From c519ba7a87026093be7d757c71ca3210490ec566 Mon Sep 17 00:00:00 2001
From: Charalampos Stratakis <stratakishar@gmail.com>
Date: Mon, 28 Sep 2026 15:57:28 +0200
Subject: [PATCH] gh-158294: Avoid relying on SystemTap probe handler ordering

Merge the tracing state and filter output in a single probe handler as
SystemTap does not guarantee the execution order of handlers sharing a
probe point.
---
 Lib/test/dtracedata/call_stack.stp | 26 +++++++-------------------
 1 file changed, 7 insertions(+), 19 deletions(-)

diff --git a/Lib/test/dtracedata/call_stack.stp b/Lib/test/dtracedata/call_stack.stp
index d4455fc8489af20..2901f44654be379 100644
--- a/Lib/test/dtracedata/call_stack.stp
+++ b/Lib/test/dtracedata/call_stack.stp
@@ -10,15 +10,6 @@ function basename:string(path:string)
     return last_token;
 }
 
-probe @PYTHON_SYSTEMTAP_PROBE@("function__entry")
-{
-    funcname = user_string($arg2);
-
-    if (funcname == "start") {
-        tracing = 1;
-    }
-}
-
 probe @PYTHON_SYSTEMTAP_PROBE@("function__entry"),
       @PYTHON_SYSTEMTAP_PROBE@("function__return")
 {
@@ -26,17 +17,14 @@ probe @PYTHON_SYSTEMTAP_PROBE@("function__entry"),
     funcname = user_string($arg2);
     lineno = $arg3;
 
-    if (tracing) {
+    if (funcname == "start") {
+        if ($$name == "function__entry") {
+            tracing = 1;
+        } else {
+            tracing = 0;
+        }
+    } else if (tracing) {
         printf("%d\t%s:%s:%s:%d\n", gettimeofday_us(), $$name,
                basename(filename), funcname, lineno);
     }
 }
-
-probe @PYTHON_SYSTEMTAP_PROBE@("function__return")
-{
-    funcname = user_string($arg2);
-
-    if (funcname == "start") {
-        tracing = 0;
-    }
-}