It turns out that truss also used kdump's mkioctls script, and expected

ioctlname() to return a pointer to the name rather than print it.  This did
not show up in testing because truss had its own prototype for ioctlname(),
so it would build fine and run fine as long as the program being traced did
not issue an ioctl.

Teach mkioctls to generate different versions of ioctlname() based on its
first command-line argument.

Pointed out by:	Garrett Cooper <yanegomi@gmail.com>

2 files changed, 35 insertions, 18 deletions

diff --git a/usr.bin/kdump/Makefile b/usr.bin/kdump/Makefile
index 0af84cc..afa94bb 100644
--- a/usr.bin/kdump/Makefile
+++ b/usr.bin/kdump/Makefile
@@ -22,7 +22,7 @@ CLEANFILES=	ioctl.c kdump_subr.c kdump_subr.h linux_syscalls.c
 
 ioctl.c: mkioctls
 	env MACHINE=${MACHINE} \
-	    sh ${.CURDIR}/mkioctls ${DESTDIR}/usr/include > ${.TARGET}
+	    sh ${.CURDIR}/mkioctls print ${DESTDIR}/usr/include > ${.TARGET}
 
 kdump_subr.h: mksubr
 	sh ${.CURDIR}/mksubr ${DESTDIR}/usr/include | \
diff --git a/usr.bin/kdump/mkioctls b/usr.bin/kdump/mkioctls
index 7ef2865..22ca268 100644
--- a/usr.bin/kdump/mkioctls
+++ b/usr.bin/kdump/mkioctls
@@ -1,20 +1,26 @@
 #!/bin/sh
 #
 # $FreeBSD$
+#
+# When editing this script, keep in mind that truss also uses it.
+#
 
 set -e
 
-if [ -z "$1" ]; then
-	echo "usage: sh $0 include-dir"
+if [ $# -ne 2 -o \( $1 != "print" -a $1 != "return" \) ]; then
+	echo "usage: sh $0 print|return include-dir"
 	exit 1
 fi
 
+style="$1"
+includedir="$2"
+
 LC_ALL=C; export LC_ALL
 
 # Build a list of headers that have ioctls in them.
 # XXX should we use an ANSI cpp?
 ioctl_includes=$(
-	cd $1
+	cd $includedir
 	find -H -s * -name '*.h' | grep -v '.*disk.*\.h' | \
 		xargs egrep -l \
 '^#[ 	]*define[ 	]+[A-Za-z_][A-Za-z0-9_]*[ 	]+_IO[^a-z0-9_]' |
@@ -33,7 +39,7 @@ esac
 
 awk -v x="$ioctl_includes" 'BEGIN {print x}' |
 	gcc -E -I$1 -dM -DCOMPAT_43TTY - |
-	awk -v ioctl_includes="$ioctl_includes" '
+	awk -v ioctl_includes="$ioctl_includes" -v style="$style" '
 BEGIN {
 	print "/* XXX obnoxious prerequisites. */"
 	print "#define COMPAT_43"
@@ -58,12 +64,19 @@ BEGIN {
 	print "#include <stdio.h>"
 	print "#include <cam/cam.h>"
 	print ""
-	print "void ioctlname(unsigned long val, int decimal);"
-	print ""
 	print ioctl_includes
 	print ""
-	print "void"
-	print "ioctlname(unsigned long val, int decimal)"
+	if (style == "print") {
+		print "void ioctlname(unsigned long val, int decimal);"
+		print ""
+		print "void"
+		print "ioctlname(unsigned long val, int decimal)"
+	} else {
+		print "const char *ioctlname(unsigned long val);"
+		print ""
+		print "const char *"
+		print "ioctlname(unsigned long val)"
+	}
 	print "{"
 	print "\tconst char *str = NULL;"
 	print ""
@@ -77,20 +90,24 @@ BEGIN {
 			break;
 	++i;
 	#
-	print("\t");
+	printf("\t");
 	if (n++ > 0)
-		print("else ");
+		printf("else ");
 	printf("if (val == %s)\n", $i);
 	printf("\t\tstr = \"%s\";\n", $i);
 }
 END {
-	print "\n"
-	print "\tif (str != NULL)\n"
-	print "\t\tprintf(\"%s\", str);\n"
-	print "\telse if (decimal)\n"
-	print "\t\tprintf(\"%lu\", val);\n"
-	print "\telse\n"
-	print "\t\tprintf(\"%#lx\", val);\n"
+	print ""
+	if (style == "print") {
+		print "\tif (str != NULL)"
+		print "\t\tprintf(\"%s\", str);"
+		print "\telse if (decimal)"
+		print "\t\tprintf(\"%lu\", val);"
+		print "\telse"
+		print "\t\tprintf(\"%#lx\", val);"
+	} else {
+		print "\treturn (str);"
+	}
 	print "}"
 }
 '