Re: [PATCH bpf-next 13/20] libbpf: Resolve the compiler's _Unwind_Resume to the kernel's kfunc

[sashiko-bot@kernel.org]

Thank you for your contribution! Sashiko AI review found 1 potential issue(s) to consider:
- [Low] bpf: multi-line comment violates BPF subsystem style guide
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commit 082b791c15a0d9341a2e4f4d61c9b916d48b95fc
Author: Yonghong Song <yonghong.song@linux.dev>

libbpf: Resolve the compiler's _Unwind_Resume to the kernel's kfunc

This commit maps LLVM's _Unwind_Resume function calls in cleanup landing pads
to the kernel's corresponding bpf_unwind_resume kfunc. This ensures proper
symbol resolution without polluting the kernel's symbol table.

> diff --git a/tools/lib/bpf/libbpf.c b/tools/lib/bpf/libbpf.c
> index 613afae265199..ea1c09fa37939 100644
> --- a/tools/lib/bpf/libbpf.c
> +++ b/tools/lib/bpf/libbpf.c
> @@ -8346,6 +8346,15 @@ static void fixup_verifier_log(struct bpf_program *prog, char *buf, size_t buf_s
>  	}
>  }
>  
> +/* LLVM terminates a cleanup landing pad with a call to _Unwind_Resume, the
> + * base unwind ABI's entry point for carrying an unwind on once a frame's
> + * cleanups have run. The kernel knows it as bpf_unwind_resume.
> + */

[Severity: Low]
This isn't a bug, but does this multi-line comment format violate the
BPF subsystem style guide? The guide specifies that multi-line comments
must have the opening /* on its own line, rather than starting the text
on the same line as the opening characters.

> +static const char *kern_extern_name(const char *name)
> +{
> +	return strcmp(name, "_Unwind_Resume") ? name : "bpf_unwind_resume";
> +}

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Sashiko AI review · https://sashiko.dev/#/patchset/20260917055645.3926444-1-yonghong.song@linux.dev?part=13