Re: [PATCH v11 bpf-next 04/12] selftests/bpf: add selftests for new insn_array map

[Anton Protopopov <a.s.protopopov@gmail.com>]

On 25/11/05 09:28AM, bot+bpf-ci@kernel.org wrote:
> > diff --git a/tools/testing/selftests/bpf/prog_tests/bpf_insn_array.c b/tools/testing/selftests/bpf/prog_tests/bpf_insn_array.c
> > new file mode 100644
> > index 000000000..96ee9c998
> > --- /dev/null
> > +++ b/tools/testing/selftests/bpf/prog_tests/bpf_insn_array.c
> 
> [ ... ]
> 
> > +/* Map can be used only by one BPF program */
> > +static void check_no_map_reuse(void)
> > +{
> > +	struct bpf_insn insns[] = {
> > +		BPF_MOV64_IMM(BPF_REG_0, 0),
> > +		BPF_EXIT_INSN(),
> > +	};
> > +	int prog_fd = -1, map_fd, extra_fd = -1;
> > +	struct bpf_insn_array_value val = {};
> > +	int i;
> > +
> > +	map_fd = map_create(BPF_MAP_TYPE_INSN_ARRAY, ARRAY_SIZE(insns));
> > +	if (!ASSERT_GE(map_fd, 0, "map_create"))
> > +		return;
> > +
> > +	for (i = 0; i < ARRAY_SIZE(insns); i++) {
> > +		val.orig_off = i;
> > +		if (!ASSERT_EQ(bpf_map_update_elem(map_fd, &i, &val, 0), 0, "bpf_map_update_elem"))
> > +			goto cleanup;
> > +	}
> > +
> > +	if (!ASSERT_EQ(bpf_map_freeze(map_fd), 0, "bpf_map_freeze"))
> > +		goto cleanup;
> > +
> > +	prog_fd = prog_load(insns, ARRAY_SIZE(insns), &map_fd, 1);
> > +	if (!ASSERT_GE(prog_fd, 0, "bpf(BPF_PROG_LOAD)"))
> > +		goto cleanup;
> > +
> > +	for (i = 0; i < ARRAY_SIZE(insns); i++) {
> > +		if (!ASSERT_EQ(bpf_map_lookup_elem(map_fd, &i, &val), 0, "bpf_map_lookup_elem"))
> > +			goto cleanup;
> > +
> > +		ASSERT_EQ(val.xlated_off, i, "val should be equal i");
> > +	}
> > +
> > +	extra_fd = prog_load(insns, ARRAY_SIZE(insns), &map_fd, 1);
> > +	if (!ASSERT_EQ(extra_fd, -EBUSY, "program should have been rejected (extra_fd != -EBUSY)"))
> > +		goto cleanup;
> > +
> > +	/* correctness: check that prog is still loadable without fd_array */
> > +	extra_fd = prog_load(insns, ARRAY_SIZE(insns), NULL, 0);
> > +	if (!ASSERT_GE(prog_fd, 0, "bpf(BPF_PROG_LOAD): expected no error"))
> >                          ^^^^^^^
> 
> In check_no_map_reuse(), is it correct to check prog_fd here? The
> function just loaded a program into extra_fd, so this check appears
> to be validating the wrong variable.

Indeed, the extra_fd should be checked

> 
> > +		goto cleanup;
> > +
> > +cleanup:
> > +	close(extra_fd);
> > +	close(prog_fd);
> > +	close(map_fd);
> > +}
> 
> [ ... ]
> 
> 
> ---
> AI reviewed your patch. Please fix the bug or email reply why it's not a bug.
> See: https://github.com/kernel-patches/vmtest/blob/master/ci/claude/README.md
> 
> CI run summary: https://github.com/kernel-patches/bpf/actions/runs/19096860051