在 2025/7/2 04:37, Andrii Nakryiko 写道:
On Fri, Jun 27, 2025 at 1:23 AM Tao Chen <chen.dylane@xxxxxxxxx> wrote:
Show kprobe_multi link info with fdinfo, the info as follows:
link_type: kprobe_multi
link_id: 1
prog_tag: 33be53a4fd673e1d
prog_id: 21
kprobe_cnt: 8
missed: 0
cookie func
1 bpf_fentry_test1+0x0/0x20
7 bpf_fentry_test2+0x0/0x20
2 bpf_fentry_test3+0x0/0x20
3 bpf_fentry_test4+0x0/0x20
4 bpf_fentry_test5+0x0/0x20
5 bpf_fentry_test6+0x0/0x20
6 bpf_fentry_test7+0x0/0x20
8 bpf_fentry_test8+0x0/0x10
two nits:
1) order of cookie. For uprobes you have cookie at the end, here in
the front. Given variable-sized func name, I'd move cookie to the
front for uprobes for consistency.
Ok, will change it in v7.
2) field sizing for cookie (16) is a) not sufficient for maximum
possible u64 (20 digits) and b) very wasteful in common case of small
numbers. So use tab instead of fixed-sized column? And why 16
character sizing for the func column? Just to have more spaces
emitted?
I just referred to the implementation in bpftool/link.c, i will use tab
format in v7. "16 character sizing for the func" just keeps consistency
with cookie, " %s" for func name maybe better.
Other than that the series looks good to me.
pw-bot: cr
Signed-off-by: Tao Chen <chen.dylane@xxxxxxxxx>
---
kernel/trace/bpf_trace.c | 27 +++++++++++++++++++++++++++
1 file changed, 27 insertions(+)
diff --git a/kernel/trace/bpf_trace.c b/kernel/trace/bpf_trace.c
index 1c75f9c6c66..e8f070504c4 100644
--- a/kernel/trace/bpf_trace.c
+++ b/kernel/trace/bpf_trace.c
@@ -2622,10 +2622,37 @@ static int bpf_kprobe_multi_link_fill_link_info(const struct bpf_link *link,
return err;
}
+#ifdef CONFIG_PROC_FS
+static void bpf_kprobe_multi_show_fdinfo(const struct bpf_link *link,
+ struct seq_file *seq)
+{
+ struct bpf_kprobe_multi_link *kmulti_link;
+
+ kmulti_link = container_of(link, struct bpf_kprobe_multi_link, link);
+
+ seq_printf(seq,
+ "kprobe_cnt:\t%u\n"
+ "missed:\t%lu\n",
+ kmulti_link->cnt,
+ kmulti_link->fp.nmissed);
+
+ seq_printf(seq, "%-16s %-16s\n", "cookie", "func");
+ for (int i = 0; i < kmulti_link->cnt; i++) {
+ seq_printf(seq,
+ "%-16llu %-16pS\n",
+ kmulti_link->cookies[i],
+ (void *)kmulti_link->addrs[i]);
+ }
+}
+#endif
+
static const struct bpf_link_ops bpf_kprobe_multi_link_lops = {
.release = bpf_kprobe_multi_link_release,
.dealloc_deferred = bpf_kprobe_multi_link_dealloc,
.fill_link_info = bpf_kprobe_multi_link_fill_link_info,
+#ifdef CONFIG_PROC_FS
+ .show_fdinfo = bpf_kprobe_multi_show_fdinfo,
+#endif
};
static void bpf_kprobe_multi_cookie_swap(void *a, void *b, int size, const void *priv)
--
2.48.1
--
Best Regards
Tao Chen
