fs/proc/base.c

   1 /*
   2  *  linux/fs/proc/base.c
   3  *
   4  *  Copyright (C) 1991, 1992 Linus Torvalds
   5  *
   6  *  proc base directory handling functions
   7  */
   8
   9 #include <asm/uaccess.h>
  10
  11 #include <linux/config.h>
  12 #include <linux/errno.h>
  13 #include <linux/sched.h>
  14 #include <linux/proc_fs.h>
  15 #include <linux/stat.h>
  16 #include <linux/init.h>
  17
  18 static struct file_operations proc_base_operations = {
  19         NULL,                   /* lseek - default */
  20         NULL,                   /* read - bad */
  21         NULL,                   /* write - bad */
  22         proc_readdir,           /* readdir */
  23         NULL,                   /* poll - default */
  24         NULL,                   /* ioctl - default */
  25         NULL,                   /* mmap */
  26         NULL,                   /* no special open code */
  27         NULL,                   /* flush */
  28         NULL,                   /* no special release code */
  29         NULL                    /* can't fsync */
  30 };
  31
  32 /*
  33  * proc directories can do almost nothing..
  34  */
  35 static struct inode_operations proc_base_inode_operations = {
  36         &proc_base_operations,  /* default base directory file-ops */
  37         NULL,                   /* create */
  38         proc_lookup,            /* lookup */
  39         NULL,                   /* link */
  40         NULL,                   /* unlink */
  41         NULL,                   /* symlink */
  42         NULL,                   /* mkdir */
  43         NULL,                   /* rmdir */
  44         NULL,                   /* mknod */
  45         NULL,                   /* rename */
  46         NULL,                   /* readlink */
  47         NULL,                   /* follow_link */
  48         NULL,                   /* readpage */
  49         NULL,                   /* writepage */
  50         NULL,                   /* bmap */
  51         NULL,                   /* truncate */
  52         NULL                    /* permission */
  53 };
  54
  55 /*
  56  * The fill argument is non-zero when the inode is being filled ...
  57  * we don't need to do anything when it's being deleted.
  58  */
  59 static void proc_pid_fill_inode(struct inode * inode, int fill)
  60 {
  61         struct task_struct *p;
  62         int pid = inode->i_ino >> 16;
  63         int ino = inode->i_ino & 0xffff;
  64
  65         read_lock(&tasklist_lock);
  66         if (fill && (p = find_task_by_pid(pid)) != NULL) {
  67                 uid_t uid = 0;
  68                 gid_t gid = 0;
  69                 if (p->dumpable || ino == PROC_PID_INO) {
  70                         uid = p->euid;
  71                         gid = p->egid;
  72                 }
  73                 inode->i_uid = uid;
  74                 inode->i_gid = gid;
  75         }
  76         read_unlock(&tasklist_lock);
  77 }
  78
  79 /*
  80  * This is really a pseudo-entry, and only links
  81  * backwards to the parent with no link from the
  82  * root directory to this. This way we can have just
  83  * one entry for every /proc/<pid>/ directory.
  84  */
  85 struct proc_dir_entry proc_pid = {
  86         PROC_PID_INO, 5, "<pid>",
  87         S_IFDIR | S_IRUGO | S_IXUGO, 2, 0, 0,
  88         0, &proc_base_inode_operations,
  89         NULL, proc_pid_fill_inode,
  90         NULL, &proc_root, NULL
  91 };
  92
  93 static struct proc_dir_entry proc_pid_status = {
  94         PROC_PID_STATUS, 6, "status",
  95         S_IFREG | S_IRUGO, 1, 0, 0,
  96         0, &proc_array_inode_operations,
  97         NULL, proc_pid_fill_inode,
  98 };
  99 static struct proc_dir_entry proc_pid_mem = {
 100         PROC_PID_MEM, 3, "mem",
 101         S_IFREG | S_IRUSR | S_IWUSR, 1, 0, 0,
 102         0, &proc_mem_inode_operations,
 103         NULL, proc_pid_fill_inode,
 104 };
 105 static struct proc_dir_entry proc_pid_cwd = {
 106         PROC_PID_CWD, 3, "cwd",
 107         S_IFLNK | S_IRWXU, 1, 0, 0,
 108         0, &proc_link_inode_operations,
 109         NULL, proc_pid_fill_inode,
 110 };
 111 static struct proc_dir_entry proc_pid_root = {
 112         PROC_PID_ROOT, 4, "root",
 113         S_IFLNK | S_IRWXU, 1, 0, 0,
 114         0, &proc_link_inode_operations,
 115         NULL, proc_pid_fill_inode,
 116 };
 117 static struct proc_dir_entry proc_pid_exe = {
 118         PROC_PID_EXE, 3, "exe",
 119         S_IFLNK | S_IRWXU, 1, 0, 0,
 120         0, &proc_link_inode_operations,
 121         NULL, proc_pid_fill_inode,
 122 };
 123 static struct proc_dir_entry proc_pid_fd = {
 124         PROC_PID_FD, 2, "fd",
 125         S_IFDIR | S_IRUSR | S_IXUSR, 2, 0, 0,
 126         0, &proc_fd_inode_operations,
 127         NULL, proc_pid_fill_inode,
 128 };
 129 static struct proc_dir_entry proc_pid_environ = {
 130         PROC_PID_ENVIRON, 7, "environ",
 131         S_IFREG | S_IRUSR, 1, 0, 0,
 132         0, &proc_array_inode_operations,
 133         NULL, proc_pid_fill_inode,
 134 };
 135 static struct proc_dir_entry proc_pid_cmdline = {
 136         PROC_PID_CMDLINE, 7, "cmdline",
 137         S_IFREG | S_IRUGO, 1, 0, 0,
 138         0, &proc_array_inode_operations,
 139         NULL, proc_pid_fill_inode,
 140 };
 141 static struct proc_dir_entry proc_pid_stat = {
 142         PROC_PID_STAT, 4, "stat",
 143         S_IFREG | S_IRUGO, 1, 0, 0,
 144         0, &proc_array_inode_operations,
 145         NULL, proc_pid_fill_inode,
 146 };
 147 static struct proc_dir_entry proc_pid_statm = {
 148         PROC_PID_STATM, 5, "statm",
 149         S_IFREG | S_IRUGO, 1, 0, 0,
 150         0, &proc_array_inode_operations,
 151         NULL, proc_pid_fill_inode,
 152 };
 153 static struct proc_dir_entry proc_pid_maps = {
 154         PROC_PID_MAPS, 4, "maps",
 155         S_IFIFO | S_IRUGO, 1, 0, 0,
 156         0, &proc_arraylong_inode_operations,
 157         NULL, proc_pid_fill_inode,
 158 };
 159
 160 #if CONFIG_AP1000
 161 static struct proc_dir_entry proc_pid_ringbuf = {
 162         PROC_PID_RINGBUF, 7, "ringbuf",
 163         S_IFREG | S_IRUGO | S_IWUSR, 1, 0, 0,
 164         0, &proc_ringbuf_inode_operations,
 165         NULL, proc_pid_fill_inode,
 166 };
 167 #endif
 168
 169 #ifdef __SMP__
 170 static struct proc_dir_entry proc_pid_cpu = {
 171         PROC_PID_CPU, 3, "cpu",
 172         S_IFREG | S_IRUGO, 1, 0, 0,
 173         0, &proc_array_inode_operations,
 174         NULL, proc_pid_fill_inode,
 175 };
 176 #endif
 177
 178 __initfunc(void proc_base_init(void))
 179 {
 180 #if CONFIG_AP1000
 181         proc_register(&proc_pid, &proc_pid_ringbuf);
 182 #endif
 183         proc_register(&proc_pid, &proc_pid_status);
 184         proc_register(&proc_pid, &proc_pid_mem);
 185         proc_register(&proc_pid, &proc_pid_cwd);
 186         proc_register(&proc_pid, &proc_pid_root);
 187         proc_register(&proc_pid, &proc_pid_exe);
 188         proc_register(&proc_pid, &proc_pid_fd);
 189         proc_register(&proc_pid, &proc_pid_environ);
 190         proc_register(&proc_pid, &proc_pid_cmdline);
 191         proc_register(&proc_pid, &proc_pid_stat);
 192         proc_register(&proc_pid, &proc_pid_statm);
 193         proc_register(&proc_pid, &proc_pid_maps);
 194 #ifdef __SMP__
 195         proc_register(&proc_pid, &proc_pid_cpu);
 196 #endif
 197 };
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