kern_ktr.c revision 154940 
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 154940 2006-01-27 23:06:08Z 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_compile = KTR_COMPILE;
92SYSCTL_INT(_debug_ktr, OID_AUTO, compile, CTLFLAG_RD, &ktr_compile, 0, "");
93
94int	ktr_entries = KTR_ENTRIES;
95SYSCTL_INT(_debug_ktr, OID_AUTO, entries, CTLFLAG_RD, &ktr_entries, 0, "");
96
97int	ktr_version = KTR_VERSION;
98SYSCTL_INT(_debug_ktr, OID_AUTO, version, CTLFLAG_RD, &ktr_version, 0, "");
99
100volatile int	ktr_idx = 0;
101struct	ktr_entry ktr_buf[KTR_ENTRIES];
102
103static int
104sysctl_debug_ktr_clear(SYSCTL_HANDLER_ARGS)
105{
106	int clear, error;
107
108	clear = 0;
109	error = sysctl_handle_int(oidp, &clear, 0, req);
110	if (error || !req->newptr)
111		return (error);
112
113	if (clear) {
114		bzero(ktr_buf, sizeof(ktr_buf));
115		ktr_idx = 0;
116	}
117
118	return (error);
119}
120SYSCTL_PROC(_debug_ktr, OID_AUTO, clear, CTLTYPE_INT|CTLFLAG_RW, 0, 0,
121    sysctl_debug_ktr_clear, "I", "Clear KTR Buffer");
122
123#ifdef KTR_VERBOSE
124int	ktr_verbose = KTR_VERBOSE;
125TUNABLE_INT("debug.ktr.verbose", &ktr_verbose);
126SYSCTL_INT(_debug_ktr, OID_AUTO, verbose, CTLFLAG_RW, &ktr_verbose, 0, "");
127#endif
128
129#ifdef KTR_ALQ
130struct alq *ktr_alq;
131char	ktr_alq_file[MAXPATHLEN] = "/tmp/ktr.out";
132int	ktr_alq_cnt = 0;
133int	ktr_alq_depth = KTR_ENTRIES;
134int	ktr_alq_enabled = 0;
135int	ktr_alq_failed = 0;
136int	ktr_alq_max = 0;
137
138SYSCTL_INT(_debug_ktr, OID_AUTO, alq_max, CTLFLAG_RW, &ktr_alq_max, 0,
139    "Maximum number of entries to write");
140SYSCTL_INT(_debug_ktr, OID_AUTO, alq_cnt, CTLFLAG_RD, &ktr_alq_cnt, 0,
141    "Current number of written entries");
142SYSCTL_INT(_debug_ktr, OID_AUTO, alq_failed, CTLFLAG_RD, &ktr_alq_failed, 0,
143    "Number of times we overran the buffer");
144SYSCTL_INT(_debug_ktr, OID_AUTO, alq_depth, CTLFLAG_RW, &ktr_alq_depth, 0,
145    "Number of items in the write buffer");
146SYSCTL_STRING(_debug_ktr, OID_AUTO, alq_file, CTLFLAG_RW, ktr_alq_file,
147    sizeof(ktr_alq_file), "KTR logging file");
148
149static int
150sysctl_debug_ktr_alq_enable(SYSCTL_HANDLER_ARGS)
151{
152	int error;
153	int enable;
154
155	enable = ktr_alq_enabled;
156
157	error = sysctl_handle_int(oidp, &enable, 0, req);
158	if (error || !req->newptr)
159		return (error);
160
161	if (enable) {
162		if (ktr_alq_enabled)
163			return (0);
164		error = suser(curthread);
165		if (error)
166			return (error);
167		error = alq_open(&ktr_alq, (const char *)ktr_alq_file,
168		    req->td->td_ucred, ALQ_DEFAULT_CMODE,
169		    sizeof(struct ktr_entry), ktr_alq_depth);
170		if (error == 0) {
171			ktr_alq_cnt = 0;
172			ktr_alq_failed = 0;
173			ktr_alq_enabled = 1;
174		}
175	} else {
176		if (ktr_alq_enabled == 0)
177			return (0);
178		ktr_alq_enabled = 0;
179		alq_close(ktr_alq);
180		ktr_alq = NULL;
181	}
182
183	return (error);
184}
185SYSCTL_PROC(_debug_ktr, OID_AUTO, alq_enable,
186    CTLTYPE_INT|CTLFLAG_RW, 0, 0, sysctl_debug_ktr_alq_enable,
187    "I", "Enable KTR logging");
188#endif
189
190void
191ktr_tracepoint(u_int mask, const char *file, int line, const char *format,
192    u_long arg1, u_long arg2, u_long arg3, u_long arg4, u_long arg5,
193    u_long arg6)
194{
195	struct ktr_entry *entry;
196#ifdef KTR_ALQ
197	struct ale *ale = NULL;
198#else
199	int newindex, saveindex;
200#endif
201#if defined(KTR_VERBOSE) || defined(KTR_ALQ)
202	struct thread *td;
203#endif
204	int cpu;
205
206	if (panicstr)
207		return;
208	if ((ktr_mask & mask) == 0)
209		return;
210	cpu = KTR_CPU;
211	if (((1 << cpu) & ktr_cpumask) == 0)
212		return;
213#if defined(KTR_VERBOSE) || defined(KTR_ALQ)
214	td = curthread;
215	if (td->td_pflags & TDP_INKTR)
216		return;
217	td->td_pflags |= TDP_INKTR;
218#endif
219#ifdef KTR_ALQ
220	if (ktr_alq_enabled &&
221	    td->td_critnest == 0 &&
222	    (td->td_flags & TDF_IDLETD) == 0 &&
223	    td != ald_thread) {
224		if (ktr_alq_max && ktr_alq_cnt > ktr_alq_max)
225			goto done;
226		if ((ale = alq_get(ktr_alq, ALQ_NOWAIT)) == NULL) {
227			ktr_alq_failed++;
228			goto done;
229		}
230		ktr_alq_cnt++;
231		entry = (struct ktr_entry *)ale->ae_data;
232	} else
233		goto done;
234#else
235	do {
236		saveindex = ktr_idx;
237		newindex = (saveindex + 1) & (KTR_ENTRIES - 1);
238	} while (atomic_cmpset_rel_int(&ktr_idx, saveindex, newindex) == 0);
239	entry = &ktr_buf[saveindex];
240#endif
241	entry->ktr_timestamp = KTR_TIME;
242	entry->ktr_cpu = cpu;
243	entry->ktr_thread = curthread;
244	if (file != NULL)
245		while (strncmp(file, "../", 3) == 0)
246			file += 3;
247	entry->ktr_file = file;
248	entry->ktr_line = line;
249#ifdef KTR_VERBOSE
250	if (ktr_verbose) {
251#ifdef SMP
252		printf("cpu%d ", cpu);
253#endif
254		if (ktr_verbose > 1) {
255			printf("%s.%d\t", entry->ktr_file,
256			    entry->ktr_line);
257		}
258		printf(format, arg1, arg2, arg3, arg4, arg5, arg6);
259		printf("\n");
260	}
261#endif
262	entry->ktr_desc = format;
263	entry->ktr_parms[0] = arg1;
264	entry->ktr_parms[1] = arg2;
265	entry->ktr_parms[2] = arg3;
266	entry->ktr_parms[3] = arg4;
267	entry->ktr_parms[4] = arg5;
268	entry->ktr_parms[5] = arg6;
269#ifdef KTR_ALQ
270	if (ale)
271		alq_post(ktr_alq, ale);
272done:
273#endif
274#if defined(KTR_VERBOSE) || defined(KTR_ALQ)
275	td->td_pflags &= ~TDP_INKTR;
276#endif
277}
278
279#ifdef DDB
280
281struct tstate {
282	int	cur;
283	int	first;
284};
285static	struct tstate tstate;
286static	int db_ktr_verbose;
287static	int db_mach_vtrace(void);
288
289DB_SHOW_COMMAND(ktr, db_ktr_all)
290{
291	int quit;
292
293	quit = 0;
294	tstate.cur = (ktr_idx - 1) & (KTR_ENTRIES - 1);
295	tstate.first = -1;
296	if (strcmp(modif, "v") == 0)
297		db_ktr_verbose = 1;
298	else
299		db_ktr_verbose = 0;
300	if (strcmp(modif, "a") == 0) {
301		while (cncheckc() != -1)
302			if (db_mach_vtrace() == 0)
303				break;
304	} else {
305		db_setup_paging(db_simple_pager, &quit, db_lines_per_page);
306		while (!quit)
307			if (db_mach_vtrace() == 0)
308				break;
309	}
310}
311
312static int
313db_mach_vtrace(void)
314{
315	struct ktr_entry	*kp;
316
317	if (tstate.cur == tstate.first) {
318		db_printf("--- End of trace buffer ---\n");
319		return (0);
320	}
321	kp = &ktr_buf[tstate.cur];
322
323	/* Skip over unused entries. */
324	if (kp->ktr_desc == NULL) {
325		db_printf("--- End of trace buffer ---\n");
326		return (0);
327	}
328	db_printf("%d (%p", tstate.cur, kp->ktr_thread);
329#ifdef SMP
330	db_printf(":cpu%d", kp->ktr_cpu);
331#endif
332	db_printf(")");
333	if (db_ktr_verbose) {
334		db_printf(" %10.10lld %s.%d", (long long)kp->ktr_timestamp,
335		    kp->ktr_file, kp->ktr_line);
336	}
337	db_printf(": ");
338	db_printf(kp->ktr_desc, kp->ktr_parms[0], kp->ktr_parms[1],
339	    kp->ktr_parms[2], kp->ktr_parms[3], kp->ktr_parms[4],
340	    kp->ktr_parms[5]);
341	db_printf("\n");
342
343	if (tstate.first == -1)
344		tstate.first = tstate.cur;
345
346	if (--tstate.cur < 0)
347		tstate.cur = KTR_ENTRIES - 1;
348
349	return (1);
350}
351
352#endif	/* DDB */
353