ia64/kvm: compilation fix. export account_system_vtime.
[pv_ops_mirror.git] / arch / um / drivers / mconsole_kern.c
blob19d579d74d27f18ae67bb1b5c9adcf93f963a288
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 */
7 #include <linux/console.h>
8 #include <linux/ctype.h>
9 #include <linux/interrupt.h>
10 #include <linux/list.h>
11 #include <linux/mm.h>
12 #include <linux/module.h>
13 #include <linux/notifier.h>
14 #include <linux/reboot.h>
15 #include <linux/proc_fs.h>
16 #include <linux/slab.h>
17 #include <linux/syscalls.h>
18 #include <linux/utsname.h>
19 #include <linux/workqueue.h>
20 #include <linux/mutex.h>
21 #include <asm/uaccess.h>
23 #include "init.h"
24 #include "irq_kern.h"
25 #include "irq_user.h"
26 #include "kern_util.h"
27 #include "mconsole.h"
28 #include "mconsole_kern.h"
29 #include "os.h"
31 static int do_unlink_socket(struct notifier_block *notifier,
32 unsigned long what, void *data)
34 return mconsole_unlink_socket();
38 static struct notifier_block reboot_notifier = {
39 .notifier_call = do_unlink_socket,
40 .priority = 0,
43 /* Safe without explicit locking for now. Tasklets provide their own
44 * locking, and the interrupt handler is safe because it can't interrupt
45 * itself and it can only happen on CPU 0.
48 static LIST_HEAD(mc_requests);
50 static void mc_work_proc(struct work_struct *unused)
52 struct mconsole_entry *req;
53 unsigned long flags;
55 while (!list_empty(&mc_requests)) {
56 local_irq_save(flags);
57 req = list_entry(mc_requests.next, struct mconsole_entry, list);
58 list_del(&req->list);
59 local_irq_restore(flags);
60 req->request.cmd->handler(&req->request);
61 kfree(req);
65 static DECLARE_WORK(mconsole_work, mc_work_proc);
67 static irqreturn_t mconsole_interrupt(int irq, void *dev_id)
69 /* long to avoid size mismatch warnings from gcc */
70 long fd;
71 struct mconsole_entry *new;
72 static struct mc_request req; /* that's OK */
74 fd = (long) dev_id;
75 while (mconsole_get_request(fd, &req)) {
76 if (req.cmd->context == MCONSOLE_INTR)
77 (*req.cmd->handler)(&req);
78 else {
79 new = kmalloc(sizeof(*new), GFP_NOWAIT);
80 if (new == NULL)
81 mconsole_reply(&req, "Out of memory", 1, 0);
82 else {
83 new->request = req;
84 new->request.regs = get_irq_regs()->regs;
85 list_add(&new->list, &mc_requests);
89 if (!list_empty(&mc_requests))
90 schedule_work(&mconsole_work);
91 reactivate_fd(fd, MCONSOLE_IRQ);
92 return IRQ_HANDLED;
95 void mconsole_version(struct mc_request *req)
97 char version[256];
99 sprintf(version, "%s %s %s %s %s", utsname()->sysname,
100 utsname()->nodename, utsname()->release, utsname()->version,
101 utsname()->machine);
102 mconsole_reply(req, version, 0, 0);
105 void mconsole_log(struct mc_request *req)
107 int len;
108 char *ptr = req->request.data;
110 ptr += strlen("log ");
112 len = req->len - (ptr - req->request.data);
113 printk(KERN_WARNING "%.*s", len, ptr);
114 mconsole_reply(req, "", 0, 0);
117 /* This is a more convoluted version of mconsole_proc, which has some stability
118 * problems; however, we need it fixed, because it is expected that UML users
119 * mount HPPFS instead of procfs on /proc. And we want mconsole_proc to still
120 * show the real procfs content, not the ones from hppfs.*/
121 #if 0
122 void mconsole_proc(struct mc_request *req)
124 struct nameidata nd;
125 struct file_system_type *proc;
126 struct super_block *super;
127 struct file *file;
128 int n, err;
129 char *ptr = req->request.data, *buf;
131 ptr += strlen("proc");
132 while (isspace(*ptr)) ptr++;
134 proc = get_fs_type("proc");
135 if (proc == NULL) {
136 mconsole_reply(req, "procfs not registered", 1, 0);
137 goto out;
140 super = (*proc->get_sb)(proc, 0, NULL, NULL);
141 put_filesystem(proc);
142 if (super == NULL) {
143 mconsole_reply(req, "Failed to get procfs superblock", 1, 0);
144 goto out;
146 up_write(&super->s_umount);
148 nd.path.dentry = super->s_root;
149 nd.path.mnt = NULL;
150 nd.flags = O_RDONLY + 1;
151 nd.last_type = LAST_ROOT;
153 /* START: it was experienced that the stability problems are closed
154 * if commenting out these two calls + the below read cycle. To
155 * make UML crash again, it was enough to readd either one.*/
156 err = link_path_walk(ptr, &nd);
157 if (err) {
158 mconsole_reply(req, "Failed to look up file", 1, 0);
159 goto out_kill;
162 file = dentry_open(nd.path.dentry, nd.path.mnt, O_RDONLY);
163 if (IS_ERR(file)) {
164 mconsole_reply(req, "Failed to open file", 1, 0);
165 goto out_kill;
167 /*END*/
169 buf = kmalloc(PAGE_SIZE, GFP_KERNEL);
170 if (buf == NULL) {
171 mconsole_reply(req, "Failed to allocate buffer", 1, 0);
172 goto out_fput;
175 if ((file->f_op != NULL) && (file->f_op->read != NULL)) {
176 do {
177 n = (*file->f_op->read)(file, buf, PAGE_SIZE - 1,
178 &file->f_pos);
179 if (n >= 0) {
180 buf[n] = '\0';
181 mconsole_reply(req, buf, 0, (n > 0));
183 else {
184 mconsole_reply(req, "Read of file failed",
185 1, 0);
186 goto out_free;
188 } while (n > 0);
190 else mconsole_reply(req, "", 0, 0);
192 out_free:
193 kfree(buf);
194 out_fput:
195 fput(file);
196 out_kill:
197 deactivate_super(super);
198 out: ;
200 #endif
202 void mconsole_proc(struct mc_request *req)
204 char path[64];
205 char *buf;
206 int len;
207 int fd;
208 int first_chunk = 1;
209 char *ptr = req->request.data;
211 ptr += strlen("proc");
212 while (isspace(*ptr))
213 ptr++;
214 snprintf(path, sizeof(path), "/proc/%s", ptr);
216 fd = sys_open(path, 0, 0);
217 if (fd < 0) {
218 mconsole_reply(req, "Failed to open file", 1, 0);
219 printk(KERN_ERR "open %s: %d\n",path,fd);
220 goto out;
223 buf = kmalloc(PAGE_SIZE, GFP_KERNEL);
224 if (buf == NULL) {
225 mconsole_reply(req, "Failed to allocate buffer", 1, 0);
226 goto out_close;
229 for (;;) {
230 len = sys_read(fd, buf, PAGE_SIZE-1);
231 if (len < 0) {
232 mconsole_reply(req, "Read of file failed", 1, 0);
233 goto out_free;
235 /* Begin the file content on his own line. */
236 if (first_chunk) {
237 mconsole_reply(req, "\n", 0, 1);
238 first_chunk = 0;
240 if (len == PAGE_SIZE-1) {
241 buf[len] = '\0';
242 mconsole_reply(req, buf, 0, 1);
243 } else {
244 buf[len] = '\0';
245 mconsole_reply(req, buf, 0, 0);
246 break;
250 out_free:
251 kfree(buf);
252 out_close:
253 sys_close(fd);
254 out:
255 /* nothing */;
258 #define UML_MCONSOLE_HELPTEXT \
259 "Commands: \n\
260 version - Get kernel version \n\
261 help - Print this message \n\
262 halt - Halt UML \n\
263 reboot - Reboot UML \n\
264 config <dev>=<config> - Add a new device to UML; \n\
265 same syntax as command line \n\
266 config <dev> - Query the configuration of a device \n\
267 remove <dev> - Remove a device from UML \n\
268 sysrq <letter> - Performs the SysRq action controlled by the letter \n\
269 cad - invoke the Ctrl-Alt-Del handler \n\
270 stop - pause the UML; it will do nothing until it receives a 'go' \n\
271 go - continue the UML after a 'stop' \n\
272 log <string> - make UML enter <string> into the kernel log\n\
273 proc <file> - returns the contents of the UML's /proc/<file>\n\
274 stack <pid> - returns the stack of the specified pid\n\
277 void mconsole_help(struct mc_request *req)
279 mconsole_reply(req, UML_MCONSOLE_HELPTEXT, 0, 0);
282 void mconsole_halt(struct mc_request *req)
284 mconsole_reply(req, "", 0, 0);
285 machine_halt();
288 void mconsole_reboot(struct mc_request *req)
290 mconsole_reply(req, "", 0, 0);
291 machine_restart(NULL);
294 void mconsole_cad(struct mc_request *req)
296 mconsole_reply(req, "", 0, 0);
297 ctrl_alt_del();
300 void mconsole_go(struct mc_request *req)
302 mconsole_reply(req, "Not stopped", 1, 0);
305 void mconsole_stop(struct mc_request *req)
307 deactivate_fd(req->originating_fd, MCONSOLE_IRQ);
308 os_set_fd_block(req->originating_fd, 1);
309 mconsole_reply(req, "stopped", 0, 0);
310 for (;;) {
311 if (!mconsole_get_request(req->originating_fd, req))
312 continue;
313 if (req->cmd->handler == mconsole_go)
314 break;
315 if (req->cmd->handler == mconsole_stop) {
316 mconsole_reply(req, "Already stopped", 1, 0);
317 continue;
319 if (req->cmd->handler == mconsole_sysrq) {
320 struct pt_regs *old_regs;
321 old_regs = set_irq_regs((struct pt_regs *)&req->regs);
322 mconsole_sysrq(req);
323 set_irq_regs(old_regs);
324 continue;
326 (*req->cmd->handler)(req);
328 os_set_fd_block(req->originating_fd, 0);
329 reactivate_fd(req->originating_fd, MCONSOLE_IRQ);
330 mconsole_reply(req, "", 0, 0);
333 static DEFINE_SPINLOCK(mc_devices_lock);
334 static LIST_HEAD(mconsole_devices);
336 void mconsole_register_dev(struct mc_device *new)
338 spin_lock(&mc_devices_lock);
339 BUG_ON(!list_empty(&new->list));
340 list_add(&new->list, &mconsole_devices);
341 spin_unlock(&mc_devices_lock);
344 static struct mc_device *mconsole_find_dev(char *name)
346 struct list_head *ele;
347 struct mc_device *dev;
349 list_for_each(ele, &mconsole_devices) {
350 dev = list_entry(ele, struct mc_device, list);
351 if (!strncmp(name, dev->name, strlen(dev->name)))
352 return dev;
354 return NULL;
357 #define UNPLUGGED_PER_PAGE \
358 ((PAGE_SIZE - sizeof(struct list_head)) / sizeof(unsigned long))
360 struct unplugged_pages {
361 struct list_head list;
362 void *pages[UNPLUGGED_PER_PAGE];
365 static DEFINE_MUTEX(plug_mem_mutex);
366 static unsigned long long unplugged_pages_count = 0;
367 static LIST_HEAD(unplugged_pages);
368 static int unplug_index = UNPLUGGED_PER_PAGE;
370 static int mem_config(char *str, char **error_out)
372 unsigned long long diff;
373 int err = -EINVAL, i, add;
374 char *ret;
376 if (str[0] != '=') {
377 *error_out = "Expected '=' after 'mem'";
378 goto out;
381 str++;
382 if (str[0] == '-')
383 add = 0;
384 else if (str[0] == '+') {
385 add = 1;
387 else {
388 *error_out = "Expected increment to start with '-' or '+'";
389 goto out;
392 str++;
393 diff = memparse(str, &ret);
394 if (*ret != '\0') {
395 *error_out = "Failed to parse memory increment";
396 goto out;
399 diff /= PAGE_SIZE;
401 mutex_lock(&plug_mem_mutex);
402 for (i = 0; i < diff; i++) {
403 struct unplugged_pages *unplugged;
404 void *addr;
406 if (add) {
407 if (list_empty(&unplugged_pages))
408 break;
410 unplugged = list_entry(unplugged_pages.next,
411 struct unplugged_pages, list);
412 if (unplug_index > 0)
413 addr = unplugged->pages[--unplug_index];
414 else {
415 list_del(&unplugged->list);
416 addr = unplugged;
417 unplug_index = UNPLUGGED_PER_PAGE;
420 free_page((unsigned long) addr);
421 unplugged_pages_count--;
423 else {
424 struct page *page;
426 page = alloc_page(GFP_ATOMIC);
427 if (page == NULL)
428 break;
430 unplugged = page_address(page);
431 if (unplug_index == UNPLUGGED_PER_PAGE) {
432 list_add(&unplugged->list, &unplugged_pages);
433 unplug_index = 0;
435 else {
436 struct list_head *entry = unplugged_pages.next;
437 addr = unplugged;
439 unplugged = list_entry(entry,
440 struct unplugged_pages,
441 list);
442 err = os_drop_memory(addr, PAGE_SIZE);
443 if (err) {
444 printk(KERN_ERR "Failed to release "
445 "memory - errno = %d\n", err);
446 *error_out = "Failed to release memory";
447 goto out_unlock;
449 unplugged->pages[unplug_index++] = addr;
452 unplugged_pages_count++;
456 err = 0;
457 out_unlock:
458 mutex_unlock(&plug_mem_mutex);
459 out:
460 return err;
463 static int mem_get_config(char *name, char *str, int size, char **error_out)
465 char buf[sizeof("18446744073709551615")];
466 int len = 0;
468 sprintf(buf, "%ld", uml_physmem);
469 CONFIG_CHUNK(str, size, len, buf, 1);
471 return len;
474 static int mem_id(char **str, int *start_out, int *end_out)
476 *start_out = 0;
477 *end_out = 0;
479 return 0;
482 static int mem_remove(int n, char **error_out)
484 *error_out = "Memory doesn't support the remove operation";
485 return -EBUSY;
488 static struct mc_device mem_mc = {
489 .list = LIST_HEAD_INIT(mem_mc.list),
490 .name = "mem",
491 .config = mem_config,
492 .get_config = mem_get_config,
493 .id = mem_id,
494 .remove = mem_remove,
497 static int __init mem_mc_init(void)
499 if (can_drop_memory())
500 mconsole_register_dev(&mem_mc);
501 else printk(KERN_ERR "Can't release memory to the host - memory "
502 "hotplug won't be supported\n");
503 return 0;
506 __initcall(mem_mc_init);
508 #define CONFIG_BUF_SIZE 64
510 static void mconsole_get_config(int (*get_config)(char *, char *, int,
511 char **),
512 struct mc_request *req, char *name)
514 char default_buf[CONFIG_BUF_SIZE], *error, *buf;
515 int n, size;
517 if (get_config == NULL) {
518 mconsole_reply(req, "No get_config routine defined", 1, 0);
519 return;
522 error = NULL;
523 size = ARRAY_SIZE(default_buf);
524 buf = default_buf;
526 while (1) {
527 n = (*get_config)(name, buf, size, &error);
528 if (error != NULL) {
529 mconsole_reply(req, error, 1, 0);
530 goto out;
533 if (n <= size) {
534 mconsole_reply(req, buf, 0, 0);
535 goto out;
538 if (buf != default_buf)
539 kfree(buf);
541 size = n;
542 buf = kmalloc(size, GFP_KERNEL);
543 if (buf == NULL) {
544 mconsole_reply(req, "Failed to allocate buffer", 1, 0);
545 return;
548 out:
549 if (buf != default_buf)
550 kfree(buf);
553 void mconsole_config(struct mc_request *req)
555 struct mc_device *dev;
556 char *ptr = req->request.data, *name, *error_string = "";
557 int err;
559 ptr += strlen("config");
560 while (isspace(*ptr))
561 ptr++;
562 dev = mconsole_find_dev(ptr);
563 if (dev == NULL) {
564 mconsole_reply(req, "Bad configuration option", 1, 0);
565 return;
568 name = &ptr[strlen(dev->name)];
569 ptr = name;
570 while ((*ptr != '=') && (*ptr != '\0'))
571 ptr++;
573 if (*ptr == '=') {
574 err = (*dev->config)(name, &error_string);
575 mconsole_reply(req, error_string, err, 0);
577 else mconsole_get_config(dev->get_config, req, name);
580 void mconsole_remove(struct mc_request *req)
582 struct mc_device *dev;
583 char *ptr = req->request.data, *err_msg = "";
584 char error[256];
585 int err, start, end, n;
587 ptr += strlen("remove");
588 while (isspace(*ptr)) ptr++;
589 dev = mconsole_find_dev(ptr);
590 if (dev == NULL) {
591 mconsole_reply(req, "Bad remove option", 1, 0);
592 return;
595 ptr = &ptr[strlen(dev->name)];
597 err = 1;
598 n = (*dev->id)(&ptr, &start, &end);
599 if (n < 0) {
600 err_msg = "Couldn't parse device number";
601 goto out;
603 else if ((n < start) || (n > end)) {
604 sprintf(error, "Invalid device number - must be between "
605 "%d and %d", start, end);
606 err_msg = error;
607 goto out;
610 err_msg = NULL;
611 err = (*dev->remove)(n, &err_msg);
612 switch(err) {
613 case 0:
614 err_msg = "";
615 break;
616 case -ENODEV:
617 if (err_msg == NULL)
618 err_msg = "Device doesn't exist";
619 break;
620 case -EBUSY:
621 if (err_msg == NULL)
622 err_msg = "Device is currently open";
623 break;
624 default:
625 break;
627 out:
628 mconsole_reply(req, err_msg, err, 0);
631 struct mconsole_output {
632 struct list_head list;
633 struct mc_request *req;
636 static DEFINE_SPINLOCK(client_lock);
637 static LIST_HEAD(clients);
638 static char console_buf[MCONSOLE_MAX_DATA];
640 static void console_write(struct console *console, const char *string,
641 unsigned int len)
643 struct list_head *ele;
644 int n;
646 if (list_empty(&clients))
647 return;
649 while (len > 0) {
650 n = min((size_t) len, ARRAY_SIZE(console_buf));
651 strncpy(console_buf, string, n);
652 string += n;
653 len -= n;
655 list_for_each(ele, &clients) {
656 struct mconsole_output *entry;
658 entry = list_entry(ele, struct mconsole_output, list);
659 mconsole_reply_len(entry->req, console_buf, n, 0, 1);
664 static struct console mc_console = { .name = "mc",
665 .write = console_write,
666 .flags = CON_ENABLED,
667 .index = -1 };
669 static int mc_add_console(void)
671 register_console(&mc_console);
672 return 0;
675 late_initcall(mc_add_console);
677 static void with_console(struct mc_request *req, void (*proc)(void *),
678 void *arg)
680 struct mconsole_output entry;
681 unsigned long flags;
683 entry.req = req;
684 spin_lock_irqsave(&client_lock, flags);
685 list_add(&entry.list, &clients);
686 spin_unlock_irqrestore(&client_lock, flags);
688 (*proc)(arg);
690 mconsole_reply_len(req, "", 0, 0, 0);
692 spin_lock_irqsave(&client_lock, flags);
693 list_del(&entry.list);
694 spin_unlock_irqrestore(&client_lock, flags);
697 #ifdef CONFIG_MAGIC_SYSRQ
699 #include <linux/sysrq.h>
701 static void sysrq_proc(void *arg)
703 char *op = arg;
704 handle_sysrq(*op, NULL);
707 void mconsole_sysrq(struct mc_request *req)
709 char *ptr = req->request.data;
711 ptr += strlen("sysrq");
712 while (isspace(*ptr)) ptr++;
715 * With 'b', the system will shut down without a chance to reply,
716 * so in this case, we reply first.
718 if (*ptr == 'b')
719 mconsole_reply(req, "", 0, 0);
721 with_console(req, sysrq_proc, ptr);
723 #else
724 void mconsole_sysrq(struct mc_request *req)
726 mconsole_reply(req, "Sysrq not compiled in", 1, 0);
728 #endif
730 static void stack_proc(void *arg)
732 struct task_struct *from = current, *to = arg;
734 to->thread.saved_task = from;
735 switch_to(from, to, from);
739 * Mconsole stack trace
740 * Added by Allan Graves, Jeff Dike
741 * Dumps a stacks registers to the linux console.
742 * Usage stack <pid>.
744 void mconsole_stack(struct mc_request *req)
746 char *ptr = req->request.data;
747 int pid_requested= -1;
748 struct task_struct *to = NULL;
751 * Would be nice:
752 * 1) Send showregs output to mconsole.
753 * 2) Add a way to stack dump all pids.
756 ptr += strlen("stack");
757 while (isspace(*ptr))
758 ptr++;
761 * Should really check for multiple pids or reject bad args here
763 /* What do the arguments in mconsole_reply mean? */
764 if (sscanf(ptr, "%d", &pid_requested) == 0) {
765 mconsole_reply(req, "Please specify a pid", 1, 0);
766 return;
769 to = find_task_by_pid_ns(pid_requested, &init_pid_ns);
770 if ((to == NULL) || (pid_requested == 0)) {
771 mconsole_reply(req, "Couldn't find that pid", 1, 0);
772 return;
774 with_console(req, stack_proc, to);
778 * Changed by mconsole_setup, which is __setup, and called before SMP is
779 * active.
781 static char *notify_socket = NULL;
783 static int __init mconsole_init(void)
785 /* long to avoid size mismatch warnings from gcc */
786 long sock;
787 int err;
788 char file[256];
790 if (umid_file_name("mconsole", file, sizeof(file)))
791 return -1;
792 snprintf(mconsole_socket_name, sizeof(file), "%s", file);
794 sock = os_create_unix_socket(file, sizeof(file), 1);
795 if (sock < 0) {
796 printk(KERN_ERR "Failed to initialize management console\n");
797 return 1;
799 if (os_set_fd_block(sock, 0))
800 goto out;
802 register_reboot_notifier(&reboot_notifier);
804 err = um_request_irq(MCONSOLE_IRQ, sock, IRQ_READ, mconsole_interrupt,
805 IRQF_DISABLED | IRQF_SHARED | IRQF_SAMPLE_RANDOM,
806 "mconsole", (void *)sock);
807 if (err) {
808 printk(KERN_ERR "Failed to get IRQ for management console\n");
809 goto out;
812 if (notify_socket != NULL) {
813 notify_socket = kstrdup(notify_socket, GFP_KERNEL);
814 if (notify_socket != NULL)
815 mconsole_notify(notify_socket, MCONSOLE_SOCKET,
816 mconsole_socket_name,
817 strlen(mconsole_socket_name) + 1);
818 else printk(KERN_ERR "mconsole_setup failed to strdup "
819 "string\n");
822 printk(KERN_INFO "mconsole (version %d) initialized on %s\n",
823 MCONSOLE_VERSION, mconsole_socket_name);
824 return 0;
826 out:
827 os_close_file(sock);
828 return 1;
831 __initcall(mconsole_init);
833 static int write_proc_mconsole(struct file *file, const char __user *buffer,
834 unsigned long count, void *data)
836 char *buf;
838 buf = kmalloc(count + 1, GFP_KERNEL);
839 if (buf == NULL)
840 return -ENOMEM;
842 if (copy_from_user(buf, buffer, count)) {
843 count = -EFAULT;
844 goto out;
847 buf[count] = '\0';
849 mconsole_notify(notify_socket, MCONSOLE_USER_NOTIFY, buf, count);
850 out:
851 kfree(buf);
852 return count;
855 static int create_proc_mconsole(void)
857 struct proc_dir_entry *ent;
859 if (notify_socket == NULL)
860 return 0;
862 ent = create_proc_entry("mconsole", S_IFREG | 0200, NULL);
863 if (ent == NULL) {
864 printk(KERN_INFO "create_proc_mconsole : create_proc_entry "
865 "failed\n");
866 return 0;
869 ent->read_proc = NULL;
870 ent->write_proc = write_proc_mconsole;
871 return 0;
874 static DEFINE_SPINLOCK(notify_spinlock);
876 void lock_notify(void)
878 spin_lock(&notify_spinlock);
881 void unlock_notify(void)
883 spin_unlock(&notify_spinlock);
886 __initcall(create_proc_mconsole);
888 #define NOTIFY "notify:"
890 static int mconsole_setup(char *str)
892 if (!strncmp(str, NOTIFY, strlen(NOTIFY))) {
893 str += strlen(NOTIFY);
894 notify_socket = str;
896 else printk(KERN_ERR "mconsole_setup : Unknown option - '%s'\n", str);
897 return 1;
900 __setup("mconsole=", mconsole_setup);
902 __uml_help(mconsole_setup,
903 "mconsole=notify:<socket>\n"
904 " Requests that the mconsole driver send a message to the named Unix\n"
905 " socket containing the name of the mconsole socket. This also serves\n"
906 " to notify outside processes when UML has booted far enough to respond\n"
907 " to mconsole requests.\n\n"
910 static int notify_panic(struct notifier_block *self, unsigned long unused1,
911 void *ptr)
913 char *message = ptr;
915 if (notify_socket == NULL)
916 return 0;
918 mconsole_notify(notify_socket, MCONSOLE_PANIC, message,
919 strlen(message) + 1);
920 return 0;
923 static struct notifier_block panic_exit_notifier = {
924 .notifier_call = notify_panic,
925 .next = NULL,
926 .priority = 1
929 static int add_notifier(void)
931 atomic_notifier_chain_register(&panic_notifier_list,
932 &panic_exit_notifier);
933 return 0;
936 __initcall(add_notifier);
938 char *mconsole_notify_socket(void)
940 return notify_socket;
943 EXPORT_SYMBOL(mconsole_notify_socket);