[DTrace-devel] [PATCH 2/3] test: make tst.dash.sh work for position-independent code

[Kris Van Hees]

When code is compiled as position-independent code, the logic for
comparing the reported PC at probe firing needs to adjust for the
fact that the reported addresses are absolute whereas the addresses
obtained from the executable are relative to the mapping base

Signed-off-by: Kris Van Hees <kris.van.hees at oracle.com>
---
 test/unittest/pid/tst.dash.sh | 20 ++++++++++++++++----
 1 file changed, 16 insertions(+), 4 deletions(-)

diff --git a/test/unittest/pid/tst.dash.sh b/test/unittest/pid/tst.dash.sh
index 0289b609..d793e081 100755
--- a/test/unittest/pid/tst.dash.sh
+++ b/test/unittest/pid/tst.dash.sh
@@ -1,7 +1,7 @@
 #!/bin/bash
 #
 # Oracle Linux DTrace.
-# Copyright (c) 2025, Oracle and/or its affiliates. All rights reserved.
+# Copyright (c) 2025, 2026, Oracle and/or its affiliates. All rights reserved.
 # Licensed under the Universal Permissive License v 1.0 as shown at
 # http://oss.oracle.com/licenses/upl.
 #
@@ -16,6 +16,8 @@ cd $DIRNAME
 # Make trigger program.
 
 cat << EOF > main.c
+#include <stdio.h>
+
 int foo0(int i) {
     int j, k;
 
@@ -46,6 +48,10 @@ int foo2(int i) {
 int main(int c, char **v) {
     int i = 0;
 
+    printf("foo0 %p\n"
+	   "foo1 %p\n"
+	   "foo2 %p\n"
+	   "main %p\n", &foo0, &foo1, &foo2, &main);
     i = foo0(i) ^ i;
     i = foo1(i) ^ i;
     i = foo2(i) ^ i;
@@ -85,8 +91,8 @@ for func in foo0 foo1 foo2 main; do
 	  }'`
 
 	# Write the expected output to the compare file.
-	echo got $ABS $func:$REL >> dtrace.exp
-	echo got $ABS "-":$ABS   >> dtrace.exp
+#	echo got $ABS $func:$REL >> dtrace.exp
+#	echo got $ABS "-":$ABS   >> dtrace.exp
 
 	# Write the actual dtrace output to the output file.
 	# Specify the pid probe with both relative and absolute
@@ -95,12 +101,18 @@ for func in foo0 foo1 foo2 main; do
 		$dtrace -c ./a.out -o dtrace.out -qn '
 		    pid$target:a.out:'$probe'
 		    { printf("got %x %s:%s", uregs[R_PC], probefunc,
-							  probename); }'
+							  probename); }' > addrs
 		if [ $? -ne 0 ]; then
 			echo ERROR: dtrace
 			cat dtrace.out
 			exit 1
 		fi
+
+		awk -vfn="$func" -vrel="$REL" -vprobe="$probe" \
+		    '$1 == fn {
+			addr = strtonum($2) + int(rel);
+			printf "got %x %s\n", addr, probe;
+		     }' addrs >> dtrace.exp
 	done
 done
 
-- 
2.51.0