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  *  1999, Al Viro. Rewritten. Now it covers the whole per-process part.
   9  *  Instead of using magical inumbers to determine the kind of object
  10  *  we allocate and fill in-core inodes upon lookup. They don't even
  11  *  go into icache. We cache the reference to task_struct upon lookup too.
  12  *  Eventually it should become a filesystem in its own. We don't use the
  13  *  rest of procfs anymore.
  14  *
  15  *
  16  *  Changelog:
  17  *  17-Jan-2005
  18  *  Allan Bezerra
  19  *  Bruna Moreira <bruna.moreira@indt.org.br>
  20  *  Edjard Mota <edjard.mota@indt.org.br>
  21  *  Ilias Biris <ilias.biris@indt.org.br>
  22  *  Mauricio Lin <mauricio.lin@indt.org.br>
  23  *
  24  *  Embedded Linux Lab - 10LE Instituto Nokia de Tecnologia - INdT
  25  *
  26  *  A new process specific entry (smaps) included in /proc. It shows the
  27  *  size of rss for each memory area. The maps entry lacks information
  28  *  about physical memory size (rss) for each mapped file, i.e.,
  29  *  rss information for executables and library files.
  30  *  This additional information is useful for any tools that need to know
  31  *  about physical memory consumption for a process specific library.
  32  *
  33  *  Changelog:
  34  *  21-Feb-2005
  35  *  Embedded Linux Lab - 10LE Instituto Nokia de Tecnologia - INdT
  36  *  Pud inclusion in the page table walking.
  37  *
  38  *  ChangeLog:
  39  *  10-Mar-2005
  40  *  10LE Instituto Nokia de Tecnologia - INdT:
  41  *  A better way to walks through the page table as suggested by Hugh Dickins.
  42  *
  43  *  Simo Piiroinen <simo.piiroinen@nokia.com>:
  44  *  Smaps information related to shared, private, clean and dirty pages.
  45  *
  46  *  Paul Mundt <paul.mundt@nokia.com>:
  47  *  Overall revision about smaps.
  48  */
  49
  50 #include <asm/uaccess.h>
  51
  52 #include <linux/config.h>
  53 #include <linux/errno.h>
  54 #include <linux/time.h>
  55 #include <linux/proc_fs.h>
  56 #include <linux/stat.h>
  57 #include <linux/init.h>
  58 #include <linux/capability.h>
  59 #include <linux/file.h>
  60 #include <linux/string.h>
  61 #include <linux/seq_file.h>
  62 #include <linux/namei.h>
  63 #include <linux/namespace.h>
  64 #include <linux/mm.h>
  65 #include <linux/smp_lock.h>
  66 #include <linux/rcupdate.h>
  67 #include <linux/kallsyms.h>
  68 #include <linux/mount.h>
  69 #include <linux/security.h>
  70 #include <linux/ptrace.h>
  71 #include <linux/seccomp.h>
  72 #include <linux/cpuset.h>
  73 #include <linux/audit.h>
  74 #include <linux/poll.h>
  75 #include "internal.h"
  76
  77 /*
  78  * For hysterical raisins we keep the same inumbers as in the old procfs.
  79  * Feel free to change the macro below - just keep the range distinct from
  80  * inumbers of the rest of procfs (currently those are in 0x0000--0xffff).
  81  * As soon as we'll get a separate superblock we will be able to forget
  82  * about magical ranges too.
  83  */
  84
  85 #define fake_ino(pid,ino) (((pid)<<16)|(ino))
  86
  87 enum pid_directory_inos {
  88         PROC_TGID_INO = 2,
  89         PROC_TGID_TASK,
  90         PROC_TGID_STATUS,
  91         PROC_TGID_MEM,
  92 #ifdef CONFIG_SECCOMP
  93         PROC_TGID_SECCOMP,
  94 #endif
  95         PROC_TGID_CWD,
  96         PROC_TGID_ROOT,
  97         PROC_TGID_EXE,
  98         PROC_TGID_FD,
  99         PROC_TGID_ENVIRON,
 100         PROC_TGID_AUXV,
 101         PROC_TGID_CMDLINE,
 102         PROC_TGID_STAT,
 103         PROC_TGID_STATM,
 104         PROC_TGID_MAPS,
 105         PROC_TGID_NUMA_MAPS,
 106         PROC_TGID_MOUNTS,
 107         PROC_TGID_MOUNTSTATS,
 108         PROC_TGID_WCHAN,
 109 #ifdef CONFIG_MMU
 110         PROC_TGID_SMAPS,
 111 #endif
 112 #ifdef CONFIG_SCHEDSTATS
 113         PROC_TGID_SCHEDSTAT,
 114 #endif
 115 #ifdef CONFIG_CPUSETS
 116         PROC_TGID_CPUSET,
 117 #endif
 118 #ifdef CONFIG_SECURITY
 119         PROC_TGID_ATTR,
 120         PROC_TGID_ATTR_CURRENT,
 121         PROC_TGID_ATTR_PREV,
 122         PROC_TGID_ATTR_EXEC,
 123         PROC_TGID_ATTR_FSCREATE,
 124         PROC_TGID_ATTR_KEYCREATE,
 125 #endif
 126 #ifdef CONFIG_AUDITSYSCALL
 127         PROC_TGID_LOGINUID,
 128 #endif
 129         PROC_TGID_OOM_SCORE,
 130         PROC_TGID_OOM_ADJUST,
 131         PROC_TID_INO,
 132         PROC_TID_STATUS,
 133         PROC_TID_MEM,
 134 #ifdef CONFIG_SECCOMP
 135         PROC_TID_SECCOMP,
 136 #endif
 137         PROC_TID_CWD,
 138         PROC_TID_ROOT,
 139         PROC_TID_EXE,
 140         PROC_TID_FD,
 141         PROC_TID_ENVIRON,
 142         PROC_TID_AUXV,
 143         PROC_TID_CMDLINE,
 144         PROC_TID_STAT,
 145         PROC_TID_STATM,
 146         PROC_TID_MAPS,
 147         PROC_TID_NUMA_MAPS,
 148         PROC_TID_MOUNTS,
 149         PROC_TID_MOUNTSTATS,
 150         PROC_TID_WCHAN,
 151 #ifdef CONFIG_MMU
 152         PROC_TID_SMAPS,
 153 #endif
 154 #ifdef CONFIG_SCHEDSTATS
 155         PROC_TID_SCHEDSTAT,
 156 #endif
 157 #ifdef CONFIG_CPUSETS
 158         PROC_TID_CPUSET,
 159 #endif
 160 #ifdef CONFIG_SECURITY
 161         PROC_TID_ATTR,
 162         PROC_TID_ATTR_CURRENT,
 163         PROC_TID_ATTR_PREV,
 164         PROC_TID_ATTR_EXEC,
 165         PROC_TID_ATTR_FSCREATE,
 166         PROC_TID_ATTR_KEYCREATE,
 167 #endif
 168 #ifdef CONFIG_AUDITSYSCALL
 169         PROC_TID_LOGINUID,
 170 #endif
 171         PROC_TID_OOM_SCORE,
 172         PROC_TID_OOM_ADJUST,
 173
 174         /* Add new entries before this */
 175         PROC_TID_FD_DIR = 0x8000,       /* 0x8000-0xffff */
 176 };
 177
 178 struct pid_entry {
 179         int type;
 180         int len;
 181         char *name;
 182         mode_t mode;
 183 };
 184
 185 #define E(type,name,mode) {(type),sizeof(name)-1,(name),(mode)}
 186
 187 static struct pid_entry tgid_base_stuff[] = {
 188         E(PROC_TGID_TASK,      "task",    S_IFDIR|S_IRUGO|S_IXUGO),
 189         E(PROC_TGID_FD,        "fd",      S_IFDIR|S_IRUSR|S_IXUSR),
 190         E(PROC_TGID_ENVIRON,   "environ", S_IFREG|S_IRUSR),
 191         E(PROC_TGID_AUXV,      "auxv",    S_IFREG|S_IRUSR),
 192         E(PROC_TGID_STATUS,    "status",  S_IFREG|S_IRUGO),
 193         E(PROC_TGID_CMDLINE,   "cmdline", S_IFREG|S_IRUGO),
 194         E(PROC_TGID_STAT,      "stat",    S_IFREG|S_IRUGO),
 195         E(PROC_TGID_STATM,     "statm",   S_IFREG|S_IRUGO),
 196         E(PROC_TGID_MAPS,      "maps",    S_IFREG|S_IRUGO),
 197 #ifdef CONFIG_NUMA
 198         E(PROC_TGID_NUMA_MAPS, "numa_maps", S_IFREG|S_IRUGO),
 199 #endif
 200         E(PROC_TGID_MEM,       "mem",     S_IFREG|S_IRUSR|S_IWUSR),
 201 #ifdef CONFIG_SECCOMP
 202         E(PROC_TGID_SECCOMP,   "seccomp", S_IFREG|S_IRUSR|S_IWUSR),
 203 #endif
 204         E(PROC_TGID_CWD,       "cwd",     S_IFLNK|S_IRWXUGO),
 205         E(PROC_TGID_ROOT,      "root",    S_IFLNK|S_IRWXUGO),
 206         E(PROC_TGID_EXE,       "exe",     S_IFLNK|S_IRWXUGO),
 207         E(PROC_TGID_MOUNTS,    "mounts",  S_IFREG|S_IRUGO),
 208         E(PROC_TGID_MOUNTSTATS, "mountstats", S_IFREG|S_IRUSR),
 209 #ifdef CONFIG_MMU
 210         E(PROC_TGID_SMAPS,     "smaps",   S_IFREG|S_IRUGO),
 211 #endif
 212 #ifdef CONFIG_SECURITY
 213         E(PROC_TGID_ATTR,      "attr",    S_IFDIR|S_IRUGO|S_IXUGO),
 214 #endif
 215 #ifdef CONFIG_KALLSYMS
 216         E(PROC_TGID_WCHAN,     "wchan",   S_IFREG|S_IRUGO),
 217 #endif
 218 #ifdef CONFIG_SCHEDSTATS
 219         E(PROC_TGID_SCHEDSTAT, "schedstat", S_IFREG|S_IRUGO),
 220 #endif
 221 #ifdef CONFIG_CPUSETS
 222         E(PROC_TGID_CPUSET,    "cpuset",  S_IFREG|S_IRUGO),
 223 #endif
 224         E(PROC_TGID_OOM_SCORE, "oom_score",S_IFREG|S_IRUGO),
 225         E(PROC_TGID_OOM_ADJUST,"oom_adj", S_IFREG|S_IRUGO|S_IWUSR),
 226 #ifdef CONFIG_AUDITSYSCALL
 227         E(PROC_TGID_LOGINUID, "loginuid", S_IFREG|S_IWUSR|S_IRUGO),
 228 #endif
 229         {0,0,NULL,0}
 230 };
 231 static struct pid_entry tid_base_stuff[] = {
 232         E(PROC_TID_FD,         "fd",      S_IFDIR|S_IRUSR|S_IXUSR),
 233         E(PROC_TID_ENVIRON,    "environ", S_IFREG|S_IRUSR),
 234         E(PROC_TID_AUXV,       "auxv",    S_IFREG|S_IRUSR),
 235         E(PROC_TID_STATUS,     "status",  S_IFREG|S_IRUGO),
 236         E(PROC_TID_CMDLINE,    "cmdline", S_IFREG|S_IRUGO),
 237         E(PROC_TID_STAT,       "stat",    S_IFREG|S_IRUGO),
 238         E(PROC_TID_STATM,      "statm",   S_IFREG|S_IRUGO),
 239         E(PROC_TID_MAPS,       "maps",    S_IFREG|S_IRUGO),
 240 #ifdef CONFIG_NUMA
 241         E(PROC_TID_NUMA_MAPS,  "numa_maps",    S_IFREG|S_IRUGO),
 242 #endif
 243         E(PROC_TID_MEM,        "mem",     S_IFREG|S_IRUSR|S_IWUSR),
 244 #ifdef CONFIG_SECCOMP
 245         E(PROC_TID_SECCOMP,    "seccomp", S_IFREG|S_IRUSR|S_IWUSR),
 246 #endif
 247         E(PROC_TID_CWD,        "cwd",     S_IFLNK|S_IRWXUGO),
 248         E(PROC_TID_ROOT,       "root",    S_IFLNK|S_IRWXUGO),
 249         E(PROC_TID_EXE,        "exe",     S_IFLNK|S_IRWXUGO),
 250         E(PROC_TID_MOUNTS,     "mounts",  S_IFREG|S_IRUGO),
 251 #ifdef CONFIG_MMU
 252         E(PROC_TID_SMAPS,      "smaps",   S_IFREG|S_IRUGO),
 253 #endif
 254 #ifdef CONFIG_SECURITY
 255         E(PROC_TID_ATTR,       "attr",    S_IFDIR|S_IRUGO|S_IXUGO),
 256 #endif
 257 #ifdef CONFIG_KALLSYMS
 258         E(PROC_TID_WCHAN,      "wchan",   S_IFREG|S_IRUGO),
 259 #endif
 260 #ifdef CONFIG_SCHEDSTATS
 261         E(PROC_TID_SCHEDSTAT, "schedstat",S_IFREG|S_IRUGO),
 262 #endif
 263 #ifdef CONFIG_CPUSETS
 264         E(PROC_TID_CPUSET,     "cpuset",  S_IFREG|S_IRUGO),
 265 #endif
 266         E(PROC_TID_OOM_SCORE,  "oom_score",S_IFREG|S_IRUGO),
 267         E(PROC_TID_OOM_ADJUST, "oom_adj", S_IFREG|S_IRUGO|S_IWUSR),
 268 #ifdef CONFIG_AUDITSYSCALL
 269         E(PROC_TID_LOGINUID, "loginuid", S_IFREG|S_IWUSR|S_IRUGO),
 270 #endif
 271         {0,0,NULL,0}
 272 };
 273
 274 #ifdef CONFIG_SECURITY
 275 static struct pid_entry tgid_attr_stuff[] = {
 276         E(PROC_TGID_ATTR_CURRENT,  "current",  S_IFREG|S_IRUGO|S_IWUGO),
 277         E(PROC_TGID_ATTR_PREV,     "prev",     S_IFREG|S_IRUGO),
 278         E(PROC_TGID_ATTR_EXEC,     "exec",     S_IFREG|S_IRUGO|S_IWUGO),
 279         E(PROC_TGID_ATTR_FSCREATE, "fscreate", S_IFREG|S_IRUGO|S_IWUGO),
 280         E(PROC_TGID_ATTR_KEYCREATE, "keycreate", S_IFREG|S_IRUGO|S_IWUGO),
 281         {0,0,NULL,0}
 282 };
 283 static struct pid_entry tid_attr_stuff[] = {
 284         E(PROC_TID_ATTR_CURRENT,   "current",  S_IFREG|S_IRUGO|S_IWUGO),
 285         E(PROC_TID_ATTR_PREV,      "prev",     S_IFREG|S_IRUGO),
 286         E(PROC_TID_ATTR_EXEC,      "exec",     S_IFREG|S_IRUGO|S_IWUGO),
 287         E(PROC_TID_ATTR_FSCREATE,  "fscreate", S_IFREG|S_IRUGO|S_IWUGO),
 288         E(PROC_TID_ATTR_KEYCREATE, "keycreate", S_IFREG|S_IRUGO|S_IWUGO),
 289         {0,0,NULL,0}
 290 };
 291 #endif
 292
 293 #undef E
 294
 295 static int proc_fd_link(struct inode *inode, struct dentry **dentry, struct vfsmount **mnt)
 296 {
 297         struct task_struct *task = proc_task(inode);
 298         struct files_struct *files;
 299         struct file *file;
 300         int fd = proc_type(inode) - PROC_TID_FD_DIR;
 301
 302         files = get_files_struct(task);
 303         if (files) {
 304                 /*
 305                  * We are not taking a ref to the file structure, so we must
 306                  * hold ->file_lock.
 307                  */
 308                 spin_lock(&files->file_lock);
 309                 file = fcheck_files(files, fd);
 310                 if (file) {
 311                         *mnt = mntget(file->f_vfsmnt);
 312                         *dentry = dget(file->f_dentry);
 313                         spin_unlock(&files->file_lock);
 314                         put_files_struct(files);
 315                         return 0;
 316                 }
 317                 spin_unlock(&files->file_lock);
 318                 put_files_struct(files);
 319         }
 320         return -ENOENT;
 321 }
 322
 323 static struct fs_struct *get_fs_struct(struct task_struct *task)
 324 {
 325         struct fs_struct *fs;
 326         task_lock(task);
 327         fs = task->fs;
 328         if(fs)
 329                 atomic_inc(&fs->count);
 330         task_unlock(task);
 331         return fs;
 332 }
 333
 334 static int proc_cwd_link(struct inode *inode, struct dentry **dentry, struct vfsmount **mnt)
 335 {
 336         struct fs_struct *fs = get_fs_struct(proc_task(inode));
 337         int result = -ENOENT;
 338         if (fs) {
 339                 read_lock(&fs->lock);
 340                 *mnt = mntget(fs->pwdmnt);
 341                 *dentry = dget(fs->pwd);
 342                 read_unlock(&fs->lock);
 343                 result = 0;
 344                 put_fs_struct(fs);
 345         }
 346         return result;
 347 }
 348
 349 static int proc_root_link(struct inode *inode, struct dentry **dentry, struct vfsmount **mnt)
 350 {
 351         struct fs_struct *fs = get_fs_struct(proc_task(inode));
 352         int result = -ENOENT;
 353         if (fs) {
 354                 read_lock(&fs->lock);
 355                 *mnt = mntget(fs->rootmnt);
 356                 *dentry = dget(fs->root);
 357                 read_unlock(&fs->lock);
 358                 result = 0;
 359                 put_fs_struct(fs);
 360         }
 361         return result;
 362 }
 363
 364
 365 /* Same as proc_root_link, but this addionally tries to get fs from other
 366  * threads in the group */
 367 static int proc_task_root_link(struct inode *inode, struct dentry **dentry,
 368                                 struct vfsmount **mnt)
 369 {
 370         struct fs_struct *fs;
 371         int result = -ENOENT;
 372         struct task_struct *leader = proc_task(inode);
 373
 374         task_lock(leader);
 375         fs = leader->fs;
 376         if (fs) {
 377                 atomic_inc(&fs->count);
 378                 task_unlock(leader);
 379         } else {
 380                 /* Try to get fs from other threads */
 381                 task_unlock(leader);
 382                 read_lock(&tasklist_lock);
 383                 if (pid_alive(leader)) {
 384                         struct task_struct *task = leader;
 385
 386                         while ((task = next_thread(task)) != leader) {
 387                                 task_lock(task);
 388                                 fs = task->fs;
 389                                 if (fs) {
 390                                         atomic_inc(&fs->count);
 391                                         task_unlock(task);
 392                                         break;
 393                                 }
 394                                 task_unlock(task);
 395                         }
 396                 }
 397                 read_unlock(&tasklist_lock);
 398         }
 399
 400         if (fs) {
 401                 read_lock(&fs->lock);
 402                 *mnt = mntget(fs->rootmnt);
 403                 *dentry = dget(fs->root);
 404                 read_unlock(&fs->lock);
 405                 result = 0;
 406                 put_fs_struct(fs);
 407         }
 408         return result;
 409 }
 410
 411
 412 #define MAY_PTRACE(task) \
 413         (task == current || \
 414         (task->parent == current && \
 415         (task->ptrace & PT_PTRACED) && \
 416          (task->state == TASK_STOPPED || task->state == TASK_TRACED) && \
 417          security_ptrace(current,task) == 0))
 418
 419 static int proc_pid_environ(struct task_struct *task, char * buffer)
 420 {
 421         int res = 0;
 422         struct mm_struct *mm = get_task_mm(task);
 423         if (mm) {
 424                 unsigned int len = mm->env_end - mm->env_start;
 425                 if (len > PAGE_SIZE)
 426                         len = PAGE_SIZE;
 427                 res = access_process_vm(task, mm->env_start, buffer, len, 0);
 428                 if (!ptrace_may_attach(task))
 429                         res = -ESRCH;
 430                 mmput(mm);
 431         }
 432         return res;
 433 }
 434
 435 static int proc_pid_cmdline(struct task_struct *task, char * buffer)
 436 {
 437         int res = 0;
 438         unsigned int len;
 439         struct mm_struct *mm = get_task_mm(task);
 440         if (!mm)
 441                 goto out;
 442         if (!mm->arg_end)
 443                 goto out_mm;    /* Shh! No looking before we're done */
 444
 445         len = mm->arg_end - mm->arg_start;
 446
 447         if (len > PAGE_SIZE)
 448                 len = PAGE_SIZE;
 449
 450         res = access_process_vm(task, mm->arg_start, buffer, len, 0);
 451
 452         // If the nul at the end of args has been overwritten, then
 453         // assume application is using setproctitle(3).
 454         if (res > 0 && buffer[res-1] != '\0' && len < PAGE_SIZE) {
 455                 len = strnlen(buffer, res);
 456                 if (len < res) {
 457                     res = len;
 458                 } else {
 459                         len = mm->env_end - mm->env_start;
 460                         if (len > PAGE_SIZE - res)
 461                                 len = PAGE_SIZE - res;
 462                         res += access_process_vm(task, mm->env_start, buffer+res, len, 0);
 463                         res = strnlen(buffer, res);
 464                 }
 465         }
 466 out_mm:
 467         mmput(mm);
 468 out:
 469         return res;
 470 }
 471
 472 static int proc_pid_auxv(struct task_struct *task, char *buffer)
 473 {
 474         int res = 0;
 475         struct mm_struct *mm = get_task_mm(task);
 476         if (mm) {
 477                 unsigned int nwords = 0;
 478                 do
 479                         nwords += 2;
 480                 while (mm->saved_auxv[nwords - 2] != 0); /* AT_NULL */
 481                 res = nwords * sizeof(mm->saved_auxv[0]);
 482                 if (res > PAGE_SIZE)
 483                         res = PAGE_SIZE;
 484                 memcpy(buffer, mm->saved_auxv, res);
 485                 mmput(mm);
 486         }
 487         return res;
 488 }
 489
 490
 491 #ifdef CONFIG_KALLSYMS
 492 /*
 493  * Provides a wchan file via kallsyms in a proper one-value-per-file format.
 494  * Returns the resolved symbol.  If that fails, simply return the address.
 495  */
 496 static int proc_pid_wchan(struct task_struct *task, char *buffer)
 497 {
 498         char *modname;
 499         const char *sym_name;
 500         unsigned long wchan, size, offset;
 501         char namebuf[KSYM_NAME_LEN+1];
 502
 503         wchan = get_wchan(task);
 504
 505         sym_name = kallsyms_lookup(wchan, &size, &offset, &modname, namebuf);
 506         if (sym_name)
 507                 return sprintf(buffer, "%s", sym_name);
 508         return sprintf(buffer, "%lu", wchan);
 509 }
 510 #endif /* CONFIG_KALLSYMS */
 511
 512 #ifdef CONFIG_SCHEDSTATS
 513 /*
 514  * Provides /proc/PID/schedstat
 515  */
 516 static int proc_pid_schedstat(struct task_struct *task, char *buffer)
 517 {
 518         return sprintf(buffer, "%lu %lu %lu\n",
 519                         task->sched_info.cpu_time,
 520                         task->sched_info.run_delay,
 521                         task->sched_info.pcnt);
 522 }
 523 #endif
 524
 525 /* The badness from the OOM killer */
 526 unsigned long badness(struct task_struct *p, unsigned long uptime);
 527 static int proc_oom_score(struct task_struct *task, char *buffer)
 528 {
 529         unsigned long points;
 530         struct timespec uptime;
 531
 532         do_posix_clock_monotonic_gettime(&uptime);
 533         points = badness(task, uptime.tv_sec);
 534         return sprintf(buffer, "%lu\n", points);
 535 }
 536
 537 /************************************************************************/
 538 /*                       Here the fs part begins                        */
 539 /************************************************************************/
 540
 541 /* permission checks */
 542
 543 /* If the process being read is separated by chroot from the reading process,
 544  * don't let the reader access the threads.
 545  *
 546  * note: this does dput(root) and mntput(vfsmnt) on exit.
 547  */
 548 static int proc_check_chroot(struct dentry *root, struct vfsmount *vfsmnt)
 549 {
 550         struct dentry *de, *base;
 551         struct vfsmount *our_vfsmnt, *mnt;
 552         int res = 0;
 553
 554         read_lock(&current->fs->lock);
 555         our_vfsmnt = mntget(current->fs->rootmnt);
 556         base = dget(current->fs->root);
 557         read_unlock(&current->fs->lock);
 558
 559         spin_lock(&vfsmount_lock);
 560         de = root;
 561         mnt = vfsmnt;
 562
 563         while (mnt != our_vfsmnt) {
 564                 if (mnt == mnt->mnt_parent)
 565                         goto out;
 566                 de = mnt->mnt_mountpoint;
 567                 mnt = mnt->mnt_parent;
 568         }
 569
 570         if (!is_subdir(de, base))
 571                 goto out;
 572         spin_unlock(&vfsmount_lock);
 573
 574 exit:
 575         dput(base);
 576         mntput(our_vfsmnt);
 577         dput(root);
 578         mntput(vfsmnt);
 579         return res;
 580 out:
 581         spin_unlock(&vfsmount_lock);
 582         res = -EACCES;
 583         goto exit;
 584 }
 585
 586 static int proc_check_root(struct inode *inode)
 587 {
 588         struct dentry *root;
 589         struct vfsmount *vfsmnt;
 590
 591         if (proc_root_link(inode, &root, &vfsmnt)) /* Ewww... */
 592                 return -ENOENT;
 593         return proc_check_chroot(root, vfsmnt);
 594 }
 595
 596 static int proc_permission(struct inode *inode, int mask, struct nameidata *nd)
 597 {
 598         if (generic_permission(inode, mask, NULL) != 0)
 599                 return -EACCES;
 600         return proc_check_root(inode);
 601 }
 602
 603 static int proc_task_permission(struct inode *inode, int mask, struct nameidata *nd)
 604 {
 605         struct dentry *root;
 606         struct vfsmount *vfsmnt;
 607
 608         if (generic_permission(inode, mask, NULL) != 0)
 609                 return -EACCES;
 610
 611         if (proc_task_root_link(inode, &root, &vfsmnt))
 612                 return -ENOENT;
 613
 614         return proc_check_chroot(root, vfsmnt);
 615 }
 616
 617 extern struct seq_operations proc_pid_maps_op;
 618 static int maps_open(struct inode *inode, struct file *file)
 619 {
 620         struct task_struct *task = proc_task(inode);
 621         int ret = seq_open(file, &proc_pid_maps_op);
 622         if (!ret) {
 623                 struct seq_file *m = file->private_data;
 624                 m->private = task;
 625         }
 626         return ret;
 627 }
 628
 629 static struct file_operations proc_maps_operations = {
 630         .open           = maps_open,
 631         .read           = seq_read,
 632         .llseek         = seq_lseek,
 633         .release        = seq_release,
 634 };
 635
 636 #ifdef CONFIG_NUMA
 637 extern struct seq_operations proc_pid_numa_maps_op;
 638 static int numa_maps_open(struct inode *inode, struct file *file)
 639 {
 640         struct task_struct *task = proc_task(inode);
 641         int ret = seq_open(file, &proc_pid_numa_maps_op);
 642         if (!ret) {
 643                 struct seq_file *m = file->private_data;
 644                 m->private = task;
 645         }
 646         return ret;
 647 }
 648
 649 static struct file_operations proc_numa_maps_operations = {
 650         .open           = numa_maps_open,
 651         .read           = seq_read,
 652         .llseek         = seq_lseek,
 653         .release        = seq_release,
 654 };
 655 #endif
 656
 657 #ifdef CONFIG_MMU
 658 extern struct seq_operations proc_pid_smaps_op;
 659 static int smaps_open(struct inode *inode, struct file *file)
 660 {
 661         struct task_struct *task = proc_task(inode);
 662         int ret = seq_open(file, &proc_pid_smaps_op);
 663         if (!ret) {
 664                 struct seq_file *m = file->private_data;
 665                 m->private = task;
 666         }
 667         return ret;
 668 }
 669
 670 static struct file_operations proc_smaps_operations = {
 671         .open           = smaps_open,
 672         .read           = seq_read,
 673         .llseek         = seq_lseek,
 674         .release        = seq_release,
 675 };
 676 #endif
 677
 678 extern struct seq_operations mounts_op;
 679 struct proc_mounts {
 680         struct seq_file m;
 681         int event;
 682 };
 683
 684 static int mounts_open(struct inode *inode, struct file *file)
 685 {
 686         struct task_struct *task = proc_task(inode);
 687         struct namespace *namespace;
 688         struct proc_mounts *p;
 689         int ret = -EINVAL;
 690
 691         task_lock(task);
 692         namespace = task->namespace;
 693         if (namespace)
 694                 get_namespace(namespace);
 695         task_unlock(task);
 696
 697         if (namespace) {
 698                 ret = -ENOMEM;
 699                 p = kmalloc(sizeof(struct proc_mounts), GFP_KERNEL);
 700                 if (p) {
 701                         file->private_data = &p->m;
 702                         ret = seq_open(file, &mounts_op);
 703                         if (!ret) {
 704                                 p->m.private = namespace;
 705                                 p->event = namespace->event;
 706                                 return 0;
 707                         }
 708                         kfree(p);
 709                 }
 710                 put_namespace(namespace);
 711         }
 712         return ret;
 713 }
 714
 715 static int mounts_release(struct inode *inode, struct file *file)
 716 {
 717         struct seq_file *m = file->private_data;
 718         struct namespace *namespace = m->private;
 719         put_namespace(namespace);
 720         return seq_release(inode, file);
 721 }
 722
 723 static unsigned mounts_poll(struct file *file, poll_table *wait)
 724 {
 725         struct proc_mounts *p = file->private_data;
 726         struct namespace *ns = p->m.private;
 727         unsigned res = 0;
 728
 729         poll_wait(file, &ns->poll, wait);
 730
 731         spin_lock(&vfsmount_lock);
 732         if (p->event != ns->event) {
 733                 p->event = ns->event;
 734                 res = POLLERR;
 735         }
 736         spin_unlock(&vfsmount_lock);
 737
 738         return res;
 739 }
 740
 741 static struct file_operations proc_mounts_operations = {
 742         .open           = mounts_open,
 743         .read           = seq_read,
 744         .llseek         = seq_lseek,
 745         .release        = mounts_release,
 746         .poll           = mounts_poll,
 747 };
 748
 749 extern struct seq_operations mountstats_op;
 750 static int mountstats_open(struct inode *inode, struct file *file)
 751 {
 752         struct task_struct *task = proc_task(inode);
 753         int ret = seq_open(file, &mountstats_op);
 754
 755         if (!ret) {
 756                 struct seq_file *m = file->private_data;
 757                 struct namespace *namespace;
 758                 task_lock(task);
 759                 namespace = task->namespace;
 760                 if (namespace)
 761                         get_namespace(namespace);
 762                 task_unlock(task);
 763
 764                 if (namespace)
 765                         m->private = namespace;
 766                 else {
 767                         seq_release(inode, file);
 768                         ret = -EINVAL;
 769                 }
 770         }
 771         return ret;
 772 }
 773
 774 static struct file_operations proc_mountstats_operations = {
 775         .open           = mountstats_open,
 776         .read           = seq_read,
 777         .llseek         = seq_lseek,
 778         .release        = mounts_release,
 779 };
 780
 781 #define PROC_BLOCK_SIZE (3*1024)                /* 4K page size but our output routines use some slack for overruns */
 782
 783 static ssize_t proc_info_read(struct file * file, char __user * buf,
 784                           size_t count, loff_t *ppos)
 785 {
 786         struct inode * inode = file->f_dentry->d_inode;
 787         unsigned long page;
 788         ssize_t length;
 789         struct task_struct *task = proc_task(inode);
 790
 791         if (count > PROC_BLOCK_SIZE)
 792                 count = PROC_BLOCK_SIZE;
 793         if (!(page = __get_free_page(GFP_KERNEL)))
 794                 return -ENOMEM;
 795
 796         length = PROC_I(inode)->op.proc_read(task, (char*)page);
 797
 798         if (length >= 0)
 799                 length = simple_read_from_buffer(buf, count, ppos, (char *)page, length);
 800         free_page(page);
 801         return length;
 802 }
 803
 804 static struct file_operations proc_info_file_operations = {
 805         .read           = proc_info_read,
 806 };
 807
 808 static int mem_open(struct inode* inode, struct file* file)
 809 {
 810         file->private_data = (void*)((long)current->self_exec_id);
 811         return 0;
 812 }
 813
 814 static ssize_t mem_read(struct file * file, char __user * buf,
 815                         size_t count, loff_t *ppos)
 816 {
 817         struct task_struct *task = proc_task(file->f_dentry->d_inode);
 818         char *page;
 819         unsigned long src = *ppos;
 820         int ret = -ESRCH;
 821         struct mm_struct *mm;
 822
 823         if (!MAY_PTRACE(task) || !ptrace_may_attach(task))
 824                 goto out;
 825
 826         ret = -ENOMEM;
 827         page = (char *)__get_free_page(GFP_USER);
 828         if (!page)
 829                 goto out;
 830
 831         ret = 0;
 832
 833         mm = get_task_mm(task);
 834         if (!mm)
 835                 goto out_free;
 836
 837         ret = -EIO;
 838
 839         if (file->private_data != (void*)((long)current->self_exec_id))
 840                 goto out_put;
 841
 842         ret = 0;
 843
 844         while (count > 0) {
 845                 int this_len, retval;
 846
 847                 this_len = (count > PAGE_SIZE) ? PAGE_SIZE : count;
 848                 retval = access_process_vm(task, src, page, this_len, 0);
 849                 if (!retval || !MAY_PTRACE(task) || !ptrace_may_attach(task)) {
 850                         if (!ret)
 851                                 ret = -EIO;
 852                         break;
 853                 }
 854
 855                 if (copy_to_user(buf, page, retval)) {
 856                         ret = -EFAULT;
 857                         break;
 858                 }
 859
 860                 ret += retval;
 861                 src += retval;
 862                 buf += retval;
 863                 count -= retval;
 864         }
 865         *ppos = src;
 866
 867 out_put:
 868         mmput(mm);
 869 out_free:
 870         free_page((unsigned long) page);
 871 out:
 872         return ret;
 873 }
 874
 875 #define mem_write NULL
 876
 877 #ifndef mem_write
 878 /* This is a security hazard */
 879 static ssize_t mem_write(struct file * file, const char * buf,
 880                          size_t count, loff_t *ppos)
 881 {
 882         int copied = 0;
 883         char *page;
 884         struct task_struct *task = proc_task(file->f_dentry->d_inode);
 885         unsigned long dst = *ppos;
 886
 887         if (!MAY_PTRACE(task) || !ptrace_may_attach(task))
 888                 return -ESRCH;
 889
 890         page = (char *)__get_free_page(GFP_USER);
 891         if (!page)
 892                 return -ENOMEM;
 893
 894         while (count > 0) {
 895                 int this_len, retval;
 896
 897                 this_len = (count > PAGE_SIZE) ? PAGE_SIZE : count;
 898                 if (copy_from_user(page, buf, this_len)) {
 899                         copied = -EFAULT;
 900                         break;
 901                 }
 902                 retval = access_process_vm(task, dst, page, this_len, 1);
 903                 if (!retval) {
 904                         if (!copied)
 905                                 copied = -EIO;
 906                         break;
 907                 }
 908                 copied += retval;
 909                 buf += retval;
 910                 dst += retval;
 911                 count -= retval;
 912         }
 913         *ppos = dst;
 914         free_page((unsigned long) page);
 915         return copied;
 916 }
 917 #endif
 918
 919 static loff_t mem_lseek(struct file * file, loff_t offset, int orig)
 920 {
 921         switch (orig) {
 922         case 0:
 923                 file->f_pos = offset;
 924                 break;
 925         case 1:
 926                 file->f_pos += offset;
 927                 break;
 928         default:
 929                 return -EINVAL;
 930         }
 931         force_successful_syscall_return();
 932         return file->f_pos;
 933 }
 934
 935 static struct file_operations proc_mem_operations = {
 936         .llseek         = mem_lseek,
 937         .read           = mem_read,
 938         .write          = mem_write,
 939         .open           = mem_open,
 940 };
 941
 942 static ssize_t oom_adjust_read(struct file *file, char __user *buf,
 943                                 size_t count, loff_t *ppos)
 944 {
 945         struct task_struct *task = proc_task(file->f_dentry->d_inode);
 946         char buffer[8];
 947         size_t len;
 948         int oom_adjust = task->oomkilladj;
 949         loff_t __ppos = *ppos;
 950
 951         len = sprintf(buffer, "%i\n", oom_adjust);
 952         if (__ppos >= len)
 953                 return 0;
 954         if (count > len-__ppos)
 955                 count = len-__ppos;
 956         if (copy_to_user(buf, buffer + __ppos, count))
 957                 return -EFAULT;
 958         *ppos = __ppos + count;
 959         return count;
 960 }
 961
 962 static ssize_t oom_adjust_write(struct file *file, const char __user *buf,
 963                                 size_t count, loff_t *ppos)
 964 {
 965         struct task_struct *task = proc_task(file->f_dentry->d_inode);
 966         char buffer[8], *end;
 967         int oom_adjust;
 968
 969         if (!capable(CAP_SYS_RESOURCE))
 970                 return -EPERM;
 971         memset(buffer, 0, 8);
 972         if (count > 6)
 973                 count = 6;
 974         if (copy_from_user(buffer, buf, count))
 975                 return -EFAULT;
 976         oom_adjust = simple_strtol(buffer, &end, 0);
 977         if ((oom_adjust < -16 || oom_adjust > 15) && oom_adjust != OOM_DISABLE)
 978                 return -EINVAL;
 979         if (*end == '\n')
 980                 end++;
 981         task->oomkilladj = oom_adjust;
 982         if (end - buffer == 0)
 983                 return -EIO;
 984         return end - buffer;
 985 }
 986
 987 static struct file_operations proc_oom_adjust_operations = {
 988         .read           = oom_adjust_read,
 989         .write          = oom_adjust_write,
 990 };
 991
 992 static struct inode_operations proc_mem_inode_operations = {
 993         .permission     = proc_permission,
 994 };
 995
 996 #ifdef CONFIG_AUDITSYSCALL
 997 #define TMPBUFLEN 21
 998 static ssize_t proc_loginuid_read(struct file * file, char __user * buf,
 999                                   size_t count, loff_t *ppos)
1000 {
1001         struct inode * inode = file->f_dentry->d_inode;
1002         struct task_struct *task = proc_task(inode);
1003         ssize_t length;
1004         char tmpbuf[TMPBUFLEN];
1005
1006         length = scnprintf(tmpbuf, TMPBUFLEN, "%u",
1007                                 audit_get_loginuid(task->audit_context));
1008         return simple_read_from_buffer(buf, count, ppos, tmpbuf, length);
1009 }
1010
1011 static ssize_t proc_loginuid_write(struct file * file, const char __user * buf,
1012                                    size_t count, loff_t *ppos)
1013 {
1014         struct inode * inode = file->f_dentry->d_inode;
1015         char *page, *tmp;
1016         ssize_t length;
1017         struct task_struct *task = proc_task(inode);
1018         uid_t loginuid;
1019
1020         if (!capable(CAP_AUDIT_CONTROL))
1021                 return -EPERM;
1022
1023         if (current != task)
1024                 return -EPERM;
1025
1026         if (count >= PAGE_SIZE)
1027                 count = PAGE_SIZE - 1;
1028
1029         if (*ppos != 0) {
1030                 /* No partial writes. */
1031                 return -EINVAL;
1032         }
1033         page = (char*)__get_free_page(GFP_USER);
1034         if (!page)
1035                 return -ENOMEM;
1036         length = -EFAULT;
1037         if (copy_from_user(page, buf, count))
1038                 goto out_free_page;
1039
1040         page[count] = '\0';
1041         loginuid = simple_strtoul(page, &tmp, 10);
1042         if (tmp == page) {
1043                 length = -EINVAL;
1044                 goto out_free_page;
1045
1046         }
1047         length = audit_set_loginuid(task, loginuid);
1048         if (likely(length == 0))
1049                 length = count;
1050
1051 out_free_page:
1052         free_page((unsigned long) page);
1053         return length;
1054 }
1055
1056 static struct file_operations proc_loginuid_operations = {
1057         .read           = proc_loginuid_read,
1058         .write          = proc_loginuid_write,
1059 };
1060 #endif
1061
1062 #ifdef CONFIG_SECCOMP
1063 static ssize_t seccomp_read(struct file *file, char __user *buf,
1064                             size_t count, loff_t *ppos)
1065 {
1066         struct task_struct *tsk = proc_task(file->f_dentry->d_inode);
1067         char __buf[20];
1068         loff_t __ppos = *ppos;
1069         size_t len;
1070
1071         /* no need to print the trailing zero, so use only len */
1072         len = sprintf(__buf, "%u\n", tsk->seccomp.mode);
1073         if (__ppos >= len)
1074                 return 0;
1075         if (count > len - __ppos)
1076                 count = len - __ppos;
1077         if (copy_to_user(buf, __buf + __ppos, count))
1078                 return -EFAULT;
1079         *ppos = __ppos + count;
1080         return count;
1081 }
1082
1083 static ssize_t seccomp_write(struct file *file, const char __user *buf,
1084                              size_t count, loff_t *ppos)
1085 {
1086         struct task_struct *tsk = proc_task(file->f_dentry->d_inode);
1087         char __buf[20], *end;
1088         unsigned int seccomp_mode;
1089
1090         /* can set it only once to be even more secure */
1091         if (unlikely(tsk->seccomp.mode))
1092                 return -EPERM;
1093
1094         memset(__buf, 0, sizeof(__buf));
1095         count = min(count, sizeof(__buf) - 1);
1096         if (copy_from_user(__buf, buf, count))
1097                 return -EFAULT;
1098         seccomp_mode = simple_strtoul(__buf, &end, 0);
1099         if (*end == '\n')
1100                 end++;
1101         if (seccomp_mode && seccomp_mode <= NR_SECCOMP_MODES) {
1102                 tsk->seccomp.mode = seccomp_mode;
1103                 set_tsk_thread_flag(tsk, TIF_SECCOMP);
1104         } else
1105                 return -EINVAL;
1106         if (unlikely(!(end - __buf)))
1107                 return -EIO;
1108         return end - __buf;
1109 }
1110
1111 static struct file_operations proc_seccomp_operations = {
1112         .read           = seccomp_read,
1113         .write          = seccomp_write,
1114 };
1115 #endif /* CONFIG_SECCOMP */
1116
1117 static void *proc_pid_follow_link(struct dentry *dentry, struct nameidata *nd)
1118 {
1119         struct inode *inode = dentry->d_inode;
1120         int error = -EACCES;
1121
1122         /* We don't need a base pointer in the /proc filesystem */
1123         path_release(nd);
1124
1125         if (current->fsuid != inode->i_uid && !capable(CAP_DAC_OVERRIDE))
1126                 goto out;
1127         error = proc_check_root(inode);
1128         if (error)
1129                 goto out;
1130
1131         error = PROC_I(inode)->op.proc_get_link(inode, &nd->dentry, &nd->mnt);
1132         nd->last_type = LAST_BIND;
1133 out:
1134         return ERR_PTR(error);
1135 }
1136
1137 static int do_proc_readlink(struct dentry *dentry, struct vfsmount *mnt,
1138                             char __user *buffer, int buflen)
1139 {
1140         struct inode * inode;
1141         char *tmp = (char*)__get_free_page(GFP_KERNEL), *path;
1142         int len;
1143
1144         if (!tmp)
1145                 return -ENOMEM;
1146
1147         inode = dentry->d_inode;
1148         path = d_path(dentry, mnt, tmp, PAGE_SIZE);
1149         len = PTR_ERR(path);
1150         if (IS_ERR(path))
1151                 goto out;
1152         len = tmp + PAGE_SIZE - 1 - path;
1153
1154         if (len > buflen)
1155                 len = buflen;
1156         if (copy_to_user(buffer, path, len))
1157                 len = -EFAULT;
1158  out:
1159         free_page((unsigned long)tmp);
1160         return len;
1161 }
1162
1163 static int proc_pid_readlink(struct dentry * dentry, char __user * buffer, int buflen)
1164 {
1165         int error = -EACCES;
1166         struct inode *inode = dentry->d_inode;
1167         struct dentry *de;
1168         struct vfsmount *mnt = NULL;
1169
1170         lock_kernel();
1171
1172         if (current->fsuid != inode->i_uid && !capable(CAP_DAC_OVERRIDE))
1173                 goto out;
1174         error = proc_check_root(inode);
1175         if (error)
1176                 goto out;
1177
1178         error = PROC_I(inode)->op.proc_get_link(inode, &de, &mnt);
1179         if (error)
1180                 goto out;
1181
1182         error = do_proc_readlink(de, mnt, buffer, buflen);
1183         dput(de);
1184         mntput(mnt);
1185 out:
1186         unlock_kernel();
1187         return error;
1188 }
1189
1190 static struct inode_operations proc_pid_link_inode_operations = {
1191         .readlink       = proc_pid_readlink,
1192         .follow_link    = proc_pid_follow_link
1193 };
1194
1195 #define NUMBUF 10
1196
1197 static int proc_readfd(struct file * filp, void * dirent, filldir_t filldir)
1198 {
1199         struct dentry *dentry = filp->f_dentry;
1200         struct inode *inode = dentry->d_inode;
1201         struct task_struct *p = proc_task(inode);
1202         unsigned int fd, tid, ino;
1203         int retval;
1204         char buf[NUMBUF];
1205         struct files_struct * files;
1206         struct fdtable *fdt;
1207
1208         retval = -ENOENT;
1209         if (!pid_alive(p))
1210                 goto out;
1211         retval = 0;
1212         tid = p->pid;
1213
1214         fd = filp->f_pos;
1215         switch (fd) {
1216                 case 0:
1217                         if (filldir(dirent, ".", 1, 0, inode->i_ino, DT_DIR) < 0)
1218                                 goto out;
1219                         filp->f_pos++;
1220                 case 1:
1221                         ino = parent_ino(dentry);
1222                         if (filldir(dirent, "..", 2, 1, ino, DT_DIR) < 0)
1223                                 goto out;
1224                         filp->f_pos++;
1225                 default:
1226                         files = get_files_struct(p);
1227                         if (!files)
1228                                 goto out;
1229                         rcu_read_lock();
1230                         fdt = files_fdtable(files);
1231                         for (fd = filp->f_pos-2;
1232                              fd < fdt->max_fds;
1233                              fd++, filp->f_pos++) {
1234                                 unsigned int i,j;
1235
1236                                 if (!fcheck_files(files, fd))
1237                                         continue;
1238                                 rcu_read_unlock();
1239
1240                                 j = NUMBUF;
1241                                 i = fd;
1242                                 do {
1243                                         j--;
1244                                         buf[j] = '0' + (i % 10);
1245                                         i /= 10;
1246                                 } while (i);
1247
1248                                 ino = fake_ino(tid, PROC_TID_FD_DIR + fd);
1249                                 if (filldir(dirent, buf+j, NUMBUF-j, fd+2, ino, DT_LNK) < 0) {
1250                                         rcu_read_lock();
1251                                         break;
1252                                 }
1253                                 rcu_read_lock();
1254                         }
1255                         rcu_read_unlock();
1256                         put_files_struct(files);
1257         }
1258 out:
1259         return retval;
1260 }
1261
1262 static int proc_pident_readdir(struct file *filp,
1263                 void *dirent, filldir_t filldir,
1264                 struct pid_entry *ents, unsigned int nents)
1265 {
1266         int i;
1267         int pid;
1268         struct dentry *dentry = filp->f_dentry;
1269         struct inode *inode = dentry->d_inode;
1270         struct pid_entry *p;
1271         ino_t ino;
1272         int ret;
1273
1274         ret = -ENOENT;
1275         if (!pid_alive(proc_task(inode)))
1276                 goto out;
1277
1278         ret = 0;
1279         pid = proc_task(inode)->pid;
1280         i = filp->f_pos;
1281         switch (i) {
1282         case 0:
1283                 ino = inode->i_ino;
1284                 if (filldir(dirent, ".", 1, i, ino, DT_DIR) < 0)
1285                         goto out;
1286                 i++;
1287                 filp->f_pos++;
1288                 /* fall through */
1289         case 1:
1290                 ino = parent_ino(dentry);
1291                 if (filldir(dirent, "..", 2, i, ino, DT_DIR) < 0)
1292                         goto out;
1293                 i++;
1294                 filp->f_pos++;
1295                 /* fall through */
1296         default:
1297                 i -= 2;
1298                 if (i >= nents) {
1299                         ret = 1;
1300                         goto out;
1301                 }
1302                 p = ents + i;
1303                 while (p->name) {
1304                         if (filldir(dirent, p->name, p->len, filp->f_pos,
1305                                     fake_ino(pid, p->type), p->mode >> 12) < 0)
1306                                 goto out;
1307                         filp->f_pos++;
1308                         p++;
1309                 }
1310         }
1311
1312         ret = 1;
1313 out:
1314         return ret;
1315 }
1316
1317 static int proc_tgid_base_readdir(struct file * filp,
1318                              void * dirent, filldir_t filldir)
1319 {
1320         return proc_pident_readdir(filp,dirent,filldir,
1321                                    tgid_base_stuff,ARRAY_SIZE(tgid_base_stuff));
1322 }
1323
1324 static int proc_tid_base_readdir(struct file * filp,
1325                              void * dirent, filldir_t filldir)
1326 {
1327         return proc_pident_readdir(filp,dirent,filldir,
1328                                    tid_base_stuff,ARRAY_SIZE(tid_base_stuff));
1329 }
1330
1331 /* building an inode */
1332
1333 static int task_dumpable(struct task_struct *task)
1334 {
1335         int dumpable = 0;
1336         struct mm_struct *mm;
1337
1338         task_lock(task);
1339         mm = task->mm;
1340         if (mm)
1341                 dumpable = mm->dumpable;
1342         task_unlock(task);
1343         if(dumpable == 1)
1344                 return 1;
1345         return 0;
1346 }
1347
1348
1349 static struct inode *proc_pid_make_inode(struct super_block * sb, struct task_struct *task, int ino)
1350 {
1351         struct inode * inode;
1352         struct proc_inode *ei;
1353
1354         /* We need a new inode */
1355
1356         inode = new_inode(sb);
1357         if (!inode)
1358                 goto out;
1359
1360         /* Common stuff */
1361         ei = PROC_I(inode);
1362         ei->task = NULL;
1363         inode->i_mtime = inode->i_atime = inode->i_ctime = CURRENT_TIME;
1364         inode->i_ino = fake_ino(task->pid, ino);
1365
1366         if (!pid_alive(task))
1367                 goto out_unlock;
1368
1369         /*
1370          * grab the reference to task.
1371          */
1372         get_task_struct(task);
1373         ei->task = task;
1374         ei->type = ino;
1375         inode->i_uid = 0;
1376         inode->i_gid = 0;
1377         if (ino == PROC_TGID_INO || ino == PROC_TID_INO || task_dumpable(task)) {
1378                 inode->i_uid = task->euid;
1379                 inode->i_gid = task->egid;
1380         }
1381         security_task_to_inode(task, inode);
1382
1383 out:
1384         return inode;
1385
1386 out_unlock:
1387         ei->pde = NULL;
1388         iput(inode);
1389         return NULL;
1390 }
1391
1392 /* dentry stuff */
1393
1394 /*
1395  *      Exceptional case: normally we are not allowed to unhash a busy
1396  * directory. In this case, however, we can do it - no aliasing problems
1397  * due to the way we treat inodes.
1398  *
1399  * Rewrite the inode's ownerships here because the owning task may have
1400  * performed a setuid(), etc.
1401  */
1402 static int pid_revalidate(struct dentry *dentry, struct nameidata *nd)
1403 {
1404         struct inode *inode = dentry->d_inode;
1405         struct task_struct *task = proc_task(inode);
1406         if (pid_alive(task)) {
1407                 if (proc_type(inode) == PROC_TGID_INO || proc_type(inode) == PROC_TID_INO || task_dumpable(task)) {
1408                         inode->i_uid = task->euid;
1409                         inode->i_gid = task->egid;
1410                 } else {
1411                         inode->i_uid = 0;
1412                         inode->i_gid = 0;
1413                 }
1414                 security_task_to_inode(task, inode);
1415                 return 1;
1416         }
1417         d_drop(dentry);
1418         return 0;
1419 }
1420
1421 static int tid_fd_revalidate(struct dentry *dentry, struct nameidata *nd)
1422 {
1423         struct inode *inode = dentry->d_inode;
1424         struct task_struct *task = proc_task(inode);
1425         int fd = proc_type(inode) - PROC_TID_FD_DIR;
1426         struct files_struct *files;
1427
1428         files = get_files_struct(task);
1429         if (files) {
1430                 rcu_read_lock();
1431                 if (fcheck_files(files, fd)) {
1432                         rcu_read_unlock();
1433                         put_files_struct(files);
1434                         if (task_dumpable(task)) {
1435                                 inode->i_uid = task->euid;
1436                                 inode->i_gid = task->egid;
1437                         } else {
1438                                 inode->i_uid = 0;
1439                                 inode->i_gid = 0;
1440                         }
1441                         security_task_to_inode(task, inode);
1442                         return 1;
1443                 }
1444                 rcu_read_unlock();
1445                 put_files_struct(files);
1446         }
1447         d_drop(dentry);
1448         return 0;
1449 }
1450
1451 static void pid_base_iput(struct dentry *dentry, struct inode *inode)
1452 {
1453         struct task_struct *task = proc_task(inode);
1454         spin_lock(&task->proc_lock);
1455         if (task->proc_dentry == dentry)
1456                 task->proc_dentry = NULL;
1457         spin_unlock(&task->proc_lock);
1458         iput(inode);
1459 }
1460
1461 static int pid_delete_dentry(struct dentry * dentry)
1462 {
1463         /* Is the task we represent dead?
1464          * If so, then don't put the dentry on the lru list,
1465          * kill it immediately.
1466          */
1467         return !pid_alive(proc_task(dentry->d_inode));
1468 }
1469
1470 static struct dentry_operations tid_fd_dentry_operations =
1471 {
1472         .d_revalidate   = tid_fd_revalidate,
1473         .d_delete       = pid_delete_dentry,
1474 };
1475
1476 static struct dentry_operations pid_dentry_operations =
1477 {
1478         .d_revalidate   = pid_revalidate,
1479         .d_delete       = pid_delete_dentry,
1480 };
1481
1482 static struct dentry_operations pid_base_dentry_operations =
1483 {
1484         .d_revalidate   = pid_revalidate,
1485         .d_iput         = pid_base_iput,
1486         .d_delete       = pid_delete_dentry,
1487 };
1488
1489 /* Lookups */
1490
1491 static unsigned name_to_int(struct dentry *dentry)
1492 {
1493         const char *name = dentry->d_name.name;
1494         int len = dentry->d_name.len;
1495         unsigned n = 0;
1496
1497         if (len > 1 && *name == '0')
1498                 goto out;
1499         while (len-- > 0) {
1500                 unsigned c = *name++ - '0';
1501                 if (c > 9)
1502                         goto out;
1503                 if (n >= (~0U-9)/10)
1504                         goto out;
1505                 n *= 10;
1506                 n += c;
1507         }
1508         return n;
1509 out:
1510         return ~0U;
1511 }
1512
1513 /* SMP-safe */
1514 static struct dentry *proc_lookupfd(struct inode * dir, struct dentry * dentry, struct nameidata *nd)
1515 {
1516         struct task_struct *task = proc_task(dir);
1517         unsigned fd = name_to_int(dentry);
1518         struct file * file;
1519         struct files_struct * files;
1520         struct inode *inode;
1521         struct proc_inode *ei;
1522
1523         if (fd == ~0U)
1524                 goto out;
1525         if (!pid_alive(task))
1526                 goto out;
1527
1528         inode = proc_pid_make_inode(dir->i_sb, task, PROC_TID_FD_DIR+fd);
1529         if (!inode)
1530                 goto out;
1531         ei = PROC_I(inode);
1532         files = get_files_struct(task);
1533         if (!files)
1534                 goto out_unlock;
1535         inode->i_mode = S_IFLNK;
1536
1537         /*
1538          * We are not taking a ref to the file structure, so we must
1539          * hold ->file_lock.
1540          */
1541         spin_lock(&files->file_lock);
1542         file = fcheck_files(files, fd);
1543         if (!file)
1544                 goto out_unlock2;
1545         if (file->f_mode & 1)
1546                 inode->i_mode |= S_IRUSR | S_IXUSR;
1547         if (file->f_mode & 2)
1548                 inode->i_mode |= S_IWUSR | S_IXUSR;
1549         spin_unlock(&files->file_lock);
1550         put_files_struct(files);
1551         inode->i_op = &proc_pid_link_inode_operations;
1552         inode->i_size = 64;
1553         ei->op.proc_get_link = proc_fd_link;
1554         dentry->d_op = &tid_fd_dentry_operations;
1555         d_add(dentry, inode);
1556         return NULL;
1557
1558 out_unlock2:
1559         spin_unlock(&files->file_lock);
1560         put_files_struct(files);
1561 out_unlock:
1562         iput(inode);
1563 out:
1564         return ERR_PTR(-ENOENT);
1565 }
1566
1567 static int proc_task_readdir(struct file * filp, void * dirent, filldir_t filldir);
1568 static struct dentry *proc_task_lookup(struct inode *dir, struct dentry * dentry, struct nameidata *nd);
1569
1570 static struct file_operations proc_fd_operations = {
1571         .read           = generic_read_dir,
1572         .readdir        = proc_readfd,
1573 };
1574
1575 static struct file_operations proc_task_operations = {
1576         .read           = generic_read_dir,
1577         .readdir        = proc_task_readdir,
1578 };
1579
1580 /*
1581  * proc directories can do almost nothing..
1582  */
1583 static struct inode_operations proc_fd_inode_operations = {
1584         .lookup         = proc_lookupfd,
1585         .permission     = proc_permission,
1586 };
1587
1588 static struct inode_operations proc_task_inode_operations = {
1589         .lookup         = proc_task_lookup,
1590         .permission     = proc_task_permission,
1591 };
1592
1593 #ifdef CONFIG_SECURITY
1594 static ssize_t proc_pid_attr_read(struct file * file, char __user * buf,
1595                                   size_t count, loff_t *ppos)
1596 {
1597         struct inode * inode = file->f_dentry->d_inode;
1598         unsigned long page;
1599         ssize_t length;
1600         struct task_struct *task = proc_task(inode);
1601
1602         if (count > PAGE_SIZE)
1603                 count = PAGE_SIZE;
1604         if (!(page = __get_free_page(GFP_KERNEL)))
1605                 return -ENOMEM;
1606
1607         length = security_getprocattr(task,
1608                                       (char*)file->f_dentry->d_name.name,
1609                                       (void*)page, count);
1610         if (length >= 0)
1611                 length = simple_read_from_buffer(buf, count, ppos, (char *)page, length);
1612         free_page(page);
1613         return length;
1614 }
1615
1616 static ssize_t proc_pid_attr_write(struct file * file, const char __user * buf,
1617                                    size_t count, loff_t *ppos)
1618 {
1619         struct inode * inode = file->f_dentry->d_inode;
1620         char *page;
1621         ssize_t length;
1622         struct task_struct *task = proc_task(inode);
1623
1624         if (count > PAGE_SIZE)
1625                 count = PAGE_SIZE;
1626         if (*ppos != 0) {
1627                 /* No partial writes. */
1628                 return -EINVAL;
1629         }
1630         page = (char*)__get_free_page(GFP_USER);
1631         if (!page)
1632                 return -ENOMEM;
1633         length = -EFAULT;
1634         if (copy_from_user(page, buf, count))
1635                 goto out;
1636
1637         length = security_setprocattr(task,
1638                                       (char*)file->f_dentry->d_name.name,
1639                                       (void*)page, count);
1640 out:
1641         free_page((unsigned long) page);
1642         return length;
1643 }
1644
1645 static struct file_operations proc_pid_attr_operations = {
1646         .read           = proc_pid_attr_read,
1647         .write          = proc_pid_attr_write,
1648 };
1649
1650 static struct file_operations proc_tid_attr_operations;
1651 static struct inode_operations proc_tid_attr_inode_operations;
1652 static struct file_operations proc_tgid_attr_operations;
1653 static struct inode_operations proc_tgid_attr_inode_operations;
1654 #endif
1655
1656 static int get_tid_list(int index, unsigned int *tids, struct inode *dir);
1657
1658 /* SMP-safe */
1659 static struct dentry *proc_pident_lookup(struct inode *dir,
1660                                          struct dentry *dentry,
1661                                          struct pid_entry *ents)
1662 {
1663         struct inode *inode;
1664         int error;
1665         struct task_struct *task = proc_task(dir);
1666         struct pid_entry *p;
1667         struct proc_inode *ei;
1668
1669         error = -ENOENT;
1670         inode = NULL;
1671
1672         if (!pid_alive(task))
1673                 goto out;
1674
1675         for (p = ents; p->name; p++) {
1676                 if (p->len != dentry->d_name.len)
1677                         continue;
1678                 if (!memcmp(dentry->d_name.name, p->name, p->len))
1679                         break;
1680         }
1681         if (!p->name)
1682                 goto out;
1683
1684         error = -EINVAL;
1685         inode = proc_pid_make_inode(dir->i_sb, task, p->type);
1686         if (!inode)
1687                 goto out;
1688
1689         ei = PROC_I(inode);
1690         inode->i_mode = p->mode;
1691         /*
1692          * Yes, it does not scale. And it should not. Don't add
1693          * new entries into /proc/<tgid>/ without very good reasons.
1694          */
1695         switch(p->type) {
1696                 case PROC_TGID_TASK:
1697                         inode->i_nlink = 2 + get_tid_list(2, NULL, dir);
1698                         inode->i_op = &proc_task_inode_operations;
1699                         inode->i_fop = &proc_task_operations;
1700                         break;
1701                 case PROC_TID_FD:
1702                 case PROC_TGID_FD:
1703                         inode->i_nlink = 2;
1704                         inode->i_op = &proc_fd_inode_operations;
1705                         inode->i_fop = &proc_fd_operations;
1706                         break;
1707                 case PROC_TID_EXE:
1708                 case PROC_TGID_EXE:
1709                         inode->i_op = &proc_pid_link_inode_operations;
1710                         ei->op.proc_get_link = proc_exe_link;
1711                         break;
1712                 case PROC_TID_CWD:
1713                 case PROC_TGID_CWD:
1714                         inode->i_op = &proc_pid_link_inode_operations;
1715                         ei->op.proc_get_link = proc_cwd_link;
1716                         break;
1717                 case PROC_TID_ROOT:
1718                 case PROC_TGID_ROOT:
1719                         inode->i_op = &proc_pid_link_inode_operations;
1720                         ei->op.proc_get_link = proc_root_link;
1721                         break;
1722                 case PROC_TID_ENVIRON:
1723                 case PROC_TGID_ENVIRON:
1724                         inode->i_fop = &proc_info_file_operations;
1725                         ei->op.proc_read = proc_pid_environ;
1726                         break;
1727                 case PROC_TID_AUXV:
1728                 case PROC_TGID_AUXV:
1729                         inode->i_fop = &proc_info_file_operations;
1730                         ei->op.proc_read = proc_pid_auxv;
1731                         break;
1732                 case PROC_TID_STATUS:
1733                 case PROC_TGID_STATUS:
1734                         inode->i_fop = &proc_info_file_operations;
1735                         ei->op.proc_read = proc_pid_status;
1736                         break;
1737                 case PROC_TID_STAT:
1738                         inode->i_fop = &proc_info_file_operations;
1739                         ei->op.proc_read = proc_tid_stat;
1740                         break;
1741                 case PROC_TGID_STAT:
1742                         inode->i_fop = &proc_info_file_operations;
1743                         ei->op.proc_read = proc_tgid_stat;
1744                         break;
1745                 case PROC_TID_CMDLINE:
1746                 case PROC_TGID_CMDLINE:
1747                         inode->i_fop = &proc_info_file_operations;
1748                         ei->op.proc_read = proc_pid_cmdline;
1749                         break;
1750                 case PROC_TID_STATM:
1751                 case PROC_TGID_STATM:
1752                         inode->i_fop = &proc_info_file_operations;
1753                         ei->op.proc_read = proc_pid_statm;
1754                         break;
1755                 case PROC_TID_MAPS:
1756                 case PROC_TGID_MAPS:
1757                         inode->i_fop = &proc_maps_operations;
1758                         break;
1759 #ifdef CONFIG_NUMA
1760                 case PROC_TID_NUMA_MAPS:
1761                 case PROC_TGID_NUMA_MAPS:
1762                         inode->i_fop = &proc_numa_maps_operations;
1763                         break;
1764 #endif
1765                 case PROC_TID_MEM:
1766                 case PROC_TGID_MEM:
1767                         inode->i_op = &proc_mem_inode_operations;
1768                         inode->i_fop = &proc_mem_operations;
1769                         break;
1770 #ifdef CONFIG_SECCOMP
1771                 case PROC_TID_SECCOMP:
1772                 case PROC_TGID_SECCOMP:
1773                         inode->i_fop = &proc_seccomp_operations;
1774                         break;
1775 #endif /* CONFIG_SECCOMP */
1776                 case PROC_TID_MOUNTS:
1777                 case PROC_TGID_MOUNTS:
1778                         inode->i_fop = &proc_mounts_operations;
1779                         break;
1780 #ifdef CONFIG_MMU
1781                 case PROC_TID_SMAPS:
1782                 case PROC_TGID_SMAPS:
1783                         inode->i_fop = &proc_smaps_operations;
1784                         break;
1785 #endif
1786                 case PROC_TID_MOUNTSTATS:
1787                 case PROC_TGID_MOUNTSTATS:
1788                         inode->i_fop = &proc_mountstats_operations;
1789                         break;
1790 #ifdef CONFIG_SECURITY
1791                 case PROC_TID_ATTR:
1792                         inode->i_nlink = 2;
1793                         inode->i_op = &proc_tid_attr_inode_operations;
1794                         inode->i_fop = &proc_tid_attr_operations;
1795                         break;
1796                 case PROC_TGID_ATTR:
1797                         inode->i_nlink = 2;
1798                         inode->i_op = &proc_tgid_attr_inode_operations;
1799                         inode->i_fop = &proc_tgid_attr_operations;
1800                         break;
1801                 case PROC_TID_ATTR_CURRENT:
1802                 case PROC_TGID_ATTR_CURRENT:
1803                 case PROC_TID_ATTR_PREV:
1804                 case PROC_TGID_ATTR_PREV:
1805                 case PROC_TID_ATTR_EXEC:
1806                 case PROC_TGID_ATTR_EXEC:
1807                 case PROC_TID_ATTR_FSCREATE:
1808                 case PROC_TGID_ATTR_FSCREATE:
1809                 case PROC_TID_ATTR_KEYCREATE:
1810                 case PROC_TGID_ATTR_KEYCREATE:
1811                         inode->i_fop = &proc_pid_attr_operations;
1812                         break;
1813 #endif
1814 #ifdef CONFIG_KALLSYMS
1815                 case PROC_TID_WCHAN:
1816                 case PROC_TGID_WCHAN:
1817                         inode->i_fop = &proc_info_file_operations;
1818                         ei->op.proc_read = proc_pid_wchan;
1819                         break;
1820 #endif
1821 #ifdef CONFIG_SCHEDSTATS
1822                 case PROC_TID_SCHEDSTAT:
1823                 case PROC_TGID_SCHEDSTAT:
1824                         inode->i_fop = &proc_info_file_operations;
1825                         ei->op.proc_read = proc_pid_schedstat;
1826                         break;
1827 #endif
1828 #ifdef CONFIG_CPUSETS
1829                 case PROC_TID_CPUSET:
1830                 case PROC_TGID_CPUSET:
1831                         inode->i_fop = &proc_cpuset_operations;
1832                         break;
1833 #endif
1834                 case PROC_TID_OOM_SCORE:
1835                 case PROC_TGID_OOM_SCORE:
1836                         inode->i_fop = &proc_info_file_operations;
1837                         ei->op.proc_read = proc_oom_score;
1838                         break;
1839                 case PROC_TID_OOM_ADJUST:
1840                 case PROC_TGID_OOM_ADJUST:
1841                         inode->i_fop = &proc_oom_adjust_operations;
1842                         break;
1843 #ifdef CONFIG_AUDITSYSCALL
1844                 case PROC_TID_LOGINUID:
1845                 case PROC_TGID_LOGINUID:
1846                         inode->i_fop = &proc_loginuid_operations;
1847                         break;
1848 #endif
1849                 default:
1850                         printk("procfs: impossible type (%d)",p->type);
1851                         iput(inode);
1852                         return ERR_PTR(-EINVAL);
1853         }
1854         dentry->d_op = &pid_dentry_operations;
1855         d_add(dentry, inode);
1856         return NULL;
1857
1858 out:
1859         return ERR_PTR(error);
1860 }
1861
1862 static struct dentry *proc_tgid_base_lookup(struct inode *dir, struct dentry *dentry, struct nameidata *nd){
1863         return proc_pident_lookup(dir, dentry, tgid_base_stuff);
1864 }
1865
1866 static struct dentry *proc_tid_base_lookup(struct inode *dir, struct dentry *dentry, struct nameidata *nd){
1867         return proc_pident_lookup(dir, dentry, tid_base_stuff);
1868 }
1869
1870 static struct file_operations proc_tgid_base_operations = {
1871         .read           = generic_read_dir,
1872         .readdir        = proc_tgid_base_readdir,
1873 };
1874
1875 static struct file_operations proc_tid_base_operations = {
1876         .read           = generic_read_dir,
1877         .readdir        = proc_tid_base_readdir,
1878 };
1879
1880 static struct inode_operations proc_tgid_base_inode_operations = {
1881         .lookup         = proc_tgid_base_lookup,
1882 };
1883
1884 static struct inode_operations proc_tid_base_inode_operations = {
1885         .lookup         = proc_tid_base_lookup,
1886 };
1887
1888 #ifdef CONFIG_SECURITY
1889 static int proc_tgid_attr_readdir(struct file * filp,
1890                              void * dirent, filldir_t filldir)
1891 {
1892         return proc_pident_readdir(filp,dirent,filldir,
1893                                    tgid_attr_stuff,ARRAY_SIZE(tgid_attr_stuff));
1894 }
1895
1896 static int proc_tid_attr_readdir(struct file * filp,
1897                              void * dirent, filldir_t filldir)
1898 {
1899         return proc_pident_readdir(filp,dirent,filldir,
1900                                    tid_attr_stuff,ARRAY_SIZE(tid_attr_stuff));
1901 }
1902
1903 static struct file_operations proc_tgid_attr_operations = {
1904         .read           = generic_read_dir,
1905         .readdir        = proc_tgid_attr_readdir,
1906 };
1907
1908 static struct file_operations proc_tid_attr_operations = {
1909         .read           = generic_read_dir,
1910         .readdir        = proc_tid_attr_readdir,
1911 };
1912
1913 static struct dentry *proc_tgid_attr_lookup(struct inode *dir,
1914                                 struct dentry *dentry, struct nameidata *nd)
1915 {
1916         return proc_pident_lookup(dir, dentry, tgid_attr_stuff);
1917 }
1918
1919 static struct dentry *proc_tid_attr_lookup(struct inode *dir,
1920                                 struct dentry *dentry, struct nameidata *nd)
1921 {
1922         return proc_pident_lookup(dir, dentry, tid_attr_stuff);
1923 }
1924
1925 static struct inode_operations proc_tgid_attr_inode_operations = {
1926         .lookup         = proc_tgid_attr_lookup,
1927 };
1928
1929 static struct inode_operations proc_tid_attr_inode_operations = {
1930         .lookup         = proc_tid_attr_lookup,
1931 };
1932 #endif
1933
1934 /*
1935  * /proc/self:
1936  */
1937 static int proc_self_readlink(struct dentry *dentry, char __user *buffer,
1938                               int buflen)
1939 {
1940         char tmp[30];
1941         sprintf(tmp, "%d", current->tgid);
1942         return vfs_readlink(dentry,buffer,buflen,tmp);
1943 }
1944
1945 static void *proc_self_follow_link(struct dentry *dentry, struct nameidata *nd)
1946 {
1947         char tmp[30];
1948         sprintf(tmp, "%d", current->tgid);
1949         return ERR_PTR(vfs_follow_link(nd,tmp));
1950 }
1951
1952 static struct inode_operations proc_self_inode_operations = {
1953         .readlink       = proc_self_readlink,
1954         .follow_link    = proc_self_follow_link,
1955 };
1956
1957 /**
1958  * proc_pid_unhash -  Unhash /proc/@pid entry from the dcache.
1959  * @p: task that should be flushed.
1960  *
1961  * Drops the /proc/@pid dcache entry from the hash chains.
1962  *
1963  * Dropping /proc/@pid entries and detach_pid must be synchroneous,
1964  * otherwise e.g. /proc/@pid/exe might point to the wrong executable,
1965  * if the pid value is immediately reused. This is enforced by
1966  * - caller must acquire spin_lock(p->proc_lock)
1967  * - must be called before detach_pid()
1968  * - proc_pid_lookup acquires proc_lock, and checks that
1969  *   the target is not dead by looking at the attach count
1970  *   of PIDTYPE_PID.
1971  */
1972
1973 struct dentry *proc_pid_unhash(struct task_struct *p)
1974 {
1975         struct dentry *proc_dentry;
1976
1977         proc_dentry = p->proc_dentry;
1978         if (proc_dentry != NULL) {
1979
1980                 spin_lock(&dcache_lock);
1981                 spin_lock(&proc_dentry->d_lock);
1982                 if (!d_unhashed(proc_dentry)) {
1983                         dget_locked(proc_dentry);
1984                         __d_drop(proc_dentry);
1985                         spin_unlock(&proc_dentry->d_lock);
1986                 } else {
1987                         spin_unlock(&proc_dentry->d_lock);
1988                         proc_dentry = NULL;
1989                 }
1990                 spin_unlock(&dcache_lock);
1991         }
1992         return proc_dentry;
1993 }
1994
1995 /**
1996  * proc_pid_flush - recover memory used by stale /proc/@pid/x entries
1997  * @proc_dentry: directoy to prune.
1998  *
1999  * Shrink the /proc directory that was used by the just killed thread.
2000  */
2001
2002 void proc_pid_flush(struct dentry *proc_dentry)
2003 {
2004         might_sleep();
2005         if(proc_dentry != NULL) {
2006                 shrink_dcache_parent(proc_dentry);
2007                 dput(proc_dentry);
2008         }
2009 }
2010
2011 /* SMP-safe */
2012 struct dentry *proc_pid_lookup(struct inode *dir, struct dentry * dentry, struct nameidata *nd)
2013 {
2014         struct task_struct *task;
2015         struct inode *inode;
2016         struct proc_inode *ei;
2017         unsigned tgid;
2018         int died;
2019
2020         if (dentry->d_name.len == 4 && !memcmp(dentry->d_name.name,"self",4)) {
2021                 inode = new_inode(dir->i_sb);
2022                 if (!inode)
2023                         return ERR_PTR(-ENOMEM);
2024                 ei = PROC_I(inode);
2025                 inode->i_mtime = inode->i_atime = inode->i_ctime = CURRENT_TIME;
2026                 inode->i_ino = fake_ino(0, PROC_TGID_INO);
2027                 ei->pde = NULL;
2028                 inode->i_mode = S_IFLNK|S_IRWXUGO;
2029                 inode->i_uid = inode->i_gid = 0;
2030                 inode->i_size = 64;
2031                 inode->i_op = &proc_self_inode_operations;
2032                 d_add(dentry, inode);
2033                 return NULL;
2034         }
2035         tgid = name_to_int(dentry);
2036         if (tgid == ~0U)
2037                 goto out;
2038
2039         read_lock(&tasklist_lock);
2040         task = find_task_by_pid(tgid);
2041         if (task)
2042                 get_task_struct(task);
2043         read_unlock(&tasklist_lock);
2044         if (!task)
2045                 goto out;
2046
2047         inode = proc_pid_make_inode(dir->i_sb, task, PROC_TGID_INO);
2048
2049
2050         if (!inode) {
2051                 put_task_struct(task);
2052                 goto out;
2053         }
2054         inode->i_mode = S_IFDIR|S_IRUGO|S_IXUGO;
2055         inode->i_op = &proc_tgid_base_inode_operations;
2056         inode->i_fop = &proc_tgid_base_operations;
2057         inode->i_flags|=S_IMMUTABLE;
2058 #ifdef CONFIG_SECURITY
2059         inode->i_nlink = 5;
2060 #else
2061         inode->i_nlink = 4;
2062 #endif
2063
2064         dentry->d_op = &pid_base_dentry_operations;
2065
2066         died = 0;
2067         d_add(dentry, inode);
2068         spin_lock(&task->proc_lock);
2069         task->proc_dentry = dentry;
2070         if (!pid_alive(task)) {
2071                 dentry = proc_pid_unhash(task);
2072                 died = 1;
2073         }
2074         spin_unlock(&task->proc_lock);
2075
2076         put_task_struct(task);
2077         if (died) {
2078                 proc_pid_flush(dentry);
2079                 goto out;
2080         }
2081         return NULL;
2082 out:
2083         return ERR_PTR(-ENOENT);
2084 }
2085
2086 /* SMP-safe */
2087 static struct dentry *proc_task_lookup(struct inode *dir, struct dentry * dentry, struct nameidata *nd)
2088 {
2089         struct task_struct *task;
2090         struct task_struct *leader = proc_task(dir);
2091         struct inode *inode;
2092         unsigned tid;
2093
2094         tid = name_to_int(dentry);
2095         if (tid == ~0U)
2096                 goto out;
2097
2098         read_lock(&tasklist_lock);
2099         task = find_task_by_pid(tid);
2100         if (task)
2101                 get_task_struct(task);
2102         read_unlock(&tasklist_lock);
2103         if (!task)
2104                 goto out;
2105         if (leader->tgid != task->tgid)
2106                 goto out_drop_task;
2107
2108         inode = proc_pid_make_inode(dir->i_sb, task, PROC_TID_INO);
2109
2110
2111         if (!inode)
2112                 goto out_drop_task;
2113         inode->i_mode = S_IFDIR|S_IRUGO|S_IXUGO;
2114         inode->i_op = &proc_tid_base_inode_operations;
2115         inode->i_fop = &proc_tid_base_operations;
2116         inode->i_flags|=S_IMMUTABLE;
2117 #ifdef CONFIG_SECURITY
2118         inode->i_nlink = 4;
2119 #else
2120         inode->i_nlink = 3;
2121 #endif
2122
2123         dentry->d_op = &pid_base_dentry_operations;
2124
2125         d_add(dentry, inode);
2126
2127         put_task_struct(task);
2128         return NULL;
2129 out_drop_task:
2130         put_task_struct(task);
2131 out:
2132         return ERR_PTR(-ENOENT);
2133 }
2134
2135 #define PROC_NUMBUF 10
2136 #define PROC_MAXPIDS 20
2137
2138 /*
2139  * Get a few tgid's to return for filldir - we need to hold the
2140  * tasklist lock while doing this, and we must release it before
2141  * we actually do the filldir itself, so we use a temp buffer..
2142  */
2143 static int get_tgid_list(int index, unsigned long version, unsigned int *tgids)
2144 {
2145         struct task_struct *p;
2146         int nr_tgids = 0;
2147
2148         index--;
2149         read_lock(&tasklist_lock);
2150         p = NULL;
2151         if (version) {
2152                 p = find_task_by_pid(version);
2153                 if (p && !thread_group_leader(p))
2154                         p = NULL;
2155         }
2156
2157         if (p)
2158                 index = 0;
2159         else
2160                 p = next_task(&init_task);
2161
2162         for ( ; p != &init_task; p = next_task(p)) {
2163                 int tgid = p->pid;
2164                 if (!pid_alive(p))
2165                         continue;
2166                 if (--index >= 0)
2167                         continue;
2168                 tgids[nr_tgids] = tgid;
2169                 nr_tgids++;
2170                 if (nr_tgids >= PROC_MAXPIDS)
2171                         break;
2172         }
2173         read_unlock(&tasklist_lock);
2174         return nr_tgids;
2175 }
2176
2177 /*
2178  * Get a few tid's to return for filldir - we need to hold the
2179  * tasklist lock while doing this, and we must release it before
2180  * we actually do the filldir itself, so we use a temp buffer..
2181  */
2182 static int get_tid_list(int index, unsigned int *tids, struct inode *dir)
2183 {
2184         struct task_struct *leader_task = proc_task(dir);
2185         struct task_struct *task = leader_task;
2186         int nr_tids = 0;
2187
2188         index -= 2;
2189         read_lock(&tasklist_lock);
2190         /*
2191          * The starting point task (leader_task) might be an already
2192          * unlinked task, which cannot be used to access the task-list
2193          * via next_thread().
2194          */
2195         if (pid_alive(task)) do {
2196                 int tid = task->pid;
2197
2198                 if (--index >= 0)
2199                         continue;
2200                 if (tids != NULL)
2201                         tids[nr_tids] = tid;
2202                 nr_tids++;
2203                 if (nr_tids >= PROC_MAXPIDS)
2204                         break;
2205         } while ((task = next_thread(task)) != leader_task);
2206         read_unlock(&tasklist_lock);
2207         return nr_tids;
2208 }
2209
2210 /* for the /proc/ directory itself, after non-process stuff has been done */
2211 int proc_pid_readdir(struct file * filp, void * dirent, filldir_t filldir)
2212 {
2213         unsigned int tgid_array[PROC_MAXPIDS];
2214         char buf[PROC_NUMBUF];
2215         unsigned int nr = filp->f_pos - FIRST_PROCESS_ENTRY;
2216         unsigned int nr_tgids, i;
2217         int next_tgid;
2218
2219         if (!nr) {
2220                 ino_t ino = fake_ino(0,PROC_TGID_INO);
2221                 if (filldir(dirent, "self", 4, filp->f_pos, ino, DT_LNK) < 0)
2222                         return 0;
2223                 filp->f_pos++;
2224                 nr++;
2225         }
2226
2227         /* f_version caches the tgid value that the last readdir call couldn't
2228          * return. lseek aka telldir automagically resets f_version to 0.
2229          */
2230         next_tgid = filp->f_version;
2231         filp->f_version = 0;
2232         for (;;) {
2233                 nr_tgids = get_tgid_list(nr, next_tgid, tgid_array);
2234                 if (!nr_tgids) {
2235                         /* no more entries ! */
2236                         break;
2237                 }
2238                 next_tgid = 0;
2239
2240                 /* do not use the last found pid, reserve it for next_tgid */
2241                 if (nr_tgids == PROC_MAXPIDS) {
2242                         nr_tgids--;
2243                         next_tgid = tgid_array[nr_tgids];
2244                 }
2245
2246                 for (i=0;i<nr_tgids;i++) {
2247                         int tgid = tgid_array[i];
2248                         ino_t ino = fake_ino(tgid,PROC_TGID_INO);
2249                         unsigned long j = PROC_NUMBUF;
2250
2251                         do
2252                                 buf[--j] = '0' + (tgid % 10);
2253                         while ((tgid /= 10) != 0);
2254
2255                         if (filldir(dirent, buf+j, PROC_NUMBUF-j, filp->f_pos, ino, DT_DIR) < 0) {
2256                                 /* returning this tgid failed, save it as the first
2257                                  * pid for the next readir call */
2258                                 filp->f_version = tgid_array[i];
2259                                 goto out;
2260                         }
2261                         filp->f_pos++;
2262                         nr++;
2263                 }
2264         }
2265 out:
2266         return 0;
2267 }
2268
2269 /* for the /proc/TGID/task/ directories */
2270 static int proc_task_readdir(struct file * filp, void * dirent, filldir_t filldir)
2271 {
2272         unsigned int tid_array[PROC_MAXPIDS];
2273         char buf[PROC_NUMBUF];
2274         unsigned int nr_tids, i;
2275         struct dentry *dentry = filp->f_dentry;
2276         struct inode *inode = dentry->d_inode;
2277         int retval = -ENOENT;
2278         ino_t ino;
2279         unsigned long pos = filp->f_pos;  /* avoiding "long long" filp->f_pos */
2280
2281         if (!pid_alive(proc_task(inode)))
2282                 goto out;
2283         retval = 0;
2284
2285         switch (pos) {
2286         case 0:
2287                 ino = inode->i_ino;
2288                 if (filldir(dirent, ".", 1, pos, ino, DT_DIR) < 0)
2289                         goto out;
2290                 pos++;
2291                 /* fall through */
2292         case 1:
2293                 ino = parent_ino(dentry);
2294                 if (filldir(dirent, "..", 2, pos, ino, DT_DIR) < 0)
2295                         goto out;
2296                 pos++;
2297                 /* fall through */
2298         }
2299
2300         nr_tids = get_tid_list(pos, tid_array, inode);
2301         inode->i_nlink = pos + nr_tids;
2302
2303         for (i = 0; i < nr_tids; i++) {
2304                 unsigned long j = PROC_NUMBUF;
2305                 int tid = tid_array[i];
2306
2307                 ino = fake_ino(tid,PROC_TID_INO);
2308
2309                 do
2310                         buf[--j] = '0' + (tid % 10);
2311                 while ((tid /= 10) != 0);
2312
2313                 if (filldir(dirent, buf+j, PROC_NUMBUF-j, pos, ino, DT_DIR) < 0)
2314                         break;
2315                 pos++;
2316         }
2317 out:
2318         filp->f_pos = pos;
2319         return retval;
2320 }