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/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/socket.h>
20 #include <linux/un.h>
21 #include <linux/workqueue.h>
22 #include <linux/mutex.h>
23 #include <asm/uaccess.h>
24
25 #include "init.h"
26 #include "irq_kern.h"
27 #include "irq_user.h"
28 #include "kern_util.h"
29 #include "mconsole.h"
30 #include "mconsole_kern.h"
31 #include "os.h"
32
do_unlink_socket(struct notifier_block * notifier,unsigned long what,void * data)33 static int do_unlink_socket(struct notifier_block *notifier,
34 unsigned long what, void *data)
35 {
36 return mconsole_unlink_socket();
37 }
38
39
40 static struct notifier_block reboot_notifier = {
41 .notifier_call = do_unlink_socket,
42 .priority = 0,
43 };
44
45 /* Safe without explicit locking for now. Tasklets provide their own
46 * locking, and the interrupt handler is safe because it can't interrupt
47 * itself and it can only happen on CPU 0.
48 */
49
50 static LIST_HEAD(mc_requests);
51
mc_work_proc(struct work_struct * unused)52 static void mc_work_proc(struct work_struct *unused)
53 {
54 struct mconsole_entry *req;
55 unsigned long flags;
56
57 while (!list_empty(&mc_requests)) {
58 local_irq_save(flags);
59 req = list_entry(mc_requests.next, struct mconsole_entry, list);
60 list_del(&req->list);
61 local_irq_restore(flags);
62 req->request.cmd->handler(&req->request);
63 kfree(req);
64 }
65 }
66
67 static DECLARE_WORK(mconsole_work, mc_work_proc);
68
mconsole_interrupt(int irq,void * dev_id)69 static irqreturn_t mconsole_interrupt(int irq, void *dev_id)
70 {
71 /* long to avoid size mismatch warnings from gcc */
72 long fd;
73 struct mconsole_entry *new;
74 static struct mc_request req; /* that's OK */
75
76 fd = (long) dev_id;
77 while (mconsole_get_request(fd, &req)) {
78 if (req.cmd->context == MCONSOLE_INTR)
79 (*req.cmd->handler)(&req);
80 else {
81 new = kmalloc(sizeof(*new), GFP_NOWAIT);
82 if (new == NULL)
83 mconsole_reply(&req, "Out of memory", 1, 0);
84 else {
85 new->request = req;
86 new->request.regs = get_irq_regs()->regs;
87 list_add(&new->list, &mc_requests);
88 }
89 }
90 }
91 if (!list_empty(&mc_requests))
92 schedule_work(&mconsole_work);
93 reactivate_fd(fd, MCONSOLE_IRQ);
94 return IRQ_HANDLED;
95 }
96
mconsole_version(struct mc_request * req)97 void mconsole_version(struct mc_request *req)
98 {
99 char version[256];
100
101 sprintf(version, "%s %s %s %s %s", utsname()->sysname,
102 utsname()->nodename, utsname()->release, utsname()->version,
103 utsname()->machine);
104 mconsole_reply(req, version, 0, 0);
105 }
106
mconsole_log(struct mc_request * req)107 void mconsole_log(struct mc_request *req)
108 {
109 int len;
110 char *ptr = req->request.data;
111
112 ptr += strlen("log ");
113
114 len = req->len - (ptr - req->request.data);
115 printk(KERN_WARNING "%.*s", len, ptr);
116 mconsole_reply(req, "", 0, 0);
117 }
118
119 /* This is a more convoluted version of mconsole_proc, which has some stability
120 * problems; however, we need it fixed, because it is expected that UML users
121 * mount HPPFS instead of procfs on /proc. And we want mconsole_proc to still
122 * show the real procfs content, not the ones from hppfs.*/
123 #if 0
124 void mconsole_proc(struct mc_request *req)
125 {
126 struct nameidata nd;
127 struct file_system_type *proc;
128 struct super_block *super;
129 struct file *file;
130 int n, err;
131 char *ptr = req->request.data, *buf;
132
133 ptr += strlen("proc");
134 while (isspace(*ptr)) ptr++;
135
136 proc = get_fs_type("proc");
137 if (proc == NULL) {
138 mconsole_reply(req, "procfs not registered", 1, 0);
139 goto out;
140 }
141
142 super = (*proc->get_sb)(proc, 0, NULL, NULL);
143 put_filesystem(proc);
144 if (super == NULL) {
145 mconsole_reply(req, "Failed to get procfs superblock", 1, 0);
146 goto out;
147 }
148 up_write(&super->s_umount);
149
150 nd.path.dentry = super->s_root;
151 nd.path.mnt = NULL;
152 nd.flags = O_RDONLY + 1;
153 nd.last_type = LAST_ROOT;
154
155 /* START: it was experienced that the stability problems are closed
156 * if commenting out these two calls + the below read cycle. To
157 * make UML crash again, it was enough to readd either one.*/
158 err = link_path_walk(ptr, &nd);
159 if (err) {
160 mconsole_reply(req, "Failed to look up file", 1, 0);
161 goto out_kill;
162 }
163
164 file = dentry_open(nd.path.dentry, nd.path.mnt, O_RDONLY,
165 current_cred());
166 if (IS_ERR(file)) {
167 mconsole_reply(req, "Failed to open file", 1, 0);
168 goto out_kill;
169 }
170 /*END*/
171
172 buf = kmalloc(PAGE_SIZE, GFP_KERNEL);
173 if (buf == NULL) {
174 mconsole_reply(req, "Failed to allocate buffer", 1, 0);
175 goto out_fput;
176 }
177
178 if ((file->f_op != NULL) && (file->f_op->read != NULL)) {
179 do {
180 n = (*file->f_op->read)(file, buf, PAGE_SIZE - 1,
181 &file->f_pos);
182 if (n >= 0) {
183 buf[n] = '\0';
184 mconsole_reply(req, buf, 0, (n > 0));
185 }
186 else {
187 mconsole_reply(req, "Read of file failed",
188 1, 0);
189 goto out_free;
190 }
191 } while (n > 0);
192 }
193 else mconsole_reply(req, "", 0, 0);
194
195 out_free:
196 kfree(buf);
197 out_fput:
198 fput(file);
199 out_kill:
200 deactivate_super(super);
201 out: ;
202 }
203 #endif
204
mconsole_proc(struct mc_request * req)205 void mconsole_proc(struct mc_request *req)
206 {
207 char path[64];
208 char *buf;
209 int len;
210 int fd;
211 int first_chunk = 1;
212 char *ptr = req->request.data;
213
214 ptr += strlen("proc");
215 while (isspace(*ptr))
216 ptr++;
217 snprintf(path, sizeof(path), "/proc/%s", ptr);
218
219 fd = sys_open(path, 0, 0);
220 if (fd < 0) {
221 mconsole_reply(req, "Failed to open file", 1, 0);
222 printk(KERN_ERR "open %s: %d\n",path,fd);
223 goto out;
224 }
225
226 buf = kmalloc(PAGE_SIZE, GFP_KERNEL);
227 if (buf == NULL) {
228 mconsole_reply(req, "Failed to allocate buffer", 1, 0);
229 goto out_close;
230 }
231
232 for (;;) {
233 len = sys_read(fd, buf, PAGE_SIZE-1);
234 if (len < 0) {
235 mconsole_reply(req, "Read of file failed", 1, 0);
236 goto out_free;
237 }
238 /* Begin the file content on his own line. */
239 if (first_chunk) {
240 mconsole_reply(req, "\n", 0, 1);
241 first_chunk = 0;
242 }
243 if (len == PAGE_SIZE-1) {
244 buf[len] = '\0';
245 mconsole_reply(req, buf, 0, 1);
246 } else {
247 buf[len] = '\0';
248 mconsole_reply(req, buf, 0, 0);
249 break;
250 }
251 }
252
253 out_free:
254 kfree(buf);
255 out_close:
256 sys_close(fd);
257 out:
258 /* nothing */;
259 }
260
261 #define UML_MCONSOLE_HELPTEXT \
262 "Commands: \n\
263 version - Get kernel version \n\
264 help - Print this message \n\
265 halt - Halt UML \n\
266 reboot - Reboot UML \n\
267 config <dev>=<config> - Add a new device to UML; \n\
268 same syntax as command line \n\
269 config <dev> - Query the configuration of a device \n\
270 remove <dev> - Remove a device from UML \n\
271 sysrq <letter> - Performs the SysRq action controlled by the letter \n\
272 cad - invoke the Ctrl-Alt-Del handler \n\
273 stop - pause the UML; it will do nothing until it receives a 'go' \n\
274 go - continue the UML after a 'stop' \n\
275 log <string> - make UML enter <string> into the kernel log\n\
276 proc <file> - returns the contents of the UML's /proc/<file>\n\
277 stack <pid> - returns the stack of the specified pid\n\
278 "
279
mconsole_help(struct mc_request * req)280 void mconsole_help(struct mc_request *req)
281 {
282 mconsole_reply(req, UML_MCONSOLE_HELPTEXT, 0, 0);
283 }
284
mconsole_halt(struct mc_request * req)285 void mconsole_halt(struct mc_request *req)
286 {
287 mconsole_reply(req, "", 0, 0);
288 machine_halt();
289 }
290
mconsole_reboot(struct mc_request * req)291 void mconsole_reboot(struct mc_request *req)
292 {
293 mconsole_reply(req, "", 0, 0);
294 machine_restart(NULL);
295 }
296
mconsole_cad(struct mc_request * req)297 void mconsole_cad(struct mc_request *req)
298 {
299 mconsole_reply(req, "", 0, 0);
300 ctrl_alt_del();
301 }
302
mconsole_go(struct mc_request * req)303 void mconsole_go(struct mc_request *req)
304 {
305 mconsole_reply(req, "Not stopped", 1, 0);
306 }
307
mconsole_stop(struct mc_request * req)308 void mconsole_stop(struct mc_request *req)
309 {
310 deactivate_fd(req->originating_fd, MCONSOLE_IRQ);
311 os_set_fd_block(req->originating_fd, 1);
312 mconsole_reply(req, "stopped", 0, 0);
313 for (;;) {
314 if (!mconsole_get_request(req->originating_fd, req))
315 continue;
316 if (req->cmd->handler == mconsole_go)
317 break;
318 if (req->cmd->handler == mconsole_stop) {
319 mconsole_reply(req, "Already stopped", 1, 0);
320 continue;
321 }
322 if (req->cmd->handler == mconsole_sysrq) {
323 struct pt_regs *old_regs;
324 old_regs = set_irq_regs((struct pt_regs *)&req->regs);
325 mconsole_sysrq(req);
326 set_irq_regs(old_regs);
327 continue;
328 }
329 (*req->cmd->handler)(req);
330 }
331 os_set_fd_block(req->originating_fd, 0);
332 reactivate_fd(req->originating_fd, MCONSOLE_IRQ);
333 mconsole_reply(req, "", 0, 0);
334 }
335
336 static DEFINE_SPINLOCK(mc_devices_lock);
337 static LIST_HEAD(mconsole_devices);
338
mconsole_register_dev(struct mc_device * new)339 void mconsole_register_dev(struct mc_device *new)
340 {
341 spin_lock(&mc_devices_lock);
342 BUG_ON(!list_empty(&new->list));
343 list_add(&new->list, &mconsole_devices);
344 spin_unlock(&mc_devices_lock);
345 }
346
mconsole_find_dev(char * name)347 static struct mc_device *mconsole_find_dev(char *name)
348 {
349 struct list_head *ele;
350 struct mc_device *dev;
351
352 list_for_each(ele, &mconsole_devices) {
353 dev = list_entry(ele, struct mc_device, list);
354 if (!strncmp(name, dev->name, strlen(dev->name)))
355 return dev;
356 }
357 return NULL;
358 }
359
360 #define UNPLUGGED_PER_PAGE \
361 ((PAGE_SIZE - sizeof(struct list_head)) / sizeof(unsigned long))
362
363 struct unplugged_pages {
364 struct list_head list;
365 void *pages[UNPLUGGED_PER_PAGE];
366 };
367
368 static DEFINE_MUTEX(plug_mem_mutex);
369 static unsigned long long unplugged_pages_count = 0;
370 static LIST_HEAD(unplugged_pages);
371 static int unplug_index = UNPLUGGED_PER_PAGE;
372
mem_config(char * str,char ** error_out)373 static int mem_config(char *str, char **error_out)
374 {
375 unsigned long long diff;
376 int err = -EINVAL, i, add;
377 char *ret;
378
379 if (str[0] != '=') {
380 *error_out = "Expected '=' after 'mem'";
381 goto out;
382 }
383
384 str++;
385 if (str[0] == '-')
386 add = 0;
387 else if (str[0] == '+') {
388 add = 1;
389 }
390 else {
391 *error_out = "Expected increment to start with '-' or '+'";
392 goto out;
393 }
394
395 str++;
396 diff = memparse(str, &ret);
397 if (*ret != '\0') {
398 *error_out = "Failed to parse memory increment";
399 goto out;
400 }
401
402 diff /= PAGE_SIZE;
403
404 mutex_lock(&plug_mem_mutex);
405 for (i = 0; i < diff; i++) {
406 struct unplugged_pages *unplugged;
407 void *addr;
408
409 if (add) {
410 if (list_empty(&unplugged_pages))
411 break;
412
413 unplugged = list_entry(unplugged_pages.next,
414 struct unplugged_pages, list);
415 if (unplug_index > 0)
416 addr = unplugged->pages[--unplug_index];
417 else {
418 list_del(&unplugged->list);
419 addr = unplugged;
420 unplug_index = UNPLUGGED_PER_PAGE;
421 }
422
423 free_page((unsigned long) addr);
424 unplugged_pages_count--;
425 }
426 else {
427 struct page *page;
428
429 page = alloc_page(GFP_ATOMIC);
430 if (page == NULL)
431 break;
432
433 unplugged = page_address(page);
434 if (unplug_index == UNPLUGGED_PER_PAGE) {
435 list_add(&unplugged->list, &unplugged_pages);
436 unplug_index = 0;
437 }
438 else {
439 struct list_head *entry = unplugged_pages.next;
440 addr = unplugged;
441
442 unplugged = list_entry(entry,
443 struct unplugged_pages,
444 list);
445 err = os_drop_memory(addr, PAGE_SIZE);
446 if (err) {
447 printk(KERN_ERR "Failed to release "
448 "memory - errno = %d\n", err);
449 *error_out = "Failed to release memory";
450 goto out_unlock;
451 }
452 unplugged->pages[unplug_index++] = addr;
453 }
454
455 unplugged_pages_count++;
456 }
457 }
458
459 err = 0;
460 out_unlock:
461 mutex_unlock(&plug_mem_mutex);
462 out:
463 return err;
464 }
465
mem_get_config(char * name,char * str,int size,char ** error_out)466 static int mem_get_config(char *name, char *str, int size, char **error_out)
467 {
468 char buf[sizeof("18446744073709551615")];
469 int len = 0;
470
471 sprintf(buf, "%ld", uml_physmem);
472 CONFIG_CHUNK(str, size, len, buf, 1);
473
474 return len;
475 }
476
mem_id(char ** str,int * start_out,int * end_out)477 static int mem_id(char **str, int *start_out, int *end_out)
478 {
479 *start_out = 0;
480 *end_out = 0;
481
482 return 0;
483 }
484
mem_remove(int n,char ** error_out)485 static int mem_remove(int n, char **error_out)
486 {
487 *error_out = "Memory doesn't support the remove operation";
488 return -EBUSY;
489 }
490
491 static struct mc_device mem_mc = {
492 .list = LIST_HEAD_INIT(mem_mc.list),
493 .name = "mem",
494 .config = mem_config,
495 .get_config = mem_get_config,
496 .id = mem_id,
497 .remove = mem_remove,
498 };
499
mem_mc_init(void)500 static int __init mem_mc_init(void)
501 {
502 if (can_drop_memory())
503 mconsole_register_dev(&mem_mc);
504 else printk(KERN_ERR "Can't release memory to the host - memory "
505 "hotplug won't be supported\n");
506 return 0;
507 }
508
509 __initcall(mem_mc_init);
510
511 #define CONFIG_BUF_SIZE 64
512
mconsole_get_config(int (* get_config)(char *,char *,int,char **),struct mc_request * req,char * name)513 static void mconsole_get_config(int (*get_config)(char *, char *, int,
514 char **),
515 struct mc_request *req, char *name)
516 {
517 char default_buf[CONFIG_BUF_SIZE], *error, *buf;
518 int n, size;
519
520 if (get_config == NULL) {
521 mconsole_reply(req, "No get_config routine defined", 1, 0);
522 return;
523 }
524
525 error = NULL;
526 size = ARRAY_SIZE(default_buf);
527 buf = default_buf;
528
529 while (1) {
530 n = (*get_config)(name, buf, size, &error);
531 if (error != NULL) {
532 mconsole_reply(req, error, 1, 0);
533 goto out;
534 }
535
536 if (n <= size) {
537 mconsole_reply(req, buf, 0, 0);
538 goto out;
539 }
540
541 if (buf != default_buf)
542 kfree(buf);
543
544 size = n;
545 buf = kmalloc(size, GFP_KERNEL);
546 if (buf == NULL) {
547 mconsole_reply(req, "Failed to allocate buffer", 1, 0);
548 return;
549 }
550 }
551 out:
552 if (buf != default_buf)
553 kfree(buf);
554 }
555
mconsole_config(struct mc_request * req)556 void mconsole_config(struct mc_request *req)
557 {
558 struct mc_device *dev;
559 char *ptr = req->request.data, *name, *error_string = "";
560 int err;
561
562 ptr += strlen("config");
563 while (isspace(*ptr))
564 ptr++;
565 dev = mconsole_find_dev(ptr);
566 if (dev == NULL) {
567 mconsole_reply(req, "Bad configuration option", 1, 0);
568 return;
569 }
570
571 name = &ptr[strlen(dev->name)];
572 ptr = name;
573 while ((*ptr != '=') && (*ptr != '\0'))
574 ptr++;
575
576 if (*ptr == '=') {
577 err = (*dev->config)(name, &error_string);
578 mconsole_reply(req, error_string, err, 0);
579 }
580 else mconsole_get_config(dev->get_config, req, name);
581 }
582
mconsole_remove(struct mc_request * req)583 void mconsole_remove(struct mc_request *req)
584 {
585 struct mc_device *dev;
586 char *ptr = req->request.data, *err_msg = "";
587 char error[256];
588 int err, start, end, n;
589
590 ptr += strlen("remove");
591 while (isspace(*ptr)) ptr++;
592 dev = mconsole_find_dev(ptr);
593 if (dev == NULL) {
594 mconsole_reply(req, "Bad remove option", 1, 0);
595 return;
596 }
597
598 ptr = &ptr[strlen(dev->name)];
599
600 err = 1;
601 n = (*dev->id)(&ptr, &start, &end);
602 if (n < 0) {
603 err_msg = "Couldn't parse device number";
604 goto out;
605 }
606 else if ((n < start) || (n > end)) {
607 sprintf(error, "Invalid device number - must be between "
608 "%d and %d", start, end);
609 err_msg = error;
610 goto out;
611 }
612
613 err_msg = NULL;
614 err = (*dev->remove)(n, &err_msg);
615 switch(err) {
616 case 0:
617 err_msg = "";
618 break;
619 case -ENODEV:
620 if (err_msg == NULL)
621 err_msg = "Device doesn't exist";
622 break;
623 case -EBUSY:
624 if (err_msg == NULL)
625 err_msg = "Device is currently open";
626 break;
627 default:
628 break;
629 }
630 out:
631 mconsole_reply(req, err_msg, err, 0);
632 }
633
634 struct mconsole_output {
635 struct list_head list;
636 struct mc_request *req;
637 };
638
639 static DEFINE_SPINLOCK(client_lock);
640 static LIST_HEAD(clients);
641 static char console_buf[MCONSOLE_MAX_DATA];
642
console_write(struct console * console,const char * string,unsigned int len)643 static void console_write(struct console *console, const char *string,
644 unsigned int len)
645 {
646 struct list_head *ele;
647 int n;
648
649 if (list_empty(&clients))
650 return;
651
652 while (len > 0) {
653 n = min((size_t) len, ARRAY_SIZE(console_buf));
654 strncpy(console_buf, string, n);
655 string += n;
656 len -= n;
657
658 list_for_each(ele, &clients) {
659 struct mconsole_output *entry;
660
661 entry = list_entry(ele, struct mconsole_output, list);
662 mconsole_reply_len(entry->req, console_buf, n, 0, 1);
663 }
664 }
665 }
666
667 static struct console mc_console = { .name = "mc",
668 .write = console_write,
669 .flags = CON_ENABLED,
670 .index = -1 };
671
mc_add_console(void)672 static int mc_add_console(void)
673 {
674 register_console(&mc_console);
675 return 0;
676 }
677
678 late_initcall(mc_add_console);
679
with_console(struct mc_request * req,void (* proc)(void *),void * arg)680 static void with_console(struct mc_request *req, void (*proc)(void *),
681 void *arg)
682 {
683 struct mconsole_output entry;
684 unsigned long flags;
685
686 entry.req = req;
687 spin_lock_irqsave(&client_lock, flags);
688 list_add(&entry.list, &clients);
689 spin_unlock_irqrestore(&client_lock, flags);
690
691 (*proc)(arg);
692
693 mconsole_reply_len(req, "", 0, 0, 0);
694
695 spin_lock_irqsave(&client_lock, flags);
696 list_del(&entry.list);
697 spin_unlock_irqrestore(&client_lock, flags);
698 }
699
700 #ifdef CONFIG_MAGIC_SYSRQ
701
702 #include <linux/sysrq.h>
703
sysrq_proc(void * arg)704 static void sysrq_proc(void *arg)
705 {
706 char *op = arg;
707 handle_sysrq(*op, NULL);
708 }
709
mconsole_sysrq(struct mc_request * req)710 void mconsole_sysrq(struct mc_request *req)
711 {
712 char *ptr = req->request.data;
713
714 ptr += strlen("sysrq");
715 while (isspace(*ptr)) ptr++;
716
717 /*
718 * With 'b', the system will shut down without a chance to reply,
719 * so in this case, we reply first.
720 */
721 if (*ptr == 'b')
722 mconsole_reply(req, "", 0, 0);
723
724 with_console(req, sysrq_proc, ptr);
725 }
726 #else
mconsole_sysrq(struct mc_request * req)727 void mconsole_sysrq(struct mc_request *req)
728 {
729 mconsole_reply(req, "Sysrq not compiled in", 1, 0);
730 }
731 #endif
732
stack_proc(void * arg)733 static void stack_proc(void *arg)
734 {
735 struct task_struct *from = current, *to = arg;
736
737 to->thread.saved_task = from;
738 switch_to(from, to, from);
739 }
740
741 /*
742 * Mconsole stack trace
743 * Added by Allan Graves, Jeff Dike
744 * Dumps a stacks registers to the linux console.
745 * Usage stack <pid>.
746 */
mconsole_stack(struct mc_request * req)747 void mconsole_stack(struct mc_request *req)
748 {
749 char *ptr = req->request.data;
750 int pid_requested= -1;
751 struct task_struct *to = NULL;
752
753 /*
754 * Would be nice:
755 * 1) Send showregs output to mconsole.
756 * 2) Add a way to stack dump all pids.
757 */
758
759 ptr += strlen("stack");
760 while (isspace(*ptr))
761 ptr++;
762
763 /*
764 * Should really check for multiple pids or reject bad args here
765 */
766 /* What do the arguments in mconsole_reply mean? */
767 if (sscanf(ptr, "%d", &pid_requested) == 0) {
768 mconsole_reply(req, "Please specify a pid", 1, 0);
769 return;
770 }
771
772 to = find_task_by_pid_ns(pid_requested, &init_pid_ns);
773 if ((to == NULL) || (pid_requested == 0)) {
774 mconsole_reply(req, "Couldn't find that pid", 1, 0);
775 return;
776 }
777 with_console(req, stack_proc, to);
778 }
779
780 /*
781 * Changed by mconsole_setup, which is __setup, and called before SMP is
782 * active.
783 */
784 static char *notify_socket = NULL;
785
mconsole_init(void)786 static int __init mconsole_init(void)
787 {
788 /* long to avoid size mismatch warnings from gcc */
789 long sock;
790 int err;
791 char file[UNIX_PATH_MAX];
792
793 if (umid_file_name("mconsole", file, sizeof(file)))
794 return -1;
795 snprintf(mconsole_socket_name, sizeof(file), "%s", file);
796
797 sock = os_create_unix_socket(file, sizeof(file), 1);
798 if (sock < 0) {
799 printk(KERN_ERR "Failed to initialize management console\n");
800 return 1;
801 }
802 if (os_set_fd_block(sock, 0))
803 goto out;
804
805 register_reboot_notifier(&reboot_notifier);
806
807 err = um_request_irq(MCONSOLE_IRQ, sock, IRQ_READ, mconsole_interrupt,
808 IRQF_DISABLED | IRQF_SHARED | IRQF_SAMPLE_RANDOM,
809 "mconsole", (void *)sock);
810 if (err) {
811 printk(KERN_ERR "Failed to get IRQ for management console\n");
812 goto out;
813 }
814
815 if (notify_socket != NULL) {
816 notify_socket = kstrdup(notify_socket, GFP_KERNEL);
817 if (notify_socket != NULL)
818 mconsole_notify(notify_socket, MCONSOLE_SOCKET,
819 mconsole_socket_name,
820 strlen(mconsole_socket_name) + 1);
821 else printk(KERN_ERR "mconsole_setup failed to strdup "
822 "string\n");
823 }
824
825 printk(KERN_INFO "mconsole (version %d) initialized on %s\n",
826 MCONSOLE_VERSION, mconsole_socket_name);
827 return 0;
828
829 out:
830 os_close_file(sock);
831 return 1;
832 }
833
834 __initcall(mconsole_init);
835
write_proc_mconsole(struct file * file,const char __user * buffer,unsigned long count,void * data)836 static int write_proc_mconsole(struct file *file, const char __user *buffer,
837 unsigned long count, void *data)
838 {
839 char *buf;
840
841 buf = kmalloc(count + 1, GFP_KERNEL);
842 if (buf == NULL)
843 return -ENOMEM;
844
845 if (copy_from_user(buf, buffer, count)) {
846 count = -EFAULT;
847 goto out;
848 }
849
850 buf[count] = '\0';
851
852 mconsole_notify(notify_socket, MCONSOLE_USER_NOTIFY, buf, count);
853 out:
854 kfree(buf);
855 return count;
856 }
857
create_proc_mconsole(void)858 static int create_proc_mconsole(void)
859 {
860 struct proc_dir_entry *ent;
861
862 if (notify_socket == NULL)
863 return 0;
864
865 ent = create_proc_entry("mconsole", S_IFREG | 0200, NULL);
866 if (ent == NULL) {
867 printk(KERN_INFO "create_proc_mconsole : create_proc_entry "
868 "failed\n");
869 return 0;
870 }
871
872 ent->read_proc = NULL;
873 ent->write_proc = write_proc_mconsole;
874 return 0;
875 }
876
877 static DEFINE_SPINLOCK(notify_spinlock);
878
lock_notify(void)879 void lock_notify(void)
880 {
881 spin_lock(¬ify_spinlock);
882 }
883
unlock_notify(void)884 void unlock_notify(void)
885 {
886 spin_unlock(¬ify_spinlock);
887 }
888
889 __initcall(create_proc_mconsole);
890
891 #define NOTIFY "notify:"
892
mconsole_setup(char * str)893 static int mconsole_setup(char *str)
894 {
895 if (!strncmp(str, NOTIFY, strlen(NOTIFY))) {
896 str += strlen(NOTIFY);
897 notify_socket = str;
898 }
899 else printk(KERN_ERR "mconsole_setup : Unknown option - '%s'\n", str);
900 return 1;
901 }
902
903 __setup("mconsole=", mconsole_setup);
904
905 __uml_help(mconsole_setup,
906 "mconsole=notify:<socket>\n"
907 " Requests that the mconsole driver send a message to the named Unix\n"
908 " socket containing the name of the mconsole socket. This also serves\n"
909 " to notify outside processes when UML has booted far enough to respond\n"
910 " to mconsole requests.\n\n"
911 );
912
notify_panic(struct notifier_block * self,unsigned long unused1,void * ptr)913 static int notify_panic(struct notifier_block *self, unsigned long unused1,
914 void *ptr)
915 {
916 char *message = ptr;
917
918 if (notify_socket == NULL)
919 return 0;
920
921 mconsole_notify(notify_socket, MCONSOLE_PANIC, message,
922 strlen(message) + 1);
923 return 0;
924 }
925
926 static struct notifier_block panic_exit_notifier = {
927 .notifier_call = notify_panic,
928 .next = NULL,
929 .priority = 1
930 };
931
add_notifier(void)932 static int add_notifier(void)
933 {
934 atomic_notifier_chain_register(&panic_notifier_list,
935 &panic_exit_notifier);
936 return 0;
937 }
938
939 __initcall(add_notifier);
940
mconsole_notify_socket(void)941 char *mconsole_notify_socket(void)
942 {
943 return notify_socket;
944 }
945
946 EXPORT_SYMBOL(mconsole_notify_socket);
947