On Tue, Mar 4, 2025 at 1:15 PM Mykyta Yatsenko
<mykyta.yatsenko5@xxxxxxxxx> wrote:
>
> From: Mykyta Yatsenko <yatsenko@xxxxxxxx>
>
> Add selftests to verify that it is possible to load freplace program
> from user namespace if BPF token is initialized by bpf_object__prepare
> before calling bpf_program__set_attach_target.
> Negative test is added as well.
>
> Signed-off-by: Mykyta Yatsenko <yatsenko@xxxxxxxx>
> ---
> .../testing/selftests/bpf/prog_tests/token.c | 94 +++++++++++++++++++
> .../selftests/bpf/progs/priv_freplace_prog.c | 13 +++
> tools/testing/selftests/bpf/progs/priv_prog.c | 4 +-
> 3 files changed, 109 insertions(+), 2 deletions(-)
> create mode 100644 tools/testing/selftests/bpf/progs/priv_freplace_prog.c
[...]
> +/* Verify that freplace works from user namespace, because bpf token is loaded
> + * in bpf_object__prepare
> + */
> +static int userns_obj_priv_freplace_prog(int mnt_fd, struct token_lsm *lsm_skel)
> +{
> + struct priv_freplace_prog *fr_skel = NULL;
> + struct priv_prog *skel = NULL;
> + int err, tgt_fd;
> +
> + err = userns_obj_priv_freplace_setup(mnt_fd, &fr_skel, &skel, &tgt_fd);
> + if (!ASSERT_OK(err, "setup"))
> + goto out;
> +
> + err = bpf_object__prepare(fr_skel->obj);
> + if (!ASSERT_OK(err, "freplace__prepare"))
> + goto out;
> +
> + err = bpf_program__set_attach_target(fr_skel->progs.new_kprobe_prog, tgt_fd, "kprobe_prog");
> + if (err)
if (!ASSERT_OK(err, "set_attach_target"))
> + goto out;
> +
> + err = priv_freplace_prog__load(fr_skel);
> + ASSERT_OK(err, "priv_freplace_prog__load");
> +out:
> + priv_freplace_prog__destroy(fr_skel);
> + priv_prog__destroy(skel);
> + return err;
> +}
> +
[...]
> diff --git a/tools/testing/selftests/bpf/progs/priv_prog.c b/tools/testing/selftests/bpf/progs/priv_prog.c
> index 3c7b2b618c8a..be9deda38b52 100644
> --- a/tools/testing/selftests/bpf/progs/priv_prog.c
> +++ b/tools/testing/selftests/bpf/progs/priv_prog.c
> @@ -1,5 +1,5 @@
> // SPDX-License-Identifier: GPL-2.0
> -/* Copyright (c) 2023 Meta Platforms, Inc. and affiliates. */
> +/* Copyright (c) 2025 Meta Platforms, Inc. and affiliates. */
you don't need to update copyright year when updating the file, just
leave it as is here and above
>
> #include "vmlinux.h"
> #include <bpf/bpf_helpers.h>
> @@ -7,7 +7,7 @@
> char _license[] SEC("license") = "GPL";
>
> SEC("kprobe")
> -int kprobe_prog(void *ctx)
> +int kprobe_prog(struct pt_regs *ctx)
> {
> return 1;
> }
> --
> 2.48.1
>
