kern_ktr.c revision 70464 
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 70464 2000-12-29 06:27:39Z grog $
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/types.h>
42#include <sys/cons.h>
43#include <sys/time.h>
44#include <sys/ktr.h>
45#include <sys/libkern.h>
46#include <sys/linker_set.h>
47#include <sys/sysctl.h>
48#include <sys/systm.h>
49#include <machine/globals.h>
50#include <machine/stdarg.h>
51
52#include <ddb/ddb.h>
53
54#ifndef KTR_MASK
55#define	KTR_MASK	(KTR_GEN)
56#endif
57
58#ifndef KTR_CPUMASK
59#define	KTR_CPUMASK	(~0)
60#endif
61
62#ifdef SMP
63#define KTR_CPU		cpuid
64#else
65#define KTR_CPU		0
66#endif
67
68#ifdef KTR_EXTEND
69/*
70 * This variable is used only by gdb to work out what fields are in
71 * ktr_entry.
72 */
73int     ktr_extend = 1;
74SYSCTL_INT(_debug, OID_AUTO, ktr_extend, CTLFLAG_RD, &ktr_extend, 1, "");
75#else
76int     ktr_extend = 0;
77SYSCTL_INT(_debug, OID_AUTO, ktr_extend, CTLFLAG_RD, &ktr_extend, 0, "");
78#endif	/* KTR_EXTEND */
79
80int	ktr_cpumask = KTR_CPUMASK;
81SYSCTL_INT(_debug, OID_AUTO, ktr_cpumask, CTLFLAG_RW, &ktr_cpumask, KTR_CPUMASK, "");
82
83int	ktr_mask = KTR_MASK;
84SYSCTL_INT(_debug, OID_AUTO, ktr_mask, CTLFLAG_RW, &ktr_mask, KTR_MASK, "");
85
86int	ktr_entries = KTR_ENTRIES;
87SYSCTL_INT(_debug, OID_AUTO, ktr_entries, CTLFLAG_RD, &ktr_entries, KTR_ENTRIES, "");
88
89volatile int	ktr_idx = 0;
90struct	ktr_entry ktr_buf[KTR_ENTRIES];
91
92#ifdef KTR_VERBOSE
93int	ktr_verbose = 1;
94#else
95int	ktr_verbose = 0;
96#endif
97SYSCTL_INT(_debug, OID_AUTO, ktr_verbose, CTLFLAG_RW, &ktr_verbose, 0, "");
98
99#ifdef KTR
100#ifdef KTR_EXTEND
101void
102ktr_tracepoint(u_int mask, char *filename, u_int line, char *format, ...)
103#else
104void
105ktr_tracepoint(u_int mask, char *format, u_long arg1, u_long arg2, u_long arg3,
106	       u_long arg4, u_long arg5)
107#endif
108{
109	struct ktr_entry *entry;
110	int newindex, saveindex, saveintr;
111#ifdef KTR_EXTEND
112	va_list ap;
113#endif
114
115	if (panicstr)
116		return;
117	if ((ktr_mask & mask) == 0)
118		return;
119#ifdef KTR_EXTEND
120	if (((1 << KTR_CPU) & ktr_cpumask) == 0)
121		return;
122#endif
123	saveintr = save_intr();
124	disable_intr();
125	do {
126		saveindex = ktr_idx;
127		newindex = (saveindex + 1) & (KTR_ENTRIES - 1);
128	} while (atomic_cmpset_rel_int(&ktr_idx, saveindex, newindex) == 0);
129	entry = &ktr_buf[saveindex];
130	restore_intr(saveintr);
131	if (ktr_mask & KTR_LOCK)
132		/*
133		 * We can't use nanotime with KTR_LOCK, it would cause
134		 * endless recursion, at least under the Intel
135		 * architecture.
136		 */
137		getnanotime(&entry->ktr_tv);
138	else
139		nanotime(&entry->ktr_tv);
140#ifdef KTR_EXTEND
141	strncpy(entry->ktr_filename, filename, KTRFILENAMESIZE - 1);
142	entry->ktr_filename[KTRFILENAMESIZE - 1] = '\0';
143	entry->ktr_line = line;
144	entry->ktr_cpu = KTR_CPU;
145	va_start(ap, format);
146	vsnprintf(entry->ktr_desc, KTRDESCSIZE, format, ap);
147	va_end(ap);
148	if (ktr_verbose) {
149#ifdef SMP
150		printf("cpu%d ", entry->ktr_cpu);
151#endif
152		if (ktr_verbose > 1)
153			printf("%s.%d\t", entry->ktr_filename, entry->ktr_line);
154		va_start(ap, format);
155		vprintf(format, ap);
156		printf("\n");
157		va_end(ap);
158	}
159#else
160	entry->ktr_desc = format;
161	entry->ktr_parm1 = arg1;
162	entry->ktr_parm2 = arg2;
163	entry->ktr_parm3 = arg3;
164	entry->ktr_parm4 = arg4;
165	entry->ktr_parm5 = arg5;
166#endif
167}
168
169#ifdef DDB
170
171struct tstate {
172	int	cur;
173	int	first;
174};
175static	struct tstate tstate;
176static	int db_ktr_verbose;
177static	int db_mach_vtrace(void);
178
179DB_COMMAND(tbuf, db_mach_tbuf)
180{
181
182	tstate.cur = (ktr_idx - 1) & (KTR_ENTRIES - 1);
183	tstate.first = -1;
184	if (strcmp(modif, "v") == 0)
185		db_ktr_verbose = 1;
186	else
187		db_ktr_verbose = 0;
188	db_mach_vtrace();
189
190	return;
191}
192
193DB_COMMAND(tall, db_mach_tall)
194{
195	int	c;
196
197	db_mach_tbuf(addr, have_addr, count, modif);
198	while (db_mach_vtrace()) {
199		c = cncheckc();
200		if (c != -1)
201			break;
202	}
203
204	return;
205}
206
207DB_COMMAND(tnext, db_mach_tnext)
208{
209
210	if (strcmp(modif, "v") == 0)
211		db_ktr_verbose ^= 1;
212	db_mach_vtrace();
213}
214
215static int
216db_mach_vtrace(void)
217{
218	struct ktr_entry	*kp;
219
220	if (tstate.cur == tstate.first) {
221		db_printf("--- End of trace buffer ---\n");
222		return (0);
223	}
224	kp = &ktr_buf[tstate.cur];
225
226	/* Skip over unused entries. */
227#ifdef KTR_EXTEND
228	if (kp->ktr_desc[0] != '\0') {
229#else
230	if (kp->ktr_desc != NULL) {
231#endif
232		db_printf("%d: ", tstate.cur);
233		if (db_ktr_verbose)
234			db_printf("%4ld.%06ld ", kp->ktr_tv.tv_sec,
235			    kp->ktr_tv.tv_nsec / 1000);
236#ifdef KTR_EXTEND
237#ifdef SMP
238		db_printf("cpu%d ", kp->ktr_cpu);
239#endif
240		if (db_ktr_verbose)
241			db_printf("%s.%d\t", kp->ktr_filename, kp->ktr_line);
242		db_printf("%s", kp->ktr_desc);
243#else
244		db_printf(kp->ktr_desc, kp->ktr_parm1, kp->ktr_parm2,
245		    kp->ktr_parm3, kp->ktr_parm4, kp->ktr_parm5);
246#endif
247		db_printf("\n");
248	}
249
250	if (tstate.first == -1)
251		tstate.first = tstate.cur;
252
253	if (--tstate.cur < 0)
254		tstate.cur = KTR_ENTRIES - 1;
255
256	return (1);
257}
258
259#endif	/* DDB */
260#endif	/* KTR */
261