kern_proc.c revision 1.29
1 /* $NetBSD: kern_proc.c,v 1.29 1998/09/01 00:08:44 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 struct proclist allproc; 77 struct proclist zombproc; 78 struct pool proc_pool; 79 struct pool pcred_pool; 80 struct pool plimit_pool; 81 struct pool pgrp_pool; 82 83 static void orphanpg __P((struct pgrp *)); 84 #ifdef DEBUG 85 void pgrpdump __P((void)); 86 #endif 87 88 /* 89 * Initialize global process hashing structures. 90 */ 91 void 92 procinit() 93 { 94 95 LIST_INIT(&allproc); 96 LIST_INIT(&zombproc); 97 pidhashtbl = hashinit(maxproc / 4, M_PROC, M_WAITOK, &pidhash); 98 pgrphashtbl = hashinit(maxproc / 4, M_PROC, M_WAITOK, &pgrphash); 99 uihashtbl = hashinit(maxproc / 16, M_PROC, M_WAITOK, &uihash); 100 pool_init(&proc_pool, sizeof(struct proc), 0, 0, 0, "procpl", 101 0, pool_page_alloc_nointr, pool_page_free_nointr, M_PROC); 102 pool_init(&pgrp_pool, sizeof(struct pgrp), 0, 0, 0, "pgrppl", 103 0, pool_page_alloc_nointr, pool_page_free_nointr, M_PGRP); 104 pool_init(&pcred_pool, sizeof(struct pcred), 0, 0, 0, "pcredpl", 105 0, pool_page_alloc_nointr, pool_page_free_nointr, M_SUBPROC); 106 pool_init(&plimit_pool, sizeof(struct plimit), 0, 0, 0, "plimitpl", 107 0, pool_page_alloc_nointr, pool_page_free_nointr, M_SUBPROC); 108 } 109 110 /* 111 * Change the count associated with number of processes 112 * a given user is using. 113 */ 114 int 115 chgproccnt(uid, diff) 116 uid_t uid; 117 int diff; 118 { 119 register struct uidinfo *uip; 120 register struct uihashhead *uipp; 121 122 uipp = UIHASH(uid); 123 for (uip = uipp->lh_first; uip != 0; uip = uip->ui_hash.le_next) 124 if (uip->ui_uid == uid) 125 break; 126 if (uip) { 127 uip->ui_proccnt += diff; 128 if (uip->ui_proccnt > 0) 129 return (uip->ui_proccnt); 130 if (uip->ui_proccnt < 0) 131 panic("chgproccnt: procs < 0"); 132 LIST_REMOVE(uip, ui_hash); 133 FREE(uip, M_PROC); 134 return (0); 135 } 136 if (diff <= 0) { 137 if (diff == 0) 138 return(0); 139 panic("chgproccnt: lost user"); 140 } 141 MALLOC(uip, struct uidinfo *, sizeof(*uip), M_PROC, M_WAITOK); 142 LIST_INSERT_HEAD(uipp, uip, ui_hash); 143 uip->ui_uid = uid; 144 uip->ui_proccnt = diff; 145 return (diff); 146 } 147 148 /* 149 * Is p an inferior of the current process? 150 */ 151 int 152 inferior(p) 153 register struct proc *p; 154 { 155 156 for (; p != curproc; p = p->p_pptr) 157 if (p->p_pid == 0) 158 return (0); 159 return (1); 160 } 161 162 /* 163 * Locate a process by number 164 */ 165 struct proc * 166 pfind(pid) 167 register pid_t pid; 168 { 169 register struct proc *p; 170 171 for (p = PIDHASH(pid)->lh_first; p != 0; p = p->p_hash.le_next) 172 if (p->p_pid == pid) 173 return (p); 174 return (NULL); 175 } 176 177 /* 178 * Locate a process group by number 179 */ 180 struct pgrp * 181 pgfind(pgid) 182 register pid_t pgid; 183 { 184 register struct pgrp *pgrp; 185 186 for (pgrp = PGRPHASH(pgid)->lh_first; pgrp != 0; pgrp = pgrp->pg_hash.le_next) 187 if (pgrp->pg_id == pgid) 188 return (pgrp); 189 return (NULL); 190 } 191 192 /* 193 * Move p to a new or existing process group (and session) 194 */ 195 int 196 enterpgrp(p, pgid, mksess) 197 register struct proc *p; 198 pid_t pgid; 199 int mksess; 200 { 201 register struct pgrp *pgrp = pgfind(pgid); 202 203 #ifdef DIAGNOSTIC 204 if (pgrp != NULL && mksess) /* firewalls */ 205 panic("enterpgrp: setsid into non-empty pgrp"); 206 if (SESS_LEADER(p)) 207 panic("enterpgrp: session leader attempted setpgrp"); 208 #endif 209 if (pgrp == NULL) { 210 pid_t savepid = p->p_pid; 211 struct proc *np; 212 /* 213 * new process group 214 */ 215 #ifdef DIAGNOSTIC 216 if (p->p_pid != pgid) 217 panic("enterpgrp: new pgrp and pid != pgid"); 218 #endif 219 pgrp = pool_get(&pgrp_pool, PR_WAITOK); 220 if ((np = pfind(savepid)) == NULL || np != p) 221 return (ESRCH); 222 if (mksess) { 223 register struct session *sess; 224 225 /* 226 * new session 227 */ 228 MALLOC(sess, struct session *, sizeof(struct session), 229 M_SESSION, M_WAITOK); 230 sess->s_sid = p->p_pid; 231 sess->s_leader = p; 232 sess->s_count = 1; 233 sess->s_ttyvp = NULL; 234 sess->s_ttyp = NULL; 235 memcpy(sess->s_login, p->p_session->s_login, 236 sizeof(sess->s_login)); 237 p->p_flag &= ~P_CONTROLT; 238 pgrp->pg_session = sess; 239 #ifdef DIAGNOSTIC 240 if (p != curproc) 241 panic("enterpgrp: mksession and p != curproc"); 242 #endif 243 } else { 244 pgrp->pg_session = p->p_session; 245 pgrp->pg_session->s_count++; 246 } 247 pgrp->pg_id = pgid; 248 LIST_INIT(&pgrp->pg_members); 249 LIST_INSERT_HEAD(PGRPHASH(pgid), pgrp, pg_hash); 250 pgrp->pg_jobc = 0; 251 } else if (pgrp == p->p_pgrp) 252 return (0); 253 254 /* 255 * Adjust eligibility of affected pgrps to participate in job control. 256 * Increment eligibility counts before decrementing, otherwise we 257 * could reach 0 spuriously during the first call. 258 */ 259 fixjobc(p, pgrp, 1); 260 fixjobc(p, p->p_pgrp, 0); 261 262 LIST_REMOVE(p, p_pglist); 263 if (p->p_pgrp->pg_members.lh_first == 0) 264 pgdelete(p->p_pgrp); 265 p->p_pgrp = pgrp; 266 LIST_INSERT_HEAD(&pgrp->pg_members, p, p_pglist); 267 return (0); 268 } 269 270 /* 271 * remove process from process group 272 */ 273 int 274 leavepgrp(p) 275 register struct proc *p; 276 { 277 278 LIST_REMOVE(p, p_pglist); 279 if (p->p_pgrp->pg_members.lh_first == 0) 280 pgdelete(p->p_pgrp); 281 p->p_pgrp = 0; 282 return (0); 283 } 284 285 /* 286 * delete a process group 287 */ 288 void 289 pgdelete(pgrp) 290 register struct pgrp *pgrp; 291 { 292 293 if (pgrp->pg_session->s_ttyp != NULL && 294 pgrp->pg_session->s_ttyp->t_pgrp == pgrp) 295 pgrp->pg_session->s_ttyp->t_pgrp = NULL; 296 LIST_REMOVE(pgrp, pg_hash); 297 if (--pgrp->pg_session->s_count == 0) 298 FREE(pgrp->pg_session, M_SESSION); 299 pool_put(&pgrp_pool, pgrp); 300 } 301 302 /* 303 * Adjust pgrp jobc counters when specified process changes process group. 304 * We count the number of processes in each process group that "qualify" 305 * the group for terminal job control (those with a parent in a different 306 * process group of the same session). If that count reaches zero, the 307 * process group becomes orphaned. Check both the specified process' 308 * process group and that of its children. 309 * entering == 0 => p is leaving specified group. 310 * entering == 1 => p is entering specified group. 311 */ 312 void 313 fixjobc(p, pgrp, entering) 314 register struct proc *p; 315 register struct pgrp *pgrp; 316 int entering; 317 { 318 register struct pgrp *hispgrp; 319 register struct session *mysession = pgrp->pg_session; 320 321 /* 322 * Check p's parent to see whether p qualifies its own process 323 * group; if so, adjust count for p's process group. 324 */ 325 if ((hispgrp = p->p_pptr->p_pgrp) != pgrp && 326 hispgrp->pg_session == mysession) { 327 if (entering) 328 pgrp->pg_jobc++; 329 else if (--pgrp->pg_jobc == 0) 330 orphanpg(pgrp); 331 } 332 333 /* 334 * Check this process' children to see whether they qualify 335 * their process groups; if so, adjust counts for children's 336 * process groups. 337 */ 338 for (p = p->p_children.lh_first; p != 0; p = p->p_sibling.le_next) { 339 if ((hispgrp = p->p_pgrp) != pgrp && 340 hispgrp->pg_session == mysession && 341 p->p_stat != SZOMB) { 342 if (entering) 343 hispgrp->pg_jobc++; 344 else if (--hispgrp->pg_jobc == 0) 345 orphanpg(hispgrp); 346 } 347 } 348 } 349 350 /* 351 * A process group has become orphaned; 352 * if there are any stopped processes in the group, 353 * hang-up all process in that group. 354 */ 355 static void 356 orphanpg(pg) 357 struct pgrp *pg; 358 { 359 register struct proc *p; 360 361 for (p = pg->pg_members.lh_first; p != 0; p = p->p_pglist.le_next) { 362 if (p->p_stat == SSTOP) { 363 for (p = pg->pg_members.lh_first; p != 0; 364 p = p->p_pglist.le_next) { 365 psignal(p, SIGHUP); 366 psignal(p, SIGCONT); 367 } 368 return; 369 } 370 } 371 } 372 373 #ifdef DEBUG 374 void 375 pgrpdump() 376 { 377 register struct pgrp *pgrp; 378 register struct proc *p; 379 register int i; 380 381 for (i = 0; i <= pgrphash; i++) { 382 if ((pgrp = pgrphashtbl[i].lh_first) != NULL) { 383 printf("\tindx %d\n", i); 384 for (; pgrp != 0; pgrp = pgrp->pg_hash.le_next) { 385 printf("\tpgrp %p, pgid %d, sess %p, sesscnt %d, mem %p\n", 386 pgrp, pgrp->pg_id, pgrp->pg_session, 387 pgrp->pg_session->s_count, 388 pgrp->pg_members.lh_first); 389 for (p = pgrp->pg_members.lh_first; p != 0; 390 p = p->p_pglist.le_next) { 391 printf("\t\tpid %d addr %p pgrp %p\n", 392 p->p_pid, p, p->p_pgrp); 393 } 394 } 395 } 396 } 397 } 398 #endif /* DEBUG */ 399
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