[linux-2.6-block.git] / fs / efivarfs / file.c

/*
 * Copyright (C) 2012 Red Hat, Inc.
 * Copyright (C) 2012 Jeremy Kerr <jeremy.kerr@canonical.com>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation.
 */

#include <linux/efi.h>
#include <linux/fs.h>

#include "internal.h"

static ssize_t efivarfs_file_write(struct file *file,
		const char __user *userbuf, size_t count, loff_t *ppos)
{
	struct efivar_entry *var = file->private_data;
	void *data;
	u32 attributes;
	struct inode *inode = file->f_mapping->host;
	unsigned long datasize = count - sizeof(attributes);
	ssize_t bytes = 0;
	bool set = false;

	if (count < sizeof(attributes))
		return -EINVAL;

	if (copy_from_user(&attributes, userbuf, sizeof(attributes)))
		return -EFAULT;

	if (attributes & ~(EFI_VARIABLE_MASK))
		return -EINVAL;

	data = kmalloc(datasize, GFP_KERNEL);
	if (!data)
		return -ENOMEM;

	if (copy_from_user(data, userbuf + sizeof(attributes), datasize)) {
		bytes = -EFAULT;
		goto out;
	}

	bytes = efivar_entry_set_get_size(var, attributes, &datasize,
					  data, &set);
	if (!set && bytes)
		goto out;

	if (bytes == -ENOENT) {
		drop_nlink(inode);
		d_delete(file->f_dentry);
		dput(file->f_dentry);
	} else {
		mutex_lock(&inode->i_mutex);
		i_size_write(inode, datasize + sizeof(attributes));
		mutex_unlock(&inode->i_mutex);
	}

	bytes = count;

out:
	kfree(data);

	return bytes;
}

static ssize_t efivarfs_file_read(struct file *file, char __user *userbuf,
		size_t count, loff_t *ppos)
{
	struct efivar_entry *var = file->private_data;
	unsigned long datasize = 0;
	u32 attributes;
	void *data;
	ssize_t size = 0;
	int err;

	err = efivar_entry_size(var, &datasize);
	if (err)
		return err;

	data = kmalloc(datasize + sizeof(attributes), GFP_KERNEL);

	if (!data)
		return -ENOMEM;

	size = efivar_entry_get(var, &attributes, &datasize,
				data + sizeof(attributes));
	if (size)
		goto out_free;

	memcpy(data, &attributes, sizeof(attributes));
	size = simple_read_from_buffer(userbuf, count, ppos,
				       data, datasize + sizeof(attributes));
out_free:
	kfree(data);

	return size;
}

const struct file_operations efivarfs_file_operations = {
	.open	= simple_open,
	.read	= efivarfs_file_read,
	.write	= efivarfs_file_write,
	.llseek	= no_llseek,
};
Commit	Line	Data
d68772b7 MF	1	/*
	2	* Copyright (C) 2012 Red Hat, Inc.
	3	* Copyright (C) 2012 Jeremy Kerr <jeremy.kerr@canonical.com>
	4	*
	5	* This program is free software; you can redistribute it and/or modify
	6	* it under the terms of the GNU General Public License version 2 as
	7	* published by the Free Software Foundation.
	8	*/
	9
	10	#include <linux/efi.h>
	11	#include <linux/fs.h>
	12
	13	#include "internal.h"
	14
d68772b7 MF	15	static ssize_t efivarfs_file_write(struct file *file,
	16	const char __user userbuf, size_t count, loff_t ppos)
	17	{
	18	struct efivar_entry *var = file->private_data;
	19	void *data;
	20	u32 attributes;
	21	struct inode *inode = file->f_mapping->host;
	22	unsigned long datasize = count - sizeof(attributes);
	23	ssize_t bytes = 0;
	24	bool set = false;
	25
	26	if (count < sizeof(attributes))
	27	return -EINVAL;
	28
	29	if (copy_from_user(&attributes, userbuf, sizeof(attributes)))
	30	return -EFAULT;
	31
	32	if (attributes & ~(EFI_VARIABLE_MASK))
	33	return -EINVAL;
	34
	35	data = kmalloc(datasize, GFP_KERNEL);
	36	if (!data)
	37	return -ENOMEM;
	38
	39	if (copy_from_user(data, userbuf + sizeof(attributes), datasize)) {
	40	bytes = -EFAULT;
	41	goto out;
	42	}
	43
	44	bytes = efivar_entry_set_get_size(var, attributes, &datasize,
	45	data, &set);
	46	if (!set && bytes)
	47	goto out;
	48
	49	if (bytes == -ENOENT) {
	50	drop_nlink(inode);
	51	d_delete(file->f_dentry);
	52	dput(file->f_dentry);
	53	} else {
	54	mutex_lock(&inode->i_mutex);
	55	i_size_write(inode, datasize + sizeof(attributes));
	56	mutex_unlock(&inode->i_mutex);
	57	}
	58
	59	bytes = count;
	60
	61	out:
	62	kfree(data);
	63
	64	return bytes;
	65	}
	66
	67	static ssize_t efivarfs_file_read(struct file file, char __user userbuf,
	68	size_t count, loff_t *ppos)
	69	{
	70	struct efivar_entry *var = file->private_data;
	71	unsigned long datasize = 0;
	72	u32 attributes;
	73	void *data;
	74	ssize_t size = 0;
	75	int err;
	76
	77	err = efivar_entry_size(var, &datasize);
	78	if (err)
79	return err;
80
81	data = kmalloc(datasize + sizeof(attributes), GFP_KERNEL);
82
83	if (!data)
84	return -ENOMEM;
85
86	size = efivar_entry_get(var, &attributes, &datasize,
87	data + sizeof(attributes));
88	if (size)
89	goto out_free;
90
91	memcpy(data, &attributes, sizeof(attributes));
92	size = simple_read_from_buffer(userbuf, count, ppos,
93	data, datasize + sizeof(attributes));
94	out_free:
95	kfree(data);
96
97	return size;
98	}
99
100	const struct file_operations efivarfs_file_operations = {
f53f292e	101	.open = simple_open,
d68772b7 MF	102	.read = efivarfs_file_read,
	103	.write = efivarfs_file_write,
	104	.llseek = no_llseek,
	105	};