1 /* 2 * Copyright (C) 2001 Lennert Buytenhek (buytenh@gnu.org) 3 * Copyright (C) 2001 - 2003 Jeff Dike (jdike@addtoit.com) 4 * Licensed under the GPL 5 */ 6 7 #include "linux/kernel.h" 8 #include "linux/slab.h" 9 #include "linux/init.h" 10 #include "linux/notifier.h" 11 #include "linux/reboot.h" 12 #include "linux/utsname.h" 13 #include "linux/ctype.h" 14 #include "linux/interrupt.h" 15 #include "linux/sysrq.h" 16 #include "linux/workqueue.h" 17 #include "linux/module.h" 18 #include "linux/file.h" 19 #include "linux/fs.h" 20 #include "linux/namei.h" 21 #include "linux/proc_fs.h" 22 #include "linux/syscalls.h" 23 #include "linux/list.h" 24 #include "linux/mm.h" 25 #include "linux/console.h" 26 #include "asm/irq.h" 27 #include "asm/uaccess.h" 28 #include "user_util.h" 29 #include "kern_util.h" 30 #include "kern.h" 31 #include "mconsole.h" 32 #include "mconsole_kern.h" 33 #include "irq_user.h" 34 #include "init.h" 35 #include "os.h" 36 #include "umid.h" 37 #include "irq_kern.h" 38 #include "choose-mode.h" 39 40 static int do_unlink_socket(struct notifier_block *notifier, 41 unsigned long what, void *data) 42 { 43 return(mconsole_unlink_socket()); 44 } 45 46 47 static struct notifier_block reboot_notifier = { 48 .notifier_call = do_unlink_socket, 49 .priority = 0, 50 }; 51 52 /* Safe without explicit locking for now. Tasklets provide their own 53 * locking, and the interrupt handler is safe because it can't interrupt 54 * itself and it can only happen on CPU 0. 55 */ 56 57 static LIST_HEAD(mc_requests); 58 59 static void mc_work_proc(void *unused) 60 { 61 struct mconsole_entry *req; 62 unsigned long flags; 63 64 while(!list_empty(&mc_requests)){ 65 local_save_flags(flags); 66 req = list_entry(mc_requests.next, struct mconsole_entry, 67 list); 68 list_del(&req->list); 69 local_irq_restore(flags); 70 req->request.cmd->handler(&req->request); 71 kfree(req); 72 } 73 } 74 75 static DECLARE_WORK(mconsole_work, mc_work_proc, NULL); 76 77 static irqreturn_t mconsole_interrupt(int irq, void *dev_id, 78 struct pt_regs *regs) 79 { 80 /* long to avoid size mismatch warnings from gcc */ 81 long fd; 82 struct mconsole_entry *new; 83 struct mc_request req; 84 85 fd = (long) dev_id; 86 while (mconsole_get_request(fd, &req)){ 87 if(req.cmd->context == MCONSOLE_INTR) 88 (*req.cmd->handler)(&req); 89 else { 90 new = kmalloc(sizeof(*new), GFP_ATOMIC); 91 if(new == NULL) 92 mconsole_reply(&req, "Out of memory", 1, 0); 93 else { 94 new->request = req; 95 list_add(&new->list, &mc_requests); 96 } 97 } 98 } 99 if(!list_empty(&mc_requests)) 100 schedule_work(&mconsole_work); 101 reactivate_fd(fd, MCONSOLE_IRQ); 102 return(IRQ_HANDLED); 103 } 104 105 void mconsole_version(struct mc_request *req) 106 { 107 char version[256]; 108 109 sprintf(version, "%s %s %s %s %s", system_utsname.sysname, 110 system_utsname.nodename, system_utsname.release, 111 system_utsname.version, system_utsname.machine); 112 mconsole_reply(req, version, 0, 0); 113 } 114 115 void mconsole_log(struct mc_request *req) 116 { 117 int len; 118 char *ptr = req->request.data; 119 120 ptr += strlen("log "); 121 122 len = req->len - (ptr - req->request.data); 123 printk("%.*s", len, ptr); 124 mconsole_reply(req, "", 0, 0); 125 } 126 127 /* This is a more convoluted version of mconsole_proc, which has some stability 128 * problems; however, we need it fixed, because it is expected that UML users 129 * mount HPPFS instead of procfs on /proc. And we want mconsole_proc to still 130 * show the real procfs content, not the ones from hppfs.*/ 131 #if 0 132 void mconsole_proc(struct mc_request *req) 133 { 134 struct nameidata nd; 135 struct file_system_type *proc; 136 struct super_block *super; 137 struct file *file; 138 int n, err; 139 char *ptr = req->request.data, *buf; 140 141 ptr += strlen("proc"); 142 while(isspace(*ptr)) ptr++; 143 144 proc = get_fs_type("proc"); 145 if(proc == NULL){ 146 mconsole_reply(req, "procfs not registered", 1, 0); 147 goto out; 148 } 149 150 super = (*proc->get_sb)(proc, 0, NULL, NULL); 151 put_filesystem(proc); 152 if(super == NULL){ 153 mconsole_reply(req, "Failed to get procfs superblock", 1, 0); 154 goto out; 155 } 156 up_write(&super->s_umount); 157 158 nd.dentry = super->s_root; 159 nd.mnt = NULL; 160 nd.flags = O_RDONLY + 1; 161 nd.last_type = LAST_ROOT; 162 163 /* START: it was experienced that the stability problems are closed 164 * if commenting out these two calls + the below read cycle. To 165 * make UML crash again, it was enough to readd either one.*/ 166 err = link_path_walk(ptr, &nd); 167 if(err){ 168 mconsole_reply(req, "Failed to look up file", 1, 0); 169 goto out_kill; 170 } 171 172 file = dentry_open(nd.dentry, nd.mnt, O_RDONLY); 173 if(IS_ERR(file)){ 174 mconsole_reply(req, "Failed to open file", 1, 0); 175 goto out_kill; 176 } 177 /*END*/ 178 179 buf = kmalloc(PAGE_SIZE, GFP_KERNEL); 180 if(buf == NULL){ 181 mconsole_reply(req, "Failed to allocate buffer", 1, 0); 182 goto out_fput; 183 } 184 185 if((file->f_op != NULL) && (file->f_op->read != NULL)){ 186 do { 187 n = (*file->f_op->read)(file, buf, PAGE_SIZE - 1, 188 &file->f_pos); 189 if(n >= 0){ 190 buf[n] = '\0'; 191 mconsole_reply(req, buf, 0, (n > 0)); 192 } 193 else { 194 mconsole_reply(req, "Read of file failed", 195 1, 0); 196 goto out_free; 197 } 198 } while(n > 0); 199 } 200 else mconsole_reply(req, "", 0, 0); 201 202 out_free: 203 kfree(buf); 204 out_fput: 205 fput(file); 206 out_kill: 207 deactivate_super(super); 208 out: ; 209 } 210 #endif 211 212 void mconsole_proc(struct mc_request *req) 213 { 214 char path[64]; 215 char *buf; 216 int len; 217 int fd; 218 int first_chunk = 1; 219 char *ptr = req->request.data; 220 221 ptr += strlen("proc"); 222 while(isspace(*ptr)) ptr++; 223 snprintf(path, sizeof(path), "/proc/%s", ptr); 224 225 fd = sys_open(path, 0, 0); 226 if (fd < 0) { 227 mconsole_reply(req, "Failed to open file", 1, 0); 228 printk("open %s: %d\n",path,fd); 229 goto out; 230 } 231 232 buf = kmalloc(PAGE_SIZE, GFP_KERNEL); 233 if(buf == NULL){ 234 mconsole_reply(req, "Failed to allocate buffer", 1, 0); 235 goto out_close; 236 } 237 238 for (;;) { 239 len = sys_read(fd, buf, PAGE_SIZE-1); 240 if (len < 0) { 241 mconsole_reply(req, "Read of file failed", 1, 0); 242 goto out_free; 243 } 244 /*Begin the file content on his own line.*/ 245 if (first_chunk) { 246 mconsole_reply(req, "\n", 0, 1); 247 first_chunk = 0; 248 } 249 if (len == PAGE_SIZE-1) { 250 buf[len] = '\0'; 251 mconsole_reply(req, buf, 0, 1); 252 } else { 253 buf[len] = '\0'; 254 mconsole_reply(req, buf, 0, 0); 255 break; 256 } 257 } 258 259 out_free: 260 kfree(buf); 261 out_close: 262 sys_close(fd); 263 out: 264 /* nothing */; 265 } 266 267 #define UML_MCONSOLE_HELPTEXT \ 268 "Commands: \n\ 269 version - Get kernel version \n\ 270 help - Print this message \n\ 271 halt - Halt UML \n\ 272 reboot - Reboot UML \n\ 273 config <dev>=<config> - Add a new device to UML; \n\ 274 same syntax as command line \n\ 275 config <dev> - Query the configuration of a device \n\ 276 remove <dev> - Remove a device from UML \n\ 277 sysrq <letter> - Performs the SysRq action controlled by the letter \n\ 278 cad - invoke the Ctrl-Alt-Del handler \n\ 279 stop - pause the UML; it will do nothing until it receives a 'go' \n\ 280 go - continue the UML after a 'stop' \n\ 281 log <string> - make UML enter <string> into the kernel log\n\ 282 proc <file> - returns the contents of the UML's /proc/<file>\n\ 283 stack <pid> - returns the stack of the specified pid\n\ 284 " 285 286 void mconsole_help(struct mc_request *req) 287 { 288 mconsole_reply(req, UML_MCONSOLE_HELPTEXT, 0, 0); 289 } 290 291 void mconsole_halt(struct mc_request *req) 292 { 293 mconsole_reply(req, "", 0, 0); 294 machine_halt(); 295 } 296 297 void mconsole_reboot(struct mc_request *req) 298 { 299 mconsole_reply(req, "", 0, 0); 300 machine_restart(NULL); 301 } 302 303 extern void ctrl_alt_del(void); 304 305 void mconsole_cad(struct mc_request *req) 306 { 307 mconsole_reply(req, "", 0, 0); 308 ctrl_alt_del(); 309 } 310 311 void mconsole_go(struct mc_request *req) 312 { 313 mconsole_reply(req, "Not stopped", 1, 0); 314 } 315 316 void mconsole_stop(struct mc_request *req) 317 { 318 deactivate_fd(req->originating_fd, MCONSOLE_IRQ); 319 os_set_fd_block(req->originating_fd, 1); 320 mconsole_reply(req, "", 0, 0); 321 while(mconsole_get_request(req->originating_fd, req)){ 322 if(req->cmd->handler == mconsole_go) break; 323 (*req->cmd->handler)(req); 324 } 325 os_set_fd_block(req->originating_fd, 0); 326 reactivate_fd(req->originating_fd, MCONSOLE_IRQ); 327 mconsole_reply(req, "", 0, 0); 328 } 329 330 /* This list is populated by __initcall routines. */ 331 332 static LIST_HEAD(mconsole_devices); 333 334 void mconsole_register_dev(struct mc_device *new) 335 { 336 list_add(&new->list, &mconsole_devices); 337 } 338 339 static struct mc_device *mconsole_find_dev(char *name) 340 { 341 struct list_head *ele; 342 struct mc_device *dev; 343 344 list_for_each(ele, &mconsole_devices){ 345 dev = list_entry(ele, struct mc_device, list); 346 if(!strncmp(name, dev->name, strlen(dev->name))) 347 return(dev); 348 } 349 return(NULL); 350 } 351 352 #define UNPLUGGED_PER_PAGE \ 353 ((PAGE_SIZE - sizeof(struct list_head)) / sizeof(unsigned long)) 354 355 struct unplugged_pages { 356 struct list_head list; 357 void *pages[UNPLUGGED_PER_PAGE]; 358 }; 359 360 static unsigned long long unplugged_pages_count = 0; 361 static struct list_head unplugged_pages = LIST_HEAD_INIT(unplugged_pages); 362 static int unplug_index = UNPLUGGED_PER_PAGE; 363 364 static int mem_config(char *str) 365 { 366 unsigned long long diff; 367 int err = -EINVAL, i, add; 368 char *ret; 369 370 if(str[0] != '=') 371 goto out; 372 373 str++; 374 if(str[0] == '-') 375 add = 0; 376 else if(str[0] == '+'){ 377 add = 1; 378 } 379 else goto out; 380 381 str++; 382 diff = memparse(str, &ret); 383 if(*ret != '\0') 384 goto out; 385 386 diff /= PAGE_SIZE; 387 388 for(i = 0; i < diff; i++){ 389 struct unplugged_pages *unplugged; 390 void *addr; 391 392 if(add){ 393 if(list_empty(&unplugged_pages)) 394 break; 395 396 unplugged = list_entry(unplugged_pages.next, 397 struct unplugged_pages, list); 398 if(unplug_index > 0) 399 addr = unplugged->pages[--unplug_index]; 400 else { 401 list_del(&unplugged->list); 402 addr = unplugged; 403 unplug_index = UNPLUGGED_PER_PAGE; 404 } 405 406 free_page((unsigned long) addr); 407 unplugged_pages_count--; 408 } 409 else { 410 struct page *page; 411 412 page = alloc_page(GFP_ATOMIC); 413 if(page == NULL) 414 break; 415 416 unplugged = page_address(page); 417 if(unplug_index == UNPLUGGED_PER_PAGE){ 418 INIT_LIST_HEAD(&unplugged->list); 419 list_add(&unplugged->list, &unplugged_pages); 420 unplug_index = 0; 421 } 422 else { 423 struct list_head *entry = unplugged_pages.next; 424 addr = unplugged; 425 426 unplugged = list_entry(entry, 427 struct unplugged_pages, 428 list); 429 unplugged->pages[unplug_index++] = addr; 430 err = os_drop_memory(addr, PAGE_SIZE); 431 if(err) 432 printk("Failed to release memory - " 433 "errno = %d\n", err); 434 } 435 436 unplugged_pages_count++; 437 } 438 } 439 440 err = 0; 441 out: 442 return err; 443 } 444 445 static int mem_get_config(char *name, char *str, int size, char **error_out) 446 { 447 char buf[sizeof("18446744073709551615")]; 448 int len = 0; 449 450 sprintf(buf, "%ld", uml_physmem); 451 CONFIG_CHUNK(str, size, len, buf, 1); 452 453 return len; 454 } 455 456 static int mem_id(char **str, int *start_out, int *end_out) 457 { 458 *start_out = 0; 459 *end_out = 0; 460 461 return 0; 462 } 463 464 static int mem_remove(int n) 465 { 466 return -EBUSY; 467 } 468 469 static struct mc_device mem_mc = { 470 .name = "mem", 471 .config = mem_config, 472 .get_config = mem_get_config, 473 .id = mem_id, 474 .remove = mem_remove, 475 }; 476 477 static int mem_mc_init(void) 478 { 479 if(can_drop_memory()) 480 mconsole_register_dev(&mem_mc); 481 else printk("Can't release memory to the host - memory hotplug won't " 482 "be supported\n"); 483 return 0; 484 } 485 486 __initcall(mem_mc_init); 487 488 #define CONFIG_BUF_SIZE 64 489 490 static void mconsole_get_config(int (*get_config)(char *, char *, int, 491 char **), 492 struct mc_request *req, char *name) 493 { 494 char default_buf[CONFIG_BUF_SIZE], *error, *buf; 495 int n, size; 496 497 if(get_config == NULL){ 498 mconsole_reply(req, "No get_config routine defined", 1, 0); 499 return; 500 } 501 502 error = NULL; 503 size = sizeof(default_buf)/sizeof(default_buf[0]); 504 buf = default_buf; 505 506 while(1){ 507 n = (*get_config)(name, buf, size, &error); 508 if(error != NULL){ 509 mconsole_reply(req, error, 1, 0); 510 goto out; 511 } 512 513 if(n <= size){ 514 mconsole_reply(req, buf, 0, 0); 515 goto out; 516 } 517 518 if(buf != default_buf) 519 kfree(buf); 520 521 size = n; 522 buf = kmalloc(size, GFP_KERNEL); 523 if(buf == NULL){ 524 mconsole_reply(req, "Failed to allocate buffer", 1, 0); 525 return; 526 } 527 } 528 out: 529 if(buf != default_buf) 530 kfree(buf); 531 } 532 533 void mconsole_config(struct mc_request *req) 534 { 535 struct mc_device *dev; 536 char *ptr = req->request.data, *name; 537 int err; 538 539 ptr += strlen("config"); 540 while(isspace(*ptr)) ptr++; 541 dev = mconsole_find_dev(ptr); 542 if(dev == NULL){ 543 mconsole_reply(req, "Bad configuration option", 1, 0); 544 return; 545 } 546 547 name = &ptr[strlen(dev->name)]; 548 ptr = name; 549 while((*ptr != '=') && (*ptr != '\0')) 550 ptr++; 551 552 if(*ptr == '='){ 553 err = (*dev->config)(name); 554 mconsole_reply(req, "", err, 0); 555 } 556 else mconsole_get_config(dev->get_config, req, name); 557 } 558 559 void mconsole_remove(struct mc_request *req) 560 { 561 struct mc_device *dev; 562 char *ptr = req->request.data, *err_msg = ""; 563 char error[256]; 564 int err, start, end, n; 565 566 ptr += strlen("remove"); 567 while(isspace(*ptr)) ptr++; 568 dev = mconsole_find_dev(ptr); 569 if(dev == NULL){ 570 mconsole_reply(req, "Bad remove option", 1, 0); 571 return; 572 } 573 574 ptr = &ptr[strlen(dev->name)]; 575 576 err = 1; 577 n = (*dev->id)(&ptr, &start, &end); 578 if(n < 0){ 579 err_msg = "Couldn't parse device number"; 580 goto out; 581 } 582 else if((n < start) || (n > end)){ 583 sprintf(error, "Invalid device number - must be between " 584 "%d and %d", start, end); 585 err_msg = error; 586 goto out; 587 } 588 589 err = (*dev->remove)(n); 590 switch(err){ 591 case -ENODEV: 592 err_msg = "Device doesn't exist"; 593 break; 594 case -EBUSY: 595 err_msg = "Device is currently open"; 596 break; 597 default: 598 break; 599 } 600 out: 601 mconsole_reply(req, err_msg, err, 0); 602 } 603 604 static DEFINE_SPINLOCK(console_lock); 605 static LIST_HEAD(clients); 606 static char console_buf[MCONSOLE_MAX_DATA]; 607 static int console_index = 0; 608 609 static void console_write(struct console *console, const char *string, 610 unsigned len) 611 { 612 struct list_head *ele; 613 int n; 614 615 if(list_empty(&clients)) 616 return; 617 618 while(1){ 619 n = min(len, ARRAY_SIZE(console_buf) - console_index); 620 strncpy(&console_buf[console_index], string, n); 621 console_index += n; 622 string += n; 623 len -= n; 624 if(len == 0) 625 return; 626 627 list_for_each(ele, &clients){ 628 struct mconsole_entry *entry; 629 630 entry = list_entry(ele, struct mconsole_entry, list); 631 mconsole_reply_len(&entry->request, console_buf, 632 console_index, 0, 1); 633 } 634 635 console_index = 0; 636 } 637 } 638 639 static struct console mc_console = { .name = "mc", 640 .write = console_write, 641 .flags = CON_ENABLED, 642 .index = -1 }; 643 644 static int mc_add_console(void) 645 { 646 register_console(&mc_console); 647 return 0; 648 } 649 650 late_initcall(mc_add_console); 651 652 static void with_console(struct mc_request *req, void (*proc)(void *), 653 void *arg) 654 { 655 struct mconsole_entry entry; 656 unsigned long flags; 657 658 INIT_LIST_HEAD(&entry.list); 659 entry.request = *req; 660 list_add(&entry.list, &clients); 661 spin_lock_irqsave(&console_lock, flags); 662 663 (*proc)(arg); 664 665 mconsole_reply_len(req, console_buf, console_index, 0, 0); 666 console_index = 0; 667 668 spin_unlock_irqrestore(&console_lock, flags); 669 list_del(&entry.list); 670 } 671 672 #ifdef CONFIG_MAGIC_SYSRQ 673 static void sysrq_proc(void *arg) 674 { 675 char *op = arg; 676 677 handle_sysrq(*op, ¤t->thread.regs, NULL); 678 } 679 680 void mconsole_sysrq(struct mc_request *req) 681 { 682 char *ptr = req->request.data; 683 684 ptr += strlen("sysrq"); 685 while(isspace(*ptr)) ptr++; 686 687 /* With 'b', the system will shut down without a chance to reply, 688 * so in this case, we reply first. 689 */ 690 if(*ptr == 'b') 691 mconsole_reply(req, "", 0, 0); 692 693 with_console(req, sysrq_proc, ptr); 694 } 695 #else 696 void mconsole_sysrq(struct mc_request *req) 697 { 698 mconsole_reply(req, "Sysrq not compiled in", 1, 0); 699 } 700 #endif 701 702 #ifdef CONFIG_MODE_SKAS 703 704 static void stack_proc(void *arg) 705 { 706 struct task_struct *from = current, *to = arg; 707 708 to->thread.saved_task = from; 709 switch_to(from, to, from); 710 } 711 712 /* Mconsole stack trace 713 * Added by Allan Graves, Jeff Dike 714 * Dumps a stacks registers to the linux console. 715 * Usage stack <pid>. 716 */ 717 static void do_stack_trace(struct mc_request *req) 718 { 719 char *ptr = req->request.data; 720 int pid_requested= -1; 721 struct task_struct *from = NULL; 722 struct task_struct *to = NULL; 723 724 /* Would be nice: 725 * 1) Send showregs output to mconsole. 726 * 2) Add a way to stack dump all pids. 727 */ 728 729 ptr += strlen("stack"); 730 while(isspace(*ptr)) ptr++; 731 732 /* Should really check for multiple pids or reject bad args here */ 733 /* What do the arguments in mconsole_reply mean? */ 734 if(sscanf(ptr, "%d", &pid_requested) == 0){ 735 mconsole_reply(req, "Please specify a pid", 1, 0); 736 return; 737 } 738 739 from = current; 740 741 to = find_task_by_pid(pid_requested); 742 if((to == NULL) || (pid_requested == 0)) { 743 mconsole_reply(req, "Couldn't find that pid", 1, 0); 744 return; 745 } 746 with_console(req, stack_proc, to); 747 } 748 #endif /* CONFIG_MODE_SKAS */ 749 750 void mconsole_stack(struct mc_request *req) 751 { 752 /* This command doesn't work in TT mode, so let's check and then 753 * get out of here 754 */ 755 CHOOSE_MODE(mconsole_reply(req, "Sorry, this doesn't work in TT mode", 756 1, 0), 757 do_stack_trace(req)); 758 } 759 760 /* Changed by mconsole_setup, which is __setup, and called before SMP is 761 * active. 762 */ 763 static char *notify_socket = NULL; 764 765 static int mconsole_init(void) 766 { 767 /* long to avoid size mismatch warnings from gcc */ 768 long sock; 769 int err; 770 char file[256]; 771 772 if(umid_file_name("mconsole", file, sizeof(file))) return(-1); 773 snprintf(mconsole_socket_name, sizeof(file), "%s", file); 774 775 sock = os_create_unix_socket(file, sizeof(file), 1); 776 if (sock < 0){ 777 printk("Failed to initialize management console\n"); 778 return(1); 779 } 780 781 register_reboot_notifier(&reboot_notifier); 782 783 err = um_request_irq(MCONSOLE_IRQ, sock, IRQ_READ, mconsole_interrupt, 784 SA_INTERRUPT | SA_SHIRQ | SA_SAMPLE_RANDOM, 785 "mconsole", (void *)sock); 786 if (err){ 787 printk("Failed to get IRQ for management console\n"); 788 return(1); 789 } 790 791 if(notify_socket != NULL){ 792 notify_socket = kstrdup(notify_socket, GFP_KERNEL); 793 if(notify_socket != NULL) 794 mconsole_notify(notify_socket, MCONSOLE_SOCKET, 795 mconsole_socket_name, 796 strlen(mconsole_socket_name) + 1); 797 else printk(KERN_ERR "mconsole_setup failed to strdup " 798 "string\n"); 799 } 800 801 printk("mconsole (version %d) initialized on %s\n", 802 MCONSOLE_VERSION, mconsole_socket_name); 803 return(0); 804 } 805 806 __initcall(mconsole_init); 807 808 static int write_proc_mconsole(struct file *file, const char __user *buffer, 809 unsigned long count, void *data) 810 { 811 char *buf; 812 813 buf = kmalloc(count + 1, GFP_KERNEL); 814 if(buf == NULL) 815 return(-ENOMEM); 816 817 if(copy_from_user(buf, buffer, count)){ 818 count = -EFAULT; 819 goto out; 820 } 821 822 buf[count] = '\0'; 823 824 mconsole_notify(notify_socket, MCONSOLE_USER_NOTIFY, buf, count); 825 out: 826 kfree(buf); 827 return(count); 828 } 829 830 static int create_proc_mconsole(void) 831 { 832 struct proc_dir_entry *ent; 833 834 if(notify_socket == NULL) return(0); 835 836 ent = create_proc_entry("mconsole", S_IFREG | 0200, NULL); 837 if(ent == NULL){ 838 printk(KERN_INFO "create_proc_mconsole : create_proc_entry failed\n"); 839 return(0); 840 } 841 842 ent->read_proc = NULL; 843 ent->write_proc = write_proc_mconsole; 844 return(0); 845 } 846 847 static DEFINE_SPINLOCK(notify_spinlock); 848 849 void lock_notify(void) 850 { 851 spin_lock(¬ify_spinlock); 852 } 853 854 void unlock_notify(void) 855 { 856 spin_unlock(¬ify_spinlock); 857 } 858 859 __initcall(create_proc_mconsole); 860 861 #define NOTIFY "=notify:" 862 863 static int mconsole_setup(char *str) 864 { 865 if(!strncmp(str, NOTIFY, strlen(NOTIFY))){ 866 str += strlen(NOTIFY); 867 notify_socket = str; 868 } 869 else printk(KERN_ERR "mconsole_setup : Unknown option - '%s'\n", str); 870 return(1); 871 } 872 873 __setup("mconsole", mconsole_setup); 874 875 __uml_help(mconsole_setup, 876 "mconsole=notify:<socket>\n" 877 " Requests that the mconsole driver send a message to the named Unix\n" 878 " socket containing the name of the mconsole socket. This also serves\n" 879 " to notify outside processes when UML has booted far enough to respond\n" 880 " to mconsole requests.\n\n" 881 ); 882 883 static int notify_panic(struct notifier_block *self, unsigned long unused1, 884 void *ptr) 885 { 886 char *message = ptr; 887 888 if(notify_socket == NULL) return(0); 889 890 mconsole_notify(notify_socket, MCONSOLE_PANIC, message, 891 strlen(message) + 1); 892 return(0); 893 } 894 895 static struct notifier_block panic_exit_notifier = { 896 .notifier_call = notify_panic, 897 .next = NULL, 898 .priority = 1 899 }; 900 901 static int add_notifier(void) 902 { 903 atomic_notifier_chain_register(&panic_notifier_list, 904 &panic_exit_notifier); 905 return(0); 906 } 907 908 __initcall(add_notifier); 909 910 char *mconsole_notify_socket(void) 911 { 912 return(notify_socket); 913 } 914 915 EXPORT_SYMBOL(mconsole_notify_socket); 916