Re: [PATCH bpf-next v4 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 style violation in kern_extern_name()
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commit 293bdf5bcf5e7193069a28fa045283b34511449e
Author: Yonghong Song <yonghong.song@linux.dev>

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

LLVM terminates a cleanup landing pad with a call to _Unwind_Resume.
The kernel provides that terminator as a kfunc, but under the name
bpf_unwind_resume. This patch translates the name during both direct
load and light skeleton resolutions to ensure it resolves correctly.

> diff --git a/tools/lib/bpf/libbpf.c b/tools/lib/bpf/libbpf.c
> index cd1ea1bb53cbf..13ae9175e9686 100644
> --- a/tools/lib/bpf/libbpf.c
> +++ b/tools/lib/bpf/libbpf.c
> @@ -8379,6 +8379,15 @@ 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 newly added comment violate the strict BPF
subsystem multi-line comment style rules? The BPF subsystem guide requires
multi-line comments to have the opening /* on its own line, with the text
starting on the subsequent line.

> +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/20260921210033.1715000-1-yonghong.song@linux.dev?part=13