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