xref: /freebsd/sys/kern/kern_ktr.c (revision 13de33a5dc2304b13d595d75d48c51793958474f)
1 /*-
2  * Copyright (c) 2000 John Baldwin <jhb@FreeBSD.org>
3  * All rights reserved.
4  *
5  * Redistribution and use in source and binary forms, with or without
6  * modification, are permitted provided that the following conditions
7  * are met:
8  * 1. Redistributions of source code must retain the above copyright
9  *    notice, this list of conditions and the following disclaimer.
10  * 2. Redistributions in binary form must reproduce the above copyright
11  *    notice, this list of conditions and the following disclaimer in the
12  *    documentation and/or other materials provided with the distribution.
13  * 3. Neither the name of the author nor the names of any co-contributors
14  *    may be used to endorse or promote products derived from this software
15  *    without specific prior written permission.
16  *
17  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
18  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
19  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
20  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
21  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
22  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
23  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
24  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
25  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
26  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
27  * SUCH DAMAGE.
28  */
29 
30 /*
31  * This module holds the global variables used by KTR and the ktr_tracepoint()
32  * function that does the actual tracing.
33  */
34 
35 #include <sys/cdefs.h>
36 __FBSDID("$FreeBSD$");
37 
38 #include "opt_ddb.h"
39 #include "opt_ktr.h"
40 #include "opt_alq.h"
41 
42 #include <sys/param.h>
43 #include <sys/queue.h>
44 #include <sys/alq.h>
45 #include <sys/cons.h>
46 #include <sys/cpuset.h>
47 #include <sys/kernel.h>
48 #include <sys/ktr.h>
49 #include <sys/libkern.h>
50 #include <sys/lock.h>
51 #include <sys/malloc.h>
52 #include <sys/mutex.h>
53 #include <sys/proc.h>
54 #include <sys/smp.h>
55 #include <sys/sysctl.h>
56 #include <sys/systm.h>
57 #include <sys/time.h>
58 
59 #include <machine/cpu.h>
60 #ifdef __sparc64__
61 #include <machine/ktr.h>
62 #endif
63 
64 #ifdef DDB
65 #include <ddb/ddb.h>
66 #include <ddb/db_output.h>
67 #endif
68 
69 #ifndef KTR_BOOT_ENTRIES
70 #define	KTR_BOOT_ENTRIES	1024
71 #endif
72 
73 #ifndef KTR_ENTRIES
74 #define	KTR_ENTRIES	1024
75 #endif
76 
77 /* Limit the allocations to something manageable. */
78 #define	KTR_ENTRIES_MAX	(8 * 1024 * 1024)
79 
80 #ifndef KTR_MASK
81 #define	KTR_MASK	(0)
82 #endif
83 
84 #ifndef KTR_CPUMASK
85 #define	KTR_CPUMASK	CPUSET_FSET
86 #endif
87 
88 #ifndef KTR_TIME
89 #define	KTR_TIME	get_cyclecount()
90 #endif
91 
92 #ifndef KTR_CPU
93 #define	KTR_CPU		PCPU_GET(cpuid)
94 #endif
95 
96 static MALLOC_DEFINE(M_KTR, "KTR", "KTR");
97 
98 FEATURE(ktr, "Kernel support for KTR kernel tracing facility");
99 
100 volatile int	ktr_idx = 0;
101 int	ktr_mask = KTR_MASK;
102 int	ktr_compile = KTR_COMPILE;
103 int	ktr_entries = KTR_BOOT_ENTRIES;
104 int	ktr_version = KTR_VERSION;
105 struct	ktr_entry ktr_buf_init[KTR_BOOT_ENTRIES];
106 struct	ktr_entry *ktr_buf = ktr_buf_init;
107 cpuset_t ktr_cpumask = CPUSET_T_INITIALIZER(KTR_CPUMASK);
108 static char ktr_cpumask_str[CPUSETBUFSIZ];
109 
110 TUNABLE_INT("debug.ktr.mask", &ktr_mask);
111 
112 TUNABLE_STR("debug.ktr.cpumask", ktr_cpumask_str, sizeof(ktr_cpumask_str));
113 
114 static SYSCTL_NODE(_debug, OID_AUTO, ktr, CTLFLAG_RD, 0, "KTR options");
115 
116 SYSCTL_INT(_debug_ktr, OID_AUTO, version, CTLFLAG_RD,
117     &ktr_version, 0, "Version of the KTR interface");
118 
119 SYSCTL_UINT(_debug_ktr, OID_AUTO, compile, CTLFLAG_RD,
120     &ktr_compile, 0, "Bitmask of KTR event classes compiled into the kernel");
121 
122 static void
123 ktr_cpumask_initializer(void *dummy __unused)
124 {
125 
126 	/*
127 	 * TUNABLE_STR() runs with SI_ORDER_MIDDLE priority, thus it must be
128 	 * already set, if necessary.
129 	 */
130 	if (ktr_cpumask_str[0] != '\0' &&
131 	    cpusetobj_strscan(&ktr_cpumask, ktr_cpumask_str) == -1)
132 		CPU_FILL(&ktr_cpumask);
133 }
134 SYSINIT(ktr_cpumask_initializer, SI_SUB_TUNABLES, SI_ORDER_ANY,
135     ktr_cpumask_initializer, NULL);
136 
137 static int
138 sysctl_debug_ktr_cpumask(SYSCTL_HANDLER_ARGS)
139 {
140 	char lktr_cpumask_str[CPUSETBUFSIZ];
141 	cpuset_t imask;
142 	int error;
143 
144 	cpusetobj_strprint(lktr_cpumask_str, &ktr_cpumask);
145 	error = sysctl_handle_string(oidp, lktr_cpumask_str,
146 	    sizeof(lktr_cpumask_str), req);
147 	if (error != 0 || req->newptr == NULL)
148 		return (error);
149 	if (cpusetobj_strscan(&imask, lktr_cpumask_str) == -1)
150 		return (EINVAL);
151 	CPU_COPY(&imask, &ktr_cpumask);
152 
153 	return (error);
154 }
155 SYSCTL_PROC(_debug_ktr, OID_AUTO, cpumask,
156     CTLFLAG_RW | CTLFLAG_MPSAFE | CTLTYPE_STRING, NULL, 0,
157     sysctl_debug_ktr_cpumask, "S",
158     "Bitmask of CPUs on which KTR logging is enabled");
159 
160 static int
161 sysctl_debug_ktr_clear(SYSCTL_HANDLER_ARGS)
162 {
163 	int clear, error;
164 
165 	clear = 0;
166 	error = sysctl_handle_int(oidp, &clear, 0, req);
167 	if (error || !req->newptr)
168 		return (error);
169 
170 	if (clear) {
171 		bzero(ktr_buf, sizeof(*ktr_buf) * ktr_entries);
172 		ktr_idx = 0;
173 	}
174 
175 	return (error);
176 }
177 SYSCTL_PROC(_debug_ktr, OID_AUTO, clear, CTLTYPE_INT|CTLFLAG_RW, 0, 0,
178     sysctl_debug_ktr_clear, "I", "Clear KTR Buffer");
179 
180 /*
181  * This is a sysctl proc so that it is serialized as !MPSAFE along with
182  * the other ktr sysctl procs.
183  */
184 static int
185 sysctl_debug_ktr_mask(SYSCTL_HANDLER_ARGS)
186 {
187 	int mask, error;
188 
189 	mask = ktr_mask;
190 	error = sysctl_handle_int(oidp, &mask, 0, req);
191 	if (error || !req->newptr)
192 		return (error);
193 	ktr_mask = mask;
194 	return (error);
195 }
196 
197 SYSCTL_PROC(_debug_ktr, OID_AUTO, mask, CTLTYPE_UINT|CTLFLAG_RW, 0, 0,
198     sysctl_debug_ktr_mask, "IU",
199     "Bitmask of KTR event classes for which logging is enabled");
200 
201 #if KTR_ENTRIES > KTR_BOOT_ENTRIES
202 /*
203  * A simplified version of sysctl_debug_ktr_entries.
204  * No need to care about SMP, scheduling, etc.
205  */
206 static void
207 ktr_entries_initializer(void *dummy __unused)
208 {
209 	int mask;
210 
211 	/* Temporarily disable ktr in case malloc() is being traced. */
212 	mask = ktr_mask;
213 	ktr_mask = 0;
214 	ktr_buf = malloc(sizeof(*ktr_buf) * KTR_ENTRIES, M_KTR,
215 	    M_WAITOK | M_ZERO);
216 	memcpy(ktr_buf, ktr_buf_init + ktr_idx,
217 	    (KTR_BOOT_ENTRIES - ktr_idx) * sizeof(*ktr_buf));
218 	if (ktr_idx != 0)
219 		memcpy(ktr_buf + KTR_BOOT_ENTRIES - ktr_idx, ktr_buf_init,
220 		    ktr_idx * sizeof(*ktr_buf));
221 	ktr_entries = KTR_ENTRIES;
222 	ktr_mask = mask;
223 }
224 SYSINIT(ktr_entries_initializer, SI_SUB_KMEM, SI_ORDER_ANY,
225     ktr_entries_initializer, NULL);
226 #endif
227 
228 static int
229 sysctl_debug_ktr_entries(SYSCTL_HANDLER_ARGS)
230 {
231 	int entries, error, mask;
232 	struct ktr_entry *buf, *oldbuf;
233 
234 	entries = ktr_entries;
235 	error = sysctl_handle_int(oidp, &entries, 0, req);
236 	if (error || !req->newptr)
237 		return (error);
238 	if (entries > KTR_ENTRIES_MAX)
239 		return (ERANGE);
240 	/* Disable ktr temporarily. */
241 	mask = ktr_mask;
242 	atomic_store_rel_int(&ktr_mask, 0);
243 	/* Wait for threads to go idle. */
244 	if ((error = quiesce_all_cpus("ktrent", PCATCH)) != 0) {
245 		ktr_mask = mask;
246 		return (error);
247 	}
248 	if (ktr_buf != ktr_buf_init)
249 		oldbuf = ktr_buf;
250 	else
251 		oldbuf = NULL;
252 	/* Allocate a new buffer. */
253 	buf = malloc(sizeof(*buf) * entries, M_KTR, M_WAITOK | M_ZERO);
254 	/* Install the new buffer and restart ktr. */
255 	ktr_buf = buf;
256 	ktr_entries = entries;
257 	ktr_idx = 0;
258 	atomic_store_rel_int(&ktr_mask, mask);
259 	if (oldbuf != NULL)
260 		free(oldbuf, M_KTR);
261 
262 	return (error);
263 }
264 
265 SYSCTL_PROC(_debug_ktr, OID_AUTO, entries, CTLTYPE_INT|CTLFLAG_RW, 0, 0,
266     sysctl_debug_ktr_entries, "I", "Number of entries in the KTR buffer");
267 
268 #ifdef KTR_VERBOSE
269 int	ktr_verbose = KTR_VERBOSE;
270 TUNABLE_INT("debug.ktr.verbose", &ktr_verbose);
271 SYSCTL_INT(_debug_ktr, OID_AUTO, verbose, CTLFLAG_RW, &ktr_verbose, 0, "");
272 #endif
273 
274 #ifdef KTR_ALQ
275 struct alq *ktr_alq;
276 char	ktr_alq_file[MAXPATHLEN] = "/tmp/ktr.out";
277 int	ktr_alq_cnt = 0;
278 int	ktr_alq_depth = KTR_ENTRIES;
279 int	ktr_alq_enabled = 0;
280 int	ktr_alq_failed = 0;
281 int	ktr_alq_max = 0;
282 
283 SYSCTL_INT(_debug_ktr, OID_AUTO, alq_max, CTLFLAG_RW, &ktr_alq_max, 0,
284     "Maximum number of entries to write");
285 SYSCTL_INT(_debug_ktr, OID_AUTO, alq_cnt, CTLFLAG_RD, &ktr_alq_cnt, 0,
286     "Current number of written entries");
287 SYSCTL_INT(_debug_ktr, OID_AUTO, alq_failed, CTLFLAG_RD, &ktr_alq_failed, 0,
288     "Number of times we overran the buffer");
289 SYSCTL_INT(_debug_ktr, OID_AUTO, alq_depth, CTLFLAG_RW, &ktr_alq_depth, 0,
290     "Number of items in the write buffer");
291 SYSCTL_STRING(_debug_ktr, OID_AUTO, alq_file, CTLFLAG_RW, ktr_alq_file,
292     sizeof(ktr_alq_file), "KTR logging file");
293 
294 static int
295 sysctl_debug_ktr_alq_enable(SYSCTL_HANDLER_ARGS)
296 {
297 	int error;
298 	int enable;
299 
300 	enable = ktr_alq_enabled;
301 
302 	error = sysctl_handle_int(oidp, &enable, 0, req);
303 	if (error || !req->newptr)
304 		return (error);
305 
306 	if (enable) {
307 		if (ktr_alq_enabled)
308 			return (0);
309 		error = alq_open(&ktr_alq, (const char *)ktr_alq_file,
310 		    req->td->td_ucred, ALQ_DEFAULT_CMODE,
311 		    sizeof(struct ktr_entry), ktr_alq_depth);
312 		if (error == 0) {
313 			ktr_alq_cnt = 0;
314 			ktr_alq_failed = 0;
315 			ktr_alq_enabled = 1;
316 		}
317 	} else {
318 		if (ktr_alq_enabled == 0)
319 			return (0);
320 		ktr_alq_enabled = 0;
321 		alq_close(ktr_alq);
322 		ktr_alq = NULL;
323 	}
324 
325 	return (error);
326 }
327 SYSCTL_PROC(_debug_ktr, OID_AUTO, alq_enable,
328     CTLTYPE_INT|CTLFLAG_RW, 0, 0, sysctl_debug_ktr_alq_enable,
329     "I", "Enable KTR logging");
330 #endif
331 
332 void
333 ktr_tracepoint(u_int mask, const char *file, int line, const char *format,
334     u_long arg1, u_long arg2, u_long arg3, u_long arg4, u_long arg5,
335     u_long arg6)
336 {
337 	struct ktr_entry *entry;
338 #ifdef KTR_ALQ
339 	struct ale *ale = NULL;
340 #endif
341 	int newindex, saveindex;
342 #if defined(KTR_VERBOSE) || defined(KTR_ALQ)
343 	struct thread *td;
344 #endif
345 	int cpu;
346 
347 	if (panicstr)
348 		return;
349 	if ((ktr_mask & mask) == 0 || ktr_buf == NULL)
350 		return;
351 	cpu = KTR_CPU;
352 	if (!CPU_ISSET(cpu, &ktr_cpumask))
353 		return;
354 #if defined(KTR_VERBOSE) || defined(KTR_ALQ)
355 	td = curthread;
356 	if (td->td_pflags & TDP_INKTR)
357 		return;
358 	td->td_pflags |= TDP_INKTR;
359 #endif
360 #ifdef KTR_ALQ
361 	if (ktr_alq_enabled) {
362 		if (td->td_critnest == 0 &&
363 		    (td->td_flags & TDF_IDLETD) == 0 &&
364 		    td != ald_thread) {
365 			if (ktr_alq_max && ktr_alq_cnt > ktr_alq_max)
366 				goto done;
367 			if ((ale = alq_get(ktr_alq, ALQ_NOWAIT)) == NULL) {
368 				ktr_alq_failed++;
369 				goto done;
370 			}
371 			ktr_alq_cnt++;
372 			entry = (struct ktr_entry *)ale->ae_data;
373 		} else {
374 			goto done;
375 		}
376 	} else
377 #endif
378 	{
379 		do {
380 			saveindex = ktr_idx;
381 			newindex = (saveindex + 1) % ktr_entries;
382 		} while (atomic_cmpset_rel_int(&ktr_idx, saveindex, newindex) == 0);
383 		entry = &ktr_buf[saveindex];
384 	}
385 	entry->ktr_timestamp = KTR_TIME;
386 	entry->ktr_cpu = cpu;
387 	entry->ktr_thread = curthread;
388 	if (file != NULL)
389 		while (strncmp(file, "../", 3) == 0)
390 			file += 3;
391 	entry->ktr_file = file;
392 	entry->ktr_line = line;
393 #ifdef KTR_VERBOSE
394 	if (ktr_verbose) {
395 #ifdef SMP
396 		printf("cpu%d ", cpu);
397 #endif
398 		if (ktr_verbose > 1) {
399 			printf("%s.%d\t", entry->ktr_file,
400 			    entry->ktr_line);
401 		}
402 		printf(format, arg1, arg2, arg3, arg4, arg5, arg6);
403 		printf("\n");
404 	}
405 #endif
406 	entry->ktr_desc = format;
407 	entry->ktr_parms[0] = arg1;
408 	entry->ktr_parms[1] = arg2;
409 	entry->ktr_parms[2] = arg3;
410 	entry->ktr_parms[3] = arg4;
411 	entry->ktr_parms[4] = arg5;
412 	entry->ktr_parms[5] = arg6;
413 #ifdef KTR_ALQ
414 	if (ktr_alq_enabled && ale)
415 		alq_post(ktr_alq, ale);
416 done:
417 #endif
418 #if defined(KTR_VERBOSE) || defined(KTR_ALQ)
419 	td->td_pflags &= ~TDP_INKTR;
420 #endif
421 }
422 
423 #ifdef DDB
424 
425 struct tstate {
426 	int	cur;
427 	int	first;
428 };
429 static	struct tstate tstate;
430 static	int db_ktr_verbose;
431 static	int db_mach_vtrace(void);
432 
433 DB_SHOW_COMMAND(ktr, db_ktr_all)
434 {
435 
436 	tstate.cur = (ktr_idx - 1) % ktr_entries;
437 	tstate.first = -1;
438 	db_ktr_verbose = 0;
439 	db_ktr_verbose |= (strchr(modif, 'v') != NULL) ? 2 : 0;
440 	db_ktr_verbose |= (strchr(modif, 'V') != NULL) ? 1 : 0; /* just timestap please */
441 	if (strchr(modif, 'a') != NULL) {
442 		db_disable_pager();
443 		while (cncheckc() != -1)
444 			if (db_mach_vtrace() == 0)
445 				break;
446 	} else {
447 		while (!db_pager_quit)
448 			if (db_mach_vtrace() == 0)
449 				break;
450 	}
451 }
452 
453 static int
454 db_mach_vtrace(void)
455 {
456 	struct ktr_entry	*kp;
457 
458 	if (tstate.cur == tstate.first || ktr_buf == NULL) {
459 		db_printf("--- End of trace buffer ---\n");
460 		return (0);
461 	}
462 	kp = &ktr_buf[tstate.cur];
463 
464 	/* Skip over unused entries. */
465 	if (kp->ktr_desc == NULL) {
466 		db_printf("--- End of trace buffer ---\n");
467 		return (0);
468 	}
469 	db_printf("%d (%p", tstate.cur, kp->ktr_thread);
470 #ifdef SMP
471 	db_printf(":cpu%d", kp->ktr_cpu);
472 #endif
473 	db_printf(")");
474 	if (db_ktr_verbose >= 1) {
475 		db_printf(" %10.10lld", (long long)kp->ktr_timestamp);
476 	}
477 	if (db_ktr_verbose >= 2) {
478 		db_printf(" %s.%d", kp->ktr_file, kp->ktr_line);
479 	}
480 	db_printf(": ");
481 	db_printf(kp->ktr_desc, kp->ktr_parms[0], kp->ktr_parms[1],
482 	    kp->ktr_parms[2], kp->ktr_parms[3], kp->ktr_parms[4],
483 	    kp->ktr_parms[5]);
484 	db_printf("\n");
485 
486 	if (tstate.first == -1)
487 		tstate.first = tstate.cur;
488 
489 	if (--tstate.cur < 0)
490 		tstate.cur = ktr_entries - 1;
491 
492 	return (1);
493 }
494 
495 #endif	/* DDB */
496