1 /* $OpenBSD: kern_proc.c,v 1.8 2001/03/23 18:42:06 art Exp $ */ 2 /* $NetBSD: kern_proc.c,v 1.14 1996/02/09 18:59:41 christos Exp $ */ 3 4 /* 5 * Copyright (c) 1982, 1986, 1989, 1991, 1993 6 * The Regents of the University of California. All rights reserved. 7 * 8 * Redistribution and use in source and binary forms, with or without 9 * modification, are permitted provided that the following conditions 10 * are met: 11 * 1. Redistributions of source code must retain the above copyright 12 * notice, this list of conditions and the following disclaimer. 13 * 2. Redistributions in binary form must reproduce the above copyright 14 * notice, this list of conditions and the following disclaimer in the 15 * documentation and/or other materials provided with the distribution. 16 * 3. All advertising materials mentioning features or use of this software 17 * must display the following acknowledgement: 18 * This product includes software developed by the University of 19 * California, Berkeley and its contributors. 20 * 4. Neither the name of the University nor the names of its contributors 21 * may be used to endorse or promote products derived from this software 22 * without specific prior written permission. 23 * 24 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 25 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 26 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 27 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 28 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 29 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 30 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 31 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 32 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 33 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 34 * SUCH DAMAGE. 35 * 36 * @(#)kern_proc.c 8.4 (Berkeley) 1/4/94 37 */ 38 39 #include <sys/param.h> 40 #include <sys/systm.h> 41 #include <sys/map.h> 42 #include <sys/kernel.h> 43 #include <sys/proc.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/mbuf.h> 52 #include <sys/ioctl.h> 53 #include <sys/tty.h> 54 #include <sys/signalvar.h> 55 #include <sys/pool.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 struct proclist allproc; 77 struct proclist zombproc; 78 79 struct pool proc_pool; 80 81 /* 82 * Locking of this proclist is special; it's accessed in a 83 * critical section of process exit, and thus locking it can't 84 * modify interrupt state. We use a simple spin lock for this 85 * proclist. Processes on this proclist are also on zombproc; 86 * we use the p_hash member to linkup to deadproc. 87 */ 88 struct simplelock deadproc_slock; 89 struct proclist deadproc; /* dead, but not yet undead */ 90 91 static void orphanpg __P((struct pgrp *)); 92 #ifdef DEBUG 93 void pgrpdump __P((void)); 94 #endif 95 96 /* 97 * Initialize global process hashing structures. 98 */ 99 void 100 procinit() 101 { 102 103 LIST_INIT(&allproc); 104 LIST_INIT(&zombproc); 105 106 LIST_INIT(&deadproc); 107 simple_lock_init(&deadproc_slock); 108 109 pidhashtbl = hashinit(maxproc / 4, M_PROC, M_WAITOK, &pidhash); 110 pgrphashtbl = hashinit(maxproc / 4, M_PROC, M_WAITOK, &pgrphash); 111 uihashtbl = hashinit(maxproc / 16, M_PROC, M_WAITOK, &uihash); 112 113 pool_init(&proc_pool, sizeof(struct proc), 0, 0, 0, "procpl", 114 0, pool_page_alloc_nointr, pool_page_free_nointr, M_PROC); 115 } 116 117 /* 118 * Change the count associated with number of processes 119 * a given user is using. 120 */ 121 int 122 chgproccnt(uid, diff) 123 uid_t uid; 124 int diff; 125 { 126 register struct uidinfo *uip; 127 register struct uihashhead *uipp; 128 129 uipp = UIHASH(uid); 130 for (uip = uipp->lh_first; uip != 0; uip = uip->ui_hash.le_next) 131 if (uip->ui_uid == uid) 132 break; 133 if (uip) { 134 uip->ui_proccnt += diff; 135 if (uip->ui_proccnt > 0) 136 return (uip->ui_proccnt); 137 if (uip->ui_proccnt < 0) 138 panic("chgproccnt: procs < 0"); 139 LIST_REMOVE(uip, ui_hash); 140 FREE(uip, M_PROC); 141 return (0); 142 } 143 if (diff <= 0) { 144 if (diff == 0) 145 return(0); 146 panic("chgproccnt: lost user"); 147 } 148 MALLOC(uip, struct uidinfo *, sizeof(*uip), M_PROC, M_WAITOK); 149 LIST_INSERT_HEAD(uipp, uip, ui_hash); 150 uip->ui_uid = uid; 151 uip->ui_proccnt = diff; 152 return (diff); 153 } 154 155 /* 156 * Is p an inferior of the current process? 157 */ 158 int 159 inferior(p) 160 register struct proc *p; 161 { 162 163 for (; p != curproc; p = p->p_pptr) 164 if (p->p_pid == 0) 165 return (0); 166 return (1); 167 } 168 169 /* 170 * Locate a process by number 171 */ 172 struct proc * 173 pfind(pid) 174 register pid_t pid; 175 { 176 register struct proc *p; 177 178 for (p = PIDHASH(pid)->lh_first; p != 0; p = p->p_hash.le_next) 179 if (p->p_pid == pid) 180 return (p); 181 return (NULL); 182 } 183 184 /* 185 * Locate a process group by number 186 */ 187 struct pgrp * 188 pgfind(pgid) 189 register pid_t pgid; 190 { 191 register struct pgrp *pgrp; 192 193 for (pgrp = PGRPHASH(pgid)->lh_first; pgrp != 0; pgrp = pgrp->pg_hash.le_next) 194 if (pgrp->pg_id == pgid) 195 return (pgrp); 196 return (NULL); 197 } 198 199 /* 200 * Move p to a new or existing process group (and session) 201 */ 202 int 203 enterpgrp(p, pgid, mksess) 204 register struct proc *p; 205 pid_t pgid; 206 int mksess; 207 { 208 register struct pgrp *pgrp = pgfind(pgid); 209 210 #ifdef DIAGNOSTIC 211 if (pgrp != NULL && mksess) /* firewalls */ 212 panic("enterpgrp: setsid into non-empty pgrp"); 213 if (SESS_LEADER(p)) 214 panic("enterpgrp: session leader attempted setpgrp"); 215 #endif 216 if (pgrp == NULL) { 217 pid_t savepid = p->p_pid; 218 struct proc *np; 219 /* 220 * new process group 221 */ 222 #ifdef DIAGNOSTIC 223 if (p->p_pid != pgid) 224 panic("enterpgrp: new pgrp and pid != pgid"); 225 #endif 226 if ((np = pfind(savepid)) == NULL || np != p) 227 return (ESRCH); 228 MALLOC(pgrp, struct pgrp *, sizeof(struct pgrp), M_PGRP, 229 M_WAITOK); 230 if (mksess) { 231 register struct session *sess; 232 233 /* 234 * new session 235 */ 236 MALLOC(sess, struct session *, sizeof(struct session), 237 M_SESSION, M_WAITOK); 238 sess->s_leader = p; 239 sess->s_count = 1; 240 sess->s_ttyvp = NULL; 241 sess->s_ttyp = NULL; 242 bcopy(p->p_session->s_login, sess->s_login, 243 sizeof(sess->s_login)); 244 p->p_flag &= ~P_CONTROLT; 245 pgrp->pg_session = sess; 246 #ifdef DIAGNOSTIC 247 if (p != curproc) 248 panic("enterpgrp: mksession and p != curproc"); 249 #endif 250 } else { 251 pgrp->pg_session = p->p_session; 252 pgrp->pg_session->s_count++; 253 } 254 pgrp->pg_id = pgid; 255 LIST_INIT(&pgrp->pg_members); 256 LIST_INSERT_HEAD(PGRPHASH(pgid), pgrp, pg_hash); 257 pgrp->pg_jobc = 0; 258 } else if (pgrp == p->p_pgrp) 259 return (0); 260 261 /* 262 * Adjust eligibility of affected pgrps to participate in job control. 263 * Increment eligibility counts before decrementing, otherwise we 264 * could reach 0 spuriously during the first call. 265 */ 266 fixjobc(p, pgrp, 1); 267 fixjobc(p, p->p_pgrp, 0); 268 269 LIST_REMOVE(p, p_pglist); 270 if (p->p_pgrp->pg_members.lh_first == 0) 271 pgdelete(p->p_pgrp); 272 p->p_pgrp = pgrp; 273 LIST_INSERT_HEAD(&pgrp->pg_members, p, p_pglist); 274 return (0); 275 } 276 277 /* 278 * remove process from process group 279 */ 280 int 281 leavepgrp(p) 282 register struct proc *p; 283 { 284 285 LIST_REMOVE(p, p_pglist); 286 if (p->p_pgrp->pg_members.lh_first == 0) 287 pgdelete(p->p_pgrp); 288 p->p_pgrp = 0; 289 return (0); 290 } 291 292 /* 293 * delete a process group 294 */ 295 void 296 pgdelete(pgrp) 297 register struct pgrp *pgrp; 298 { 299 300 if (pgrp->pg_session->s_ttyp != NULL && 301 pgrp->pg_session->s_ttyp->t_pgrp == pgrp) 302 pgrp->pg_session->s_ttyp->t_pgrp = NULL; 303 LIST_REMOVE(pgrp, pg_hash); 304 if (--pgrp->pg_session->s_count == 0) 305 FREE(pgrp->pg_session, M_SESSION); 306 FREE(pgrp, M_PGRP); 307 } 308 309 /* 310 * Adjust pgrp jobc counters when specified process changes process group. 311 * We count the number of processes in each process group that "qualify" 312 * the group for terminal job control (those with a parent in a different 313 * process group of the same session). If that count reaches zero, the 314 * process group becomes orphaned. Check both the specified process' 315 * process group and that of its children. 316 * entering == 0 => p is leaving specified group. 317 * entering == 1 => p is entering specified group. 318 */ 319 void 320 fixjobc(p, pgrp, entering) 321 register struct proc *p; 322 register struct pgrp *pgrp; 323 int entering; 324 { 325 register struct pgrp *hispgrp; 326 register struct session *mysession = pgrp->pg_session; 327 328 /* 329 * Check p's parent to see whether p qualifies its own process 330 * group; if so, adjust count for p's process group. 331 */ 332 if ((hispgrp = p->p_pptr->p_pgrp) != pgrp && 333 hispgrp->pg_session == mysession) { 334 if (entering) 335 pgrp->pg_jobc++; 336 else if (--pgrp->pg_jobc == 0) 337 orphanpg(pgrp); 338 } 339 340 /* 341 * Check this process' children to see whether they qualify 342 * their process groups; if so, adjust counts for children's 343 * process groups. 344 */ 345 for (p = p->p_children.lh_first; p != 0; p = p->p_sibling.le_next) 346 if ((hispgrp = p->p_pgrp) != pgrp && 347 hispgrp->pg_session == mysession && 348 P_ZOMBIE(p) == 0) { 349 if (entering) 350 hispgrp->pg_jobc++; 351 else if (--hispgrp->pg_jobc == 0) 352 orphanpg(hispgrp); 353 } 354 } 355 356 /* 357 * A process group has become orphaned; 358 * if there are any stopped processes in the group, 359 * hang-up all process in that group. 360 */ 361 static void 362 orphanpg(pg) 363 struct pgrp *pg; 364 { 365 register struct proc *p; 366 367 for (p = pg->pg_members.lh_first; p != 0; p = p->p_pglist.le_next) { 368 if (p->p_stat == SSTOP) { 369 for (p = pg->pg_members.lh_first; p != 0; 370 p = p->p_pglist.le_next) { 371 psignal(p, SIGHUP); 372 psignal(p, SIGCONT); 373 } 374 return; 375 } 376 } 377 } 378 379 #ifdef DEBUG 380 void 381 pgrpdump() 382 { 383 register struct pgrp *pgrp; 384 register struct proc *p; 385 register int i; 386 387 for (i = 0; i <= pgrphash; i++) { 388 if ((pgrp = pgrphashtbl[i].lh_first) != NULL) { 389 printf("\tindx %d\n", i); 390 for (; pgrp != 0; pgrp = pgrp->pg_hash.le_next) { 391 printf("\tpgrp %p, pgid %d, sess %p, sesscnt %d, mem %p\n", 392 pgrp, pgrp->pg_id, pgrp->pg_session, 393 pgrp->pg_session->s_count, 394 pgrp->pg_members.lh_first); 395 for (p = pgrp->pg_members.lh_first; p != 0; 396 p = p->p_pglist.le_next) { 397 printf("\t\tpid %d addr %p pgrp %p\n", 398 p->p_pid, p, p->p_pgrp); 399 } 400 } 401 } 402 } 403 } 404 #endif /* DEBUG */ 405