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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procfs.c (1901B)

      1// SPDX-License-Identifier: GPL-2.0
      2/*
      3 * Procfs support for lockd
      4 *
      5 * Copyright (c) 2014 Jeff Layton <jlayton@primarydata.com>
      6 */
      7
      8#include <linux/fs.h>
      9#include <linux/proc_fs.h>
     10#include <linux/module.h>
     11#include <linux/nsproxy.h>
     12#include <net/net_namespace.h>
     13
     14#include "netns.h"
     15#include "procfs.h"
     16
     17/*
     18 * We only allow strings that start with 'Y', 'y', or '1'.
     19 */
     20static ssize_t
     21nlm_end_grace_write(struct file *file, const char __user *buf, size_t size,
     22		    loff_t *pos)
     23{
     24	char *data;
     25	struct lockd_net *ln = net_generic(current->nsproxy->net_ns,
     26					   lockd_net_id);
     27
     28	if (size < 1)
     29		return -EINVAL;
     30
     31	data = simple_transaction_get(file, buf, size);
     32	if (IS_ERR(data))
     33		return PTR_ERR(data);
     34
     35	switch(data[0]) {
     36	case 'Y':
     37	case 'y':
     38	case '1':
     39		locks_end_grace(&ln->lockd_manager);
     40		break;
     41	default:
     42		return -EINVAL;
     43	}
     44
     45	return size;
     46}
     47
     48static ssize_t
     49nlm_end_grace_read(struct file *file, char __user *buf, size_t size,
     50		   loff_t *pos)
     51{
     52	struct lockd_net *ln = net_generic(current->nsproxy->net_ns,
     53					   lockd_net_id);
     54	char resp[3];
     55
     56	resp[0] = list_empty(&ln->lockd_manager.list) ? 'Y' : 'N';
     57	resp[1] = '\n';
     58	resp[2] = '\0';
     59
     60	return simple_read_from_buffer(buf, size, pos, resp, sizeof(resp));
     61}
     62
     63static const struct proc_ops lockd_end_grace_proc_ops = {
     64	.proc_write	= nlm_end_grace_write,
     65	.proc_read	= nlm_end_grace_read,
     66	.proc_lseek	= default_llseek,
     67	.proc_release	= simple_transaction_release,
     68};
     69
     70int __init
     71lockd_create_procfs(void)
     72{
     73	struct proc_dir_entry *entry;
     74
     75	entry = proc_mkdir("fs/lockd", NULL);
     76	if (!entry)
     77		return -ENOMEM;
     78	entry = proc_create("nlm_end_grace", S_IRUGO|S_IWUSR, entry,
     79			    &lockd_end_grace_proc_ops);
     80	if (!entry) {
     81		remove_proc_entry("fs/lockd", NULL);
     82		return -ENOMEM;
     83	}
     84	return 0;
     85}
     86
     87void __exit
     88lockd_remove_procfs(void)
     89{
     90	remove_proc_entry("fs/lockd/nlm_end_grace", NULL);
     91	remove_proc_entry("fs/lockd", NULL);
     92}