path: root/arch/um/drivers/mconsole_kern.c

/*
 * 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: