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/param.h> 28 #include <sys/kernel.h> 29 #include <sys/linker.h> 30 #include <sys/malloc.h> 31 #include <sys/proc.h> 32 #include <sys/sbuf.h> 33 #include <sys/sysctl.h> 34 #include <sys/systm.h> 35 #include <sys/tslog.h> 36 37 #include <machine/atomic.h> 38 #include <machine/cpu.h> 39 40 #ifndef TSLOGSIZE 41 #define TSLOGSIZE 262144 42 #endif 43 44 static volatile long nrecs = 0; 45 static struct timestamp { 46 void * td; 47 int type; 48 const char * f; 49 const char * s; 50 uint64_t tsc; 51 } timestamps[TSLOGSIZE]; 52 53 void 54 tslog(void * td, int type, const char * f, const char * s) 55 { 56 uint64_t tsc = get_cyclecount(); 57 long pos; 58 59 /* A NULL thread is thread0 before curthread is set. */ 60 if (td == NULL) 61 td = &thread0; 62 63 /* Grab a slot. */ 64 pos = atomic_fetchadd_long(&nrecs, 1); 65 66 /* Store record. */ 67 if (pos < nitems(timestamps)) { 68 timestamps[pos].td = td; 69 timestamps[pos].type = type; 70 timestamps[pos].f = f; 71 timestamps[pos].s = s; 72 timestamps[pos].tsc = tsc; 73 } 74 } 75 76 static int 77 sysctl_debug_tslog(SYSCTL_HANDLER_ARGS) 78 { 79 int error; 80 struct sbuf *sb; 81 size_t i, limit; 82 caddr_t loader_tslog; 83 void * loader_tslog_buf; 84 size_t loader_tslog_len; 85 86 /* 87 * This code can race against the code in tslog() which stores 88 * records: Theoretically we could end up reading a record after 89 * its slots have been reserved but before it has been written. 90 * Since this code takes orders of magnitude longer to run than 91 * tslog() takes to write a record, it is highly unlikely that 92 * anyone will ever experience this race. 93 */ 94 sb = sbuf_new_for_sysctl(NULL, NULL, 1024, req); 95 96 /* Get data from the boot loader, if it provided any. */ 97 loader_tslog = preload_search_by_type("TSLOG data"); 98 if (loader_tslog != NULL) { 99 loader_tslog_buf = preload_fetch_addr(loader_tslog); 100 loader_tslog_len = preload_fetch_size(loader_tslog); 101 sbuf_bcat(sb, loader_tslog_buf, loader_tslog_len); 102 } 103 104 /* Add data logged within the kernel. */ 105 limit = MIN(nrecs, nitems(timestamps)); 106 for (i = 0; i < limit; i++) { 107 sbuf_printf(sb, "%p", timestamps[i].td); 108 sbuf_printf(sb, " %llu", 109 (unsigned long long)timestamps[i].tsc); 110 switch (timestamps[i].type) { 111 case TS_ENTER: 112 sbuf_cat(sb, " ENTER"); 113 break; 114 case TS_EXIT: 115 sbuf_cat(sb, " EXIT"); 116 break; 117 case TS_THREAD: 118 sbuf_cat(sb, " THREAD"); 119 break; 120 case TS_EVENT: 121 sbuf_cat(sb, " EVENT"); 122 break; 123 } 124 sbuf_printf(sb, " %s", timestamps[i].f ? timestamps[i].f : "(null)"); 125 if (timestamps[i].s) 126 sbuf_printf(sb, " %s\n", timestamps[i].s); 127 else 128 sbuf_putc(sb, '\n'); 129 } 130 error = sbuf_finish(sb); 131 sbuf_delete(sb); 132 return (error); 133 } 134 135 SYSCTL_PROC(_debug, OID_AUTO, tslog, 136 CTLTYPE_STRING|CTLFLAG_RD|CTLFLAG_MPSAFE|CTLFLAG_SKIP, 137 0, 0, sysctl_debug_tslog, "", "Dump recorded event timestamps"); 138 139 MALLOC_DEFINE(M_TSLOGUSER, "tsloguser", "Strings used by userland tslog"); 140 static struct procdata { 141 pid_t ppid; 142 uint64_t tsc_forked; 143 uint64_t tsc_exited; 144 char * execname; 145 char * namei; 146 int reused; 147 } procs[PID_MAX + 1]; 148 149 void 150 tslog_user(pid_t pid, pid_t ppid, const char * execname, const char * namei) 151 { 152 uint64_t tsc = get_cyclecount(); 153 154 /* If we wrapped, do nothing. */ 155 if (procs[pid].reused) 156 return; 157 158 /* If we have a ppid, we're recording a fork. */ 159 if (ppid != (pid_t)(-1)) { 160 /* If we have a ppid already, we wrapped. */ 161 if (procs[pid].ppid) { 162 procs[pid].reused = 1; 163 return; 164 } 165 166 /* Fill in some fields. */ 167 procs[pid].ppid = ppid; 168 procs[pid].tsc_forked = tsc; 169 return; 170 } 171 172 /* If we have an execname, record it. */ 173 if (execname != NULL) { 174 if (procs[pid].execname != NULL) 175 free(procs[pid].execname, M_TSLOGUSER); 176 procs[pid].execname = strdup(execname, M_TSLOGUSER); 177 return; 178 } 179 180 /* Record the first namei for the process. */ 181 if (namei != NULL) { 182 if (procs[pid].namei == NULL) 183 procs[pid].namei = strdup(namei, M_TSLOGUSER); 184 return; 185 } 186 187 /* Otherwise we're recording an exit. */ 188 procs[pid].tsc_exited = tsc; 189 } 190 191 static int 192 sysctl_debug_tslog_user(SYSCTL_HANDLER_ARGS) 193 { 194 int error; 195 struct sbuf *sb; 196 pid_t pid; 197 198 sb = sbuf_new_for_sysctl(NULL, NULL, 1024, req); 199 200 /* Export the data we logged. */ 201 for (pid = 0; pid <= PID_MAX; pid++) { 202 sbuf_printf(sb, "%zu", (size_t)pid); 203 sbuf_printf(sb, " %zu", (size_t)procs[pid].ppid); 204 sbuf_printf(sb, " %llu", 205 (unsigned long long)procs[pid].tsc_forked); 206 sbuf_printf(sb, " %llu", 207 (unsigned long long)procs[pid].tsc_exited); 208 sbuf_printf(sb, " \"%s\"", procs[pid].execname ? 209 procs[pid].execname : ""); 210 sbuf_printf(sb, " \"%s\"", procs[pid].namei ? 211 procs[pid].namei : ""); 212 sbuf_putc(sb, '\n'); 213 } 214 error = sbuf_finish(sb); 215 sbuf_delete(sb); 216 return (error); 217 } 218 219 SYSCTL_PROC(_debug, OID_AUTO, tslog_user, 220 CTLTYPE_STRING|CTLFLAG_RD|CTLFLAG_MPSAFE|CTLFLAG_SKIP, 221 0, 0, sysctl_debug_tslog_user, 222 "", "Dump recorded userland event timestamps"); 223