xref: /freebsd/sys/kern/kern_ktr.c (revision d056fa046c6a91b90cd98165face0e42a33a5173)
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/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 = suser(curthread);
167 		if (error)
168 			return (error);
169 		error = alq_open(&ktr_alq, (const char *)ktr_alq_file,
170 		    req->td->td_ucred, ALQ_DEFAULT_CMODE,
171 		    sizeof(struct ktr_entry), ktr_alq_depth);
172 		if (error == 0) {
173 			ktr_alq_cnt = 0;
174 			ktr_alq_failed = 0;
175 			ktr_alq_enabled = 1;
176 		}
177 	} else {
178 		if (ktr_alq_enabled == 0)
179 			return (0);
180 		ktr_alq_enabled = 0;
181 		alq_close(ktr_alq);
182 		ktr_alq = NULL;
183 	}
184 
185 	return (error);
186 }
187 SYSCTL_PROC(_debug_ktr, OID_AUTO, alq_enable,
188     CTLTYPE_INT|CTLFLAG_RW, 0, 0, sysctl_debug_ktr_alq_enable,
189     "I", "Enable KTR logging");
190 #endif
191 
192 void
193 ktr_tracepoint(u_int mask, const char *file, int line, const char *format,
194     u_long arg1, u_long arg2, u_long arg3, u_long arg4, u_long arg5,
195     u_long arg6)
196 {
197 	struct ktr_entry *entry;
198 #ifdef KTR_ALQ
199 	struct ale *ale = NULL;
200 #else
201 	int newindex, saveindex;
202 #endif
203 #if defined(KTR_VERBOSE) || defined(KTR_ALQ)
204 	struct thread *td;
205 #endif
206 	int cpu;
207 
208 	if (panicstr)
209 		return;
210 	if ((ktr_mask & mask) == 0)
211 		return;
212 	cpu = KTR_CPU;
213 	if (((1 << cpu) & ktr_cpumask) == 0)
214 		return;
215 #if defined(KTR_VERBOSE) || defined(KTR_ALQ)
216 	td = curthread;
217 	if (td->td_pflags & TDP_INKTR)
218 		return;
219 	td->td_pflags |= TDP_INKTR;
220 #endif
221 #ifdef KTR_ALQ
222 	if (ktr_alq_enabled &&
223 	    td->td_critnest == 0 &&
224 	    (td->td_flags & TDF_IDLETD) == 0 &&
225 	    td != ald_thread) {
226 		if (ktr_alq_max && ktr_alq_cnt > ktr_alq_max)
227 			goto done;
228 		if ((ale = alq_get(ktr_alq, ALQ_NOWAIT)) == NULL) {
229 			ktr_alq_failed++;
230 			goto done;
231 		}
232 		ktr_alq_cnt++;
233 		entry = (struct ktr_entry *)ale->ae_data;
234 	} else
235 		goto done;
236 #else
237 	do {
238 		saveindex = ktr_idx;
239 		newindex = (saveindex + 1) & (KTR_ENTRIES - 1);
240 	} while (atomic_cmpset_rel_int(&ktr_idx, saveindex, newindex) == 0);
241 	entry = &ktr_buf[saveindex];
242 #endif
243 	entry->ktr_timestamp = KTR_TIME;
244 	entry->ktr_cpu = cpu;
245 	entry->ktr_thread = curthread;
246 	if (file != NULL)
247 		while (strncmp(file, "../", 3) == 0)
248 			file += 3;
249 	entry->ktr_file = file;
250 	entry->ktr_line = line;
251 #ifdef KTR_VERBOSE
252 	if (ktr_verbose) {
253 #ifdef SMP
254 		printf("cpu%d ", cpu);
255 #endif
256 		if (ktr_verbose > 1) {
257 			printf("%s.%d\t", entry->ktr_file,
258 			    entry->ktr_line);
259 		}
260 		printf(format, arg1, arg2, arg3, arg4, arg5, arg6);
261 		printf("\n");
262 	}
263 #endif
264 	entry->ktr_desc = format;
265 	entry->ktr_parms[0] = arg1;
266 	entry->ktr_parms[1] = arg2;
267 	entry->ktr_parms[2] = arg3;
268 	entry->ktr_parms[3] = arg4;
269 	entry->ktr_parms[4] = arg5;
270 	entry->ktr_parms[5] = arg6;
271 #ifdef KTR_ALQ
272 	if (ale)
273 		alq_post(ktr_alq, ale);
274 done:
275 #endif
276 #if defined(KTR_VERBOSE) || defined(KTR_ALQ)
277 	td->td_pflags &= ~TDP_INKTR;
278 #endif
279 }
280 
281 #ifdef DDB
282 
283 struct tstate {
284 	int	cur;
285 	int	first;
286 };
287 static	struct tstate tstate;
288 static	int db_ktr_verbose;
289 static	int db_mach_vtrace(void);
290 
291 DB_SHOW_COMMAND(ktr, db_ktr_all)
292 {
293 
294 	tstate.cur = (ktr_idx - 1) & (KTR_ENTRIES - 1);
295 	tstate.first = -1;
296 	db_ktr_verbose = index(modif, 'v') != NULL;
297 	if (index(modif, 'a') != NULL) {
298 		db_disable_pager();
299 		while (cncheckc() != -1)
300 			if (db_mach_vtrace() == 0)
301 				break;
302 	} else {
303 		while (!db_pager_quit)
304 			if (db_mach_vtrace() == 0)
305 				break;
306 	}
307 }
308 
309 static int
310 db_mach_vtrace(void)
311 {
312 	struct ktr_entry	*kp;
313 
314 	if (tstate.cur == tstate.first) {
315 		db_printf("--- End of trace buffer ---\n");
316 		return (0);
317 	}
318 	kp = &ktr_buf[tstate.cur];
319 
320 	/* Skip over unused entries. */
321 	if (kp->ktr_desc == NULL) {
322 		db_printf("--- End of trace buffer ---\n");
323 		return (0);
324 	}
325 	db_printf("%d (%p", tstate.cur, kp->ktr_thread);
326 #ifdef SMP
327 	db_printf(":cpu%d", kp->ktr_cpu);
328 #endif
329 	db_printf(")");
330 	if (db_ktr_verbose) {
331 		db_printf(" %10.10lld %s.%d", (long long)kp->ktr_timestamp,
332 		    kp->ktr_file, kp->ktr_line);
333 	}
334 	db_printf(": ");
335 	db_printf(kp->ktr_desc, kp->ktr_parms[0], kp->ktr_parms[1],
336 	    kp->ktr_parms[2], kp->ktr_parms[3], kp->ktr_parms[4],
337 	    kp->ktr_parms[5]);
338 	db_printf("\n");
339 
340 	if (tstate.first == -1)
341 		tstate.first = tstate.cur;
342 
343 	if (--tstate.cur < 0)
344 		tstate.cur = KTR_ENTRIES - 1;
345 
346 	return (1);
347 }
348 
349 #endif	/* DDB */
350