xref: /xnu-8020.121.3/bsd/kern/kdebug_triage.c (revision fdd8201d7b966f0c3ea610489d29bd841d358941)
1 /*
2  * Copyright (c) 2000-2020 Apple Inc. All rights reserved.
3  *
4  * @Apple_LICENSE_HEADER_START@
5  *
6  * The contents of this file constitute Original Code as defined in and
7  * are subject to the Apple Public Source License Version 1.1 (the
8  * "License").  You may not use this file except in compliance with the
9  * License.  Please obtain a copy of the License at
10  * http://www.apple.com/publicsource and read it before using this file.
11  *
12  * This Original Code and all software distributed under the License are
13  * distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY KIND, EITHER
14  * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
15  * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
16  * FITNESS FOR A PARTICULAR PURPOSE OR NON-INFRINGEMENT.  Please see the
17  * License for the specific language governing rights and limitations
18  * under the License.
19  *
20  * @APPLE_OSREFERENCE_LICENSE_HEADER_END@
21  */
22 
23 #include <sys/kdebug_common.h>
24 #include <sys/kdebug_triage.h>
25 
26 #define TRIAGE_KDCOPYBUF_COUNT 128
27 #define TRIAGE_KDCOPYBUF_SIZE  (TRIAGE_KDCOPYBUF_COUNT * sizeof(kd_buf))
28 
29 struct kd_ctrl_page_t kd_ctrl_page_triage = {
30 	.kds_free_list = {.raw = KDS_PTR_NULL},
31 	.mode = KDEBUG_MODE_TRIAGE,
32 	.kdebug_events_per_storage_unit = TRIAGE_EVENTS_PER_STORAGE_UNIT,
33 	.kdebug_min_storage_units_per_cpu = TRIAGE_MIN_STORAGE_UNITS_PER_CPU,
34 	.kdebug_kdcopybuf_count = TRIAGE_KDCOPYBUF_COUNT,
35 	.kdebug_kdcopybuf_size = TRIAGE_KDCOPYBUF_SIZE,
36 	.kdebug_flags = KDBG_DEBUGID_64,
37 	.kdebug_slowcheck = SLOW_NOLOG,
38 	.oldest_time = 0
39 };
40 
41 struct kd_data_page_t kd_data_page_triage = {
42 	.nkdbufs = 0,
43 	.n_storage_units = 0,
44 	.n_storage_threshold = 0,
45 	.n_storage_buffer = 0,
46 	.kdbip = NULL,
47 	.kd_bufs = NULL,
48 	.kdcopybuf = NULL
49 };
50 
51 static LCK_GRP_DECLARE(ktriage_grp, "ktriage");
52 static LCK_MTX_DECLARE(ktriage_mtx, &ktriage_grp);
53 
54 static void
ktriage_lock(void)55 ktriage_lock(void)
56 {
57 	lck_mtx_lock(&ktriage_mtx);
58 }
59 
60 static void
ktriage_unlock(void)61 ktriage_unlock(void)
62 {
63 	lck_mtx_unlock(&ktriage_mtx);
64 }
65 
66 int
create_buffers_triage(bool early_trace)67 create_buffers_triage(bool early_trace)
68 {
69 	int error = 0;
70 	int events_per_storage_unit, min_storage_units_per_cpu;
71 
72 	if (kd_ctrl_page_triage.kdebug_flags & KDBG_BUFINIT) {
73 		panic("create_buffers_triage shouldn't be called once we have inited the triage system.");
74 	}
75 
76 	events_per_storage_unit = kd_ctrl_page_triage.kdebug_events_per_storage_unit;
77 	min_storage_units_per_cpu = kd_ctrl_page_triage.kdebug_min_storage_units_per_cpu;
78 
79 	kd_ctrl_page_triage.kdebug_cpus = kdbg_cpu_count(early_trace);
80 	kd_ctrl_page_triage.kdebug_iops = NULL;
81 
82 	if (kd_data_page_triage.nkdbufs < (kd_ctrl_page_triage.kdebug_cpus * events_per_storage_unit * min_storage_units_per_cpu)) {
83 		kd_data_page_triage.n_storage_units = kd_ctrl_page_triage.kdebug_cpus * min_storage_units_per_cpu;
84 	} else {
85 		kd_data_page_triage.n_storage_units = kd_data_page_triage.nkdbufs / events_per_storage_unit;
86 	}
87 
88 	kd_data_page_triage.nkdbufs = kd_data_page_triage.n_storage_units * events_per_storage_unit;
89 
90 	kd_data_page_triage.kd_bufs = NULL;
91 
92 	error = create_buffers(&kd_ctrl_page_triage, &kd_data_page_triage, VM_KERN_MEMORY_TRIAGE);
93 
94 	if (!error) {
95 		kd_ctrl_page_triage.oldest_time = mach_continuous_time();
96 		kd_ctrl_page_triage.enabled = 1;
97 		kd_data_page_triage.n_storage_threshold = kd_data_page_triage.n_storage_units / 2;
98 	}
99 
100 	return error;
101 }
102 
103 __attribute__((noreturn))
104 void
delete_buffers_triage(void)105 delete_buffers_triage(void)
106 {
107 	/*
108 	 * If create_buffers() for triage mode fails, it will call the generic delete_buffers() to
109 	 * free the resources. This specific call should never be invoked because we expect the
110 	 * triage system to always be ON.
111 	 */
112 	panic("delete_buffers_triage shouldn't be invoked");
113 }
114 
115 const char *ktriage_error_index_invalid_str = "Error descr index invalid\n";
116 const char *ktriage_error_subsyscode_invalid_str = "KTriage: Subsystem code invalid\n";
117 
118 static void
kernel_triage_convert_to_string(uint64_t debugid,char * buf)119 kernel_triage_convert_to_string(uint64_t debugid, char *buf)
120 {
121 	if (buf == NULL) {
122 		return;
123 	}
124 
125 	int subsystem = KDBG_TRIAGE_EXTRACT_CLASS(debugid);
126 	size_t prefixlen, msglen;
127 
128 	if (subsystem <= KDBG_TRIAGE_SUBSYS_MAX) {
129 		switch (subsystem) {
130 		case KDBG_TRIAGE_SUBSYS_VM:
131 		{
132 			prefixlen = strlen(*vm_triage_strings[0]);
133 			strlcpy(buf, (const char*)(*vm_triage_strings[0]), prefixlen + 1); /* we'll overwrite NULL with rest of string below */
134 
135 			int strindx = KDBG_TRIAGE_EXTRACT_CODE(debugid);
136 			if (strindx >= 1) { /* 0 is reserved for prefix */
137 				if (strindx < VM_MAX_TRIAGE_STRINGS) {
138 					msglen = MIN(KDBG_TRIAGE_MAX_STRLEN - prefixlen, strlen(*vm_triage_strings[strindx]) + 1); /* incl. NULL termination */
139 					strlcpy(buf + prefixlen, (const char*)(*vm_triage_strings[strindx]), msglen);
140 				} else {
141 					msglen = MIN(KDBG_TRIAGE_MAX_STRLEN - prefixlen, strlen(ktriage_error_index_invalid_str) + 1); /* incl. NULL termination */
142 					strlcpy(buf + prefixlen, ktriage_error_index_invalid_str, msglen);
143 				}
144 			} else {
145 				msglen = MIN(KDBG_TRIAGE_MAX_STRLEN - prefixlen, strlen(ktriage_error_index_invalid_str) + 1); /* incl. NULL termination */
146 				strlcpy(buf + prefixlen, ktriage_error_index_invalid_str, msglen);
147 			}
148 			break;
149 		}
150 
151 		case KDBG_TRIAGE_SUBSYS_CLUSTER:
152 		{
153 			prefixlen = strlen(*cluster_triage_strings[0]);
154 			strlcpy(buf, (const char*)(*cluster_triage_strings[0]), prefixlen + 1); /* we'll overwrite NULL with rest of string below */
155 
156 			int strindx = KDBG_TRIAGE_EXTRACT_CODE(debugid);
157 			if (strindx >= 1) { /* 0 is reserved for prefix */
158 				if (strindx < CLUSTER_MAX_TRIAGE_STRINGS) {
159 					msglen = MIN(KDBG_TRIAGE_MAX_STRLEN - prefixlen, strlen(*cluster_triage_strings[strindx]) + 1); /* incl. NULL termination */
160 					strlcpy(buf + prefixlen, (const char*)(*cluster_triage_strings[strindx]), msglen);
161 				} else {
162 					msglen = MIN(KDBG_TRIAGE_MAX_STRLEN - prefixlen, strlen(ktriage_error_index_invalid_str) + 1); /* incl. NULL termination */
163 					strlcpy(buf + prefixlen, ktriage_error_index_invalid_str, msglen);
164 				}
165 			} else {
166 				msglen = MIN(KDBG_TRIAGE_MAX_STRLEN - prefixlen, strlen(ktriage_error_index_invalid_str) + 1); /* incl. NULL termination */
167 				strlcpy(buf + prefixlen, ktriage_error_index_invalid_str, msglen);
168 			}
169 			break;
170 		}
171 		case KDBG_TRIAGE_SUBSYS_SHARED_REGION:
172 		{
173 			prefixlen = strlen(*shared_region_triage_strings[0]);
174 			strlcpy(buf, (const char*)(*shared_region_triage_strings[0]), prefixlen + 1); /* we'll overwrite NULL with rest of string below */
175 
176 			int strindx = KDBG_TRIAGE_EXTRACT_CODE(debugid);
177 			if (strindx >= 1) { /* 0 is reserved for prefix */
178 				if (strindx < SHARED_REGION_MAX_TRIAGE_STRINGS) {
179 					msglen = MIN(KDBG_TRIAGE_MAX_STRLEN - prefixlen, strlen(*shared_region_triage_strings[strindx]) + 1); /* incl. NULL termination */
180 					strlcpy(buf + prefixlen, (const char*)(*shared_region_triage_strings[strindx]), msglen);
181 				} else {
182 					msglen = MIN(KDBG_TRIAGE_MAX_STRLEN - prefixlen, strlen(ktriage_error_index_invalid_str) + 1); /* incl. NULL termination */
183 					strlcpy(buf + prefixlen, ktriage_error_index_invalid_str, msglen);
184 				}
185 			} else {
186 				msglen = MIN(KDBG_TRIAGE_MAX_STRLEN - prefixlen, strlen(ktriage_error_index_invalid_str) + 1); /* incl. NULL termination */
187 				strlcpy(buf + prefixlen, ktriage_error_index_invalid_str, msglen);
188 			}
189 			break;
190 		}
191 		default:
192 			break;
193 		}
194 		;
195 	} else {
196 		msglen = MIN(KDBG_TRIAGE_MAX_STRLEN, strlen(ktriage_error_subsyscode_invalid_str) + 1);  /* incl. NULL termination */
197 		strlcpy(buf, ktriage_error_subsyscode_invalid_str, msglen);
198 	}
199 
200 	return;
201 }
202 
203 void
kernel_triage_record(uint64_t thread_id,uint64_t debugid,uintptr_t arg)204 kernel_triage_record(
205 	uint64_t thread_id,
206 	uint64_t debugid,
207 	uintptr_t arg)
208 {
209 	struct kd_record kd_rec;
210 
211 	if (thread_id == 0) {
212 		thread_id = thread_tid(current_thread());
213 	}
214 
215 	kd_rec.cpu = -1;
216 	kd_rec.timestamp = -1;
217 
218 	/*
219 	 * use 64-bit debugid per our flag KDBG_DEBUGID_64
220 	 * that is set in kd_ctrl_page_triage (on LP64 only).
221 	 */
222 	assert(kd_ctrl_page_triage.kdebug_flags & KDBG_DEBUGID_64);
223 
224 	kd_rec.debugid = 0;
225 	kd_rec.arg4 = (uintptr_t)debugid;
226 
227 	kd_rec.arg1 = arg;
228 	kd_rec.arg2 = 0;
229 	kd_rec.arg3 = 0;
230 	kd_rec.arg5 = (uintptr_t)thread_id;
231 
232 	kernel_debug_write(&kd_ctrl_page_triage,
233 	    &kd_data_page_triage,
234 	    kd_rec);
235 }
236 
237 void
kernel_triage_extract(uint64_t thread_id,void * buf,uint32_t bufsz)238 kernel_triage_extract(
239 	uint64_t thread_id,
240 	void *buf,
241 	uint32_t bufsz)
242 {
243 	size_t i, record_bytes, record_cnt, record_bufsz;
244 	void *record_buf;
245 	void *local_buf;
246 	int ret;
247 
248 
249 	if (thread_id == 0 || buf == NULL || bufsz < KDBG_TRIAGE_MAX_STRLEN) {
250 		return;
251 	}
252 
253 	local_buf = buf;
254 	bzero(local_buf, bufsz);
255 
256 	record_bytes = record_bufsz = kd_data_page_triage.nkdbufs * sizeof(kd_buf);
257 	record_buf = kalloc_data(record_bufsz, Z_WAITOK);
258 
259 	if (record_buf == NULL) {
260 		ret = ENOMEM;
261 	} else {
262 		ktriage_lock();
263 		ret = kernel_debug_read(&kd_ctrl_page_triage,
264 		    &kd_data_page_triage,
265 		    (user_addr_t) record_buf, &record_bytes, NULL, NULL, 0);
266 		ktriage_unlock();
267 	}
268 
269 	if (ret) {
270 		printf("kernel_triage_extract: kernel_debug_read failed with %d\n", ret);
271 		kfree_data(record_buf, record_bufsz);
272 		return;
273 	}
274 
275 	kd_buf *kd = (kd_buf*) record_buf;
276 	i = 0;
277 	record_cnt = record_bytes; /* kernel_debug_read() takes number of bytes that it
278 	                            * converts to kd_bufs. It processes a max of those and
279 	                            * returns number of kd_buf read/processed. We use a
280 	                            * different variable here to make our units clear.
281 	                            */
282 
283 	while (i < record_cnt) {
284 		if (kd->arg5 == (uintptr_t)thread_id) {
285 			kernel_triage_convert_to_string(kd->arg4, local_buf);
286 			local_buf = (void *)((uintptr_t)local_buf + KDBG_TRIAGE_MAX_STRLEN);
287 			bufsz -= KDBG_TRIAGE_MAX_STRLEN;
288 			if (bufsz < KDBG_TRIAGE_MAX_STRLEN) {
289 				break;
290 			}
291 		}
292 		i++;
293 		kd++;
294 	}
295 
296 	kfree_data(record_buf, record_bufsz);
297 }
298 
299 
300 /* KDBG_TRIAGE_CODE_* section */
301 /* VM begin */
302 
303 const char *vm_triage_strings[VM_MAX_TRIAGE_STRINGS][KDBG_TRIAGE_MAX_STRLEN] =
304 {
305 	{"VM - "}, /* VM message prefix */
306 	{"Didn't get back data for this file\n"}, /* KDBG_TRIAGE_VM_NO_DATA */
307 	{"A memory corruption was found in executable text\n"}, /* KDBG_TRIAGE_VM_TEXT_CORRUPTION */
308 	{"Found no valid range containing this address\n"}, /* KDBG_TRIAGE_VM_ADDRESS_NOT_FOUND */
309 	{"Fault hit protection failure\n"}, /* KDBG_TRIAGE_VM_PROTECTION_FAILURE */
310 	{"Fault hit memory shortage\n"}, /* KDBG_TRIAGE_VM_MEMORY_SHORTAGE */
311 	{"Fault was interrupted\n"}, /* KDBG_TRIAGE_VM_FAULT_INTERRUPTED */
312 	{"Returned success with no page\n"}, /* KDBG_TRIAGE_VM_SUCCESS_NO_PAGE */
313 	{"Guard page fault\n"}, /* KDBG_TRIAGE_VM_GUARDPAGE_FAULT */
314 	{"Fault entered with non-zero preemption level\n"}, /* KDBG_TRIAGE_VM_NONZERO_PREEMPTION_LEVEL */
315 	{"Waiting on busy page was interrupted\n"}, /* KDBG_TRIAGE_VM_BUSYPAGE_WAIT_INTERRUPTED */
316 	{"Purgeable object hit an error in fault\n"}, /* KDBG_TRIAGE_VM_PURGEABLE_FAULT_ERROR */
317 	{"Object has a shadow severed\n"}, /* KDBG_TRIAGE_VM_OBJECT_SHADOW_SEVERED */
318 	{"Object is not alive\n"}, /* KDBG_TRIAGE_VM_OBJECT_NOT_ALIVE */
319 	{"Object has no pager\n"}, /* KDBG_TRIAGE_VM_OBJECT_NO_PAGER */
320 	{"Page has error bit set\n"}, /* KDBG_TRIAGE_VM_PAGE_HAS_ERROR */
321 	{"Page has restart bit set\n"}, /* KDBG_TRIAGE_VM_PAGE_HAS_RESTART */
322 	{"Failed a writable mapping of an immutable page\n"}, /* KDBG_TRIAGE_VM_FAILED_IMMUTABLE_PAGE_WRITE */
323 	{"Failed an executable mapping of a nx page\n"}, /* KDBG_TRIAGE_VM_FAILED_NX_PAGE_EXEC_MAPPING */
324 	{"pmap_enter failed with resource shortage\n"}, /* KDBG_TRIAGE_VM_PMAP_ENTER_RESOURCE_SHORTAGE */
325 	{"Compressor offset requested out of range\n"}, /* KDBG_TRIAGE_VM_COMPRESSOR_GET_OUT_OF_RANGE */
326 	{"Compressor doesn't have this page\n"}, /* KDBG_TRIAGE_VM_COMPRESSOR_GET_NO_PAGE */
327 	{"Decompressor hit a failure\n"}, /* KDBG_TRIAGE_VM_COMPRESSOR_DECOMPRESS_FAILED */
328 	{"Compressor failed a blocking pager_get\n"}, /* KDBG_TRIAGE_VM_COMPRESSOR_BLOCKING_OP_FAILED */
329 	{"Submap disallowed cow on executable range\n"}, /* KDBG_TRIAGE_VM_SUBMAP_NO_COW_ON_EXECUTABLE */
330 	{"Submap object copy_slowly failed\n"}, /* KDBG_TRIAGE_VM_SUBMAP_COPY_SLOWLY_FAILED */
331 	{"Submap object copy_strategically failed\n"}, /* KDBG_TRIAGE_VM_SUBMAP_COPY_STRAT_FAILED */
332 	{"vnode_pager_cluster_read couldn't create a UPL\n"}, /* KDBG_TRIAGE_VM_VNODEPAGER_CLREAD_NO_UPL */
333 	{"vnode_pagein got a vnode with no ubcinfo\n"}, /* KDBG_TRIAGE_VM_VNODEPAGEIN_NO_UBCINFO */
334 	{"Filesystem pagein returned an error in vnode_pagein\n"}, /* KDBG_TRIAGE_VM_VNODEPAGEIN_FSPAGEIN_FAIL */
335 	{"vnode_pagein couldn't create a UPL\n"} /* KDBG_TRIAGE_VM_VNODEPAGEIN_NO_UPL*/
336 };
337 /* VM end */
338 
339 /* Cluster begin */
340 
341 const char *cluster_triage_strings[CLUSTER_MAX_TRIAGE_STRINGS][KDBG_TRIAGE_MAX_STRLEN] =
342 {
343 	{"CL - "}, /* Cluster message prefix */
344 	{"cluster_pagein past EOF\n"} /* KDBG_TRIAGE_CL_PGIN_PAST_EOF */
345 };
346 /* Cluster end */
347 
348 /* Shared Region begin */
349 
350 const char *shared_region_triage_strings[SHARED_REGION_MAX_TRIAGE_STRINGS][KDBG_TRIAGE_MAX_STRLEN] =
351 {
352 	{"SR - "}, /* Shared region message prefix */
353 	{"shared_region_pager_data_request couldn't create a upl\n"}, /* KDBG_TRIAGE_SHARED_REGION_NO_UPL */
354 	{"shared_region_pager_data_request hit a page sliding error\n"} /* KDBG_TRIAGE_SHARED_REGION_SLIDE_ERROR */
355 };
356 /* Shared Region end */
357 /* KDBG_TRIAGE_CODE_* section */
358