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![Arjan van de Ven](/assets/img/avatar_default.png)
Many struct file_operations in the kernel can be "const". Marking them const moves these to the .rodata section, which avoids false sharing with potential dirty data. In addition it'll catch accidental writes at compile time to these shared resources. Signed-off-by: Arjan van de Ven <arjan@linux.intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
175 lines
4.2 KiB
C
175 lines
4.2 KiB
C
/*
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* linux/fs/proc/root.c
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*
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* Copyright (C) 1991, 1992 Linus Torvalds
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*
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* proc root directory handling functions
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*/
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#include <asm/uaccess.h>
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#include <linux/errno.h>
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#include <linux/time.h>
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#include <linux/proc_fs.h>
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#include <linux/stat.h>
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#include <linux/init.h>
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#include <linux/sched.h>
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#include <linux/module.h>
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#include <linux/bitops.h>
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#include <linux/smp_lock.h>
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#include <linux/mount.h>
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#include "internal.h"
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struct proc_dir_entry *proc_net, *proc_net_stat, *proc_bus, *proc_root_fs, *proc_root_driver;
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#ifdef CONFIG_SYSCTL
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struct proc_dir_entry *proc_sys_root;
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#endif
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static int proc_get_sb(struct file_system_type *fs_type,
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int flags, const char *dev_name, void *data, struct vfsmount *mnt)
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{
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if (proc_mnt) {
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/* Seed the root directory with a pid so it doesn't need
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* to be special in base.c. I would do this earlier but
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* the only task alive when /proc is mounted the first time
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* is the init_task and it doesn't have any pids.
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*/
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struct proc_inode *ei;
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ei = PROC_I(proc_mnt->mnt_sb->s_root->d_inode);
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if (!ei->pid)
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ei->pid = find_get_pid(1);
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}
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return get_sb_single(fs_type, flags, data, proc_fill_super, mnt);
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}
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static struct file_system_type proc_fs_type = {
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.name = "proc",
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.get_sb = proc_get_sb,
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.kill_sb = kill_anon_super,
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};
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void __init proc_root_init(void)
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{
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int err = proc_init_inodecache();
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if (err)
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return;
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err = register_filesystem(&proc_fs_type);
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if (err)
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return;
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proc_mnt = kern_mount(&proc_fs_type);
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err = PTR_ERR(proc_mnt);
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if (IS_ERR(proc_mnt)) {
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unregister_filesystem(&proc_fs_type);
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return;
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}
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proc_misc_init();
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proc_net = proc_mkdir("net", NULL);
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proc_net_stat = proc_mkdir("net/stat", NULL);
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#ifdef CONFIG_SYSVIPC
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proc_mkdir("sysvipc", NULL);
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#endif
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#ifdef CONFIG_SYSCTL
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proc_sys_root = proc_mkdir("sys", NULL);
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#endif
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#if defined(CONFIG_BINFMT_MISC) || defined(CONFIG_BINFMT_MISC_MODULE)
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proc_mkdir("sys/fs", NULL);
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proc_mkdir("sys/fs/binfmt_misc", NULL);
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#endif
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proc_root_fs = proc_mkdir("fs", NULL);
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proc_root_driver = proc_mkdir("driver", NULL);
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proc_mkdir("fs/nfsd", NULL); /* somewhere for the nfsd filesystem to be mounted */
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#if defined(CONFIG_SUN_OPENPROMFS) || defined(CONFIG_SUN_OPENPROMFS_MODULE)
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/* just give it a mountpoint */
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proc_mkdir("openprom", NULL);
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#endif
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proc_tty_init();
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#ifdef CONFIG_PROC_DEVICETREE
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proc_device_tree_init();
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#endif
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proc_bus = proc_mkdir("bus", NULL);
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}
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static int proc_root_getattr(struct vfsmount *mnt, struct dentry *dentry, struct kstat *stat
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)
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{
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generic_fillattr(dentry->d_inode, stat);
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stat->nlink = proc_root.nlink + nr_processes();
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return 0;
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}
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static struct dentry *proc_root_lookup(struct inode * dir, struct dentry * dentry, struct nameidata *nd)
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{
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if (!proc_lookup(dir, dentry, nd)) {
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return NULL;
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}
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return proc_pid_lookup(dir, dentry, nd);
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}
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static int proc_root_readdir(struct file * filp,
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void * dirent, filldir_t filldir)
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{
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unsigned int nr = filp->f_pos;
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int ret;
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lock_kernel();
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if (nr < FIRST_PROCESS_ENTRY) {
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int error = proc_readdir(filp, dirent, filldir);
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if (error <= 0) {
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unlock_kernel();
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return error;
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}
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filp->f_pos = FIRST_PROCESS_ENTRY;
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}
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unlock_kernel();
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ret = proc_pid_readdir(filp, dirent, filldir);
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return ret;
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}
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/*
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* The root /proc directory is special, as it has the
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* <pid> directories. Thus we don't use the generic
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* directory handling functions for that..
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*/
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static const struct file_operations proc_root_operations = {
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.read = generic_read_dir,
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.readdir = proc_root_readdir,
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};
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/*
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* proc root can do almost nothing..
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*/
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static struct inode_operations proc_root_inode_operations = {
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.lookup = proc_root_lookup,
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.getattr = proc_root_getattr,
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};
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/*
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* This is the root "inode" in the /proc tree..
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*/
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struct proc_dir_entry proc_root = {
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.low_ino = PROC_ROOT_INO,
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.namelen = 5,
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.name = "/proc",
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.mode = S_IFDIR | S_IRUGO | S_IXUGO,
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.nlink = 2,
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.proc_iops = &proc_root_inode_operations,
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.proc_fops = &proc_root_operations,
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.parent = &proc_root,
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};
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EXPORT_SYMBOL(proc_symlink);
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EXPORT_SYMBOL(proc_mkdir);
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EXPORT_SYMBOL(create_proc_entry);
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EXPORT_SYMBOL(remove_proc_entry);
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EXPORT_SYMBOL(proc_root);
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EXPORT_SYMBOL(proc_root_fs);
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EXPORT_SYMBOL(proc_net);
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EXPORT_SYMBOL(proc_net_stat);
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EXPORT_SYMBOL(proc_bus);
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EXPORT_SYMBOL(proc_root_driver);
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