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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inode.c (8861B)


      1// SPDX-License-Identifier: GPL-2.0-or-later
      2/*
      3 * Copyright 1997-1998 Transmeta Corporation -- All Rights Reserved
      4 * Copyright 2005-2006 Ian Kent <raven@themaw.net>
      5 */
      6
      7#include <linux/seq_file.h>
      8#include <linux/pagemap.h>
      9#include <linux/parser.h>
     10
     11#include "autofs_i.h"
     12
     13struct autofs_info *autofs_new_ino(struct autofs_sb_info *sbi)
     14{
     15	struct autofs_info *ino;
     16
     17	ino = kzalloc(sizeof(*ino), GFP_KERNEL);
     18	if (ino) {
     19		INIT_LIST_HEAD(&ino->active);
     20		INIT_LIST_HEAD(&ino->expiring);
     21		ino->last_used = jiffies;
     22		ino->sbi = sbi;
     23	}
     24	return ino;
     25}
     26
     27void autofs_clean_ino(struct autofs_info *ino)
     28{
     29	ino->uid = GLOBAL_ROOT_UID;
     30	ino->gid = GLOBAL_ROOT_GID;
     31	ino->last_used = jiffies;
     32}
     33
     34void autofs_free_ino(struct autofs_info *ino)
     35{
     36	kfree_rcu(ino, rcu);
     37}
     38
     39void autofs_kill_sb(struct super_block *sb)
     40{
     41	struct autofs_sb_info *sbi = autofs_sbi(sb);
     42
     43	/*
     44	 * In the event of a failure in get_sb_nodev the superblock
     45	 * info is not present so nothing else has been setup, so
     46	 * just call kill_anon_super when we are called from
     47	 * deactivate_super.
     48	 */
     49	if (sbi) {
     50		/* Free wait queues, close pipe */
     51		autofs_catatonic_mode(sbi);
     52		put_pid(sbi->oz_pgrp);
     53	}
     54
     55	pr_debug("shutting down\n");
     56	kill_litter_super(sb);
     57	if (sbi)
     58		kfree_rcu(sbi, rcu);
     59}
     60
     61static int autofs_show_options(struct seq_file *m, struct dentry *root)
     62{
     63	struct autofs_sb_info *sbi = autofs_sbi(root->d_sb);
     64	struct inode *root_inode = d_inode(root->d_sb->s_root);
     65
     66	if (!sbi)
     67		return 0;
     68
     69	seq_printf(m, ",fd=%d", sbi->pipefd);
     70	if (!uid_eq(root_inode->i_uid, GLOBAL_ROOT_UID))
     71		seq_printf(m, ",uid=%u",
     72			from_kuid_munged(&init_user_ns, root_inode->i_uid));
     73	if (!gid_eq(root_inode->i_gid, GLOBAL_ROOT_GID))
     74		seq_printf(m, ",gid=%u",
     75			from_kgid_munged(&init_user_ns, root_inode->i_gid));
     76	seq_printf(m, ",pgrp=%d", pid_vnr(sbi->oz_pgrp));
     77	seq_printf(m, ",timeout=%lu", sbi->exp_timeout/HZ);
     78	seq_printf(m, ",minproto=%d", sbi->min_proto);
     79	seq_printf(m, ",maxproto=%d", sbi->max_proto);
     80
     81	if (autofs_type_offset(sbi->type))
     82		seq_puts(m, ",offset");
     83	else if (autofs_type_direct(sbi->type))
     84		seq_puts(m, ",direct");
     85	else
     86		seq_puts(m, ",indirect");
     87	if (sbi->flags & AUTOFS_SBI_STRICTEXPIRE)
     88		seq_puts(m, ",strictexpire");
     89	if (sbi->flags & AUTOFS_SBI_IGNORE)
     90		seq_puts(m, ",ignore");
     91#ifdef CONFIG_CHECKPOINT_RESTORE
     92	if (sbi->pipe)
     93		seq_printf(m, ",pipe_ino=%ld", file_inode(sbi->pipe)->i_ino);
     94	else
     95		seq_puts(m, ",pipe_ino=-1");
     96#endif
     97	return 0;
     98}
     99
    100static void autofs_evict_inode(struct inode *inode)
    101{
    102	clear_inode(inode);
    103	kfree(inode->i_private);
    104}
    105
    106static const struct super_operations autofs_sops = {
    107	.statfs		= simple_statfs,
    108	.show_options	= autofs_show_options,
    109	.evict_inode	= autofs_evict_inode,
    110};
    111
    112enum {Opt_err, Opt_fd, Opt_uid, Opt_gid, Opt_pgrp, Opt_minproto, Opt_maxproto,
    113	Opt_indirect, Opt_direct, Opt_offset, Opt_strictexpire,
    114	Opt_ignore};
    115
    116static const match_table_t tokens = {
    117	{Opt_fd, "fd=%u"},
    118	{Opt_uid, "uid=%u"},
    119	{Opt_gid, "gid=%u"},
    120	{Opt_pgrp, "pgrp=%u"},
    121	{Opt_minproto, "minproto=%u"},
    122	{Opt_maxproto, "maxproto=%u"},
    123	{Opt_indirect, "indirect"},
    124	{Opt_direct, "direct"},
    125	{Opt_offset, "offset"},
    126	{Opt_strictexpire, "strictexpire"},
    127	{Opt_ignore, "ignore"},
    128	{Opt_err, NULL}
    129};
    130
    131static int parse_options(char *options,
    132			 struct inode *root, int *pgrp, bool *pgrp_set,
    133			 struct autofs_sb_info *sbi)
    134{
    135	char *p;
    136	substring_t args[MAX_OPT_ARGS];
    137	int option;
    138	int pipefd = -1;
    139	kuid_t uid;
    140	kgid_t gid;
    141
    142	root->i_uid = current_uid();
    143	root->i_gid = current_gid();
    144
    145	sbi->min_proto = AUTOFS_MIN_PROTO_VERSION;
    146	sbi->max_proto = AUTOFS_MAX_PROTO_VERSION;
    147
    148	sbi->pipefd = -1;
    149
    150	if (!options)
    151		return 1;
    152
    153	while ((p = strsep(&options, ",")) != NULL) {
    154		int token;
    155
    156		if (!*p)
    157			continue;
    158
    159		token = match_token(p, tokens, args);
    160		switch (token) {
    161		case Opt_fd:
    162			if (match_int(args, &pipefd))
    163				return 1;
    164			sbi->pipefd = pipefd;
    165			break;
    166		case Opt_uid:
    167			if (match_int(args, &option))
    168				return 1;
    169			uid = make_kuid(current_user_ns(), option);
    170			if (!uid_valid(uid))
    171				return 1;
    172			root->i_uid = uid;
    173			break;
    174		case Opt_gid:
    175			if (match_int(args, &option))
    176				return 1;
    177			gid = make_kgid(current_user_ns(), option);
    178			if (!gid_valid(gid))
    179				return 1;
    180			root->i_gid = gid;
    181			break;
    182		case Opt_pgrp:
    183			if (match_int(args, &option))
    184				return 1;
    185			*pgrp = option;
    186			*pgrp_set = true;
    187			break;
    188		case Opt_minproto:
    189			if (match_int(args, &option))
    190				return 1;
    191			sbi->min_proto = option;
    192			break;
    193		case Opt_maxproto:
    194			if (match_int(args, &option))
    195				return 1;
    196			sbi->max_proto = option;
    197			break;
    198		case Opt_indirect:
    199			set_autofs_type_indirect(&sbi->type);
    200			break;
    201		case Opt_direct:
    202			set_autofs_type_direct(&sbi->type);
    203			break;
    204		case Opt_offset:
    205			set_autofs_type_offset(&sbi->type);
    206			break;
    207		case Opt_strictexpire:
    208			sbi->flags |= AUTOFS_SBI_STRICTEXPIRE;
    209			break;
    210		case Opt_ignore:
    211			sbi->flags |= AUTOFS_SBI_IGNORE;
    212			break;
    213		default:
    214			return 1;
    215		}
    216	}
    217	return (sbi->pipefd < 0);
    218}
    219
    220int autofs_fill_super(struct super_block *s, void *data, int silent)
    221{
    222	struct inode *root_inode;
    223	struct dentry *root;
    224	struct file *pipe;
    225	struct autofs_sb_info *sbi;
    226	struct autofs_info *ino;
    227	int pgrp = 0;
    228	bool pgrp_set = false;
    229	int ret = -EINVAL;
    230
    231	sbi = kzalloc(sizeof(*sbi), GFP_KERNEL);
    232	if (!sbi)
    233		return -ENOMEM;
    234	pr_debug("starting up, sbi = %p\n", sbi);
    235
    236	s->s_fs_info = sbi;
    237	sbi->magic = AUTOFS_SBI_MAGIC;
    238	sbi->pipefd = -1;
    239	sbi->pipe = NULL;
    240	sbi->exp_timeout = 0;
    241	sbi->oz_pgrp = NULL;
    242	sbi->sb = s;
    243	sbi->version = 0;
    244	sbi->sub_version = 0;
    245	sbi->flags = AUTOFS_SBI_CATATONIC;
    246	set_autofs_type_indirect(&sbi->type);
    247	sbi->min_proto = 0;
    248	sbi->max_proto = 0;
    249	mutex_init(&sbi->wq_mutex);
    250	mutex_init(&sbi->pipe_mutex);
    251	spin_lock_init(&sbi->fs_lock);
    252	sbi->queues = NULL;
    253	spin_lock_init(&sbi->lookup_lock);
    254	INIT_LIST_HEAD(&sbi->active_list);
    255	INIT_LIST_HEAD(&sbi->expiring_list);
    256	s->s_blocksize = 1024;
    257	s->s_blocksize_bits = 10;
    258	s->s_magic = AUTOFS_SUPER_MAGIC;
    259	s->s_op = &autofs_sops;
    260	s->s_d_op = &autofs_dentry_operations;
    261	s->s_time_gran = 1;
    262
    263	/*
    264	 * Get the root inode and dentry, but defer checking for errors.
    265	 */
    266	ino = autofs_new_ino(sbi);
    267	if (!ino) {
    268		ret = -ENOMEM;
    269		goto fail_free;
    270	}
    271	root_inode = autofs_get_inode(s, S_IFDIR | 0755);
    272	root = d_make_root(root_inode);
    273	if (!root) {
    274		ret = -ENOMEM;
    275		goto fail_ino;
    276	}
    277	pipe = NULL;
    278
    279	root->d_fsdata = ino;
    280
    281	/* Can this call block? */
    282	if (parse_options(data, root_inode, &pgrp, &pgrp_set, sbi)) {
    283		pr_err("called with bogus options\n");
    284		goto fail_dput;
    285	}
    286
    287	/* Test versions first */
    288	if (sbi->max_proto < AUTOFS_MIN_PROTO_VERSION ||
    289	    sbi->min_proto > AUTOFS_MAX_PROTO_VERSION) {
    290		pr_err("kernel does not match daemon version "
    291		       "daemon (%d, %d) kernel (%d, %d)\n",
    292		       sbi->min_proto, sbi->max_proto,
    293		       AUTOFS_MIN_PROTO_VERSION, AUTOFS_MAX_PROTO_VERSION);
    294		goto fail_dput;
    295	}
    296
    297	/* Establish highest kernel protocol version */
    298	if (sbi->max_proto > AUTOFS_MAX_PROTO_VERSION)
    299		sbi->version = AUTOFS_MAX_PROTO_VERSION;
    300	else
    301		sbi->version = sbi->max_proto;
    302	sbi->sub_version = AUTOFS_PROTO_SUBVERSION;
    303
    304	if (pgrp_set) {
    305		sbi->oz_pgrp = find_get_pid(pgrp);
    306		if (!sbi->oz_pgrp) {
    307			pr_err("could not find process group %d\n",
    308				pgrp);
    309			goto fail_dput;
    310		}
    311	} else {
    312		sbi->oz_pgrp = get_task_pid(current, PIDTYPE_PGID);
    313	}
    314
    315	if (autofs_type_trigger(sbi->type))
    316		__managed_dentry_set_managed(root);
    317
    318	root_inode->i_fop = &autofs_root_operations;
    319	root_inode->i_op = &autofs_dir_inode_operations;
    320
    321	pr_debug("pipe fd = %d, pgrp = %u\n",
    322		 sbi->pipefd, pid_nr(sbi->oz_pgrp));
    323	pipe = fget(sbi->pipefd);
    324
    325	if (!pipe) {
    326		pr_err("could not open pipe file descriptor\n");
    327		goto fail_put_pid;
    328	}
    329	ret = autofs_prepare_pipe(pipe);
    330	if (ret < 0)
    331		goto fail_fput;
    332	sbi->pipe = pipe;
    333	sbi->flags &= ~AUTOFS_SBI_CATATONIC;
    334
    335	/*
    336	 * Success! Install the root dentry now to indicate completion.
    337	 */
    338	s->s_root = root;
    339	return 0;
    340
    341	/*
    342	 * Failure ... clean up.
    343	 */
    344fail_fput:
    345	pr_err("pipe file descriptor does not contain proper ops\n");
    346	fput(pipe);
    347fail_put_pid:
    348	put_pid(sbi->oz_pgrp);
    349fail_dput:
    350	dput(root);
    351	goto fail_free;
    352fail_ino:
    353	autofs_free_ino(ino);
    354fail_free:
    355	kfree(sbi);
    356	s->s_fs_info = NULL;
    357	return ret;
    358}
    359
    360struct inode *autofs_get_inode(struct super_block *sb, umode_t mode)
    361{
    362	struct inode *inode = new_inode(sb);
    363
    364	if (inode == NULL)
    365		return NULL;
    366
    367	inode->i_mode = mode;
    368	if (sb->s_root) {
    369		inode->i_uid = d_inode(sb->s_root)->i_uid;
    370		inode->i_gid = d_inode(sb->s_root)->i_gid;
    371	}
    372	inode->i_atime = inode->i_mtime = inode->i_ctime = current_time(inode);
    373	inode->i_ino = get_next_ino();
    374
    375	if (S_ISDIR(mode)) {
    376		set_nlink(inode, 2);
    377		inode->i_op = &autofs_dir_inode_operations;
    378		inode->i_fop = &autofs_dir_operations;
    379	} else if (S_ISLNK(mode)) {
    380		inode->i_op = &autofs_symlink_inode_operations;
    381	} else
    382		WARN_ON(1);
    383
    384	return inode;
    385}