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