On Sun, May 28, 2023 at 02:20:22PM +0000, Yafang Shao wrote:
> Show the already expose kprobe_multi link info in bpftool. The result as
> follows,
>
> $ bpftool link show
> 2: kprobe_multi prog 11
> func_cnt 4 addrs ffffffffaad475c0 ffffffffaad47600
> ffffffffaad47640 ffffffffaad47680
> pids trace(10936)
>
> $ bpftool link show -j
> [{"id":1,"type":"perf_event","prog_id":5,"bpf_cookie":0,"pids":[{"pid":10658,"comm":"trace"}]},{"id":2,"type":"kprobe_multi","prog_id":11,"func_cnt":4,"addrs":[18446744072280634816,18446744072280634880,18446744072280634944,18446744072280635008],"pids":[{"pid":10936,"comm":"trace"}]},{"id":120,"type":"iter","prog_id":266,"target_name":"bpf_map"},{"id":121,"type":"iter","prog_id":267,"target_name":"bpf_prog"}]
>
> $ bpftool link show | grep -A 1 "func_cnt" | \
> awk '{if (NR == 1) {print $4; print $5;} else {print $1; print $2} }' | \
> awk '{"grep " $1 " /proc/kallsyms" | getline f; print f;}'
This is not human friendly.
Either make bpftool print complete info or don't do it all.
> ffffffffaad475c0 T schedule_timeout_interruptible
> ffffffffaad47600 T schedule_timeout_killable
> ffffffffaad47640 T schedule_timeout_uninterruptible
> ffffffffaad47680 T schedule_timeout_idle
>
> Signed-off-by: Yafang Shao <laoar.shao@xxxxxxxxx>
> ---
> tools/bpf/bpftool/link.c | 50 ++++++++++++++++++++++++++++++++++++++++++++++++
> 1 file changed, 50 insertions(+)
>
> diff --git a/tools/bpf/bpftool/link.c b/tools/bpf/bpftool/link.c
> index 2d78607..76f1bb2 100644
> --- a/tools/bpf/bpftool/link.c
> +++ b/tools/bpf/bpftool/link.c
> @@ -218,6 +218,20 @@ static int show_link_close_json(int fd, struct bpf_link_info *info)
> jsonw_uint_field(json_wtr, "map_id",
> info->struct_ops.map_id);
> break;
> + case BPF_LINK_TYPE_KPROBE_MULTI:
> + const __u64 *addrs;
> + __u32 i;
> +
> + jsonw_uint_field(json_wtr, "func_cnt", info->kprobe_multi.count);
> + if (!info->kprobe_multi.count)
> + break;
> + jsonw_name(json_wtr, "addrs");
> + jsonw_start_array(json_wtr);
> + addrs = (const __u64 *)u64_to_ptr(info->kprobe_multi.addrs);
> + for (i = 0; i < info->kprobe_multi.count; i++)
> + jsonw_lluint(json_wtr, addrs[i]);
> + jsonw_end_array(json_wtr);
> + break;
> default:
> break;
> }
> @@ -396,6 +410,24 @@ static int show_link_close_plain(int fd, struct bpf_link_info *info)
> case BPF_LINK_TYPE_NETFILTER:
> netfilter_dump_plain(info);
> break;
> + case BPF_LINK_TYPE_KPROBE_MULTI:
> + __u32 indent, cnt, i;
> + const __u64 *addrs;
> +
> + cnt = info->kprobe_multi.count;
> + if (!cnt)
> + break;
> + printf("\n\tfunc_cnt %d addrs", cnt);
> + for (i = 0; cnt; i++)
> + cnt /= 10;
> + indent = strlen("func_cnt ") + i + strlen(" addrs");
> + addrs = (const __u64 *)u64_to_ptr(info->kprobe_multi.addrs);
> + for (i = 0; i < info->kprobe_multi.count; i++) {
> + if (i && !(i & 0x1))
> + printf("\n\t%*s", indent, "");
> + printf(" %0*llx", 16, addrs[i]);
> + }
> + break;
> default:
> break;
> }
> @@ -417,7 +449,9 @@ static int do_show_link(int fd)
> {
> struct bpf_link_info info;
> __u32 len = sizeof(info);
> + __u64 *addrs = NULL;
> char buf[256];
> + int count;
> int err;
>
> memset(&info, 0, sizeof(info));
> @@ -441,12 +475,28 @@ static int do_show_link(int fd)
> info.iter.target_name_len = sizeof(buf);
> goto again;
> }
> + if (info.type == BPF_LINK_TYPE_KPROBE_MULTI &&
> + !info.kprobe_multi.addrs) {
> + count = info.kprobe_multi.count;
> + if (count) {
> + addrs = malloc(count * sizeof(__u64));
> + if (!addrs) {
> + p_err("mem alloc failed");
> + close(fd);
> + return -1;
> + }
> + info.kprobe_multi.addrs = (unsigned long)addrs;
> + goto again;
> + }
> + }
>
> if (json_output)
> show_link_close_json(fd, &info);
> else
> show_link_close_plain(fd, &info);
>
> + if (addrs)
> + free(addrs);
> close(fd);
> return 0;
> }
> --
> 1.8.3.1
>
