2 * Copyright (c) 2017 Colin Percival
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
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.
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
27 #include <sys/cdefs.h>
28 __FBSDID("$FreeBSD$");
30 #include <sys/param.h>
31 #include <sys/kernel.h>
32 #include <sys/linker.h>
33 #include <sys/malloc.h>
36 #include <sys/sysctl.h>
37 #include <sys/systm.h>
38 #include <sys/tslog.h>
40 #include <machine/atomic.h>
41 #include <machine/cpu.h>
44 #define TSLOGSIZE 262144
47 static volatile long nrecs = 0;
48 static struct timestamp {
54 } timestamps[TSLOGSIZE];
57 tslog(void * td, int type, const char * f, const char * s)
59 uint64_t tsc = get_cyclecount();
63 pos = atomic_fetchadd_long(&nrecs, 1);
66 if (pos < nitems(timestamps)) {
67 timestamps[pos].td = td;
68 timestamps[pos].type = type;
69 timestamps[pos].f = f;
70 timestamps[pos].s = s;
71 timestamps[pos].tsc = tsc;
76 sysctl_debug_tslog(SYSCTL_HANDLER_ARGS)
82 void * loader_tslog_buf;
83 size_t loader_tslog_len;
86 * This code can race against the code in tslog() which stores
87 * records: Theoretically we could end up reading a record after
88 * its slots have been reserved but before it has been written.
89 * Since this code takes orders of magnitude longer to run than
90 * tslog() takes to write a record, it is highly unlikely that
91 * anyone will ever experience this race.
93 sb = sbuf_new_for_sysctl(NULL, NULL, 1024, req);
95 /* Get data from the boot loader, if it provided any. */
96 loader_tslog = preload_search_by_type("TSLOG data");
97 if (loader_tslog != NULL) {
98 loader_tslog_buf = preload_fetch_addr(loader_tslog);
99 loader_tslog_len = preload_fetch_size(loader_tslog);
100 sbuf_bcat(sb, loader_tslog_buf, loader_tslog_len);
103 /* Add data logged within the kernel. */
104 limit = MIN(nrecs, nitems(timestamps));
105 for (i = 0; i < limit; i++) {
106 sbuf_printf(sb, "%p", timestamps[i].td);
107 sbuf_printf(sb, " %llu",
108 (unsigned long long)timestamps[i].tsc);
109 switch (timestamps[i].type) {
111 sbuf_printf(sb, " ENTER");
114 sbuf_printf(sb, " EXIT");
117 sbuf_printf(sb, " THREAD");
120 sbuf_printf(sb, " EVENT");
123 sbuf_printf(sb, " %s", timestamps[i].f ? timestamps[i].f : "(null)");
125 sbuf_printf(sb, " %s\n", timestamps[i].s);
127 sbuf_printf(sb, "\n");
129 error = sbuf_finish(sb);
134 SYSCTL_PROC(_debug, OID_AUTO, tslog, CTLTYPE_STRING|CTLFLAG_RD|CTLFLAG_MPSAFE,
135 0, 0, sysctl_debug_tslog, "", "Dump recorded event timestamps");
137 MALLOC_DEFINE(M_TSLOGUSER, "tsloguser", "Strings used by userland tslog");
138 static struct procdata {
145 } procs[PID_MAX + 1];
148 tslog_user(pid_t pid, pid_t ppid, const char * execname, const char * namei)
150 uint64_t tsc = get_cyclecount();
152 /* If we wrapped, do nothing. */
153 if (procs[pid].reused)
156 /* If we have a ppid, we're recording a fork. */
157 if (ppid != (pid_t)(-1)) {
158 /* If we have a ppid already, we wrapped. */
159 if (procs[pid].ppid) {
160 procs[pid].reused = 1;
164 /* Fill in some fields. */
165 procs[pid].ppid = ppid;
166 procs[pid].tsc_forked = tsc;
170 /* If we have an execname, record it. */
171 if (execname != NULL) {
172 if (procs[pid].execname != NULL)
173 free(procs[pid].execname, M_TSLOGUSER);
174 procs[pid].execname = strdup(execname, M_TSLOGUSER);
178 /* Record the first namei for the process. */
180 if (procs[pid].namei == NULL)
181 procs[pid].namei = strdup(namei, M_TSLOGUSER);
185 /* Otherwise we're recording an exit. */
186 procs[pid].tsc_exited = tsc;
190 sysctl_debug_tslog_user(SYSCTL_HANDLER_ARGS)
196 sb = sbuf_new_for_sysctl(NULL, NULL, 1024, req);
198 /* Export the data we logged. */
199 for (pid = 0; pid <= PID_MAX; pid++) {
200 sbuf_printf(sb, "%zu", (size_t)pid);
201 sbuf_printf(sb, " %zu", (size_t)procs[pid].ppid);
202 sbuf_printf(sb, " %llu",
203 (unsigned long long)procs[pid].tsc_forked);
204 sbuf_printf(sb, " %llu",
205 (unsigned long long)procs[pid].tsc_exited);
206 sbuf_printf(sb, " \"%s\"", procs[pid].execname ?
207 procs[pid].execname : "");
208 sbuf_printf(sb, " \"%s\"", procs[pid].namei ?
209 procs[pid].namei : "");
210 sbuf_printf(sb, "\n");
212 error = sbuf_finish(sb);
217 SYSCTL_PROC(_debug, OID_AUTO, tslog_user,
218 CTLTYPE_STRING|CTLFLAG_RD|CTLFLAG_MPSAFE, 0, 0, sysctl_debug_tslog_user,
219 "", "Dump recorded userland event timestamps");