diff options
Diffstat (limited to 'arch/um/drivers/mconsole_kern.c')
| -rw-r--r-- | arch/um/drivers/mconsole_kern.c | 619 |
1 files changed, 619 insertions, 0 deletions
diff --git a/arch/um/drivers/mconsole_kern.c b/arch/um/drivers/mconsole_kern.c new file mode 100644 index 00000000000..d7c7adcc0a6 --- /dev/null +++ b/arch/um/drivers/mconsole_kern.c @@ -0,0 +1,619 @@ +/* + * Copyright (C) 2001 Lennert Buytenhek (buytenh@gnu.org) + * Copyright (C) 2001 - 2003 Jeff Dike (jdike@addtoit.com) + * Licensed under the GPL + */ + +#include "linux/kernel.h" +#include "linux/slab.h" +#include "linux/init.h" +#include "linux/notifier.h" +#include "linux/reboot.h" +#include "linux/utsname.h" +#include "linux/ctype.h" +#include "linux/interrupt.h" +#include "linux/sysrq.h" +#include "linux/workqueue.h" +#include "linux/module.h" +#include "linux/file.h" +#include "linux/fs.h" +#include "linux/namei.h" +#include "linux/proc_fs.h" +#include "linux/syscalls.h" +#include "asm/irq.h" +#include "asm/uaccess.h" +#include "user_util.h" +#include "kern_util.h" +#include "kern.h" +#include "mconsole.h" +#include "mconsole_kern.h" +#include "irq_user.h" +#include "init.h" +#include "os.h" +#include "umid.h" +#include "irq_kern.h" + +static int do_unlink_socket(struct notifier_block *notifier, + unsigned long what, void *data) +{ + return(mconsole_unlink_socket()); +} + + +static struct notifier_block reboot_notifier = { + .notifier_call = do_unlink_socket, + .priority = 0, +}; + +/* Safe without explicit locking for now. Tasklets provide their own + * locking, and the interrupt handler is safe because it can't interrupt + * itself and it can only happen on CPU 0. + */ + +LIST_HEAD(mc_requests); + +static void mc_work_proc(void *unused) +{ + struct mconsole_entry *req; + unsigned long flags; + + while(!list_empty(&mc_requests)){ + local_save_flags(flags); + req = list_entry(mc_requests.next, struct mconsole_entry, + list); + list_del(&req->list); + local_irq_restore(flags); + req->request.cmd->handler(&req->request); + kfree(req); + } +} + +DECLARE_WORK(mconsole_work, mc_work_proc, NULL); + +static irqreturn_t mconsole_interrupt(int irq, void *dev_id, + struct pt_regs *regs) +{ + /* long to avoid size mismatch warnings from gcc */ + long fd; + struct mconsole_entry *new; + struct mc_request req; + + fd = (long) dev_id; + while (mconsole_get_request(fd, &req)){ + if(req.cmd->context == MCONSOLE_INTR) + (*req.cmd->handler)(&req); + else { + new = kmalloc(sizeof(*new), GFP_ATOMIC); + if(new == NULL) + mconsole_reply(&req, "Out of memory", 1, 0); + else { + new->request = req; + list_add(&new->list, &mc_requests); + } + } + } + if(!list_empty(&mc_requests)) + schedule_work(&mconsole_work); + reactivate_fd(fd, MCONSOLE_IRQ); + return(IRQ_HANDLED); +} + +void mconsole_version(struct mc_request *req) +{ + char version[256]; + + sprintf(version, "%s %s %s %s %s", system_utsname.sysname, + system_utsname.nodename, system_utsname.release, + system_utsname.version, system_utsname.machine); + mconsole_reply(req, version, 0, 0); +} + +void mconsole_log(struct mc_request *req) +{ + int len; + char *ptr = req->request.data; + + ptr += strlen("log "); + + len = req->len - (ptr - req->request.data); + printk("%.*s", len, ptr); + mconsole_reply(req, "", 0, 0); +} + +/* This is a more convoluted version of mconsole_proc, which has some stability + * problems; however, we need it fixed, because it is expected that UML users + * mount HPPFS instead of procfs on /proc. And we want mconsole_proc to still + * show the real procfs content, not the ones from hppfs.*/ +#if 0 +void mconsole_proc(struct mc_request *req) +{ + struct nameidata nd; + struct file_system_type *proc; + struct super_block *super; + struct file *file; + int n, err; + char *ptr = req->request.data, *buf; + + ptr += strlen("proc"); + while(isspace(*ptr)) ptr++; + + proc = get_fs_type("proc"); + if(proc == NULL){ + mconsole_reply(req, "procfs not registered", 1, 0); + goto out; + } + + super = (*proc->get_sb)(proc, 0, NULL, NULL); + put_filesystem(proc); + if(super == NULL){ + mconsole_reply(req, "Failed to get procfs superblock", 1, 0); + goto out; + } + up_write(&super->s_umount); + + nd.dentry = super->s_root; + nd.mnt = NULL; + nd.flags = O_RDONLY + 1; + nd.last_type = LAST_ROOT; + + /* START: it was experienced that the stability problems are closed + * if commenting out these two calls + the below read cycle. To + * make UML crash again, it was enough to readd either one.*/ + err = link_path_walk(ptr, &nd); + if(err){ + mconsole_reply(req, "Failed to look up file", 1, 0); + goto out_kill; + } + + file = dentry_open(nd.dentry, nd.mnt, O_RDONLY); + if(IS_ERR(file)){ + mconsole_reply(req, "Failed to open file", 1, 0); + goto out_kill; + } + /*END*/ + + buf = kmalloc(PAGE_SIZE, GFP_KERNEL); + if(buf == NULL){ + mconsole_reply(req, "Failed to allocate buffer", 1, 0); + goto out_fput; + } + + if((file->f_op != NULL) && (file->f_op->read != NULL)){ + do { + n = (*file->f_op->read)(file, buf, PAGE_SIZE - 1, + &file->f_pos); + if(n >= 0){ + buf[n] = '\0'; + mconsole_reply(req, buf, 0, (n > 0)); + } + else { + mconsole_reply(req, "Read of file failed", + 1, 0); + goto out_free; + } + } while(n > 0); + } + else mconsole_reply(req, "", 0, 0); + + out_free: + kfree(buf); + out_fput: + fput(file); + out_kill: + deactivate_super(super); + out: ; +} +#endif + +void mconsole_proc(struct mc_request *req) +{ + char path[64]; + char *buf; + int len; + int fd; + int first_chunk = 1; + char *ptr = req->request.data; + + ptr += strlen("proc"); + while(isspace(*ptr)) ptr++; + snprintf(path, sizeof(path), "/proc/%s", ptr); + + fd = sys_open(path, 0, 0); + if (fd < 0) { + mconsole_reply(req, "Failed to open file", 1, 0); + printk("open %s: %d\n",path,fd); + goto out; + } + + buf = kmalloc(PAGE_SIZE, GFP_KERNEL); + if(buf == NULL){ + mconsole_reply(req, "Failed to allocate buffer", 1, 0); + goto out_close; + } + + for (;;) { + len = sys_read(fd, buf, PAGE_SIZE-1); + if (len < 0) { + mconsole_reply(req, "Read of file failed", 1, 0); + goto out_free; + } + /*Begin the file content on his own line.*/ + if (first_chunk) { + mconsole_reply(req, "\n", 0, 1); + first_chunk = 0; + } + if (len == PAGE_SIZE-1) { + buf[len] = '\0'; + mconsole_reply(req, buf, 0, 1); + } else { + buf[len] = '\0'; + mconsole_reply(req, buf, 0, 0); + break; + } + } + + out_free: + kfree(buf); + out_close: + sys_close(fd); + out: + /* nothing */; +} + +#define UML_MCONSOLE_HELPTEXT \ +"Commands: \n\ + version - Get kernel version \n\ + help - Print this message \n\ + halt - Halt UML \n\ + reboot - Reboot UML \n\ + config <dev>=<config> - Add a new device to UML; \n\ + same syntax as command line \n\ + config <dev> - Query the configuration of a device \n\ + remove <dev> - Remove a device from UML \n\ + sysrq <letter> - Performs the SysRq action controlled by the letter \n\ + cad - invoke the Ctl-Alt-Del handler \n\ + stop - pause the UML; it will do nothing until it receives a 'go' \n\ + go - continue the UML after a 'stop' \n\ + log <string> - make UML enter <string> into the kernel log\n\ + proc <file> - returns the contents of the UML's /proc/<file>\n\ +" + +void mconsole_help(struct mc_request *req) +{ + mconsole_reply(req, UML_MCONSOLE_HELPTEXT, 0, 0); +} + +void mconsole_halt(struct mc_request *req) +{ + mconsole_reply(req, "", 0, 0); + machine_halt(); +} + +void mconsole_reboot(struct mc_request *req) +{ + mconsole_reply(req, "", 0, 0); + machine_restart(NULL); +} + +extern void ctrl_alt_del(void); + +void mconsole_cad(struct mc_request *req) +{ + mconsole_reply(req, "", 0, 0); + ctrl_alt_del(); +} + +void mconsole_go(struct mc_request *req) +{ + mconsole_reply(req, "Not stopped", 1, 0); +} + +void mconsole_stop(struct mc_request *req) +{ + deactivate_fd(req->originating_fd, MCONSOLE_IRQ); + os_set_fd_block(req->originating_fd, 1); + mconsole_reply(req, "", 0, 0); + while(mconsole_get_request(req->originating_fd, req)){ + if(req->cmd->handler == mconsole_go) break; + (*req->cmd->handler)(req); + } + os_set_fd_block(req->originating_fd, 0); + reactivate_fd(req->originating_fd, MCONSOLE_IRQ); + mconsole_reply(req, "", 0, 0); +} + +/* This list is populated by __initcall routines. */ + +LIST_HEAD(mconsole_devices); + +void mconsole_register_dev(struct mc_device *new) +{ + list_add(&new->list, &mconsole_devices); +} + +static struct mc_device *mconsole_find_dev(char *name) +{ + struct list_head *ele; + struct mc_device *dev; + + list_for_each(ele, &mconsole_devices){ + dev = list_entry(ele, struct mc_device, list); + if(!strncmp(name, dev->name, strlen(dev->name))) + return(dev); + } + return(NULL); +} + +#define CONFIG_BUF_SIZE 64 + +static void mconsole_get_config(int (*get_config)(char *, char *, int, + char **), + struct mc_request *req, char *name) +{ + char default_buf[CONFIG_BUF_SIZE], *error, *buf; + int n, size; + + if(get_config == NULL){ + mconsole_reply(req, "No get_config routine defined", 1, 0); + return; + } + + error = NULL; + size = sizeof(default_buf)/sizeof(default_buf[0]); + buf = default_buf; + + while(1){ + n = (*get_config)(name, buf, size, &error); + if(error != NULL){ + mconsole_reply(req, error, 1, 0); + goto out; + } + + if(n <= size){ + mconsole_reply(req, buf, 0, 0); + goto out; + } + + if(buf != default_buf) + kfree(buf); + + size = n; + buf = kmalloc(size, GFP_KERNEL); + if(buf == NULL){ + mconsole_reply(req, "Failed to allocate buffer", 1, 0); + return; + } + } + out: + if(buf != default_buf) + kfree(buf); + +} + +void mconsole_config(struct mc_request *req) +{ + struct mc_device *dev; + char *ptr = req->request.data, *name; + int err; + + ptr += strlen("config"); + while(isspace(*ptr)) ptr++; + dev = mconsole_find_dev(ptr); + if(dev == NULL){ + mconsole_reply(req, "Bad configuration option", 1, 0); + return; + } + + name = &ptr[strlen(dev->name)]; + ptr = name; + while((*ptr != '=') && (*ptr != '\0')) + ptr++; + + if(*ptr == '='){ + err = (*dev->config)(name); + mconsole_reply(req, "", err, 0); + } + else mconsole_get_config(dev->get_config, req, name); +} + +void mconsole_remove(struct mc_request *req) +{ + struct mc_device *dev; + char *ptr = req->request.data; + int err; + + ptr += strlen("remove"); + while(isspace(*ptr)) ptr++; + dev = mconsole_find_dev(ptr); + if(dev == NULL){ + mconsole_reply(req, "Bad remove option", 1, 0); + return; + } + err = (*dev->remove)(&ptr[strlen(dev->name)]); + mconsole_reply(req, "", err, 0); +} + +#ifdef CONFIG_MAGIC_SYSRQ +void mconsole_sysrq(struct mc_request *req) +{ + char *ptr = req->request.data; + + ptr += strlen("sysrq"); + while(isspace(*ptr)) ptr++; + + mconsole_reply(req, "", 0, 0); + handle_sysrq(*ptr, ¤t->thread.regs, NULL); +} +#else +void mconsole_sysrq(struct mc_request *req) +{ + mconsole_reply(req, "Sysrq not compiled in", 1, 0); +} +#endif + +/* Changed by mconsole_setup, which is __setup, and called before SMP is + * active. + */ +static char *notify_socket = NULL; + +int mconsole_init(void) +{ + /* long to avoid size mismatch warnings from gcc */ + long sock; + int err; + char file[256]; + + if(umid_file_name("mconsole", file, sizeof(file))) return(-1); + snprintf(mconsole_socket_name, sizeof(file), "%s", file); + + sock = os_create_unix_socket(file, sizeof(file), 1); + if (sock < 0){ + printk("Failed to initialize management console\n"); + return(1); + } + + register_reboot_notifier(&reboot_notifier); + + err = um_request_irq(MCONSOLE_IRQ, sock, IRQ_READ, mconsole_interrupt, + SA_INTERRUPT | SA_SHIRQ | SA_SAMPLE_RANDOM, + "mconsole", (void *)sock); + if (err){ + printk("Failed to get IRQ for management console\n"); + return(1); + } + + if(notify_socket != NULL){ + notify_socket = uml_strdup(notify_socket); + if(notify_socket != NULL) + mconsole_notify(notify_socket, MCONSOLE_SOCKET, + mconsole_socket_name, + strlen(mconsole_socket_name) + 1); + else printk(KERN_ERR "mconsole_setup failed to strdup " + "string\n"); + } + + printk("mconsole (version %d) initialized on %s\n", + MCONSOLE_VERSION, mconsole_socket_name); + return(0); +} + +__initcall(mconsole_init); + +static int write_proc_mconsole(struct file *file, const char __user *buffer, + unsigned long count, void *data) +{ + char *buf; + + buf = kmalloc(count + 1, GFP_KERNEL); + if(buf == NULL) + return(-ENOMEM); + + if(copy_from_user(buf, buffer, count)){ + count = -EFAULT; + goto out; + } + + buf[count] = '\0'; + + mconsole_notify(notify_socket, MCONSOLE_USER_NOTIFY, buf, count); + out: + kfree(buf); + return(count); +} + +static int create_proc_mconsole(void) +{ + struct proc_dir_entry *ent; + + if(notify_socket == NULL) return(0); + + ent = create_proc_entry("mconsole", S_IFREG | 0200, NULL); + if(ent == NULL){ + printk("create_proc_mconsole : create_proc_entry failed\n"); + return(0); + } + + ent->read_proc = NULL; + ent->write_proc = write_proc_mconsole; + return(0); +} + +static DEFINE_SPINLOCK(notify_spinlock); + +void lock_notify(void) +{ + spin_lock(¬ify_spinlock); +} + +void unlock_notify(void) +{ + spin_unlock(¬ify_spinlock); +} + +__initcall(create_proc_mconsole); + +#define NOTIFY "=notify:" + +static int mconsole_setup(char *str) +{ + if(!strncmp(str, NOTIFY, strlen(NOTIFY))){ + str += strlen(NOTIFY); + notify_socket = str; + } + else printk(KERN_ERR "mconsole_setup : Unknown option - '%s'\n", str); + return(1); +} + +__setup("mconsole", mconsole_setup); + +__uml_help(mconsole_setup, +"mconsole=notify:<socket>\n" +" Requests that the mconsole driver send a message to the named Unix\n" +" socket containing the name of the mconsole socket. This also serves\n" +" to notify outside processes when UML has booted far enough to respond\n" +" to mconsole requests.\n\n" +); + +static int notify_panic(struct notifier_block *self, unsigned long unused1, + void *ptr) +{ + char *message = ptr; + + if(notify_socket == NULL) return(0); + + mconsole_notify(notify_socket, MCONSOLE_PANIC, message, + strlen(message) + 1); + return(0); +} + +static struct notifier_block panic_exit_notifier = { + .notifier_call = notify_panic, + .next = NULL, + .priority = 1 +}; + +static int add_notifier(void) +{ + notifier_chain_register(&panic_notifier_list, &panic_exit_notifier); + return(0); +} + +__initcall(add_notifier); + +char *mconsole_notify_socket(void) +{ + return(notify_socket); +} + +EXPORT_SYMBOL(mconsole_notify_socket); + +/* + * Overrides for Emacs so that we follow Linus's tabbing style. + * Emacs will notice this stuff at the end of the file and automatically + * adjust the settings for this buffer only. This must remain at the end + * of the file. + * --------------------------------------------------------------------------- + * Local variables: + * c-file-style: "linux" + * End: + */ |