From: Qiang Wang <wangqiang.wq.frank@bytedance.com>
Date: Mon, 27 Dec 2021 21:07:13 +0800
Subject: libbpf: Support repeated legacy kprobes on same function
Patch-mainline: v5.17-rc1
Git-commit: 51a33c60f1c22c0d2dafad774315ba1537765442
References: jsc#PED-1368

If repeated legacy kprobes on same function in one process,
libbpf will register using the same probe name and got -EBUSY
error. So append index to the probe name format to fix this
problem.

Co-developed-by: Chengming Zhou <zhouchengming@bytedance.com>
Signed-off-by: Qiang Wang <wangqiang.wq.frank@bytedance.com>
Signed-off-by: Chengming Zhou <zhouchengming@bytedance.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20211227130713.66933-2-wangqiang.wq.frank@bytedance.com
Acked-by: Shung-Hsi Yu <shung-hsi.yu@suse.com>
---
 tools/lib/bpf/libbpf.c |    5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

--- a/tools/lib/bpf/libbpf.c
+++ b/tools/lib/bpf/libbpf.c
@@ -9914,7 +9914,10 @@ static int append_to_file(const char *fi
 static void gen_kprobe_legacy_event_name(char *buf, size_t buf_sz,
 					 const char *kfunc_name, size_t offset)
 {
-	snprintf(buf, buf_sz, "libbpf_%u_%s_0x%zx", getpid(), kfunc_name, offset);
+	static int index = 0;
+
+	snprintf(buf, buf_sz, "libbpf_%u_%s_0x%zx_%d", getpid(), kfunc_name, offset,
+		 __sync_fetch_and_add(&index, 1));
 }
 
 static int add_kprobe_event_legacy(const char *probe_name, bool retprobe,