FreeBSD/Linux Kernel Cross Reference
sys/kern/kern_ktr.c
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: releng/9.1/sys/kern/kern_ktr.c 222813 2011-06-07 08:46:13Z attilio $");
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/proc.h>
51 #include <sys/sysctl.h>
52 #include <sys/systm.h>
53 #include <sys/time.h>
54
55 #include <machine/cpu.h>
56 #ifdef __sparc64__
57 #include <machine/ktr.h>
58 #endif
59
60 #ifdef DDB
61 #include <ddb/ddb.h>
62 #include <ddb/db_output.h>
63 #endif
64
65 #ifndef KTR_ENTRIES
66 #define KTR_ENTRIES 1024
67 #endif
68
69 #ifndef KTR_MASK
70 #define KTR_MASK (0)
71 #endif
72
73 #ifndef KTR_TIME
74 #define KTR_TIME get_cyclecount()
75 #endif
76
77 #ifndef KTR_CPU
78 #define KTR_CPU PCPU_GET(cpuid)
79 #endif
80
81 FEATURE(ktr, "Kernel support for KTR kernel tracing facility");
82
83 SYSCTL_NODE(_debug, OID_AUTO, ktr, CTLFLAG_RD, 0, "KTR options");
84
85 int ktr_mask = KTR_MASK;
86 TUNABLE_INT("debug.ktr.mask", &ktr_mask);
87 SYSCTL_INT(_debug_ktr, OID_AUTO, mask, CTLFLAG_RW,
88 &ktr_mask, 0, "Bitmask of KTR event classes for which logging is enabled");
89
90 int ktr_compile = KTR_COMPILE;
91 SYSCTL_INT(_debug_ktr, OID_AUTO, compile, CTLFLAG_RD,
92 &ktr_compile, 0, "Bitmask of KTR event classes compiled into the kernel");
93
94 int ktr_entries = KTR_ENTRIES;
95 SYSCTL_INT(_debug_ktr, OID_AUTO, entries, CTLFLAG_RD,
96 &ktr_entries, 0, "Number of entries in the KTR buffer");
97
98 int ktr_version = KTR_VERSION;
99 SYSCTL_INT(_debug_ktr, OID_AUTO, version, CTLFLAG_RD,
100 &ktr_version, 0, "Version of the KTR interface");
101
102 cpuset_t ktr_cpumask;
103 static char ktr_cpumask_str[CPUSETBUFSIZ];
104 TUNABLE_STR("debug.ktr.cpumask", ktr_cpumask_str, sizeof(ktr_cpumask_str));
105
106 static void
107 ktr_cpumask_initializer(void *dummy __unused)
108 {
109
110 CPU_FILL(&ktr_cpumask);
111 #ifdef KTR_CPUMASK
112 if (cpusetobj_strscan(&ktr_cpumask, KTR_CPUMASK) == -1)
113 CPU_FILL(&ktr_cpumask);
114 #endif
115
116 /*
117 * TUNABLE_STR() runs with SI_ORDER_MIDDLE priority, thus it must be
118 * already set, if necessary.
119 */
120 if (ktr_cpumask_str[0] != '\0' &&
121 cpusetobj_strscan(&ktr_cpumask, ktr_cpumask_str) == -1)
122 CPU_FILL(&ktr_cpumask);
123 }
124 SYSINIT(ktr_cpumask_initializer, SI_SUB_TUNABLES, SI_ORDER_ANY,
125 ktr_cpumask_initializer, NULL);
126
127 static int
128 sysctl_debug_ktr_cpumask(SYSCTL_HANDLER_ARGS)
129 {
130 char lktr_cpumask_str[CPUSETBUFSIZ];
131 cpuset_t imask;
132 int error;
133
134 cpusetobj_strprint(lktr_cpumask_str, &ktr_cpumask);
135 error = sysctl_handle_string(oidp, lktr_cpumask_str,
136 sizeof(lktr_cpumask_str), req);
137 if (error != 0 || req->newptr == NULL)
138 return (error);
139 if (cpusetobj_strscan(&imask, lktr_cpumask_str) == -1)
140 return (EINVAL);
141 CPU_COPY(&imask, &ktr_cpumask);
142
143 return (error);
144 }
145 SYSCTL_PROC(_debug_ktr, OID_AUTO, cpumask,
146 CTLFLAG_RW | CTLFLAG_MPSAFE | CTLTYPE_STRING, NULL, 0,
147 sysctl_debug_ktr_cpumask, "S",
148 "Bitmask of CPUs on which KTR logging is enabled");
149
150 volatile int ktr_idx = 0;
151 struct ktr_entry ktr_buf[KTR_ENTRIES];
152
153 static int
154 sysctl_debug_ktr_clear(SYSCTL_HANDLER_ARGS)
155 {
156 int clear, error;
157
158 clear = 0;
159 error = sysctl_handle_int(oidp, &clear, 0, req);
160 if (error || !req->newptr)
161 return (error);
162
163 if (clear) {
164 bzero(ktr_buf, sizeof(ktr_buf));
165 ktr_idx = 0;
166 }
167
168 return (error);
169 }
170 SYSCTL_PROC(_debug_ktr, OID_AUTO, clear, CTLTYPE_INT|CTLFLAG_RW, 0, 0,
171 sysctl_debug_ktr_clear, "I", "Clear KTR Buffer");
172
173 #ifdef KTR_VERBOSE
174 int ktr_verbose = KTR_VERBOSE;
175 TUNABLE_INT("debug.ktr.verbose", &ktr_verbose);
176 SYSCTL_INT(_debug_ktr, OID_AUTO, verbose, CTLFLAG_RW, &ktr_verbose, 0, "");
177 #endif
178
179 #ifdef KTR_ALQ
180 struct alq *ktr_alq;
181 char ktr_alq_file[MAXPATHLEN] = "/tmp/ktr.out";
182 int ktr_alq_cnt = 0;
183 int ktr_alq_depth = KTR_ENTRIES;
184 int ktr_alq_enabled = 0;
185 int ktr_alq_failed = 0;
186 int ktr_alq_max = 0;
187
188 SYSCTL_INT(_debug_ktr, OID_AUTO, alq_max, CTLFLAG_RW, &ktr_alq_max, 0,
189 "Maximum number of entries to write");
190 SYSCTL_INT(_debug_ktr, OID_AUTO, alq_cnt, CTLFLAG_RD, &ktr_alq_cnt, 0,
191 "Current number of written entries");
192 SYSCTL_INT(_debug_ktr, OID_AUTO, alq_failed, CTLFLAG_RD, &ktr_alq_failed, 0,
193 "Number of times we overran the buffer");
194 SYSCTL_INT(_debug_ktr, OID_AUTO, alq_depth, CTLFLAG_RW, &ktr_alq_depth, 0,
195 "Number of items in the write buffer");
196 SYSCTL_STRING(_debug_ktr, OID_AUTO, alq_file, CTLFLAG_RW, ktr_alq_file,
197 sizeof(ktr_alq_file), "KTR logging file");
198
199 static int
200 sysctl_debug_ktr_alq_enable(SYSCTL_HANDLER_ARGS)
201 {
202 int error;
203 int enable;
204
205 enable = ktr_alq_enabled;
206
207 error = sysctl_handle_int(oidp, &enable, 0, req);
208 if (error || !req->newptr)
209 return (error);
210
211 if (enable) {
212 if (ktr_alq_enabled)
213 return (0);
214 error = alq_open(&ktr_alq, (const char *)ktr_alq_file,
215 req->td->td_ucred, ALQ_DEFAULT_CMODE,
216 sizeof(struct ktr_entry), ktr_alq_depth);
217 if (error == 0) {
218 ktr_alq_cnt = 0;
219 ktr_alq_failed = 0;
220 ktr_alq_enabled = 1;
221 }
222 } else {
223 if (ktr_alq_enabled == 0)
224 return (0);
225 ktr_alq_enabled = 0;
226 alq_close(ktr_alq);
227 ktr_alq = NULL;
228 }
229
230 return (error);
231 }
232 SYSCTL_PROC(_debug_ktr, OID_AUTO, alq_enable,
233 CTLTYPE_INT|CTLFLAG_RW, 0, 0, sysctl_debug_ktr_alq_enable,
234 "I", "Enable KTR logging");
235 #endif
236
237 void
238 ktr_tracepoint(u_int mask, const char *file, int line, const char *format,
239 u_long arg1, u_long arg2, u_long arg3, u_long arg4, u_long arg5,
240 u_long arg6)
241 {
242 struct ktr_entry *entry;
243 #ifdef KTR_ALQ
244 struct ale *ale = NULL;
245 #endif
246 int newindex, saveindex;
247 #if defined(KTR_VERBOSE) || defined(KTR_ALQ)
248 struct thread *td;
249 #endif
250 int cpu;
251
252 if (panicstr)
253 return;
254 if ((ktr_mask & mask) == 0)
255 return;
256 cpu = KTR_CPU;
257 if (!CPU_ISSET(cpu, &ktr_cpumask))
258 return;
259 #if defined(KTR_VERBOSE) || defined(KTR_ALQ)
260 td = curthread;
261 if (td->td_pflags & TDP_INKTR)
262 return;
263 td->td_pflags |= TDP_INKTR;
264 #endif
265 #ifdef KTR_ALQ
266 if (ktr_alq_enabled) {
267 if (td->td_critnest == 0 &&
268 (td->td_flags & TDF_IDLETD) == 0 &&
269 td != ald_thread) {
270 if (ktr_alq_max && ktr_alq_cnt > ktr_alq_max)
271 goto done;
272 if ((ale = alq_get(ktr_alq, ALQ_NOWAIT)) == NULL) {
273 ktr_alq_failed++;
274 goto done;
275 }
276 ktr_alq_cnt++;
277 entry = (struct ktr_entry *)ale->ae_data;
278 } else {
279 goto done;
280 }
281 } else
282 #endif
283 {
284 do {
285 saveindex = ktr_idx;
286 newindex = (saveindex + 1) & (KTR_ENTRIES - 1);
287 } while (atomic_cmpset_rel_int(&ktr_idx, saveindex, newindex) == 0);
288 entry = &ktr_buf[saveindex];
289 }
290 entry->ktr_timestamp = KTR_TIME;
291 entry->ktr_cpu = cpu;
292 entry->ktr_thread = curthread;
293 if (file != NULL)
294 while (strncmp(file, "../", 3) == 0)
295 file += 3;
296 entry->ktr_file = file;
297 entry->ktr_line = line;
298 #ifdef KTR_VERBOSE
299 if (ktr_verbose) {
300 #ifdef SMP
301 printf("cpu%d ", cpu);
302 #endif
303 if (ktr_verbose > 1) {
304 printf("%s.%d\t", entry->ktr_file,
305 entry->ktr_line);
306 }
307 printf(format, arg1, arg2, arg3, arg4, arg5, arg6);
308 printf("\n");
309 }
310 #endif
311 entry->ktr_desc = format;
312 entry->ktr_parms[0] = arg1;
313 entry->ktr_parms[1] = arg2;
314 entry->ktr_parms[2] = arg3;
315 entry->ktr_parms[3] = arg4;
316 entry->ktr_parms[4] = arg5;
317 entry->ktr_parms[5] = arg6;
318 #ifdef KTR_ALQ
319 if (ktr_alq_enabled && ale)
320 alq_post(ktr_alq, ale);
321 done:
322 #endif
323 #if defined(KTR_VERBOSE) || defined(KTR_ALQ)
324 td->td_pflags &= ~TDP_INKTR;
325 #endif
326 }
327
328 #ifdef DDB
329
330 struct tstate {
331 int cur;
332 int first;
333 };
334 static struct tstate tstate;
335 static int db_ktr_verbose;
336 static int db_mach_vtrace(void);
337
338 DB_SHOW_COMMAND(ktr, db_ktr_all)
339 {
340
341 tstate.cur = (ktr_idx - 1) & (KTR_ENTRIES - 1);
342 tstate.first = -1;
343 db_ktr_verbose = 0;
344 db_ktr_verbose |= (index(modif, 'v') != NULL) ? 2 : 0;
345 db_ktr_verbose |= (index(modif, 'V') != NULL) ? 1 : 0; /* just timestap please */
346 if (index(modif, 'a') != NULL) {
347 db_disable_pager();
348 while (cncheckc() != -1)
349 if (db_mach_vtrace() == 0)
350 break;
351 } else {
352 while (!db_pager_quit)
353 if (db_mach_vtrace() == 0)
354 break;
355 }
356 }
357
358 static int
359 db_mach_vtrace(void)
360 {
361 struct ktr_entry *kp;
362
363 if (tstate.cur == tstate.first) {
364 db_printf("--- End of trace buffer ---\n");
365 return (0);
366 }
367 kp = &ktr_buf[tstate.cur];
368
369 /* Skip over unused entries. */
370 if (kp->ktr_desc == NULL) {
371 db_printf("--- End of trace buffer ---\n");
372 return (0);
373 }
374 db_printf("%d (%p", tstate.cur, kp->ktr_thread);
375 #ifdef SMP
376 db_printf(":cpu%d", kp->ktr_cpu);
377 #endif
378 db_printf(")");
379 if (db_ktr_verbose >= 1) {
380 db_printf(" %10.10lld", (long long)kp->ktr_timestamp);
381 }
382 if (db_ktr_verbose >= 2) {
383 db_printf(" %s.%d", kp->ktr_file, kp->ktr_line);
384 }
385 db_printf(": ");
386 db_printf(kp->ktr_desc, kp->ktr_parms[0], kp->ktr_parms[1],
387 kp->ktr_parms[2], kp->ktr_parms[3], kp->ktr_parms[4],
388 kp->ktr_parms[5]);
389 db_printf("\n");
390
391 if (tstate.first == -1)
392 tstate.first = tstate.cur;
393
394 if (--tstate.cur < 0)
395 tstate.cur = KTR_ENTRIES - 1;
396
397 return (1);
398 }
399
400 #endif /* DDB */
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