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"
27 #include "asm/uaccess.h"
28 #include "user_util.h"
29 #include "kern_util.h"
32 #include "mconsole_kern.h"
38 #include "choose-mode.h"
40 static int do_unlink_socket(struct notifier_block *notifier,
41 unsigned long what, void *data)
43 return(mconsole_unlink_socket());
47 static struct notifier_block reboot_notifier = {
48 .notifier_call = do_unlink_socket,
52 /* Safe without explicit locking for now. Tasklets provide their own
53 * locking, and the interrupt handler is safe because it can't interrupt
54 * itself and it can only happen on CPU 0.
57 static LIST_HEAD(mc_requests);
59 static void mc_work_proc(struct work_struct *unused)
61 struct mconsole_entry *req;
64 while(!list_empty(&mc_requests)){
65 local_irq_save(flags);
66 req = list_entry(mc_requests.next, struct mconsole_entry,
69 local_irq_restore(flags);
70 req->request.cmd->handler(&req->request);
75 static DECLARE_WORK(mconsole_work, mc_work_proc);
77 static irqreturn_t mconsole_interrupt(int irq, void *dev_id)
79 /* long to avoid size mismatch warnings from gcc */
81 struct mconsole_entry *new;
82 static struct mc_request req; /* that's OK */
85 while (mconsole_get_request(fd, &req)){
86 if(req.cmd->context == MCONSOLE_INTR)
87 (*req.cmd->handler)(&req);
89 new = kmalloc(sizeof(*new), GFP_NOWAIT);
91 mconsole_reply(&req, "Out of memory", 1, 0);
94 new->request.regs = get_irq_regs()->regs;
95 list_add(&new->list, &mc_requests);
99 if(!list_empty(&mc_requests))
100 schedule_work(&mconsole_work);
101 reactivate_fd(fd, MCONSOLE_IRQ);
105 void mconsole_version(struct mc_request *req)
109 sprintf(version, "%s %s %s %s %s", utsname()->sysname,
110 utsname()->nodename, utsname()->release,
111 utsname()->version, utsname()->machine);
112 mconsole_reply(req, version, 0, 0);
115 void mconsole_log(struct mc_request *req)
118 char *ptr = req->request.data;
120 ptr += strlen("log ");
122 len = req->len - (ptr - req->request.data);
123 printk("%.*s", len, ptr);
124 mconsole_reply(req, "", 0, 0);
127 /* This is a more convoluted version of mconsole_proc, which has some stability
128 * problems; however, we need it fixed, because it is expected that UML users
129 * mount HPPFS instead of procfs on /proc. And we want mconsole_proc to still
130 * show the real procfs content, not the ones from hppfs.*/
132 void mconsole_proc(struct mc_request *req)
135 struct file_system_type *proc;
136 struct super_block *super;
139 char *ptr = req->request.data, *buf;
141 ptr += strlen("proc");
142 while(isspace(*ptr)) ptr++;
144 proc = get_fs_type("proc");
146 mconsole_reply(req, "procfs not registered", 1, 0);
150 super = (*proc->get_sb)(proc, 0, NULL, NULL);
151 put_filesystem(proc);
153 mconsole_reply(req, "Failed to get procfs superblock", 1, 0);
156 up_write(&super->s_umount);
158 nd.dentry = super->s_root;
160 nd.flags = O_RDONLY + 1;
161 nd.last_type = LAST_ROOT;
163 /* START: it was experienced that the stability problems are closed
164 * if commenting out these two calls + the below read cycle. To
165 * make UML crash again, it was enough to readd either one.*/
166 err = link_path_walk(ptr, &nd);
168 mconsole_reply(req, "Failed to look up file", 1, 0);
172 file = dentry_open(nd.dentry, nd.mnt, O_RDONLY);
174 mconsole_reply(req, "Failed to open file", 1, 0);
179 buf = kmalloc(PAGE_SIZE, GFP_KERNEL);
181 mconsole_reply(req, "Failed to allocate buffer", 1, 0);
185 if((file->f_op != NULL) && (file->f_op->read != NULL)){
187 n = (*file->f_op->read)(file, buf, PAGE_SIZE - 1,
191 mconsole_reply(req, buf, 0, (n > 0));
194 mconsole_reply(req, "Read of file failed",
200 else mconsole_reply(req, "", 0, 0);
207 deactivate_super(super);
212 void mconsole_proc(struct mc_request *req)
219 char *ptr = req->request.data;
221 ptr += strlen("proc");
222 while(isspace(*ptr)) ptr++;
223 snprintf(path, sizeof(path), "/proc/%s", ptr);
225 fd = sys_open(path, 0, 0);
227 mconsole_reply(req, "Failed to open file", 1, 0);
228 printk("open %s: %d\n",path,fd);
232 buf = kmalloc(PAGE_SIZE, GFP_KERNEL);
234 mconsole_reply(req, "Failed to allocate buffer", 1, 0);
239 len = sys_read(fd, buf, PAGE_SIZE-1);
241 mconsole_reply(req, "Read of file failed", 1, 0);
244 /*Begin the file content on his own line.*/
246 mconsole_reply(req, "\n", 0, 1);
249 if (len == PAGE_SIZE-1) {
251 mconsole_reply(req, buf, 0, 1);
254 mconsole_reply(req, buf, 0, 0);
267 #define UML_MCONSOLE_HELPTEXT \
269 version - Get kernel version \n\
270 help - Print this message \n\
272 reboot - Reboot UML \n\
273 config <dev>=<config> - Add a new device to UML; \n\
274 same syntax as command line \n\
275 config <dev> - Query the configuration of a device \n\
276 remove <dev> - Remove a device from UML \n\
277 sysrq <letter> - Performs the SysRq action controlled by the letter \n\
278 cad - invoke the Ctrl-Alt-Del handler \n\
279 stop - pause the UML; it will do nothing until it receives a 'go' \n\
280 go - continue the UML after a 'stop' \n\
281 log <string> - make UML enter <string> into the kernel log\n\
282 proc <file> - returns the contents of the UML's /proc/<file>\n\
283 stack <pid> - returns the stack of the specified pid\n\
286 void mconsole_help(struct mc_request *req)
288 mconsole_reply(req, UML_MCONSOLE_HELPTEXT, 0, 0);
291 void mconsole_halt(struct mc_request *req)
293 mconsole_reply(req, "", 0, 0);
297 void mconsole_reboot(struct mc_request *req)
299 mconsole_reply(req, "", 0, 0);
300 machine_restart(NULL);
303 void mconsole_cad(struct mc_request *req)
305 mconsole_reply(req, "", 0, 0);
309 void mconsole_go(struct mc_request *req)
311 mconsole_reply(req, "Not stopped", 1, 0);
314 void mconsole_stop(struct mc_request *req)
316 deactivate_fd(req->originating_fd, MCONSOLE_IRQ);
317 os_set_fd_block(req->originating_fd, 1);
318 mconsole_reply(req, "stopped", 0, 0);
319 while (mconsole_get_request(req->originating_fd, req)) {
320 if (req->cmd->handler == mconsole_go)
322 if (req->cmd->handler == mconsole_stop) {
323 mconsole_reply(req, "Already stopped", 1, 0);
326 if (req->cmd->handler == mconsole_sysrq) {
327 struct pt_regs *old_regs;
328 old_regs = set_irq_regs((struct pt_regs *)&req->regs);
330 set_irq_regs(old_regs);
333 (*req->cmd->handler)(req);
335 os_set_fd_block(req->originating_fd, 0);
336 reactivate_fd(req->originating_fd, MCONSOLE_IRQ);
337 mconsole_reply(req, "", 0, 0);
340 /* This list is populated by __initcall routines. */
342 static LIST_HEAD(mconsole_devices);
344 void mconsole_register_dev(struct mc_device *new)
346 list_add(&new->list, &mconsole_devices);
349 static struct mc_device *mconsole_find_dev(char *name)
351 struct list_head *ele;
352 struct mc_device *dev;
354 list_for_each(ele, &mconsole_devices){
355 dev = list_entry(ele, struct mc_device, list);
356 if(!strncmp(name, dev->name, strlen(dev->name)))
362 #define UNPLUGGED_PER_PAGE \
363 ((PAGE_SIZE - sizeof(struct list_head)) / sizeof(unsigned long))
365 struct unplugged_pages {
366 struct list_head list;
367 void *pages[UNPLUGGED_PER_PAGE];
370 static unsigned long long unplugged_pages_count = 0;
371 static struct list_head unplugged_pages = LIST_HEAD_INIT(unplugged_pages);
372 static int unplug_index = UNPLUGGED_PER_PAGE;
374 static int mem_config(char *str, char **error_out)
376 unsigned long long diff;
377 int err = -EINVAL, i, add;
381 *error_out = "Expected '=' after 'mem'";
388 else if(str[0] == '+'){
392 *error_out = "Expected increment to start with '-' or '+'";
397 diff = memparse(str, &ret);
399 *error_out = "Failed to parse memory increment";
405 for(i = 0; i < diff; i++){
406 struct unplugged_pages *unplugged;
410 if(list_empty(&unplugged_pages))
413 unplugged = list_entry(unplugged_pages.next,
414 struct unplugged_pages, list);
416 addr = unplugged->pages[--unplug_index];
418 list_del(&unplugged->list);
420 unplug_index = UNPLUGGED_PER_PAGE;
423 free_page((unsigned long) addr);
424 unplugged_pages_count--;
429 page = alloc_page(GFP_ATOMIC);
433 unplugged = page_address(page);
434 if(unplug_index == UNPLUGGED_PER_PAGE){
435 list_add(&unplugged->list, &unplugged_pages);
439 struct list_head *entry = unplugged_pages.next;
442 unplugged = list_entry(entry,
443 struct unplugged_pages,
445 err = os_drop_memory(addr, PAGE_SIZE);
447 printk("Failed to release memory - "
448 "errno = %d\n", err);
449 *error_out = "Failed to release memory";
452 unplugged->pages[unplug_index++] = addr;
455 unplugged_pages_count++;
464 static int mem_get_config(char *name, char *str, int size, char **error_out)
466 char buf[sizeof("18446744073709551615")];
469 sprintf(buf, "%ld", uml_physmem);
470 CONFIG_CHUNK(str, size, len, buf, 1);
475 static int mem_id(char **str, int *start_out, int *end_out)
483 static int mem_remove(int n, char **error_out)
485 *error_out = "Memory doesn't support the remove operation";
489 static struct mc_device mem_mc = {
491 .config = mem_config,
492 .get_config = mem_get_config,
494 .remove = mem_remove,
497 static int mem_mc_init(void)
499 if(can_drop_memory())
500 mconsole_register_dev(&mem_mc);
501 else printk("Can't release memory to the host - memory hotplug won't "
506 __initcall(mem_mc_init);
508 #define CONFIG_BUF_SIZE 64
510 static void mconsole_get_config(int (*get_config)(char *, char *, int,
512 struct mc_request *req, char *name)
514 char default_buf[CONFIG_BUF_SIZE], *error, *buf;
517 if(get_config == NULL){
518 mconsole_reply(req, "No get_config routine defined", 1, 0);
523 size = ARRAY_SIZE(default_buf);
527 n = (*get_config)(name, buf, size, &error);
529 mconsole_reply(req, error, 1, 0);
534 mconsole_reply(req, buf, 0, 0);
538 if(buf != default_buf)
542 buf = kmalloc(size, GFP_KERNEL);
544 mconsole_reply(req, "Failed to allocate buffer", 1, 0);
549 if(buf != default_buf)
553 void mconsole_config(struct mc_request *req)
555 struct mc_device *dev;
556 char *ptr = req->request.data, *name, *error_string = "";
559 ptr += strlen("config");
560 while(isspace(*ptr)) ptr++;
561 dev = mconsole_find_dev(ptr);
563 mconsole_reply(req, "Bad configuration option", 1, 0);
567 name = &ptr[strlen(dev->name)];
569 while((*ptr != '=') && (*ptr != '\0'))
573 err = (*dev->config)(name, &error_string);
574 mconsole_reply(req, error_string, err, 0);
576 else mconsole_get_config(dev->get_config, req, name);
579 void mconsole_remove(struct mc_request *req)
581 struct mc_device *dev;
582 char *ptr = req->request.data, *err_msg = "";
584 int err, start, end, n;
586 ptr += strlen("remove");
587 while(isspace(*ptr)) ptr++;
588 dev = mconsole_find_dev(ptr);
590 mconsole_reply(req, "Bad remove option", 1, 0);
594 ptr = &ptr[strlen(dev->name)];
597 n = (*dev->id)(&ptr, &start, &end);
599 err_msg = "Couldn't parse device number";
602 else if((n < start) || (n > end)){
603 sprintf(error, "Invalid device number - must be between "
604 "%d and %d", start, end);
610 err = (*dev->remove)(n, &err_msg);
614 err_msg = "Device doesn't exist";
618 err_msg = "Device is currently open";
624 mconsole_reply(req, err_msg, err, 0);
627 struct mconsole_output {
628 struct list_head list;
629 struct mc_request *req;
632 static DEFINE_SPINLOCK(console_lock);
633 static LIST_HEAD(clients);
634 static char console_buf[MCONSOLE_MAX_DATA];
635 static int console_index = 0;
637 static void console_write(struct console *console, const char *string,
640 struct list_head *ele;
643 if(list_empty(&clients))
647 n = min((size_t) len, ARRAY_SIZE(console_buf) - console_index);
648 strncpy(&console_buf[console_index], string, n);
655 list_for_each(ele, &clients){
656 struct mconsole_output *entry;
658 entry = list_entry(ele, struct mconsole_output, list);
659 mconsole_reply_len(entry->req, console_buf,
660 console_index, 0, 1);
667 static struct console mc_console = { .name = "mc",
668 .write = console_write,
669 .flags = CON_ENABLED,
672 static int mc_add_console(void)
674 register_console(&mc_console);
678 late_initcall(mc_add_console);
680 static void with_console(struct mc_request *req, void (*proc)(void *),
683 struct mconsole_output entry;
687 list_add(&entry.list, &clients);
688 spin_lock_irqsave(&console_lock, flags);
692 mconsole_reply_len(req, console_buf, console_index, 0, 0);
695 spin_unlock_irqrestore(&console_lock, flags);
696 list_del(&entry.list);
699 #ifdef CONFIG_MAGIC_SYSRQ
700 static void sysrq_proc(void *arg)
703 handle_sysrq(*op, NULL);
706 void mconsole_sysrq(struct mc_request *req)
708 char *ptr = req->request.data;
710 ptr += strlen("sysrq");
711 while(isspace(*ptr)) ptr++;
713 /* With 'b', the system will shut down without a chance to reply,
714 * so in this case, we reply first.
717 mconsole_reply(req, "", 0, 0);
719 with_console(req, sysrq_proc, ptr);
722 void mconsole_sysrq(struct mc_request *req)
724 mconsole_reply(req, "Sysrq not compiled in", 1, 0);
728 #ifdef CONFIG_MODE_SKAS
730 static void stack_proc(void *arg)
732 struct task_struct *from = current, *to = arg;
734 to->thread.saved_task = from;
735 switch_to(from, to, from);
738 /* Mconsole stack trace
739 * Added by Allan Graves, Jeff Dike
740 * Dumps a stacks registers to the linux console.
743 static void do_stack_trace(struct mc_request *req)
745 char *ptr = req->request.data;
746 int pid_requested= -1;
747 struct task_struct *from = NULL;
748 struct task_struct *to = NULL;
751 * 1) Send showregs output to mconsole.
752 * 2) Add a way to stack dump all pids.
755 ptr += strlen("stack");
756 while(isspace(*ptr)) ptr++;
758 /* Should really check for multiple pids or reject bad args here */
759 /* What do the arguments in mconsole_reply mean? */
760 if(sscanf(ptr, "%d", &pid_requested) == 0){
761 mconsole_reply(req, "Please specify a pid", 1, 0);
767 to = find_task_by_pid(pid_requested);
768 if((to == NULL) || (pid_requested == 0)) {
769 mconsole_reply(req, "Couldn't find that pid", 1, 0);
772 with_console(req, stack_proc, to);
774 #endif /* CONFIG_MODE_SKAS */
776 void mconsole_stack(struct mc_request *req)
778 /* This command doesn't work in TT mode, so let's check and then
781 CHOOSE_MODE(mconsole_reply(req, "Sorry, this doesn't work in TT mode",
783 do_stack_trace(req));
786 /* Changed by mconsole_setup, which is __setup, and called before SMP is
789 static char *notify_socket = NULL;
791 static int mconsole_init(void)
793 /* long to avoid size mismatch warnings from gcc */
798 if(umid_file_name("mconsole", file, sizeof(file))) return(-1);
799 snprintf(mconsole_socket_name, sizeof(file), "%s", file);
801 sock = os_create_unix_socket(file, sizeof(file), 1);
803 printk("Failed to initialize management console\n");
807 register_reboot_notifier(&reboot_notifier);
809 err = um_request_irq(MCONSOLE_IRQ, sock, IRQ_READ, mconsole_interrupt,
810 IRQF_DISABLED | IRQF_SHARED | IRQF_SAMPLE_RANDOM,
811 "mconsole", (void *)sock);
813 printk("Failed to get IRQ for management console\n");
817 if(notify_socket != NULL){
818 notify_socket = kstrdup(notify_socket, GFP_KERNEL);
819 if(notify_socket != NULL)
820 mconsole_notify(notify_socket, MCONSOLE_SOCKET,
821 mconsole_socket_name,
822 strlen(mconsole_socket_name) + 1);
823 else printk(KERN_ERR "mconsole_setup failed to strdup "
827 printk("mconsole (version %d) initialized on %s\n",
828 MCONSOLE_VERSION, mconsole_socket_name);
832 __initcall(mconsole_init);
834 static int write_proc_mconsole(struct file *file, const char __user *buffer,
835 unsigned long count, void *data)
839 buf = kmalloc(count + 1, GFP_KERNEL);
843 if(copy_from_user(buf, buffer, count)){
850 mconsole_notify(notify_socket, MCONSOLE_USER_NOTIFY, buf, count);
856 static int create_proc_mconsole(void)
858 struct proc_dir_entry *ent;
860 if(notify_socket == NULL) return(0);
862 ent = create_proc_entry("mconsole", S_IFREG | 0200, NULL);
864 printk(KERN_INFO "create_proc_mconsole : create_proc_entry failed\n");
868 ent->read_proc = NULL;
869 ent->write_proc = write_proc_mconsole;
873 static DEFINE_SPINLOCK(notify_spinlock);
875 void lock_notify(void)
877 spin_lock(¬ify_spinlock);
880 void unlock_notify(void)
882 spin_unlock(¬ify_spinlock);
885 __initcall(create_proc_mconsole);
887 #define NOTIFY "=notify:"
889 static int mconsole_setup(char *str)
891 if(!strncmp(str, NOTIFY, strlen(NOTIFY))){
892 str += strlen(NOTIFY);
895 else printk(KERN_ERR "mconsole_setup : Unknown option - '%s'\n", str);
899 __setup("mconsole", mconsole_setup);
901 __uml_help(mconsole_setup,
902 "mconsole=notify:<socket>\n"
903 " Requests that the mconsole driver send a message to the named Unix\n"
904 " socket containing the name of the mconsole socket. This also serves\n"
905 " to notify outside processes when UML has booted far enough to respond\n"
906 " to mconsole requests.\n\n"
909 static int notify_panic(struct notifier_block *self, unsigned long unused1,
914 if(notify_socket == NULL) return(0);
916 mconsole_notify(notify_socket, MCONSOLE_PANIC, message,
917 strlen(message) + 1);
921 static struct notifier_block panic_exit_notifier = {
922 .notifier_call = notify_panic,
927 static int add_notifier(void)
929 atomic_notifier_chain_register(&panic_notifier_list,
930 &panic_exit_notifier);
934 __initcall(add_notifier);
936 char *mconsole_notify_socket(void)
938 return(notify_socket);
941 EXPORT_SYMBOL(mconsole_notify_socket);