xref: /freebsd/sys/kern/kern_ktr.c (revision 6fd05b64b5b65dd4ba9b86482a0634a5f0b96c29)
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_entries = KTR_ENTRIES;
92 SYSCTL_INT(_debug_ktr, OID_AUTO, entries, CTLFLAG_RD, &ktr_entries, 0, "");
93 
94 int	ktr_version = KTR_VERSION;
95 SYSCTL_INT(_debug_ktr, OID_AUTO, version, CTLFLAG_RD, &ktr_version, 0, "");
96 
97 volatile int	ktr_idx = 0;
98 struct	ktr_entry ktr_buf[KTR_ENTRIES];
99 
100 #ifdef KTR_VERBOSE
101 int	ktr_verbose = KTR_VERBOSE;
102 TUNABLE_INT("debug.ktr.verbose", &ktr_verbose);
103 SYSCTL_INT(_debug_ktr, OID_AUTO, verbose, CTLFLAG_RW, &ktr_verbose, 0, "");
104 #endif
105 
106 #ifdef KTR_ALQ
107 struct alq *ktr_alq;
108 char	ktr_alq_file[MAXPATHLEN] = "/tmp/ktr.out";
109 int	ktr_alq_cnt = 0;
110 int	ktr_alq_depth = KTR_ENTRIES;
111 int	ktr_alq_enabled = 0;
112 int	ktr_alq_failed = 0;
113 int	ktr_alq_max = 0;
114 
115 SYSCTL_INT(_debug_ktr, OID_AUTO, alq_max, CTLFLAG_RW, &ktr_alq_max, 0,
116     "Maximum number of entries to write");
117 SYSCTL_INT(_debug_ktr, OID_AUTO, alq_cnt, CTLFLAG_RD, &ktr_alq_cnt, 0,
118     "Current number of written entries");
119 SYSCTL_INT(_debug_ktr, OID_AUTO, alq_failed, CTLFLAG_RD, &ktr_alq_failed, 0,
120     "Number of times we overran the buffer");
121 SYSCTL_INT(_debug_ktr, OID_AUTO, alq_depth, CTLFLAG_RW, &ktr_alq_depth, 0,
122     "Number of items in the write buffer");
123 SYSCTL_STRING(_debug_ktr, OID_AUTO, alq_file, CTLFLAG_RW, ktr_alq_file,
124     sizeof(ktr_alq_file), "KTR logging file");
125 
126 static int
127 sysctl_debug_ktr_alq_enable(SYSCTL_HANDLER_ARGS)
128 {
129 	int error;
130 	int enable;
131 
132 	enable = ktr_alq_enabled;
133 
134         error = sysctl_handle_int(oidp, &enable, 0, req);
135         if (error || !req->newptr)
136                 return (error);
137 
138 	if (enable) {
139 		if (ktr_alq_enabled)
140 			return (0);
141 		error = suser(curthread);
142 		if (error)
143 			return (error);
144 		error = alq_open(&ktr_alq, (const char *)ktr_alq_file,
145 		    req->td->td_ucred, sizeof(struct ktr_entry),
146 		    ktr_alq_depth);
147 		if (error == 0) {
148 			ktr_mask &= ~KTR_ALQ_MASK;
149 			ktr_alq_cnt = 0;
150 			ktr_alq_failed = 0;
151 			ktr_alq_enabled = 1;
152 		}
153 	} else {
154 		if (ktr_alq_enabled == 0)
155 			return (0);
156 		ktr_alq_enabled = 0;
157 		alq_close(ktr_alq);
158 		ktr_alq = NULL;
159 	}
160 
161 	return (error);
162 }
163 SYSCTL_PROC(_debug_ktr, OID_AUTO, alq_enable,
164     CTLTYPE_INT|CTLFLAG_RW, 0, 0, sysctl_debug_ktr_alq_enable,
165     "I", "Enable KTR logging");
166 #endif
167 
168 void
169 ktr_tracepoint(u_int mask, const char *file, int line, const char *format,
170     u_long arg1, u_long arg2, u_long arg3, u_long arg4, u_long arg5,
171     u_long arg6)
172 {
173 	struct ktr_entry *entry;
174 #ifdef KTR_ALQ
175 	struct ale *ale = NULL;
176 #else
177 	int newindex, saveindex;
178 #endif
179 #if defined(KTR_VERBOSE) || defined(KTR_ALQ)
180 	struct thread *td;
181 #endif
182 	int cpu;
183 
184 	if (panicstr)
185 		return;
186 	if ((ktr_mask & mask) == 0)
187 		return;
188 	cpu = KTR_CPU;
189 	if (((1 << cpu) & ktr_cpumask) == 0)
190 		return;
191 #if defined(KTR_VERBOSE) || defined(KTR_ALQ)
192 	td = curthread;
193 	if (td->td_pflags & TDP_INKTR)
194 		return;
195 	td->td_pflags |= TDP_INKTR;
196 #endif
197 #ifdef KTR_ALQ
198 	if (ktr_alq_enabled &&
199 	    td->td_critnest == 0 &&
200 	    (td->td_flags & TDF_IDLETD) == 0 &&
201 	    td != ald_thread) {
202 		if (ktr_alq_max && ktr_alq_cnt > ktr_alq_max)
203 			goto done;
204 		if ((ale = alq_get(ktr_alq, ALQ_NOWAIT)) == NULL) {
205 			ktr_alq_failed++;
206 			goto done;
207 		}
208 		ktr_alq_cnt++;
209 		entry = (struct ktr_entry *)ale->ae_data;
210 	} else
211 		goto done;
212 #else
213 	do {
214 		saveindex = ktr_idx;
215 		newindex = (saveindex + 1) & (KTR_ENTRIES - 1);
216 	} while (atomic_cmpset_rel_int(&ktr_idx, saveindex, newindex) == 0);
217 	entry = &ktr_buf[saveindex];
218 #endif
219 	entry->ktr_timestamp = KTR_TIME;
220 	entry->ktr_cpu = cpu;
221 	if (file != NULL)
222 		while (strncmp(file, "../", 3) == 0)
223 			file += 3;
224 	entry->ktr_file = file;
225 	entry->ktr_line = line;
226 #ifdef KTR_VERBOSE
227 	if (ktr_verbose) {
228 #ifdef SMP
229 		printf("cpu%d ", cpu);
230 #endif
231 		if (ktr_verbose > 1) {
232 			printf("%s.%d\t", entry->ktr_file,
233 			    entry->ktr_line);
234 		}
235 		printf(format, arg1, arg2, arg3, arg4, arg5, arg6);
236 		printf("\n");
237 	}
238 #endif
239 	entry->ktr_desc = format;
240 	entry->ktr_parms[0] = arg1;
241 	entry->ktr_parms[1] = arg2;
242 	entry->ktr_parms[2] = arg3;
243 	entry->ktr_parms[3] = arg4;
244 	entry->ktr_parms[4] = arg5;
245 	entry->ktr_parms[5] = arg6;
246 #ifdef KTR_ALQ
247 	if (ale)
248 		alq_post(ktr_alq, ale);
249 done:
250 #endif
251 #if defined(KTR_VERBOSE) || defined(KTR_ALQ)
252 	td->td_pflags &= ~TDP_INKTR;
253 #endif
254 }
255 
256 #ifdef DDB
257 
258 struct tstate {
259 	int	cur;
260 	int	first;
261 };
262 static	struct tstate tstate;
263 static	int db_ktr_verbose;
264 static	int db_mach_vtrace(void);
265 
266 #define	NUM_LINES_PER_PAGE	18
267 
268 DB_SHOW_COMMAND(ktr, db_ktr_all)
269 {
270 	int quit;
271 
272 	quit = 0;
273 	tstate.cur = (ktr_idx - 1) & (KTR_ENTRIES - 1);
274 	tstate.first = -1;
275 	if (strcmp(modif, "v") == 0)
276 		db_ktr_verbose = 1;
277 	else
278 		db_ktr_verbose = 0;
279 	if (strcmp(modif, "a") == 0) {
280 		while (cncheckc() != -1)
281 			if (db_mach_vtrace() == 0)
282 				break;
283 	} else {
284 		db_setup_paging(db_simple_pager, &quit, DB_LINES_PER_PAGE);
285 		while (!quit)
286 			if (db_mach_vtrace() == 0)
287 				break;
288 	}
289 }
290 
291 static int
292 db_mach_vtrace(void)
293 {
294 	struct ktr_entry	*kp;
295 
296 	if (tstate.cur == tstate.first) {
297 		db_printf("--- End of trace buffer ---\n");
298 		return (0);
299 	}
300 	kp = &ktr_buf[tstate.cur];
301 
302 	/* Skip over unused entries. */
303 	if (kp->ktr_desc == NULL) {
304 		db_printf("--- End of trace buffer ---\n");
305 		return (0);
306 	}
307 	db_printf("%d: ", tstate.cur);
308 #ifdef SMP
309 	db_printf("cpu%d ", kp->ktr_cpu);
310 #endif
311 	if (db_ktr_verbose) {
312 		db_printf("%10.10lld %s.%d\t", (long long)kp->ktr_timestamp,
313 		    kp->ktr_file, kp->ktr_line);
314 	}
315 	db_printf(kp->ktr_desc, kp->ktr_parms[0], kp->ktr_parms[1],
316 	    kp->ktr_parms[2], kp->ktr_parms[3], kp->ktr_parms[4],
317 	    kp->ktr_parms[5]);
318 	db_printf("\n");
319 
320 	if (tstate.first == -1)
321 		tstate.first = tstate.cur;
322 
323 	if (--tstate.cur < 0)
324 		tstate.cur = KTR_ENTRIES - 1;
325 
326 	return (1);
327 }
328 
329 #endif	/* DDB */
330