xref: /freebsd/sys/kern/kern_ktr.c (revision c17d43407fe04133a94055b0dbc7ea8965654a9f)
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/proc.h>
46 #include <sys/sysctl.h>
47 #include <sys/systm.h>
48 #include <sys/time.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, u_long arg6)
119 #endif
120 {
121 	struct ktr_entry *entry;
122 	int newindex, saveindex;
123 	struct thread *td;
124 	int cpu;
125 #ifdef KTR_EXTEND
126 	va_list ap;
127 #endif
128 
129 	if (panicstr)
130 		return;
131 	if ((ktr_mask & mask) == 0)
132 		return;
133 	td = curthread;
134 	if (td->td_inktr)
135 		return;
136 	cpu = KTR_CPU;
137 	if (((1 << cpu) & ktr_cpumask) == 0)
138 		return;
139 	td->td_inktr++;
140 	do {
141 		saveindex = ktr_idx;
142 		newindex = (saveindex + 1) & (KTR_ENTRIES - 1);
143 	} while (atomic_cmpset_rel_int(&ktr_idx, saveindex, newindex) == 0);
144 	entry = &ktr_buf[saveindex];
145 	entry->ktr_cpu = cpu;
146 	nanotime(&entry->ktr_tv);
147 #ifdef KTR_EXTEND
148 	entry->ktr_filename = filename;
149 	entry->ktr_line = line;
150 	va_start(ap, format);
151 	vsnprintf(entry->ktr_desc, KTRDESCSIZE, format, ap);
152 	va_end(ap);
153 	if (ktr_verbose) {
154 #ifdef SMP
155 		printf("cpu%d ", entry->ktr_cpu);
156 #endif
157 		if (ktr_verbose > 1)
158 			printf("%s.%d\t", entry->ktr_filename, entry->ktr_line);
159 		va_start(ap, format);
160 		vprintf(format, ap);
161 		printf("\n");
162 		va_end(ap);
163 	}
164 #else
165 	entry->ktr_desc = format;
166 	entry->ktr_parm1 = arg1;
167 	entry->ktr_parm2 = arg2;
168 	entry->ktr_parm3 = arg3;
169 	entry->ktr_parm4 = arg4;
170 	entry->ktr_parm5 = arg5;
171 	entry->ktr_parm6 = arg6;
172 #endif
173 	td->td_inktr--;
174 }
175 
176 #ifdef DDB
177 
178 struct tstate {
179 	int	cur;
180 	int	first;
181 };
182 static	struct tstate tstate;
183 static	int db_ktr_verbose;
184 static	int db_mach_vtrace(void);
185 
186 #define	NUM_LINES_PER_PAGE	18
187 
188 DB_SHOW_COMMAND(ktr, db_ktr_all)
189 {
190 	int	c, lines;
191 
192 	lines = NUM_LINES_PER_PAGE;
193 	tstate.cur = (ktr_idx - 1) & (KTR_ENTRIES - 1);
194 	tstate.first = -1;
195 	if (strcmp(modif, "v") == 0)
196 		db_ktr_verbose = 1;
197 	else
198 		db_ktr_verbose = 0;
199 	while (db_mach_vtrace())
200 		if (--lines == 0) {
201 			db_printf("--More--");
202 			c = cngetc();
203 			db_printf("\r");
204 			switch (c) {
205 			case '\n':	/* one more line */
206 				lines = 1;
207 				break;
208 			case ' ':	/* one more page */
209 				lines = NUM_LINES_PER_PAGE;
210 				break;
211 			default:
212 				db_printf("\n");
213 				return;
214 			}
215 		}
216 }
217 
218 static int
219 db_mach_vtrace(void)
220 {
221 	struct ktr_entry	*kp;
222 
223 	if (tstate.cur == tstate.first) {
224 		db_printf("--- End of trace buffer ---\n");
225 		return (0);
226 	}
227 	kp = &ktr_buf[tstate.cur];
228 
229 	/* Skip over unused entries. */
230 #ifdef KTR_EXTEND
231 	if (kp->ktr_desc[0] == '\0') {
232 #else
233 	if (kp->ktr_desc == NULL) {
234 #endif
235 		db_printf("--- End of trace buffer ---\n");
236 		return (0);
237 	}
238 	db_printf("%d: ", tstate.cur);
239 	if (db_ktr_verbose)
240 		db_printf("%4ld.%06ld ", (long)kp->ktr_tv.tv_sec,
241 		    kp->ktr_tv.tv_nsec / 1000);
242 #ifdef KTR_EXTEND
243 #ifdef SMP
244 	db_printf("cpu%d ", kp->ktr_cpu);
245 #endif
246 	if (db_ktr_verbose)
247 		db_printf("%s.%d\t", kp->ktr_filename, kp->ktr_line);
248 	db_printf("%s", kp->ktr_desc);
249 #else
250 	db_printf(kp->ktr_desc, kp->ktr_parm1, kp->ktr_parm2, kp->ktr_parm3,
251 	    kp->ktr_parm4, kp->ktr_parm5, kp->ktr_parm6);
252 #endif
253 	db_printf("\n");
254 
255 	if (tstate.first == -1)
256 		tstate.first = tstate.cur;
257 
258 	if (--tstate.cur < 0)
259 		tstate.cur = KTR_ENTRIES - 1;
260 
261 	return (1);
262 }
263 
264 #endif	/* DDB */
265 #endif	/* KTR */
266