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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pioctl.c (2269B)

      1// SPDX-License-Identifier: GPL-2.0
      2/*
      3 * Pioctl operations for Coda.
      4 * Original version: (C) 1996 Peter Braam
      5 * Rewritten for Linux 2.1: (C) 1997 Carnegie Mellon University
      6 *
      7 * Carnegie Mellon encourages users of this code to contribute improvements
      8 * to the Coda project. Contact Peter Braam <coda@cs.cmu.edu>.
      9 */
     10
     11#include <linux/types.h>
     12#include <linux/kernel.h>
     13#include <linux/time.h>
     14#include <linux/fs.h>
     15#include <linux/stat.h>
     16#include <linux/errno.h>
     17#include <linux/string.h>
     18#include <linux/namei.h>
     19#include <linux/module.h>
     20#include <linux/uaccess.h>
     21
     22#include <linux/coda.h>
     23#include "coda_psdev.h"
     24#include "coda_linux.h"
     25
     26/* pioctl ops */
     27static int coda_ioctl_permission(struct user_namespace *mnt_userns,
     28				 struct inode *inode, int mask);
     29static long coda_pioctl(struct file *filp, unsigned int cmd,
     30			unsigned long user_data);
     31
     32/* exported from this file */
     33const struct inode_operations coda_ioctl_inode_operations = {
     34	.permission	= coda_ioctl_permission,
     35	.setattr	= coda_setattr,
     36};
     37
     38const struct file_operations coda_ioctl_operations = {
     39	.unlocked_ioctl	= coda_pioctl,
     40	.llseek		= noop_llseek,
     41};
     42
     43/* the coda pioctl inode ops */
     44static int coda_ioctl_permission(struct user_namespace *mnt_userns,
     45				 struct inode *inode, int mask)
     46{
     47	return (mask & MAY_EXEC) ? -EACCES : 0;
     48}
     49
     50static long coda_pioctl(struct file *filp, unsigned int cmd,
     51			unsigned long user_data)
     52{
     53	struct path path;
     54	int error;
     55	struct PioctlData data;
     56	struct inode *inode = file_inode(filp);
     57	struct inode *target_inode = NULL;
     58	struct coda_inode_info *cnp;
     59
     60	/* get the Pioctl data arguments from user space */
     61	if (copy_from_user(&data, (void __user *)user_data, sizeof(data)))
     62		return -EINVAL;
     63
     64	/*
     65	 * Look up the pathname. Note that the pathname is in
     66	 * user memory, and namei takes care of this
     67	 */
     68	error = user_path_at(AT_FDCWD, data.path,
     69			     data.follow ? LOOKUP_FOLLOW : 0, &path);
     70	if (error)
     71		return error;
     72
     73	target_inode = d_inode(path.dentry);
     74
     75	/* return if it is not a Coda inode */
     76	if (target_inode->i_sb != inode->i_sb) {
     77		error = -EINVAL;
     78		goto out;
     79	}
     80
     81	/* now proceed to make the upcall */
     82	cnp = ITOC(target_inode);
     83
     84	error = venus_pioctl(inode->i_sb, &(cnp->c_fid), cmd, &data);
     85out:
     86	path_put(&path);
     87	return error;
     88}