kern_proc.c revision 1.30
1 /* $NetBSD: kern_proc.c,v 1.30 1998/09/01 01:02:33 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 struct pool rusage_pool; 83 84 static void orphanpg __P((struct pgrp *)); 85 #ifdef DEBUG 86 void pgrpdump __P((void)); 87 #endif 88 89 /* 90 * Initialize global process hashing structures. 91 */ 92 void 93 procinit() 94 { 95 96 LIST_INIT(&allproc); 97 LIST_INIT(&zombproc); 98 pidhashtbl = hashinit(maxproc / 4, M_PROC, M_WAITOK, &pidhash); 99 pgrphashtbl = hashinit(maxproc / 4, M_PROC, M_WAITOK, &pgrphash); 100 uihashtbl = hashinit(maxproc / 16, M_PROC, M_WAITOK, &uihash); 101 pool_init(&proc_pool, sizeof(struct proc), 0, 0, 0, "procpl", 102 0, pool_page_alloc_nointr, pool_page_free_nointr, M_PROC); 103 pool_init(&pgrp_pool, sizeof(struct pgrp), 0, 0, 0, "pgrppl", 104 0, pool_page_alloc_nointr, pool_page_free_nointr, M_PGRP); 105 pool_init(&pcred_pool, sizeof(struct pcred), 0, 0, 0, "pcredpl", 106 0, pool_page_alloc_nointr, pool_page_free_nointr, M_SUBPROC); 107 pool_init(&plimit_pool, sizeof(struct plimit), 0, 0, 0, "plimitpl", 108 0, pool_page_alloc_nointr, pool_page_free_nointr, M_SUBPROC); 109 pool_init(&rusage_pool, sizeof(struct rusage), 0, 0, 0, "rusgepl", 110 0, pool_page_alloc_nointr, pool_page_free_nointr, M_ZOMBIE); 111 } 112 113 /* 114 * Change the count associated with number of processes 115 * a given user is using. 116 */ 117 int 118 chgproccnt(uid, diff) 119 uid_t uid; 120 int diff; 121 { 122 register struct uidinfo *uip; 123 register struct uihashhead *uipp; 124 125 uipp = UIHASH(uid); 126 for (uip = uipp->lh_first; uip != 0; uip = uip->ui_hash.le_next) 127 if (uip->ui_uid == uid) 128 break; 129 if (uip) { 130 uip->ui_proccnt += diff; 131 if (uip->ui_proccnt > 0) 132 return (uip->ui_proccnt); 133 if (uip->ui_proccnt < 0) 134 panic("chgproccnt: procs < 0"); 135 LIST_REMOVE(uip, ui_hash); 136 FREE(uip, M_PROC); 137 return (0); 138 } 139 if (diff <= 0) { 140 if (diff == 0) 141 return(0); 142 panic("chgproccnt: lost user"); 143 } 144 MALLOC(uip, struct uidinfo *, sizeof(*uip), M_PROC, M_WAITOK); 145 LIST_INSERT_HEAD(uipp, uip, ui_hash); 146 uip->ui_uid = uid; 147 uip->ui_proccnt = diff; 148 return (diff); 149 } 150 151 /* 152 * Is p an inferior of the current process? 153 */ 154 int 155 inferior(p) 156 register struct proc *p; 157 { 158 159 for (; p != curproc; p = p->p_pptr) 160 if (p->p_pid == 0) 161 return (0); 162 return (1); 163 } 164 165 /* 166 * Locate a process by number 167 */ 168 struct proc * 169 pfind(pid) 170 register pid_t pid; 171 { 172 register struct proc *p; 173 174 for (p = PIDHASH(pid)->lh_first; p != 0; p = p->p_hash.le_next) 175 if (p->p_pid == pid) 176 return (p); 177 return (NULL); 178 } 179 180 /* 181 * Locate a process group by number 182 */ 183 struct pgrp * 184 pgfind(pgid) 185 register pid_t pgid; 186 { 187 register struct pgrp *pgrp; 188 189 for (pgrp = PGRPHASH(pgid)->lh_first; pgrp != 0; pgrp = pgrp->pg_hash.le_next) 190 if (pgrp->pg_id == pgid) 191 return (pgrp); 192 return (NULL); 193 } 194 195 /* 196 * Move p to a new or existing process group (and session) 197 */ 198 int 199 enterpgrp(p, pgid, mksess) 200 register struct proc *p; 201 pid_t pgid; 202 int mksess; 203 { 204 register struct pgrp *pgrp = pgfind(pgid); 205 206 #ifdef DIAGNOSTIC 207 if (pgrp != NULL && mksess) /* firewalls */ 208 panic("enterpgrp: setsid into non-empty pgrp"); 209 if (SESS_LEADER(p)) 210 panic("enterpgrp: session leader attempted setpgrp"); 211 #endif 212 if (pgrp == NULL) { 213 pid_t savepid = p->p_pid; 214 struct proc *np; 215 /* 216 * new process group 217 */ 218 #ifdef DIAGNOSTIC 219 if (p->p_pid != pgid) 220 panic("enterpgrp: new pgrp and pid != pgid"); 221 #endif 222 pgrp = pool_get(&pgrp_pool, PR_WAITOK); 223 if ((np = pfind(savepid)) == NULL || np != p) 224 return (ESRCH); 225 if (mksess) { 226 register struct session *sess; 227 228 /* 229 * new session 230 */ 231 MALLOC(sess, struct session *, sizeof(struct session), 232 M_SESSION, M_WAITOK); 233 sess->s_sid = p->p_pid; 234 sess->s_leader = p; 235 sess->s_count = 1; 236 sess->s_ttyvp = NULL; 237 sess->s_ttyp = NULL; 238 memcpy(sess->s_login, p->p_session->s_login, 239 sizeof(sess->s_login)); 240 p->p_flag &= ~P_CONTROLT; 241 pgrp->pg_session = sess; 242 #ifdef DIAGNOSTIC 243 if (p != curproc) 244 panic("enterpgrp: mksession and p != curproc"); 245 #endif 246 } else { 247 pgrp->pg_session = p->p_session; 248 pgrp->pg_session->s_count++; 249 } 250 pgrp->pg_id = pgid; 251 LIST_INIT(&pgrp->pg_members); 252 LIST_INSERT_HEAD(PGRPHASH(pgid), pgrp, pg_hash); 253 pgrp->pg_jobc = 0; 254 } else if (pgrp == p->p_pgrp) 255 return (0); 256 257 /* 258 * Adjust eligibility of affected pgrps to participate in job control. 259 * Increment eligibility counts before decrementing, otherwise we 260 * could reach 0 spuriously during the first call. 261 */ 262 fixjobc(p, pgrp, 1); 263 fixjobc(p, p->p_pgrp, 0); 264 265 LIST_REMOVE(p, p_pglist); 266 if (p->p_pgrp->pg_members.lh_first == 0) 267 pgdelete(p->p_pgrp); 268 p->p_pgrp = pgrp; 269 LIST_INSERT_HEAD(&pgrp->pg_members, p, p_pglist); 270 return (0); 271 } 272 273 /* 274 * remove process from process group 275 */ 276 int 277 leavepgrp(p) 278 register struct proc *p; 279 { 280 281 LIST_REMOVE(p, p_pglist); 282 if (p->p_pgrp->pg_members.lh_first == 0) 283 pgdelete(p->p_pgrp); 284 p->p_pgrp = 0; 285 return (0); 286 } 287 288 /* 289 * delete a process group 290 */ 291 void 292 pgdelete(pgrp) 293 register struct pgrp *pgrp; 294 { 295 296 if (pgrp->pg_session->s_ttyp != NULL && 297 pgrp->pg_session->s_ttyp->t_pgrp == pgrp) 298 pgrp->pg_session->s_ttyp->t_pgrp = NULL; 299 LIST_REMOVE(pgrp, pg_hash); 300 if (--pgrp->pg_session->s_count == 0) 301 FREE(pgrp->pg_session, M_SESSION); 302 pool_put(&pgrp_pool, pgrp); 303 } 304 305 /* 306 * Adjust pgrp jobc counters when specified process changes process group. 307 * We count the number of processes in each process group that "qualify" 308 * the group for terminal job control (those with a parent in a different 309 * process group of the same session). If that count reaches zero, the 310 * process group becomes orphaned. Check both the specified process' 311 * process group and that of its children. 312 * entering == 0 => p is leaving specified group. 313 * entering == 1 => p is entering specified group. 314 */ 315 void 316 fixjobc(p, pgrp, entering) 317 register struct proc *p; 318 register struct pgrp *pgrp; 319 int entering; 320 { 321 register struct pgrp *hispgrp; 322 register struct session *mysession = pgrp->pg_session; 323 324 /* 325 * Check p's parent to see whether p qualifies its own process 326 * group; if so, adjust count for p's process group. 327 */ 328 if ((hispgrp = p->p_pptr->p_pgrp) != pgrp && 329 hispgrp->pg_session == mysession) { 330 if (entering) 331 pgrp->pg_jobc++; 332 else if (--pgrp->pg_jobc == 0) 333 orphanpg(pgrp); 334 } 335 336 /* 337 * Check this process' children to see whether they qualify 338 * their process groups; if so, adjust counts for children's 339 * process groups. 340 */ 341 for (p = p->p_children.lh_first; p != 0; p = p->p_sibling.le_next) { 342 if ((hispgrp = p->p_pgrp) != pgrp && 343 hispgrp->pg_session == mysession && 344 p->p_stat != SZOMB) { 345 if (entering) 346 hispgrp->pg_jobc++; 347 else if (--hispgrp->pg_jobc == 0) 348 orphanpg(hispgrp); 349 } 350 } 351 } 352 353 /* 354 * A process group has become orphaned; 355 * if there are any stopped processes in the group, 356 * hang-up all process in that group. 357 */ 358 static void 359 orphanpg(pg) 360 struct pgrp *pg; 361 { 362 register struct proc *p; 363 364 for (p = pg->pg_members.lh_first; p != 0; p = p->p_pglist.le_next) { 365 if (p->p_stat == SSTOP) { 366 for (p = pg->pg_members.lh_first; p != 0; 367 p = p->p_pglist.le_next) { 368 psignal(p, SIGHUP); 369 psignal(p, SIGCONT); 370 } 371 return; 372 } 373 } 374 } 375 376 #ifdef DEBUG 377 void 378 pgrpdump() 379 { 380 register struct pgrp *pgrp; 381 register struct proc *p; 382 register int i; 383 384 for (i = 0; i <= pgrphash; i++) { 385 if ((pgrp = pgrphashtbl[i].lh_first) != NULL) { 386 printf("\tindx %d\n", i); 387 for (; pgrp != 0; pgrp = pgrp->pg_hash.le_next) { 388 printf("\tpgrp %p, pgid %d, sess %p, sesscnt %d, mem %p\n", 389 pgrp, pgrp->pg_id, pgrp->pg_session, 390 pgrp->pg_session->s_count, 391 pgrp->pg_members.lh_first); 392 for (p = pgrp->pg_members.lh_first; p != 0; 393 p = p->p_pglist.le_next) { 394 printf("\t\tpid %d addr %p pgrp %p\n", 395 p->p_pid, p, p->p_pgrp); 396 } 397 } 398 } 399 } 400 } 401 #endif /* DEBUG */ 402
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