Re: [PATCH bpf-next v2 2/2] selftests/bpf: Add test to verify the fix of kprobe_write_ctx abuse

[Leon Hwang <leon.hwang@linux.dev>]

On 2026/3/30 17:28, Jiri Olsa wrote:
> On Thu, Mar 26, 2026 at 10:17:18PM +0800, Leon Hwang wrote:
> 
> SNIP
> 
>> +	prog_fd = bpf_program__fd(skel_kprobe->progs.kprobe_write_ctx);
>> +	bpf_program__set_attach_target(prog_ext, prog_fd, "kprobe_write_ctx");
>> +
>> +	err = kprobe_write_ctx__load(skel_ext);
>> +	if (!ASSERT_OK(err, "kprobe_write_ctx__load ext"))
>> +		goto out;
>> +
>> +	prog_fd = bpf_program__fd(prog_kprobe);
>> +	link_ext = bpf_program__attach_freplace(prog_ext, prog_fd, "kprobe_dummy");
>> +	ASSERT_ERR_PTR(link_ext, "bpf_program__attach_freplace link");
>> +	ASSERT_EQ(errno, EINVAL, "bpf_program__attach_freplace errno");
> 
> nit, I prefer libbpf_get_error call instead, because it's not obvious
> that ASSERT_ERR_PTR sets errno, smth like:
> 
>         if (!ASSERT_EQ(libbpf_get_error(link_ext), -EINVAL, ..
> 

Yeah, libbpf_get_error() is better. Will use it.

> anyway lgtm
> 
> Acked-by: Jiri Olsa <jolsa@kernel.org>
> 

Thanks for your review.

Thanks,
Leon

[...]