2 * Copyright (C) 2001 Lennert Buytenhek (buytenh@gnu.org)
3 * Copyright (C) 2001 - 2007 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/interrupt.h"
10 #include "linux/list.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/workqueue.h"
20 #include "linux/mutex.h"
21 #include "asm/uaccess.h"
25 #include "kern_util.h"
27 #include "mconsole_kern.h"
30 static int do_unlink_socket(struct notifier_block
*notifier
,
31 unsigned long what
, void *data
)
33 return mconsole_unlink_socket();
37 static struct notifier_block reboot_notifier
= {
38 .notifier_call
= do_unlink_socket
,
42 /* Safe without explicit locking for now. Tasklets provide their own
43 * locking, and the interrupt handler is safe because it can't interrupt
44 * itself and it can only happen on CPU 0.
47 static LIST_HEAD(mc_requests
);
49 static void mc_work_proc(struct work_struct
*unused
)
51 struct mconsole_entry
*req
;
54 while (!list_empty(&mc_requests
)) {
55 local_irq_save(flags
);
56 req
= list_entry(mc_requests
.next
, struct mconsole_entry
, list
);
58 local_irq_restore(flags
);
59 req
->request
.cmd
->handler(&req
->request
);
64 static DECLARE_WORK(mconsole_work
, mc_work_proc
);
66 static irqreturn_t
mconsole_interrupt(int irq
, void *dev_id
)
68 /* long to avoid size mismatch warnings from gcc */
70 struct mconsole_entry
*new;
71 static struct mc_request req
; /* that's OK */
74 while (mconsole_get_request(fd
, &req
)) {
75 if (req
.cmd
->context
== MCONSOLE_INTR
)
76 (*req
.cmd
->handler
)(&req
);
78 new = kmalloc(sizeof(*new), GFP_NOWAIT
);
80 mconsole_reply(&req
, "Out of memory", 1, 0);
83 new->request
.regs
= get_irq_regs()->regs
;
84 list_add(&new->list
, &mc_requests
);
88 if (!list_empty(&mc_requests
))
89 schedule_work(&mconsole_work
);
90 reactivate_fd(fd
, MCONSOLE_IRQ
);
94 void mconsole_version(struct mc_request
*req
)
98 sprintf(version
, "%s %s %s %s %s", utsname()->sysname
,
99 utsname()->nodename
, utsname()->release
, utsname()->version
,
101 mconsole_reply(req
, version
, 0, 0);
104 void mconsole_log(struct mc_request
*req
)
107 char *ptr
= req
->request
.data
;
109 ptr
+= strlen("log ");
111 len
= req
->len
- (ptr
- req
->request
.data
);
112 printk(KERN_WARNING
"%.*s", len
, ptr
);
113 mconsole_reply(req
, "", 0, 0);
116 /* This is a more convoluted version of mconsole_proc, which has some stability
117 * problems; however, we need it fixed, because it is expected that UML users
118 * mount HPPFS instead of procfs on /proc. And we want mconsole_proc to still
119 * show the real procfs content, not the ones from hppfs.*/
121 void mconsole_proc(struct mc_request
*req
)
124 struct file_system_type
*proc
;
125 struct super_block
*super
;
128 char *ptr
= req
->request
.data
, *buf
;
130 ptr
+= strlen("proc");
131 while (isspace(*ptr
)) ptr
++;
133 proc
= get_fs_type("proc");
135 mconsole_reply(req
, "procfs not registered", 1, 0);
139 super
= (*proc
->get_sb
)(proc
, 0, NULL
, NULL
);
140 put_filesystem(proc
);
142 mconsole_reply(req
, "Failed to get procfs superblock", 1, 0);
145 up_write(&super
->s_umount
);
147 nd
.dentry
= super
->s_root
;
149 nd
.flags
= O_RDONLY
+ 1;
150 nd
.last_type
= LAST_ROOT
;
152 /* START: it was experienced that the stability problems are closed
153 * if commenting out these two calls + the below read cycle. To
154 * make UML crash again, it was enough to readd either one.*/
155 err
= link_path_walk(ptr
, &nd
);
157 mconsole_reply(req
, "Failed to look up file", 1, 0);
161 file
= dentry_open(nd
.dentry
, nd
.mnt
, O_RDONLY
);
163 mconsole_reply(req
, "Failed to open file", 1, 0);
168 buf
= kmalloc(PAGE_SIZE
, GFP_KERNEL
);
170 mconsole_reply(req
, "Failed to allocate buffer", 1, 0);
174 if ((file
->f_op
!= NULL
) && (file
->f_op
->read
!= NULL
)) {
176 n
= (*file
->f_op
->read
)(file
, buf
, PAGE_SIZE
- 1,
180 mconsole_reply(req
, buf
, 0, (n
> 0));
183 mconsole_reply(req
, "Read of file failed",
189 else mconsole_reply(req
, "", 0, 0);
196 deactivate_super(super
);
201 void mconsole_proc(struct mc_request
*req
)
208 char *ptr
= req
->request
.data
;
210 ptr
+= strlen("proc");
211 while (isspace(*ptr
))
213 snprintf(path
, sizeof(path
), "/proc/%s", ptr
);
215 fd
= sys_open(path
, 0, 0);
217 mconsole_reply(req
, "Failed to open file", 1, 0);
218 printk(KERN_ERR
"open %s: %d\n",path
,fd
);
222 buf
= kmalloc(PAGE_SIZE
, GFP_KERNEL
);
224 mconsole_reply(req
, "Failed to allocate buffer", 1, 0);
229 len
= sys_read(fd
, buf
, PAGE_SIZE
-1);
231 mconsole_reply(req
, "Read of file failed", 1, 0);
234 /* Begin the file content on his own line. */
236 mconsole_reply(req
, "\n", 0, 1);
239 if (len
== PAGE_SIZE
-1) {
241 mconsole_reply(req
, buf
, 0, 1);
244 mconsole_reply(req
, buf
, 0, 0);
257 #define UML_MCONSOLE_HELPTEXT \
259 version - Get kernel version \n\
260 help - Print this message \n\
262 reboot - Reboot UML \n\
263 config <dev>=<config> - Add a new device to UML; \n\
264 same syntax as command line \n\
265 config <dev> - Query the configuration of a device \n\
266 remove <dev> - Remove a device from UML \n\
267 sysrq <letter> - Performs the SysRq action controlled by the letter \n\
268 cad - invoke the Ctrl-Alt-Del handler \n\
269 stop - pause the UML; it will do nothing until it receives a 'go' \n\
270 go - continue the UML after a 'stop' \n\
271 log <string> - make UML enter <string> into the kernel log\n\
272 proc <file> - returns the contents of the UML's /proc/<file>\n\
273 stack <pid> - returns the stack of the specified pid\n\
276 void mconsole_help(struct mc_request
*req
)
278 mconsole_reply(req
, UML_MCONSOLE_HELPTEXT
, 0, 0);
281 void mconsole_halt(struct mc_request
*req
)
283 mconsole_reply(req
, "", 0, 0);
287 void mconsole_reboot(struct mc_request
*req
)
289 mconsole_reply(req
, "", 0, 0);
290 machine_restart(NULL
);
293 void mconsole_cad(struct mc_request
*req
)
295 mconsole_reply(req
, "", 0, 0);
299 void mconsole_go(struct mc_request
*req
)
301 mconsole_reply(req
, "Not stopped", 1, 0);
304 void mconsole_stop(struct mc_request
*req
)
306 deactivate_fd(req
->originating_fd
, MCONSOLE_IRQ
);
307 os_set_fd_block(req
->originating_fd
, 1);
308 mconsole_reply(req
, "stopped", 0, 0);
310 if (!mconsole_get_request(req
->originating_fd
, req
))
312 if (req
->cmd
->handler
== mconsole_go
)
314 if (req
->cmd
->handler
== mconsole_stop
) {
315 mconsole_reply(req
, "Already stopped", 1, 0);
318 if (req
->cmd
->handler
== mconsole_sysrq
) {
319 struct pt_regs
*old_regs
;
320 old_regs
= set_irq_regs((struct pt_regs
*)&req
->regs
);
322 set_irq_regs(old_regs
);
325 (*req
->cmd
->handler
)(req
);
327 os_set_fd_block(req
->originating_fd
, 0);
328 reactivate_fd(req
->originating_fd
, MCONSOLE_IRQ
);
329 mconsole_reply(req
, "", 0, 0);
332 static DEFINE_SPINLOCK(mc_devices_lock
);
333 static LIST_HEAD(mconsole_devices
);
335 void mconsole_register_dev(struct mc_device
*new)
337 spin_lock(&mc_devices_lock
);
338 BUG_ON(!list_empty(&new->list
));
339 list_add(&new->list
, &mconsole_devices
);
340 spin_unlock(&mc_devices_lock
);
343 static struct mc_device
*mconsole_find_dev(char *name
)
345 struct list_head
*ele
;
346 struct mc_device
*dev
;
348 list_for_each(ele
, &mconsole_devices
) {
349 dev
= list_entry(ele
, struct mc_device
, list
);
350 if (!strncmp(name
, dev
->name
, strlen(dev
->name
)))
356 #define UNPLUGGED_PER_PAGE \
357 ((PAGE_SIZE - sizeof(struct list_head)) / sizeof(unsigned long))
359 struct unplugged_pages
{
360 struct list_head list
;
361 void *pages
[UNPLUGGED_PER_PAGE
];
364 static DEFINE_MUTEX(plug_mem_mutex
);
365 static unsigned long long unplugged_pages_count
= 0;
366 static LIST_HEAD(unplugged_pages
);
367 static int unplug_index
= UNPLUGGED_PER_PAGE
;
369 static int mem_config(char *str
, char **error_out
)
371 unsigned long long diff
;
372 int err
= -EINVAL
, i
, add
;
376 *error_out
= "Expected '=' after 'mem'";
383 else if (str
[0] == '+') {
387 *error_out
= "Expected increment to start with '-' or '+'";
392 diff
= memparse(str
, &ret
);
394 *error_out
= "Failed to parse memory increment";
400 mutex_lock(&plug_mem_mutex
);
401 for (i
= 0; i
< diff
; i
++) {
402 struct unplugged_pages
*unplugged
;
406 if (list_empty(&unplugged_pages
))
409 unplugged
= list_entry(unplugged_pages
.next
,
410 struct unplugged_pages
, list
);
411 if (unplug_index
> 0)
412 addr
= unplugged
->pages
[--unplug_index
];
414 list_del(&unplugged
->list
);
416 unplug_index
= UNPLUGGED_PER_PAGE
;
419 free_page((unsigned long) addr
);
420 unplugged_pages_count
--;
425 page
= alloc_page(GFP_ATOMIC
);
429 unplugged
= page_address(page
);
430 if (unplug_index
== UNPLUGGED_PER_PAGE
) {
431 list_add(&unplugged
->list
, &unplugged_pages
);
435 struct list_head
*entry
= unplugged_pages
.next
;
438 unplugged
= list_entry(entry
,
439 struct unplugged_pages
,
441 err
= os_drop_memory(addr
, PAGE_SIZE
);
443 printk(KERN_ERR
"Failed to release "
444 "memory - errno = %d\n", err
);
445 *error_out
= "Failed to release memory";
448 unplugged
->pages
[unplug_index
++] = addr
;
451 unplugged_pages_count
++;
457 mutex_unlock(&plug_mem_mutex
);
462 static int mem_get_config(char *name
, char *str
, int size
, char **error_out
)
464 char buf
[sizeof("18446744073709551615")];
467 sprintf(buf
, "%ld", uml_physmem
);
468 CONFIG_CHUNK(str
, size
, len
, buf
, 1);
473 static int mem_id(char **str
, int *start_out
, int *end_out
)
481 static int mem_remove(int n
, char **error_out
)
483 *error_out
= "Memory doesn't support the remove operation";
487 static struct mc_device mem_mc
= {
488 .list
= LIST_HEAD_INIT(mem_mc
.list
),
490 .config
= mem_config
,
491 .get_config
= mem_get_config
,
493 .remove
= mem_remove
,
496 static int __init
mem_mc_init(void)
498 if (can_drop_memory())
499 mconsole_register_dev(&mem_mc
);
500 else printk(KERN_ERR
"Can't release memory to the host - memory "
501 "hotplug won't be supported\n");
505 __initcall(mem_mc_init
);
507 #define CONFIG_BUF_SIZE 64
509 static void mconsole_get_config(int (*get_config
)(char *, char *, int,
511 struct mc_request
*req
, char *name
)
513 char default_buf
[CONFIG_BUF_SIZE
], *error
, *buf
;
516 if (get_config
== NULL
) {
517 mconsole_reply(req
, "No get_config routine defined", 1, 0);
522 size
= ARRAY_SIZE(default_buf
);
526 n
= (*get_config
)(name
, buf
, size
, &error
);
528 mconsole_reply(req
, error
, 1, 0);
533 mconsole_reply(req
, buf
, 0, 0);
537 if (buf
!= default_buf
)
541 buf
= kmalloc(size
, GFP_KERNEL
);
543 mconsole_reply(req
, "Failed to allocate buffer", 1, 0);
548 if (buf
!= default_buf
)
552 void mconsole_config(struct mc_request
*req
)
554 struct mc_device
*dev
;
555 char *ptr
= req
->request
.data
, *name
, *error_string
= "";
558 ptr
+= strlen("config");
559 while (isspace(*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
);
617 err_msg
= "Device doesn't exist";
621 err_msg
= "Device is currently open";
627 mconsole_reply(req
, err_msg
, err
, 0);
630 struct mconsole_output
{
631 struct list_head list
;
632 struct mc_request
*req
;
635 static DEFINE_SPINLOCK(client_lock
);
636 static LIST_HEAD(clients
);
637 static char console_buf
[MCONSOLE_MAX_DATA
];
639 static void console_write(struct console
*console
, const char *string
,
642 struct list_head
*ele
;
645 if (list_empty(&clients
))
649 n
= min((size_t) len
, ARRAY_SIZE(console_buf
));
650 strncpy(console_buf
, string
, n
);
654 list_for_each(ele
, &clients
) {
655 struct mconsole_output
*entry
;
657 entry
= list_entry(ele
, struct mconsole_output
, list
);
658 mconsole_reply_len(entry
->req
, console_buf
, n
, 0, 1);
663 static struct console mc_console
= { .name
= "mc",
664 .write
= console_write
,
665 .flags
= CON_ENABLED
,
668 static int mc_add_console(void)
670 register_console(&mc_console
);
674 late_initcall(mc_add_console
);
676 static void with_console(struct mc_request
*req
, void (*proc
)(void *),
679 struct mconsole_output entry
;
683 spin_lock_irqsave(&client_lock
, flags
);
684 list_add(&entry
.list
, &clients
);
685 spin_unlock_irqrestore(&client_lock
, flags
);
689 mconsole_reply_len(req
, "", 0, 0, 0);
691 spin_lock_irqsave(&client_lock
, flags
);
692 list_del(&entry
.list
);
693 spin_unlock_irqrestore(&client_lock
, flags
);
696 #ifdef CONFIG_MAGIC_SYSRQ
698 #include <linux/sysrq.h>
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
++;
714 * With 'b', the system will shut down without a chance to reply,
715 * so in this case, we reply first.
718 mconsole_reply(req
, "", 0, 0);
720 with_console(req
, sysrq_proc
, ptr
);
723 void mconsole_sysrq(struct mc_request
*req
)
725 mconsole_reply(req
, "Sysrq not compiled in", 1, 0);
729 static void stack_proc(void *arg
)
731 struct task_struct
*from
= current
, *to
= arg
;
733 to
->thread
.saved_task
= from
;
734 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 void mconsole_stack(struct mc_request
*req
)
745 char *ptr
= req
->request
.data
;
746 int pid_requested
= -1;
747 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
))
760 * Should really check for multiple pids or reject bad args here
762 /* What do the arguments in mconsole_reply mean? */
763 if (sscanf(ptr
, "%d", &pid_requested
) == 0) {
764 mconsole_reply(req
, "Please specify a pid", 1, 0);
768 to
= find_task_by_pid(pid_requested
);
769 if ((to
== NULL
) || (pid_requested
== 0)) {
770 mconsole_reply(req
, "Couldn't find that pid", 1, 0);
773 with_console(req
, stack_proc
, to
);
777 * Changed by mconsole_setup, which is __setup, and called before SMP is
780 static char *notify_socket
= NULL
;
782 static int __init
mconsole_init(void)
784 /* long to avoid size mismatch warnings from gcc */
789 if (umid_file_name("mconsole", file
, sizeof(file
)))
791 snprintf(mconsole_socket_name
, sizeof(file
), "%s", file
);
793 sock
= os_create_unix_socket(file
, sizeof(file
), 1);
795 printk(KERN_ERR
"Failed to initialize management console\n");
798 if (os_set_fd_block(sock
, 0))
801 register_reboot_notifier(&reboot_notifier
);
803 err
= um_request_irq(MCONSOLE_IRQ
, sock
, IRQ_READ
, mconsole_interrupt
,
804 IRQF_DISABLED
| IRQF_SHARED
| IRQF_SAMPLE_RANDOM
,
805 "mconsole", (void *)sock
);
807 printk(KERN_ERR
"Failed to get IRQ for management console\n");
811 if (notify_socket
!= NULL
) {
812 notify_socket
= kstrdup(notify_socket
, GFP_KERNEL
);
813 if (notify_socket
!= NULL
)
814 mconsole_notify(notify_socket
, MCONSOLE_SOCKET
,
815 mconsole_socket_name
,
816 strlen(mconsole_socket_name
) + 1);
817 else printk(KERN_ERR
"mconsole_setup failed to strdup "
821 printk(KERN_INFO
"mconsole (version %d) initialized on %s\n",
822 MCONSOLE_VERSION
, mconsole_socket_name
);
830 __initcall(mconsole_init
);
832 static int write_proc_mconsole(struct file
*file
, const char __user
*buffer
,
833 unsigned long count
, void *data
)
837 buf
= kmalloc(count
+ 1, GFP_KERNEL
);
841 if (copy_from_user(buf
, buffer
, count
)) {
848 mconsole_notify(notify_socket
, MCONSOLE_USER_NOTIFY
, buf
, count
);
854 static int create_proc_mconsole(void)
856 struct proc_dir_entry
*ent
;
858 if (notify_socket
== NULL
)
861 ent
= create_proc_entry("mconsole", S_IFREG
| 0200, NULL
);
863 printk(KERN_INFO
"create_proc_mconsole : create_proc_entry "
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
)
917 mconsole_notify(notify_socket
, MCONSOLE_PANIC
, message
,
918 strlen(message
) + 1);
922 static struct notifier_block panic_exit_notifier
= {
923 .notifier_call
= notify_panic
,
928 static int add_notifier(void)
930 atomic_notifier_chain_register(&panic_notifier_list
,
931 &panic_exit_notifier
);
935 __initcall(add_notifier
);
937 char *mconsole_notify_socket(void)
939 return notify_socket
;
942 EXPORT_SYMBOL(mconsole_notify_socket
);