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1// SPDX-License-Identifier: GPL-2.0
2/*
3 * Copyright (C) 2001 Lennert Buytenhek (buytenh@gnu.org)
4 * Copyright (C) 2001 - 2008 Jeff Dike (jdike@{addtoit,linux.intel}.com)
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/panic_notifier.h>
16#include <linux/reboot.h>
17#include <linux/sched/debug.h>
18#include <linux/proc_fs.h>
19#include <linux/slab.h>
20#include <linux/syscalls.h>
21#include <linux/utsname.h>
22#include <linux/socket.h>
23#include <linux/un.h>
24#include <linux/workqueue.h>
25#include <linux/mutex.h>
26#include <linux/fs.h>
27#include <linux/mount.h>
28#include <linux/file.h>
29#include <linux/uaccess.h>
30#include <asm/switch_to.h>
31
32#include <init.h>
33#include <irq_kern.h>
34#include <irq_user.h>
35#include <kern_util.h>
36#include "mconsole.h"
37#include "mconsole_kern.h"
38#include <os.h>
39
40static struct vfsmount *proc_mnt = NULL;
41
42static int do_unlink_socket(struct notifier_block *notifier,
43 unsigned long what, void *data)
44{
45 return mconsole_unlink_socket();
46}
47
48
49static struct notifier_block reboot_notifier = {
50 .notifier_call = do_unlink_socket,
51 .priority = 0,
52};
53
54/* Safe without explicit locking for now. Tasklets provide their own
55 * locking, and the interrupt handler is safe because it can't interrupt
56 * itself and it can only happen on CPU 0.
57 */
58
59static LIST_HEAD(mc_requests);
60
61static void mc_work_proc(struct work_struct *unused)
62{
63 struct mconsole_entry *req;
64 unsigned long flags;
65
66 while (!list_empty(&mc_requests)) {
67 local_irq_save(flags);
68 req = list_entry(mc_requests.next, struct mconsole_entry, list);
69 list_del(&req->list);
70 local_irq_restore(flags);
71 req->request.cmd->handler(&req->request);
72 kfree(req);
73 }
74}
75
76static DECLARE_WORK(mconsole_work, mc_work_proc);
77
78static irqreturn_t mconsole_interrupt(int irq, void *dev_id)
79{
80 /* long to avoid size mismatch warnings from gcc */
81 long fd;
82 struct mconsole_entry *new;
83 static struct mc_request req; /* that's OK */
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 new->request.regs = get_irq_regs()->regs;
96 list_add(&new->list, &mc_requests);
97 }
98 }
99 }
100 if (!list_empty(&mc_requests))
101 schedule_work(&mconsole_work);
102 return IRQ_HANDLED;
103}
104
105void mconsole_version(struct mc_request *req)
106{
107 char version[256];
108
109 sprintf(version, "%s %s %s %s %s", utsname()->sysname,
110 utsname()->nodename, utsname()->release, utsname()->version,
111 utsname()->machine);
112 mconsole_reply(req, version, 0, 0);
113}
114
115void 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(KERN_WARNING "%.*s", len, ptr);
124 mconsole_reply(req, "", 0, 0);
125}
126
127void mconsole_proc(struct mc_request *req)
128{
129 struct vfsmount *mnt = proc_mnt;
130 char *buf;
131 int len;
132 struct file *file;
133 int first_chunk = 1;
134 char *ptr = req->request.data;
135 loff_t pos = 0;
136
137 ptr += strlen("proc");
138 ptr = skip_spaces(ptr);
139
140 if (!mnt) {
141 mconsole_reply(req, "Proc not available", 1, 0);
142 goto out;
143 }
144 file = file_open_root_mnt(mnt, ptr, O_RDONLY, 0);
145 if (IS_ERR(file)) {
146 mconsole_reply(req, "Failed to open file", 1, 0);
147 printk(KERN_ERR "open /proc/%s: %ld\n", ptr, PTR_ERR(file));
148 goto out;
149 }
150
151 buf = kmalloc(PAGE_SIZE, GFP_KERNEL);
152 if (buf == NULL) {
153 mconsole_reply(req, "Failed to allocate buffer", 1, 0);
154 goto out_fput;
155 }
156
157 do {
158 len = kernel_read(file, buf, PAGE_SIZE - 1, &pos);
159 if (len < 0) {
160 mconsole_reply(req, "Read of file failed", 1, 0);
161 goto out_free;
162 }
163 /* Begin the file content on his own line. */
164 if (first_chunk) {
165 mconsole_reply(req, "\n", 0, 1);
166 first_chunk = 0;
167 }
168 buf[len] = '\0';
169 mconsole_reply(req, buf, 0, (len > 0));
170 } while (len > 0);
171 out_free:
172 kfree(buf);
173 out_fput:
174 fput(file);
175 out: ;
176}
177
178#define UML_MCONSOLE_HELPTEXT \
179"Commands: \n\
180 version - Get kernel version \n\
181 help - Print this message \n\
182 halt - Halt UML \n\
183 reboot - Reboot UML \n\
184 config <dev>=<config> - Add a new device to UML; \n\
185 same syntax as command line \n\
186 config <dev> - Query the configuration of a device \n\
187 remove <dev> - Remove a device from UML \n\
188 sysrq <letter> - Performs the SysRq action controlled by the letter \n\
189 cad - invoke the Ctrl-Alt-Del handler \n\
190 stop - pause the UML; it will do nothing until it receives a 'go' \n\
191 go - continue the UML after a 'stop' \n\
192 log <string> - make UML enter <string> into the kernel log\n\
193 proc <file> - returns the contents of the UML's /proc/<file>\n\
194 stack <pid> - returns the stack of the specified pid\n\
195"
196
197void mconsole_help(struct mc_request *req)
198{
199 mconsole_reply(req, UML_MCONSOLE_HELPTEXT, 0, 0);
200}
201
202void mconsole_halt(struct mc_request *req)
203{
204 mconsole_reply(req, "", 0, 0);
205 machine_halt();
206}
207
208void mconsole_reboot(struct mc_request *req)
209{
210 mconsole_reply(req, "", 0, 0);
211 machine_restart(NULL);
212}
213
214void mconsole_cad(struct mc_request *req)
215{
216 mconsole_reply(req, "", 0, 0);
217 ctrl_alt_del();
218}
219
220void mconsole_go(struct mc_request *req)
221{
222 mconsole_reply(req, "Not stopped", 1, 0);
223}
224
225void mconsole_stop(struct mc_request *req)
226{
227 block_signals();
228 os_set_fd_block(req->originating_fd, 1);
229 mconsole_reply(req, "stopped", 0, 0);
230 for (;;) {
231 if (!mconsole_get_request(req->originating_fd, req))
232 continue;
233 if (req->cmd->handler == mconsole_go)
234 break;
235 if (req->cmd->handler == mconsole_stop) {
236 mconsole_reply(req, "Already stopped", 1, 0);
237 continue;
238 }
239 if (req->cmd->handler == mconsole_sysrq) {
240 struct pt_regs *old_regs;
241 old_regs = set_irq_regs((struct pt_regs *)&req->regs);
242 mconsole_sysrq(req);
243 set_irq_regs(old_regs);
244 continue;
245 }
246 (*req->cmd->handler)(req);
247 }
248 os_set_fd_block(req->originating_fd, 0);
249 mconsole_reply(req, "", 0, 0);
250 unblock_signals();
251}
252
253static DEFINE_SPINLOCK(mc_devices_lock);
254static LIST_HEAD(mconsole_devices);
255
256void mconsole_register_dev(struct mc_device *new)
257{
258 spin_lock(&mc_devices_lock);
259 BUG_ON(!list_empty(&new->list));
260 list_add(&new->list, &mconsole_devices);
261 spin_unlock(&mc_devices_lock);
262}
263
264static struct mc_device *mconsole_find_dev(char *name)
265{
266 struct list_head *ele;
267 struct mc_device *dev;
268
269 list_for_each(ele, &mconsole_devices) {
270 dev = list_entry(ele, struct mc_device, list);
271 if (!strncmp(name, dev->name, strlen(dev->name)))
272 return dev;
273 }
274 return NULL;
275}
276
277#define UNPLUGGED_PER_PAGE \
278 ((PAGE_SIZE - sizeof(struct list_head)) / sizeof(unsigned long))
279
280struct unplugged_pages {
281 struct list_head list;
282 void *pages[UNPLUGGED_PER_PAGE];
283};
284
285static DEFINE_MUTEX(plug_mem_mutex);
286static unsigned long long unplugged_pages_count;
287static LIST_HEAD(unplugged_pages);
288static int unplug_index = UNPLUGGED_PER_PAGE;
289
290static int mem_config(char *str, char **error_out)
291{
292 unsigned long long diff;
293 int err = -EINVAL, i, add;
294 char *ret;
295
296 if (str[0] != '=') {
297 *error_out = "Expected '=' after 'mem'";
298 goto out;
299 }
300
301 str++;
302 if (str[0] == '-')
303 add = 0;
304 else if (str[0] == '+') {
305 add = 1;
306 }
307 else {
308 *error_out = "Expected increment to start with '-' or '+'";
309 goto out;
310 }
311
312 str++;
313 diff = memparse(str, &ret);
314 if (*ret != '\0') {
315 *error_out = "Failed to parse memory increment";
316 goto out;
317 }
318
319 diff /= PAGE_SIZE;
320
321 mutex_lock(&plug_mem_mutex);
322 for (i = 0; i < diff; i++) {
323 struct unplugged_pages *unplugged;
324 void *addr;
325
326 if (add) {
327 if (list_empty(&unplugged_pages))
328 break;
329
330 unplugged = list_entry(unplugged_pages.next,
331 struct unplugged_pages, list);
332 if (unplug_index > 0)
333 addr = unplugged->pages[--unplug_index];
334 else {
335 list_del(&unplugged->list);
336 addr = unplugged;
337 unplug_index = UNPLUGGED_PER_PAGE;
338 }
339
340 free_page((unsigned long) addr);
341 unplugged_pages_count--;
342 }
343 else {
344 struct page *page;
345
346 page = alloc_page(GFP_ATOMIC);
347 if (page == NULL)
348 break;
349
350 unplugged = page_address(page);
351 if (unplug_index == UNPLUGGED_PER_PAGE) {
352 list_add(&unplugged->list, &unplugged_pages);
353 unplug_index = 0;
354 }
355 else {
356 struct list_head *entry = unplugged_pages.next;
357 addr = unplugged;
358
359 unplugged = list_entry(entry,
360 struct unplugged_pages,
361 list);
362 err = os_drop_memory(addr, PAGE_SIZE);
363 if (err) {
364 printk(KERN_ERR "Failed to release "
365 "memory - errno = %d\n", err);
366 *error_out = "Failed to release memory";
367 goto out_unlock;
368 }
369 unplugged->pages[unplug_index++] = addr;
370 }
371
372 unplugged_pages_count++;
373 }
374 }
375
376 err = 0;
377out_unlock:
378 mutex_unlock(&plug_mem_mutex);
379out:
380 return err;
381}
382
383static int mem_get_config(char *name, char *str, int size, char **error_out)
384{
385 char buf[sizeof("18446744073709551615")];
386 int len = 0;
387
388 sprintf(buf, "%ld", uml_physmem);
389 CONFIG_CHUNK(str, size, len, buf, 1);
390
391 return len;
392}
393
394static int mem_id(char **str, int *start_out, int *end_out)
395{
396 *start_out = 0;
397 *end_out = 0;
398
399 return 0;
400}
401
402static int mem_remove(int n, char **error_out)
403{
404 *error_out = "Memory doesn't support the remove operation";
405 return -EBUSY;
406}
407
408static struct mc_device mem_mc = {
409 .list = LIST_HEAD_INIT(mem_mc.list),
410 .name = "mem",
411 .config = mem_config,
412 .get_config = mem_get_config,
413 .id = mem_id,
414 .remove = mem_remove,
415};
416
417static int __init mem_mc_init(void)
418{
419 if (can_drop_memory())
420 mconsole_register_dev(&mem_mc);
421 else printk(KERN_ERR "Can't release memory to the host - memory "
422 "hotplug won't be supported\n");
423 return 0;
424}
425
426__initcall(mem_mc_init);
427
428#define CONFIG_BUF_SIZE 64
429
430static void mconsole_get_config(int (*get_config)(char *, char *, int,
431 char **),
432 struct mc_request *req, char *name)
433{
434 char default_buf[CONFIG_BUF_SIZE], *error, *buf;
435 int n, size;
436
437 if (get_config == NULL) {
438 mconsole_reply(req, "No get_config routine defined", 1, 0);
439 return;
440 }
441
442 error = NULL;
443 size = ARRAY_SIZE(default_buf);
444 buf = default_buf;
445
446 while (1) {
447 n = (*get_config)(name, buf, size, &error);
448 if (error != NULL) {
449 mconsole_reply(req, error, 1, 0);
450 goto out;
451 }
452
453 if (n <= size) {
454 mconsole_reply(req, buf, 0, 0);
455 goto out;
456 }
457
458 if (buf != default_buf)
459 kfree(buf);
460
461 size = n;
462 buf = kmalloc(size, GFP_KERNEL);
463 if (buf == NULL) {
464 mconsole_reply(req, "Failed to allocate buffer", 1, 0);
465 return;
466 }
467 }
468 out:
469 if (buf != default_buf)
470 kfree(buf);
471}
472
473void mconsole_config(struct mc_request *req)
474{
475 struct mc_device *dev;
476 char *ptr = req->request.data, *name, *error_string = "";
477 int err;
478
479 ptr += strlen("config");
480 ptr = skip_spaces(ptr);
481 dev = mconsole_find_dev(ptr);
482 if (dev == NULL) {
483 mconsole_reply(req, "Bad configuration option", 1, 0);
484 return;
485 }
486
487 name = &ptr[strlen(dev->name)];
488 ptr = name;
489 while ((*ptr != '=') && (*ptr != '\0'))
490 ptr++;
491
492 if (*ptr == '=') {
493 err = (*dev->config)(name, &error_string);
494 mconsole_reply(req, error_string, err, 0);
495 }
496 else mconsole_get_config(dev->get_config, req, name);
497}
498
499void mconsole_remove(struct mc_request *req)
500{
501 struct mc_device *dev;
502 char *ptr = req->request.data, *err_msg = "";
503 char error[256];
504 int err, start, end, n;
505
506 ptr += strlen("remove");
507 ptr = skip_spaces(ptr);
508 dev = mconsole_find_dev(ptr);
509 if (dev == NULL) {
510 mconsole_reply(req, "Bad remove option", 1, 0);
511 return;
512 }
513
514 ptr = &ptr[strlen(dev->name)];
515
516 err = 1;
517 n = (*dev->id)(&ptr, &start, &end);
518 if (n < 0) {
519 err_msg = "Couldn't parse device number";
520 goto out;
521 }
522 else if ((n < start) || (n > end)) {
523 sprintf(error, "Invalid device number - must be between "
524 "%d and %d", start, end);
525 err_msg = error;
526 goto out;
527 }
528
529 err_msg = NULL;
530 err = (*dev->remove)(n, &err_msg);
531 switch(err) {
532 case 0:
533 err_msg = "";
534 break;
535 case -ENODEV:
536 if (err_msg == NULL)
537 err_msg = "Device doesn't exist";
538 break;
539 case -EBUSY:
540 if (err_msg == NULL)
541 err_msg = "Device is currently open";
542 break;
543 default:
544 break;
545 }
546out:
547 mconsole_reply(req, err_msg, err, 0);
548}
549
550struct mconsole_output {
551 struct list_head list;
552 struct mc_request *req;
553};
554
555static DEFINE_SPINLOCK(client_lock);
556static LIST_HEAD(clients);
557static char console_buf[MCONSOLE_MAX_DATA] __nonstring;
558
559static void console_write(struct console *console, const char *string,
560 unsigned int len)
561{
562 struct list_head *ele;
563 int n;
564
565 if (list_empty(&clients))
566 return;
567
568 while (len > 0) {
569 n = min((size_t) len, ARRAY_SIZE(console_buf));
570 memcpy(console_buf, string, n);
571 string += n;
572 len -= n;
573
574 list_for_each(ele, &clients) {
575 struct mconsole_output *entry;
576
577 entry = list_entry(ele, struct mconsole_output, list);
578 mconsole_reply_len(entry->req, console_buf, n, 0, 1);
579 }
580 }
581}
582
583static struct console mc_console = { .name = "mc",
584 .write = console_write,
585 .flags = CON_ENABLED,
586 .index = -1 };
587
588static int mc_add_console(void)
589{
590 register_console(&mc_console);
591 return 0;
592}
593
594late_initcall(mc_add_console);
595
596static void with_console(struct mc_request *req, void (*proc)(void *),
597 void *arg)
598{
599 struct mconsole_output entry;
600 unsigned long flags;
601
602 entry.req = req;
603 spin_lock_irqsave(&client_lock, flags);
604 list_add(&entry.list, &clients);
605 spin_unlock_irqrestore(&client_lock, flags);
606
607 (*proc)(arg);
608
609 mconsole_reply_len(req, "", 0, 0, 0);
610
611 spin_lock_irqsave(&client_lock, flags);
612 list_del(&entry.list);
613 spin_unlock_irqrestore(&client_lock, flags);
614}
615
616#ifdef CONFIG_MAGIC_SYSRQ
617
618#include <linux/sysrq.h>
619
620static void sysrq_proc(void *arg)
621{
622 char *op = arg;
623 handle_sysrq(*op);
624}
625
626void mconsole_sysrq(struct mc_request *req)
627{
628 char *ptr = req->request.data;
629
630 ptr += strlen("sysrq");
631 ptr = skip_spaces(ptr);
632
633 /*
634 * With 'b', the system will shut down without a chance to reply,
635 * so in this case, we reply first.
636 */
637 if (*ptr == 'b')
638 mconsole_reply(req, "", 0, 0);
639
640 with_console(req, sysrq_proc, ptr);
641}
642#else
643void mconsole_sysrq(struct mc_request *req)
644{
645 mconsole_reply(req, "Sysrq not compiled in", 1, 0);
646}
647#endif
648
649static void stack_proc(void *arg)
650{
651 struct task_struct *task = arg;
652
653 show_stack(task, NULL, KERN_INFO);
654}
655
656/*
657 * Mconsole stack trace
658 * Added by Allan Graves, Jeff Dike
659 * Dumps a stacks registers to the linux console.
660 * Usage stack <pid>.
661 */
662void mconsole_stack(struct mc_request *req)
663{
664 char *ptr = req->request.data;
665 int pid_requested= -1;
666 struct task_struct *to = NULL;
667
668 /*
669 * Would be nice:
670 * 1) Send showregs output to mconsole.
671 * 2) Add a way to stack dump all pids.
672 */
673
674 ptr += strlen("stack");
675 ptr = skip_spaces(ptr);
676
677 /*
678 * Should really check for multiple pids or reject bad args here
679 */
680 /* What do the arguments in mconsole_reply mean? */
681 if (sscanf(ptr, "%d", &pid_requested) == 0) {
682 mconsole_reply(req, "Please specify a pid", 1, 0);
683 return;
684 }
685
686 to = find_task_by_pid_ns(pid_requested, &init_pid_ns);
687 if ((to == NULL) || (pid_requested == 0)) {
688 mconsole_reply(req, "Couldn't find that pid", 1, 0);
689 return;
690 }
691 with_console(req, stack_proc, to);
692}
693
694static int __init mount_proc(void)
695{
696 struct file_system_type *proc_fs_type;
697 struct vfsmount *mnt;
698
699 proc_fs_type = get_fs_type("proc");
700 if (!proc_fs_type)
701 return -ENODEV;
702
703 mnt = kern_mount(proc_fs_type);
704 put_filesystem(proc_fs_type);
705 if (IS_ERR(mnt))
706 return PTR_ERR(mnt);
707
708 proc_mnt = mnt;
709 return 0;
710}
711
712/*
713 * Changed by mconsole_setup, which is __setup, and called before SMP is
714 * active.
715 */
716static char *notify_socket = NULL;
717
718static int __init mconsole_init(void)
719{
720 /* long to avoid size mismatch warnings from gcc */
721 long sock;
722 int err;
723 char file[UNIX_PATH_MAX];
724
725 mount_proc();
726
727 if (umid_file_name("mconsole", file, sizeof(file)))
728 return -1;
729 snprintf(mconsole_socket_name, sizeof(file), "%s", file);
730
731 sock = os_create_unix_socket(file, sizeof(file), 1);
732 if (sock < 0) {
733 printk(KERN_ERR "Failed to initialize management console\n");
734 return 1;
735 }
736 if (os_set_fd_block(sock, 0))
737 goto out;
738
739 register_reboot_notifier(&reboot_notifier);
740
741 err = um_request_irq(MCONSOLE_IRQ, sock, IRQ_READ, mconsole_interrupt,
742 IRQF_SHARED, "mconsole", (void *)sock);
743 if (err < 0) {
744 printk(KERN_ERR "Failed to get IRQ for management console\n");
745 goto out;
746 }
747
748 if (notify_socket != NULL) {
749 notify_socket = kstrdup(notify_socket, GFP_KERNEL);
750 if (notify_socket != NULL)
751 mconsole_notify(notify_socket, MCONSOLE_SOCKET,
752 mconsole_socket_name,
753 strlen(mconsole_socket_name) + 1);
754 else printk(KERN_ERR "mconsole_setup failed to strdup "
755 "string\n");
756 }
757
758 printk(KERN_INFO "mconsole (version %d) initialized on %s\n",
759 MCONSOLE_VERSION, mconsole_socket_name);
760 return 0;
761
762 out:
763 os_close_file(sock);
764 return 1;
765}
766
767__initcall(mconsole_init);
768
769static ssize_t mconsole_proc_write(struct file *file,
770 const char __user *buffer, size_t count, loff_t *pos)
771{
772 char *buf;
773
774 buf = memdup_user_nul(buffer, count);
775 if (IS_ERR(buf))
776 return PTR_ERR(buf);
777
778 mconsole_notify(notify_socket, MCONSOLE_USER_NOTIFY, buf, count);
779 kfree(buf);
780 return count;
781}
782
783static const struct proc_ops mconsole_proc_ops = {
784 .proc_write = mconsole_proc_write,
785 .proc_lseek = noop_llseek,
786};
787
788static int create_proc_mconsole(void)
789{
790 struct proc_dir_entry *ent;
791
792 if (notify_socket == NULL)
793 return 0;
794
795 ent = proc_create("mconsole", 0200, NULL, &mconsole_proc_ops);
796 if (ent == NULL) {
797 printk(KERN_INFO "create_proc_mconsole : proc_create failed\n");
798 return 0;
799 }
800 return 0;
801}
802
803static DEFINE_SPINLOCK(notify_spinlock);
804
805void lock_notify(void)
806{
807 spin_lock(¬ify_spinlock);
808}
809
810void unlock_notify(void)
811{
812 spin_unlock(¬ify_spinlock);
813}
814
815__initcall(create_proc_mconsole);
816
817#define NOTIFY "notify:"
818
819static int mconsole_setup(char *str)
820{
821 if (!strncmp(str, NOTIFY, strlen(NOTIFY))) {
822 str += strlen(NOTIFY);
823 notify_socket = str;
824 }
825 else printk(KERN_ERR "mconsole_setup : Unknown option - '%s'\n", str);
826 return 1;
827}
828
829__setup("mconsole=", mconsole_setup);
830
831__uml_help(mconsole_setup,
832"mconsole=notify:<socket>\n"
833" Requests that the mconsole driver send a message to the named Unix\n"
834" socket containing the name of the mconsole socket. This also serves\n"
835" to notify outside processes when UML has booted far enough to respond\n"
836" to mconsole requests.\n\n"
837);
838
839static int notify_panic(struct notifier_block *self, unsigned long unused1,
840 void *ptr)
841{
842 char *message = ptr;
843
844 if (notify_socket == NULL)
845 return 0;
846
847 mconsole_notify(notify_socket, MCONSOLE_PANIC, message,
848 strlen(message) + 1);
849 return NOTIFY_DONE;
850}
851
852static struct notifier_block panic_exit_notifier = {
853 .notifier_call = notify_panic,
854 .priority = INT_MAX, /* run as soon as possible */
855};
856
857static int add_notifier(void)
858{
859 atomic_notifier_chain_register(&panic_notifier_list,
860 &panic_exit_notifier);
861 return 0;
862}
863
864__initcall(add_notifier);
865
866char *mconsole_notify_socket(void)
867{
868 return notify_socket;
869}
870
871EXPORT_SYMBOL(mconsole_notify_socket);
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 <asm/uaccess.h>
25
26#include "init.h"
27#include "irq_kern.h"
28#include "irq_user.h"
29#include "kern_util.h"
30#include "mconsole.h"
31#include "mconsole_kern.h"
32#include "os.h"
33
34static int do_unlink_socket(struct notifier_block *notifier,
35 unsigned long what, void *data)
36{
37 return mconsole_unlink_socket();
38}
39
40
41static struct notifier_block reboot_notifier = {
42 .notifier_call = do_unlink_socket,
43 .priority = 0,
44};
45
46/* Safe without explicit locking for now. Tasklets provide their own
47 * locking, and the interrupt handler is safe because it can't interrupt
48 * itself and it can only happen on CPU 0.
49 */
50
51static LIST_HEAD(mc_requests);
52
53static void mc_work_proc(struct work_struct *unused)
54{
55 struct mconsole_entry *req;
56 unsigned long flags;
57
58 while (!list_empty(&mc_requests)) {
59 local_irq_save(flags);
60 req = list_entry(mc_requests.next, struct mconsole_entry, list);
61 list_del(&req->list);
62 local_irq_restore(flags);
63 req->request.cmd->handler(&req->request);
64 kfree(req);
65 }
66}
67
68static DECLARE_WORK(mconsole_work, mc_work_proc);
69
70static irqreturn_t mconsole_interrupt(int irq, void *dev_id)
71{
72 /* long to avoid size mismatch warnings from gcc */
73 long fd;
74 struct mconsole_entry *new;
75 static struct mc_request req; /* that's OK */
76
77 fd = (long) dev_id;
78 while (mconsole_get_request(fd, &req)) {
79 if (req.cmd->context == MCONSOLE_INTR)
80 (*req.cmd->handler)(&req);
81 else {
82 new = kmalloc(sizeof(*new), GFP_NOWAIT);
83 if (new == NULL)
84 mconsole_reply(&req, "Out of memory", 1, 0);
85 else {
86 new->request = req;
87 new->request.regs = get_irq_regs()->regs;
88 list_add(&new->list, &mc_requests);
89 }
90 }
91 }
92 if (!list_empty(&mc_requests))
93 schedule_work(&mconsole_work);
94 reactivate_fd(fd, MCONSOLE_IRQ);
95 return IRQ_HANDLED;
96}
97
98void mconsole_version(struct mc_request *req)
99{
100 char version[256];
101
102 sprintf(version, "%s %s %s %s %s", utsname()->sysname,
103 utsname()->nodename, utsname()->release, utsname()->version,
104 utsname()->machine);
105 mconsole_reply(req, version, 0, 0);
106}
107
108void mconsole_log(struct mc_request *req)
109{
110 int len;
111 char *ptr = req->request.data;
112
113 ptr += strlen("log ");
114
115 len = req->len - (ptr - req->request.data);
116 printk(KERN_WARNING "%.*s", len, ptr);
117 mconsole_reply(req, "", 0, 0);
118}
119
120/* This is a more convoluted version of mconsole_proc, which has some stability
121 * problems; however, we need it fixed, because it is expected that UML users
122 * mount HPPFS instead of procfs on /proc. And we want mconsole_proc to still
123 * show the real procfs content, not the ones from hppfs.*/
124#if 0
125void mconsole_proc(struct mc_request *req)
126{
127 struct vfsmount *mnt = current->nsproxy->pid_ns->proc_mnt;
128 struct file *file;
129 int n;
130 char *ptr = req->request.data, *buf;
131 mm_segment_t old_fs = get_fs();
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 goto out;
140 }
141
142 buf = kmalloc(PAGE_SIZE, GFP_KERNEL);
143 if (buf == NULL) {
144 mconsole_reply(req, "Failed to allocate buffer", 1, 0);
145 goto out_fput;
146 }
147
148 if (file->f_op->read) {
149 do {
150 loff_t pos;
151 set_fs(KERNEL_DS);
152 n = vfs_read(file, buf, PAGE_SIZE - 1, &pos);
153 file_pos_write(file, pos);
154 set_fs(old_fs);
155 if (n >= 0) {
156 buf[n] = '\0';
157 mconsole_reply(req, buf, 0, (n > 0));
158 }
159 else {
160 mconsole_reply(req, "Read of file failed",
161 1, 0);
162 goto out_free;
163 }
164 } while (n > 0);
165 }
166 else mconsole_reply(req, "", 0, 0);
167
168 out_free:
169 kfree(buf);
170 out_fput:
171 fput(file);
172 out: ;
173}
174#endif
175
176void mconsole_proc(struct mc_request *req)
177{
178 char path[64];
179 char *buf;
180 int len;
181 int fd;
182 int first_chunk = 1;
183 char *ptr = req->request.data;
184
185 ptr += strlen("proc");
186 ptr = skip_spaces(ptr);
187 snprintf(path, sizeof(path), "/proc/%s", ptr);
188
189 fd = sys_open(path, 0, 0);
190 if (fd < 0) {
191 mconsole_reply(req, "Failed to open file", 1, 0);
192 printk(KERN_ERR "open %s: %d\n",path,fd);
193 goto out;
194 }
195
196 buf = kmalloc(PAGE_SIZE, GFP_KERNEL);
197 if (buf == NULL) {
198 mconsole_reply(req, "Failed to allocate buffer", 1, 0);
199 goto out_close;
200 }
201
202 for (;;) {
203 len = sys_read(fd, buf, PAGE_SIZE-1);
204 if (len < 0) {
205 mconsole_reply(req, "Read of file failed", 1, 0);
206 goto out_free;
207 }
208 /* Begin the file content on his own line. */
209 if (first_chunk) {
210 mconsole_reply(req, "\n", 0, 1);
211 first_chunk = 0;
212 }
213 if (len == PAGE_SIZE-1) {
214 buf[len] = '\0';
215 mconsole_reply(req, buf, 0, 1);
216 } else {
217 buf[len] = '\0';
218 mconsole_reply(req, buf, 0, 0);
219 break;
220 }
221 }
222
223 out_free:
224 kfree(buf);
225 out_close:
226 sys_close(fd);
227 out:
228 /* nothing */;
229}
230
231#define UML_MCONSOLE_HELPTEXT \
232"Commands: \n\
233 version - Get kernel version \n\
234 help - Print this message \n\
235 halt - Halt UML \n\
236 reboot - Reboot UML \n\
237 config <dev>=<config> - Add a new device to UML; \n\
238 same syntax as command line \n\
239 config <dev> - Query the configuration of a device \n\
240 remove <dev> - Remove a device from UML \n\
241 sysrq <letter> - Performs the SysRq action controlled by the letter \n\
242 cad - invoke the Ctrl-Alt-Del handler \n\
243 stop - pause the UML; it will do nothing until it receives a 'go' \n\
244 go - continue the UML after a 'stop' \n\
245 log <string> - make UML enter <string> into the kernel log\n\
246 proc <file> - returns the contents of the UML's /proc/<file>\n\
247 stack <pid> - returns the stack of the specified pid\n\
248"
249
250void mconsole_help(struct mc_request *req)
251{
252 mconsole_reply(req, UML_MCONSOLE_HELPTEXT, 0, 0);
253}
254
255void mconsole_halt(struct mc_request *req)
256{
257 mconsole_reply(req, "", 0, 0);
258 machine_halt();
259}
260
261void mconsole_reboot(struct mc_request *req)
262{
263 mconsole_reply(req, "", 0, 0);
264 machine_restart(NULL);
265}
266
267void mconsole_cad(struct mc_request *req)
268{
269 mconsole_reply(req, "", 0, 0);
270 ctrl_alt_del();
271}
272
273void mconsole_go(struct mc_request *req)
274{
275 mconsole_reply(req, "Not stopped", 1, 0);
276}
277
278void mconsole_stop(struct mc_request *req)
279{
280 deactivate_fd(req->originating_fd, MCONSOLE_IRQ);
281 os_set_fd_block(req->originating_fd, 1);
282 mconsole_reply(req, "stopped", 0, 0);
283 for (;;) {
284 if (!mconsole_get_request(req->originating_fd, req))
285 continue;
286 if (req->cmd->handler == mconsole_go)
287 break;
288 if (req->cmd->handler == mconsole_stop) {
289 mconsole_reply(req, "Already stopped", 1, 0);
290 continue;
291 }
292 if (req->cmd->handler == mconsole_sysrq) {
293 struct pt_regs *old_regs;
294 old_regs = set_irq_regs((struct pt_regs *)&req->regs);
295 mconsole_sysrq(req);
296 set_irq_regs(old_regs);
297 continue;
298 }
299 (*req->cmd->handler)(req);
300 }
301 os_set_fd_block(req->originating_fd, 0);
302 reactivate_fd(req->originating_fd, MCONSOLE_IRQ);
303 mconsole_reply(req, "", 0, 0);
304}
305
306static DEFINE_SPINLOCK(mc_devices_lock);
307static LIST_HEAD(mconsole_devices);
308
309void mconsole_register_dev(struct mc_device *new)
310{
311 spin_lock(&mc_devices_lock);
312 BUG_ON(!list_empty(&new->list));
313 list_add(&new->list, &mconsole_devices);
314 spin_unlock(&mc_devices_lock);
315}
316
317static struct mc_device *mconsole_find_dev(char *name)
318{
319 struct list_head *ele;
320 struct mc_device *dev;
321
322 list_for_each(ele, &mconsole_devices) {
323 dev = list_entry(ele, struct mc_device, list);
324 if (!strncmp(name, dev->name, strlen(dev->name)))
325 return dev;
326 }
327 return NULL;
328}
329
330#define UNPLUGGED_PER_PAGE \
331 ((PAGE_SIZE - sizeof(struct list_head)) / sizeof(unsigned long))
332
333struct unplugged_pages {
334 struct list_head list;
335 void *pages[UNPLUGGED_PER_PAGE];
336};
337
338static DEFINE_MUTEX(plug_mem_mutex);
339static unsigned long long unplugged_pages_count = 0;
340static LIST_HEAD(unplugged_pages);
341static int unplug_index = UNPLUGGED_PER_PAGE;
342
343static int mem_config(char *str, char **error_out)
344{
345 unsigned long long diff;
346 int err = -EINVAL, i, add;
347 char *ret;
348
349 if (str[0] != '=') {
350 *error_out = "Expected '=' after 'mem'";
351 goto out;
352 }
353
354 str++;
355 if (str[0] == '-')
356 add = 0;
357 else if (str[0] == '+') {
358 add = 1;
359 }
360 else {
361 *error_out = "Expected increment to start with '-' or '+'";
362 goto out;
363 }
364
365 str++;
366 diff = memparse(str, &ret);
367 if (*ret != '\0') {
368 *error_out = "Failed to parse memory increment";
369 goto out;
370 }
371
372 diff /= PAGE_SIZE;
373
374 mutex_lock(&plug_mem_mutex);
375 for (i = 0; i < diff; i++) {
376 struct unplugged_pages *unplugged;
377 void *addr;
378
379 if (add) {
380 if (list_empty(&unplugged_pages))
381 break;
382
383 unplugged = list_entry(unplugged_pages.next,
384 struct unplugged_pages, list);
385 if (unplug_index > 0)
386 addr = unplugged->pages[--unplug_index];
387 else {
388 list_del(&unplugged->list);
389 addr = unplugged;
390 unplug_index = UNPLUGGED_PER_PAGE;
391 }
392
393 free_page((unsigned long) addr);
394 unplugged_pages_count--;
395 }
396 else {
397 struct page *page;
398
399 page = alloc_page(GFP_ATOMIC);
400 if (page == NULL)
401 break;
402
403 unplugged = page_address(page);
404 if (unplug_index == UNPLUGGED_PER_PAGE) {
405 list_add(&unplugged->list, &unplugged_pages);
406 unplug_index = 0;
407 }
408 else {
409 struct list_head *entry = unplugged_pages.next;
410 addr = unplugged;
411
412 unplugged = list_entry(entry,
413 struct unplugged_pages,
414 list);
415 err = os_drop_memory(addr, PAGE_SIZE);
416 if (err) {
417 printk(KERN_ERR "Failed to release "
418 "memory - errno = %d\n", err);
419 *error_out = "Failed to release memory";
420 goto out_unlock;
421 }
422 unplugged->pages[unplug_index++] = addr;
423 }
424
425 unplugged_pages_count++;
426 }
427 }
428
429 err = 0;
430out_unlock:
431 mutex_unlock(&plug_mem_mutex);
432out:
433 return err;
434}
435
436static int mem_get_config(char *name, char *str, int size, char **error_out)
437{
438 char buf[sizeof("18446744073709551615")];
439 int len = 0;
440
441 sprintf(buf, "%ld", uml_physmem);
442 CONFIG_CHUNK(str, size, len, buf, 1);
443
444 return len;
445}
446
447static int mem_id(char **str, int *start_out, int *end_out)
448{
449 *start_out = 0;
450 *end_out = 0;
451
452 return 0;
453}
454
455static int mem_remove(int n, char **error_out)
456{
457 *error_out = "Memory doesn't support the remove operation";
458 return -EBUSY;
459}
460
461static struct mc_device mem_mc = {
462 .list = LIST_HEAD_INIT(mem_mc.list),
463 .name = "mem",
464 .config = mem_config,
465 .get_config = mem_get_config,
466 .id = mem_id,
467 .remove = mem_remove,
468};
469
470static int __init mem_mc_init(void)
471{
472 if (can_drop_memory())
473 mconsole_register_dev(&mem_mc);
474 else printk(KERN_ERR "Can't release memory to the host - memory "
475 "hotplug won't be supported\n");
476 return 0;
477}
478
479__initcall(mem_mc_init);
480
481#define CONFIG_BUF_SIZE 64
482
483static void mconsole_get_config(int (*get_config)(char *, char *, int,
484 char **),
485 struct mc_request *req, char *name)
486{
487 char default_buf[CONFIG_BUF_SIZE], *error, *buf;
488 int n, size;
489
490 if (get_config == NULL) {
491 mconsole_reply(req, "No get_config routine defined", 1, 0);
492 return;
493 }
494
495 error = NULL;
496 size = ARRAY_SIZE(default_buf);
497 buf = default_buf;
498
499 while (1) {
500 n = (*get_config)(name, buf, size, &error);
501 if (error != NULL) {
502 mconsole_reply(req, error, 1, 0);
503 goto out;
504 }
505
506 if (n <= size) {
507 mconsole_reply(req, buf, 0, 0);
508 goto out;
509 }
510
511 if (buf != default_buf)
512 kfree(buf);
513
514 size = n;
515 buf = kmalloc(size, GFP_KERNEL);
516 if (buf == NULL) {
517 mconsole_reply(req, "Failed to allocate buffer", 1, 0);
518 return;
519 }
520 }
521 out:
522 if (buf != default_buf)
523 kfree(buf);
524}
525
526void mconsole_config(struct mc_request *req)
527{
528 struct mc_device *dev;
529 char *ptr = req->request.data, *name, *error_string = "";
530 int err;
531
532 ptr += strlen("config");
533 ptr = skip_spaces(ptr);
534 dev = mconsole_find_dev(ptr);
535 if (dev == NULL) {
536 mconsole_reply(req, "Bad configuration option", 1, 0);
537 return;
538 }
539
540 name = &ptr[strlen(dev->name)];
541 ptr = name;
542 while ((*ptr != '=') && (*ptr != '\0'))
543 ptr++;
544
545 if (*ptr == '=') {
546 err = (*dev->config)(name, &error_string);
547 mconsole_reply(req, error_string, err, 0);
548 }
549 else mconsole_get_config(dev->get_config, req, name);
550}
551
552void mconsole_remove(struct mc_request *req)
553{
554 struct mc_device *dev;
555 char *ptr = req->request.data, *err_msg = "";
556 char error[256];
557 int err, start, end, n;
558
559 ptr += strlen("remove");
560 ptr = skip_spaces(ptr);
561 dev = mconsole_find_dev(ptr);
562 if (dev == NULL) {
563 mconsole_reply(req, "Bad remove option", 1, 0);
564 return;
565 }
566
567 ptr = &ptr[strlen(dev->name)];
568
569 err = 1;
570 n = (*dev->id)(&ptr, &start, &end);
571 if (n < 0) {
572 err_msg = "Couldn't parse device number";
573 goto out;
574 }
575 else if ((n < start) || (n > end)) {
576 sprintf(error, "Invalid device number - must be between "
577 "%d and %d", start, end);
578 err_msg = error;
579 goto out;
580 }
581
582 err_msg = NULL;
583 err = (*dev->remove)(n, &err_msg);
584 switch(err) {
585 case 0:
586 err_msg = "";
587 break;
588 case -ENODEV:
589 if (err_msg == NULL)
590 err_msg = "Device doesn't exist";
591 break;
592 case -EBUSY:
593 if (err_msg == NULL)
594 err_msg = "Device is currently open";
595 break;
596 default:
597 break;
598 }
599out:
600 mconsole_reply(req, err_msg, err, 0);
601}
602
603struct mconsole_output {
604 struct list_head list;
605 struct mc_request *req;
606};
607
608static DEFINE_SPINLOCK(client_lock);
609static LIST_HEAD(clients);
610static char console_buf[MCONSOLE_MAX_DATA];
611
612static void console_write(struct console *console, const char *string,
613 unsigned int len)
614{
615 struct list_head *ele;
616 int n;
617
618 if (list_empty(&clients))
619 return;
620
621 while (len > 0) {
622 n = min((size_t) len, ARRAY_SIZE(console_buf));
623 strncpy(console_buf, string, n);
624 string += n;
625 len -= n;
626
627 list_for_each(ele, &clients) {
628 struct mconsole_output *entry;
629
630 entry = list_entry(ele, struct mconsole_output, list);
631 mconsole_reply_len(entry->req, console_buf, n, 0, 1);
632 }
633 }
634}
635
636static struct console mc_console = { .name = "mc",
637 .write = console_write,
638 .flags = CON_ENABLED,
639 .index = -1 };
640
641static int mc_add_console(void)
642{
643 register_console(&mc_console);
644 return 0;
645}
646
647late_initcall(mc_add_console);
648
649static void with_console(struct mc_request *req, void (*proc)(void *),
650 void *arg)
651{
652 struct mconsole_output entry;
653 unsigned long flags;
654
655 entry.req = req;
656 spin_lock_irqsave(&client_lock, flags);
657 list_add(&entry.list, &clients);
658 spin_unlock_irqrestore(&client_lock, flags);
659
660 (*proc)(arg);
661
662 mconsole_reply_len(req, "", 0, 0, 0);
663
664 spin_lock_irqsave(&client_lock, flags);
665 list_del(&entry.list);
666 spin_unlock_irqrestore(&client_lock, flags);
667}
668
669#ifdef CONFIG_MAGIC_SYSRQ
670
671#include <linux/sysrq.h>
672
673static void sysrq_proc(void *arg)
674{
675 char *op = arg;
676 handle_sysrq(*op);
677}
678
679void mconsole_sysrq(struct mc_request *req)
680{
681 char *ptr = req->request.data;
682
683 ptr += strlen("sysrq");
684 ptr = skip_spaces(ptr);
685
686 /*
687 * With 'b', the system will shut down without a chance to reply,
688 * so in this case, we reply first.
689 */
690 if (*ptr == 'b')
691 mconsole_reply(req, "", 0, 0);
692
693 with_console(req, sysrq_proc, ptr);
694}
695#else
696void mconsole_sysrq(struct mc_request *req)
697{
698 mconsole_reply(req, "Sysrq not compiled in", 1, 0);
699}
700#endif
701
702static void stack_proc(void *arg)
703{
704 struct task_struct *from = current, *to = arg;
705
706 to->thread.saved_task = from;
707 switch_to(from, to, from);
708}
709
710/*
711 * Mconsole stack trace
712 * Added by Allan Graves, Jeff Dike
713 * Dumps a stacks registers to the linux console.
714 * Usage stack <pid>.
715 */
716void mconsole_stack(struct mc_request *req)
717{
718 char *ptr = req->request.data;
719 int pid_requested= -1;
720 struct task_struct *to = NULL;
721
722 /*
723 * Would be nice:
724 * 1) Send showregs output to mconsole.
725 * 2) Add a way to stack dump all pids.
726 */
727
728 ptr += strlen("stack");
729 ptr = skip_spaces(ptr);
730
731 /*
732 * Should really check for multiple pids or reject bad args here
733 */
734 /* What do the arguments in mconsole_reply mean? */
735 if (sscanf(ptr, "%d", &pid_requested) == 0) {
736 mconsole_reply(req, "Please specify a pid", 1, 0);
737 return;
738 }
739
740 to = find_task_by_pid_ns(pid_requested, &init_pid_ns);
741 if ((to == NULL) || (pid_requested == 0)) {
742 mconsole_reply(req, "Couldn't find that pid", 1, 0);
743 return;
744 }
745 with_console(req, stack_proc, to);
746}
747
748/*
749 * Changed by mconsole_setup, which is __setup, and called before SMP is
750 * active.
751 */
752static char *notify_socket = NULL;
753
754static int __init mconsole_init(void)
755{
756 /* long to avoid size mismatch warnings from gcc */
757 long sock;
758 int err;
759 char file[UNIX_PATH_MAX];
760
761 if (umid_file_name("mconsole", file, sizeof(file)))
762 return -1;
763 snprintf(mconsole_socket_name, sizeof(file), "%s", file);
764
765 sock = os_create_unix_socket(file, sizeof(file), 1);
766 if (sock < 0) {
767 printk(KERN_ERR "Failed to initialize management console\n");
768 return 1;
769 }
770 if (os_set_fd_block(sock, 0))
771 goto out;
772
773 register_reboot_notifier(&reboot_notifier);
774
775 err = um_request_irq(MCONSOLE_IRQ, sock, IRQ_READ, mconsole_interrupt,
776 IRQF_DISABLED | IRQF_SHARED | IRQF_SAMPLE_RANDOM,
777 "mconsole", (void *)sock);
778 if (err) {
779 printk(KERN_ERR "Failed to get IRQ for management console\n");
780 goto out;
781 }
782
783 if (notify_socket != NULL) {
784 notify_socket = kstrdup(notify_socket, GFP_KERNEL);
785 if (notify_socket != NULL)
786 mconsole_notify(notify_socket, MCONSOLE_SOCKET,
787 mconsole_socket_name,
788 strlen(mconsole_socket_name) + 1);
789 else printk(KERN_ERR "mconsole_setup failed to strdup "
790 "string\n");
791 }
792
793 printk(KERN_INFO "mconsole (version %d) initialized on %s\n",
794 MCONSOLE_VERSION, mconsole_socket_name);
795 return 0;
796
797 out:
798 os_close_file(sock);
799 return 1;
800}
801
802__initcall(mconsole_init);
803
804static ssize_t mconsole_proc_write(struct file *file,
805 const char __user *buffer, size_t count, loff_t *pos)
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
826static const struct file_operations mconsole_proc_fops = {
827 .owner = THIS_MODULE,
828 .write = mconsole_proc_write,
829 .llseek = noop_llseek,
830};
831
832static int create_proc_mconsole(void)
833{
834 struct proc_dir_entry *ent;
835
836 if (notify_socket == NULL)
837 return 0;
838
839 ent = proc_create("mconsole", 0200, NULL, &mconsole_proc_fops);
840 if (ent == NULL) {
841 printk(KERN_INFO "create_proc_mconsole : create_proc_entry "
842 "failed\n");
843 return 0;
844 }
845 return 0;
846}
847
848static DEFINE_SPINLOCK(notify_spinlock);
849
850void lock_notify(void)
851{
852 spin_lock(¬ify_spinlock);
853}
854
855void unlock_notify(void)
856{
857 spin_unlock(¬ify_spinlock);
858}
859
860__initcall(create_proc_mconsole);
861
862#define NOTIFY "notify:"
863
864static int mconsole_setup(char *str)
865{
866 if (!strncmp(str, NOTIFY, strlen(NOTIFY))) {
867 str += strlen(NOTIFY);
868 notify_socket = str;
869 }
870 else printk(KERN_ERR "mconsole_setup : Unknown option - '%s'\n", str);
871 return 1;
872}
873
874__setup("mconsole=", mconsole_setup);
875
876__uml_help(mconsole_setup,
877"mconsole=notify:<socket>\n"
878" Requests that the mconsole driver send a message to the named Unix\n"
879" socket containing the name of the mconsole socket. This also serves\n"
880" to notify outside processes when UML has booted far enough to respond\n"
881" to mconsole requests.\n\n"
882);
883
884static int notify_panic(struct notifier_block *self, unsigned long unused1,
885 void *ptr)
886{
887 char *message = ptr;
888
889 if (notify_socket == NULL)
890 return 0;
891
892 mconsole_notify(notify_socket, MCONSOLE_PANIC, message,
893 strlen(message) + 1);
894 return 0;
895}
896
897static struct notifier_block panic_exit_notifier = {
898 .notifier_call = notify_panic,
899 .next = NULL,
900 .priority = 1
901};
902
903static int add_notifier(void)
904{
905 atomic_notifier_chain_register(&panic_notifier_list,
906 &panic_exit_notifier);
907 return 0;
908}
909
910__initcall(add_notifier);
911
912char *mconsole_notify_socket(void)
913{
914 return notify_socket;
915}
916
917EXPORT_SYMBOL(mconsole_notify_socket);