From: Serhei Makarov <smakarov@redhat.com>
Date: Fri, 8 Mar 2019 22:53:48 +0000 (-0500)
Subject: stapbpf PR22330 WIP :: change exit.stp to send perf_events message
X-Git-Tag: release-4.1~66^2~9
X-Git-Url: https://sourceware.org/git/?a=commitdiff_plain;h=5e20bfa70cc95da5fa238130c506961e3611d2c3;p=systemtap.git

stapbpf PR22330 WIP :: change exit.stp to send perf_events message

* tapset/bpf/exit.stp (_set_exit_status): comment fix.
(_send_exit_msg): new embedded-code function sending STP_EXIT.
* tapset/logging.stp (exit): switch to using _send_exit_msg.
---

diff --git a/bpf-internal.h b/bpf-internal.h
index 8de9b890b..ec27d26af 100644
--- a/bpf-internal.h
+++ b/bpf-internal.h
@@ -383,7 +383,7 @@ struct globals
   // Types of transport messages supported:
   enum perf_event_type
   {
-    STP_EXIT,
+    STP_EXIT = 0,
     STP_PRINTF_START,
     STP_PRINTF_END,
     STP_PRINTF_FORMAT,
diff --git a/tapset/bpf/exit.stp b/tapset/bpf/exit.stp
index 18d4d843e..d2c98ded4 100644
--- a/tapset/bpf/exit.stp
+++ b/tapset/bpf/exit.stp
@@ -1,5 +1,5 @@
 /**
- * function exit - 
+ * function _set_exit_status - 
  *
  * Description: Set exit flag.
  */
@@ -16,3 +16,16 @@ function _set_exit_status:long ()
     0x85, 0, 0, 0, 2;   	/* call bpf_map_update_elem */ 
     0xbf, $$, 0, 0, 0           /* return r0 */
 %}
+
+/**
+ * function _exit
+ *
+ * Description: Send an exit request through perf_events transport.
+ */
+function _send_exit_msg:long ()
+%{ /* bpf */ /* unprivileged */
+    0x118, $perf_events_map, 0, 0, 1; /* BPF_LD_MAP_FD($perf_events_map, map1) */
+    alloc, $data, 8;
+    0x7a, $data, -, -, 0x0;  /* stdw [$data+0], STP_EXIT */
+    call, $$, perf_event_output, $ctx, $perf_events_map, -1, $data, 8;
+%}
diff --git a/tapset/logging.stp b/tapset/logging.stp
index be4a6c4e7..838123ca7 100644
--- a/tapset/logging.stp
+++ b/tapset/logging.stp
@@ -69,7 +69,7 @@ function exit ()
 %:
   { /* unprivileged */ /* bpf */
     _set_exit_status()
-    printf("")
+    _send_exit_msg()
   }
 %)