1 /*- 2 * Copyright (c) 2017 Colin Percival 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 #include <sys/cdefs.h> 28 __FBSDID("$FreeBSD$"); 29 30 #include <sys/param.h> 31 #include <sys/kernel.h> 32 #include <sys/linker.h> 33 #include <sys/malloc.h> 34 #include <sys/proc.h> 35 #include <sys/sbuf.h> 36 #include <sys/sysctl.h> 37 #include <sys/systm.h> 38 #include <sys/tslog.h> 39 40 #include <machine/atomic.h> 41 #include <machine/cpu.h> 42 43 #ifndef TSLOGSIZE 44 #define TSLOGSIZE 262144 45 #endif 46 47 static volatile long nrecs = 0; 48 static struct timestamp { 49 void * td; 50 int type; 51 const char * f; 52 const char * s; 53 uint64_t tsc; 54 } timestamps[TSLOGSIZE]; 55 56 void 57 tslog(void * td, int type, const char * f, const char * s) 58 { 59 uint64_t tsc = get_cyclecount(); 60 long pos; 61 62 /* Grab a slot. */ 63 pos = atomic_fetchadd_long(&nrecs, 1); 64 65 /* Store record. */ 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; 72 } 73 } 74 75 static int 76 sysctl_debug_tslog(SYSCTL_HANDLER_ARGS) 77 { 78 int error; 79 struct sbuf *sb; 80 size_t i, limit; 81 caddr_t loader_tslog; 82 void * loader_tslog_buf; 83 size_t loader_tslog_len; 84 85 /* 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. 92 */ 93 sb = sbuf_new_for_sysctl(NULL, NULL, 1024, req); 94 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); 101 } 102 103 /* 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) { 110 case TS_ENTER: 111 sbuf_printf(sb, " ENTER"); 112 break; 113 case TS_EXIT: 114 sbuf_printf(sb, " EXIT"); 115 break; 116 case TS_THREAD: 117 sbuf_printf(sb, " THREAD"); 118 break; 119 case TS_EVENT: 120 sbuf_printf(sb, " EVENT"); 121 break; 122 } 123 sbuf_printf(sb, " %s", timestamps[i].f ? timestamps[i].f : "(null)"); 124 if (timestamps[i].s) 125 sbuf_printf(sb, " %s\n", timestamps[i].s); 126 else 127 sbuf_printf(sb, "\n"); 128 } 129 error = sbuf_finish(sb); 130 sbuf_delete(sb); 131 return (error); 132 } 133 134 SYSCTL_PROC(_debug, OID_AUTO, tslog, CTLTYPE_STRING|CTLFLAG_RD|CTLFLAG_MPSAFE, 135 0, 0, sysctl_debug_tslog, "", "Dump recorded event timestamps"); 136 137 MALLOC_DEFINE(M_TSLOGUSER, "tsloguser", "Strings used by userland tslog"); 138 static struct procdata { 139 pid_t ppid; 140 uint64_t tsc_forked; 141 uint64_t tsc_exited; 142 char * execname; 143 char * namei; 144 int reused; 145 } procs[PID_MAX + 1]; 146 147 void 148 tslog_user(pid_t pid, pid_t ppid, const char * execname, const char * namei) 149 { 150 uint64_t tsc = get_cyclecount(); 151 152 /* If we wrapped, do nothing. */ 153 if (procs[pid].reused) 154 return; 155 156 /* 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; 161 return; 162 } 163 164 /* Fill in some fields. */ 165 procs[pid].ppid = ppid; 166 procs[pid].tsc_forked = tsc; 167 return; 168 } 169 170 /* 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); 175 return; 176 } 177 178 /* Record the first namei for the process. */ 179 if (namei != NULL) { 180 if (procs[pid].namei == NULL) 181 procs[pid].namei = strdup(namei, M_TSLOGUSER); 182 return; 183 } 184 185 /* Otherwise we're recording an exit. */ 186 procs[pid].tsc_exited = tsc; 187 } 188 189 static int 190 sysctl_debug_tslog_user(SYSCTL_HANDLER_ARGS) 191 { 192 int error; 193 struct sbuf *sb; 194 pid_t pid; 195 196 sb = sbuf_new_for_sysctl(NULL, NULL, 1024, req); 197 198 /* 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"); 211 } 212 error = sbuf_finish(sb); 213 sbuf_delete(sb); 214 return (error); 215 } 216 217 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"); 220