Re: [PATCH] tools libbpf: Fix signed shift UB in btf_type_info()

[bot+bpf-ci]

> In btf_type_info(), the expression `kflag << 31` performs a signed
> integer shift. When kflag is 1, this sets the sign bit of a 32-bit
> signed integer, which is undefined behavior in C.
>
> Fix it by casting kflag to unsigned int before the shift.
>
> Signed-off-by: Liu Jing <liujing@xxxxxxxxxxxxxxxxxxxx>

This looks like a bug fix for undefined behavior that was introduced in
an earlier commit. Should this include a Fixes: tag?

The signed shift undefined behavior in btf_type_info() appears to have
been introduced by commit aea28a602fa1 ("libbpf: Mark BPF subprogs with
hidden visibility as static for BPF verifier"). Would it be appropriate
to add:

  Fixes: aea28a602fa1 ("libbpf: Mark BPF subprogs with hidden visibility as static for BPF verifier")


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