fs/proc/proc_misc.c

   1 /*
   2  *  linux/fs/proc/proc_misc.c
   3  *
   4  *  linux/fs/proc/array.c
   5  *  Copyright (C) 1992  by Linus Torvalds
   6  *  based on ideas by Darren Senn
   7  *
   8  *  This used to be the part of array.c. See the rest of history and credits
   9  *  there. I took this into a separate file and switched the thing to generic
  10  *  proc_file_inode_operations, leaving in array.c only per-process stuff.
  11  *  Inumbers allocation made dynamic (via create_proc_entry()).  AV, May 1999.
  12  *
  13  * Changes:
  14  * Fulton Green      :  Encapsulated position metric calculations.
  15  *                      <kernel@FultonGreen.com>
  16  */
  17
  18 #include <linux/types.h>
  19 #include <linux/errno.h>
  20 #include <linux/time.h>
  21 #include <linux/kernel.h>
  22 #include <linux/kernel_stat.h>
  23 #include <linux/tty.h>
  24 #include <linux/string.h>
  25 #include <linux/mman.h>
  26 #include <linux/proc_fs.h>
  27 #include <linux/ioport.h>
  28 #include <linux/config.h>
  29 #include <linux/mm.h>
  30 #include <linux/mmzone.h>
  31 #include <linux/pagemap.h>
  32 #include <linux/swap.h>
  33 #include <linux/slab.h>
  34 #include <linux/smp.h>
  35 #include <linux/signal.h>
  36 #include <linux/module.h>
  37 #include <linux/init.h>
  38 #include <linux/smp_lock.h>
  39 #include <linux/seq_file.h>
  40 #include <linux/times.h>
  41 #include <linux/profile.h>
  42 #include <linux/blkdev.h>
  43 #include <linux/hugetlb.h>
  44 #include <linux/jiffies.h>
  45 #include <linux/sysrq.h>
  46 #include <linux/vmalloc.h>
  47 #include <linux/crash_dump.h>
  48 #include <linux/vs_base.h>
  49 #include <linux/vs_cvirt.h>
  50
  51 #include <asm/uaccess.h>
  52 #include <asm/pgtable.h>
  53 #include <asm/io.h>
  54 #include <asm/tlb.h>
  55 #include <asm/div64.h>
  56 #include "internal.h"
  57
  58 #include <linux/vs_cvirt.h>
  59
  60 #define LOAD_INT(x) ((x) >> FSHIFT)
  61 #define LOAD_FRAC(x) LOAD_INT(((x) & (FIXED_1-1)) * 100)
  62 /*
  63  * Warning: stuff below (imported functions) assumes that its output will fit
  64  * into one page. For some of those functions it may be wrong. Moreover, we
  65  * have a way to deal with that gracefully. Right now I used straightforward
  66  * wrappers, but this needs further analysis wrt potential overflows.
  67  */
  68 extern int get_hardware_list(char *);
  69 extern int get_stram_list(char *);
  70 extern int get_chrdev_list(char *);
  71 extern int get_filesystem_list(char *);
  72 extern int get_exec_domain_list(char *);
  73 extern int get_dma_list(char *);
  74 extern int get_locks_status (char *, char **, off_t, int);
  75
  76 static int proc_calc_metrics(char *page, char **start, off_t off,
  77                                  int count, int *eof, int len)
  78 {
  79         if (len <= off+count) *eof = 1;
  80         *start = page + off;
  81         len -= off;
  82         if (len>count) len = count;
  83         if (len<0) len = 0;
  84         return len;
  85 }
  86
  87 static int loadavg_read_proc(char *page, char **start, off_t off,
  88                                  int count, int *eof, void *data)
  89 {
  90         unsigned int running, threads;
  91         int a, b, c;
  92         int len;
  93
  94         if (vx_flags(VXF_VIRT_LOAD, 0)) {
  95                 struct vx_info *vxi = current->vx_info;
  96
  97                 a = vxi->cvirt.load[0] + (FIXED_1/200);
  98                 b = vxi->cvirt.load[1] + (FIXED_1/200);
  99                 c = vxi->cvirt.load[2] + (FIXED_1/200);
 100
 101                 running = atomic_read(&vxi->cvirt.nr_running);
 102                 threads = atomic_read(&vxi->cvirt.nr_threads);
 103         } else {
 104                 a = avenrun[0] + (FIXED_1/200);
 105                 b = avenrun[1] + (FIXED_1/200);
 106                 c = avenrun[2] + (FIXED_1/200);
 107
 108                 running = nr_running();
 109                 threads = nr_threads;
 110         }
 111         len = sprintf(page,"%d.%02d %d.%02d %d.%02d %d/%d %d\n",
 112                 LOAD_INT(a), LOAD_FRAC(a),
 113                 LOAD_INT(b), LOAD_FRAC(b),
 114                 LOAD_INT(c), LOAD_FRAC(c),
 115                 running, threads, last_pid);
 116         return proc_calc_metrics(page, start, off, count, eof, len);
 117 }
 118
 119 static int uptime_read_proc(char *page, char **start, off_t off,
 120                                  int count, int *eof, void *data)
 121 {
 122         struct timespec uptime;
 123         struct timespec idle;
 124         int len;
 125         cputime_t idletime = cputime_add(init_task.utime, init_task.stime);
 126
 127         do_posix_clock_monotonic_gettime(&uptime);
 128         cputime_to_timespec(idletime, &idle);
 129         if (vx_flags(VXF_VIRT_UPTIME, 0))
 130                 vx_vsi_uptime(&uptime, &idle);
 131
 132         len = sprintf(page,"%lu.%02lu %lu.%02lu\n",
 133                         (unsigned long) uptime.tv_sec,
 134                         (uptime.tv_nsec / (NSEC_PER_SEC / 100)),
 135                         (unsigned long) idle.tv_sec,
 136                         (idle.tv_nsec / (NSEC_PER_SEC / 100)));
 137
 138         return proc_calc_metrics(page, start, off, count, eof, len);
 139 }
 140
 141 static int meminfo_read_proc(char *page, char **start, off_t off,
 142                                  int count, int *eof, void *data)
 143 {
 144         struct sysinfo i;
 145         int len;
 146         struct page_state ps;
 147         unsigned long inactive;
 148         unsigned long active;
 149         unsigned long free;
 150         unsigned long committed;
 151         unsigned long allowed;
 152         struct vmalloc_info vmi;
 153         long cached;
 154
 155         get_page_state(&ps);
 156         get_zone_counts(&active, &inactive, &free);
 157
 158 /*
 159  * display in kilobytes.
 160  */
 161 #define K(x) ((x) << (PAGE_SHIFT - 10))
 162         si_meminfo(&i);
 163         si_swapinfo(&i);
 164         committed = atomic_read(&vm_committed_space);
 165         allowed = ((totalram_pages - hugetlb_total_pages())
 166                 * sysctl_overcommit_ratio / 100) + total_swap_pages;
 167
 168         cached = get_page_cache_size() - total_swapcache_pages - i.bufferram;
 169         if (cached < 0)
 170                 cached = 0;
 171
 172         get_vmalloc_info(&vmi);
 173
 174         /*
 175          * Tagged format, for easy grepping and expansion.
 176          */
 177         len = sprintf(page,
 178                 "MemTotal:     %8lu kB\n"
 179                 "MemFree:      %8lu kB\n"
 180                 "Buffers:      %8lu kB\n"
 181                 "Cached:       %8lu kB\n"
 182                 "SwapCached:   %8lu kB\n"
 183                 "Active:       %8lu kB\n"
 184                 "Inactive:     %8lu kB\n"
 185                 "HighTotal:    %8lu kB\n"
 186                 "HighFree:     %8lu kB\n"
 187                 "LowTotal:     %8lu kB\n"
 188                 "LowFree:      %8lu kB\n"
 189                 "SwapTotal:    %8lu kB\n"
 190                 "SwapFree:     %8lu kB\n"
 191                 "Dirty:        %8lu kB\n"
 192                 "Writeback:    %8lu kB\n"
 193                 "Mapped:       %8lu kB\n"
 194                 "Slab:         %8lu kB\n"
 195                 "CommitLimit:  %8lu kB\n"
 196                 "Committed_AS: %8lu kB\n"
 197                 "PageTables:   %8lu kB\n"
 198                 "VmallocTotal: %8lu kB\n"
 199                 "VmallocUsed:  %8lu kB\n"
 200                 "VmallocChunk: %8lu kB\n",
 201                 K(i.totalram),
 202                 K(i.freeram),
 203                 K(i.bufferram),
 204                 K(cached),
 205                 K(total_swapcache_pages),
 206                 K(active),
 207                 K(inactive),
 208                 K(i.totalhigh),
 209                 K(i.freehigh),
 210                 K(i.totalram-i.totalhigh),
 211                 K(i.freeram-i.freehigh),
 212                 K(i.totalswap),
 213                 K(i.freeswap),
 214                 K(ps.nr_dirty),
 215                 K(ps.nr_writeback),
 216                 K(ps.nr_mapped),
 217                 K(ps.nr_slab),
 218                 K(allowed),
 219                 K(committed),
 220                 K(ps.nr_page_table_pages),
 221                 (unsigned long)VMALLOC_TOTAL >> 10,
 222                 vmi.used >> 10,
 223                 vmi.largest_chunk >> 10
 224                 );
 225
 226                 len += hugetlb_report_meminfo(page + len);
 227
 228         return proc_calc_metrics(page, start, off, count, eof, len);
 229 #undef K
 230 }
 231
 232 extern struct seq_operations fragmentation_op;
 233 static int fragmentation_open(struct inode *inode, struct file *file)
 234 {
 235         (void)inode;
 236         return seq_open(file, &fragmentation_op);
 237 }
 238
 239 static struct file_operations fragmentation_file_operations = {
 240         .open           = fragmentation_open,
 241         .read           = seq_read,
 242         .llseek         = seq_lseek,
 243         .release        = seq_release,
 244 };
 245
 246 static int version_read_proc(char *page, char **start, off_t off,
 247                                  int count, int *eof, void *data)
 248 {
 249         int len;
 250
 251         len = sprintf(page, vx_linux_banner,
 252                 vx_new_uts(release),
 253                 vx_new_uts(version));
 254         return proc_calc_metrics(page, start, off, count, eof, len);
 255 }
 256
 257 extern struct seq_operations cpuinfo_op;
 258 static int cpuinfo_open(struct inode *inode, struct file *file)
 259 {
 260         return seq_open(file, &cpuinfo_op);
 261 }
 262 static struct file_operations proc_cpuinfo_operations = {
 263         .open           = cpuinfo_open,
 264         .read           = seq_read,
 265         .llseek         = seq_lseek,
 266         .release        = seq_release,
 267 };
 268
 269 extern struct seq_operations vmstat_op;
 270 static int vmstat_open(struct inode *inode, struct file *file)
 271 {
 272         return seq_open(file, &vmstat_op);
 273 }
 274 static struct file_operations proc_vmstat_file_operations = {
 275         .open           = vmstat_open,
 276         .read           = seq_read,
 277         .llseek         = seq_lseek,
 278         .release        = seq_release,
 279 };
 280
 281 #ifdef CONFIG_PROC_HARDWARE
 282 static int hardware_read_proc(char *page, char **start, off_t off,
 283                                  int count, int *eof, void *data)
 284 {
 285         int len = get_hardware_list(page);
 286         return proc_calc_metrics(page, start, off, count, eof, len);
 287 }
 288 #endif
 289
 290 #ifdef CONFIG_STRAM_PROC
 291 static int stram_read_proc(char *page, char **start, off_t off,
 292                                  int count, int *eof, void *data)
 293 {
 294         int len = get_stram_list(page);
 295         return proc_calc_metrics(page, start, off, count, eof, len);
 296 }
 297 #endif
 298
 299 extern struct seq_operations partitions_op;
 300 static int partitions_open(struct inode *inode, struct file *file)
 301 {
 302         return seq_open(file, &partitions_op);
 303 }
 304 static struct file_operations proc_partitions_operations = {
 305         .open           = partitions_open,
 306         .read           = seq_read,
 307         .llseek         = seq_lseek,
 308         .release        = seq_release,
 309 };
 310
 311 extern struct seq_operations diskstats_op;
 312 static int diskstats_open(struct inode *inode, struct file *file)
 313 {
 314         return seq_open(file, &diskstats_op);
 315 }
 316 static struct file_operations proc_diskstats_operations = {
 317         .open           = diskstats_open,
 318         .read           = seq_read,
 319         .llseek         = seq_lseek,
 320         .release        = seq_release,
 321 };
 322
 323 #ifdef CONFIG_MODULES
 324 extern struct seq_operations modules_op;
 325 static int modules_open(struct inode *inode, struct file *file)
 326 {
 327         return seq_open(file, &modules_op);
 328 }
 329 static struct file_operations proc_modules_operations = {
 330         .open           = modules_open,
 331         .read           = seq_read,
 332         .llseek         = seq_lseek,
 333         .release        = seq_release,
 334 };
 335 #endif
 336
 337 extern struct seq_operations slabinfo_op;
 338 extern ssize_t slabinfo_write(struct file *, const char __user *, size_t, loff_t *);
 339 static int slabinfo_open(struct inode *inode, struct file *file)
 340 {
 341         return seq_open(file, &slabinfo_op);
 342 }
 343 static struct file_operations proc_slabinfo_operations = {
 344         .open           = slabinfo_open,
 345         .read           = seq_read,
 346         .write          = slabinfo_write,
 347         .llseek         = seq_lseek,
 348         .release        = seq_release,
 349 };
 350
 351 static int show_stat(struct seq_file *p, void *v)
 352 {
 353         int i;
 354         unsigned long jif;
 355         cputime64_t user, nice, system, idle, iowait, irq, softirq, steal;
 356         u64 sum = 0;
 357
 358         user = nice = system = idle = iowait =
 359                 irq = softirq = steal = cputime64_zero;
 360         jif = - wall_to_monotonic.tv_sec;
 361         if (wall_to_monotonic.tv_nsec)
 362                 --jif;
 363
 364         for_each_cpu(i) {
 365                 int j;
 366
 367                 user = cputime64_add(user, kstat_cpu(i).cpustat.user);
 368                 nice = cputime64_add(nice, kstat_cpu(i).cpustat.nice);
 369                 system = cputime64_add(system, kstat_cpu(i).cpustat.system);
 370                 idle = cputime64_add(idle, kstat_cpu(i).cpustat.idle);
 371                 iowait = cputime64_add(iowait, kstat_cpu(i).cpustat.iowait);
 372                 irq = cputime64_add(irq, kstat_cpu(i).cpustat.irq);
 373                 softirq = cputime64_add(softirq, kstat_cpu(i).cpustat.softirq);
 374                 steal = cputime64_add(steal, kstat_cpu(i).cpustat.steal);
 375                 for (j = 0 ; j < NR_IRQS ; j++)
 376                         sum += kstat_cpu(i).irqs[j];
 377         }
 378
 379         seq_printf(p, "cpu  %llu %llu %llu %llu %llu %llu %llu %llu\n",
 380                 (unsigned long long)cputime64_to_clock_t(user),
 381                 (unsigned long long)cputime64_to_clock_t(nice),
 382                 (unsigned long long)cputime64_to_clock_t(system),
 383                 (unsigned long long)cputime64_to_clock_t(idle),
 384                 (unsigned long long)cputime64_to_clock_t(iowait),
 385                 (unsigned long long)cputime64_to_clock_t(irq),
 386                 (unsigned long long)cputime64_to_clock_t(softirq),
 387                 (unsigned long long)cputime64_to_clock_t(steal));
 388         for_each_online_cpu(i) {
 389
 390                 /* Copy values here to work around gcc-2.95.3, gcc-2.96 */
 391                 user = kstat_cpu(i).cpustat.user;
 392                 nice = kstat_cpu(i).cpustat.nice;
 393                 system = kstat_cpu(i).cpustat.system;
 394                 idle = kstat_cpu(i).cpustat.idle;
 395                 iowait = kstat_cpu(i).cpustat.iowait;
 396                 irq = kstat_cpu(i).cpustat.irq;
 397                 softirq = kstat_cpu(i).cpustat.softirq;
 398                 steal = kstat_cpu(i).cpustat.steal;
 399                 seq_printf(p, "cpu%d %llu %llu %llu %llu %llu %llu %llu %llu\n",
 400                         i,
 401                         (unsigned long long)cputime64_to_clock_t(user),
 402                         (unsigned long long)cputime64_to_clock_t(nice),
 403                         (unsigned long long)cputime64_to_clock_t(system),
 404                         (unsigned long long)cputime64_to_clock_t(idle),
 405                         (unsigned long long)cputime64_to_clock_t(iowait),
 406                         (unsigned long long)cputime64_to_clock_t(irq),
 407                         (unsigned long long)cputime64_to_clock_t(softirq),
 408                         (unsigned long long)cputime64_to_clock_t(steal));
 409         }
 410         seq_printf(p, "intr %llu", (unsigned long long)sum);
 411
 412 #if !defined(CONFIG_PPC64) && !defined(CONFIG_ALPHA)
 413         for (i = 0; i < NR_IRQS; i++)
 414                 seq_printf(p, " %u", kstat_irqs(i));
 415 #endif
 416
 417         seq_printf(p,
 418                 "\nctxt %llu\n"
 419                 "btime %lu\n"
 420                 "processes %lu\n"
 421                 "procs_running %lu\n"
 422                 "procs_blocked %lu\n",
 423                 nr_context_switches(),
 424                 (unsigned long)jif,
 425                 total_forks,
 426                 nr_running(),
 427                 nr_iowait());
 428
 429         return 0;
 430 }
 431
 432 static int stat_open(struct inode *inode, struct file *file)
 433 {
 434         unsigned size = 4096 * (1 + num_possible_cpus() / 32);
 435         char *buf;
 436         struct seq_file *m;
 437         int res;
 438
 439         /* don't ask for more than the kmalloc() max size, currently 128 KB */
 440         if (size > 128 * 1024)
 441                 size = 128 * 1024;
 442         buf = kmalloc(size, GFP_KERNEL);
 443         if (!buf)
 444                 return -ENOMEM;
 445
 446         res = single_open(file, show_stat, NULL);
 447         if (!res) {
 448                 m = file->private_data;
 449                 m->buf = buf;
 450                 m->size = size;
 451         } else
 452                 kfree(buf);
 453         return res;
 454 }
 455 static struct file_operations proc_stat_operations = {
 456         .open           = stat_open,
 457         .read           = seq_read,
 458         .llseek         = seq_lseek,
 459         .release        = single_release,
 460 };
 461
 462 static int devices_read_proc(char *page, char **start, off_t off,
 463                                  int count, int *eof, void *data)
 464 {
 465         int len = get_chrdev_list(page);
 466         len += get_blkdev_list(page+len);
 467         return proc_calc_metrics(page, start, off, count, eof, len);
 468 }
 469
 470 /*
 471  * /proc/interrupts
 472  */
 473 static void *int_seq_start(struct seq_file *f, loff_t *pos)
 474 {
 475         return (*pos <= NR_IRQS) ? pos : NULL;
 476 }
 477
 478 static void *int_seq_next(struct seq_file *f, void *v, loff_t *pos)
 479 {
 480         (*pos)++;
 481         if (*pos > NR_IRQS)
 482                 return NULL;
 483         return pos;
 484 }
 485
 486 static void int_seq_stop(struct seq_file *f, void *v)
 487 {
 488         /* Nothing to do */
 489 }
 490
 491
 492 extern int show_interrupts(struct seq_file *f, void *v); /* In arch code */
 493 static struct seq_operations int_seq_ops = {
 494         .start = int_seq_start,
 495         .next  = int_seq_next,
 496         .stop  = int_seq_stop,
 497         .show  = show_interrupts
 498 };
 499
 500 static int interrupts_open(struct inode *inode, struct file *filp)
 501 {
 502         return seq_open(filp, &int_seq_ops);
 503 }
 504
 505 static struct file_operations proc_interrupts_operations = {
 506         .open           = interrupts_open,
 507         .read           = seq_read,
 508         .llseek         = seq_lseek,
 509         .release        = seq_release,
 510 };
 511
 512 static int filesystems_read_proc(char *page, char **start, off_t off,
 513                                  int count, int *eof, void *data)
 514 {
 515         int len = get_filesystem_list(page);
 516         return proc_calc_metrics(page, start, off, count, eof, len);
 517 }
 518
 519 static int cmdline_read_proc(char *page, char **start, off_t off,
 520                                  int count, int *eof, void *data)
 521 {
 522         int len;
 523
 524         len = sprintf(page, "%s\n", saved_command_line);
 525         return proc_calc_metrics(page, start, off, count, eof, len);
 526 }
 527
 528 static int locks_read_proc(char *page, char **start, off_t off,
 529                                  int count, int *eof, void *data)
 530 {
 531         int len = get_locks_status(page, start, off, count);
 532
 533         if (len < count)
 534                 *eof = 1;
 535         return len;
 536 }
 537
 538 static int execdomains_read_proc(char *page, char **start, off_t off,
 539                                  int count, int *eof, void *data)
 540 {
 541         int len = get_exec_domain_list(page);
 542         return proc_calc_metrics(page, start, off, count, eof, len);
 543 }
 544
 545 #ifdef CONFIG_MAGIC_SYSRQ
 546 /*
 547  * writing 'C' to /proc/sysrq-trigger is like sysrq-C
 548  */
 549 static ssize_t write_sysrq_trigger(struct file *file, const char __user *buf,
 550                                    size_t count, loff_t *ppos)
 551 {
 552         if (count) {
 553                 char c;
 554
 555                 if (get_user(c, buf))
 556                         return -EFAULT;
 557                 __handle_sysrq(c, NULL, NULL, 0);
 558         }
 559         return count;
 560 }
 561
 562 static struct file_operations proc_sysrq_trigger_operations = {
 563         .write          = write_sysrq_trigger,
 564 };
 565 #endif
 566
 567 struct proc_dir_entry *proc_root_kcore;
 568
 569 void create_seq_entry(char *name, mode_t mode, struct file_operations *f)
 570 {
 571         struct proc_dir_entry *entry;
 572         entry = create_proc_entry(name, mode, NULL);
 573         if (entry)
 574                 entry->proc_fops = f;
 575 }
 576
 577 void __init proc_misc_init(void)
 578 {
 579         struct proc_dir_entry *entry;
 580         static struct {
 581                 char *name;
 582                 int (*read_proc)(char*,char**,off_t,int,int*,void*);
 583         } *p, simple_ones[] = {
 584                 {"loadavg",     loadavg_read_proc},
 585                 {"uptime",      uptime_read_proc},
 586                 {"meminfo",     meminfo_read_proc},
 587                 {"version",     version_read_proc},
 588 #ifdef CONFIG_PROC_HARDWARE
 589                 {"hardware",    hardware_read_proc},
 590 #endif
 591 #ifdef CONFIG_STRAM_PROC
 592                 {"stram",       stram_read_proc},
 593 #endif
 594                 {"devices",     devices_read_proc},
 595                 {"filesystems", filesystems_read_proc},
 596                 {"cmdline",     cmdline_read_proc},
 597                 {"locks",       locks_read_proc},
 598                 {"execdomains", execdomains_read_proc},
 599                 {NULL,}
 600         };
 601         for (p = simple_ones; p->name; p++)
 602                 create_proc_read_entry(p->name, 0, NULL, p->read_proc, NULL);
 603
 604         proc_symlink("mounts", NULL, "self/mounts");
 605
 606         /* And now for trickier ones */
 607         entry = create_proc_entry("kmsg", S_IRUSR, &proc_root);
 608         if (entry)
 609                 entry->proc_fops = &proc_kmsg_operations;
 610         create_seq_entry("cpuinfo", 0, &proc_cpuinfo_operations);
 611         create_seq_entry("partitions", 0, &proc_partitions_operations);
 612         create_seq_entry("stat", 0, &proc_stat_operations);
 613         create_seq_entry("interrupts", 0, &proc_interrupts_operations);
 614         create_seq_entry("slabinfo",S_IWUSR|S_IRUGO,&proc_slabinfo_operations);
 615         create_seq_entry("buddyinfo",S_IRUGO, &fragmentation_file_operations);
 616         create_seq_entry("vmstat",S_IRUGO, &proc_vmstat_file_operations);
 617         create_seq_entry("diskstats", 0, &proc_diskstats_operations);
 618 #ifdef CONFIG_MODULES
 619         create_seq_entry("modules", 0, &proc_modules_operations);
 620 #endif
 621 #ifdef CONFIG_SCHEDSTATS
 622         create_seq_entry("schedstat", 0, &proc_schedstat_operations);
 623 #endif
 624 #ifdef CONFIG_PROC_KCORE
 625         proc_root_kcore = create_proc_entry("kcore", S_IRUSR, NULL);
 626         if (proc_root_kcore) {
 627                 proc_root_kcore->proc_fops = &proc_kcore_operations;
 628                 proc_root_kcore->size =
 629                                 (size_t)high_memory - PAGE_OFFSET + PAGE_SIZE;
 630         }
 631 #endif
 632         crash_create_proc_entry();
 633 #ifdef CONFIG_MAGIC_SYSRQ
 634         entry = create_proc_entry("sysrq-trigger", S_IWUSR, NULL);
 635         if (entry)
 636                 entry->proc_fops = &proc_sysrq_trigger_operations;
 637 #endif
 638         crash_enable_by_proc();
 639 #ifdef CONFIG_PPC32
 640         {
 641                 extern struct file_operations ppc_htab_operations;
 642                 entry = create_proc_entry("ppc_htab", S_IRUGO|S_IWUSR, NULL);
 643                 if (entry)
 644                         entry->proc_fops = &ppc_htab_operations;
 645         }
 646 #endif
 647 }