kern_ktr.c revision 119936 
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: head/sys/kern/kern_ktr.c 119936 2003-09-10 01:09:32Z jhb $");
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
81SYSCTL_NODE(_debug, OID_AUTO, ktr, CTLFLAG_RD, 0, "KTR options");
82
83int	ktr_cpumask = KTR_CPUMASK;
84TUNABLE_INT("debug.ktr.cpumask", &ktr_cpumask);
85SYSCTL_INT(_debug_ktr, OID_AUTO, cpumask, CTLFLAG_RW, &ktr_cpumask, 0, "");
86
87int	ktr_mask = KTR_MASK;
88TUNABLE_INT("debug.ktr.mask", &ktr_mask);
89SYSCTL_INT(_debug_ktr, OID_AUTO, mask, CTLFLAG_RW, &ktr_mask, 0, "");
90
91int	ktr_entries = KTR_ENTRIES;
92SYSCTL_INT(_debug_ktr, OID_AUTO, entries, CTLFLAG_RD, &ktr_entries, 0, "");
93
94int	ktr_version = KTR_VERSION;
95SYSCTL_INT(_debug_ktr, OID_AUTO, version, CTLFLAG_RD, &ktr_version, 0, "");
96
97volatile int	ktr_idx = 0;
98struct	ktr_entry ktr_buf[KTR_ENTRIES];
99
100#ifdef KTR_VERBOSE
101int	ktr_verbose = KTR_VERBOSE;
102TUNABLE_INT("debug.ktr.verbose", &ktr_verbose);
103SYSCTL_INT(_debug_ktr, OID_AUTO, verbose, CTLFLAG_RW, &ktr_verbose, 0, "");
104#endif
105
106#ifdef KTR_ALQ
107struct alq *ktr_alq;
108char	ktr_alq_file[MAXPATHLEN] = "/tmp/ktr.out";
109int	ktr_alq_cnt = 0;
110int	ktr_alq_depth = KTR_ENTRIES;
111int	ktr_alq_enabled = 0;
112int	ktr_alq_failed = 0;
113int	ktr_alq_max = 0;
114
115SYSCTL_INT(_debug_ktr, OID_AUTO, alq_max, CTLFLAG_RW, &ktr_alq_max, 0,
116    "Maximum number of entries to write");
117SYSCTL_INT(_debug_ktr, OID_AUTO, alq_cnt, CTLFLAG_RD, &ktr_alq_cnt, 0,
118    "Current number of written entries");
119SYSCTL_INT(_debug_ktr, OID_AUTO, alq_failed, CTLFLAG_RD, &ktr_alq_failed, 0,
120    "Number of times we overran the buffer");
121SYSCTL_INT(_debug_ktr, OID_AUTO, alq_depth, CTLFLAG_RW, &ktr_alq_depth, 0,
122    "Number of items in the write buffer");
123SYSCTL_STRING(_debug_ktr, OID_AUTO, alq_file, CTLFLAG_RW, ktr_alq_file,
124    sizeof(ktr_alq_file), "KTR logging file");
125
126static int
127sysctl_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}
163SYSCTL_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
168void
169ktr_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);
249done:
250#endif
251#if defined(KTR_VERBOSE) || defined(KTR_ALQ)
252	td->td_pflags &= ~TDP_INKTR;
253#endif
254}
255
256#ifdef DDB
257
258struct tstate {
259	int	cur;
260	int	first;
261};
262static	struct tstate tstate;
263static	int db_ktr_verbose;
264static	int db_mach_vtrace(void);
265
266#define	NUM_LINES_PER_PAGE	18
267
268DB_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
291static int
292db_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