arch/um/drivers/mconsole_kern.c

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