2 * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
4 * Copyright (c) 2000 John Baldwin <jhb@FreeBSD.org>
6 * Redistribution and use in source and binary forms, with or without
7 * modification, are permitted provided that the following conditions
9 * 1. Redistributions of source code must retain the above copyright
10 * notice, this list of conditions and the following disclaimer.
11 * 2. Redistributions in binary form must reproduce the above copyright
12 * notice, this list of conditions and the following disclaimer in the
13 * documentation and/or other materials provided with the distribution.
15 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
16 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
17 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
18 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
19 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
20 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
21 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
22 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
23 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
24 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
29 * This module holds the global variables used by KTR and the ktr_tracepoint()
30 * function that does the actual tracing.
33 #include <sys/cdefs.h>
34 __FBSDID("$FreeBSD$");
40 #include <sys/param.h>
41 #include <sys/queue.h>
44 #include <sys/cpuset.h>
46 #include <sys/kernel.h>
48 #include <sys/libkern.h>
50 #include <sys/malloc.h>
51 #include <sys/mutex.h>
54 #include <sys/sysctl.h>
55 #include <sys/systm.h>
58 #include <machine/cpu.h>
62 #include <ddb/db_output.h>
65 #ifndef KTR_BOOT_ENTRIES
66 #define KTR_BOOT_ENTRIES 1024
70 #define KTR_ENTRIES 1024
73 /* Limit the allocations to something manageable. */
74 #define KTR_ENTRIES_MAX (8 * 1024 * 1024)
81 #define KTR_CPUMASK CPUSET_FSET
85 #define KTR_TIME get_cyclecount()
89 #define KTR_CPU PCPU_GET(cpuid)
92 static MALLOC_DEFINE(M_KTR, "KTR", "KTR");
94 FEATURE(ktr, "Kernel support for KTR kernel tracing facility");
96 volatile int ktr_idx = 0;
97 uint64_t ktr_mask = KTR_MASK;
98 uint64_t ktr_compile = KTR_COMPILE;
99 int ktr_entries = KTR_BOOT_ENTRIES;
100 int ktr_version = KTR_VERSION;
101 struct ktr_entry ktr_buf_init[KTR_BOOT_ENTRIES];
102 struct ktr_entry *ktr_buf = ktr_buf_init;
103 cpuset_t ktr_cpumask = CPUSET_T_INITIALIZER(KTR_CPUMASK);
105 static SYSCTL_NODE(_debug, OID_AUTO, ktr, CTLFLAG_RD | CTLFLAG_MPSAFE, 0,
108 SYSCTL_INT(_debug_ktr, OID_AUTO, version, CTLFLAG_RD,
109 &ktr_version, 0, "Version of the KTR interface");
111 SYSCTL_UQUAD(_debug_ktr, OID_AUTO, compile, CTLFLAG_RD,
112 &ktr_compile, 0, "Bitmask of KTR event classes compiled into the kernel");
115 sysctl_debug_ktr_cpumask(SYSCTL_HANDLER_ARGS)
117 char lktr_cpumask_str[CPUSETBUFSIZ];
121 cpusetobj_strprint(lktr_cpumask_str, &ktr_cpumask);
122 error = sysctl_handle_string(oidp, lktr_cpumask_str,
123 sizeof(lktr_cpumask_str), req);
124 if (error != 0 || req->newptr == NULL)
126 if (cpusetobj_strscan(&imask, lktr_cpumask_str) == -1)
128 CPU_COPY(&imask, &ktr_cpumask);
132 SYSCTL_PROC(_debug_ktr, OID_AUTO, cpumask,
133 CTLFLAG_RWTUN | CTLFLAG_MPSAFE | CTLTYPE_STRING, NULL, 0,
134 sysctl_debug_ktr_cpumask, "S",
135 "Bitmask of CPUs on which KTR logging is enabled");
138 sysctl_debug_ktr_clear(SYSCTL_HANDLER_ARGS)
143 error = sysctl_handle_int(oidp, &clear, 0, req);
144 if (error || !req->newptr)
148 bzero(ktr_buf, sizeof(*ktr_buf) * ktr_entries);
154 SYSCTL_PROC(_debug_ktr, OID_AUTO, clear,
155 CTLTYPE_INT | CTLFLAG_RW | CTLFLAG_NEEDGIANT, 0, 0,
156 sysctl_debug_ktr_clear, "I",
160 * This is a sysctl proc so that it is serialized as !MPSAFE along with
161 * the other ktr sysctl procs.
164 sysctl_debug_ktr_mask(SYSCTL_HANDLER_ARGS)
170 error = sysctl_handle_64(oidp, &mask, 0, req);
171 if (error || !req->newptr)
177 SYSCTL_PROC(_debug_ktr, OID_AUTO, mask,
178 CTLTYPE_U64 | CTLFLAG_RWTUN | CTLFLAG_NEEDGIANT,
179 0, 0, sysctl_debug_ktr_mask, "QU",
180 "Bitmask of KTR event classes for which logging is enabled");
182 #if KTR_ENTRIES > KTR_BOOT_ENTRIES
184 * A simplified version of sysctl_debug_ktr_entries.
185 * No need to care about SMP, scheduling, etc.
188 ktr_entries_initializer(void *dummy __unused)
192 /* Temporarily disable ktr in case malloc() is being traced. */
195 ktr_buf = malloc(sizeof(*ktr_buf) * KTR_ENTRIES, M_KTR,
197 memcpy(ktr_buf, ktr_buf_init + ktr_idx,
198 (KTR_BOOT_ENTRIES - ktr_idx) * sizeof(*ktr_buf));
200 memcpy(ktr_buf + KTR_BOOT_ENTRIES - ktr_idx, ktr_buf_init,
201 ktr_idx * sizeof(*ktr_buf));
202 ktr_idx = KTR_BOOT_ENTRIES;
204 ktr_entries = KTR_ENTRIES;
207 SYSINIT(ktr_entries_initializer, SI_SUB_KMEM, SI_ORDER_ANY,
208 ktr_entries_initializer, NULL);
212 sysctl_debug_ktr_entries(SYSCTL_HANDLER_ARGS)
216 struct ktr_entry *buf, *oldbuf;
218 entries = ktr_entries;
219 error = sysctl_handle_int(oidp, &entries, 0, req);
220 if (error || !req->newptr)
222 if (entries > KTR_ENTRIES_MAX)
224 /* Disable ktr temporarily. */
227 /* Wait for threads to go idle. */
228 if ((error = quiesce_all_cpus("ktrent", PCATCH)) != 0) {
232 if (ktr_buf != ktr_buf_init)
236 /* Allocate a new buffer. */
237 buf = malloc(sizeof(*buf) * entries, M_KTR, M_WAITOK | M_ZERO);
238 /* Install the new buffer and restart ktr. */
240 ktr_entries = entries;
249 SYSCTL_PROC(_debug_ktr, OID_AUTO, entries,
250 CTLTYPE_INT | CTLFLAG_RW | CTLFLAG_NEEDGIANT,
251 0, 0, sysctl_debug_ktr_entries, "I",
252 "Number of entries in the KTR buffer");
255 int ktr_verbose = KTR_VERBOSE;
256 TUNABLE_INT("debug.ktr.verbose", &ktr_verbose);
257 SYSCTL_INT(_debug_ktr, OID_AUTO, verbose, CTLFLAG_RW, &ktr_verbose, 0, "");
262 char ktr_alq_file[MAXPATHLEN] = "/tmp/ktr.out";
264 int ktr_alq_depth = KTR_ENTRIES;
265 int ktr_alq_enabled = 0;
266 int ktr_alq_failed = 0;
269 SYSCTL_INT(_debug_ktr, OID_AUTO, alq_max, CTLFLAG_RW, &ktr_alq_max, 0,
270 "Maximum number of entries to write");
271 SYSCTL_INT(_debug_ktr, OID_AUTO, alq_cnt, CTLFLAG_RD, &ktr_alq_cnt, 0,
272 "Current number of written entries");
273 SYSCTL_INT(_debug_ktr, OID_AUTO, alq_failed, CTLFLAG_RD, &ktr_alq_failed, 0,
274 "Number of times we overran the buffer");
275 SYSCTL_INT(_debug_ktr, OID_AUTO, alq_depth, CTLFLAG_RW, &ktr_alq_depth, 0,
276 "Number of items in the write buffer");
277 SYSCTL_STRING(_debug_ktr, OID_AUTO, alq_file, CTLFLAG_RW, ktr_alq_file,
278 sizeof(ktr_alq_file), "KTR logging file");
281 sysctl_debug_ktr_alq_enable(SYSCTL_HANDLER_ARGS)
286 enable = ktr_alq_enabled;
288 error = sysctl_handle_int(oidp, &enable, 0, req);
289 if (error || !req->newptr)
295 error = alq_open(&ktr_alq, (const char *)ktr_alq_file,
296 req->td->td_ucred, ALQ_DEFAULT_CMODE,
297 sizeof(struct ktr_entry), ktr_alq_depth);
304 if (ktr_alq_enabled == 0)
313 SYSCTL_PROC(_debug_ktr, OID_AUTO, alq_enable,
314 CTLTYPE_INT | CTLFLAG_RW | CTLFLAG_NEEDGIANT, 0, 0,
315 sysctl_debug_ktr_alq_enable, "I",
316 "Enable KTR logging");
320 ktr_tracepoint(uint64_t mask, const char *file, int line, const char *format,
321 u_long arg1, u_long arg2, u_long arg3, u_long arg4, u_long arg5,
324 struct ktr_entry *entry;
326 struct ale *ale = NULL;
328 int newindex, saveindex;
329 #if defined(KTR_VERBOSE) || defined(KTR_ALQ)
334 if (KERNEL_PANICKED() || kdb_active)
336 if ((ktr_mask & mask) == 0 || ktr_buf == NULL)
339 if (!CPU_ISSET(cpu, &ktr_cpumask))
341 #if defined(KTR_VERBOSE) || defined(KTR_ALQ)
343 if (td->td_pflags & TDP_INKTR)
345 td->td_pflags |= TDP_INKTR;
348 if (ktr_alq_enabled) {
349 if (td->td_critnest == 0 &&
350 (TD_IS_IDLETHREAD(td)) == 0 &&
352 if (ktr_alq_max && ktr_alq_cnt > ktr_alq_max)
354 if ((ale = alq_get(ktr_alq, ALQ_NOWAIT)) == NULL) {
359 entry = (struct ktr_entry *)ale->ae_data;
368 newindex = (saveindex + 1) % ktr_entries;
369 } while (atomic_cmpset_rel_int(&ktr_idx, saveindex, newindex) == 0);
370 entry = &ktr_buf[saveindex];
372 entry->ktr_timestamp = KTR_TIME;
373 entry->ktr_cpu = cpu;
374 entry->ktr_thread = curthread;
376 while (strncmp(file, "../", 3) == 0)
378 entry->ktr_file = file;
379 entry->ktr_line = line;
383 printf("cpu%d ", cpu);
385 if (ktr_verbose > 1) {
386 printf("%s.%d\t", entry->ktr_file,
389 printf(format, arg1, arg2, arg3, arg4, arg5, arg6);
393 entry->ktr_desc = format;
394 entry->ktr_parms[0] = arg1;
395 entry->ktr_parms[1] = arg2;
396 entry->ktr_parms[2] = arg3;
397 entry->ktr_parms[3] = arg4;
398 entry->ktr_parms[4] = arg5;
399 entry->ktr_parms[5] = arg6;
401 if (ktr_alq_enabled && ale)
402 alq_post(ktr_alq, ale);
405 #if defined(KTR_VERBOSE) || defined(KTR_ALQ)
406 td->td_pflags &= ~TDP_INKTR;
416 static struct tstate tstate;
417 static int db_ktr_verbose;
418 static int db_mach_vtrace(void);
420 DB_SHOW_COMMAND(ktr, db_ktr_all)
423 tstate.cur = (ktr_idx - 1) % ktr_entries;
426 db_ktr_verbose |= (strchr(modif, 'v') != NULL) ? 2 : 0;
427 db_ktr_verbose |= (strchr(modif, 'V') != NULL) ? 1 : 0; /* just timestamp please */
428 if (strchr(modif, 'a') != NULL) {
430 while (cncheckc() == -1)
431 if (db_mach_vtrace() == 0)
434 while (!db_pager_quit)
435 if (db_mach_vtrace() == 0)
443 struct ktr_entry *kp;
445 if (tstate.cur == tstate.first || ktr_buf == NULL) {
446 db_printf("--- End of trace buffer ---\n");
449 kp = &ktr_buf[tstate.cur];
451 /* Skip over unused entries. */
452 if (kp->ktr_desc == NULL) {
453 db_printf("--- End of trace buffer ---\n");
456 db_printf("%d (%p", tstate.cur, kp->ktr_thread);
458 db_printf(":cpu%d", kp->ktr_cpu);
461 if (db_ktr_verbose >= 1) {
462 db_printf(" %10.10lld", (long long)kp->ktr_timestamp);
464 if (db_ktr_verbose >= 2) {
465 db_printf(" %s.%d", kp->ktr_file, kp->ktr_line);
468 db_printf(kp->ktr_desc, kp->ktr_parms[0], kp->ktr_parms[1],
469 kp->ktr_parms[2], kp->ktr_parms[3], kp->ktr_parms[4],
473 if (tstate.first == -1)
474 tstate.first = tstate.cur;
476 if (--tstate.cur < 0)
477 tstate.cur = ktr_entries - 1;