Re: [PATCH bpf-next v3 2/6] libbpf: BPF programs manual loading and attaching

[sashiko-bot@kernel.org]

Thank you for your contribution! Sashiko AI review found 1 potential issue(s) to consider:
- [Low] bpf: raw error code logged instead of error string
--

commit 41645c9f0ca68e1802db1c78d41589ed30fa75e4
Author: Slava Imameev <slava.imameev@crowdstrike.com>

libbpf: BPF programs manual loading and attaching

This commit introduces a manual load strategy for BPF programs. It permits
programs to be loaded and attached independently after the initial bpf_object
loading, which skips the auto-load pass to improve performance for utilities
with hundreds of programs.

> diff --git a/tools/lib/bpf/libbpf.c b/tools/lib/bpf/libbpf.c
> index bd510a4e4941c..acb8caffa442e 100644
> --- a/tools/lib/bpf/libbpf.c
> +++ b/tools/lib/bpf/libbpf.c

[ ... ]

> @@ -15247,3 +15310,49 @@ enum bpf_prog_load_strategy bpf_program__load_strategy(const struct bpf_program
>  {
>  	return prog->load_strategy;
>  }
> +
> +/*
> + * This function must be called after bpf_object__prepare (or
> + * bpf_object__load, which calls bpf_object__prepare internally).
> + * Manually-loaded program data is initialized on object prepare.
> + * Post-prepare initialization is not supported.
> + */
> +int
> +bpf_program__load_manually(struct bpf_program *prog)
> +{
> +	int err;
> +	struct bpf_object *obj = prog->obj;
> +
> +	if (obj->state < OBJ_PREPARED)
> +		return libbpf_err(-EINVAL);
> +
> +	if (prog_is_subprog(obj, prog) || prog->load_strategy != BPF_PROG_LOAD_STRATEGY_MANUAL)
> +		return libbpf_err(-EINVAL);
> +
> +	if (prog->fd >= 0)
> +		return libbpf_err(-EBUSY);
> +
> +	err = bpf_object_load_prog(obj, prog, prog->insns, prog->insns_cnt,
> +				   obj->license, obj->kern_version, &prog->fd);
> +	if (err) {
> +		pr_warn("prog '%s': failed to load manually: %d\n", prog->name, err);

[Severity: Low]
Does this code log the raw integer error code instead of a descriptive error 
string? When bpf_program__load_manually is called and bpf_object_load_prog 
returns an error, this will print the %d format specifier. Other libbpf 
load functions typically use %s with errstr(err) to improve debuggability.

> +		return libbpf_err(err);
> +	}
> +
> +	return 0;
> +}

-- 
Sashiko AI review · https://sashiko.dev/#/patchset/20260917203040.3150212-1-andrey.grodzovsky@crowdstrike.com?part=2