xref: /freebsd/sys/kern/kern_ktr.c (revision 5521ff5a4d1929056e7ffc982fac3341ca54df7c)
1 /*
2  * Copyright (c) 2000
3  *	John Baldwin <jhb@FreeBSD.org>.  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  * 4. 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 JOHN BALDWIN 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 JOHN BALDWIN OR THE VOICES IN HIS HEAD
21  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
22  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
23  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
24  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
25  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
26  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF
27  * THE POSSIBILITY OF SUCH DAMAGE.
28  *
29  * $FreeBSD$
30  */
31 
32 /*
33  * This module holds the global variables used by KTR and the ktr_tracepoint()
34  * function that does the actual tracing.
35  */
36 
37 #include "opt_ddb.h"
38 #include "opt_ktr.h"
39 
40 #include <sys/param.h>
41 #include <sys/cons.h>
42 #include <sys/kernel.h>
43 #include <sys/ktr.h>
44 #include <sys/libkern.h>
45 #include <sys/sysctl.h>
46 #include <sys/systm.h>
47 #include <sys/time.h>
48 #include <machine/globals.h>
49 #include <machine/stdarg.h>
50 
51 #include <ddb/ddb.h>
52 
53 #ifndef KTR_ENTRIES
54 #define	KTR_ENTRIES	1024
55 #endif
56 
57 #ifndef KTR_MASK
58 #define	KTR_MASK	(KTR_GEN)
59 #endif
60 
61 #ifndef KTR_CPUMASK
62 #define	KTR_CPUMASK	(~0)
63 #endif
64 
65 #ifdef SMP
66 #define KTR_CPU		PCPU_GET(cpuid)
67 #else
68 #define KTR_CPU		0
69 #endif
70 
71 #ifdef KTR_EXTEND
72 #define KTR_EXTEND_DEFAULT	1
73 #else
74 #define KTR_EXTEND_DEFAULT	0
75 #endif
76 
77 #ifdef KTR_VERBOSE
78 #define KTR_VERBOSE_DEFAULT	1
79 #else
80 #define KTR_VERBOSE_DEFAULT	0
81 #endif
82 
83 SYSCTL_NODE(_debug, OID_AUTO, ktr, CTLFLAG_RD, 0, "KTR options");
84 
85 /*
86  * This variable is used only by gdb to work out what fields are in
87  * ktr_entry.
88  */
89 int     ktr_extend = KTR_EXTEND_DEFAULT;
90 SYSCTL_INT(_debug_ktr, OID_AUTO, extend, CTLFLAG_RD, &ktr_extend, 0, "");
91 
92 int	ktr_cpumask = KTR_CPUMASK;
93 TUNABLE_INT("debug.ktr.cpumask", &ktr_cpumask);
94 SYSCTL_INT(_debug_ktr, OID_AUTO, cpumask, CTLFLAG_RW, &ktr_cpumask, 0, "");
95 
96 int	ktr_mask = KTR_MASK;
97 TUNABLE_INT("debug.ktr.mask", &ktr_mask);
98 SYSCTL_INT(_debug_ktr, OID_AUTO, mask, CTLFLAG_RW, &ktr_mask, 0, "");
99 
100 int	ktr_entries = KTR_ENTRIES;
101 SYSCTL_INT(_debug_ktr, OID_AUTO, entries, CTLFLAG_RD, &ktr_entries, 0, "");
102 
103 volatile int	ktr_idx = 0;
104 struct	ktr_entry ktr_buf[KTR_ENTRIES];
105 
106 int	ktr_verbose = KTR_VERBOSE_DEFAULT;
107 TUNABLE_INT("debug.ktr.verbose", &ktr_verbose);
108 SYSCTL_INT(_debug_ktr, OID_AUTO, verbose, CTLFLAG_RW, &ktr_verbose, 0, "");
109 
110 #ifdef KTR
111 #ifdef KTR_EXTEND
112 void
113 ktr_tracepoint(u_int mask, const char *filename, u_int line,
114 	       const char *format, ...)
115 #else
116 void
117 ktr_tracepoint(u_int mask, const char *format, u_long arg1, u_long arg2,
118 	       u_long arg3, u_long arg4, u_long arg5)
119 #endif
120 {
121 	struct ktr_entry *entry;
122 	int newindex, saveindex;
123 	critical_t savecrit;
124 #ifdef KTR_EXTEND
125 	va_list ap;
126 #endif
127 
128 	if (panicstr)
129 		return;
130 	if ((ktr_mask & mask) == 0)
131 		return;
132 	savecrit = critical_enter();
133 	if (((1 << KTR_CPU) & ktr_cpumask) == 0) {
134 		critical_exit(savecrit);
135 		return;
136 	}
137 	atomic_clear_int(&ktr_cpumask, 1 << KTR_CPU);
138 	do {
139 		saveindex = ktr_idx;
140 		newindex = (saveindex + 1) & (KTR_ENTRIES - 1);
141 	} while (atomic_cmpset_rel_int(&ktr_idx, saveindex, newindex) == 0);
142 	entry = &ktr_buf[saveindex];
143 	/*
144 	 * XXX: The ktr_cpumask atomic ops should make this unnecessary.
145 	 */
146 	if ((ktr_mask & (KTR_LOCK | KTR_WITNESS)) != 0)
147 		getnanotime(&entry->ktr_tv);
148 	else
149 		nanotime(&entry->ktr_tv);
150 	atomic_set_int(&ktr_cpumask, 1 << KTR_CPU);
151 	entry->ktr_cpu = KTR_CPU;
152 	critical_exit(savecrit);
153 #ifdef KTR_EXTEND
154 	entry->ktr_filename = filename;
155 	entry->ktr_line = line;
156 	va_start(ap, format);
157 	vsnprintf(entry->ktr_desc, KTRDESCSIZE, format, ap);
158 	va_end(ap);
159 	if (ktr_verbose) {
160 #ifdef SMP
161 		printf("cpu%d ", entry->ktr_cpu);
162 #endif
163 		if (ktr_verbose > 1)
164 			printf("%s.%d\t", entry->ktr_filename, entry->ktr_line);
165 		va_start(ap, format);
166 		vprintf(format, ap);
167 		printf("\n");
168 		va_end(ap);
169 	}
170 #else
171 	entry->ktr_desc = format;
172 	entry->ktr_parm1 = arg1;
173 	entry->ktr_parm2 = arg2;
174 	entry->ktr_parm3 = arg3;
175 	entry->ktr_parm4 = arg4;
176 	entry->ktr_parm5 = arg5;
177 #endif
178 }
179 
180 #ifdef DDB
181 
182 struct tstate {
183 	int	cur;
184 	int	first;
185 };
186 static	struct tstate tstate;
187 static	int db_ktr_verbose;
188 static	int db_mach_vtrace(void);
189 
190 #define	NUM_LINES_PER_PAGE	18
191 
192 DB_SHOW_COMMAND(ktr, db_ktr_all)
193 {
194 	int	c, lines;
195 
196 	lines = NUM_LINES_PER_PAGE;
197 	tstate.cur = (ktr_idx - 1) & (KTR_ENTRIES - 1);
198 	tstate.first = -1;
199 	if (strcmp(modif, "v") == 0)
200 		db_ktr_verbose = 1;
201 	else
202 		db_ktr_verbose = 0;
203 	while (db_mach_vtrace())
204 		if (--lines == 0) {
205 			db_printf("--More--");
206 			c = cngetc();
207 			db_printf("\r");
208 			switch (c) {
209 			case '\n':	/* one more line */
210 				lines = 1;
211 				break;
212 			case ' ':	/* one more page */
213 				lines = NUM_LINES_PER_PAGE;
214 				break;
215 			default:
216 				db_printf("\n");
217 				return;
218 			}
219 		}
220 }
221 
222 static int
223 db_mach_vtrace(void)
224 {
225 	struct ktr_entry	*kp;
226 
227 	if (tstate.cur == tstate.first) {
228 		db_printf("--- End of trace buffer ---\n");
229 		return (0);
230 	}
231 	kp = &ktr_buf[tstate.cur];
232 
233 	/* Skip over unused entries. */
234 #ifdef KTR_EXTEND
235 	if (kp->ktr_desc[0] == '\0') {
236 #else
237 	if (kp->ktr_desc == NULL) {
238 #endif
239 		db_printf("--- End of trace buffer ---\n");
240 		return (0);
241 	}
242 	db_printf("%d: ", tstate.cur);
243 	if (db_ktr_verbose)
244 		db_printf("%4ld.%06ld ", (long)kp->ktr_tv.tv_sec,
245 		    kp->ktr_tv.tv_nsec / 1000);
246 #ifdef KTR_EXTEND
247 #ifdef SMP
248 	db_printf("cpu%d ", kp->ktr_cpu);
249 #endif
250 	if (db_ktr_verbose)
251 		db_printf("%s.%d\t", kp->ktr_filename, kp->ktr_line);
252 	db_printf("%s", kp->ktr_desc);
253 #else
254 	db_printf(kp->ktr_desc, kp->ktr_parm1, kp->ktr_parm2, kp->ktr_parm3,
255 	    kp->ktr_parm4, kp->ktr_parm5);
256 #endif
257 	db_printf("\n");
258 
259 	if (tstate.first == -1)
260 		tstate.first = tstate.cur;
261 
262 	if (--tstate.cur < 0)
263 		tstate.cur = KTR_ENTRIES - 1;
264 
265 	return (1);
266 }
267 
268 #endif	/* DDB */
269 #endif	/* KTR */
270