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 <assert.h> 29 #include "mproc.h" 30 31 #include "kernel/const.h" 32 #include "kernel/config.h" 33 #include "kernel/proc.h" 34 35 #if ENABLE_SYSCALL_STATS 36 EXTERN unsigned long calls_stats[NR_PM_CALLS]; 37 #endif 38 39 static int get_nice_value(int queue); 40 static void handle_vfs_reply(void); 41 42 /* SEF functions and variables. */ 43 static void sef_local_startup(void); 44 static int sef_cb_init_fresh(int type, sef_init_info_t *info); 45 46 /*===========================================================================* 47 * main * 48 *===========================================================================*/ 49 int 50 main(void) 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 116 sef_local_startup(void) 117 { 118 /* Register init callbacks. */ 119 sef_setcb_init_fresh(sef_cb_init_fresh); 120 sef_setcb_init_restart(SEF_CB_INIT_RESTART_STATEFUL); 121 122 /* Register signal callbacks. */ 123 sef_setcb_signal_manager(process_ksig); 124 125 /* Let SEF perform startup. */ 126 sef_startup(); 127 } 128 129 /*===========================================================================* 130 * sef_cb_init_fresh * 131 *===========================================================================*/ 132 static int sef_cb_init_fresh(int UNUSED(type), sef_init_info_t *UNUSED(info)) 133 { 134 /* Initialize the process manager. */ 135 int s; 136 static struct boot_image image[NR_BOOT_PROCS]; 137 register struct boot_image *ip; 138 static char core_sigs[] = { SIGQUIT, SIGILL, SIGTRAP, SIGABRT, 139 SIGEMT, SIGFPE, SIGBUS, SIGSEGV }; 140 static char ign_sigs[] = { SIGCHLD, SIGWINCH, SIGCONT, SIGINFO }; 141 static char noign_sigs[] = { SIGILL, SIGTRAP, SIGEMT, SIGFPE, 142 SIGBUS, SIGSEGV }; 143 register struct mproc *rmp; 144 register char *sig_ptr; 145 message mess; 146 147 /* Initialize process table, including timers. */ 148 for (rmp=&mproc[0]; rmp<&mproc[NR_PROCS]; rmp++) { 149 init_timer(&rmp->mp_timer); 150 rmp->mp_magic = MP_MAGIC; 151 rmp->mp_sigact = mpsigact[rmp - mproc]; 152 rmp->mp_eventsub = NO_EVENTSUB; 153 } 154 155 /* Build the set of signals which cause core dumps, and the set of signals 156 * that are by default ignored. 157 */ 158 sigemptyset(&core_sset); 159 for (sig_ptr = core_sigs; sig_ptr < core_sigs+sizeof(core_sigs); sig_ptr++) 160 sigaddset(&core_sset, *sig_ptr); 161 sigemptyset(&ign_sset); 162 for (sig_ptr = ign_sigs; sig_ptr < ign_sigs+sizeof(ign_sigs); sig_ptr++) 163 sigaddset(&ign_sset, *sig_ptr); 164 sigemptyset(&noign_sset); 165 for (sig_ptr = noign_sigs; sig_ptr < noign_sigs+sizeof(noign_sigs); sig_ptr++) 166 sigaddset(&noign_sset, *sig_ptr); 167 168 /* Obtain a copy of the boot monitor parameters. 169 */ 170 if ((s=sys_getmonparams(monitor_params, sizeof(monitor_params))) != OK) 171 panic("get monitor params failed: %d", s); 172 173 /* Initialize PM's process table. Request a copy of the system image table 174 * that is defined at the kernel level to see which slots to fill in. 175 */ 176 if (OK != (s=sys_getimage(image))) 177 panic("couldn't get image table: %d", s); 178 procs_in_use = 0; /* start populating table */ 179 for (ip = &image[0]; ip < &image[NR_BOOT_PROCS]; ip++) { 180 if (ip->proc_nr >= 0) { /* task have negative nrs */ 181 procs_in_use += 1; /* found user process */ 182 183 /* Set process details found in the image table. */ 184 rmp = &mproc[ip->proc_nr]; 185 strlcpy(rmp->mp_name, ip->proc_name, PROC_NAME_LEN); 186 (void) sigemptyset(&rmp->mp_ignore); 187 (void) sigemptyset(&rmp->mp_sigmask); 188 (void) sigemptyset(&rmp->mp_catch); 189 if (ip->proc_nr == INIT_PROC_NR) { /* user process */ 190 /* INIT is root, we make it father of itself. This is 191 * not really OK, INIT should have no father, i.e. 192 * a father with pid NO_PID. But PM currently assumes 193 * that mp_parent always points to a valid slot number. 194 */ 195 rmp->mp_parent = INIT_PROC_NR; 196 rmp->mp_procgrp = rmp->mp_pid = INIT_PID; 197 rmp->mp_flags |= IN_USE; 198 199 /* Set scheduling info */ 200 rmp->mp_scheduler = KERNEL; 201 rmp->mp_nice = get_nice_value(USR_Q); 202 } 203 else { /* system process */ 204 if(ip->proc_nr == RS_PROC_NR) { 205 rmp->mp_parent = INIT_PROC_NR; 206 } 207 else { 208 rmp->mp_parent = RS_PROC_NR; 209 } 210 rmp->mp_pid = get_free_pid(); 211 rmp->mp_flags |= IN_USE | PRIV_PROC; 212 213 /* RS schedules this process */ 214 rmp->mp_scheduler = NONE; 215 rmp->mp_nice = get_nice_value(SRV_Q); 216 } 217 218 /* Get kernel endpoint identifier. */ 219 rmp->mp_endpoint = ip->endpoint; 220 221 /* Tell VFS about this system process. */ 222 memset(&mess, 0, sizeof(mess)); 223 mess.m_type = VFS_PM_INIT; 224 mess.VFS_PM_SLOT = ip->proc_nr; 225 mess.VFS_PM_PID = rmp->mp_pid; 226 mess.VFS_PM_ENDPT = rmp->mp_endpoint; 227 if (OK != (s=ipc_send(VFS_PROC_NR, &mess))) 228 panic("can't sync up with VFS: %d", s); 229 } 230 } 231 232 /* Tell VFS that no more system processes follow and synchronize. */ 233 memset(&mess, 0, sizeof(mess)); 234 mess.m_type = VFS_PM_INIT; 235 mess.VFS_PM_ENDPT = NONE; 236 if (ipc_sendrec(VFS_PROC_NR, &mess) != OK || mess.m_type != OK) 237 panic("can't sync up with VFS"); 238 239 system_hz = sys_hz(); 240 241 /* Initialize user-space scheduling. */ 242 sched_init(); 243 244 return(OK); 245 } 246 247 /*===========================================================================* 248 * reply * 249 *===========================================================================*/ 250 void 251 reply( 252 int proc_nr, /* process to reply to */ 253 int result /* result of call (usually OK or error #) */ 254 ) 255 { 256 /* Send a reply to a user process. System calls may occasionally fill in other 257 * fields, this is only for the main return value and for sending the reply. 258 */ 259 struct mproc *rmp; 260 int r; 261 262 if(proc_nr < 0 || proc_nr >= NR_PROCS) 263 panic("reply arg out of range: %d", proc_nr); 264 265 rmp = &mproc[proc_nr]; 266 rmp->mp_reply.m_type = result; 267 268 if ((r = ipc_sendnb(rmp->mp_endpoint, &rmp->mp_reply)) != OK) 269 printf("PM can't reply to %d (%s): %d\n", rmp->mp_endpoint, 270 rmp->mp_name, r); 271 } 272 273 /*===========================================================================* 274 * get_nice_value * 275 *===========================================================================*/ 276 static int 277 get_nice_value( 278 int queue /* store mem chunks here */ 279 ) 280 { 281 /* Processes in the boot image have a priority assigned. The PM doesn't know 282 * about priorities, but uses 'nice' values instead. The priority is between 283 * MIN_USER_Q and MAX_USER_Q. We have to scale between PRIO_MIN and PRIO_MAX. 284 */ 285 int nice_val = (queue - USER_Q) * (PRIO_MAX-PRIO_MIN+1) / 286 (MIN_USER_Q-MAX_USER_Q+1); 287 if (nice_val > PRIO_MAX) nice_val = PRIO_MAX; /* shouldn't happen */ 288 if (nice_val < PRIO_MIN) nice_val = PRIO_MIN; /* shouldn't happen */ 289 return nice_val; 290 } 291 292 /*===========================================================================* 293 * handle_vfs_reply * 294 *===========================================================================*/ 295 static void 296 handle_vfs_reply(void) 297 { 298 struct mproc *rmp; 299 endpoint_t proc_e; 300 int r, proc_n, new_parent; 301 302 /* VFS_PM_REBOOT is the only request not associated with a process. 303 * Handle its reply first. 304 */ 305 if (call_nr == VFS_PM_REBOOT_REPLY) { 306 /* Ask the kernel to abort. All system services, including 307 * the PM, will get a HARD_STOP notification. Await the 308 * notification in the main loop. 309 */ 310 sys_abort(abort_flag); 311 312 return; 313 } 314 315 /* Get the process associated with this call */ 316 proc_e = m_in.VFS_PM_ENDPT; 317 318 if (pm_isokendpt(proc_e, &proc_n) != OK) { 319 panic("handle_vfs_reply: got bad endpoint from VFS: %d", proc_e); 320 } 321 322 rmp = &mproc[proc_n]; 323 324 /* Now that VFS replied, mark the process as VFS-idle again */ 325 if (!(rmp->mp_flags & VFS_CALL)) 326 panic("handle_vfs_reply: reply without request: %d", call_nr); 327 328 new_parent = rmp->mp_flags & NEW_PARENT; 329 rmp->mp_flags &= ~(VFS_CALL | NEW_PARENT); 330 331 if (rmp->mp_flags & UNPAUSED) 332 panic("handle_vfs_reply: UNPAUSED set on entry: %d", call_nr); 333 334 /* Call-specific handler code */ 335 switch (call_nr) { 336 case VFS_PM_SETUID_REPLY: 337 case VFS_PM_SETGID_REPLY: 338 case VFS_PM_SETGROUPS_REPLY: 339 /* Wake up the original caller */ 340 reply(rmp-mproc, OK); 341 342 break; 343 344 case VFS_PM_SETSID_REPLY: 345 /* Wake up the original caller */ 346 reply(rmp-mproc, rmp->mp_procgrp); 347 348 break; 349 350 case VFS_PM_EXEC_REPLY: 351 exec_restart(rmp, m_in.VFS_PM_STATUS, (vir_bytes)m_in.VFS_PM_PC, 352 (vir_bytes)m_in.VFS_PM_NEWSP, 353 (vir_bytes)m_in.VFS_PM_NEWPS_STR); 354 355 break; 356 357 case VFS_PM_CORE_REPLY: 358 if (m_in.VFS_PM_STATUS == OK) 359 rmp->mp_sigstatus |= WCOREFLAG; 360 361 /* FALLTHROUGH */ 362 case VFS_PM_EXIT_REPLY: 363 assert(rmp->mp_flags & EXITING); 364 365 /* Publish the exit event. Continue exiting the process after that. */ 366 publish_event(rmp); 367 368 return; /* do not take the default action */ 369 370 case VFS_PM_FORK_REPLY: 371 /* Schedule the newly created process ... */ 372 r = OK; 373 if (rmp->mp_scheduler != KERNEL && rmp->mp_scheduler != NONE) { 374 r = sched_start_user(rmp->mp_scheduler, rmp); 375 } 376 377 /* If scheduling the process failed, we want to tear down the process 378 * and fail the fork */ 379 if (r != OK) { 380 /* Tear down the newly created process */ 381 rmp->mp_scheduler = NONE; /* don't try to stop scheduling */ 382 exit_proc(rmp, -1, FALSE /*dump_core*/); 383 384 /* Wake up the parent with a failed fork (unless dead) */ 385 if (!new_parent) 386 reply(rmp->mp_parent, -1); 387 } 388 else { 389 /* Wake up the child */ 390 reply(proc_n, OK); 391 392 /* Wake up the parent, unless the parent is already dead */ 393 if (!new_parent) 394 reply(rmp->mp_parent, rmp->mp_pid); 395 } 396 397 break; 398 399 case VFS_PM_SRV_FORK_REPLY: 400 /* Nothing to do */ 401 402 break; 403 404 case VFS_PM_UNPAUSE_REPLY: 405 /* The target process must always be stopped while unpausing; otherwise 406 * it could just end up pausing itself on a new call afterwards. 407 */ 408 assert(rmp->mp_flags & PROC_STOPPED); 409 410 /* Process is now unpaused */ 411 rmp->mp_flags |= UNPAUSED; 412 413 /* Publish the signal event. Continue with signals only after that. */ 414 publish_event(rmp); 415 416 return; /* do not take the default action */ 417 418 default: 419 panic("handle_vfs_reply: unknown reply code: %d", call_nr); 420 } 421 422 /* Now that the process is idle again, look at pending signals */ 423 if ((rmp->mp_flags & (IN_USE | EXITING)) == IN_USE) 424 restart_sigs(rmp); 425 } 426