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/endpoint.h> 17 #include <minix/minlib.h> 18 #include <minix/type.h> 19 #include <minix/vm.h> 20 #include <signal.h> 21 #include <stdlib.h> 22 #include <fcntl.h> 23 #include <sys/resource.h> 24 #include <sys/utsname.h> 25 #include <sys/wait.h> 26 #include <machine/archtypes.h> 27 #include <assert.h> 28 #include "mproc.h" 29 30 #include "kernel/const.h" 31 #include "kernel/config.h" 32 #include "kernel/proc.h" 33 34 #if ENABLE_SYSCALL_STATS 35 EXTERN unsigned long calls_stats[NR_PM_CALLS]; 36 #endif 37 38 static int get_nice_value(int queue); 39 static void handle_vfs_reply(void); 40 41 /* SEF functions and variables. */ 42 static void sef_local_startup(void); 43 static int sef_cb_init_fresh(int type, sef_init_info_t *info); 44 45 /*===========================================================================* 46 * main * 47 *===========================================================================*/ 48 int 49 main(void) 50 { 51 /* Main routine of the process manager. */ 52 unsigned int call_index; 53 int ipc_status, result; 54 55 /* SEF local startup. */ 56 sef_local_startup(); 57 58 /* This is PM's main loop- get work and do it, forever and forever. */ 59 while (TRUE) { 60 /* Wait for the next message. */ 61 if (sef_receive_status(ANY, &m_in, &ipc_status) != OK) 62 panic("PM sef_receive_status error"); 63 64 /* Check for system notifications first. Special cases. */ 65 if (is_ipc_notify(ipc_status)) { 66 if (_ENDPOINT_P(m_in.m_source) == CLOCK) 67 expire_timers(m_in.m_notify.timestamp); 68 69 /* done, continue */ 70 continue; 71 } 72 73 /* Extract useful information from the message. */ 74 who_e = m_in.m_source; /* who sent the message */ 75 if (pm_isokendpt(who_e, &who_p) != OK) 76 panic("PM got message from invalid endpoint: %d", who_e); 77 mp = &mproc[who_p]; /* process slot of caller */ 78 call_nr = m_in.m_type; /* system call number */ 79 80 /* Drop delayed calls from exiting processes. */ 81 if (mp->mp_flags & EXITING) 82 continue; 83 84 if (IS_VFS_PM_RS(call_nr) && who_e == VFS_PROC_NR) { 85 handle_vfs_reply(); 86 87 result = SUSPEND; /* don't reply */ 88 } else if (call_nr == PROC_EVENT_REPLY) { 89 result = do_proc_event_reply(); 90 } else if (IS_PM_CALL(call_nr)) { 91 /* If the system call number is valid, perform the call. */ 92 call_index = (unsigned int) (call_nr - PM_BASE); 93 94 if (call_index < NR_PM_CALLS && call_vec[call_index] != NULL) { 95 #if ENABLE_SYSCALL_STATS 96 calls_stats[call_index]++; 97 #endif 98 99 result = (*call_vec[call_index])(); 100 } else 101 result = ENOSYS; 102 } else 103 result = ENOSYS; 104 105 /* Send reply. */ 106 if (result != SUSPEND) reply(who_p, result); 107 } 108 return(OK); 109 } 110 111 /*===========================================================================* 112 * sef_local_startup * 113 *===========================================================================*/ 114 static void 115 sef_local_startup(void) 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 250 reply( 251 int proc_nr, /* process to reply to */ 252 int result /* result of call (usually OK or error #) */ 253 ) 254 { 255 /* Send a reply to a user process. System calls may occasionally fill in other 256 * fields, this is only for the main return value and for sending the reply. 257 */ 258 struct mproc *rmp; 259 int r; 260 261 if(proc_nr < 0 || proc_nr >= NR_PROCS) 262 panic("reply arg out of range: %d", proc_nr); 263 264 rmp = &mproc[proc_nr]; 265 rmp->mp_reply.m_type = result; 266 267 if ((r = ipc_sendnb(rmp->mp_endpoint, &rmp->mp_reply)) != OK) 268 printf("PM can't reply to %d (%s): %d\n", rmp->mp_endpoint, 269 rmp->mp_name, r); 270 } 271 272 /*===========================================================================* 273 * get_nice_value * 274 *===========================================================================*/ 275 static int 276 get_nice_value( 277 int queue /* store mem chunks here */ 278 ) 279 { 280 /* Processes in the boot image have a priority assigned. The PM doesn't know 281 * about priorities, but uses 'nice' values instead. The priority is between 282 * MIN_USER_Q and MAX_USER_Q. We have to scale between PRIO_MIN and PRIO_MAX. 283 */ 284 int nice_val = (queue - USER_Q) * (PRIO_MAX-PRIO_MIN+1) / 285 (MIN_USER_Q-MAX_USER_Q+1); 286 if (nice_val > PRIO_MAX) nice_val = PRIO_MAX; /* shouldn't happen */ 287 if (nice_val < PRIO_MIN) nice_val = PRIO_MIN; /* shouldn't happen */ 288 return nice_val; 289 } 290 291 /*===========================================================================* 292 * handle_vfs_reply * 293 *===========================================================================*/ 294 static void 295 handle_vfs_reply(void) 296 { 297 struct mproc *rmp; 298 endpoint_t proc_e; 299 int r, proc_n, new_parent; 300 301 /* VFS_PM_REBOOT is the only request not associated with a process. 302 * Handle its reply first. 303 */ 304 if (call_nr == VFS_PM_REBOOT_REPLY) { 305 /* Ask the kernel to abort. All system services, including 306 * the PM, will get a HARD_STOP notification. Await the 307 * notification in the main loop. 308 */ 309 sys_abort(abort_flag); 310 311 return; 312 } 313 314 /* Get the process associated with this call */ 315 proc_e = m_in.VFS_PM_ENDPT; 316 317 if (pm_isokendpt(proc_e, &proc_n) != OK) { 318 panic("handle_vfs_reply: got bad endpoint from VFS: %d", proc_e); 319 } 320 321 rmp = &mproc[proc_n]; 322 323 /* Now that VFS replied, mark the process as VFS-idle again */ 324 if (!(rmp->mp_flags & VFS_CALL)) 325 panic("handle_vfs_reply: reply without request: %d", call_nr); 326 327 new_parent = rmp->mp_flags & NEW_PARENT; 328 rmp->mp_flags &= ~(VFS_CALL | NEW_PARENT); 329 330 if (rmp->mp_flags & UNPAUSED) 331 panic("handle_vfs_reply: UNPAUSED set on entry: %d", call_nr); 332 333 /* Call-specific handler code */ 334 switch (call_nr) { 335 case VFS_PM_SETUID_REPLY: 336 case VFS_PM_SETGID_REPLY: 337 case VFS_PM_SETGROUPS_REPLY: 338 /* Wake up the original caller */ 339 reply(rmp-mproc, OK); 340 341 break; 342 343 case VFS_PM_SETSID_REPLY: 344 /* Wake up the original caller */ 345 reply(rmp-mproc, rmp->mp_procgrp); 346 347 break; 348 349 case VFS_PM_EXEC_REPLY: 350 exec_restart(rmp, m_in.VFS_PM_STATUS, (vir_bytes)m_in.VFS_PM_PC, 351 (vir_bytes)m_in.VFS_PM_NEWSP, 352 (vir_bytes)m_in.VFS_PM_NEWPS_STR); 353 354 break; 355 356 case VFS_PM_CORE_REPLY: 357 if (m_in.VFS_PM_STATUS == OK) 358 rmp->mp_sigstatus |= WCOREFLAG; 359 360 /* FALLTHROUGH */ 361 case VFS_PM_EXIT_REPLY: 362 assert(rmp->mp_flags & EXITING); 363 364 /* Publish the exit event. Continue exiting the process after that. */ 365 publish_event(rmp); 366 367 return; /* do not take the default action */ 368 369 case VFS_PM_FORK_REPLY: 370 /* Schedule the newly created process ... */ 371 r = OK; 372 if (rmp->mp_scheduler != KERNEL && rmp->mp_scheduler != NONE) { 373 r = sched_start_user(rmp->mp_scheduler, rmp); 374 } 375 376 /* If scheduling the process failed, we want to tear down the process 377 * and fail the fork */ 378 if (r != OK) { 379 /* Tear down the newly created process */ 380 rmp->mp_scheduler = NONE; /* don't try to stop scheduling */ 381 exit_proc(rmp, -1, FALSE /*dump_core*/); 382 383 /* Wake up the parent with a failed fork (unless dead) */ 384 if (!new_parent) 385 reply(rmp->mp_parent, -1); 386 } 387 else { 388 /* Wake up the child */ 389 reply(proc_n, OK); 390 391 /* Wake up the parent, unless the parent is already dead */ 392 if (!new_parent) 393 reply(rmp->mp_parent, rmp->mp_pid); 394 } 395 396 break; 397 398 case VFS_PM_SRV_FORK_REPLY: 399 /* Nothing to do */ 400 401 break; 402 403 case VFS_PM_UNPAUSE_REPLY: 404 /* The target process must always be stopped while unpausing; otherwise 405 * it could just end up pausing itself on a new call afterwards. 406 */ 407 assert(rmp->mp_flags & PROC_STOPPED); 408 409 /* Process is now unpaused */ 410 rmp->mp_flags |= UNPAUSED; 411 412 /* Publish the signal event. Continue with signals only after that. */ 413 publish_event(rmp); 414 415 return; /* do not take the default action */ 416 417 default: 418 panic("handle_vfs_reply: unknown reply code: %d", call_nr); 419 } 420 421 /* Now that the process is idle again, look at pending signals */ 422 if ((rmp->mp_flags & (IN_USE | EXITING)) == IN_USE) 423 restart_sigs(rmp); 424 } 425