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Diffstat (limited to 'arch/um/drivers/mconsole_kern.c')
-rw-r--r--arch/um/drivers/mconsole_kern.c619
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 000000000000..d7c7adcc0a67
--- /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, &current->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(&notify_spinlock);
+}
+
+void unlock_notify(void)
+{
+ spin_unlock(&notify_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:
+ */
generated by cgit v1.2.3 (git 2.0.4) at 2024-11-13 02:20:42 +0000