Show uprobe_multi link info with fdinfo, the info as follows:
link_type: uprobe_multi
link_id: 9
prog_tag: e729f789e34a8eca
prog_id: 39
type: uprobe_multi
uprobe_cnt: 3
pid: 0
path: /home/dylane/bpf/tools/testing/selftests/bpf/test_progs
offset ref_ctr_offset cookie
0xa69f13 0x0 3
0xa69f1e 0x0 1
0xa69f29 0x0 2
Signed-off-by: Tao Chen <chen.dylane@xxxxxxxxx>
---
kernel/trace/bpf_trace.c | 47 ++++++++++++++++++++++++++++++++++++++++
1 file changed, 47 insertions(+)
Change list:
v3 -> v4:
- use %pS to print func info.(Alexei)
v3:
https://lore.kernel.org/bpf/20250616130233.451439-1-chen.dylane@xxxxxxxxx
v2 -> v3:
- show info in one line for multi events.(Jiri)
v2:
https://lore.kernel.org/bpf/20250615150514.418581-1-chen.dylane@xxxxxxxxx
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..2d422f897ac 100644
--- a/kernel/trace/bpf_trace.c
+++ b/kernel/trace/bpf_trace.c
@@ -3157,10 +3157,57 @@ 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);
+
+ seq_printf(seq, "%-16s %-16s %-16s\n", "offset", "ref_ctr_offset", "cookie");
+ for (int i = 0; i < umulti_link->cnt; i++) {
+ seq_printf(seq,
+ "%#-16llx %#-16lx %-16llu\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
