Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1 | /* |
| 2 | * linux/fs/proc/inode.c |
| 3 | * |
| 4 | * Copyright (C) 1991, 1992 Linus Torvalds |
| 5 | */ |
| 6 | |
| 7 | #include <linux/time.h> |
| 8 | #include <linux/proc_fs.h> |
| 9 | #include <linux/kernel.h> |
Vasiliy Kulikov | 9741295 | 2012-01-10 15:11:27 -0800 | [diff] [blame] | 10 | #include <linux/pid_namespace.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 11 | #include <linux/mm.h> |
| 12 | #include <linux/string.h> |
| 13 | #include <linux/stat.h> |
Alexey Dobriyan | 786d7e1 | 2007-07-15 23:39:00 -0700 | [diff] [blame] | 14 | #include <linux/completion.h> |
Alexey Dobriyan | dd23aae | 2007-09-11 15:23:55 -0700 | [diff] [blame] | 15 | #include <linux/poll.h> |
Andrew Morton | 87ebdc0 | 2013-02-27 17:03:16 -0800 | [diff] [blame] | 16 | #include <linux/printk.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 17 | #include <linux/file.h> |
| 18 | #include <linux/limits.h> |
| 19 | #include <linux/init.h> |
| 20 | #include <linux/module.h> |
Al Viro | 9043476f | 2008-07-15 08:54:06 -0400 | [diff] [blame] | 21 | #include <linux/sysctl.h> |
Vasiliy Kulikov | 9741295 | 2012-01-10 15:11:27 -0800 | [diff] [blame] | 22 | #include <linux/seq_file.h> |
Tejun Heo | 5a0e3ad | 2010-03-24 17:04:11 +0900 | [diff] [blame] | 23 | #include <linux/slab.h> |
Vasiliy Kulikov | 9741295 | 2012-01-10 15:11:27 -0800 | [diff] [blame] | 24 | #include <linux/mount.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 25 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 26 | #include <asm/uaccess.h> |
| 27 | |
Adrian Bunk | fee781e | 2006-01-08 01:04:16 -0800 | [diff] [blame] | 28 | #include "internal.h" |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 29 | |
Al Viro | 8267952 | 2010-06-04 22:17:56 -0400 | [diff] [blame] | 30 | static void proc_evict_inode(struct inode *inode) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 31 | { |
| 32 | struct proc_dir_entry *de; |
Al Viro | dfef6dcd3 | 2011-03-08 01:25:28 -0500 | [diff] [blame] | 33 | struct ctl_table_header *head; |
Eric W. Biederman | 6b4e306 | 2010-03-07 16:41:34 -0800 | [diff] [blame] | 34 | const struct proc_ns_operations *ns_ops; |
Eric W. Biederman | bf056bf | 2011-06-18 17:48:18 -0700 | [diff] [blame] | 35 | void *ns; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 36 | |
Mark Fasheh | fef2665 | 2005-09-09 13:01:31 -0700 | [diff] [blame] | 37 | truncate_inode_pages(&inode->i_data, 0); |
Jan Kara | dbd5768 | 2012-05-03 14:48:02 +0200 | [diff] [blame] | 38 | clear_inode(inode); |
Mark Fasheh | fef2665 | 2005-09-09 13:01:31 -0700 | [diff] [blame] | 39 | |
Eric W. Biederman | 99f8955 | 2006-06-26 00:25:55 -0700 | [diff] [blame] | 40 | /* Stop tracking associated processes */ |
Eric W. Biederman | 13b41b0 | 2006-06-26 00:25:56 -0700 | [diff] [blame] | 41 | put_pid(PROC_I(inode)->pid); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 42 | |
| 43 | /* Let go of any associated proc directory entry */ |
| 44 | de = PROC_I(inode)->pde; |
Alexey Dobriyan | 99b7623 | 2009-03-25 22:48:06 +0300 | [diff] [blame] | 45 | if (de) |
Alexey Dobriyan | 135d565 | 2009-12-15 16:45:39 -0800 | [diff] [blame] | 46 | pde_put(de); |
Al Viro | dfef6dcd3 | 2011-03-08 01:25:28 -0500 | [diff] [blame] | 47 | head = PROC_I(inode)->sysctl; |
| 48 | if (head) { |
| 49 | rcu_assign_pointer(PROC_I(inode)->sysctl, NULL); |
| 50 | sysctl_head_put(head); |
| 51 | } |
Eric W. Biederman | 6b4e306 | 2010-03-07 16:41:34 -0800 | [diff] [blame] | 52 | /* Release any associated namespace */ |
| 53 | ns_ops = PROC_I(inode)->ns_ops; |
Eric W. Biederman | bf056bf | 2011-06-18 17:48:18 -0700 | [diff] [blame] | 54 | ns = PROC_I(inode)->ns; |
| 55 | if (ns_ops && ns) |
| 56 | ns_ops->put(ns); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 57 | } |
| 58 | |
Christoph Lameter | e18b890 | 2006-12-06 20:33:20 -0800 | [diff] [blame] | 59 | static struct kmem_cache * proc_inode_cachep; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 60 | |
| 61 | static struct inode *proc_alloc_inode(struct super_block *sb) |
| 62 | { |
| 63 | struct proc_inode *ei; |
| 64 | struct inode *inode; |
| 65 | |
Christoph Lameter | e94b176 | 2006-12-06 20:33:17 -0800 | [diff] [blame] | 66 | ei = (struct proc_inode *)kmem_cache_alloc(proc_inode_cachep, GFP_KERNEL); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 67 | if (!ei) |
| 68 | return NULL; |
Eric W. Biederman | 13b41b0 | 2006-06-26 00:25:56 -0700 | [diff] [blame] | 69 | ei->pid = NULL; |
Eric W. Biederman | aed7a6c | 2006-06-26 00:25:44 -0700 | [diff] [blame] | 70 | ei->fd = 0; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 71 | ei->op.proc_get_link = NULL; |
| 72 | ei->pde = NULL; |
Al Viro | 9043476f | 2008-07-15 08:54:06 -0400 | [diff] [blame] | 73 | ei->sysctl = NULL; |
| 74 | ei->sysctl_entry = NULL; |
Eric W. Biederman | 6b4e306 | 2010-03-07 16:41:34 -0800 | [diff] [blame] | 75 | ei->ns = NULL; |
| 76 | ei->ns_ops = NULL; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 77 | inode = &ei->vfs_inode; |
| 78 | inode->i_mtime = inode->i_atime = inode->i_ctime = CURRENT_TIME; |
| 79 | return inode; |
| 80 | } |
| 81 | |
Nick Piggin | fa0d7e3d | 2011-01-07 17:49:49 +1100 | [diff] [blame] | 82 | static void proc_i_callback(struct rcu_head *head) |
| 83 | { |
| 84 | struct inode *inode = container_of(head, struct inode, i_rcu); |
Nick Piggin | fa0d7e3d | 2011-01-07 17:49:49 +1100 | [diff] [blame] | 85 | kmem_cache_free(proc_inode_cachep, PROC_I(inode)); |
| 86 | } |
| 87 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 88 | static void proc_destroy_inode(struct inode *inode) |
| 89 | { |
Nick Piggin | fa0d7e3d | 2011-01-07 17:49:49 +1100 | [diff] [blame] | 90 | call_rcu(&inode->i_rcu, proc_i_callback); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 91 | } |
| 92 | |
Alexey Dobriyan | 51cc506 | 2008-07-25 19:45:34 -0700 | [diff] [blame] | 93 | static void init_once(void *foo) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 94 | { |
| 95 | struct proc_inode *ei = (struct proc_inode *) foo; |
| 96 | |
Christoph Lameter | a35afb8 | 2007-05-16 22:10:57 -0700 | [diff] [blame] | 97 | inode_init_once(&ei->vfs_inode); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 98 | } |
Paul Mundt | 20c2df8 | 2007-07-20 10:11:58 +0900 | [diff] [blame] | 99 | |
Alexey Dobriyan | 5bcd7ff | 2008-10-17 03:43:55 +0400 | [diff] [blame] | 100 | void __init proc_init_inodecache(void) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 101 | { |
| 102 | proc_inode_cachep = kmem_cache_create("proc_inode_cache", |
| 103 | sizeof(struct proc_inode), |
Paul Jackson | fffb60f | 2006-03-24 03:16:06 -0800 | [diff] [blame] | 104 | 0, (SLAB_RECLAIM_ACCOUNT| |
Alexey Dobriyan | 040b5c6 | 2007-10-16 23:26:10 -0700 | [diff] [blame] | 105 | SLAB_MEM_SPREAD|SLAB_PANIC), |
Paul Mundt | 20c2df8 | 2007-07-20 10:11:58 +0900 | [diff] [blame] | 106 | init_once); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 107 | } |
| 108 | |
Vasiliy Kulikov | 9741295 | 2012-01-10 15:11:27 -0800 | [diff] [blame] | 109 | static int proc_show_options(struct seq_file *seq, struct dentry *root) |
| 110 | { |
Vasiliy Kulikov | 0499680 | 2012-01-10 15:11:31 -0800 | [diff] [blame] | 111 | struct super_block *sb = root->d_sb; |
| 112 | struct pid_namespace *pid = sb->s_fs_info; |
| 113 | |
Eric W. Biederman | dcb0f22 | 2012-02-09 08:48:21 -0800 | [diff] [blame] | 114 | if (!gid_eq(pid->pid_gid, GLOBAL_ROOT_GID)) |
| 115 | seq_printf(seq, ",gid=%u", from_kgid_munged(&init_user_ns, pid->pid_gid)); |
Vasiliy Kulikov | 0499680 | 2012-01-10 15:11:31 -0800 | [diff] [blame] | 116 | if (pid->hide_pid != 0) |
| 117 | seq_printf(seq, ",hidepid=%u", pid->hide_pid); |
| 118 | |
Vasiliy Kulikov | 9741295 | 2012-01-10 15:11:27 -0800 | [diff] [blame] | 119 | return 0; |
| 120 | } |
| 121 | |
Josef 'Jeff' Sipek | ee9b6d6 | 2007-02-12 00:55:41 -0800 | [diff] [blame] | 122 | static const struct super_operations proc_sops = { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 123 | .alloc_inode = proc_alloc_inode, |
| 124 | .destroy_inode = proc_destroy_inode, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 125 | .drop_inode = generic_delete_inode, |
Al Viro | 8267952 | 2010-06-04 22:17:56 -0400 | [diff] [blame] | 126 | .evict_inode = proc_evict_inode, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 127 | .statfs = simple_statfs, |
Vasiliy Kulikov | 9741295 | 2012-01-10 15:11:27 -0800 | [diff] [blame] | 128 | .remount_fs = proc_remount, |
| 129 | .show_options = proc_show_options, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 130 | }; |
| 131 | |
Al Viro | 866ad9a | 2013-04-03 19:07:30 -0400 | [diff] [blame] | 132 | enum {BIAS = -1U<<31}; |
| 133 | |
| 134 | static inline int use_pde(struct proc_dir_entry *pde) |
| 135 | { |
| 136 | int res = 1; |
| 137 | spin_lock(&pde->pde_unload_lock); |
| 138 | if (unlikely(pde->pde_users < 0)) |
| 139 | res = 0; |
| 140 | else |
| 141 | pde->pde_users++; |
| 142 | spin_unlock(&pde->pde_unload_lock); |
| 143 | return res; |
| 144 | } |
| 145 | |
Alexey Dobriyan | 881adb8 | 2008-07-25 01:48:29 -0700 | [diff] [blame] | 146 | static void __pde_users_dec(struct proc_dir_entry *pde) |
Alexey Dobriyan | 786d7e1 | 2007-07-15 23:39:00 -0700 | [diff] [blame] | 147 | { |
Al Viro | 866ad9a | 2013-04-03 19:07:30 -0400 | [diff] [blame] | 148 | if (--pde->pde_users == BIAS) |
Alexey Dobriyan | 786d7e1 | 2007-07-15 23:39:00 -0700 | [diff] [blame] | 149 | complete(pde->pde_unload_completion); |
Alexey Dobriyan | 881adb8 | 2008-07-25 01:48:29 -0700 | [diff] [blame] | 150 | } |
| 151 | |
Al Viro | 866ad9a | 2013-04-03 19:07:30 -0400 | [diff] [blame] | 152 | static void unuse_pde(struct proc_dir_entry *pde) |
Alexey Dobriyan | 881adb8 | 2008-07-25 01:48:29 -0700 | [diff] [blame] | 153 | { |
| 154 | spin_lock(&pde->pde_unload_lock); |
| 155 | __pde_users_dec(pde); |
Alexey Dobriyan | 786d7e1 | 2007-07-15 23:39:00 -0700 | [diff] [blame] | 156 | spin_unlock(&pde->pde_unload_lock); |
| 157 | } |
| 158 | |
Al Viro | ca469f3 | 2013-04-03 19:57:00 -0400 | [diff] [blame^] | 159 | /* pde is locked */ |
| 160 | static void close_pdeo(struct proc_dir_entry *pde, struct pde_opener *pdeo) |
| 161 | { |
| 162 | pdeo->count++; |
| 163 | if (!mutex_trylock(&pdeo->mutex)) { |
| 164 | /* somebody else is doing that, just wait */ |
| 165 | spin_unlock(&pde->pde_unload_lock); |
| 166 | mutex_lock(&pdeo->mutex); |
| 167 | spin_lock(&pde->pde_unload_lock); |
| 168 | WARN_ON(!list_empty(&pdeo->lh)); |
| 169 | } else { |
| 170 | struct file *file; |
| 171 | spin_unlock(&pde->pde_unload_lock); |
| 172 | file = pdeo->file; |
| 173 | pde->proc_fops->release(file_inode(file), file); |
| 174 | spin_lock(&pde->pde_unload_lock); |
| 175 | list_del_init(&pdeo->lh); |
| 176 | } |
| 177 | mutex_unlock(&pdeo->mutex); |
| 178 | if (!--pdeo->count) |
| 179 | kfree(pdeo); |
| 180 | } |
| 181 | |
Al Viro | 866ad9a | 2013-04-03 19:07:30 -0400 | [diff] [blame] | 182 | void proc_entry_rundown(struct proc_dir_entry *de) |
| 183 | { |
| 184 | spin_lock(&de->pde_unload_lock); |
| 185 | de->pde_users += BIAS; |
| 186 | /* Wait until all existing callers into module are done. */ |
| 187 | if (de->pde_users != BIAS) { |
| 188 | DECLARE_COMPLETION_ONSTACK(c); |
| 189 | de->pde_unload_completion = &c; |
| 190 | spin_unlock(&de->pde_unload_lock); |
| 191 | |
| 192 | wait_for_completion(de->pde_unload_completion); |
| 193 | |
| 194 | spin_lock(&de->pde_unload_lock); |
| 195 | } |
| 196 | |
| 197 | while (!list_empty(&de->pde_openers)) { |
| 198 | struct pde_opener *pdeo; |
Al Viro | 866ad9a | 2013-04-03 19:07:30 -0400 | [diff] [blame] | 199 | pdeo = list_first_entry(&de->pde_openers, struct pde_opener, lh); |
Al Viro | ca469f3 | 2013-04-03 19:57:00 -0400 | [diff] [blame^] | 200 | close_pdeo(de, pdeo); |
Al Viro | 866ad9a | 2013-04-03 19:07:30 -0400 | [diff] [blame] | 201 | } |
| 202 | spin_unlock(&de->pde_unload_lock); |
| 203 | } |
| 204 | |
| 205 | /* ->read_proc() users - legacy crap */ |
| 206 | static ssize_t |
| 207 | proc_file_read(struct file *file, char __user *buf, size_t nbytes, |
| 208 | loff_t *ppos) |
| 209 | { |
| 210 | struct proc_dir_entry *pde = PDE(file_inode(file)); |
| 211 | ssize_t rv = -EIO; |
| 212 | if (use_pde(pde)) { |
| 213 | rv = __proc_file_read(file, buf, nbytes, ppos); |
| 214 | unuse_pde(pde); |
| 215 | } |
| 216 | return rv; |
| 217 | } |
| 218 | |
| 219 | static loff_t |
| 220 | proc_file_lseek(struct file *file, loff_t offset, int orig) |
| 221 | { |
| 222 | loff_t retval = -EINVAL; |
| 223 | switch (orig) { |
| 224 | case 1: |
| 225 | offset += file->f_pos; |
| 226 | /* fallthrough */ |
| 227 | case 0: |
| 228 | if (offset < 0 || offset > MAX_NON_LFS) |
| 229 | break; |
| 230 | file->f_pos = retval = offset; |
| 231 | } |
| 232 | return retval; |
| 233 | } |
| 234 | |
| 235 | const struct file_operations proc_file_operations = { |
| 236 | .llseek = proc_file_lseek, |
| 237 | .read = proc_file_read, |
| 238 | }; |
| 239 | |
Alexey Dobriyan | 786d7e1 | 2007-07-15 23:39:00 -0700 | [diff] [blame] | 240 | static loff_t proc_reg_llseek(struct file *file, loff_t offset, int whence) |
| 241 | { |
Al Viro | 496ad9a | 2013-01-23 17:07:38 -0500 | [diff] [blame] | 242 | struct proc_dir_entry *pde = PDE(file_inode(file)); |
Alexey Dobriyan | 786d7e1 | 2007-07-15 23:39:00 -0700 | [diff] [blame] | 243 | loff_t rv = -EINVAL; |
Al Viro | 866ad9a | 2013-04-03 19:07:30 -0400 | [diff] [blame] | 244 | if (use_pde(pde)) { |
| 245 | loff_t (*llseek)(struct file *, loff_t, int); |
| 246 | llseek = pde->proc_fops->llseek; |
| 247 | if (!llseek) |
| 248 | llseek = default_llseek; |
| 249 | rv = llseek(file, offset, whence); |
| 250 | unuse_pde(pde); |
Alexey Dobriyan | 786d7e1 | 2007-07-15 23:39:00 -0700 | [diff] [blame] | 251 | } |
Alexey Dobriyan | 786d7e1 | 2007-07-15 23:39:00 -0700 | [diff] [blame] | 252 | return rv; |
| 253 | } |
| 254 | |
| 255 | static ssize_t proc_reg_read(struct file *file, char __user *buf, size_t count, loff_t *ppos) |
| 256 | { |
Al Viro | 866ad9a | 2013-04-03 19:07:30 -0400 | [diff] [blame] | 257 | ssize_t (*read)(struct file *, char __user *, size_t, loff_t *); |
Al Viro | 496ad9a | 2013-01-23 17:07:38 -0500 | [diff] [blame] | 258 | struct proc_dir_entry *pde = PDE(file_inode(file)); |
Alexey Dobriyan | 786d7e1 | 2007-07-15 23:39:00 -0700 | [diff] [blame] | 259 | ssize_t rv = -EIO; |
Al Viro | 866ad9a | 2013-04-03 19:07:30 -0400 | [diff] [blame] | 260 | if (use_pde(pde)) { |
| 261 | read = pde->proc_fops->read; |
| 262 | if (read) |
| 263 | rv = read(file, buf, count, ppos); |
| 264 | unuse_pde(pde); |
Alexey Dobriyan | 786d7e1 | 2007-07-15 23:39:00 -0700 | [diff] [blame] | 265 | } |
Alexey Dobriyan | 786d7e1 | 2007-07-15 23:39:00 -0700 | [diff] [blame] | 266 | return rv; |
| 267 | } |
| 268 | |
| 269 | static ssize_t proc_reg_write(struct file *file, const char __user *buf, size_t count, loff_t *ppos) |
| 270 | { |
Al Viro | 866ad9a | 2013-04-03 19:07:30 -0400 | [diff] [blame] | 271 | ssize_t (*write)(struct file *, const char __user *, size_t, loff_t *); |
Al Viro | 496ad9a | 2013-01-23 17:07:38 -0500 | [diff] [blame] | 272 | struct proc_dir_entry *pde = PDE(file_inode(file)); |
Alexey Dobriyan | 786d7e1 | 2007-07-15 23:39:00 -0700 | [diff] [blame] | 273 | ssize_t rv = -EIO; |
Al Viro | 866ad9a | 2013-04-03 19:07:30 -0400 | [diff] [blame] | 274 | if (use_pde(pde)) { |
| 275 | write = pde->proc_fops->write; |
| 276 | if (write) |
| 277 | rv = write(file, buf, count, ppos); |
| 278 | unuse_pde(pde); |
Alexey Dobriyan | 786d7e1 | 2007-07-15 23:39:00 -0700 | [diff] [blame] | 279 | } |
Alexey Dobriyan | 786d7e1 | 2007-07-15 23:39:00 -0700 | [diff] [blame] | 280 | return rv; |
| 281 | } |
| 282 | |
| 283 | static unsigned int proc_reg_poll(struct file *file, struct poll_table_struct *pts) |
| 284 | { |
Al Viro | 496ad9a | 2013-01-23 17:07:38 -0500 | [diff] [blame] | 285 | struct proc_dir_entry *pde = PDE(file_inode(file)); |
Alexey Dobriyan | dd23aae | 2007-09-11 15:23:55 -0700 | [diff] [blame] | 286 | unsigned int rv = DEFAULT_POLLMASK; |
Alexey Dobriyan | 786d7e1 | 2007-07-15 23:39:00 -0700 | [diff] [blame] | 287 | unsigned int (*poll)(struct file *, struct poll_table_struct *); |
Al Viro | 866ad9a | 2013-04-03 19:07:30 -0400 | [diff] [blame] | 288 | if (use_pde(pde)) { |
| 289 | poll = pde->proc_fops->poll; |
| 290 | if (poll) |
| 291 | rv = poll(file, pts); |
| 292 | unuse_pde(pde); |
Alexey Dobriyan | 786d7e1 | 2007-07-15 23:39:00 -0700 | [diff] [blame] | 293 | } |
Alexey Dobriyan | 786d7e1 | 2007-07-15 23:39:00 -0700 | [diff] [blame] | 294 | return rv; |
| 295 | } |
| 296 | |
| 297 | static long proc_reg_unlocked_ioctl(struct file *file, unsigned int cmd, unsigned long arg) |
| 298 | { |
Al Viro | 496ad9a | 2013-01-23 17:07:38 -0500 | [diff] [blame] | 299 | struct proc_dir_entry *pde = PDE(file_inode(file)); |
Alexey Dobriyan | 786d7e1 | 2007-07-15 23:39:00 -0700 | [diff] [blame] | 300 | long rv = -ENOTTY; |
Arnd Bergmann | b19dd42 | 2010-07-04 00:15:10 +0200 | [diff] [blame] | 301 | long (*ioctl)(struct file *, unsigned int, unsigned long); |
Al Viro | 866ad9a | 2013-04-03 19:07:30 -0400 | [diff] [blame] | 302 | if (use_pde(pde)) { |
| 303 | ioctl = pde->proc_fops->unlocked_ioctl; |
| 304 | if (ioctl) |
| 305 | rv = ioctl(file, cmd, arg); |
| 306 | unuse_pde(pde); |
Alexey Dobriyan | 786d7e1 | 2007-07-15 23:39:00 -0700 | [diff] [blame] | 307 | } |
Alexey Dobriyan | 786d7e1 | 2007-07-15 23:39:00 -0700 | [diff] [blame] | 308 | return rv; |
| 309 | } |
| 310 | |
| 311 | #ifdef CONFIG_COMPAT |
| 312 | static long proc_reg_compat_ioctl(struct file *file, unsigned int cmd, unsigned long arg) |
| 313 | { |
Al Viro | 496ad9a | 2013-01-23 17:07:38 -0500 | [diff] [blame] | 314 | struct proc_dir_entry *pde = PDE(file_inode(file)); |
Alexey Dobriyan | 786d7e1 | 2007-07-15 23:39:00 -0700 | [diff] [blame] | 315 | long rv = -ENOTTY; |
| 316 | long (*compat_ioctl)(struct file *, unsigned int, unsigned long); |
Al Viro | 866ad9a | 2013-04-03 19:07:30 -0400 | [diff] [blame] | 317 | if (use_pde(pde)) { |
| 318 | compat_ioctl = pde->proc_fops->compat_ioctl; |
| 319 | if (compat_ioctl) |
| 320 | rv = compat_ioctl(file, cmd, arg); |
| 321 | unuse_pde(pde); |
Alexey Dobriyan | 786d7e1 | 2007-07-15 23:39:00 -0700 | [diff] [blame] | 322 | } |
Alexey Dobriyan | 786d7e1 | 2007-07-15 23:39:00 -0700 | [diff] [blame] | 323 | return rv; |
| 324 | } |
| 325 | #endif |
| 326 | |
| 327 | static int proc_reg_mmap(struct file *file, struct vm_area_struct *vma) |
| 328 | { |
Al Viro | 496ad9a | 2013-01-23 17:07:38 -0500 | [diff] [blame] | 329 | struct proc_dir_entry *pde = PDE(file_inode(file)); |
Alexey Dobriyan | 786d7e1 | 2007-07-15 23:39:00 -0700 | [diff] [blame] | 330 | int rv = -EIO; |
| 331 | int (*mmap)(struct file *, struct vm_area_struct *); |
Al Viro | 866ad9a | 2013-04-03 19:07:30 -0400 | [diff] [blame] | 332 | if (use_pde(pde)) { |
| 333 | mmap = pde->proc_fops->mmap; |
| 334 | if (mmap) |
| 335 | rv = mmap(file, vma); |
| 336 | unuse_pde(pde); |
Alexey Dobriyan | 786d7e1 | 2007-07-15 23:39:00 -0700 | [diff] [blame] | 337 | } |
Alexey Dobriyan | 786d7e1 | 2007-07-15 23:39:00 -0700 | [diff] [blame] | 338 | return rv; |
| 339 | } |
| 340 | |
| 341 | static int proc_reg_open(struct inode *inode, struct file *file) |
| 342 | { |
| 343 | struct proc_dir_entry *pde = PDE(inode); |
| 344 | int rv = 0; |
| 345 | int (*open)(struct inode *, struct file *); |
Alexey Dobriyan | 881adb8 | 2008-07-25 01:48:29 -0700 | [diff] [blame] | 346 | int (*release)(struct inode *, struct file *); |
| 347 | struct pde_opener *pdeo; |
| 348 | |
| 349 | /* |
| 350 | * What for, you ask? Well, we can have open, rmmod, remove_proc_entry |
| 351 | * sequence. ->release won't be called because ->proc_fops will be |
| 352 | * cleared. Depending on complexity of ->release, consequences vary. |
| 353 | * |
| 354 | * We can't wait for mercy when close will be done for real, it's |
| 355 | * deadlockable: rmmod foo </proc/foo . So, we're going to do ->release |
| 356 | * by hand in remove_proc_entry(). For this, save opener's credentials |
| 357 | * for later. |
| 358 | */ |
| 359 | pdeo = kmalloc(sizeof(struct pde_opener), GFP_KERNEL); |
| 360 | if (!pdeo) |
| 361 | return -ENOMEM; |
Alexey Dobriyan | 786d7e1 | 2007-07-15 23:39:00 -0700 | [diff] [blame] | 362 | |
Al Viro | 866ad9a | 2013-04-03 19:07:30 -0400 | [diff] [blame] | 363 | if (!use_pde(pde)) { |
Alexey Dobriyan | 881adb8 | 2008-07-25 01:48:29 -0700 | [diff] [blame] | 364 | kfree(pdeo); |
Daisuke Ogino | d2857e7 | 2011-07-26 16:08:37 -0700 | [diff] [blame] | 365 | return -ENOENT; |
Alexey Dobriyan | 786d7e1 | 2007-07-15 23:39:00 -0700 | [diff] [blame] | 366 | } |
Alexey Dobriyan | 786d7e1 | 2007-07-15 23:39:00 -0700 | [diff] [blame] | 367 | open = pde->proc_fops->open; |
Alexey Dobriyan | 881adb8 | 2008-07-25 01:48:29 -0700 | [diff] [blame] | 368 | release = pde->proc_fops->release; |
Alexey Dobriyan | 786d7e1 | 2007-07-15 23:39:00 -0700 | [diff] [blame] | 369 | |
| 370 | if (open) |
| 371 | rv = open(inode, file); |
| 372 | |
Alexey Dobriyan | 881adb8 | 2008-07-25 01:48:29 -0700 | [diff] [blame] | 373 | spin_lock(&pde->pde_unload_lock); |
| 374 | if (rv == 0 && release) { |
| 375 | /* To know what to release. */ |
Al Viro | ca469f3 | 2013-04-03 19:57:00 -0400 | [diff] [blame^] | 376 | mutex_init(&pdeo->mutex); |
| 377 | pdeo->count = 0; |
Alexey Dobriyan | 881adb8 | 2008-07-25 01:48:29 -0700 | [diff] [blame] | 378 | pdeo->file = file; |
| 379 | /* Strictly for "too late" ->release in proc_reg_release(). */ |
Alexey Dobriyan | 881adb8 | 2008-07-25 01:48:29 -0700 | [diff] [blame] | 380 | list_add(&pdeo->lh, &pde->pde_openers); |
| 381 | } else |
| 382 | kfree(pdeo); |
| 383 | __pde_users_dec(pde); |
| 384 | spin_unlock(&pde->pde_unload_lock); |
Alexey Dobriyan | 786d7e1 | 2007-07-15 23:39:00 -0700 | [diff] [blame] | 385 | return rv; |
| 386 | } |
| 387 | |
| 388 | static int proc_reg_release(struct inode *inode, struct file *file) |
| 389 | { |
| 390 | struct proc_dir_entry *pde = PDE(inode); |
Alexey Dobriyan | 881adb8 | 2008-07-25 01:48:29 -0700 | [diff] [blame] | 391 | struct pde_opener *pdeo; |
Alexey Dobriyan | 786d7e1 | 2007-07-15 23:39:00 -0700 | [diff] [blame] | 392 | spin_lock(&pde->pde_unload_lock); |
Al Viro | ca469f3 | 2013-04-03 19:57:00 -0400 | [diff] [blame^] | 393 | list_for_each_entry(pdeo, &pde->pde_openers, lh) { |
| 394 | if (pdeo->file == file) { |
| 395 | close_pdeo(pde, pdeo); |
| 396 | break; |
| 397 | } |
Alexey Dobriyan | 881adb8 | 2008-07-25 01:48:29 -0700 | [diff] [blame] | 398 | } |
Alexey Dobriyan | 786d7e1 | 2007-07-15 23:39:00 -0700 | [diff] [blame] | 399 | spin_unlock(&pde->pde_unload_lock); |
Al Viro | ca469f3 | 2013-04-03 19:57:00 -0400 | [diff] [blame^] | 400 | return 0; |
Alexey Dobriyan | 786d7e1 | 2007-07-15 23:39:00 -0700 | [diff] [blame] | 401 | } |
| 402 | |
| 403 | static const struct file_operations proc_reg_file_ops = { |
| 404 | .llseek = proc_reg_llseek, |
| 405 | .read = proc_reg_read, |
| 406 | .write = proc_reg_write, |
| 407 | .poll = proc_reg_poll, |
| 408 | .unlocked_ioctl = proc_reg_unlocked_ioctl, |
| 409 | #ifdef CONFIG_COMPAT |
| 410 | .compat_ioctl = proc_reg_compat_ioctl, |
| 411 | #endif |
| 412 | .mmap = proc_reg_mmap, |
| 413 | .open = proc_reg_open, |
| 414 | .release = proc_reg_release, |
| 415 | }; |
| 416 | |
David Miller | 778f3dd | 2007-07-27 22:58:37 -0700 | [diff] [blame] | 417 | #ifdef CONFIG_COMPAT |
| 418 | static const struct file_operations proc_reg_file_ops_no_compat = { |
| 419 | .llseek = proc_reg_llseek, |
| 420 | .read = proc_reg_read, |
| 421 | .write = proc_reg_write, |
| 422 | .poll = proc_reg_poll, |
| 423 | .unlocked_ioctl = proc_reg_unlocked_ioctl, |
| 424 | .mmap = proc_reg_mmap, |
| 425 | .open = proc_reg_open, |
| 426 | .release = proc_reg_release, |
| 427 | }; |
| 428 | #endif |
| 429 | |
Alexey Dobriyan | 6d1b6e4 | 2011-01-12 17:00:33 -0800 | [diff] [blame] | 430 | struct inode *proc_get_inode(struct super_block *sb, struct proc_dir_entry *de) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 431 | { |
Linus Torvalds | 51f0885 | 2013-03-22 11:44:04 -0700 | [diff] [blame] | 432 | struct inode *inode = new_inode_pseudo(sb); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 433 | |
Linus Torvalds | 51f0885 | 2013-03-22 11:44:04 -0700 | [diff] [blame] | 434 | if (inode) { |
| 435 | inode->i_ino = de->low_ino; |
David Howells | a1d4aeb | 2008-02-07 00:15:45 -0800 | [diff] [blame] | 436 | inode->i_mtime = inode->i_atime = inode->i_ctime = CURRENT_TIME; |
David Howells | a1d4aeb | 2008-02-07 00:15:45 -0800 | [diff] [blame] | 437 | PROC_I(inode)->pde = de; |
Alexey Dobriyan | 5e971dc | 2008-04-29 01:01:41 -0700 | [diff] [blame] | 438 | |
| 439 | if (de->mode) { |
| 440 | inode->i_mode = de->mode; |
| 441 | inode->i_uid = de->uid; |
| 442 | inode->i_gid = de->gid; |
| 443 | } |
| 444 | if (de->size) |
| 445 | inode->i_size = de->size; |
| 446 | if (de->nlink) |
Miklos Szeredi | bfe8684 | 2011-10-28 14:13:29 +0200 | [diff] [blame] | 447 | set_nlink(inode, de->nlink); |
Al Viro | b6cdc73 | 2013-03-30 21:20:14 -0400 | [diff] [blame] | 448 | WARN_ON(!de->proc_iops); |
| 449 | inode->i_op = de->proc_iops; |
Alexey Dobriyan | 5e971dc | 2008-04-29 01:01:41 -0700 | [diff] [blame] | 450 | if (de->proc_fops) { |
| 451 | if (S_ISREG(inode->i_mode)) { |
David Howells | a1d4aeb | 2008-02-07 00:15:45 -0800 | [diff] [blame] | 452 | #ifdef CONFIG_COMPAT |
Alexey Dobriyan | 5e971dc | 2008-04-29 01:01:41 -0700 | [diff] [blame] | 453 | if (!de->proc_fops->compat_ioctl) |
| 454 | inode->i_fop = |
| 455 | &proc_reg_file_ops_no_compat; |
| 456 | else |
David Howells | a1d4aeb | 2008-02-07 00:15:45 -0800 | [diff] [blame] | 457 | #endif |
Alexey Dobriyan | 5e971dc | 2008-04-29 01:01:41 -0700 | [diff] [blame] | 458 | inode->i_fop = &proc_reg_file_ops; |
| 459 | } else { |
| 460 | inode->i_fop = de->proc_fops; |
David Howells | a1d4aeb | 2008-02-07 00:15:45 -0800 | [diff] [blame] | 461 | } |
Alexey Dobriyan | 786d7e1 | 2007-07-15 23:39:00 -0700 | [diff] [blame] | 462 | } |
Alexey Dobriyan | 99b7623 | 2009-03-25 22:48:06 +0300 | [diff] [blame] | 463 | } else |
Alexey Dobriyan | 135d565 | 2009-12-15 16:45:39 -0800 | [diff] [blame] | 464 | pde_put(de); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 465 | return inode; |
Al Viro | d3d009c | 2013-01-25 20:11:22 -0500 | [diff] [blame] | 466 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 467 | |
Pavel Emelyanov | 07543f5 | 2007-10-18 23:40:08 -0700 | [diff] [blame] | 468 | int proc_fill_super(struct super_block *s) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 469 | { |
Maxim Patlasov | 87e0aab | 2013-02-20 13:13:32 +1100 | [diff] [blame] | 470 | struct inode *root_inode; |
| 471 | |
Linus Torvalds | 92d0328 | 2006-07-15 12:20:05 -0700 | [diff] [blame] | 472 | s->s_flags |= MS_NODIRATIME | MS_NOSUID | MS_NOEXEC; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 473 | s->s_blocksize = 1024; |
| 474 | s->s_blocksize_bits = 10; |
| 475 | s->s_magic = PROC_SUPER_MAGIC; |
| 476 | s->s_op = &proc_sops; |
| 477 | s->s_time_gran = 1; |
| 478 | |
Alexey Dobriyan | 135d565 | 2009-12-15 16:45:39 -0800 | [diff] [blame] | 479 | pde_get(&proc_root); |
Maxim Patlasov | 87e0aab | 2013-02-20 13:13:32 +1100 | [diff] [blame] | 480 | root_inode = proc_get_inode(s, &proc_root); |
| 481 | if (!root_inode) { |
Andrew Morton | 87ebdc0 | 2013-02-27 17:03:16 -0800 | [diff] [blame] | 482 | pr_err("proc_fill_super: get root inode failed\n"); |
Maxim Patlasov | 87e0aab | 2013-02-20 13:13:32 +1100 | [diff] [blame] | 483 | return -ENOMEM; |
| 484 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 485 | |
Maxim Patlasov | 87e0aab | 2013-02-20 13:13:32 +1100 | [diff] [blame] | 486 | s->s_root = d_make_root(root_inode); |
| 487 | if (!s->s_root) { |
Andrew Morton | 87ebdc0 | 2013-02-27 17:03:16 -0800 | [diff] [blame] | 488 | pr_err("proc_fill_super: allocate dentry failed\n"); |
Maxim Patlasov | 87e0aab | 2013-02-20 13:13:32 +1100 | [diff] [blame] | 489 | return -ENOMEM; |
| 490 | } |
| 491 | |
Al Viro | 021ada7 | 2013-03-29 19:27:05 -0400 | [diff] [blame] | 492 | return proc_setup_self(s); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 493 | } |