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: src/sys/kern/kern_ktr.c,v 1.53 2006/09/09 16:09:01 rwatson Exp $");
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/alq.h>
44 #include <sys/cons.h>
45 #include <sys/kernel.h>
46 #include <sys/ktr.h>
47 #include <sys/libkern.h>
48 #include <sys/proc.h>
49 #include <sys/sysctl.h>
50 #include <sys/systm.h>
51 #include <sys/time.h>
52
53 #include <machine/cpu.h>
54 #ifdef __sparc64__
55 #include <machine/ktr.h>
56 #endif
57
58 #ifdef DDB
59 #include <ddb/ddb.h>
60 #include <ddb/db_output.h>
61 #endif
62
63 #ifndef KTR_ENTRIES
64 #define KTR_ENTRIES 1024
65 #endif
66
67 #ifndef KTR_MASK
68 #define KTR_MASK (KTR_GEN)
69 #endif
70
71 #ifndef KTR_CPUMASK
72 #define KTR_CPUMASK (~0)
73 #endif
74
75 #ifndef KTR_TIME
76 #define KTR_TIME get_cyclecount()
77 #endif
78
79 #ifndef KTR_CPU
80 #define KTR_CPU PCPU_GET(cpuid)
81 #endif
82
83 SYSCTL_NODE(_debug, OID_AUTO, ktr, CTLFLAG_RD, 0, "KTR options");
84
85 int ktr_cpumask = KTR_CPUMASK;
86 TUNABLE_INT("debug.ktr.cpumask", &ktr_cpumask);
87 SYSCTL_INT(_debug_ktr, OID_AUTO, cpumask, CTLFLAG_RW, &ktr_cpumask, 0, "");
88
89 int ktr_mask = KTR_MASK;
90 TUNABLE_INT("debug.ktr.mask", &ktr_mask);
91 SYSCTL_INT(_debug_ktr, OID_AUTO, mask, CTLFLAG_RW, &ktr_mask, 0, "");
92
93 int ktr_compile = KTR_COMPILE;
94 SYSCTL_INT(_debug_ktr, OID_AUTO, compile, CTLFLAG_RD, &ktr_compile, 0, "");
95
96 int ktr_entries = KTR_ENTRIES;
97 SYSCTL_INT(_debug_ktr, OID_AUTO, entries, CTLFLAG_RD, &ktr_entries, 0, "");
98
99 int ktr_version = KTR_VERSION;
100 SYSCTL_INT(_debug_ktr, OID_AUTO, version, CTLFLAG_RD, &ktr_version, 0, "");
101
102 volatile int ktr_idx = 0;
103 struct ktr_entry ktr_buf[KTR_ENTRIES];
104
105 static int
106 sysctl_debug_ktr_clear(SYSCTL_HANDLER_ARGS)
107 {
108 int clear, error;
109
110 clear = 0;
111 error = sysctl_handle_int(oidp, &clear, 0, req);
112 if (error || !req->newptr)
113 return (error);
114
115 if (clear) {
116 bzero(ktr_buf, sizeof(ktr_buf));
117 ktr_idx = 0;
118 }
119
120 return (error);
121 }
122 SYSCTL_PROC(_debug_ktr, OID_AUTO, clear, CTLTYPE_INT|CTLFLAG_RW, 0, 0,
123 sysctl_debug_ktr_clear, "I", "Clear KTR Buffer");
124
125 #ifdef KTR_VERBOSE
126 int ktr_verbose = KTR_VERBOSE;
127 TUNABLE_INT("debug.ktr.verbose", &ktr_verbose);
128 SYSCTL_INT(_debug_ktr, OID_AUTO, verbose, CTLFLAG_RW, &ktr_verbose, 0, "");
129 #endif
130
131 #ifdef KTR_ALQ
132 struct alq *ktr_alq;
133 char ktr_alq_file[MAXPATHLEN] = "/tmp/ktr.out";
134 int ktr_alq_cnt = 0;
135 int ktr_alq_depth = KTR_ENTRIES;
136 int ktr_alq_enabled = 0;
137 int ktr_alq_failed = 0;
138 int ktr_alq_max = 0;
139
140 SYSCTL_INT(_debug_ktr, OID_AUTO, alq_max, CTLFLAG_RW, &ktr_alq_max, 0,
141 "Maximum number of entries to write");
142 SYSCTL_INT(_debug_ktr, OID_AUTO, alq_cnt, CTLFLAG_RD, &ktr_alq_cnt, 0,
143 "Current number of written entries");
144 SYSCTL_INT(_debug_ktr, OID_AUTO, alq_failed, CTLFLAG_RD, &ktr_alq_failed, 0,
145 "Number of times we overran the buffer");
146 SYSCTL_INT(_debug_ktr, OID_AUTO, alq_depth, CTLFLAG_RW, &ktr_alq_depth, 0,
147 "Number of items in the write buffer");
148 SYSCTL_STRING(_debug_ktr, OID_AUTO, alq_file, CTLFLAG_RW, ktr_alq_file,
149 sizeof(ktr_alq_file), "KTR logging file");
150
151 static int
152 sysctl_debug_ktr_alq_enable(SYSCTL_HANDLER_ARGS)
153 {
154 int error;
155 int enable;
156
157 enable = ktr_alq_enabled;
158
159 error = sysctl_handle_int(oidp, &enable, 0, req);
160 if (error || !req->newptr)
161 return (error);
162
163 if (enable) {
164 if (ktr_alq_enabled)
165 return (0);
166 error = alq_open(&ktr_alq, (const char *)ktr_alq_file,
167 req->td->td_ucred, ALQ_DEFAULT_CMODE,
168 sizeof(struct ktr_entry), ktr_alq_depth);
169 if (error == 0) {
170 ktr_alq_cnt = 0;
171 ktr_alq_failed = 0;
172 ktr_alq_enabled = 1;
173 }
174 } else {
175 if (ktr_alq_enabled == 0)
176 return (0);
177 ktr_alq_enabled = 0;
178 alq_close(ktr_alq);
179 ktr_alq = NULL;
180 }
181
182 return (error);
183 }
184 SYSCTL_PROC(_debug_ktr, OID_AUTO, alq_enable,
185 CTLTYPE_INT|CTLFLAG_RW, 0, 0, sysctl_debug_ktr_alq_enable,
186 "I", "Enable KTR logging");
187 #endif
188
189 void
190 ktr_tracepoint(u_int mask, const char *file, int line, const char *format,
191 u_long arg1, u_long arg2, u_long arg3, u_long arg4, u_long arg5,
192 u_long arg6)
193 {
194 struct ktr_entry *entry;
195 #ifdef KTR_ALQ
196 struct ale *ale = NULL;
197 #else
198 int newindex, saveindex;
199 #endif
200 #if defined(KTR_VERBOSE) || defined(KTR_ALQ)
201 struct thread *td;
202 #endif
203 int cpu;
204
205 if (panicstr)
206 return;
207 if ((ktr_mask & mask) == 0)
208 return;
209 cpu = KTR_CPU;
210 if (((1 << cpu) & ktr_cpumask) == 0)
211 return;
212 #if defined(KTR_VERBOSE) || defined(KTR_ALQ)
213 td = curthread;
214 if (td->td_pflags & TDP_INKTR)
215 return;
216 td->td_pflags |= TDP_INKTR;
217 #endif
218 #ifdef KTR_ALQ
219 if (ktr_alq_enabled &&
220 td->td_critnest == 0 &&
221 (td->td_flags & TDF_IDLETD) == 0 &&
222 td != ald_thread) {
223 if (ktr_alq_max && ktr_alq_cnt > ktr_alq_max)
224 goto done;
225 if ((ale = alq_get(ktr_alq, ALQ_NOWAIT)) == NULL) {
226 ktr_alq_failed++;
227 goto done;
228 }
229 ktr_alq_cnt++;
230 entry = (struct ktr_entry *)ale->ae_data;
231 } else
232 goto done;
233 #else
234 do {
235 saveindex = ktr_idx;
236 newindex = (saveindex + 1) & (KTR_ENTRIES - 1);
237 } while (atomic_cmpset_rel_int(&ktr_idx, saveindex, newindex) == 0);
238 entry = &ktr_buf[saveindex];
239 #endif
240 entry->ktr_timestamp = KTR_TIME;
241 entry->ktr_cpu = cpu;
242 entry->ktr_thread = curthread;
243 if (file != NULL)
244 while (strncmp(file, "../", 3) == 0)
245 file += 3;
246 entry->ktr_file = file;
247 entry->ktr_line = line;
248 #ifdef KTR_VERBOSE
249 if (ktr_verbose) {
250 #ifdef SMP
251 printf("cpu%d ", cpu);
252 #endif
253 if (ktr_verbose > 1) {
254 printf("%s.%d\t", entry->ktr_file,
255 entry->ktr_line);
256 }
257 printf(format, arg1, arg2, arg3, arg4, arg5, arg6);
258 printf("\n");
259 }
260 #endif
261 entry->ktr_desc = format;
262 entry->ktr_parms[0] = arg1;
263 entry->ktr_parms[1] = arg2;
264 entry->ktr_parms[2] = arg3;
265 entry->ktr_parms[3] = arg4;
266 entry->ktr_parms[4] = arg5;
267 entry->ktr_parms[5] = arg6;
268 #ifdef KTR_ALQ
269 if (ale)
270 alq_post(ktr_alq, ale);
271 done:
272 #endif
273 #if defined(KTR_VERBOSE) || defined(KTR_ALQ)
274 td->td_pflags &= ~TDP_INKTR;
275 #endif
276 }
277
278 #ifdef DDB
279
280 struct tstate {
281 int cur;
282 int first;
283 };
284 static struct tstate tstate;
285 static int db_ktr_verbose;
286 static int db_mach_vtrace(void);
287
288 DB_SHOW_COMMAND(ktr, db_ktr_all)
289 {
290
291 tstate.cur = (ktr_idx - 1) & (KTR_ENTRIES - 1);
292 tstate.first = -1;
293 db_ktr_verbose = index(modif, 'v') != NULL;
294 if (index(modif, 'a') != NULL) {
295 db_disable_pager();
296 while (cncheckc() != -1)
297 if (db_mach_vtrace() == 0)
298 break;
299 } else {
300 while (!db_pager_quit)
301 if (db_mach_vtrace() == 0)
302 break;
303 }
304 }
305
306 static int
307 db_mach_vtrace(void)
308 {
309 struct ktr_entry *kp;
310
311 if (tstate.cur == tstate.first) {
312 db_printf("--- End of trace buffer ---\n");
313 return (0);
314 }
315 kp = &ktr_buf[tstate.cur];
316
317 /* Skip over unused entries. */
318 if (kp->ktr_desc == NULL) {
319 db_printf("--- End of trace buffer ---\n");
320 return (0);
321 }
322 db_printf("%d (%p", tstate.cur, kp->ktr_thread);
323 #ifdef SMP
324 db_printf(":cpu%d", kp->ktr_cpu);
325 #endif
326 db_printf(")");
327 if (db_ktr_verbose) {
328 db_printf(" %10.10lld %s.%d", (long long)kp->ktr_timestamp,
329 kp->ktr_file, kp->ktr_line);
330 }
331 db_printf(": ");
332 db_printf(kp->ktr_desc, kp->ktr_parms[0], kp->ktr_parms[1],
333 kp->ktr_parms[2], kp->ktr_parms[3], kp->ktr_parms[4],
334 kp->ktr_parms[5]);
335 db_printf("\n");
336
337 if (tstate.first == -1)
338 tstate.first = tstate.cur;
339
340 if (--tstate.cur < 0)
341 tstate.cur = KTR_ENTRIES - 1;
342
343 return (1);
344 }
345
346 #endif /* DDB */
347
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