xref: /freebsd/sys/kern/kern_ktr.c (revision 2546665afcaf0d53dc2c7058fee96354b3680f5a)
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 #ifdef KTR_VERBOSE
104 int	ktr_verbose = KTR_VERBOSE;
105 TUNABLE_INT("debug.ktr.verbose", &ktr_verbose);
106 SYSCTL_INT(_debug_ktr, OID_AUTO, verbose, CTLFLAG_RW, &ktr_verbose, 0, "");
107 #endif
108 
109 #ifdef KTR_ALQ
110 struct alq *ktr_alq;
111 char	ktr_alq_file[MAXPATHLEN] = "/tmp/ktr.out";
112 int	ktr_alq_cnt = 0;
113 int	ktr_alq_depth = KTR_ENTRIES;
114 int	ktr_alq_enabled = 0;
115 int	ktr_alq_failed = 0;
116 int	ktr_alq_max = 0;
117 
118 SYSCTL_INT(_debug_ktr, OID_AUTO, alq_max, CTLFLAG_RW, &ktr_alq_max, 0,
119     "Maximum number of entries to write");
120 SYSCTL_INT(_debug_ktr, OID_AUTO, alq_cnt, CTLFLAG_RD, &ktr_alq_cnt, 0,
121     "Current number of written entries");
122 SYSCTL_INT(_debug_ktr, OID_AUTO, alq_failed, CTLFLAG_RD, &ktr_alq_failed, 0,
123     "Number of times we overran the buffer");
124 SYSCTL_INT(_debug_ktr, OID_AUTO, alq_depth, CTLFLAG_RW, &ktr_alq_depth, 0,
125     "Number of items in the write buffer");
126 SYSCTL_STRING(_debug_ktr, OID_AUTO, alq_file, CTLFLAG_RW, ktr_alq_file,
127     sizeof(ktr_alq_file), "KTR logging file");
128 
129 static int
130 sysctl_debug_ktr_alq_enable(SYSCTL_HANDLER_ARGS)
131 {
132 	int error;
133 	int enable;
134 
135 	enable = ktr_alq_enabled;
136 
137         error = sysctl_handle_int(oidp, &enable, 0, req);
138         if (error || !req->newptr)
139                 return (error);
140 
141 	if (enable) {
142 		if (ktr_alq_enabled)
143 			return (0);
144 		error = suser(curthread);
145 		if (error)
146 			return (error);
147 		error = alq_open(&ktr_alq, (const char *)ktr_alq_file,
148 		    req->td->td_ucred, sizeof(struct ktr_entry),
149 		    ktr_alq_depth);
150 		if (error == 0) {
151 			ktr_mask &= ~KTR_ALQ_MASK;
152 			ktr_alq_cnt = 0;
153 			ktr_alq_failed = 0;
154 			ktr_alq_enabled = 1;
155 		}
156 	} else {
157 		if (ktr_alq_enabled == 0)
158 			return (0);
159 		ktr_alq_enabled = 0;
160 		alq_close(ktr_alq);
161 		ktr_alq = NULL;
162 	}
163 
164 	return (error);
165 }
166 SYSCTL_PROC(_debug_ktr, OID_AUTO, alq_enable,
167     CTLTYPE_INT|CTLFLAG_RW, 0, 0, sysctl_debug_ktr_alq_enable,
168     "I", "Enable KTR logging");
169 #endif
170 
171 void
172 ktr_tracepoint(u_int mask, const char *file, int line, const char *format,
173     u_long arg1, u_long arg2, u_long arg3, u_long arg4, u_long arg5,
174     u_long arg6)
175 {
176 	struct ktr_entry *entry;
177 #ifdef KTR_ALQ
178 	struct ale *ale = NULL;
179 #else
180 	int newindex, saveindex;
181 #endif
182 #if defined(KTR_VERBOSE) || defined(KTR_ALQ)
183 	struct thread *td;
184 #endif
185 	int cpu;
186 
187 	if (panicstr)
188 		return;
189 	if ((ktr_mask & mask) == 0)
190 		return;
191 	cpu = KTR_CPU;
192 	if (((1 << cpu) & ktr_cpumask) == 0)
193 		return;
194 #if defined(KTR_VERBOSE) || defined(KTR_ALQ)
195 	td = curthread;
196 	if (td->td_pflags & TDP_INKTR)
197 		return;
198 	td->td_pflags |= TDP_INKTR;
199 #endif
200 #ifdef KTR_ALQ
201 	if (ktr_alq_enabled &&
202 	    td->td_critnest == 0 &&
203 	    (td->td_flags & TDF_IDLETD) == 0 &&
204 	    td != ald_thread) {
205 		if (ktr_alq_max && ktr_alq_cnt > ktr_alq_max)
206 			goto done;
207 		if ((ale = alq_get(ktr_alq, ALQ_NOWAIT)) == NULL) {
208 			ktr_alq_failed++;
209 			goto done;
210 		}
211 		ktr_alq_cnt++;
212 		entry = (struct ktr_entry *)ale->ae_data;
213 	} else
214 		goto done;
215 #else
216 	do {
217 		saveindex = ktr_idx;
218 		newindex = (saveindex + 1) & (KTR_ENTRIES - 1);
219 	} while (atomic_cmpset_rel_int(&ktr_idx, saveindex, newindex) == 0);
220 	entry = &ktr_buf[saveindex];
221 #endif
222 	entry->ktr_timestamp = KTR_TIME;
223 	entry->ktr_cpu = cpu;
224 	if (file != NULL)
225 		while (strncmp(file, "../", 3) == 0)
226 			file += 3;
227 	entry->ktr_file = file;
228 	entry->ktr_line = line;
229 #ifdef KTR_VERBOSE
230 	if (ktr_verbose) {
231 #ifdef SMP
232 		printf("cpu%d ", cpu);
233 #endif
234 		if (ktr_verbose > 1) {
235 			printf("%s.%d\t", entry->ktr_file,
236 			    entry->ktr_line);
237 		}
238 		printf(format, arg1, arg2, arg3, arg4, arg5, arg6);
239 		printf("\n");
240 	}
241 #endif
242 	entry->ktr_desc = format;
243 	entry->ktr_parms[0] = arg1;
244 	entry->ktr_parms[1] = arg2;
245 	entry->ktr_parms[2] = arg3;
246 	entry->ktr_parms[3] = arg4;
247 	entry->ktr_parms[4] = arg5;
248 	entry->ktr_parms[5] = arg6;
249 #ifdef KTR_ALQ
250 	if (ale)
251 		alq_post(ktr_alq, ale);
252 done:
253 #endif
254 #if defined(KTR_VERBOSE) || defined(KTR_ALQ)
255 	td->td_pflags &= ~TDP_INKTR;
256 #endif
257 }
258 
259 #ifdef DDB
260 
261 struct tstate {
262 	int	cur;
263 	int	first;
264 };
265 static	struct tstate tstate;
266 static	int db_ktr_verbose;
267 static	int db_mach_vtrace(void);
268 
269 #define	NUM_LINES_PER_PAGE	18
270 
271 DB_SHOW_COMMAND(ktr, db_ktr_all)
272 {
273 	int quit;
274 
275 	quit = 0;
276 	tstate.cur = (ktr_idx - 1) & (KTR_ENTRIES - 1);
277 	tstate.first = -1;
278 	if (strcmp(modif, "v") == 0)
279 		db_ktr_verbose = 1;
280 	else
281 		db_ktr_verbose = 0;
282 	if (strcmp(modif, "a") == 0) {
283 		while (cncheckc() != -1)
284 			if (db_mach_vtrace() == 0)
285 				break;
286 	} else {
287 		db_setup_paging(db_simple_pager, &quit, DB_LINES_PER_PAGE);
288 		while (!quit)
289 			if (db_mach_vtrace() == 0)
290 				break;
291 	}
292 }
293 
294 static int
295 db_mach_vtrace(void)
296 {
297 	struct ktr_entry	*kp;
298 
299 	if (tstate.cur == tstate.first) {
300 		db_printf("--- End of trace buffer ---\n");
301 		return (0);
302 	}
303 	kp = &ktr_buf[tstate.cur];
304 
305 	/* Skip over unused entries. */
306 	if (kp->ktr_desc == NULL) {
307 		db_printf("--- End of trace buffer ---\n");
308 		return (0);
309 	}
310 	db_printf("%d: ", tstate.cur);
311 #ifdef SMP
312 	db_printf("cpu%d ", kp->ktr_cpu);
313 #endif
314 	if (db_ktr_verbose) {
315 		db_printf("%10.10lld %s.%d\t", (long long)kp->ktr_timestamp,
316 		    kp->ktr_file, kp->ktr_line);
317 	}
318 	db_printf(kp->ktr_desc, kp->ktr_parms[0], kp->ktr_parms[1],
319 	    kp->ktr_parms[2], kp->ktr_parms[3], kp->ktr_parms[4],
320 	    kp->ktr_parms[5]);
321 	db_printf("\n");
322 
323 	if (tstate.first == -1)
324 		tstate.first = tstate.cur;
325 
326 	if (--tstate.cur < 0)
327 		tstate.cur = KTR_ENTRIES - 1;
328 
329 	return (1);
330 }
331 
332 #endif	/* DDB */
333