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 (IS_PM_CALL(call_nr)) { 90 /* If the system call number is valid, perform the call. */ 91 call_index = (unsigned int) (call_nr - PM_BASE); 92 93 if (call_index < NR_PM_CALLS && call_vec[call_index] != NULL) { 94 #if ENABLE_SYSCALL_STATS 95 calls_stats[call_index]++; 96 #endif 97 98 result = (*call_vec[call_index])(); 99 } else 100 result = ENOSYS; 101 } else 102 result = ENOSYS; 103 104 /* Send reply. */ 105 if (result != SUSPEND) reply(who_p, result); 106 } 107 return(OK); 108 } 109 110 /*===========================================================================* 111 * sef_local_startup * 112 *===========================================================================*/ 113 static void sef_local_startup() 114 { 115 /* Register init callbacks. */ 116 sef_setcb_init_fresh(sef_cb_init_fresh); 117 sef_setcb_init_restart(sef_cb_init_fail); 118 119 /* No live update support for now. */ 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 } 151 152 /* Build the set of signals which cause core dumps, and the set of signals 153 * that are by default ignored. 154 */ 155 sigemptyset(&core_sset); 156 for (sig_ptr = core_sigs; sig_ptr < core_sigs+sizeof(core_sigs); sig_ptr++) 157 sigaddset(&core_sset, *sig_ptr); 158 sigemptyset(&ign_sset); 159 for (sig_ptr = ign_sigs; sig_ptr < ign_sigs+sizeof(ign_sigs); sig_ptr++) 160 sigaddset(&ign_sset, *sig_ptr); 161 sigemptyset(&noign_sset); 162 for (sig_ptr = noign_sigs; sig_ptr < noign_sigs+sizeof(noign_sigs); sig_ptr++) 163 sigaddset(&noign_sset, *sig_ptr); 164 165 /* Obtain a copy of the boot monitor parameters. 166 */ 167 if ((s=sys_getmonparams(monitor_params, sizeof(monitor_params))) != OK) 168 panic("get monitor params failed: %d", s); 169 170 /* Initialize PM's process table. Request a copy of the system image table 171 * that is defined at the kernel level to see which slots to fill in. 172 */ 173 if (OK != (s=sys_getimage(image))) 174 panic("couldn't get image table: %d", s); 175 procs_in_use = 0; /* start populating table */ 176 for (ip = &image[0]; ip < &image[NR_BOOT_PROCS]; ip++) { 177 if (ip->proc_nr >= 0) { /* task have negative nrs */ 178 procs_in_use += 1; /* found user process */ 179 180 /* Set process details found in the image table. */ 181 rmp = &mproc[ip->proc_nr]; 182 strlcpy(rmp->mp_name, ip->proc_name, PROC_NAME_LEN); 183 (void) sigemptyset(&rmp->mp_ignore); 184 (void) sigemptyset(&rmp->mp_sigmask); 185 (void) sigemptyset(&rmp->mp_catch); 186 if (ip->proc_nr == INIT_PROC_NR) { /* user process */ 187 /* INIT is root, we make it father of itself. This is 188 * not really OK, INIT should have no father, i.e. 189 * a father with pid NO_PID. But PM currently assumes 190 * that mp_parent always points to a valid slot number. 191 */ 192 rmp->mp_parent = INIT_PROC_NR; 193 rmp->mp_procgrp = rmp->mp_pid = INIT_PID; 194 rmp->mp_flags |= IN_USE; 195 196 /* Set scheduling info */ 197 rmp->mp_scheduler = KERNEL; 198 rmp->mp_nice = get_nice_value(USR_Q); 199 } 200 else { /* system process */ 201 if(ip->proc_nr == RS_PROC_NR) { 202 rmp->mp_parent = INIT_PROC_NR; 203 } 204 else { 205 rmp->mp_parent = RS_PROC_NR; 206 } 207 rmp->mp_pid = get_free_pid(); 208 rmp->mp_flags |= IN_USE | PRIV_PROC; 209 210 /* RS schedules this process */ 211 rmp->mp_scheduler = NONE; 212 rmp->mp_nice = get_nice_value(SRV_Q); 213 } 214 215 /* Get kernel endpoint identifier. */ 216 rmp->mp_endpoint = ip->endpoint; 217 218 /* Tell VFS about this system process. */ 219 memset(&mess, 0, sizeof(mess)); 220 mess.m_type = VFS_PM_INIT; 221 mess.VFS_PM_SLOT = ip->proc_nr; 222 mess.VFS_PM_PID = rmp->mp_pid; 223 mess.VFS_PM_ENDPT = rmp->mp_endpoint; 224 if (OK != (s=ipc_send(VFS_PROC_NR, &mess))) 225 panic("can't sync up with VFS: %d", s); 226 } 227 } 228 229 /* Tell VFS that no more system processes follow and synchronize. */ 230 memset(&mess, 0, sizeof(mess)); 231 mess.m_type = VFS_PM_INIT; 232 mess.VFS_PM_ENDPT = NONE; 233 if (ipc_sendrec(VFS_PROC_NR, &mess) != OK || mess.m_type != OK) 234 panic("can't sync up with VFS"); 235 236 #if defined(__i386__) 237 uts_val.machine[0] = 'i'; 238 strcpy(uts_val.machine + 1, itoa(getprocessor())); 239 #elif defined(__arm__) 240 strcpy(uts_val.machine, "arm"); 241 #endif 242 243 system_hz = sys_hz(); 244 245 /* Initialize user-space scheduling. */ 246 sched_init(); 247 248 return(OK); 249 } 250 251 /*===========================================================================* 252 * reply * 253 *===========================================================================*/ 254 void reply(proc_nr, result) 255 int proc_nr; /* process to reply to */ 256 int result; /* result of call (usually OK or error #) */ 257 { 258 /* Send a reply to a user process. System calls may occasionally fill in other 259 * fields, this is only for the main return value and for sending the reply. 260 */ 261 struct mproc *rmp; 262 int r; 263 264 if(proc_nr < 0 || proc_nr >= NR_PROCS) 265 panic("reply arg out of range: %d", proc_nr); 266 267 rmp = &mproc[proc_nr]; 268 rmp->mp_reply.m_type = result; 269 270 if ((r = ipc_sendnb(rmp->mp_endpoint, &rmp->mp_reply)) != OK) 271 printf("PM can't reply to %d (%s): %d\n", rmp->mp_endpoint, 272 rmp->mp_name, r); 273 } 274 275 /*===========================================================================* 276 * get_nice_value * 277 *===========================================================================*/ 278 static int get_nice_value(queue) 279 int queue; /* store mem chunks here */ 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 handle_vfs_reply() 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_EXIT_REPLY: 357 exit_restart(rmp, FALSE /*dump_core*/); 358 359 break; 360 361 case VFS_PM_CORE_REPLY: 362 if (m_in.VFS_PM_STATUS == OK) 363 rmp->mp_sigstatus |= WCOREFLAG; 364 365 exit_restart(rmp, TRUE /*dump_core*/); 366 367 break; 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 break; 413 414 default: 415 panic("handle_vfs_reply: unknown reply code: %d", call_nr); 416 } 417 418 /* Now that the process is idle again, look at pending signals */ 419 if ((rmp->mp_flags & (IN_USE | EXITING)) == IN_USE) 420 restart_sigs(rmp); 421 } 422