1 /* $NetBSD: kern_proc.c,v 1.31 1998/09/08 23:47:49 thorpej Exp $ */ 2 3 /* 4 * Copyright (c) 1982, 1986, 1989, 1991, 1993 5 * The Regents of the University of California. All rights reserved. 6 * 7 * Redistribution and use in source and binary forms, with or without 8 * modification, are permitted provided that the following conditions 9 * are met: 10 * 1. Redistributions of source code must retain the above copyright 11 * notice, this list of conditions and the following disclaimer. 12 * 2. Redistributions in binary form must reproduce the above copyright 13 * notice, this list of conditions and the following disclaimer in the 14 * documentation and/or other materials provided with the distribution. 15 * 3. All advertising materials mentioning features or use of this software 16 * must display the following acknowledgement: 17 * This product includes software developed by the University of 18 * California, Berkeley and its contributors. 19 * 4. Neither the name of the University nor the names of its contributors 20 * may be used to endorse or promote products derived from this software 21 * without specific prior written permission. 22 * 23 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 24 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 25 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 26 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 27 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 28 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 29 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 30 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 31 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 32 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 33 * SUCH DAMAGE. 34 * 35 * @(#)kern_proc.c 8.7 (Berkeley) 2/14/95 36 */ 37 38 #include <sys/param.h> 39 #include <sys/systm.h> 40 #include <sys/map.h> 41 #include <sys/kernel.h> 42 #include <sys/proc.h> 43 #include <sys/resourcevar.h> 44 #include <sys/buf.h> 45 #include <sys/acct.h> 46 #include <sys/wait.h> 47 #include <sys/file.h> 48 #include <ufs/ufs/quota.h> 49 #include <sys/uio.h> 50 #include <sys/malloc.h> 51 #include <sys/pool.h> 52 #include <sys/mbuf.h> 53 #include <sys/ioctl.h> 54 #include <sys/tty.h> 55 #include <sys/signalvar.h> 56 57 /* 58 * Structure associated with user cacheing. 59 */ 60 struct uidinfo { 61 LIST_ENTRY(uidinfo) ui_hash; 62 uid_t ui_uid; 63 long ui_proccnt; 64 }; 65 #define UIHASH(uid) (&uihashtbl[(uid) & uihash]) 66 LIST_HEAD(uihashhead, uidinfo) *uihashtbl; 67 u_long uihash; /* size of hash table - 1 */ 68 69 /* 70 * Other process lists 71 */ 72 struct pidhashhead *pidhashtbl; 73 u_long pidhash; 74 struct pgrphashhead *pgrphashtbl; 75 u_long pgrphash; 76 77 struct proclist allproc; 78 struct proclist deadproc; /* dead, but not yet undead */ 79 struct proclist zombproc; /* resources have been freed */ 80 81 struct pool proc_pool; 82 struct pool pcred_pool; 83 struct pool plimit_pool; 84 struct pool pgrp_pool; 85 struct pool rusage_pool; 86 87 /* 88 * The process list descriptors, used during pid allocation and 89 * by sysctl. No locking on this data structure is needed since 90 * it is completely static. 91 */ 92 const struct proclist_desc proclists[] = { 93 { &allproc }, 94 { &deadproc }, 95 { &zombproc }, 96 { NULL }, 97 }; 98 99 static void orphanpg __P((struct pgrp *)); 100 #ifdef DEBUG 101 void pgrpdump __P((void)); 102 #endif 103 104 /* 105 * Initialize global process hashing structures. 106 */ 107 void 108 procinit() 109 { 110 const struct proclist_desc *pd; 111 112 for (pd = proclists; pd->pd_list != NULL; pd++) 113 LIST_INIT(pd->pd_list); 114 115 pidhashtbl = hashinit(maxproc / 4, M_PROC, M_WAITOK, &pidhash); 116 pgrphashtbl = hashinit(maxproc / 4, M_PROC, M_WAITOK, &pgrphash); 117 uihashtbl = hashinit(maxproc / 16, M_PROC, M_WAITOK, &uihash); 118 119 pool_init(&proc_pool, sizeof(struct proc), 0, 0, 0, "procpl", 120 0, pool_page_alloc_nointr, pool_page_free_nointr, M_PROC); 121 pool_init(&pgrp_pool, sizeof(struct pgrp), 0, 0, 0, "pgrppl", 122 0, pool_page_alloc_nointr, pool_page_free_nointr, M_PGRP); 123 pool_init(&pcred_pool, sizeof(struct pcred), 0, 0, 0, "pcredpl", 124 0, pool_page_alloc_nointr, pool_page_free_nointr, M_SUBPROC); 125 pool_init(&plimit_pool, sizeof(struct plimit), 0, 0, 0, "plimitpl", 126 0, pool_page_alloc_nointr, pool_page_free_nointr, M_SUBPROC); 127 pool_init(&rusage_pool, sizeof(struct rusage), 0, 0, 0, "rusgepl", 128 0, pool_page_alloc_nointr, pool_page_free_nointr, M_ZOMBIE); 129 } 130 131 /* 132 * Change the count associated with number of processes 133 * a given user is using. 134 */ 135 int 136 chgproccnt(uid, diff) 137 uid_t uid; 138 int diff; 139 { 140 register struct uidinfo *uip; 141 register struct uihashhead *uipp; 142 143 uipp = UIHASH(uid); 144 for (uip = uipp->lh_first; uip != 0; uip = uip->ui_hash.le_next) 145 if (uip->ui_uid == uid) 146 break; 147 if (uip) { 148 uip->ui_proccnt += diff; 149 if (uip->ui_proccnt > 0) 150 return (uip->ui_proccnt); 151 if (uip->ui_proccnt < 0) 152 panic("chgproccnt: procs < 0"); 153 LIST_REMOVE(uip, ui_hash); 154 FREE(uip, M_PROC); 155 return (0); 156 } 157 if (diff <= 0) { 158 if (diff == 0) 159 return(0); 160 panic("chgproccnt: lost user"); 161 } 162 MALLOC(uip, struct uidinfo *, sizeof(*uip), M_PROC, M_WAITOK); 163 LIST_INSERT_HEAD(uipp, uip, ui_hash); 164 uip->ui_uid = uid; 165 uip->ui_proccnt = diff; 166 return (diff); 167 } 168 169 /* 170 * Is p an inferior of the current process? 171 */ 172 int 173 inferior(p) 174 register struct proc *p; 175 { 176 177 for (; p != curproc; p = p->p_pptr) 178 if (p->p_pid == 0) 179 return (0); 180 return (1); 181 } 182 183 /* 184 * Locate a process by number 185 */ 186 struct proc * 187 pfind(pid) 188 register pid_t pid; 189 { 190 register struct proc *p; 191 192 for (p = PIDHASH(pid)->lh_first; p != 0; p = p->p_hash.le_next) 193 if (p->p_pid == pid) 194 return (p); 195 return (NULL); 196 } 197 198 /* 199 * Locate a process group by number 200 */ 201 struct pgrp * 202 pgfind(pgid) 203 register pid_t pgid; 204 { 205 register struct pgrp *pgrp; 206 207 for (pgrp = PGRPHASH(pgid)->lh_first; pgrp != 0; pgrp = pgrp->pg_hash.le_next) 208 if (pgrp->pg_id == pgid) 209 return (pgrp); 210 return (NULL); 211 } 212 213 /* 214 * Move p to a new or existing process group (and session) 215 */ 216 int 217 enterpgrp(p, pgid, mksess) 218 register struct proc *p; 219 pid_t pgid; 220 int mksess; 221 { 222 register struct pgrp *pgrp = pgfind(pgid); 223 224 #ifdef DIAGNOSTIC 225 if (pgrp != NULL && mksess) /* firewalls */ 226 panic("enterpgrp: setsid into non-empty pgrp"); 227 if (SESS_LEADER(p)) 228 panic("enterpgrp: session leader attempted setpgrp"); 229 #endif 230 if (pgrp == NULL) { 231 pid_t savepid = p->p_pid; 232 struct proc *np; 233 /* 234 * new process group 235 */ 236 #ifdef DIAGNOSTIC 237 if (p->p_pid != pgid) 238 panic("enterpgrp: new pgrp and pid != pgid"); 239 #endif 240 pgrp = pool_get(&pgrp_pool, PR_WAITOK); 241 if ((np = pfind(savepid)) == NULL || np != p) 242 return (ESRCH); 243 if (mksess) { 244 register struct session *sess; 245 246 /* 247 * new session 248 */ 249 MALLOC(sess, struct session *, sizeof(struct session), 250 M_SESSION, M_WAITOK); 251 sess->s_sid = p->p_pid; 252 sess->s_leader = p; 253 sess->s_count = 1; 254 sess->s_ttyvp = NULL; 255 sess->s_ttyp = NULL; 256 memcpy(sess->s_login, p->p_session->s_login, 257 sizeof(sess->s_login)); 258 p->p_flag &= ~P_CONTROLT; 259 pgrp->pg_session = sess; 260 #ifdef DIAGNOSTIC 261 if (p != curproc) 262 panic("enterpgrp: mksession and p != curproc"); 263 #endif 264 } else { 265 pgrp->pg_session = p->p_session; 266 pgrp->pg_session->s_count++; 267 } 268 pgrp->pg_id = pgid; 269 LIST_INIT(&pgrp->pg_members); 270 LIST_INSERT_HEAD(PGRPHASH(pgid), pgrp, pg_hash); 271 pgrp->pg_jobc = 0; 272 } else if (pgrp == p->p_pgrp) 273 return (0); 274 275 /* 276 * Adjust eligibility of affected pgrps to participate in job control. 277 * Increment eligibility counts before decrementing, otherwise we 278 * could reach 0 spuriously during the first call. 279 */ 280 fixjobc(p, pgrp, 1); 281 fixjobc(p, p->p_pgrp, 0); 282 283 LIST_REMOVE(p, p_pglist); 284 if (p->p_pgrp->pg_members.lh_first == 0) 285 pgdelete(p->p_pgrp); 286 p->p_pgrp = pgrp; 287 LIST_INSERT_HEAD(&pgrp->pg_members, p, p_pglist); 288 return (0); 289 } 290 291 /* 292 * remove process from process group 293 */ 294 int 295 leavepgrp(p) 296 register struct proc *p; 297 { 298 299 LIST_REMOVE(p, p_pglist); 300 if (p->p_pgrp->pg_members.lh_first == 0) 301 pgdelete(p->p_pgrp); 302 p->p_pgrp = 0; 303 return (0); 304 } 305 306 /* 307 * delete a process group 308 */ 309 void 310 pgdelete(pgrp) 311 register struct pgrp *pgrp; 312 { 313 314 if (pgrp->pg_session->s_ttyp != NULL && 315 pgrp->pg_session->s_ttyp->t_pgrp == pgrp) 316 pgrp->pg_session->s_ttyp->t_pgrp = NULL; 317 LIST_REMOVE(pgrp, pg_hash); 318 if (--pgrp->pg_session->s_count == 0) 319 FREE(pgrp->pg_session, M_SESSION); 320 pool_put(&pgrp_pool, pgrp); 321 } 322 323 /* 324 * Adjust pgrp jobc counters when specified process changes process group. 325 * We count the number of processes in each process group that "qualify" 326 * the group for terminal job control (those with a parent in a different 327 * process group of the same session). If that count reaches zero, the 328 * process group becomes orphaned. Check both the specified process' 329 * process group and that of its children. 330 * entering == 0 => p is leaving specified group. 331 * entering == 1 => p is entering specified group. 332 */ 333 void 334 fixjobc(p, pgrp, entering) 335 register struct proc *p; 336 register struct pgrp *pgrp; 337 int entering; 338 { 339 register struct pgrp *hispgrp; 340 register struct session *mysession = pgrp->pg_session; 341 342 /* 343 * Check p's parent to see whether p qualifies its own process 344 * group; if so, adjust count for p's process group. 345 */ 346 if ((hispgrp = p->p_pptr->p_pgrp) != pgrp && 347 hispgrp->pg_session == mysession) { 348 if (entering) 349 pgrp->pg_jobc++; 350 else if (--pgrp->pg_jobc == 0) 351 orphanpg(pgrp); 352 } 353 354 /* 355 * Check this process' children to see whether they qualify 356 * their process groups; if so, adjust counts for children's 357 * process groups. 358 */ 359 for (p = p->p_children.lh_first; p != 0; p = p->p_sibling.le_next) { 360 if ((hispgrp = p->p_pgrp) != pgrp && 361 hispgrp->pg_session == mysession && 362 p->p_stat != SZOMB) { 363 if (entering) 364 hispgrp->pg_jobc++; 365 else if (--hispgrp->pg_jobc == 0) 366 orphanpg(hispgrp); 367 } 368 } 369 } 370 371 /* 372 * A process group has become orphaned; 373 * if there are any stopped processes in the group, 374 * hang-up all process in that group. 375 */ 376 static void 377 orphanpg(pg) 378 struct pgrp *pg; 379 { 380 register struct proc *p; 381 382 for (p = pg->pg_members.lh_first; p != 0; p = p->p_pglist.le_next) { 383 if (p->p_stat == SSTOP) { 384 for (p = pg->pg_members.lh_first; p != 0; 385 p = p->p_pglist.le_next) { 386 psignal(p, SIGHUP); 387 psignal(p, SIGCONT); 388 } 389 return; 390 } 391 } 392 } 393 394 #ifdef DEBUG 395 void 396 pgrpdump() 397 { 398 register struct pgrp *pgrp; 399 register struct proc *p; 400 register int i; 401 402 for (i = 0; i <= pgrphash; i++) { 403 if ((pgrp = pgrphashtbl[i].lh_first) != NULL) { 404 printf("\tindx %d\n", i); 405 for (; pgrp != 0; pgrp = pgrp->pg_hash.le_next) { 406 printf("\tpgrp %p, pgid %d, sess %p, sesscnt %d, mem %p\n", 407 pgrp, pgrp->pg_id, pgrp->pg_session, 408 pgrp->pg_session->s_count, 409 pgrp->pg_members.lh_first); 410 for (p = pgrp->pg_members.lh_first; p != 0; 411 p = p->p_pglist.le_next) { 412 printf("\t\tpid %d addr %p pgrp %p\n", 413 p->p_pid, p, p->p_pgrp); 414 } 415 } 416 } 417 } 418 } 419 #endif /* DEBUG */ 420