After commit 1b715e1b0ec5 ("bpf: Support ->fill_link_info for perf_event") add
perf_event info, we can also show the info with the method of cat /proc/[fd]/fdinfo.
kprobe fdinfo:
link_type: perf
link_id: 2
prog_tag: bcf7977d3b93787c
prog_id: 18
name: bpf_fentry_test1
offset: 0
missed: 0
addr: ffffffffaea8d134
event_type: 3
cookie: 3735928559
uprobe fdinfo:
link_type: perf
link_id: 6
prog_tag: bcf7977d3b93787c
prog_id: 7
name: /proc/self/exe
offset: 6507541
event_type: 1
cookie: 3735928559
tracepoint fdinfo:
link_type: perf
link_id: 4
prog_tag: bcf7977d3b93787c
prog_id: 8
tp_name: sched_switch
event_type: 5
cookie: 3735928559
perf_event fdinfo:
link_type: perf
link_id: 5
prog_tag: bcf7977d3b93787c
prog_id: 9
type: 1
config: 2
event_type: 6
cookie: 3735928559
Signed-off-by: Tao Chen <chen.dylane@xxxxxxxxx>
---
kernel/bpf/syscall.c | 126 +++++++++++++++++++++++++++++++++++++++++++
1 file changed, 126 insertions(+)
diff --git a/kernel/bpf/syscall.c b/kernel/bpf/syscall.c
index 9794446bc8..9af54852eb 100644
--- a/kernel/bpf/syscall.c
+++ b/kernel/bpf/syscall.c
@@ -3793,6 +3793,35 @@ static int bpf_perf_link_fill_kprobe(const struct perf_event *event,
info->perf_event.kprobe.cookie = event->bpf_cookie;
return 0;
}
+
+static void bpf_perf_link_fdinfo_kprobe(const struct perf_event *event,
+ struct seq_file *seq)
+{
+ const char *name;
+ int err;
+ u32 prog_id, type;
+ u64 offset, addr;
+ unsigned long missed;
+
+ err = bpf_get_perf_event_info(event, &prog_id, &type, &name,
+ &offset, &addr, &missed);
+ if (err)
+ return;
+
+ if (type == BPF_FD_TYPE_KRETPROBE)
+ type = BPF_PERF_EVENT_KRETPROBE;
+ else
+ type = BPF_PERF_EVENT_KPROBE;
+
+ seq_printf(seq,
+ "name:\t%s\n"
+ "offset:\t%llu\n"
+ "missed:\t%lu\n"
+ "addr:\t%llx\n"
+ "event_type:\t%u\n"
+ "cookie:\t%llu\n",
+ name, offset, missed, addr, type, event->bpf_cookie);
+}
#endif
#ifdef CONFIG_UPROBE_EVENTS
@@ -3820,6 +3849,34 @@ static int bpf_perf_link_fill_uprobe(const struct perf_event *event,
info->perf_event.uprobe.cookie = event->bpf_cookie;
return 0;
}
+
+static void bpf_perf_link_fdinfo_uprobe(const struct perf_event *event,
+ struct seq_file *seq)
+{
+ const char *name;
+ int err;
+ u32 prog_id, type;
+ u64 offset, addr;
+ unsigned long missed;
+
+ err = bpf_get_perf_event_info(event, &prog_id, &type, &name,
+ &offset, &addr, &missed);
+ if (err)
+ return;
+
+ if (type == BPF_FD_TYPE_URETPROBE)
+ type = BPF_PERF_EVENT_URETPROBE;
+ else
+ type = BPF_PERF_EVENT_UPROBE;
+
+ seq_printf(seq,
+ "name:\t%s\n"
+ "offset:\t%llu\n"
+ "event_type:\t%u\n"
+ "cookie:\t%llu\n",
+ name, offset, type, event->bpf_cookie);
+
+}
#endif
static int bpf_perf_link_fill_probe(const struct perf_event *event,
@@ -3888,10 +3945,79 @@ static int bpf_perf_link_fill_link_info(const struct bpf_link *link,
}
}
+static void bpf_perf_event_link_show_fdinfo(const struct perf_event *event,
+ struct seq_file *seq)
+{
+ seq_printf(seq,
+ "type:\t%u\n"
+ "config:\t%llu\n"
+ "event_type:\t%u\n"
+ "cookie:\t%llu\n",
+ event->attr.type, event->attr.config,
+ BPF_PERF_EVENT_EVENT, event->bpf_cookie);
+}
+
+static void bpf_tracepoint_link_show_fdinfo(const struct perf_event *event,
+ struct seq_file *seq)
+{
+ int err;
+ const char *name;
+ u32 prog_id;
+
+ err = bpf_get_perf_event_info(event, &prog_id, NULL, &name, NULL,
+ NULL, NULL);
+ if (err)
+ return;
+
+ seq_printf(seq,
+ "tp_name:\t%s\n"
+ "event_type:\t%u\n"
+ "cookie:\t%llu\n",
+ name, BPF_PERF_EVENT_TRACEPOINT, event->bpf_cookie);
+}
+
+static void bpf_probe_link_show_fdinfo(const struct perf_event *event,
+ struct seq_file *seq)
+{
+#ifdef CONFIG_KPROBE_EVENTS
+ if (event->tp_event->flags & TRACE_EVENT_FL_KPROBE)
+ return bpf_perf_link_fdinfo_kprobe(event, seq);
+#endif
+
+#ifdef CONFIG_UPROBE_EVENTS
+ if (event->tp_event->flags & TRACE_EVENT_FL_UPROBE)
+ return bpf_perf_link_fdinfo_uprobe(event, seq);
+#endif
+}
+
+static void bpf_perf_link_show_fdinfo(const struct bpf_link *link,
+ struct seq_file *seq)
+{
+ struct bpf_perf_link *perf_link;
+ const struct perf_event *event;
+
+ perf_link = container_of(link, struct bpf_perf_link, link);
+ event = perf_get_event(perf_link->perf_file);
+ if (IS_ERR(event))
+ return;
+
+ switch (event->prog->type) {
+ case BPF_PROG_TYPE_PERF_EVENT:
+ return bpf_perf_event_link_show_fdinfo(event, seq);
+ case BPF_PROG_TYPE_TRACEPOINT:
+ return bpf_tracepoint_link_show_fdinfo(event, seq);
+ case BPF_PROG_TYPE_KPROBE:
+ return bpf_probe_link_show_fdinfo(event, seq);
+ default:
+ return;
+ }
+}
+
static const struct bpf_link_ops bpf_perf_link_lops = {
.release = bpf_perf_link_release,
.dealloc = bpf_perf_link_dealloc,
.fill_link_info = bpf_perf_link_fill_link_info,
+ .show_fdinfo = bpf_perf_link_show_fdinfo,
};
static int bpf_perf_link_attach(const union bpf_attr *attr, struct bpf_prog *prog)
--
2.43.0
