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/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_irq_save(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_NOWAIT);
  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 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 UNPLUGGED_PER_PAGE \
 351         ((PAGE_SIZE - sizeof(struct list_head)) / sizeof(unsigned long))
 352
 353 struct unplugged_pages {
 354         struct list_head list;
 355         void *pages[UNPLUGGED_PER_PAGE];
 356 };
 357
 358 static unsigned long long unplugged_pages_count = 0;
 359 static struct list_head unplugged_pages = LIST_HEAD_INIT(unplugged_pages);
 360 static int unplug_index = UNPLUGGED_PER_PAGE;
 361
 362 static int mem_config(char *str)
 363 {
 364         unsigned long long diff;
 365         int err = -EINVAL, i, add;
 366         char *ret;
 367
 368         if(str[0] != '=')
 369                 goto out;
 370
 371         str++;
 372         if(str[0] == '-')
 373                 add = 0;
 374         else if(str[0] == '+'){
 375                 add = 1;
 376         }
 377         else goto out;
 378
 379         str++;
 380         diff = memparse(str, &ret);
 381         if(*ret != '\0')
 382                 goto out;
 383
 384         diff /= PAGE_SIZE;
 385
 386         for(i = 0; i < diff; i++){
 387                 struct unplugged_pages *unplugged;
 388                 void *addr;
 389
 390                 if(add){
 391                         if(list_empty(&unplugged_pages))
 392                                 break;
 393
 394                         unplugged = list_entry(unplugged_pages.next,
 395                                                struct unplugged_pages, list);
 396                         if(unplug_index > 0)
 397                                 addr = unplugged->pages[--unplug_index];
 398                         else {
 399                                 list_del(&unplugged->list);
 400                                 addr = unplugged;
 401                                 unplug_index = UNPLUGGED_PER_PAGE;
 402                         }
 403
 404                         free_page((unsigned long) addr);
 405                         unplugged_pages_count--;
 406                 }
 407                 else {
 408                         struct page *page;
 409
 410                         page = alloc_page(GFP_ATOMIC);
 411                         if(page == NULL)
 412                                 break;
 413
 414                         unplugged = page_address(page);
 415                         if(unplug_index == UNPLUGGED_PER_PAGE){
 416                                 list_add(&unplugged->list, &unplugged_pages);
 417                                 unplug_index = 0;
 418                         }
 419                         else {
 420                                 struct list_head *entry = unplugged_pages.next;
 421                                 addr = unplugged;
 422
 423                                 unplugged = list_entry(entry,
 424                                                        struct unplugged_pages,
 425                                                        list);
 426                                 unplugged->pages[unplug_index++] = addr;
 427                                 err = os_drop_memory(addr, PAGE_SIZE);
 428                                 if(err)
 429                                         printk("Failed to release memory - "
 430                                                "errno = %d\n", err);
 431                         }
 432
 433                         unplugged_pages_count++;
 434                 }
 435         }
 436
 437         err = 0;
 438 out:
 439         return err;
 440 }
 441
 442 static int mem_get_config(char *name, char *str, int size, char **error_out)
 443 {
 444         char buf[sizeof("18446744073709551615")];
 445         int len = 0;
 446
 447         sprintf(buf, "%ld", uml_physmem);
 448         CONFIG_CHUNK(str, size, len, buf, 1);
 449
 450         return len;
 451 }
 452
 453 static int mem_id(char **str, int *start_out, int *end_out)
 454 {
 455         *start_out = 0;
 456         *end_out = 0;
 457
 458         return 0;
 459 }
 460
 461 static int mem_remove(int n)
 462 {
 463         return -EBUSY;
 464 }
 465
 466 static struct mc_device mem_mc = {
 467         .name           = "mem",
 468         .config         = mem_config,
 469         .get_config     = mem_get_config,
 470         .id             = mem_id,
 471         .remove         = mem_remove,
 472 };
 473
 474 static int mem_mc_init(void)
 475 {
 476         if(can_drop_memory())
 477                 mconsole_register_dev(&mem_mc);
 478         else printk("Can't release memory to the host - memory hotplug won't "
 479                     "be supported\n");
 480         return 0;
 481 }
 482
 483 __initcall(mem_mc_init);
 484
 485 #define CONFIG_BUF_SIZE 64
 486
 487 static void mconsole_get_config(int (*get_config)(char *, char *, int,
 488                                                   char **),
 489                                 struct mc_request *req, char *name)
 490 {
 491         char default_buf[CONFIG_BUF_SIZE], *error, *buf;
 492         int n, size;
 493
 494         if(get_config == NULL){
 495                 mconsole_reply(req, "No get_config routine defined", 1, 0);
 496                 return;
 497         }
 498
 499         error = NULL;
 500         size = sizeof(default_buf)/sizeof(default_buf[0]);
 501         buf = default_buf;
 502
 503         while(1){
 504                 n = (*get_config)(name, buf, size, &error);
 505                 if(error != NULL){
 506                         mconsole_reply(req, error, 1, 0);
 507                         goto out;
 508                 }
 509
 510                 if(n <= size){
 511                         mconsole_reply(req, buf, 0, 0);
 512                         goto out;
 513                 }
 514
 515                 if(buf != default_buf)
 516                         kfree(buf);
 517
 518                 size = n;
 519                 buf = kmalloc(size, GFP_KERNEL);
 520                 if(buf == NULL){
 521                         mconsole_reply(req, "Failed to allocate buffer", 1, 0);
 522                         return;
 523                 }
 524         }
 525  out:
 526         if(buf != default_buf)
 527                 kfree(buf);
 528 }
 529
 530 void mconsole_config(struct mc_request *req)
 531 {
 532         struct mc_device *dev;
 533         char *ptr = req->request.data, *name;
 534         int err;
 535
 536         ptr += strlen("config");
 537         while(isspace(*ptr)) ptr++;
 538         dev = mconsole_find_dev(ptr);
 539         if(dev == NULL){
 540                 mconsole_reply(req, "Bad configuration option", 1, 0);
 541                 return;
 542         }
 543
 544         name = &ptr[strlen(dev->name)];
 545         ptr = name;
 546         while((*ptr != '=') && (*ptr != '\0'))
 547                 ptr++;
 548
 549         if(*ptr == '='){
 550                 err = (*dev->config)(name);
 551                 mconsole_reply(req, "", err, 0);
 552         }
 553         else mconsole_get_config(dev->get_config, req, name);
 554 }
 555
 556 void mconsole_remove(struct mc_request *req)
 557 {
 558         struct mc_device *dev;
 559         char *ptr = req->request.data, *err_msg = "";
 560         char error[256];
 561         int err, start, end, n;
 562
 563         ptr += strlen("remove");
 564         while(isspace(*ptr)) ptr++;
 565         dev = mconsole_find_dev(ptr);
 566         if(dev == NULL){
 567                 mconsole_reply(req, "Bad remove option", 1, 0);
 568                 return;
 569         }
 570
 571         ptr = &ptr[strlen(dev->name)];
 572
 573         err = 1;
 574         n = (*dev->id)(&ptr, &start, &end);
 575         if(n < 0){
 576                 err_msg = "Couldn't parse device number";
 577                 goto out;
 578         }
 579         else if((n < start) || (n > end)){
 580                 sprintf(error, "Invalid device number - must be between "
 581                         "%d and %d", start, end);
 582                 err_msg = error;
 583                 goto out;
 584         }
 585
 586         err = (*dev->remove)(n);
 587         switch(err){
 588         case -ENODEV:
 589                 err_msg = "Device doesn't exist";
 590                 break;
 591         case -EBUSY:
 592                 err_msg = "Device is currently open";
 593                 break;
 594         default:
 595                 break;
 596         }
 597 out:
 598         mconsole_reply(req, err_msg, err, 0);
 599 }
 600
 601 static DEFINE_SPINLOCK(console_lock);
 602 static LIST_HEAD(clients);
 603 static char console_buf[MCONSOLE_MAX_DATA];
 604 static int console_index = 0;
 605
 606 static void console_write(struct console *console, const char *string,
 607                           unsigned len)
 608 {
 609         struct list_head *ele;
 610         int n;
 611
 612         if(list_empty(&clients))
 613                 return;
 614
 615         while(1){
 616                 n = min((size_t) len, ARRAY_SIZE(console_buf) - console_index);
 617                 strncpy(&console_buf[console_index], string, n);
 618                 console_index += n;
 619                 string += n;
 620                 len -= n;
 621                 if(len == 0)
 622                         return;
 623
 624                 list_for_each(ele, &clients){
 625                         struct mconsole_entry *entry;
 626
 627                         entry = list_entry(ele, struct mconsole_entry, list);
 628                         mconsole_reply_len(&entry->request, console_buf,
 629                                            console_index, 0, 1);
 630                 }
 631
 632                 console_index = 0;
 633         }
 634 }
 635
 636 static struct console mc_console = { .name      = "mc",
 637                                      .write     = console_write,
 638                                      .flags     = CON_ENABLED,
 639                                      .index     = -1 };
 640
 641 static int mc_add_console(void)
 642 {
 643         register_console(&mc_console);
 644         return 0;
 645 }
 646
 647 late_initcall(mc_add_console);
 648
 649 static void with_console(struct mc_request *req, void (*proc)(void *),
 650                          void *arg)
 651 {
 652         struct mconsole_entry entry;
 653         unsigned long flags;
 654
 655         entry.request = *req;
 656         list_add(&entry.list, &clients);
 657         spin_lock_irqsave(&console_lock, flags);
 658
 659         (*proc)(arg);
 660
 661         mconsole_reply_len(req, console_buf, console_index, 0, 0);
 662         console_index = 0;
 663
 664         spin_unlock_irqrestore(&console_lock, flags);
 665         list_del(&entry.list);
 666 }
 667
 668 #ifdef CONFIG_MAGIC_SYSRQ
 669 static void sysrq_proc(void *arg)
 670 {
 671         char *op = arg;
 672
 673         handle_sysrq(*op, &current->thread.regs, NULL);
 674 }
 675
 676 void mconsole_sysrq(struct mc_request *req)
 677 {
 678         char *ptr = req->request.data;
 679
 680         ptr += strlen("sysrq");
 681         while(isspace(*ptr)) ptr++;
 682
 683         /* With 'b', the system will shut down without a chance to reply,
 684          * so in this case, we reply first.
 685          */
 686         if(*ptr == 'b')
 687                 mconsole_reply(req, "", 0, 0);
 688
 689         with_console(req, sysrq_proc, ptr);
 690 }
 691 #else
 692 void mconsole_sysrq(struct mc_request *req)
 693 {
 694         mconsole_reply(req, "Sysrq not compiled in", 1, 0);
 695 }
 696 #endif
 697
 698 #ifdef CONFIG_MODE_SKAS
 699
 700 static void stack_proc(void *arg)
 701 {
 702         struct task_struct *from = current, *to = arg;
 703
 704         to->thread.saved_task = from;
 705         switch_to(from, to, from);
 706 }
 707
 708 /* Mconsole stack trace
 709  *  Added by Allan Graves, Jeff Dike
 710  *  Dumps a stacks registers to the linux console.
 711  *  Usage stack <pid>.
 712  */
 713 static void do_stack_trace(struct mc_request *req)
 714 {
 715         char *ptr = req->request.data;
 716         int pid_requested= -1;
 717         struct task_struct *from = NULL;
 718         struct task_struct *to = NULL;
 719
 720         /* Would be nice:
 721          * 1) Send showregs output to mconsole.
 722          * 2) Add a way to stack dump all pids.
 723          */
 724
 725         ptr += strlen("stack");
 726         while(isspace(*ptr)) ptr++;
 727
 728         /* Should really check for multiple pids or reject bad args here */
 729         /* What do the arguments in mconsole_reply mean? */
 730         if(sscanf(ptr, "%d", &pid_requested) == 0){
 731                 mconsole_reply(req, "Please specify a pid", 1, 0);
 732                 return;
 733         }
 734
 735         from = current;
 736
 737         to = find_task_by_pid(pid_requested);
 738         if((to == NULL) || (pid_requested == 0)) {
 739                 mconsole_reply(req, "Couldn't find that pid", 1, 0);
 740                 return;
 741         }
 742         with_console(req, stack_proc, to);
 743 }
 744 #endif /* CONFIG_MODE_SKAS */
 745
 746 void mconsole_stack(struct mc_request *req)
 747 {
 748         /* This command doesn't work in TT mode, so let's check and then
 749          * get out of here
 750          */
 751         CHOOSE_MODE(mconsole_reply(req, "Sorry, this doesn't work in TT mode",
 752                                    1, 0),
 753                     do_stack_trace(req));
 754 }
 755
 756 /* Changed by mconsole_setup, which is __setup, and called before SMP is
 757  * active.
 758  */
 759 static char *notify_socket = NULL;
 760
 761 static int mconsole_init(void)
 762 {
 763         /* long to avoid size mismatch warnings from gcc */
 764         long sock;
 765         int err;
 766         char file[256];
 767
 768         if(umid_file_name("mconsole", file, sizeof(file))) return(-1);
 769         snprintf(mconsole_socket_name, sizeof(file), "%s", file);
 770
 771         sock = os_create_unix_socket(file, sizeof(file), 1);
 772         if (sock < 0){
 773                 printk("Failed to initialize management console\n");
 774                 return(1);
 775         }
 776
 777         register_reboot_notifier(&reboot_notifier);
 778
 779         err = um_request_irq(MCONSOLE_IRQ, sock, IRQ_READ, mconsole_interrupt,
 780                              IRQF_DISABLED | IRQF_SHARED | IRQF_SAMPLE_RANDOM,
 781                              "mconsole", (void *)sock);
 782         if (err){
 783                 printk("Failed to get IRQ for management console\n");
 784                 return(1);
 785         }
 786
 787         if(notify_socket != NULL){
 788                 notify_socket = kstrdup(notify_socket, GFP_KERNEL);
 789                 if(notify_socket != NULL)
 790                         mconsole_notify(notify_socket, MCONSOLE_SOCKET,
 791                                         mconsole_socket_name,
 792                                         strlen(mconsole_socket_name) + 1);
 793                 else printk(KERN_ERR "mconsole_setup failed to strdup "
 794                             "string\n");
 795         }
 796
 797         printk("mconsole (version %d) initialized on %s\n",
 798                MCONSOLE_VERSION, mconsole_socket_name);
 799         return(0);
 800 }
 801
 802 __initcall(mconsole_init);
 803
 804 static int write_proc_mconsole(struct file *file, const char __user *buffer,
 805                                unsigned long count, void *data)
 806 {
 807         char *buf;
 808
 809         buf = kmalloc(count + 1, GFP_KERNEL);
 810         if(buf == NULL)
 811                 return(-ENOMEM);
 812
 813         if(copy_from_user(buf, buffer, count)){
 814                 count = -EFAULT;
 815                 goto out;
 816         }
 817
 818         buf[count] = '\0';
 819
 820         mconsole_notify(notify_socket, MCONSOLE_USER_NOTIFY, buf, count);
 821  out:
 822         kfree(buf);
 823         return(count);
 824 }
 825
 826 static int create_proc_mconsole(void)
 827 {
 828         struct proc_dir_entry *ent;
 829
 830         if(notify_socket == NULL) return(0);
 831
 832         ent = create_proc_entry("mconsole", S_IFREG | 0200, NULL);
 833         if(ent == NULL){
 834                 printk(KERN_INFO "create_proc_mconsole : create_proc_entry failed\n");
 835                 return(0);
 836         }
 837
 838         ent->read_proc = NULL;
 839         ent->write_proc = write_proc_mconsole;
 840         return(0);
 841 }
 842
 843 static DEFINE_SPINLOCK(notify_spinlock);
 844
 845 void lock_notify(void)
 846 {
 847         spin_lock(&notify_spinlock);
 848 }
 849
 850 void unlock_notify(void)
 851 {
 852         spin_unlock(&notify_spinlock);
 853 }
 854
 855 __initcall(create_proc_mconsole);
 856
 857 #define NOTIFY "=notify:"
 858
 859 static int mconsole_setup(char *str)
 860 {
 861         if(!strncmp(str, NOTIFY, strlen(NOTIFY))){
 862                 str += strlen(NOTIFY);
 863                 notify_socket = str;
 864         }
 865         else printk(KERN_ERR "mconsole_setup : Unknown option - '%s'\n", str);
 866         return(1);
 867 }
 868
 869 __setup("mconsole", mconsole_setup);
 870
 871 __uml_help(mconsole_setup,
 872 "mconsole=notify:<socket>\n"
 873 "    Requests that the mconsole driver send a message to the named Unix\n"
 874 "    socket containing the name of the mconsole socket.  This also serves\n"
 875 "    to notify outside processes when UML has booted far enough to respond\n"
 876 "    to mconsole requests.\n\n"
 877 );
 878
 879 static int notify_panic(struct notifier_block *self, unsigned long unused1,
 880                         void *ptr)
 881 {
 882         char *message = ptr;
 883
 884         if(notify_socket == NULL) return(0);
 885
 886         mconsole_notify(notify_socket, MCONSOLE_PANIC, message,
 887                         strlen(message) + 1);
 888         return(0);
 889 }
 890
 891 static struct notifier_block panic_exit_notifier = {
 892         .notifier_call          = notify_panic,
 893         .next                   = NULL,
 894         .priority               = 1
 895 };
 896
 897 static int add_notifier(void)
 898 {
 899         atomic_notifier_chain_register(&panic_notifier_list,
 900                         &panic_exit_notifier);
 901         return(0);
 902 }
 903
 904 __initcall(add_notifier);
 905
 906 char *mconsole_notify_socket(void)
 907 {
 908         return(notify_socket);
 909 }
 910
 911 EXPORT_SYMBOL(mconsole_notify_socket);