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/console.h"
25 #include "asm/uaccess.h"
26 #include "user_util.h"
27 #include "kern_util.h"
30 #include "mconsole_kern.h"
36 #include "choose-mode.h"
38 static int do_unlink_socket(struct notifier_block
*notifier
,
39 unsigned long what
, void *data
)
41 return(mconsole_unlink_socket());
45 static struct notifier_block reboot_notifier
= {
46 .notifier_call
= do_unlink_socket
,
50 /* Safe without explicit locking for now. Tasklets provide their own
51 * locking, and the interrupt handler is safe because it can't interrupt
52 * itself and it can only happen on CPU 0.
55 static LIST_HEAD(mc_requests
);
57 static void mc_work_proc(void *unused
)
59 struct mconsole_entry
*req
;
62 while(!list_empty(&mc_requests
)){
63 local_save_flags(flags
);
64 req
= list_entry(mc_requests
.next
, struct mconsole_entry
,
67 local_irq_restore(flags
);
68 req
->request
.cmd
->handler(&req
->request
);
73 static DECLARE_WORK(mconsole_work
, mc_work_proc
, NULL
);
75 static irqreturn_t
mconsole_interrupt(int irq
, void *dev_id
,
78 /* long to avoid size mismatch warnings from gcc */
80 struct mconsole_entry
*new;
81 struct mc_request req
;
84 while (mconsole_get_request(fd
, &req
)){
85 if(req
.cmd
->context
== MCONSOLE_INTR
)
86 (*req
.cmd
->handler
)(&req
);
88 new = kmalloc(sizeof(*new), GFP_ATOMIC
);
90 mconsole_reply(&req
, "Out of memory", 1, 0);
93 list_add(&new->list
, &mc_requests
);
97 if(!list_empty(&mc_requests
))
98 schedule_work(&mconsole_work
);
99 reactivate_fd(fd
, MCONSOLE_IRQ
);
103 void mconsole_version(struct mc_request
*req
)
107 sprintf(version
, "%s %s %s %s %s", system_utsname
.sysname
,
108 system_utsname
.nodename
, system_utsname
.release
,
109 system_utsname
.version
, system_utsname
.machine
);
110 mconsole_reply(req
, version
, 0, 0);
113 void mconsole_log(struct mc_request
*req
)
116 char *ptr
= req
->request
.data
;
118 ptr
+= strlen("log ");
120 len
= req
->len
- (ptr
- req
->request
.data
);
121 printk("%.*s", len
, ptr
);
122 mconsole_reply(req
, "", 0, 0);
125 /* This is a more convoluted version of mconsole_proc, which has some stability
126 * problems; however, we need it fixed, because it is expected that UML users
127 * mount HPPFS instead of procfs on /proc. And we want mconsole_proc to still
128 * show the real procfs content, not the ones from hppfs.*/
130 void mconsole_proc(struct mc_request
*req
)
133 struct file_system_type
*proc
;
134 struct super_block
*super
;
137 char *ptr
= req
->request
.data
, *buf
;
139 ptr
+= strlen("proc");
140 while(isspace(*ptr
)) ptr
++;
142 proc
= get_fs_type("proc");
144 mconsole_reply(req
, "procfs not registered", 1, 0);
148 super
= (*proc
->get_sb
)(proc
, 0, NULL
, NULL
);
149 put_filesystem(proc
);
151 mconsole_reply(req
, "Failed to get procfs superblock", 1, 0);
154 up_write(&super
->s_umount
);
156 nd
.dentry
= super
->s_root
;
158 nd
.flags
= O_RDONLY
+ 1;
159 nd
.last_type
= LAST_ROOT
;
161 /* START: it was experienced that the stability problems are closed
162 * if commenting out these two calls + the below read cycle. To
163 * make UML crash again, it was enough to readd either one.*/
164 err
= link_path_walk(ptr
, &nd
);
166 mconsole_reply(req
, "Failed to look up file", 1, 0);
170 file
= dentry_open(nd
.dentry
, nd
.mnt
, O_RDONLY
);
172 mconsole_reply(req
, "Failed to open file", 1, 0);
177 buf
= kmalloc(PAGE_SIZE
, GFP_KERNEL
);
179 mconsole_reply(req
, "Failed to allocate buffer", 1, 0);
183 if((file
->f_op
!= NULL
) && (file
->f_op
->read
!= NULL
)){
185 n
= (*file
->f_op
->read
)(file
, buf
, PAGE_SIZE
- 1,
189 mconsole_reply(req
, buf
, 0, (n
> 0));
192 mconsole_reply(req
, "Read of file failed",
198 else mconsole_reply(req
, "", 0, 0);
205 deactivate_super(super
);
210 void mconsole_proc(struct mc_request
*req
)
217 char *ptr
= req
->request
.data
;
219 ptr
+= strlen("proc");
220 while(isspace(*ptr
)) ptr
++;
221 snprintf(path
, sizeof(path
), "/proc/%s", ptr
);
223 fd
= sys_open(path
, 0, 0);
225 mconsole_reply(req
, "Failed to open file", 1, 0);
226 printk("open %s: %d\n",path
,fd
);
230 buf
= kmalloc(PAGE_SIZE
, GFP_KERNEL
);
232 mconsole_reply(req
, "Failed to allocate buffer", 1, 0);
237 len
= sys_read(fd
, buf
, PAGE_SIZE
-1);
239 mconsole_reply(req
, "Read of file failed", 1, 0);
242 /*Begin the file content on his own line.*/
244 mconsole_reply(req
, "\n", 0, 1);
247 if (len
== PAGE_SIZE
-1) {
249 mconsole_reply(req
, buf
, 0, 1);
252 mconsole_reply(req
, buf
, 0, 0);
265 #define UML_MCONSOLE_HELPTEXT \
267 version - Get kernel version \n\
268 help - Print this message \n\
270 reboot - Reboot UML \n\
271 config <dev>=<config> - Add a new device to UML; \n\
272 same syntax as command line \n\
273 config <dev> - Query the configuration of a device \n\
274 remove <dev> - Remove a device from UML \n\
275 sysrq <letter> - Performs the SysRq action controlled by the letter \n\
276 cad - invoke the Ctrl-Alt-Del handler \n\
277 stop - pause the UML; it will do nothing until it receives a 'go' \n\
278 go - continue the UML after a 'stop' \n\
279 log <string> - make UML enter <string> into the kernel log\n\
280 proc <file> - returns the contents of the UML's /proc/<file>\n\
281 stack <pid> - returns the stack of the specified pid\n\
284 void mconsole_help(struct mc_request
*req
)
286 mconsole_reply(req
, UML_MCONSOLE_HELPTEXT
, 0, 0);
289 void mconsole_halt(struct mc_request
*req
)
291 mconsole_reply(req
, "", 0, 0);
295 void mconsole_reboot(struct mc_request
*req
)
297 mconsole_reply(req
, "", 0, 0);
298 machine_restart(NULL
);
301 extern void ctrl_alt_del(void);
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
, "", 0, 0);
319 while(mconsole_get_request(req
->originating_fd
, req
)){
320 if(req
->cmd
->handler
== mconsole_go
) break;
321 (*req
->cmd
->handler
)(req
);
323 os_set_fd_block(req
->originating_fd
, 0);
324 reactivate_fd(req
->originating_fd
, MCONSOLE_IRQ
);
325 mconsole_reply(req
, "", 0, 0);
328 /* This list is populated by __initcall routines. */
330 static LIST_HEAD(mconsole_devices
);
332 void mconsole_register_dev(struct mc_device
*new)
334 list_add(&new->list
, &mconsole_devices
);
337 static struct mc_device
*mconsole_find_dev(char *name
)
339 struct list_head
*ele
;
340 struct mc_device
*dev
;
342 list_for_each(ele
, &mconsole_devices
){
343 dev
= list_entry(ele
, struct mc_device
, list
);
344 if(!strncmp(name
, dev
->name
, strlen(dev
->name
)))
350 #define CONFIG_BUF_SIZE 64
352 static void mconsole_get_config(int (*get_config
)(char *, char *, int,
354 struct mc_request
*req
, char *name
)
356 char default_buf
[CONFIG_BUF_SIZE
], *error
, *buf
;
359 if(get_config
== NULL
){
360 mconsole_reply(req
, "No get_config routine defined", 1, 0);
365 size
= sizeof(default_buf
)/sizeof(default_buf
[0]);
369 n
= (*get_config
)(name
, buf
, size
, &error
);
371 mconsole_reply(req
, error
, 1, 0);
376 mconsole_reply(req
, buf
, 0, 0);
380 if(buf
!= default_buf
)
384 buf
= kmalloc(size
, GFP_KERNEL
);
386 mconsole_reply(req
, "Failed to allocate buffer", 1, 0);
391 if(buf
!= default_buf
)
395 void mconsole_config(struct mc_request
*req
)
397 struct mc_device
*dev
;
398 char *ptr
= req
->request
.data
, *name
;
401 ptr
+= strlen("config");
402 while(isspace(*ptr
)) ptr
++;
403 dev
= mconsole_find_dev(ptr
);
405 mconsole_reply(req
, "Bad configuration option", 1, 0);
409 name
= &ptr
[strlen(dev
->name
)];
411 while((*ptr
!= '=') && (*ptr
!= '\0'))
415 err
= (*dev
->config
)(name
);
416 mconsole_reply(req
, "", err
, 0);
418 else mconsole_get_config(dev
->get_config
, req
, name
);
421 void mconsole_remove(struct mc_request
*req
)
423 struct mc_device
*dev
;
424 char *ptr
= req
->request
.data
, *err_msg
= "";
426 int err
, start
, end
, n
;
428 ptr
+= strlen("remove");
429 while(isspace(*ptr
)) ptr
++;
430 dev
= mconsole_find_dev(ptr
);
432 mconsole_reply(req
, "Bad remove option", 1, 0);
436 ptr
= &ptr
[strlen(dev
->name
)];
439 n
= (*dev
->id
)(&ptr
, &start
, &end
);
441 err_msg
= "Couldn't parse device number";
444 else if((n
< start
) || (n
> end
)){
445 sprintf(error
, "Invalid device number - must be between "
446 "%d and %d", start
, end
);
451 err
= (*dev
->remove
)(n
);
454 err_msg
= "Device doesn't exist";
457 err_msg
= "Device is currently open";
463 mconsole_reply(req
, err_msg
, err
, 0);
466 static DEFINE_SPINLOCK(console_lock
);
467 static LIST_HEAD(clients
);
468 static char console_buf
[MCONSOLE_MAX_DATA
];
469 static int console_index
= 0;
471 static void console_write(struct console
*console
, const char *string
,
474 struct list_head
*ele
;
477 if(list_empty(&clients
))
481 n
= min(len
, ARRAY_SIZE(console_buf
) - console_index
);
482 strncpy(&console_buf
[console_index
], string
, n
);
489 list_for_each(ele
, &clients
){
490 struct mconsole_entry
*entry
;
492 entry
= list_entry(ele
, struct mconsole_entry
, list
);
493 mconsole_reply_len(&entry
->request
, console_buf
,
494 console_index
, 0, 1);
501 static struct console mc_console
= { .name
= "mc",
502 .write
= console_write
,
503 .flags
= CON_ENABLED
,
506 static int mc_add_console(void)
508 register_console(&mc_console
);
512 late_initcall(mc_add_console
);
514 static void with_console(struct mc_request
*req
, void (*proc
)(void *),
517 struct mconsole_entry entry
;
520 INIT_LIST_HEAD(&entry
.list
);
521 entry
.request
= *req
;
522 list_add(&entry
.list
, &clients
);
523 spin_lock_irqsave(&console_lock
, flags
);
527 mconsole_reply_len(req
, console_buf
, console_index
, 0, 0);
530 spin_unlock_irqrestore(&console_lock
, flags
);
531 list_del(&entry
.list
);
534 #ifdef CONFIG_MAGIC_SYSRQ
535 static void sysrq_proc(void *arg
)
539 handle_sysrq(*op
, ¤t
->thread
.regs
, NULL
);
542 void mconsole_sysrq(struct mc_request
*req
)
544 char *ptr
= req
->request
.data
;
546 ptr
+= strlen("sysrq");
547 while(isspace(*ptr
)) ptr
++;
549 /* With 'b', the system will shut down without a chance to reply,
550 * so in this case, we reply first.
553 mconsole_reply(req
, "", 0, 0);
555 with_console(req
, sysrq_proc
, ptr
);
558 void mconsole_sysrq(struct mc_request
*req
)
560 mconsole_reply(req
, "Sysrq not compiled in", 1, 0);
564 #ifdef CONFIG_MODE_SKAS
566 static void stack_proc(void *arg
)
568 struct task_struct
*from
= current
, *to
= arg
;
570 to
->thread
.saved_task
= from
;
571 switch_to(from
, to
, from
);
574 /* Mconsole stack trace
575 * Added by Allan Graves, Jeff Dike
576 * Dumps a stacks registers to the linux console.
579 static void do_stack_trace(struct mc_request
*req
)
581 char *ptr
= req
->request
.data
;
582 int pid_requested
= -1;
583 struct task_struct
*from
= NULL
;
584 struct task_struct
*to
= NULL
;
587 * 1) Send showregs output to mconsole.
588 * 2) Add a way to stack dump all pids.
591 ptr
+= strlen("stack");
592 while(isspace(*ptr
)) ptr
++;
594 /* Should really check for multiple pids or reject bad args here */
595 /* What do the arguments in mconsole_reply mean? */
596 if(sscanf(ptr
, "%d", &pid_requested
) == 0){
597 mconsole_reply(req
, "Please specify a pid", 1, 0);
603 to
= find_task_by_pid(pid_requested
);
604 if((to
== NULL
) || (pid_requested
== 0)) {
605 mconsole_reply(req
, "Couldn't find that pid", 1, 0);
608 with_console(req
, stack_proc
, to
);
610 #endif /* CONFIG_MODE_SKAS */
612 void mconsole_stack(struct mc_request
*req
)
614 /* This command doesn't work in TT mode, so let's check and then
617 CHOOSE_MODE(mconsole_reply(req
, "Sorry, this doesn't work in TT mode",
619 do_stack_trace(req
));
622 /* Changed by mconsole_setup, which is __setup, and called before SMP is
625 static char *notify_socket
= NULL
;
627 static int mconsole_init(void)
629 /* long to avoid size mismatch warnings from gcc */
634 if(umid_file_name("mconsole", file
, sizeof(file
))) return(-1);
635 snprintf(mconsole_socket_name
, sizeof(file
), "%s", file
);
637 sock
= os_create_unix_socket(file
, sizeof(file
), 1);
639 printk("Failed to initialize management console\n");
643 register_reboot_notifier(&reboot_notifier
);
645 err
= um_request_irq(MCONSOLE_IRQ
, sock
, IRQ_READ
, mconsole_interrupt
,
646 SA_INTERRUPT
| SA_SHIRQ
| SA_SAMPLE_RANDOM
,
647 "mconsole", (void *)sock
);
649 printk("Failed to get IRQ for management console\n");
653 if(notify_socket
!= NULL
){
654 notify_socket
= kstrdup(notify_socket
, GFP_KERNEL
);
655 if(notify_socket
!= NULL
)
656 mconsole_notify(notify_socket
, MCONSOLE_SOCKET
,
657 mconsole_socket_name
,
658 strlen(mconsole_socket_name
) + 1);
659 else printk(KERN_ERR
"mconsole_setup failed to strdup "
663 printk("mconsole (version %d) initialized on %s\n",
664 MCONSOLE_VERSION
, mconsole_socket_name
);
668 __initcall(mconsole_init
);
670 static int write_proc_mconsole(struct file
*file
, const char __user
*buffer
,
671 unsigned long count
, void *data
)
675 buf
= kmalloc(count
+ 1, GFP_KERNEL
);
679 if(copy_from_user(buf
, buffer
, count
)){
686 mconsole_notify(notify_socket
, MCONSOLE_USER_NOTIFY
, buf
, count
);
692 static int create_proc_mconsole(void)
694 struct proc_dir_entry
*ent
;
696 if(notify_socket
== NULL
) return(0);
698 ent
= create_proc_entry("mconsole", S_IFREG
| 0200, NULL
);
700 printk(KERN_INFO
"create_proc_mconsole : create_proc_entry failed\n");
704 ent
->read_proc
= NULL
;
705 ent
->write_proc
= write_proc_mconsole
;
709 static DEFINE_SPINLOCK(notify_spinlock
);
711 void lock_notify(void)
713 spin_lock(¬ify_spinlock
);
716 void unlock_notify(void)
718 spin_unlock(¬ify_spinlock
);
721 __initcall(create_proc_mconsole
);
723 #define NOTIFY "=notify:"
725 static int mconsole_setup(char *str
)
727 if(!strncmp(str
, NOTIFY
, strlen(NOTIFY
))){
728 str
+= strlen(NOTIFY
);
731 else printk(KERN_ERR
"mconsole_setup : Unknown option - '%s'\n", str
);
735 __setup("mconsole", mconsole_setup
);
737 __uml_help(mconsole_setup
,
738 "mconsole=notify:<socket>\n"
739 " Requests that the mconsole driver send a message to the named Unix\n"
740 " socket containing the name of the mconsole socket. This also serves\n"
741 " to notify outside processes when UML has booted far enough to respond\n"
742 " to mconsole requests.\n\n"
745 static int notify_panic(struct notifier_block
*self
, unsigned long unused1
,
750 if(notify_socket
== NULL
) return(0);
752 mconsole_notify(notify_socket
, MCONSOLE_PANIC
, message
,
753 strlen(message
) + 1);
757 static struct notifier_block panic_exit_notifier
= {
758 .notifier_call
= notify_panic
,
763 static int add_notifier(void)
765 atomic_notifier_chain_register(&panic_notifier_list
,
766 &panic_exit_notifier
);
770 __initcall(add_notifier
);
772 char *mconsole_notify_socket(void)
774 return(notify_socket
);
777 EXPORT_SYMBOL(mconsole_notify_socket
);