1 /*
2 * Copyright (c) 2010 Apple Inc. All rights reserved.
3 *
4 * @APPLE_OSREFERENCE_LICENSE_HEADER_START@
5 *
6 * This file contains Original Code and/or Modifications of Original Code
7 * as defined in and that are subject to the Apple Public Source License
8 * Version 2.0 (the 'License'). You may not use this file except in
9 * compliance with the License. The rights granted to you under the License
10 * may not be used to create, or enable the creation or redistribution of,
11 * unlawful or unlicensed copies of an Apple operating system, or to
12 * circumvent, violate, or enable the circumvention or violation of, any
13 * terms of an Apple operating system software license agreement.
14 *
15 * Please obtain a copy of the License at
16 * http://www.opensource.apple.com/apsl/ and read it before using this file.
17 *
18 * The Original Code and all software distributed under the License are
19 * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
20 * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
21 * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
22 * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
23 * Please see the License for the specific language governing rights and
24 * limitations under the License.
25 *
26 * @APPLE_OSREFERENCE_LICENSE_HEADER_END@
27 */
28
29 #include <mach/mach.h>
30 #include <mach/mach_init.h>
31 #include <sys/cdefs.h>
32 #include "tsd.h"
33
34
35 #pragma mark Utilities
36 #define _mach_assert(__op, __kr) \
37 do { \
38 if (kr != KERN_SUCCESS) { \
39 __builtin_trap(); \
40 } \
41 } while (0)
42
43 __XNU_PRIVATE_EXTERN mach_port_t _task_reply_port = MACH_PORT_NULL;
44
45 static inline mach_port_t
_mig_get_reply_port(void)46 _mig_get_reply_port(void)
47 {
48 return (mach_port_t)(uintptr_t)_os_tsd_get_direct(__TSD_MIG_REPLY);
49 }
50
51 static inline void
_mig_set_reply_port(mach_port_t port)52 _mig_set_reply_port(mach_port_t port)
53 {
54 _os_tsd_set_direct(__TSD_MIG_REPLY, (void *)(uintptr_t)port);
55 }
56
57 /*
58 * Called by mig interface code whenever a reply port is needed.
59 * Tracing is masked during this call; otherwise, a call to printf()
60 * can result in a call to malloc() which eventually reenters
61 * mig_get_reply_port() and deadlocks.
62 */
63 mach_port_t
mig_get_reply_port(void)64 mig_get_reply_port(void)
65 {
66 mach_port_t port = _mig_get_reply_port();
67 if (port == MACH_PORT_NULL) {
68 kern_return_t kr;
69 mach_port_options_t opts = {
70 .flags = MPO_REPLY_PORT,
71 };
72
73 kr = mach_port_construct(mach_task_self(), &opts, NULL, &port);
74 _mach_assert("mach_port_construct for mig_get_reply_port", kr);
75 _mig_set_reply_port(port);
76 }
77 return port;
78 }
79
80 /*
81 * Called by mig interface code after a timeout on the reply port.
82 * May also be called by user. The new mig calls with port passed in.
83 */
84 void
mig_dealloc_reply_port(mach_port_t migport)85 mig_dealloc_reply_port(mach_port_t migport)
86 {
87 mach_port_t port = _mig_get_reply_port();
88 if (port != MACH_PORT_NULL && port != _task_reply_port) {
89 _mig_set_reply_port(_task_reply_port);
90 (void) mach_port_mod_refs(mach_task_self(), port, MACH_PORT_RIGHT_RECEIVE, -1);
91 if (migport != port) {
92 (void) mach_port_deallocate(mach_task_self(), migport);
93 }
94 _mig_set_reply_port(MACH_PORT_NULL);
95 }
96 }
97
98 /*************************************************************
99 * Called by mig interfaces after each RPC.
100 * Could be called by user.
101 ***********************************************************/
102
103 void
mig_put_reply_port(mach_port_t reply_port __unused)104 mig_put_reply_port(mach_port_t reply_port __unused)
105 {
106 }
107