Fix the read data address one more time

tap/tlstapper/bpf/golang_uprobes.c

@@ -81,8 +81,17 @@ static __always_inline int golang_crypto_tls_read_uprobe(struct pt_regs *ctx) {
     b->conn_addr = ctx->rsi; // go.itab.*net.TCPConn,net.Conn address
     b->is_request = false;
 
-    // Address at ctx->rbx & 0xfffffff000 holds the data
-    __u32 status = bpf_probe_read_str(&b->data, sizeof(b->data), (void*)(ctx->rbx & 0xfffffff000));
+    void* stack_addr = (void*)ctx->rsp;
+    __u64 data_p;
+    // Address at ctx->rsp + 0xd8 holds the data
+    __u32 status = bpf_probe_read(&data_p, sizeof(data_p), stack_addr + 0xd8);
+    if (status < 0) {
+        bpf_printk("[golang_net_http_read_uprobe] error reading data pointer: %d", status);
+        bpf_ringbuf_discard(b, BPF_RB_FORCE_WAKEUP);
+        return 0;
+    }
+
+    status = bpf_probe_read_str(&b->data, sizeof(b->data), (void*)(data_p));
     if (status < 0) {
         bpf_printk("[golang_crypto_tls_read_uprobe] error reading data: %d", status);
         bpf_ringbuf_discard(b, BPF_RB_FORCE_WAKEUP);