1 files changed, 477 insertions, 318 deletions

diff --git a/arch/um/drivers/mconsole_kern.c b/arch/um/drivers/mconsole_kern.c
index 12c95368124..29880c9b324 100644
--- a/arch/um/drivers/mconsole_kern.c
+++ b/arch/um/drivers/mconsole_kern.c
@@ -1,43 +1,44 @@
 /*
  * Copyright (C) 2001 Lennert Buytenhek (buytenh@gnu.org)
- * Copyright (C) 2001 - 2003 Jeff Dike (jdike@addtoit.com)
+ * Copyright (C) 2001 - 2008 Jeff Dike (jdike@{addtoit,linux.intel}.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 <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 "irq_user.h"
-#include "init.h"
-#include "os.h"
-#include "umid.h"
-#include "irq_kern.h"
-#include "choose-mode.h"
-
-static int do_unlink_socket(struct notifier_block *notifier, 
+#include <os.h>
+
+static int do_unlink_socket(struct notifier_block *notifier,
 			    unsigned long what, void *data)
 {
-	return(mconsole_unlink_socket());
+	return mconsole_unlink_socket();
 }
 
 
@@ -46,22 +47,21 @@ static struct notifier_block reboot_notifier = {
 	.priority		= 0,
 };
 
-/* Safe without explicit locking for now.  Tasklets provide their own 
+/* 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 LIST_HEAD(mc_requests);
 
-static void mc_work_proc(void *unused)
+static void mc_work_proc(struct work_struct *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);
+	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);
@@ -69,43 +69,43 @@ static void mc_work_proc(void *unused)
 	}
 }
 
-DECLARE_WORK(mconsole_work, mc_work_proc, NULL);
+static DECLARE_WORK(mconsole_work, mc_work_proc);
 
-static irqreturn_t mconsole_interrupt(int irq, void *dev_id,
-				      struct pt_regs *regs)
+static irqreturn_t mconsole_interrupt(int irq, void *dev_id)
 {
 	/* long to avoid size mismatch warnings from gcc */
 	long fd;
 	struct mconsole_entry *new;
-	struct mc_request req;
+	static struct mc_request req;	/* that's OK */
 
 	fd = (long) dev_id;
-	while (mconsole_get_request(fd, &req)){
-		if(req.cmd->context == MCONSOLE_INTR)
+	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)
+			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))
+	if (!list_empty(&mc_requests))
 		schedule_work(&mconsole_work);
 	reactivate_fd(fd, MCONSOLE_IRQ);
-	return(IRQ_HANDLED);
+	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);
+	sprintf(version, "%s %s %s %s %s", utsname()->sysname,
+		utsname()->nodename, utsname()->release, utsname()->version,
+		utsname()->machine);
 	mconsole_reply(req, version, 0, 0);
 }
 
@@ -117,148 +117,59 @@ void mconsole_log(struct mc_request *req)
 	ptr += strlen("log ");
 
 	len = req->len - (ptr - req->request.data);
-	printk("%.*s", len, ptr);
+	printk(KERN_WARNING "%.*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];
+	struct vfsmount *mnt = task_active_pid_ns(current)->proc_mnt;
 	char *buf;
 	int len;
-	int fd;
+	struct file *file;
 	int first_chunk = 1;
 	char *ptr = req->request.data;
 
 	ptr += strlen("proc");
-	while(isspace(*ptr)) ptr++;
-	snprintf(path, sizeof(path), "/proc/%s", ptr);
+	ptr = skip_spaces(ptr);
 
-	fd = sys_open(path, 0, 0);
-	if (fd < 0) {
+	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("open %s: %d\n",path,fd);
+		printk(KERN_ERR "open /proc/%s: %ld\n", ptr, PTR_ERR(file));
 		goto out;
 	}
 
 	buf = kmalloc(PAGE_SIZE, GFP_KERNEL);
-	if(buf == NULL){
+	if (buf == NULL) {
 		mconsole_reply(req, "Failed to allocate buffer", 1, 0);
-		goto out_close;
+		goto out_fput;
 	}
 
-	for (;;) {
-		len = sys_read(fd, buf, PAGE_SIZE-1);
+	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.*/
+		/* 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;
-		}
-	}
-
+		buf[len] = '\0';
+		mconsole_reply(req, buf, 0, (len > 0));
+	} while (len > 0);
  out_free:
 	kfree(buf);
- out_close:
-	sys_close(fd);
- out:
-	/* nothing */;
+ out_fput:
+	fput(file);
+ out: ;
 }
 
 #define UML_MCONSOLE_HELPTEXT \
@@ -272,7 +183,7 @@ void mconsole_proc(struct mc_request *req)
     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\
+    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\
@@ -297,8 +208,6 @@ void mconsole_reboot(struct mc_request *req)
 	machine_restart(NULL);
 }
 
-extern void ctrl_alt_del(void);
-
 void mconsole_cad(struct mc_request *req)
 {
 	mconsole_reply(req, "", 0, 0);
@@ -314,9 +223,23 @@ 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;
+	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);
@@ -324,13 +247,15 @@ void mconsole_stop(struct mc_request *req)
 	mconsole_reply(req, "", 0, 0);
 }
 
-/* This list is populated by __initcall routines. */
-
-LIST_HEAD(mconsole_devices);
+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)
@@ -338,141 +263,378 @@ static struct mc_device *mconsole_find_dev(char *name)
 	struct list_head *ele;
 	struct mc_device *dev;
 
-	list_for_each(ele, &mconsole_devices){
+	list_for_each(ele, &mconsole_devices) {
 		dev = list_entry(ele, struct mc_device, list);
-		if(!strncmp(name, dev->name, strlen(dev->name)))
-			return(dev);
+		if (!strncmp(name, dev->name, strlen(dev->name)))
+			return dev;
 	}
-	return(NULL);
+	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, 
+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){
+	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]);
+	size = ARRAY_SIZE(default_buf);
 	buf = default_buf;
 
-	while(1){
+	while (1) {
 		n = (*get_config)(name, buf, size, &error);
-		if(error != NULL){
+		if (error != NULL) {
 			mconsole_reply(req, error, 1, 0);
 			goto out;
 		}
 
-		if(n <= size){
+		if (n <= size) {
 			mconsole_reply(req, buf, 0, 0);
 			goto out;
 		}
 
-		if(buf != default_buf)
+		if (buf != default_buf)
 			kfree(buf);
 
 		size = n;
 		buf = kmalloc(size, GFP_KERNEL);
-		if(buf == NULL){
+		if (buf == NULL) {
 			mconsole_reply(req, "Failed to allocate buffer", 1, 0);
 			return;
 		}
 	}
  out:
-	if(buf != default_buf)
+	if (buf != default_buf)
 		kfree(buf);
-	
 }
 
 void mconsole_config(struct mc_request *req)
 {
 	struct mc_device *dev;
-	char *ptr = req->request.data, *name;
+	char *ptr = req->request.data, *name, *error_string = "";
 	int err;
 
 	ptr += strlen("config");
-	while(isspace(*ptr)) ptr++;
+	ptr = skip_spaces(ptr);
 	dev = mconsole_find_dev(ptr);
-	if(dev == NULL){
+	if (dev == NULL) {
 		mconsole_reply(req, "Bad configuration option", 1, 0);
 		return;
 	}
 
 	name = &ptr[strlen(dev->name)];
 	ptr = name;
-	while((*ptr != '=') && (*ptr != '\0'))
+	while ((*ptr != '=') && (*ptr != '\0'))
 		ptr++;
 
-	if(*ptr == '='){
-		err = (*dev->config)(name);
-		mconsole_reply(req, "", err, 0);
+	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;	
+	struct mc_device *dev;
 	char *ptr = req->request.data, *err_msg = "";
-        char error[256];
+	char error[256];
 	int err, start, end, n;
 
 	ptr += strlen("remove");
-	while(isspace(*ptr)) ptr++;
+	ptr = skip_spaces(ptr);
 	dev = mconsole_find_dev(ptr);
-	if(dev == NULL){
+	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 = (*dev->remove)(n);
-        switch(err){
-        case -ENODEV:
-                err_msg = "Device doesn't exist";
-                break;
-        case -EBUSY:
-                err_msg = "Device is currently open";
-                break;
-        default:
-                break;
-        }
- out:
+	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");
-	while(isspace(*ptr)) ptr++;
+	ptr = skip_spaces(ptr);
 
-	mconsole_reply(req, "", 0, 0);
-	handle_sysrq(*ptr, &current->thread.regs, NULL);
+	/*
+	 * 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)
@@ -481,114 +643,116 @@ void mconsole_sysrq(struct mc_request *req)
 }
 #endif
 
-/* Mconsole stack trace
+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 do_stack(struct mc_request *req)
+void mconsole_stack(struct mc_request *req)
 {
-        char *ptr = req->request.data;
-        int pid_requested= -1;
-        struct task_struct *from = NULL;
+	char *ptr = req->request.data;
+	int pid_requested= -1;
 	struct task_struct *to = NULL;
 
-        /* Would be nice:
-         * 1) Send showregs output to mconsole.
+	/*
+	 * Would be nice:
+	 * 1) Send showregs output to mconsole.
 	 * 2) Add a way to stack dump all pids.
 	 */
 
-        ptr += strlen("stack");
-        while(isspace(*ptr)) 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;
-        }
+	ptr += strlen("stack");
+	ptr = skip_spaces(ptr);
 
-        from = current;
-        to = find_task_by_pid(pid_requested);
-
-        if((to == NULL) || (pid_requested == 0)) {
-                mconsole_reply(req, "Couldn't find that pid", 1, 0);
-                return;
-        }
-        to->thread.saved_task = current;
-
-        switch_to(from, to, from);
-        mconsole_reply(req, "Stack Dumped to console and message log", 0, 0);
-}
-
-void mconsole_stack(struct mc_request *req)
-{
-	/* This command doesn't work in TT mode, so let's check and then
-	 * get out of here
+	/*
+	 * Should really check for multiple pids or reject bad args here
 	 */
-	CHOOSE_MODE(mconsole_reply(req, "Sorry, this doesn't work in TT mode",
-				   1, 0),
-		    do_stack(req));
+	/* 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
+/*
+ * Changed by mconsole_setup, which is __setup, and called before SMP is
  * active.
  */
-static char *notify_socket = NULL; 
+static char *notify_socket = NULL;
 
-int mconsole_init(void)
+static int __init mconsole_init(void)
 {
 	/* long to avoid size mismatch warnings from gcc */
 	long sock;
 	int err;
-	char file[256];
+	char file[UNIX_PATH_MAX];
 
-	if(umid_file_name("mconsole", file, sizeof(file))) return(-1);
+	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);
+	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,
-			     SA_INTERRUPT | SA_SHIRQ | SA_SAMPLE_RANDOM,
-			     "mconsole", (void *)sock);
-	if (err){
-		printk("Failed to get IRQ for management console\n");
-		return(1);
+			     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 = uml_strdup(notify_socket);
-		if(notify_socket != NULL)
+	if (notify_socket != NULL) {
+		notify_socket = kstrdup(notify_socket, GFP_KERNEL);
+		if (notify_socket != NULL)
 			mconsole_notify(notify_socket, MCONSOLE_SOCKET,
-					mconsole_socket_name, 
+					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", 
+	printk(KERN_INFO "mconsole (version %d) initialized on %s\n",
 	       MCONSOLE_VERSION, mconsole_socket_name);
-	return(0);
+	return 0;
+
+ out:
+	os_close_file(sock);
+	return 1;
 }
 
 __initcall(mconsole_init);
 
-static int write_proc_mconsole(struct file *file, const char __user *buffer,
-			       unsigned long count, void *data)
+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 (buf == NULL)
+		return -ENOMEM;
 
-	if(copy_from_user(buf, buffer, count)){
+	if (copy_from_user(buf, buffer, count)) {
 		count = -EFAULT;
 		goto out;
 	}
@@ -598,24 +762,28 @@ static int write_proc_mconsole(struct file *file, const char __user *buffer,
 	mconsole_notify(notify_socket, MCONSOLE_USER_NOTIFY, buf, count);
  out:
 	kfree(buf);
-	return(count);
+	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);
+	if (notify_socket == NULL)
+		return 0;
 
-	ent = create_proc_entry("mconsole", S_IFREG | 0200, NULL);
-	if(ent == NULL){
-		printk(KERN_INFO "create_proc_mconsole : create_proc_entry failed\n");
-		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;
 	}
-
-	ent->read_proc = NULL;
-	ent->write_proc = write_proc_mconsole;
-	return(0);
+	return 0;
 }
 
 static DEFINE_SPINLOCK(notify_spinlock);
@@ -632,19 +800,19 @@ void unlock_notify(void)
 
 __initcall(create_proc_mconsole);
 
-#define NOTIFY "=notify:"
+#define NOTIFY "notify:"
 
 static int mconsole_setup(char *str)
 {
-	if(!strncmp(str, NOTIFY, strlen(NOTIFY))){
+	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);
+	return 1;
 }
 
-__setup("mconsole", mconsole_setup);
+__setup("mconsole=", mconsole_setup);
 
 __uml_help(mconsole_setup,
 "mconsole=notify:<socket>\n"
@@ -659,11 +827,12 @@ static int notify_panic(struct notifier_block *self, unsigned long unused1,
 {
 	char *message = ptr;
 
-	if(notify_socket == NULL) return(0);
+	if (notify_socket == NULL)
+		return 0;
 
-	mconsole_notify(notify_socket, MCONSOLE_PANIC, message, 
+	mconsole_notify(notify_socket, MCONSOLE_PANIC, message,
 			strlen(message) + 1);
-	return(0);
+	return 0;
 }
 
 static struct notifier_block panic_exit_notifier = {
@@ -674,26 +843,16 @@ static struct notifier_block panic_exit_notifier = {
 
 static int add_notifier(void)
 {
-	notifier_chain_register(&panic_notifier_list, &panic_exit_notifier);
-	return(0);
+	atomic_notifier_chain_register(&panic_notifier_list,
+			&panic_exit_notifier);
+	return 0;
 }
 
 __initcall(add_notifier);
 
 char *mconsole_notify_socket(void)
 {
-	return(notify_socket);
+	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:
- */