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