diff options
Diffstat (limited to 'kernel/arch/um/drivers/mconsole_kern.c')
-rw-r--r-- | kernel/arch/um/drivers/mconsole_kern.c | 858 |
1 files changed, 858 insertions, 0 deletions
diff --git a/kernel/arch/um/drivers/mconsole_kern.c b/kernel/arch/um/drivers/mconsole_kern.c new file mode 100644 index 000000000..29880c9b3 --- /dev/null +++ b/kernel/arch/um/drivers/mconsole_kern.c @@ -0,0 +1,858 @@ +/* + * Copyright (C) 2001 Lennert Buytenhek (buytenh@gnu.org) + * Copyright (C) 2001 - 2008 Jeff Dike (jdike@{addtoit,linux.intel}.com) + * Licensed under the GPL + */ + +#include <linux/console.h> +#include <linux/ctype.h> +#include <linux/string.h> +#include <linux/interrupt.h> +#include <linux/list.h> +#include <linux/mm.h> +#include <linux/module.h> +#include <linux/notifier.h> +#include <linux/reboot.h> +#include <linux/proc_fs.h> +#include <linux/slab.h> +#include <linux/syscalls.h> +#include <linux/utsname.h> +#include <linux/socket.h> +#include <linux/un.h> +#include <linux/workqueue.h> +#include <linux/mutex.h> +#include <linux/fs.h> +#include <linux/mount.h> +#include <linux/file.h> +#include <asm/uaccess.h> +#include <asm/switch_to.h> + +#include <init.h> +#include <irq_kern.h> +#include <irq_user.h> +#include <kern_util.h> +#include "mconsole.h" +#include "mconsole_kern.h" +#include <os.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. + */ + +static LIST_HEAD(mc_requests); + +static void mc_work_proc(struct work_struct *unused) +{ + struct mconsole_entry *req; + unsigned long flags; + + while (!list_empty(&mc_requests)) { + local_irq_save(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); + } +} + +static DECLARE_WORK(mconsole_work, mc_work_proc); + +static irqreturn_t mconsole_interrupt(int irq, void *dev_id) +{ + /* long to avoid size mismatch warnings from gcc */ + long fd; + struct mconsole_entry *new; + static struct mc_request req; /* that's OK */ + + 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_NOWAIT); + if (new == NULL) + mconsole_reply(&req, "Out of memory", 1, 0); + else { + new->request = req; + new->request.regs = get_irq_regs()->regs; + 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", utsname()->sysname, + utsname()->nodename, utsname()->release, utsname()->version, + 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(KERN_WARNING "%.*s", len, ptr); + mconsole_reply(req, "", 0, 0); +} + +void mconsole_proc(struct mc_request *req) +{ + struct vfsmount *mnt = task_active_pid_ns(current)->proc_mnt; + char *buf; + int len; + struct file *file; + int first_chunk = 1; + char *ptr = req->request.data; + + ptr += strlen("proc"); + ptr = skip_spaces(ptr); + + file = file_open_root(mnt->mnt_root, mnt, ptr, O_RDONLY); + if (IS_ERR(file)) { + mconsole_reply(req, "Failed to open file", 1, 0); + printk(KERN_ERR "open /proc/%s: %ld\n", ptr, PTR_ERR(file)); + goto out; + } + + buf = kmalloc(PAGE_SIZE, GFP_KERNEL); + if (buf == NULL) { + mconsole_reply(req, "Failed to allocate buffer", 1, 0); + goto out_fput; + } + + do { + loff_t pos = file->f_pos; + mm_segment_t old_fs = get_fs(); + set_fs(KERNEL_DS); + len = vfs_read(file, buf, PAGE_SIZE - 1, &pos); + set_fs(old_fs); + file->f_pos = pos; + 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; + } + buf[len] = '\0'; + mconsole_reply(req, buf, 0, (len > 0)); + } while (len > 0); + out_free: + kfree(buf); + out_fput: + fput(file); + out: ; +} + +#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 Ctrl-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\ + stack <pid> - returns the stack of the specified pid\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); +} + +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, "stopped", 0, 0); + for (;;) { + if (!mconsole_get_request(req->originating_fd, req)) + continue; + if (req->cmd->handler == mconsole_go) + break; + if (req->cmd->handler == mconsole_stop) { + mconsole_reply(req, "Already stopped", 1, 0); + continue; + } + if (req->cmd->handler == mconsole_sysrq) { + struct pt_regs *old_regs; + old_regs = set_irq_regs((struct pt_regs *)&req->regs); + mconsole_sysrq(req); + set_irq_regs(old_regs); + continue; + } + (*req->cmd->handler)(req); + } + os_set_fd_block(req->originating_fd, 0); + reactivate_fd(req->originating_fd, MCONSOLE_IRQ); + mconsole_reply(req, "", 0, 0); +} + +static DEFINE_SPINLOCK(mc_devices_lock); +static LIST_HEAD(mconsole_devices); + +void mconsole_register_dev(struct mc_device *new) +{ + spin_lock(&mc_devices_lock); + BUG_ON(!list_empty(&new->list)); + list_add(&new->list, &mconsole_devices); + spin_unlock(&mc_devices_lock); +} + +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 UNPLUGGED_PER_PAGE \ + ((PAGE_SIZE - sizeof(struct list_head)) / sizeof(unsigned long)) + +struct unplugged_pages { + struct list_head list; + void *pages[UNPLUGGED_PER_PAGE]; +}; + +static DEFINE_MUTEX(plug_mem_mutex); +static unsigned long long unplugged_pages_count = 0; +static LIST_HEAD(unplugged_pages); +static int unplug_index = UNPLUGGED_PER_PAGE; + +static int mem_config(char *str, char **error_out) +{ + unsigned long long diff; + int err = -EINVAL, i, add; + char *ret; + + if (str[0] != '=') { + *error_out = "Expected '=' after 'mem'"; + goto out; + } + + str++; + if (str[0] == '-') + add = 0; + else if (str[0] == '+') { + add = 1; + } + else { + *error_out = "Expected increment to start with '-' or '+'"; + goto out; + } + + str++; + diff = memparse(str, &ret); + if (*ret != '\0') { + *error_out = "Failed to parse memory increment"; + goto out; + } + + diff /= PAGE_SIZE; + + mutex_lock(&plug_mem_mutex); + for (i = 0; i < diff; i++) { + struct unplugged_pages *unplugged; + void *addr; + + if (add) { + if (list_empty(&unplugged_pages)) + break; + + unplugged = list_entry(unplugged_pages.next, + struct unplugged_pages, list); + if (unplug_index > 0) + addr = unplugged->pages[--unplug_index]; + else { + list_del(&unplugged->list); + addr = unplugged; + unplug_index = UNPLUGGED_PER_PAGE; + } + + free_page((unsigned long) addr); + unplugged_pages_count--; + } + else { + struct page *page; + + page = alloc_page(GFP_ATOMIC); + if (page == NULL) + break; + + unplugged = page_address(page); + if (unplug_index == UNPLUGGED_PER_PAGE) { + list_add(&unplugged->list, &unplugged_pages); + unplug_index = 0; + } + else { + struct list_head *entry = unplugged_pages.next; + addr = unplugged; + + unplugged = list_entry(entry, + struct unplugged_pages, + list); + err = os_drop_memory(addr, PAGE_SIZE); + if (err) { + printk(KERN_ERR "Failed to release " + "memory - errno = %d\n", err); + *error_out = "Failed to release memory"; + goto out_unlock; + } + unplugged->pages[unplug_index++] = addr; + } + + unplugged_pages_count++; + } + } + + err = 0; +out_unlock: + mutex_unlock(&plug_mem_mutex); +out: + return err; +} + +static int mem_get_config(char *name, char *str, int size, char **error_out) +{ + char buf[sizeof("18446744073709551615")]; + int len = 0; + + sprintf(buf, "%ld", uml_physmem); + CONFIG_CHUNK(str, size, len, buf, 1); + + return len; +} + +static int mem_id(char **str, int *start_out, int *end_out) +{ + *start_out = 0; + *end_out = 0; + + return 0; +} + +static int mem_remove(int n, char **error_out) +{ + *error_out = "Memory doesn't support the remove operation"; + return -EBUSY; +} + +static struct mc_device mem_mc = { + .list = LIST_HEAD_INIT(mem_mc.list), + .name = "mem", + .config = mem_config, + .get_config = mem_get_config, + .id = mem_id, + .remove = mem_remove, +}; + +static int __init mem_mc_init(void) +{ + if (can_drop_memory()) + mconsole_register_dev(&mem_mc); + else printk(KERN_ERR "Can't release memory to the host - memory " + "hotplug won't be supported\n"); + return 0; +} + +__initcall(mem_mc_init); + +#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 = ARRAY_SIZE(default_buf); + 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, *error_string = ""; + int err; + + ptr += strlen("config"); + ptr = skip_spaces(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, &error_string); + mconsole_reply(req, error_string, 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, *err_msg = ""; + char error[256]; + int err, start, end, n; + + ptr += strlen("remove"); + ptr = skip_spaces(ptr); + dev = mconsole_find_dev(ptr); + if (dev == NULL) { + mconsole_reply(req, "Bad remove option", 1, 0); + return; + } + + ptr = &ptr[strlen(dev->name)]; + + err = 1; + n = (*dev->id)(&ptr, &start, &end); + if (n < 0) { + err_msg = "Couldn't parse device number"; + goto out; + } + else if ((n < start) || (n > end)) { + sprintf(error, "Invalid device number - must be between " + "%d and %d", start, end); + err_msg = error; + goto out; + } + + err_msg = NULL; + err = (*dev->remove)(n, &err_msg); + switch(err) { + case 0: + err_msg = ""; + break; + case -ENODEV: + if (err_msg == NULL) + err_msg = "Device doesn't exist"; + break; + case -EBUSY: + if (err_msg == NULL) + err_msg = "Device is currently open"; + break; + default: + break; + } +out: + mconsole_reply(req, err_msg, err, 0); +} + +struct mconsole_output { + struct list_head list; + struct mc_request *req; +}; + +static DEFINE_SPINLOCK(client_lock); +static LIST_HEAD(clients); +static char console_buf[MCONSOLE_MAX_DATA]; + +static void console_write(struct console *console, const char *string, + unsigned int len) +{ + struct list_head *ele; + int n; + + if (list_empty(&clients)) + return; + + while (len > 0) { + n = min((size_t) len, ARRAY_SIZE(console_buf)); + strncpy(console_buf, string, n); + string += n; + len -= n; + + list_for_each(ele, &clients) { + struct mconsole_output *entry; + + entry = list_entry(ele, struct mconsole_output, list); + mconsole_reply_len(entry->req, console_buf, n, 0, 1); + } + } +} + +static struct console mc_console = { .name = "mc", + .write = console_write, + .flags = CON_ENABLED, + .index = -1 }; + +static int mc_add_console(void) +{ + register_console(&mc_console); + return 0; +} + +late_initcall(mc_add_console); + +static void with_console(struct mc_request *req, void (*proc)(void *), + void *arg) +{ + struct mconsole_output entry; + unsigned long flags; + + entry.req = req; + spin_lock_irqsave(&client_lock, flags); + list_add(&entry.list, &clients); + spin_unlock_irqrestore(&client_lock, flags); + + (*proc)(arg); + + mconsole_reply_len(req, "", 0, 0, 0); + + spin_lock_irqsave(&client_lock, flags); + list_del(&entry.list); + spin_unlock_irqrestore(&client_lock, flags); +} + +#ifdef CONFIG_MAGIC_SYSRQ + +#include <linux/sysrq.h> + +static void sysrq_proc(void *arg) +{ + char *op = arg; + handle_sysrq(*op); +} + +void mconsole_sysrq(struct mc_request *req) +{ + char *ptr = req->request.data; + + ptr += strlen("sysrq"); + ptr = skip_spaces(ptr); + + /* + * With 'b', the system will shut down without a chance to reply, + * so in this case, we reply first. + */ + if (*ptr == 'b') + mconsole_reply(req, "", 0, 0); + + with_console(req, sysrq_proc, ptr); +} +#else +void mconsole_sysrq(struct mc_request *req) +{ + mconsole_reply(req, "Sysrq not compiled in", 1, 0); +} +#endif + +static void stack_proc(void *arg) +{ + struct task_struct *task = arg; + + show_stack(task, NULL); +} + +/* + * Mconsole stack trace + * Added by Allan Graves, Jeff Dike + * Dumps a stacks registers to the linux console. + * Usage stack <pid>. + */ +void mconsole_stack(struct mc_request *req) +{ + char *ptr = req->request.data; + int pid_requested= -1; + struct task_struct *to = NULL; + + /* + * Would be nice: + * 1) Send showregs output to mconsole. + * 2) Add a way to stack dump all pids. + */ + + ptr += strlen("stack"); + ptr = skip_spaces(ptr); + + /* + * Should really check for multiple pids or reject bad args here + */ + /* What do the arguments in mconsole_reply mean? */ + if (sscanf(ptr, "%d", &pid_requested) == 0) { + mconsole_reply(req, "Please specify a pid", 1, 0); + return; + } + + to = find_task_by_pid_ns(pid_requested, &init_pid_ns); + if ((to == NULL) || (pid_requested == 0)) { + mconsole_reply(req, "Couldn't find that pid", 1, 0); + return; + } + with_console(req, stack_proc, to); +} + +/* + * Changed by mconsole_setup, which is __setup, and called before SMP is + * active. + */ +static char *notify_socket = NULL; + +static int __init mconsole_init(void) +{ + /* long to avoid size mismatch warnings from gcc */ + long sock; + int err; + char file[UNIX_PATH_MAX]; + + 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(KERN_ERR "Failed to initialize management console\n"); + return 1; + } + if (os_set_fd_block(sock, 0)) + goto out; + + register_reboot_notifier(&reboot_notifier); + + err = um_request_irq(MCONSOLE_IRQ, sock, IRQ_READ, mconsole_interrupt, + IRQF_SHARED, "mconsole", (void *)sock); + if (err) { + printk(KERN_ERR "Failed to get IRQ for management console\n"); + goto out; + } + + if (notify_socket != NULL) { + notify_socket = kstrdup(notify_socket, GFP_KERNEL); + 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(KERN_INFO "mconsole (version %d) initialized on %s\n", + MCONSOLE_VERSION, mconsole_socket_name); + return 0; + + out: + os_close_file(sock); + return 1; +} + +__initcall(mconsole_init); + +static ssize_t mconsole_proc_write(struct file *file, + const char __user *buffer, size_t count, loff_t *pos) +{ + 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 const struct file_operations mconsole_proc_fops = { + .owner = THIS_MODULE, + .write = mconsole_proc_write, + .llseek = noop_llseek, +}; + +static int create_proc_mconsole(void) +{ + struct proc_dir_entry *ent; + + if (notify_socket == NULL) + return 0; + + ent = proc_create("mconsole", 0200, NULL, &mconsole_proc_fops); + if (ent == NULL) { + printk(KERN_INFO "create_proc_mconsole : proc_create failed\n"); + return 0; + } + 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) +{ + atomic_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); |