xref: /freebsd/sys/kern/kern_ktr.c (revision 7dfd9569a2f0637fb9a48157b1c1bfe5709faee3)
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 
59 #include <ddb/ddb.h>
60 
61 #ifndef KTR_ENTRIES
62 #define	KTR_ENTRIES	1024
63 #endif
64 
65 #ifndef KTR_MASK
66 #define	KTR_MASK	(KTR_GEN)
67 #endif
68 
69 #ifndef KTR_CPUMASK
70 #define	KTR_CPUMASK	(~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 SYSCTL_NODE(_debug, OID_AUTO, ktr, CTLFLAG_RD, 0, "KTR options");
82 
83 int	ktr_cpumask = KTR_CPUMASK;
84 TUNABLE_INT("debug.ktr.cpumask", &ktr_cpumask);
85 SYSCTL_INT(_debug_ktr, OID_AUTO, cpumask, CTLFLAG_RW, &ktr_cpumask, 0, "");
86 
87 int	ktr_mask = KTR_MASK;
88 TUNABLE_INT("debug.ktr.mask", &ktr_mask);
89 SYSCTL_INT(_debug_ktr, OID_AUTO, mask, CTLFLAG_RW, &ktr_mask, 0, "");
90 
91 int	ktr_compile = KTR_COMPILE;
92 SYSCTL_INT(_debug_ktr, OID_AUTO, compile, CTLFLAG_RD, &ktr_compile, 0, "");
93 
94 int	ktr_entries = KTR_ENTRIES;
95 SYSCTL_INT(_debug_ktr, OID_AUTO, entries, CTLFLAG_RD, &ktr_entries, 0, "");
96 
97 int	ktr_version = KTR_VERSION;
98 SYSCTL_INT(_debug_ktr, OID_AUTO, version, CTLFLAG_RD, &ktr_version, 0, "");
99 
100 volatile int	ktr_idx = 0;
101 struct	ktr_entry ktr_buf[KTR_ENTRIES];
102 
103 static int
104 sysctl_debug_ktr_clear(SYSCTL_HANDLER_ARGS)
105 {
106 	int clear, error;
107 
108 	clear = 0;
109 	error = sysctl_handle_int(oidp, &clear, 0, req);
110 	if (error || !req->newptr)
111 		return (error);
112 
113 	if (clear) {
114 		bzero(ktr_buf, sizeof(ktr_buf));
115 		ktr_idx = 0;
116 	}
117 
118 	return (error);
119 }
120 SYSCTL_PROC(_debug_ktr, OID_AUTO, clear, CTLTYPE_INT|CTLFLAG_RW, 0, 0,
121     sysctl_debug_ktr_clear, "I", "Clear KTR Buffer");
122 
123 #ifdef KTR_VERBOSE
124 int	ktr_verbose = KTR_VERBOSE;
125 TUNABLE_INT("debug.ktr.verbose", &ktr_verbose);
126 SYSCTL_INT(_debug_ktr, OID_AUTO, verbose, CTLFLAG_RW, &ktr_verbose, 0, "");
127 #endif
128 
129 #ifdef KTR_ALQ
130 struct alq *ktr_alq;
131 char	ktr_alq_file[MAXPATHLEN] = "/tmp/ktr.out";
132 int	ktr_alq_cnt = 0;
133 int	ktr_alq_depth = KTR_ENTRIES;
134 int	ktr_alq_enabled = 0;
135 int	ktr_alq_failed = 0;
136 int	ktr_alq_max = 0;
137 
138 SYSCTL_INT(_debug_ktr, OID_AUTO, alq_max, CTLFLAG_RW, &ktr_alq_max, 0,
139     "Maximum number of entries to write");
140 SYSCTL_INT(_debug_ktr, OID_AUTO, alq_cnt, CTLFLAG_RD, &ktr_alq_cnt, 0,
141     "Current number of written entries");
142 SYSCTL_INT(_debug_ktr, OID_AUTO, alq_failed, CTLFLAG_RD, &ktr_alq_failed, 0,
143     "Number of times we overran the buffer");
144 SYSCTL_INT(_debug_ktr, OID_AUTO, alq_depth, CTLFLAG_RW, &ktr_alq_depth, 0,
145     "Number of items in the write buffer");
146 SYSCTL_STRING(_debug_ktr, OID_AUTO, alq_file, CTLFLAG_RW, ktr_alq_file,
147     sizeof(ktr_alq_file), "KTR logging file");
148 
149 static int
150 sysctl_debug_ktr_alq_enable(SYSCTL_HANDLER_ARGS)
151 {
152 	int error;
153 	int enable;
154 
155 	enable = ktr_alq_enabled;
156 
157 	error = sysctl_handle_int(oidp, &enable, 0, req);
158 	if (error || !req->newptr)
159 		return (error);
160 
161 	if (enable) {
162 		if (ktr_alq_enabled)
163 			return (0);
164 		error = suser(curthread);
165 		if (error)
166 			return (error);
167 		error = alq_open(&ktr_alq, (const char *)ktr_alq_file,
168 		    req->td->td_ucred, ALQ_DEFAULT_CMODE,
169 		    sizeof(struct ktr_entry), ktr_alq_depth);
170 		if (error == 0) {
171 			ktr_alq_cnt = 0;
172 			ktr_alq_failed = 0;
173 			ktr_alq_enabled = 1;
174 		}
175 	} else {
176 		if (ktr_alq_enabled == 0)
177 			return (0);
178 		ktr_alq_enabled = 0;
179 		alq_close(ktr_alq);
180 		ktr_alq = NULL;
181 	}
182 
183 	return (error);
184 }
185 SYSCTL_PROC(_debug_ktr, OID_AUTO, alq_enable,
186     CTLTYPE_INT|CTLFLAG_RW, 0, 0, sysctl_debug_ktr_alq_enable,
187     "I", "Enable KTR logging");
188 #endif
189 
190 void
191 ktr_tracepoint(u_int mask, const char *file, int line, const char *format,
192     u_long arg1, u_long arg2, u_long arg3, u_long arg4, u_long arg5,
193     u_long arg6)
194 {
195 	struct ktr_entry *entry;
196 #ifdef KTR_ALQ
197 	struct ale *ale = NULL;
198 #else
199 	int newindex, saveindex;
200 #endif
201 #if defined(KTR_VERBOSE) || defined(KTR_ALQ)
202 	struct thread *td;
203 #endif
204 	int cpu;
205 
206 	if (panicstr)
207 		return;
208 	if ((ktr_mask & mask) == 0)
209 		return;
210 	cpu = KTR_CPU;
211 	if (((1 << cpu) & ktr_cpumask) == 0)
212 		return;
213 #if defined(KTR_VERBOSE) || defined(KTR_ALQ)
214 	td = curthread;
215 	if (td->td_pflags & TDP_INKTR)
216 		return;
217 	td->td_pflags |= TDP_INKTR;
218 #endif
219 #ifdef KTR_ALQ
220 	if (ktr_alq_enabled &&
221 	    td->td_critnest == 0 &&
222 	    (td->td_flags & TDF_IDLETD) == 0 &&
223 	    td != ald_thread) {
224 		if (ktr_alq_max && ktr_alq_cnt > ktr_alq_max)
225 			goto done;
226 		if ((ale = alq_get(ktr_alq, ALQ_NOWAIT)) == NULL) {
227 			ktr_alq_failed++;
228 			goto done;
229 		}
230 		ktr_alq_cnt++;
231 		entry = (struct ktr_entry *)ale->ae_data;
232 	} else
233 		goto done;
234 #else
235 	do {
236 		saveindex = ktr_idx;
237 		newindex = (saveindex + 1) & (KTR_ENTRIES - 1);
238 	} while (atomic_cmpset_rel_int(&ktr_idx, saveindex, newindex) == 0);
239 	entry = &ktr_buf[saveindex];
240 #endif
241 	entry->ktr_timestamp = KTR_TIME;
242 	entry->ktr_cpu = cpu;
243 	entry->ktr_thread = curthread;
244 	if (file != NULL)
245 		while (strncmp(file, "../", 3) == 0)
246 			file += 3;
247 	entry->ktr_file = file;
248 	entry->ktr_line = line;
249 #ifdef KTR_VERBOSE
250 	if (ktr_verbose) {
251 #ifdef SMP
252 		printf("cpu%d ", cpu);
253 #endif
254 		if (ktr_verbose > 1) {
255 			printf("%s.%d\t", entry->ktr_file,
256 			    entry->ktr_line);
257 		}
258 		printf(format, arg1, arg2, arg3, arg4, arg5, arg6);
259 		printf("\n");
260 	}
261 #endif
262 	entry->ktr_desc = format;
263 	entry->ktr_parms[0] = arg1;
264 	entry->ktr_parms[1] = arg2;
265 	entry->ktr_parms[2] = arg3;
266 	entry->ktr_parms[3] = arg4;
267 	entry->ktr_parms[4] = arg5;
268 	entry->ktr_parms[5] = arg6;
269 #ifdef KTR_ALQ
270 	if (ale)
271 		alq_post(ktr_alq, ale);
272 done:
273 #endif
274 #if defined(KTR_VERBOSE) || defined(KTR_ALQ)
275 	td->td_pflags &= ~TDP_INKTR;
276 #endif
277 }
278 
279 #ifdef DDB
280 
281 struct tstate {
282 	int	cur;
283 	int	first;
284 };
285 static	struct tstate tstate;
286 static	int db_ktr_verbose;
287 static	int db_mach_vtrace(void);
288 
289 DB_SHOW_COMMAND(ktr, db_ktr_all)
290 {
291 	int quit;
292 
293 	quit = 0;
294 	tstate.cur = (ktr_idx - 1) & (KTR_ENTRIES - 1);
295 	tstate.first = -1;
296 	if (strcmp(modif, "v") == 0)
297 		db_ktr_verbose = 1;
298 	else
299 		db_ktr_verbose = 0;
300 	if (strcmp(modif, "a") == 0) {
301 		while (cncheckc() != -1)
302 			if (db_mach_vtrace() == 0)
303 				break;
304 	} else {
305 		db_setup_paging(db_simple_pager, &quit, db_lines_per_page);
306 		while (!quit)
307 			if (db_mach_vtrace() == 0)
308 				break;
309 	}
310 }
311 
312 static int
313 db_mach_vtrace(void)
314 {
315 	struct ktr_entry	*kp;
316 
317 	if (tstate.cur == tstate.first) {
318 		db_printf("--- End of trace buffer ---\n");
319 		return (0);
320 	}
321 	kp = &ktr_buf[tstate.cur];
322 
323 	/* Skip over unused entries. */
324 	if (kp->ktr_desc == NULL) {
325 		db_printf("--- End of trace buffer ---\n");
326 		return (0);
327 	}
328 	db_printf("%d (%p", tstate.cur, kp->ktr_thread);
329 #ifdef SMP
330 	db_printf(":cpu%d", kp->ktr_cpu);
331 #endif
332 	db_printf(")");
333 	if (db_ktr_verbose) {
334 		db_printf(" %10.10lld %s.%d", (long long)kp->ktr_timestamp,
335 		    kp->ktr_file, kp->ktr_line);
336 	}
337 	db_printf(": ");
338 	db_printf(kp->ktr_desc, kp->ktr_parms[0], kp->ktr_parms[1],
339 	    kp->ktr_parms[2], kp->ktr_parms[3], kp->ktr_parms[4],
340 	    kp->ktr_parms[5]);
341 	db_printf("\n");
342 
343 	if (tstate.first == -1)
344 		tstate.first = tstate.cur;
345 
346 	if (--tstate.cur < 0)
347 		tstate.cur = KTR_ENTRIES - 1;
348 
349 	return (1);
350 }
351 
352 #endif	/* DDB */
353