Build sudo_noexec.so as a module on systems other then Darwin.

On Darwin, shared modules and shared libraries are not interchangable
and since we preload sudo_noexec.so via DYLD_INSERT_LIBRARIES it
must be a library, not a module.  We must relax the requirement
that libraries begin with a "lib" prefix to work around this
difference.  This does mean you must use sudo's libtool on Darwin
(macOS) but that is already a requirement on other systems (notably
HP-UX and SCO) due to a number of libtool patches we require that
haven't be accepted upstream.  This is a different fix for PR #102.

configure

@@ -808,6 +808,7 @@ LDAP
 SELINUX_USAGE
 BSDAUTH_USAGE
 DONT_LEAK_PATH_INFO
+NOEXEC_MODULE
 CHECK_NOEXEC
 INSTALL_NOEXEC
 INSTALL_BACKUP
@@ -3536,6 +3537,7 @@ ac_config_headers="$ac_config_headers config.h pathnames.h"
 
 
 
+
 
 
 #
@@ -3593,6 +3595,7 @@ devsearch="/dev/pts:/dev/vt:/dev/term:/dev/zcons:/dev/pty:/dev"
 INSTALL_BACKUP=
 INSTALL_NOEXEC=
 CHECK_NOEXEC=
+NOEXEC_MODULE=-module
 exampledir='$(docdir)/examples'
 devdir='$(srcdir)'
 PROGS="sudo"
@@ -16604,6 +16607,10 @@ done
 		fi
 		RTLD_PRELOAD_VAR="DYLD_INSERT_LIBRARIES"
 
+		# Build sudo_noexec.so as a shared library, not a module.
+		# On Darwin, modules and shared libraries are incompatible.
+		NOEXEC_MODULE=
+
 		# Mach monotonic timer that runs while sleeping
 		ac_fn_c_check_func "$LINENO" "mach_continuous_time" "ac_cv_func_mach_continuous_time"
 if test "x$ac_cv_func_mach_continuous_time" = xyes

configure.ac

@@ -76,6 +76,7 @@ AC_SUBST([sesh_file])
 AC_SUBST([INSTALL_BACKUP])
 AC_SUBST([INSTALL_NOEXEC])
 AC_SUBST([CHECK_NOEXEC])
+AC_SUBST([NOEXEC_MODULE])
 AC_SUBST([DONT_LEAK_PATH_INFO])
 AC_SUBST([BSDAUTH_USAGE])
 AC_SUBST([SELINUX_USAGE])
@@ -227,6 +228,7 @@ dnl
 INSTALL_BACKUP=
 INSTALL_NOEXEC=
 CHECK_NOEXEC=
+NOEXEC_MODULE=-module
 exampledir='$(docdir)/examples'
 devdir='$(srcdir)'
 PROGS="sudo"
@@ -2170,6 +2172,10 @@ case "$host" in
 		fi
 		RTLD_PRELOAD_VAR="DYLD_INSERT_LIBRARIES"
 
+		# Build sudo_noexec.so as a shared library, not a module.
+		# On Darwin, modules and shared libraries are incompatible.
+		NOEXEC_MODULE=
+
 		# Mach monotonic timer that runs while sleeping
 		AC_CHECK_FUNCS([mach_continuous_time])
 

scripts/ltmain.sh

@@ -8742,9 +8742,6 @@ func_mode_link ()
 	eval libname=\"$libname_spec\"
 	;;
       *)
-	test no = "$module" \
-	  && func_fatal_help "libtool library '$output' must begin with 'lib'"
-
 	if test no != "$need_lib_prefix"; then
 	  # Add the "lib" prefix for modules if required
 	  func_stripname '' '.la' "$outputname"

src/Makefile.in

@@ -64,6 +64,9 @@ LT_LDFLAGS = @LT_LDFLAGS@
 # Flags to pass to libtool
 LTFLAGS = --tag=disable-static
 
+# Build sudo_noexec as a module instead of a shared lib (except on macOS)
+NOEXEC_MODULE = @NOEXEC_MODULE@
+
 # Address sanitizer flags
 ASAN_CFLAGS = @ASAN_CFLAGS@
 ASAN_LDFLAGS = @ASAN_LDFLAGS@
@@ -175,15 +178,8 @@ Makefile: $(srcdir)/Makefile.in
 sudo: $(OBJS) $(LT_LIBS) @STATIC_SUDOERS@
 	$(LIBTOOL) $(LTFLAGS) --mode=link $(CC) -o $@ $(OBJS) $(SUDO_LDFLAGS) $(ASAN_LDFLAGS) $(PIE_LDFLAGS) $(SSP_LDFLAGS) $(LIBS) @STATIC_SUDOERS@
 
-# We can't use -module here since you cannot preload a module on Darwin
+sudo_noexec.la: sudo_noexec.lo
-libsudo_noexec.la: sudo_noexec.lo
+	$(LIBTOOL) $(LTFLAGS) --mode=link $(CC) $(LDFLAGS) $(LT_LDFLAGS) $(SSP_LDFLAGS) @LIBDL@ -o $@ sudo_noexec.lo $(NOEXEC_MODULE) -avoid-version -rpath $(noexecdir) -shrext .so
-	$(LIBTOOL) $(LTFLAGS) --mode=link $(CC) $(LDFLAGS) $(LT_LDFLAGS) $(SSP_LDFLAGS) @LIBDL@ -o $@ sudo_noexec.lo -avoid-version -rpath $(noexecdir) -shrext .so
-
-# Some hackery is required to install this as sudo_noexec, not libsudo_noexec
-sudo_noexec.la: libsudo_noexec.la
-	sed 's/libsudo_noexec/sudo_noexec/g' libsudo_noexec.la > sudo_noexec.la
-	if test -f .libs/libsudo_noexec.lai; then sed 's/libsudo_noexec/sudo_noexec/g' .libs/libsudo_noexec.lai > .libs/sudo_noexec.lai; fi
-	cp -p .libs/libsudo_noexec.so .libs/sudo_noexec.so
 
 sesh: $(SESH_OBJS) $(LT_LIBS)
 	$(LIBTOOL) $(LTFLAGS) --mode=link $(CC) -o $@ $(SESH_OBJS) $(LDFLAGS) $(ASAN_LDFLAGS) $(PIE_LDFLAGS) $(SSP_LDFLAGS) $(LIBS)