xref: /freebsd/sys/kern/kern_ktr.c (revision 282a3889ebf826db9839be296ff1dd903f6d6d6e)
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 = 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