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/fs.h>
  24 #include <linux/tty.h>
  25 #include <linux/string.h>
  26 #include <linux/mman.h>
  27 #include <linux/proc_fs.h>
  28 #include <linux/ioport.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 <asm/uaccess.h>
  49 #include <asm/pgtable.h>
  50 #include <asm/io.h>
  51 #include <asm/tlb.h>
  52 #include <asm/div64.h>
  53 #include "internal.h"
  54 #include <linux/vs_cvirt.h>
  55
  56 #define LOAD_INT(x) ((x) >> FSHIFT)
  57 #define LOAD_FRAC(x) LOAD_INT(((x) & (FIXED_1-1)) * 100)
  58 /*
  59  * Warning: stuff below (imported functions) assumes that its output will fit
  60  * into one page. For some of those functions it may be wrong. Moreover, we
  61  * have a way to deal with that gracefully. Right now I used straightforward
  62  * wrappers, but this needs further analysis wrt potential overflows.
  63  */
  64 extern int get_hardware_list(char *);
  65 extern int get_stram_list(char *);
  66 extern int get_filesystem_list(char *);
  67 extern int get_exec_domain_list(char *);
  68 extern int get_dma_list(char *);
  69 extern int get_locks_status (char *, char **, off_t, int);
  70
  71 static int proc_calc_metrics(char *page, char **start, off_t off,
  72                                  int count, int *eof, int len)
  73 {
  74         if (len <= off+count) *eof = 1;
  75         *start = page + off;
  76         len -= off;
  77         if (len>count) len = count;
  78         if (len<0) len = 0;
  79         return len;
  80 }
  81
  82 static int loadavg_read_proc(char *page, char **start, off_t off,
  83                                  int count, int *eof, void *data)
  84 {
  85         unsigned int running, threads;
  86         int a, b, c;
  87         int len;
  88
  89         if (vx_flags(VXF_VIRT_LOAD, 0)) {
  90                 struct vx_info *vxi = current->vx_info;
  91
  92                 a = vxi->cvirt.load[0] + (FIXED_1/200);
  93                 b = vxi->cvirt.load[1] + (FIXED_1/200);
  94                 c = vxi->cvirt.load[2] + (FIXED_1/200);
  95
  96                 running = atomic_read(&vxi->cvirt.nr_running);
  97                 threads = atomic_read(&vxi->cvirt.nr_threads);
  98         } else {
  99                 a = avenrun[0] + (FIXED_1/200);
 100                 b = avenrun[1] + (FIXED_1/200);
 101                 c = avenrun[2] + (FIXED_1/200);
 102
 103                 running = nr_running();
 104                 threads = nr_threads;
 105         }
 106         len = sprintf(page,"%d.%02d %d.%02d %d.%02d %d/%d %d\n",
 107                 LOAD_INT(a), LOAD_FRAC(a),
 108                 LOAD_INT(b), LOAD_FRAC(b),
 109                 LOAD_INT(c), LOAD_FRAC(c),
 110                 running, threads, last_pid);
 111         return proc_calc_metrics(page, start, off, count, eof, len);
 112 }
 113
 114 static int uptime_read_proc(char *page, char **start, off_t off,
 115                                  int count, int *eof, void *data)
 116 {
 117         struct timespec uptime;
 118         struct timespec idle;
 119         int len;
 120         cputime_t idletime = cputime_add(init_task.utime, init_task.stime);
 121
 122         do_posix_clock_monotonic_gettime(&uptime);
 123         cputime_to_timespec(idletime, &idle);
 124         if (vx_flags(VXF_VIRT_UPTIME, 0))
 125                 vx_vsi_uptime(&uptime, &idle);
 126
 127         len = sprintf(page,"%lu.%02lu %lu.%02lu\n",
 128                         (unsigned long) uptime.tv_sec,
 129                         (uptime.tv_nsec / (NSEC_PER_SEC / 100)),
 130                         (unsigned long) idle.tv_sec,
 131                         (idle.tv_nsec / (NSEC_PER_SEC / 100)));
 132
 133         return proc_calc_metrics(page, start, off, count, eof, len);
 134 }
 135
 136 static int meminfo_read_proc(char *page, char **start, off_t off,
 137                                  int count, int *eof, void *data)
 138 {
 139         struct sysinfo i;
 140         int len;
 141         unsigned long inactive;
 142         unsigned long active;
 143         unsigned long free;
 144         unsigned long committed;
 145         unsigned long allowed;
 146         struct vmalloc_info vmi;
 147         long cached;
 148
 149         get_zone_counts(&active, &inactive, &free);
 150
 151 /*
 152  * display in kilobytes.
 153  */
 154 #define K(x) ((x) << (PAGE_SHIFT - 10))
 155         si_meminfo(&i);
 156         si_swapinfo(&i);
 157         committed = atomic_read(&vm_committed_space);
 158         allowed = ((totalram_pages - hugetlb_total_pages())
 159                 * sysctl_overcommit_ratio / 100) + total_swap_pages;
 160
 161         cached = global_page_state(NR_FILE_PAGES) -
 162                         total_swapcache_pages - i.bufferram;
 163         if (cached < 0 || vx_flags(VXF_VIRT_MEM, 0))
 164                 cached = 0;
 165
 166         get_vmalloc_info(&vmi);
 167
 168         /*
 169          * Tagged format, for easy grepping and expansion.
 170          */
 171         len = sprintf(page,
 172                 "MemTotal:     %8lu kB\n"
 173                 "MemFree:      %8lu kB\n"
 174                 "Buffers:      %8lu kB\n"
 175                 "Cached:       %8lu kB\n"
 176                 "SwapCached:   %8lu kB\n"
 177                 "Active:       %8lu kB\n"
 178                 "Inactive:     %8lu kB\n"
 179                 "HighTotal:    %8lu kB\n"
 180                 "HighFree:     %8lu kB\n"
 181                 "LowTotal:     %8lu kB\n"
 182                 "LowFree:      %8lu kB\n"
 183                 "SwapTotal:    %8lu kB\n"
 184                 "SwapFree:     %8lu kB\n"
 185                 "Dirty:        %8lu kB\n"
 186                 "Writeback:    %8lu kB\n"
 187                 "AnonPages:    %8lu kB\n"
 188                 "Mapped:       %8lu kB\n"
 189                 "Slab:         %8lu kB\n"
 190                 "PageTables:   %8lu kB\n"
 191                 "NFS_Unstable: %8lu kB\n"
 192                 "Bounce:       %8lu kB\n"
 193                 "CommitLimit:  %8lu kB\n"
 194                 "Committed_AS: %8lu kB\n"
 195                 "VmallocTotal: %8lu kB\n"
 196                 "VmallocUsed:  %8lu kB\n"
 197                 "VmallocChunk: %8lu kB\n",
 198                 K(i.totalram),
 199                 K(i.freeram),
 200                 K(i.bufferram),
 201                 K(cached),
 202                 K(total_swapcache_pages),
 203                 K(active),
 204                 K(inactive),
 205                 K(i.totalhigh),
 206                 K(i.freehigh),
 207                 K(i.totalram-i.totalhigh),
 208                 K(i.freeram-i.freehigh),
 209                 K(i.totalswap),
 210                 K(i.freeswap),
 211                 K(global_page_state(NR_FILE_DIRTY)),
 212                 K(global_page_state(NR_WRITEBACK)),
 213                 K(global_page_state(NR_ANON_PAGES)),
 214                 K(global_page_state(NR_FILE_MAPPED)),
 215                 K(global_page_state(NR_SLAB)),
 216                 K(global_page_state(NR_PAGETABLE)),
 217                 K(global_page_state(NR_UNSTABLE_NFS)),
 218                 K(global_page_state(NR_BOUNCE)),
 219                 K(allowed),
 220                 K(committed),
 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 extern struct seq_operations zoneinfo_op;
 247 static int zoneinfo_open(struct inode *inode, struct file *file)
 248 {
 249         return seq_open(file, &zoneinfo_op);
 250 }
 251
 252 static struct file_operations proc_zoneinfo_file_operations = {
 253         .open           = zoneinfo_open,
 254         .read           = seq_read,
 255         .llseek         = seq_lseek,
 256         .release        = seq_release,
 257 };
 258
 259 static int version_read_proc(char *page, char **start, off_t off,
 260                                  int count, int *eof, void *data)
 261 {
 262         int len;
 263
 264         len = sprintf(page, vx_linux_banner,
 265                 vx_new_uts(release),
 266                 vx_new_uts(version));
 267         return proc_calc_metrics(page, start, off, count, eof, len);
 268 }
 269
 270 extern struct seq_operations cpuinfo_op;
 271 static int cpuinfo_open(struct inode *inode, struct file *file)
 272 {
 273         return seq_open(file, &cpuinfo_op);
 274 }
 275
 276 static struct file_operations proc_cpuinfo_operations = {
 277         .open           = cpuinfo_open,
 278         .read           = seq_read,
 279         .llseek         = seq_lseek,
 280         .release        = seq_release,
 281 };
 282
 283 static int devinfo_show(struct seq_file *f, void *v)
 284 {
 285         int i = *(loff_t *) v;
 286
 287         if (i < CHRDEV_MAJOR_HASH_SIZE) {
 288                 if (i == 0)
 289                         seq_printf(f, "Character devices:\n");
 290                 chrdev_show(f, i);
 291         } else {
 292                 i -= CHRDEV_MAJOR_HASH_SIZE;
 293                 if (i == 0)
 294                         seq_printf(f, "\nBlock devices:\n");
 295                 blkdev_show(f, i);
 296         }
 297         return 0;
 298 }
 299
 300 static void *devinfo_start(struct seq_file *f, loff_t *pos)
 301 {
 302         if (*pos < (BLKDEV_MAJOR_HASH_SIZE + CHRDEV_MAJOR_HASH_SIZE))
 303                 return pos;
 304         return NULL;
 305 }
 306
 307 static void *devinfo_next(struct seq_file *f, void *v, loff_t *pos)
 308 {
 309         (*pos)++;
 310         if (*pos >= (BLKDEV_MAJOR_HASH_SIZE + CHRDEV_MAJOR_HASH_SIZE))
 311                 return NULL;
 312         return pos;
 313 }
 314
 315 static void devinfo_stop(struct seq_file *f, void *v)
 316 {
 317         /* Nothing to do */
 318 }
 319
 320 static struct seq_operations devinfo_ops = {
 321         .start = devinfo_start,
 322         .next  = devinfo_next,
 323         .stop  = devinfo_stop,
 324         .show  = devinfo_show
 325 };
 326
 327 static int devinfo_open(struct inode *inode, struct file *filp)
 328 {
 329         return seq_open(filp, &devinfo_ops);
 330 }
 331
 332 static struct file_operations proc_devinfo_operations = {
 333         .open           = devinfo_open,
 334         .read           = seq_read,
 335         .llseek         = seq_lseek,
 336         .release        = seq_release,
 337 };
 338
 339 extern struct seq_operations vmstat_op;
 340 static int vmstat_open(struct inode *inode, struct file *file)
 341 {
 342         return seq_open(file, &vmstat_op);
 343 }
 344 static struct file_operations proc_vmstat_file_operations = {
 345         .open           = vmstat_open,
 346         .read           = seq_read,
 347         .llseek         = seq_lseek,
 348         .release        = seq_release,
 349 };
 350
 351 #ifdef CONFIG_PROC_HARDWARE
 352 static int hardware_read_proc(char *page, char **start, off_t off,
 353                                  int count, int *eof, void *data)
 354 {
 355         int len = get_hardware_list(page);
 356         return proc_calc_metrics(page, start, off, count, eof, len);
 357 }
 358 #endif
 359
 360 #ifdef CONFIG_STRAM_PROC
 361 static int stram_read_proc(char *page, char **start, off_t off,
 362                                  int count, int *eof, void *data)
 363 {
 364         int len = get_stram_list(page);
 365         return proc_calc_metrics(page, start, off, count, eof, len);
 366 }
 367 #endif
 368
 369 extern struct seq_operations partitions_op;
 370 static int partitions_open(struct inode *inode, struct file *file)
 371 {
 372         return seq_open(file, &partitions_op);
 373 }
 374 static struct file_operations proc_partitions_operations = {
 375         .open           = partitions_open,
 376         .read           = seq_read,
 377         .llseek         = seq_lseek,
 378         .release        = seq_release,
 379 };
 380
 381 extern struct seq_operations diskstats_op;
 382 static int diskstats_open(struct inode *inode, struct file *file)
 383 {
 384         return seq_open(file, &diskstats_op);
 385 }
 386 static struct file_operations proc_diskstats_operations = {
 387         .open           = diskstats_open,
 388         .read           = seq_read,
 389         .llseek         = seq_lseek,
 390         .release        = seq_release,
 391 };
 392
 393 #ifdef CONFIG_MODULES
 394 extern struct seq_operations modules_op;
 395 static int modules_open(struct inode *inode, struct file *file)
 396 {
 397         return seq_open(file, &modules_op);
 398 }
 399 static struct file_operations proc_modules_operations = {
 400         .open           = modules_open,
 401         .read           = seq_read,
 402         .llseek         = seq_lseek,
 403         .release        = seq_release,
 404 };
 405 #endif
 406
 407 #ifdef CONFIG_SLAB
 408 extern struct seq_operations slabinfo_op;
 409 extern ssize_t slabinfo_write(struct file *, const char __user *, size_t, loff_t *);
 410 static int slabinfo_open(struct inode *inode, struct file *file)
 411 {
 412         return seq_open(file, &slabinfo_op);
 413 }
 414 static struct file_operations proc_slabinfo_operations = {
 415         .open           = slabinfo_open,
 416         .read           = seq_read,
 417         .write          = slabinfo_write,
 418         .llseek         = seq_lseek,
 419         .release        = seq_release,
 420 };
 421
 422 #ifdef CONFIG_DEBUG_SLAB_LEAK
 423 extern struct seq_operations slabstats_op;
 424 static int slabstats_open(struct inode *inode, struct file *file)
 425 {
 426         unsigned long *n = kzalloc(PAGE_SIZE, GFP_KERNEL);
 427         int ret = -ENOMEM;
 428         if (n) {
 429                 ret = seq_open(file, &slabstats_op);
 430                 if (!ret) {
 431                         struct seq_file *m = file->private_data;
 432                         *n = PAGE_SIZE / (2 * sizeof(unsigned long));
 433                         m->private = n;
 434                         n = NULL;
 435                 }
 436                 kfree(n);
 437         }
 438         return ret;
 439 }
 440
 441 static int slabstats_release(struct inode *inode, struct file *file)
 442 {
 443         struct seq_file *m = file->private_data;
 444         kfree(m->private);
 445         return seq_release(inode, file);
 446 }
 447
 448 static struct file_operations proc_slabstats_operations = {
 449         .open           = slabstats_open,
 450         .read           = seq_read,
 451         .llseek         = seq_lseek,
 452         .release        = slabstats_release,
 453 };
 454 #endif
 455 #endif
 456
 457 static int show_stat(struct seq_file *p, void *v)
 458 {
 459         int i;
 460         unsigned long jif;
 461         cputime64_t user, nice, system, idle, iowait, irq, softirq, steal;
 462         u64 sum = 0;
 463
 464         user = nice = system = idle = iowait =
 465                 irq = softirq = steal = cputime64_zero;
 466         jif = - wall_to_monotonic.tv_sec;
 467         if (wall_to_monotonic.tv_nsec)
 468                 --jif;
 469
 470         for_each_possible_cpu(i) {
 471                 int j;
 472
 473                 user = cputime64_add(user, kstat_cpu(i).cpustat.user);
 474                 nice = cputime64_add(nice, kstat_cpu(i).cpustat.nice);
 475                 system = cputime64_add(system, kstat_cpu(i).cpustat.system);
 476                 idle = cputime64_add(idle, kstat_cpu(i).cpustat.idle);
 477                 iowait = cputime64_add(iowait, kstat_cpu(i).cpustat.iowait);
 478                 irq = cputime64_add(irq, kstat_cpu(i).cpustat.irq);
 479                 softirq = cputime64_add(softirq, kstat_cpu(i).cpustat.softirq);
 480                 steal = cputime64_add(steal, kstat_cpu(i).cpustat.steal);
 481                 for (j = 0 ; j < NR_IRQS ; j++)
 482                         sum += kstat_cpu(i).irqs[j];
 483         }
 484
 485         seq_printf(p, "cpu  %llu %llu %llu %llu %llu %llu %llu %llu\n",
 486                 (unsigned long long)cputime64_to_clock_t(user),
 487                 (unsigned long long)cputime64_to_clock_t(nice),
 488                 (unsigned long long)cputime64_to_clock_t(system),
 489                 (unsigned long long)cputime64_to_clock_t(idle),
 490                 (unsigned long long)cputime64_to_clock_t(iowait),
 491                 (unsigned long long)cputime64_to_clock_t(irq),
 492                 (unsigned long long)cputime64_to_clock_t(softirq),
 493                 (unsigned long long)cputime64_to_clock_t(steal));
 494         for_each_online_cpu(i) {
 495
 496                 /* Copy values here to work around gcc-2.95.3, gcc-2.96 */
 497                 user = kstat_cpu(i).cpustat.user;
 498                 nice = kstat_cpu(i).cpustat.nice;
 499                 system = kstat_cpu(i).cpustat.system;
 500                 idle = kstat_cpu(i).cpustat.idle;
 501                 iowait = kstat_cpu(i).cpustat.iowait;
 502                 irq = kstat_cpu(i).cpustat.irq;
 503                 softirq = kstat_cpu(i).cpustat.softirq;
 504                 steal = kstat_cpu(i).cpustat.steal;
 505                 seq_printf(p, "cpu%d %llu %llu %llu %llu %llu %llu %llu %llu\n",
 506                         i,
 507                         (unsigned long long)cputime64_to_clock_t(user),
 508                         (unsigned long long)cputime64_to_clock_t(nice),
 509                         (unsigned long long)cputime64_to_clock_t(system),
 510                         (unsigned long long)cputime64_to_clock_t(idle),
 511                         (unsigned long long)cputime64_to_clock_t(iowait),
 512                         (unsigned long long)cputime64_to_clock_t(irq),
 513                         (unsigned long long)cputime64_to_clock_t(softirq),
 514                         (unsigned long long)cputime64_to_clock_t(steal));
 515         }
 516         seq_printf(p, "intr %llu", (unsigned long long)sum);
 517
 518 #if !defined(CONFIG_PPC64) && !defined(CONFIG_ALPHA) && !defined(CONFIG_IA64)
 519         for (i = 0; i < NR_IRQS; i++)
 520                 seq_printf(p, " %u", kstat_irqs(i));
 521 #endif
 522
 523         seq_printf(p,
 524                 "\nctxt %llu\n"
 525                 "btime %lu\n"
 526                 "processes %lu\n"
 527                 "procs_running %lu\n"
 528                 "procs_blocked %lu\n",
 529                 nr_context_switches(),
 530                 (unsigned long)jif,
 531                 total_forks,
 532                 nr_running(),
 533                 nr_iowait());
 534
 535         return 0;
 536 }
 537
 538 static int stat_open(struct inode *inode, struct file *file)
 539 {
 540         unsigned size = 4096 * (1 + num_possible_cpus() / 32);
 541         char *buf;
 542         struct seq_file *m;
 543         int res;
 544
 545         /* don't ask for more than the kmalloc() max size, currently 128 KB */
 546         if (size > 128 * 1024)
 547                 size = 128 * 1024;
 548         buf = kmalloc(size, GFP_KERNEL);
 549         if (!buf)
 550                 return -ENOMEM;
 551
 552         res = single_open(file, show_stat, NULL);
 553         if (!res) {
 554                 m = file->private_data;
 555                 m->buf = buf;
 556                 m->size = size;
 557         } else
 558                 kfree(buf);
 559         return res;
 560 }
 561 static struct file_operations proc_stat_operations = {
 562         .open           = stat_open,
 563         .read           = seq_read,
 564         .llseek         = seq_lseek,
 565         .release        = single_release,
 566 };
 567
 568 /*
 569  * /proc/interrupts
 570  */
 571 static void *int_seq_start(struct seq_file *f, loff_t *pos)
 572 {
 573         return (*pos <= NR_IRQS) ? pos : NULL;
 574 }
 575
 576 static void *int_seq_next(struct seq_file *f, void *v, loff_t *pos)
 577 {
 578         (*pos)++;
 579         if (*pos > NR_IRQS)
 580                 return NULL;
 581         return pos;
 582 }
 583
 584 static void int_seq_stop(struct seq_file *f, void *v)
 585 {
 586         /* Nothing to do */
 587 }
 588
 589
 590 extern int show_interrupts(struct seq_file *f, void *v); /* In arch code */
 591 static struct seq_operations int_seq_ops = {
 592         .start = int_seq_start,
 593         .next  = int_seq_next,
 594         .stop  = int_seq_stop,
 595         .show  = show_interrupts
 596 };
 597
 598 static int interrupts_open(struct inode *inode, struct file *filp)
 599 {
 600         return seq_open(filp, &int_seq_ops);
 601 }
 602
 603 static struct file_operations proc_interrupts_operations = {
 604         .open           = interrupts_open,
 605         .read           = seq_read,
 606         .llseek         = seq_lseek,
 607         .release        = seq_release,
 608 };
 609
 610 static int filesystems_read_proc(char *page, char **start, off_t off,
 611                                  int count, int *eof, void *data)
 612 {
 613         int len = get_filesystem_list(page);
 614         return proc_calc_metrics(page, start, off, count, eof, len);
 615 }
 616
 617 static int cmdline_read_proc(char *page, char **start, off_t off,
 618                                  int count, int *eof, void *data)
 619 {
 620         int len;
 621
 622         len = sprintf(page, "%s\n", saved_command_line);
 623         return proc_calc_metrics(page, start, off, count, eof, len);
 624 }
 625
 626 static int locks_read_proc(char *page, char **start, off_t off,
 627                                  int count, int *eof, void *data)
 628 {
 629         int len = get_locks_status(page, start, off, count);
 630
 631         if (len < count)
 632                 *eof = 1;
 633         return len;
 634 }
 635
 636 static int execdomains_read_proc(char *page, char **start, off_t off,
 637                                  int count, int *eof, void *data)
 638 {
 639         int len = get_exec_domain_list(page);
 640         return proc_calc_metrics(page, start, off, count, eof, len);
 641 }
 642
 643 #ifdef CONFIG_MAGIC_SYSRQ
 644 /*
 645  * writing 'C' to /proc/sysrq-trigger is like sysrq-C
 646  */
 647 static ssize_t write_sysrq_trigger(struct file *file, const char __user *buf,
 648                                    size_t count, loff_t *ppos)
 649 {
 650         if (count) {
 651                 char c;
 652
 653                 if (get_user(c, buf))
 654                         return -EFAULT;
 655                 __handle_sysrq(c, NULL, NULL, 0);
 656         }
 657         return count;
 658 }
 659
 660 static struct file_operations proc_sysrq_trigger_operations = {
 661         .write          = write_sysrq_trigger,
 662 };
 663 #endif
 664
 665 struct proc_dir_entry *proc_root_kcore;
 666
 667 void create_seq_entry(char *name, mode_t mode, const struct file_operations *f)
 668 {
 669         struct proc_dir_entry *entry;
 670         entry = create_proc_entry(name, mode, NULL);
 671         if (entry)
 672                 entry->proc_fops = f;
 673 }
 674
 675 void __init proc_misc_init(void)
 676 {
 677         struct proc_dir_entry *entry;
 678         static struct {
 679                 char *name;
 680                 int (*read_proc)(char*,char**,off_t,int,int*,void*);
 681         } *p, simple_ones[] = {
 682                 {"loadavg",     loadavg_read_proc},
 683                 {"uptime",      uptime_read_proc},
 684                 {"meminfo",     meminfo_read_proc},
 685                 {"version",     version_read_proc},
 686 #ifdef CONFIG_PROC_HARDWARE
 687                 {"hardware",    hardware_read_proc},
 688 #endif
 689 #ifdef CONFIG_STRAM_PROC
 690                 {"stram",       stram_read_proc},
 691 #endif
 692                 {"filesystems", filesystems_read_proc},
 693                 {"cmdline",     cmdline_read_proc},
 694                 {"locks",       locks_read_proc},
 695                 {"execdomains", execdomains_read_proc},
 696                 {NULL,}
 697         };
 698         for (p = simple_ones; p->name; p++)
 699                 create_proc_read_entry(p->name, 0, NULL, p->read_proc, NULL);
 700
 701         proc_symlink("mounts", NULL, "self/mounts");
 702
 703         /* And now for trickier ones */
 704         entry = create_proc_entry("kmsg", S_IRUSR, &proc_root);
 705         if (entry)
 706                 entry->proc_fops = &proc_kmsg_operations;
 707         create_seq_entry("devices", 0, &proc_devinfo_operations);
 708         create_seq_entry("cpuinfo", 0, &proc_cpuinfo_operations);
 709         create_seq_entry("partitions", 0, &proc_partitions_operations);
 710         create_seq_entry("stat", 0, &proc_stat_operations);
 711         create_seq_entry("interrupts", 0, &proc_interrupts_operations);
 712 #ifdef CONFIG_SLAB
 713         create_seq_entry("slabinfo",S_IWUSR|S_IRUGO,&proc_slabinfo_operations);
 714 #ifdef CONFIG_DEBUG_SLAB_LEAK
 715         create_seq_entry("slab_allocators", 0 ,&proc_slabstats_operations);
 716 #endif
 717 #endif
 718         create_seq_entry("buddyinfo",S_IRUGO, &fragmentation_file_operations);
 719         create_seq_entry("vmstat",S_IRUGO, &proc_vmstat_file_operations);
 720         create_seq_entry("zoneinfo",S_IRUGO, &proc_zoneinfo_file_operations);
 721         create_seq_entry("diskstats", 0, &proc_diskstats_operations);
 722 #ifdef CONFIG_MODULES
 723         create_seq_entry("modules", 0, &proc_modules_operations);
 724 #endif
 725 #ifdef CONFIG_SCHEDSTATS
 726         create_seq_entry("schedstat", 0, &proc_schedstat_operations);
 727 #endif
 728 #ifdef CONFIG_PROC_KCORE
 729         proc_root_kcore = create_proc_entry("kcore", S_IRUSR, NULL);
 730         if (proc_root_kcore) {
 731                 proc_root_kcore->proc_fops = &proc_kcore_operations;
 732                 proc_root_kcore->size =
 733                                 (size_t)high_memory - PAGE_OFFSET + PAGE_SIZE;
 734         }
 735 #endif
 736 #ifdef CONFIG_PROC_VMCORE
 737         proc_vmcore = create_proc_entry("vmcore", S_IRUSR, NULL);
 738         if (proc_vmcore)
 739                 proc_vmcore->proc_fops = &proc_vmcore_operations;
 740 #endif
 741 #ifdef CONFIG_MAGIC_SYSRQ
 742         entry = create_proc_entry("sysrq-trigger", S_IWUSR, NULL);
 743         if (entry)
 744                 entry->proc_fops = &proc_sysrq_trigger_operations;
 745 #endif
 746 }