1 /*
2 * Copyright (c) 2017 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 <kern/ux_handler.h>
30 #include <sys/ux_exception.h>
31
32 #include <mach/exception.h>
33 #include <mach/kern_return.h>
34 #include <mach/port.h>
35 #include <mach/mach_port.h>
36 #include <mach/mig_errors.h>
37
38 #include <kern/thread.h>
39 #include <kern/task.h>
40 #include <kern/ipc_kobject.h>
41 #include <kern/ipc_tt.h>
42
43 #include <ipc/ipc_port.h>
44
45 #include <mach/host_priv.h>
46 #include <kern/host.h>
47
48 #include <mach/exc_server.h>
49 #include <mach/mach_exc_server.h>
50
51 #include <libkern/section_keywords.h>
52
53 /*
54 * Mach kobject port to reflect Mach exceptions into Unix signals.
55 *
56 * This is the default Mach exception handler for initproc, which
57 * then filters to all subprocesses as the host level exception handler for
58 * most Mach exceptions.
59 */
60
61 static SECURITY_READ_ONLY_LATE(const void *) ux_handler_kobject = NULL;
62 SECURITY_READ_ONLY_LATE(ipc_port_t) ux_handler_port = IP_NULL;
63
64 IPC_KOBJECT_DEFINE(IKOT_UX_HANDLER,
65 .iko_op_stable = true,
66 .iko_op_permanent = true);
67
68 /*
69 * init is called early in Mach initialization
70 * when we can initialize read-only memory
71 */
72 void
ux_handler_init(void)73 ux_handler_init(void)
74 {
75 ux_handler_port = ipc_kobject_alloc_port((ipc_kobject_t)&ux_handler_kobject,
76 IKOT_UX_HANDLER, IPC_KOBJECT_ALLOC_NONE);
77 }
78
79 /*
80 * setup is called late in BSD initialization from initproc's context
81 * so the MAC hook goo inside host_set_exception_ports will be able to
82 * set up labels without falling over.
83 */
84 void
ux_handler_setup(void)85 ux_handler_setup(void)
86 {
87 ipc_port_t ux_handler_send_right = ipc_port_make_send(ux_handler_port);
88
89 if (!IP_VALID(ux_handler_send_right)) {
90 panic("Couldn't allocate send right for ux_handler_port!");
91 }
92
93 kern_return_t kr = KERN_SUCCESS;
94
95 /*
96 * Consumes 1 send right.
97 *
98 * Instruments uses the RPC_ALERT port, so don't register for that.
99 */
100 kr = host_set_exception_ports(host_priv_self(),
101 EXC_MASK_ALL & ~(EXC_MASK_RPC_ALERT | EXC_MASK_GUARD),
102 ux_handler_send_right,
103 EXCEPTION_DEFAULT | MACH_EXCEPTION_CODES,
104 0);
105
106 if (kr != KERN_SUCCESS) {
107 panic("host_set_exception_ports failed to set ux_handler! %d", kr);
108 }
109 }
110
111 /*
112 * Is this port the ux_handler?
113 * If so, it's safe to send an exception without checking labels.
114 */
115 boolean_t
is_ux_handler_port(mach_port_t port)116 is_ux_handler_port(mach_port_t port)
117 {
118 if (ux_handler_port == port) {
119 return TRUE;
120 } else {
121 return FALSE;
122 }
123 }
124
125 kern_return_t
catch_mach_exception_raise(mach_port_t exception_port,mach_port_t thread_port,mach_port_t task_port,exception_type_t exception,mach_exception_data_t code,__unused mach_msg_type_number_t codeCnt)126 catch_mach_exception_raise(
127 mach_port_t exception_port,
128 mach_port_t thread_port,
129 mach_port_t task_port,
130 exception_type_t exception,
131 mach_exception_data_t code,
132 __unused mach_msg_type_number_t codeCnt)
133 {
134 if (exception_port != ux_handler_port) {
135 return KERN_FAILURE;
136 }
137
138 kern_return_t kr = KERN_SUCCESS;
139
140 thread_t target_thread = THREAD_NULL;
141 task_t target_task = TASK_NULL;
142
143 if ((target_thread = convert_port_to_thread(thread_port)) == THREAD_NULL) {
144 kr = KERN_INVALID_ARGUMENT;
145 goto out;
146 }
147
148 if ((target_task = convert_port_to_task(task_port)) == TASK_NULL) {
149 kr = KERN_INVALID_ARGUMENT;
150 goto out;
151 }
152
153 kr = handle_ux_exception(target_thread, exception, code[0], code[1]);
154
155 out:
156 if (kr == KERN_SUCCESS) {
157 /*
158 * Following the MIG 'consume on success' protocol,
159 * consume references to the port arguments.
160 * (but NOT the exception_port, as the first argument is borrowed)
161 *
162 * If we return non-success, the kobject server will eat the port
163 * references for us.
164 */
165
166 ipc_port_release_send(thread_port);
167 ipc_port_release_send(task_port);
168 }
169
170 thread_deallocate(target_thread);
171 task_deallocate(target_task);
172
173 return kr;
174 }
175
176 kern_return_t
catch_exception_raise(mach_port_t exception_port,mach_port_t thread,mach_port_t task,exception_type_t exception,exception_data_t code,mach_msg_type_number_t codeCnt)177 catch_exception_raise(
178 mach_port_t exception_port,
179 mach_port_t thread,
180 mach_port_t task,
181 exception_type_t exception,
182 exception_data_t code,
183 mach_msg_type_number_t codeCnt)
184 {
185 if (exception_port != ux_handler_port) {
186 return KERN_FAILURE;
187 }
188
189 mach_exception_data_type_t big_code[EXCEPTION_CODE_MAX] = {
190 [0] = code[0],
191 [1] = code[1],
192 };
193
194 return catch_mach_exception_raise(exception_port,
195 thread,
196 task,
197 exception,
198 big_code,
199 codeCnt);
200 }
201
202 kern_return_t
catch_exception_raise_state(__unused mach_port_t exception_port,__unused exception_type_t exception,__unused const exception_data_t code,__unused mach_msg_type_number_t codeCnt,__unused int * flavor,__unused const thread_state_t old_state,__unused mach_msg_type_number_t old_stateCnt,__unused thread_state_t new_state,__unused mach_msg_type_number_t * new_stateCnt)203 catch_exception_raise_state(
204 __unused mach_port_t exception_port,
205 __unused exception_type_t exception,
206 __unused const exception_data_t code,
207 __unused mach_msg_type_number_t codeCnt,
208 __unused int *flavor,
209 __unused const thread_state_t old_state,
210 __unused mach_msg_type_number_t old_stateCnt,
211 __unused thread_state_t new_state,
212 __unused mach_msg_type_number_t *new_stateCnt)
213 {
214 return KERN_INVALID_ARGUMENT;
215 }
216
217 kern_return_t
catch_mach_exception_raise_state(__unused mach_port_t exception_port,__unused exception_type_t exception,__unused const mach_exception_data_t code,__unused mach_msg_type_number_t codeCnt,__unused int * flavor,__unused const thread_state_t old_state,__unused mach_msg_type_number_t old_stateCnt,__unused thread_state_t new_state,__unused mach_msg_type_number_t * new_stateCnt)218 catch_mach_exception_raise_state(
219 __unused mach_port_t exception_port,
220 __unused exception_type_t exception,
221 __unused const mach_exception_data_t code,
222 __unused mach_msg_type_number_t codeCnt,
223 __unused int *flavor,
224 __unused const thread_state_t old_state,
225 __unused mach_msg_type_number_t old_stateCnt,
226 __unused thread_state_t new_state,
227 __unused mach_msg_type_number_t *new_stateCnt)
228 {
229 return KERN_INVALID_ARGUMENT;
230 }
231
232 kern_return_t
catch_exception_raise_state_identity(__unused mach_port_t exception_port,__unused mach_port_t thread,__unused mach_port_t task,__unused exception_type_t exception,__unused exception_data_t code,__unused mach_msg_type_number_t codeCnt,__unused int * flavor,__unused thread_state_t old_state,__unused mach_msg_type_number_t old_stateCnt,__unused thread_state_t new_state,__unused mach_msg_type_number_t * new_stateCnt)233 catch_exception_raise_state_identity(
234 __unused mach_port_t exception_port,
235 __unused mach_port_t thread,
236 __unused mach_port_t task,
237 __unused exception_type_t exception,
238 __unused exception_data_t code,
239 __unused mach_msg_type_number_t codeCnt,
240 __unused int *flavor,
241 __unused thread_state_t old_state,
242 __unused mach_msg_type_number_t old_stateCnt,
243 __unused thread_state_t new_state,
244 __unused mach_msg_type_number_t *new_stateCnt)
245 {
246 return KERN_INVALID_ARGUMENT;
247 }
248
249 kern_return_t
catch_mach_exception_raise_state_identity(__unused mach_port_t exception_port,__unused mach_port_t thread,__unused mach_port_t task,__unused exception_type_t exception,__unused mach_exception_data_t code,__unused mach_msg_type_number_t codeCnt,__unused int * flavor,__unused thread_state_t old_state,__unused mach_msg_type_number_t old_stateCnt,__unused thread_state_t new_state,__unused mach_msg_type_number_t * new_stateCnt)250 catch_mach_exception_raise_state_identity(
251 __unused mach_port_t exception_port,
252 __unused mach_port_t thread,
253 __unused mach_port_t task,
254 __unused exception_type_t exception,
255 __unused mach_exception_data_t code,
256 __unused mach_msg_type_number_t codeCnt,
257 __unused int *flavor,
258 __unused thread_state_t old_state,
259 __unused mach_msg_type_number_t old_stateCnt,
260 __unused thread_state_t new_state,
261 __unused mach_msg_type_number_t *new_stateCnt)
262 {
263 return KERN_INVALID_ARGUMENT;
264 }
265
266 kern_return_t
catch_mach_exception_raise_identity_protected(__unused mach_port_t exception_port,__unused uint64_t thread_id,__unused mach_port_t task_id_token,__unused exception_type_t exception,__unused mach_exception_data_t code,__unused mach_msg_type_number_t codeCnt)267 catch_mach_exception_raise_identity_protected(
268 __unused mach_port_t exception_port,
269 __unused uint64_t thread_id,
270 __unused mach_port_t task_id_token,
271 __unused exception_type_t exception,
272 __unused mach_exception_data_t code,
273 __unused mach_msg_type_number_t codeCnt)
274 {
275 return KERN_INVALID_ARGUMENT;
276 }
277