On Sun, Jun 15, 2025 at 11:05:13PM +0800, Tao Chen wrote:
> Show uprobe_multi link info with fdinfo, the info as follows:
>
> link_type: uprobe_multi
> link_id: 9
> prog_tag: e729f789e34a8eca
> prog_id: 58
> type: uprobe_multi
> uprobe_cnt: 3
> pid: 0
> path: /home/dylane/bpf/tools/testing/selftests/bpf/test_progs
> offset: 0xa69ed7
> ref_ctr_offset: 0x0
> cookie: 3
> offset: 0xa69ee2
> ref_ctr_offset: 0x0
> cookie: 1
> offset: 0xa69eed
> ref_ctr_offset: 0x0
> cookie: 2
hi,
does this need to be 'tag: value' format ? bpftool uses:
offset ref_ctr_offset cookies
0xe558 0x0 0x0
0x2574e 0x0 0x0
0x6c393 0x0 0x0
which might be more readable, or at least extra line after each uprobe?
also using spaces instead of tabs to align the values might help
same for kprobe_multi, otherwise looks lgtm
thanks,
jirka
>
> Signed-off-by: Tao Chen <chen.dylane@xxxxxxxxx>
> ---
> kernel/trace/bpf_trace.c | 48 ++++++++++++++++++++++++++++++++++++++++
> 1 file changed, 48 insertions(+)
>
> Change list:
> v1 -> v2:
> - replace 'func_cnt' with 'uprobe_cnt'.(Andrii)
> - print func name is more readable and security for kprobe_multi.(Alexei)
> v1:
> https://lore.kernel.org/bpf/20250612115556.295103-1-chen.dylane@xxxxxxxxx
>
> diff --git a/kernel/trace/bpf_trace.c b/kernel/trace/bpf_trace.c
> index 24b94870b50..9a8ca8a8e2b 100644
> --- a/kernel/trace/bpf_trace.c
> +++ b/kernel/trace/bpf_trace.c
> @@ -3157,10 +3157,58 @@ static int bpf_uprobe_multi_link_fill_link_info(const struct bpf_link *link,
> return err;
> }
>
> +#ifdef CONFIG_PROC_FS
> +static void bpf_uprobe_multi_show_fdinfo(const struct bpf_link *link,
> + struct seq_file *seq)
> +{
> + struct bpf_uprobe_multi_link *umulti_link;
> + char *p, *buf;
> +
> + umulti_link = container_of(link, struct bpf_uprobe_multi_link, link);
> +
> + buf = kmalloc(PATH_MAX, GFP_KERNEL);
> + if (!buf)
> + return;
> +
> + p = d_path(&umulti_link->path, buf, PATH_MAX);
> + if (IS_ERR(p)) {
> + kfree(buf);
> + return;
> + }
> +
> + seq_printf(seq,
> + "type:\t%s\n"
> + "uprobe_cnt:\t%u\n"
> + "pid:\t%u\n"
> + "path:\t%s\n",
> + umulti_link->flags == BPF_F_UPROBE_MULTI_RETURN ?
> + "uretprobe_multi" : "uprobe_multi",
> + umulti_link->cnt,
> + umulti_link->task ? task_pid_nr_ns(umulti_link->task,
> + task_active_pid_ns(current)) : 0,
> + p);
> +
> + for (int i = 0; i < umulti_link->cnt; i++) {
> + seq_printf(seq,
> + "offset:\t%#llx\n"
> + "ref_ctr_offset:\t%#lx\n"
> + "cookie:\t%llu\n",
> + umulti_link->uprobes[i].offset,
> + umulti_link->uprobes[i].ref_ctr_offset,
> + umulti_link->uprobes[i].cookie);
> + }
> +
> + kfree(buf);
> +}
> +#endif
> +
> static const struct bpf_link_ops bpf_uprobe_multi_link_lops = {
> .release = bpf_uprobe_multi_link_release,
> .dealloc_deferred = bpf_uprobe_multi_link_dealloc,
> .fill_link_info = bpf_uprobe_multi_link_fill_link_info,
> +#ifdef CONFIG_PROC_FS
> + .show_fdinfo = bpf_uprobe_multi_show_fdinfo,
> +#endif
> };
>
> static int uprobe_prog_run(struct bpf_uprobe *uprobe,
> --
> 2.48.1
>
