cachepc-linux

Fork of AMDESE/linux with modifications for CachePC side-channel attack
git clone https://git.sinitax.com/sinitax/cachepc-linux
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ioctl.c (1884B)

      1// SPDX-License-Identifier: GPL-2.0
      2/*
      3 *  linux/fs/hfsplus/ioctl.c
      4 *
      5 * Copyright (C) 2003
      6 * Ethan Benson <erbenson@alaska.net>
      7 * partially derived from linux/fs/ext2/ioctl.c
      8 * Copyright (C) 1993, 1994, 1995
      9 * Remy Card (card@masi.ibp.fr)
     10 * Laboratoire MASI - Institut Blaise Pascal
     11 * Universite Pierre et Marie Curie (Paris VI)
     12 *
     13 * hfsplus ioctls
     14 */
     15
     16#include <linux/capability.h>
     17#include <linux/fs.h>
     18#include <linux/mount.h>
     19#include <linux/sched.h>
     20#include <linux/uaccess.h>
     21#include "hfsplus_fs.h"
     22
     23/*
     24 * "Blessing" an HFS+ filesystem writes metadata to the superblock informing
     25 * the platform firmware which file to boot from
     26 */
     27static int hfsplus_ioctl_bless(struct file *file, int __user *user_flags)
     28{
     29	struct dentry *dentry = file->f_path.dentry;
     30	struct inode *inode = d_inode(dentry);
     31	struct hfsplus_sb_info *sbi = HFSPLUS_SB(inode->i_sb);
     32	struct hfsplus_vh *vh = sbi->s_vhdr;
     33	struct hfsplus_vh *bvh = sbi->s_backup_vhdr;
     34	u32 cnid = (unsigned long)dentry->d_fsdata;
     35
     36	if (!capable(CAP_SYS_ADMIN))
     37		return -EPERM;
     38
     39	mutex_lock(&sbi->vh_mutex);
     40
     41	/* Directory containing the bootable system */
     42	vh->finder_info[0] = bvh->finder_info[0] =
     43		cpu_to_be32(parent_ino(dentry));
     44
     45	/*
     46	 * Bootloader. Just using the inode here breaks in the case of
     47	 * hard links - the firmware wants the ID of the hard link file,
     48	 * but the inode points at the indirect inode
     49	 */
     50	vh->finder_info[1] = bvh->finder_info[1] = cpu_to_be32(cnid);
     51
     52	/* Per spec, the OS X system folder - same as finder_info[0] here */
     53	vh->finder_info[5] = bvh->finder_info[5] =
     54		cpu_to_be32(parent_ino(dentry));
     55
     56	mutex_unlock(&sbi->vh_mutex);
     57	return 0;
     58}
     59
     60long hfsplus_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
     61{
     62	void __user *argp = (void __user *)arg;
     63
     64	switch (cmd) {
     65	case HFSPLUS_IOC_BLESS:
     66		return hfsplus_ioctl_bless(file, argp);
     67	default:
     68		return -ENOTTY;
     69	}
     70}