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) >= 575 current->signal->rlim[RLIMIT_NPROC].rlim_cur && 576 new_user != INIT_USER) { 577 free_uid(new_user); 578 return -EAGAIN; 579 } 580 581 free_uid(new->user); 582 new->user = new_user; 583 return 0; 584 } 585 586 /* 587 * Unprivileged users may change the real uid to the effective uid 588 * or vice versa. (BSD-style) 589 * 590 * If you set the real uid at all, or set the effective uid to a value not 591 * equal to the real uid, then the saved uid is set to the new effective uid. 592 * 593 * This makes it possible for a setuid program to completely drop its 594 * privileges, which is often a useful assertion to make when you are doing 595 * a security audit over a program. 596 * 597 * The general idea is that a program which uses just setreuid() will be 598 * 100% compatible with BSD. A program which uses just setuid() will be 599 * 100% compatible with POSIX with saved IDs. 600 */ 601 SYSCALL_DEFINE2(setreuid, uid_t, ruid, uid_t, euid) 602 { 603 const struct cred *old; 604 struct cred *new; 605 int retval; 606 607 new = prepare_creds(); 608 if (!new) 609 return -ENOMEM; 610 old = current_cred(); 611 612 retval = security_task_setuid(ruid, euid, (uid_t)-1, LSM_SETID_RE); 613 if (retval) 614 goto error; 615 616 retval = -EPERM; 617 if (ruid != (uid_t) -1) { 618 new->uid = ruid; 619 if (old->uid != ruid && 620 old->euid != ruid && 621 !capable(CAP_SETUID)) 622 goto error; 623 } 624 625 if (euid != (uid_t) -1) { 626 new->euid = euid; 627 if (old->uid != euid && 628 old->euid != euid && 629 old->suid != euid && 630 !capable(CAP_SETUID)) 631 goto error; 632 } 633 634 if (new->uid != old->uid) { 635 retval = set_user(new); 636 if (retval < 0) 637 goto error; 638 } 639 if (ruid != (uid_t) -1 || 640 (euid != (uid_t) -1 && euid != old->uid)) 641 new->suid = new->euid; 642 new->fsuid = new->euid; 643 644 retval = security_task_fix_setuid(new, old, LSM_SETID_RE); 645 if (retval < 0) 646 goto error; 647 648 return commit_creds(new); 649 650 error: 651 abort_creds(new); 652 return retval; 653 } 654 655 /* 656 * setuid() is implemented like SysV with SAVED_IDS 657 * 658 * Note that SAVED_ID's is deficient in that a setuid root program 659 * like sendmail, for example, cannot set its uid to be a normal 660 * user and then switch back, because if you're root, setuid() sets 661 * the saved uid too. If you don't like this, blame the bright people 662 * in the POSIX committee and/or USG. Note that the BSD-style setreuid() 663 * will allow a root program to temporarily drop privileges and be able to 664 * regain them by swapping the real and effective uid. 665 */ 666 SYSCALL_DEFINE1(setuid, uid_t, uid) 667 { 668 const struct cred *old; 669 struct cred *new; 670 int retval; 671 672 new = prepare_creds(); 673 if (!new) 674 return -ENOMEM; 675 old = current_cred(); 676 677 retval = security_task_setuid(uid, (uid_t)-1, (uid_t)-1, LSM_SETID_ID); 678 if (retval) 679 goto error; 680 681 retval = -EPERM; 682 if (capable(CAP_SETUID)) { 683 new->suid = new->uid = uid; 684 if (uid != old->uid) { 685 retval = set_user(new); 686 if (retval < 0) 687 goto error; 688 } 689 } else if (uid != old->uid && uid != new->suid) { 690 goto error; 691 } 692 693 new->fsuid = new->euid = uid; 694 695 retval = security_task_fix_setuid(new, old, LSM_SETID_ID); 696 if (retval < 0) 697 goto error; 698 699 return commit_creds(new); 700 701 error: 702 abort_creds(new); 703 return retval; 704 } 705 706 707 /* 708 * This function implements a generic ability to update ruid, euid, 709 * and suid. This allows you to implement the 4.4 compatible seteuid(). 710 */ 711 SYSCALL_DEFINE3(setresuid, uid_t, ruid, uid_t, euid, uid_t, suid) 712 { 713 const struct cred *old; 714 struct cred *new; 715 int retval; 716 717 new = prepare_creds(); 718 if (!new) 719 return -ENOMEM; 720 721 retval = security_task_setuid(ruid, euid, suid, LSM_SETID_RES); 722 if (retval) 723 goto error; 724 old = current_cred(); 725 726 retval = -EPERM; 727 if (!capable(CAP_SETUID)) { 728 if (ruid != (uid_t) -1 && ruid != old->uid && 729 ruid != old->euid && ruid != old->suid) 730 goto error; 731 if (euid != (uid_t) -1 && euid != old->uid && 732 euid != old->euid && euid != old->suid) 733 goto error; 734 if (suid != (uid_t) -1 && suid != old->uid && 735 suid != old->euid && suid != old->suid) 736 goto error; 737 } 738 739 if (ruid != (uid_t) -1) { 740 new->uid = ruid; 741 if (ruid != old->uid) { 742 retval = set_user(new); 743 if (retval < 0) 744 goto error; 745 } 746 } 747 if (euid != (uid_t) -1) 748 new->euid = euid; 749 if (suid != (uid_t) -1) 750 new->suid = suid; 751 new->fsuid = new->euid; 752 753 retval = security_task_fix_setuid(new, old, LSM_SETID_RES); 754 if (retval < 0) 755 goto error; 756 757 return commit_creds(new); 758 759 error: 760 abort_creds(new); 761 return retval; 762 } 763 764 SYSCALL_DEFINE3(getresuid, uid_t __user *, ruid, uid_t __user *, euid, uid_t __user *, suid) 765 { 766 const struct cred *cred = current_cred(); 767 int retval; 768 769 if (!(retval = put_user(cred->uid, ruid)) && 770 !(retval = put_user(cred->euid, euid))) 771 retval = put_user(cred->suid, suid); 772 773 return retval; 774 } 775 776 /* 777 * Same as above, but for rgid, egid, sgid. 778 */ 779 SYSCALL_DEFINE3(setresgid, gid_t, rgid, gid_t, egid, gid_t, sgid) 780 { 781 const struct cred *old; 782 struct cred *new; 783 int retval; 784 785 new = prepare_creds(); 786 if (!new) 787 return -ENOMEM; 788 old = current_cred(); 789 790 retval = security_task_setgid(rgid, egid, sgid, LSM_SETID_RES); 791 if (retval) 792 goto error; 793 794 retval = -EPERM; 795 if (!capable(CAP_SETGID)) { 796 if (rgid != (gid_t) -1 && rgid != old->gid && 797 rgid != old->egid && rgid != old->sgid) 798 goto error; 799 if (egid != (gid_t) -1 && egid != old->gid && 800 egid != old->egid && egid != old->sgid) 801 goto error; 802 if (sgid != (gid_t) -1 && sgid != old->gid && 803 sgid != old->egid && sgid != old->sgid) 804 goto error; 805 } 806 807 if (rgid != (gid_t) -1) 808 new->gid = rgid; 809 if (egid != (gid_t) -1) 810 new->egid = egid; 811 if (sgid != (gid_t) -1) 812 new->sgid = sgid; 813 new->fsgid = new->egid; 814 815 return commit_creds(new); 816 817 error: 818 abort_creds(new); 819 return retval; 820 } 821 822 SYSCALL_DEFINE3(getresgid, gid_t __user *, rgid, gid_t __user *, egid, gid_t __user *, sgid) 823 { 824 const struct cred *cred = current_cred(); 825 int retval; 826 827 if (!(retval = put_user(cred->gid, rgid)) && 828 !(retval = put_user(cred->egid, egid))) 829 retval = put_user(cred->sgid, sgid); 830 831 return retval; 832 } 833 834 835 /* 836 * "setfsuid()" sets the fsuid - the uid used for filesystem checks. This 837 * is used for "access()" and for the NFS daemon (letting nfsd stay at 838 * whatever uid it wants to). It normally shadows "euid", except when 839 * explicitly set by setfsuid() or for access.. 840 */ 841 SYSCALL_DEFINE1(setfsuid, uid_t, uid) 842 { 843 const struct cred *old; 844 struct cred *new; 845 uid_t old_fsuid; 846 847 new = prepare_creds(); 848 if (!new) 849 return current_fsuid(); 850 old = current_cred(); 851 old_fsuid = old->fsuid; 852 853 if (security_task_setuid(uid, (uid_t)-1, (uid_t)-1, LSM_SETID_FS) < 0) 854 goto error; 855 856 if (uid == old->uid || uid == old->euid || 857 uid == old->suid || uid == old->fsuid || 858 capable(CAP_SETUID)) { 859 if (uid != old_fsuid) { 860 new->fsuid = uid; 861 if (security_task_fix_setuid(new, old, LSM_SETID_FS) == 0) 862 goto change_okay; 863 } 864 } 865 866 error: 867 abort_creds(new); 868 return old_fsuid; 869 870 change_okay: 871 commit_creds(new); 872 return old_fsuid; 873 } 874 875 /* 876 * Samma på svenska.. 877 */ 878 SYSCALL_DEFINE1(setfsgid, gid_t, gid) 879 { 880 const struct cred *old; 881 struct cred *new; 882 gid_t old_fsgid; 883 884 new = prepare_creds(); 885 if (!new) 886 return current_fsgid(); 887 old = current_cred(); 888 old_fsgid = old->fsgid; 889 890 if (security_task_setgid(gid, (gid_t)-1, (gid_t)-1, LSM_SETID_FS)) 891 goto error; 892 893 if (gid == old->gid || gid == old->egid || 894 gid == old->sgid || gid == old->fsgid || 895 capable(CAP_SETGID)) { 896 if (gid != old_fsgid) { 897 new->fsgid = gid; 898 goto change_okay; 899 } 900 } 901 902 error: 903 abort_creds(new); 904 return old_fsgid; 905 906 change_okay: 907 commit_creds(new); 908 return old_fsgid; 909 } 910 911 void do_sys_times(struct tms *tms) 912 { 913 cputime_t tgutime, tgstime, cutime, cstime; 914 915 spin_lock_irq(¤t->sighand->siglock); 916 thread_group_times(current, &tgutime, &tgstime); 917 cutime = current->signal->cutime; 918 cstime = current->signal->cstime; 919 spin_unlock_irq(¤t->sighand->siglock); 920 tms->tms_utime = cputime_to_clock_t(tgutime); 921 tms->tms_stime = cputime_to_clock_t(tgstime); 922 tms->tms_cutime = cputime_to_clock_t(cutime); 923 tms->tms_cstime = cputime_to_clock_t(cstime); 924 } 925 926 SYSCALL_DEFINE1(times, struct tms __user *, tbuf) 927 { 928 if (tbuf) { 929 struct tms tmp; 930 931 do_sys_times(&tmp); 932 if (copy_to_user(tbuf, &tmp, sizeof(struct tms))) 933 return -EFAULT; 934 } 935 force_successful_syscall_return(); 936 return (long) jiffies_64_to_clock_t(get_jiffies_64()); 937 } 938 939 /* 940 * This needs some heavy checking ... 941 * I just haven't the stomach for it. I also don't fully 942 * understand sessions/pgrp etc. Let somebody who does explain it. 943 * 944 * OK, I think I have the protection semantics right.... this is really 945 * only important on a multi-user system anyway, to make sure one user 946 * can't send a signal to a process owned by another. -TYT, 12/12/91 947 * 948 * Auch. Had to add the 'did_exec' flag to conform completely to POSIX. 949 * LBT 04.03.94 950 */ 951 SYSCALL_DEFINE2(setpgid, pid_t, pid, pid_t, pgid) 952 { 953 struct task_struct *p; 954 struct task_struct *group_leader = current->group_leader; 955 struct pid *pgrp; 956 int err; 957 958 if (!pid) 959 pid = task_pid_vnr(group_leader); 960 if (!pgid) 961 pgid = pid; 962 if (pgid < 0) 963 return -EINVAL; 964 965 /* From this point forward we keep holding onto the tasklist lock 966 * so that our parent does not change from under us. -DaveM 967 */ 968 write_lock_irq(&tasklist_lock); 969 970 err = -ESRCH; 971 p = find_task_by_vpid(pid); 972 if (!p) 973 goto out; 974 975 err = -EINVAL; 976 if (!thread_group_leader(p)) 977 goto out; 978 979 if (same_thread_group(p->real_parent, group_leader)) { 980 err = -EPERM; 981 if (task_session(p) != task_session(group_leader)) 982 goto out; 983 err = -EACCES; 984 if (p->did_exec) 985 goto out; 986 } else { 987 err = -ESRCH; 988 if (p != group_leader) 989 goto out; 990 } 991 992 err = -EPERM; 993 if (p->signal->leader) 994 goto out; 995 996 pgrp = task_pid(p); 997 if (pgid != pid) { 998 struct task_struct *g; 999 1000 pgrp = find_vpid(pgid); 1001 g = pid_task(pgrp, PIDTYPE_PGID); 1002 if (!g || task_session(g) != task_session(group_leader)) 1003 goto out; 1004 } 1005 1006 err = security_task_setpgid(p, pgid); 1007 if (err) 1008 goto out; 1009 1010 if (task_pgrp(p) != pgrp) 1011 change_pid(p, PIDTYPE_PGID, pgrp); 1012 1013 err = 0; 1014 out: 1015 /* All paths lead to here, thus we are safe. -DaveM */ 1016 write_unlock_irq(&tasklist_lock); 1017 return err; 1018 } 1019 1020 SYSCALL_DEFINE1(getpgid, pid_t, pid) 1021 { 1022 struct task_struct *p; 1023 struct pid *grp; 1024 int retval; 1025 1026 rcu_read_lock(); 1027 if (!pid) 1028 grp = task_pgrp(current); 1029 else { 1030 retval = -ESRCH; 1031 p = find_task_by_vpid(pid); 1032 if (!p) 1033 goto out; 1034 grp = task_pgrp(p); 1035 if (!grp) 1036 goto out; 1037 1038 retval = security_task_getpgid(p); 1039 if (retval) 1040 goto out; 1041 } 1042 retval = pid_vnr(grp); 1043 out: 1044 rcu_read_unlock(); 1045 return retval; 1046 } 1047 1048 #ifdef __ARCH_WANT_SYS_GETPGRP 1049 1050 SYSCALL_DEFINE0(getpgrp) 1051 { 1052 return sys_getpgid(0); 1053 } 1054 1055 #endif 1056 1057 SYSCALL_DEFINE1(getsid, pid_t, pid) 1058 { 1059 struct task_struct *p; 1060 struct pid *sid; 1061 int retval; 1062 1063 rcu_read_lock(); 1064 if (!pid) 1065 sid = task_session(current); 1066 else { 1067 retval = -ESRCH; 1068 p = find_task_by_vpid(pid); 1069 if (!p) 1070 goto out; 1071 sid = task_session(p); 1072 if (!sid) 1073 goto out; 1074 1075 retval = security_task_getsid(p); 1076 if (retval) 1077 goto out; 1078 } 1079 retval = pid_vnr(sid); 1080 out: 1081 rcu_read_unlock(); 1082 return retval; 1083 } 1084 1085 SYSCALL_DEFINE0(setsid) 1086 { 1087 struct task_struct *group_leader = current->group_leader; 1088 struct pid *sid = task_pid(group_leader); 1089 pid_t session = pid_vnr(sid); 1090 int err = -EPERM; 1091 1092 write_lock_irq(&tasklist_lock); 1093 /* Fail if I am already a session leader */ 1094 if (group_leader->signal->leader) 1095 goto out; 1096 1097 /* Fail if a process group id already exists that equals the 1098 * proposed session id. 1099 */ 1100 if (pid_task(sid, PIDTYPE_PGID)) 1101 goto out; 1102 1103 group_leader->signal->leader = 1; 1104 __set_special_pids(sid); 1105 1106 proc_clear_tty(group_leader); 1107 1108 err = session; 1109 out: 1110 write_unlock_irq(&tasklist_lock); 1111 if (err > 0) 1112 proc_sid_connector(group_leader); 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 tgutime, tgstime, utime, stime; 1340 unsigned long maxrss = 0; 1341 1342 memset((char *) r, 0, sizeof *r); 1343 utime = stime = cputime_zero; 1344 1345 if (who == RUSAGE_THREAD) { 1346 task_times(current, &utime, &stime); 1347 accumulate_thread_rusage(p, r); 1348 maxrss = p->signal->maxrss; 1349 goto out; 1350 } 1351 1352 if (!lock_task_sighand(p, &flags)) 1353 return; 1354 1355 switch (who) { 1356 case RUSAGE_BOTH: 1357 case RUSAGE_CHILDREN: 1358 utime = p->signal->cutime; 1359 stime = p->signal->cstime; 1360 r->ru_nvcsw = p->signal->cnvcsw; 1361 r->ru_nivcsw = p->signal->cnivcsw; 1362 r->ru_minflt = p->signal->cmin_flt; 1363 r->ru_majflt = p->signal->cmaj_flt; 1364 r->ru_inblock = p->signal->cinblock; 1365 r->ru_oublock = p->signal->coublock; 1366 maxrss = p->signal->cmaxrss; 1367 1368 if (who == RUSAGE_CHILDREN) 1369 break; 1370 1371 case RUSAGE_SELF: 1372 thread_group_times(p, &tgutime, &tgstime); 1373 utime = cputime_add(utime, tgutime); 1374 stime = cputime_add(stime, tgstime); 1375 r->ru_nvcsw += p->signal->nvcsw; 1376 r->ru_nivcsw += p->signal->nivcsw; 1377 r->ru_minflt += p->signal->min_flt; 1378 r->ru_majflt += p->signal->maj_flt; 1379 r->ru_inblock += p->signal->inblock; 1380 r->ru_oublock += p->signal->oublock; 1381 if (maxrss < p->signal->maxrss) 1382 maxrss = p->signal->maxrss; 1383 t = p; 1384 do { 1385 accumulate_thread_rusage(t, r); 1386 t = next_thread(t); 1387 } while (t != p); 1388 break; 1389 1390 default: 1391 BUG(); 1392 } 1393 unlock_task_sighand(p, &flags); 1394 1395 out: 1396 cputime_to_timeval(utime, &r->ru_utime); 1397 cputime_to_timeval(stime, &r->ru_stime); 1398 1399 if (who != RUSAGE_CHILDREN) { 1400 struct mm_struct *mm = get_task_mm(p); 1401 if (mm) { 1402 setmax_mm_hiwater_rss(&maxrss, mm); 1403 mmput(mm); 1404 } 1405 } 1406 r->ru_maxrss = maxrss * (PAGE_SIZE / 1024); /* convert pages to KBs */ 1407 } 1408 1409 int getrusage(struct task_struct *p, int who, struct rusage __user *ru) 1410 { 1411 struct rusage r; 1412 k_getrusage(p, who, &r); 1413 return copy_to_user(ru, &r, sizeof(r)) ? -EFAULT : 0; 1414 } 1415 1416 SYSCALL_DEFINE2(getrusage, int, who, struct rusage __user *, ru) 1417 { 1418 if (who != RUSAGE_SELF && who != RUSAGE_CHILDREN && 1419 who != RUSAGE_THREAD) 1420 return -EINVAL; 1421 return getrusage(current, who, ru); 1422 } 1423 1424 SYSCALL_DEFINE1(umask, int, mask) 1425 { 1426 mask = xchg(¤t->fs->umask, mask & S_IRWXUGO); 1427 return mask; 1428 } 1429 1430 SYSCALL_DEFINE5(prctl, int, option, unsigned long, arg2, unsigned long, arg3, 1431 unsigned long, arg4, unsigned long, arg5) 1432 { 1433 struct task_struct *me = current; 1434 unsigned char comm[sizeof(me->comm)]; 1435 long error; 1436 1437 error = security_task_prctl(option, arg2, arg3, arg4, arg5); 1438 if (error != -ENOSYS) 1439 return error; 1440 1441 error = 0; 1442 switch (option) { 1443 case PR_SET_PDEATHSIG: 1444 if (!valid_signal(arg2)) { 1445 error = -EINVAL; 1446 break; 1447 } 1448 me->pdeath_signal = arg2; 1449 error = 0; 1450 break; 1451 case PR_GET_PDEATHSIG: 1452 error = put_user(me->pdeath_signal, (int __user *)arg2); 1453 break; 1454 case PR_GET_DUMPABLE: 1455 error = get_dumpable(me->mm); 1456 break; 1457 case PR_SET_DUMPABLE: 1458 if (arg2 < 0 || arg2 > 1) { 1459 error = -EINVAL; 1460 break; 1461 } 1462 set_dumpable(me->mm, arg2); 1463 error = 0; 1464 break; 1465 1466 case PR_SET_UNALIGN: 1467 error = SET_UNALIGN_CTL(me, arg2); 1468 break; 1469 case PR_GET_UNALIGN: 1470 error = GET_UNALIGN_CTL(me, arg2); 1471 break; 1472 case PR_SET_FPEMU: 1473 error = SET_FPEMU_CTL(me, arg2); 1474 break; 1475 case PR_GET_FPEMU: 1476 error = GET_FPEMU_CTL(me, arg2); 1477 break; 1478 case PR_SET_FPEXC: 1479 error = SET_FPEXC_CTL(me, arg2); 1480 break; 1481 case PR_GET_FPEXC: 1482 error = GET_FPEXC_CTL(me, arg2); 1483 break; 1484 case PR_GET_TIMING: 1485 error = PR_TIMING_STATISTICAL; 1486 break; 1487 case PR_SET_TIMING: 1488 if (arg2 != PR_TIMING_STATISTICAL) 1489 error = -EINVAL; 1490 else 1491 error = 0; 1492 break; 1493 1494 case PR_SET_NAME: 1495 comm[sizeof(me->comm)-1] = 0; 1496 if (strncpy_from_user(comm, (char __user *)arg2, 1497 sizeof(me->comm) - 1) < 0) 1498 return -EFAULT; 1499 set_task_comm(me, comm); 1500 return 0; 1501 case PR_GET_NAME: 1502 get_task_comm(comm, me); 1503 if (copy_to_user((char __user *)arg2, comm, 1504 sizeof(comm))) 1505 return -EFAULT; 1506 return 0; 1507 case PR_GET_ENDIAN: 1508 error = GET_ENDIAN(me, arg2); 1509 break; 1510 case PR_SET_ENDIAN: 1511 error = SET_ENDIAN(me, arg2); 1512 break; 1513 1514 case PR_GET_SECCOMP: 1515 error = prctl_get_seccomp(); 1516 break; 1517 case PR_SET_SECCOMP: 1518 error = prctl_set_seccomp(arg2); 1519 break; 1520 case PR_GET_TSC: 1521 error = GET_TSC_CTL(arg2); 1522 break; 1523 case PR_SET_TSC: 1524 error = SET_TSC_CTL(arg2); 1525 break; 1526 case PR_TASK_PERF_EVENTS_DISABLE: 1527 error = perf_event_task_disable(); 1528 break; 1529 case PR_TASK_PERF_EVENTS_ENABLE: 1530 error = perf_event_task_enable(); 1531 break; 1532 case PR_GET_TIMERSLACK: 1533 error = current->timer_slack_ns; 1534 break; 1535 case PR_SET_TIMERSLACK: 1536 if (arg2 <= 0) 1537 current->timer_slack_ns = 1538 current->default_timer_slack_ns; 1539 else 1540 current->timer_slack_ns = arg2; 1541 error = 0; 1542 break; 1543 case PR_MCE_KILL: 1544 if (arg4 | arg5) 1545 return -EINVAL; 1546 switch (arg2) { 1547 case PR_MCE_KILL_CLEAR: 1548 if (arg3 != 0) 1549 return -EINVAL; 1550 current->flags &= ~PF_MCE_PROCESS; 1551 break; 1552 case PR_MCE_KILL_SET: 1553 current->flags |= PF_MCE_PROCESS; 1554 if (arg3 == PR_MCE_KILL_EARLY) 1555 current->flags |= PF_MCE_EARLY; 1556 else if (arg3 == PR_MCE_KILL_LATE) 1557 current->flags &= ~PF_MCE_EARLY; 1558 else if (arg3 == PR_MCE_KILL_DEFAULT) 1559 current->flags &= 1560 ~(PF_MCE_EARLY|PF_MCE_PROCESS); 1561 else 1562 return -EINVAL; 1563 break; 1564 default: 1565 return -EINVAL; 1566 } 1567 error = 0; 1568 break; 1569 case PR_MCE_KILL_GET: 1570 if (arg2 | arg3 | arg4 | arg5) 1571 return -EINVAL; 1572 if (current->flags & PF_MCE_PROCESS) 1573 error = (current->flags & PF_MCE_EARLY) ? 1574 PR_MCE_KILL_EARLY : PR_MCE_KILL_LATE; 1575 else 1576 error = PR_MCE_KILL_DEFAULT; 1577 break; 1578 default: 1579 error = -EINVAL; 1580 break; 1581 } 1582 return error; 1583 } 1584 1585 SYSCALL_DEFINE3(getcpu, unsigned __user *, cpup, unsigned __user *, nodep, 1586 struct getcpu_cache __user *, unused) 1587 { 1588 int err = 0; 1589 int cpu = raw_smp_processor_id(); 1590 if (cpup) 1591 err |= put_user(cpu, cpup); 1592 if (nodep) 1593 err |= put_user(cpu_to_node(cpu), nodep); 1594 return err ? -EFAULT : 0; 1595 } 1596 1597 char poweroff_cmd[POWEROFF_CMD_PATH_LEN] = "/sbin/poweroff"; 1598 1599 static void argv_cleanup(char **argv, char **envp) 1600 { 1601 argv_free(argv); 1602 } 1603 1604 /** 1605 * orderly_poweroff - Trigger an orderly system poweroff 1606 * @force: force poweroff if command execution fails 1607 * 1608 * This may be called from any context to trigger a system shutdown. 1609 * If the orderly shutdown fails, it will force an immediate shutdown. 1610 */ 1611 int orderly_poweroff(bool force) 1612 { 1613 int argc; 1614 char **argv = argv_split(GFP_ATOMIC, poweroff_cmd, &argc); 1615 static char *envp[] = { 1616 "HOME=/", 1617 "PATH=/sbin:/bin:/usr/sbin:/usr/bin", 1618 NULL 1619 }; 1620 int ret = -ENOMEM; 1621 struct subprocess_info *info; 1622 1623 if (argv == NULL) { 1624 printk(KERN_WARNING "%s failed to allocate memory for \"%s\"\n", 1625 __func__, poweroff_cmd); 1626 goto out; 1627 } 1628 1629 info = call_usermodehelper_setup(argv[0], argv, envp, GFP_ATOMIC); 1630 if (info == NULL) { 1631 argv_free(argv); 1632 goto out; 1633 } 1634 1635 call_usermodehelper_setcleanup(info, argv_cleanup); 1636 1637 ret = call_usermodehelper_exec(info, UMH_NO_WAIT); 1638 1639 out: 1640 if (ret && force) { 1641 printk(KERN_WARNING "Failed to start orderly shutdown: " 1642 "forcing the issue\n"); 1643 1644 /* I guess this should try to kick off some daemon to 1645 sync and poweroff asap. Or not even bother syncing 1646 if we're doing an emergency shutdown? */ 1647 emergency_sync(); 1648 kernel_power_off(); 1649 } 1650 1651 return ret; 1652 } 1653 EXPORT_SYMBOL_GPL(orderly_poweroff); 1654