115 lines
2.4 KiB
C
115 lines
2.4 KiB
C
|
// SPDX-License-Identifier: GPL-2.0-only
|
||
|
/*
|
||
|
* Copyright (C) 2012 Red Hat, Inc.
|
||
|
* Copyright (C) 2012 Jeremy Kerr <jeremy.kerr@canonical.com>
|
||
|
*/
|
||
|
|
||
|
#include <linux/efi.h>
|
||
|
#include <linux/delay.h>
|
||
|
#include <linux/fs.h>
|
||
|
#include <linux/slab.h>
|
||
|
#include <linux/mount.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;
|
||
|
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 = memdup_user(userbuf + sizeof(attributes), datasize);
|
||
|
if (IS_ERR(data))
|
||
|
return PTR_ERR(data);
|
||
|
|
||
|
bytes = efivar_entry_set_get_size(var, attributes, &datasize,
|
||
|
data, &set);
|
||
|
if (!set && bytes) {
|
||
|
if (bytes == -ENOENT)
|
||
|
bytes = -EIO;
|
||
|
goto out;
|
||
|
}
|
||
|
|
||
|
if (bytes == -ENOENT) {
|
||
|
drop_nlink(inode);
|
||
|
d_delete(file->f_path.dentry);
|
||
|
dput(file->f_path.dentry);
|
||
|
} else {
|
||
|
inode_lock(inode);
|
||
|
i_size_write(inode, datasize + sizeof(attributes));
|
||
|
inode->i_mtime = current_time(inode);
|
||
|
inode_unlock(inode);
|
||
|
}
|
||
|
|
||
|
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;
|
||
|
|
||
|
while (!__ratelimit(&file->f_cred->user->ratelimit))
|
||
|
msleep(50);
|
||
|
|
||
|
err = efivar_entry_size(var, &datasize);
|
||
|
|
||
|
/*
|
||
|
* efivarfs represents uncommitted variables with
|
||
|
* zero-length files. Reading them should return EOF.
|
||
|
*/
|
||
|
if (err == -ENOENT)
|
||
|
return 0;
|
||
|
else 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,
|
||
|
};
|