1 /* This file contains the main program of the process manager and some related 2 * procedures. When MINIX starts up, the kernel runs for a little while, 3 * initializing itself and its tasks, and then it runs PM and VFS. Both PM 4 * and VFS initialize themselves as far as they can. PM asks the kernel for 5 * all free memory and starts serving requests. 6 * 7 * The entry points into this file are: 8 * main: starts PM running 9 * reply: send a reply to a process making a PM system call 10 */ 11 12 #include "pm.h" 13 #include <minix/callnr.h> 14 #include <minix/com.h> 15 #include <minix/ds.h> 16 #include <minix/type.h> 17 #include <minix/endpoint.h> 18 #include <minix/minlib.h> 19 #include <minix/type.h> 20 #include <minix/vm.h> 21 #include <signal.h> 22 #include <stdlib.h> 23 #include <fcntl.h> 24 #include <sys/resource.h> 25 #include <sys/utsname.h> 26 #include <sys/wait.h> 27 #include <machine/archtypes.h> 28 #include <env.h> 29 #include <assert.h> 30 #include "mproc.h" 31 32 #include "kernel/const.h" 33 #include "kernel/config.h" 34 #include "kernel/proc.h" 35 36 #if ENABLE_SYSCALL_STATS 37 EXTERN unsigned long calls_stats[NR_PM_CALLS]; 38 #endif 39 40 static int get_nice_value(int queue); 41 static void handle_vfs_reply(void); 42 43 /* SEF functions and variables. */ 44 static void sef_local_startup(void); 45 static int sef_cb_init_fresh(int type, sef_init_info_t *info); 46 47 /*===========================================================================* 48 * main * 49 *===========================================================================*/ 50 int main() 51 { 52 /* Main routine of the process manager. */ 53 unsigned int call_index; 54 int ipc_status, result; 55 56 /* SEF local startup. */ 57 sef_local_startup(); 58 59 /* This is PM's main loop- get work and do it, forever and forever. */ 60 while (TRUE) { 61 /* Wait for the next message. */ 62 if (sef_receive_status(ANY, &m_in, &ipc_status) != OK) 63 panic("PM sef_receive_status error"); 64 65 /* Check for system notifications first. Special cases. */ 66 if (is_ipc_notify(ipc_status)) { 67 if (_ENDPOINT_P(m_in.m_source) == CLOCK) 68 expire_timers(m_in.m_notify.timestamp); 69 70 /* done, continue */ 71 continue; 72 } 73 74 /* Extract useful information from the message. */ 75 who_e = m_in.m_source; /* who sent the message */ 76 if (pm_isokendpt(who_e, &who_p) != OK) 77 panic("PM got message from invalid endpoint: %d", who_e); 78 mp = &mproc[who_p]; /* process slot of caller */ 79 call_nr = m_in.m_type; /* system call number */ 80 81 /* Drop delayed calls from exiting processes. */ 82 if (mp->mp_flags & EXITING) 83 continue; 84 85 if (IS_VFS_PM_RS(call_nr) && who_e == VFS_PROC_NR) { 86 handle_vfs_reply(); 87 88 result = SUSPEND; /* don't reply */ 89 } else if (call_nr == PROC_EVENT_REPLY) { 90 result = do_proc_event_reply(); 91 } else if (IS_PM_CALL(call_nr)) { 92 /* If the system call number is valid, perform the call. */ 93 call_index = (unsigned int) (call_nr - PM_BASE); 94 95 if (call_index < NR_PM_CALLS && call_vec[call_index] != NULL) { 96 #if ENABLE_SYSCALL_STATS 97 calls_stats[call_index]++; 98 #endif 99 100 result = (*call_vec[call_index])(); 101 } else 102 result = ENOSYS; 103 } else 104 result = ENOSYS; 105 106 /* Send reply. */ 107 if (result != SUSPEND) reply(who_p, result); 108 } 109 return(OK); 110 } 111 112 /*===========================================================================* 113 * sef_local_startup * 114 *===========================================================================*/ 115 static void sef_local_startup() 116 { 117 /* Register init callbacks. */ 118 sef_setcb_init_fresh(sef_cb_init_fresh); 119 sef_setcb_init_restart(SEF_CB_INIT_RESTART_STATEFUL); 120 121 /* Register signal callbacks. */ 122 sef_setcb_signal_manager(process_ksig); 123 124 /* Let SEF perform startup. */ 125 sef_startup(); 126 } 127 128 /*===========================================================================* 129 * sef_cb_init_fresh * 130 *===========================================================================*/ 131 static int sef_cb_init_fresh(int UNUSED(type), sef_init_info_t *UNUSED(info)) 132 { 133 /* Initialize the process manager. */ 134 int s; 135 static struct boot_image image[NR_BOOT_PROCS]; 136 register struct boot_image *ip; 137 static char core_sigs[] = { SIGQUIT, SIGILL, SIGTRAP, SIGABRT, 138 SIGEMT, SIGFPE, SIGBUS, SIGSEGV }; 139 static char ign_sigs[] = { SIGCHLD, SIGWINCH, SIGCONT, SIGINFO }; 140 static char noign_sigs[] = { SIGILL, SIGTRAP, SIGEMT, SIGFPE, 141 SIGBUS, SIGSEGV }; 142 register struct mproc *rmp; 143 register char *sig_ptr; 144 message mess; 145 146 /* Initialize process table, including timers. */ 147 for (rmp=&mproc[0]; rmp<&mproc[NR_PROCS]; rmp++) { 148 init_timer(&rmp->mp_timer); 149 rmp->mp_magic = MP_MAGIC; 150 rmp->mp_sigact = mpsigact[rmp - mproc]; 151 rmp->mp_eventsub = NO_EVENTSUB; 152 } 153 154 /* Build the set of signals which cause core dumps, and the set of signals 155 * that are by default ignored. 156 */ 157 sigemptyset(&core_sset); 158 for (sig_ptr = core_sigs; sig_ptr < core_sigs+sizeof(core_sigs); sig_ptr++) 159 sigaddset(&core_sset, *sig_ptr); 160 sigemptyset(&ign_sset); 161 for (sig_ptr = ign_sigs; sig_ptr < ign_sigs+sizeof(ign_sigs); sig_ptr++) 162 sigaddset(&ign_sset, *sig_ptr); 163 sigemptyset(&noign_sset); 164 for (sig_ptr = noign_sigs; sig_ptr < noign_sigs+sizeof(noign_sigs); sig_ptr++) 165 sigaddset(&noign_sset, *sig_ptr); 166 167 /* Obtain a copy of the boot monitor parameters. 168 */ 169 if ((s=sys_getmonparams(monitor_params, sizeof(monitor_params))) != OK) 170 panic("get monitor params failed: %d", s); 171 172 /* Initialize PM's process table. Request a copy of the system image table 173 * that is defined at the kernel level to see which slots to fill in. 174 */ 175 if (OK != (s=sys_getimage(image))) 176 panic("couldn't get image table: %d", s); 177 procs_in_use = 0; /* start populating table */ 178 for (ip = &image[0]; ip < &image[NR_BOOT_PROCS]; ip++) { 179 if (ip->proc_nr >= 0) { /* task have negative nrs */ 180 procs_in_use += 1; /* found user process */ 181 182 /* Set process details found in the image table. */ 183 rmp = &mproc[ip->proc_nr]; 184 strlcpy(rmp->mp_name, ip->proc_name, PROC_NAME_LEN); 185 (void) sigemptyset(&rmp->mp_ignore); 186 (void) sigemptyset(&rmp->mp_sigmask); 187 (void) sigemptyset(&rmp->mp_catch); 188 if (ip->proc_nr == INIT_PROC_NR) { /* user process */ 189 /* INIT is root, we make it father of itself. This is 190 * not really OK, INIT should have no father, i.e. 191 * a father with pid NO_PID. But PM currently assumes 192 * that mp_parent always points to a valid slot number. 193 */ 194 rmp->mp_parent = INIT_PROC_NR; 195 rmp->mp_procgrp = rmp->mp_pid = INIT_PID; 196 rmp->mp_flags |= IN_USE; 197 198 /* Set scheduling info */ 199 rmp->mp_scheduler = KERNEL; 200 rmp->mp_nice = get_nice_value(USR_Q); 201 } 202 else { /* system process */ 203 if(ip->proc_nr == RS_PROC_NR) { 204 rmp->mp_parent = INIT_PROC_NR; 205 } 206 else { 207 rmp->mp_parent = RS_PROC_NR; 208 } 209 rmp->mp_pid = get_free_pid(); 210 rmp->mp_flags |= IN_USE | PRIV_PROC; 211 212 /* RS schedules this process */ 213 rmp->mp_scheduler = NONE; 214 rmp->mp_nice = get_nice_value(SRV_Q); 215 } 216 217 /* Get kernel endpoint identifier. */ 218 rmp->mp_endpoint = ip->endpoint; 219 220 /* Tell VFS about this system process. */ 221 memset(&mess, 0, sizeof(mess)); 222 mess.m_type = VFS_PM_INIT; 223 mess.VFS_PM_SLOT = ip->proc_nr; 224 mess.VFS_PM_PID = rmp->mp_pid; 225 mess.VFS_PM_ENDPT = rmp->mp_endpoint; 226 if (OK != (s=ipc_send(VFS_PROC_NR, &mess))) 227 panic("can't sync up with VFS: %d", s); 228 } 229 } 230 231 /* Tell VFS that no more system processes follow and synchronize. */ 232 memset(&mess, 0, sizeof(mess)); 233 mess.m_type = VFS_PM_INIT; 234 mess.VFS_PM_ENDPT = NONE; 235 if (ipc_sendrec(VFS_PROC_NR, &mess) != OK || mess.m_type != OK) 236 panic("can't sync up with VFS"); 237 238 system_hz = sys_hz(); 239 240 /* Initialize user-space scheduling. */ 241 sched_init(); 242 243 return(OK); 244 } 245 246 /*===========================================================================* 247 * reply * 248 *===========================================================================*/ 249 void reply(proc_nr, result) 250 int proc_nr; /* process to reply to */ 251 int result; /* result of call (usually OK or error #) */ 252 { 253 /* Send a reply to a user process. System calls may occasionally fill in other 254 * fields, this is only for the main return value and for sending the reply. 255 */ 256 struct mproc *rmp; 257 int r; 258 259 if(proc_nr < 0 || proc_nr >= NR_PROCS) 260 panic("reply arg out of range: %d", proc_nr); 261 262 rmp = &mproc[proc_nr]; 263 rmp->mp_reply.m_type = result; 264 265 if ((r = ipc_sendnb(rmp->mp_endpoint, &rmp->mp_reply)) != OK) 266 printf("PM can't reply to %d (%s): %d\n", rmp->mp_endpoint, 267 rmp->mp_name, r); 268 } 269 270 /*===========================================================================* 271 * get_nice_value * 272 *===========================================================================*/ 273 static int get_nice_value(queue) 274 int queue; /* store mem chunks here */ 275 { 276 /* Processes in the boot image have a priority assigned. The PM doesn't know 277 * about priorities, but uses 'nice' values instead. The priority is between 278 * MIN_USER_Q and MAX_USER_Q. We have to scale between PRIO_MIN and PRIO_MAX. 279 */ 280 int nice_val = (queue - USER_Q) * (PRIO_MAX-PRIO_MIN+1) / 281 (MIN_USER_Q-MAX_USER_Q+1); 282 if (nice_val > PRIO_MAX) nice_val = PRIO_MAX; /* shouldn't happen */ 283 if (nice_val < PRIO_MIN) nice_val = PRIO_MIN; /* shouldn't happen */ 284 return nice_val; 285 } 286 287 /*===========================================================================* 288 * handle_vfs_reply * 289 *===========================================================================*/ 290 static void handle_vfs_reply() 291 { 292 struct mproc *rmp; 293 endpoint_t proc_e; 294 int r, proc_n, new_parent; 295 296 /* VFS_PM_REBOOT is the only request not associated with a process. 297 * Handle its reply first. 298 */ 299 if (call_nr == VFS_PM_REBOOT_REPLY) { 300 /* Ask the kernel to abort. All system services, including 301 * the PM, will get a HARD_STOP notification. Await the 302 * notification in the main loop. 303 */ 304 sys_abort(abort_flag); 305 306 return; 307 } 308 309 /* Get the process associated with this call */ 310 proc_e = m_in.VFS_PM_ENDPT; 311 312 if (pm_isokendpt(proc_e, &proc_n) != OK) { 313 panic("handle_vfs_reply: got bad endpoint from VFS: %d", proc_e); 314 } 315 316 rmp = &mproc[proc_n]; 317 318 /* Now that VFS replied, mark the process as VFS-idle again */ 319 if (!(rmp->mp_flags & VFS_CALL)) 320 panic("handle_vfs_reply: reply without request: %d", call_nr); 321 322 new_parent = rmp->mp_flags & NEW_PARENT; 323 rmp->mp_flags &= ~(VFS_CALL | NEW_PARENT); 324 325 if (rmp->mp_flags & UNPAUSED) 326 panic("handle_vfs_reply: UNPAUSED set on entry: %d", call_nr); 327 328 /* Call-specific handler code */ 329 switch (call_nr) { 330 case VFS_PM_SETUID_REPLY: 331 case VFS_PM_SETGID_REPLY: 332 case VFS_PM_SETGROUPS_REPLY: 333 /* Wake up the original caller */ 334 reply(rmp-mproc, OK); 335 336 break; 337 338 case VFS_PM_SETSID_REPLY: 339 /* Wake up the original caller */ 340 reply(rmp-mproc, rmp->mp_procgrp); 341 342 break; 343 344 case VFS_PM_EXEC_REPLY: 345 exec_restart(rmp, m_in.VFS_PM_STATUS, (vir_bytes)m_in.VFS_PM_PC, 346 (vir_bytes)m_in.VFS_PM_NEWSP, 347 (vir_bytes)m_in.VFS_PM_NEWPS_STR); 348 349 break; 350 351 case VFS_PM_CORE_REPLY: 352 if (m_in.VFS_PM_STATUS == OK) 353 rmp->mp_sigstatus |= WCOREFLAG; 354 355 /* FALLTHROUGH */ 356 case VFS_PM_EXIT_REPLY: 357 assert(rmp->mp_flags & EXITING); 358 359 /* Publish the exit event. Continue exiting the process after that. */ 360 publish_event(rmp); 361 362 return; /* do not take the default action */ 363 364 case VFS_PM_FORK_REPLY: 365 /* Schedule the newly created process ... */ 366 r = OK; 367 if (rmp->mp_scheduler != KERNEL && rmp->mp_scheduler != NONE) { 368 r = sched_start_user(rmp->mp_scheduler, rmp); 369 } 370 371 /* If scheduling the process failed, we want to tear down the process 372 * and fail the fork */ 373 if (r != OK) { 374 /* Tear down the newly created process */ 375 rmp->mp_scheduler = NONE; /* don't try to stop scheduling */ 376 exit_proc(rmp, -1, FALSE /*dump_core*/); 377 378 /* Wake up the parent with a failed fork (unless dead) */ 379 if (!new_parent) 380 reply(rmp->mp_parent, -1); 381 } 382 else { 383 /* Wake up the child */ 384 reply(proc_n, OK); 385 386 /* Wake up the parent, unless the parent is already dead */ 387 if (!new_parent) 388 reply(rmp->mp_parent, rmp->mp_pid); 389 } 390 391 break; 392 393 case VFS_PM_SRV_FORK_REPLY: 394 /* Nothing to do */ 395 396 break; 397 398 case VFS_PM_UNPAUSE_REPLY: 399 /* The target process must always be stopped while unpausing; otherwise 400 * it could just end up pausing itself on a new call afterwards. 401 */ 402 assert(rmp->mp_flags & PROC_STOPPED); 403 404 /* Process is now unpaused */ 405 rmp->mp_flags |= UNPAUSED; 406 407 /* Publish the signal event. Continue with signals only after that. */ 408 publish_event(rmp); 409 410 return; /* do not take the default action */ 411 412 default: 413 panic("handle_vfs_reply: unknown reply code: %d", call_nr); 414 } 415 416 /* Now that the process is idle again, look at pending signals */ 417 if ((rmp->mp_flags & (IN_USE | EXITING)) == IN_USE) 418 restart_sigs(rmp); 419 } 420