kern_ktr.c revision 132583 
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 132583 2004-07-23 17:41:44Z rwatson $");
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
103#ifdef KTR_VERBOSE
104int	ktr_verbose = KTR_VERBOSE;
105TUNABLE_INT("debug.ktr.verbose", &ktr_verbose);
106SYSCTL_INT(_debug_ktr, OID_AUTO, verbose, CTLFLAG_RW, &ktr_verbose, 0, "");
107#endif
108
109#ifdef KTR_ALQ
110struct alq *ktr_alq;
111char	ktr_alq_file[MAXPATHLEN] = "/tmp/ktr.out";
112int	ktr_alq_cnt = 0;
113int	ktr_alq_depth = KTR_ENTRIES;
114int	ktr_alq_enabled = 0;
115int	ktr_alq_failed = 0;
116int	ktr_alq_max = 0;
117
118SYSCTL_INT(_debug_ktr, OID_AUTO, alq_max, CTLFLAG_RW, &ktr_alq_max, 0,
119    "Maximum number of entries to write");
120SYSCTL_INT(_debug_ktr, OID_AUTO, alq_cnt, CTLFLAG_RD, &ktr_alq_cnt, 0,
121    "Current number of written entries");
122SYSCTL_INT(_debug_ktr, OID_AUTO, alq_failed, CTLFLAG_RD, &ktr_alq_failed, 0,
123    "Number of times we overran the buffer");
124SYSCTL_INT(_debug_ktr, OID_AUTO, alq_depth, CTLFLAG_RW, &ktr_alq_depth, 0,
125    "Number of items in the write buffer");
126SYSCTL_STRING(_debug_ktr, OID_AUTO, alq_file, CTLFLAG_RW, ktr_alq_file,
127    sizeof(ktr_alq_file), "KTR logging file");
128
129static int
130sysctl_debug_ktr_alq_enable(SYSCTL_HANDLER_ARGS)
131{
132	int error;
133	int enable;
134
135	enable = ktr_alq_enabled;
136
137        error = sysctl_handle_int(oidp, &enable, 0, req);
138        if (error || !req->newptr)
139                return (error);
140
141	if (enable) {
142		if (ktr_alq_enabled)
143			return (0);
144		error = suser(curthread);
145		if (error)
146			return (error);
147		error = alq_open(&ktr_alq, (const char *)ktr_alq_file,
148		    req->td->td_ucred, sizeof(struct ktr_entry),
149		    ktr_alq_depth);
150		if (error == 0) {
151			ktr_mask &= ~KTR_ALQ_MASK;
152			ktr_alq_cnt = 0;
153			ktr_alq_failed = 0;
154			ktr_alq_enabled = 1;
155		}
156	} else {
157		if (ktr_alq_enabled == 0)
158			return (0);
159		ktr_alq_enabled = 0;
160		alq_close(ktr_alq);
161		ktr_alq = NULL;
162	}
163
164	return (error);
165}
166SYSCTL_PROC(_debug_ktr, OID_AUTO, alq_enable,
167    CTLTYPE_INT|CTLFLAG_RW, 0, 0, sysctl_debug_ktr_alq_enable,
168    "I", "Enable KTR logging");
169#endif
170
171void
172ktr_tracepoint(u_int mask, const char *file, int line, const char *format,
173    u_long arg1, u_long arg2, u_long arg3, u_long arg4, u_long arg5,
174    u_long arg6)
175{
176	struct ktr_entry *entry;
177#ifdef KTR_ALQ
178	struct ale *ale = NULL;
179#else
180	int newindex, saveindex;
181#endif
182#if defined(KTR_VERBOSE) || defined(KTR_ALQ)
183	struct thread *td;
184#endif
185	int cpu;
186
187	if (panicstr)
188		return;
189	if ((ktr_mask & mask) == 0)
190		return;
191	cpu = KTR_CPU;
192	if (((1 << cpu) & ktr_cpumask) == 0)
193		return;
194#if defined(KTR_VERBOSE) || defined(KTR_ALQ)
195	td = curthread;
196	if (td->td_pflags & TDP_INKTR)
197		return;
198	td->td_pflags |= TDP_INKTR;
199#endif
200#ifdef KTR_ALQ
201	if (ktr_alq_enabled &&
202	    td->td_critnest == 0 &&
203	    (td->td_flags & TDF_IDLETD) == 0 &&
204	    td != ald_thread) {
205		if (ktr_alq_max && ktr_alq_cnt > ktr_alq_max)
206			goto done;
207		if ((ale = alq_get(ktr_alq, ALQ_NOWAIT)) == NULL) {
208			ktr_alq_failed++;
209			goto done;
210		}
211		ktr_alq_cnt++;
212		entry = (struct ktr_entry *)ale->ae_data;
213	} else
214		goto done;
215#else
216	do {
217		saveindex = ktr_idx;
218		newindex = (saveindex + 1) & (KTR_ENTRIES - 1);
219	} while (atomic_cmpset_rel_int(&ktr_idx, saveindex, newindex) == 0);
220	entry = &ktr_buf[saveindex];
221#endif
222	entry->ktr_timestamp = KTR_TIME;
223	entry->ktr_cpu = cpu;
224	if (file != NULL)
225		while (strncmp(file, "../", 3) == 0)
226			file += 3;
227	entry->ktr_file = file;
228	entry->ktr_line = line;
229#ifdef KTR_VERBOSE
230	if (ktr_verbose) {
231#ifdef SMP
232		printf("cpu%d ", cpu);
233#endif
234		if (ktr_verbose > 1) {
235			printf("%s.%d\t", entry->ktr_file,
236			    entry->ktr_line);
237		}
238		printf(format, arg1, arg2, arg3, arg4, arg5, arg6);
239		printf("\n");
240	}
241#endif
242	entry->ktr_desc = format;
243	entry->ktr_parms[0] = arg1;
244	entry->ktr_parms[1] = arg2;
245	entry->ktr_parms[2] = arg3;
246	entry->ktr_parms[3] = arg4;
247	entry->ktr_parms[4] = arg5;
248	entry->ktr_parms[5] = arg6;
249#ifdef KTR_ALQ
250	if (ale)
251		alq_post(ktr_alq, ale);
252done:
253#endif
254#if defined(KTR_VERBOSE) || defined(KTR_ALQ)
255	td->td_pflags &= ~TDP_INKTR;
256#endif
257}
258
259#ifdef DDB
260
261struct tstate {
262	int	cur;
263	int	first;
264};
265static	struct tstate tstate;
266static	int db_ktr_verbose;
267static	int db_mach_vtrace(void);
268
269#define	NUM_LINES_PER_PAGE	18
270
271DB_SHOW_COMMAND(ktr, db_ktr_all)
272{
273	int quit;
274
275	quit = 0;
276	tstate.cur = (ktr_idx - 1) & (KTR_ENTRIES - 1);
277	tstate.first = -1;
278	if (strcmp(modif, "v") == 0)
279		db_ktr_verbose = 1;
280	else
281		db_ktr_verbose = 0;
282	if (strcmp(modif, "a") == 0) {
283		while (cncheckc() != -1)
284			if (db_mach_vtrace() == 0)
285				break;
286	} else {
287		db_setup_paging(db_simple_pager, &quit, DB_LINES_PER_PAGE);
288		while (!quit)
289			if (db_mach_vtrace() == 0)
290				break;
291	}
292}
293
294static int
295db_mach_vtrace(void)
296{
297	struct ktr_entry	*kp;
298
299	if (tstate.cur == tstate.first) {
300		db_printf("--- End of trace buffer ---\n");
301		return (0);
302	}
303	kp = &ktr_buf[tstate.cur];
304
305	/* Skip over unused entries. */
306	if (kp->ktr_desc == NULL) {
307		db_printf("--- End of trace buffer ---\n");
308		return (0);
309	}
310	db_printf("%d: ", tstate.cur);
311#ifdef SMP
312	db_printf("cpu%d ", kp->ktr_cpu);
313#endif
314	if (db_ktr_verbose) {
315		db_printf("%10.10lld %s.%d\t", (long long)kp->ktr_timestamp,
316		    kp->ktr_file, kp->ktr_line);
317	}
318	db_printf(kp->ktr_desc, kp->ktr_parms[0], kp->ktr_parms[1],
319	    kp->ktr_parms[2], kp->ktr_parms[3], kp->ktr_parms[4],
320	    kp->ktr_parms[5]);
321	db_printf("\n");
322
323	if (tstate.first == -1)
324		tstate.first = tstate.cur;
325
326	if (--tstate.cur < 0)
327		tstate.cur = KTR_ENTRIES - 1;
328
329	return (1);
330}
331
332#endif	/* DDB */
333