i386/linux-2.3.21/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,                   /* get_block */
  49         NULL,                   /* readpage */
  50         NULL,                   /* writepage */
  51         NULL,                   /* flushpage */
  52         NULL,                   /* truncate */
  53         NULL,                   /* permission */
  54         NULL,                   /* smap */
  55         NULL                    /* revalidate */
  56 };
  57
  58 /*
  59  * The fill argument is non-zero when the inode is being filled ...
  60  * we don't need to do anything when it's being deleted.
  61  */
  62 static void proc_pid_fill_inode(struct inode * inode, int fill)
  63 {
  64         struct task_struct *p;
  65         int pid = inode->i_ino >> 16;
  66         int ino = inode->i_ino & 0xffff;
  67
  68         read_lock(&tasklist_lock);
  69         if (fill && (p = find_task_by_pid(pid)) != NULL) {
  70                 uid_t uid = 0;
  71                 gid_t gid = 0;
  72                 if (p->dumpable || ino == PROC_PID_INO) {
  73                         uid = p->euid;
  74                         gid = p->egid;
  75                 }
  76                 inode->i_uid = uid;
  77                 inode->i_gid = gid;
  78         }
  79         read_unlock(&tasklist_lock);
  80 }
  81
  82 /*
  83  * This is really a pseudo-entry, and only links
  84  * backwards to the parent with no link from the
  85  * root directory to this. This way we can have just
  86  * one entry for every /proc/<pid>/ directory.
  87  */
  88 struct proc_dir_entry proc_pid = {
  89         PROC_PID_INO, 5, "<pid>",
  90         S_IFDIR | S_IRUGO | S_IXUGO, 2, 0, 0,
  91         0, &proc_base_inode_operations,
  92         NULL, proc_pid_fill_inode,
  93         NULL, &proc_root, NULL
  94 };
  95
  96 static struct proc_dir_entry proc_pid_status = {
  97         PROC_PID_STATUS, 6, "status",
  98         S_IFREG | S_IRUGO, 1, 0, 0,
  99         0, &proc_array_inode_operations,
 100         NULL, proc_pid_fill_inode,
 101 };
 102 static struct proc_dir_entry proc_pid_mem = {
 103         PROC_PID_MEM, 3, "mem",
 104         S_IFREG | S_IRUSR | S_IWUSR, 1, 0, 0,
 105         0, &proc_mem_inode_operations,
 106         NULL, proc_pid_fill_inode,
 107 };
 108 static struct proc_dir_entry proc_pid_cwd = {
 109         PROC_PID_CWD, 3, "cwd",
 110         S_IFLNK | S_IRWXU, 1, 0, 0,
 111         0, &proc_link_inode_operations,
 112         NULL, proc_pid_fill_inode,
 113 };
 114 static struct proc_dir_entry proc_pid_root = {
 115         PROC_PID_ROOT, 4, "root",
 116         S_IFLNK | S_IRWXU, 1, 0, 0,
 117         0, &proc_link_inode_operations,
 118         NULL, proc_pid_fill_inode,
 119 };
 120 static struct proc_dir_entry proc_pid_exe = {
 121         PROC_PID_EXE, 3, "exe",
 122         S_IFLNK | S_IRWXU, 1, 0, 0,
 123         0, &proc_link_inode_operations,
 124         NULL, proc_pid_fill_inode,
 125 };
 126 static struct proc_dir_entry proc_pid_fd = {
 127         PROC_PID_FD, 2, "fd",
 128         S_IFDIR | S_IRUSR | S_IXUSR, 2, 0, 0,
 129         0, &proc_fd_inode_operations,
 130         NULL, proc_pid_fill_inode,
 131 };
 132 static struct proc_dir_entry proc_pid_environ = {
 133         PROC_PID_ENVIRON, 7, "environ",
 134         S_IFREG | S_IRUSR, 1, 0, 0,
 135         0, &proc_array_inode_operations,
 136         NULL, proc_pid_fill_inode,
 137 };
 138 static struct proc_dir_entry proc_pid_cmdline = {
 139         PROC_PID_CMDLINE, 7, "cmdline",
 140         S_IFREG | S_IRUGO, 1, 0, 0,
 141         0, &proc_array_inode_operations,
 142         NULL, proc_pid_fill_inode,
 143 };
 144 static struct proc_dir_entry proc_pid_stat = {
 145         PROC_PID_STAT, 4, "stat",
 146         S_IFREG | S_IRUGO, 1, 0, 0,
 147         0, &proc_array_inode_operations,
 148         NULL, proc_pid_fill_inode,
 149 };
 150 static struct proc_dir_entry proc_pid_statm = {
 151         PROC_PID_STATM, 5, "statm",
 152         S_IFREG | S_IRUGO, 1, 0, 0,
 153         0, &proc_array_inode_operations,
 154         NULL, proc_pid_fill_inode,
 155 };
 156 static struct proc_dir_entry proc_pid_maps = {
 157         PROC_PID_MAPS, 4, "maps",
 158         S_IFIFO | S_IRUGO, 1, 0, 0,
 159         0, &proc_arraylong_inode_operations,
 160         NULL, proc_pid_fill_inode,
 161 };
 162
 163 #if CONFIG_AP1000
 164 static struct proc_dir_entry proc_pid_ringbuf = {
 165         PROC_PID_RINGBUF, 7, "ringbuf",
 166         S_IFREG | S_IRUGO | S_IWUSR, 1, 0, 0,
 167         0, &proc_ringbuf_inode_operations,
 168         NULL, proc_pid_fill_inode,
 169 };
 170 #endif
 171
 172 #ifdef __SMP__
 173 static struct proc_dir_entry proc_pid_cpu = {
 174         PROC_PID_CPU, 3, "cpu",
 175         S_IFREG | S_IRUGO, 1, 0, 0,
 176         0, &proc_array_inode_operations,
 177         NULL, proc_pid_fill_inode,
 178 };
 179 #endif
 180
 181 void __init proc_base_init(void)
 182 {
 183 #if CONFIG_AP1000
 184         proc_register(&proc_pid, &proc_pid_ringbuf);
 185 #endif
 186         proc_register(&proc_pid, &proc_pid_status);
 187         proc_register(&proc_pid, &proc_pid_mem);
 188         proc_register(&proc_pid, &proc_pid_cwd);
 189         proc_register(&proc_pid, &proc_pid_root);
 190         proc_register(&proc_pid, &proc_pid_exe);
 191         proc_register(&proc_pid, &proc_pid_fd);
 192         proc_register(&proc_pid, &proc_pid_environ);
 193         proc_register(&proc_pid, &proc_pid_cmdline);
 194         proc_register(&proc_pid, &proc_pid_stat);
 195         proc_register(&proc_pid, &proc_pid_statm);
 196         proc_register(&proc_pid, &proc_pid_maps);
 197 #ifdef __SMP__
 198         proc_register(&proc_pid, &proc_pid_cpu);
 199 #endif
 200 };
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