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/init.h> 33 #include <linux/kernel.h> 34 #include <linux/kobject.h> 35 #include <linux/net.h> 36 #include <linux/sysrq.h> 37 #include <linux/highuid.h> 38 #include <linux/writeback.h> 39 #include <linux/hugetlb.h> 40 #include <linux/security.h> 41 #include <linux/initrd.h> 42 #include <linux/times.h> 43 #include <linux/limits.h> 44 #include <linux/dcache.h> 45 #include <linux/syscalls.h> 46 #include <linux/nfs_fs.h> 47 #include <linux/acpi.h> 48 49 #include <asm/uaccess.h> 50 #include <asm/processor.h> 51 52 extern int proc_nr_files(ctl_table *table, int write, struct file *filp, 53 void __user *buffer, size_t *lenp, loff_t *ppos); 54 55 #ifdef CONFIG_X86 56 #include <asm/nmi.h> 57 #include <asm/stacktrace.h> 58 #endif 59 60 #if defined(CONFIG_SYSCTL) 61 62 /* External variables not in a header file. */ 63 extern int C_A_D; 64 extern int sysctl_overcommit_memory; 65 extern int sysctl_overcommit_ratio; 66 extern int sysctl_panic_on_oom; 67 extern int max_threads; 68 extern int core_uses_pid; 69 extern int suid_dumpable; 70 extern char core_pattern[]; 71 extern int pid_max; 72 extern int min_free_kbytes; 73 extern int printk_ratelimit_jiffies; 74 extern int printk_ratelimit_burst; 75 extern int pid_max_min, pid_max_max; 76 extern int sysctl_drop_caches; 77 extern int percpu_pagelist_fraction; 78 extern int compat_log; 79 80 /* this is needed for the proc_dointvec_minmax for [fs_]overflow UID and GID */ 81 static int maxolduid = 65535; 82 static int minolduid; 83 static int min_percpu_pagelist_fract = 8; 84 85 static int ngroups_max = NGROUPS_MAX; 86 87 #ifdef CONFIG_KMOD 88 extern char modprobe_path[]; 89 #endif 90 #ifdef CONFIG_CHR_DEV_SG 91 extern int sg_big_buff; 92 #endif 93 #ifdef CONFIG_SYSVIPC 94 static int proc_ipc_dointvec(ctl_table *table, int write, struct file *filp, 95 void __user *buffer, size_t *lenp, loff_t *ppos); 96 static int proc_ipc_doulongvec_minmax(ctl_table *table, int write, struct file *filp, 97 void __user *buffer, size_t *lenp, loff_t *ppos); 98 #endif 99 100 #ifdef __sparc__ 101 extern char reboot_command []; 102 extern int stop_a_enabled; 103 extern int scons_pwroff; 104 #endif 105 106 #ifdef __hppa__ 107 extern int pwrsw_enabled; 108 extern int unaligned_enabled; 109 #endif 110 111 #ifdef CONFIG_S390 112 #ifdef CONFIG_MATHEMU 113 extern int sysctl_ieee_emulation_warnings; 114 #endif 115 extern int sysctl_userprocess_debug; 116 extern int spin_retry; 117 #endif 118 119 extern int sysctl_hz_timer; 120 121 #ifdef CONFIG_BSD_PROCESS_ACCT 122 extern int acct_parm[]; 123 #endif 124 125 #ifdef CONFIG_IA64 126 extern int no_unaligned_warning; 127 #endif 128 129 #ifdef CONFIG_RT_MUTEXES 130 extern int max_lock_depth; 131 #endif 132 133 #ifdef CONFIG_SYSCTL_SYSCALL 134 static int parse_table(int __user *, int, void __user *, size_t __user *, 135 void __user *, size_t, ctl_table *); 136 #endif 137 138 static int proc_do_uts_string(ctl_table *table, int write, struct file *filp, 139 void __user *buffer, size_t *lenp, loff_t *ppos); 140 141 static int sysctl_uts_string(ctl_table *table, int __user *name, int nlen, 142 void __user *oldval, size_t __user *oldlenp, 143 void __user *newval, size_t newlen); 144 145 #ifdef CONFIG_SYSVIPC 146 static int sysctl_ipc_data(ctl_table *table, int __user *name, int nlen, 147 void __user *oldval, size_t __user *oldlenp, 148 void __user *newval, size_t newlen); 149 #endif 150 151 #ifdef CONFIG_PROC_SYSCTL 152 static int proc_do_cad_pid(ctl_table *table, int write, struct file *filp, 153 void __user *buffer, size_t *lenp, loff_t *ppos); 154 static int proc_dointvec_taint(ctl_table *table, int write, struct file *filp, 155 void __user *buffer, size_t *lenp, loff_t *ppos); 156 #endif 157 158 static ctl_table root_table[]; 159 static struct ctl_table_header root_table_header = 160 { root_table, LIST_HEAD_INIT(root_table_header.ctl_entry) }; 161 162 static ctl_table kern_table[]; 163 static ctl_table vm_table[]; 164 static ctl_table fs_table[]; 165 static ctl_table debug_table[]; 166 static ctl_table dev_table[]; 167 extern ctl_table random_table[]; 168 #ifdef CONFIG_UNIX98_PTYS 169 extern ctl_table pty_table[]; 170 #endif 171 #ifdef CONFIG_INOTIFY_USER 172 extern ctl_table inotify_table[]; 173 #endif 174 175 #ifdef HAVE_ARCH_PICK_MMAP_LAYOUT 176 int sysctl_legacy_va_layout; 177 #endif 178 179 180 static void *get_uts(ctl_table *table, int write) 181 { 182 char *which = table->data; 183 #ifdef CONFIG_UTS_NS 184 struct uts_namespace *uts_ns = current->nsproxy->uts_ns; 185 which = (which - (char *)&init_uts_ns) + (char *)uts_ns; 186 #endif 187 if (!write) 188 down_read(&uts_sem); 189 else 190 down_write(&uts_sem); 191 return which; 192 } 193 194 static void put_uts(ctl_table *table, int write, void *which) 195 { 196 if (!write) 197 up_read(&uts_sem); 198 else 199 up_write(&uts_sem); 200 } 201 202 #ifdef CONFIG_SYSVIPC 203 static void *get_ipc(ctl_table *table, int write) 204 { 205 char *which = table->data; 206 struct ipc_namespace *ipc_ns = current->nsproxy->ipc_ns; 207 which = (which - (char *)&init_ipc_ns) + (char *)ipc_ns; 208 return which; 209 } 210 #else 211 #define get_ipc(T,W) ((T)->data) 212 #endif 213 214 /* /proc declarations: */ 215 216 #ifdef CONFIG_PROC_SYSCTL 217 218 static ssize_t proc_readsys(struct file *, char __user *, size_t, loff_t *); 219 static ssize_t proc_writesys(struct file *, const char __user *, size_t, loff_t *); 220 static int proc_opensys(struct inode *, struct file *); 221 222 const struct file_operations proc_sys_file_operations = { 223 .open = proc_opensys, 224 .read = proc_readsys, 225 .write = proc_writesys, 226 }; 227 228 extern struct proc_dir_entry *proc_sys_root; 229 230 static void register_proc_table(ctl_table *, struct proc_dir_entry *, void *); 231 static void unregister_proc_table(ctl_table *, struct proc_dir_entry *); 232 #endif 233 234 /* The default sysctl tables: */ 235 236 static ctl_table root_table[] = { 237 { 238 .ctl_name = CTL_KERN, 239 .procname = "kernel", 240 .mode = 0555, 241 .child = kern_table, 242 }, 243 { 244 .ctl_name = CTL_VM, 245 .procname = "vm", 246 .mode = 0555, 247 .child = vm_table, 248 }, 249 #ifdef CONFIG_NET 250 { 251 .ctl_name = CTL_NET, 252 .procname = "net", 253 .mode = 0555, 254 .child = net_table, 255 }, 256 #endif 257 { 258 .ctl_name = CTL_FS, 259 .procname = "fs", 260 .mode = 0555, 261 .child = fs_table, 262 }, 263 { 264 .ctl_name = CTL_DEBUG, 265 .procname = "debug", 266 .mode = 0555, 267 .child = debug_table, 268 }, 269 { 270 .ctl_name = CTL_DEV, 271 .procname = "dev", 272 .mode = 0555, 273 .child = dev_table, 274 }, 275 276 { .ctl_name = 0 } 277 }; 278 279 static ctl_table kern_table[] = { 280 { 281 .ctl_name = KERN_OSTYPE, 282 .procname = "ostype", 283 .data = init_uts_ns.name.sysname, 284 .maxlen = sizeof(init_uts_ns.name.sysname), 285 .mode = 0444, 286 .proc_handler = &proc_do_uts_string, 287 .strategy = &sysctl_uts_string, 288 }, 289 { 290 .ctl_name = KERN_OSRELEASE, 291 .procname = "osrelease", 292 .data = init_uts_ns.name.release, 293 .maxlen = sizeof(init_uts_ns.name.release), 294 .mode = 0444, 295 .proc_handler = &proc_do_uts_string, 296 .strategy = &sysctl_uts_string, 297 }, 298 { 299 .ctl_name = KERN_VERSION, 300 .procname = "version", 301 .data = init_uts_ns.name.version, 302 .maxlen = sizeof(init_uts_ns.name.version), 303 .mode = 0444, 304 .proc_handler = &proc_do_uts_string, 305 .strategy = &sysctl_uts_string, 306 }, 307 { 308 .ctl_name = KERN_NODENAME, 309 .procname = "hostname", 310 .data = init_uts_ns.name.nodename, 311 .maxlen = sizeof(init_uts_ns.name.nodename), 312 .mode = 0644, 313 .proc_handler = &proc_do_uts_string, 314 .strategy = &sysctl_uts_string, 315 }, 316 { 317 .ctl_name = KERN_DOMAINNAME, 318 .procname = "domainname", 319 .data = init_uts_ns.name.domainname, 320 .maxlen = sizeof(init_uts_ns.name.domainname), 321 .mode = 0644, 322 .proc_handler = &proc_do_uts_string, 323 .strategy = &sysctl_uts_string, 324 }, 325 { 326 .ctl_name = KERN_PANIC, 327 .procname = "panic", 328 .data = &panic_timeout, 329 .maxlen = sizeof(int), 330 .mode = 0644, 331 .proc_handler = &proc_dointvec, 332 }, 333 { 334 .ctl_name = KERN_CORE_USES_PID, 335 .procname = "core_uses_pid", 336 .data = &core_uses_pid, 337 .maxlen = sizeof(int), 338 .mode = 0644, 339 .proc_handler = &proc_dointvec, 340 }, 341 { 342 .ctl_name = KERN_CORE_PATTERN, 343 .procname = "core_pattern", 344 .data = core_pattern, 345 .maxlen = 128, 346 .mode = 0644, 347 .proc_handler = &proc_dostring, 348 .strategy = &sysctl_string, 349 }, 350 #ifdef CONFIG_PROC_SYSCTL 351 { 352 .ctl_name = KERN_TAINTED, 353 .procname = "tainted", 354 .data = &tainted, 355 .maxlen = sizeof(int), 356 .mode = 0644, 357 .proc_handler = &proc_dointvec_taint, 358 }, 359 #endif 360 { 361 .ctl_name = KERN_CAP_BSET, 362 .procname = "cap-bound", 363 .data = &cap_bset, 364 .maxlen = sizeof(kernel_cap_t), 365 .mode = 0600, 366 .proc_handler = &proc_dointvec_bset, 367 }, 368 #ifdef CONFIG_BLK_DEV_INITRD 369 { 370 .ctl_name = KERN_REALROOTDEV, 371 .procname = "real-root-dev", 372 .data = &real_root_dev, 373 .maxlen = sizeof(int), 374 .mode = 0644, 375 .proc_handler = &proc_dointvec, 376 }, 377 #endif 378 #ifdef __sparc__ 379 { 380 .ctl_name = KERN_SPARC_REBOOT, 381 .procname = "reboot-cmd", 382 .data = reboot_command, 383 .maxlen = 256, 384 .mode = 0644, 385 .proc_handler = &proc_dostring, 386 .strategy = &sysctl_string, 387 }, 388 { 389 .ctl_name = KERN_SPARC_STOP_A, 390 .procname = "stop-a", 391 .data = &stop_a_enabled, 392 .maxlen = sizeof (int), 393 .mode = 0644, 394 .proc_handler = &proc_dointvec, 395 }, 396 { 397 .ctl_name = KERN_SPARC_SCONS_PWROFF, 398 .procname = "scons-poweroff", 399 .data = &scons_pwroff, 400 .maxlen = sizeof (int), 401 .mode = 0644, 402 .proc_handler = &proc_dointvec, 403 }, 404 #endif 405 #ifdef __hppa__ 406 { 407 .ctl_name = KERN_HPPA_PWRSW, 408 .procname = "soft-power", 409 .data = &pwrsw_enabled, 410 .maxlen = sizeof (int), 411 .mode = 0644, 412 .proc_handler = &proc_dointvec, 413 }, 414 { 415 .ctl_name = KERN_HPPA_UNALIGNED, 416 .procname = "unaligned-trap", 417 .data = &unaligned_enabled, 418 .maxlen = sizeof (int), 419 .mode = 0644, 420 .proc_handler = &proc_dointvec, 421 }, 422 #endif 423 { 424 .ctl_name = KERN_CTLALTDEL, 425 .procname = "ctrl-alt-del", 426 .data = &C_A_D, 427 .maxlen = sizeof(int), 428 .mode = 0644, 429 .proc_handler = &proc_dointvec, 430 }, 431 { 432 .ctl_name = KERN_PRINTK, 433 .procname = "printk", 434 .data = &console_loglevel, 435 .maxlen = 4*sizeof(int), 436 .mode = 0644, 437 .proc_handler = &proc_dointvec, 438 }, 439 #ifdef CONFIG_KMOD 440 { 441 .ctl_name = KERN_MODPROBE, 442 .procname = "modprobe", 443 .data = &modprobe_path, 444 .maxlen = KMOD_PATH_LEN, 445 .mode = 0644, 446 .proc_handler = &proc_dostring, 447 .strategy = &sysctl_string, 448 }, 449 #endif 450 #if defined(CONFIG_HOTPLUG) && defined(CONFIG_NET) 451 { 452 .ctl_name = KERN_HOTPLUG, 453 .procname = "hotplug", 454 .data = &uevent_helper, 455 .maxlen = UEVENT_HELPER_PATH_LEN, 456 .mode = 0644, 457 .proc_handler = &proc_dostring, 458 .strategy = &sysctl_string, 459 }, 460 #endif 461 #ifdef CONFIG_CHR_DEV_SG 462 { 463 .ctl_name = KERN_SG_BIG_BUFF, 464 .procname = "sg-big-buff", 465 .data = &sg_big_buff, 466 .maxlen = sizeof (int), 467 .mode = 0444, 468 .proc_handler = &proc_dointvec, 469 }, 470 #endif 471 #ifdef CONFIG_BSD_PROCESS_ACCT 472 { 473 .ctl_name = KERN_ACCT, 474 .procname = "acct", 475 .data = &acct_parm, 476 .maxlen = 3*sizeof(int), 477 .mode = 0644, 478 .proc_handler = &proc_dointvec, 479 }, 480 #endif 481 #ifdef CONFIG_SYSVIPC 482 { 483 .ctl_name = KERN_SHMMAX, 484 .procname = "shmmax", 485 .data = &init_ipc_ns.shm_ctlmax, 486 .maxlen = sizeof (init_ipc_ns.shm_ctlmax), 487 .mode = 0644, 488 .proc_handler = &proc_ipc_doulongvec_minmax, 489 .strategy = sysctl_ipc_data, 490 }, 491 { 492 .ctl_name = KERN_SHMALL, 493 .procname = "shmall", 494 .data = &init_ipc_ns.shm_ctlall, 495 .maxlen = sizeof (init_ipc_ns.shm_ctlall), 496 .mode = 0644, 497 .proc_handler = &proc_ipc_doulongvec_minmax, 498 .strategy = sysctl_ipc_data, 499 }, 500 { 501 .ctl_name = KERN_SHMMNI, 502 .procname = "shmmni", 503 .data = &init_ipc_ns.shm_ctlmni, 504 .maxlen = sizeof (init_ipc_ns.shm_ctlmni), 505 .mode = 0644, 506 .proc_handler = &proc_ipc_dointvec, 507 .strategy = sysctl_ipc_data, 508 }, 509 { 510 .ctl_name = KERN_MSGMAX, 511 .procname = "msgmax", 512 .data = &init_ipc_ns.msg_ctlmax, 513 .maxlen = sizeof (init_ipc_ns.msg_ctlmax), 514 .mode = 0644, 515 .proc_handler = &proc_ipc_dointvec, 516 .strategy = sysctl_ipc_data, 517 }, 518 { 519 .ctl_name = KERN_MSGMNI, 520 .procname = "msgmni", 521 .data = &init_ipc_ns.msg_ctlmni, 522 .maxlen = sizeof (init_ipc_ns.msg_ctlmni), 523 .mode = 0644, 524 .proc_handler = &proc_ipc_dointvec, 525 .strategy = sysctl_ipc_data, 526 }, 527 { 528 .ctl_name = KERN_MSGMNB, 529 .procname = "msgmnb", 530 .data = &init_ipc_ns.msg_ctlmnb, 531 .maxlen = sizeof (init_ipc_ns.msg_ctlmnb), 532 .mode = 0644, 533 .proc_handler = &proc_ipc_dointvec, 534 .strategy = sysctl_ipc_data, 535 }, 536 { 537 .ctl_name = KERN_SEM, 538 .procname = "sem", 539 .data = &init_ipc_ns.sem_ctls, 540 .maxlen = 4*sizeof (int), 541 .mode = 0644, 542 .proc_handler = &proc_ipc_dointvec, 543 .strategy = sysctl_ipc_data, 544 }, 545 #endif 546 #ifdef CONFIG_MAGIC_SYSRQ 547 { 548 .ctl_name = KERN_SYSRQ, 549 .procname = "sysrq", 550 .data = &__sysrq_enabled, 551 .maxlen = sizeof (int), 552 .mode = 0644, 553 .proc_handler = &proc_dointvec, 554 }, 555 #endif 556 #ifdef CONFIG_PROC_SYSCTL 557 { 558 .ctl_name = KERN_CADPID, 559 .procname = "cad_pid", 560 .data = NULL, 561 .maxlen = sizeof (int), 562 .mode = 0600, 563 .proc_handler = &proc_do_cad_pid, 564 }, 565 #endif 566 { 567 .ctl_name = KERN_MAX_THREADS, 568 .procname = "threads-max", 569 .data = &max_threads, 570 .maxlen = sizeof(int), 571 .mode = 0644, 572 .proc_handler = &proc_dointvec, 573 }, 574 { 575 .ctl_name = KERN_RANDOM, 576 .procname = "random", 577 .mode = 0555, 578 .child = random_table, 579 }, 580 #ifdef CONFIG_UNIX98_PTYS 581 { 582 .ctl_name = KERN_PTY, 583 .procname = "pty", 584 .mode = 0555, 585 .child = pty_table, 586 }, 587 #endif 588 { 589 .ctl_name = KERN_OVERFLOWUID, 590 .procname = "overflowuid", 591 .data = &overflowuid, 592 .maxlen = sizeof(int), 593 .mode = 0644, 594 .proc_handler = &proc_dointvec_minmax, 595 .strategy = &sysctl_intvec, 596 .extra1 = &minolduid, 597 .extra2 = &maxolduid, 598 }, 599 { 600 .ctl_name = KERN_OVERFLOWGID, 601 .procname = "overflowgid", 602 .data = &overflowgid, 603 .maxlen = sizeof(int), 604 .mode = 0644, 605 .proc_handler = &proc_dointvec_minmax, 606 .strategy = &sysctl_intvec, 607 .extra1 = &minolduid, 608 .extra2 = &maxolduid, 609 }, 610 #ifdef CONFIG_S390 611 #ifdef CONFIG_MATHEMU 612 { 613 .ctl_name = KERN_IEEE_EMULATION_WARNINGS, 614 .procname = "ieee_emulation_warnings", 615 .data = &sysctl_ieee_emulation_warnings, 616 .maxlen = sizeof(int), 617 .mode = 0644, 618 .proc_handler = &proc_dointvec, 619 }, 620 #endif 621 #ifdef CONFIG_NO_IDLE_HZ 622 { 623 .ctl_name = KERN_HZ_TIMER, 624 .procname = "hz_timer", 625 .data = &sysctl_hz_timer, 626 .maxlen = sizeof(int), 627 .mode = 0644, 628 .proc_handler = &proc_dointvec, 629 }, 630 #endif 631 { 632 .ctl_name = KERN_S390_USER_DEBUG_LOGGING, 633 .procname = "userprocess_debug", 634 .data = &sysctl_userprocess_debug, 635 .maxlen = sizeof(int), 636 .mode = 0644, 637 .proc_handler = &proc_dointvec, 638 }, 639 #endif 640 { 641 .ctl_name = KERN_PIDMAX, 642 .procname = "pid_max", 643 .data = &pid_max, 644 .maxlen = sizeof (int), 645 .mode = 0644, 646 .proc_handler = &proc_dointvec_minmax, 647 .strategy = sysctl_intvec, 648 .extra1 = &pid_max_min, 649 .extra2 = &pid_max_max, 650 }, 651 { 652 .ctl_name = KERN_PANIC_ON_OOPS, 653 .procname = "panic_on_oops", 654 .data = &panic_on_oops, 655 .maxlen = sizeof(int), 656 .mode = 0644, 657 .proc_handler = &proc_dointvec, 658 }, 659 { 660 .ctl_name = KERN_PRINTK_RATELIMIT, 661 .procname = "printk_ratelimit", 662 .data = &printk_ratelimit_jiffies, 663 .maxlen = sizeof(int), 664 .mode = 0644, 665 .proc_handler = &proc_dointvec_jiffies, 666 .strategy = &sysctl_jiffies, 667 }, 668 { 669 .ctl_name = KERN_PRINTK_RATELIMIT_BURST, 670 .procname = "printk_ratelimit_burst", 671 .data = &printk_ratelimit_burst, 672 .maxlen = sizeof(int), 673 .mode = 0644, 674 .proc_handler = &proc_dointvec, 675 }, 676 { 677 .ctl_name = KERN_NGROUPS_MAX, 678 .procname = "ngroups_max", 679 .data = &ngroups_max, 680 .maxlen = sizeof (int), 681 .mode = 0444, 682 .proc_handler = &proc_dointvec, 683 }, 684 #if defined(CONFIG_X86_LOCAL_APIC) && defined(CONFIG_X86) 685 { 686 .ctl_name = KERN_UNKNOWN_NMI_PANIC, 687 .procname = "unknown_nmi_panic", 688 .data = &unknown_nmi_panic, 689 .maxlen = sizeof (int), 690 .mode = 0644, 691 .proc_handler = &proc_dointvec, 692 }, 693 { 694 .ctl_name = KERN_NMI_WATCHDOG, 695 .procname = "nmi_watchdog", 696 .data = &nmi_watchdog_enabled, 697 .maxlen = sizeof (int), 698 .mode = 0644, 699 .proc_handler = &proc_nmi_enabled, 700 }, 701 #endif 702 #if defined(CONFIG_X86) 703 { 704 .ctl_name = KERN_PANIC_ON_NMI, 705 .procname = "panic_on_unrecovered_nmi", 706 .data = &panic_on_unrecovered_nmi, 707 .maxlen = sizeof(int), 708 .mode = 0644, 709 .proc_handler = &proc_dointvec, 710 }, 711 { 712 .ctl_name = KERN_BOOTLOADER_TYPE, 713 .procname = "bootloader_type", 714 .data = &bootloader_type, 715 .maxlen = sizeof (int), 716 .mode = 0444, 717 .proc_handler = &proc_dointvec, 718 }, 719 { 720 .ctl_name = CTL_UNNUMBERED, 721 .procname = "kstack_depth_to_print", 722 .data = &kstack_depth_to_print, 723 .maxlen = sizeof(int), 724 .mode = 0644, 725 .proc_handler = &proc_dointvec, 726 }, 727 #endif 728 #if defined(CONFIG_MMU) 729 { 730 .ctl_name = KERN_RANDOMIZE, 731 .procname = "randomize_va_space", 732 .data = &randomize_va_space, 733 .maxlen = sizeof(int), 734 .mode = 0644, 735 .proc_handler = &proc_dointvec, 736 }, 737 #endif 738 #if defined(CONFIG_S390) && defined(CONFIG_SMP) 739 { 740 .ctl_name = KERN_SPIN_RETRY, 741 .procname = "spin_retry", 742 .data = &spin_retry, 743 .maxlen = sizeof (int), 744 .mode = 0644, 745 .proc_handler = &proc_dointvec, 746 }, 747 #endif 748 #ifdef CONFIG_ACPI_SLEEP 749 { 750 .ctl_name = KERN_ACPI_VIDEO_FLAGS, 751 .procname = "acpi_video_flags", 752 .data = &acpi_video_flags, 753 .maxlen = sizeof (unsigned long), 754 .mode = 0644, 755 .proc_handler = &proc_doulongvec_minmax, 756 }, 757 #endif 758 #ifdef CONFIG_IA64 759 { 760 .ctl_name = KERN_IA64_UNALIGNED, 761 .procname = "ignore-unaligned-usertrap", 762 .data = &no_unaligned_warning, 763 .maxlen = sizeof (int), 764 .mode = 0644, 765 .proc_handler = &proc_dointvec, 766 }, 767 #endif 768 #ifdef CONFIG_COMPAT 769 { 770 .ctl_name = KERN_COMPAT_LOG, 771 .procname = "compat-log", 772 .data = &compat_log, 773 .maxlen = sizeof (int), 774 .mode = 0644, 775 .proc_handler = &proc_dointvec, 776 }, 777 #endif 778 #ifdef CONFIG_RT_MUTEXES 779 { 780 .ctl_name = KERN_MAX_LOCK_DEPTH, 781 .procname = "max_lock_depth", 782 .data = &max_lock_depth, 783 .maxlen = sizeof(int), 784 .mode = 0644, 785 .proc_handler = &proc_dointvec, 786 }, 787 #endif 788 789 { .ctl_name = 0 } 790 }; 791 792 /* Constants for minimum and maximum testing in vm_table. 793 We use these as one-element integer vectors. */ 794 static int zero; 795 static int one_hundred = 100; 796 797 798 static ctl_table vm_table[] = { 799 { 800 .ctl_name = VM_OVERCOMMIT_MEMORY, 801 .procname = "overcommit_memory", 802 .data = &sysctl_overcommit_memory, 803 .maxlen = sizeof(sysctl_overcommit_memory), 804 .mode = 0644, 805 .proc_handler = &proc_dointvec, 806 }, 807 { 808 .ctl_name = VM_PANIC_ON_OOM, 809 .procname = "panic_on_oom", 810 .data = &sysctl_panic_on_oom, 811 .maxlen = sizeof(sysctl_panic_on_oom), 812 .mode = 0644, 813 .proc_handler = &proc_dointvec, 814 }, 815 { 816 .ctl_name = VM_OVERCOMMIT_RATIO, 817 .procname = "overcommit_ratio", 818 .data = &sysctl_overcommit_ratio, 819 .maxlen = sizeof(sysctl_overcommit_ratio), 820 .mode = 0644, 821 .proc_handler = &proc_dointvec, 822 }, 823 { 824 .ctl_name = VM_PAGE_CLUSTER, 825 .procname = "page-cluster", 826 .data = &page_cluster, 827 .maxlen = sizeof(int), 828 .mode = 0644, 829 .proc_handler = &proc_dointvec, 830 }, 831 { 832 .ctl_name = VM_DIRTY_BACKGROUND, 833 .procname = "dirty_background_ratio", 834 .data = &dirty_background_ratio, 835 .maxlen = sizeof(dirty_background_ratio), 836 .mode = 0644, 837 .proc_handler = &proc_dointvec_minmax, 838 .strategy = &sysctl_intvec, 839 .extra1 = &zero, 840 .extra2 = &one_hundred, 841 }, 842 { 843 .ctl_name = VM_DIRTY_RATIO, 844 .procname = "dirty_ratio", 845 .data = &vm_dirty_ratio, 846 .maxlen = sizeof(vm_dirty_ratio), 847 .mode = 0644, 848 .proc_handler = &proc_dointvec_minmax, 849 .strategy = &sysctl_intvec, 850 .extra1 = &zero, 851 .extra2 = &one_hundred, 852 }, 853 { 854 .ctl_name = VM_DIRTY_WB_CS, 855 .procname = "dirty_writeback_centisecs", 856 .data = &dirty_writeback_interval, 857 .maxlen = sizeof(dirty_writeback_interval), 858 .mode = 0644, 859 .proc_handler = &dirty_writeback_centisecs_handler, 860 }, 861 { 862 .ctl_name = VM_DIRTY_EXPIRE_CS, 863 .procname = "dirty_expire_centisecs", 864 .data = &dirty_expire_interval, 865 .maxlen = sizeof(dirty_expire_interval), 866 .mode = 0644, 867 .proc_handler = &proc_dointvec_userhz_jiffies, 868 }, 869 { 870 .ctl_name = VM_NR_PDFLUSH_THREADS, 871 .procname = "nr_pdflush_threads", 872 .data = &nr_pdflush_threads, 873 .maxlen = sizeof nr_pdflush_threads, 874 .mode = 0444 /* read-only*/, 875 .proc_handler = &proc_dointvec, 876 }, 877 { 878 .ctl_name = VM_SWAPPINESS, 879 .procname = "swappiness", 880 .data = &vm_swappiness, 881 .maxlen = sizeof(vm_swappiness), 882 .mode = 0644, 883 .proc_handler = &proc_dointvec_minmax, 884 .strategy = &sysctl_intvec, 885 .extra1 = &zero, 886 .extra2 = &one_hundred, 887 }, 888 #ifdef CONFIG_HUGETLB_PAGE 889 { 890 .ctl_name = VM_HUGETLB_PAGES, 891 .procname = "nr_hugepages", 892 .data = &max_huge_pages, 893 .maxlen = sizeof(unsigned long), 894 .mode = 0644, 895 .proc_handler = &hugetlb_sysctl_handler, 896 .extra1 = (void *)&hugetlb_zero, 897 .extra2 = (void *)&hugetlb_infinity, 898 }, 899 { 900 .ctl_name = VM_HUGETLB_GROUP, 901 .procname = "hugetlb_shm_group", 902 .data = &sysctl_hugetlb_shm_group, 903 .maxlen = sizeof(gid_t), 904 .mode = 0644, 905 .proc_handler = &proc_dointvec, 906 }, 907 #endif 908 { 909 .ctl_name = VM_LOWMEM_RESERVE_RATIO, 910 .procname = "lowmem_reserve_ratio", 911 .data = &sysctl_lowmem_reserve_ratio, 912 .maxlen = sizeof(sysctl_lowmem_reserve_ratio), 913 .mode = 0644, 914 .proc_handler = &lowmem_reserve_ratio_sysctl_handler, 915 .strategy = &sysctl_intvec, 916 }, 917 { 918 .ctl_name = VM_DROP_PAGECACHE, 919 .procname = "drop_caches", 920 .data = &sysctl_drop_caches, 921 .maxlen = sizeof(int), 922 .mode = 0644, 923 .proc_handler = drop_caches_sysctl_handler, 924 .strategy = &sysctl_intvec, 925 }, 926 { 927 .ctl_name = VM_MIN_FREE_KBYTES, 928 .procname = "min_free_kbytes", 929 .data = &min_free_kbytes, 930 .maxlen = sizeof(min_free_kbytes), 931 .mode = 0644, 932 .proc_handler = &min_free_kbytes_sysctl_handler, 933 .strategy = &sysctl_intvec, 934 .extra1 = &zero, 935 }, 936 { 937 .ctl_name = VM_PERCPU_PAGELIST_FRACTION, 938 .procname = "percpu_pagelist_fraction", 939 .data = &percpu_pagelist_fraction, 940 .maxlen = sizeof(percpu_pagelist_fraction), 941 .mode = 0644, 942 .proc_handler = &percpu_pagelist_fraction_sysctl_handler, 943 .strategy = &sysctl_intvec, 944 .extra1 = &min_percpu_pagelist_fract, 945 }, 946 #ifdef CONFIG_MMU 947 { 948 .ctl_name = VM_MAX_MAP_COUNT, 949 .procname = "max_map_count", 950 .data = &sysctl_max_map_count, 951 .maxlen = sizeof(sysctl_max_map_count), 952 .mode = 0644, 953 .proc_handler = &proc_dointvec 954 }, 955 #endif 956 { 957 .ctl_name = VM_LAPTOP_MODE, 958 .procname = "laptop_mode", 959 .data = &laptop_mode, 960 .maxlen = sizeof(laptop_mode), 961 .mode = 0644, 962 .proc_handler = &proc_dointvec_jiffies, 963 .strategy = &sysctl_jiffies, 964 }, 965 { 966 .ctl_name = VM_BLOCK_DUMP, 967 .procname = "block_dump", 968 .data = &block_dump, 969 .maxlen = sizeof(block_dump), 970 .mode = 0644, 971 .proc_handler = &proc_dointvec, 972 .strategy = &sysctl_intvec, 973 .extra1 = &zero, 974 }, 975 { 976 .ctl_name = VM_VFS_CACHE_PRESSURE, 977 .procname = "vfs_cache_pressure", 978 .data = &sysctl_vfs_cache_pressure, 979 .maxlen = sizeof(sysctl_vfs_cache_pressure), 980 .mode = 0644, 981 .proc_handler = &proc_dointvec, 982 .strategy = &sysctl_intvec, 983 .extra1 = &zero, 984 }, 985 #ifdef HAVE_ARCH_PICK_MMAP_LAYOUT 986 { 987 .ctl_name = VM_LEGACY_VA_LAYOUT, 988 .procname = "legacy_va_layout", 989 .data = &sysctl_legacy_va_layout, 990 .maxlen = sizeof(sysctl_legacy_va_layout), 991 .mode = 0644, 992 .proc_handler = &proc_dointvec, 993 .strategy = &sysctl_intvec, 994 .extra1 = &zero, 995 }, 996 #endif 997 #ifdef CONFIG_NUMA 998 { 999 .ctl_name = VM_ZONE_RECLAIM_MODE, 1000 .procname = "zone_reclaim_mode", 1001 .data = &zone_reclaim_mode, 1002 .maxlen = sizeof(zone_reclaim_mode), 1003 .mode = 0644, 1004 .proc_handler = &proc_dointvec, 1005 .strategy = &sysctl_intvec, 1006 .extra1 = &zero, 1007 }, 1008 { 1009 .ctl_name = VM_MIN_UNMAPPED, 1010 .procname = "min_unmapped_ratio", 1011 .data = &sysctl_min_unmapped_ratio, 1012 .maxlen = sizeof(sysctl_min_unmapped_ratio), 1013 .mode = 0644, 1014 .proc_handler = &sysctl_min_unmapped_ratio_sysctl_handler, 1015 .strategy = &sysctl_intvec, 1016 .extra1 = &zero, 1017 .extra2 = &one_hundred, 1018 }, 1019 { 1020 .ctl_name = VM_MIN_SLAB, 1021 .procname = "min_slab_ratio", 1022 .data = &sysctl_min_slab_ratio, 1023 .maxlen = sizeof(sysctl_min_slab_ratio), 1024 .mode = 0644, 1025 .proc_handler = &sysctl_min_slab_ratio_sysctl_handler, 1026 .strategy = &sysctl_intvec, 1027 .extra1 = &zero, 1028 .extra2 = &one_hundred, 1029 }, 1030 #endif 1031 #ifdef CONFIG_X86_32 1032 { 1033 .ctl_name = VM_VDSO_ENABLED, 1034 .procname = "vdso_enabled", 1035 .data = &vdso_enabled, 1036 .maxlen = sizeof(vdso_enabled), 1037 .mode = 0644, 1038 .proc_handler = &proc_dointvec, 1039 .strategy = &sysctl_intvec, 1040 .extra1 = &zero, 1041 }, 1042 #endif 1043 { .ctl_name = 0 } 1044 }; 1045 1046 static ctl_table fs_table[] = { 1047 { 1048 .ctl_name = FS_NRINODE, 1049 .procname = "inode-nr", 1050 .data = &inodes_stat, 1051 .maxlen = 2*sizeof(int), 1052 .mode = 0444, 1053 .proc_handler = &proc_dointvec, 1054 }, 1055 { 1056 .ctl_name = FS_STATINODE, 1057 .procname = "inode-state", 1058 .data = &inodes_stat, 1059 .maxlen = 7*sizeof(int), 1060 .mode = 0444, 1061 .proc_handler = &proc_dointvec, 1062 }, 1063 { 1064 .ctl_name = FS_NRFILE, 1065 .procname = "file-nr", 1066 .data = &files_stat, 1067 .maxlen = 3*sizeof(int), 1068 .mode = 0444, 1069 .proc_handler = &proc_nr_files, 1070 }, 1071 { 1072 .ctl_name = FS_MAXFILE, 1073 .procname = "file-max", 1074 .data = &files_stat.max_files, 1075 .maxlen = sizeof(int), 1076 .mode = 0644, 1077 .proc_handler = &proc_dointvec, 1078 }, 1079 { 1080 .ctl_name = FS_DENTRY, 1081 .procname = "dentry-state", 1082 .data = &dentry_stat, 1083 .maxlen = 6*sizeof(int), 1084 .mode = 0444, 1085 .proc_handler = &proc_dointvec, 1086 }, 1087 { 1088 .ctl_name = FS_OVERFLOWUID, 1089 .procname = "overflowuid", 1090 .data = &fs_overflowuid, 1091 .maxlen = sizeof(int), 1092 .mode = 0644, 1093 .proc_handler = &proc_dointvec_minmax, 1094 .strategy = &sysctl_intvec, 1095 .extra1 = &minolduid, 1096 .extra2 = &maxolduid, 1097 }, 1098 { 1099 .ctl_name = FS_OVERFLOWGID, 1100 .procname = "overflowgid", 1101 .data = &fs_overflowgid, 1102 .maxlen = sizeof(int), 1103 .mode = 0644, 1104 .proc_handler = &proc_dointvec_minmax, 1105 .strategy = &sysctl_intvec, 1106 .extra1 = &minolduid, 1107 .extra2 = &maxolduid, 1108 }, 1109 { 1110 .ctl_name = FS_LEASES, 1111 .procname = "leases-enable", 1112 .data = &leases_enable, 1113 .maxlen = sizeof(int), 1114 .mode = 0644, 1115 .proc_handler = &proc_dointvec, 1116 }, 1117 #ifdef CONFIG_DNOTIFY 1118 { 1119 .ctl_name = FS_DIR_NOTIFY, 1120 .procname = "dir-notify-enable", 1121 .data = &dir_notify_enable, 1122 .maxlen = sizeof(int), 1123 .mode = 0644, 1124 .proc_handler = &proc_dointvec, 1125 }, 1126 #endif 1127 #ifdef CONFIG_MMU 1128 { 1129 .ctl_name = FS_LEASE_TIME, 1130 .procname = "lease-break-time", 1131 .data = &lease_break_time, 1132 .maxlen = sizeof(int), 1133 .mode = 0644, 1134 .proc_handler = &proc_dointvec, 1135 }, 1136 { 1137 .ctl_name = FS_AIO_NR, 1138 .procname = "aio-nr", 1139 .data = &aio_nr, 1140 .maxlen = sizeof(aio_nr), 1141 .mode = 0444, 1142 .proc_handler = &proc_doulongvec_minmax, 1143 }, 1144 { 1145 .ctl_name = FS_AIO_MAX_NR, 1146 .procname = "aio-max-nr", 1147 .data = &aio_max_nr, 1148 .maxlen = sizeof(aio_max_nr), 1149 .mode = 0644, 1150 .proc_handler = &proc_doulongvec_minmax, 1151 }, 1152 #ifdef CONFIG_INOTIFY_USER 1153 { 1154 .ctl_name = FS_INOTIFY, 1155 .procname = "inotify", 1156 .mode = 0555, 1157 .child = inotify_table, 1158 }, 1159 #endif 1160 #endif 1161 { 1162 .ctl_name = KERN_SETUID_DUMPABLE, 1163 .procname = "suid_dumpable", 1164 .data = &suid_dumpable, 1165 .maxlen = sizeof(int), 1166 .mode = 0644, 1167 .proc_handler = &proc_dointvec, 1168 }, 1169 { .ctl_name = 0 } 1170 }; 1171 1172 static ctl_table debug_table[] = { 1173 { .ctl_name = 0 } 1174 }; 1175 1176 static ctl_table dev_table[] = { 1177 { .ctl_name = 0 } 1178 }; 1179 1180 extern void init_irq_proc (void); 1181 1182 static DEFINE_SPINLOCK(sysctl_lock); 1183 1184 /* called under sysctl_lock */ 1185 static int use_table(struct ctl_table_header *p) 1186 { 1187 if (unlikely(p->unregistering)) 1188 return 0; 1189 p->used++; 1190 return 1; 1191 } 1192 1193 /* called under sysctl_lock */ 1194 static void unuse_table(struct ctl_table_header *p) 1195 { 1196 if (!--p->used) 1197 if (unlikely(p->unregistering)) 1198 complete(p->unregistering); 1199 } 1200 1201 /* called under sysctl_lock, will reacquire if has to wait */ 1202 static void start_unregistering(struct ctl_table_header *p) 1203 { 1204 /* 1205 * if p->used is 0, nobody will ever touch that entry again; 1206 * we'll eliminate all paths to it before dropping sysctl_lock 1207 */ 1208 if (unlikely(p->used)) { 1209 struct completion wait; 1210 init_completion(&wait); 1211 p->unregistering = &wait; 1212 spin_unlock(&sysctl_lock); 1213 wait_for_completion(&wait); 1214 spin_lock(&sysctl_lock); 1215 } 1216 /* 1217 * do not remove from the list until nobody holds it; walking the 1218 * list in do_sysctl() relies on that. 1219 */ 1220 list_del_init(&p->ctl_entry); 1221 } 1222 1223 void __init sysctl_init(void) 1224 { 1225 #ifdef CONFIG_PROC_SYSCTL 1226 register_proc_table(root_table, proc_sys_root, &root_table_header); 1227 init_irq_proc(); 1228 #endif 1229 } 1230 1231 #ifdef CONFIG_SYSCTL_SYSCALL 1232 int do_sysctl(int __user *name, int nlen, void __user *oldval, size_t __user *oldlenp, 1233 void __user *newval, size_t newlen) 1234 { 1235 struct list_head *tmp; 1236 int error = -ENOTDIR; 1237 1238 if (nlen <= 0 || nlen >= CTL_MAXNAME) 1239 return -ENOTDIR; 1240 if (oldval) { 1241 int old_len; 1242 if (!oldlenp || get_user(old_len, oldlenp)) 1243 return -EFAULT; 1244 } 1245 spin_lock(&sysctl_lock); 1246 tmp = &root_table_header.ctl_entry; 1247 do { 1248 struct ctl_table_header *head = 1249 list_entry(tmp, struct ctl_table_header, ctl_entry); 1250 1251 if (!use_table(head)) 1252 continue; 1253 1254 spin_unlock(&sysctl_lock); 1255 1256 error = parse_table(name, nlen, oldval, oldlenp, 1257 newval, newlen, head->ctl_table); 1258 1259 spin_lock(&sysctl_lock); 1260 unuse_table(head); 1261 if (error != -ENOTDIR) 1262 break; 1263 } while ((tmp = tmp->next) != &root_table_header.ctl_entry); 1264 spin_unlock(&sysctl_lock); 1265 return error; 1266 } 1267 1268 asmlinkage long sys_sysctl(struct __sysctl_args __user *args) 1269 { 1270 struct __sysctl_args tmp; 1271 int error; 1272 1273 if (copy_from_user(&tmp, args, sizeof(tmp))) 1274 return -EFAULT; 1275 1276 lock_kernel(); 1277 error = do_sysctl(tmp.name, tmp.nlen, tmp.oldval, tmp.oldlenp, 1278 tmp.newval, tmp.newlen); 1279 unlock_kernel(); 1280 return error; 1281 } 1282 #endif /* CONFIG_SYSCTL_SYSCALL */ 1283 1284 /* 1285 * ctl_perm does NOT grant the superuser all rights automatically, because 1286 * some sysctl variables are readonly even to root. 1287 */ 1288 1289 static int test_perm(int mode, int op) 1290 { 1291 if (!current->euid) 1292 mode >>= 6; 1293 else if (in_egroup_p(0)) 1294 mode >>= 3; 1295 if ((mode & op & 0007) == op) 1296 return 0; 1297 return -EACCES; 1298 } 1299 1300 static inline int ctl_perm(ctl_table *table, int op) 1301 { 1302 int error; 1303 error = security_sysctl(table, op); 1304 if (error) 1305 return error; 1306 return test_perm(table->mode, op); 1307 } 1308 1309 #ifdef CONFIG_SYSCTL_SYSCALL 1310 static int parse_table(int __user *name, int nlen, 1311 void __user *oldval, size_t __user *oldlenp, 1312 void __user *newval, size_t newlen, 1313 ctl_table *table) 1314 { 1315 int n; 1316 repeat: 1317 if (!nlen) 1318 return -ENOTDIR; 1319 if (get_user(n, name)) 1320 return -EFAULT; 1321 for ( ; table->ctl_name || table->procname; table++) { 1322 if (!table->ctl_name) 1323 continue; 1324 if (n == table->ctl_name || table->ctl_name == CTL_ANY) { 1325 int error; 1326 if (table->child) { 1327 if (ctl_perm(table, 001)) 1328 return -EPERM; 1329 if (table->strategy) { 1330 error = table->strategy( 1331 table, name, nlen, 1332 oldval, oldlenp, 1333 newval, newlen); 1334 if (error) 1335 return error; 1336 } 1337 name++; 1338 nlen--; 1339 table = table->child; 1340 goto repeat; 1341 } 1342 error = do_sysctl_strategy(table, name, nlen, 1343 oldval, oldlenp, 1344 newval, newlen); 1345 return error; 1346 } 1347 } 1348 return -ENOTDIR; 1349 } 1350 1351 /* Perform the actual read/write of a sysctl table entry. */ 1352 int do_sysctl_strategy (ctl_table *table, 1353 int __user *name, int nlen, 1354 void __user *oldval, size_t __user *oldlenp, 1355 void __user *newval, size_t newlen) 1356 { 1357 int op = 0, rc; 1358 size_t len; 1359 1360 if (oldval) 1361 op |= 004; 1362 if (newval) 1363 op |= 002; 1364 if (ctl_perm(table, op)) 1365 return -EPERM; 1366 1367 if (table->strategy) { 1368 rc = table->strategy(table, name, nlen, oldval, oldlenp, 1369 newval, newlen); 1370 if (rc < 0) 1371 return rc; 1372 if (rc > 0) 1373 return 0; 1374 } 1375 1376 /* If there is no strategy routine, or if the strategy returns 1377 * zero, proceed with automatic r/w */ 1378 if (table->data && table->maxlen) { 1379 if (oldval && oldlenp) { 1380 if (get_user(len, oldlenp)) 1381 return -EFAULT; 1382 if (len) { 1383 if (len > table->maxlen) 1384 len = table->maxlen; 1385 if(copy_to_user(oldval, table->data, len)) 1386 return -EFAULT; 1387 if(put_user(len, oldlenp)) 1388 return -EFAULT; 1389 } 1390 } 1391 if (newval && newlen) { 1392 len = newlen; 1393 if (len > table->maxlen) 1394 len = table->maxlen; 1395 if(copy_from_user(table->data, newval, len)) 1396 return -EFAULT; 1397 } 1398 } 1399 return 0; 1400 } 1401 #endif /* CONFIG_SYSCTL_SYSCALL */ 1402 1403 /** 1404 * register_sysctl_table - register a sysctl hierarchy 1405 * @table: the top-level table structure 1406 * @insert_at_head: whether the entry should be inserted in front or at the end 1407 * 1408 * Register a sysctl table hierarchy. @table should be a filled in ctl_table 1409 * array. An entry with a ctl_name of 0 terminates the table. 1410 * 1411 * The members of the &ctl_table structure are used as follows: 1412 * 1413 * ctl_name - This is the numeric sysctl value used by sysctl(2). The number 1414 * must be unique within that level of sysctl 1415 * 1416 * procname - the name of the sysctl file under /proc/sys. Set to %NULL to not 1417 * enter a sysctl file 1418 * 1419 * data - a pointer to data for use by proc_handler 1420 * 1421 * maxlen - the maximum size in bytes of the data 1422 * 1423 * mode - the file permissions for the /proc/sys file, and for sysctl(2) 1424 * 1425 * child - a pointer to the child sysctl table if this entry is a directory, or 1426 * %NULL. 1427 * 1428 * proc_handler - the text handler routine (described below) 1429 * 1430 * strategy - the strategy routine (described below) 1431 * 1432 * de - for internal use by the sysctl routines 1433 * 1434 * extra1, extra2 - extra pointers usable by the proc handler routines 1435 * 1436 * Leaf nodes in the sysctl tree will be represented by a single file 1437 * under /proc; non-leaf nodes will be represented by directories. 1438 * 1439 * sysctl(2) can automatically manage read and write requests through 1440 * the sysctl table. The data and maxlen fields of the ctl_table 1441 * struct enable minimal validation of the values being written to be 1442 * performed, and the mode field allows minimal authentication. 1443 * 1444 * More sophisticated management can be enabled by the provision of a 1445 * strategy routine with the table entry. This will be called before 1446 * any automatic read or write of the data is performed. 1447 * 1448 * The strategy routine may return 1449 * 1450 * < 0 - Error occurred (error is passed to user process) 1451 * 1452 * 0 - OK - proceed with automatic read or write. 1453 * 1454 * > 0 - OK - read or write has been done by the strategy routine, so 1455 * return immediately. 1456 * 1457 * There must be a proc_handler routine for any terminal nodes 1458 * mirrored under /proc/sys (non-terminals are handled by a built-in 1459 * directory handler). Several default handlers are available to 1460 * cover common cases - 1461 * 1462 * proc_dostring(), proc_dointvec(), proc_dointvec_jiffies(), 1463 * proc_dointvec_userhz_jiffies(), proc_dointvec_minmax(), 1464 * proc_doulongvec_ms_jiffies_minmax(), proc_doulongvec_minmax() 1465 * 1466 * It is the handler's job to read the input buffer from user memory 1467 * and process it. The handler should return 0 on success. 1468 * 1469 * This routine returns %NULL on a failure to register, and a pointer 1470 * to the table header on success. 1471 */ 1472 struct ctl_table_header *register_sysctl_table(ctl_table * table, 1473 int insert_at_head) 1474 { 1475 struct ctl_table_header *tmp; 1476 tmp = kmalloc(sizeof(struct ctl_table_header), GFP_KERNEL); 1477 if (!tmp) 1478 return NULL; 1479 tmp->ctl_table = table; 1480 INIT_LIST_HEAD(&tmp->ctl_entry); 1481 tmp->used = 0; 1482 tmp->unregistering = NULL; 1483 spin_lock(&sysctl_lock); 1484 if (insert_at_head) 1485 list_add(&tmp->ctl_entry, &root_table_header.ctl_entry); 1486 else 1487 list_add_tail(&tmp->ctl_entry, &root_table_header.ctl_entry); 1488 spin_unlock(&sysctl_lock); 1489 #ifdef CONFIG_PROC_SYSCTL 1490 register_proc_table(table, proc_sys_root, tmp); 1491 #endif 1492 return tmp; 1493 } 1494 1495 /** 1496 * unregister_sysctl_table - unregister a sysctl table hierarchy 1497 * @header: the header returned from register_sysctl_table 1498 * 1499 * Unregisters the sysctl table and all children. proc entries may not 1500 * actually be removed until they are no longer used by anyone. 1501 */ 1502 void unregister_sysctl_table(struct ctl_table_header * header) 1503 { 1504 might_sleep(); 1505 spin_lock(&sysctl_lock); 1506 start_unregistering(header); 1507 #ifdef CONFIG_PROC_SYSCTL 1508 unregister_proc_table(header->ctl_table, proc_sys_root); 1509 #endif 1510 spin_unlock(&sysctl_lock); 1511 kfree(header); 1512 } 1513 1514 #else /* !CONFIG_SYSCTL */ 1515 struct ctl_table_header * register_sysctl_table(ctl_table * table, 1516 int insert_at_head) 1517 { 1518 return NULL; 1519 } 1520 1521 void unregister_sysctl_table(struct ctl_table_header * table) 1522 { 1523 } 1524 1525 #endif /* CONFIG_SYSCTL */ 1526 1527 /* 1528 * /proc/sys support 1529 */ 1530 1531 #ifdef CONFIG_PROC_SYSCTL 1532 1533 /* Scan the sysctl entries in table and add them all into /proc */ 1534 static void register_proc_table(ctl_table * table, struct proc_dir_entry *root, void *set) 1535 { 1536 struct proc_dir_entry *de; 1537 int len; 1538 mode_t mode; 1539 1540 for (; table->ctl_name || table->procname; table++) { 1541 /* Can't do anything without a proc name. */ 1542 if (!table->procname) 1543 continue; 1544 /* Maybe we can't do anything with it... */ 1545 if (!table->proc_handler && !table->child) { 1546 printk(KERN_WARNING "SYSCTL: Can't register %s\n", 1547 table->procname); 1548 continue; 1549 } 1550 1551 len = strlen(table->procname); 1552 mode = table->mode; 1553 1554 de = NULL; 1555 if (table->proc_handler) 1556 mode |= S_IFREG; 1557 else { 1558 mode |= S_IFDIR; 1559 for (de = root->subdir; de; de = de->next) { 1560 if (proc_match(len, table->procname, de)) 1561 break; 1562 } 1563 /* If the subdir exists already, de is non-NULL */ 1564 } 1565 1566 if (!de) { 1567 de = create_proc_entry(table->procname, mode, root); 1568 if (!de) 1569 continue; 1570 de->set = set; 1571 de->data = (void *) table; 1572 if (table->proc_handler) 1573 de->proc_fops = &proc_sys_file_operations; 1574 } 1575 table->de = de; 1576 if (de->mode & S_IFDIR) 1577 register_proc_table(table->child, de, set); 1578 } 1579 } 1580 1581 /* 1582 * Unregister a /proc sysctl table and any subdirectories. 1583 */ 1584 static void unregister_proc_table(ctl_table * table, struct proc_dir_entry *root) 1585 { 1586 struct proc_dir_entry *de; 1587 for (; table->ctl_name || table->procname; table++) { 1588 if (!(de = table->de)) 1589 continue; 1590 if (de->mode & S_IFDIR) { 1591 if (!table->child) { 1592 printk (KERN_ALERT "Help - malformed sysctl tree on free\n"); 1593 continue; 1594 } 1595 unregister_proc_table(table->child, de); 1596 1597 /* Don't unregister directories which still have entries.. */ 1598 if (de->subdir) 1599 continue; 1600 } 1601 1602 /* 1603 * In any case, mark the entry as goner; we'll keep it 1604 * around if it's busy, but we'll know to do nothing with 1605 * its fields. We are under sysctl_lock here. 1606 */ 1607 de->data = NULL; 1608 1609 /* Don't unregister proc entries that are still being used.. */ 1610 if (atomic_read(&de->count)) 1611 continue; 1612 1613 table->de = NULL; 1614 remove_proc_entry(table->procname, root); 1615 } 1616 } 1617 1618 static ssize_t do_rw_proc(int write, struct file * file, char __user * buf, 1619 size_t count, loff_t *ppos) 1620 { 1621 int op; 1622 struct proc_dir_entry *de = PDE(file->f_path.dentry->d_inode); 1623 struct ctl_table *table; 1624 size_t res; 1625 ssize_t error = -ENOTDIR; 1626 1627 spin_lock(&sysctl_lock); 1628 if (de && de->data && use_table(de->set)) { 1629 /* 1630 * at that point we know that sysctl was not unregistered 1631 * and won't be until we finish 1632 */ 1633 spin_unlock(&sysctl_lock); 1634 table = (struct ctl_table *) de->data; 1635 if (!table || !table->proc_handler) 1636 goto out; 1637 error = -EPERM; 1638 op = (write ? 002 : 004); 1639 if (ctl_perm(table, op)) 1640 goto out; 1641 1642 /* careful: calling conventions are nasty here */ 1643 res = count; 1644 error = (*table->proc_handler)(table, write, file, 1645 buf, &res, ppos); 1646 if (!error) 1647 error = res; 1648 out: 1649 spin_lock(&sysctl_lock); 1650 unuse_table(de->set); 1651 } 1652 spin_unlock(&sysctl_lock); 1653 return error; 1654 } 1655 1656 static int proc_opensys(struct inode *inode, struct file *file) 1657 { 1658 if (file->f_mode & FMODE_WRITE) { 1659 /* 1660 * sysctl entries that are not writable, 1661 * are _NOT_ writable, capabilities or not. 1662 */ 1663 if (!(inode->i_mode & S_IWUSR)) 1664 return -EPERM; 1665 } 1666 1667 return 0; 1668 } 1669 1670 static ssize_t proc_readsys(struct file * file, char __user * buf, 1671 size_t count, loff_t *ppos) 1672 { 1673 return do_rw_proc(0, file, buf, count, ppos); 1674 } 1675 1676 static ssize_t proc_writesys(struct file * file, const char __user * buf, 1677 size_t count, loff_t *ppos) 1678 { 1679 return do_rw_proc(1, file, (char __user *) buf, count, ppos); 1680 } 1681 1682 static int _proc_do_string(void* data, int maxlen, int write, 1683 struct file *filp, void __user *buffer, 1684 size_t *lenp, loff_t *ppos) 1685 { 1686 size_t len; 1687 char __user *p; 1688 char c; 1689 1690 if (!data || !maxlen || !*lenp || 1691 (*ppos && !write)) { 1692 *lenp = 0; 1693 return 0; 1694 } 1695 1696 if (write) { 1697 len = 0; 1698 p = buffer; 1699 while (len < *lenp) { 1700 if (get_user(c, p++)) 1701 return -EFAULT; 1702 if (c == 0 || c == '\n') 1703 break; 1704 len++; 1705 } 1706 if (len >= maxlen) 1707 len = maxlen-1; 1708 if(copy_from_user(data, buffer, len)) 1709 return -EFAULT; 1710 ((char *) data)[len] = 0; 1711 *ppos += *lenp; 1712 } else { 1713 len = strlen(data); 1714 if (len > maxlen) 1715 len = maxlen; 1716 if (len > *lenp) 1717 len = *lenp; 1718 if (len) 1719 if(copy_to_user(buffer, data, len)) 1720 return -EFAULT; 1721 if (len < *lenp) { 1722 if(put_user('\n', ((char __user *) buffer) + len)) 1723 return -EFAULT; 1724 len++; 1725 } 1726 *lenp = len; 1727 *ppos += len; 1728 } 1729 return 0; 1730 } 1731 1732 /** 1733 * proc_dostring - read a string sysctl 1734 * @table: the sysctl table 1735 * @write: %TRUE if this is a write to the sysctl file 1736 * @filp: the file structure 1737 * @buffer: the user buffer 1738 * @lenp: the size of the user buffer 1739 * @ppos: file position 1740 * 1741 * Reads/writes a string from/to the user buffer. If the kernel 1742 * buffer provided is not large enough to hold the string, the 1743 * string is truncated. The copied string is %NULL-terminated. 1744 * If the string is being read by the user process, it is copied 1745 * and a newline '\n' is added. It is truncated if the buffer is 1746 * not large enough. 1747 * 1748 * Returns 0 on success. 1749 */ 1750 int proc_dostring(ctl_table *table, int write, struct file *filp, 1751 void __user *buffer, size_t *lenp, loff_t *ppos) 1752 { 1753 return _proc_do_string(table->data, table->maxlen, write, filp, 1754 buffer, lenp, ppos); 1755 } 1756 1757 /* 1758 * Special case of dostring for the UTS structure. This has locks 1759 * to observe. Should this be in kernel/sys.c ???? 1760 */ 1761 1762 static int proc_do_uts_string(ctl_table *table, int write, struct file *filp, 1763 void __user *buffer, size_t *lenp, loff_t *ppos) 1764 { 1765 int r; 1766 void *which; 1767 which = get_uts(table, write); 1768 r = _proc_do_string(which, table->maxlen,write,filp,buffer,lenp, ppos); 1769 put_uts(table, write, which); 1770 return r; 1771 } 1772 1773 static int do_proc_dointvec_conv(int *negp, unsigned long *lvalp, 1774 int *valp, 1775 int write, void *data) 1776 { 1777 if (write) { 1778 *valp = *negp ? -*lvalp : *lvalp; 1779 } else { 1780 int val = *valp; 1781 if (val < 0) { 1782 *negp = -1; 1783 *lvalp = (unsigned long)-val; 1784 } else { 1785 *negp = 0; 1786 *lvalp = (unsigned long)val; 1787 } 1788 } 1789 return 0; 1790 } 1791 1792 static int __do_proc_dointvec(void *tbl_data, ctl_table *table, 1793 int write, struct file *filp, void __user *buffer, 1794 size_t *lenp, loff_t *ppos, 1795 int (*conv)(int *negp, unsigned long *lvalp, int *valp, 1796 int write, void *data), 1797 void *data) 1798 { 1799 #define TMPBUFLEN 21 1800 int *i, vleft, first=1, neg, val; 1801 unsigned long lval; 1802 size_t left, len; 1803 1804 char buf[TMPBUFLEN], *p; 1805 char __user *s = buffer; 1806 1807 if (!tbl_data || !table->maxlen || !*lenp || 1808 (*ppos && !write)) { 1809 *lenp = 0; 1810 return 0; 1811 } 1812 1813 i = (int *) tbl_data; 1814 vleft = table->maxlen / sizeof(*i); 1815 left = *lenp; 1816 1817 if (!conv) 1818 conv = do_proc_dointvec_conv; 1819 1820 for (; left && vleft--; i++, first=0) { 1821 if (write) { 1822 while (left) { 1823 char c; 1824 if (get_user(c, s)) 1825 return -EFAULT; 1826 if (!isspace(c)) 1827 break; 1828 left--; 1829 s++; 1830 } 1831 if (!left) 1832 break; 1833 neg = 0; 1834 len = left; 1835 if (len > sizeof(buf) - 1) 1836 len = sizeof(buf) - 1; 1837 if (copy_from_user(buf, s, len)) 1838 return -EFAULT; 1839 buf[len] = 0; 1840 p = buf; 1841 if (*p == '-' && left > 1) { 1842 neg = 1; 1843 p++; 1844 } 1845 if (*p < '0' || *p > '9') 1846 break; 1847 1848 lval = simple_strtoul(p, &p, 0); 1849 1850 len = p-buf; 1851 if ((len < left) && *p && !isspace(*p)) 1852 break; 1853 if (neg) 1854 val = -val; 1855 s += len; 1856 left -= len; 1857 1858 if (conv(&neg, &lval, i, 1, data)) 1859 break; 1860 } else { 1861 p = buf; 1862 if (!first) 1863 *p++ = '\t'; 1864 1865 if (conv(&neg, &lval, i, 0, data)) 1866 break; 1867 1868 sprintf(p, "%s%lu", neg ? "-" : "", lval); 1869 len = strlen(buf); 1870 if (len > left) 1871 len = left; 1872 if(copy_to_user(s, buf, len)) 1873 return -EFAULT; 1874 left -= len; 1875 s += len; 1876 } 1877 } 1878 1879 if (!write && !first && left) { 1880 if(put_user('\n', s)) 1881 return -EFAULT; 1882 left--, s++; 1883 } 1884 if (write) { 1885 while (left) { 1886 char c; 1887 if (get_user(c, s++)) 1888 return -EFAULT; 1889 if (!isspace(c)) 1890 break; 1891 left--; 1892 } 1893 } 1894 if (write && first) 1895 return -EINVAL; 1896 *lenp -= left; 1897 *ppos += *lenp; 1898 return 0; 1899 #undef TMPBUFLEN 1900 } 1901 1902 static int do_proc_dointvec(ctl_table *table, int write, struct file *filp, 1903 void __user *buffer, size_t *lenp, loff_t *ppos, 1904 int (*conv)(int *negp, unsigned long *lvalp, int *valp, 1905 int write, void *data), 1906 void *data) 1907 { 1908 return __do_proc_dointvec(table->data, table, write, filp, 1909 buffer, lenp, ppos, conv, data); 1910 } 1911 1912 /** 1913 * proc_dointvec - read a vector of integers 1914 * @table: the sysctl table 1915 * @write: %TRUE if this is a write to the sysctl file 1916 * @filp: the file structure 1917 * @buffer: the user buffer 1918 * @lenp: the size of the user buffer 1919 * @ppos: file position 1920 * 1921 * Reads/writes up to table->maxlen/sizeof(unsigned int) integer 1922 * values from/to the user buffer, treated as an ASCII string. 1923 * 1924 * Returns 0 on success. 1925 */ 1926 int proc_dointvec(ctl_table *table, int write, struct file *filp, 1927 void __user *buffer, size_t *lenp, loff_t *ppos) 1928 { 1929 return do_proc_dointvec(table,write,filp,buffer,lenp,ppos, 1930 NULL,NULL); 1931 } 1932 1933 #define OP_SET 0 1934 #define OP_AND 1 1935 #define OP_OR 2 1936 1937 static int do_proc_dointvec_bset_conv(int *negp, unsigned long *lvalp, 1938 int *valp, 1939 int write, void *data) 1940 { 1941 int op = *(int *)data; 1942 if (write) { 1943 int val = *negp ? -*lvalp : *lvalp; 1944 switch(op) { 1945 case OP_SET: *valp = val; break; 1946 case OP_AND: *valp &= val; break; 1947 case OP_OR: *valp |= val; break; 1948 } 1949 } else { 1950 int val = *valp; 1951 if (val < 0) { 1952 *negp = -1; 1953 *lvalp = (unsigned long)-val; 1954 } else { 1955 *negp = 0; 1956 *lvalp = (unsigned long)val; 1957 } 1958 } 1959 return 0; 1960 } 1961 1962 /* 1963 * init may raise the set. 1964 */ 1965 1966 int proc_dointvec_bset(ctl_table *table, int write, struct file *filp, 1967 void __user *buffer, size_t *lenp, loff_t *ppos) 1968 { 1969 int op; 1970 1971 if (write && !capable(CAP_SYS_MODULE)) { 1972 return -EPERM; 1973 } 1974 1975 op = is_init(current) ? OP_SET : OP_AND; 1976 return do_proc_dointvec(table,write,filp,buffer,lenp,ppos, 1977 do_proc_dointvec_bset_conv,&op); 1978 } 1979 1980 /* 1981 * Taint values can only be increased 1982 */ 1983 static int proc_dointvec_taint(ctl_table *table, int write, struct file *filp, 1984 void __user *buffer, size_t *lenp, loff_t *ppos) 1985 { 1986 int op; 1987 1988 if (!capable(CAP_SYS_ADMIN)) 1989 return -EPERM; 1990 1991 op = OP_OR; 1992 return do_proc_dointvec(table,write,filp,buffer,lenp,ppos, 1993 do_proc_dointvec_bset_conv,&op); 1994 } 1995 1996 struct do_proc_dointvec_minmax_conv_param { 1997 int *min; 1998 int *max; 1999 }; 2000 2001 static int do_proc_dointvec_minmax_conv(int *negp, unsigned long *lvalp, 2002 int *valp, 2003 int write, void *data) 2004 { 2005 struct do_proc_dointvec_minmax_conv_param *param = data; 2006 if (write) { 2007 int val = *negp ? -*lvalp : *lvalp; 2008 if ((param->min && *param->min > val) || 2009 (param->max && *param->max < val)) 2010 return -EINVAL; 2011 *valp = val; 2012 } else { 2013 int val = *valp; 2014 if (val < 0) { 2015 *negp = -1; 2016 *lvalp = (unsigned long)-val; 2017 } else { 2018 *negp = 0; 2019 *lvalp = (unsigned long)val; 2020 } 2021 } 2022 return 0; 2023 } 2024 2025 /** 2026 * proc_dointvec_minmax - read a vector of integers with min/max values 2027 * @table: the sysctl table 2028 * @write: %TRUE if this is a write to the sysctl file 2029 * @filp: the file structure 2030 * @buffer: the user buffer 2031 * @lenp: the size of the user buffer 2032 * @ppos: file position 2033 * 2034 * Reads/writes up to table->maxlen/sizeof(unsigned int) integer 2035 * values from/to the user buffer, treated as an ASCII string. 2036 * 2037 * This routine will ensure the values are within the range specified by 2038 * table->extra1 (min) and table->extra2 (max). 2039 * 2040 * Returns 0 on success. 2041 */ 2042 int proc_dointvec_minmax(ctl_table *table, int write, struct file *filp, 2043 void __user *buffer, size_t *lenp, loff_t *ppos) 2044 { 2045 struct do_proc_dointvec_minmax_conv_param param = { 2046 .min = (int *) table->extra1, 2047 .max = (int *) table->extra2, 2048 }; 2049 return do_proc_dointvec(table, write, filp, buffer, lenp, ppos, 2050 do_proc_dointvec_minmax_conv, ¶m); 2051 } 2052 2053 static int __do_proc_doulongvec_minmax(void *data, ctl_table *table, int write, 2054 struct file *filp, 2055 void __user *buffer, 2056 size_t *lenp, loff_t *ppos, 2057 unsigned long convmul, 2058 unsigned long convdiv) 2059 { 2060 #define TMPBUFLEN 21 2061 unsigned long *i, *min, *max, val; 2062 int vleft, first=1, neg; 2063 size_t len, left; 2064 char buf[TMPBUFLEN], *p; 2065 char __user *s = buffer; 2066 2067 if (!data || !table->maxlen || !*lenp || 2068 (*ppos && !write)) { 2069 *lenp = 0; 2070 return 0; 2071 } 2072 2073 i = (unsigned long *) data; 2074 min = (unsigned long *) table->extra1; 2075 max = (unsigned long *) table->extra2; 2076 vleft = table->maxlen / sizeof(unsigned long); 2077 left = *lenp; 2078 2079 for (; left && vleft--; i++, min++, max++, first=0) { 2080 if (write) { 2081 while (left) { 2082 char c; 2083 if (get_user(c, s)) 2084 return -EFAULT; 2085 if (!isspace(c)) 2086 break; 2087 left--; 2088 s++; 2089 } 2090 if (!left) 2091 break; 2092 neg = 0; 2093 len = left; 2094 if (len > TMPBUFLEN-1) 2095 len = TMPBUFLEN-1; 2096 if (copy_from_user(buf, s, len)) 2097 return -EFAULT; 2098 buf[len] = 0; 2099 p = buf; 2100 if (*p == '-' && left > 1) { 2101 neg = 1; 2102 p++; 2103 } 2104 if (*p < '0' || *p > '9') 2105 break; 2106 val = simple_strtoul(p, &p, 0) * convmul / convdiv ; 2107 len = p-buf; 2108 if ((len < left) && *p && !isspace(*p)) 2109 break; 2110 if (neg) 2111 val = -val; 2112 s += len; 2113 left -= len; 2114 2115 if(neg) 2116 continue; 2117 if ((min && val < *min) || (max && val > *max)) 2118 continue; 2119 *i = val; 2120 } else { 2121 p = buf; 2122 if (!first) 2123 *p++ = '\t'; 2124 sprintf(p, "%lu", convdiv * (*i) / convmul); 2125 len = strlen(buf); 2126 if (len > left) 2127 len = left; 2128 if(copy_to_user(s, buf, len)) 2129 return -EFAULT; 2130 left -= len; 2131 s += len; 2132 } 2133 } 2134 2135 if (!write && !first && left) { 2136 if(put_user('\n', s)) 2137 return -EFAULT; 2138 left--, s++; 2139 } 2140 if (write) { 2141 while (left) { 2142 char c; 2143 if (get_user(c, s++)) 2144 return -EFAULT; 2145 if (!isspace(c)) 2146 break; 2147 left--; 2148 } 2149 } 2150 if (write && first) 2151 return -EINVAL; 2152 *lenp -= left; 2153 *ppos += *lenp; 2154 return 0; 2155 #undef TMPBUFLEN 2156 } 2157 2158 static int do_proc_doulongvec_minmax(ctl_table *table, int write, 2159 struct file *filp, 2160 void __user *buffer, 2161 size_t *lenp, loff_t *ppos, 2162 unsigned long convmul, 2163 unsigned long convdiv) 2164 { 2165 return __do_proc_doulongvec_minmax(table->data, table, write, 2166 filp, buffer, lenp, ppos, convmul, convdiv); 2167 } 2168 2169 /** 2170 * proc_doulongvec_minmax - read a vector of long integers with min/max values 2171 * @table: the sysctl table 2172 * @write: %TRUE if this is a write to the sysctl file 2173 * @filp: the file structure 2174 * @buffer: the user buffer 2175 * @lenp: the size of the user buffer 2176 * @ppos: file position 2177 * 2178 * Reads/writes up to table->maxlen/sizeof(unsigned long) unsigned long 2179 * values from/to the user buffer, treated as an ASCII string. 2180 * 2181 * This routine will ensure the values are within the range specified by 2182 * table->extra1 (min) and table->extra2 (max). 2183 * 2184 * Returns 0 on success. 2185 */ 2186 int proc_doulongvec_minmax(ctl_table *table, int write, struct file *filp, 2187 void __user *buffer, size_t *lenp, loff_t *ppos) 2188 { 2189 return do_proc_doulongvec_minmax(table, write, filp, buffer, lenp, ppos, 1l, 1l); 2190 } 2191 2192 /** 2193 * proc_doulongvec_ms_jiffies_minmax - read a vector of millisecond values with min/max values 2194 * @table: the sysctl table 2195 * @write: %TRUE if this is a write to the sysctl file 2196 * @filp: the file structure 2197 * @buffer: the user buffer 2198 * @lenp: the size of the user buffer 2199 * @ppos: file position 2200 * 2201 * Reads/writes up to table->maxlen/sizeof(unsigned long) unsigned long 2202 * values from/to the user buffer, treated as an ASCII string. The values 2203 * are treated as milliseconds, and converted to jiffies when they are stored. 2204 * 2205 * This routine will ensure the values are within the range specified by 2206 * table->extra1 (min) and table->extra2 (max). 2207 * 2208 * Returns 0 on success. 2209 */ 2210 int proc_doulongvec_ms_jiffies_minmax(ctl_table *table, int write, 2211 struct file *filp, 2212 void __user *buffer, 2213 size_t *lenp, loff_t *ppos) 2214 { 2215 return do_proc_doulongvec_minmax(table, write, filp, buffer, 2216 lenp, ppos, HZ, 1000l); 2217 } 2218 2219 2220 static int do_proc_dointvec_jiffies_conv(int *negp, unsigned long *lvalp, 2221 int *valp, 2222 int write, void *data) 2223 { 2224 if (write) { 2225 if (*lvalp > LONG_MAX / HZ) 2226 return 1; 2227 *valp = *negp ? -(*lvalp*HZ) : (*lvalp*HZ); 2228 } else { 2229 int val = *valp; 2230 unsigned long lval; 2231 if (val < 0) { 2232 *negp = -1; 2233 lval = (unsigned long)-val; 2234 } else { 2235 *negp = 0; 2236 lval = (unsigned long)val; 2237 } 2238 *lvalp = lval / HZ; 2239 } 2240 return 0; 2241 } 2242 2243 static int do_proc_dointvec_userhz_jiffies_conv(int *negp, unsigned long *lvalp, 2244 int *valp, 2245 int write, void *data) 2246 { 2247 if (write) { 2248 if (USER_HZ < HZ && *lvalp > (LONG_MAX / HZ) * USER_HZ) 2249 return 1; 2250 *valp = clock_t_to_jiffies(*negp ? -*lvalp : *lvalp); 2251 } else { 2252 int val = *valp; 2253 unsigned long lval; 2254 if (val < 0) { 2255 *negp = -1; 2256 lval = (unsigned long)-val; 2257 } else { 2258 *negp = 0; 2259 lval = (unsigned long)val; 2260 } 2261 *lvalp = jiffies_to_clock_t(lval); 2262 } 2263 return 0; 2264 } 2265 2266 static int do_proc_dointvec_ms_jiffies_conv(int *negp, unsigned long *lvalp, 2267 int *valp, 2268 int write, void *data) 2269 { 2270 if (write) { 2271 *valp = msecs_to_jiffies(*negp ? -*lvalp : *lvalp); 2272 } else { 2273 int val = *valp; 2274 unsigned long lval; 2275 if (val < 0) { 2276 *negp = -1; 2277 lval = (unsigned long)-val; 2278 } else { 2279 *negp = 0; 2280 lval = (unsigned long)val; 2281 } 2282 *lvalp = jiffies_to_msecs(lval); 2283 } 2284 return 0; 2285 } 2286 2287 /** 2288 * proc_dointvec_jiffies - read a vector of integers as seconds 2289 * @table: the sysctl table 2290 * @write: %TRUE if this is a write to the sysctl file 2291 * @filp: the file structure 2292 * @buffer: the user buffer 2293 * @lenp: the size of the user buffer 2294 * @ppos: file position 2295 * 2296 * Reads/writes up to table->maxlen/sizeof(unsigned int) integer 2297 * values from/to the user buffer, treated as an ASCII string. 2298 * The values read are assumed to be in seconds, and are converted into 2299 * jiffies. 2300 * 2301 * Returns 0 on success. 2302 */ 2303 int proc_dointvec_jiffies(ctl_table *table, int write, struct file *filp, 2304 void __user *buffer, size_t *lenp, loff_t *ppos) 2305 { 2306 return do_proc_dointvec(table,write,filp,buffer,lenp,ppos, 2307 do_proc_dointvec_jiffies_conv,NULL); 2308 } 2309 2310 /** 2311 * proc_dointvec_userhz_jiffies - read a vector of integers as 1/USER_HZ seconds 2312 * @table: the sysctl table 2313 * @write: %TRUE if this is a write to the sysctl file 2314 * @filp: the file structure 2315 * @buffer: the user buffer 2316 * @lenp: the size of the user buffer 2317 * @ppos: pointer to the file position 2318 * 2319 * Reads/writes up to table->maxlen/sizeof(unsigned int) integer 2320 * values from/to the user buffer, treated as an ASCII string. 2321 * The values read are assumed to be in 1/USER_HZ seconds, and 2322 * are converted into jiffies. 2323 * 2324 * Returns 0 on success. 2325 */ 2326 int proc_dointvec_userhz_jiffies(ctl_table *table, int write, struct file *filp, 2327 void __user *buffer, size_t *lenp, loff_t *ppos) 2328 { 2329 return do_proc_dointvec(table,write,filp,buffer,lenp,ppos, 2330 do_proc_dointvec_userhz_jiffies_conv,NULL); 2331 } 2332 2333 /** 2334 * proc_dointvec_ms_jiffies - read a vector of integers as 1 milliseconds 2335 * @table: the sysctl table 2336 * @write: %TRUE if this is a write to the sysctl file 2337 * @filp: the file structure 2338 * @buffer: the user buffer 2339 * @lenp: the size of the user buffer 2340 * @ppos: file position 2341 * @ppos: the current position in the file 2342 * 2343 * Reads/writes up to table->maxlen/sizeof(unsigned int) integer 2344 * values from/to the user buffer, treated as an ASCII string. 2345 * The values read are assumed to be in 1/1000 seconds, and 2346 * are converted into jiffies. 2347 * 2348 * Returns 0 on success. 2349 */ 2350 int proc_dointvec_ms_jiffies(ctl_table *table, int write, struct file *filp, 2351 void __user *buffer, size_t *lenp, loff_t *ppos) 2352 { 2353 return do_proc_dointvec(table, write, filp, buffer, lenp, ppos, 2354 do_proc_dointvec_ms_jiffies_conv, NULL); 2355 } 2356 2357 #ifdef CONFIG_SYSVIPC 2358 static int proc_ipc_dointvec(ctl_table *table, int write, struct file *filp, 2359 void __user *buffer, size_t *lenp, loff_t *ppos) 2360 { 2361 void *which; 2362 which = get_ipc(table, write); 2363 return __do_proc_dointvec(which, table, write, filp, buffer, 2364 lenp, ppos, NULL, NULL); 2365 } 2366 2367 static int proc_ipc_doulongvec_minmax(ctl_table *table, int write, 2368 struct file *filp, void __user *buffer, size_t *lenp, loff_t *ppos) 2369 { 2370 void *which; 2371 which = get_ipc(table, write); 2372 return __do_proc_doulongvec_minmax(which, table, write, filp, buffer, 2373 lenp, ppos, 1l, 1l); 2374 } 2375 2376 #endif 2377 2378 static int proc_do_cad_pid(ctl_table *table, int write, struct file *filp, 2379 void __user *buffer, size_t *lenp, loff_t *ppos) 2380 { 2381 struct pid *new_pid; 2382 pid_t tmp; 2383 int r; 2384 2385 tmp = pid_nr(cad_pid); 2386 2387 r = __do_proc_dointvec(&tmp, table, write, filp, buffer, 2388 lenp, ppos, NULL, NULL); 2389 if (r || !write) 2390 return r; 2391 2392 new_pid = find_get_pid(tmp); 2393 if (!new_pid) 2394 return -ESRCH; 2395 2396 put_pid(xchg(&cad_pid, new_pid)); 2397 return 0; 2398 } 2399 2400 #else /* CONFIG_PROC_FS */ 2401 2402 int proc_dostring(ctl_table *table, int write, struct file *filp, 2403 void __user *buffer, size_t *lenp, loff_t *ppos) 2404 { 2405 return -ENOSYS; 2406 } 2407 2408 static int proc_do_uts_string(ctl_table *table, int write, struct file *filp, 2409 void __user *buffer, size_t *lenp, loff_t *ppos) 2410 { 2411 return -ENOSYS; 2412 } 2413 2414 #ifdef CONFIG_SYSVIPC 2415 static int proc_do_ipc_string(ctl_table *table, int write, struct file *filp, 2416 void __user *buffer, size_t *lenp, loff_t *ppos) 2417 { 2418 return -ENOSYS; 2419 } 2420 static int proc_ipc_dointvec(ctl_table *table, int write, struct file *filp, 2421 void __user *buffer, size_t *lenp, loff_t *ppos) 2422 { 2423 return -ENOSYS; 2424 } 2425 static int proc_ipc_doulongvec_minmax(ctl_table *table, int write, 2426 struct file *filp, void __user *buffer, 2427 size_t *lenp, loff_t *ppos) 2428 { 2429 return -ENOSYS; 2430 } 2431 #endif 2432 2433 int proc_dointvec(ctl_table *table, int write, struct file *filp, 2434 void __user *buffer, size_t *lenp, loff_t *ppos) 2435 { 2436 return -ENOSYS; 2437 } 2438 2439 int proc_dointvec_bset(ctl_table *table, int write, struct file *filp, 2440 void __user *buffer, size_t *lenp, loff_t *ppos) 2441 { 2442 return -ENOSYS; 2443 } 2444 2445 int proc_dointvec_minmax(ctl_table *table, int write, struct file *filp, 2446 void __user *buffer, size_t *lenp, loff_t *ppos) 2447 { 2448 return -ENOSYS; 2449 } 2450 2451 int proc_dointvec_jiffies(ctl_table *table, int write, struct file *filp, 2452 void __user *buffer, size_t *lenp, loff_t *ppos) 2453 { 2454 return -ENOSYS; 2455 } 2456 2457 int proc_dointvec_userhz_jiffies(ctl_table *table, int write, struct file *filp, 2458 void __user *buffer, size_t *lenp, loff_t *ppos) 2459 { 2460 return -ENOSYS; 2461 } 2462 2463 int proc_dointvec_ms_jiffies(ctl_table *table, int write, struct file *filp, 2464 void __user *buffer, size_t *lenp, loff_t *ppos) 2465 { 2466 return -ENOSYS; 2467 } 2468 2469 int proc_doulongvec_minmax(ctl_table *table, int write, struct file *filp, 2470 void __user *buffer, size_t *lenp, loff_t *ppos) 2471 { 2472 return -ENOSYS; 2473 } 2474 2475 int proc_doulongvec_ms_jiffies_minmax(ctl_table *table, int write, 2476 struct file *filp, 2477 void __user *buffer, 2478 size_t *lenp, loff_t *ppos) 2479 { 2480 return -ENOSYS; 2481 } 2482 2483 2484 #endif /* CONFIG_PROC_FS */ 2485 2486 2487 #ifdef CONFIG_SYSCTL_SYSCALL 2488 /* 2489 * General sysctl support routines 2490 */ 2491 2492 /* The generic string strategy routine: */ 2493 int sysctl_string(ctl_table *table, int __user *name, int nlen, 2494 void __user *oldval, size_t __user *oldlenp, 2495 void __user *newval, size_t newlen) 2496 { 2497 if (!table->data || !table->maxlen) 2498 return -ENOTDIR; 2499 2500 if (oldval && oldlenp) { 2501 size_t bufsize; 2502 if (get_user(bufsize, oldlenp)) 2503 return -EFAULT; 2504 if (bufsize) { 2505 size_t len = strlen(table->data), copied; 2506 2507 /* This shouldn't trigger for a well-formed sysctl */ 2508 if (len > table->maxlen) 2509 len = table->maxlen; 2510 2511 /* Copy up to a max of bufsize-1 bytes of the string */ 2512 copied = (len >= bufsize) ? bufsize - 1 : len; 2513 2514 if (copy_to_user(oldval, table->data, copied) || 2515 put_user(0, (char __user *)(oldval + copied))) 2516 return -EFAULT; 2517 if (put_user(len, oldlenp)) 2518 return -EFAULT; 2519 } 2520 } 2521 if (newval && newlen) { 2522 size_t len = newlen; 2523 if (len > table->maxlen) 2524 len = table->maxlen; 2525 if(copy_from_user(table->data, newval, len)) 2526 return -EFAULT; 2527 if (len == table->maxlen) 2528 len--; 2529 ((char *) table->data)[len] = 0; 2530 } 2531 return 1; 2532 } 2533 2534 /* 2535 * This function makes sure that all of the integers in the vector 2536 * are between the minimum and maximum values given in the arrays 2537 * table->extra1 and table->extra2, respectively. 2538 */ 2539 int sysctl_intvec(ctl_table *table, int __user *name, int nlen, 2540 void __user *oldval, size_t __user *oldlenp, 2541 void __user *newval, size_t newlen) 2542 { 2543 2544 if (newval && newlen) { 2545 int __user *vec = (int __user *) newval; 2546 int *min = (int *) table->extra1; 2547 int *max = (int *) table->extra2; 2548 size_t length; 2549 int i; 2550 2551 if (newlen % sizeof(int) != 0) 2552 return -EINVAL; 2553 2554 if (!table->extra1 && !table->extra2) 2555 return 0; 2556 2557 if (newlen > table->maxlen) 2558 newlen = table->maxlen; 2559 length = newlen / sizeof(int); 2560 2561 for (i = 0; i < length; i++) { 2562 int value; 2563 if (get_user(value, vec + i)) 2564 return -EFAULT; 2565 if (min && value < min[i]) 2566 return -EINVAL; 2567 if (max && value > max[i]) 2568 return -EINVAL; 2569 } 2570 } 2571 return 0; 2572 } 2573 2574 /* Strategy function to convert jiffies to seconds */ 2575 int sysctl_jiffies(ctl_table *table, int __user *name, int nlen, 2576 void __user *oldval, size_t __user *oldlenp, 2577 void __user *newval, size_t newlen) 2578 { 2579 if (oldval && oldlenp) { 2580 size_t olen; 2581 2582 if (get_user(olen, oldlenp)) 2583 return -EFAULT; 2584 if (olen) { 2585 int val; 2586 2587 if (olen < sizeof(int)) 2588 return -EINVAL; 2589 2590 val = *(int *)(table->data) / HZ; 2591 if (put_user(val, (int __user *)oldval)) 2592 return -EFAULT; 2593 if (put_user(sizeof(int), oldlenp)) 2594 return -EFAULT; 2595 } 2596 } 2597 if (newval && newlen) { 2598 int new; 2599 if (newlen != sizeof(int)) 2600 return -EINVAL; 2601 if (get_user(new, (int __user *)newval)) 2602 return -EFAULT; 2603 *(int *)(table->data) = new*HZ; 2604 } 2605 return 1; 2606 } 2607 2608 /* Strategy function to convert jiffies to seconds */ 2609 int sysctl_ms_jiffies(ctl_table *table, int __user *name, int nlen, 2610 void __user *oldval, size_t __user *oldlenp, 2611 void __user *newval, size_t newlen) 2612 { 2613 if (oldval && oldlenp) { 2614 size_t olen; 2615 2616 if (get_user(olen, oldlenp)) 2617 return -EFAULT; 2618 if (olen) { 2619 int val; 2620 2621 if (olen < sizeof(int)) 2622 return -EINVAL; 2623 2624 val = jiffies_to_msecs(*(int *)(table->data)); 2625 if (put_user(val, (int __user *)oldval)) 2626 return -EFAULT; 2627 if (put_user(sizeof(int), oldlenp)) 2628 return -EFAULT; 2629 } 2630 } 2631 if (newval && newlen) { 2632 int new; 2633 if (newlen != sizeof(int)) 2634 return -EINVAL; 2635 if (get_user(new, (int __user *)newval)) 2636 return -EFAULT; 2637 *(int *)(table->data) = msecs_to_jiffies(new); 2638 } 2639 return 1; 2640 } 2641 2642 2643 /* The generic string strategy routine: */ 2644 static int sysctl_uts_string(ctl_table *table, int __user *name, int nlen, 2645 void __user *oldval, size_t __user *oldlenp, 2646 void __user *newval, size_t newlen) 2647 { 2648 struct ctl_table uts_table; 2649 int r, write; 2650 write = newval && newlen; 2651 memcpy(&uts_table, table, sizeof(uts_table)); 2652 uts_table.data = get_uts(table, write); 2653 r = sysctl_string(&uts_table, name, nlen, 2654 oldval, oldlenp, newval, newlen); 2655 put_uts(table, write, uts_table.data); 2656 return r; 2657 } 2658 2659 #ifdef CONFIG_SYSVIPC 2660 /* The generic sysctl ipc data routine. */ 2661 static int sysctl_ipc_data(ctl_table *table, int __user *name, int nlen, 2662 void __user *oldval, size_t __user *oldlenp, 2663 void __user *newval, size_t newlen) 2664 { 2665 size_t len; 2666 void *data; 2667 2668 /* Get out of I don't have a variable */ 2669 if (!table->data || !table->maxlen) 2670 return -ENOTDIR; 2671 2672 data = get_ipc(table, 1); 2673 if (!data) 2674 return -ENOTDIR; 2675 2676 if (oldval && oldlenp) { 2677 if (get_user(len, oldlenp)) 2678 return -EFAULT; 2679 if (len) { 2680 if (len > table->maxlen) 2681 len = table->maxlen; 2682 if (copy_to_user(oldval, data, len)) 2683 return -EFAULT; 2684 if (put_user(len, oldlenp)) 2685 return -EFAULT; 2686 } 2687 } 2688 2689 if (newval && newlen) { 2690 if (newlen > table->maxlen) 2691 newlen = table->maxlen; 2692 2693 if (copy_from_user(data, newval, newlen)) 2694 return -EFAULT; 2695 } 2696 return 1; 2697 } 2698 #endif 2699 2700 #else /* CONFIG_SYSCTL_SYSCALL */ 2701 2702 2703 asmlinkage long sys_sysctl(struct __sysctl_args __user *args) 2704 { 2705 static int msg_count; 2706 struct __sysctl_args tmp; 2707 int name[CTL_MAXNAME]; 2708 int i; 2709 2710 /* Read in the sysctl name for better debug message logging */ 2711 if (copy_from_user(&tmp, args, sizeof(tmp))) 2712 return -EFAULT; 2713 if (tmp.nlen <= 0 || tmp.nlen >= CTL_MAXNAME) 2714 return -ENOTDIR; 2715 for (i = 0; i < tmp.nlen; i++) 2716 if (get_user(name[i], tmp.name + i)) 2717 return -EFAULT; 2718 2719 /* Ignore accesses to kernel.version */ 2720 if ((tmp.nlen == 2) && (name[0] == CTL_KERN) && (name[1] == KERN_VERSION)) 2721 goto out; 2722 2723 if (msg_count < 5) { 2724 msg_count++; 2725 printk(KERN_INFO 2726 "warning: process `%s' used the removed sysctl " 2727 "system call with ", current->comm); 2728 for (i = 0; i < tmp.nlen; i++) 2729 printk("%d.", name[i]); 2730 printk("\n"); 2731 } 2732 out: 2733 return -ENOSYS; 2734 } 2735 2736 int sysctl_string(ctl_table *table, int __user *name, int nlen, 2737 void __user *oldval, size_t __user *oldlenp, 2738 void __user *newval, size_t newlen) 2739 { 2740 return -ENOSYS; 2741 } 2742 2743 int sysctl_intvec(ctl_table *table, int __user *name, int nlen, 2744 void __user *oldval, size_t __user *oldlenp, 2745 void __user *newval, size_t newlen) 2746 { 2747 return -ENOSYS; 2748 } 2749 2750 int sysctl_jiffies(ctl_table *table, int __user *name, int nlen, 2751 void __user *oldval, size_t __user *oldlenp, 2752 void __user *newval, size_t newlen) 2753 { 2754 return -ENOSYS; 2755 } 2756 2757 int sysctl_ms_jiffies(ctl_table *table, int __user *name, int nlen, 2758 void __user *oldval, size_t __user *oldlenp, 2759 void __user *newval, size_t newlen) 2760 { 2761 return -ENOSYS; 2762 } 2763 2764 static int sysctl_uts_string(ctl_table *table, int __user *name, int nlen, 2765 void __user *oldval, size_t __user *oldlenp, 2766 void __user *newval, size_t newlen) 2767 { 2768 return -ENOSYS; 2769 } 2770 static int sysctl_ipc_data(ctl_table *table, int __user *name, int nlen, 2771 void __user *oldval, size_t __user *oldlenp, 2772 void __user *newval, size_t newlen) 2773 { 2774 return -ENOSYS; 2775 } 2776 #endif /* CONFIG_SYSCTL_SYSCALL */ 2777 2778 /* 2779 * No sense putting this after each symbol definition, twice, 2780 * exception granted :-) 2781 */ 2782 EXPORT_SYMBOL(proc_dointvec); 2783 EXPORT_SYMBOL(proc_dointvec_jiffies); 2784 EXPORT_SYMBOL(proc_dointvec_minmax); 2785 EXPORT_SYMBOL(proc_dointvec_userhz_jiffies); 2786 EXPORT_SYMBOL(proc_dointvec_ms_jiffies); 2787 EXPORT_SYMBOL(proc_dostring); 2788 EXPORT_SYMBOL(proc_doulongvec_minmax); 2789 EXPORT_SYMBOL(proc_doulongvec_ms_jiffies_minmax); 2790 EXPORT_SYMBOL(register_sysctl_table); 2791 EXPORT_SYMBOL(sysctl_intvec); 2792 EXPORT_SYMBOL(sysctl_jiffies); 2793 EXPORT_SYMBOL(sysctl_ms_jiffies); 2794 EXPORT_SYMBOL(sysctl_string); 2795 EXPORT_SYMBOL(unregister_sysctl_table); 2796