Re: [PATCH bpf-next v5 2/3] bpf: Add show_fdinfo for uprobe_multi
From: Andrii Nakryiko <hidden>
Date: 2025-06-23 22:14:51
Also in:
bpf, lkml
On Mon, Jun 23, 2025 at 6:45 AM Tao Chen [off-list ref] wrote:
quoted hunk ↗ jump to hunk
Show uprobe_multi link info with fdinfo, the info as follows: link_type: uprobe_multi link_id: 10 prog_tag: 7db356c03e61a4d4 prog_id: 42 uprobe_cnt: 3 pid: 0 path: /home/dylane/bpf/tools/testing/selftests/bpf/test_progs offset ref_ctr_offset cookie 0xa69f13 0x0 2 0xa69f1e 0x0 3 0xa69f29 0x0 1 Signed-off-by: Tao Chen <redacted> --- kernel/trace/bpf_trace.c | 44 ++++++++++++++++++++++++++++++++++++++++ 1 file changed, 44 insertions(+)diff --git a/kernel/trace/bpf_trace.c b/kernel/trace/bpf_trace.c index 8ecb1a9f85d..90209dda819 100644 --- a/kernel/trace/bpf_trace.c +++ b/kernel/trace/bpf_trace.c@@ -3171,10 +3171,54 @@ 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, + "uprobe_cnt:\t%u\n" + "pid:\t%u\n" + "path:\t%s\n", + umulti_link->cnt, + umulti_link->task ? task_pid_nr_ns(umulti_link->task, + task_active_pid_ns(current)) : 0,
nit: either keep stuff like this on single line, or if it's too long or awkward, add a local variable. Formatting it like this is very hard to follow and looks pretty ugly...
+ 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