kern_ktr.c revision 87622 
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: head/sys/kern/kern_ktr.c 87622 2001-12-10 20:18:17Z obrien $
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
83SYSCTL_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 */
89int     ktr_extend = KTR_EXTEND_DEFAULT;
90SYSCTL_INT(_debug_ktr, OID_AUTO, extend, CTLFLAG_RD, &ktr_extend, 0, "");
91
92int	ktr_cpumask = KTR_CPUMASK;
93TUNABLE_INT("debug.ktr.cpumask", &ktr_cpumask);
94SYSCTL_INT(_debug_ktr, OID_AUTO, cpumask, CTLFLAG_RW, &ktr_cpumask, 0, "");
95
96int	ktr_mask = KTR_MASK;
97TUNABLE_INT("debug.ktr.mask", &ktr_mask);
98SYSCTL_INT(_debug_ktr, OID_AUTO, mask, CTLFLAG_RW, &ktr_mask, 0, "");
99
100int	ktr_entries = KTR_ENTRIES;
101SYSCTL_INT(_debug_ktr, OID_AUTO, entries, CTLFLAG_RD, &ktr_entries, 0, "");
102
103volatile int	ktr_idx = 0;
104struct	ktr_entry ktr_buf[KTR_ENTRIES];
105
106int	ktr_verbose = KTR_VERBOSE_DEFAULT;
107TUNABLE_INT("debug.ktr.verbose", &ktr_verbose);
108SYSCTL_INT(_debug_ktr, OID_AUTO, verbose, CTLFLAG_RW, &ktr_verbose, 0, "");
109
110#ifdef KTR
111#ifdef KTR_EXTEND
112void
113ktr_tracepoint(u_int mask, const char *filename, u_int line,
114	       const char *format, ...)
115#else
116void
117ktr_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	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
182struct tstate {
183	int	cur;
184	int	first;
185};
186static	struct tstate tstate;
187static	int db_ktr_verbose;
188static	int db_mach_vtrace(void);
189
190#define	NUM_LINES_PER_PAGE	18
191
192DB_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
222static int
223db_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