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2d21ac55 1/*
cc8bc92a 2 * Copyright (c) 2006-2017 Apple Inc. All rights reserved.
2d21ac55
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3 *
4 * @APPLE_OSREFERENCE_LICENSE_HEADER_START@
0a7de745 5 *
2d21ac55
A
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.
0a7de745 14 *
2d21ac55
A
15 * Please obtain a copy of the License at
16 * http://www.opensource.apple.com/apsl/ and read it before using this file.
0a7de745 17 *
2d21ac55
A
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.
0a7de745 25 *
2d21ac55
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26 * @APPLE_OSREFERENCE_LICENSE_HEADER_END@
27 */
28
2d21ac55
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29#include <sys/errno.h>
30#include <sys/types.h>
31#include <sys/malloc.h>
32#include <sys/buf.h>
33#include <sys/time.h>
34#include <sys/kauth.h>
35#include <sys/mount.h>
36#include <sys/vnode.h>
39236c6e 37#include <sys/syslog.h>
2d21ac55 38#include <sys/vnode_internal.h>
2d21ac55
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39#include <sys/fslog.h>
40#include <sys/mount_internal.h>
39236c6e 41#include <sys/kasl.h>
2d21ac55 42
cc8bc92a
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43#include <sys/queue.h>
44#include <kern/kalloc.h>
2d21ac55 45
39236c6e 46#include <uuid/uuid.h>
2d21ac55 47
39236c6e 48#include <stdarg.h>
2d21ac55 49
39236c6e
A
50/* Log information about external modification of a process,
51 * using MessageTracer formatting. Assumes that both the caller
52 * and target are appropriately locked.
0a7de745
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53 * Currently prints following information -
54 * 1. Caller process name (truncated to 16 characters)
39236c6e
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55 * 2. Caller process Mach-O UUID
56 * 3. Target process name (truncated to 16 characters)
57 * 4. Target process Mach-O UUID
2d21ac55 58 */
39236c6e
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59void
60fslog_extmod_msgtracer(proc_t caller, proc_t target)
2d21ac55 61{
39236c6e 62 if ((caller != PROC_NULL) && (target != PROC_NULL)) {
39236c6e
A
63 /*
64 * Print into buffer large enough for "ThisIsAnApplicat(BC223DD7-B314-42E0-B6B0-C5D2E6638337)",
65 * including space for escaping, and NUL byte included in sizeof(uuid_string_t).
2d21ac55 66 */
2d21ac55 67
39236c6e 68 uuid_string_t uuidstr;
0a7de745
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69 char c_name[2 * MAXCOMLEN + 2 /* () */ + sizeof(uuid_string_t)];
70 char t_name[2 * MAXCOMLEN + 2 /* () */ + sizeof(uuid_string_t)];
2d21ac55 71
39236c6e
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72 strlcpy(c_name, caller->p_comm, sizeof(c_name));
73 uuid_unparse_upper(caller->p_uuid, uuidstr);
74 strlcat(c_name, "(", sizeof(c_name));
75 strlcat(c_name, uuidstr, sizeof(c_name));
76 strlcat(c_name, ")", sizeof(c_name));
d9a64523 77 if (0 != escape_str(c_name, strlen(c_name) + 1, sizeof(c_name))) {
39236c6e 78 return;
2d21ac55 79 }
2d21ac55 80
39236c6e
A
81 strlcpy(t_name, target->p_comm, sizeof(t_name));
82 uuid_unparse_upper(target->p_uuid, uuidstr);
83 strlcat(t_name, "(", sizeof(t_name));
84 strlcat(t_name, uuidstr, sizeof(t_name));
85 strlcat(t_name, ")", sizeof(t_name));
d9a64523 86 if (0 != escape_str(t_name, strlen(t_name) + 1, sizeof(t_name))) {
39236c6e
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87 return;
88 }
89#if DEBUG
90 printf("EXTMOD: %s(%d) -> %s(%d)\n",
0a7de745
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91 c_name,
92 proc_pid(caller),
93 t_name,
94 proc_pid(target));
39236c6e 95#endif
2d21ac55 96
39236c6e 97 kern_asl_msg(LOG_DEBUG, "messagetracer",
0a7de745
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98 5,
99 "com.apple.message.domain", "com.apple.kernel.external_modification", /* 0 */
100 "com.apple.message.signature", c_name, /* 1 */
101 "com.apple.message.signature2", t_name, /* 2 */
102 "com.apple.message.result", "noop", /* 3 */
103 "com.apple.message.summarize", "YES", /* 4 */
104 NULL);
39236c6e 105 }
2d21ac55
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106}
107
cc8bc92a
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108#if defined(__x86_64__)
109
110/*
111 * Log information about floating point exception handling
112 */
113
114static lck_mtx_t fpxlock;
115
116void
117fpxlog_init(void)
118{
119 lck_grp_attr_t *lck_grp_attr = lck_grp_attr_alloc_init();
120 lck_grp_t *lck_grp = lck_grp_alloc_init("fpx", lck_grp_attr);
121 lck_mtx_init(&fpxlock, lck_grp, LCK_ATTR_NULL);
122}
123
124struct fpx_event {
125 uuid_t fe_uuid;
126 uint32_t fe_code;
127 uint32_t fe_xcpt;
128 TAILQ_ENTRY(fpx_event) fe_link;
129};
130
131static bool
132match_fpx_event(const struct fpx_event *fe,
133 const uuid_t uuid, const uint32_t code, const uint32_t xcpt)
134{
0a7de745
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135 return code == fe->fe_code && xcpt == fe->fe_xcpt &&
136 0 == memcmp(uuid, fe->fe_uuid, sizeof(uuid_t));
cc8bc92a
A
137}
138
139#if FPX_EVENT_DBG
140static __attribute__((noinline)) void
141print_fpx_event(const char *pfx, const struct fpx_event *fe)
142{
143 uuid_string_t uustr;
144 uuid_unparse_upper(fe->fe_uuid, uustr);
145 printf("%s: code 0x%x xcpt 0x%x uuid '%s'\n",
146 pfx, fe->fe_code, fe->fe_xcpt, uustr);
147}
0a7de745 148#define DPRINTF_FPX_EVENT(pfx, fe) print_fpx_event(pfx, fe)
cc8bc92a 149#else
0a7de745 150#define DPRINTF_FPX_EVENT(pfx, fe) /* nothing */
cc8bc92a
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151#endif
152
0a7de745 153#define MAX_DISTINCT_FPX_EVENTS 101 /* (approx one page of heap) */
cc8bc92a
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154
155/*
156 * Filter to detect "new" <uuid, code, xcpt> tuples.
157 * Uses limited amount of state, managed LRU.
158 * Optimized to ignore repeated invocation with the same tuple.
159 *
160 * Note that there are 6 exception types, two types of FP, and
161 * many binaries, so don't make the list bound too small.
162 * It's also a linear search, so don't make it too large either.
163 * Next level filtering provided by syslogd, and summarization.
164 */
165static bool
166novel_fpx_event(const uuid_t uuid, uint32_t code, uint32_t xcpt)
167{
168 static TAILQ_HEAD(fpx_event_head, fpx_event) fehead =
0a7de745 169 TAILQ_HEAD_INITIALIZER(fehead);
cc8bc92a
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170 struct fpx_event *fe;
171
172 lck_mtx_lock(&fpxlock);
173
174 fe = TAILQ_FIRST(&fehead);
175 if (NULL != fe &&
176 match_fpx_event(fe, uuid, code, xcpt)) {
177 /* seen before and element already at head */
178 lck_mtx_unlock(&fpxlock);
179 DPRINTF_FPX_EVENT("seen, head", fe);
0a7de745 180 return false;
cc8bc92a
A
181 }
182
183 unsigned int count = 0;
184
185 TAILQ_FOREACH(fe, &fehead, fe_link) {
186 if (match_fpx_event(fe, uuid, code, xcpt)) {
187 /* seen before, now move element to head */
188 TAILQ_REMOVE(&fehead, fe, fe_link);
189 TAILQ_INSERT_HEAD(&fehead, fe, fe_link);
190 lck_mtx_unlock(&fpxlock);
191 DPRINTF_FPX_EVENT("seen, moved to head", fe);
0a7de745 192 return false;
cc8bc92a
A
193 }
194 count++;
195 }
196
197 /* not recorded here => novel */
198
199 if (count >= MAX_DISTINCT_FPX_EVENTS) {
200 /* reuse LRU element */
201 fe = TAILQ_LAST(&fehead, fpx_event_head);
202 TAILQ_REMOVE(&fehead, fe, fe_link);
203 DPRINTF_FPX_EVENT("reusing", fe);
204 } else {
205 /* add a new element to the list */
0a7de745 206 fe = kalloc(sizeof(*fe));
cc8bc92a 207 }
0a7de745 208 memcpy(fe->fe_uuid, uuid, sizeof(uuid_t));
cc8bc92a
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209 fe->fe_code = code;
210 fe->fe_xcpt = xcpt;
211 TAILQ_INSERT_HEAD(&fehead, fe, fe_link);
212 lck_mtx_unlock(&fpxlock);
213
214 DPRINTF_FPX_EVENT("novel", fe);
215
0a7de745 216 return true;
cc8bc92a
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217}
218
219void
220fpxlog(
0a7de745
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221 int code, /* Mach exception code: e.g. 5 or 8 */
222 uint32_t stat, /* Full FP status register bits */
223 uint32_t ctrl, /* Full FP control register bits */
224 uint32_t xcpt) /* Exception bits from FP status */
cc8bc92a
A
225{
226 proc_t p = current_proc();
0a7de745 227 if (PROC_NULL == p) {
cc8bc92a 228 return;
0a7de745 229 }
cc8bc92a
A
230
231 uuid_t uuid;
0a7de745 232 proc_getexecutableuuid(p, uuid, sizeof(uuid));
cc8bc92a
A
233
234 /*
235 * Check to see if an exception with this <uuid, code, xcpt>
236 * has been seen before. If "novel" then log a message.
237 */
0a7de745 238 if (!novel_fpx_event(uuid, code, xcpt)) {
cc8bc92a 239 return;
0a7de745 240 }
cc8bc92a
A
241
242 const size_t nmlen = 2 * MAXCOMLEN + 1;
243 char nm[nmlen] = {};
244 proc_selfname(nm, nmlen);
0a7de745
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245 if (escape_str(nm, strlen(nm) + 1, nmlen)) {
246 snprintf(nm, nmlen, "(a.out)");
247 }
cc8bc92a
A
248
249 const size_t slen = 8 + 1 + 8 + 1;
250 char xcptstr[slen], csrstr[slen];
251
252 snprintf(xcptstr, slen, "%x.%x", code, xcpt);
0a7de745 253 if (ctrl == stat) {
cc8bc92a 254 snprintf(csrstr, slen, "%x", ctrl);
0a7de745 255 } else {
cc8bc92a 256 snprintf(csrstr, slen, "%x.%x", ctrl, stat);
0a7de745 257 }
cc8bc92a
A
258
259#if DEVELOPMENT || DEBUG
260 printf("%s[%d]: com.apple.kernel.fpx: %s, %s\n",
0a7de745 261 nm, proc_pid(p), xcptstr, csrstr);
cc8bc92a
A
262#endif
263 kern_asl_msg(LOG_DEBUG, "messagetracer", 5,
0a7de745
A
264 /* 0 */ "com.apple.message.domain", "com.apple.kernel.fpx",
265 /* 1 */ "com.apple.message.signature", nm,
266 /* 2 */ "com.apple.message.signature2", xcptstr,
267 /* 3 */ "com.apple.message.value", csrstr,
268 /* 4 */ "com.apple.message.summarize", "YES",
269 NULL);
cc8bc92a
A
270}
271
272#else
273
274void
275fpxlog_init(void)
0a7de745
A
276{
277}
cc8bc92a
A
278
279#endif /* __x86_64__ */