1 /* 2 * linux/kernel/sys.c 3 * 4 * Copyright (C) 1991, 1992 Linus Torvalds 5 */ 6 7 #include <linux/module.h> 8 #include <linux/mm.h> 9 #include <linux/utsname.h> 10 #include <linux/mman.h> 11 #include <linux/notifier.h> 12 #include <linux/reboot.h> 13 #include <linux/prctl.h> 14 #include <linux/highuid.h> 15 #include <linux/fs.h> 16 #include <linux/perf_event.h> 17 #include <linux/resource.h> 18 #include <linux/kernel.h> 19 #include <linux/kexec.h> 20 #include <linux/workqueue.h> 21 #include <linux/capability.h> 22 #include <linux/device.h> 23 #include <linux/key.h> 24 #include <linux/times.h> 25 #include <linux/posix-timers.h> 26 #include <linux/security.h> 27 #include <linux/dcookies.h> 28 #include <linux/suspend.h> 29 #include <linux/tty.h> 30 #include <linux/signal.h> 31 #include <linux/cn_proc.h> 32 #include <linux/getcpu.h> 33 #include <linux/task_io_accounting_ops.h> 34 #include <linux/seccomp.h> 35 #include <linux/cpu.h> 36 #include <linux/ptrace.h> 37 #include <linux/fs_struct.h> 38 39 #include <linux/compat.h> 40 #include <linux/syscalls.h> 41 #include <linux/kprobes.h> 42 #include <linux/user_namespace.h> 43 44 #include <asm/uaccess.h> 45 #include <asm/io.h> 46 #include <asm/unistd.h> 47 48 #ifndef SET_UNALIGN_CTL 49 # define SET_UNALIGN_CTL(a,b) (-EINVAL) 50 #endif 51 #ifndef GET_UNALIGN_CTL 52 # define GET_UNALIGN_CTL(a,b) (-EINVAL) 53 #endif 54 #ifndef SET_FPEMU_CTL 55 # define SET_FPEMU_CTL(a,b) (-EINVAL) 56 #endif 57 #ifndef GET_FPEMU_CTL 58 # define GET_FPEMU_CTL(a,b) (-EINVAL) 59 #endif 60 #ifndef SET_FPEXC_CTL 61 # define SET_FPEXC_CTL(a,b) (-EINVAL) 62 #endif 63 #ifndef GET_FPEXC_CTL 64 # define GET_FPEXC_CTL(a,b) (-EINVAL) 65 #endif 66 #ifndef GET_ENDIAN 67 # define GET_ENDIAN(a,b) (-EINVAL) 68 #endif 69 #ifndef SET_ENDIAN 70 # define SET_ENDIAN(a,b) (-EINVAL) 71 #endif 72 #ifndef GET_TSC_CTL 73 # define GET_TSC_CTL(a) (-EINVAL) 74 #endif 75 #ifndef SET_TSC_CTL 76 # define SET_TSC_CTL(a) (-EINVAL) 77 #endif 78 79 /* 80 * this is where the system-wide overflow UID and GID are defined, for 81 * architectures that now have 32-bit UID/GID but didn't in the past 82 */ 83 84 int overflowuid = DEFAULT_OVERFLOWUID; 85 int overflowgid = DEFAULT_OVERFLOWGID; 86 87 #ifdef CONFIG_UID16 88 EXPORT_SYMBOL(overflowuid); 89 EXPORT_SYMBOL(overflowgid); 90 #endif 91 92 /* 93 * the same as above, but for filesystems which can only store a 16-bit 94 * UID and GID. as such, this is needed on all architectures 95 */ 96 97 int fs_overflowuid = DEFAULT_FS_OVERFLOWUID; 98 int fs_overflowgid = DEFAULT_FS_OVERFLOWUID; 99 100 EXPORT_SYMBOL(fs_overflowuid); 101 EXPORT_SYMBOL(fs_overflowgid); 102 103 /* 104 * this indicates whether you can reboot with ctrl-alt-del: the default is yes 105 */ 106 107 int C_A_D = 1; 108 struct pid *cad_pid; 109 EXPORT_SYMBOL(cad_pid); 110 111 /* 112 * If set, this is used for preparing the system to power off. 113 */ 114 115 void (*pm_power_off_prepare)(void); 116 117 /* 118 * set the priority of a task 119 * - the caller must hold the RCU read lock 120 */ 121 static int set_one_prio(struct task_struct *p, int niceval, int error) 122 { 123 const struct cred *cred = current_cred(), *pcred = __task_cred(p); 124 int no_nice; 125 126 if (pcred->uid != cred->euid && 127 pcred->euid != cred->euid && !capable(CAP_SYS_NICE)) { 128 error = -EPERM; 129 goto out; 130 } 131 if (niceval < task_nice(p) && !can_nice(p, niceval)) { 132 error = -EACCES; 133 goto out; 134 } 135 no_nice = security_task_setnice(p, niceval); 136 if (no_nice) { 137 error = no_nice; 138 goto out; 139 } 140 if (error == -ESRCH) 141 error = 0; 142 set_user_nice(p, niceval); 143 out: 144 return error; 145 } 146 147 SYSCALL_DEFINE3(setpriority, int, which, int, who, int, niceval) 148 { 149 struct task_struct *g, *p; 150 struct user_struct *user; 151 const struct cred *cred = current_cred(); 152 int error = -EINVAL; 153 struct pid *pgrp; 154 155 if (which > PRIO_USER || which < PRIO_PROCESS) 156 goto out; 157 158 /* normalize: avoid signed division (rounding problems) */ 159 error = -ESRCH; 160 if (niceval < -20) 161 niceval = -20; 162 if (niceval > 19) 163 niceval = 19; 164 165 rcu_read_lock(); 166 read_lock(&tasklist_lock); 167 switch (which) { 168 case PRIO_PROCESS: 169 if (who) 170 p = find_task_by_vpid(who); 171 else 172 p = current; 173 if (p) 174 error = set_one_prio(p, niceval, error); 175 break; 176 case PRIO_PGRP: 177 if (who) 178 pgrp = find_vpid(who); 179 else 180 pgrp = task_pgrp(current); 181 do_each_pid_thread(pgrp, PIDTYPE_PGID, p) { 182 error = set_one_prio(p, niceval, error); 183 } while_each_pid_thread(pgrp, PIDTYPE_PGID, p); 184 break; 185 case PRIO_USER: 186 user = (struct user_struct *) cred->user; 187 if (!who) 188 who = cred->uid; 189 else if ((who != cred->uid) && 190 !(user = find_user(who))) 191 goto out_unlock; /* No processes for this user */ 192 193 do_each_thread(g, p) { 194 if (__task_cred(p)->uid == who) 195 error = set_one_prio(p, niceval, error); 196 } while_each_thread(g, p); 197 if (who != cred->uid) 198 free_uid(user); /* For find_user() */ 199 break; 200 } 201 out_unlock: 202 read_unlock(&tasklist_lock); 203 rcu_read_unlock(); 204 out: 205 return error; 206 } 207 208 /* 209 * Ugh. To avoid negative return values, "getpriority()" will 210 * not return the normal nice-value, but a negated value that 211 * has been offset by 20 (ie it returns 40..1 instead of -20..19) 212 * to stay compatible. 213 */ 214 SYSCALL_DEFINE2(getpriority, int, which, int, who) 215 { 216 struct task_struct *g, *p; 217 struct user_struct *user; 218 const struct cred *cred = current_cred(); 219 long niceval, retval = -ESRCH; 220 struct pid *pgrp; 221 222 if (which > PRIO_USER || which < PRIO_PROCESS) 223 return -EINVAL; 224 225 rcu_read_lock(); 226 read_lock(&tasklist_lock); 227 switch (which) { 228 case PRIO_PROCESS: 229 if (who) 230 p = find_task_by_vpid(who); 231 else 232 p = current; 233 if (p) { 234 niceval = 20 - task_nice(p); 235 if (niceval > retval) 236 retval = niceval; 237 } 238 break; 239 case PRIO_PGRP: 240 if (who) 241 pgrp = find_vpid(who); 242 else 243 pgrp = task_pgrp(current); 244 do_each_pid_thread(pgrp, PIDTYPE_PGID, p) { 245 niceval = 20 - task_nice(p); 246 if (niceval > retval) 247 retval = niceval; 248 } while_each_pid_thread(pgrp, PIDTYPE_PGID, p); 249 break; 250 case PRIO_USER: 251 user = (struct user_struct *) cred->user; 252 if (!who) 253 who = cred->uid; 254 else if ((who != cred->uid) && 255 !(user = find_user(who))) 256 goto out_unlock; /* No processes for this user */ 257 258 do_each_thread(g, p) { 259 if (__task_cred(p)->uid == who) { 260 niceval = 20 - task_nice(p); 261 if (niceval > retval) 262 retval = niceval; 263 } 264 } while_each_thread(g, p); 265 if (who != cred->uid) 266 free_uid(user); /* for find_user() */ 267 break; 268 } 269 out_unlock: 270 read_unlock(&tasklist_lock); 271 rcu_read_unlock(); 272 273 return retval; 274 } 275 276 /** 277 * emergency_restart - reboot the system 278 * 279 * Without shutting down any hardware or taking any locks 280 * reboot the system. This is called when we know we are in 281 * trouble so this is our best effort to reboot. This is 282 * safe to call in interrupt context. 283 */ 284 void emergency_restart(void) 285 { 286 machine_emergency_restart(); 287 } 288 EXPORT_SYMBOL_GPL(emergency_restart); 289 290 void kernel_restart_prepare(char *cmd) 291 { 292 blocking_notifier_call_chain(&reboot_notifier_list, SYS_RESTART, cmd); 293 system_state = SYSTEM_RESTART; 294 device_shutdown(); 295 sysdev_shutdown(); 296 } 297 298 /** 299 * kernel_restart - reboot the system 300 * @cmd: pointer to buffer containing command to execute for restart 301 * or %NULL 302 * 303 * Shutdown everything and perform a clean reboot. 304 * This is not safe to call in interrupt context. 305 */ 306 void kernel_restart(char *cmd) 307 { 308 kernel_restart_prepare(cmd); 309 if (!cmd) 310 printk(KERN_EMERG "Restarting system.\n"); 311 else 312 printk(KERN_EMERG "Restarting system with command '%s'.\n", cmd); 313 machine_restart(cmd); 314 } 315 EXPORT_SYMBOL_GPL(kernel_restart); 316 317 static void kernel_shutdown_prepare(enum system_states state) 318 { 319 blocking_notifier_call_chain(&reboot_notifier_list, 320 (state == SYSTEM_HALT)?SYS_HALT:SYS_POWER_OFF, NULL); 321 system_state = state; 322 device_shutdown(); 323 } 324 /** 325 * kernel_halt - halt the system 326 * 327 * Shutdown everything and perform a clean system halt. 328 */ 329 void kernel_halt(void) 330 { 331 kernel_shutdown_prepare(SYSTEM_HALT); 332 sysdev_shutdown(); 333 printk(KERN_EMERG "System halted.\n"); 334 machine_halt(); 335 } 336 337 EXPORT_SYMBOL_GPL(kernel_halt); 338 339 /** 340 * kernel_power_off - power_off the system 341 * 342 * Shutdown everything and perform a clean system power_off. 343 */ 344 void kernel_power_off(void) 345 { 346 kernel_shutdown_prepare(SYSTEM_POWER_OFF); 347 if (pm_power_off_prepare) 348 pm_power_off_prepare(); 349 disable_nonboot_cpus(); 350 sysdev_shutdown(); 351 printk(KERN_EMERG "Power down.\n"); 352 machine_power_off(); 353 } 354 EXPORT_SYMBOL_GPL(kernel_power_off); 355 356 static DEFINE_MUTEX(reboot_mutex); 357 358 /* 359 * Reboot system call: for obvious reasons only root may call it, 360 * and even root needs to set up some magic numbers in the registers 361 * so that some mistake won't make this reboot the whole machine. 362 * You can also set the meaning of the ctrl-alt-del-key here. 363 * 364 * reboot doesn't sync: do that yourself before calling this. 365 */ 366 SYSCALL_DEFINE4(reboot, int, magic1, int, magic2, unsigned int, cmd, 367 void __user *, arg) 368 { 369 char buffer[256]; 370 int ret = 0; 371 372 /* We only trust the superuser with rebooting the system. */ 373 if (!capable(CAP_SYS_BOOT)) 374 return -EPERM; 375 376 /* For safety, we require "magic" arguments. */ 377 if (magic1 != LINUX_REBOOT_MAGIC1 || 378 (magic2 != LINUX_REBOOT_MAGIC2 && 379 magic2 != LINUX_REBOOT_MAGIC2A && 380 magic2 != LINUX_REBOOT_MAGIC2B && 381 magic2 != LINUX_REBOOT_MAGIC2C)) 382 return -EINVAL; 383 384 /* Instead of trying to make the power_off code look like 385 * halt when pm_power_off is not set do it the easy way. 386 */ 387 if ((cmd == LINUX_REBOOT_CMD_POWER_OFF) && !pm_power_off) 388 cmd = LINUX_REBOOT_CMD_HALT; 389 390 mutex_lock(&reboot_mutex); 391 switch (cmd) { 392 case LINUX_REBOOT_CMD_RESTART: 393 kernel_restart(NULL); 394 break; 395 396 case LINUX_REBOOT_CMD_CAD_ON: 397 C_A_D = 1; 398 break; 399 400 case LINUX_REBOOT_CMD_CAD_OFF: 401 C_A_D = 0; 402 break; 403 404 case LINUX_REBOOT_CMD_HALT: 405 kernel_halt(); 406 do_exit(0); 407 panic("cannot halt"); 408 409 case LINUX_REBOOT_CMD_POWER_OFF: 410 kernel_power_off(); 411 do_exit(0); 412 break; 413 414 case LINUX_REBOOT_CMD_RESTART2: 415 if (strncpy_from_user(&buffer[0], arg, sizeof(buffer) - 1) < 0) { 416 ret = -EFAULT; 417 break; 418 } 419 buffer[sizeof(buffer) - 1] = '\0'; 420 421 kernel_restart(buffer); 422 break; 423 424 #ifdef CONFIG_KEXEC 425 case LINUX_REBOOT_CMD_KEXEC: 426 ret = kernel_kexec(); 427 break; 428 #endif 429 430 #ifdef CONFIG_HIBERNATION 431 case LINUX_REBOOT_CMD_SW_SUSPEND: 432 ret = hibernate(); 433 break; 434 #endif 435 436 default: 437 ret = -EINVAL; 438 break; 439 } 440 mutex_unlock(&reboot_mutex); 441 return ret; 442 } 443 444 static void deferred_cad(struct work_struct *dummy) 445 { 446 kernel_restart(NULL); 447 } 448 449 /* 450 * This function gets called by ctrl-alt-del - ie the keyboard interrupt. 451 * As it's called within an interrupt, it may NOT sync: the only choice 452 * is whether to reboot at once, or just ignore the ctrl-alt-del. 453 */ 454 void ctrl_alt_del(void) 455 { 456 static DECLARE_WORK(cad_work, deferred_cad); 457 458 if (C_A_D) 459 schedule_work(&cad_work); 460 else 461 kill_cad_pid(SIGINT, 1); 462 } 463 464 /* 465 * Unprivileged users may change the real gid to the effective gid 466 * or vice versa. (BSD-style) 467 * 468 * If you set the real gid at all, or set the effective gid to a value not 469 * equal to the real gid, then the saved gid is set to the new effective gid. 470 * 471 * This makes it possible for a setgid program to completely drop its 472 * privileges, which is often a useful assertion to make when you are doing 473 * a security audit over a program. 474 * 475 * The general idea is that a program which uses just setregid() will be 476 * 100% compatible with BSD. A program which uses just setgid() will be 477 * 100% compatible with POSIX with saved IDs. 478 * 479 * SMP: There are not races, the GIDs are checked only by filesystem 480 * operations (as far as semantic preservation is concerned). 481 */ 482 SYSCALL_DEFINE2(setregid, gid_t, rgid, gid_t, egid) 483 { 484 const struct cred *old; 485 struct cred *new; 486 int retval; 487 488 new = prepare_creds(); 489 if (!new) 490 return -ENOMEM; 491 old = current_cred(); 492 493 retval = security_task_setgid(rgid, egid, (gid_t)-1, LSM_SETID_RE); 494 if (retval) 495 goto error; 496 497 retval = -EPERM; 498 if (rgid != (gid_t) -1) { 499 if (old->gid == rgid || 500 old->egid == rgid || 501 capable(CAP_SETGID)) 502 new->gid = rgid; 503 else 504 goto error; 505 } 506 if (egid != (gid_t) -1) { 507 if (old->gid == egid || 508 old->egid == egid || 509 old->sgid == egid || 510 capable(CAP_SETGID)) 511 new->egid = egid; 512 else 513 goto error; 514 } 515 516 if (rgid != (gid_t) -1 || 517 (egid != (gid_t) -1 && egid != old->gid)) 518 new->sgid = new->egid; 519 new->fsgid = new->egid; 520 521 return commit_creds(new); 522 523 error: 524 abort_creds(new); 525 return retval; 526 } 527 528 /* 529 * setgid() is implemented like SysV w/ SAVED_IDS 530 * 531 * SMP: Same implicit races as above. 532 */ 533 SYSCALL_DEFINE1(setgid, gid_t, gid) 534 { 535 const struct cred *old; 536 struct cred *new; 537 int retval; 538 539 new = prepare_creds(); 540 if (!new) 541 return -ENOMEM; 542 old = current_cred(); 543 544 retval = security_task_setgid(gid, (gid_t)-1, (gid_t)-1, LSM_SETID_ID); 545 if (retval) 546 goto error; 547 548 retval = -EPERM; 549 if (capable(CAP_SETGID)) 550 new->gid = new->egid = new->sgid = new->fsgid = gid; 551 else if (gid == old->gid || gid == old->sgid) 552 new->egid = new->fsgid = gid; 553 else 554 goto error; 555 556 return commit_creds(new); 557 558 error: 559 abort_creds(new); 560 return retval; 561 } 562 563 /* 564 * change the user struct in a credentials set to match the new UID 565 */ 566 static int set_user(struct cred *new) 567 { 568 struct user_struct *new_user; 569 570 new_user = alloc_uid(current_user_ns(), new->uid); 571 if (!new_user) 572 return -EAGAIN; 573 574 if (atomic_read(&new_user->processes) >= rlimit(RLIMIT_NPROC) && 575 new_user != INIT_USER) { 576 free_uid(new_user); 577 return -EAGAIN; 578 } 579 580 free_uid(new->user); 581 new->user = new_user; 582 return 0; 583 } 584 585 /* 586 * Unprivileged users may change the real uid to the effective uid 587 * or vice versa. (BSD-style) 588 * 589 * If you set the real uid at all, or set the effective uid to a value not 590 * equal to the real uid, then the saved uid is set to the new effective uid. 591 * 592 * This makes it possible for a setuid program to completely drop its 593 * privileges, which is often a useful assertion to make when you are doing 594 * a security audit over a program. 595 * 596 * The general idea is that a program which uses just setreuid() will be 597 * 100% compatible with BSD. A program which uses just setuid() will be 598 * 100% compatible with POSIX with saved IDs. 599 */ 600 SYSCALL_DEFINE2(setreuid, uid_t, ruid, uid_t, euid) 601 { 602 const struct cred *old; 603 struct cred *new; 604 int retval; 605 606 new = prepare_creds(); 607 if (!new) 608 return -ENOMEM; 609 old = current_cred(); 610 611 retval = security_task_setuid(ruid, euid, (uid_t)-1, LSM_SETID_RE); 612 if (retval) 613 goto error; 614 615 retval = -EPERM; 616 if (ruid != (uid_t) -1) { 617 new->uid = ruid; 618 if (old->uid != ruid && 619 old->euid != ruid && 620 !capable(CAP_SETUID)) 621 goto error; 622 } 623 624 if (euid != (uid_t) -1) { 625 new->euid = euid; 626 if (old->uid != euid && 627 old->euid != euid && 628 old->suid != euid && 629 !capable(CAP_SETUID)) 630 goto error; 631 } 632 633 if (new->uid != old->uid) { 634 retval = set_user(new); 635 if (retval < 0) 636 goto error; 637 } 638 if (ruid != (uid_t) -1 || 639 (euid != (uid_t) -1 && euid != old->uid)) 640 new->suid = new->euid; 641 new->fsuid = new->euid; 642 643 retval = security_task_fix_setuid(new, old, LSM_SETID_RE); 644 if (retval < 0) 645 goto error; 646 647 return commit_creds(new); 648 649 error: 650 abort_creds(new); 651 return retval; 652 } 653 654 /* 655 * setuid() is implemented like SysV with SAVED_IDS 656 * 657 * Note that SAVED_ID's is deficient in that a setuid root program 658 * like sendmail, for example, cannot set its uid to be a normal 659 * user and then switch back, because if you're root, setuid() sets 660 * the saved uid too. If you don't like this, blame the bright people 661 * in the POSIX committee and/or USG. Note that the BSD-style setreuid() 662 * will allow a root program to temporarily drop privileges and be able to 663 * regain them by swapping the real and effective uid. 664 */ 665 SYSCALL_DEFINE1(setuid, uid_t, uid) 666 { 667 const struct cred *old; 668 struct cred *new; 669 int retval; 670 671 new = prepare_creds(); 672 if (!new) 673 return -ENOMEM; 674 old = current_cred(); 675 676 retval = security_task_setuid(uid, (uid_t)-1, (uid_t)-1, LSM_SETID_ID); 677 if (retval) 678 goto error; 679 680 retval = -EPERM; 681 if (capable(CAP_SETUID)) { 682 new->suid = new->uid = uid; 683 if (uid != old->uid) { 684 retval = set_user(new); 685 if (retval < 0) 686 goto error; 687 } 688 } else if (uid != old->uid && uid != new->suid) { 689 goto error; 690 } 691 692 new->fsuid = new->euid = uid; 693 694 retval = security_task_fix_setuid(new, old, LSM_SETID_ID); 695 if (retval < 0) 696 goto error; 697 698 return commit_creds(new); 699 700 error: 701 abort_creds(new); 702 return retval; 703 } 704 705 706 /* 707 * This function implements a generic ability to update ruid, euid, 708 * and suid. This allows you to implement the 4.4 compatible seteuid(). 709 */ 710 SYSCALL_DEFINE3(setresuid, uid_t, ruid, uid_t, euid, uid_t, suid) 711 { 712 const struct cred *old; 713 struct cred *new; 714 int retval; 715 716 new = prepare_creds(); 717 if (!new) 718 return -ENOMEM; 719 720 retval = security_task_setuid(ruid, euid, suid, LSM_SETID_RES); 721 if (retval) 722 goto error; 723 old = current_cred(); 724 725 retval = -EPERM; 726 if (!capable(CAP_SETUID)) { 727 if (ruid != (uid_t) -1 && ruid != old->uid && 728 ruid != old->euid && ruid != old->suid) 729 goto error; 730 if (euid != (uid_t) -1 && euid != old->uid && 731 euid != old->euid && euid != old->suid) 732 goto error; 733 if (suid != (uid_t) -1 && suid != old->uid && 734 suid != old->euid && suid != old->suid) 735 goto error; 736 } 737 738 if (ruid != (uid_t) -1) { 739 new->uid = ruid; 740 if (ruid != old->uid) { 741 retval = set_user(new); 742 if (retval < 0) 743 goto error; 744 } 745 } 746 if (euid != (uid_t) -1) 747 new->euid = euid; 748 if (suid != (uid_t) -1) 749 new->suid = suid; 750 new->fsuid = new->euid; 751 752 retval = security_task_fix_setuid(new, old, LSM_SETID_RES); 753 if (retval < 0) 754 goto error; 755 756 return commit_creds(new); 757 758 error: 759 abort_creds(new); 760 return retval; 761 } 762 763 SYSCALL_DEFINE3(getresuid, uid_t __user *, ruid, uid_t __user *, euid, uid_t __user *, suid) 764 { 765 const struct cred *cred = current_cred(); 766 int retval; 767 768 if (!(retval = put_user(cred->uid, ruid)) && 769 !(retval = put_user(cred->euid, euid))) 770 retval = put_user(cred->suid, suid); 771 772 return retval; 773 } 774 775 /* 776 * Same as above, but for rgid, egid, sgid. 777 */ 778 SYSCALL_DEFINE3(setresgid, gid_t, rgid, gid_t, egid, gid_t, sgid) 779 { 780 const struct cred *old; 781 struct cred *new; 782 int retval; 783 784 new = prepare_creds(); 785 if (!new) 786 return -ENOMEM; 787 old = current_cred(); 788 789 retval = security_task_setgid(rgid, egid, sgid, LSM_SETID_RES); 790 if (retval) 791 goto error; 792 793 retval = -EPERM; 794 if (!capable(CAP_SETGID)) { 795 if (rgid != (gid_t) -1 && rgid != old->gid && 796 rgid != old->egid && rgid != old->sgid) 797 goto error; 798 if (egid != (gid_t) -1 && egid != old->gid && 799 egid != old->egid && egid != old->sgid) 800 goto error; 801 if (sgid != (gid_t) -1 && sgid != old->gid && 802 sgid != old->egid && sgid != old->sgid) 803 goto error; 804 } 805 806 if (rgid != (gid_t) -1) 807 new->gid = rgid; 808 if (egid != (gid_t) -1) 809 new->egid = egid; 810 if (sgid != (gid_t) -1) 811 new->sgid = sgid; 812 new->fsgid = new->egid; 813 814 return commit_creds(new); 815 816 error: 817 abort_creds(new); 818 return retval; 819 } 820 821 SYSCALL_DEFINE3(getresgid, gid_t __user *, rgid, gid_t __user *, egid, gid_t __user *, sgid) 822 { 823 const struct cred *cred = current_cred(); 824 int retval; 825 826 if (!(retval = put_user(cred->gid, rgid)) && 827 !(retval = put_user(cred->egid, egid))) 828 retval = put_user(cred->sgid, sgid); 829 830 return retval; 831 } 832 833 834 /* 835 * "setfsuid()" sets the fsuid - the uid used for filesystem checks. This 836 * is used for "access()" and for the NFS daemon (letting nfsd stay at 837 * whatever uid it wants to). It normally shadows "euid", except when 838 * explicitly set by setfsuid() or for access.. 839 */ 840 SYSCALL_DEFINE1(setfsuid, uid_t, uid) 841 { 842 const struct cred *old; 843 struct cred *new; 844 uid_t old_fsuid; 845 846 new = prepare_creds(); 847 if (!new) 848 return current_fsuid(); 849 old = current_cred(); 850 old_fsuid = old->fsuid; 851 852 if (security_task_setuid(uid, (uid_t)-1, (uid_t)-1, LSM_SETID_FS) < 0) 853 goto error; 854 855 if (uid == old->uid || uid == old->euid || 856 uid == old->suid || uid == old->fsuid || 857 capable(CAP_SETUID)) { 858 if (uid != old_fsuid) { 859 new->fsuid = uid; 860 if (security_task_fix_setuid(new, old, LSM_SETID_FS) == 0) 861 goto change_okay; 862 } 863 } 864 865 error: 866 abort_creds(new); 867 return old_fsuid; 868 869 change_okay: 870 commit_creds(new); 871 return old_fsuid; 872 } 873 874 /* 875 * Samma på svenska.. 876 */ 877 SYSCALL_DEFINE1(setfsgid, gid_t, gid) 878 { 879 const struct cred *old; 880 struct cred *new; 881 gid_t old_fsgid; 882 883 new = prepare_creds(); 884 if (!new) 885 return current_fsgid(); 886 old = current_cred(); 887 old_fsgid = old->fsgid; 888 889 if (security_task_setgid(gid, (gid_t)-1, (gid_t)-1, LSM_SETID_FS)) 890 goto error; 891 892 if (gid == old->gid || gid == old->egid || 893 gid == old->sgid || gid == old->fsgid || 894 capable(CAP_SETGID)) { 895 if (gid != old_fsgid) { 896 new->fsgid = gid; 897 goto change_okay; 898 } 899 } 900 901 error: 902 abort_creds(new); 903 return old_fsgid; 904 905 change_okay: 906 commit_creds(new); 907 return old_fsgid; 908 } 909 910 void do_sys_times(struct tms *tms) 911 { 912 cputime_t tgutime, tgstime, cutime, cstime; 913 914 spin_lock_irq(¤t->sighand->siglock); 915 thread_group_times(current, &tgutime, &tgstime); 916 cutime = current->signal->cutime; 917 cstime = current->signal->cstime; 918 spin_unlock_irq(¤t->sighand->siglock); 919 tms->tms_utime = cputime_to_clock_t(tgutime); 920 tms->tms_stime = cputime_to_clock_t(tgstime); 921 tms->tms_cutime = cputime_to_clock_t(cutime); 922 tms->tms_cstime = cputime_to_clock_t(cstime); 923 } 924 925 SYSCALL_DEFINE1(times, struct tms __user *, tbuf) 926 { 927 if (tbuf) { 928 struct tms tmp; 929 930 do_sys_times(&tmp); 931 if (copy_to_user(tbuf, &tmp, sizeof(struct tms))) 932 return -EFAULT; 933 } 934 force_successful_syscall_return(); 935 return (long) jiffies_64_to_clock_t(get_jiffies_64()); 936 } 937 938 /* 939 * This needs some heavy checking ... 940 * I just haven't the stomach for it. I also don't fully 941 * understand sessions/pgrp etc. Let somebody who does explain it. 942 * 943 * OK, I think I have the protection semantics right.... this is really 944 * only important on a multi-user system anyway, to make sure one user 945 * can't send a signal to a process owned by another. -TYT, 12/12/91 946 * 947 * Auch. Had to add the 'did_exec' flag to conform completely to POSIX. 948 * LBT 04.03.94 949 */ 950 SYSCALL_DEFINE2(setpgid, pid_t, pid, pid_t, pgid) 951 { 952 struct task_struct *p; 953 struct task_struct *group_leader = current->group_leader; 954 struct pid *pgrp; 955 int err; 956 957 if (!pid) 958 pid = task_pid_vnr(group_leader); 959 if (!pgid) 960 pgid = pid; 961 if (pgid < 0) 962 return -EINVAL; 963 964 /* From this point forward we keep holding onto the tasklist lock 965 * so that our parent does not change from under us. -DaveM 966 */ 967 write_lock_irq(&tasklist_lock); 968 969 err = -ESRCH; 970 p = find_task_by_vpid(pid); 971 if (!p) 972 goto out; 973 974 err = -EINVAL; 975 if (!thread_group_leader(p)) 976 goto out; 977 978 if (same_thread_group(p->real_parent, group_leader)) { 979 err = -EPERM; 980 if (task_session(p) != task_session(group_leader)) 981 goto out; 982 err = -EACCES; 983 if (p->did_exec) 984 goto out; 985 } else { 986 err = -ESRCH; 987 if (p != group_leader) 988 goto out; 989 } 990 991 err = -EPERM; 992 if (p->signal->leader) 993 goto out; 994 995 pgrp = task_pid(p); 996 if (pgid != pid) { 997 struct task_struct *g; 998 999 pgrp = find_vpid(pgid); 1000 g = pid_task(pgrp, PIDTYPE_PGID); 1001 if (!g || task_session(g) != task_session(group_leader)) 1002 goto out; 1003 } 1004 1005 err = security_task_setpgid(p, pgid); 1006 if (err) 1007 goto out; 1008 1009 if (task_pgrp(p) != pgrp) 1010 change_pid(p, PIDTYPE_PGID, pgrp); 1011 1012 err = 0; 1013 out: 1014 /* All paths lead to here, thus we are safe. -DaveM */ 1015 write_unlock_irq(&tasklist_lock); 1016 return err; 1017 } 1018 1019 SYSCALL_DEFINE1(getpgid, pid_t, pid) 1020 { 1021 struct task_struct *p; 1022 struct pid *grp; 1023 int retval; 1024 1025 rcu_read_lock(); 1026 if (!pid) 1027 grp = task_pgrp(current); 1028 else { 1029 retval = -ESRCH; 1030 p = find_task_by_vpid(pid); 1031 if (!p) 1032 goto out; 1033 grp = task_pgrp(p); 1034 if (!grp) 1035 goto out; 1036 1037 retval = security_task_getpgid(p); 1038 if (retval) 1039 goto out; 1040 } 1041 retval = pid_vnr(grp); 1042 out: 1043 rcu_read_unlock(); 1044 return retval; 1045 } 1046 1047 #ifdef __ARCH_WANT_SYS_GETPGRP 1048 1049 SYSCALL_DEFINE0(getpgrp) 1050 { 1051 return sys_getpgid(0); 1052 } 1053 1054 #endif 1055 1056 SYSCALL_DEFINE1(getsid, pid_t, pid) 1057 { 1058 struct task_struct *p; 1059 struct pid *sid; 1060 int retval; 1061 1062 rcu_read_lock(); 1063 if (!pid) 1064 sid = task_session(current); 1065 else { 1066 retval = -ESRCH; 1067 p = find_task_by_vpid(pid); 1068 if (!p) 1069 goto out; 1070 sid = task_session(p); 1071 if (!sid) 1072 goto out; 1073 1074 retval = security_task_getsid(p); 1075 if (retval) 1076 goto out; 1077 } 1078 retval = pid_vnr(sid); 1079 out: 1080 rcu_read_unlock(); 1081 return retval; 1082 } 1083 1084 SYSCALL_DEFINE0(setsid) 1085 { 1086 struct task_struct *group_leader = current->group_leader; 1087 struct pid *sid = task_pid(group_leader); 1088 pid_t session = pid_vnr(sid); 1089 int err = -EPERM; 1090 1091 write_lock_irq(&tasklist_lock); 1092 /* Fail if I am already a session leader */ 1093 if (group_leader->signal->leader) 1094 goto out; 1095 1096 /* Fail if a process group id already exists that equals the 1097 * proposed session id. 1098 */ 1099 if (pid_task(sid, PIDTYPE_PGID)) 1100 goto out; 1101 1102 group_leader->signal->leader = 1; 1103 __set_special_pids(sid); 1104 1105 proc_clear_tty(group_leader); 1106 1107 err = session; 1108 out: 1109 write_unlock_irq(&tasklist_lock); 1110 if (err > 0) 1111 proc_sid_connector(group_leader); 1112 return err; 1113 } 1114 1115 DECLARE_RWSEM(uts_sem); 1116 1117 SYSCALL_DEFINE1(newuname, struct new_utsname __user *, name) 1118 { 1119 int errno = 0; 1120 1121 down_read(&uts_sem); 1122 if (copy_to_user(name, utsname(), sizeof *name)) 1123 errno = -EFAULT; 1124 up_read(&uts_sem); 1125 return errno; 1126 } 1127 1128 SYSCALL_DEFINE2(sethostname, char __user *, name, int, len) 1129 { 1130 int errno; 1131 char tmp[__NEW_UTS_LEN]; 1132 1133 if (!capable(CAP_SYS_ADMIN)) 1134 return -EPERM; 1135 if (len < 0 || len > __NEW_UTS_LEN) 1136 return -EINVAL; 1137 down_write(&uts_sem); 1138 errno = -EFAULT; 1139 if (!copy_from_user(tmp, name, len)) { 1140 struct new_utsname *u = utsname(); 1141 1142 memcpy(u->nodename, tmp, len); 1143 memset(u->nodename + len, 0, sizeof(u->nodename) - len); 1144 errno = 0; 1145 } 1146 up_write(&uts_sem); 1147 return errno; 1148 } 1149 1150 #ifdef __ARCH_WANT_SYS_GETHOSTNAME 1151 1152 SYSCALL_DEFINE2(gethostname, char __user *, name, int, len) 1153 { 1154 int i, errno; 1155 struct new_utsname *u; 1156 1157 if (len < 0) 1158 return -EINVAL; 1159 down_read(&uts_sem); 1160 u = utsname(); 1161 i = 1 + strlen(u->nodename); 1162 if (i > len) 1163 i = len; 1164 errno = 0; 1165 if (copy_to_user(name, u->nodename, i)) 1166 errno = -EFAULT; 1167 up_read(&uts_sem); 1168 return errno; 1169 } 1170 1171 #endif 1172 1173 /* 1174 * Only setdomainname; getdomainname can be implemented by calling 1175 * uname() 1176 */ 1177 SYSCALL_DEFINE2(setdomainname, char __user *, name, int, len) 1178 { 1179 int errno; 1180 char tmp[__NEW_UTS_LEN]; 1181 1182 if (!capable(CAP_SYS_ADMIN)) 1183 return -EPERM; 1184 if (len < 0 || len > __NEW_UTS_LEN) 1185 return -EINVAL; 1186 1187 down_write(&uts_sem); 1188 errno = -EFAULT; 1189 if (!copy_from_user(tmp, name, len)) { 1190 struct new_utsname *u = utsname(); 1191 1192 memcpy(u->domainname, tmp, len); 1193 memset(u->domainname + len, 0, sizeof(u->domainname) - len); 1194 errno = 0; 1195 } 1196 up_write(&uts_sem); 1197 return errno; 1198 } 1199 1200 SYSCALL_DEFINE2(getrlimit, unsigned int, resource, struct rlimit __user *, rlim) 1201 { 1202 if (resource >= RLIM_NLIMITS) 1203 return -EINVAL; 1204 else { 1205 struct rlimit value; 1206 task_lock(current->group_leader); 1207 value = current->signal->rlim[resource]; 1208 task_unlock(current->group_leader); 1209 return copy_to_user(rlim, &value, sizeof(*rlim)) ? -EFAULT : 0; 1210 } 1211 } 1212 1213 #ifdef __ARCH_WANT_SYS_OLD_GETRLIMIT 1214 1215 /* 1216 * Back compatibility for getrlimit. Needed for some apps. 1217 */ 1218 1219 SYSCALL_DEFINE2(old_getrlimit, unsigned int, resource, 1220 struct rlimit __user *, rlim) 1221 { 1222 struct rlimit x; 1223 if (resource >= RLIM_NLIMITS) 1224 return -EINVAL; 1225 1226 task_lock(current->group_leader); 1227 x = current->signal->rlim[resource]; 1228 task_unlock(current->group_leader); 1229 if (x.rlim_cur > 0x7FFFFFFF) 1230 x.rlim_cur = 0x7FFFFFFF; 1231 if (x.rlim_max > 0x7FFFFFFF) 1232 x.rlim_max = 0x7FFFFFFF; 1233 return copy_to_user(rlim, &x, sizeof(x))?-EFAULT:0; 1234 } 1235 1236 #endif 1237 1238 SYSCALL_DEFINE2(setrlimit, unsigned int, resource, struct rlimit __user *, rlim) 1239 { 1240 struct rlimit new_rlim, *old_rlim; 1241 int retval; 1242 1243 if (resource >= RLIM_NLIMITS) 1244 return -EINVAL; 1245 if (copy_from_user(&new_rlim, rlim, sizeof(*rlim))) 1246 return -EFAULT; 1247 if (new_rlim.rlim_cur > new_rlim.rlim_max) 1248 return -EINVAL; 1249 old_rlim = current->signal->rlim + resource; 1250 if ((new_rlim.rlim_max > old_rlim->rlim_max) && 1251 !capable(CAP_SYS_RESOURCE)) 1252 return -EPERM; 1253 if (resource == RLIMIT_NOFILE && new_rlim.rlim_max > sysctl_nr_open) 1254 return -EPERM; 1255 1256 retval = security_task_setrlimit(resource, &new_rlim); 1257 if (retval) 1258 return retval; 1259 1260 if (resource == RLIMIT_CPU && new_rlim.rlim_cur == 0) { 1261 /* 1262 * The caller is asking for an immediate RLIMIT_CPU 1263 * expiry. But we use the zero value to mean "it was 1264 * never set". So let's cheat and make it one second 1265 * instead 1266 */ 1267 new_rlim.rlim_cur = 1; 1268 } 1269 1270 task_lock(current->group_leader); 1271 *old_rlim = new_rlim; 1272 task_unlock(current->group_leader); 1273 1274 if (resource != RLIMIT_CPU) 1275 goto out; 1276 1277 /* 1278 * RLIMIT_CPU handling. Note that the kernel fails to return an error 1279 * code if it rejected the user's attempt to set RLIMIT_CPU. This is a 1280 * very long-standing error, and fixing it now risks breakage of 1281 * applications, so we live with it 1282 */ 1283 if (new_rlim.rlim_cur == RLIM_INFINITY) 1284 goto out; 1285 1286 update_rlimit_cpu(new_rlim.rlim_cur); 1287 out: 1288 return 0; 1289 } 1290 1291 /* 1292 * It would make sense to put struct rusage in the task_struct, 1293 * except that would make the task_struct be *really big*. After 1294 * task_struct gets moved into malloc'ed memory, it would 1295 * make sense to do this. It will make moving the rest of the information 1296 * a lot simpler! (Which we're not doing right now because we're not 1297 * measuring them yet). 1298 * 1299 * When sampling multiple threads for RUSAGE_SELF, under SMP we might have 1300 * races with threads incrementing their own counters. But since word 1301 * reads are atomic, we either get new values or old values and we don't 1302 * care which for the sums. We always take the siglock to protect reading 1303 * the c* fields from p->signal from races with exit.c updating those 1304 * fields when reaping, so a sample either gets all the additions of a 1305 * given child after it's reaped, or none so this sample is before reaping. 1306 * 1307 * Locking: 1308 * We need to take the siglock for CHILDEREN, SELF and BOTH 1309 * for the cases current multithreaded, non-current single threaded 1310 * non-current multithreaded. Thread traversal is now safe with 1311 * the siglock held. 1312 * Strictly speaking, we donot need to take the siglock if we are current and 1313 * single threaded, as no one else can take our signal_struct away, no one 1314 * else can reap the children to update signal->c* counters, and no one else 1315 * can race with the signal-> fields. If we do not take any lock, the 1316 * signal-> fields could be read out of order while another thread was just 1317 * exiting. So we should place a read memory barrier when we avoid the lock. 1318 * On the writer side, write memory barrier is implied in __exit_signal 1319 * as __exit_signal releases the siglock spinlock after updating the signal-> 1320 * fields. But we don't do this yet to keep things simple. 1321 * 1322 */ 1323 1324 static void accumulate_thread_rusage(struct task_struct *t, struct rusage *r) 1325 { 1326 r->ru_nvcsw += t->nvcsw; 1327 r->ru_nivcsw += t->nivcsw; 1328 r->ru_minflt += t->min_flt; 1329 r->ru_majflt += t->maj_flt; 1330 r->ru_inblock += task_io_get_inblock(t); 1331 r->ru_oublock += task_io_get_oublock(t); 1332 } 1333 1334 static void k_getrusage(struct task_struct *p, int who, struct rusage *r) 1335 { 1336 struct task_struct *t; 1337 unsigned long flags; 1338 cputime_t tgutime, tgstime, utime, stime; 1339 unsigned long maxrss = 0; 1340 1341 memset((char *) r, 0, sizeof *r); 1342 utime = stime = cputime_zero; 1343 1344 if (who == RUSAGE_THREAD) { 1345 task_times(current, &utime, &stime); 1346 accumulate_thread_rusage(p, r); 1347 maxrss = p->signal->maxrss; 1348 goto out; 1349 } 1350 1351 if (!lock_task_sighand(p, &flags)) 1352 return; 1353 1354 switch (who) { 1355 case RUSAGE_BOTH: 1356 case RUSAGE_CHILDREN: 1357 utime = p->signal->cutime; 1358 stime = p->signal->cstime; 1359 r->ru_nvcsw = p->signal->cnvcsw; 1360 r->ru_nivcsw = p->signal->cnivcsw; 1361 r->ru_minflt = p->signal->cmin_flt; 1362 r->ru_majflt = p->signal->cmaj_flt; 1363 r->ru_inblock = p->signal->cinblock; 1364 r->ru_oublock = p->signal->coublock; 1365 maxrss = p->signal->cmaxrss; 1366 1367 if (who == RUSAGE_CHILDREN) 1368 break; 1369 1370 case RUSAGE_SELF: 1371 thread_group_times(p, &tgutime, &tgstime); 1372 utime = cputime_add(utime, tgutime); 1373 stime = cputime_add(stime, tgstime); 1374 r->ru_nvcsw += p->signal->nvcsw; 1375 r->ru_nivcsw += p->signal->nivcsw; 1376 r->ru_minflt += p->signal->min_flt; 1377 r->ru_majflt += p->signal->maj_flt; 1378 r->ru_inblock += p->signal->inblock; 1379 r->ru_oublock += p->signal->oublock; 1380 if (maxrss < p->signal->maxrss) 1381 maxrss = p->signal->maxrss; 1382 t = p; 1383 do { 1384 accumulate_thread_rusage(t, r); 1385 t = next_thread(t); 1386 } while (t != p); 1387 break; 1388 1389 default: 1390 BUG(); 1391 } 1392 unlock_task_sighand(p, &flags); 1393 1394 out: 1395 cputime_to_timeval(utime, &r->ru_utime); 1396 cputime_to_timeval(stime, &r->ru_stime); 1397 1398 if (who != RUSAGE_CHILDREN) { 1399 struct mm_struct *mm = get_task_mm(p); 1400 if (mm) { 1401 setmax_mm_hiwater_rss(&maxrss, mm); 1402 mmput(mm); 1403 } 1404 } 1405 r->ru_maxrss = maxrss * (PAGE_SIZE / 1024); /* convert pages to KBs */ 1406 } 1407 1408 int getrusage(struct task_struct *p, int who, struct rusage __user *ru) 1409 { 1410 struct rusage r; 1411 k_getrusage(p, who, &r); 1412 return copy_to_user(ru, &r, sizeof(r)) ? -EFAULT : 0; 1413 } 1414 1415 SYSCALL_DEFINE2(getrusage, int, who, struct rusage __user *, ru) 1416 { 1417 if (who != RUSAGE_SELF && who != RUSAGE_CHILDREN && 1418 who != RUSAGE_THREAD) 1419 return -EINVAL; 1420 return getrusage(current, who, ru); 1421 } 1422 1423 SYSCALL_DEFINE1(umask, int, mask) 1424 { 1425 mask = xchg(¤t->fs->umask, mask & S_IRWXUGO); 1426 return mask; 1427 } 1428 1429 SYSCALL_DEFINE5(prctl, int, option, unsigned long, arg2, unsigned long, arg3, 1430 unsigned long, arg4, unsigned long, arg5) 1431 { 1432 struct task_struct *me = current; 1433 unsigned char comm[sizeof(me->comm)]; 1434 long error; 1435 1436 error = security_task_prctl(option, arg2, arg3, arg4, arg5); 1437 if (error != -ENOSYS) 1438 return error; 1439 1440 error = 0; 1441 switch (option) { 1442 case PR_SET_PDEATHSIG: 1443 if (!valid_signal(arg2)) { 1444 error = -EINVAL; 1445 break; 1446 } 1447 me->pdeath_signal = arg2; 1448 error = 0; 1449 break; 1450 case PR_GET_PDEATHSIG: 1451 error = put_user(me->pdeath_signal, (int __user *)arg2); 1452 break; 1453 case PR_GET_DUMPABLE: 1454 error = get_dumpable(me->mm); 1455 break; 1456 case PR_SET_DUMPABLE: 1457 if (arg2 < 0 || arg2 > 1) { 1458 error = -EINVAL; 1459 break; 1460 } 1461 set_dumpable(me->mm, arg2); 1462 error = 0; 1463 break; 1464 1465 case PR_SET_UNALIGN: 1466 error = SET_UNALIGN_CTL(me, arg2); 1467 break; 1468 case PR_GET_UNALIGN: 1469 error = GET_UNALIGN_CTL(me, arg2); 1470 break; 1471 case PR_SET_FPEMU: 1472 error = SET_FPEMU_CTL(me, arg2); 1473 break; 1474 case PR_GET_FPEMU: 1475 error = GET_FPEMU_CTL(me, arg2); 1476 break; 1477 case PR_SET_FPEXC: 1478 error = SET_FPEXC_CTL(me, arg2); 1479 break; 1480 case PR_GET_FPEXC: 1481 error = GET_FPEXC_CTL(me, arg2); 1482 break; 1483 case PR_GET_TIMING: 1484 error = PR_TIMING_STATISTICAL; 1485 break; 1486 case PR_SET_TIMING: 1487 if (arg2 != PR_TIMING_STATISTICAL) 1488 error = -EINVAL; 1489 else 1490 error = 0; 1491 break; 1492 1493 case PR_SET_NAME: 1494 comm[sizeof(me->comm)-1] = 0; 1495 if (strncpy_from_user(comm, (char __user *)arg2, 1496 sizeof(me->comm) - 1) < 0) 1497 return -EFAULT; 1498 set_task_comm(me, comm); 1499 return 0; 1500 case PR_GET_NAME: 1501 get_task_comm(comm, me); 1502 if (copy_to_user((char __user *)arg2, comm, 1503 sizeof(comm))) 1504 return -EFAULT; 1505 return 0; 1506 case PR_GET_ENDIAN: 1507 error = GET_ENDIAN(me, arg2); 1508 break; 1509 case PR_SET_ENDIAN: 1510 error = SET_ENDIAN(me, arg2); 1511 break; 1512 1513 case PR_GET_SECCOMP: 1514 error = prctl_get_seccomp(); 1515 break; 1516 case PR_SET_SECCOMP: 1517 error = prctl_set_seccomp(arg2); 1518 break; 1519 case PR_GET_TSC: 1520 error = GET_TSC_CTL(arg2); 1521 break; 1522 case PR_SET_TSC: 1523 error = SET_TSC_CTL(arg2); 1524 break; 1525 case PR_TASK_PERF_EVENTS_DISABLE: 1526 error = perf_event_task_disable(); 1527 break; 1528 case PR_TASK_PERF_EVENTS_ENABLE: 1529 error = perf_event_task_enable(); 1530 break; 1531 case PR_GET_TIMERSLACK: 1532 error = current->timer_slack_ns; 1533 break; 1534 case PR_SET_TIMERSLACK: 1535 if (arg2 <= 0) 1536 current->timer_slack_ns = 1537 current->default_timer_slack_ns; 1538 else 1539 current->timer_slack_ns = arg2; 1540 error = 0; 1541 break; 1542 case PR_MCE_KILL: 1543 if (arg4 | arg5) 1544 return -EINVAL; 1545 switch (arg2) { 1546 case PR_MCE_KILL_CLEAR: 1547 if (arg3 != 0) 1548 return -EINVAL; 1549 current->flags &= ~PF_MCE_PROCESS; 1550 break; 1551 case PR_MCE_KILL_SET: 1552 current->flags |= PF_MCE_PROCESS; 1553 if (arg3 == PR_MCE_KILL_EARLY) 1554 current->flags |= PF_MCE_EARLY; 1555 else if (arg3 == PR_MCE_KILL_LATE) 1556 current->flags &= ~PF_MCE_EARLY; 1557 else if (arg3 == PR_MCE_KILL_DEFAULT) 1558 current->flags &= 1559 ~(PF_MCE_EARLY|PF_MCE_PROCESS); 1560 else 1561 return -EINVAL; 1562 break; 1563 default: 1564 return -EINVAL; 1565 } 1566 error = 0; 1567 break; 1568 case PR_MCE_KILL_GET: 1569 if (arg2 | arg3 | arg4 | arg5) 1570 return -EINVAL; 1571 if (current->flags & PF_MCE_PROCESS) 1572 error = (current->flags & PF_MCE_EARLY) ? 1573 PR_MCE_KILL_EARLY : PR_MCE_KILL_LATE; 1574 else 1575 error = PR_MCE_KILL_DEFAULT; 1576 break; 1577 default: 1578 error = -EINVAL; 1579 break; 1580 } 1581 return error; 1582 } 1583 1584 SYSCALL_DEFINE3(getcpu, unsigned __user *, cpup, unsigned __user *, nodep, 1585 struct getcpu_cache __user *, unused) 1586 { 1587 int err = 0; 1588 int cpu = raw_smp_processor_id(); 1589 if (cpup) 1590 err |= put_user(cpu, cpup); 1591 if (nodep) 1592 err |= put_user(cpu_to_node(cpu), nodep); 1593 return err ? -EFAULT : 0; 1594 } 1595 1596 char poweroff_cmd[POWEROFF_CMD_PATH_LEN] = "/sbin/poweroff"; 1597 1598 static void argv_cleanup(char **argv, char **envp) 1599 { 1600 argv_free(argv); 1601 } 1602 1603 /** 1604 * orderly_poweroff - Trigger an orderly system poweroff 1605 * @force: force poweroff if command execution fails 1606 * 1607 * This may be called from any context to trigger a system shutdown. 1608 * If the orderly shutdown fails, it will force an immediate shutdown. 1609 */ 1610 int orderly_poweroff(bool force) 1611 { 1612 int argc; 1613 char **argv = argv_split(GFP_ATOMIC, poweroff_cmd, &argc); 1614 static char *envp[] = { 1615 "HOME=/", 1616 "PATH=/sbin:/bin:/usr/sbin:/usr/bin", 1617 NULL 1618 }; 1619 int ret = -ENOMEM; 1620 struct subprocess_info *info; 1621 1622 if (argv == NULL) { 1623 printk(KERN_WARNING "%s failed to allocate memory for \"%s\"\n", 1624 __func__, poweroff_cmd); 1625 goto out; 1626 } 1627 1628 info = call_usermodehelper_setup(argv[0], argv, envp, GFP_ATOMIC); 1629 if (info == NULL) { 1630 argv_free(argv); 1631 goto out; 1632 } 1633 1634 call_usermodehelper_setcleanup(info, argv_cleanup); 1635 1636 ret = call_usermodehelper_exec(info, UMH_NO_WAIT); 1637 1638 out: 1639 if (ret && force) { 1640 printk(KERN_WARNING "Failed to start orderly shutdown: " 1641 "forcing the issue\n"); 1642 1643 /* I guess this should try to kick off some daemon to 1644 sync and poweroff asap. Or not even bother syncing 1645 if we're doing an emergency shutdown? */ 1646 emergency_sync(); 1647 kernel_power_off(); 1648 } 1649 1650 return ret; 1651 } 1652 EXPORT_SYMBOL_GPL(orderly_poweroff); 1653