linux/fs/proc/base.c
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   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 <linux/uaccess.h>
  51
  52#include <linux/errno.h>
  53#include <linux/time.h>
  54#include <linux/proc_fs.h>
  55#include <linux/stat.h>
  56#include <linux/task_io_accounting_ops.h>
  57#include <linux/init.h>
  58#include <linux/capability.h>
  59#include <linux/file.h>
  60#include <linux/fdtable.h>
  61#include <linux/string.h>
  62#include <linux/seq_file.h>
  63#include <linux/namei.h>
  64#include <linux/mnt_namespace.h>
  65#include <linux/mm.h>
  66#include <linux/swap.h>
  67#include <linux/rcupdate.h>
  68#include <linux/kallsyms.h>
  69#include <linux/stacktrace.h>
  70#include <linux/resource.h>
  71#include <linux/module.h>
  72#include <linux/mount.h>
  73#include <linux/security.h>
  74#include <linux/ptrace.h>
  75#include <linux/tracehook.h>
  76#include <linux/printk.h>
  77#include <linux/cgroup.h>
  78#include <linux/cpuset.h>
  79#include <linux/audit.h>
  80#include <linux/poll.h>
  81#include <linux/nsproxy.h>
  82#include <linux/oom.h>
  83#include <linux/elf.h>
  84#include <linux/pid_namespace.h>
  85#include <linux/user_namespace.h>
  86#include <linux/fs_struct.h>
  87#include <linux/slab.h>
  88#include <linux/flex_array.h>
  89#include <linux/posix-timers.h>
  90#ifdef CONFIG_HARDWALL
  91#include <asm/hardwall.h>
  92#endif
  93#include <trace/events/oom.h>
  94#include "internal.h"
  95#include "fd.h"
  96
  97/* NOTE:
  98 *      Implementing inode permission operations in /proc is almost
  99 *      certainly an error.  Permission checks need to happen during
 100 *      each system call not at open time.  The reason is that most of
 101 *      what we wish to check for permissions in /proc varies at runtime.
 102 *
 103 *      The classic example of a problem is opening file descriptors
 104 *      in /proc for a task before it execs a suid executable.
 105 */
 106
 107static u8 nlink_tid;
 108static u8 nlink_tgid;
 109
 110struct pid_entry {
 111        const char *name;
 112        unsigned int len;
 113        umode_t mode;
 114        const struct inode_operations *iop;
 115        const struct file_operations *fop;
 116        union proc_op op;
 117};
 118
 119#define NOD(NAME, MODE, IOP, FOP, OP) {                 \
 120        .name = (NAME),                                 \
 121        .len  = sizeof(NAME) - 1,                       \
 122        .mode = MODE,                                   \
 123        .iop  = IOP,                                    \
 124        .fop  = FOP,                                    \
 125        .op   = OP,                                     \
 126}
 127
 128#define DIR(NAME, MODE, iops, fops)     \
 129        NOD(NAME, (S_IFDIR|(MODE)), &iops, &fops, {} )
 130#define LNK(NAME, get_link)                                     \
 131        NOD(NAME, (S_IFLNK|S_IRWXUGO),                          \
 132                &proc_pid_link_inode_operations, NULL,          \
 133                { .proc_get_link = get_link } )
 134#define REG(NAME, MODE, fops)                           \
 135        NOD(NAME, (S_IFREG|(MODE)), NULL, &fops, {})
 136#define ONE(NAME, MODE, show)                           \
 137        NOD(NAME, (S_IFREG|(MODE)),                     \
 138                NULL, &proc_single_file_operations,     \
 139                { .proc_show = show } )
 140
 141/*
 142 * Count the number of hardlinks for the pid_entry table, excluding the .
 143 * and .. links.
 144 */
 145static unsigned int __init pid_entry_nlink(const struct pid_entry *entries,
 146        unsigned int n)
 147{
 148        unsigned int i;
 149        unsigned int count;
 150
 151        count = 2;
 152        for (i = 0; i < n; ++i) {
 153                if (S_ISDIR(entries[i].mode))
 154                        ++count;
 155        }
 156
 157        return count;
 158}
 159
 160static int get_task_root(struct task_struct *task, struct path *root)
 161{
 162        int result = -ENOENT;
 163
 164        task_lock(task);
 165        if (task->fs) {
 166                get_fs_root(task->fs, root);
 167                result = 0;
 168        }
 169        task_unlock(task);
 170        return result;
 171}
 172
 173static int proc_cwd_link(struct dentry *dentry, struct path *path)
 174{
 175        struct task_struct *task = get_proc_task(d_inode(dentry));
 176        int result = -ENOENT;
 177
 178        if (task) {
 179                task_lock(task);
 180                if (task->fs) {
 181                        get_fs_pwd(task->fs, path);
 182                        result = 0;
 183                }
 184                task_unlock(task);
 185                put_task_struct(task);
 186        }
 187        return result;
 188}
 189
 190static int proc_root_link(struct dentry *dentry, struct path *path)
 191{
 192        struct task_struct *task = get_proc_task(d_inode(dentry));
 193        int result = -ENOENT;
 194
 195        if (task) {
 196                result = get_task_root(task, path);
 197                put_task_struct(task);
 198        }
 199        return result;
 200}
 201
 202static ssize_t proc_pid_cmdline_read(struct file *file, char __user *buf,
 203                                     size_t _count, loff_t *pos)
 204{
 205        struct task_struct *tsk;
 206        struct mm_struct *mm;
 207        char *page;
 208        unsigned long count = _count;
 209        unsigned long arg_start, arg_end, env_start, env_end;
 210        unsigned long len1, len2, len;
 211        unsigned long p;
 212        char c;
 213        ssize_t rv;
 214
 215        BUG_ON(*pos < 0);
 216
 217        tsk = get_proc_task(file_inode(file));
 218        if (!tsk)
 219                return -ESRCH;
 220        mm = get_task_mm(tsk);
 221        put_task_struct(tsk);
 222        if (!mm)
 223                return 0;
 224        /* Check if process spawned far enough to have cmdline. */
 225        if (!mm->env_end) {
 226                rv = 0;
 227                goto out_mmput;
 228        }
 229
 230        page = (char *)__get_free_page(GFP_TEMPORARY);
 231        if (!page) {
 232                rv = -ENOMEM;
 233                goto out_mmput;
 234        }
 235
 236        down_read(&mm->mmap_sem);
 237        arg_start = mm->arg_start;
 238        arg_end = mm->arg_end;
 239        env_start = mm->env_start;
 240        env_end = mm->env_end;
 241        up_read(&mm->mmap_sem);
 242
 243        BUG_ON(arg_start > arg_end);
 244        BUG_ON(env_start > env_end);
 245
 246        len1 = arg_end - arg_start;
 247        len2 = env_end - env_start;
 248
 249        /* Empty ARGV. */
 250        if (len1 == 0) {
 251                rv = 0;
 252                goto out_free_page;
 253        }
 254        /*
 255         * Inherently racy -- command line shares address space
 256         * with code and data.
 257         */
 258        rv = access_remote_vm(mm, arg_end - 1, &c, 1, 0);
 259        if (rv <= 0)
 260                goto out_free_page;
 261
 262        rv = 0;
 263
 264        if (c == '\0') {
 265                /* Command line (set of strings) occupies whole ARGV. */
 266                if (len1 <= *pos)
 267                        goto out_free_page;
 268
 269                p = arg_start + *pos;
 270                len = len1 - *pos;
 271                while (count > 0 && len > 0) {
 272                        unsigned int _count;
 273                        int nr_read;
 274
 275                        _count = min3(count, len, PAGE_SIZE);
 276                        nr_read = access_remote_vm(mm, p, page, _count, 0);
 277                        if (nr_read < 0)
 278                                rv = nr_read;
 279                        if (nr_read <= 0)
 280                                goto out_free_page;
 281
 282                        if (copy_to_user(buf, page, nr_read)) {
 283                                rv = -EFAULT;
 284                                goto out_free_page;
 285                        }
 286
 287                        p       += nr_read;
 288                        len     -= nr_read;
 289                        buf     += nr_read;
 290                        count   -= nr_read;
 291                        rv      += nr_read;
 292                }
 293        } else {
 294                /*
 295                 * Command line (1 string) occupies ARGV and maybe
 296                 * extends into ENVP.
 297                 */
 298                if (len1 + len2 <= *pos)
 299                        goto skip_argv_envp;
 300                if (len1 <= *pos)
 301                        goto skip_argv;
 302
 303                p = arg_start + *pos;
 304                len = len1 - *pos;
 305                while (count > 0 && len > 0) {
 306                        unsigned int _count, l;
 307                        int nr_read;
 308                        bool final;
 309
 310                        _count = min3(count, len, PAGE_SIZE);
 311                        nr_read = access_remote_vm(mm, p, page, _count, 0);
 312                        if (nr_read < 0)
 313                                rv = nr_read;
 314                        if (nr_read <= 0)
 315                                goto out_free_page;
 316
 317                        /*
 318                         * Command line can be shorter than whole ARGV
 319                         * even if last "marker" byte says it is not.
 320                         */
 321                        final = false;
 322                        l = strnlen(page, nr_read);
 323                        if (l < nr_read) {
 324                                nr_read = l;
 325                                final = true;
 326                        }
 327
 328                        if (copy_to_user(buf, page, nr_read)) {
 329                                rv = -EFAULT;
 330                                goto out_free_page;
 331                        }
 332
 333                        p       += nr_read;
 334                        len     -= nr_read;
 335                        buf     += nr_read;
 336                        count   -= nr_read;
 337                        rv      += nr_read;
 338
 339                        if (final)
 340                                goto out_free_page;
 341                }
 342skip_argv:
 343                /*
 344                 * Command line (1 string) occupies ARGV and
 345                 * extends into ENVP.
 346                 */
 347                if (len1 <= *pos) {
 348                        p = env_start + *pos - len1;
 349                        len = len1 + len2 - *pos;
 350                } else {
 351                        p = env_start;
 352                        len = len2;
 353                }
 354                while (count > 0 && len > 0) {
 355                        unsigned int _count, l;
 356                        int nr_read;
 357                        bool final;
 358
 359                        _count = min3(count, len, PAGE_SIZE);
 360                        nr_read = access_remote_vm(mm, p, page, _count, 0);
 361                        if (nr_read < 0)
 362                                rv = nr_read;
 363                        if (nr_read <= 0)
 364                                goto out_free_page;
 365
 366                        /* Find EOS. */
 367                        final = false;
 368                        l = strnlen(page, nr_read);
 369                        if (l < nr_read) {
 370                                nr_read = l;
 371                                final = true;
 372                        }
 373
 374                        if (copy_to_user(buf, page, nr_read)) {
 375                                rv = -EFAULT;
 376                                goto out_free_page;
 377                        }
 378
 379                        p       += nr_read;
 380                        len     -= nr_read;
 381                        buf     += nr_read;
 382                        count   -= nr_read;
 383                        rv      += nr_read;
 384
 385                        if (final)
 386                                goto out_free_page;
 387                }
 388skip_argv_envp:
 389                ;
 390        }
 391
 392out_free_page:
 393        free_page((unsigned long)page);
 394out_mmput:
 395        mmput(mm);
 396        if (rv > 0)
 397                *pos += rv;
 398        return rv;
 399}
 400
 401static const struct file_operations proc_pid_cmdline_ops = {
 402        .read   = proc_pid_cmdline_read,
 403        .llseek = generic_file_llseek,
 404};
 405
 406#ifdef CONFIG_KALLSYMS
 407/*
 408 * Provides a wchan file via kallsyms in a proper one-value-per-file format.
 409 * Returns the resolved symbol.  If that fails, simply return the address.
 410 */
 411static int proc_pid_wchan(struct seq_file *m, struct pid_namespace *ns,
 412                          struct pid *pid, struct task_struct *task)
 413{
 414        unsigned long wchan;
 415        char symname[KSYM_NAME_LEN];
 416
 417        wchan = get_wchan(task);
 418
 419        if (wchan && ptrace_may_access(task, PTRACE_MODE_READ_FSCREDS)
 420                        && !lookup_symbol_name(wchan, symname))
 421                seq_printf(m, "%s", symname);
 422        else
 423                seq_putc(m, '0');
 424
 425        return 0;
 426}
 427#endif /* CONFIG_KALLSYMS */
 428
 429static int lock_trace(struct task_struct *task)
 430{
 431        int err = mutex_lock_killable(&task->signal->cred_guard_mutex);
 432        if (err)
 433                return err;
 434        if (!ptrace_may_access(task, PTRACE_MODE_ATTACH_FSCREDS)) {
 435                mutex_unlock(&task->signal->cred_guard_mutex);
 436                return -EPERM;
 437        }
 438        return 0;
 439}
 440
 441static void unlock_trace(struct task_struct *task)
 442{
 443        mutex_unlock(&task->signal->cred_guard_mutex);
 444}
 445
 446#ifdef CONFIG_STACKTRACE
 447
 448#define MAX_STACK_TRACE_DEPTH   64
 449
 450static int proc_pid_stack(struct seq_file *m, struct pid_namespace *ns,
 451                          struct pid *pid, struct task_struct *task)
 452{
 453        struct stack_trace trace;
 454        unsigned long *entries;
 455        int err;
 456        int i;
 457
 458        entries = kmalloc(MAX_STACK_TRACE_DEPTH * sizeof(*entries), GFP_KERNEL);
 459        if (!entries)
 460                return -ENOMEM;
 461
 462        trace.nr_entries        = 0;
 463        trace.max_entries       = MAX_STACK_TRACE_DEPTH;
 464        trace.entries           = entries;
 465        trace.skip              = 0;
 466
 467        err = lock_trace(task);
 468        if (!err) {
 469                save_stack_trace_tsk(task, &trace);
 470
 471                for (i = 0; i < trace.nr_entries; i++) {
 472                        seq_printf(m, "[<%pK>] %pB\n",
 473                                   (void *)entries[i], (void *)entries[i]);
 474                }
 475                unlock_trace(task);
 476        }
 477        kfree(entries);
 478
 479        return err;
 480}
 481#endif
 482
 483#ifdef CONFIG_SCHED_INFO
 484/*
 485 * Provides /proc/PID/schedstat
 486 */
 487static int proc_pid_schedstat(struct seq_file *m, struct pid_namespace *ns,
 488                              struct pid *pid, struct task_struct *task)
 489{
 490        if (unlikely(!sched_info_on()))
 491                seq_printf(m, "0 0 0\n");
 492        else
 493                seq_printf(m, "%llu %llu %lu\n",
 494                   (unsigned long long)task->se.sum_exec_runtime,
 495                   (unsigned long long)task->sched_info.run_delay,
 496                   task->sched_info.pcount);
 497
 498        return 0;
 499}
 500#endif
 501
 502#ifdef CONFIG_LATENCYTOP
 503static int lstats_show_proc(struct seq_file *m, void *v)
 504{
 505        int i;
 506        struct inode *inode = m->private;
 507        struct task_struct *task = get_proc_task(inode);
 508
 509        if (!task)
 510                return -ESRCH;
 511        seq_puts(m, "Latency Top version : v0.1\n");
 512        for (i = 0; i < 32; i++) {
 513                struct latency_record *lr = &task->latency_record[i];
 514                if (lr->backtrace[0]) {
 515                        int q;
 516                        seq_printf(m, "%i %li %li",
 517                                   lr->count, lr->time, lr->max);
 518                        for (q = 0; q < LT_BACKTRACEDEPTH; q++) {
 519                                unsigned long bt = lr->backtrace[q];
 520                                if (!bt)
 521                                        break;
 522                                if (bt == ULONG_MAX)
 523                                        break;
 524                                seq_printf(m, " %ps", (void *)bt);
 525                        }
 526                        seq_putc(m, '\n');
 527                }
 528
 529        }
 530        put_task_struct(task);
 531        return 0;
 532}
 533
 534static int lstats_open(struct inode *inode, struct file *file)
 535{
 536        return single_open(file, lstats_show_proc, inode);
 537}
 538
 539static ssize_t lstats_write(struct file *file, const char __user *buf,
 540                            size_t count, loff_t *offs)
 541{
 542        struct task_struct *task = get_proc_task(file_inode(file));
 543
 544        if (!task)
 545                return -ESRCH;
 546        clear_all_latency_tracing(task);
 547        put_task_struct(task);
 548
 549        return count;
 550}
 551
 552static const struct file_operations proc_lstats_operations = {
 553        .open           = lstats_open,
 554        .read           = seq_read,
 555        .write          = lstats_write,
 556        .llseek         = seq_lseek,
 557        .release        = single_release,
 558};
 559
 560#endif
 561
 562static int proc_oom_score(struct seq_file *m, struct pid_namespace *ns,
 563                          struct pid *pid, struct task_struct *task)
 564{
 565        unsigned long totalpages = totalram_pages + total_swap_pages;
 566        unsigned long points = 0;
 567
 568        points = oom_badness(task, NULL, NULL, totalpages) *
 569                                        1000 / totalpages;
 570        seq_printf(m, "%lu\n", points);
 571
 572        return 0;
 573}
 574
 575struct limit_names {
 576        const char *name;
 577        const char *unit;
 578};
 579
 580static const struct limit_names lnames[RLIM_NLIMITS] = {
 581        [RLIMIT_CPU] = {"Max cpu time", "seconds"},
 582        [RLIMIT_FSIZE] = {"Max file size", "bytes"},
 583        [RLIMIT_DATA] = {"Max data size", "bytes"},
 584        [RLIMIT_STACK] = {"Max stack size", "bytes"},
 585        [RLIMIT_CORE] = {"Max core file size", "bytes"},
 586        [RLIMIT_RSS] = {"Max resident set", "bytes"},
 587        [RLIMIT_NPROC] = {"Max processes", "processes"},
 588        [RLIMIT_NOFILE] = {"Max open files", "files"},
 589        [RLIMIT_MEMLOCK] = {"Max locked memory", "bytes"},
 590        [RLIMIT_AS] = {"Max address space", "bytes"},
 591        [RLIMIT_LOCKS] = {"Max file locks", "locks"},
 592        [RLIMIT_SIGPENDING] = {"Max pending signals", "signals"},
 593        [RLIMIT_MSGQUEUE] = {"Max msgqueue size", "bytes"},
 594        [RLIMIT_NICE] = {"Max nice priority", NULL},
 595        [RLIMIT_RTPRIO] = {"Max realtime priority", NULL},
 596        [RLIMIT_RTTIME] = {"Max realtime timeout", "us"},
 597};
 598
 599/* Display limits for a process */
 600static int proc_pid_limits(struct seq_file *m, struct pid_namespace *ns,
 601                           struct pid *pid, struct task_struct *task)
 602{
 603        unsigned int i;
 604        unsigned long flags;
 605
 606        struct rlimit rlim[RLIM_NLIMITS];
 607
 608        if (!lock_task_sighand(task, &flags))
 609                return 0;
 610        memcpy(rlim, task->signal->rlim, sizeof(struct rlimit) * RLIM_NLIMITS);
 611        unlock_task_sighand(task, &flags);
 612
 613        /*
 614         * print the file header
 615         */
 616       seq_printf(m, "%-25s %-20s %-20s %-10s\n",
 617                  "Limit", "Soft Limit", "Hard Limit", "Units");
 618
 619        for (i = 0; i < RLIM_NLIMITS; i++) {
 620                if (rlim[i].rlim_cur == RLIM_INFINITY)
 621                        seq_printf(m, "%-25s %-20s ",
 622                                   lnames[i].name, "unlimited");
 623                else
 624                        seq_printf(m, "%-25s %-20lu ",
 625                                   lnames[i].name, rlim[i].rlim_cur);
 626
 627                if (rlim[i].rlim_max == RLIM_INFINITY)
 628                        seq_printf(m, "%-20s ", "unlimited");
 629                else
 630                        seq_printf(m, "%-20lu ", rlim[i].rlim_max);
 631
 632                if (lnames[i].unit)
 633                        seq_printf(m, "%-10s\n", lnames[i].unit);
 634                else
 635                        seq_putc(m, '\n');
 636        }
 637
 638        return 0;
 639}
 640
 641#ifdef CONFIG_HAVE_ARCH_TRACEHOOK
 642static int proc_pid_syscall(struct seq_file *m, struct pid_namespace *ns,
 643                            struct pid *pid, struct task_struct *task)
 644{
 645        long nr;
 646        unsigned long args[6], sp, pc;
 647        int res;
 648
 649        res = lock_trace(task);
 650        if (res)
 651                return res;
 652
 653        if (task_current_syscall(task, &nr, args, 6, &sp, &pc))
 654                seq_puts(m, "running\n");
 655        else if (nr < 0)
 656                seq_printf(m, "%ld 0x%lx 0x%lx\n", nr, sp, pc);
 657        else
 658                seq_printf(m,
 659                       "%ld 0x%lx 0x%lx 0x%lx 0x%lx 0x%lx 0x%lx 0x%lx 0x%lx\n",
 660                       nr,
 661                       args[0], args[1], args[2], args[3], args[4], args[5],
 662                       sp, pc);
 663        unlock_trace(task);
 664
 665        return 0;
 666}
 667#endif /* CONFIG_HAVE_ARCH_TRACEHOOK */
 668
 669/************************************************************************/
 670/*                       Here the fs part begins                        */
 671/************************************************************************/
 672
 673/* permission checks */
 674static int proc_fd_access_allowed(struct inode *inode)
 675{
 676        struct task_struct *task;
 677        int allowed = 0;
 678        /* Allow access to a task's file descriptors if it is us or we
 679         * may use ptrace attach to the process and find out that
 680         * information.
 681         */
 682        task = get_proc_task(inode);
 683        if (task) {
 684                allowed = ptrace_may_access(task, PTRACE_MODE_READ_FSCREDS);
 685                put_task_struct(task);
 686        }
 687        return allowed;
 688}
 689
 690int proc_setattr(struct dentry *dentry, struct iattr *attr)
 691{
 692        int error;
 693        struct inode *inode = d_inode(dentry);
 694
 695        if (attr->ia_valid & ATTR_MODE)
 696                return -EPERM;
 697
 698        error = setattr_prepare(dentry, attr);
 699        if (error)
 700                return error;
 701
 702        setattr_copy(inode, attr);
 703        mark_inode_dirty(inode);
 704        return 0;
 705}
 706
 707/*
 708 * May current process learn task's sched/cmdline info (for hide_pid_min=1)
 709 * or euid/egid (for hide_pid_min=2)?
 710 */
 711static bool has_pid_permissions(struct pid_namespace *pid,
 712                                 struct task_struct *task,
 713                                 int hide_pid_min)
 714{
 715        if (pid->hide_pid < hide_pid_min)
 716                return true;
 717        if (in_group_p(pid->pid_gid))
 718                return true;
 719        return ptrace_may_access(task, PTRACE_MODE_READ_FSCREDS);
 720}
 721
 722
 723static int proc_pid_permission(struct inode *inode, int mask)
 724{
 725        struct pid_namespace *pid = inode->i_sb->s_fs_info;
 726        struct task_struct *task;
 727        bool has_perms;
 728
 729        task = get_proc_task(inode);
 730        if (!task)
 731                return -ESRCH;
 732        has_perms = has_pid_permissions(pid, task, 1);
 733        put_task_struct(task);
 734
 735        if (!has_perms) {
 736                if (pid->hide_pid == 2) {
 737                        /*
 738                         * Let's make getdents(), stat(), and open()
 739                         * consistent with each other.  If a process
 740                         * may not stat() a file, it shouldn't be seen
 741                         * in procfs at all.
 742                         */
 743                        return -ENOENT;
 744                }
 745
 746                return -EPERM;
 747        }
 748        return generic_permission(inode, mask);
 749}
 750
 751
 752
 753static const struct inode_operations proc_def_inode_operations = {
 754        .setattr        = proc_setattr,
 755};
 756
 757static int proc_single_show(struct seq_file *m, void *v)
 758{
 759        struct inode *inode = m->private;
 760        struct pid_namespace *ns;
 761        struct pid *pid;
 762        struct task_struct *task;
 763        int ret;
 764
 765        ns = inode->i_sb->s_fs_info;
 766        pid = proc_pid(inode);
 767        task = get_pid_task(pid, PIDTYPE_PID);
 768        if (!task)
 769                return -ESRCH;
 770
 771        ret = PROC_I(inode)->op.proc_show(m, ns, pid, task);
 772
 773        put_task_struct(task);
 774        return ret;
 775}
 776
 777static int proc_single_open(struct inode *inode, struct file *filp)
 778{
 779        return single_open(filp, proc_single_show, inode);
 780}
 781
 782static const struct file_operations proc_single_file_operations = {
 783        .open           = proc_single_open,
 784        .read           = seq_read,
 785        .llseek         = seq_lseek,
 786        .release        = single_release,
 787};
 788
 789
 790struct mm_struct *proc_mem_open(struct inode *inode, unsigned int mode)
 791{
 792        struct task_struct *task = get_proc_task(inode);
 793        struct mm_struct *mm = ERR_PTR(-ESRCH);
 794
 795        if (task) {
 796                mm = mm_access(task, mode | PTRACE_MODE_FSCREDS);
 797                put_task_struct(task);
 798
 799                if (!IS_ERR_OR_NULL(mm)) {
 800                        /* ensure this mm_struct can't be freed */
 801                        atomic_inc(&mm->mm_count);
 802                        /* but do not pin its memory */
 803                        mmput(mm);
 804                }
 805        }
 806
 807        return mm;
 808}
 809
 810static int __mem_open(struct inode *inode, struct file *file, unsigned int mode)
 811{
 812        struct mm_struct *mm = proc_mem_open(inode, mode);
 813
 814        if (IS_ERR(mm))
 815                return PTR_ERR(mm);
 816
 817        file->private_data = mm;
 818        return 0;
 819}
 820
 821static int mem_open(struct inode *inode, struct file *file)
 822{
 823        int ret = __mem_open(inode, file, PTRACE_MODE_ATTACH);
 824
 825        /* OK to pass negative loff_t, we can catch out-of-range */
 826        file->f_mode |= FMODE_UNSIGNED_OFFSET;
 827
 828        return ret;
 829}
 830
 831static ssize_t mem_rw(struct file *file, char __user *buf,
 832                        size_t count, loff_t *ppos, int write)
 833{
 834        struct mm_struct *mm = file->private_data;
 835        unsigned long addr = *ppos;
 836        ssize_t copied;
 837        char *page;
 838        unsigned int flags;
 839
 840        if (!mm)
 841                return 0;
 842
 843        page = (char *)__get_free_page(GFP_TEMPORARY);
 844        if (!page)
 845                return -ENOMEM;
 846
 847        copied = 0;
 848        if (!atomic_inc_not_zero(&mm->mm_users))
 849                goto free;
 850
 851        /* Maybe we should limit FOLL_FORCE to actual ptrace users? */
 852        flags = FOLL_FORCE;
 853        if (write)
 854                flags |= FOLL_WRITE;
 855
 856        while (count > 0) {
 857                int this_len = min_t(int, count, PAGE_SIZE);
 858
 859                if (write && copy_from_user(page, buf, this_len)) {
 860                        copied = -EFAULT;
 861                        break;
 862                }
 863
 864                this_len = access_remote_vm(mm, addr, page, this_len, flags);
 865                if (!this_len) {
 866                        if (!copied)
 867                                copied = -EIO;
 868                        break;
 869                }
 870
 871                if (!write && copy_to_user(buf, page, this_len)) {
 872                        copied = -EFAULT;
 873                        break;
 874                }
 875
 876                buf += this_len;
 877                addr += this_len;
 878                copied += this_len;
 879                count -= this_len;
 880        }
 881        *ppos = addr;
 882
 883        mmput(mm);
 884free:
 885        free_page((unsigned long) page);
 886        return copied;
 887}
 888
 889static ssize_t mem_read(struct file *file, char __user *buf,
 890                        size_t count, loff_t *ppos)
 891{
 892        return mem_rw(file, buf, count, ppos, 0);
 893}
 894
 895static ssize_t mem_write(struct file *file, const char __user *buf,
 896                         size_t count, loff_t *ppos)
 897{
 898        return mem_rw(file, (char __user*)buf, count, ppos, 1);
 899}
 900
 901loff_t mem_lseek(struct file *file, loff_t offset, int orig)
 902{
 903        switch (orig) {
 904        case 0:
 905                file->f_pos = offset;
 906                break;
 907        case 1:
 908                file->f_pos += offset;
 909                break;
 910        default:
 911                return -EINVAL;
 912        }
 913        force_successful_syscall_return();
 914        return file->f_pos;
 915}
 916
 917static int mem_release(struct inode *inode, struct file *file)
 918{
 919        struct mm_struct *mm = file->private_data;
 920        if (mm)
 921                mmdrop(mm);
 922        return 0;
 923}
 924
 925static const struct file_operations proc_mem_operations = {
 926        .llseek         = mem_lseek,
 927        .read           = mem_read,
 928        .write          = mem_write,
 929        .open           = mem_open,
 930        .release        = mem_release,
 931};
 932
 933static int environ_open(struct inode *inode, struct file *file)
 934{
 935        return __mem_open(inode, file, PTRACE_MODE_READ);
 936}
 937
 938static ssize_t environ_read(struct file *file, char __user *buf,
 939                        size_t count, loff_t *ppos)
 940{
 941        char *page;
 942        unsigned long src = *ppos;
 943        int ret = 0;
 944        struct mm_struct *mm = file->private_data;
 945        unsigned long env_start, env_end;
 946
 947        /* Ensure the process spawned far enough to have an environment. */
 948        if (!mm || !mm->env_end)
 949                return 0;
 950
 951        page = (char *)__get_free_page(GFP_TEMPORARY);
 952        if (!page)
 953                return -ENOMEM;
 954
 955        ret = 0;
 956        if (!atomic_inc_not_zero(&mm->mm_users))
 957                goto free;
 958
 959        down_read(&mm->mmap_sem);
 960        env_start = mm->env_start;
 961        env_end = mm->env_end;
 962        up_read(&mm->mmap_sem);
 963
 964        while (count > 0) {
 965                size_t this_len, max_len;
 966                int retval;
 967
 968                if (src >= (env_end - env_start))
 969                        break;
 970
 971                this_len = env_end - (env_start + src);
 972
 973                max_len = min_t(size_t, PAGE_SIZE, count);
 974                this_len = min(max_len, this_len);
 975
 976                retval = access_remote_vm(mm, (env_start + src), page, this_len, 0);
 977
 978                if (retval <= 0) {
 979                        ret = retval;
 980                        break;
 981                }
 982
 983                if (copy_to_user(buf, page, retval)) {
 984                        ret = -EFAULT;
 985                        break;
 986                }
 987
 988                ret += retval;
 989                src += retval;
 990                buf += retval;
 991                count -= retval;
 992        }
 993        *ppos = src;
 994        mmput(mm);
 995
 996free:
 997        free_page((unsigned long) page);
 998        return ret;
 999}
1000
1001static const struct file_operations proc_environ_operations = {
1002        .open           = environ_open,
1003        .read           = environ_read,
1004        .llseek         = generic_file_llseek,
1005        .release        = mem_release,
1006};
1007
1008static int auxv_open(struct inode *inode, struct file *file)
1009{
1010        return __mem_open(inode, file, PTRACE_MODE_READ_FSCREDS);
1011}
1012
1013static ssize_t auxv_read(struct file *file, char __user *buf,
1014                        size_t count, loff_t *ppos)
1015{
1016        struct mm_struct *mm = file->private_data;
1017        unsigned int nwords = 0;
1018
1019        if (!mm)
1020                return 0;
1021        do {
1022                nwords += 2;
1023        } while (mm->saved_auxv[nwords - 2] != 0); /* AT_NULL */
1024        return simple_read_from_buffer(buf, count, ppos, mm->saved_auxv,
1025                                       nwords * sizeof(mm->saved_auxv[0]));
1026}
1027
1028static const struct file_operations proc_auxv_operations = {
1029        .open           = auxv_open,
1030        .read           = auxv_read,
1031        .llseek         = generic_file_llseek,
1032        .release        = mem_release,
1033};
1034
1035static ssize_t oom_adj_read(struct file *file, char __user *buf, size_t count,
1036                            loff_t *ppos)
1037{
1038        struct task_struct *task = get_proc_task(file_inode(file));
1039        char buffer[PROC_NUMBUF];
1040        int oom_adj = OOM_ADJUST_MIN;
1041        size_t len;
1042
1043        if (!task)
1044                return -ESRCH;
1045        if (task->signal->oom_score_adj == OOM_SCORE_ADJ_MAX)
1046                oom_adj = OOM_ADJUST_MAX;
1047        else
1048                oom_adj = (task->signal->oom_score_adj * -OOM_DISABLE) /
1049                          OOM_SCORE_ADJ_MAX;
1050        put_task_struct(task);
1051        len = snprintf(buffer, sizeof(buffer), "%d\n", oom_adj);
1052        return simple_read_from_buffer(buf, count, ppos, buffer, len);
1053}
1054
1055static int __set_oom_adj(struct file *file, int oom_adj, bool legacy)
1056{
1057        static DEFINE_MUTEX(oom_adj_mutex);
1058        struct mm_struct *mm = NULL;
1059        struct task_struct *task;
1060        int err = 0;
1061
1062        task = get_proc_task(file_inode(file));
1063        if (!task)
1064                return -ESRCH;
1065
1066        mutex_lock(&oom_adj_mutex);
1067        if (legacy) {
1068                if (oom_adj < task->signal->oom_score_adj &&
1069                                !capable(CAP_SYS_RESOURCE)) {
1070                        err = -EACCES;
1071                        goto err_unlock;
1072                }
1073                /*
1074                 * /proc/pid/oom_adj is provided for legacy purposes, ask users to use
1075                 * /proc/pid/oom_score_adj instead.
1076                 */
1077                pr_warn_once("%s (%d): /proc/%d/oom_adj is deprecated, please use /proc/%d/oom_score_adj instead.\n",
1078                          current->comm, task_pid_nr(current), task_pid_nr(task),
1079                          task_pid_nr(task));
1080        } else {
1081                if ((short)oom_adj < task->signal->oom_score_adj_min &&
1082                                !capable(CAP_SYS_RESOURCE)) {
1083                        err = -EACCES;
1084                        goto err_unlock;
1085                }
1086        }
1087
1088        /*
1089         * Make sure we will check other processes sharing the mm if this is
1090         * not vfrok which wants its own oom_score_adj.
1091         * pin the mm so it doesn't go away and get reused after task_unlock
1092         */
1093        if (!task->vfork_done) {
1094                struct task_struct *p = find_lock_task_mm(task);
1095
1096                if (p) {
1097                        if (atomic_read(&p->mm->mm_users) > 1) {
1098                                mm = p->mm;
1099                                atomic_inc(&mm->mm_count);
1100                        }
1101                        task_unlock(p);
1102                }
1103        }
1104
1105        task->signal->oom_score_adj = oom_adj;
1106        if (!legacy && has_capability_noaudit(current, CAP_SYS_RESOURCE))
1107                task->signal->oom_score_adj_min = (short)oom_adj;
1108        trace_oom_score_adj_update(task);
1109
1110        if (mm) {
1111                struct task_struct *p;
1112
1113                rcu_read_lock();
1114                for_each_process(p) {
1115                        if (same_thread_group(task, p))
1116                                continue;
1117
1118                        /* do not touch kernel threads or the global init */
1119                        if (p->flags & PF_KTHREAD || is_global_init(p))
1120                                continue;
1121
1122                        task_lock(p);
1123                        if (!p->vfork_done && process_shares_mm(p, mm)) {
1124                                pr_info("updating oom_score_adj for %d (%s) from %d to %d because it shares mm with %d (%s). Report if this is unexpected.\n",
1125                                                task_pid_nr(p), p->comm,
1126                                                p->signal->oom_score_adj, oom_adj,
1127                                                task_pid_nr(task), task->comm);
1128                                p->signal->oom_score_adj = oom_adj;
1129                                if (!legacy && has_capability_noaudit(current, CAP_SYS_RESOURCE))
1130                                        p->signal->oom_score_adj_min = (short)oom_adj;
1131                        }
1132                        task_unlock(p);
1133                }
1134                rcu_read_unlock();
1135                mmdrop(mm);
1136        }
1137err_unlock:
1138        mutex_unlock(&oom_adj_mutex);
1139        put_task_struct(task);
1140        return err;
1141}
1142
1143/*
1144 * /proc/pid/oom_adj exists solely for backwards compatibility with previous
1145 * kernels.  The effective policy is defined by oom_score_adj, which has a
1146 * different scale: oom_adj grew exponentially and oom_score_adj grows linearly.
1147 * Values written to oom_adj are simply mapped linearly to oom_score_adj.
1148 * Processes that become oom disabled via oom_adj will still be oom disabled
1149 * with this implementation.
1150 *
1151 * oom_adj cannot be removed since existing userspace binaries use it.
1152 */
1153static ssize_t oom_adj_write(struct file *file, const char __user *buf,
1154                             size_t count, loff_t *ppos)
1155{
1156        char buffer[PROC_NUMBUF];
1157        int oom_adj;
1158        int err;
1159
1160        memset(buffer, 0, sizeof(buffer));
1161        if (count > sizeof(buffer) - 1)
1162                count = sizeof(buffer) - 1;
1163        if (copy_from_user(buffer, buf, count)) {
1164                err = -EFAULT;
1165                goto out;
1166        }
1167
1168        err = kstrtoint(strstrip(buffer), 0, &oom_adj);
1169        if (err)
1170                goto out;
1171        if ((oom_adj < OOM_ADJUST_MIN || oom_adj > OOM_ADJUST_MAX) &&
1172             oom_adj != OOM_DISABLE) {
1173                err = -EINVAL;
1174                goto out;
1175        }
1176
1177        /*
1178         * Scale /proc/pid/oom_score_adj appropriately ensuring that a maximum
1179         * value is always attainable.
1180         */
1181        if (oom_adj == OOM_ADJUST_MAX)
1182                oom_adj = OOM_SCORE_ADJ_MAX;
1183        else
1184                oom_adj = (oom_adj * OOM_SCORE_ADJ_MAX) / -OOM_DISABLE;
1185
1186        err = __set_oom_adj(file, oom_adj, true);
1187out:
1188        return err < 0 ? err : count;
1189}
1190
1191static const struct file_operations proc_oom_adj_operations = {
1192        .read           = oom_adj_read,
1193        .write          = oom_adj_write,
1194        .llseek         = generic_file_llseek,
1195};
1196
1197static ssize_t oom_score_adj_read(struct file *file, char __user *buf,
1198                                        size_t count, loff_t *ppos)
1199{
1200        struct task_struct *task = get_proc_task(file_inode(file));
1201        char buffer[PROC_NUMBUF];
1202        short oom_score_adj = OOM_SCORE_ADJ_MIN;
1203        size_t len;
1204
1205        if (!task)
1206                return -ESRCH;
1207        oom_score_adj = task->signal->oom_score_adj;
1208        put_task_struct(task);
1209        len = snprintf(buffer, sizeof(buffer), "%hd\n", oom_score_adj);
1210        return simple_read_from_buffer(buf, count, ppos, buffer, len);
1211}
1212
1213static ssize_t oom_score_adj_write(struct file *file, const char __user *buf,
1214                                        size_t count, loff_t *ppos)
1215{
1216        char buffer[PROC_NUMBUF];
1217        int oom_score_adj;
1218        int err;
1219
1220        memset(buffer, 0, sizeof(buffer));
1221        if (count > sizeof(buffer) - 1)
1222                count = sizeof(buffer) - 1;
1223        if (copy_from_user(buffer, buf, count)) {
1224                err = -EFAULT;
1225                goto out;
1226        }
1227
1228        err = kstrtoint(strstrip(buffer), 0, &oom_score_adj);
1229        if (err)
1230                goto out;
1231        if (oom_score_adj < OOM_SCORE_ADJ_MIN ||
1232                        oom_score_adj > OOM_SCORE_ADJ_MAX) {
1233                err = -EINVAL;
1234                goto out;
1235        }
1236
1237        err = __set_oom_adj(file, oom_score_adj, false);
1238out:
1239        return err < 0 ? err : count;
1240}
1241
1242static const struct file_operations proc_oom_score_adj_operations = {
1243        .read           = oom_score_adj_read,
1244        .write          = oom_score_adj_write,
1245        .llseek         = default_llseek,
1246};
1247
1248#ifdef CONFIG_AUDITSYSCALL
1249#define TMPBUFLEN 11
1250static ssize_t proc_loginuid_read(struct file * file, char __user * buf,
1251                                  size_t count, loff_t *ppos)
1252{
1253        struct inode * inode = file_inode(file);
1254        struct task_struct *task = get_proc_task(inode);
1255        ssize_t length;
1256        char tmpbuf[TMPBUFLEN];
1257
1258        if (!task)
1259                return -ESRCH;
1260        length = scnprintf(tmpbuf, TMPBUFLEN, "%u",
1261                           from_kuid(file->f_cred->user_ns,
1262                                     audit_get_loginuid(task)));
1263        put_task_struct(task);
1264        return simple_read_from_buffer(buf, count, ppos, tmpbuf, length);
1265}
1266
1267static ssize_t proc_loginuid_write(struct file * file, const char __user * buf,
1268                                   size_t count, loff_t *ppos)
1269{
1270        struct inode * inode = file_inode(file);
1271        uid_t loginuid;
1272        kuid_t kloginuid;
1273        int rv;
1274
1275        rcu_read_lock();
1276        if (current != pid_task(proc_pid(inode), PIDTYPE_PID)) {
1277                rcu_read_unlock();
1278                return -EPERM;
1279        }
1280        rcu_read_unlock();
1281
1282        if (*ppos != 0) {
1283                /* No partial writes. */
1284                return -EINVAL;
1285        }
1286
1287        rv = kstrtou32_from_user(buf, count, 10, &loginuid);
1288        if (rv < 0)
1289                return rv;
1290
1291        /* is userspace tring to explicitly UNSET the loginuid? */
1292        if (loginuid == AUDIT_UID_UNSET) {
1293                kloginuid = INVALID_UID;
1294        } else {
1295                kloginuid = make_kuid(file->f_cred->user_ns, loginuid);
1296                if (!uid_valid(kloginuid))
1297                        return -EINVAL;
1298        }
1299
1300        rv = audit_set_loginuid(kloginuid);
1301        if (rv < 0)
1302                return rv;
1303        return count;
1304}
1305
1306static const struct file_operations proc_loginuid_operations = {
1307        .read           = proc_loginuid_read,
1308        .write          = proc_loginuid_write,
1309        .llseek         = generic_file_llseek,
1310};
1311
1312static ssize_t proc_sessionid_read(struct file * file, char __user * buf,
1313                                  size_t count, loff_t *ppos)
1314{
1315        struct inode * inode = file_inode(file);
1316        struct task_struct *task = get_proc_task(inode);
1317        ssize_t length;
1318        char tmpbuf[TMPBUFLEN];
1319
1320        if (!task)
1321                return -ESRCH;
1322        length = scnprintf(tmpbuf, TMPBUFLEN, "%u",
1323                                audit_get_sessionid(task));
1324        put_task_struct(task);
1325        return simple_read_from_buffer(buf, count, ppos, tmpbuf, length);
1326}
1327
1328static const struct file_operations proc_sessionid_operations = {
1329        .read           = proc_sessionid_read,
1330        .llseek         = generic_file_llseek,
1331};
1332#endif
1333
1334#ifdef CONFIG_FAULT_INJECTION
1335static ssize_t proc_fault_inject_read(struct file * file, char __user * buf,
1336                                      size_t count, loff_t *ppos)
1337{
1338        struct task_struct *task = get_proc_task(file_inode(file));
1339        char buffer[PROC_NUMBUF];
1340        size_t len;
1341        int make_it_fail;
1342
1343        if (!task)
1344                return -ESRCH;
1345        make_it_fail = task->make_it_fail;
1346        put_task_struct(task);
1347
1348        len = snprintf(buffer, sizeof(buffer), "%i\n", make_it_fail);
1349
1350        return simple_read_from_buffer(buf, count, ppos, buffer, len);
1351}
1352
1353static ssize_t proc_fault_inject_write(struct file * file,
1354                        const char __user * buf, size_t count, loff_t *ppos)
1355{
1356        struct task_struct *task;
1357        char buffer[PROC_NUMBUF];
1358        int make_it_fail;
1359        int rv;
1360
1361        if (!capable(CAP_SYS_RESOURCE))
1362                return -EPERM;
1363        memset(buffer, 0, sizeof(buffer));
1364        if (count > sizeof(buffer) - 1)
1365                count = sizeof(buffer) - 1;
1366        if (copy_from_user(buffer, buf, count))
1367                return -EFAULT;
1368        rv = kstrtoint(strstrip(buffer), 0, &make_it_fail);
1369        if (rv < 0)
1370                return rv;
1371        if (make_it_fail < 0 || make_it_fail > 1)
1372                return -EINVAL;
1373
1374        task = get_proc_task(file_inode(file));
1375        if (!task)
1376                return -ESRCH;
1377        task->make_it_fail = make_it_fail;
1378        put_task_struct(task);
1379
1380        return count;
1381}
1382
1383static const struct file_operations proc_fault_inject_operations = {
1384        .read           = proc_fault_inject_read,
1385        .write          = proc_fault_inject_write,
1386        .llseek         = generic_file_llseek,
1387};
1388#endif
1389
1390
1391#ifdef CONFIG_SCHED_DEBUG
1392/*
1393 * Print out various scheduling related per-task fields:
1394 */
1395static int sched_show(struct seq_file *m, void *v)
1396{
1397        struct inode *inode = m->private;
1398        struct task_struct *p;
1399
1400        p = get_proc_task(inode);
1401        if (!p)
1402                return -ESRCH;
1403        proc_sched_show_task(p, m);
1404
1405        put_task_struct(p);
1406
1407        return 0;
1408}
1409
1410static ssize_t
1411sched_write(struct file *file, const char __user *buf,
1412            size_t count, loff_t *offset)
1413{
1414        struct inode *inode = file_inode(file);
1415        struct task_struct *p;
1416
1417        p = get_proc_task(inode);
1418        if (!p)
1419                return -ESRCH;
1420        proc_sched_set_task(p);
1421
1422        put_task_struct(p);
1423
1424        return count;
1425}
1426
1427static int sched_open(struct inode *inode, struct file *filp)
1428{
1429        return single_open(filp, sched_show, inode);
1430}
1431
1432static const struct file_operations proc_pid_sched_operations = {
1433        .open           = sched_open,
1434        .read           = seq_read,
1435        .write          = sched_write,
1436        .llseek         = seq_lseek,
1437        .release        = single_release,
1438};
1439
1440#endif
1441
1442#ifdef CONFIG_SCHED_AUTOGROUP
1443/*
1444 * Print out autogroup related information:
1445 */
1446static int sched_autogroup_show(struct seq_file *m, void *v)
1447{
1448        struct inode *inode = m->private;
1449        struct task_struct *p;
1450
1451        p = get_proc_task(inode);
1452        if (!p)
1453                return -ESRCH;
1454        proc_sched_autogroup_show_task(p, m);
1455
1456        put_task_struct(p);
1457
1458        return 0;
1459}
1460
1461static ssize_t
1462sched_autogroup_write(struct file *file, const char __user *buf,
1463            size_t count, loff_t *offset)
1464{
1465        struct inode *inode = file_inode(file);
1466        struct task_struct *p;
1467        char buffer[PROC_NUMBUF];
1468        int nice;
1469        int err;
1470
1471        memset(buffer, 0, sizeof(buffer));
1472        if (count > sizeof(buffer) - 1)
1473                count = sizeof(buffer) - 1;
1474        if (copy_from_user(buffer, buf, count))
1475                return -EFAULT;
1476
1477        err = kstrtoint(strstrip(buffer), 0, &nice);
1478        if (err < 0)
1479                return err;
1480
1481        p = get_proc_task(inode);
1482        if (!p)
1483                return -ESRCH;
1484
1485        err = proc_sched_autogroup_set_nice(p, nice);
1486        if (err)
1487                count = err;
1488
1489        put_task_struct(p);
1490
1491        return count;
1492}
1493
1494static int sched_autogroup_open(struct inode *inode, struct file *filp)
1495{
1496        int ret;
1497
1498        ret = single_open(filp, sched_autogroup_show, NULL);
1499        if (!ret) {
1500                struct seq_file *m = filp->private_data;
1501
1502                m->private = inode;
1503        }
1504        return ret;
1505}
1506
1507static const struct file_operations proc_pid_sched_autogroup_operations = {
1508        .open           = sched_autogroup_open,
1509        .read           = seq_read,
1510        .write          = sched_autogroup_write,
1511        .llseek         = seq_lseek,
1512        .release        = single_release,
1513};
1514
1515#endif /* CONFIG_SCHED_AUTOGROUP */
1516
1517static ssize_t comm_write(struct file *file, const char __user *buf,
1518                                size_t count, loff_t *offset)
1519{
1520        struct inode *inode = file_inode(file);
1521        struct task_struct *p;
1522        char buffer[TASK_COMM_LEN];
1523        const size_t maxlen = sizeof(buffer) - 1;
1524
1525        memset(buffer, 0, sizeof(buffer));
1526        if (copy_from_user(buffer, buf, count > maxlen ? maxlen : count))
1527                return -EFAULT;
1528
1529        p = get_proc_task(inode);
1530        if (!p)
1531                return -ESRCH;
1532
1533        if (same_thread_group(current, p))
1534                set_task_comm(p, buffer);
1535        else
1536                count = -EINVAL;
1537
1538        put_task_struct(p);
1539
1540        return count;
1541}
1542
1543static int comm_show(struct seq_file *m, void *v)
1544{
1545        struct inode *inode = m->private;
1546        struct task_struct *p;
1547
1548        p = get_proc_task(inode);
1549        if (!p)
1550                return -ESRCH;
1551
1552        task_lock(p);
1553        seq_printf(m, "%s\n", p->comm);
1554        task_unlock(p);
1555
1556        put_task_struct(p);
1557
1558        return 0;
1559}
1560
1561static int comm_open(struct inode *inode, struct file *filp)
1562{
1563        return single_open(filp, comm_show, inode);
1564}
1565
1566static const struct file_operations proc_pid_set_comm_operations = {
1567        .open           = comm_open,
1568        .read           = seq_read,
1569        .write          = comm_write,
1570        .llseek         = seq_lseek,
1571        .release        = single_release,
1572};
1573
1574static int proc_exe_link(struct dentry *dentry, struct path *exe_path)
1575{
1576        struct task_struct *task;
1577        struct file *exe_file;
1578
1579        task = get_proc_task(d_inode(dentry));
1580        if (!task)
1581                return -ENOENT;
1582        exe_file = get_task_exe_file(task);
1583        put_task_struct(task);
1584        if (exe_file) {
1585                *exe_path = exe_file->f_path;
1586                path_get(&exe_file->f_path);
1587                fput(exe_file);
1588                return 0;
1589        } else
1590                return -ENOENT;
1591}
1592
1593static const char *proc_pid_get_link(struct dentry *dentry,
1594                                     struct inode *inode,
1595                                     struct delayed_call *done)
1596{
1597        struct path path;
1598        int error = -EACCES;
1599
1600        if (!dentry)
1601                return ERR_PTR(-ECHILD);
1602
1603        /* Are we allowed to snoop on the tasks file descriptors? */
1604        if (!proc_fd_access_allowed(inode))
1605                goto out;
1606
1607        error = PROC_I(inode)->op.proc_get_link(dentry, &path);
1608        if (error)
1609                goto out;
1610
1611        nd_jump_link(&path);
1612        return NULL;
1613out:
1614        return ERR_PTR(error);
1615}
1616
1617static int do_proc_readlink(struct path *path, char __user *buffer, int buflen)
1618{
1619        char *tmp = (char*)__get_free_page(GFP_TEMPORARY);
1620        char *pathname;
1621        int len;
1622
1623        if (!tmp)
1624                return -ENOMEM;
1625
1626        pathname = d_path(path, tmp, PAGE_SIZE);
1627        len = PTR_ERR(pathname);
1628        if (IS_ERR(pathname))
1629                goto out;
1630        len = tmp + PAGE_SIZE - 1 - pathname;
1631
1632        if (len > buflen)
1633                len = buflen;
1634        if (copy_to_user(buffer, pathname, len))
1635                len = -EFAULT;
1636 out:
1637        free_page((unsigned long)tmp);
1638        return len;
1639}
1640
1641static int proc_pid_readlink(struct dentry * dentry, char __user * buffer, int buflen)
1642{
1643        int error = -EACCES;
1644        struct inode *inode = d_inode(dentry);
1645        struct path path;
1646
1647        /* Are we allowed to snoop on the tasks file descriptors? */
1648        if (!proc_fd_access_allowed(inode))
1649                goto out;
1650
1651        error = PROC_I(inode)->op.proc_get_link(dentry, &path);
1652        if (error)
1653                goto out;
1654
1655        error = do_proc_readlink(&path, buffer, buflen);
1656        path_put(&path);
1657out:
1658        return error;
1659}
1660
1661const struct inode_operations proc_pid_link_inode_operations = {
1662        .readlink       = proc_pid_readlink,
1663        .get_link       = proc_pid_get_link,
1664        .setattr        = proc_setattr,
1665};
1666
1667
1668/* building an inode */
1669
1670struct inode *proc_pid_make_inode(struct super_block * sb,
1671                                  struct task_struct *task, umode_t mode)
1672{
1673        struct inode * inode;
1674        struct proc_inode *ei;
1675        const struct cred *cred;
1676
1677        /* We need a new inode */
1678
1679        inode = new_inode(sb);
1680        if (!inode)
1681                goto out;
1682
1683        /* Common stuff */
1684        ei = PROC_I(inode);
1685        inode->i_mode = mode;
1686        inode->i_ino = get_next_ino();
1687        inode->i_mtime = inode->i_atime = inode->i_ctime = current_time(inode);
1688        inode->i_op = &proc_def_inode_operations;
1689
1690        /*
1691         * grab the reference to task.
1692         */
1693        ei->pid = get_task_pid(task, PIDTYPE_PID);
1694        if (!ei->pid)
1695                goto out_unlock;
1696
1697        if (task_dumpable(task)) {
1698                rcu_read_lock();
1699                cred = __task_cred(task);
1700                inode->i_uid = cred->euid;
1701                inode->i_gid = cred->egid;
1702                rcu_read_unlock();
1703        }
1704        security_task_to_inode(task, inode);
1705
1706out:
1707        return inode;
1708
1709out_unlock:
1710        iput(inode);
1711        return NULL;
1712}
1713
1714int pid_getattr(struct vfsmount *mnt, struct dentry *dentry, struct kstat *stat)
1715{
1716        struct inode *inode = d_inode(dentry);
1717        struct task_struct *task;
1718        const struct cred *cred;
1719        struct pid_namespace *pid = dentry->d_sb->s_fs_info;
1720
1721        generic_fillattr(inode, stat);
1722
1723        rcu_read_lock();
1724        stat->uid = GLOBAL_ROOT_UID;
1725        stat->gid = GLOBAL_ROOT_GID;
1726        task = pid_task(proc_pid(inode), PIDTYPE_PID);
1727        if (task) {
1728                if (!has_pid_permissions(pid, task, 2)) {
1729                        rcu_read_unlock();
1730                        /*
1731                         * This doesn't prevent learning whether PID exists,
1732                         * it only makes getattr() consistent with readdir().
1733                         */
1734                        return -ENOENT;
1735                }
1736                if ((inode->i_mode == (S_IFDIR|S_IRUGO|S_IXUGO)) ||
1737                    task_dumpable(task)) {
1738                        cred = __task_cred(task);
1739                        stat->uid = cred->euid;
1740                        stat->gid = cred->egid;
1741                }
1742        }
1743        rcu_read_unlock();
1744        return 0;
1745}
1746
1747/* dentry stuff */
1748
1749/*
1750 *      Exceptional case: normally we are not allowed to unhash a busy
1751 * directory. In this case, however, we can do it - no aliasing problems
1752 * due to the way we treat inodes.
1753 *
1754 * Rewrite the inode's ownerships here because the owning task may have
1755 * performed a setuid(), etc.
1756 *
1757 * Before the /proc/pid/status file was created the only way to read
1758 * the effective uid of a /process was to stat /proc/pid.  Reading
1759 * /proc/pid/status is slow enough that procps and other packages
1760 * kept stating /proc/pid.  To keep the rules in /proc simple I have
1761 * made this apply to all per process world readable and executable
1762 * directories.
1763 */
1764int pid_revalidate(struct dentry *dentry, unsigned int flags)
1765{
1766        struct inode *inode;
1767        struct task_struct *task;
1768        const struct cred *cred;
1769
1770        if (flags & LOOKUP_RCU)
1771                return -ECHILD;
1772
1773        inode = d_inode(dentry);
1774        task = get_proc_task(inode);
1775
1776        if (task) {
1777                if ((inode->i_mode == (S_IFDIR|S_IRUGO|S_IXUGO)) ||
1778                    task_dumpable(task)) {
1779                        rcu_read_lock();
1780                        cred = __task_cred(task);
1781                        inode->i_uid = cred->euid;
1782                        inode->i_gid = cred->egid;
1783                        rcu_read_unlock();
1784                } else {
1785                        inode->i_uid = GLOBAL_ROOT_UID;
1786                        inode->i_gid = GLOBAL_ROOT_GID;
1787                }
1788                inode->i_mode &= ~(S_ISUID | S_ISGID);
1789                security_task_to_inode(task, inode);
1790                put_task_struct(task);
1791                return 1;
1792        }
1793        return 0;
1794}
1795
1796static inline bool proc_inode_is_dead(struct inode *inode)
1797{
1798        return !proc_pid(inode)->tasks[PIDTYPE_PID].first;
1799}
1800
1801int pid_delete_dentry(const struct dentry *dentry)
1802{
1803        /* Is the task we represent dead?
1804         * If so, then don't put the dentry on the lru list,
1805         * kill it immediately.
1806         */
1807        return proc_inode_is_dead(d_inode(dentry));
1808}
1809
1810const struct dentry_operations pid_dentry_operations =
1811{
1812        .d_revalidate   = pid_revalidate,
1813        .d_delete       = pid_delete_dentry,
1814};
1815
1816/* Lookups */
1817
1818/*
1819 * Fill a directory entry.
1820 *
1821 * If possible create the dcache entry and derive our inode number and
1822 * file type from dcache entry.
1823 *
1824 * Since all of the proc inode numbers are dynamically generated, the inode
1825 * numbers do not exist until the inode is cache.  This means creating the
1826 * the dcache entry in readdir is necessary to keep the inode numbers
1827 * reported by readdir in sync with the inode numbers reported
1828 * by stat.
1829 */
1830bool proc_fill_cache(struct file *file, struct dir_context *ctx,
1831        const char *name, int len,
1832        instantiate_t instantiate, struct task_struct *task, const void *ptr)
1833{
1834        struct dentry *child, *dir = file->f_path.dentry;
1835        struct qstr qname = QSTR_INIT(name, len);
1836        struct inode *inode;
1837        unsigned type;
1838        ino_t ino;
1839
1840        child = d_hash_and_lookup(dir, &qname);
1841        if (!child) {
1842                DECLARE_WAIT_QUEUE_HEAD_ONSTACK(wq);
1843                child = d_alloc_parallel(dir, &qname, &wq);
1844                if (IS_ERR(child))
1845                        goto end_instantiate;
1846                if (d_in_lookup(child)) {
1847                        int err = instantiate(d_inode(dir), child, task, ptr);
1848                        d_lookup_done(child);
1849                        if (err < 0) {
1850                                dput(child);
1851                                goto end_instantiate;
1852                        }
1853                }
1854        }
1855        inode = d_inode(child);
1856        ino = inode->i_ino;
1857        type = inode->i_mode >> 12;
1858        dput(child);
1859        return dir_emit(ctx, name, len, ino, type);
1860
1861end_instantiate:
1862        return dir_emit(ctx, name, len, 1, DT_UNKNOWN);
1863}
1864
1865/*
1866 * dname_to_vma_addr - maps a dentry name into two unsigned longs
1867 * which represent vma start and end addresses.
1868 */
1869static int dname_to_vma_addr(struct dentry *dentry,
1870                             unsigned long *start, unsigned long *end)
1871{
1872        if (sscanf(dentry->d_name.name, "%lx-%lx", start, end) != 2)
1873                return -EINVAL;
1874
1875        return 0;
1876}
1877
1878static int map_files_d_revalidate(struct dentry *dentry, unsigned int flags)
1879{
1880        unsigned long vm_start, vm_end;
1881        bool exact_vma_exists = false;
1882        struct mm_struct *mm = NULL;
1883        struct task_struct *task;
1884        const struct cred *cred;
1885        struct inode *inode;
1886        int status = 0;
1887
1888        if (flags & LOOKUP_RCU)
1889                return -ECHILD;
1890
1891        inode = d_inode(dentry);
1892        task = get_proc_task(inode);
1893        if (!task)
1894                goto out_notask;
1895
1896        mm = mm_access(task, PTRACE_MODE_READ_FSCREDS);
1897        if (IS_ERR_OR_NULL(mm))
1898                goto out;
1899
1900        if (!dname_to_vma_addr(dentry, &vm_start, &vm_end)) {
1901                down_read(&mm->mmap_sem);
1902                exact_vma_exists = !!find_exact_vma(mm, vm_start, vm_end);
1903                up_read(&mm->mmap_sem);
1904        }
1905
1906        mmput(mm);
1907
1908        if (exact_vma_exists) {
1909                if (task_dumpable(task)) {
1910                        rcu_read_lock();
1911                        cred = __task_cred(task);
1912                        inode->i_uid = cred->euid;
1913                        inode->i_gid = cred->egid;
1914                        rcu_read_unlock();
1915                } else {
1916                        inode->i_uid = GLOBAL_ROOT_UID;
1917                        inode->i_gid = GLOBAL_ROOT_GID;
1918                }
1919                security_task_to_inode(task, inode);
1920                status = 1;
1921        }
1922
1923out:
1924        put_task_struct(task);
1925
1926out_notask:
1927        return status;
1928}
1929
1930static const struct dentry_operations tid_map_files_dentry_operations = {
1931        .d_revalidate   = map_files_d_revalidate,
1932        .d_delete       = pid_delete_dentry,
1933};
1934
1935static int map_files_get_link(struct dentry *dentry, struct path *path)
1936{
1937        unsigned long vm_start, vm_end;
1938        struct vm_area_struct *vma;
1939        struct task_struct *task;
1940        struct mm_struct *mm;
1941        int rc;
1942
1943        rc = -ENOENT;
1944        task = get_proc_task(d_inode(dentry));
1945        if (!task)
1946                goto out;
1947
1948        mm = get_task_mm(task);
1949        put_task_struct(task);
1950        if (!mm)
1951                goto out;
1952
1953        rc = dname_to_vma_addr(dentry, &vm_start, &vm_end);
1954        if (rc)
1955                goto out_mmput;
1956
1957        rc = -ENOENT;
1958        down_read(&mm->mmap_sem);
1959        vma = find_exact_vma(mm, vm_start, vm_end);
1960        if (vma && vma->vm_file) {
1961                *path = vma->vm_file->f_path;
1962                path_get(path);
1963                rc = 0;
1964        }
1965        up_read(&mm->mmap_sem);
1966
1967out_mmput:
1968        mmput(mm);
1969out:
1970        return rc;
1971}
1972
1973struct map_files_info {
1974        fmode_t         mode;
1975        unsigned int    len;
1976        unsigned char   name[4*sizeof(long)+2]; /* max: %lx-%lx\0 */
1977};
1978
1979/*
1980 * Only allow CAP_SYS_ADMIN to follow the links, due to concerns about how the
1981 * symlinks may be used to bypass permissions on ancestor directories in the
1982 * path to the file in question.
1983 */
1984static const char *
1985proc_map_files_get_link(struct dentry *dentry,
1986                        struct inode *inode,
1987                        struct delayed_call *done)
1988{
1989        if (!capable(CAP_SYS_ADMIN))
1990                return ERR_PTR(-EPERM);
1991
1992        return proc_pid_get_link(dentry, inode, done);
1993}
1994
1995/*
1996 * Identical to proc_pid_link_inode_operations except for get_link()
1997 */
1998static const struct inode_operations proc_map_files_link_inode_operations = {
1999        .readlink       = proc_pid_readlink,
2000        .get_link       = proc_map_files_get_link,
2001        .setattr        = proc_setattr,
2002};
2003
2004static int
2005proc_map_files_instantiate(struct inode *dir, struct dentry *dentry,
2006                           struct task_struct *task, const void *ptr)
2007{
2008        fmode_t mode = (fmode_t)(unsigned long)ptr;
2009        struct proc_inode *ei;
2010        struct inode *inode;
2011
2012        inode = proc_pid_make_inode(dir->i_sb, task, S_IFLNK |
2013                                    ((mode & FMODE_READ ) ? S_IRUSR : 0) |
2014                                    ((mode & FMODE_WRITE) ? S_IWUSR : 0));
2015        if (!inode)
2016                return -ENOENT;
2017
2018        ei = PROC_I(inode);
2019        ei->op.proc_get_link = map_files_get_link;
2020
2021        inode->i_op = &proc_map_files_link_inode_operations;
2022        inode->i_size = 64;
2023
2024        d_set_d_op(dentry, &tid_map_files_dentry_operations);
2025        d_add(dentry, inode);
2026
2027        return 0;
2028}
2029
2030static struct dentry *proc_map_files_lookup(struct inode *dir,
2031                struct dentry *dentry, unsigned int flags)
2032{
2033        unsigned long vm_start, vm_end;
2034        struct vm_area_struct *vma;
2035        struct task_struct *task;
2036        int result;
2037        struct mm_struct *mm;
2038
2039        result = -ENOENT;
2040        task = get_proc_task(dir);
2041        if (!task)
2042                goto out;
2043
2044        result = -EACCES;
2045        if (!ptrace_may_access(task, PTRACE_MODE_READ_FSCREDS))
2046                goto out_put_task;
2047
2048        result = -ENOENT;
2049        if (dname_to_vma_addr(dentry, &vm_start, &vm_end))
2050                goto out_put_task;
2051
2052        mm = get_task_mm(task);
2053        if (!mm)
2054                goto out_put_task;
2055
2056        down_read(&mm->mmap_sem);
2057        vma = find_exact_vma(mm, vm_start, vm_end);
2058        if (!vma)
2059                goto out_no_vma;
2060
2061        if (vma->vm_file)
2062                result = proc_map_files_instantiate(dir, dentry, task,
2063                                (void *)(unsigned long)vma->vm_file->f_mode);
2064
2065out_no_vma:
2066        up_read(&mm->mmap_sem);
2067        mmput(mm);
2068out_put_task:
2069        put_task_struct(task);
2070out:
2071        return ERR_PTR(result);
2072}
2073
2074static const struct inode_operations proc_map_files_inode_operations = {
2075        .lookup         = proc_map_files_lookup,
2076        .permission     = proc_fd_permission,
2077        .setattr        = proc_setattr,
2078};
2079
2080static int
2081proc_map_files_readdir(struct file *file, struct dir_context *ctx)
2082{
2083        struct vm_area_struct *vma;
2084        struct task_struct *task;
2085        struct mm_struct *mm;
2086        unsigned long nr_files, pos, i;
2087        struct flex_array *fa = NULL;
2088        struct map_files_info info;
2089        struct map_files_info *p;
2090        int ret;
2091
2092        ret = -ENOENT;
2093        task = get_proc_task(file_inode(file));
2094        if (!task)
2095                goto out;
2096
2097        ret = -EACCES;
2098        if (!ptrace_may_access(task, PTRACE_MODE_READ_FSCREDS))
2099                goto out_put_task;
2100
2101        ret = 0;
2102        if (!dir_emit_dots(file, ctx))
2103                goto out_put_task;
2104
2105        mm = get_task_mm(task);
2106        if (!mm)
2107                goto out_put_task;
2108        down_read(&mm->mmap_sem);
2109
2110        nr_files = 0;
2111
2112        /*
2113         * We need two passes here:
2114         *
2115         *  1) Collect vmas of mapped files with mmap_sem taken
2116         *  2) Release mmap_sem and instantiate entries
2117         *
2118         * otherwise we get lockdep complained, since filldir()
2119         * routine might require mmap_sem taken in might_fault().
2120         */
2121
2122        for (vma = mm->mmap, pos = 2; vma; vma = vma->vm_next) {
2123                if (vma->vm_file && ++pos > ctx->pos)
2124                        nr_files++;
2125        }
2126
2127        if (nr_files) {
2128                fa = flex_array_alloc(sizeof(info), nr_files,
2129                                        GFP_KERNEL);
2130                if (!fa || flex_array_prealloc(fa, 0, nr_files,
2131                                                GFP_KERNEL)) {
2132                        ret = -ENOMEM;
2133                        if (fa)
2134                                flex_array_free(fa);
2135                        up_read(&mm->mmap_sem);
2136                        mmput(mm);
2137                        goto out_put_task;
2138                }
2139                for (i = 0, vma = mm->mmap, pos = 2; vma;
2140                                vma = vma->vm_next) {
2141                        if (!vma->vm_file)
2142                                continue;
2143                        if (++pos <= ctx->pos)
2144                                continue;
2145
2146                        info.mode = vma->vm_file->f_mode;
2147                        info.len = snprintf(info.name,
2148                                        sizeof(info.name), "%lx-%lx",
2149                                        vma->vm_start, vma->vm_end);
2150                        if (flex_array_put(fa, i++, &info, GFP_KERNEL))
2151                                BUG();
2152                }
2153        }
2154        up_read(&mm->mmap_sem);
2155
2156        for (i = 0; i < nr_files; i++) {
2157                p = flex_array_get(fa, i);
2158                if (!proc_fill_cache(file, ctx,
2159                                      p->name, p->len,
2160                                      proc_map_files_instantiate,
2161                                      task,
2162                                      (void *)(unsigned long)p->mode))
2163                        break;
2164                ctx->pos++;
2165        }
2166        if (fa)
2167                flex_array_free(fa);
2168        mmput(mm);
2169
2170out_put_task:
2171        put_task_struct(task);
2172out:
2173        return ret;
2174}
2175
2176static const struct file_operations proc_map_files_operations = {
2177        .read           = generic_read_dir,
2178        .iterate_shared = proc_map_files_readdir,
2179        .llseek         = generic_file_llseek,
2180};
2181
2182#ifdef CONFIG_CHECKPOINT_RESTORE
2183struct timers_private {
2184        struct pid *pid;
2185        struct task_struct *task;
2186        struct sighand_struct *sighand;
2187        struct pid_namespace *ns;
2188        unsigned long flags;
2189};
2190
2191static void *timers_start(struct seq_file *m, loff_t *pos)
2192{
2193        struct timers_private *tp = m->private;
2194
2195        tp->task = get_pid_task(tp->pid, PIDTYPE_PID);
2196        if (!tp->task)
2197                return ERR_PTR(-ESRCH);
2198
2199        tp->sighand = lock_task_sighand(tp->task, &tp->flags);
2200        if (!tp->sighand)
2201                return ERR_PTR(-ESRCH);
2202
2203        return seq_list_start(&tp->task->signal->posix_timers, *pos);
2204}
2205
2206static void *timers_next(struct seq_file *m, void *v, loff_t *pos)
2207{
2208        struct timers_private *tp = m->private;
2209        return seq_list_next(v, &tp->task->signal->posix_timers, pos);
2210}
2211
2212static void timers_stop(struct seq_file *m, void *v)
2213{
2214        struct timers_private *tp = m->private;
2215
2216        if (tp->sighand) {
2217                unlock_task_sighand(tp->task, &tp->flags);
2218                tp->sighand = NULL;
2219        }
2220
2221        if (tp->task) {
2222                put_task_struct(tp->task);
2223                tp->task = NULL;
2224        }
2225}
2226
2227static int show_timer(struct seq_file *m, void *v)
2228{
2229        struct k_itimer *timer;
2230        struct timers_private *tp = m->private;
2231        int notify;
2232        static const char * const nstr[] = {
2233                [SIGEV_SIGNAL] = "signal",
2234                [SIGEV_NONE] = "none",
2235                [SIGEV_THREAD] = "thread",
2236        };
2237
2238        timer = list_entry((struct list_head *)v, struct k_itimer, list);
2239        notify = timer->it_sigev_notify;
2240
2241        seq_printf(m, "ID: %d\n", timer->it_id);
2242        seq_printf(m, "signal: %d/%p\n",
2243                   timer->sigq->info.si_signo,
2244                   timer->sigq->info.si_value.sival_ptr);
2245        seq_printf(m, "notify: %s/%s.%d\n",
2246                   nstr[notify & ~SIGEV_THREAD_ID],
2247                   (notify & SIGEV_THREAD_ID) ? "tid" : "pid",
2248                   pid_nr_ns(timer->it_pid, tp->ns));
2249        seq_printf(m, "ClockID: %d\n", timer->it_clock);
2250
2251        return 0;
2252}
2253
2254static const struct seq_operations proc_timers_seq_ops = {
2255        .start  = timers_start,
2256        .next   = timers_next,
2257        .stop   = timers_stop,
2258        .show   = show_timer,
2259};
2260
2261static int proc_timers_open(struct inode *inode, struct file *file)
2262{
2263        struct timers_private *tp;
2264
2265        tp = __seq_open_private(file, &proc_timers_seq_ops,
2266                        sizeof(struct timers_private));
2267        if (!tp)
2268                return -ENOMEM;
2269
2270        tp->pid = proc_pid(inode);
2271        tp->ns = inode->i_sb->s_fs_info;
2272        return 0;
2273}
2274
2275static const struct file_operations proc_timers_operations = {
2276        .open           = proc_timers_open,
2277        .read           = seq_read,
2278        .llseek         = seq_lseek,
2279        .release        = seq_release_private,
2280};
2281#endif
2282
2283static ssize_t timerslack_ns_write(struct file *file, const char __user *buf,
2284                                        size_t count, loff_t *offset)
2285{
2286        struct inode *inode = file_inode(file);
2287        struct task_struct *p;
2288        u64 slack_ns;
2289        int err;
2290
2291        err = kstrtoull_from_user(buf, count, 10, &slack_ns);
2292        if (err < 0)
2293                return err;
2294
2295        p = get_proc_task(inode);
2296        if (!p)
2297                return -ESRCH;
2298
2299        if (p != current) {
2300                if (!capable(CAP_SYS_NICE)) {
2301                        count = -EPERM;
2302                        goto out;
2303                }
2304
2305                err = security_task_setscheduler(p);
2306                if (err) {
2307                        count = err;
2308                        goto out;
2309                }
2310        }
2311
2312        task_lock(p);
2313        if (slack_ns == 0)
2314                p->timer_slack_ns = p->default_timer_slack_ns;
2315        else
2316                p->timer_slack_ns = slack_ns;
2317        task_unlock(p);
2318
2319out:
2320        put_task_struct(p);
2321
2322        return count;
2323}
2324
2325static int timerslack_ns_show(struct seq_file *m, void *v)
2326{
2327        struct inode *inode = m->private;
2328        struct task_struct *p;
2329        int err = 0;
2330
2331        p = get_proc_task(inode);
2332        if (!p)
2333                return -ESRCH;
2334
2335        if (p != current) {
2336
2337                if (!capable(CAP_SYS_NICE)) {
2338                        err = -EPERM;
2339                        goto out;
2340                }
2341                err = security_task_getscheduler(p);
2342                if (err)
2343                        goto out;
2344        }
2345
2346        task_lock(p);
2347        seq_printf(m, "%llu\n", p->timer_slack_ns);
2348        task_unlock(p);
2349
2350out:
2351        put_task_struct(p);
2352
2353        return err;
2354}
2355
2356static int timerslack_ns_open(struct inode *inode, struct file *filp)
2357{
2358        return single_open(filp, timerslack_ns_show, inode);
2359}
2360
2361static const struct file_operations proc_pid_set_timerslack_ns_operations = {
2362        .open           = timerslack_ns_open,
2363        .read           = seq_read,
2364        .write          = timerslack_ns_write,
2365        .llseek         = seq_lseek,
2366        .release        = single_release,
2367};
2368
2369static int proc_pident_instantiate(struct inode *dir,
2370        struct dentry *dentry, struct task_struct *task, const void *ptr)
2371{
2372        const struct pid_entry *p = ptr;
2373        struct inode *inode;
2374        struct proc_inode *ei;
2375
2376        inode = proc_pid_make_inode(dir->i_sb, task, p->mode);
2377        if (!inode)
2378                goto out;
2379
2380        ei = PROC_I(inode);
2381        if (S_ISDIR(inode->i_mode))
2382                set_nlink(inode, 2);    /* Use getattr to fix if necessary */
2383        if (p->iop)
2384                inode->i_op = p->iop;
2385        if (p->fop)
2386                inode->i_fop = p->fop;
2387        ei->op = p->op;
2388        d_set_d_op(dentry, &pid_dentry_operations);
2389        d_add(dentry, inode);
2390        /* Close the race of the process dying before we return the dentry */
2391        if (pid_revalidate(dentry, 0))
2392                return 0;
2393out:
2394        return -ENOENT;
2395}
2396
2397static struct dentry *proc_pident_lookup(struct inode *dir, 
2398                                         struct dentry *dentry,
2399                                         const struct pid_entry *ents,
2400                                         unsigned int nents)
2401{
2402        int error;
2403        struct task_struct *task = get_proc_task(dir);
2404        const struct pid_entry *p, *last;
2405
2406        error = -ENOENT;
2407
2408        if (!task)
2409                goto out_no_task;
2410
2411        /*
2412         * Yes, it does not scale. And it should not. Don't add
2413         * new entries into /proc/<tgid>/ without very good reasons.
2414         */
2415        last = &ents[nents];
2416        for (p = ents; p < last; p++) {
2417                if (p->len != dentry->d_name.len)
2418                        continue;
2419                if (!memcmp(dentry->d_name.name, p->name, p->len))
2420                        break;
2421        }
2422        if (p >= last)
2423                goto out;
2424
2425        error = proc_pident_instantiate(dir, dentry, task, p);
2426out:
2427        put_task_struct(task);
2428out_no_task:
2429        return ERR_PTR(error);
2430}
2431
2432static int proc_pident_readdir(struct file *file, struct dir_context *ctx,
2433                const struct pid_entry *ents, unsigned int nents)
2434{
2435        struct task_struct *task = get_proc_task(file_inode(file));
2436        const struct pid_entry *p;
2437
2438        if (!task)
2439                return -ENOENT;
2440
2441        if (!dir_emit_dots(file, ctx))
2442                goto out;
2443
2444        if (ctx->pos >= nents + 2)
2445                goto out;
2446
2447        for (p = ents + (ctx->pos - 2); p < ents + nents; p++) {
2448                if (!proc_fill_cache(file, ctx, p->name, p->len,
2449                                proc_pident_instantiate, task, p))
2450                        break;
2451                ctx->pos++;
2452        }
2453out:
2454        put_task_struct(task);
2455        return 0;
2456}
2457
2458#ifdef CONFIG_SECURITY
2459static ssize_t proc_pid_attr_read(struct file * file, char __user * buf,
2460                                  size_t count, loff_t *ppos)
2461{
2462        struct inode * inode = file_inode(file);
2463        char *p = NULL;
2464        ssize_t length;
2465        struct task_struct *task = get_proc_task(inode);
2466
2467        if (!task)
2468                return -ESRCH;
2469
2470        length = security_getprocattr(task,
2471                                      (char*)file->f_path.dentry->d_name.name,
2472                                      &p);
2473        put_task_struct(task);
2474        if (length > 0)
2475                length = simple_read_from_buffer(buf, count, ppos, p, length);
2476        kfree(p);
2477        return length;
2478}
2479
2480static ssize_t proc_pid_attr_write(struct file * file, const char __user * buf,
2481                                   size_t count, loff_t *ppos)
2482{
2483        struct inode * inode = file_inode(file);
2484        void *page;
2485        ssize_t length;
2486        struct task_struct *task = get_proc_task(inode);
2487
2488        length = -ESRCH;
2489        if (!task)
2490                goto out_no_task;
2491        if (count > PAGE_SIZE)
2492                count = PAGE_SIZE;
2493
2494        /* No partial writes. */
2495        length = -EINVAL;
2496        if (*ppos != 0)
2497                goto out;
2498
2499        page = memdup_user(buf, count);
2500        if (IS_ERR(page)) {
2501                length = PTR_ERR(page);
2502                goto out;
2503        }
2504
2505        /* Guard against adverse ptrace interaction */
2506        length = mutex_lock_interruptible(&task->signal->cred_guard_mutex);
2507        if (length < 0)
2508                goto out_free;
2509
2510        length = security_setprocattr(task,
2511                                      (char*)file->f_path.dentry->d_name.name,
2512                                      page, count);
2513        mutex_unlock(&task->signal->cred_guard_mutex);
2514out_free:
2515        kfree(page);
2516out:
2517        put_task_struct(task);
2518out_no_task:
2519        return length;
2520}
2521
2522static const struct file_operations proc_pid_attr_operations = {
2523        .read           = proc_pid_attr_read,
2524        .write          = proc_pid_attr_write,
2525        .llseek         = generic_file_llseek,
2526};
2527
2528static const struct pid_entry attr_dir_stuff[] = {
2529        REG("current",    S_IRUGO|S_IWUGO, proc_pid_attr_operations),
2530        REG("prev",       S_IRUGO,         proc_pid_attr_operations),
2531        REG("exec",       S_IRUGO|S_IWUGO, proc_pid_attr_operations),
2532        REG("fscreate",   S_IRUGO|S_IWUGO, proc_pid_attr_operations),
2533        REG("keycreate",  S_IRUGO|S_IWUGO, proc_pid_attr_operations),
2534        REG("sockcreate", S_IRUGO|S_IWUGO, proc_pid_attr_operations),
2535};
2536
2537static int proc_attr_dir_readdir(struct file *file, struct dir_context *ctx)
2538{
2539        return proc_pident_readdir(file, ctx, 
2540                                   attr_dir_stuff, ARRAY_SIZE(attr_dir_stuff));
2541}
2542
2543static const struct file_operations proc_attr_dir_operations = {
2544        .read           = generic_read_dir,
2545        .iterate_shared = proc_attr_dir_readdir,
2546        .llseek         = generic_file_llseek,
2547};
2548
2549static struct dentry *proc_attr_dir_lookup(struct inode *dir,
2550                                struct dentry *dentry, unsigned int flags)
2551{
2552        return proc_pident_lookup(dir, dentry,
2553                                  attr_dir_stuff, ARRAY_SIZE(attr_dir_stuff));
2554}
2555
2556static const struct inode_operations proc_attr_dir_inode_operations = {
2557        .lookup         = proc_attr_dir_lookup,
2558        .getattr        = pid_getattr,
2559        .setattr        = proc_setattr,
2560};
2561
2562#endif
2563
2564#ifdef CONFIG_ELF_CORE
2565static ssize_t proc_coredump_filter_read(struct file *file, char __user *buf,
2566                                         size_t count, loff_t *ppos)
2567{
2568        struct task_struct *task = get_proc_task(file_inode(file));
2569        struct mm_struct *mm;
2570        char buffer[PROC_NUMBUF];
2571        size_t len;
2572        int ret;
2573
2574        if (!task)
2575                return -ESRCH;
2576
2577        ret = 0;
2578        mm = get_task_mm(task);
2579        if (mm) {
2580                len = snprintf(buffer, sizeof(buffer), "%08lx\n",
2581                               ((mm->flags & MMF_DUMP_FILTER_MASK) >>
2582                                MMF_DUMP_FILTER_SHIFT));
2583                mmput(mm);
2584                ret = simple_read_from_buffer(buf, count, ppos, buffer, len);
2585        }
2586
2587        put_task_struct(task);
2588
2589        return ret;
2590}
2591
2592static ssize_t proc_coredump_filter_write(struct file *file,
2593                                          const char __user *buf,
2594                                          size_t count,
2595                                          loff_t *ppos)
2596{
2597        struct task_struct *task;
2598        struct mm_struct *mm;
2599        unsigned int val;
2600        int ret;
2601        int i;
2602        unsigned long mask;
2603
2604        ret = kstrtouint_from_user(buf, count, 0, &val);
2605        if (ret < 0)
2606                return ret;
2607
2608        ret = -ESRCH;
2609        task = get_proc_task(file_inode(file));
2610        if (!task)
2611                goto out_no_task;
2612
2613        mm = get_task_mm(task);
2614        if (!mm)
2615                goto out_no_mm;
2616        ret = 0;
2617
2618        for (i = 0, mask = 1; i < MMF_DUMP_FILTER_BITS; i++, mask <<= 1) {
2619                if (val & mask)
2620                        set_bit(i + MMF_DUMP_FILTER_SHIFT, &mm->flags);
2621                else
2622                        clear_bit(i + MMF_DUMP_FILTER_SHIFT, &mm->flags);
2623        }
2624
2625        mmput(mm);
2626 out_no_mm:
2627        put_task_struct(task);
2628 out_no_task:
2629        if (ret < 0)
2630                return ret;
2631        return count;
2632}
2633
2634static const struct file_operations proc_coredump_filter_operations = {
2635        .read           = proc_coredump_filter_read,
2636        .write          = proc_coredump_filter_write,
2637        .llseek         = generic_file_llseek,
2638};
2639#endif
2640
2641#ifdef CONFIG_TASK_IO_ACCOUNTING
2642static int do_io_accounting(struct task_struct *task, struct seq_file *m, int whole)
2643{
2644        struct task_io_accounting acct = task->ioac;
2645        unsigned long flags;
2646        int result;
2647
2648        result = mutex_lock_killable(&task->signal->cred_guard_mutex);
2649        if (result)
2650                return result;
2651
2652        if (!ptrace_may_access(task, PTRACE_MODE_READ_FSCREDS)) {
2653                result = -EACCES;
2654                goto out_unlock;
2655        }
2656
2657        if (whole && lock_task_sighand(task, &flags)) {
2658                struct task_struct *t = task;
2659
2660                task_io_accounting_add(&acct, &task->signal->ioac);
2661                while_each_thread(task, t)
2662                        task_io_accounting_add(&acct, &t->ioac);
2663
2664                unlock_task_sighand(task, &flags);
2665        }
2666        seq_printf(m,
2667                   "rchar: %llu\n"
2668                   "wchar: %llu\n"
2669                   "syscr: %llu\n"
2670                   "syscw: %llu\n"
2671                   "read_bytes: %llu\n"
2672                   "write_bytes: %llu\n"
2673                   "cancelled_write_bytes: %llu\n",
2674                   (unsigned long long)acct.rchar,
2675                   (unsigned long long)acct.wchar,
2676                   (unsigned long long)acct.syscr,
2677                   (unsigned long long)acct.syscw,
2678                   (unsigned long long)acct.read_bytes,
2679                   (unsigned long long)acct.write_bytes,
2680                   (unsigned long long)acct.cancelled_write_bytes);
2681        result = 0;
2682
2683out_unlock:
2684        mutex_unlock(&task->signal->cred_guard_mutex);
2685        return result;
2686}
2687
2688static int proc_tid_io_accounting(struct seq_file *m, struct pid_namespace *ns,
2689                                  struct pid *pid, struct task_struct *task)
2690{
2691        return do_io_accounting(task, m, 0);
2692}
2693
2694static int proc_tgid_io_accounting(struct seq_file *m, struct pid_namespace *ns,
2695                                   struct pid *pid, struct task_struct *task)
2696{
2697        return do_io_accounting(task, m, 1);
2698}
2699#endif /* CONFIG_TASK_IO_ACCOUNTING */
2700
2701#ifdef CONFIG_USER_NS
2702static int proc_id_map_open(struct inode *inode, struct file *file,
2703        const struct seq_operations *seq_ops)
2704{
2705        struct user_namespace *ns = NULL;
2706        struct task_struct *task;
2707        struct seq_file *seq;
2708        int ret = -EINVAL;
2709
2710        task = get_proc_task(inode);
2711        if (task) {
2712                rcu_read_lock();
2713                ns = get_user_ns(task_cred_xxx(task, user_ns));
2714                rcu_read_unlock();
2715                put_task_struct(task);
2716        }
2717        if (!ns)
2718                goto err;
2719
2720        ret = seq_open(file, seq_ops);
2721        if (ret)
2722                goto err_put_ns;
2723
2724        seq = file->private_data;
2725        seq->private = ns;
2726
2727        return 0;
2728err_put_ns:
2729        put_user_ns(ns);
2730err:
2731        return ret;
2732}
2733
2734static int proc_id_map_release(struct inode *inode, struct file *file)
2735{
2736        struct seq_file *seq = file->private_data;
2737        struct user_namespace *ns = seq->private;
2738        put_user_ns(ns);
2739        return seq_release(inode, file);
2740}
2741
2742static int proc_uid_map_open(struct inode *inode, struct file *file)
2743{
2744        return proc_id_map_open(inode, file, &proc_uid_seq_operations);
2745}
2746
2747static int proc_gid_map_open(struct inode *inode, struct file *file)
2748{
2749        return proc_id_map_open(inode, file, &proc_gid_seq_operations);
2750}
2751
2752static int proc_projid_map_open(struct inode *inode, struct file *file)
2753{
2754        return proc_id_map_open(inode, file, &proc_projid_seq_operations);
2755}
2756
2757static const struct file_operations proc_uid_map_operations = {
2758        .open           = proc_uid_map_open,
2759        .write          = proc_uid_map_write,
2760        .read           = seq_read,
2761        .llseek         = seq_lseek,
2762        .release        = proc_id_map_release,
2763};
2764
2765static const struct file_operations proc_gid_map_operations = {
2766        .open           = proc_gid_map_open,
2767        .write          = proc_gid_map_write,
2768        .read           = seq_read,
2769        .llseek         = seq_lseek,
2770        .release        = proc_id_map_release,
2771};
2772
2773static const struct file_operations proc_projid_map_operations = {
2774        .open           = proc_projid_map_open,
2775        .write          = proc_projid_map_write,
2776        .read           = seq_read,
2777        .llseek         = seq_lseek,
2778        .release        = proc_id_map_release,
2779};
2780
2781static int proc_setgroups_open(struct inode *inode, struct file *file)
2782{
2783        struct user_namespace *ns = NULL;
2784        struct task_struct *task;
2785        int ret;
2786
2787        ret = -ESRCH;
2788        task = get_proc_task(inode);
2789        if (task) {
2790                rcu_read_lock();
2791                ns = get_user_ns(task_cred_xxx(task, user_ns));
2792                rcu_read_unlock();
2793                put_task_struct(task);
2794        }
2795        if (!ns)
2796                goto err;
2797
2798        if (file->f_mode & FMODE_WRITE) {
2799                ret = -EACCES;
2800                if (!ns_capable(ns, CAP_SYS_ADMIN))
2801                        goto err_put_ns;
2802        }
2803
2804        ret = single_open(file, &proc_setgroups_show, ns);
2805        if (ret)
2806                goto err_put_ns;
2807
2808        return 0;
2809err_put_ns:
2810        put_user_ns(ns);
2811err:
2812        return ret;
2813}
2814
2815static int proc_setgroups_release(struct inode *inode, struct file *file)
2816{
2817        struct seq_file *seq = file->private_data;
2818        struct user_namespace *ns = seq->private;
2819        int ret = single_release(inode, file);
2820        put_user_ns(ns);
2821        return ret;
2822}
2823
2824static const struct file_operations proc_setgroups_operations = {
2825        .open           = proc_setgroups_open,
2826        .write          = proc_setgroups_write,
2827        .read           = seq_read,
2828        .llseek         = seq_lseek,
2829        .release        = proc_setgroups_release,
2830};
2831#endif /* CONFIG_USER_NS */
2832
2833static int proc_pid_personality(struct seq_file *m, struct pid_namespace *ns,
2834                                struct pid *pid, struct task_struct *task)
2835{
2836        int err = lock_trace(task);
2837        if (!err) {
2838                seq_printf(m, "%08x\n", task->personality);
2839                unlock_trace(task);
2840        }
2841        return err;
2842}
2843
2844/*
2845 * Thread groups
2846 */
2847static const struct file_operations proc_task_operations;
2848static const struct inode_operations proc_task_inode_operations;
2849
2850static const struct pid_entry tgid_base_stuff[] = {
2851        DIR("task",       S_IRUGO|S_IXUGO, proc_task_inode_operations, proc_task_operations),
2852        DIR("fd",         S_IRUSR|S_IXUSR, proc_fd_inode_operations, proc_fd_operations),
2853        DIR("map_files",  S_IRUSR|S_IXUSR, proc_map_files_inode_operations, proc_map_files_operations),
2854        DIR("fdinfo",     S_IRUSR|S_IXUSR, proc_fdinfo_inode_operations, proc_fdinfo_operations),
2855        DIR("ns",         S_IRUSR|S_IXUGO, proc_ns_dir_inode_operations, proc_ns_dir_operations),
2856#ifdef CONFIG_NET
2857        DIR("net",        S_IRUGO|S_IXUGO, proc_net_inode_operations, proc_net_operations),
2858#endif
2859        REG("environ",    S_IRUSR, proc_environ_operations),
2860        REG("auxv",       S_IRUSR, proc_auxv_operations),
2861        ONE("status",     S_IRUGO, proc_pid_status),
2862        ONE("personality", S_IRUSR, proc_pid_personality),
2863        ONE("limits",     S_IRUGO, proc_pid_limits),
2864#ifdef CONFIG_SCHED_DEBUG
2865        REG("sched",      S_IRUGO|S_IWUSR, proc_pid_sched_operations),
2866#endif
2867#ifdef CONFIG_SCHED_AUTOGROUP
2868        REG("autogroup",  S_IRUGO|S_IWUSR, proc_pid_sched_autogroup_operations),
2869#endif
2870        REG("comm",      S_IRUGO|S_IWUSR, proc_pid_set_comm_operations),
2871#ifdef CONFIG_HAVE_ARCH_TRACEHOOK
2872        ONE("syscall",    S_IRUSR, proc_pid_syscall),
2873#endif
2874        REG("cmdline",    S_IRUGO, proc_pid_cmdline_ops),
2875        ONE("stat",       S_IRUGO, proc_tgid_stat),
2876        ONE("statm",      S_IRUGO, proc_pid_statm),
2877        REG("maps",       S_IRUGO, proc_pid_maps_operations),
2878#ifdef CONFIG_NUMA
2879        REG("numa_maps",  S_IRUGO, proc_pid_numa_maps_operations),
2880#endif
2881        REG("mem",        S_IRUSR|S_IWUSR, proc_mem_operations),
2882        LNK("cwd",        proc_cwd_link),
2883        LNK("root",       proc_root_link),
2884        LNK("exe",        proc_exe_link),
2885        REG("mounts",     S_IRUGO, proc_mounts_operations),
2886        REG("mountinfo",  S_IRUGO, proc_mountinfo_operations),
2887        REG("mountstats", S_IRUSR, proc_mountstats_operations),
2888#ifdef CONFIG_PROC_PAGE_MONITOR
2889        REG("clear_refs", S_IWUSR, proc_clear_refs_operations),
2890        REG("smaps",      S_IRUGO, proc_pid_smaps_operations),
2891        REG("pagemap",    S_IRUSR, proc_pagemap_operations),
2892#endif
2893#ifdef CONFIG_SECURITY
2894        DIR("attr",       S_IRUGO|S_IXUGO, proc_attr_dir_inode_operations, proc_attr_dir_operations),
2895#endif
2896#ifdef CONFIG_KALLSYMS
2897        ONE("wchan",      S_IRUGO, proc_pid_wchan),
2898#endif
2899#ifdef CONFIG_STACKTRACE
2900        ONE("stack",      S_IRUSR, proc_pid_stack),
2901#endif
2902#ifdef CONFIG_SCHED_INFO
2903        ONE("schedstat",  S_IRUGO, proc_pid_schedstat),
2904#endif
2905#ifdef CONFIG_LATENCYTOP
2906        REG("latency",  S_IRUGO, proc_lstats_operations),
2907#endif
2908#ifdef CONFIG_PROC_PID_CPUSET
2909        ONE("cpuset",     S_IRUGO, proc_cpuset_show),
2910#endif
2911#ifdef CONFIG_CGROUPS
2912        ONE("cgroup",  S_IRUGO, proc_cgroup_show),
2913#endif
2914        ONE("oom_score",  S_IRUGO, proc_oom_score),
2915        REG("oom_adj",    S_IRUGO|S_IWUSR, proc_oom_adj_operations),
2916        REG("oom_score_adj", S_IRUGO|S_IWUSR, proc_oom_score_adj_operations),
2917#ifdef CONFIG_AUDITSYSCALL
2918        REG("loginuid",   S_IWUSR|S_IRUGO, proc_loginuid_operations),
2919        REG("sessionid",  S_IRUGO, proc_sessionid_operations),
2920#endif
2921#ifdef CONFIG_FAULT_INJECTION
2922        REG("make-it-fail", S_IRUGO|S_IWUSR, proc_fault_inject_operations),
2923#endif
2924#ifdef CONFIG_ELF_CORE
2925        REG("coredump_filter", S_IRUGO|S_IWUSR, proc_coredump_filter_operations),
2926#endif
2927#ifdef CONFIG_TASK_IO_ACCOUNTING
2928        ONE("io",       S_IRUSR, proc_tgid_io_accounting),
2929#endif
2930#ifdef CONFIG_HARDWALL
2931        ONE("hardwall",   S_IRUGO, proc_pid_hardwall),
2932#endif
2933#ifdef CONFIG_USER_NS
2934        REG("uid_map",    S_IRUGO|S_IWUSR, proc_uid_map_operations),
2935        REG("gid_map",    S_IRUGO|S_IWUSR, proc_gid_map_operations),
2936        REG("projid_map", S_IRUGO|S_IWUSR, proc_projid_map_operations),
2937        REG("setgroups",  S_IRUGO|S_IWUSR, proc_setgroups_operations),
2938#endif
2939#ifdef CONFIG_CHECKPOINT_RESTORE
2940        REG("timers",     S_IRUGO, proc_timers_operations),
2941#endif
2942        REG("timerslack_ns", S_IRUGO|S_IWUGO, proc_pid_set_timerslack_ns_operations),
2943};
2944
2945static int proc_tgid_base_readdir(struct file *file, struct dir_context *ctx)
2946{
2947        return proc_pident_readdir(file, ctx,
2948                                   tgid_base_stuff, ARRAY_SIZE(tgid_base_stuff));
2949}
2950
2951static const struct file_operations proc_tgid_base_operations = {
2952        .read           = generic_read_dir,
2953        .iterate_shared = proc_tgid_base_readdir,
2954        .llseek         = generic_file_llseek,
2955};
2956
2957static struct dentry *proc_tgid_base_lookup(struct inode *dir, struct dentry *dentry, unsigned int flags)
2958{
2959        return proc_pident_lookup(dir, dentry,
2960                                  tgid_base_stuff, ARRAY_SIZE(tgid_base_stuff));
2961}
2962
2963static const struct inode_operations proc_tgid_base_inode_operations = {
2964        .lookup         = proc_tgid_base_lookup,
2965        .getattr        = pid_getattr,
2966        .setattr        = proc_setattr,
2967        .permission     = proc_pid_permission,
2968};
2969
2970static void proc_flush_task_mnt(struct vfsmount *mnt, pid_t pid, pid_t tgid)
2971{
2972        struct dentry *dentry, *leader, *dir;
2973        char buf[PROC_NUMBUF];
2974        struct qstr name;
2975
2976        name.name = buf;
2977        name.len = snprintf(buf, sizeof(buf), "%d", pid);
2978        /* no ->d_hash() rejects on procfs */
2979        dentry = d_hash_and_lookup(mnt->mnt_root, &name);
2980        if (dentry) {
2981                d_invalidate(dentry);
2982                dput(dentry);
2983        }
2984
2985        if (pid == tgid)
2986                return;
2987
2988        name.name = buf;
2989        name.len = snprintf(buf, sizeof(buf), "%d", tgid);
2990        leader = d_hash_and_lookup(mnt->mnt_root, &name);
2991        if (!leader)
2992                goto out;
2993
2994        name.name = "task";
2995        name.len = strlen(name.name);
2996        dir = d_hash_and_lookup(leader, &name);
2997        if (!dir)
2998                goto out_put_leader;
2999
3000        name.name = buf;
3001        name.len = snprintf(buf, sizeof(buf), "%d", pid);
3002        dentry = d_hash_and_lookup(dir, &name);
3003        if (dentry) {
3004                d_invalidate(dentry);
3005                dput(dentry);
3006        }
3007
3008        dput(dir);
3009out_put_leader:
3010        dput(leader);
3011out:
3012        return;
3013}
3014
3015/**
3016 * proc_flush_task -  Remove dcache entries for @task from the /proc dcache.
3017 * @task: task that should be flushed.
3018 *
3019 * When flushing dentries from proc, one needs to flush them from global
3020 * proc (proc_mnt) and from all the namespaces' procs this task was seen
3021 * in. This call is supposed to do all of this job.
3022 *
3023 * Looks in the dcache for
3024 * /proc/@pid
3025 * /proc/@tgid/task/@pid
3026 * if either directory is present flushes it and all of it'ts children
3027 * from the dcache.
3028 *
3029 * It is safe and reasonable to cache /proc entries for a task until
3030 * that task exits.  After that they just clog up the dcache with
3031 * useless entries, possibly causing useful dcache entries to be
3032 * flushed instead.  This routine is proved to flush those useless
3033 * dcache entries at process exit time.
3034 *
3035 * NOTE: This routine is just an optimization so it does not guarantee
3036 *       that no dcache entries will exist at process exit time it
3037 *       just makes it very unlikely that any will persist.
3038 */
3039
3040void proc_flush_task(struct task_struct *task)
3041{
3042        int i;
3043        struct pid *pid, *tgid;
3044        struct upid *upid;
3045
3046        pid = task_pid(task);
3047        tgid = task_tgid(task);
3048
3049        for (i = 0; i <= pid->level; i++) {
3050                upid = &pid->numbers[i];
3051                proc_flush_task_mnt(upid->ns->proc_mnt, upid->nr,
3052                                        tgid->numbers[i].nr);
3053        }
3054}
3055
3056static int proc_pid_instantiate(struct inode *dir,
3057                                   struct dentry * dentry,
3058                                   struct task_struct *task, const void *ptr)
3059{
3060        struct inode *inode;
3061
3062        inode = proc_pid_make_inode(dir->i_sb, task, S_IFDIR | S_IRUGO | S_IXUGO);
3063        if (!inode)
3064                goto out;
3065
3066        inode->i_op = &proc_tgid_base_inode_operations;
3067        inode->i_fop = &proc_tgid_base_operations;
3068        inode->i_flags|=S_IMMUTABLE;
3069
3070        set_nlink(inode, nlink_tgid);
3071
3072        d_set_d_op(dentry, &pid_dentry_operations);
3073
3074        d_add(dentry, inode);
3075        /* Close the race of the process dying before we return the dentry */
3076        if (pid_revalidate(dentry, 0))
3077                return 0;
3078out:
3079        return -ENOENT;
3080}
3081
3082struct dentry *proc_pid_lookup(struct inode *dir, struct dentry * dentry, unsigned int flags)
3083{
3084        int result = -ENOENT;
3085        struct task_struct *task;
3086        unsigned tgid;
3087        struct pid_namespace *ns;
3088
3089        tgid = name_to_int(&dentry->d_name);
3090        if (tgid == ~0U)
3091                goto out;
3092
3093        ns = dentry->d_sb->s_fs_info;
3094        rcu_read_lock();
3095        task = find_task_by_pid_ns(tgid, ns);
3096        if (task)
3097                get_task_struct(task);
3098        rcu_read_unlock();
3099        if (!task)
3100                goto out;
3101
3102        result = proc_pid_instantiate(dir, dentry, task, NULL);
3103        put_task_struct(task);
3104out:
3105        return ERR_PTR(result);
3106}
3107
3108/*
3109 * Find the first task with tgid >= tgid
3110 *
3111 */
3112struct tgid_iter {
3113        unsigned int tgid;
3114        struct task_struct *task;
3115};
3116static struct tgid_iter next_tgid(struct pid_namespace *ns, struct tgid_iter iter)
3117{
3118        struct pid *pid;
3119
3120        if (iter.task)
3121                put_task_struct(iter.task);
3122        rcu_read_lock();
3123retry:
3124        iter.task = NULL;
3125        pid = find_ge_pid(iter.tgid, ns);
3126        if (pid) {
3127                iter.tgid = pid_nr_ns(pid, ns);
3128                iter.task = pid_task(pid, PIDTYPE_PID);
3129                /* What we to know is if the pid we have find is the
3130                 * pid of a thread_group_leader.  Testing for task
3131                 * being a thread_group_leader is the obvious thing
3132                 * todo but there is a window when it fails, due to
3133                 * the pid transfer logic in de_thread.
3134                 *
3135                 * So we perform the straight forward test of seeing
3136                 * if the pid we have found is the pid of a thread
3137                 * group leader, and don't worry if the task we have
3138                 * found doesn't happen to be a thread group leader.
3139                 * As we don't care in the case of readdir.
3140                 */
3141                if (!iter.task || !has_group_leader_pid(iter.task)) {
3142                        iter.tgid += 1;
3143                        goto retry;
3144                }
3145                get_task_struct(iter.task);
3146        }
3147        rcu_read_unlock();
3148        return iter;
3149}
3150
3151#define TGID_OFFSET (FIRST_PROCESS_ENTRY + 2)
3152
3153/* for the /proc/ directory itself, after non-process stuff has been done */
3154int proc_pid_readdir(struct file *file, struct dir_context *ctx)
3155{
3156        struct tgid_iter iter;
3157        struct pid_namespace *ns = file_inode(file)->i_sb->s_fs_info;
3158        loff_t pos = ctx->pos;
3159
3160        if (pos >= PID_MAX_LIMIT + TGID_OFFSET)
3161                return 0;
3162
3163        if (pos == TGID_OFFSET - 2) {
3164                struct inode *inode = d_inode(ns->proc_self);
3165                if (!dir_emit(ctx, "self", 4, inode->i_ino, DT_LNK))
3166                        return 0;
3167                ctx->pos = pos = pos + 1;
3168        }
3169        if (pos == TGID_OFFSET - 1) {
3170                struct inode *inode = d_inode(ns->proc_thread_self);
3171                if (!dir_emit(ctx, "thread-self", 11, inode->i_ino, DT_LNK))
3172                        return 0;
3173                ctx->pos = pos = pos + 1;
3174        }
3175        iter.tgid = pos - TGID_OFFSET;
3176        iter.task = NULL;
3177        for (iter = next_tgid(ns, iter);
3178             iter.task;
3179             iter.tgid += 1, iter = next_tgid(ns, iter)) {
3180                char name[PROC_NUMBUF];
3181                int len;
3182
3183                cond_resched();
3184                if (!has_pid_permissions(ns, iter.task, 2))
3185                        continue;
3186
3187                len = snprintf(name, sizeof(name), "%d", iter.tgid);
3188                ctx->pos = iter.tgid + TGID_OFFSET;
3189                if (!proc_fill_cache(file, ctx, name, len,
3190                                     proc_pid_instantiate, iter.task, NULL)) {
3191                        put_task_struct(iter.task);
3192                        return 0;
3193                }
3194        }
3195        ctx->pos = PID_MAX_LIMIT + TGID_OFFSET;
3196        return 0;
3197}
3198
3199/*
3200 * proc_tid_comm_permission is a special permission function exclusively
3201 * used for the node /proc/<pid>/task/<tid>/comm.
3202 * It bypasses generic permission checks in the case where a task of the same
3203 * task group attempts to access the node.
3204 * The rationale behind this is that glibc and bionic access this node for
3205 * cross thread naming (pthread_set/getname_np(!self)). However, if
3206 * PR_SET_DUMPABLE gets set to 0 this node among others becomes uid=0 gid=0,
3207 * which locks out the cross thread naming implementation.
3208 * This function makes sure that the node is always accessible for members of
3209 * same thread group.
3210 */
3211static int proc_tid_comm_permission(struct inode *inode, int mask)
3212{
3213        bool is_same_tgroup;
3214        struct task_struct *task;
3215
3216        task = get_proc_task(inode);
3217        if (!task)
3218                return -ESRCH;
3219        is_same_tgroup = same_thread_group(current, task);
3220        put_task_struct(task);
3221
3222        if (likely(is_same_tgroup && !(mask & MAY_EXEC))) {
3223                /* This file (/proc/<pid>/task/<tid>/comm) can always be
3224                 * read or written by the members of the corresponding
3225                 * thread group.
3226                 */
3227                return 0;
3228        }
3229
3230        return generic_permission(inode, mask);
3231}
3232
3233static const struct inode_operations proc_tid_comm_inode_operations = {
3234                .permission = proc_tid_comm_permission,
3235};
3236
3237/*
3238 * Tasks
3239 */
3240static const struct pid_entry tid_base_stuff[] = {
3241        DIR("fd",        S_IRUSR|S_IXUSR, proc_fd_inode_operations, proc_fd_operations),
3242        DIR("fdinfo",    S_IRUSR|S_IXUSR, proc_fdinfo_inode_operations, proc_fdinfo_operations),
3243        DIR("ns",        S_IRUSR|S_IXUGO, proc_ns_dir_inode_operations, proc_ns_dir_operations),
3244#ifdef CONFIG_NET
3245        DIR("net",        S_IRUGO|S_IXUGO, proc_net_inode_operations, proc_net_operations),
3246#endif
3247        REG("environ",   S_IRUSR, proc_environ_operations),
3248        REG("auxv",      S_IRUSR, proc_auxv_operations),
3249        ONE("status",    S_IRUGO, proc_pid_status),
3250        ONE("personality", S_IRUSR, proc_pid_personality),
3251        ONE("limits",    S_IRUGO, proc_pid_limits),
3252#ifdef CONFIG_SCHED_DEBUG
3253        REG("sched",     S_IRUGO|S_IWUSR, proc_pid_sched_operations),
3254#endif
3255        NOD("comm",      S_IFREG|S_IRUGO|S_IWUSR,
3256                         &proc_tid_comm_inode_operations,
3257                         &proc_pid_set_comm_operations, {}),
3258#ifdef CONFIG_HAVE_ARCH_TRACEHOOK
3259        ONE("syscall",   S_IRUSR, proc_pid_syscall),
3260#endif
3261        REG("cmdline",   S_IRUGO, proc_pid_cmdline_ops),
3262        ONE("stat",      S_IRUGO, proc_tid_stat),
3263        ONE("statm",     S_IRUGO, proc_pid_statm),
3264        REG("maps",      S_IRUGO, proc_tid_maps_operations),
3265#ifdef CONFIG_PROC_CHILDREN
3266        REG("children",  S_IRUGO, proc_tid_children_operations),
3267#endif
3268#ifdef CONFIG_NUMA
3269        REG("numa_maps", S_IRUGO, proc_tid_numa_maps_operations),
3270#endif
3271        REG("mem",       S_IRUSR|S_IWUSR, proc_mem_operations),
3272        LNK("cwd",       proc_cwd_link),
3273        LNK("root",      proc_root_link),
3274        LNK("exe",       proc_exe_link),
3275        REG("mounts",    S_IRUGO, proc_mounts_operations),
3276        REG("mountinfo",  S_IRUGO, proc_mountinfo_operations),
3277#ifdef CONFIG_PROC_PAGE_MONITOR
3278        REG("clear_refs", S_IWUSR, proc_clear_refs_operations),
3279        REG("smaps",     S_IRUGO, proc_tid_smaps_operations),
3280        REG("pagemap",    S_IRUSR, proc_pagemap_operations),
3281#endif
3282#ifdef CONFIG_SECURITY
3283        DIR("attr",      S_IRUGO|S_IXUGO, proc_attr_dir_inode_operations, proc_attr_dir_operations),
3284#endif
3285#ifdef CONFIG_KALLSYMS
3286        ONE("wchan",     S_IRUGO, proc_pid_wchan),
3287#endif
3288#ifdef CONFIG_STACKTRACE
3289        ONE("stack",      S_IRUSR, proc_pid_stack),
3290#endif
3291#ifdef CONFIG_SCHED_INFO
3292        ONE("schedstat", S_IRUGO, proc_pid_schedstat),
3293#endif
3294#ifdef CONFIG_LATENCYTOP
3295        REG("latency",  S_IRUGO, proc_lstats_operations),
3296#endif
3297#ifdef CONFIG_PROC_PID_CPUSET
3298        ONE("cpuset",    S_IRUGO, proc_cpuset_show),
3299#endif
3300#ifdef CONFIG_CGROUPS
3301        ONE("cgroup",  S_IRUGO, proc_cgroup_show),
3302#endif
3303        ONE("oom_score", S_IRUGO, proc_oom_score),
3304        REG("oom_adj",   S_IRUGO|S_IWUSR, proc_oom_adj_operations),
3305        REG("oom_score_adj", S_IRUGO|S_IWUSR, proc_oom_score_adj_operations),
3306#ifdef CONFIG_AUDITSYSCALL
3307        REG("loginuid",  S_IWUSR|S_IRUGO, proc_loginuid_operations),
3308        REG("sessionid",  S_IRUGO, proc_sessionid_operations),
3309#endif
3310#ifdef CONFIG_FAULT_INJECTION
3311        REG("make-it-fail", S_IRUGO|S_IWUSR, proc_fault_inject_operations),
3312#endif
3313#ifdef CONFIG_TASK_IO_ACCOUNTING
3314        ONE("io",       S_IRUSR, proc_tid_io_accounting),
3315#endif
3316#ifdef CONFIG_HARDWALL
3317        ONE("hardwall",   S_IRUGO, proc_pid_hardwall),
3318#endif
3319#ifdef CONFIG_USER_NS
3320        REG("uid_map",    S_IRUGO|S_IWUSR, proc_uid_map_operations),
3321        REG("gid_map",    S_IRUGO|S_IWUSR, proc_gid_map_operations),
3322        REG("projid_map", S_IRUGO|S_IWUSR, proc_projid_map_operations),
3323        REG("setgroups",  S_IRUGO|S_IWUSR, proc_setgroups_operations),
3324#endif
3325};
3326
3327static int proc_tid_base_readdir(struct file *file, struct dir_context *ctx)
3328{
3329        return proc_pident_readdir(file, ctx,
3330                                   tid_base_stuff, ARRAY_SIZE(tid_base_stuff));
3331}
3332
3333static struct dentry *proc_tid_base_lookup(struct inode *dir, struct dentry *dentry, unsigned int flags)
3334{
3335        return proc_pident_lookup(dir, dentry,
3336                                  tid_base_stuff, ARRAY_SIZE(tid_base_stuff));
3337}
3338
3339static const struct file_operations proc_tid_base_operations = {
3340        .read           = generic_read_dir,
3341        .iterate_shared = proc_tid_base_readdir,
3342        .llseek         = generic_file_llseek,
3343};
3344
3345static const struct inode_operations proc_tid_base_inode_operations = {
3346        .lookup         = proc_tid_base_lookup,
3347        .getattr        = pid_getattr,
3348        .setattr        = proc_setattr,
3349};
3350
3351static int proc_task_instantiate(struct inode *dir,
3352        struct dentry *dentry, struct task_struct *task, const void *ptr)
3353{
3354        struct inode *inode;
3355        inode = proc_pid_make_inode(dir->i_sb, task, S_IFDIR | S_IRUGO | S_IXUGO);
3356
3357        if (!inode)
3358                goto out;
3359        inode->i_op = &proc_tid_base_inode_operations;
3360        inode->i_fop = &proc_tid_base_operations;
3361        inode->i_flags|=S_IMMUTABLE;
3362
3363        set_nlink(inode, nlink_tid);
3364
3365        d_set_d_op(dentry, &pid_dentry_operations);
3366
3367        d_add(dentry, inode);
3368        /* Close the race of the process dying before we return the dentry */
3369        if (pid_revalidate(dentry, 0))
3370                return 0;
3371out:
3372        return -ENOENT;
3373}
3374
3375static struct dentry *proc_task_lookup(struct inode *dir, struct dentry * dentry, unsigned int flags)
3376{
3377        int result = -ENOENT;
3378        struct task_struct *task;
3379        struct task_struct *leader = get_proc_task(dir);
3380        unsigned tid;
3381        struct pid_namespace *ns;
3382
3383        if (!leader)
3384                goto out_no_task;
3385
3386        tid = name_to_int(&dentry->d_name);
3387        if (tid == ~0U)
3388                goto out;
3389
3390        ns = dentry->d_sb->s_fs_info;
3391        rcu_read_lock();
3392        task = find_task_by_pid_ns(tid, ns);
3393        if (task)
3394                get_task_struct(task);
3395        rcu_read_unlock();
3396        if (!task)
3397                goto out;
3398        if (!same_thread_group(leader, task))
3399                goto out_drop_task;
3400
3401        result = proc_task_instantiate(dir, dentry, task, NULL);
3402out_drop_task:
3403        put_task_struct(task);
3404out:
3405        put_task_struct(leader);
3406out_no_task:
3407        return ERR_PTR(result);
3408}
3409
3410/*
3411 * Find the first tid of a thread group to return to user space.
3412 *
3413 * Usually this is just the thread group leader, but if the users
3414 * buffer was too small or there was a seek into the middle of the
3415 * directory we have more work todo.
3416 *
3417 * In the case of a short read we start with find_task_by_pid.
3418 *
3419 * In the case of a seek we start with the leader and walk nr
3420 * threads past it.
3421 */
3422static struct task_struct *first_tid(struct pid *pid, int tid, loff_t f_pos,
3423                                        struct pid_namespace *ns)
3424{
3425        struct task_struct *pos, *task;
3426        unsigned long nr = f_pos;
3427
3428        if (nr != f_pos)        /* 32bit overflow? */
3429                return NULL;
3430
3431        rcu_read_lock();
3432        task = pid_task(pid, PIDTYPE_PID);
3433        if (!task)
3434                goto fail;
3435
3436        /* Attempt to start with the tid of a thread */
3437        if (tid && nr) {
3438                pos = find_task_by_pid_ns(tid, ns);
3439                if (pos && same_thread_group(pos, task))
3440                        goto found;
3441        }
3442
3443        /* If nr exceeds the number of threads there is nothing todo */
3444        if (nr >= get_nr_threads(task))
3445                goto fail;
3446
3447        /* If we haven't found our starting place yet start
3448         * with the leader and walk nr threads forward.
3449         */
3450        pos = task = task->group_leader;
3451        do {
3452                if (!nr--)
3453                        goto found;
3454        } while_each_thread(task, pos);
3455fail:
3456        pos = NULL;
3457        goto out;
3458found:
3459        get_task_struct(pos);
3460out:
3461        rcu_read_unlock();
3462        return pos;
3463}
3464
3465/*
3466 * Find the next thread in the thread list.
3467 * Return NULL if there is an error or no next thread.
3468 *
3469 * The reference to the input task_struct is released.
3470 */
3471static struct task_struct *next_tid(struct task_struct *start)
3472{
3473        struct task_struct *pos = NULL;
3474        rcu_read_lock();
3475        if (pid_alive(start)) {
3476                pos = next_thread(start);
3477                if (thread_group_leader(pos))
3478                        pos = NULL;
3479                else
3480                        get_task_struct(pos);
3481        }
3482        rcu_read_unlock();
3483        put_task_struct(start);
3484        return pos;
3485}
3486
3487/* for the /proc/TGID/task/ directories */
3488static int proc_task_readdir(struct file *file, struct dir_context *ctx)
3489{
3490        struct inode *inode = file_inode(file);
3491        struct task_struct *task;
3492        struct pid_namespace *ns;
3493        int tid;
3494
3495        if (proc_inode_is_dead(inode))
3496                return -ENOENT;
3497
3498        if (!dir_emit_dots(file, ctx))
3499                return 0;
3500
3501        /* f_version caches the tgid value that the last readdir call couldn't
3502         * return. lseek aka telldir automagically resets f_version to 0.
3503         */
3504        ns = inode->i_sb->s_fs_info;
3505        tid = (int)file->f_version;
3506        file->f_version = 0;
3507        for (task = first_tid(proc_pid(inode), tid, ctx->pos - 2, ns);
3508             task;
3509             task = next_tid(task), ctx->pos++) {
3510                char name[PROC_NUMBUF];
3511                int len;
3512                tid = task_pid_nr_ns(task, ns);
3513                len = snprintf(name, sizeof(name), "%d", tid);
3514                if (!proc_fill_cache(file, ctx, name, len,
3515                                proc_task_instantiate, task, NULL)) {
3516                        /* returning this tgid failed, save it as the first
3517                         * pid for the next readir call */
3518                        file->f_version = (u64)tid;
3519                        put_task_struct(task);
3520                        break;
3521                }
3522        }
3523
3524        return 0;
3525}
3526
3527static int proc_task_getattr(struct vfsmount *mnt, struct dentry *dentry, struct kstat *stat)
3528{
3529        struct inode *inode = d_inode(dentry);
3530        struct task_struct *p = get_proc_task(inode);
3531        generic_fillattr(inode, stat);
3532
3533        if (p) {
3534                stat->nlink += get_nr_threads(p);
3535                put_task_struct(p);
3536        }
3537
3538        return 0;
3539}
3540
3541static const struct inode_operations proc_task_inode_operations = {
3542        .lookup         = proc_task_lookup,
3543        .getattr        = proc_task_getattr,
3544        .setattr        = proc_setattr,
3545        .permission     = proc_pid_permission,
3546};
3547
3548static const struct file_operations proc_task_operations = {
3549        .read           = generic_read_dir,
3550        .iterate_shared = proc_task_readdir,
3551        .llseek         = generic_file_llseek,
3552};
3553
3554void __init set_proc_pid_nlink(void)
3555{
3556        nlink_tid = pid_entry_nlink(tid_base_stuff, ARRAY_SIZE(tid_base_stuff));
3557        nlink_tgid = pid_entry_nlink(tgid_base_stuff, ARRAY_SIZE(tgid_base_stuff));
3558}
3559
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