1 /* 2 * Copyright (c) 1982, 1986, 1989, 1991 Regents of the University of California. 3 * All rights reserved. 4 * 5 * %sccs.include.redist.c% 6 * 7 * @(#)kern_proc.c 7.19 (Berkeley) 02/14/92 8 */ 9 10 #include <sys/param.h> 11 #include <sys/systm.h> 12 #include <sys/map.h> 13 #include <sys/kernel.h> 14 #include <sys/proc.h> 15 #include <sys/buf.h> 16 #include <sys/acct.h> 17 #include <sys/wait.h> 18 #include <sys/file.h> 19 #include <ufs/ufs/quota.h> 20 #include <sys/uio.h> 21 #include <sys/malloc.h> 22 #include <sys/mbuf.h> 23 #include <sys/ioctl.h> 24 #include <sys/tty.h> 25 26 /* 27 * Is p an inferior of the current process? 28 */ 29 inferior(p) 30 register struct proc *p; 31 { 32 33 for (; p != curproc; p = p->p_pptr) 34 if (p->p_pid == 0) 35 return (0); 36 return (1); 37 } 38 39 /* 40 * Locate a process by number 41 */ 42 struct proc * 43 pfind(pid) 44 register pid; 45 { 46 register struct proc *p = pidhash[PIDHASH(pid)]; 47 48 for (; p; p = p->p_hash) 49 if (p->p_pid == pid) 50 return (p); 51 return ((struct proc *)0); 52 } 53 54 /* 55 * Locate a process group by number 56 */ 57 struct pgrp * 58 pgfind(pgid) 59 register pid_t pgid; 60 { 61 register struct pgrp *pgrp = pgrphash[PIDHASH(pgid)]; 62 63 for (; pgrp; pgrp = pgrp->pg_hforw) 64 if (pgrp->pg_id == pgid) 65 return (pgrp); 66 return ((struct pgrp *)0); 67 } 68 69 /* 70 * Move p to a new or existing process group (and session) 71 */ 72 enterpgrp(p, pgid, mksess) 73 register struct proc *p; 74 pid_t pgid; 75 int mksess; 76 { 77 register struct pgrp *pgrp = pgfind(pgid); 78 register struct proc **pp; 79 register struct proc *cp; 80 int n; 81 82 #ifdef DIAGNOSTIC 83 if (pgrp && mksess) /* firewalls */ 84 panic("enterpgrp: setsid into non-empty pgrp"); 85 if (SESS_LEADER(p)) 86 panic("enterpgrp: session leader attempted setpgrp"); 87 #endif 88 if (pgrp == NULL) { 89 /* 90 * new process group 91 */ 92 #ifdef DIAGNOSTIC 93 if (p->p_pid != pgid) 94 panic("enterpgrp: new pgrp and pid != pgid"); 95 #endif 96 MALLOC(pgrp, struct pgrp *, sizeof(struct pgrp), M_PGRP, 97 M_WAITOK); 98 if (mksess) { 99 register struct session *sess; 100 101 /* 102 * new session 103 */ 104 MALLOC(sess, struct session *, sizeof(struct session), 105 M_SESSION, M_WAITOK); 106 sess->s_leader = p; 107 sess->s_count = 1; 108 sess->s_ttyvp = NULL; 109 sess->s_ttyp = NULL; 110 bcopy(p->p_session->s_login, sess->s_login, 111 sizeof(sess->s_login)); 112 p->p_flag &= ~SCTTY; 113 pgrp->pg_session = sess; 114 #ifdef DIAGNOSTIC 115 if (p != curproc) 116 panic("enterpgrp: mksession and p != curproc"); 117 #endif 118 } else { 119 pgrp->pg_session = p->p_session; 120 pgrp->pg_session->s_count++; 121 } 122 pgrp->pg_id = pgid; 123 pgrp->pg_hforw = pgrphash[n = PIDHASH(pgid)]; 124 pgrphash[n] = pgrp; 125 pgrp->pg_jobc = 0; 126 pgrp->pg_mem = NULL; 127 } else if (pgrp == p->p_pgrp) 128 return; 129 130 /* 131 * Adjust eligibility of affected pgrps to participate in job control. 132 * Increment eligibility counts before decrementing, otherwise we 133 * could reach 0 spuriously during the first call. 134 */ 135 fixjobc(p, pgrp, 1); 136 fixjobc(p, p->p_pgrp, 0); 137 138 /* 139 * unlink p from old process group 140 */ 141 for (pp = &p->p_pgrp->pg_mem; *pp; pp = &(*pp)->p_pgrpnxt) 142 if (*pp == p) { 143 *pp = p->p_pgrpnxt; 144 goto done; 145 } 146 panic("enterpgrp: can't find p on old pgrp"); 147 done: 148 /* 149 * delete old if empty 150 */ 151 if (p->p_pgrp->pg_mem == 0) 152 pgdelete(p->p_pgrp); 153 /* 154 * link into new one 155 */ 156 p->p_pgrp = pgrp; 157 p->p_pgrpnxt = pgrp->pg_mem; 158 pgrp->pg_mem = p; 159 } 160 161 /* 162 * remove process from process group 163 */ 164 leavepgrp(p) 165 register struct proc *p; 166 { 167 register struct proc **pp = &p->p_pgrp->pg_mem; 168 169 for (; *pp; pp = &(*pp)->p_pgrpnxt) 170 if (*pp == p) { 171 *pp = p->p_pgrpnxt; 172 goto done; 173 } 174 panic("leavepgrp: can't find p in pgrp"); 175 done: 176 if (!p->p_pgrp->pg_mem) 177 pgdelete(p->p_pgrp); 178 p->p_pgrp = 0; 179 } 180 181 /* 182 * delete a process group 183 */ 184 pgdelete(pgrp) 185 register struct pgrp *pgrp; 186 { 187 register struct pgrp **pgp = &pgrphash[PIDHASH(pgrp->pg_id)]; 188 189 if (pgrp->pg_session->s_ttyp != NULL && 190 pgrp->pg_session->s_ttyp->t_pgrp == pgrp) 191 pgrp->pg_session->s_ttyp->t_pgrp = NULL; 192 for (; *pgp; pgp = &(*pgp)->pg_hforw) 193 if (*pgp == pgrp) { 194 *pgp = pgrp->pg_hforw; 195 goto done; 196 } 197 panic("pgdelete: can't find pgrp on hash chain"); 198 done: 199 if (--pgrp->pg_session->s_count == 0) 200 FREE(pgrp->pg_session, M_SESSION); 201 FREE(pgrp, M_PGRP); 202 } 203 204 static void orphanpg(); 205 206 /* 207 * Adjust pgrp jobc counters when specified process changes process group. 208 * We count the number of processes in each process group that "qualify" 209 * the group for terminal job control (those with a parent in a different 210 * process group of the same session). If that count reaches zero, the 211 * process group becomes orphaned. Check both the specified process' 212 * process group and that of its children. 213 * entering == 0 => p is leaving specified group. 214 * entering == 1 => p is entering specified group. 215 */ 216 fixjobc(p, pgrp, entering) 217 register struct proc *p; 218 register struct pgrp *pgrp; 219 int entering; 220 { 221 register struct pgrp *hispgrp; 222 register struct session *mysession = pgrp->pg_session; 223 224 /* 225 * Check p's parent to see whether p qualifies its own process 226 * group; if so, adjust count for p's process group. 227 */ 228 if ((hispgrp = p->p_pptr->p_pgrp) != pgrp && 229 hispgrp->pg_session == mysession) 230 if (entering) 231 pgrp->pg_jobc++; 232 else if (--pgrp->pg_jobc == 0) 233 orphanpg(pgrp); 234 235 /* 236 * Check this process' children to see whether they qualify 237 * their process groups; if so, adjust counts for children's 238 * process groups. 239 */ 240 for (p = p->p_cptr; p; p = p->p_osptr) 241 if ((hispgrp = p->p_pgrp) != pgrp && 242 hispgrp->pg_session == mysession && 243 p->p_stat != SZOMB) 244 if (entering) 245 hispgrp->pg_jobc++; 246 else if (--hispgrp->pg_jobc == 0) 247 orphanpg(hispgrp); 248 } 249 250 /* 251 * A process group has become orphaned; 252 * if there are any stopped processes in the group, 253 * hang-up all process in that group. 254 */ 255 static void 256 orphanpg(pg) 257 struct pgrp *pg; 258 { 259 register struct proc *p; 260 261 for (p = pg->pg_mem; p; p = p->p_pgrpnxt) { 262 if (p->p_stat == SSTOP) { 263 for (p = pg->pg_mem; p; p = p->p_pgrpnxt) { 264 psignal(p, SIGHUP); 265 psignal(p, SIGCONT); 266 } 267 return; 268 } 269 } 270 } 271 272 #ifdef debug 273 /* DEBUG */ 274 pgrpdump() 275 { 276 register struct pgrp *pgrp; 277 register struct proc *p; 278 register i; 279 280 for (i=0; i<PIDHSZ; i++) { 281 if (pgrphash[i]) { 282 printf("\tindx %d\n", i); 283 for (pgrp=pgrphash[i]; pgrp; pgrp=pgrp->pg_hforw) { 284 printf("\tpgrp %x, pgid %d, sess %x, sesscnt %d, mem %x\n", 285 pgrp, pgrp->pg_id, pgrp->pg_session, 286 pgrp->pg_session->s_count, pgrp->pg_mem); 287 for (p=pgrp->pg_mem; p; p=p->p_pgrpnxt) { 288 printf("\t\tpid %d addr %x pgrp %x\n", 289 p->p_pid, p, p->p_pgrp); 290 } 291 } 292 293 } 294 } 295 } 296 #endif /* debug */ 297