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
proc_sum(struct proc * p,fixpt_t * estcpup)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
thread_compare(struct thread * td,struct thread * td2)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
proc_compare(struct proc * p1,struct proc * p2)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
sbuf_tty_drain(void * a,const char * d,int len)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
sysctl_tty_info_kstacks(SYSCTL_HANDLER_ARGS)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
tty_info(struct tty * tp)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_cat(&sb, "not a controlling terminal\n");
313 goto out;
314 }
315 if (tp->t_pgrp == NULL) {
316 sbuf_cat(&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_cat(&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