2 * Copyright (C) 2001 Lennert Buytenhek (buytenh@gnu.org)
3 * Copyright (C) 2001 - 2003 Jeff Dike (jdike@addtoit.com)
4 * Licensed under the GPL
7 #include "linux/kernel.h"
8 #include "linux/slab.h"
9 #include "linux/init.h"
10 #include "linux/notifier.h"
11 #include "linux/reboot.h"
12 #include "linux/utsname.h"
13 #include "linux/ctype.h"
14 #include "linux/interrupt.h"
15 #include "linux/sysrq.h"
16 #include "linux/workqueue.h"
17 #include "linux/module.h"
18 #include "linux/file.h"
20 #include "linux/namei.h"
21 #include "linux/proc_fs.h"
22 #include "linux/syscalls.h"
23 #include "linux/list.h"
25 #include "linux/console.h"
26 #include "linux/vs_cvirt.h"
28 #include "asm/uaccess.h"
29 #include "user_util.h"
30 #include "kern_util.h"
33 #include "mconsole_kern.h"
39 #include "choose-mode.h"
41 static int do_unlink_socket(struct notifier_block *notifier,
42 unsigned long what, void *data)
44 return(mconsole_unlink_socket());
48 static struct notifier_block reboot_notifier = {
49 .notifier_call = do_unlink_socket,
53 /* Safe without explicit locking for now. Tasklets provide their own
54 * locking, and the interrupt handler is safe because it can't interrupt
55 * itself and it can only happen on CPU 0.
58 static LIST_HEAD(mc_requests);
60 static void mc_work_proc(void *unused)
62 struct mconsole_entry *req;
65 while(!list_empty(&mc_requests)){
66 local_irq_save(flags);
67 req = list_entry(mc_requests.next, struct mconsole_entry,
70 local_irq_restore(flags);
71 req->request.cmd->handler(&req->request);
76 static DECLARE_WORK(mconsole_work, mc_work_proc, NULL);
78 static irqreturn_t mconsole_interrupt(int irq, void *dev_id,
81 /* long to avoid size mismatch warnings from gcc */
83 struct mconsole_entry *new;
84 struct mc_request req;
87 while (mconsole_get_request(fd, &req)){
88 if(req.cmd->context == MCONSOLE_INTR)
89 (*req.cmd->handler)(&req);
91 new = kmalloc(sizeof(*new), GFP_NOWAIT);
93 mconsole_reply(&req, "Out of memory", 1, 0);
96 list_add(&new->list, &mc_requests);
100 if(!list_empty(&mc_requests))
101 schedule_work(&mconsole_work);
102 reactivate_fd(fd, MCONSOLE_IRQ);
106 void mconsole_version(struct mc_request *req)
110 sprintf(version, "%s %s %s %s %s", system_utsname.sysname,
111 system_utsname.nodename, system_utsname.release,
112 system_utsname.version, system_utsname.machine);
113 mconsole_reply(req, version, 0, 0);
116 void mconsole_log(struct mc_request *req)
119 char *ptr = req->request.data;
121 ptr += strlen("log ");
123 len = req->len - (ptr - req->request.data);
124 printk("%.*s", len, ptr);
125 mconsole_reply(req, "", 0, 0);
128 /* This is a more convoluted version of mconsole_proc, which has some stability
129 * problems; however, we need it fixed, because it is expected that UML users
130 * mount HPPFS instead of procfs on /proc. And we want mconsole_proc to still
131 * show the real procfs content, not the ones from hppfs.*/
133 void mconsole_proc(struct mc_request *req)
136 struct file_system_type *proc;
137 struct super_block *super;
140 char *ptr = req->request.data, *buf;
142 ptr += strlen("proc");
143 while(isspace(*ptr)) ptr++;
145 proc = get_fs_type("proc");
147 mconsole_reply(req, "procfs not registered", 1, 0);
151 super = (*proc->get_sb)(proc, 0, NULL, NULL);
152 put_filesystem(proc);
154 mconsole_reply(req, "Failed to get procfs superblock", 1, 0);
157 up_write(&super->s_umount);
159 nd.dentry = super->s_root;
161 nd.flags = O_RDONLY + 1;
162 nd.last_type = LAST_ROOT;
164 /* START: it was experienced that the stability problems are closed
165 * if commenting out these two calls + the below read cycle. To
166 * make UML crash again, it was enough to readd either one.*/
167 err = link_path_walk(ptr, &nd);
169 mconsole_reply(req, "Failed to look up file", 1, 0);
173 file = dentry_open(nd.dentry, nd.mnt, O_RDONLY);
175 mconsole_reply(req, "Failed to open file", 1, 0);
180 buf = kmalloc(PAGE_SIZE, GFP_KERNEL);
182 mconsole_reply(req, "Failed to allocate buffer", 1, 0);
186 if((file->f_op != NULL) && (file->f_op->read != NULL)){
188 n = (*file->f_op->read)(file, buf, PAGE_SIZE - 1,
192 mconsole_reply(req, buf, 0, (n > 0));
195 mconsole_reply(req, "Read of file failed",
201 else mconsole_reply(req, "", 0, 0);
208 deactivate_super(super);
213 void mconsole_proc(struct mc_request *req)
220 char *ptr = req->request.data;
222 ptr += strlen("proc");
223 while(isspace(*ptr)) ptr++;
224 snprintf(path, sizeof(path), "/proc/%s", ptr);
226 fd = sys_open(path, 0, 0);
228 mconsole_reply(req, "Failed to open file", 1, 0);
229 printk("open %s: %d\n",path,fd);
233 buf = kmalloc(PAGE_SIZE, GFP_KERNEL);
235 mconsole_reply(req, "Failed to allocate buffer", 1, 0);
240 len = sys_read(fd, buf, PAGE_SIZE-1);
242 mconsole_reply(req, "Read of file failed", 1, 0);
245 /*Begin the file content on his own line.*/
247 mconsole_reply(req, "\n", 0, 1);
250 if (len == PAGE_SIZE-1) {
252 mconsole_reply(req, buf, 0, 1);
255 mconsole_reply(req, buf, 0, 0);
268 #define UML_MCONSOLE_HELPTEXT \
270 version - Get kernel version \n\
271 help - Print this message \n\
273 reboot - Reboot UML \n\
274 config <dev>=<config> - Add a new device to UML; \n\
275 same syntax as command line \n\
276 config <dev> - Query the configuration of a device \n\
277 remove <dev> - Remove a device from UML \n\
278 sysrq <letter> - Performs the SysRq action controlled by the letter \n\
279 cad - invoke the Ctrl-Alt-Del handler \n\
280 stop - pause the UML; it will do nothing until it receives a 'go' \n\
281 go - continue the UML after a 'stop' \n\
282 log <string> - make UML enter <string> into the kernel log\n\
283 proc <file> - returns the contents of the UML's /proc/<file>\n\
284 stack <pid> - returns the stack of the specified pid\n\
287 void mconsole_help(struct mc_request *req)
289 mconsole_reply(req, UML_MCONSOLE_HELPTEXT, 0, 0);
292 void mconsole_halt(struct mc_request *req)
294 mconsole_reply(req, "", 0, 0);
298 void mconsole_reboot(struct mc_request *req)
300 mconsole_reply(req, "", 0, 0);
301 machine_restart(NULL);
304 extern void ctrl_alt_del(void);
306 void mconsole_cad(struct mc_request *req)
308 mconsole_reply(req, "", 0, 0);
312 void mconsole_go(struct mc_request *req)
314 mconsole_reply(req, "Not stopped", 1, 0);
317 void mconsole_stop(struct mc_request *req)
319 deactivate_fd(req->originating_fd, MCONSOLE_IRQ);
320 os_set_fd_block(req->originating_fd, 1);
321 mconsole_reply(req, "", 0, 0);
322 while(mconsole_get_request(req->originating_fd, req)){
323 if(req->cmd->handler == mconsole_go) break;
324 (*req->cmd->handler)(req);
326 os_set_fd_block(req->originating_fd, 0);
327 reactivate_fd(req->originating_fd, MCONSOLE_IRQ);
328 mconsole_reply(req, "", 0, 0);
331 /* This list is populated by __initcall routines. */
333 static LIST_HEAD(mconsole_devices);
335 void mconsole_register_dev(struct mc_device *new)
337 list_add(&new->list, &mconsole_devices);
340 static struct mc_device *mconsole_find_dev(char *name)
342 struct list_head *ele;
343 struct mc_device *dev;
345 list_for_each(ele, &mconsole_devices){
346 dev = list_entry(ele, struct mc_device, list);
347 if(!strncmp(name, dev->name, strlen(dev->name)))
353 #define UNPLUGGED_PER_PAGE \
354 ((PAGE_SIZE - sizeof(struct list_head)) / sizeof(unsigned long))
356 struct unplugged_pages {
357 struct list_head list;
358 void *pages[UNPLUGGED_PER_PAGE];
361 static unsigned long long unplugged_pages_count = 0;
362 static struct list_head unplugged_pages = LIST_HEAD_INIT(unplugged_pages);
363 static int unplug_index = UNPLUGGED_PER_PAGE;
365 static int mem_config(char *str)
367 unsigned long long diff;
368 int err = -EINVAL, i, add;
377 else if(str[0] == '+'){
383 diff = memparse(str, &ret);
389 for(i = 0; i < diff; i++){
390 struct unplugged_pages *unplugged;
394 if(list_empty(&unplugged_pages))
397 unplugged = list_entry(unplugged_pages.next,
398 struct unplugged_pages, list);
400 addr = unplugged->pages[--unplug_index];
402 list_del(&unplugged->list);
404 unplug_index = UNPLUGGED_PER_PAGE;
407 free_page((unsigned long) addr);
408 unplugged_pages_count--;
413 page = alloc_page(GFP_ATOMIC);
417 unplugged = page_address(page);
418 if(unplug_index == UNPLUGGED_PER_PAGE){
419 list_add(&unplugged->list, &unplugged_pages);
423 struct list_head *entry = unplugged_pages.next;
426 unplugged = list_entry(entry,
427 struct unplugged_pages,
429 unplugged->pages[unplug_index++] = addr;
430 err = os_drop_memory(addr, PAGE_SIZE);
432 printk("Failed to release memory - "
433 "errno = %d\n", err);
436 unplugged_pages_count++;
445 static int mem_get_config(char *name, char *str, int size, char **error_out)
447 char buf[sizeof("18446744073709551615")];
450 sprintf(buf, "%ld", uml_physmem);
451 CONFIG_CHUNK(str, size, len, buf, 1);
456 static int mem_id(char **str, int *start_out, int *end_out)
464 static int mem_remove(int n)
469 static struct mc_device mem_mc = {
471 .config = mem_config,
472 .get_config = mem_get_config,
474 .remove = mem_remove,
477 static int mem_mc_init(void)
479 if(can_drop_memory())
480 mconsole_register_dev(&mem_mc);
481 else printk("Can't release memory to the host - memory hotplug won't "
486 __initcall(mem_mc_init);
488 #define CONFIG_BUF_SIZE 64
490 static void mconsole_get_config(int (*get_config)(char *, char *, int,
492 struct mc_request *req, char *name)
494 char default_buf[CONFIG_BUF_SIZE], *error, *buf;
497 if(get_config == NULL){
498 mconsole_reply(req, "No get_config routine defined", 1, 0);
503 size = sizeof(default_buf)/sizeof(default_buf[0]);
507 n = (*get_config)(name, buf, size, &error);
509 mconsole_reply(req, error, 1, 0);
514 mconsole_reply(req, buf, 0, 0);
518 if(buf != default_buf)
522 buf = kmalloc(size, GFP_KERNEL);
524 mconsole_reply(req, "Failed to allocate buffer", 1, 0);
529 if(buf != default_buf)
533 void mconsole_config(struct mc_request *req)
535 struct mc_device *dev;
536 char *ptr = req->request.data, *name;
539 ptr += strlen("config");
540 while(isspace(*ptr)) ptr++;
541 dev = mconsole_find_dev(ptr);
543 mconsole_reply(req, "Bad configuration option", 1, 0);
547 name = &ptr[strlen(dev->name)];
549 while((*ptr != '=') && (*ptr != '\0'))
553 err = (*dev->config)(name);
554 mconsole_reply(req, "", err, 0);
556 else mconsole_get_config(dev->get_config, req, name);
559 void mconsole_remove(struct mc_request *req)
561 struct mc_device *dev;
562 char *ptr = req->request.data, *err_msg = "";
564 int err, start, end, n;
566 ptr += strlen("remove");
567 while(isspace(*ptr)) ptr++;
568 dev = mconsole_find_dev(ptr);
570 mconsole_reply(req, "Bad remove option", 1, 0);
574 ptr = &ptr[strlen(dev->name)];
577 n = (*dev->id)(&ptr, &start, &end);
579 err_msg = "Couldn't parse device number";
582 else if((n < start) || (n > end)){
583 sprintf(error, "Invalid device number - must be between "
584 "%d and %d", start, end);
589 err = (*dev->remove)(n);
592 err_msg = "Device doesn't exist";
595 err_msg = "Device is currently open";
601 mconsole_reply(req, err_msg, err, 0);
604 static DEFINE_SPINLOCK(console_lock);
605 static LIST_HEAD(clients);
606 static char console_buf[MCONSOLE_MAX_DATA];
607 static int console_index = 0;
609 static void console_write(struct console *console, const char *string,
612 struct list_head *ele;
615 if(list_empty(&clients))
619 n = min((size_t) len, ARRAY_SIZE(console_buf) - console_index);
620 strncpy(&console_buf[console_index], string, n);
627 list_for_each(ele, &clients){
628 struct mconsole_entry *entry;
630 entry = list_entry(ele, struct mconsole_entry, list);
631 mconsole_reply_len(&entry->request, console_buf,
632 console_index, 0, 1);
639 static struct console mc_console = { .name = "mc",
640 .write = console_write,
641 .flags = CON_ENABLED,
644 static int mc_add_console(void)
646 register_console(&mc_console);
650 late_initcall(mc_add_console);
652 static void with_console(struct mc_request *req, void (*proc)(void *),
655 struct mconsole_entry entry;
658 entry.request = *req;
659 list_add(&entry.list, &clients);
660 spin_lock_irqsave(&console_lock, flags);
664 mconsole_reply_len(req, console_buf, console_index, 0, 0);
667 spin_unlock_irqrestore(&console_lock, flags);
668 list_del(&entry.list);
671 #ifdef CONFIG_MAGIC_SYSRQ
672 static void sysrq_proc(void *arg)
676 handle_sysrq(*op, ¤t->thread.regs, NULL);
679 void mconsole_sysrq(struct mc_request *req)
681 char *ptr = req->request.data;
683 ptr += strlen("sysrq");
684 while(isspace(*ptr)) ptr++;
686 /* With 'b', the system will shut down without a chance to reply,
687 * so in this case, we reply first.
690 mconsole_reply(req, "", 0, 0);
692 with_console(req, sysrq_proc, ptr);
695 void mconsole_sysrq(struct mc_request *req)
697 mconsole_reply(req, "Sysrq not compiled in", 1, 0);
701 #ifdef CONFIG_MODE_SKAS
703 static void stack_proc(void *arg)
705 struct task_struct *from = current, *to = arg;
707 to->thread.saved_task = from;
708 switch_to(from, to, from);
711 /* Mconsole stack trace
712 * Added by Allan Graves, Jeff Dike
713 * Dumps a stacks registers to the linux console.
716 static void do_stack_trace(struct mc_request *req)
718 char *ptr = req->request.data;
719 int pid_requested= -1;
720 struct task_struct *from = NULL;
721 struct task_struct *to = NULL;
724 * 1) Send showregs output to mconsole.
725 * 2) Add a way to stack dump all pids.
728 ptr += strlen("stack");
729 while(isspace(*ptr)) ptr++;
731 /* Should really check for multiple pids or reject bad args here */
732 /* What do the arguments in mconsole_reply mean? */
733 if(sscanf(ptr, "%d", &pid_requested) == 0){
734 mconsole_reply(req, "Please specify a pid", 1, 0);
740 to = find_task_by_pid(pid_requested);
741 if((to == NULL) || (pid_requested == 0)) {
742 mconsole_reply(req, "Couldn't find that pid", 1, 0);
745 with_console(req, stack_proc, to);
747 #endif /* CONFIG_MODE_SKAS */
749 void mconsole_stack(struct mc_request *req)
751 /* This command doesn't work in TT mode, so let's check and then
754 CHOOSE_MODE(mconsole_reply(req, "Sorry, this doesn't work in TT mode",
756 do_stack_trace(req));
759 /* Changed by mconsole_setup, which is __setup, and called before SMP is
762 static char *notify_socket = NULL;
764 static int mconsole_init(void)
766 /* long to avoid size mismatch warnings from gcc */
771 if(umid_file_name("mconsole", file, sizeof(file))) return(-1);
772 snprintf(mconsole_socket_name, sizeof(file), "%s", file);
774 sock = os_create_unix_socket(file, sizeof(file), 1);
776 printk("Failed to initialize management console\n");
780 register_reboot_notifier(&reboot_notifier);
782 err = um_request_irq(MCONSOLE_IRQ, sock, IRQ_READ, mconsole_interrupt,
783 SA_INTERRUPT | SA_SHIRQ | SA_SAMPLE_RANDOM,
784 "mconsole", (void *)sock);
786 printk("Failed to get IRQ for management console\n");
790 if(notify_socket != NULL){
791 notify_socket = kstrdup(notify_socket, GFP_KERNEL);
792 if(notify_socket != NULL)
793 mconsole_notify(notify_socket, MCONSOLE_SOCKET,
794 mconsole_socket_name,
795 strlen(mconsole_socket_name) + 1);
796 else printk(KERN_ERR "mconsole_setup failed to strdup "
800 printk("mconsole (version %d) initialized on %s\n",
801 MCONSOLE_VERSION, mconsole_socket_name);
805 __initcall(mconsole_init);
807 static int write_proc_mconsole(struct file *file, const char __user *buffer,
808 unsigned long count, void *data)
812 buf = kmalloc(count + 1, GFP_KERNEL);
816 if(copy_from_user(buf, buffer, count)){
823 mconsole_notify(notify_socket, MCONSOLE_USER_NOTIFY, buf, count);
829 static int create_proc_mconsole(void)
831 struct proc_dir_entry *ent;
833 if(notify_socket == NULL) return(0);
835 ent = create_proc_entry("mconsole", S_IFREG | 0200, NULL);
837 printk(KERN_INFO "create_proc_mconsole : create_proc_entry failed\n");
841 ent->read_proc = NULL;
842 ent->write_proc = write_proc_mconsole;
846 static DEFINE_SPINLOCK(notify_spinlock);
848 void lock_notify(void)
850 spin_lock(¬ify_spinlock);
853 void unlock_notify(void)
855 spin_unlock(¬ify_spinlock);
858 __initcall(create_proc_mconsole);
860 #define NOTIFY "=notify:"
862 static int mconsole_setup(char *str)
864 if(!strncmp(str, NOTIFY, strlen(NOTIFY))){
865 str += strlen(NOTIFY);
868 else printk(KERN_ERR "mconsole_setup : Unknown option - '%s'\n", str);
872 __setup("mconsole", mconsole_setup);
874 __uml_help(mconsole_setup,
875 "mconsole=notify:<socket>\n"
876 " Requests that the mconsole driver send a message to the named Unix\n"
877 " socket containing the name of the mconsole socket. This also serves\n"
878 " to notify outside processes when UML has booted far enough to respond\n"
879 " to mconsole requests.\n\n"
882 static int notify_panic(struct notifier_block *self, unsigned long unused1,
887 if(notify_socket == NULL) return(0);
889 mconsole_notify(notify_socket, MCONSOLE_PANIC, message,
890 strlen(message) + 1);
894 static struct notifier_block panic_exit_notifier = {
895 .notifier_call = notify_panic,
900 static int add_notifier(void)
902 atomic_notifier_chain_register(&panic_notifier_list,
903 &panic_exit_notifier);
907 __initcall(add_notifier);
909 char *mconsole_notify_socket(void)
911 return(notify_socket);
914 EXPORT_SYMBOL(mconsole_notify_socket);