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
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>
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>
22 #include <linux/workqueue.h>
23 #include <linux/mutex.h>
24 #include <asm/uaccess.h>
29 #include "kern_util.h"
31 #include "mconsole_kern.h"
34 static int do_unlink_socket(struct notifier_block
*notifier
,
35 unsigned long what
, void *data
)
37 return mconsole_unlink_socket();
41 static struct notifier_block reboot_notifier
= {
42 .notifier_call
= do_unlink_socket
,
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.
51 static LIST_HEAD(mc_requests
);
53 static void mc_work_proc(struct work_struct
*unused
)
55 struct mconsole_entry
*req
;
58 while (!list_empty(&mc_requests
)) {
59 local_irq_save(flags
);
60 req
= list_entry(mc_requests
.next
, struct mconsole_entry
, list
);
62 local_irq_restore(flags
);
63 req
->request
.cmd
->handler(&req
->request
);
68 static DECLARE_WORK(mconsole_work
, mc_work_proc
);
70 static irqreturn_t
mconsole_interrupt(int irq
, void *dev_id
)
72 /* long to avoid size mismatch warnings from gcc */
74 struct mconsole_entry
*new;
75 static struct mc_request req
; /* that's OK */
78 while (mconsole_get_request(fd
, &req
)) {
79 if (req
.cmd
->context
== MCONSOLE_INTR
)
80 (*req
.cmd
->handler
)(&req
);
82 new = kmalloc(sizeof(*new), GFP_NOWAIT
);
84 mconsole_reply(&req
, "Out of memory", 1, 0);
87 new->request
.regs
= get_irq_regs()->regs
;
88 list_add(&new->list
, &mc_requests
);
92 if (!list_empty(&mc_requests
))
93 schedule_work(&mconsole_work
);
94 reactivate_fd(fd
, MCONSOLE_IRQ
);
98 void mconsole_version(struct mc_request
*req
)
102 sprintf(version
, "%s %s %s %s %s", utsname()->sysname
,
103 utsname()->nodename
, utsname()->release
, utsname()->version
,
105 mconsole_reply(req
, version
, 0, 0);
108 void mconsole_log(struct mc_request
*req
)
111 char *ptr
= req
->request
.data
;
113 ptr
+= strlen("log ");
115 len
= req
->len
- (ptr
- req
->request
.data
);
116 printk(KERN_WARNING
"%.*s", len
, ptr
);
117 mconsole_reply(req
, "", 0, 0);
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.*/
125 void mconsole_proc(struct mc_request
*req
)
132 char *ptr
= req
->request
.data
;
134 ptr
+= strlen("proc");
135 ptr
= skip_spaces(ptr
);
136 snprintf(path
, sizeof(path
), "/proc/%s", ptr
);
138 fd
= sys_open(path
, 0, 0);
140 mconsole_reply(req
, "Failed to open file", 1, 0);
141 printk(KERN_ERR
"open %s: %d\n",path
,fd
);
145 buf
= kmalloc(PAGE_SIZE
, GFP_KERNEL
);
147 mconsole_reply(req
, "Failed to allocate buffer", 1, 0);
152 len
= sys_read(fd
, buf
, PAGE_SIZE
-1);
154 mconsole_reply(req
, "Read of file failed", 1, 0);
157 /* Begin the file content on his own line. */
159 mconsole_reply(req
, "\n", 0, 1);
162 if (len
== PAGE_SIZE
-1) {
164 mconsole_reply(req
, buf
, 0, 1);
167 mconsole_reply(req
, buf
, 0, 0);
180 #define UML_MCONSOLE_HELPTEXT \
182 version - Get kernel version \n\
183 help - Print this message \n\
185 reboot - Reboot UML \n\
186 config <dev>=<config> - Add a new device to UML; \n\
187 same syntax as command line \n\
188 config <dev> - Query the configuration of a device \n\
189 remove <dev> - Remove a device from UML \n\
190 sysrq <letter> - Performs the SysRq action controlled by the letter \n\
191 cad - invoke the Ctrl-Alt-Del handler \n\
192 stop - pause the UML; it will do nothing until it receives a 'go' \n\
193 go - continue the UML after a 'stop' \n\
194 log <string> - make UML enter <string> into the kernel log\n\
195 proc <file> - returns the contents of the UML's /proc/<file>\n\
196 stack <pid> - returns the stack of the specified pid\n\
199 void mconsole_help(struct mc_request
*req
)
201 mconsole_reply(req
, UML_MCONSOLE_HELPTEXT
, 0, 0);
204 void mconsole_halt(struct mc_request
*req
)
206 mconsole_reply(req
, "", 0, 0);
210 void mconsole_reboot(struct mc_request
*req
)
212 mconsole_reply(req
, "", 0, 0);
213 machine_restart(NULL
);
216 void mconsole_cad(struct mc_request
*req
)
218 mconsole_reply(req
, "", 0, 0);
222 void mconsole_go(struct mc_request
*req
)
224 mconsole_reply(req
, "Not stopped", 1, 0);
227 void mconsole_stop(struct mc_request
*req
)
229 deactivate_fd(req
->originating_fd
, MCONSOLE_IRQ
);
230 os_set_fd_block(req
->originating_fd
, 1);
231 mconsole_reply(req
, "stopped", 0, 0);
233 if (!mconsole_get_request(req
->originating_fd
, req
))
235 if (req
->cmd
->handler
== mconsole_go
)
237 if (req
->cmd
->handler
== mconsole_stop
) {
238 mconsole_reply(req
, "Already stopped", 1, 0);
241 if (req
->cmd
->handler
== mconsole_sysrq
) {
242 struct pt_regs
*old_regs
;
243 old_regs
= set_irq_regs((struct pt_regs
*)&req
->regs
);
245 set_irq_regs(old_regs
);
248 (*req
->cmd
->handler
)(req
);
250 os_set_fd_block(req
->originating_fd
, 0);
251 reactivate_fd(req
->originating_fd
, MCONSOLE_IRQ
);
252 mconsole_reply(req
, "", 0, 0);
255 static DEFINE_SPINLOCK(mc_devices_lock
);
256 static LIST_HEAD(mconsole_devices
);
258 void mconsole_register_dev(struct mc_device
*new)
260 spin_lock(&mc_devices_lock
);
261 BUG_ON(!list_empty(&new->list
));
262 list_add(&new->list
, &mconsole_devices
);
263 spin_unlock(&mc_devices_lock
);
266 static struct mc_device
*mconsole_find_dev(char *name
)
268 struct list_head
*ele
;
269 struct mc_device
*dev
;
271 list_for_each(ele
, &mconsole_devices
) {
272 dev
= list_entry(ele
, struct mc_device
, list
);
273 if (!strncmp(name
, dev
->name
, strlen(dev
->name
)))
279 #define UNPLUGGED_PER_PAGE \
280 ((PAGE_SIZE - sizeof(struct list_head)) / sizeof(unsigned long))
282 struct unplugged_pages
{
283 struct list_head list
;
284 void *pages
[UNPLUGGED_PER_PAGE
];
287 static DEFINE_MUTEX(plug_mem_mutex
);
288 static unsigned long long unplugged_pages_count
= 0;
289 static LIST_HEAD(unplugged_pages
);
290 static int unplug_index
= UNPLUGGED_PER_PAGE
;
292 static int mem_config(char *str
, char **error_out
)
294 unsigned long long diff
;
295 int err
= -EINVAL
, i
, add
;
299 *error_out
= "Expected '=' after 'mem'";
306 else if (str
[0] == '+') {
310 *error_out
= "Expected increment to start with '-' or '+'";
315 diff
= memparse(str
, &ret
);
317 *error_out
= "Failed to parse memory increment";
323 mutex_lock(&plug_mem_mutex
);
324 for (i
= 0; i
< diff
; i
++) {
325 struct unplugged_pages
*unplugged
;
329 if (list_empty(&unplugged_pages
))
332 unplugged
= list_entry(unplugged_pages
.next
,
333 struct unplugged_pages
, list
);
334 if (unplug_index
> 0)
335 addr
= unplugged
->pages
[--unplug_index
];
337 list_del(&unplugged
->list
);
339 unplug_index
= UNPLUGGED_PER_PAGE
;
342 free_page((unsigned long) addr
);
343 unplugged_pages_count
--;
348 page
= alloc_page(GFP_ATOMIC
);
352 unplugged
= page_address(page
);
353 if (unplug_index
== UNPLUGGED_PER_PAGE
) {
354 list_add(&unplugged
->list
, &unplugged_pages
);
358 struct list_head
*entry
= unplugged_pages
.next
;
361 unplugged
= list_entry(entry
,
362 struct unplugged_pages
,
364 err
= os_drop_memory(addr
, PAGE_SIZE
);
366 printk(KERN_ERR
"Failed to release "
367 "memory - errno = %d\n", err
);
368 *error_out
= "Failed to release memory";
371 unplugged
->pages
[unplug_index
++] = addr
;
374 unplugged_pages_count
++;
380 mutex_unlock(&plug_mem_mutex
);
385 static int mem_get_config(char *name
, char *str
, int size
, char **error_out
)
387 char buf
[sizeof("18446744073709551615")];
390 sprintf(buf
, "%ld", uml_physmem
);
391 CONFIG_CHUNK(str
, size
, len
, buf
, 1);
396 static int mem_id(char **str
, int *start_out
, int *end_out
)
404 static int mem_remove(int n
, char **error_out
)
406 *error_out
= "Memory doesn't support the remove operation";
410 static struct mc_device mem_mc
= {
411 .list
= LIST_HEAD_INIT(mem_mc
.list
),
413 .config
= mem_config
,
414 .get_config
= mem_get_config
,
416 .remove
= mem_remove
,
419 static int __init
mem_mc_init(void)
421 if (can_drop_memory())
422 mconsole_register_dev(&mem_mc
);
423 else printk(KERN_ERR
"Can't release memory to the host - memory "
424 "hotplug won't be supported\n");
428 __initcall(mem_mc_init
);
430 #define CONFIG_BUF_SIZE 64
432 static void mconsole_get_config(int (*get_config
)(char *, char *, int,
434 struct mc_request
*req
, char *name
)
436 char default_buf
[CONFIG_BUF_SIZE
], *error
, *buf
;
439 if (get_config
== NULL
) {
440 mconsole_reply(req
, "No get_config routine defined", 1, 0);
445 size
= ARRAY_SIZE(default_buf
);
449 n
= (*get_config
)(name
, buf
, size
, &error
);
451 mconsole_reply(req
, error
, 1, 0);
456 mconsole_reply(req
, buf
, 0, 0);
460 if (buf
!= default_buf
)
464 buf
= kmalloc(size
, GFP_KERNEL
);
466 mconsole_reply(req
, "Failed to allocate buffer", 1, 0);
471 if (buf
!= default_buf
)
475 void mconsole_config(struct mc_request
*req
)
477 struct mc_device
*dev
;
478 char *ptr
= req
->request
.data
, *name
, *error_string
= "";
481 ptr
+= strlen("config");
482 ptr
= skip_spaces(ptr
);
483 dev
= mconsole_find_dev(ptr
);
485 mconsole_reply(req
, "Bad configuration option", 1, 0);
489 name
= &ptr
[strlen(dev
->name
)];
491 while ((*ptr
!= '=') && (*ptr
!= '\0'))
495 err
= (*dev
->config
)(name
, &error_string
);
496 mconsole_reply(req
, error_string
, err
, 0);
498 else mconsole_get_config(dev
->get_config
, req
, name
);
501 void mconsole_remove(struct mc_request
*req
)
503 struct mc_device
*dev
;
504 char *ptr
= req
->request
.data
, *err_msg
= "";
506 int err
, start
, end
, n
;
508 ptr
+= strlen("remove");
509 ptr
= skip_spaces(ptr
);
510 dev
= mconsole_find_dev(ptr
);
512 mconsole_reply(req
, "Bad remove option", 1, 0);
516 ptr
= &ptr
[strlen(dev
->name
)];
519 n
= (*dev
->id
)(&ptr
, &start
, &end
);
521 err_msg
= "Couldn't parse device number";
524 else if ((n
< start
) || (n
> end
)) {
525 sprintf(error
, "Invalid device number - must be between "
526 "%d and %d", start
, end
);
532 err
= (*dev
->remove
)(n
, &err_msg
);
539 err_msg
= "Device doesn't exist";
543 err_msg
= "Device is currently open";
549 mconsole_reply(req
, err_msg
, err
, 0);
552 struct mconsole_output
{
553 struct list_head list
;
554 struct mc_request
*req
;
557 static DEFINE_SPINLOCK(client_lock
);
558 static LIST_HEAD(clients
);
559 static char console_buf
[MCONSOLE_MAX_DATA
];
561 static void console_write(struct console
*console
, const char *string
,
564 struct list_head
*ele
;
567 if (list_empty(&clients
))
571 n
= min((size_t) len
, ARRAY_SIZE(console_buf
));
572 strncpy(console_buf
, string
, n
);
576 list_for_each(ele
, &clients
) {
577 struct mconsole_output
*entry
;
579 entry
= list_entry(ele
, struct mconsole_output
, list
);
580 mconsole_reply_len(entry
->req
, console_buf
, n
, 0, 1);
585 static struct console mc_console
= { .name
= "mc",
586 .write
= console_write
,
587 .flags
= CON_ENABLED
,
590 static int mc_add_console(void)
592 register_console(&mc_console
);
596 late_initcall(mc_add_console
);
598 static void with_console(struct mc_request
*req
, void (*proc
)(void *),
601 struct mconsole_output entry
;
605 spin_lock_irqsave(&client_lock
, flags
);
606 list_add(&entry
.list
, &clients
);
607 spin_unlock_irqrestore(&client_lock
, flags
);
611 mconsole_reply_len(req
, "", 0, 0, 0);
613 spin_lock_irqsave(&client_lock
, flags
);
614 list_del(&entry
.list
);
615 spin_unlock_irqrestore(&client_lock
, flags
);
618 #ifdef CONFIG_MAGIC_SYSRQ
620 #include <linux/sysrq.h>
622 static void sysrq_proc(void *arg
)
628 void mconsole_sysrq(struct mc_request
*req
)
630 char *ptr
= req
->request
.data
;
632 ptr
+= strlen("sysrq");
633 ptr
= skip_spaces(ptr
);
636 * With 'b', the system will shut down without a chance to reply,
637 * so in this case, we reply first.
640 mconsole_reply(req
, "", 0, 0);
642 with_console(req
, sysrq_proc
, ptr
);
645 void mconsole_sysrq(struct mc_request
*req
)
647 mconsole_reply(req
, "Sysrq not compiled in", 1, 0);
651 static void stack_proc(void *arg
)
653 struct task_struct
*from
= current
, *to
= arg
;
655 to
->thread
.saved_task
= from
;
656 switch_to(from
, to
, from
);
660 * Mconsole stack trace
661 * Added by Allan Graves, Jeff Dike
662 * Dumps a stacks registers to the linux console.
665 void mconsole_stack(struct mc_request
*req
)
667 char *ptr
= req
->request
.data
;
668 int pid_requested
= -1;
669 struct task_struct
*to
= NULL
;
673 * 1) Send showregs output to mconsole.
674 * 2) Add a way to stack dump all pids.
677 ptr
+= strlen("stack");
678 ptr
= skip_spaces(ptr
);
681 * Should really check for multiple pids or reject bad args here
683 /* What do the arguments in mconsole_reply mean? */
684 if (sscanf(ptr
, "%d", &pid_requested
) == 0) {
685 mconsole_reply(req
, "Please specify a pid", 1, 0);
689 to
= find_task_by_pid_ns(pid_requested
, &init_pid_ns
);
690 if ((to
== NULL
) || (pid_requested
== 0)) {
691 mconsole_reply(req
, "Couldn't find that pid", 1, 0);
694 with_console(req
, stack_proc
, to
);
698 * Changed by mconsole_setup, which is __setup, and called before SMP is
701 static char *notify_socket
= NULL
;
703 static int __init
mconsole_init(void)
705 /* long to avoid size mismatch warnings from gcc */
708 char file
[UNIX_PATH_MAX
];
710 if (umid_file_name("mconsole", file
, sizeof(file
)))
712 snprintf(mconsole_socket_name
, sizeof(file
), "%s", file
);
714 sock
= os_create_unix_socket(file
, sizeof(file
), 1);
716 printk(KERN_ERR
"Failed to initialize management console\n");
719 if (os_set_fd_block(sock
, 0))
722 register_reboot_notifier(&reboot_notifier
);
724 err
= um_request_irq(MCONSOLE_IRQ
, sock
, IRQ_READ
, mconsole_interrupt
,
725 IRQF_DISABLED
| IRQF_SHARED
| IRQF_SAMPLE_RANDOM
,
726 "mconsole", (void *)sock
);
728 printk(KERN_ERR
"Failed to get IRQ for management console\n");
732 if (notify_socket
!= NULL
) {
733 notify_socket
= kstrdup(notify_socket
, GFP_KERNEL
);
734 if (notify_socket
!= NULL
)
735 mconsole_notify(notify_socket
, MCONSOLE_SOCKET
,
736 mconsole_socket_name
,
737 strlen(mconsole_socket_name
) + 1);
738 else printk(KERN_ERR
"mconsole_setup failed to strdup "
742 printk(KERN_INFO
"mconsole (version %d) initialized on %s\n",
743 MCONSOLE_VERSION
, mconsole_socket_name
);
751 __initcall(mconsole_init
);
753 static ssize_t
mconsole_proc_write(struct file
*file
,
754 const char __user
*buffer
, size_t count
, loff_t
*pos
)
758 buf
= kmalloc(count
+ 1, GFP_KERNEL
);
762 if (copy_from_user(buf
, buffer
, count
)) {
769 mconsole_notify(notify_socket
, MCONSOLE_USER_NOTIFY
, buf
, count
);
775 static const struct file_operations mconsole_proc_fops
= {
776 .owner
= THIS_MODULE
,
777 .write
= mconsole_proc_write
,
780 static int create_proc_mconsole(void)
782 struct proc_dir_entry
*ent
;
784 if (notify_socket
== NULL
)
787 ent
= proc_create("mconsole", 0200, NULL
, &mconsole_proc_fops
);
789 printk(KERN_INFO
"create_proc_mconsole : create_proc_entry "
796 static DEFINE_SPINLOCK(notify_spinlock
);
798 void lock_notify(void)
800 spin_lock(¬ify_spinlock
);
803 void unlock_notify(void)
805 spin_unlock(¬ify_spinlock
);
808 __initcall(create_proc_mconsole
);
810 #define NOTIFY "notify:"
812 static int mconsole_setup(char *str
)
814 if (!strncmp(str
, NOTIFY
, strlen(NOTIFY
))) {
815 str
+= strlen(NOTIFY
);
818 else printk(KERN_ERR
"mconsole_setup : Unknown option - '%s'\n", str
);
822 __setup("mconsole=", mconsole_setup
);
824 __uml_help(mconsole_setup
,
825 "mconsole=notify:<socket>\n"
826 " Requests that the mconsole driver send a message to the named Unix\n"
827 " socket containing the name of the mconsole socket. This also serves\n"
828 " to notify outside processes when UML has booted far enough to respond\n"
829 " to mconsole requests.\n\n"
832 static int notify_panic(struct notifier_block
*self
, unsigned long unused1
,
837 if (notify_socket
== NULL
)
840 mconsole_notify(notify_socket
, MCONSOLE_PANIC
, message
,
841 strlen(message
) + 1);
845 static struct notifier_block panic_exit_notifier
= {
846 .notifier_call
= notify_panic
,
851 static int add_notifier(void)
853 atomic_notifier_chain_register(&panic_notifier_list
,
854 &panic_exit_notifier
);
858 __initcall(add_notifier
);
860 char *mconsole_notify_socket(void)
862 return notify_socket
;
865 EXPORT_SYMBOL(mconsole_notify_socket
);