >
> > Signed-off-by: Andrii Nakryiko <andrii@xxxxxxxxxx>
> > ---
> > kernel/bpf/verifier.c | 115 ++++++++++++++++++++++++------------------
> > 1 file changed, 66 insertions(+), 49 deletions(-)
> >
> > diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c
> > index df3be12096cf..14e4ef687a59 100644
> > --- a/kernel/bpf/verifier.c
> > +++ b/kernel/bpf/verifier.c
> > @@ -18865,6 +18865,58 @@ static bool bpf_map_is_cgroup_storage(struct bpf_map *map)
> > map->map_type == BPF_MAP_TYPE_PERCPU_CGROUP_STORAGE);
> > }
> >
> > +/* Add map behind fd to used maps list, if it's not already there, and return
> > + * its index. Also set *reused to true if this map was already in the list of
> > + * used maps.
> > + * Returns <0 on error, or >= 0 index, on success.
> > + */
> > +static int add_used_map_from_fd(struct bpf_verifier_env *env, int fd, bool *reused)
> > +{
> > + struct fd f = fdget(fd);
>
> using 'CLASS(fd, f)(fd)' would remove few fdput lines below?
That's done in the next patch once we change __bpf_map_get() behavior
to allow usage of CLASS(fd, ...)
>
> jirka
>
> > + struct bpf_map *map;
> > + int i;
> > +
> > + map = __bpf_map_get(f);
> > + if (IS_ERR(map)) {
> > + verbose(env, "fd %d is not pointing to valid bpf_map\n", fd);
> > + return PTR_ERR(map);
> > + }
> > +
[...]
