1 /* 2 * sysctl.c: General linux system control interface 3 * 4 * Begun 24 March 1995, Stephen Tweedie 5 * Added /proc support, Dec 1995 6 * Added bdflush entry and intvec min/max checking, 2/23/96, Tom Dyas. 7 * Added hooks for /proc/sys/net (minor, minor patch), 96/4/1, Mike Shaver. 8 * Added kernel/java-{interpreter,appletviewer}, 96/5/10, Mike Shaver. 9 * Dynamic registration fixes, Stephen Tweedie. 10 * Added kswapd-interval, ctrl-alt-del, printk stuff, 1/8/97, Chris Horn. 11 * Made sysctl support optional via CONFIG_SYSCTL, 1/10/97, Chris 12 * Horn. 13 * Added proc_doulongvec_ms_jiffies_minmax, 09/08/99, Carlos H. Bauer. 14 * Added proc_doulongvec_minmax, 09/08/99, Carlos H. Bauer. 15 * Changed linked lists to use list.h instead of lists.h, 02/24/00, Bill 16 * Wendling. 17 * The list_for_each() macro wasn't appropriate for the sysctl loop. 18 * Removed it and replaced it with older style, 03/23/00, Bill Wendling 19 */ 20 21 #include <linux/module.h> 22 #include <linux/mm.h> 23 #include <linux/swap.h> 24 #include <linux/slab.h> 25 #include <linux/sysctl.h> 26 #include <linux/proc_fs.h> 27 #include <linux/capability.h> 28 #include <linux/ctype.h> 29 #include <linux/utsname.h> 30 #include <linux/capability.h> 31 #include <linux/smp_lock.h> 32 #include <linux/fs.h> 33 #include <linux/init.h> 34 #include <linux/kernel.h> 35 #include <linux/kobject.h> 36 #include <linux/net.h> 37 #include <linux/sysrq.h> 38 #include <linux/highuid.h> 39 #include <linux/writeback.h> 40 #include <linux/hugetlb.h> 41 #include <linux/security.h> 42 #include <linux/initrd.h> 43 #include <linux/times.h> 44 #include <linux/limits.h> 45 #include <linux/dcache.h> 46 #include <linux/syscalls.h> 47 #include <linux/nfs_fs.h> 48 #include <linux/acpi.h> 49 50 #include <asm/uaccess.h> 51 #include <asm/processor.h> 52 53 #ifdef CONFIG_X86 54 #include <asm/nmi.h> 55 #include <asm/stacktrace.h> 56 #endif 57 58 #if defined(CONFIG_SYSCTL) 59 60 /* External variables not in a header file. */ 61 extern int C_A_D; 62 extern int print_fatal_signals; 63 extern int sysctl_overcommit_memory; 64 extern int sysctl_overcommit_ratio; 65 extern int sysctl_panic_on_oom; 66 extern int max_threads; 67 extern int core_uses_pid; 68 extern int suid_dumpable; 69 extern char core_pattern[]; 70 extern int pid_max; 71 extern int min_free_kbytes; 72 extern int printk_ratelimit_jiffies; 73 extern int printk_ratelimit_burst; 74 extern int pid_max_min, pid_max_max; 75 extern int sysctl_drop_caches; 76 extern int percpu_pagelist_fraction; 77 extern int compat_log; 78 extern int maps_protect; 79 extern int sysctl_stat_interval; 80 81 /* this is needed for the proc_dointvec_minmax for [fs_]overflow UID and GID */ 82 static int maxolduid = 65535; 83 static int minolduid; 84 static int min_percpu_pagelist_fract = 8; 85 86 static int ngroups_max = NGROUPS_MAX; 87 88 #ifdef CONFIG_KMOD 89 extern char modprobe_path[]; 90 #endif 91 #ifdef CONFIG_CHR_DEV_SG 92 extern int sg_big_buff; 93 #endif 94 95 #ifdef __sparc__ 96 extern char reboot_command []; 97 extern int stop_a_enabled; 98 extern int scons_pwroff; 99 #endif 100 101 #ifdef __hppa__ 102 extern int pwrsw_enabled; 103 extern int unaligned_enabled; 104 #endif 105 106 #ifdef CONFIG_S390 107 #ifdef CONFIG_MATHEMU 108 extern int sysctl_ieee_emulation_warnings; 109 #endif 110 extern int sysctl_userprocess_debug; 111 extern int spin_retry; 112 #endif 113 114 extern int sysctl_hz_timer; 115 116 #ifdef CONFIG_BSD_PROCESS_ACCT 117 extern int acct_parm[]; 118 #endif 119 120 #ifdef CONFIG_IA64 121 extern int no_unaligned_warning; 122 #endif 123 124 #ifdef CONFIG_RT_MUTEXES 125 extern int max_lock_depth; 126 #endif 127 128 #ifdef CONFIG_SYSCTL_SYSCALL 129 static int parse_table(int __user *, int, void __user *, size_t __user *, 130 void __user *, size_t, ctl_table *); 131 #endif 132 133 134 #ifdef CONFIG_PROC_SYSCTL 135 static int proc_do_cad_pid(ctl_table *table, int write, struct file *filp, 136 void __user *buffer, size_t *lenp, loff_t *ppos); 137 static int proc_dointvec_taint(ctl_table *table, int write, struct file *filp, 138 void __user *buffer, size_t *lenp, loff_t *ppos); 139 #endif 140 141 static ctl_table root_table[]; 142 static struct ctl_table_header root_table_header = 143 { root_table, LIST_HEAD_INIT(root_table_header.ctl_entry) }; 144 145 static ctl_table kern_table[]; 146 static ctl_table vm_table[]; 147 static ctl_table fs_table[]; 148 static ctl_table debug_table[]; 149 static ctl_table dev_table[]; 150 extern ctl_table random_table[]; 151 #ifdef CONFIG_UNIX98_PTYS 152 extern ctl_table pty_table[]; 153 #endif 154 #ifdef CONFIG_INOTIFY_USER 155 extern ctl_table inotify_table[]; 156 #endif 157 158 #ifdef HAVE_ARCH_PICK_MMAP_LAYOUT 159 int sysctl_legacy_va_layout; 160 #endif 161 162 163 /* The default sysctl tables: */ 164 165 static ctl_table root_table[] = { 166 { 167 .ctl_name = CTL_KERN, 168 .procname = "kernel", 169 .mode = 0555, 170 .child = kern_table, 171 }, 172 { 173 .ctl_name = CTL_VM, 174 .procname = "vm", 175 .mode = 0555, 176 .child = vm_table, 177 }, 178 #ifdef CONFIG_NET 179 { 180 .ctl_name = CTL_NET, 181 .procname = "net", 182 .mode = 0555, 183 .child = net_table, 184 }, 185 #endif 186 { 187 .ctl_name = CTL_FS, 188 .procname = "fs", 189 .mode = 0555, 190 .child = fs_table, 191 }, 192 { 193 .ctl_name = CTL_DEBUG, 194 .procname = "debug", 195 .mode = 0555, 196 .child = debug_table, 197 }, 198 { 199 .ctl_name = CTL_DEV, 200 .procname = "dev", 201 .mode = 0555, 202 .child = dev_table, 203 }, 204 /* 205 * NOTE: do not add new entries to this table unless you have read 206 * Documentation/sysctl/ctl_unnumbered.txt 207 */ 208 { .ctl_name = 0 } 209 }; 210 211 #ifdef CONFIG_SCHED_DEBUG 212 static unsigned long min_sched_granularity_ns = 100000; /* 100 usecs */ 213 static unsigned long max_sched_granularity_ns = 1000000000; /* 1 second */ 214 static unsigned long min_wakeup_granularity_ns; /* 0 usecs */ 215 static unsigned long max_wakeup_granularity_ns = 1000000000; /* 1 second */ 216 #endif 217 218 static ctl_table kern_table[] = { 219 #ifdef CONFIG_SCHED_DEBUG 220 { 221 .ctl_name = CTL_UNNUMBERED, 222 .procname = "sched_granularity_ns", 223 .data = &sysctl_sched_granularity, 224 .maxlen = sizeof(unsigned int), 225 .mode = 0644, 226 .proc_handler = &proc_dointvec_minmax, 227 .strategy = &sysctl_intvec, 228 .extra1 = &min_sched_granularity_ns, 229 .extra2 = &max_sched_granularity_ns, 230 }, 231 { 232 .ctl_name = CTL_UNNUMBERED, 233 .procname = "sched_wakeup_granularity_ns", 234 .data = &sysctl_sched_wakeup_granularity, 235 .maxlen = sizeof(unsigned int), 236 .mode = 0644, 237 .proc_handler = &proc_dointvec_minmax, 238 .strategy = &sysctl_intvec, 239 .extra1 = &min_wakeup_granularity_ns, 240 .extra2 = &max_wakeup_granularity_ns, 241 }, 242 { 243 .ctl_name = CTL_UNNUMBERED, 244 .procname = "sched_batch_wakeup_granularity_ns", 245 .data = &sysctl_sched_batch_wakeup_granularity, 246 .maxlen = sizeof(unsigned int), 247 .mode = 0644, 248 .proc_handler = &proc_dointvec_minmax, 249 .strategy = &sysctl_intvec, 250 .extra1 = &min_wakeup_granularity_ns, 251 .extra2 = &max_wakeup_granularity_ns, 252 }, 253 { 254 .ctl_name = CTL_UNNUMBERED, 255 .procname = "sched_stat_granularity_ns", 256 .data = &sysctl_sched_stat_granularity, 257 .maxlen = sizeof(unsigned int), 258 .mode = 0644, 259 .proc_handler = &proc_dointvec_minmax, 260 .strategy = &sysctl_intvec, 261 .extra1 = &min_wakeup_granularity_ns, 262 .extra2 = &max_wakeup_granularity_ns, 263 }, 264 { 265 .ctl_name = CTL_UNNUMBERED, 266 .procname = "sched_runtime_limit_ns", 267 .data = &sysctl_sched_runtime_limit, 268 .maxlen = sizeof(unsigned int), 269 .mode = 0644, 270 .proc_handler = &proc_dointvec_minmax, 271 .strategy = &sysctl_intvec, 272 .extra1 = &min_sched_granularity_ns, 273 .extra2 = &max_sched_granularity_ns, 274 }, 275 { 276 .ctl_name = CTL_UNNUMBERED, 277 .procname = "sched_child_runs_first", 278 .data = &sysctl_sched_child_runs_first, 279 .maxlen = sizeof(unsigned int), 280 .mode = 0644, 281 .proc_handler = &proc_dointvec, 282 }, 283 { 284 .ctl_name = CTL_UNNUMBERED, 285 .procname = "sched_features", 286 .data = &sysctl_sched_features, 287 .maxlen = sizeof(unsigned int), 288 .mode = 0644, 289 .proc_handler = &proc_dointvec, 290 }, 291 #endif 292 { 293 .ctl_name = KERN_PANIC, 294 .procname = "panic", 295 .data = &panic_timeout, 296 .maxlen = sizeof(int), 297 .mode = 0644, 298 .proc_handler = &proc_dointvec, 299 }, 300 { 301 .ctl_name = KERN_CORE_USES_PID, 302 .procname = "core_uses_pid", 303 .data = &core_uses_pid, 304 .maxlen = sizeof(int), 305 .mode = 0644, 306 .proc_handler = &proc_dointvec, 307 }, 308 { 309 .ctl_name = KERN_CORE_PATTERN, 310 .procname = "core_pattern", 311 .data = core_pattern, 312 .maxlen = CORENAME_MAX_SIZE, 313 .mode = 0644, 314 .proc_handler = &proc_dostring, 315 .strategy = &sysctl_string, 316 }, 317 #ifdef CONFIG_PROC_SYSCTL 318 { 319 .ctl_name = KERN_TAINTED, 320 .procname = "tainted", 321 .data = &tainted, 322 .maxlen = sizeof(int), 323 .mode = 0644, 324 .proc_handler = &proc_dointvec_taint, 325 }, 326 #endif 327 { 328 .ctl_name = KERN_CAP_BSET, 329 .procname = "cap-bound", 330 .data = &cap_bset, 331 .maxlen = sizeof(kernel_cap_t), 332 .mode = 0600, 333 .proc_handler = &proc_dointvec_bset, 334 }, 335 #ifdef CONFIG_BLK_DEV_INITRD 336 { 337 .ctl_name = KERN_REALROOTDEV, 338 .procname = "real-root-dev", 339 .data = &real_root_dev, 340 .maxlen = sizeof(int), 341 .mode = 0644, 342 .proc_handler = &proc_dointvec, 343 }, 344 #endif 345 { 346 .ctl_name = CTL_UNNUMBERED, 347 .procname = "print-fatal-signals", 348 .data = &print_fatal_signals, 349 .maxlen = sizeof(int), 350 .mode = 0644, 351 .proc_handler = &proc_dointvec, 352 }, 353 #ifdef __sparc__ 354 { 355 .ctl_name = KERN_SPARC_REBOOT, 356 .procname = "reboot-cmd", 357 .data = reboot_command, 358 .maxlen = 256, 359 .mode = 0644, 360 .proc_handler = &proc_dostring, 361 .strategy = &sysctl_string, 362 }, 363 { 364 .ctl_name = KERN_SPARC_STOP_A, 365 .procname = "stop-a", 366 .data = &stop_a_enabled, 367 .maxlen = sizeof (int), 368 .mode = 0644, 369 .proc_handler = &proc_dointvec, 370 }, 371 { 372 .ctl_name = KERN_SPARC_SCONS_PWROFF, 373 .procname = "scons-poweroff", 374 .data = &scons_pwroff, 375 .maxlen = sizeof (int), 376 .mode = 0644, 377 .proc_handler = &proc_dointvec, 378 }, 379 #endif 380 #ifdef __hppa__ 381 { 382 .ctl_name = KERN_HPPA_PWRSW, 383 .procname = "soft-power", 384 .data = &pwrsw_enabled, 385 .maxlen = sizeof (int), 386 .mode = 0644, 387 .proc_handler = &proc_dointvec, 388 }, 389 { 390 .ctl_name = KERN_HPPA_UNALIGNED, 391 .procname = "unaligned-trap", 392 .data = &unaligned_enabled, 393 .maxlen = sizeof (int), 394 .mode = 0644, 395 .proc_handler = &proc_dointvec, 396 }, 397 #endif 398 { 399 .ctl_name = KERN_CTLALTDEL, 400 .procname = "ctrl-alt-del", 401 .data = &C_A_D, 402 .maxlen = sizeof(int), 403 .mode = 0644, 404 .proc_handler = &proc_dointvec, 405 }, 406 { 407 .ctl_name = KERN_PRINTK, 408 .procname = "printk", 409 .data = &console_loglevel, 410 .maxlen = 4*sizeof(int), 411 .mode = 0644, 412 .proc_handler = &proc_dointvec, 413 }, 414 #ifdef CONFIG_KMOD 415 { 416 .ctl_name = KERN_MODPROBE, 417 .procname = "modprobe", 418 .data = &modprobe_path, 419 .maxlen = KMOD_PATH_LEN, 420 .mode = 0644, 421 .proc_handler = &proc_dostring, 422 .strategy = &sysctl_string, 423 }, 424 #endif 425 #if defined(CONFIG_HOTPLUG) && defined(CONFIG_NET) 426 { 427 .ctl_name = KERN_HOTPLUG, 428 .procname = "hotplug", 429 .data = &uevent_helper, 430 .maxlen = UEVENT_HELPER_PATH_LEN, 431 .mode = 0644, 432 .proc_handler = &proc_dostring, 433 .strategy = &sysctl_string, 434 }, 435 #endif 436 #ifdef CONFIG_CHR_DEV_SG 437 { 438 .ctl_name = KERN_SG_BIG_BUFF, 439 .procname = "sg-big-buff", 440 .data = &sg_big_buff, 441 .maxlen = sizeof (int), 442 .mode = 0444, 443 .proc_handler = &proc_dointvec, 444 }, 445 #endif 446 #ifdef CONFIG_BSD_PROCESS_ACCT 447 { 448 .ctl_name = KERN_ACCT, 449 .procname = "acct", 450 .data = &acct_parm, 451 .maxlen = 3*sizeof(int), 452 .mode = 0644, 453 .proc_handler = &proc_dointvec, 454 }, 455 #endif 456 #ifdef CONFIG_MAGIC_SYSRQ 457 { 458 .ctl_name = KERN_SYSRQ, 459 .procname = "sysrq", 460 .data = &__sysrq_enabled, 461 .maxlen = sizeof (int), 462 .mode = 0644, 463 .proc_handler = &proc_dointvec, 464 }, 465 #endif 466 #ifdef CONFIG_PROC_SYSCTL 467 { 468 .ctl_name = KERN_CADPID, 469 .procname = "cad_pid", 470 .data = NULL, 471 .maxlen = sizeof (int), 472 .mode = 0600, 473 .proc_handler = &proc_do_cad_pid, 474 }, 475 #endif 476 { 477 .ctl_name = KERN_MAX_THREADS, 478 .procname = "threads-max", 479 .data = &max_threads, 480 .maxlen = sizeof(int), 481 .mode = 0644, 482 .proc_handler = &proc_dointvec, 483 }, 484 { 485 .ctl_name = KERN_RANDOM, 486 .procname = "random", 487 .mode = 0555, 488 .child = random_table, 489 }, 490 #ifdef CONFIG_UNIX98_PTYS 491 { 492 .ctl_name = KERN_PTY, 493 .procname = "pty", 494 .mode = 0555, 495 .child = pty_table, 496 }, 497 #endif 498 { 499 .ctl_name = KERN_OVERFLOWUID, 500 .procname = "overflowuid", 501 .data = &overflowuid, 502 .maxlen = sizeof(int), 503 .mode = 0644, 504 .proc_handler = &proc_dointvec_minmax, 505 .strategy = &sysctl_intvec, 506 .extra1 = &minolduid, 507 .extra2 = &maxolduid, 508 }, 509 { 510 .ctl_name = KERN_OVERFLOWGID, 511 .procname = "overflowgid", 512 .data = &overflowgid, 513 .maxlen = sizeof(int), 514 .mode = 0644, 515 .proc_handler = &proc_dointvec_minmax, 516 .strategy = &sysctl_intvec, 517 .extra1 = &minolduid, 518 .extra2 = &maxolduid, 519 }, 520 #ifdef CONFIG_S390 521 #ifdef CONFIG_MATHEMU 522 { 523 .ctl_name = KERN_IEEE_EMULATION_WARNINGS, 524 .procname = "ieee_emulation_warnings", 525 .data = &sysctl_ieee_emulation_warnings, 526 .maxlen = sizeof(int), 527 .mode = 0644, 528 .proc_handler = &proc_dointvec, 529 }, 530 #endif 531 #ifdef CONFIG_NO_IDLE_HZ 532 { 533 .ctl_name = KERN_HZ_TIMER, 534 .procname = "hz_timer", 535 .data = &sysctl_hz_timer, 536 .maxlen = sizeof(int), 537 .mode = 0644, 538 .proc_handler = &proc_dointvec, 539 }, 540 #endif 541 { 542 .ctl_name = KERN_S390_USER_DEBUG_LOGGING, 543 .procname = "userprocess_debug", 544 .data = &sysctl_userprocess_debug, 545 .maxlen = sizeof(int), 546 .mode = 0644, 547 .proc_handler = &proc_dointvec, 548 }, 549 #endif 550 { 551 .ctl_name = KERN_PIDMAX, 552 .procname = "pid_max", 553 .data = &pid_max, 554 .maxlen = sizeof (int), 555 .mode = 0644, 556 .proc_handler = &proc_dointvec_minmax, 557 .strategy = sysctl_intvec, 558 .extra1 = &pid_max_min, 559 .extra2 = &pid_max_max, 560 }, 561 { 562 .ctl_name = KERN_PANIC_ON_OOPS, 563 .procname = "panic_on_oops", 564 .data = &panic_on_oops, 565 .maxlen = sizeof(int), 566 .mode = 0644, 567 .proc_handler = &proc_dointvec, 568 }, 569 { 570 .ctl_name = KERN_PRINTK_RATELIMIT, 571 .procname = "printk_ratelimit", 572 .data = &printk_ratelimit_jiffies, 573 .maxlen = sizeof(int), 574 .mode = 0644, 575 .proc_handler = &proc_dointvec_jiffies, 576 .strategy = &sysctl_jiffies, 577 }, 578 { 579 .ctl_name = KERN_PRINTK_RATELIMIT_BURST, 580 .procname = "printk_ratelimit_burst", 581 .data = &printk_ratelimit_burst, 582 .maxlen = sizeof(int), 583 .mode = 0644, 584 .proc_handler = &proc_dointvec, 585 }, 586 { 587 .ctl_name = KERN_NGROUPS_MAX, 588 .procname = "ngroups_max", 589 .data = &ngroups_max, 590 .maxlen = sizeof (int), 591 .mode = 0444, 592 .proc_handler = &proc_dointvec, 593 }, 594 #if defined(CONFIG_X86_LOCAL_APIC) && defined(CONFIG_X86) 595 { 596 .ctl_name = KERN_UNKNOWN_NMI_PANIC, 597 .procname = "unknown_nmi_panic", 598 .data = &unknown_nmi_panic, 599 .maxlen = sizeof (int), 600 .mode = 0644, 601 .proc_handler = &proc_dointvec, 602 }, 603 { 604 .ctl_name = KERN_NMI_WATCHDOG, 605 .procname = "nmi_watchdog", 606 .data = &nmi_watchdog_enabled, 607 .maxlen = sizeof (int), 608 .mode = 0644, 609 .proc_handler = &proc_nmi_enabled, 610 }, 611 #endif 612 #if defined(CONFIG_X86) 613 { 614 .ctl_name = KERN_PANIC_ON_NMI, 615 .procname = "panic_on_unrecovered_nmi", 616 .data = &panic_on_unrecovered_nmi, 617 .maxlen = sizeof(int), 618 .mode = 0644, 619 .proc_handler = &proc_dointvec, 620 }, 621 { 622 .ctl_name = KERN_BOOTLOADER_TYPE, 623 .procname = "bootloader_type", 624 .data = &bootloader_type, 625 .maxlen = sizeof (int), 626 .mode = 0444, 627 .proc_handler = &proc_dointvec, 628 }, 629 { 630 .ctl_name = CTL_UNNUMBERED, 631 .procname = "kstack_depth_to_print", 632 .data = &kstack_depth_to_print, 633 .maxlen = sizeof(int), 634 .mode = 0644, 635 .proc_handler = &proc_dointvec, 636 }, 637 #endif 638 #if defined(CONFIG_MMU) 639 { 640 .ctl_name = KERN_RANDOMIZE, 641 .procname = "randomize_va_space", 642 .data = &randomize_va_space, 643 .maxlen = sizeof(int), 644 .mode = 0644, 645 .proc_handler = &proc_dointvec, 646 }, 647 #endif 648 #if defined(CONFIG_S390) && defined(CONFIG_SMP) 649 { 650 .ctl_name = KERN_SPIN_RETRY, 651 .procname = "spin_retry", 652 .data = &spin_retry, 653 .maxlen = sizeof (int), 654 .mode = 0644, 655 .proc_handler = &proc_dointvec, 656 }, 657 #endif 658 #ifdef CONFIG_ACPI_SLEEP 659 { 660 .ctl_name = KERN_ACPI_VIDEO_FLAGS, 661 .procname = "acpi_video_flags", 662 .data = &acpi_video_flags, 663 .maxlen = sizeof (unsigned long), 664 .mode = 0644, 665 .proc_handler = &proc_doulongvec_minmax, 666 }, 667 #endif 668 #ifdef CONFIG_IA64 669 { 670 .ctl_name = KERN_IA64_UNALIGNED, 671 .procname = "ignore-unaligned-usertrap", 672 .data = &no_unaligned_warning, 673 .maxlen = sizeof (int), 674 .mode = 0644, 675 .proc_handler = &proc_dointvec, 676 }, 677 #endif 678 #ifdef CONFIG_COMPAT 679 { 680 .ctl_name = KERN_COMPAT_LOG, 681 .procname = "compat-log", 682 .data = &compat_log, 683 .maxlen = sizeof (int), 684 .mode = 0644, 685 .proc_handler = &proc_dointvec, 686 }, 687 #endif 688 #ifdef CONFIG_RT_MUTEXES 689 { 690 .ctl_name = KERN_MAX_LOCK_DEPTH, 691 .procname = "max_lock_depth", 692 .data = &max_lock_depth, 693 .maxlen = sizeof(int), 694 .mode = 0644, 695 .proc_handler = &proc_dointvec, 696 }, 697 #endif 698 #ifdef CONFIG_PROC_FS 699 { 700 .ctl_name = CTL_UNNUMBERED, 701 .procname = "maps_protect", 702 .data = &maps_protect, 703 .maxlen = sizeof(int), 704 .mode = 0644, 705 .proc_handler = &proc_dointvec, 706 }, 707 #endif 708 709 { .ctl_name = 0 } 710 }; 711 712 /* Constants for minimum and maximum testing in vm_table. 713 We use these as one-element integer vectors. */ 714 static int zero; 715 static int one_hundred = 100; 716 717 718 static ctl_table vm_table[] = { 719 { 720 .ctl_name = VM_OVERCOMMIT_MEMORY, 721 .procname = "overcommit_memory", 722 .data = &sysctl_overcommit_memory, 723 .maxlen = sizeof(sysctl_overcommit_memory), 724 .mode = 0644, 725 .proc_handler = &proc_dointvec, 726 }, 727 { 728 .ctl_name = VM_PANIC_ON_OOM, 729 .procname = "panic_on_oom", 730 .data = &sysctl_panic_on_oom, 731 .maxlen = sizeof(sysctl_panic_on_oom), 732 .mode = 0644, 733 .proc_handler = &proc_dointvec, 734 }, 735 { 736 .ctl_name = VM_OVERCOMMIT_RATIO, 737 .procname = "overcommit_ratio", 738 .data = &sysctl_overcommit_ratio, 739 .maxlen = sizeof(sysctl_overcommit_ratio), 740 .mode = 0644, 741 .proc_handler = &proc_dointvec, 742 }, 743 { 744 .ctl_name = VM_PAGE_CLUSTER, 745 .procname = "page-cluster", 746 .data = &page_cluster, 747 .maxlen = sizeof(int), 748 .mode = 0644, 749 .proc_handler = &proc_dointvec, 750 }, 751 { 752 .ctl_name = VM_DIRTY_BACKGROUND, 753 .procname = "dirty_background_ratio", 754 .data = &dirty_background_ratio, 755 .maxlen = sizeof(dirty_background_ratio), 756 .mode = 0644, 757 .proc_handler = &proc_dointvec_minmax, 758 .strategy = &sysctl_intvec, 759 .extra1 = &zero, 760 .extra2 = &one_hundred, 761 }, 762 { 763 .ctl_name = VM_DIRTY_RATIO, 764 .procname = "dirty_ratio", 765 .data = &vm_dirty_ratio, 766 .maxlen = sizeof(vm_dirty_ratio), 767 .mode = 0644, 768 .proc_handler = &proc_dointvec_minmax, 769 .strategy = &sysctl_intvec, 770 .extra1 = &zero, 771 .extra2 = &one_hundred, 772 }, 773 { 774 .ctl_name = VM_DIRTY_WB_CS, 775 .procname = "dirty_writeback_centisecs", 776 .data = &dirty_writeback_interval, 777 .maxlen = sizeof(dirty_writeback_interval), 778 .mode = 0644, 779 .proc_handler = &dirty_writeback_centisecs_handler, 780 }, 781 { 782 .ctl_name = VM_DIRTY_EXPIRE_CS, 783 .procname = "dirty_expire_centisecs", 784 .data = &dirty_expire_interval, 785 .maxlen = sizeof(dirty_expire_interval), 786 .mode = 0644, 787 .proc_handler = &proc_dointvec_userhz_jiffies, 788 }, 789 { 790 .ctl_name = VM_NR_PDFLUSH_THREADS, 791 .procname = "nr_pdflush_threads", 792 .data = &nr_pdflush_threads, 793 .maxlen = sizeof nr_pdflush_threads, 794 .mode = 0444 /* read-only*/, 795 .proc_handler = &proc_dointvec, 796 }, 797 { 798 .ctl_name = VM_SWAPPINESS, 799 .procname = "swappiness", 800 .data = &vm_swappiness, 801 .maxlen = sizeof(vm_swappiness), 802 .mode = 0644, 803 .proc_handler = &proc_dointvec_minmax, 804 .strategy = &sysctl_intvec, 805 .extra1 = &zero, 806 .extra2 = &one_hundred, 807 }, 808 #ifdef CONFIG_HUGETLB_PAGE 809 { 810 .ctl_name = VM_HUGETLB_PAGES, 811 .procname = "nr_hugepages", 812 .data = &max_huge_pages, 813 .maxlen = sizeof(unsigned long), 814 .mode = 0644, 815 .proc_handler = &hugetlb_sysctl_handler, 816 .extra1 = (void *)&hugetlb_zero, 817 .extra2 = (void *)&hugetlb_infinity, 818 }, 819 { 820 .ctl_name = VM_HUGETLB_GROUP, 821 .procname = "hugetlb_shm_group", 822 .data = &sysctl_hugetlb_shm_group, 823 .maxlen = sizeof(gid_t), 824 .mode = 0644, 825 .proc_handler = &proc_dointvec, 826 }, 827 { 828 .ctl_name = CTL_UNNUMBERED, 829 .procname = "hugepages_treat_as_movable", 830 .data = &hugepages_treat_as_movable, 831 .maxlen = sizeof(int), 832 .mode = 0644, 833 .proc_handler = &hugetlb_treat_movable_handler, 834 }, 835 #endif 836 { 837 .ctl_name = VM_LOWMEM_RESERVE_RATIO, 838 .procname = "lowmem_reserve_ratio", 839 .data = &sysctl_lowmem_reserve_ratio, 840 .maxlen = sizeof(sysctl_lowmem_reserve_ratio), 841 .mode = 0644, 842 .proc_handler = &lowmem_reserve_ratio_sysctl_handler, 843 .strategy = &sysctl_intvec, 844 }, 845 { 846 .ctl_name = VM_DROP_PAGECACHE, 847 .procname = "drop_caches", 848 .data = &sysctl_drop_caches, 849 .maxlen = sizeof(int), 850 .mode = 0644, 851 .proc_handler = drop_caches_sysctl_handler, 852 .strategy = &sysctl_intvec, 853 }, 854 { 855 .ctl_name = VM_MIN_FREE_KBYTES, 856 .procname = "min_free_kbytes", 857 .data = &min_free_kbytes, 858 .maxlen = sizeof(min_free_kbytes), 859 .mode = 0644, 860 .proc_handler = &min_free_kbytes_sysctl_handler, 861 .strategy = &sysctl_intvec, 862 .extra1 = &zero, 863 }, 864 { 865 .ctl_name = VM_PERCPU_PAGELIST_FRACTION, 866 .procname = "percpu_pagelist_fraction", 867 .data = &percpu_pagelist_fraction, 868 .maxlen = sizeof(percpu_pagelist_fraction), 869 .mode = 0644, 870 .proc_handler = &percpu_pagelist_fraction_sysctl_handler, 871 .strategy = &sysctl_intvec, 872 .extra1 = &min_percpu_pagelist_fract, 873 }, 874 #ifdef CONFIG_MMU 875 { 876 .ctl_name = VM_MAX_MAP_COUNT, 877 .procname = "max_map_count", 878 .data = &sysctl_max_map_count, 879 .maxlen = sizeof(sysctl_max_map_count), 880 .mode = 0644, 881 .proc_handler = &proc_dointvec 882 }, 883 #endif 884 { 885 .ctl_name = VM_LAPTOP_MODE, 886 .procname = "laptop_mode", 887 .data = &laptop_mode, 888 .maxlen = sizeof(laptop_mode), 889 .mode = 0644, 890 .proc_handler = &proc_dointvec_jiffies, 891 .strategy = &sysctl_jiffies, 892 }, 893 { 894 .ctl_name = VM_BLOCK_DUMP, 895 .procname = "block_dump", 896 .data = &block_dump, 897 .maxlen = sizeof(block_dump), 898 .mode = 0644, 899 .proc_handler = &proc_dointvec, 900 .strategy = &sysctl_intvec, 901 .extra1 = &zero, 902 }, 903 { 904 .ctl_name = VM_VFS_CACHE_PRESSURE, 905 .procname = "vfs_cache_pressure", 906 .data = &sysctl_vfs_cache_pressure, 907 .maxlen = sizeof(sysctl_vfs_cache_pressure), 908 .mode = 0644, 909 .proc_handler = &proc_dointvec, 910 .strategy = &sysctl_intvec, 911 .extra1 = &zero, 912 }, 913 #ifdef HAVE_ARCH_PICK_MMAP_LAYOUT 914 { 915 .ctl_name = VM_LEGACY_VA_LAYOUT, 916 .procname = "legacy_va_layout", 917 .data = &sysctl_legacy_va_layout, 918 .maxlen = sizeof(sysctl_legacy_va_layout), 919 .mode = 0644, 920 .proc_handler = &proc_dointvec, 921 .strategy = &sysctl_intvec, 922 .extra1 = &zero, 923 }, 924 #endif 925 #ifdef CONFIG_NUMA 926 { 927 .ctl_name = VM_ZONE_RECLAIM_MODE, 928 .procname = "zone_reclaim_mode", 929 .data = &zone_reclaim_mode, 930 .maxlen = sizeof(zone_reclaim_mode), 931 .mode = 0644, 932 .proc_handler = &proc_dointvec, 933 .strategy = &sysctl_intvec, 934 .extra1 = &zero, 935 }, 936 { 937 .ctl_name = VM_MIN_UNMAPPED, 938 .procname = "min_unmapped_ratio", 939 .data = &sysctl_min_unmapped_ratio, 940 .maxlen = sizeof(sysctl_min_unmapped_ratio), 941 .mode = 0644, 942 .proc_handler = &sysctl_min_unmapped_ratio_sysctl_handler, 943 .strategy = &sysctl_intvec, 944 .extra1 = &zero, 945 .extra2 = &one_hundred, 946 }, 947 { 948 .ctl_name = VM_MIN_SLAB, 949 .procname = "min_slab_ratio", 950 .data = &sysctl_min_slab_ratio, 951 .maxlen = sizeof(sysctl_min_slab_ratio), 952 .mode = 0644, 953 .proc_handler = &sysctl_min_slab_ratio_sysctl_handler, 954 .strategy = &sysctl_intvec, 955 .extra1 = &zero, 956 .extra2 = &one_hundred, 957 }, 958 #endif 959 #ifdef CONFIG_SMP 960 { 961 .ctl_name = CTL_UNNUMBERED, 962 .procname = "stat_interval", 963 .data = &sysctl_stat_interval, 964 .maxlen = sizeof(sysctl_stat_interval), 965 .mode = 0644, 966 .proc_handler = &proc_dointvec_jiffies, 967 .strategy = &sysctl_jiffies, 968 }, 969 #endif 970 #ifdef CONFIG_SECURITY 971 { 972 .ctl_name = CTL_UNNUMBERED, 973 .procname = "mmap_min_addr", 974 .data = &mmap_min_addr, 975 .maxlen = sizeof(unsigned long), 976 .mode = 0644, 977 .proc_handler = &proc_doulongvec_minmax, 978 }, 979 #ifdef CONFIG_NUMA 980 { 981 .ctl_name = CTL_UNNUMBERED, 982 .procname = "numa_zonelist_order", 983 .data = &numa_zonelist_order, 984 .maxlen = NUMA_ZONELIST_ORDER_LEN, 985 .mode = 0644, 986 .proc_handler = &numa_zonelist_order_handler, 987 .strategy = &sysctl_string, 988 }, 989 #endif 990 #endif 991 #if defined(CONFIG_X86_32) || \ 992 (defined(CONFIG_SUPERH) && defined(CONFIG_VSYSCALL)) 993 { 994 .ctl_name = VM_VDSO_ENABLED, 995 .procname = "vdso_enabled", 996 .data = &vdso_enabled, 997 .maxlen = sizeof(vdso_enabled), 998 .mode = 0644, 999 .proc_handler = &proc_dointvec, 1000 .strategy = &sysctl_intvec, 1001 .extra1 = &zero, 1002 }, 1003 #endif 1004 /* 1005 * NOTE: do not add new entries to this table unless you have read 1006 * Documentation/sysctl/ctl_unnumbered.txt 1007 */ 1008 { .ctl_name = 0 } 1009 }; 1010 1011 #if defined(CONFIG_BINFMT_MISC) || defined(CONFIG_BINFMT_MISC_MODULE) 1012 static ctl_table binfmt_misc_table[] = { 1013 { .ctl_name = 0 } 1014 }; 1015 #endif 1016 1017 static ctl_table fs_table[] = { 1018 { 1019 .ctl_name = FS_NRINODE, 1020 .procname = "inode-nr", 1021 .data = &inodes_stat, 1022 .maxlen = 2*sizeof(int), 1023 .mode = 0444, 1024 .proc_handler = &proc_dointvec, 1025 }, 1026 { 1027 .ctl_name = FS_STATINODE, 1028 .procname = "inode-state", 1029 .data = &inodes_stat, 1030 .maxlen = 7*sizeof(int), 1031 .mode = 0444, 1032 .proc_handler = &proc_dointvec, 1033 }, 1034 { 1035 .ctl_name = FS_NRFILE, 1036 .procname = "file-nr", 1037 .data = &files_stat, 1038 .maxlen = 3*sizeof(int), 1039 .mode = 0444, 1040 .proc_handler = &proc_nr_files, 1041 }, 1042 { 1043 .ctl_name = FS_MAXFILE, 1044 .procname = "file-max", 1045 .data = &files_stat.max_files, 1046 .maxlen = sizeof(int), 1047 .mode = 0644, 1048 .proc_handler = &proc_dointvec, 1049 }, 1050 { 1051 .ctl_name = FS_DENTRY, 1052 .procname = "dentry-state", 1053 .data = &dentry_stat, 1054 .maxlen = 6*sizeof(int), 1055 .mode = 0444, 1056 .proc_handler = &proc_dointvec, 1057 }, 1058 { 1059 .ctl_name = FS_OVERFLOWUID, 1060 .procname = "overflowuid", 1061 .data = &fs_overflowuid, 1062 .maxlen = sizeof(int), 1063 .mode = 0644, 1064 .proc_handler = &proc_dointvec_minmax, 1065 .strategy = &sysctl_intvec, 1066 .extra1 = &minolduid, 1067 .extra2 = &maxolduid, 1068 }, 1069 { 1070 .ctl_name = FS_OVERFLOWGID, 1071 .procname = "overflowgid", 1072 .data = &fs_overflowgid, 1073 .maxlen = sizeof(int), 1074 .mode = 0644, 1075 .proc_handler = &proc_dointvec_minmax, 1076 .strategy = &sysctl_intvec, 1077 .extra1 = &minolduid, 1078 .extra2 = &maxolduid, 1079 }, 1080 { 1081 .ctl_name = FS_LEASES, 1082 .procname = "leases-enable", 1083 .data = &leases_enable, 1084 .maxlen = sizeof(int), 1085 .mode = 0644, 1086 .proc_handler = &proc_dointvec, 1087 }, 1088 #ifdef CONFIG_DNOTIFY 1089 { 1090 .ctl_name = FS_DIR_NOTIFY, 1091 .procname = "dir-notify-enable", 1092 .data = &dir_notify_enable, 1093 .maxlen = sizeof(int), 1094 .mode = 0644, 1095 .proc_handler = &proc_dointvec, 1096 }, 1097 #endif 1098 #ifdef CONFIG_MMU 1099 { 1100 .ctl_name = FS_LEASE_TIME, 1101 .procname = "lease-break-time", 1102 .data = &lease_break_time, 1103 .maxlen = sizeof(int), 1104 .mode = 0644, 1105 .proc_handler = &proc_dointvec, 1106 }, 1107 { 1108 .ctl_name = FS_AIO_NR, 1109 .procname = "aio-nr", 1110 .data = &aio_nr, 1111 .maxlen = sizeof(aio_nr), 1112 .mode = 0444, 1113 .proc_handler = &proc_doulongvec_minmax, 1114 }, 1115 { 1116 .ctl_name = FS_AIO_MAX_NR, 1117 .procname = "aio-max-nr", 1118 .data = &aio_max_nr, 1119 .maxlen = sizeof(aio_max_nr), 1120 .mode = 0644, 1121 .proc_handler = &proc_doulongvec_minmax, 1122 }, 1123 #ifdef CONFIG_INOTIFY_USER 1124 { 1125 .ctl_name = FS_INOTIFY, 1126 .procname = "inotify", 1127 .mode = 0555, 1128 .child = inotify_table, 1129 }, 1130 #endif 1131 #endif 1132 { 1133 .ctl_name = KERN_SETUID_DUMPABLE, 1134 .procname = "suid_dumpable", 1135 .data = &suid_dumpable, 1136 .maxlen = sizeof(int), 1137 .mode = 0644, 1138 .proc_handler = &proc_dointvec, 1139 }, 1140 #if defined(CONFIG_BINFMT_MISC) || defined(CONFIG_BINFMT_MISC_MODULE) 1141 { 1142 .ctl_name = CTL_UNNUMBERED, 1143 .procname = "binfmt_misc", 1144 .mode = 0555, 1145 .child = binfmt_misc_table, 1146 }, 1147 #endif 1148 /* 1149 * NOTE: do not add new entries to this table unless you have read 1150 * Documentation/sysctl/ctl_unnumbered.txt 1151 */ 1152 { .ctl_name = 0 } 1153 }; 1154 1155 static ctl_table debug_table[] = { 1156 { .ctl_name = 0 } 1157 }; 1158 1159 static ctl_table dev_table[] = { 1160 { .ctl_name = 0 } 1161 }; 1162 1163 static DEFINE_SPINLOCK(sysctl_lock); 1164 1165 /* called under sysctl_lock */ 1166 static int use_table(struct ctl_table_header *p) 1167 { 1168 if (unlikely(p->unregistering)) 1169 return 0; 1170 p->used++; 1171 return 1; 1172 } 1173 1174 /* called under sysctl_lock */ 1175 static void unuse_table(struct ctl_table_header *p) 1176 { 1177 if (!--p->used) 1178 if (unlikely(p->unregistering)) 1179 complete(p->unregistering); 1180 } 1181 1182 /* called under sysctl_lock, will reacquire if has to wait */ 1183 static void start_unregistering(struct ctl_table_header *p) 1184 { 1185 /* 1186 * if p->used is 0, nobody will ever touch that entry again; 1187 * we'll eliminate all paths to it before dropping sysctl_lock 1188 */ 1189 if (unlikely(p->used)) { 1190 struct completion wait; 1191 init_completion(&wait); 1192 p->unregistering = &wait; 1193 spin_unlock(&sysctl_lock); 1194 wait_for_completion(&wait); 1195 spin_lock(&sysctl_lock); 1196 } 1197 /* 1198 * do not remove from the list until nobody holds it; walking the 1199 * list in do_sysctl() relies on that. 1200 */ 1201 list_del_init(&p->ctl_entry); 1202 } 1203 1204 void sysctl_head_finish(struct ctl_table_header *head) 1205 { 1206 if (!head) 1207 return; 1208 spin_lock(&sysctl_lock); 1209 unuse_table(head); 1210 spin_unlock(&sysctl_lock); 1211 } 1212 1213 struct ctl_table_header *sysctl_head_next(struct ctl_table_header *prev) 1214 { 1215 struct ctl_table_header *head; 1216 struct list_head *tmp; 1217 spin_lock(&sysctl_lock); 1218 if (prev) { 1219 tmp = &prev->ctl_entry; 1220 unuse_table(prev); 1221 goto next; 1222 } 1223 tmp = &root_table_header.ctl_entry; 1224 for (;;) { 1225 head = list_entry(tmp, struct ctl_table_header, ctl_entry); 1226 1227 if (!use_table(head)) 1228 goto next; 1229 spin_unlock(&sysctl_lock); 1230 return head; 1231 next: 1232 tmp = tmp->next; 1233 if (tmp == &root_table_header.ctl_entry) 1234 break; 1235 } 1236 spin_unlock(&sysctl_lock); 1237 return NULL; 1238 } 1239 1240 #ifdef CONFIG_SYSCTL_SYSCALL 1241 int do_sysctl(int __user *name, int nlen, void __user *oldval, size_t __user *oldlenp, 1242 void __user *newval, size_t newlen) 1243 { 1244 struct ctl_table_header *head; 1245 int error = -ENOTDIR; 1246 1247 if (nlen <= 0 || nlen >= CTL_MAXNAME) 1248 return -ENOTDIR; 1249 if (oldval) { 1250 int old_len; 1251 if (!oldlenp || get_user(old_len, oldlenp)) 1252 return -EFAULT; 1253 } 1254 1255 for (head = sysctl_head_next(NULL); head; 1256 head = sysctl_head_next(head)) { 1257 error = parse_table(name, nlen, oldval, oldlenp, 1258 newval, newlen, head->ctl_table); 1259 if (error != -ENOTDIR) { 1260 sysctl_head_finish(head); 1261 break; 1262 } 1263 } 1264 return error; 1265 } 1266 1267 asmlinkage long sys_sysctl(struct __sysctl_args __user *args) 1268 { 1269 struct __sysctl_args tmp; 1270 int error; 1271 1272 if (copy_from_user(&tmp, args, sizeof(tmp))) 1273 return -EFAULT; 1274 1275 lock_kernel(); 1276 error = do_sysctl(tmp.name, tmp.nlen, tmp.oldval, tmp.oldlenp, 1277 tmp.newval, tmp.newlen); 1278 unlock_kernel(); 1279 return error; 1280 } 1281 #endif /* CONFIG_SYSCTL_SYSCALL */ 1282 1283 /* 1284 * sysctl_perm does NOT grant the superuser all rights automatically, because 1285 * some sysctl variables are readonly even to root. 1286 */ 1287 1288 static int test_perm(int mode, int op) 1289 { 1290 if (!current->euid) 1291 mode >>= 6; 1292 else if (in_egroup_p(0)) 1293 mode >>= 3; 1294 if ((mode & op & 0007) == op) 1295 return 0; 1296 return -EACCES; 1297 } 1298 1299 int sysctl_perm(ctl_table *table, int op) 1300 { 1301 int error; 1302 error = security_sysctl(table, op); 1303 if (error) 1304 return error; 1305 return test_perm(table->mode, op); 1306 } 1307 1308 #ifdef CONFIG_SYSCTL_SYSCALL 1309 static int parse_table(int __user *name, int nlen, 1310 void __user *oldval, size_t __user *oldlenp, 1311 void __user *newval, size_t newlen, 1312 ctl_table *table) 1313 { 1314 int n; 1315 repeat: 1316 if (!nlen) 1317 return -ENOTDIR; 1318 if (get_user(n, name)) 1319 return -EFAULT; 1320 for ( ; table->ctl_name || table->procname; table++) { 1321 if (!table->ctl_name) 1322 continue; 1323 if (n == table->ctl_name) { 1324 int error; 1325 if (table->child) { 1326 if (sysctl_perm(table, 001)) 1327 return -EPERM; 1328 name++; 1329 nlen--; 1330 table = table->child; 1331 goto repeat; 1332 } 1333 error = do_sysctl_strategy(table, name, nlen, 1334 oldval, oldlenp, 1335 newval, newlen); 1336 return error; 1337 } 1338 } 1339 return -ENOTDIR; 1340 } 1341 1342 /* Perform the actual read/write of a sysctl table entry. */ 1343 int do_sysctl_strategy (ctl_table *table, 1344 int __user *name, int nlen, 1345 void __user *oldval, size_t __user *oldlenp, 1346 void __user *newval, size_t newlen) 1347 { 1348 int op = 0, rc; 1349 size_t len; 1350 1351 if (oldval) 1352 op |= 004; 1353 if (newval) 1354 op |= 002; 1355 if (sysctl_perm(table, op)) 1356 return -EPERM; 1357 1358 if (table->strategy) { 1359 rc = table->strategy(table, name, nlen, oldval, oldlenp, 1360 newval, newlen); 1361 if (rc < 0) 1362 return rc; 1363 if (rc > 0) 1364 return 0; 1365 } 1366 1367 /* If there is no strategy routine, or if the strategy returns 1368 * zero, proceed with automatic r/w */ 1369 if (table->data && table->maxlen) { 1370 if (oldval && oldlenp) { 1371 if (get_user(len, oldlenp)) 1372 return -EFAULT; 1373 if (len) { 1374 if (len > table->maxlen) 1375 len = table->maxlen; 1376 if(copy_to_user(oldval, table->data, len)) 1377 return -EFAULT; 1378 if(put_user(len, oldlenp)) 1379 return -EFAULT; 1380 } 1381 } 1382 if (newval && newlen) { 1383 len = newlen; 1384 if (len > table->maxlen) 1385 len = table->maxlen; 1386 if(copy_from_user(table->data, newval, len)) 1387 return -EFAULT; 1388 } 1389 } 1390 return 0; 1391 } 1392 #endif /* CONFIG_SYSCTL_SYSCALL */ 1393 1394 static void sysctl_set_parent(struct ctl_table *parent, struct ctl_table *table) 1395 { 1396 for (; table->ctl_name || table->procname; table++) { 1397 table->parent = parent; 1398 if (table->child) 1399 sysctl_set_parent(table, table->child); 1400 } 1401 } 1402 1403 static __init int sysctl_init(void) 1404 { 1405 sysctl_set_parent(NULL, root_table); 1406 return 0; 1407 } 1408 1409 core_initcall(sysctl_init); 1410 1411 /** 1412 * register_sysctl_table - register a sysctl hierarchy 1413 * @table: the top-level table structure 1414 * 1415 * Register a sysctl table hierarchy. @table should be a filled in ctl_table 1416 * array. An entry with a ctl_name of 0 terminates the table. 1417 * 1418 * The members of the &ctl_table structure are used as follows: 1419 * 1420 * ctl_name - This is the numeric sysctl value used by sysctl(2). The number 1421 * must be unique within that level of sysctl 1422 * 1423 * procname - the name of the sysctl file under /proc/sys. Set to %NULL to not 1424 * enter a sysctl file 1425 * 1426 * data - a pointer to data for use by proc_handler 1427 * 1428 * maxlen - the maximum size in bytes of the data 1429 * 1430 * mode - the file permissions for the /proc/sys file, and for sysctl(2) 1431 * 1432 * child - a pointer to the child sysctl table if this entry is a directory, or 1433 * %NULL. 1434 * 1435 * proc_handler - the text handler routine (described below) 1436 * 1437 * strategy - the strategy routine (described below) 1438 * 1439 * de - for internal use by the sysctl routines 1440 * 1441 * extra1, extra2 - extra pointers usable by the proc handler routines 1442 * 1443 * Leaf nodes in the sysctl tree will be represented by a single file 1444 * under /proc; non-leaf nodes will be represented by directories. 1445 * 1446 * sysctl(2) can automatically manage read and write requests through 1447 * the sysctl table. The data and maxlen fields of the ctl_table 1448 * struct enable minimal validation of the values being written to be 1449 * performed, and the mode field allows minimal authentication. 1450 * 1451 * More sophisticated management can be enabled by the provision of a 1452 * strategy routine with the table entry. This will be called before 1453 * any automatic read or write of the data is performed. 1454 * 1455 * The strategy routine may return 1456 * 1457 * < 0 - Error occurred (error is passed to user process) 1458 * 1459 * 0 - OK - proceed with automatic read or write. 1460 * 1461 * > 0 - OK - read or write has been done by the strategy routine, so 1462 * return immediately. 1463 * 1464 * There must be a proc_handler routine for any terminal nodes 1465 * mirrored under /proc/sys (non-terminals are handled by a built-in 1466 * directory handler). Several default handlers are available to 1467 * cover common cases - 1468 * 1469 * proc_dostring(), proc_dointvec(), proc_dointvec_jiffies(), 1470 * proc_dointvec_userhz_jiffies(), proc_dointvec_minmax(), 1471 * proc_doulongvec_ms_jiffies_minmax(), proc_doulongvec_minmax() 1472 * 1473 * It is the handler's job to read the input buffer from user memory 1474 * and process it. The handler should return 0 on success. 1475 * 1476 * This routine returns %NULL on a failure to register, and a pointer 1477 * to the table header on success. 1478 */ 1479 struct ctl_table_header *register_sysctl_table(ctl_table * table) 1480 { 1481 struct ctl_table_header *tmp; 1482 tmp = kmalloc(sizeof(struct ctl_table_header), GFP_KERNEL); 1483 if (!tmp) 1484 return NULL; 1485 tmp->ctl_table = table; 1486 INIT_LIST_HEAD(&tmp->ctl_entry); 1487 tmp->used = 0; 1488 tmp->unregistering = NULL; 1489 sysctl_set_parent(NULL, table); 1490 spin_lock(&sysctl_lock); 1491 list_add_tail(&tmp->ctl_entry, &root_table_header.ctl_entry); 1492 spin_unlock(&sysctl_lock); 1493 return tmp; 1494 } 1495 1496 /** 1497 * unregister_sysctl_table - unregister a sysctl table hierarchy 1498 * @header: the header returned from register_sysctl_table 1499 * 1500 * Unregisters the sysctl table and all children. proc entries may not 1501 * actually be removed until they are no longer used by anyone. 1502 */ 1503 void unregister_sysctl_table(struct ctl_table_header * header) 1504 { 1505 might_sleep(); 1506 spin_lock(&sysctl_lock); 1507 start_unregistering(header); 1508 spin_unlock(&sysctl_lock); 1509 kfree(header); 1510 } 1511 1512 #else /* !CONFIG_SYSCTL */ 1513 struct ctl_table_header *register_sysctl_table(ctl_table * table) 1514 { 1515 return NULL; 1516 } 1517 1518 void unregister_sysctl_table(struct ctl_table_header * table) 1519 { 1520 } 1521 1522 #endif /* CONFIG_SYSCTL */ 1523 1524 /* 1525 * /proc/sys support 1526 */ 1527 1528 #ifdef CONFIG_PROC_SYSCTL 1529 1530 static int _proc_do_string(void* data, int maxlen, int write, 1531 struct file *filp, void __user *buffer, 1532 size_t *lenp, loff_t *ppos) 1533 { 1534 size_t len; 1535 char __user *p; 1536 char c; 1537 1538 if (!data || !maxlen || !*lenp) { 1539 *lenp = 0; 1540 return 0; 1541 } 1542 1543 if (write) { 1544 len = 0; 1545 p = buffer; 1546 while (len < *lenp) { 1547 if (get_user(c, p++)) 1548 return -EFAULT; 1549 if (c == 0 || c == '\n') 1550 break; 1551 len++; 1552 } 1553 if (len >= maxlen) 1554 len = maxlen-1; 1555 if(copy_from_user(data, buffer, len)) 1556 return -EFAULT; 1557 ((char *) data)[len] = 0; 1558 *ppos += *lenp; 1559 } else { 1560 len = strlen(data); 1561 if (len > maxlen) 1562 len = maxlen; 1563 1564 if (*ppos > len) { 1565 *lenp = 0; 1566 return 0; 1567 } 1568 1569 data += *ppos; 1570 len -= *ppos; 1571 1572 if (len > *lenp) 1573 len = *lenp; 1574 if (len) 1575 if(copy_to_user(buffer, data, len)) 1576 return -EFAULT; 1577 if (len < *lenp) { 1578 if(put_user('\n', ((char __user *) buffer) + len)) 1579 return -EFAULT; 1580 len++; 1581 } 1582 *lenp = len; 1583 *ppos += len; 1584 } 1585 return 0; 1586 } 1587 1588 /** 1589 * proc_dostring - read a string sysctl 1590 * @table: the sysctl table 1591 * @write: %TRUE if this is a write to the sysctl file 1592 * @filp: the file structure 1593 * @buffer: the user buffer 1594 * @lenp: the size of the user buffer 1595 * @ppos: file position 1596 * 1597 * Reads/writes a string from/to the user buffer. If the kernel 1598 * buffer provided is not large enough to hold the string, the 1599 * string is truncated. The copied string is %NULL-terminated. 1600 * If the string is being read by the user process, it is copied 1601 * and a newline '\n' is added. It is truncated if the buffer is 1602 * not large enough. 1603 * 1604 * Returns 0 on success. 1605 */ 1606 int proc_dostring(ctl_table *table, int write, struct file *filp, 1607 void __user *buffer, size_t *lenp, loff_t *ppos) 1608 { 1609 return _proc_do_string(table->data, table->maxlen, write, filp, 1610 buffer, lenp, ppos); 1611 } 1612 1613 1614 static int do_proc_dointvec_conv(int *negp, unsigned long *lvalp, 1615 int *valp, 1616 int write, void *data) 1617 { 1618 if (write) { 1619 *valp = *negp ? -*lvalp : *lvalp; 1620 } else { 1621 int val = *valp; 1622 if (val < 0) { 1623 *negp = -1; 1624 *lvalp = (unsigned long)-val; 1625 } else { 1626 *negp = 0; 1627 *lvalp = (unsigned long)val; 1628 } 1629 } 1630 return 0; 1631 } 1632 1633 static int __do_proc_dointvec(void *tbl_data, ctl_table *table, 1634 int write, struct file *filp, void __user *buffer, 1635 size_t *lenp, loff_t *ppos, 1636 int (*conv)(int *negp, unsigned long *lvalp, int *valp, 1637 int write, void *data), 1638 void *data) 1639 { 1640 #define TMPBUFLEN 21 1641 int *i, vleft, first=1, neg, val; 1642 unsigned long lval; 1643 size_t left, len; 1644 1645 char buf[TMPBUFLEN], *p; 1646 char __user *s = buffer; 1647 1648 if (!tbl_data || !table->maxlen || !*lenp || 1649 (*ppos && !write)) { 1650 *lenp = 0; 1651 return 0; 1652 } 1653 1654 i = (int *) tbl_data; 1655 vleft = table->maxlen / sizeof(*i); 1656 left = *lenp; 1657 1658 if (!conv) 1659 conv = do_proc_dointvec_conv; 1660 1661 for (; left && vleft--; i++, first=0) { 1662 if (write) { 1663 while (left) { 1664 char c; 1665 if (get_user(c, s)) 1666 return -EFAULT; 1667 if (!isspace(c)) 1668 break; 1669 left--; 1670 s++; 1671 } 1672 if (!left) 1673 break; 1674 neg = 0; 1675 len = left; 1676 if (len > sizeof(buf) - 1) 1677 len = sizeof(buf) - 1; 1678 if (copy_from_user(buf, s, len)) 1679 return -EFAULT; 1680 buf[len] = 0; 1681 p = buf; 1682 if (*p == '-' && left > 1) { 1683 neg = 1; 1684 p++; 1685 } 1686 if (*p < '0' || *p > '9') 1687 break; 1688 1689 lval = simple_strtoul(p, &p, 0); 1690 1691 len = p-buf; 1692 if ((len < left) && *p && !isspace(*p)) 1693 break; 1694 if (neg) 1695 val = -val; 1696 s += len; 1697 left -= len; 1698 1699 if (conv(&neg, &lval, i, 1, data)) 1700 break; 1701 } else { 1702 p = buf; 1703 if (!first) 1704 *p++ = '\t'; 1705 1706 if (conv(&neg, &lval, i, 0, data)) 1707 break; 1708 1709 sprintf(p, "%s%lu", neg ? "-" : "", lval); 1710 len = strlen(buf); 1711 if (len > left) 1712 len = left; 1713 if(copy_to_user(s, buf, len)) 1714 return -EFAULT; 1715 left -= len; 1716 s += len; 1717 } 1718 } 1719 1720 if (!write && !first && left) { 1721 if(put_user('\n', s)) 1722 return -EFAULT; 1723 left--, s++; 1724 } 1725 if (write) { 1726 while (left) { 1727 char c; 1728 if (get_user(c, s++)) 1729 return -EFAULT; 1730 if (!isspace(c)) 1731 break; 1732 left--; 1733 } 1734 } 1735 if (write && first) 1736 return -EINVAL; 1737 *lenp -= left; 1738 *ppos += *lenp; 1739 return 0; 1740 #undef TMPBUFLEN 1741 } 1742 1743 static int do_proc_dointvec(ctl_table *table, int write, struct file *filp, 1744 void __user *buffer, size_t *lenp, loff_t *ppos, 1745 int (*conv)(int *negp, unsigned long *lvalp, int *valp, 1746 int write, void *data), 1747 void *data) 1748 { 1749 return __do_proc_dointvec(table->data, table, write, filp, 1750 buffer, lenp, ppos, conv, data); 1751 } 1752 1753 /** 1754 * proc_dointvec - read a vector of integers 1755 * @table: the sysctl table 1756 * @write: %TRUE if this is a write to the sysctl file 1757 * @filp: the file structure 1758 * @buffer: the user buffer 1759 * @lenp: the size of the user buffer 1760 * @ppos: file position 1761 * 1762 * Reads/writes up to table->maxlen/sizeof(unsigned int) integer 1763 * values from/to the user buffer, treated as an ASCII string. 1764 * 1765 * Returns 0 on success. 1766 */ 1767 int proc_dointvec(ctl_table *table, int write, struct file *filp, 1768 void __user *buffer, size_t *lenp, loff_t *ppos) 1769 { 1770 return do_proc_dointvec(table,write,filp,buffer,lenp,ppos, 1771 NULL,NULL); 1772 } 1773 1774 #define OP_SET 0 1775 #define OP_AND 1 1776 #define OP_OR 2 1777 1778 static int do_proc_dointvec_bset_conv(int *negp, unsigned long *lvalp, 1779 int *valp, 1780 int write, void *data) 1781 { 1782 int op = *(int *)data; 1783 if (write) { 1784 int val = *negp ? -*lvalp : *lvalp; 1785 switch(op) { 1786 case OP_SET: *valp = val; break; 1787 case OP_AND: *valp &= val; break; 1788 case OP_OR: *valp |= val; break; 1789 } 1790 } else { 1791 int val = *valp; 1792 if (val < 0) { 1793 *negp = -1; 1794 *lvalp = (unsigned long)-val; 1795 } else { 1796 *negp = 0; 1797 *lvalp = (unsigned long)val; 1798 } 1799 } 1800 return 0; 1801 } 1802 1803 /* 1804 * init may raise the set. 1805 */ 1806 1807 int proc_dointvec_bset(ctl_table *table, int write, struct file *filp, 1808 void __user *buffer, size_t *lenp, loff_t *ppos) 1809 { 1810 int op; 1811 1812 if (write && !capable(CAP_SYS_MODULE)) { 1813 return -EPERM; 1814 } 1815 1816 op = is_init(current) ? OP_SET : OP_AND; 1817 return do_proc_dointvec(table,write,filp,buffer,lenp,ppos, 1818 do_proc_dointvec_bset_conv,&op); 1819 } 1820 1821 /* 1822 * Taint values can only be increased 1823 */ 1824 static int proc_dointvec_taint(ctl_table *table, int write, struct file *filp, 1825 void __user *buffer, size_t *lenp, loff_t *ppos) 1826 { 1827 int op; 1828 1829 if (write && !capable(CAP_SYS_ADMIN)) 1830 return -EPERM; 1831 1832 op = OP_OR; 1833 return do_proc_dointvec(table,write,filp,buffer,lenp,ppos, 1834 do_proc_dointvec_bset_conv,&op); 1835 } 1836 1837 struct do_proc_dointvec_minmax_conv_param { 1838 int *min; 1839 int *max; 1840 }; 1841 1842 static int do_proc_dointvec_minmax_conv(int *negp, unsigned long *lvalp, 1843 int *valp, 1844 int write, void *data) 1845 { 1846 struct do_proc_dointvec_minmax_conv_param *param = data; 1847 if (write) { 1848 int val = *negp ? -*lvalp : *lvalp; 1849 if ((param->min && *param->min > val) || 1850 (param->max && *param->max < val)) 1851 return -EINVAL; 1852 *valp = val; 1853 } else { 1854 int val = *valp; 1855 if (val < 0) { 1856 *negp = -1; 1857 *lvalp = (unsigned long)-val; 1858 } else { 1859 *negp = 0; 1860 *lvalp = (unsigned long)val; 1861 } 1862 } 1863 return 0; 1864 } 1865 1866 /** 1867 * proc_dointvec_minmax - read a vector of integers with min/max values 1868 * @table: the sysctl table 1869 * @write: %TRUE if this is a write to the sysctl file 1870 * @filp: the file structure 1871 * @buffer: the user buffer 1872 * @lenp: the size of the user buffer 1873 * @ppos: file position 1874 * 1875 * Reads/writes up to table->maxlen/sizeof(unsigned int) integer 1876 * values from/to the user buffer, treated as an ASCII string. 1877 * 1878 * This routine will ensure the values are within the range specified by 1879 * table->extra1 (min) and table->extra2 (max). 1880 * 1881 * Returns 0 on success. 1882 */ 1883 int proc_dointvec_minmax(ctl_table *table, int write, struct file *filp, 1884 void __user *buffer, size_t *lenp, loff_t *ppos) 1885 { 1886 struct do_proc_dointvec_minmax_conv_param param = { 1887 .min = (int *) table->extra1, 1888 .max = (int *) table->extra2, 1889 }; 1890 return do_proc_dointvec(table, write, filp, buffer, lenp, ppos, 1891 do_proc_dointvec_minmax_conv, ¶m); 1892 } 1893 1894 static int __do_proc_doulongvec_minmax(void *data, ctl_table *table, int write, 1895 struct file *filp, 1896 void __user *buffer, 1897 size_t *lenp, loff_t *ppos, 1898 unsigned long convmul, 1899 unsigned long convdiv) 1900 { 1901 #define TMPBUFLEN 21 1902 unsigned long *i, *min, *max, val; 1903 int vleft, first=1, neg; 1904 size_t len, left; 1905 char buf[TMPBUFLEN], *p; 1906 char __user *s = buffer; 1907 1908 if (!data || !table->maxlen || !*lenp || 1909 (*ppos && !write)) { 1910 *lenp = 0; 1911 return 0; 1912 } 1913 1914 i = (unsigned long *) data; 1915 min = (unsigned long *) table->extra1; 1916 max = (unsigned long *) table->extra2; 1917 vleft = table->maxlen / sizeof(unsigned long); 1918 left = *lenp; 1919 1920 for (; left && vleft--; i++, min++, max++, first=0) { 1921 if (write) { 1922 while (left) { 1923 char c; 1924 if (get_user(c, s)) 1925 return -EFAULT; 1926 if (!isspace(c)) 1927 break; 1928 left--; 1929 s++; 1930 } 1931 if (!left) 1932 break; 1933 neg = 0; 1934 len = left; 1935 if (len > TMPBUFLEN-1) 1936 len = TMPBUFLEN-1; 1937 if (copy_from_user(buf, s, len)) 1938 return -EFAULT; 1939 buf[len] = 0; 1940 p = buf; 1941 if (*p == '-' && left > 1) { 1942 neg = 1; 1943 p++; 1944 } 1945 if (*p < '0' || *p > '9') 1946 break; 1947 val = simple_strtoul(p, &p, 0) * convmul / convdiv ; 1948 len = p-buf; 1949 if ((len < left) && *p && !isspace(*p)) 1950 break; 1951 if (neg) 1952 val = -val; 1953 s += len; 1954 left -= len; 1955 1956 if(neg) 1957 continue; 1958 if ((min && val < *min) || (max && val > *max)) 1959 continue; 1960 *i = val; 1961 } else { 1962 p = buf; 1963 if (!first) 1964 *p++ = '\t'; 1965 sprintf(p, "%lu", convdiv * (*i) / convmul); 1966 len = strlen(buf); 1967 if (len > left) 1968 len = left; 1969 if(copy_to_user(s, buf, len)) 1970 return -EFAULT; 1971 left -= len; 1972 s += len; 1973 } 1974 } 1975 1976 if (!write && !first && left) { 1977 if(put_user('\n', s)) 1978 return -EFAULT; 1979 left--, s++; 1980 } 1981 if (write) { 1982 while (left) { 1983 char c; 1984 if (get_user(c, s++)) 1985 return -EFAULT; 1986 if (!isspace(c)) 1987 break; 1988 left--; 1989 } 1990 } 1991 if (write && first) 1992 return -EINVAL; 1993 *lenp -= left; 1994 *ppos += *lenp; 1995 return 0; 1996 #undef TMPBUFLEN 1997 } 1998 1999 static int do_proc_doulongvec_minmax(ctl_table *table, int write, 2000 struct file *filp, 2001 void __user *buffer, 2002 size_t *lenp, loff_t *ppos, 2003 unsigned long convmul, 2004 unsigned long convdiv) 2005 { 2006 return __do_proc_doulongvec_minmax(table->data, table, write, 2007 filp, buffer, lenp, ppos, convmul, convdiv); 2008 } 2009 2010 /** 2011 * proc_doulongvec_minmax - read a vector of long integers with min/max values 2012 * @table: the sysctl table 2013 * @write: %TRUE if this is a write to the sysctl file 2014 * @filp: the file structure 2015 * @buffer: the user buffer 2016 * @lenp: the size of the user buffer 2017 * @ppos: file position 2018 * 2019 * Reads/writes up to table->maxlen/sizeof(unsigned long) unsigned long 2020 * values from/to the user buffer, treated as an ASCII string. 2021 * 2022 * This routine will ensure the values are within the range specified by 2023 * table->extra1 (min) and table->extra2 (max). 2024 * 2025 * Returns 0 on success. 2026 */ 2027 int proc_doulongvec_minmax(ctl_table *table, int write, struct file *filp, 2028 void __user *buffer, size_t *lenp, loff_t *ppos) 2029 { 2030 return do_proc_doulongvec_minmax(table, write, filp, buffer, lenp, ppos, 1l, 1l); 2031 } 2032 2033 /** 2034 * proc_doulongvec_ms_jiffies_minmax - read a vector of millisecond values with min/max values 2035 * @table: the sysctl table 2036 * @write: %TRUE if this is a write to the sysctl file 2037 * @filp: the file structure 2038 * @buffer: the user buffer 2039 * @lenp: the size of the user buffer 2040 * @ppos: file position 2041 * 2042 * Reads/writes up to table->maxlen/sizeof(unsigned long) unsigned long 2043 * values from/to the user buffer, treated as an ASCII string. The values 2044 * are treated as milliseconds, and converted to jiffies when they are stored. 2045 * 2046 * This routine will ensure the values are within the range specified by 2047 * table->extra1 (min) and table->extra2 (max). 2048 * 2049 * Returns 0 on success. 2050 */ 2051 int proc_doulongvec_ms_jiffies_minmax(ctl_table *table, int write, 2052 struct file *filp, 2053 void __user *buffer, 2054 size_t *lenp, loff_t *ppos) 2055 { 2056 return do_proc_doulongvec_minmax(table, write, filp, buffer, 2057 lenp, ppos, HZ, 1000l); 2058 } 2059 2060 2061 static int do_proc_dointvec_jiffies_conv(int *negp, unsigned long *lvalp, 2062 int *valp, 2063 int write, void *data) 2064 { 2065 if (write) { 2066 if (*lvalp > LONG_MAX / HZ) 2067 return 1; 2068 *valp = *negp ? -(*lvalp*HZ) : (*lvalp*HZ); 2069 } else { 2070 int val = *valp; 2071 unsigned long lval; 2072 if (val < 0) { 2073 *negp = -1; 2074 lval = (unsigned long)-val; 2075 } else { 2076 *negp = 0; 2077 lval = (unsigned long)val; 2078 } 2079 *lvalp = lval / HZ; 2080 } 2081 return 0; 2082 } 2083 2084 static int do_proc_dointvec_userhz_jiffies_conv(int *negp, unsigned long *lvalp, 2085 int *valp, 2086 int write, void *data) 2087 { 2088 if (write) { 2089 if (USER_HZ < HZ && *lvalp > (LONG_MAX / HZ) * USER_HZ) 2090 return 1; 2091 *valp = clock_t_to_jiffies(*negp ? -*lvalp : *lvalp); 2092 } else { 2093 int val = *valp; 2094 unsigned long lval; 2095 if (val < 0) { 2096 *negp = -1; 2097 lval = (unsigned long)-val; 2098 } else { 2099 *negp = 0; 2100 lval = (unsigned long)val; 2101 } 2102 *lvalp = jiffies_to_clock_t(lval); 2103 } 2104 return 0; 2105 } 2106 2107 static int do_proc_dointvec_ms_jiffies_conv(int *negp, unsigned long *lvalp, 2108 int *valp, 2109 int write, void *data) 2110 { 2111 if (write) { 2112 *valp = msecs_to_jiffies(*negp ? -*lvalp : *lvalp); 2113 } else { 2114 int val = *valp; 2115 unsigned long lval; 2116 if (val < 0) { 2117 *negp = -1; 2118 lval = (unsigned long)-val; 2119 } else { 2120 *negp = 0; 2121 lval = (unsigned long)val; 2122 } 2123 *lvalp = jiffies_to_msecs(lval); 2124 } 2125 return 0; 2126 } 2127 2128 /** 2129 * proc_dointvec_jiffies - read a vector of integers as seconds 2130 * @table: the sysctl table 2131 * @write: %TRUE if this is a write to the sysctl file 2132 * @filp: the file structure 2133 * @buffer: the user buffer 2134 * @lenp: the size of the user buffer 2135 * @ppos: file position 2136 * 2137 * Reads/writes up to table->maxlen/sizeof(unsigned int) integer 2138 * values from/to the user buffer, treated as an ASCII string. 2139 * The values read are assumed to be in seconds, and are converted into 2140 * jiffies. 2141 * 2142 * Returns 0 on success. 2143 */ 2144 int proc_dointvec_jiffies(ctl_table *table, int write, struct file *filp, 2145 void __user *buffer, size_t *lenp, loff_t *ppos) 2146 { 2147 return do_proc_dointvec(table,write,filp,buffer,lenp,ppos, 2148 do_proc_dointvec_jiffies_conv,NULL); 2149 } 2150 2151 /** 2152 * proc_dointvec_userhz_jiffies - read a vector of integers as 1/USER_HZ seconds 2153 * @table: the sysctl table 2154 * @write: %TRUE if this is a write to the sysctl file 2155 * @filp: the file structure 2156 * @buffer: the user buffer 2157 * @lenp: the size of the user buffer 2158 * @ppos: pointer to the file position 2159 * 2160 * Reads/writes up to table->maxlen/sizeof(unsigned int) integer 2161 * values from/to the user buffer, treated as an ASCII string. 2162 * The values read are assumed to be in 1/USER_HZ seconds, and 2163 * are converted into jiffies. 2164 * 2165 * Returns 0 on success. 2166 */ 2167 int proc_dointvec_userhz_jiffies(ctl_table *table, int write, struct file *filp, 2168 void __user *buffer, size_t *lenp, loff_t *ppos) 2169 { 2170 return do_proc_dointvec(table,write,filp,buffer,lenp,ppos, 2171 do_proc_dointvec_userhz_jiffies_conv,NULL); 2172 } 2173 2174 /** 2175 * proc_dointvec_ms_jiffies - read a vector of integers as 1 milliseconds 2176 * @table: the sysctl table 2177 * @write: %TRUE if this is a write to the sysctl file 2178 * @filp: the file structure 2179 * @buffer: the user buffer 2180 * @lenp: the size of the user buffer 2181 * @ppos: file position 2182 * @ppos: the current position in the file 2183 * 2184 * Reads/writes up to table->maxlen/sizeof(unsigned int) integer 2185 * values from/to the user buffer, treated as an ASCII string. 2186 * The values read are assumed to be in 1/1000 seconds, and 2187 * are converted into jiffies. 2188 * 2189 * Returns 0 on success. 2190 */ 2191 int proc_dointvec_ms_jiffies(ctl_table *table, int write, struct file *filp, 2192 void __user *buffer, size_t *lenp, loff_t *ppos) 2193 { 2194 return do_proc_dointvec(table, write, filp, buffer, lenp, ppos, 2195 do_proc_dointvec_ms_jiffies_conv, NULL); 2196 } 2197 2198 static int proc_do_cad_pid(ctl_table *table, int write, struct file *filp, 2199 void __user *buffer, size_t *lenp, loff_t *ppos) 2200 { 2201 struct pid *new_pid; 2202 pid_t tmp; 2203 int r; 2204 2205 tmp = pid_nr(cad_pid); 2206 2207 r = __do_proc_dointvec(&tmp, table, write, filp, buffer, 2208 lenp, ppos, NULL, NULL); 2209 if (r || !write) 2210 return r; 2211 2212 new_pid = find_get_pid(tmp); 2213 if (!new_pid) 2214 return -ESRCH; 2215 2216 put_pid(xchg(&cad_pid, new_pid)); 2217 return 0; 2218 } 2219 2220 #else /* CONFIG_PROC_FS */ 2221 2222 int proc_dostring(ctl_table *table, int write, struct file *filp, 2223 void __user *buffer, size_t *lenp, loff_t *ppos) 2224 { 2225 return -ENOSYS; 2226 } 2227 2228 int proc_dointvec(ctl_table *table, int write, struct file *filp, 2229 void __user *buffer, size_t *lenp, loff_t *ppos) 2230 { 2231 return -ENOSYS; 2232 } 2233 2234 int proc_dointvec_bset(ctl_table *table, int write, struct file *filp, 2235 void __user *buffer, size_t *lenp, loff_t *ppos) 2236 { 2237 return -ENOSYS; 2238 } 2239 2240 int proc_dointvec_minmax(ctl_table *table, int write, struct file *filp, 2241 void __user *buffer, size_t *lenp, loff_t *ppos) 2242 { 2243 return -ENOSYS; 2244 } 2245 2246 int proc_dointvec_jiffies(ctl_table *table, int write, struct file *filp, 2247 void __user *buffer, size_t *lenp, loff_t *ppos) 2248 { 2249 return -ENOSYS; 2250 } 2251 2252 int proc_dointvec_userhz_jiffies(ctl_table *table, int write, struct file *filp, 2253 void __user *buffer, size_t *lenp, loff_t *ppos) 2254 { 2255 return -ENOSYS; 2256 } 2257 2258 int proc_dointvec_ms_jiffies(ctl_table *table, int write, struct file *filp, 2259 void __user *buffer, size_t *lenp, loff_t *ppos) 2260 { 2261 return -ENOSYS; 2262 } 2263 2264 int proc_doulongvec_minmax(ctl_table *table, int write, struct file *filp, 2265 void __user *buffer, size_t *lenp, loff_t *ppos) 2266 { 2267 return -ENOSYS; 2268 } 2269 2270 int proc_doulongvec_ms_jiffies_minmax(ctl_table *table, int write, 2271 struct file *filp, 2272 void __user *buffer, 2273 size_t *lenp, loff_t *ppos) 2274 { 2275 return -ENOSYS; 2276 } 2277 2278 2279 #endif /* CONFIG_PROC_FS */ 2280 2281 2282 #ifdef CONFIG_SYSCTL_SYSCALL 2283 /* 2284 * General sysctl support routines 2285 */ 2286 2287 /* The generic string strategy routine: */ 2288 int sysctl_string(ctl_table *table, int __user *name, int nlen, 2289 void __user *oldval, size_t __user *oldlenp, 2290 void __user *newval, size_t newlen) 2291 { 2292 if (!table->data || !table->maxlen) 2293 return -ENOTDIR; 2294 2295 if (oldval && oldlenp) { 2296 size_t bufsize; 2297 if (get_user(bufsize, oldlenp)) 2298 return -EFAULT; 2299 if (bufsize) { 2300 size_t len = strlen(table->data), copied; 2301 2302 /* This shouldn't trigger for a well-formed sysctl */ 2303 if (len > table->maxlen) 2304 len = table->maxlen; 2305 2306 /* Copy up to a max of bufsize-1 bytes of the string */ 2307 copied = (len >= bufsize) ? bufsize - 1 : len; 2308 2309 if (copy_to_user(oldval, table->data, copied) || 2310 put_user(0, (char __user *)(oldval + copied))) 2311 return -EFAULT; 2312 if (put_user(len, oldlenp)) 2313 return -EFAULT; 2314 } 2315 } 2316 if (newval && newlen) { 2317 size_t len = newlen; 2318 if (len > table->maxlen) 2319 len = table->maxlen; 2320 if(copy_from_user(table->data, newval, len)) 2321 return -EFAULT; 2322 if (len == table->maxlen) 2323 len--; 2324 ((char *) table->data)[len] = 0; 2325 } 2326 return 1; 2327 } 2328 2329 /* 2330 * This function makes sure that all of the integers in the vector 2331 * are between the minimum and maximum values given in the arrays 2332 * table->extra1 and table->extra2, respectively. 2333 */ 2334 int sysctl_intvec(ctl_table *table, int __user *name, int nlen, 2335 void __user *oldval, size_t __user *oldlenp, 2336 void __user *newval, size_t newlen) 2337 { 2338 2339 if (newval && newlen) { 2340 int __user *vec = (int __user *) newval; 2341 int *min = (int *) table->extra1; 2342 int *max = (int *) table->extra2; 2343 size_t length; 2344 int i; 2345 2346 if (newlen % sizeof(int) != 0) 2347 return -EINVAL; 2348 2349 if (!table->extra1 && !table->extra2) 2350 return 0; 2351 2352 if (newlen > table->maxlen) 2353 newlen = table->maxlen; 2354 length = newlen / sizeof(int); 2355 2356 for (i = 0; i < length; i++) { 2357 int value; 2358 if (get_user(value, vec + i)) 2359 return -EFAULT; 2360 if (min && value < min[i]) 2361 return -EINVAL; 2362 if (max && value > max[i]) 2363 return -EINVAL; 2364 } 2365 } 2366 return 0; 2367 } 2368 2369 /* Strategy function to convert jiffies to seconds */ 2370 int sysctl_jiffies(ctl_table *table, int __user *name, int nlen, 2371 void __user *oldval, size_t __user *oldlenp, 2372 void __user *newval, size_t newlen) 2373 { 2374 if (oldval && oldlenp) { 2375 size_t olen; 2376 2377 if (get_user(olen, oldlenp)) 2378 return -EFAULT; 2379 if (olen) { 2380 int val; 2381 2382 if (olen < sizeof(int)) 2383 return -EINVAL; 2384 2385 val = *(int *)(table->data) / HZ; 2386 if (put_user(val, (int __user *)oldval)) 2387 return -EFAULT; 2388 if (put_user(sizeof(int), oldlenp)) 2389 return -EFAULT; 2390 } 2391 } 2392 if (newval && newlen) { 2393 int new; 2394 if (newlen != sizeof(int)) 2395 return -EINVAL; 2396 if (get_user(new, (int __user *)newval)) 2397 return -EFAULT; 2398 *(int *)(table->data) = new*HZ; 2399 } 2400 return 1; 2401 } 2402 2403 /* Strategy function to convert jiffies to seconds */ 2404 int sysctl_ms_jiffies(ctl_table *table, int __user *name, int nlen, 2405 void __user *oldval, size_t __user *oldlenp, 2406 void __user *newval, size_t newlen) 2407 { 2408 if (oldval && oldlenp) { 2409 size_t olen; 2410 2411 if (get_user(olen, oldlenp)) 2412 return -EFAULT; 2413 if (olen) { 2414 int val; 2415 2416 if (olen < sizeof(int)) 2417 return -EINVAL; 2418 2419 val = jiffies_to_msecs(*(int *)(table->data)); 2420 if (put_user(val, (int __user *)oldval)) 2421 return -EFAULT; 2422 if (put_user(sizeof(int), oldlenp)) 2423 return -EFAULT; 2424 } 2425 } 2426 if (newval && newlen) { 2427 int new; 2428 if (newlen != sizeof(int)) 2429 return -EINVAL; 2430 if (get_user(new, (int __user *)newval)) 2431 return -EFAULT; 2432 *(int *)(table->data) = msecs_to_jiffies(new); 2433 } 2434 return 1; 2435 } 2436 2437 2438 2439 #else /* CONFIG_SYSCTL_SYSCALL */ 2440 2441 2442 asmlinkage long sys_sysctl(struct __sysctl_args __user *args) 2443 { 2444 static int msg_count; 2445 struct __sysctl_args tmp; 2446 int name[CTL_MAXNAME]; 2447 int i; 2448 2449 /* Read in the sysctl name for better debug message logging */ 2450 if (copy_from_user(&tmp, args, sizeof(tmp))) 2451 return -EFAULT; 2452 if (tmp.nlen <= 0 || tmp.nlen >= CTL_MAXNAME) 2453 return -ENOTDIR; 2454 for (i = 0; i < tmp.nlen; i++) 2455 if (get_user(name[i], tmp.name + i)) 2456 return -EFAULT; 2457 2458 /* Ignore accesses to kernel.version */ 2459 if ((tmp.nlen == 2) && (name[0] == CTL_KERN) && (name[1] == KERN_VERSION)) 2460 goto out; 2461 2462 if (msg_count < 5) { 2463 msg_count++; 2464 printk(KERN_INFO 2465 "warning: process `%s' used the removed sysctl " 2466 "system call with ", current->comm); 2467 for (i = 0; i < tmp.nlen; i++) 2468 printk("%d.", name[i]); 2469 printk("\n"); 2470 } 2471 out: 2472 return -ENOSYS; 2473 } 2474 2475 int sysctl_string(ctl_table *table, int __user *name, int nlen, 2476 void __user *oldval, size_t __user *oldlenp, 2477 void __user *newval, size_t newlen) 2478 { 2479 return -ENOSYS; 2480 } 2481 2482 int sysctl_intvec(ctl_table *table, int __user *name, int nlen, 2483 void __user *oldval, size_t __user *oldlenp, 2484 void __user *newval, size_t newlen) 2485 { 2486 return -ENOSYS; 2487 } 2488 2489 int sysctl_jiffies(ctl_table *table, int __user *name, int nlen, 2490 void __user *oldval, size_t __user *oldlenp, 2491 void __user *newval, size_t newlen) 2492 { 2493 return -ENOSYS; 2494 } 2495 2496 int sysctl_ms_jiffies(ctl_table *table, int __user *name, int nlen, 2497 void __user *oldval, size_t __user *oldlenp, 2498 void __user *newval, size_t newlen) 2499 { 2500 return -ENOSYS; 2501 } 2502 2503 #endif /* CONFIG_SYSCTL_SYSCALL */ 2504 2505 /* 2506 * No sense putting this after each symbol definition, twice, 2507 * exception granted :-) 2508 */ 2509 EXPORT_SYMBOL(proc_dointvec); 2510 EXPORT_SYMBOL(proc_dointvec_jiffies); 2511 EXPORT_SYMBOL(proc_dointvec_minmax); 2512 EXPORT_SYMBOL(proc_dointvec_userhz_jiffies); 2513 EXPORT_SYMBOL(proc_dointvec_ms_jiffies); 2514 EXPORT_SYMBOL(proc_dostring); 2515 EXPORT_SYMBOL(proc_doulongvec_minmax); 2516 EXPORT_SYMBOL(proc_doulongvec_ms_jiffies_minmax); 2517 EXPORT_SYMBOL(register_sysctl_table); 2518 EXPORT_SYMBOL(sysctl_intvec); 2519 EXPORT_SYMBOL(sysctl_jiffies); 2520 EXPORT_SYMBOL(sysctl_ms_jiffies); 2521 EXPORT_SYMBOL(sysctl_string); 2522 EXPORT_SYMBOL(unregister_sysctl_table); 2523