0
0
mirror of https://mirrors.bfsu.edu.cn/git/linux.git synced 2024-12-18 16:44:27 +08:00
linux/fs/pstore/pmsg.c
Linus Torvalds 0835b5ee87 pstore update for v6.4-rc1
- Revert pmsg_lock back to a normal mutex (John Stultz)
 -----BEGIN PGP SIGNATURE-----
 
 iQJKBAABCgA0FiEEpcP2jyKd1g9yPm4TiXL039xtwCYFAmRJaPkWHGtlZXNjb29r
 QGNocm9taXVtLm9yZwAKCRCJcvTf3G3AJtADD/42DSLBg9dAvFHUpXSuffbbhL/w
 HhbfPlsmSujWWWRE3xmEaWJrUQ+Ag6NHyHR7Euko6tBhtj1MhtPle4Di57H5sMid
 8R+7C+3XDmy5WeUF60dribiiKjtNiRIzWefsQyHn4fguaZ5SWHN+iwtvmBofWC44
 YQXaLR5lbxukZTKwiPjdJefS139/QMsKXx3mKu7IdtjjZ5yemH8iTvsQS/2nLkIS
 LWgBN2boopSVtJJslam/29JIhtT9UGoS/ooFJGkoFKXJrVY1+aiqxrYDihgH1K6b
 FoEb/+G/z9M9KxCNGOqv/h+Nl2Oa5L8hdvBy5UsUxhGUNG8/nqsjIwWjJmba9fJu
 3bJfMpsEja955Omq73UFVsgR8OTuy5z91XbR3jJk+4YQlXWgcqvoAYiM0SHX4z7W
 tB1OPCTGDaNLInYA6YHESlbiAmtk/Peizgs9n4PkOeCN26LWGV/FfjR+zorO+6xO
 NNbM1XN/Xdzp/oNwnU3TqRdI6F7v81uQfIiS0VDJoJ7jpHAVQA042l2zwihoopC2
 ErIBKUqpgfGUDxu29QEdfhdwkSfofyjfOzZ5iHYVsvxhn7oS7Xx+zxyp/mFReoIF
 bsqUsAZdCeMgye8wZZmNDlGaLsmLJB/bnt6XqNYMtSzp6ktpIkyBn/rRqhQYRrZK
 g//x5fMMz8fNZK1z0w==
 =5Jr7
 -----END PGP SIGNATURE-----

Merge tag 'pstore-v6.4-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux

Pull pstore update from Kees Cook:

 - Revert pmsg_lock back to a normal mutex (John Stultz)

* tag 'pstore-v6.4-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux:
  pstore: Revert pmsg_lock back to a normal mutex
2023-04-27 17:03:40 -07:00

95 lines
1.9 KiB
C

// SPDX-License-Identifier: GPL-2.0-only
/*
* Copyright 2014 Google, Inc.
*/
#include <linux/cdev.h>
#include <linux/device.h>
#include <linux/fs.h>
#include <linux/uaccess.h>
#include "internal.h"
static DEFINE_MUTEX(pmsg_lock);
static ssize_t write_pmsg(struct file *file, const char __user *buf,
size_t count, loff_t *ppos)
{
struct pstore_record record;
int ret;
if (!count)
return 0;
pstore_record_init(&record, psinfo);
record.type = PSTORE_TYPE_PMSG;
record.size = count;
/* check outside lock, page in any data. write_user also checks */
if (!access_ok(buf, count))
return -EFAULT;
mutex_lock(&pmsg_lock);
ret = psinfo->write_user(&record, buf);
mutex_unlock(&pmsg_lock);
return ret ? ret : count;
}
static const struct file_operations pmsg_fops = {
.owner = THIS_MODULE,
.llseek = noop_llseek,
.write = write_pmsg,
};
static struct class *pmsg_class;
static int pmsg_major;
#define PMSG_NAME "pmsg"
#undef pr_fmt
#define pr_fmt(fmt) PMSG_NAME ": " fmt
static char *pmsg_devnode(const struct device *dev, umode_t *mode)
{
if (mode)
*mode = 0220;
return NULL;
}
void pstore_register_pmsg(void)
{
struct device *pmsg_device;
pmsg_major = register_chrdev(0, PMSG_NAME, &pmsg_fops);
if (pmsg_major < 0) {
pr_err("register_chrdev failed\n");
goto err;
}
pmsg_class = class_create(PMSG_NAME);
if (IS_ERR(pmsg_class)) {
pr_err("device class file already in use\n");
goto err_class;
}
pmsg_class->devnode = pmsg_devnode;
pmsg_device = device_create(pmsg_class, NULL, MKDEV(pmsg_major, 0),
NULL, "%s%d", PMSG_NAME, 0);
if (IS_ERR(pmsg_device)) {
pr_err("failed to create device\n");
goto err_device;
}
return;
err_device:
class_destroy(pmsg_class);
err_class:
unregister_chrdev(pmsg_major, PMSG_NAME);
err:
return;
}
void pstore_unregister_pmsg(void)
{
device_destroy(pmsg_class, MKDEV(pmsg_major, 0));
class_destroy(pmsg_class);
unregister_chrdev(pmsg_major, PMSG_NAME);
}