1 /*- 2 * SPDX-License-Identifier: BSD-3-Clause 3 * 4 * Copyright (c) 1982, 1986, 1990, 1991, 1993 5 * The Regents of the University of California. All rights reserved. 6 * (c) UNIX System Laboratories, Inc. 7 * All or some portions of this file are derived from material licensed 8 * to the University of California by American Telephone and Telegraph 9 * Co. or Unix System Laboratories, Inc. and are reproduced herein with 10 * the permission of UNIX System Laboratories, Inc. 11 * 12 * Copyright (c) 2002 Networks Associates Technologies, Inc. 13 * All rights reserved. 14 * 15 * Portions of this software were developed for the FreeBSD Project by 16 * ThinkSec AS and NAI Labs, the Security Research Division of Network 17 * Associates, Inc. under DARPA/SPAWAR contract N66001-01-C-8035 18 * ("CBOSS"), as part of the DARPA CHATS research program. 19 * 20 * Redistribution and use in source and binary forms, with or without 21 * modification, are permitted provided that the following conditions 22 * are met: 23 * 1. Redistributions of source code must retain the above copyright 24 * notice, this list of conditions and the following disclaimer. 25 * 2. Redistributions in binary form must reproduce the above copyright 26 * notice, this list of conditions and the following disclaimer in the 27 * documentation and/or other materials provided with the distribution. 28 * 3. Neither the name of the University nor the names of its contributors 29 * may be used to endorse or promote products derived from this software 30 * without specific prior written permission. 31 * 32 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 33 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 34 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 35 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 36 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 37 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 38 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 39 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 40 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 41 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 42 * SUCH DAMAGE. 43 */ 44 45 #include <sys/cdefs.h> 46 #include "opt_stack.h" 47 48 #include <sys/param.h> 49 #include <sys/cons.h> 50 #include <sys/kdb.h> 51 #include <sys/lock.h> 52 #include <sys/malloc.h> 53 #include <sys/mutex.h> 54 #include <sys/proc.h> 55 #include <sys/resourcevar.h> 56 #include <sys/sbuf.h> 57 #include <sys/sched.h> 58 #include <sys/stack.h> 59 #include <sys/sysctl.h> 60 #include <sys/systm.h> 61 #include <sys/tty.h> 62 63 #include <vm/vm.h> 64 #include <vm/pmap.h> 65 #include <vm/vm_map.h> 66 67 /* 68 * Returns 1 if p2 is "better" than p1 69 * 70 * The algorithm for picking the "interesting" process is thus: 71 * 72 * 1) Only foreground processes are eligible - implied. 73 * 2) Runnable processes are favored over anything else. The runner 74 * with the highest cpu utilization is picked (p_estcpu). Ties are 75 * broken by picking the highest pid. 76 * 3) The sleeper with the shortest sleep time is next. With ties, 77 * we pick out just "short-term" sleepers (P_SINTR == 0). 78 * 4) Further ties are broken by picking the highest pid. 79 */ 80 81 #define TESTAB(a, b) ((a)<<1 | (b)) 82 #define ONLYA 2 83 #define ONLYB 1 84 #define BOTH 3 85 86 static int 87 proc_sum(struct proc *p, fixpt_t *estcpup) 88 { 89 struct thread *td; 90 int estcpu; 91 int val; 92 93 val = 0; 94 estcpu = 0; 95 FOREACH_THREAD_IN_PROC(p, td) { 96 thread_lock(td); 97 if (TD_ON_RUNQ(td) || 98 TD_IS_RUNNING(td)) 99 val = 1; 100 estcpu += sched_pctcpu(td); 101 thread_unlock(td); 102 } 103 *estcpup = estcpu; 104 105 return (val); 106 } 107 108 static int 109 thread_compare(struct thread *td, struct thread *td2) 110 { 111 int runa, runb; 112 int slpa, slpb; 113 fixpt_t esta, estb; 114 115 if (td == NULL) 116 return (1); 117 118 /* 119 * Fetch running stats, pctcpu usage, and interruptable flag. 120 */ 121 thread_lock(td); 122 runa = TD_IS_RUNNING(td) || TD_ON_RUNQ(td); 123 slpa = td->td_flags & TDF_SINTR; 124 esta = sched_pctcpu(td); 125 thread_unlock(td); 126 thread_lock(td2); 127 runb = TD_IS_RUNNING(td2) || TD_ON_RUNQ(td2); 128 estb = sched_pctcpu(td2); 129 slpb = td2->td_flags & TDF_SINTR; 130 thread_unlock(td2); 131 /* 132 * see if at least one of them is runnable 133 */ 134 switch (TESTAB(runa, runb)) { 135 case ONLYA: 136 return (0); 137 case ONLYB: 138 return (1); 139 case BOTH: 140 break; 141 } 142 /* 143 * favor one with highest recent cpu utilization 144 */ 145 if (estb > esta) 146 return (1); 147 if (esta > estb) 148 return (0); 149 /* 150 * favor one sleeping in a non-interruptible sleep 151 */ 152 switch (TESTAB(slpa, slpb)) { 153 case ONLYA: 154 return (0); 155 case ONLYB: 156 return (1); 157 case BOTH: 158 break; 159 } 160 161 return (td < td2); 162 } 163 164 static int 165 proc_compare(struct proc *p1, struct proc *p2) 166 { 167 168 int runa, runb; 169 fixpt_t esta, estb; 170 171 if (p1 == NULL) 172 return (1); 173 174 /* 175 * Fetch various stats about these processes. After we drop the 176 * lock the information could be stale but the race is unimportant. 177 */ 178 PROC_LOCK(p1); 179 runa = proc_sum(p1, &esta); 180 PROC_UNLOCK(p1); 181 PROC_LOCK(p2); 182 runb = proc_sum(p2, &estb); 183 PROC_UNLOCK(p2); 184 185 /* 186 * see if at least one of them is runnable 187 */ 188 switch (TESTAB(runa, runb)) { 189 case ONLYA: 190 return (0); 191 case ONLYB: 192 return (1); 193 case BOTH: 194 break; 195 } 196 /* 197 * favor one with highest recent cpu utilization 198 */ 199 if (estb > esta) 200 return (1); 201 if (esta > estb) 202 return (0); 203 /* 204 * weed out zombies 205 */ 206 switch (TESTAB(p1->p_state == PRS_ZOMBIE, p2->p_state == PRS_ZOMBIE)) { 207 case ONLYA: 208 return (1); 209 case ONLYB: 210 return (0); 211 case BOTH: 212 break; 213 } 214 215 return (p2->p_pid > p1->p_pid); /* tie - return highest pid */ 216 } 217 218 static int 219 sbuf_tty_drain(void *a, const char *d, int len) 220 { 221 struct tty *tp; 222 int rc; 223 224 tp = a; 225 226 if (kdb_active) { 227 cnputsn(d, len); 228 return (len); 229 } 230 if (tp != NULL && !KERNEL_PANICKED()) { 231 rc = tty_putstrn(tp, d, len); 232 if (rc != 0) 233 return (-ENXIO); 234 return (len); 235 } 236 return (-ENXIO); 237 } 238 239 #ifdef STACK 240 #ifdef INVARIANTS 241 static int tty_info_kstacks = STACK_SBUF_FMT_COMPACT; 242 #else 243 static int tty_info_kstacks = STACK_SBUF_FMT_NONE; 244 #endif 245 246 static int 247 sysctl_tty_info_kstacks(SYSCTL_HANDLER_ARGS) 248 { 249 enum stack_sbuf_fmt val; 250 int error; 251 252 val = tty_info_kstacks; 253 error = sysctl_handle_int(oidp, &val, 0, req); 254 if (error != 0 || req->newptr == NULL) 255 return (error); 256 257 switch (val) { 258 case STACK_SBUF_FMT_NONE: 259 case STACK_SBUF_FMT_LONG: 260 case STACK_SBUF_FMT_COMPACT: 261 tty_info_kstacks = val; 262 break; 263 default: 264 error = EINVAL; 265 } 266 267 return (error); 268 } 269 SYSCTL_PROC(_kern, OID_AUTO, tty_info_kstacks, 270 CTLFLAG_RWTUN | CTLFLAG_MPSAFE | CTLTYPE_INT, NULL, 0, 271 sysctl_tty_info_kstacks, "I", 272 "Adjust format of kernel stack(9) traces on ^T (tty info): " 273 "0 - disabled; 1 - long; 2 - compact"); 274 #endif 275 276 /* 277 * Report on state of foreground process group. 278 */ 279 void 280 tty_info(struct tty *tp) 281 { 282 struct timeval rtime, utime, stime; 283 #ifdef STACK 284 struct stack stack; 285 int sterr, kstacks_val; 286 bool print_kstacks; 287 #endif 288 struct proc *p, *ppick; 289 struct thread *td, *tdpick; 290 const char *stateprefix, *state; 291 struct sbuf sb; 292 long rss; 293 int load, pctcpu; 294 pid_t pid; 295 char comm[MAXCOMLEN + 1]; 296 struct rusage ru; 297 298 tty_assert_locked(tp); 299 300 if (tty_checkoutq(tp) == 0) 301 return; 302 303 (void)sbuf_new(&sb, tp->t_prbuf, tp->t_prbufsz, SBUF_FIXEDLEN); 304 sbuf_set_drain(&sb, sbuf_tty_drain, tp); 305 306 /* Print load average. */ 307 load = ((int64_t)averunnable.ldavg[0] * 100 + FSCALE / 2) >> FSHIFT; 308 sbuf_printf(&sb, "%sload: %d.%02d ", tp->t_column == 0 ? "" : "\n", 309 load / 100, load % 100); 310 311 if (tp->t_session == NULL) { 312 sbuf_printf(&sb, "not a controlling terminal\n"); 313 goto out; 314 } 315 if (tp->t_pgrp == NULL) { 316 sbuf_printf(&sb, "no foreground process group\n"); 317 goto out; 318 } 319 PGRP_LOCK(tp->t_pgrp); 320 if (LIST_EMPTY(&tp->t_pgrp->pg_members)) { 321 PGRP_UNLOCK(tp->t_pgrp); 322 sbuf_printf(&sb, "empty foreground process group\n"); 323 goto out; 324 } 325 326 /* 327 * Pick the most interesting process and copy some of its 328 * state for printing later. This operation could rely on stale 329 * data as we can't hold the proc slock or thread locks over the 330 * whole list. However, we're guaranteed not to reference an exited 331 * thread or proc since we hold the tty locked. 332 */ 333 p = NULL; 334 LIST_FOREACH(ppick, &tp->t_pgrp->pg_members, p_pglist) 335 if (proc_compare(p, ppick)) 336 p = ppick; 337 338 PROC_LOCK(p); 339 PGRP_UNLOCK(tp->t_pgrp); 340 td = NULL; 341 FOREACH_THREAD_IN_PROC(p, tdpick) 342 if (thread_compare(td, tdpick)) 343 td = tdpick; 344 stateprefix = ""; 345 thread_lock(td); 346 if (TD_IS_RUNNING(td)) 347 state = "running"; 348 else if (TD_ON_RUNQ(td) || TD_CAN_RUN(td)) 349 state = "runnable"; 350 else if (TD_IS_SLEEPING(td)) { 351 /* XXX: If we're sleeping, are we ever not in a queue? */ 352 if (TD_ON_SLEEPQ(td)) 353 state = td->td_wmesg; 354 else 355 state = "sleeping without queue"; 356 } else if (TD_ON_LOCK(td)) { 357 state = td->td_lockname; 358 stateprefix = "*"; 359 } else if (TD_IS_SUSPENDED(td)) 360 state = "suspended"; 361 else if (TD_AWAITING_INTR(td)) 362 state = "intrwait"; 363 else if (p->p_state == PRS_ZOMBIE) 364 state = "zombie"; 365 else 366 state = "unknown"; 367 pctcpu = (sched_pctcpu(td) * 10000 + FSCALE / 2) >> FSHIFT; 368 #ifdef STACK 369 kstacks_val = atomic_load_int(&tty_info_kstacks); 370 print_kstacks = (kstacks_val != STACK_SBUF_FMT_NONE); 371 372 if (print_kstacks) { 373 if (TD_IS_SWAPPED(td)) 374 sterr = ENOENT; 375 else 376 sterr = stack_save_td(&stack, td); 377 } 378 #endif 379 thread_unlock(td); 380 if (p->p_state == PRS_NEW || p->p_state == PRS_ZOMBIE) 381 rss = 0; 382 else 383 rss = pgtok(vmspace_resident_count(p->p_vmspace)); 384 microuptime(&rtime); 385 timevalsub(&rtime, &p->p_stats->p_start); 386 rufetchcalc(p, &ru, &utime, &stime); 387 pid = p->p_pid; 388 strlcpy(comm, p->p_comm, sizeof comm); 389 PROC_UNLOCK(p); 390 391 /* Print command, pid, state, rtime, utime, stime, %cpu, and rss. */ 392 sbuf_printf(&sb, 393 " cmd: %s %d [%s%s] %ld.%02ldr %ld.%02ldu %ld.%02lds %d%% %ldk\n", 394 comm, pid, stateprefix, state, 395 (long)rtime.tv_sec, rtime.tv_usec / 10000, 396 (long)utime.tv_sec, utime.tv_usec / 10000, 397 (long)stime.tv_sec, stime.tv_usec / 10000, 398 pctcpu / 100, rss); 399 400 #ifdef STACK 401 if (print_kstacks && sterr == 0) 402 stack_sbuf_print_flags(&sb, &stack, M_NOWAIT, kstacks_val); 403 #endif 404 405 out: 406 sbuf_finish(&sb); 407 sbuf_delete(&sb); 408 } 409