Hi,
On 8/3/2024 8:11 AM, Amery Hung wrote:
> From: Dave Marchevsky <davemarchevsky@xxxxxx>
>
> Test stashing a referenced kptr in to a local kptr.
>
> Acked-by: Martin KaFai Lau <martin.lau@xxxxxxxxxx>
> Signed-off-by: Dave Marchevsky <davemarchevsky@xxxxxx>
> Signed-off-by: Amery Hung <amery.hung@xxxxxxxxxxxxx>
> ---
> .../selftests/bpf/progs/local_kptr_stash.c | 22 +++++++++++++++++--
> 1 file changed, 20 insertions(+), 2 deletions(-)
>
> diff --git a/tools/testing/selftests/bpf/progs/local_kptr_stash.c b/tools/testing/selftests/bpf/progs/local_kptr_stash.c
> index 75043ffc5dad..a0d784e8a05b 100644
> --- a/tools/testing/selftests/bpf/progs/local_kptr_stash.c
> +++ b/tools/testing/selftests/bpf/progs/local_kptr_stash.c
> @@ -11,6 +11,7 @@
> struct node_data {
> long key;
> long data;
> + struct prog_test_ref_kfunc __kptr *stashed_in_node;
> struct bpf_rb_node node;
> };
Because prog_test_ref_kfunc is a module btf, so the btf_get() in
btf_parse_kptr() will not be invoked. I would like to suggest to add a
user-defined type kptr in node_data to exercise the btf_get() in
btf_parse_kptr().
>
> @@ -85,18 +86,35 @@ static bool less(struct bpf_rb_node *a, const struct bpf_rb_node *b)
>
> static int create_and_stash(int idx, int val)
> {
> + struct prog_test_ref_kfunc *inner;
> struct map_value *mapval;
> struct node_data *res;
> + unsigned long dummy;
>
> mapval = bpf_map_lookup_elem(&some_nodes, &idx);
> if (!mapval)
> return 1;
>
> + dummy = 0;
> + inner = bpf_kfunc_call_test_acquire(&dummy);
> + if (!inner)
> + return 2;
> +
> res = bpf_obj_new(typeof(*res));
> - if (!res)
> - return 1;
> + if (!res) {
> + bpf_kfunc_call_test_release(inner);
> + return 3;
> + }
> res->key = val;
>
> + inner = bpf_kptr_xchg(&res->stashed_in_node, inner);
> + if (inner) {
> + /* Should never happen, we just obj_new'd res */
> + bpf_kfunc_call_test_release(inner);
> + bpf_obj_drop(res);
> + return 4;
> + }
> +
> res = bpf_kptr_xchg(&mapval->node, res);
> if (res)
> bpf_obj_drop(res);
