Re: [PATCH bpf-next v2 18/23] selftests/bpf: Add BTF fixup for __naked subprog parameter names

[sashiko-bot@kernel.org]

Thank you for your contribution! Sashiko AI review found 1 potential issue(s) to consider:
- [Medium] The BPF object 'tobj' is leaked when 'fixup_btf_from_path()' fails.
--

commit af529dd65e68c8ac479551b0ac6332c3b5f56771
Author: Yonghong Song <yonghong.song@linux.dev>

selftests/bpf: Add BTF fixup for __naked subprog parameter names

This commit adds a mechanism to fix up missing parameter names in the BTF
FUNC_PROTO entries of __naked subprogs by reading them from a separate BTF
file. This allows the verifier to resolve stack argument slots by name.

> diff --git a/tools/testing/selftests/bpf/test_loader.c b/tools/testing/selftests/bpf/test_loader.c
> --- a/tools/testing/selftests/bpf/test_loader.c
> +++ b/tools/testing/selftests/bpf/test_loader.c

[ ... ]

> @@ -1231,13 +1351,27 @@ void run_subtest(struct test_loader *tester,
>  		}
>  	}
>  
> -	/* Implicitly reset to NULL if next test case doesn't specify */
> +	/* Implicitly reset to NULL if next test case doesn't specify.
> +	 * btf_custom_func_path also serves as btf_custom_path for kfunc resolution.
> +	 */
>  	open_opts->btf_custom_path = spec->btf_custom_path;
> +	if (!open_opts->btf_custom_path)
> +		open_opts->btf_custom_path = spec->btf_custom_func_path;
>  
>  	tobj = bpf_object__open_mem(obj_bytes, obj_byte_cnt, open_opts);
>  	if (!ASSERT_OK_PTR(tobj, "obj_open_mem")) /* shouldn't happen */
>  		goto subtest_cleanup;
>  
> +	/* Fix up __naked subprog BTF using a separate file with named params */
> +	if (spec->btf_custom_func_path) {
> +		err = fixup_btf_from_path(tobj, spec->btf_custom_func_path);
> +		if (err) {
> +			PRINT_FAIL("failed to fixup BTF from %s: %d\n",
> +				   spec->btf_custom_func_path, err);
> +			goto subtest_cleanup;

Does this error path leak tobj?

If fixup_btf_from_path() fails, the code jumps to subtest_cleanup, which
appears to bypass the tobj_cleanup label where tobj would normally be
closed and freed. Should this be goto tobj_cleanup instead?

-- 
Sashiko AI review · https://sashiko.dev/#/patchset/20260507212942.1122000-1-yonghong.song@linux.dev?part=18