fs/proc/array.c

   1 /*
   2  *  linux/fs/proc/array.c
   3  *
   4  *  Copyright (C) 1992  by Linus Torvalds
   5  *  based on ideas by Darren Senn
   6  *
   7  * Fixes:
   8  * Michael. K. Johnson: stat,statm extensions.
   9  *                      <johnsonm@stolaf.edu>
  10  *
  11  * Pauline Middelink :  Made cmdline,envline only break at '\0's, to
  12  *                      make sure SET_PROCTITLE works. Also removed
  13  *                      bad '!' which forced address recalculation for
  14  *                      EVERY character on the current page.
  15  *                      <middelin@polyware.iaf.nl>
  16  *
  17  * Danny ter Haar    :  added cpuinfo
  18  *                      <dth@cistron.nl>
  19  *
  20  * Alessandro Rubini :  profile extension.
  21  *                      <rubini@ipvvis.unipv.it>
  22  *
  23  * Jeff Tranter      :  added BogoMips field to cpuinfo
  24  *                      <Jeff_Tranter@Mitel.COM>
  25  *
  26  * Bruno Haible      :  remove 4K limit for the maps file
  27  *                      <haible@ma2s2.mathematik.uni-karlsruhe.de>
  28  *
  29  * Yves Arrouye      :  remove removal of trailing spaces in get_array.
  30  *                      <Yves.Arrouye@marin.fdn.fr>
  31  *
  32  * Jerome Forissier  :  added per-CPU time information to /proc/stat
  33  *                      and /proc/<pid>/cpu extension
  34  *                      <forissier@isia.cma.fr>
  35  *                      - Incorporation and non-SMP safe operation
  36  *                      of forissier patch in 2.1.78 by
  37  *                      Hans Marcus <crowbar@concepts.nl>
  38  *
  39  * aeb@cwi.nl        :  /proc/partitions
  40  *
  41  *
  42  * Alan Cox          :  security fixes.
  43  *                      <Alan.Cox@linux.org>
  44  *
  45  * Al Viro           :  safe handling of mm_struct
  46  *
  47  * Gerhard Wichert   :  added BIGMEM support
  48  * Siemens AG           <Gerhard.Wichert@pdb.siemens.de>
  49  *
  50  * Al Viro & Jeff Garzik :  moved most of the thing into base.c and
  51  *                       :  proc_misc.c. The rest may eventually go into
  52  *                       :  base.c too.
  53  */
  54
  55 #include <linux/config.h>
  56 #include <linux/types.h>
  57 #include <linux/errno.h>
  58 #include <linux/sched.h>
  59 #include <linux/kernel.h>
  60 #include <linux/kernel_stat.h>
  61 #include <linux/tty.h>
  62 #include <linux/string.h>
  63 #include <linux/mman.h>
  64 #include <linux/proc_fs.h>
  65 #include <linux/ioport.h>
  66 #include <linux/mm.h>
  67 #include <linux/pagemap.h>
  68 #include <linux/swap.h>
  69 #include <linux/slab.h>
  70 #include <linux/smp.h>
  71 #include <linux/signal.h>
  72 #include <linux/highmem.h>
  73
  74 #include <asm/uaccess.h>
  75 #include <asm/pgtable.h>
  76 #include <asm/io.h>
  77 #include <asm/processor.h>
  78
  79 /* Gcc optimizes away "strlen(x)" for constant x */
  80 #define ADDBUF(buffer, string) \
  81 do { memcpy(buffer, string, strlen(string)); \
  82      buffer += strlen(string); } while (0)
  83
  84 static inline char * task_name(struct task_struct *p, char * buf)
  85 {
  86         int i;
  87         char * name;
  88
  89         ADDBUF(buf, "Name:\t");
  90         name = p->comm;
  91         i = sizeof(p->comm);
  92         do {
  93                 unsigned char c = *name;
  94                 name++;
  95                 i--;
  96                 *buf = c;
  97                 if (!c)
  98                         break;
  99                 if (c == '\\') {
 100                         buf[1] = c;
 101                         buf += 2;
 102                         continue;
 103                 }
 104                 if (c == '\n') {
 105                         buf[0] = '\\';
 106                         buf[1] = 'n';
 107                         buf += 2;
 108                         continue;
 109                 }
 110                 buf++;
 111         } while (i);
 112         *buf = '\n';
 113         return buf+1;
 114 }
 115
 116 /*
 117  * The task state array is a strange "bitmap" of
 118  * reasons to sleep. Thus "running" is zero, and
 119  * you can test for combinations of others with
 120  * simple bit tests.
 121  */
 122 static const char *task_state_array[] = {
 123         "R (running)",          /*  0 */
 124         "S (sleeping)",         /*  1 */
 125         "D (disk sleep)",       /*  2 */
 126         "Z (zombie)",           /*  4 */
 127         "T (stopped)",          /*  8 */
 128         "W (paging)"            /* 16 */
 129 };
 130
 131 static inline const char * get_task_state(struct task_struct *tsk)
 132 {
 133         unsigned int state = tsk->state & (TASK_RUNNING |
 134                                            TASK_INTERRUPTIBLE |
 135                                            TASK_UNINTERRUPTIBLE |
 136                                            TASK_ZOMBIE |
 137                                            TASK_STOPPED);
 138         const char **p = &task_state_array[0];
 139
 140         while (state) {
 141                 p++;
 142                 state >>= 1;
 143         }
 144         return *p;
 145 }
 146
 147 static inline char * task_state(struct task_struct *p, char *buffer)
 148 {
 149         int g;
 150
 151         read_lock(&tasklist_lock);
 152         buffer += sprintf(buffer,
 153                 "State:\t%s\n"
 154                 "Pid:\t%d\n"
 155                 "PPid:\t%d\n"
 156                 "TracerPid:\t%d\n"
 157                 "Uid:\t%d\t%d\t%d\t%d\n"
 158                 "Gid:\t%d\t%d\t%d\t%d\n",
 159                 get_task_state(p),
 160                 p->pid, p->p_opptr->pid, p->p_pptr->pid != p->p_opptr->pid ? p->p_opptr->pid : 0,
 161                 p->uid, p->euid, p->suid, p->fsuid,
 162                 p->gid, p->egid, p->sgid, p->fsgid);
 163         read_unlock(&tasklist_lock);
 164         task_lock(p);
 165         buffer += sprintf(buffer,
 166                 "FDSize:\t%d\n"
 167                 "Groups:\t",
 168                 p->files ? p->files->max_fds : 0);
 169         task_unlock(p);
 170
 171         for (g = 0; g < p->ngroups; g++)
 172                 buffer += sprintf(buffer, "%d ", p->groups[g]);
 173
 174         buffer += sprintf(buffer, "\n");
 175         return buffer;
 176 }
 177
 178 static inline char * task_mem(struct mm_struct *mm, char *buffer)
 179 {
 180         struct vm_area_struct * vma;
 181         unsigned long data = 0, stack = 0;
 182         unsigned long exec = 0, lib = 0;
 183
 184         down(&mm->mmap_sem);
 185         for (vma = mm->mmap; vma; vma = vma->vm_next) {
 186                 unsigned long len = (vma->vm_end - vma->vm_start) >> 10;
 187                 if (!vma->vm_file) {
 188                         data += len;
 189                         if (vma->vm_flags & VM_GROWSDOWN)
 190                                 stack += len;
 191                         continue;
 192                 }
 193                 if (vma->vm_flags & VM_WRITE)
 194                         continue;
 195                 if (vma->vm_flags & VM_EXEC) {
 196                         exec += len;
 197                         if (vma->vm_flags & VM_EXECUTABLE)
 198                                 continue;
 199                         lib += len;
 200                 }
 201         }
 202         buffer += sprintf(buffer,
 203                 "VmSize:\t%8lu kB\n"
 204                 "VmLck:\t%8lu kB\n"
 205                 "VmRSS:\t%8lu kB\n"
 206                 "VmData:\t%8lu kB\n"
 207                 "VmStk:\t%8lu kB\n"
 208                 "VmExe:\t%8lu kB\n"
 209                 "VmLib:\t%8lu kB\n",
 210                 mm->total_vm << (PAGE_SHIFT-10),
 211                 mm->locked_vm << (PAGE_SHIFT-10),
 212                 mm->rss << (PAGE_SHIFT-10),
 213                 data - stack, stack,
 214                 exec - lib, lib);
 215         up(&mm->mmap_sem);
 216         return buffer;
 217 }
 218
 219 static void collect_sigign_sigcatch(struct task_struct *p, sigset_t *ign,
 220                                     sigset_t *catch)
 221 {
 222         struct k_sigaction *k;
 223         int i;
 224
 225         sigemptyset(ign);
 226         sigemptyset(catch);
 227
 228         if (p->sig) {
 229                 k = p->sig->action;
 230                 for (i = 1; i <= _NSIG; ++i, ++k) {
 231                         if (k->sa.sa_handler == SIG_IGN)
 232                                 sigaddset(ign, i);
 233                         else if (k->sa.sa_handler != SIG_DFL)
 234                                 sigaddset(catch, i);
 235                 }
 236         }
 237 }
 238
 239 static inline char * task_sig(struct task_struct *p, char *buffer)
 240 {
 241         sigset_t ign, catch;
 242
 243         buffer += sprintf(buffer, "SigPnd:\t");
 244         buffer = render_sigset_t(&p->signal, buffer);
 245         *buffer++ = '\n';
 246         buffer += sprintf(buffer, "SigBlk:\t");
 247         buffer = render_sigset_t(&p->blocked, buffer);
 248         *buffer++ = '\n';
 249
 250         collect_sigign_sigcatch(p, &ign, &catch);
 251         buffer += sprintf(buffer, "SigIgn:\t");
 252         buffer = render_sigset_t(&ign, buffer);
 253         *buffer++ = '\n';
 254         buffer += sprintf(buffer, "SigCgt:\t"); /* Linux 2.0 uses "SigCgt" */
 255         buffer = render_sigset_t(&catch, buffer);
 256         *buffer++ = '\n';
 257
 258         return buffer;
 259 }
 260
 261 extern inline char *task_cap(struct task_struct *p, char *buffer)
 262 {
 263     return buffer + sprintf(buffer, "CapInh:\t%016x\n"
 264                             "CapPrm:\t%016x\n"
 265                             "CapEff:\t%016x\n",
 266                             cap_t(p->cap_inheritable),
 267                             cap_t(p->cap_permitted),
 268                             cap_t(p->cap_effective));
 269 }
 270
 271
 272 int proc_pid_status(struct task_struct *task, char * buffer)
 273 {
 274         char * orig = buffer;
 275         struct mm_struct *mm;
 276 #if defined(CONFIG_ARCH_S390)
 277         int line,len;
 278 #endif
 279
 280         buffer = task_name(task, buffer);
 281         buffer = task_state(task, buffer);
 282         task_lock(task);
 283         mm = task->mm;
 284         if(mm)
 285                 atomic_inc(&mm->mm_users);
 286         task_unlock(task);
 287         if (mm) {
 288                 buffer = task_mem(mm, buffer);
 289                 mmput(mm);
 290         }
 291         buffer = task_sig(task, buffer);
 292         buffer = task_cap(task, buffer);
 293 #if defined(CONFIG_ARCH_S390)
 294         for(line=0;(len=sprintf_regs(line,buffer,task,NULL,NULL))!=0;line++)
 295                 buffer+=len;
 296 #endif
 297         return buffer - orig;
 298 }
 299
 300 int proc_pid_stat(struct task_struct *task, char * buffer)
 301 {
 302         unsigned long vsize, eip, esp, wchan;
 303         long priority, nice;
 304         int tty_pgrp;
 305         sigset_t sigign, sigcatch;
 306         char state;
 307         int res;
 308         pid_t ppid;
 309         int tty_nr;
 310         struct mm_struct *mm;
 311
 312         state = *get_task_state(task);
 313         vsize = eip = esp = 0;
 314         task_lock(task);
 315         mm = task->mm;
 316         if(mm)
 317                 atomic_inc(&mm->mm_users);
 318         task_unlock(task);
 319         if (mm) {
 320                 struct vm_area_struct *vma;
 321                 down(&mm->mmap_sem);
 322                 vma = mm->mmap;
 323                 while (vma) {
 324                         vsize += vma->vm_end - vma->vm_start;
 325                         vma = vma->vm_next;
 326                 }
 327                 eip = KSTK_EIP(task);
 328                 esp = KSTK_ESP(task);
 329                 up(&mm->mmap_sem);
 330         }
 331
 332         wchan = get_wchan(task);
 333
 334         collect_sigign_sigcatch(task, &sigign, &sigcatch);
 335
 336         task_lock(task);
 337         if (task->tty)
 338                 tty_pgrp = task->tty->pgrp;
 339         else
 340                 tty_pgrp = -1;
 341         tty_nr = task->tty ? kdev_t_to_nr(task->tty->device) : 0;
 342         task_unlock(task);
 343
 344         /* scale priority and nice values from timeslices to -20..20 */
 345         /* to make it look like a "normal" Unix priority/nice value  */
 346         priority = task->counter;
 347         priority = 20 - (priority * 10 + DEF_COUNTER / 2) / DEF_COUNTER;
 348         nice = task->nice;
 349
 350         read_lock(&tasklist_lock);
 351         ppid = task->p_opptr->pid;
 352         read_unlock(&tasklist_lock);
 353         res = sprintf(buffer,"%d (%s) %c %d %d %d %d %d %lu %lu \
 354 %lu %lu %lu %lu %lu %ld %ld %ld %ld %ld %ld %lu %lu %ld %lu %lu %lu %lu %lu \
 355 %lu %lu %lu %lu %lu %lu %lu %lu %d %d\n",
 356                 task->pid,
 357                 task->comm,
 358                 state,
 359                 ppid,
 360                 task->pgrp,
 361                 task->session,
 362                 tty_nr,
 363                 tty_pgrp,
 364                 task->flags,
 365                 task->min_flt,
 366                 task->cmin_flt,
 367                 task->maj_flt,
 368                 task->cmaj_flt,
 369                 hz_to_std(task->times.tms_utime),
 370                 hz_to_std(task->times.tms_stime),
 371                 hz_to_std(task->times.tms_cutime),
 372                 hz_to_std(task->times.tms_cstime),
 373                 priority,
 374                 nice,
 375                 0UL /* removed */,
 376                 task->it_real_value,
 377                 task->start_time,
 378                 vsize,
 379                 mm ? mm->rss : 0, /* you might want to shift this left 3 */
 380                 task->rlim ? task->rlim[RLIMIT_RSS].rlim_cur : 0,
 381                 mm ? mm->start_code : 0,
 382                 mm ? mm->end_code : 0,
 383                 mm ? mm->start_stack : 0,
 384                 esp,
 385                 eip,
 386                 /* The signal information here is obsolete.
 387                  * It must be decimal for Linux 2.0 compatibility.
 388                  * Use /proc/#/status for real-time signals.
 389                  */
 390                 task->signal .sig[0] & 0x7fffffffUL,
 391                 task->blocked.sig[0] & 0x7fffffffUL,
 392                 sigign      .sig[0] & 0x7fffffffUL,
 393                 sigcatch    .sig[0] & 0x7fffffffUL,
 394                 wchan,
 395                 task->nswap,
 396                 task->cnswap,
 397                 task->exit_signal,
 398                 task->processor);
 399         if(mm)
 400                 mmput(mm);
 401         return res;
 402 }
 403
 404 static inline void statm_pte_range(pmd_t * pmd, unsigned long address, unsigned long size,
 405         int * pages, int * shared, int * dirty, int * total)
 406 {
 407         pte_t * pte;
 408         unsigned long end;
 409
 410         if (pmd_none(*pmd))
 411                 return;
 412         if (pmd_bad(*pmd)) {
 413                 pmd_ERROR(*pmd);
 414                 pmd_clear(pmd);
 415                 return;
 416         }
 417         pte = pte_offset(pmd, address);
 418         address &= ~PMD_MASK;
 419         end = address + size;
 420         if (end > PMD_SIZE)
 421                 end = PMD_SIZE;
 422         do {
 423                 pte_t page = *pte;
 424
 425                 address += PAGE_SIZE;
 426                 pte++;
 427                 if (pte_none(page))
 428                         continue;
 429                 ++*total;
 430                 if (!pte_present(page))
 431                         continue;
 432                 ++*pages;
 433                 if (pte_dirty(page))
 434                         ++*dirty;
 435                 if ((pte_pagenr(page) >= max_mapnr) ||
 436                                         PageReserved(pte_pagenr(page) + mem_map))
 437                         continue;
 438                 if (page_count(pte_page(page)) > 1)
 439                         ++*shared;
 440         } while (address < end);
 441 }
 442
 443 static inline void statm_pmd_range(pgd_t * pgd, unsigned long address, unsigned long size,
 444         int * pages, int * shared, int * dirty, int * total)
 445 {
 446         pmd_t * pmd;
 447         unsigned long end;
 448
 449         if (pgd_none(*pgd))
 450                 return;
 451         if (pgd_bad(*pgd)) {
 452                 pgd_ERROR(*pgd);
 453                 pgd_clear(pgd);
 454                 return;
 455         }
 456         pmd = pmd_offset(pgd, address);
 457         address &= ~PGDIR_MASK;
 458         end = address + size;
 459         if (end > PGDIR_SIZE)
 460                 end = PGDIR_SIZE;
 461         do {
 462                 statm_pte_range(pmd, address, end - address, pages, shared, dirty, total);
 463                 address = (address + PMD_SIZE) & PMD_MASK;
 464                 pmd++;
 465         } while (address < end);
 466 }
 467
 468 static void statm_pgd_range(pgd_t * pgd, unsigned long address, unsigned long end,
 469         int * pages, int * shared, int * dirty, int * total)
 470 {
 471         while (address < end) {
 472                 statm_pmd_range(pgd, address, end - address, pages, shared, dirty, total);
 473                 address = (address + PGDIR_SIZE) & PGDIR_MASK;
 474                 pgd++;
 475         }
 476 }
 477
 478 int proc_pid_statm(struct task_struct *task, char * buffer)
 479 {
 480         struct mm_struct *mm;
 481         int size=0, resident=0, share=0, trs=0, lrs=0, drs=0, dt=0;
 482
 483         task_lock(task);
 484         mm = task->mm;
 485         if(mm)
 486                 atomic_inc(&mm->mm_users);
 487         task_unlock(task);
 488         if (mm) {
 489                 struct vm_area_struct * vma;
 490                 down(&mm->mmap_sem);
 491                 vma = mm->mmap;
 492                 while (vma) {
 493                         pgd_t *pgd = pgd_offset(mm, vma->vm_start);
 494                         int pages = 0, shared = 0, dirty = 0, total = 0;
 495
 496                         statm_pgd_range(pgd, vma->vm_start, vma->vm_end, &pages, &shared, &dirty, &total);
 497                         resident += pages;
 498                         share += shared;
 499                         dt += dirty;
 500                         size += total;
 501                         if (vma->vm_flags & VM_EXECUTABLE)
 502                                 trs += pages;   /* text */
 503                         else if (vma->vm_flags & VM_GROWSDOWN)
 504                                 drs += pages;   /* stack */
 505                         else if (vma->vm_end > 0x60000000)
 506                                 lrs += pages;   /* library */
 507                         else
 508                                 drs += pages;
 509                         vma = vma->vm_next;
 510                 }
 511                 up(&mm->mmap_sem);
 512                 mmput(mm);
 513         }
 514         return sprintf(buffer,"%d %d %d %d %d %d %d\n",
 515                        size, resident, share, trs, lrs, drs, dt);
 516 }
 517
 518 /*
 519  * The way we support synthetic files > 4K
 520  * - without storing their contents in some buffer and
 521  * - without walking through the entire synthetic file until we reach the
 522  *   position of the requested data
 523  * is to cleverly encode the current position in the file's f_pos field.
 524  * There is no requirement that a read() call which returns `count' bytes
 525  * of data increases f_pos by exactly `count'.
 526  *
 527  * This idea is Linus' one. Bruno implemented it.
 528  */
 529
 530 /*
 531  * For the /proc/<pid>/maps file, we use fixed length records, each containing
 532  * a single line.
 533  */
 534 #define MAPS_LINE_LENGTH        4096
 535 #define MAPS_LINE_SHIFT         12
 536 /*
 537  * f_pos = (number of the vma in the task->mm->mmap list) * MAPS_LINE_LENGTH
 538  *         + (index into the line)
 539  */
 540 /* for systems with sizeof(void*) == 4: */
 541 #define MAPS_LINE_FORMAT4         "%08lx-%08lx %s %08lx %s %lu"
 542 #define MAPS_LINE_MAX4  49 /* sum of 8  1  8  1 4 1 8 1 5 1 10 1 */
 543
 544 /* for systems with sizeof(void*) == 8: */
 545 #define MAPS_LINE_FORMAT8         "%016lx-%016lx %s %016lx %s %lu"
 546 #define MAPS_LINE_MAX8  73 /* sum of 16  1  16  1 4 1 16 1 5 1 10 1 */
 547
 548 #define MAPS_LINE_MAX   MAPS_LINE_MAX8
 549
 550
 551 ssize_t proc_pid_read_maps (struct task_struct *task, struct file * file, char * buf,
 552                           size_t count, loff_t *ppos)
 553 {
 554         struct mm_struct *mm;
 555         struct vm_area_struct * map, * next;
 556         char * destptr = buf, * buffer;
 557         loff_t lineno;
 558         ssize_t column, i;
 559         int volatile_task;
 560         long retval;
 561
 562         /*
 563          * We might sleep getting the page, so get it first.
 564          */
 565         retval = -ENOMEM;
 566         buffer = (char*)__get_free_page(GFP_KERNEL);
 567         if (!buffer)
 568                 goto out;
 569
 570         if (count == 0)
 571                 goto getlen_out;
 572         task_lock(task);
 573         mm = task->mm;
 574         if (mm)
 575                 atomic_inc(&mm->mm_users);
 576         task_unlock(task);
 577         if (!mm)
 578                 goto getlen_out;
 579
 580         /* Check whether the mmaps could change if we sleep */
 581         volatile_task = (task != current || atomic_read(&mm->mm_users) > 1);
 582
 583         /* decode f_pos */
 584         lineno = *ppos >> MAPS_LINE_SHIFT;
 585         column = *ppos & (MAPS_LINE_LENGTH-1);
 586
 587         /* quickly go to line lineno */
 588         down(&mm->mmap_sem);
 589         for (map = mm->mmap, i = 0; map && (i < lineno); map = map->vm_next, i++)
 590                 continue;
 591
 592         for ( ; map ; map = next ) {
 593                 /* produce the next line */
 594                 char *line;
 595                 char str[5], *cp = str;
 596                 int flags;
 597                 kdev_t dev;
 598                 unsigned long ino;
 599                 int maxlen = (sizeof(void*) == 4) ?
 600                         MAPS_LINE_MAX4 :  MAPS_LINE_MAX8;
 601                 int len;
 602
 603                 /*
 604                  * Get the next vma now (but it won't be used if we sleep).
 605                  */
 606                 next = map->vm_next;
 607                 flags = map->vm_flags;
 608
 609                 *cp++ = flags & VM_READ ? 'r' : '-';
 610                 *cp++ = flags & VM_WRITE ? 'w' : '-';
 611                 *cp++ = flags & VM_EXEC ? 'x' : '-';
 612                 *cp++ = flags & VM_MAYSHARE ? 's' : 'p';
 613                 *cp++ = 0;
 614
 615                 dev = 0;
 616                 ino = 0;
 617                 if (map->vm_file != NULL) {
 618                         dev = map->vm_file->f_dentry->d_inode->i_dev;
 619                         ino = map->vm_file->f_dentry->d_inode->i_ino;
 620                         line = d_path(map->vm_file->f_dentry,
 621                                       map->vm_file->f_vfsmnt,
 622                                       buffer, PAGE_SIZE);
 623                         buffer[PAGE_SIZE-1] = '\n';
 624                         line -= maxlen;
 625                         if(line < buffer)
 626                                 line = buffer;
 627                 } else
 628                         line = buffer;
 629
 630                 len = sprintf(line,
 631                               sizeof(void*) == 4 ? MAPS_LINE_FORMAT4 : MAPS_LINE_FORMAT8,
 632                               map->vm_start, map->vm_end, str, map->vm_pgoff << PAGE_SHIFT,
 633                               kdevname(dev), ino);
 634
 635                 if(map->vm_file) {
 636                         for(i = len; i < maxlen; i++)
 637                                 line[i] = ' ';
 638                         len = buffer + PAGE_SIZE - line;
 639                 } else
 640                         line[len++] = '\n';
 641                 if (column >= len) {
 642                         column = 0; /* continue with next line at column 0 */
 643                         lineno++;
 644                         continue; /* we haven't slept */
 645                 }
 646
 647                 i = len-column;
 648                 if (i > count)
 649                         i = count;
 650                 up(&mm->mmap_sem);
 651                 copy_to_user(destptr, line+column, i); /* may have slept */
 652                 down(&mm->mmap_sem);
 653                 destptr += i;
 654                 count   -= i;
 655                 column  += i;
 656                 if (column >= len) {
 657                         column = 0; /* next time: next line at column 0 */
 658                         lineno++;
 659                 }
 660
 661                 /* done? */
 662                 if (count == 0)
 663                         break;
 664
 665                 /* By writing to user space, we might have slept.
 666                  * Stop the loop, to avoid a race condition.
 667                  */
 668                 if (volatile_task)
 669                         break;
 670         }
 671         up(&mm->mmap_sem);
 672
 673         /* encode f_pos */
 674         *ppos = (lineno << MAPS_LINE_SHIFT) + column;
 675         mmput(mm);
 676
 677 getlen_out:
 678         retval = destptr - buf;
 679         free_page((unsigned long)buffer);
 680 out:
 681         return retval;
 682 }
 683
 684 #ifdef CONFIG_SMP
 685 int proc_pid_cpu(struct task_struct *task, char * buffer)
 686 {
 687         int i, len;
 688
 689         len = sprintf(buffer,
 690                 "cpu  %lu %lu\n",
 691                 hz_to_std(task->times.tms_utime),
 692                 hz_to_std(task->times.tms_stime));
 693
 694         for (i = 0 ; i < smp_num_cpus; i++)
 695                 len += sprintf(buffer + len, "cpu%d %lu %lu\n",
 696                         i,
 697                         hz_to_std(task->per_cpu_utime[cpu_logical_map(i)]),
 698                         hz_to_std(task->per_cpu_stime[cpu_logical_map(i)]));
 699
 700         return len;
 701 }
 702 #endif