1# 2# CDDL HEADER START 3# 4# The contents of this file are subject to the terms of the 5# Common Development and Distribution License (the "License"). 6# You may not use this file except in compliance with the License. 7# 8# You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE 9# or http://www.opensolaris.org/os/licensing. 10# See the License for the specific language governing permissions 11# and limitations under the License. 12# 13# When distributing Covered Code, include this CDDL HEADER in each 14# file and include the License file at usr/src/OPENSOLARIS.LICENSE. 15# If applicable, add the following below this CDDL HEADER, with the 16# fields enclosed by brackets "[]" replaced with your own identifying 17# information: Portions Copyright [yyyy] [name of copyright owner] 18# 19# CDDL HEADER END 20# 21 22# 23# Copyright (c) 2012, Joyent, Inc. All rights reserved. 24# 25 26# 27# Somewhat surprisingly, DTrace very much relies on the fact that when 32-bit 28# is forced, pointers are not, in fact, narrowed to 32-bits. In particular, if 29# this is not so (that is, if pointers are narrowed to their seemingly correct 30# 32-bit width), helpers attached to 32-bit programs will fail to operate: 31# they will erroneously zero the high 32-bits of the return values of 64-bit 32# kernel pointers as returned by copyin(), alloca(), etc. This test asserts 33# this implicit behavior -- and this comment regrettably serves as this 34# behavior's only documentation. 35# 36doit() 37{ 38 /usr/sbin/dtrace $1 -n BEGIN'{trace(sizeof (long))}' \ 39 -n 'BEGIN{*(int *)alloca(4) = 21506; exit(0)}' \ 40 -n 'ERROR{exit(1)}' 41 42 if [ "$?" -ne 0 ]; then 43 exit $? 44 fi 45} 46 47doit 48doit -32 49