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/personality.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 rcu_read_lock(); 167 read_lock(&tasklist_lock); 168 switch (which) { 169 case PRIO_PROCESS: 170 if (who) 171 p = find_task_by_vpid(who); 172 else 173 p = current; 174 if (p) 175 error = set_one_prio(p, niceval, error); 176 break; 177 case PRIO_PGRP: 178 if (who) 179 pgrp = find_vpid(who); 180 else 181 pgrp = task_pgrp(current); 182 do_each_pid_thread(pgrp, PIDTYPE_PGID, p) { 183 error = set_one_prio(p, niceval, error); 184 } while_each_pid_thread(pgrp, PIDTYPE_PGID, p); 185 break; 186 case PRIO_USER: 187 user = (struct user_struct *) cred->user; 188 if (!who) 189 who = cred->uid; 190 else if ((who != cred->uid) && 191 !(user = find_user(who))) 192 goto out_unlock; /* No processes for this user */ 193 194 do_each_thread(g, p) { 195 if (__task_cred(p)->uid == who) 196 error = set_one_prio(p, niceval, error); 197 } while_each_thread(g, p); 198 if (who != cred->uid) 199 free_uid(user); /* For find_user() */ 200 break; 201 } 202 out_unlock: 203 read_unlock(&tasklist_lock); 204 rcu_read_unlock(); 205 out: 206 return error; 207 } 208 209 /* 210 * Ugh. To avoid negative return values, "getpriority()" will 211 * not return the normal nice-value, but a negated value that 212 * has been offset by 20 (ie it returns 40..1 instead of -20..19) 213 * to stay compatible. 214 */ 215 SYSCALL_DEFINE2(getpriority, int, which, int, who) 216 { 217 struct task_struct *g, *p; 218 struct user_struct *user; 219 const struct cred *cred = current_cred(); 220 long niceval, retval = -ESRCH; 221 struct pid *pgrp; 222 223 if (which > PRIO_USER || which < PRIO_PROCESS) 224 return -EINVAL; 225 226 rcu_read_lock(); 227 read_lock(&tasklist_lock); 228 switch (which) { 229 case PRIO_PROCESS: 230 if (who) 231 p = find_task_by_vpid(who); 232 else 233 p = current; 234 if (p) { 235 niceval = 20 - task_nice(p); 236 if (niceval > retval) 237 retval = niceval; 238 } 239 break; 240 case PRIO_PGRP: 241 if (who) 242 pgrp = find_vpid(who); 243 else 244 pgrp = task_pgrp(current); 245 do_each_pid_thread(pgrp, PIDTYPE_PGID, p) { 246 niceval = 20 - task_nice(p); 247 if (niceval > retval) 248 retval = niceval; 249 } while_each_pid_thread(pgrp, PIDTYPE_PGID, p); 250 break; 251 case PRIO_USER: 252 user = (struct user_struct *) cred->user; 253 if (!who) 254 who = cred->uid; 255 else if ((who != cred->uid) && 256 !(user = find_user(who))) 257 goto out_unlock; /* No processes for this user */ 258 259 do_each_thread(g, p) { 260 if (__task_cred(p)->uid == who) { 261 niceval = 20 - task_nice(p); 262 if (niceval > retval) 263 retval = niceval; 264 } 265 } while_each_thread(g, p); 266 if (who != cred->uid) 267 free_uid(user); /* for find_user() */ 268 break; 269 } 270 out_unlock: 271 read_unlock(&tasklist_lock); 272 rcu_read_unlock(); 273 274 return retval; 275 } 276 277 /** 278 * emergency_restart - reboot the system 279 * 280 * Without shutting down any hardware or taking any locks 281 * reboot the system. This is called when we know we are in 282 * trouble so this is our best effort to reboot. This is 283 * safe to call in interrupt context. 284 */ 285 void emergency_restart(void) 286 { 287 machine_emergency_restart(); 288 } 289 EXPORT_SYMBOL_GPL(emergency_restart); 290 291 void kernel_restart_prepare(char *cmd) 292 { 293 blocking_notifier_call_chain(&reboot_notifier_list, SYS_RESTART, cmd); 294 system_state = SYSTEM_RESTART; 295 device_shutdown(); 296 sysdev_shutdown(); 297 } 298 299 /** 300 * kernel_restart - reboot the system 301 * @cmd: pointer to buffer containing command to execute for restart 302 * or %NULL 303 * 304 * Shutdown everything and perform a clean reboot. 305 * This is not safe to call in interrupt context. 306 */ 307 void kernel_restart(char *cmd) 308 { 309 kernel_restart_prepare(cmd); 310 if (!cmd) 311 printk(KERN_EMERG "Restarting system.\n"); 312 else 313 printk(KERN_EMERG "Restarting system with command '%s'.\n", cmd); 314 machine_restart(cmd); 315 } 316 EXPORT_SYMBOL_GPL(kernel_restart); 317 318 static void kernel_shutdown_prepare(enum system_states state) 319 { 320 blocking_notifier_call_chain(&reboot_notifier_list, 321 (state == SYSTEM_HALT)?SYS_HALT:SYS_POWER_OFF, NULL); 322 system_state = state; 323 device_shutdown(); 324 } 325 /** 326 * kernel_halt - halt the system 327 * 328 * Shutdown everything and perform a clean system halt. 329 */ 330 void kernel_halt(void) 331 { 332 kernel_shutdown_prepare(SYSTEM_HALT); 333 sysdev_shutdown(); 334 printk(KERN_EMERG "System halted.\n"); 335 machine_halt(); 336 } 337 338 EXPORT_SYMBOL_GPL(kernel_halt); 339 340 /** 341 * kernel_power_off - power_off the system 342 * 343 * Shutdown everything and perform a clean system power_off. 344 */ 345 void kernel_power_off(void) 346 { 347 kernel_shutdown_prepare(SYSTEM_POWER_OFF); 348 if (pm_power_off_prepare) 349 pm_power_off_prepare(); 350 disable_nonboot_cpus(); 351 sysdev_shutdown(); 352 printk(KERN_EMERG "Power down.\n"); 353 machine_power_off(); 354 } 355 EXPORT_SYMBOL_GPL(kernel_power_off); 356 357 static DEFINE_MUTEX(reboot_mutex); 358 359 /* 360 * Reboot system call: for obvious reasons only root may call it, 361 * and even root needs to set up some magic numbers in the registers 362 * so that some mistake won't make this reboot the whole machine. 363 * You can also set the meaning of the ctrl-alt-del-key here. 364 * 365 * reboot doesn't sync: do that yourself before calling this. 366 */ 367 SYSCALL_DEFINE4(reboot, int, magic1, int, magic2, unsigned int, cmd, 368 void __user *, arg) 369 { 370 char buffer[256]; 371 int ret = 0; 372 373 /* We only trust the superuser with rebooting the system. */ 374 if (!capable(CAP_SYS_BOOT)) 375 return -EPERM; 376 377 /* For safety, we require "magic" arguments. */ 378 if (magic1 != LINUX_REBOOT_MAGIC1 || 379 (magic2 != LINUX_REBOOT_MAGIC2 && 380 magic2 != LINUX_REBOOT_MAGIC2A && 381 magic2 != LINUX_REBOOT_MAGIC2B && 382 magic2 != LINUX_REBOOT_MAGIC2C)) 383 return -EINVAL; 384 385 /* Instead of trying to make the power_off code look like 386 * halt when pm_power_off is not set do it the easy way. 387 */ 388 if ((cmd == LINUX_REBOOT_CMD_POWER_OFF) && !pm_power_off) 389 cmd = LINUX_REBOOT_CMD_HALT; 390 391 mutex_lock(&reboot_mutex); 392 switch (cmd) { 393 case LINUX_REBOOT_CMD_RESTART: 394 kernel_restart(NULL); 395 break; 396 397 case LINUX_REBOOT_CMD_CAD_ON: 398 C_A_D = 1; 399 break; 400 401 case LINUX_REBOOT_CMD_CAD_OFF: 402 C_A_D = 0; 403 break; 404 405 case LINUX_REBOOT_CMD_HALT: 406 kernel_halt(); 407 do_exit(0); 408 panic("cannot halt"); 409 410 case LINUX_REBOOT_CMD_POWER_OFF: 411 kernel_power_off(); 412 do_exit(0); 413 break; 414 415 case LINUX_REBOOT_CMD_RESTART2: 416 if (strncpy_from_user(&buffer[0], arg, sizeof(buffer) - 1) < 0) { 417 ret = -EFAULT; 418 break; 419 } 420 buffer[sizeof(buffer) - 1] = '\0'; 421 422 kernel_restart(buffer); 423 break; 424 425 #ifdef CONFIG_KEXEC 426 case LINUX_REBOOT_CMD_KEXEC: 427 ret = kernel_kexec(); 428 break; 429 #endif 430 431 #ifdef CONFIG_HIBERNATION 432 case LINUX_REBOOT_CMD_SW_SUSPEND: 433 ret = hibernate(); 434 break; 435 #endif 436 437 default: 438 ret = -EINVAL; 439 break; 440 } 441 mutex_unlock(&reboot_mutex); 442 return ret; 443 } 444 445 static void deferred_cad(struct work_struct *dummy) 446 { 447 kernel_restart(NULL); 448 } 449 450 /* 451 * This function gets called by ctrl-alt-del - ie the keyboard interrupt. 452 * As it's called within an interrupt, it may NOT sync: the only choice 453 * is whether to reboot at once, or just ignore the ctrl-alt-del. 454 */ 455 void ctrl_alt_del(void) 456 { 457 static DECLARE_WORK(cad_work, deferred_cad); 458 459 if (C_A_D) 460 schedule_work(&cad_work); 461 else 462 kill_cad_pid(SIGINT, 1); 463 } 464 465 /* 466 * Unprivileged users may change the real gid to the effective gid 467 * or vice versa. (BSD-style) 468 * 469 * If you set the real gid at all, or set the effective gid to a value not 470 * equal to the real gid, then the saved gid is set to the new effective gid. 471 * 472 * This makes it possible for a setgid program to completely drop its 473 * privileges, which is often a useful assertion to make when you are doing 474 * a security audit over a program. 475 * 476 * The general idea is that a program which uses just setregid() will be 477 * 100% compatible with BSD. A program which uses just setgid() will be 478 * 100% compatible with POSIX with saved IDs. 479 * 480 * SMP: There are not races, the GIDs are checked only by filesystem 481 * operations (as far as semantic preservation is concerned). 482 */ 483 SYSCALL_DEFINE2(setregid, gid_t, rgid, gid_t, egid) 484 { 485 const struct cred *old; 486 struct cred *new; 487 int retval; 488 489 new = prepare_creds(); 490 if (!new) 491 return -ENOMEM; 492 old = current_cred(); 493 494 retval = security_task_setgid(rgid, egid, (gid_t)-1, LSM_SETID_RE); 495 if (retval) 496 goto error; 497 498 retval = -EPERM; 499 if (rgid != (gid_t) -1) { 500 if (old->gid == rgid || 501 old->egid == rgid || 502 capable(CAP_SETGID)) 503 new->gid = rgid; 504 else 505 goto error; 506 } 507 if (egid != (gid_t) -1) { 508 if (old->gid == egid || 509 old->egid == egid || 510 old->sgid == egid || 511 capable(CAP_SETGID)) 512 new->egid = egid; 513 else 514 goto error; 515 } 516 517 if (rgid != (gid_t) -1 || 518 (egid != (gid_t) -1 && egid != old->gid)) 519 new->sgid = new->egid; 520 new->fsgid = new->egid; 521 522 return commit_creds(new); 523 524 error: 525 abort_creds(new); 526 return retval; 527 } 528 529 /* 530 * setgid() is implemented like SysV w/ SAVED_IDS 531 * 532 * SMP: Same implicit races as above. 533 */ 534 SYSCALL_DEFINE1(setgid, gid_t, gid) 535 { 536 const struct cred *old; 537 struct cred *new; 538 int retval; 539 540 new = prepare_creds(); 541 if (!new) 542 return -ENOMEM; 543 old = current_cred(); 544 545 retval = security_task_setgid(gid, (gid_t)-1, (gid_t)-1, LSM_SETID_ID); 546 if (retval) 547 goto error; 548 549 retval = -EPERM; 550 if (capable(CAP_SETGID)) 551 new->gid = new->egid = new->sgid = new->fsgid = gid; 552 else if (gid == old->gid || gid == old->sgid) 553 new->egid = new->fsgid = gid; 554 else 555 goto error; 556 557 return commit_creds(new); 558 559 error: 560 abort_creds(new); 561 return retval; 562 } 563 564 /* 565 * change the user struct in a credentials set to match the new UID 566 */ 567 static int set_user(struct cred *new) 568 { 569 struct user_struct *new_user; 570 571 new_user = alloc_uid(current_user_ns(), new->uid); 572 if (!new_user) 573 return -EAGAIN; 574 575 if (atomic_read(&new_user->processes) >= rlimit(RLIMIT_NPROC) && 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 #ifdef COMPAT_UTS_MACHINE 1119 #define override_architecture(name) \ 1120 (current->personality == PER_LINUX32 && \ 1121 copy_to_user(name->machine, COMPAT_UTS_MACHINE, \ 1122 sizeof(COMPAT_UTS_MACHINE))) 1123 #else 1124 #define override_architecture(name) 0 1125 #endif 1126 1127 SYSCALL_DEFINE1(newuname, struct new_utsname __user *, name) 1128 { 1129 int errno = 0; 1130 1131 down_read(&uts_sem); 1132 if (copy_to_user(name, utsname(), sizeof *name)) 1133 errno = -EFAULT; 1134 up_read(&uts_sem); 1135 1136 if (!errno && override_architecture(name)) 1137 errno = -EFAULT; 1138 return errno; 1139 } 1140 1141 #ifdef __ARCH_WANT_SYS_OLD_UNAME 1142 /* 1143 * Old cruft 1144 */ 1145 SYSCALL_DEFINE1(uname, struct old_utsname __user *, name) 1146 { 1147 int error = 0; 1148 1149 if (!name) 1150 return -EFAULT; 1151 1152 down_read(&uts_sem); 1153 if (copy_to_user(name, utsname(), sizeof(*name))) 1154 error = -EFAULT; 1155 up_read(&uts_sem); 1156 1157 if (!error && override_architecture(name)) 1158 error = -EFAULT; 1159 return error; 1160 } 1161 1162 SYSCALL_DEFINE1(olduname, struct oldold_utsname __user *, name) 1163 { 1164 int error; 1165 1166 if (!name) 1167 return -EFAULT; 1168 if (!access_ok(VERIFY_WRITE, name, sizeof(struct oldold_utsname))) 1169 return -EFAULT; 1170 1171 down_read(&uts_sem); 1172 error = __copy_to_user(&name->sysname, &utsname()->sysname, 1173 __OLD_UTS_LEN); 1174 error |= __put_user(0, name->sysname + __OLD_UTS_LEN); 1175 error |= __copy_to_user(&name->nodename, &utsname()->nodename, 1176 __OLD_UTS_LEN); 1177 error |= __put_user(0, name->nodename + __OLD_UTS_LEN); 1178 error |= __copy_to_user(&name->release, &utsname()->release, 1179 __OLD_UTS_LEN); 1180 error |= __put_user(0, name->release + __OLD_UTS_LEN); 1181 error |= __copy_to_user(&name->version, &utsname()->version, 1182 __OLD_UTS_LEN); 1183 error |= __put_user(0, name->version + __OLD_UTS_LEN); 1184 error |= __copy_to_user(&name->machine, &utsname()->machine, 1185 __OLD_UTS_LEN); 1186 error |= __put_user(0, name->machine + __OLD_UTS_LEN); 1187 up_read(&uts_sem); 1188 1189 if (!error && override_architecture(name)) 1190 error = -EFAULT; 1191 return error ? -EFAULT : 0; 1192 } 1193 #endif 1194 1195 SYSCALL_DEFINE2(sethostname, char __user *, name, int, len) 1196 { 1197 int errno; 1198 char tmp[__NEW_UTS_LEN]; 1199 1200 if (!capable(CAP_SYS_ADMIN)) 1201 return -EPERM; 1202 if (len < 0 || len > __NEW_UTS_LEN) 1203 return -EINVAL; 1204 down_write(&uts_sem); 1205 errno = -EFAULT; 1206 if (!copy_from_user(tmp, name, len)) { 1207 struct new_utsname *u = utsname(); 1208 1209 memcpy(u->nodename, tmp, len); 1210 memset(u->nodename + len, 0, sizeof(u->nodename) - len); 1211 errno = 0; 1212 } 1213 up_write(&uts_sem); 1214 return errno; 1215 } 1216 1217 #ifdef __ARCH_WANT_SYS_GETHOSTNAME 1218 1219 SYSCALL_DEFINE2(gethostname, char __user *, name, int, len) 1220 { 1221 int i, errno; 1222 struct new_utsname *u; 1223 1224 if (len < 0) 1225 return -EINVAL; 1226 down_read(&uts_sem); 1227 u = utsname(); 1228 i = 1 + strlen(u->nodename); 1229 if (i > len) 1230 i = len; 1231 errno = 0; 1232 if (copy_to_user(name, u->nodename, i)) 1233 errno = -EFAULT; 1234 up_read(&uts_sem); 1235 return errno; 1236 } 1237 1238 #endif 1239 1240 /* 1241 * Only setdomainname; getdomainname can be implemented by calling 1242 * uname() 1243 */ 1244 SYSCALL_DEFINE2(setdomainname, char __user *, name, int, len) 1245 { 1246 int errno; 1247 char tmp[__NEW_UTS_LEN]; 1248 1249 if (!capable(CAP_SYS_ADMIN)) 1250 return -EPERM; 1251 if (len < 0 || len > __NEW_UTS_LEN) 1252 return -EINVAL; 1253 1254 down_write(&uts_sem); 1255 errno = -EFAULT; 1256 if (!copy_from_user(tmp, name, len)) { 1257 struct new_utsname *u = utsname(); 1258 1259 memcpy(u->domainname, tmp, len); 1260 memset(u->domainname + len, 0, sizeof(u->domainname) - len); 1261 errno = 0; 1262 } 1263 up_write(&uts_sem); 1264 return errno; 1265 } 1266 1267 SYSCALL_DEFINE2(getrlimit, unsigned int, resource, struct rlimit __user *, rlim) 1268 { 1269 if (resource >= RLIM_NLIMITS) 1270 return -EINVAL; 1271 else { 1272 struct rlimit value; 1273 task_lock(current->group_leader); 1274 value = current->signal->rlim[resource]; 1275 task_unlock(current->group_leader); 1276 return copy_to_user(rlim, &value, sizeof(*rlim)) ? -EFAULT : 0; 1277 } 1278 } 1279 1280 #ifdef __ARCH_WANT_SYS_OLD_GETRLIMIT 1281 1282 /* 1283 * Back compatibility for getrlimit. Needed for some apps. 1284 */ 1285 1286 SYSCALL_DEFINE2(old_getrlimit, unsigned int, resource, 1287 struct rlimit __user *, rlim) 1288 { 1289 struct rlimit x; 1290 if (resource >= RLIM_NLIMITS) 1291 return -EINVAL; 1292 1293 task_lock(current->group_leader); 1294 x = current->signal->rlim[resource]; 1295 task_unlock(current->group_leader); 1296 if (x.rlim_cur > 0x7FFFFFFF) 1297 x.rlim_cur = 0x7FFFFFFF; 1298 if (x.rlim_max > 0x7FFFFFFF) 1299 x.rlim_max = 0x7FFFFFFF; 1300 return copy_to_user(rlim, &x, sizeof(x))?-EFAULT:0; 1301 } 1302 1303 #endif 1304 1305 SYSCALL_DEFINE2(setrlimit, unsigned int, resource, struct rlimit __user *, rlim) 1306 { 1307 struct rlimit new_rlim, *old_rlim; 1308 int retval; 1309 1310 if (resource >= RLIM_NLIMITS) 1311 return -EINVAL; 1312 if (copy_from_user(&new_rlim, rlim, sizeof(*rlim))) 1313 return -EFAULT; 1314 if (new_rlim.rlim_cur > new_rlim.rlim_max) 1315 return -EINVAL; 1316 old_rlim = current->signal->rlim + resource; 1317 if ((new_rlim.rlim_max > old_rlim->rlim_max) && 1318 !capable(CAP_SYS_RESOURCE)) 1319 return -EPERM; 1320 if (resource == RLIMIT_NOFILE && new_rlim.rlim_max > sysctl_nr_open) 1321 return -EPERM; 1322 1323 retval = security_task_setrlimit(resource, &new_rlim); 1324 if (retval) 1325 return retval; 1326 1327 if (resource == RLIMIT_CPU && new_rlim.rlim_cur == 0) { 1328 /* 1329 * The caller is asking for an immediate RLIMIT_CPU 1330 * expiry. But we use the zero value to mean "it was 1331 * never set". So let's cheat and make it one second 1332 * instead 1333 */ 1334 new_rlim.rlim_cur = 1; 1335 } 1336 1337 task_lock(current->group_leader); 1338 *old_rlim = new_rlim; 1339 task_unlock(current->group_leader); 1340 1341 if (resource != RLIMIT_CPU) 1342 goto out; 1343 1344 /* 1345 * RLIMIT_CPU handling. Note that the kernel fails to return an error 1346 * code if it rejected the user's attempt to set RLIMIT_CPU. This is a 1347 * very long-standing error, and fixing it now risks breakage of 1348 * applications, so we live with it 1349 */ 1350 if (new_rlim.rlim_cur == RLIM_INFINITY) 1351 goto out; 1352 1353 update_rlimit_cpu(new_rlim.rlim_cur); 1354 out: 1355 return 0; 1356 } 1357 1358 /* 1359 * It would make sense to put struct rusage in the task_struct, 1360 * except that would make the task_struct be *really big*. After 1361 * task_struct gets moved into malloc'ed memory, it would 1362 * make sense to do this. It will make moving the rest of the information 1363 * a lot simpler! (Which we're not doing right now because we're not 1364 * measuring them yet). 1365 * 1366 * When sampling multiple threads for RUSAGE_SELF, under SMP we might have 1367 * races with threads incrementing their own counters. But since word 1368 * reads are atomic, we either get new values or old values and we don't 1369 * care which for the sums. We always take the siglock to protect reading 1370 * the c* fields from p->signal from races with exit.c updating those 1371 * fields when reaping, so a sample either gets all the additions of a 1372 * given child after it's reaped, or none so this sample is before reaping. 1373 * 1374 * Locking: 1375 * We need to take the siglock for CHILDEREN, SELF and BOTH 1376 * for the cases current multithreaded, non-current single threaded 1377 * non-current multithreaded. Thread traversal is now safe with 1378 * the siglock held. 1379 * Strictly speaking, we donot need to take the siglock if we are current and 1380 * single threaded, as no one else can take our signal_struct away, no one 1381 * else can reap the children to update signal->c* counters, and no one else 1382 * can race with the signal-> fields. If we do not take any lock, the 1383 * signal-> fields could be read out of order while another thread was just 1384 * exiting. So we should place a read memory barrier when we avoid the lock. 1385 * On the writer side, write memory barrier is implied in __exit_signal 1386 * as __exit_signal releases the siglock spinlock after updating the signal-> 1387 * fields. But we don't do this yet to keep things simple. 1388 * 1389 */ 1390 1391 static void accumulate_thread_rusage(struct task_struct *t, struct rusage *r) 1392 { 1393 r->ru_nvcsw += t->nvcsw; 1394 r->ru_nivcsw += t->nivcsw; 1395 r->ru_minflt += t->min_flt; 1396 r->ru_majflt += t->maj_flt; 1397 r->ru_inblock += task_io_get_inblock(t); 1398 r->ru_oublock += task_io_get_oublock(t); 1399 } 1400 1401 static void k_getrusage(struct task_struct *p, int who, struct rusage *r) 1402 { 1403 struct task_struct *t; 1404 unsigned long flags; 1405 cputime_t tgutime, tgstime, utime, stime; 1406 unsigned long maxrss = 0; 1407 1408 memset((char *) r, 0, sizeof *r); 1409 utime = stime = cputime_zero; 1410 1411 if (who == RUSAGE_THREAD) { 1412 task_times(current, &utime, &stime); 1413 accumulate_thread_rusage(p, r); 1414 maxrss = p->signal->maxrss; 1415 goto out; 1416 } 1417 1418 if (!lock_task_sighand(p, &flags)) 1419 return; 1420 1421 switch (who) { 1422 case RUSAGE_BOTH: 1423 case RUSAGE_CHILDREN: 1424 utime = p->signal->cutime; 1425 stime = p->signal->cstime; 1426 r->ru_nvcsw = p->signal->cnvcsw; 1427 r->ru_nivcsw = p->signal->cnivcsw; 1428 r->ru_minflt = p->signal->cmin_flt; 1429 r->ru_majflt = p->signal->cmaj_flt; 1430 r->ru_inblock = p->signal->cinblock; 1431 r->ru_oublock = p->signal->coublock; 1432 maxrss = p->signal->cmaxrss; 1433 1434 if (who == RUSAGE_CHILDREN) 1435 break; 1436 1437 case RUSAGE_SELF: 1438 thread_group_times(p, &tgutime, &tgstime); 1439 utime = cputime_add(utime, tgutime); 1440 stime = cputime_add(stime, tgstime); 1441 r->ru_nvcsw += p->signal->nvcsw; 1442 r->ru_nivcsw += p->signal->nivcsw; 1443 r->ru_minflt += p->signal->min_flt; 1444 r->ru_majflt += p->signal->maj_flt; 1445 r->ru_inblock += p->signal->inblock; 1446 r->ru_oublock += p->signal->oublock; 1447 if (maxrss < p->signal->maxrss) 1448 maxrss = p->signal->maxrss; 1449 t = p; 1450 do { 1451 accumulate_thread_rusage(t, r); 1452 t = next_thread(t); 1453 } while (t != p); 1454 break; 1455 1456 default: 1457 BUG(); 1458 } 1459 unlock_task_sighand(p, &flags); 1460 1461 out: 1462 cputime_to_timeval(utime, &r->ru_utime); 1463 cputime_to_timeval(stime, &r->ru_stime); 1464 1465 if (who != RUSAGE_CHILDREN) { 1466 struct mm_struct *mm = get_task_mm(p); 1467 if (mm) { 1468 setmax_mm_hiwater_rss(&maxrss, mm); 1469 mmput(mm); 1470 } 1471 } 1472 r->ru_maxrss = maxrss * (PAGE_SIZE / 1024); /* convert pages to KBs */ 1473 } 1474 1475 int getrusage(struct task_struct *p, int who, struct rusage __user *ru) 1476 { 1477 struct rusage r; 1478 k_getrusage(p, who, &r); 1479 return copy_to_user(ru, &r, sizeof(r)) ? -EFAULT : 0; 1480 } 1481 1482 SYSCALL_DEFINE2(getrusage, int, who, struct rusage __user *, ru) 1483 { 1484 if (who != RUSAGE_SELF && who != RUSAGE_CHILDREN && 1485 who != RUSAGE_THREAD) 1486 return -EINVAL; 1487 return getrusage(current, who, ru); 1488 } 1489 1490 SYSCALL_DEFINE1(umask, int, mask) 1491 { 1492 mask = xchg(¤t->fs->umask, mask & S_IRWXUGO); 1493 return mask; 1494 } 1495 1496 SYSCALL_DEFINE5(prctl, int, option, unsigned long, arg2, unsigned long, arg3, 1497 unsigned long, arg4, unsigned long, arg5) 1498 { 1499 struct task_struct *me = current; 1500 unsigned char comm[sizeof(me->comm)]; 1501 long error; 1502 1503 error = security_task_prctl(option, arg2, arg3, arg4, arg5); 1504 if (error != -ENOSYS) 1505 return error; 1506 1507 error = 0; 1508 switch (option) { 1509 case PR_SET_PDEATHSIG: 1510 if (!valid_signal(arg2)) { 1511 error = -EINVAL; 1512 break; 1513 } 1514 me->pdeath_signal = arg2; 1515 error = 0; 1516 break; 1517 case PR_GET_PDEATHSIG: 1518 error = put_user(me->pdeath_signal, (int __user *)arg2); 1519 break; 1520 case PR_GET_DUMPABLE: 1521 error = get_dumpable(me->mm); 1522 break; 1523 case PR_SET_DUMPABLE: 1524 if (arg2 < 0 || arg2 > 1) { 1525 error = -EINVAL; 1526 break; 1527 } 1528 set_dumpable(me->mm, arg2); 1529 error = 0; 1530 break; 1531 1532 case PR_SET_UNALIGN: 1533 error = SET_UNALIGN_CTL(me, arg2); 1534 break; 1535 case PR_GET_UNALIGN: 1536 error = GET_UNALIGN_CTL(me, arg2); 1537 break; 1538 case PR_SET_FPEMU: 1539 error = SET_FPEMU_CTL(me, arg2); 1540 break; 1541 case PR_GET_FPEMU: 1542 error = GET_FPEMU_CTL(me, arg2); 1543 break; 1544 case PR_SET_FPEXC: 1545 error = SET_FPEXC_CTL(me, arg2); 1546 break; 1547 case PR_GET_FPEXC: 1548 error = GET_FPEXC_CTL(me, arg2); 1549 break; 1550 case PR_GET_TIMING: 1551 error = PR_TIMING_STATISTICAL; 1552 break; 1553 case PR_SET_TIMING: 1554 if (arg2 != PR_TIMING_STATISTICAL) 1555 error = -EINVAL; 1556 else 1557 error = 0; 1558 break; 1559 1560 case PR_SET_NAME: 1561 comm[sizeof(me->comm)-1] = 0; 1562 if (strncpy_from_user(comm, (char __user *)arg2, 1563 sizeof(me->comm) - 1) < 0) 1564 return -EFAULT; 1565 set_task_comm(me, comm); 1566 return 0; 1567 case PR_GET_NAME: 1568 get_task_comm(comm, me); 1569 if (copy_to_user((char __user *)arg2, comm, 1570 sizeof(comm))) 1571 return -EFAULT; 1572 return 0; 1573 case PR_GET_ENDIAN: 1574 error = GET_ENDIAN(me, arg2); 1575 break; 1576 case PR_SET_ENDIAN: 1577 error = SET_ENDIAN(me, arg2); 1578 break; 1579 1580 case PR_GET_SECCOMP: 1581 error = prctl_get_seccomp(); 1582 break; 1583 case PR_SET_SECCOMP: 1584 error = prctl_set_seccomp(arg2); 1585 break; 1586 case PR_GET_TSC: 1587 error = GET_TSC_CTL(arg2); 1588 break; 1589 case PR_SET_TSC: 1590 error = SET_TSC_CTL(arg2); 1591 break; 1592 case PR_TASK_PERF_EVENTS_DISABLE: 1593 error = perf_event_task_disable(); 1594 break; 1595 case PR_TASK_PERF_EVENTS_ENABLE: 1596 error = perf_event_task_enable(); 1597 break; 1598 case PR_GET_TIMERSLACK: 1599 error = current->timer_slack_ns; 1600 break; 1601 case PR_SET_TIMERSLACK: 1602 if (arg2 <= 0) 1603 current->timer_slack_ns = 1604 current->default_timer_slack_ns; 1605 else 1606 current->timer_slack_ns = arg2; 1607 error = 0; 1608 break; 1609 case PR_MCE_KILL: 1610 if (arg4 | arg5) 1611 return -EINVAL; 1612 switch (arg2) { 1613 case PR_MCE_KILL_CLEAR: 1614 if (arg3 != 0) 1615 return -EINVAL; 1616 current->flags &= ~PF_MCE_PROCESS; 1617 break; 1618 case PR_MCE_KILL_SET: 1619 current->flags |= PF_MCE_PROCESS; 1620 if (arg3 == PR_MCE_KILL_EARLY) 1621 current->flags |= PF_MCE_EARLY; 1622 else if (arg3 == PR_MCE_KILL_LATE) 1623 current->flags &= ~PF_MCE_EARLY; 1624 else if (arg3 == PR_MCE_KILL_DEFAULT) 1625 current->flags &= 1626 ~(PF_MCE_EARLY|PF_MCE_PROCESS); 1627 else 1628 return -EINVAL; 1629 break; 1630 default: 1631 return -EINVAL; 1632 } 1633 error = 0; 1634 break; 1635 case PR_MCE_KILL_GET: 1636 if (arg2 | arg3 | arg4 | arg5) 1637 return -EINVAL; 1638 if (current->flags & PF_MCE_PROCESS) 1639 error = (current->flags & PF_MCE_EARLY) ? 1640 PR_MCE_KILL_EARLY : PR_MCE_KILL_LATE; 1641 else 1642 error = PR_MCE_KILL_DEFAULT; 1643 break; 1644 default: 1645 error = -EINVAL; 1646 break; 1647 } 1648 return error; 1649 } 1650 1651 SYSCALL_DEFINE3(getcpu, unsigned __user *, cpup, unsigned __user *, nodep, 1652 struct getcpu_cache __user *, unused) 1653 { 1654 int err = 0; 1655 int cpu = raw_smp_processor_id(); 1656 if (cpup) 1657 err |= put_user(cpu, cpup); 1658 if (nodep) 1659 err |= put_user(cpu_to_node(cpu), nodep); 1660 return err ? -EFAULT : 0; 1661 } 1662 1663 char poweroff_cmd[POWEROFF_CMD_PATH_LEN] = "/sbin/poweroff"; 1664 1665 static void argv_cleanup(char **argv, char **envp) 1666 { 1667 argv_free(argv); 1668 } 1669 1670 /** 1671 * orderly_poweroff - Trigger an orderly system poweroff 1672 * @force: force poweroff if command execution fails 1673 * 1674 * This may be called from any context to trigger a system shutdown. 1675 * If the orderly shutdown fails, it will force an immediate shutdown. 1676 */ 1677 int orderly_poweroff(bool force) 1678 { 1679 int argc; 1680 char **argv = argv_split(GFP_ATOMIC, poweroff_cmd, &argc); 1681 static char *envp[] = { 1682 "HOME=/", 1683 "PATH=/sbin:/bin:/usr/sbin:/usr/bin", 1684 NULL 1685 }; 1686 int ret = -ENOMEM; 1687 struct subprocess_info *info; 1688 1689 if (argv == NULL) { 1690 printk(KERN_WARNING "%s failed to allocate memory for \"%s\"\n", 1691 __func__, poweroff_cmd); 1692 goto out; 1693 } 1694 1695 info = call_usermodehelper_setup(argv[0], argv, envp, GFP_ATOMIC); 1696 if (info == NULL) { 1697 argv_free(argv); 1698 goto out; 1699 } 1700 1701 call_usermodehelper_setcleanup(info, argv_cleanup); 1702 1703 ret = call_usermodehelper_exec(info, UMH_NO_WAIT); 1704 1705 out: 1706 if (ret && force) { 1707 printk(KERN_WARNING "Failed to start orderly shutdown: " 1708 "forcing the issue\n"); 1709 1710 /* I guess this should try to kick off some daemon to 1711 sync and poweroff asap. Or not even bother syncing 1712 if we're doing an emergency shutdown? */ 1713 emergency_sync(); 1714 kernel_power_off(); 1715 } 1716 1717 return ret; 1718 } 1719 EXPORT_SYMBOL_GPL(orderly_poweroff); 1720