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 *
14 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
15 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
16 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
17 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
18 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
19 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
20 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
21 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
22 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
23 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
24 * SUCH DAMAGE.
25 */
26
27/*
28 * This module holds the global variables used by KTR and the ktr_tracepoint()
29 * function that does the actual tracing.
30 */
31
32#include <sys/cdefs.h>
33__FBSDID("$FreeBSD$");
34
35#include "opt_ddb.h"
36#include "opt_ktr.h"
37#include "opt_alq.h"
38
39#include <sys/param.h>
40#include <sys/queue.h>
41#include <sys/alq.h>
42#include <sys/cons.h>
43#include <sys/cpuset.h>
44#include <sys/kernel.h>
45#include <sys/ktr.h>
46#include <sys/libkern.h>
47#include <sys/proc.h>
48#include <sys/sysctl.h>
49#include <sys/systm.h>
50#include <sys/time.h>
51
52#include <machine/cpu.h>
53#ifdef __sparc64__
54#include <machine/ktr.h>
55#endif
56
57#ifdef DDB
58#include <ddb/ddb.h>
59#include <ddb/db_output.h>
60#endif
61
62#ifndef KTR_ENTRIES
63#define	KTR_ENTRIES	1024
64#endif
65
66#ifndef KTR_MASK
67#define	KTR_MASK	(0)
68#endif
69
70#ifndef KTR_TIME
71#define	KTR_TIME	get_cyclecount()
72#endif
73
74#ifndef KTR_CPU
75#define	KTR_CPU		PCPU_GET(cpuid)
76#endif
77
78FEATURE(ktr, "Kernel support for KTR kernel tracing facility");
79
80static SYSCTL_NODE(_debug, OID_AUTO, ktr, CTLFLAG_RD, 0, "KTR options");
81
82int	ktr_mask = KTR_MASK;
83TUNABLE_INT("debug.ktr.mask", &ktr_mask);
84SYSCTL_INT(_debug_ktr, OID_AUTO, mask, CTLFLAG_RW,
85    &ktr_mask, 0, "Bitmask of KTR event classes for which logging is enabled");
86
87int	ktr_compile = KTR_COMPILE;
88SYSCTL_INT(_debug_ktr, OID_AUTO, compile, CTLFLAG_RD,
89    &ktr_compile, 0, "Bitmask of KTR event classes compiled into the kernel");
90
91int	ktr_entries = KTR_ENTRIES;
92SYSCTL_INT(_debug_ktr, OID_AUTO, entries, CTLFLAG_RD,
93    &ktr_entries, 0, "Number of entries in the KTR buffer");
94
95int	ktr_version = KTR_VERSION;
96SYSCTL_INT(_debug_ktr, OID_AUTO, version, CTLFLAG_RD,
97    &ktr_version, 0, "Version of the KTR interface");
98
99cpuset_t ktr_cpumask;
100static char ktr_cpumask_str[CPUSETBUFSIZ];
101TUNABLE_STR("debug.ktr.cpumask", ktr_cpumask_str, sizeof(ktr_cpumask_str));
102
103static void
104ktr_cpumask_initializer(void *dummy __unused)
105{
106
107	CPU_FILL(&ktr_cpumask);
108#ifdef KTR_CPUMASK
109	if (cpusetobj_strscan(&ktr_cpumask, KTR_CPUMASK) == -1)
110		CPU_FILL(&ktr_cpumask);
111#endif
112
113	/*
114	 * TUNABLE_STR() runs with SI_ORDER_MIDDLE priority, thus it must be
115	 * already set, if necessary.
116	 */
117	if (ktr_cpumask_str[0] != '\0' &&
118	    cpusetobj_strscan(&ktr_cpumask, ktr_cpumask_str) == -1)
119		CPU_FILL(&ktr_cpumask);
120}
121SYSINIT(ktr_cpumask_initializer, SI_SUB_TUNABLES, SI_ORDER_ANY,
122    ktr_cpumask_initializer, NULL);
123
124static int
125sysctl_debug_ktr_cpumask(SYSCTL_HANDLER_ARGS)
126{
127	char lktr_cpumask_str[CPUSETBUFSIZ];
128	cpuset_t imask;
129	int error;
130
131	cpusetobj_strprint(lktr_cpumask_str, &ktr_cpumask);
132	error = sysctl_handle_string(oidp, lktr_cpumask_str,
133	    sizeof(lktr_cpumask_str), req);
134	if (error != 0 || req->newptr == NULL)
135		return (error);
136	if (cpusetobj_strscan(&imask, lktr_cpumask_str) == -1)
137		return (EINVAL);
138	CPU_COPY(&imask, &ktr_cpumask);
139
140	return (error);
141}
142SYSCTL_PROC(_debug_ktr, OID_AUTO, cpumask,
143    CTLFLAG_RW | CTLFLAG_MPSAFE | CTLTYPE_STRING, NULL, 0,
144    sysctl_debug_ktr_cpumask, "S",
145    "Bitmask of CPUs on which KTR logging is enabled");
146
147volatile int	ktr_idx = 0;
148struct	ktr_entry ktr_buf[KTR_ENTRIES];
149
150static int
151sysctl_debug_ktr_clear(SYSCTL_HANDLER_ARGS)
152{
153	int clear, error;
154
155	clear = 0;
156	error = sysctl_handle_int(oidp, &clear, 0, req);
157	if (error || !req->newptr)
158		return (error);
159
160	if (clear) {
161		bzero(ktr_buf, sizeof(ktr_buf));
162		ktr_idx = 0;
163	}
164
165	return (error);
166}
167SYSCTL_PROC(_debug_ktr, OID_AUTO, clear, CTLTYPE_INT|CTLFLAG_RW, 0, 0,
168    sysctl_debug_ktr_clear, "I", "Clear KTR Buffer");
169
170#ifdef KTR_VERBOSE
171int	ktr_verbose = KTR_VERBOSE;
172TUNABLE_INT("debug.ktr.verbose", &ktr_verbose);
173SYSCTL_INT(_debug_ktr, OID_AUTO, verbose, CTLFLAG_RW, &ktr_verbose, 0, "");
174#endif
175
176#ifdef KTR_ALQ
177struct alq *ktr_alq;
178char	ktr_alq_file[MAXPATHLEN] = "/tmp/ktr.out";
179int	ktr_alq_cnt = 0;
180int	ktr_alq_depth = KTR_ENTRIES;
181int	ktr_alq_enabled = 0;
182int	ktr_alq_failed = 0;
183int	ktr_alq_max = 0;
184
185SYSCTL_INT(_debug_ktr, OID_AUTO, alq_max, CTLFLAG_RW, &ktr_alq_max, 0,
186    "Maximum number of entries to write");
187SYSCTL_INT(_debug_ktr, OID_AUTO, alq_cnt, CTLFLAG_RD, &ktr_alq_cnt, 0,
188    "Current number of written entries");
189SYSCTL_INT(_debug_ktr, OID_AUTO, alq_failed, CTLFLAG_RD, &ktr_alq_failed, 0,
190    "Number of times we overran the buffer");
191SYSCTL_INT(_debug_ktr, OID_AUTO, alq_depth, CTLFLAG_RW, &ktr_alq_depth, 0,
192    "Number of items in the write buffer");
193SYSCTL_STRING(_debug_ktr, OID_AUTO, alq_file, CTLFLAG_RW, ktr_alq_file,
194    sizeof(ktr_alq_file), "KTR logging file");
195
196static int
197sysctl_debug_ktr_alq_enable(SYSCTL_HANDLER_ARGS)
198{
199	int error;
200	int enable;
201
202	enable = ktr_alq_enabled;
203
204	error = sysctl_handle_int(oidp, &enable, 0, req);
205	if (error || !req->newptr)
206		return (error);
207
208	if (enable) {
209		if (ktr_alq_enabled)
210			return (0);
211		error = alq_open(&ktr_alq, (const char *)ktr_alq_file,
212		    req->td->td_ucred, ALQ_DEFAULT_CMODE,
213		    sizeof(struct ktr_entry), ktr_alq_depth);
214		if (error == 0) {
215			ktr_alq_cnt = 0;
216			ktr_alq_failed = 0;
217			ktr_alq_enabled = 1;
218		}
219	} else {
220		if (ktr_alq_enabled == 0)
221			return (0);
222		ktr_alq_enabled = 0;
223		alq_close(ktr_alq);
224		ktr_alq = NULL;
225	}
226
227	return (error);
228}
229SYSCTL_PROC(_debug_ktr, OID_AUTO, alq_enable,
230    CTLTYPE_INT|CTLFLAG_RW, 0, 0, sysctl_debug_ktr_alq_enable,
231    "I", "Enable KTR logging");
232#endif
233
234void
235ktr_tracepoint(u_int mask, const char *file, int line, const char *format,
236    u_long arg1, u_long arg2, u_long arg3, u_long arg4, u_long arg5,
237    u_long arg6)
238{
239	struct ktr_entry *entry;
240#ifdef KTR_ALQ
241	struct ale *ale = NULL;
242#endif
243	int newindex, saveindex;
244#if defined(KTR_VERBOSE) || defined(KTR_ALQ)
245	struct thread *td;
246#endif
247	int cpu;
248
249	if (panicstr)
250		return;
251	if ((ktr_mask & mask) == 0)
252		return;
253	cpu = KTR_CPU;
254	if (!CPU_ISSET(cpu, &ktr_cpumask))
255		return;
256#if defined(KTR_VERBOSE) || defined(KTR_ALQ)
257	td = curthread;
258	if (td->td_pflags & TDP_INKTR)
259		return;
260	td->td_pflags |= TDP_INKTR;
261#endif
262#ifdef KTR_ALQ
263	if (ktr_alq_enabled) {
264		if (td->td_critnest == 0 &&
265		    (td->td_flags & TDF_IDLETD) == 0 &&
266		    td != ald_thread) {
267			if (ktr_alq_max && ktr_alq_cnt > ktr_alq_max)
268				goto done;
269			if ((ale = alq_get(ktr_alq, ALQ_NOWAIT)) == NULL) {
270				ktr_alq_failed++;
271				goto done;
272			}
273			ktr_alq_cnt++;
274			entry = (struct ktr_entry *)ale->ae_data;
275		} else {
276			goto done;
277		}
278	} else
279#endif
280	{
281		do {
282			saveindex = ktr_idx;
283			newindex = (saveindex + 1) % KTR_ENTRIES;
284		} while (atomic_cmpset_rel_int(&ktr_idx, saveindex, newindex) == 0);
285		entry = &ktr_buf[saveindex];
286	}
287	entry->ktr_timestamp = KTR_TIME;
288	entry->ktr_cpu = cpu;
289	entry->ktr_thread = curthread;
290	if (file != NULL)
291		while (strncmp(file, "../", 3) == 0)
292			file += 3;
293	entry->ktr_file = file;
294	entry->ktr_line = line;
295#ifdef KTR_VERBOSE
296	if (ktr_verbose) {
297#ifdef SMP
298		printf("cpu%d ", cpu);
299#endif
300		if (ktr_verbose > 1) {
301			printf("%s.%d\t", entry->ktr_file,
302			    entry->ktr_line);
303		}
304		printf(format, arg1, arg2, arg3, arg4, arg5, arg6);
305		printf("\n");
306	}
307#endif
308	entry->ktr_desc = format;
309	entry->ktr_parms[0] = arg1;
310	entry->ktr_parms[1] = arg2;
311	entry->ktr_parms[2] = arg3;
312	entry->ktr_parms[3] = arg4;
313	entry->ktr_parms[4] = arg5;
314	entry->ktr_parms[5] = arg6;
315#ifdef KTR_ALQ
316	if (ktr_alq_enabled && ale)
317		alq_post(ktr_alq, ale);
318done:
319#endif
320#if defined(KTR_VERBOSE) || defined(KTR_ALQ)
321	td->td_pflags &= ~TDP_INKTR;
322#endif
323}
324
325#ifdef DDB
326
327struct tstate {
328	int	cur;
329	int	first;
330};
331static	struct tstate tstate;
332static	int db_ktr_verbose;
333static	int db_mach_vtrace(void);
334
335DB_SHOW_COMMAND(ktr, db_ktr_all)
336{
337
338	tstate.cur = (ktr_idx - 1) % KTR_ENTRIES;
339	tstate.first = -1;
340	db_ktr_verbose = 0;
341	db_ktr_verbose |= (index(modif, 'v') != NULL) ? 2 : 0;
342	db_ktr_verbose |= (index(modif, 'V') != NULL) ? 1 : 0; /* just timestap please */
343	if (index(modif, 'a') != NULL) {
344		db_disable_pager();
345		while (cncheckc() != -1)
346			if (db_mach_vtrace() == 0)
347				break;
348	} else {
349		while (!db_pager_quit)
350			if (db_mach_vtrace() == 0)
351				break;
352	}
353}
354
355static int
356db_mach_vtrace(void)
357{
358	struct ktr_entry	*kp;
359
360	if (tstate.cur == tstate.first) {
361		db_printf("--- End of trace buffer ---\n");
362		return (0);
363	}
364	kp = &ktr_buf[tstate.cur];
365
366	/* Skip over unused entries. */
367	if (kp->ktr_desc == NULL) {
368		db_printf("--- End of trace buffer ---\n");
369		return (0);
370	}
371	db_printf("%d (%p", tstate.cur, kp->ktr_thread);
372#ifdef SMP
373	db_printf(":cpu%d", kp->ktr_cpu);
374#endif
375	db_printf(")");
376	if (db_ktr_verbose >= 1) {
377		db_printf(" %10.10lld", (long long)kp->ktr_timestamp);
378	}
379	if (db_ktr_verbose >= 2) {
380		db_printf(" %s.%d", kp->ktr_file, kp->ktr_line);
381	}
382	db_printf(": ");
383	db_printf(kp->ktr_desc, kp->ktr_parms[0], kp->ktr_parms[1],
384	    kp->ktr_parms[2], kp->ktr_parms[3], kp->ktr_parms[4],
385	    kp->ktr_parms[5]);
386	db_printf("\n");
387
388	if (tstate.first == -1)
389		tstate.first = tstate.cur;
390
391	if (--tstate.cur < 0)
392		tstate.cur = KTR_ENTRIES - 1;
393
394	return (1);
395}
396
397#endif	/* DDB */
398