1 /* 2 * Copyright (C) 2001 Lennert Buytenhek (buytenh@gnu.org) 3 * Copyright (C) 2001 - 2008 Jeff Dike (jdike@{addtoit,linux.intel}.com) 4 * Licensed under the GPL 5 */ 6 7 #include <linux/console.h> 8 #include <linux/ctype.h> 9 #include <linux/string.h> 10 #include <linux/interrupt.h> 11 #include <linux/list.h> 12 #include <linux/mm.h> 13 #include <linux/module.h> 14 #include <linux/notifier.h> 15 #include <linux/reboot.h> 16 #include <linux/proc_fs.h> 17 #include <linux/slab.h> 18 #include <linux/syscalls.h> 19 #include <linux/utsname.h> 20 #include <linux/socket.h> 21 #include <linux/un.h> 22 #include <linux/workqueue.h> 23 #include <linux/mutex.h> 24 #include <linux/fs.h> 25 #include <linux/mount.h> 26 #include <linux/file.h> 27 #include <asm/uaccess.h> 28 #include <asm/switch_to.h> 29 30 #include <init.h> 31 #include <irq_kern.h> 32 #include <irq_user.h> 33 #include <kern_util.h> 34 #include "mconsole.h" 35 #include "mconsole_kern.h" 36 #include <os.h> 37 38 static int do_unlink_socket(struct notifier_block *notifier, 39 unsigned long what, void *data) 40 { 41 return mconsole_unlink_socket(); 42 } 43 44 45 static struct notifier_block reboot_notifier = { 46 .notifier_call = do_unlink_socket, 47 .priority = 0, 48 }; 49 50 /* Safe without explicit locking for now. Tasklets provide their own 51 * locking, and the interrupt handler is safe because it can't interrupt 52 * itself and it can only happen on CPU 0. 53 */ 54 55 static LIST_HEAD(mc_requests); 56 57 static void mc_work_proc(struct work_struct *unused) 58 { 59 struct mconsole_entry *req; 60 unsigned long flags; 61 62 while (!list_empty(&mc_requests)) { 63 local_irq_save(flags); 64 req = list_entry(mc_requests.next, struct mconsole_entry, list); 65 list_del(&req->list); 66 local_irq_restore(flags); 67 req->request.cmd->handler(&req->request); 68 kfree(req); 69 } 70 } 71 72 static DECLARE_WORK(mconsole_work, mc_work_proc); 73 74 static irqreturn_t mconsole_interrupt(int irq, void *dev_id) 75 { 76 /* long to avoid size mismatch warnings from gcc */ 77 long fd; 78 struct mconsole_entry *new; 79 static struct mc_request req; /* that's OK */ 80 81 fd = (long) dev_id; 82 while (mconsole_get_request(fd, &req)) { 83 if (req.cmd->context == MCONSOLE_INTR) 84 (*req.cmd->handler)(&req); 85 else { 86 new = kmalloc(sizeof(*new), GFP_NOWAIT); 87 if (new == NULL) 88 mconsole_reply(&req, "Out of memory", 1, 0); 89 else { 90 new->request = req; 91 new->request.regs = get_irq_regs()->regs; 92 list_add(&new->list, &mc_requests); 93 } 94 } 95 } 96 if (!list_empty(&mc_requests)) 97 schedule_work(&mconsole_work); 98 reactivate_fd(fd, MCONSOLE_IRQ); 99 return IRQ_HANDLED; 100 } 101 102 void mconsole_version(struct mc_request *req) 103 { 104 char version[256]; 105 106 sprintf(version, "%s %s %s %s %s", utsname()->sysname, 107 utsname()->nodename, utsname()->release, utsname()->version, 108 utsname()->machine); 109 mconsole_reply(req, version, 0, 0); 110 } 111 112 void mconsole_log(struct mc_request *req) 113 { 114 int len; 115 char *ptr = req->request.data; 116 117 ptr += strlen("log "); 118 119 len = req->len - (ptr - req->request.data); 120 printk(KERN_WARNING "%.*s", len, ptr); 121 mconsole_reply(req, "", 0, 0); 122 } 123 124 void mconsole_proc(struct mc_request *req) 125 { 126 struct vfsmount *mnt = task_active_pid_ns(current)->proc_mnt; 127 char *buf; 128 int len; 129 struct file *file; 130 int first_chunk = 1; 131 char *ptr = req->request.data; 132 133 ptr += strlen("proc"); 134 ptr = skip_spaces(ptr); 135 136 file = file_open_root(mnt->mnt_root, mnt, ptr, O_RDONLY); 137 if (IS_ERR(file)) { 138 mconsole_reply(req, "Failed to open file", 1, 0); 139 printk(KERN_ERR "open /proc/%s: %ld\n", ptr, PTR_ERR(file)); 140 goto out; 141 } 142 143 buf = kmalloc(PAGE_SIZE, GFP_KERNEL); 144 if (buf == NULL) { 145 mconsole_reply(req, "Failed to allocate buffer", 1, 0); 146 goto out_fput; 147 } 148 149 do { 150 loff_t pos = file->f_pos; 151 mm_segment_t old_fs = get_fs(); 152 set_fs(KERNEL_DS); 153 len = vfs_read(file, buf, PAGE_SIZE - 1, &pos); 154 set_fs(old_fs); 155 file->f_pos = pos; 156 if (len < 0) { 157 mconsole_reply(req, "Read of file failed", 1, 0); 158 goto out_free; 159 } 160 /* Begin the file content on his own line. */ 161 if (first_chunk) { 162 mconsole_reply(req, "\n", 0, 1); 163 first_chunk = 0; 164 } 165 buf[len] = '\0'; 166 mconsole_reply(req, buf, 0, (len > 0)); 167 } while (len > 0); 168 out_free: 169 kfree(buf); 170 out_fput: 171 fput(file); 172 out: ; 173 } 174 175 #define UML_MCONSOLE_HELPTEXT \ 176 "Commands: \n\ 177 version - Get kernel version \n\ 178 help - Print this message \n\ 179 halt - Halt UML \n\ 180 reboot - Reboot UML \n\ 181 config <dev>=<config> - Add a new device to UML; \n\ 182 same syntax as command line \n\ 183 config <dev> - Query the configuration of a device \n\ 184 remove <dev> - Remove a device from UML \n\ 185 sysrq <letter> - Performs the SysRq action controlled by the letter \n\ 186 cad - invoke the Ctrl-Alt-Del handler \n\ 187 stop - pause the UML; it will do nothing until it receives a 'go' \n\ 188 go - continue the UML after a 'stop' \n\ 189 log <string> - make UML enter <string> into the kernel log\n\ 190 proc <file> - returns the contents of the UML's /proc/<file>\n\ 191 stack <pid> - returns the stack of the specified pid\n\ 192 " 193 194 void mconsole_help(struct mc_request *req) 195 { 196 mconsole_reply(req, UML_MCONSOLE_HELPTEXT, 0, 0); 197 } 198 199 void mconsole_halt(struct mc_request *req) 200 { 201 mconsole_reply(req, "", 0, 0); 202 machine_halt(); 203 } 204 205 void mconsole_reboot(struct mc_request *req) 206 { 207 mconsole_reply(req, "", 0, 0); 208 machine_restart(NULL); 209 } 210 211 void mconsole_cad(struct mc_request *req) 212 { 213 mconsole_reply(req, "", 0, 0); 214 ctrl_alt_del(); 215 } 216 217 void mconsole_go(struct mc_request *req) 218 { 219 mconsole_reply(req, "Not stopped", 1, 0); 220 } 221 222 void mconsole_stop(struct mc_request *req) 223 { 224 deactivate_fd(req->originating_fd, MCONSOLE_IRQ); 225 os_set_fd_block(req->originating_fd, 1); 226 mconsole_reply(req, "stopped", 0, 0); 227 for (;;) { 228 if (!mconsole_get_request(req->originating_fd, req)) 229 continue; 230 if (req->cmd->handler == mconsole_go) 231 break; 232 if (req->cmd->handler == mconsole_stop) { 233 mconsole_reply(req, "Already stopped", 1, 0); 234 continue; 235 } 236 if (req->cmd->handler == mconsole_sysrq) { 237 struct pt_regs *old_regs; 238 old_regs = set_irq_regs((struct pt_regs *)&req->regs); 239 mconsole_sysrq(req); 240 set_irq_regs(old_regs); 241 continue; 242 } 243 (*req->cmd->handler)(req); 244 } 245 os_set_fd_block(req->originating_fd, 0); 246 reactivate_fd(req->originating_fd, MCONSOLE_IRQ); 247 mconsole_reply(req, "", 0, 0); 248 } 249 250 static DEFINE_SPINLOCK(mc_devices_lock); 251 static LIST_HEAD(mconsole_devices); 252 253 void mconsole_register_dev(struct mc_device *new) 254 { 255 spin_lock(&mc_devices_lock); 256 BUG_ON(!list_empty(&new->list)); 257 list_add(&new->list, &mconsole_devices); 258 spin_unlock(&mc_devices_lock); 259 } 260 261 static struct mc_device *mconsole_find_dev(char *name) 262 { 263 struct list_head *ele; 264 struct mc_device *dev; 265 266 list_for_each(ele, &mconsole_devices) { 267 dev = list_entry(ele, struct mc_device, list); 268 if (!strncmp(name, dev->name, strlen(dev->name))) 269 return dev; 270 } 271 return NULL; 272 } 273 274 #define UNPLUGGED_PER_PAGE \ 275 ((PAGE_SIZE - sizeof(struct list_head)) / sizeof(unsigned long)) 276 277 struct unplugged_pages { 278 struct list_head list; 279 void *pages[UNPLUGGED_PER_PAGE]; 280 }; 281 282 static DEFINE_MUTEX(plug_mem_mutex); 283 static unsigned long long unplugged_pages_count = 0; 284 static LIST_HEAD(unplugged_pages); 285 static int unplug_index = UNPLUGGED_PER_PAGE; 286 287 static int mem_config(char *str, char **error_out) 288 { 289 unsigned long long diff; 290 int err = -EINVAL, i, add; 291 char *ret; 292 293 if (str[0] != '=') { 294 *error_out = "Expected '=' after 'mem'"; 295 goto out; 296 } 297 298 str++; 299 if (str[0] == '-') 300 add = 0; 301 else if (str[0] == '+') { 302 add = 1; 303 } 304 else { 305 *error_out = "Expected increment to start with '-' or '+'"; 306 goto out; 307 } 308 309 str++; 310 diff = memparse(str, &ret); 311 if (*ret != '\0') { 312 *error_out = "Failed to parse memory increment"; 313 goto out; 314 } 315 316 diff /= PAGE_SIZE; 317 318 mutex_lock(&plug_mem_mutex); 319 for (i = 0; i < diff; i++) { 320 struct unplugged_pages *unplugged; 321 void *addr; 322 323 if (add) { 324 if (list_empty(&unplugged_pages)) 325 break; 326 327 unplugged = list_entry(unplugged_pages.next, 328 struct unplugged_pages, list); 329 if (unplug_index > 0) 330 addr = unplugged->pages[--unplug_index]; 331 else { 332 list_del(&unplugged->list); 333 addr = unplugged; 334 unplug_index = UNPLUGGED_PER_PAGE; 335 } 336 337 free_page((unsigned long) addr); 338 unplugged_pages_count--; 339 } 340 else { 341 struct page *page; 342 343 page = alloc_page(GFP_ATOMIC); 344 if (page == NULL) 345 break; 346 347 unplugged = page_address(page); 348 if (unplug_index == UNPLUGGED_PER_PAGE) { 349 list_add(&unplugged->list, &unplugged_pages); 350 unplug_index = 0; 351 } 352 else { 353 struct list_head *entry = unplugged_pages.next; 354 addr = unplugged; 355 356 unplugged = list_entry(entry, 357 struct unplugged_pages, 358 list); 359 err = os_drop_memory(addr, PAGE_SIZE); 360 if (err) { 361 printk(KERN_ERR "Failed to release " 362 "memory - errno = %d\n", err); 363 *error_out = "Failed to release memory"; 364 goto out_unlock; 365 } 366 unplugged->pages[unplug_index++] = addr; 367 } 368 369 unplugged_pages_count++; 370 } 371 } 372 373 err = 0; 374 out_unlock: 375 mutex_unlock(&plug_mem_mutex); 376 out: 377 return err; 378 } 379 380 static int mem_get_config(char *name, char *str, int size, char **error_out) 381 { 382 char buf[sizeof("18446744073709551615")]; 383 int len = 0; 384 385 sprintf(buf, "%ld", uml_physmem); 386 CONFIG_CHUNK(str, size, len, buf, 1); 387 388 return len; 389 } 390 391 static int mem_id(char **str, int *start_out, int *end_out) 392 { 393 *start_out = 0; 394 *end_out = 0; 395 396 return 0; 397 } 398 399 static int mem_remove(int n, char **error_out) 400 { 401 *error_out = "Memory doesn't support the remove operation"; 402 return -EBUSY; 403 } 404 405 static struct mc_device mem_mc = { 406 .list = LIST_HEAD_INIT(mem_mc.list), 407 .name = "mem", 408 .config = mem_config, 409 .get_config = mem_get_config, 410 .id = mem_id, 411 .remove = mem_remove, 412 }; 413 414 static int __init mem_mc_init(void) 415 { 416 if (can_drop_memory()) 417 mconsole_register_dev(&mem_mc); 418 else printk(KERN_ERR "Can't release memory to the host - memory " 419 "hotplug won't be supported\n"); 420 return 0; 421 } 422 423 __initcall(mem_mc_init); 424 425 #define CONFIG_BUF_SIZE 64 426 427 static void mconsole_get_config(int (*get_config)(char *, char *, int, 428 char **), 429 struct mc_request *req, char *name) 430 { 431 char default_buf[CONFIG_BUF_SIZE], *error, *buf; 432 int n, size; 433 434 if (get_config == NULL) { 435 mconsole_reply(req, "No get_config routine defined", 1, 0); 436 return; 437 } 438 439 error = NULL; 440 size = ARRAY_SIZE(default_buf); 441 buf = default_buf; 442 443 while (1) { 444 n = (*get_config)(name, buf, size, &error); 445 if (error != NULL) { 446 mconsole_reply(req, error, 1, 0); 447 goto out; 448 } 449 450 if (n <= size) { 451 mconsole_reply(req, buf, 0, 0); 452 goto out; 453 } 454 455 if (buf != default_buf) 456 kfree(buf); 457 458 size = n; 459 buf = kmalloc(size, GFP_KERNEL); 460 if (buf == NULL) { 461 mconsole_reply(req, "Failed to allocate buffer", 1, 0); 462 return; 463 } 464 } 465 out: 466 if (buf != default_buf) 467 kfree(buf); 468 } 469 470 void mconsole_config(struct mc_request *req) 471 { 472 struct mc_device *dev; 473 char *ptr = req->request.data, *name, *error_string = ""; 474 int err; 475 476 ptr += strlen("config"); 477 ptr = skip_spaces(ptr); 478 dev = mconsole_find_dev(ptr); 479 if (dev == NULL) { 480 mconsole_reply(req, "Bad configuration option", 1, 0); 481 return; 482 } 483 484 name = &ptr[strlen(dev->name)]; 485 ptr = name; 486 while ((*ptr != '=') && (*ptr != '\0')) 487 ptr++; 488 489 if (*ptr == '=') { 490 err = (*dev->config)(name, &error_string); 491 mconsole_reply(req, error_string, err, 0); 492 } 493 else mconsole_get_config(dev->get_config, req, name); 494 } 495 496 void mconsole_remove(struct mc_request *req) 497 { 498 struct mc_device *dev; 499 char *ptr = req->request.data, *err_msg = ""; 500 char error[256]; 501 int err, start, end, n; 502 503 ptr += strlen("remove"); 504 ptr = skip_spaces(ptr); 505 dev = mconsole_find_dev(ptr); 506 if (dev == NULL) { 507 mconsole_reply(req, "Bad remove option", 1, 0); 508 return; 509 } 510 511 ptr = &ptr[strlen(dev->name)]; 512 513 err = 1; 514 n = (*dev->id)(&ptr, &start, &end); 515 if (n < 0) { 516 err_msg = "Couldn't parse device number"; 517 goto out; 518 } 519 else if ((n < start) || (n > end)) { 520 sprintf(error, "Invalid device number - must be between " 521 "%d and %d", start, end); 522 err_msg = error; 523 goto out; 524 } 525 526 err_msg = NULL; 527 err = (*dev->remove)(n, &err_msg); 528 switch(err) { 529 case 0: 530 err_msg = ""; 531 break; 532 case -ENODEV: 533 if (err_msg == NULL) 534 err_msg = "Device doesn't exist"; 535 break; 536 case -EBUSY: 537 if (err_msg == NULL) 538 err_msg = "Device is currently open"; 539 break; 540 default: 541 break; 542 } 543 out: 544 mconsole_reply(req, err_msg, err, 0); 545 } 546 547 struct mconsole_output { 548 struct list_head list; 549 struct mc_request *req; 550 }; 551 552 static DEFINE_SPINLOCK(client_lock); 553 static LIST_HEAD(clients); 554 static char console_buf[MCONSOLE_MAX_DATA]; 555 556 static void console_write(struct console *console, const char *string, 557 unsigned int len) 558 { 559 struct list_head *ele; 560 int n; 561 562 if (list_empty(&clients)) 563 return; 564 565 while (len > 0) { 566 n = min((size_t) len, ARRAY_SIZE(console_buf)); 567 strncpy(console_buf, string, n); 568 string += n; 569 len -= n; 570 571 list_for_each(ele, &clients) { 572 struct mconsole_output *entry; 573 574 entry = list_entry(ele, struct mconsole_output, list); 575 mconsole_reply_len(entry->req, console_buf, n, 0, 1); 576 } 577 } 578 } 579 580 static struct console mc_console = { .name = "mc", 581 .write = console_write, 582 .flags = CON_ENABLED, 583 .index = -1 }; 584 585 static int mc_add_console(void) 586 { 587 register_console(&mc_console); 588 return 0; 589 } 590 591 late_initcall(mc_add_console); 592 593 static void with_console(struct mc_request *req, void (*proc)(void *), 594 void *arg) 595 { 596 struct mconsole_output entry; 597 unsigned long flags; 598 599 entry.req = req; 600 spin_lock_irqsave(&client_lock, flags); 601 list_add(&entry.list, &clients); 602 spin_unlock_irqrestore(&client_lock, flags); 603 604 (*proc)(arg); 605 606 mconsole_reply_len(req, "", 0, 0, 0); 607 608 spin_lock_irqsave(&client_lock, flags); 609 list_del(&entry.list); 610 spin_unlock_irqrestore(&client_lock, flags); 611 } 612 613 #ifdef CONFIG_MAGIC_SYSRQ 614 615 #include <linux/sysrq.h> 616 617 static void sysrq_proc(void *arg) 618 { 619 char *op = arg; 620 handle_sysrq(*op); 621 } 622 623 void mconsole_sysrq(struct mc_request *req) 624 { 625 char *ptr = req->request.data; 626 627 ptr += strlen("sysrq"); 628 ptr = skip_spaces(ptr); 629 630 /* 631 * With 'b', the system will shut down without a chance to reply, 632 * so in this case, we reply first. 633 */ 634 if (*ptr == 'b') 635 mconsole_reply(req, "", 0, 0); 636 637 with_console(req, sysrq_proc, ptr); 638 } 639 #else 640 void mconsole_sysrq(struct mc_request *req) 641 { 642 mconsole_reply(req, "Sysrq not compiled in", 1, 0); 643 } 644 #endif 645 646 static void stack_proc(void *arg) 647 { 648 struct task_struct *task = arg; 649 650 show_stack(task, NULL); 651 } 652 653 /* 654 * Mconsole stack trace 655 * Added by Allan Graves, Jeff Dike 656 * Dumps a stacks registers to the linux console. 657 * Usage stack <pid>. 658 */ 659 void mconsole_stack(struct mc_request *req) 660 { 661 char *ptr = req->request.data; 662 int pid_requested= -1; 663 struct task_struct *to = NULL; 664 665 /* 666 * Would be nice: 667 * 1) Send showregs output to mconsole. 668 * 2) Add a way to stack dump all pids. 669 */ 670 671 ptr += strlen("stack"); 672 ptr = skip_spaces(ptr); 673 674 /* 675 * Should really check for multiple pids or reject bad args here 676 */ 677 /* What do the arguments in mconsole_reply mean? */ 678 if (sscanf(ptr, "%d", &pid_requested) == 0) { 679 mconsole_reply(req, "Please specify a pid", 1, 0); 680 return; 681 } 682 683 to = find_task_by_pid_ns(pid_requested, &init_pid_ns); 684 if ((to == NULL) || (pid_requested == 0)) { 685 mconsole_reply(req, "Couldn't find that pid", 1, 0); 686 return; 687 } 688 with_console(req, stack_proc, to); 689 } 690 691 /* 692 * Changed by mconsole_setup, which is __setup, and called before SMP is 693 * active. 694 */ 695 static char *notify_socket = NULL; 696 697 static int __init mconsole_init(void) 698 { 699 /* long to avoid size mismatch warnings from gcc */ 700 long sock; 701 int err; 702 char file[UNIX_PATH_MAX]; 703 704 if (umid_file_name("mconsole", file, sizeof(file))) 705 return -1; 706 snprintf(mconsole_socket_name, sizeof(file), "%s", file); 707 708 sock = os_create_unix_socket(file, sizeof(file), 1); 709 if (sock < 0) { 710 printk(KERN_ERR "Failed to initialize management console\n"); 711 return 1; 712 } 713 if (os_set_fd_block(sock, 0)) 714 goto out; 715 716 register_reboot_notifier(&reboot_notifier); 717 718 err = um_request_irq(MCONSOLE_IRQ, sock, IRQ_READ, mconsole_interrupt, 719 IRQF_SHARED, "mconsole", (void *)sock); 720 if (err) { 721 printk(KERN_ERR "Failed to get IRQ for management console\n"); 722 goto out; 723 } 724 725 if (notify_socket != NULL) { 726 notify_socket = kstrdup(notify_socket, GFP_KERNEL); 727 if (notify_socket != NULL) 728 mconsole_notify(notify_socket, MCONSOLE_SOCKET, 729 mconsole_socket_name, 730 strlen(mconsole_socket_name) + 1); 731 else printk(KERN_ERR "mconsole_setup failed to strdup " 732 "string\n"); 733 } 734 735 printk(KERN_INFO "mconsole (version %d) initialized on %s\n", 736 MCONSOLE_VERSION, mconsole_socket_name); 737 return 0; 738 739 out: 740 os_close_file(sock); 741 return 1; 742 } 743 744 __initcall(mconsole_init); 745 746 static ssize_t mconsole_proc_write(struct file *file, 747 const char __user *buffer, size_t count, loff_t *pos) 748 { 749 char *buf; 750 751 buf = kmalloc(count + 1, GFP_KERNEL); 752 if (buf == NULL) 753 return -ENOMEM; 754 755 if (copy_from_user(buf, buffer, count)) { 756 count = -EFAULT; 757 goto out; 758 } 759 760 buf[count] = '\0'; 761 762 mconsole_notify(notify_socket, MCONSOLE_USER_NOTIFY, buf, count); 763 out: 764 kfree(buf); 765 return count; 766 } 767 768 static const struct file_operations mconsole_proc_fops = { 769 .owner = THIS_MODULE, 770 .write = mconsole_proc_write, 771 .llseek = noop_llseek, 772 }; 773 774 static int create_proc_mconsole(void) 775 { 776 struct proc_dir_entry *ent; 777 778 if (notify_socket == NULL) 779 return 0; 780 781 ent = proc_create("mconsole", 0200, NULL, &mconsole_proc_fops); 782 if (ent == NULL) { 783 printk(KERN_INFO "create_proc_mconsole : proc_create failed\n"); 784 return 0; 785 } 786 return 0; 787 } 788 789 static DEFINE_SPINLOCK(notify_spinlock); 790 791 void lock_notify(void) 792 { 793 spin_lock(¬ify_spinlock); 794 } 795 796 void unlock_notify(void) 797 { 798 spin_unlock(¬ify_spinlock); 799 } 800 801 __initcall(create_proc_mconsole); 802 803 #define NOTIFY "notify:" 804 805 static int mconsole_setup(char *str) 806 { 807 if (!strncmp(str, NOTIFY, strlen(NOTIFY))) { 808 str += strlen(NOTIFY); 809 notify_socket = str; 810 } 811 else printk(KERN_ERR "mconsole_setup : Unknown option - '%s'\n", str); 812 return 1; 813 } 814 815 __setup("mconsole=", mconsole_setup); 816 817 __uml_help(mconsole_setup, 818 "mconsole=notify:<socket>\n" 819 " Requests that the mconsole driver send a message to the named Unix\n" 820 " socket containing the name of the mconsole socket. This also serves\n" 821 " to notify outside processes when UML has booted far enough to respond\n" 822 " to mconsole requests.\n\n" 823 ); 824 825 static int notify_panic(struct notifier_block *self, unsigned long unused1, 826 void *ptr) 827 { 828 char *message = ptr; 829 830 if (notify_socket == NULL) 831 return 0; 832 833 mconsole_notify(notify_socket, MCONSOLE_PANIC, message, 834 strlen(message) + 1); 835 return 0; 836 } 837 838 static struct notifier_block panic_exit_notifier = { 839 .notifier_call = notify_panic, 840 .next = NULL, 841 .priority = 1 842 }; 843 844 static int add_notifier(void) 845 { 846 atomic_notifier_chain_register(&panic_notifier_list, 847 &panic_exit_notifier); 848 return 0; 849 } 850 851 __initcall(add_notifier); 852 853 char *mconsole_notify_socket(void) 854 { 855 return notify_socket; 856 } 857 858 EXPORT_SYMBOL(mconsole_notify_socket); 859