From: Yonghong Song <yonghong.song@linux.dev>
To: Jiri Olsa <jolsa@kernel.org>, Alexei Starovoitov <ast@kernel.org>,
Daniel Borkmann <daniel@iogearbox.net>,
Andrii Nakryiko <andrii@kernel.org>
Cc: Song Liu <song@kernel.org>,
Quentin Monnet <quentin@isovalent.com>,
bpf@vger.kernel.org, Martin KaFai Lau <kafai@fb.com>,
Song Liu <songliubraving@fb.com>, Yonghong Song <yhs@fb.com>,
John Fastabend <john.fastabend@gmail.com>,
KP Singh <kpsingh@chromium.org>,
Stanislav Fomichev <sdf@google.com>, Hao Luo <haoluo@google.com>,
Yafang Shao <laoar.shao@gmail.com>
Subject: Re: [PATCHv3 bpf-next 6/6] bpftool: Add support to display uprobe_multi links
Date: Mon, 20 Nov 2023 10:32:02 -0800 [thread overview]
Message-ID: <769b00a5-88ac-4902-a69e-01ec977338ee@linux.dev> (raw)
In-Reply-To: <20231120145639.3179656-7-jolsa@kernel.org>
On 11/20/23 9:56 AM, Jiri Olsa wrote:
> Adding support to display details for uprobe_multi links,
> both plain:
>
> # bpftool link -p
> ...
> 24: uprobe_multi prog 126
> uprobe.multi path /home/jolsa/bpf/test_progs func_cnt 3 pid 4143
> offset ref_ctr_offset cookies
> 0xd1f88 0xf5d5a8 0xdead
> 0xd1f8f 0xf5d5aa 0xbeef
> 0xd1f96 0xf5d5ac 0xcafe
>
> and json:
>
> # bpftool link -p
> [{
> ...
> },{
> "id": 24,
> "type": "uprobe_multi",
> "prog_id": 126,
> "retprobe": false,
> "path": "/home/jolsa/bpf/test_progs",
> "func_cnt": 3,
> "pid": 4143,
> "funcs": [{
> "offset": 860040,
> "ref_ctr_offset": 16111016,
> "cookie": 57005
> },{
> "offset": 860047,
> "ref_ctr_offset": 16111018,
> "cookie": 48879
> },{
> "offset": 860054,
> "ref_ctr_offset": 16111020,
> "cookie": 51966
> }
> ]
> }
> ]
>
> Acked-by: Song Liu <song@kernel.org>
> Reviewed-by: Quentin Monnet <quentin@isovalent.com>
> Signed-off-by: Jiri Olsa <jolsa@kernel.org>
> ---
> tools/bpf/bpftool/link.c | 105 ++++++++++++++++++++++++++++++++++++++-
> 1 file changed, 103 insertions(+), 2 deletions(-)
>
> diff --git a/tools/bpf/bpftool/link.c b/tools/bpf/bpftool/link.c
> index a1528cde81ab..d198adf77d81 100644
> --- a/tools/bpf/bpftool/link.c
> +++ b/tools/bpf/bpftool/link.c
> @@ -294,6 +294,37 @@ show_kprobe_multi_json(struct bpf_link_info *info, json_writer_t *wtr)
> jsonw_end_array(json_wtr);
> }
>
> +static __u64 *u64_to_arr(__u64 val)
> +{
> + return (__u64 *) u64_to_ptr(val);
> +}
> +
> +static void
> +show_uprobe_multi_json(struct bpf_link_info *info, json_writer_t *wtr)
> +{
> + __u32 i;
> +
> + jsonw_bool_field(json_wtr, "retprobe",
> + info->uprobe_multi.flags & BPF_F_UPROBE_MULTI_RETURN);
> + jsonw_string_field(json_wtr, "path", (char *) u64_to_ptr(info->uprobe_multi.path));
> + jsonw_uint_field(json_wtr, "func_cnt", info->uprobe_multi.count);
> + jsonw_int_field(json_wtr, "pid", (int) info->uprobe_multi.pid);
> + jsonw_name(json_wtr, "funcs");
> + jsonw_start_array(json_wtr);
> +
> + for (i = 0; i < info->uprobe_multi.count; i++) {
> + jsonw_start_object(json_wtr);
> + jsonw_uint_field(json_wtr, "offset",
> + u64_to_arr(info->uprobe_multi.offsets)[i]);
> + jsonw_uint_field(json_wtr, "ref_ctr_offset",
> + u64_to_arr(info->uprobe_multi.ref_ctr_offsets)[i]);
> + jsonw_uint_field(json_wtr, "cookie",
> + u64_to_arr(info->uprobe_multi.cookies)[i]);
> + jsonw_end_object(json_wtr);
> + }
> + jsonw_end_array(json_wtr);
> +}
> +
> static void
> show_perf_event_kprobe_json(struct bpf_link_info *info, json_writer_t *wtr)
> {
> @@ -465,6 +496,9 @@ static int show_link_close_json(int fd, struct bpf_link_info *info)
> case BPF_LINK_TYPE_KPROBE_MULTI:
> show_kprobe_multi_json(info, json_wtr);
> break;
> + case BPF_LINK_TYPE_UPROBE_MULTI:
> + show_uprobe_multi_json(info, json_wtr);
> + break;
> case BPF_LINK_TYPE_PERF_EVENT:
> switch (info->perf_event.type) {
> case BPF_PERF_EVENT_EVENT:
> @@ -674,6 +708,33 @@ static void show_kprobe_multi_plain(struct bpf_link_info *info)
> }
> }
>
> +static void show_uprobe_multi_plain(struct bpf_link_info *info)
> +{
> + __u32 i;
> +
> + if (!info->uprobe_multi.count)
> + return;
> +
> + if (info->uprobe_multi.flags & BPF_F_UPROBE_MULTI_RETURN)
> + printf("\n\turetprobe.multi ");
> + else
> + printf("\n\tuprobe.multi ");
> +
> + printf("path %s ", (char *) u64_to_ptr(info->uprobe_multi.path));
> + printf("func_cnt %u ", info->uprobe_multi.count);
> +
> + if (info->uprobe_multi.pid != (__u32) -1)
> + printf("pid %d ", info->uprobe_multi.pid);
Could you explain when info->uprobe_multi.pid could be -1?
From patch 3, I see:
info->uprobe_multi.pid = umulti_link->task ?
task_pid_nr_ns(umulti_link->task, task_active_pid_ns(current)) : 0;
and cannot find how -1 could be assigned to info->uprobe_multi.pid.
> +
> + printf("\n\t%-16s %-16s %-16s", "offset", "ref_ctr_offset", "cookies");
> + for (i = 0; i < info->uprobe_multi.count; i++) {
> + printf("\n\t0x%-16llx 0x%-16llx 0x%-16llx",
> + u64_to_arr(info->uprobe_multi.offsets)[i],
> + u64_to_arr(info->uprobe_multi.ref_ctr_offsets)[i],
> + u64_to_arr(info->uprobe_multi.cookies)[i]);
> + }
> +}
> +
> static void show_perf_event_kprobe_plain(struct bpf_link_info *info)
> {
> const char *buf;
> [...]
next prev parent reply other threads:[~2023-11-20 18:32 UTC|newest]
Thread overview: 18+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-11-20 14:56 [PATCHv3 bpf-next 0/6] bpf: Add link_info support for uprobe multi link Jiri Olsa
2023-11-20 14:56 ` [PATCHv3 bpf-next 1/6] libbpf: Add st_type argument to elf_resolve_syms_offsets function Jiri Olsa
2023-11-20 14:56 ` [PATCHv3 bpf-next 2/6] bpf: Store ref_ctr_offsets values in bpf_uprobe array Jiri Olsa
2023-11-20 14:56 ` [PATCHv3 bpf-next 3/6] bpf: Add link_info support for uprobe multi link Jiri Olsa
2023-11-20 18:04 ` Yonghong Song
2023-11-22 21:50 ` Jiri Olsa
2023-11-23 9:20 ` Jiri Olsa
2023-11-23 18:26 ` Yonghong Song
2023-11-21 18:41 ` Andrii Nakryiko
2023-11-22 13:48 ` Jiri Olsa
2023-11-20 14:56 ` [PATCHv3 bpf-next 4/6] selftests/bpf: Use bpf_link__destroy in fill_link_info tests Jiri Olsa
2023-11-20 18:06 ` Yonghong Song
2023-11-20 14:56 ` [PATCHv3 bpf-next 5/6] selftests/bpf: Add link_info test for uprobe_multi link Jiri Olsa
2023-11-20 18:22 ` Yonghong Song
2023-11-21 11:29 ` Jiri Olsa
2023-11-20 14:56 ` [PATCHv3 bpf-next 6/6] bpftool: Add support to display uprobe_multi links Jiri Olsa
2023-11-20 18:32 ` Yonghong Song [this message]
2023-11-21 11:35 ` Jiri Olsa
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