kern_proc.c revision 1.28
1 /* $NetBSD: kern_proc.c,v 1.28 1998/08/31 23:20:16 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 82 static void orphanpg __P((struct pgrp *)); 83 #ifdef DEBUG 84 void pgrpdump __P((void)); 85 #endif 86 87 /* 88 * Initialize global process hashing structures. 89 */ 90 void 91 procinit() 92 { 93 94 LIST_INIT(&allproc); 95 LIST_INIT(&zombproc); 96 pidhashtbl = hashinit(maxproc / 4, M_PROC, M_WAITOK, &pidhash); 97 pgrphashtbl = hashinit(maxproc / 4, M_PROC, M_WAITOK, &pgrphash); 98 uihashtbl = hashinit(maxproc / 16, M_PROC, M_WAITOK, &uihash); 99 pool_init(&proc_pool, sizeof(struct proc), 0, 0, 0, "procpl", 100 0, pool_page_alloc_nointr, pool_page_free_nointr, M_PROC); 101 pool_init(&pcred_pool, sizeof(struct pcred), 0, 0, 0, "pcredpl", 102 0, pool_page_alloc_nointr, pool_page_free_nointr, M_SUBPROC); 103 pool_init(&plimit_pool, sizeof(struct plimit), 0, 0, 0, "plimitpl", 104 0, pool_page_alloc_nointr, pool_page_free_nointr, M_SUBPROC); 105 } 106 107 /* 108 * Change the count associated with number of processes 109 * a given user is using. 110 */ 111 int 112 chgproccnt(uid, diff) 113 uid_t uid; 114 int diff; 115 { 116 register struct uidinfo *uip; 117 register struct uihashhead *uipp; 118 119 uipp = UIHASH(uid); 120 for (uip = uipp->lh_first; uip != 0; uip = uip->ui_hash.le_next) 121 if (uip->ui_uid == uid) 122 break; 123 if (uip) { 124 uip->ui_proccnt += diff; 125 if (uip->ui_proccnt > 0) 126 return (uip->ui_proccnt); 127 if (uip->ui_proccnt < 0) 128 panic("chgproccnt: procs < 0"); 129 LIST_REMOVE(uip, ui_hash); 130 FREE(uip, M_PROC); 131 return (0); 132 } 133 if (diff <= 0) { 134 if (diff == 0) 135 return(0); 136 panic("chgproccnt: lost user"); 137 } 138 MALLOC(uip, struct uidinfo *, sizeof(*uip), M_PROC, M_WAITOK); 139 LIST_INSERT_HEAD(uipp, uip, ui_hash); 140 uip->ui_uid = uid; 141 uip->ui_proccnt = diff; 142 return (diff); 143 } 144 145 /* 146 * Is p an inferior of the current process? 147 */ 148 int 149 inferior(p) 150 register struct proc *p; 151 { 152 153 for (; p != curproc; p = p->p_pptr) 154 if (p->p_pid == 0) 155 return (0); 156 return (1); 157 } 158 159 /* 160 * Locate a process by number 161 */ 162 struct proc * 163 pfind(pid) 164 register pid_t pid; 165 { 166 register struct proc *p; 167 168 for (p = PIDHASH(pid)->lh_first; p != 0; p = p->p_hash.le_next) 169 if (p->p_pid == pid) 170 return (p); 171 return (NULL); 172 } 173 174 /* 175 * Locate a process group by number 176 */ 177 struct pgrp * 178 pgfind(pgid) 179 register pid_t pgid; 180 { 181 register struct pgrp *pgrp; 182 183 for (pgrp = PGRPHASH(pgid)->lh_first; pgrp != 0; pgrp = pgrp->pg_hash.le_next) 184 if (pgrp->pg_id == pgid) 185 return (pgrp); 186 return (NULL); 187 } 188 189 /* 190 * Move p to a new or existing process group (and session) 191 */ 192 int 193 enterpgrp(p, pgid, mksess) 194 register struct proc *p; 195 pid_t pgid; 196 int mksess; 197 { 198 register struct pgrp *pgrp = pgfind(pgid); 199 200 #ifdef DIAGNOSTIC 201 if (pgrp != NULL && mksess) /* firewalls */ 202 panic("enterpgrp: setsid into non-empty pgrp"); 203 if (SESS_LEADER(p)) 204 panic("enterpgrp: session leader attempted setpgrp"); 205 #endif 206 if (pgrp == NULL) { 207 pid_t savepid = p->p_pid; 208 struct proc *np; 209 /* 210 * new process group 211 */ 212 #ifdef DIAGNOSTIC 213 if (p->p_pid != pgid) 214 panic("enterpgrp: new pgrp and pid != pgid"); 215 #endif 216 MALLOC(pgrp, struct pgrp *, sizeof(struct pgrp), M_PGRP, 217 M_WAITOK); 218 if ((np = pfind(savepid)) == NULL || np != p) 219 return (ESRCH); 220 if (mksess) { 221 register struct session *sess; 222 223 /* 224 * new session 225 */ 226 MALLOC(sess, struct session *, sizeof(struct session), 227 M_SESSION, M_WAITOK); 228 sess->s_sid = p->p_pid; 229 sess->s_leader = p; 230 sess->s_count = 1; 231 sess->s_ttyvp = NULL; 232 sess->s_ttyp = NULL; 233 memcpy(sess->s_login, p->p_session->s_login, 234 sizeof(sess->s_login)); 235 p->p_flag &= ~P_CONTROLT; 236 pgrp->pg_session = sess; 237 #ifdef DIAGNOSTIC 238 if (p != curproc) 239 panic("enterpgrp: mksession and p != curproc"); 240 #endif 241 } else { 242 pgrp->pg_session = p->p_session; 243 pgrp->pg_session->s_count++; 244 } 245 pgrp->pg_id = pgid; 246 LIST_INIT(&pgrp->pg_members); 247 LIST_INSERT_HEAD(PGRPHASH(pgid), pgrp, pg_hash); 248 pgrp->pg_jobc = 0; 249 } else if (pgrp == p->p_pgrp) 250 return (0); 251 252 /* 253 * Adjust eligibility of affected pgrps to participate in job control. 254 * Increment eligibility counts before decrementing, otherwise we 255 * could reach 0 spuriously during the first call. 256 */ 257 fixjobc(p, pgrp, 1); 258 fixjobc(p, p->p_pgrp, 0); 259 260 LIST_REMOVE(p, p_pglist); 261 if (p->p_pgrp->pg_members.lh_first == 0) 262 pgdelete(p->p_pgrp); 263 p->p_pgrp = pgrp; 264 LIST_INSERT_HEAD(&pgrp->pg_members, p, p_pglist); 265 return (0); 266 } 267 268 /* 269 * remove process from process group 270 */ 271 int 272 leavepgrp(p) 273 register struct proc *p; 274 { 275 276 LIST_REMOVE(p, p_pglist); 277 if (p->p_pgrp->pg_members.lh_first == 0) 278 pgdelete(p->p_pgrp); 279 p->p_pgrp = 0; 280 return (0); 281 } 282 283 /* 284 * delete a process group 285 */ 286 void 287 pgdelete(pgrp) 288 register struct pgrp *pgrp; 289 { 290 291 if (pgrp->pg_session->s_ttyp != NULL && 292 pgrp->pg_session->s_ttyp->t_pgrp == pgrp) 293 pgrp->pg_session->s_ttyp->t_pgrp = NULL; 294 LIST_REMOVE(pgrp, pg_hash); 295 if (--pgrp->pg_session->s_count == 0) 296 FREE(pgrp->pg_session, M_SESSION); 297 FREE(pgrp, M_PGRP); 298 } 299 300 /* 301 * Adjust pgrp jobc counters when specified process changes process group. 302 * We count the number of processes in each process group that "qualify" 303 * the group for terminal job control (those with a parent in a different 304 * process group of the same session). If that count reaches zero, the 305 * process group becomes orphaned. Check both the specified process' 306 * process group and that of its children. 307 * entering == 0 => p is leaving specified group. 308 * entering == 1 => p is entering specified group. 309 */ 310 void 311 fixjobc(p, pgrp, entering) 312 register struct proc *p; 313 register struct pgrp *pgrp; 314 int entering; 315 { 316 register struct pgrp *hispgrp; 317 register struct session *mysession = pgrp->pg_session; 318 319 /* 320 * Check p's parent to see whether p qualifies its own process 321 * group; if so, adjust count for p's process group. 322 */ 323 if ((hispgrp = p->p_pptr->p_pgrp) != pgrp && 324 hispgrp->pg_session == mysession) { 325 if (entering) 326 pgrp->pg_jobc++; 327 else if (--pgrp->pg_jobc == 0) 328 orphanpg(pgrp); 329 } 330 331 /* 332 * Check this process' children to see whether they qualify 333 * their process groups; if so, adjust counts for children's 334 * process groups. 335 */ 336 for (p = p->p_children.lh_first; p != 0; p = p->p_sibling.le_next) { 337 if ((hispgrp = p->p_pgrp) != pgrp && 338 hispgrp->pg_session == mysession && 339 p->p_stat != SZOMB) { 340 if (entering) 341 hispgrp->pg_jobc++; 342 else if (--hispgrp->pg_jobc == 0) 343 orphanpg(hispgrp); 344 } 345 } 346 } 347 348 /* 349 * A process group has become orphaned; 350 * if there are any stopped processes in the group, 351 * hang-up all process in that group. 352 */ 353 static void 354 orphanpg(pg) 355 struct pgrp *pg; 356 { 357 register struct proc *p; 358 359 for (p = pg->pg_members.lh_first; p != 0; p = p->p_pglist.le_next) { 360 if (p->p_stat == SSTOP) { 361 for (p = pg->pg_members.lh_first; p != 0; 362 p = p->p_pglist.le_next) { 363 psignal(p, SIGHUP); 364 psignal(p, SIGCONT); 365 } 366 return; 367 } 368 } 369 } 370 371 #ifdef DEBUG 372 void 373 pgrpdump() 374 { 375 register struct pgrp *pgrp; 376 register struct proc *p; 377 register int i; 378 379 for (i = 0; i <= pgrphash; i++) { 380 if ((pgrp = pgrphashtbl[i].lh_first) != NULL) { 381 printf("\tindx %d\n", i); 382 for (; pgrp != 0; pgrp = pgrp->pg_hash.le_next) { 383 printf("\tpgrp %p, pgid %d, sess %p, sesscnt %d, mem %p\n", 384 pgrp, pgrp->pg_id, pgrp->pg_session, 385 pgrp->pg_session->s_count, 386 pgrp->pg_members.lh_first); 387 for (p = pgrp->pg_members.lh_first; p != 0; 388 p = p->p_pglist.le_next) { 389 printf("\t\tpid %d addr %p pgrp %p\n", 390 p->p_pid, p, p->p_pgrp); 391 } 392 } 393 } 394 } 395 } 396 #endif /* DEBUG */ 397
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