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