stap command fails to resolve some of the kernel function parameters

Issue

• The stap command fails to resolve some of the kernel function parameters.

# stap -p4 -e 'probe module("*").function("rpc_call_sync") { println($clnt) }'
semantic error: while processing probe module("sunrpc").function("rpc_call_sync@net/sunrpc/clnt.c:1064") from: module("*").function("rpc_call_sync")

semantic error: failed to retrieve location attribute for 'clnt' [man error::dwarf]: identifier '$clnt' at <input>:1:55
        dieoffset: 0x2e95b from /usr/lib/debug/lib/modules/4.18.0-64.el8.x86_64/kernel/net/sunrpc/sunrpc.ko.debug
        function: rpc_call_sync at net/sunrpc/clnt.c:1064:5
        source: probe module("*").function("rpc_call_sync") { println($clnt) }
                                                                      ^

Pass 2: analysis failed.  [man error::pass2]

Kernel Source: net/sunrpc/clnt.c

1064 int rpc_call_sync(struct rpc_clnt *clnt, const struct rpc_message *msg, int flags)
1065 {