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 #include <linux/gfp.h> 40 41 #include <linux/compat.h> 42 #include <linux/syscalls.h> 43 #include <linux/kprobes.h> 44 #include <linux/user_namespace.h> 45 46 #include <asm/uaccess.h> 47 #include <asm/io.h> 48 #include <asm/unistd.h> 49 50 #ifndef SET_UNALIGN_CTL 51 # define SET_UNALIGN_CTL(a,b) (-EINVAL) 52 #endif 53 #ifndef GET_UNALIGN_CTL 54 # define GET_UNALIGN_CTL(a,b) (-EINVAL) 55 #endif 56 #ifndef SET_FPEMU_CTL 57 # define SET_FPEMU_CTL(a,b) (-EINVAL) 58 #endif 59 #ifndef GET_FPEMU_CTL 60 # define GET_FPEMU_CTL(a,b) (-EINVAL) 61 #endif 62 #ifndef SET_FPEXC_CTL 63 # define SET_FPEXC_CTL(a,b) (-EINVAL) 64 #endif 65 #ifndef GET_FPEXC_CTL 66 # define GET_FPEXC_CTL(a,b) (-EINVAL) 67 #endif 68 #ifndef GET_ENDIAN 69 # define GET_ENDIAN(a,b) (-EINVAL) 70 #endif 71 #ifndef SET_ENDIAN 72 # define SET_ENDIAN(a,b) (-EINVAL) 73 #endif 74 #ifndef GET_TSC_CTL 75 # define GET_TSC_CTL(a) (-EINVAL) 76 #endif 77 #ifndef SET_TSC_CTL 78 # define SET_TSC_CTL(a) (-EINVAL) 79 #endif 80 81 /* 82 * this is where the system-wide overflow UID and GID are defined, for 83 * architectures that now have 32-bit UID/GID but didn't in the past 84 */ 85 86 int overflowuid = DEFAULT_OVERFLOWUID; 87 int overflowgid = DEFAULT_OVERFLOWGID; 88 89 #ifdef CONFIG_UID16 90 EXPORT_SYMBOL(overflowuid); 91 EXPORT_SYMBOL(overflowgid); 92 #endif 93 94 /* 95 * the same as above, but for filesystems which can only store a 16-bit 96 * UID and GID. as such, this is needed on all architectures 97 */ 98 99 int fs_overflowuid = DEFAULT_FS_OVERFLOWUID; 100 int fs_overflowgid = DEFAULT_FS_OVERFLOWUID; 101 102 EXPORT_SYMBOL(fs_overflowuid); 103 EXPORT_SYMBOL(fs_overflowgid); 104 105 /* 106 * this indicates whether you can reboot with ctrl-alt-del: the default is yes 107 */ 108 109 int C_A_D = 1; 110 struct pid *cad_pid; 111 EXPORT_SYMBOL(cad_pid); 112 113 /* 114 * If set, this is used for preparing the system to power off. 115 */ 116 117 void (*pm_power_off_prepare)(void); 118 119 /* 120 * set the priority of a task 121 * - the caller must hold the RCU read lock 122 */ 123 static int set_one_prio(struct task_struct *p, int niceval, int error) 124 { 125 const struct cred *cred = current_cred(), *pcred = __task_cred(p); 126 int no_nice; 127 128 if (pcred->uid != cred->euid && 129 pcred->euid != cred->euid && !capable(CAP_SYS_NICE)) { 130 error = -EPERM; 131 goto out; 132 } 133 if (niceval < task_nice(p) && !can_nice(p, niceval)) { 134 error = -EACCES; 135 goto out; 136 } 137 no_nice = security_task_setnice(p, niceval); 138 if (no_nice) { 139 error = no_nice; 140 goto out; 141 } 142 if (error == -ESRCH) 143 error = 0; 144 set_user_nice(p, niceval); 145 out: 146 return error; 147 } 148 149 SYSCALL_DEFINE3(setpriority, int, which, int, who, int, niceval) 150 { 151 struct task_struct *g, *p; 152 struct user_struct *user; 153 const struct cred *cred = current_cred(); 154 int error = -EINVAL; 155 struct pid *pgrp; 156 157 if (which > PRIO_USER || which < PRIO_PROCESS) 158 goto out; 159 160 /* normalize: avoid signed division (rounding problems) */ 161 error = -ESRCH; 162 if (niceval < -20) 163 niceval = -20; 164 if (niceval > 19) 165 niceval = 19; 166 167 rcu_read_lock(); 168 read_lock(&tasklist_lock); 169 switch (which) { 170 case PRIO_PROCESS: 171 if (who) 172 p = find_task_by_vpid(who); 173 else 174 p = current; 175 if (p) 176 error = set_one_prio(p, niceval, error); 177 break; 178 case PRIO_PGRP: 179 if (who) 180 pgrp = find_vpid(who); 181 else 182 pgrp = task_pgrp(current); 183 do_each_pid_thread(pgrp, PIDTYPE_PGID, p) { 184 error = set_one_prio(p, niceval, error); 185 } while_each_pid_thread(pgrp, PIDTYPE_PGID, p); 186 break; 187 case PRIO_USER: 188 user = (struct user_struct *) cred->user; 189 if (!who) 190 who = cred->uid; 191 else if ((who != cred->uid) && 192 !(user = find_user(who))) 193 goto out_unlock; /* No processes for this user */ 194 195 do_each_thread(g, p) { 196 if (__task_cred(p)->uid == who) 197 error = set_one_prio(p, niceval, error); 198 } while_each_thread(g, p); 199 if (who != cred->uid) 200 free_uid(user); /* For find_user() */ 201 break; 202 } 203 out_unlock: 204 read_unlock(&tasklist_lock); 205 rcu_read_unlock(); 206 out: 207 return error; 208 } 209 210 /* 211 * Ugh. To avoid negative return values, "getpriority()" will 212 * not return the normal nice-value, but a negated value that 213 * has been offset by 20 (ie it returns 40..1 instead of -20..19) 214 * to stay compatible. 215 */ 216 SYSCALL_DEFINE2(getpriority, int, which, int, who) 217 { 218 struct task_struct *g, *p; 219 struct user_struct *user; 220 const struct cred *cred = current_cred(); 221 long niceval, retval = -ESRCH; 222 struct pid *pgrp; 223 224 if (which > PRIO_USER || which < PRIO_PROCESS) 225 return -EINVAL; 226 227 rcu_read_lock(); 228 read_lock(&tasklist_lock); 229 switch (which) { 230 case PRIO_PROCESS: 231 if (who) 232 p = find_task_by_vpid(who); 233 else 234 p = current; 235 if (p) { 236 niceval = 20 - task_nice(p); 237 if (niceval > retval) 238 retval = niceval; 239 } 240 break; 241 case PRIO_PGRP: 242 if (who) 243 pgrp = find_vpid(who); 244 else 245 pgrp = task_pgrp(current); 246 do_each_pid_thread(pgrp, PIDTYPE_PGID, p) { 247 niceval = 20 - task_nice(p); 248 if (niceval > retval) 249 retval = niceval; 250 } while_each_pid_thread(pgrp, PIDTYPE_PGID, p); 251 break; 252 case PRIO_USER: 253 user = (struct user_struct *) cred->user; 254 if (!who) 255 who = cred->uid; 256 else if ((who != cred->uid) && 257 !(user = find_user(who))) 258 goto out_unlock; /* No processes for this user */ 259 260 do_each_thread(g, p) { 261 if (__task_cred(p)->uid == who) { 262 niceval = 20 - task_nice(p); 263 if (niceval > retval) 264 retval = niceval; 265 } 266 } while_each_thread(g, p); 267 if (who != cred->uid) 268 free_uid(user); /* for find_user() */ 269 break; 270 } 271 out_unlock: 272 read_unlock(&tasklist_lock); 273 rcu_read_unlock(); 274 275 return retval; 276 } 277 278 /** 279 * emergency_restart - reboot the system 280 * 281 * Without shutting down any hardware or taking any locks 282 * reboot the system. This is called when we know we are in 283 * trouble so this is our best effort to reboot. This is 284 * safe to call in interrupt context. 285 */ 286 void emergency_restart(void) 287 { 288 machine_emergency_restart(); 289 } 290 EXPORT_SYMBOL_GPL(emergency_restart); 291 292 void kernel_restart_prepare(char *cmd) 293 { 294 blocking_notifier_call_chain(&reboot_notifier_list, SYS_RESTART, cmd); 295 system_state = SYSTEM_RESTART; 296 device_shutdown(); 297 sysdev_shutdown(); 298 } 299 300 /** 301 * kernel_restart - reboot the system 302 * @cmd: pointer to buffer containing command to execute for restart 303 * or %NULL 304 * 305 * Shutdown everything and perform a clean reboot. 306 * This is not safe to call in interrupt context. 307 */ 308 void kernel_restart(char *cmd) 309 { 310 kernel_restart_prepare(cmd); 311 if (!cmd) 312 printk(KERN_EMERG "Restarting system.\n"); 313 else 314 printk(KERN_EMERG "Restarting system with command '%s'.\n", cmd); 315 machine_restart(cmd); 316 } 317 EXPORT_SYMBOL_GPL(kernel_restart); 318 319 static void kernel_shutdown_prepare(enum system_states state) 320 { 321 blocking_notifier_call_chain(&reboot_notifier_list, 322 (state == SYSTEM_HALT)?SYS_HALT:SYS_POWER_OFF, NULL); 323 system_state = state; 324 device_shutdown(); 325 } 326 /** 327 * kernel_halt - halt the system 328 * 329 * Shutdown everything and perform a clean system halt. 330 */ 331 void kernel_halt(void) 332 { 333 kernel_shutdown_prepare(SYSTEM_HALT); 334 sysdev_shutdown(); 335 printk(KERN_EMERG "System halted.\n"); 336 machine_halt(); 337 } 338 339 EXPORT_SYMBOL_GPL(kernel_halt); 340 341 /** 342 * kernel_power_off - power_off the system 343 * 344 * Shutdown everything and perform a clean system power_off. 345 */ 346 void kernel_power_off(void) 347 { 348 kernel_shutdown_prepare(SYSTEM_POWER_OFF); 349 if (pm_power_off_prepare) 350 pm_power_off_prepare(); 351 disable_nonboot_cpus(); 352 sysdev_shutdown(); 353 printk(KERN_EMERG "Power down.\n"); 354 machine_power_off(); 355 } 356 EXPORT_SYMBOL_GPL(kernel_power_off); 357 358 static DEFINE_MUTEX(reboot_mutex); 359 360 /* 361 * Reboot system call: for obvious reasons only root may call it, 362 * and even root needs to set up some magic numbers in the registers 363 * so that some mistake won't make this reboot the whole machine. 364 * You can also set the meaning of the ctrl-alt-del-key here. 365 * 366 * reboot doesn't sync: do that yourself before calling this. 367 */ 368 SYSCALL_DEFINE4(reboot, int, magic1, int, magic2, unsigned int, cmd, 369 void __user *, arg) 370 { 371 char buffer[256]; 372 int ret = 0; 373 374 /* We only trust the superuser with rebooting the system. */ 375 if (!capable(CAP_SYS_BOOT)) 376 return -EPERM; 377 378 /* For safety, we require "magic" arguments. */ 379 if (magic1 != LINUX_REBOOT_MAGIC1 || 380 (magic2 != LINUX_REBOOT_MAGIC2 && 381 magic2 != LINUX_REBOOT_MAGIC2A && 382 magic2 != LINUX_REBOOT_MAGIC2B && 383 magic2 != LINUX_REBOOT_MAGIC2C)) 384 return -EINVAL; 385 386 /* Instead of trying to make the power_off code look like 387 * halt when pm_power_off is not set do it the easy way. 388 */ 389 if ((cmd == LINUX_REBOOT_CMD_POWER_OFF) && !pm_power_off) 390 cmd = LINUX_REBOOT_CMD_HALT; 391 392 mutex_lock(&reboot_mutex); 393 switch (cmd) { 394 case LINUX_REBOOT_CMD_RESTART: 395 kernel_restart(NULL); 396 break; 397 398 case LINUX_REBOOT_CMD_CAD_ON: 399 C_A_D = 1; 400 break; 401 402 case LINUX_REBOOT_CMD_CAD_OFF: 403 C_A_D = 0; 404 break; 405 406 case LINUX_REBOOT_CMD_HALT: 407 kernel_halt(); 408 do_exit(0); 409 panic("cannot halt"); 410 411 case LINUX_REBOOT_CMD_POWER_OFF: 412 kernel_power_off(); 413 do_exit(0); 414 break; 415 416 case LINUX_REBOOT_CMD_RESTART2: 417 if (strncpy_from_user(&buffer[0], arg, sizeof(buffer) - 1) < 0) { 418 ret = -EFAULT; 419 break; 420 } 421 buffer[sizeof(buffer) - 1] = '\0'; 422 423 kernel_restart(buffer); 424 break; 425 426 #ifdef CONFIG_KEXEC 427 case LINUX_REBOOT_CMD_KEXEC: 428 ret = kernel_kexec(); 429 break; 430 #endif 431 432 #ifdef CONFIG_HIBERNATION 433 case LINUX_REBOOT_CMD_SW_SUSPEND: 434 ret = hibernate(); 435 break; 436 #endif 437 438 default: 439 ret = -EINVAL; 440 break; 441 } 442 mutex_unlock(&reboot_mutex); 443 return ret; 444 } 445 446 static void deferred_cad(struct work_struct *dummy) 447 { 448 kernel_restart(NULL); 449 } 450 451 /* 452 * This function gets called by ctrl-alt-del - ie the keyboard interrupt. 453 * As it's called within an interrupt, it may NOT sync: the only choice 454 * is whether to reboot at once, or just ignore the ctrl-alt-del. 455 */ 456 void ctrl_alt_del(void) 457 { 458 static DECLARE_WORK(cad_work, deferred_cad); 459 460 if (C_A_D) 461 schedule_work(&cad_work); 462 else 463 kill_cad_pid(SIGINT, 1); 464 } 465 466 /* 467 * Unprivileged users may change the real gid to the effective gid 468 * or vice versa. (BSD-style) 469 * 470 * If you set the real gid at all, or set the effective gid to a value not 471 * equal to the real gid, then the saved gid is set to the new effective gid. 472 * 473 * This makes it possible for a setgid program to completely drop its 474 * privileges, which is often a useful assertion to make when you are doing 475 * a security audit over a program. 476 * 477 * The general idea is that a program which uses just setregid() will be 478 * 100% compatible with BSD. A program which uses just setgid() will be 479 * 100% compatible with POSIX with saved IDs. 480 * 481 * SMP: There are not races, the GIDs are checked only by filesystem 482 * operations (as far as semantic preservation is concerned). 483 */ 484 SYSCALL_DEFINE2(setregid, gid_t, rgid, gid_t, egid) 485 { 486 const struct cred *old; 487 struct cred *new; 488 int retval; 489 490 new = prepare_creds(); 491 if (!new) 492 return -ENOMEM; 493 old = current_cred(); 494 495 retval = security_task_setgid(rgid, egid, (gid_t)-1, LSM_SETID_RE); 496 if (retval) 497 goto error; 498 499 retval = -EPERM; 500 if (rgid != (gid_t) -1) { 501 if (old->gid == rgid || 502 old->egid == rgid || 503 capable(CAP_SETGID)) 504 new->gid = rgid; 505 else 506 goto error; 507 } 508 if (egid != (gid_t) -1) { 509 if (old->gid == egid || 510 old->egid == egid || 511 old->sgid == egid || 512 capable(CAP_SETGID)) 513 new->egid = egid; 514 else 515 goto error; 516 } 517 518 if (rgid != (gid_t) -1 || 519 (egid != (gid_t) -1 && egid != old->gid)) 520 new->sgid = new->egid; 521 new->fsgid = new->egid; 522 523 return commit_creds(new); 524 525 error: 526 abort_creds(new); 527 return retval; 528 } 529 530 /* 531 * setgid() is implemented like SysV w/ SAVED_IDS 532 * 533 * SMP: Same implicit races as above. 534 */ 535 SYSCALL_DEFINE1(setgid, gid_t, gid) 536 { 537 const struct cred *old; 538 struct cred *new; 539 int retval; 540 541 new = prepare_creds(); 542 if (!new) 543 return -ENOMEM; 544 old = current_cred(); 545 546 retval = security_task_setgid(gid, (gid_t)-1, (gid_t)-1, LSM_SETID_ID); 547 if (retval) 548 goto error; 549 550 retval = -EPERM; 551 if (capable(CAP_SETGID)) 552 new->gid = new->egid = new->sgid = new->fsgid = gid; 553 else if (gid == old->gid || gid == old->sgid) 554 new->egid = new->fsgid = gid; 555 else 556 goto error; 557 558 return commit_creds(new); 559 560 error: 561 abort_creds(new); 562 return retval; 563 } 564 565 /* 566 * change the user struct in a credentials set to match the new UID 567 */ 568 static int set_user(struct cred *new) 569 { 570 struct user_struct *new_user; 571 572 new_user = alloc_uid(current_user_ns(), new->uid); 573 if (!new_user) 574 return -EAGAIN; 575 576 if (atomic_read(&new_user->processes) >= rlimit(RLIMIT_NPROC) && 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 cputime_t tgutime, tgstime, cutime, cstime; 915 916 spin_lock_irq(¤t->sighand->siglock); 917 thread_group_times(current, &tgutime, &tgstime); 918 cutime = current->signal->cutime; 919 cstime = current->signal->cstime; 920 spin_unlock_irq(¤t->sighand->siglock); 921 tms->tms_utime = cputime_to_clock_t(tgutime); 922 tms->tms_stime = cputime_to_clock_t(tgstime); 923 tms->tms_cutime = cputime_to_clock_t(cutime); 924 tms->tms_cstime = cputime_to_clock_t(cstime); 925 } 926 927 SYSCALL_DEFINE1(times, struct tms __user *, tbuf) 928 { 929 if (tbuf) { 930 struct tms tmp; 931 932 do_sys_times(&tmp); 933 if (copy_to_user(tbuf, &tmp, sizeof(struct tms))) 934 return -EFAULT; 935 } 936 force_successful_syscall_return(); 937 return (long) jiffies_64_to_clock_t(get_jiffies_64()); 938 } 939 940 /* 941 * This needs some heavy checking ... 942 * I just haven't the stomach for it. I also don't fully 943 * understand sessions/pgrp etc. Let somebody who does explain it. 944 * 945 * OK, I think I have the protection semantics right.... this is really 946 * only important on a multi-user system anyway, to make sure one user 947 * can't send a signal to a process owned by another. -TYT, 12/12/91 948 * 949 * Auch. Had to add the 'did_exec' flag to conform completely to POSIX. 950 * LBT 04.03.94 951 */ 952 SYSCALL_DEFINE2(setpgid, pid_t, pid, pid_t, pgid) 953 { 954 struct task_struct *p; 955 struct task_struct *group_leader = current->group_leader; 956 struct pid *pgrp; 957 int err; 958 959 if (!pid) 960 pid = task_pid_vnr(group_leader); 961 if (!pgid) 962 pgid = pid; 963 if (pgid < 0) 964 return -EINVAL; 965 966 /* From this point forward we keep holding onto the tasklist lock 967 * so that our parent does not change from under us. -DaveM 968 */ 969 write_lock_irq(&tasklist_lock); 970 971 err = -ESRCH; 972 p = find_task_by_vpid(pid); 973 if (!p) 974 goto out; 975 976 err = -EINVAL; 977 if (!thread_group_leader(p)) 978 goto out; 979 980 if (same_thread_group(p->real_parent, group_leader)) { 981 err = -EPERM; 982 if (task_session(p) != task_session(group_leader)) 983 goto out; 984 err = -EACCES; 985 if (p->did_exec) 986 goto out; 987 } else { 988 err = -ESRCH; 989 if (p != group_leader) 990 goto out; 991 } 992 993 err = -EPERM; 994 if (p->signal->leader) 995 goto out; 996 997 pgrp = task_pid(p); 998 if (pgid != pid) { 999 struct task_struct *g; 1000 1001 pgrp = find_vpid(pgid); 1002 g = pid_task(pgrp, PIDTYPE_PGID); 1003 if (!g || task_session(g) != task_session(group_leader)) 1004 goto out; 1005 } 1006 1007 err = security_task_setpgid(p, pgid); 1008 if (err) 1009 goto out; 1010 1011 if (task_pgrp(p) != pgrp) 1012 change_pid(p, PIDTYPE_PGID, pgrp); 1013 1014 err = 0; 1015 out: 1016 /* All paths lead to here, thus we are safe. -DaveM */ 1017 write_unlock_irq(&tasklist_lock); 1018 return err; 1019 } 1020 1021 SYSCALL_DEFINE1(getpgid, pid_t, pid) 1022 { 1023 struct task_struct *p; 1024 struct pid *grp; 1025 int retval; 1026 1027 rcu_read_lock(); 1028 if (!pid) 1029 grp = task_pgrp(current); 1030 else { 1031 retval = -ESRCH; 1032 p = find_task_by_vpid(pid); 1033 if (!p) 1034 goto out; 1035 grp = task_pgrp(p); 1036 if (!grp) 1037 goto out; 1038 1039 retval = security_task_getpgid(p); 1040 if (retval) 1041 goto out; 1042 } 1043 retval = pid_vnr(grp); 1044 out: 1045 rcu_read_unlock(); 1046 return retval; 1047 } 1048 1049 #ifdef __ARCH_WANT_SYS_GETPGRP 1050 1051 SYSCALL_DEFINE0(getpgrp) 1052 { 1053 return sys_getpgid(0); 1054 } 1055 1056 #endif 1057 1058 SYSCALL_DEFINE1(getsid, pid_t, pid) 1059 { 1060 struct task_struct *p; 1061 struct pid *sid; 1062 int retval; 1063 1064 rcu_read_lock(); 1065 if (!pid) 1066 sid = task_session(current); 1067 else { 1068 retval = -ESRCH; 1069 p = find_task_by_vpid(pid); 1070 if (!p) 1071 goto out; 1072 sid = task_session(p); 1073 if (!sid) 1074 goto out; 1075 1076 retval = security_task_getsid(p); 1077 if (retval) 1078 goto out; 1079 } 1080 retval = pid_vnr(sid); 1081 out: 1082 rcu_read_unlock(); 1083 return retval; 1084 } 1085 1086 SYSCALL_DEFINE0(setsid) 1087 { 1088 struct task_struct *group_leader = current->group_leader; 1089 struct pid *sid = task_pid(group_leader); 1090 pid_t session = pid_vnr(sid); 1091 int err = -EPERM; 1092 1093 write_lock_irq(&tasklist_lock); 1094 /* Fail if I am already a session leader */ 1095 if (group_leader->signal->leader) 1096 goto out; 1097 1098 /* Fail if a process group id already exists that equals the 1099 * proposed session id. 1100 */ 1101 if (pid_task(sid, PIDTYPE_PGID)) 1102 goto out; 1103 1104 group_leader->signal->leader = 1; 1105 __set_special_pids(sid); 1106 1107 proc_clear_tty(group_leader); 1108 1109 err = session; 1110 out: 1111 write_unlock_irq(&tasklist_lock); 1112 if (err > 0) 1113 proc_sid_connector(group_leader); 1114 return err; 1115 } 1116 1117 DECLARE_RWSEM(uts_sem); 1118 1119 #ifdef COMPAT_UTS_MACHINE 1120 #define override_architecture(name) \ 1121 (current->personality == PER_LINUX32 && \ 1122 copy_to_user(name->machine, COMPAT_UTS_MACHINE, \ 1123 sizeof(COMPAT_UTS_MACHINE))) 1124 #else 1125 #define override_architecture(name) 0 1126 #endif 1127 1128 SYSCALL_DEFINE1(newuname, struct new_utsname __user *, name) 1129 { 1130 int errno = 0; 1131 1132 down_read(&uts_sem); 1133 if (copy_to_user(name, utsname(), sizeof *name)) 1134 errno = -EFAULT; 1135 up_read(&uts_sem); 1136 1137 if (!errno && override_architecture(name)) 1138 errno = -EFAULT; 1139 return errno; 1140 } 1141 1142 #ifdef __ARCH_WANT_SYS_OLD_UNAME 1143 /* 1144 * Old cruft 1145 */ 1146 SYSCALL_DEFINE1(uname, struct old_utsname __user *, name) 1147 { 1148 int error = 0; 1149 1150 if (!name) 1151 return -EFAULT; 1152 1153 down_read(&uts_sem); 1154 if (copy_to_user(name, utsname(), sizeof(*name))) 1155 error = -EFAULT; 1156 up_read(&uts_sem); 1157 1158 if (!error && override_architecture(name)) 1159 error = -EFAULT; 1160 return error; 1161 } 1162 1163 SYSCALL_DEFINE1(olduname, struct oldold_utsname __user *, name) 1164 { 1165 int error; 1166 1167 if (!name) 1168 return -EFAULT; 1169 if (!access_ok(VERIFY_WRITE, name, sizeof(struct oldold_utsname))) 1170 return -EFAULT; 1171 1172 down_read(&uts_sem); 1173 error = __copy_to_user(&name->sysname, &utsname()->sysname, 1174 __OLD_UTS_LEN); 1175 error |= __put_user(0, name->sysname + __OLD_UTS_LEN); 1176 error |= __copy_to_user(&name->nodename, &utsname()->nodename, 1177 __OLD_UTS_LEN); 1178 error |= __put_user(0, name->nodename + __OLD_UTS_LEN); 1179 error |= __copy_to_user(&name->release, &utsname()->release, 1180 __OLD_UTS_LEN); 1181 error |= __put_user(0, name->release + __OLD_UTS_LEN); 1182 error |= __copy_to_user(&name->version, &utsname()->version, 1183 __OLD_UTS_LEN); 1184 error |= __put_user(0, name->version + __OLD_UTS_LEN); 1185 error |= __copy_to_user(&name->machine, &utsname()->machine, 1186 __OLD_UTS_LEN); 1187 error |= __put_user(0, name->machine + __OLD_UTS_LEN); 1188 up_read(&uts_sem); 1189 1190 if (!error && override_architecture(name)) 1191 error = -EFAULT; 1192 return error ? -EFAULT : 0; 1193 } 1194 #endif 1195 1196 SYSCALL_DEFINE2(sethostname, char __user *, name, int, len) 1197 { 1198 int errno; 1199 char tmp[__NEW_UTS_LEN]; 1200 1201 if (!capable(CAP_SYS_ADMIN)) 1202 return -EPERM; 1203 if (len < 0 || len > __NEW_UTS_LEN) 1204 return -EINVAL; 1205 down_write(&uts_sem); 1206 errno = -EFAULT; 1207 if (!copy_from_user(tmp, name, len)) { 1208 struct new_utsname *u = utsname(); 1209 1210 memcpy(u->nodename, tmp, len); 1211 memset(u->nodename + len, 0, sizeof(u->nodename) - len); 1212 errno = 0; 1213 } 1214 up_write(&uts_sem); 1215 return errno; 1216 } 1217 1218 #ifdef __ARCH_WANT_SYS_GETHOSTNAME 1219 1220 SYSCALL_DEFINE2(gethostname, char __user *, name, int, len) 1221 { 1222 int i, errno; 1223 struct new_utsname *u; 1224 1225 if (len < 0) 1226 return -EINVAL; 1227 down_read(&uts_sem); 1228 u = utsname(); 1229 i = 1 + strlen(u->nodename); 1230 if (i > len) 1231 i = len; 1232 errno = 0; 1233 if (copy_to_user(name, u->nodename, i)) 1234 errno = -EFAULT; 1235 up_read(&uts_sem); 1236 return errno; 1237 } 1238 1239 #endif 1240 1241 /* 1242 * Only setdomainname; getdomainname can be implemented by calling 1243 * uname() 1244 */ 1245 SYSCALL_DEFINE2(setdomainname, char __user *, name, int, len) 1246 { 1247 int errno; 1248 char tmp[__NEW_UTS_LEN]; 1249 1250 if (!capable(CAP_SYS_ADMIN)) 1251 return -EPERM; 1252 if (len < 0 || len > __NEW_UTS_LEN) 1253 return -EINVAL; 1254 1255 down_write(&uts_sem); 1256 errno = -EFAULT; 1257 if (!copy_from_user(tmp, name, len)) { 1258 struct new_utsname *u = utsname(); 1259 1260 memcpy(u->domainname, tmp, len); 1261 memset(u->domainname + len, 0, sizeof(u->domainname) - len); 1262 errno = 0; 1263 } 1264 up_write(&uts_sem); 1265 return errno; 1266 } 1267 1268 SYSCALL_DEFINE2(getrlimit, unsigned int, resource, struct rlimit __user *, rlim) 1269 { 1270 if (resource >= RLIM_NLIMITS) 1271 return -EINVAL; 1272 else { 1273 struct rlimit value; 1274 task_lock(current->group_leader); 1275 value = current->signal->rlim[resource]; 1276 task_unlock(current->group_leader); 1277 return copy_to_user(rlim, &value, sizeof(*rlim)) ? -EFAULT : 0; 1278 } 1279 } 1280 1281 #ifdef __ARCH_WANT_SYS_OLD_GETRLIMIT 1282 1283 /* 1284 * Back compatibility for getrlimit. Needed for some apps. 1285 */ 1286 1287 SYSCALL_DEFINE2(old_getrlimit, unsigned int, resource, 1288 struct rlimit __user *, rlim) 1289 { 1290 struct rlimit x; 1291 if (resource >= RLIM_NLIMITS) 1292 return -EINVAL; 1293 1294 task_lock(current->group_leader); 1295 x = current->signal->rlim[resource]; 1296 task_unlock(current->group_leader); 1297 if (x.rlim_cur > 0x7FFFFFFF) 1298 x.rlim_cur = 0x7FFFFFFF; 1299 if (x.rlim_max > 0x7FFFFFFF) 1300 x.rlim_max = 0x7FFFFFFF; 1301 return copy_to_user(rlim, &x, sizeof(x))?-EFAULT:0; 1302 } 1303 1304 #endif 1305 1306 SYSCALL_DEFINE2(setrlimit, unsigned int, resource, struct rlimit __user *, rlim) 1307 { 1308 struct rlimit new_rlim, *old_rlim; 1309 int retval; 1310 1311 if (resource >= RLIM_NLIMITS) 1312 return -EINVAL; 1313 if (copy_from_user(&new_rlim, rlim, sizeof(*rlim))) 1314 return -EFAULT; 1315 if (new_rlim.rlim_cur > new_rlim.rlim_max) 1316 return -EINVAL; 1317 old_rlim = current->signal->rlim + resource; 1318 if ((new_rlim.rlim_max > old_rlim->rlim_max) && 1319 !capable(CAP_SYS_RESOURCE)) 1320 return -EPERM; 1321 if (resource == RLIMIT_NOFILE && new_rlim.rlim_max > sysctl_nr_open) 1322 return -EPERM; 1323 1324 retval = security_task_setrlimit(resource, &new_rlim); 1325 if (retval) 1326 return retval; 1327 1328 if (resource == RLIMIT_CPU && new_rlim.rlim_cur == 0) { 1329 /* 1330 * The caller is asking for an immediate RLIMIT_CPU 1331 * expiry. But we use the zero value to mean "it was 1332 * never set". So let's cheat and make it one second 1333 * instead 1334 */ 1335 new_rlim.rlim_cur = 1; 1336 } 1337 1338 task_lock(current->group_leader); 1339 *old_rlim = new_rlim; 1340 task_unlock(current->group_leader); 1341 1342 if (resource != RLIMIT_CPU) 1343 goto out; 1344 1345 /* 1346 * RLIMIT_CPU handling. Note that the kernel fails to return an error 1347 * code if it rejected the user's attempt to set RLIMIT_CPU. This is a 1348 * very long-standing error, and fixing it now risks breakage of 1349 * applications, so we live with it 1350 */ 1351 if (new_rlim.rlim_cur == RLIM_INFINITY) 1352 goto out; 1353 1354 update_rlimit_cpu(new_rlim.rlim_cur); 1355 out: 1356 return 0; 1357 } 1358 1359 /* 1360 * It would make sense to put struct rusage in the task_struct, 1361 * except that would make the task_struct be *really big*. After 1362 * task_struct gets moved into malloc'ed memory, it would 1363 * make sense to do this. It will make moving the rest of the information 1364 * a lot simpler! (Which we're not doing right now because we're not 1365 * measuring them yet). 1366 * 1367 * When sampling multiple threads for RUSAGE_SELF, under SMP we might have 1368 * races with threads incrementing their own counters. But since word 1369 * reads are atomic, we either get new values or old values and we don't 1370 * care which for the sums. We always take the siglock to protect reading 1371 * the c* fields from p->signal from races with exit.c updating those 1372 * fields when reaping, so a sample either gets all the additions of a 1373 * given child after it's reaped, or none so this sample is before reaping. 1374 * 1375 * Locking: 1376 * We need to take the siglock for CHILDEREN, SELF and BOTH 1377 * for the cases current multithreaded, non-current single threaded 1378 * non-current multithreaded. Thread traversal is now safe with 1379 * the siglock held. 1380 * Strictly speaking, we donot need to take the siglock if we are current and 1381 * single threaded, as no one else can take our signal_struct away, no one 1382 * else can reap the children to update signal->c* counters, and no one else 1383 * can race with the signal-> fields. If we do not take any lock, the 1384 * signal-> fields could be read out of order while another thread was just 1385 * exiting. So we should place a read memory barrier when we avoid the lock. 1386 * On the writer side, write memory barrier is implied in __exit_signal 1387 * as __exit_signal releases the siglock spinlock after updating the signal-> 1388 * fields. But we don't do this yet to keep things simple. 1389 * 1390 */ 1391 1392 static void accumulate_thread_rusage(struct task_struct *t, struct rusage *r) 1393 { 1394 r->ru_nvcsw += t->nvcsw; 1395 r->ru_nivcsw += t->nivcsw; 1396 r->ru_minflt += t->min_flt; 1397 r->ru_majflt += t->maj_flt; 1398 r->ru_inblock += task_io_get_inblock(t); 1399 r->ru_oublock += task_io_get_oublock(t); 1400 } 1401 1402 static void k_getrusage(struct task_struct *p, int who, struct rusage *r) 1403 { 1404 struct task_struct *t; 1405 unsigned long flags; 1406 cputime_t tgutime, tgstime, utime, stime; 1407 unsigned long maxrss = 0; 1408 1409 memset((char *) r, 0, sizeof *r); 1410 utime = stime = cputime_zero; 1411 1412 if (who == RUSAGE_THREAD) { 1413 task_times(current, &utime, &stime); 1414 accumulate_thread_rusage(p, r); 1415 maxrss = p->signal->maxrss; 1416 goto out; 1417 } 1418 1419 if (!lock_task_sighand(p, &flags)) 1420 return; 1421 1422 switch (who) { 1423 case RUSAGE_BOTH: 1424 case RUSAGE_CHILDREN: 1425 utime = p->signal->cutime; 1426 stime = p->signal->cstime; 1427 r->ru_nvcsw = p->signal->cnvcsw; 1428 r->ru_nivcsw = p->signal->cnivcsw; 1429 r->ru_minflt = p->signal->cmin_flt; 1430 r->ru_majflt = p->signal->cmaj_flt; 1431 r->ru_inblock = p->signal->cinblock; 1432 r->ru_oublock = p->signal->coublock; 1433 maxrss = p->signal->cmaxrss; 1434 1435 if (who == RUSAGE_CHILDREN) 1436 break; 1437 1438 case RUSAGE_SELF: 1439 thread_group_times(p, &tgutime, &tgstime); 1440 utime = cputime_add(utime, tgutime); 1441 stime = cputime_add(stime, tgstime); 1442 r->ru_nvcsw += p->signal->nvcsw; 1443 r->ru_nivcsw += p->signal->nivcsw; 1444 r->ru_minflt += p->signal->min_flt; 1445 r->ru_majflt += p->signal->maj_flt; 1446 r->ru_inblock += p->signal->inblock; 1447 r->ru_oublock += p->signal->oublock; 1448 if (maxrss < p->signal->maxrss) 1449 maxrss = p->signal->maxrss; 1450 t = p; 1451 do { 1452 accumulate_thread_rusage(t, r); 1453 t = next_thread(t); 1454 } while (t != p); 1455 break; 1456 1457 default: 1458 BUG(); 1459 } 1460 unlock_task_sighand(p, &flags); 1461 1462 out: 1463 cputime_to_timeval(utime, &r->ru_utime); 1464 cputime_to_timeval(stime, &r->ru_stime); 1465 1466 if (who != RUSAGE_CHILDREN) { 1467 struct mm_struct *mm = get_task_mm(p); 1468 if (mm) { 1469 setmax_mm_hiwater_rss(&maxrss, mm); 1470 mmput(mm); 1471 } 1472 } 1473 r->ru_maxrss = maxrss * (PAGE_SIZE / 1024); /* convert pages to KBs */ 1474 } 1475 1476 int getrusage(struct task_struct *p, int who, struct rusage __user *ru) 1477 { 1478 struct rusage r; 1479 k_getrusage(p, who, &r); 1480 return copy_to_user(ru, &r, sizeof(r)) ? -EFAULT : 0; 1481 } 1482 1483 SYSCALL_DEFINE2(getrusage, int, who, struct rusage __user *, ru) 1484 { 1485 if (who != RUSAGE_SELF && who != RUSAGE_CHILDREN && 1486 who != RUSAGE_THREAD) 1487 return -EINVAL; 1488 return getrusage(current, who, ru); 1489 } 1490 1491 SYSCALL_DEFINE1(umask, int, mask) 1492 { 1493 mask = xchg(¤t->fs->umask, mask & S_IRWXUGO); 1494 return mask; 1495 } 1496 1497 SYSCALL_DEFINE5(prctl, int, option, unsigned long, arg2, unsigned long, arg3, 1498 unsigned long, arg4, unsigned long, arg5) 1499 { 1500 struct task_struct *me = current; 1501 unsigned char comm[sizeof(me->comm)]; 1502 long error; 1503 1504 error = security_task_prctl(option, arg2, arg3, arg4, arg5); 1505 if (error != -ENOSYS) 1506 return error; 1507 1508 error = 0; 1509 switch (option) { 1510 case PR_SET_PDEATHSIG: 1511 if (!valid_signal(arg2)) { 1512 error = -EINVAL; 1513 break; 1514 } 1515 me->pdeath_signal = arg2; 1516 error = 0; 1517 break; 1518 case PR_GET_PDEATHSIG: 1519 error = put_user(me->pdeath_signal, (int __user *)arg2); 1520 break; 1521 case PR_GET_DUMPABLE: 1522 error = get_dumpable(me->mm); 1523 break; 1524 case PR_SET_DUMPABLE: 1525 if (arg2 < 0 || arg2 > 1) { 1526 error = -EINVAL; 1527 break; 1528 } 1529 set_dumpable(me->mm, arg2); 1530 error = 0; 1531 break; 1532 1533 case PR_SET_UNALIGN: 1534 error = SET_UNALIGN_CTL(me, arg2); 1535 break; 1536 case PR_GET_UNALIGN: 1537 error = GET_UNALIGN_CTL(me, arg2); 1538 break; 1539 case PR_SET_FPEMU: 1540 error = SET_FPEMU_CTL(me, arg2); 1541 break; 1542 case PR_GET_FPEMU: 1543 error = GET_FPEMU_CTL(me, arg2); 1544 break; 1545 case PR_SET_FPEXC: 1546 error = SET_FPEXC_CTL(me, arg2); 1547 break; 1548 case PR_GET_FPEXC: 1549 error = GET_FPEXC_CTL(me, arg2); 1550 break; 1551 case PR_GET_TIMING: 1552 error = PR_TIMING_STATISTICAL; 1553 break; 1554 case PR_SET_TIMING: 1555 if (arg2 != PR_TIMING_STATISTICAL) 1556 error = -EINVAL; 1557 else 1558 error = 0; 1559 break; 1560 1561 case PR_SET_NAME: 1562 comm[sizeof(me->comm)-1] = 0; 1563 if (strncpy_from_user(comm, (char __user *)arg2, 1564 sizeof(me->comm) - 1) < 0) 1565 return -EFAULT; 1566 set_task_comm(me, comm); 1567 return 0; 1568 case PR_GET_NAME: 1569 get_task_comm(comm, me); 1570 if (copy_to_user((char __user *)arg2, comm, 1571 sizeof(comm))) 1572 return -EFAULT; 1573 return 0; 1574 case PR_GET_ENDIAN: 1575 error = GET_ENDIAN(me, arg2); 1576 break; 1577 case PR_SET_ENDIAN: 1578 error = SET_ENDIAN(me, arg2); 1579 break; 1580 1581 case PR_GET_SECCOMP: 1582 error = prctl_get_seccomp(); 1583 break; 1584 case PR_SET_SECCOMP: 1585 error = prctl_set_seccomp(arg2); 1586 break; 1587 case PR_GET_TSC: 1588 error = GET_TSC_CTL(arg2); 1589 break; 1590 case PR_SET_TSC: 1591 error = SET_TSC_CTL(arg2); 1592 break; 1593 case PR_TASK_PERF_EVENTS_DISABLE: 1594 error = perf_event_task_disable(); 1595 break; 1596 case PR_TASK_PERF_EVENTS_ENABLE: 1597 error = perf_event_task_enable(); 1598 break; 1599 case PR_GET_TIMERSLACK: 1600 error = current->timer_slack_ns; 1601 break; 1602 case PR_SET_TIMERSLACK: 1603 if (arg2 <= 0) 1604 current->timer_slack_ns = 1605 current->default_timer_slack_ns; 1606 else 1607 current->timer_slack_ns = arg2; 1608 error = 0; 1609 break; 1610 case PR_MCE_KILL: 1611 if (arg4 | arg5) 1612 return -EINVAL; 1613 switch (arg2) { 1614 case PR_MCE_KILL_CLEAR: 1615 if (arg3 != 0) 1616 return -EINVAL; 1617 current->flags &= ~PF_MCE_PROCESS; 1618 break; 1619 case PR_MCE_KILL_SET: 1620 current->flags |= PF_MCE_PROCESS; 1621 if (arg3 == PR_MCE_KILL_EARLY) 1622 current->flags |= PF_MCE_EARLY; 1623 else if (arg3 == PR_MCE_KILL_LATE) 1624 current->flags &= ~PF_MCE_EARLY; 1625 else if (arg3 == PR_MCE_KILL_DEFAULT) 1626 current->flags &= 1627 ~(PF_MCE_EARLY|PF_MCE_PROCESS); 1628 else 1629 return -EINVAL; 1630 break; 1631 default: 1632 return -EINVAL; 1633 } 1634 error = 0; 1635 break; 1636 case PR_MCE_KILL_GET: 1637 if (arg2 | arg3 | arg4 | arg5) 1638 return -EINVAL; 1639 if (current->flags & PF_MCE_PROCESS) 1640 error = (current->flags & PF_MCE_EARLY) ? 1641 PR_MCE_KILL_EARLY : PR_MCE_KILL_LATE; 1642 else 1643 error = PR_MCE_KILL_DEFAULT; 1644 break; 1645 default: 1646 error = -EINVAL; 1647 break; 1648 } 1649 return error; 1650 } 1651 1652 SYSCALL_DEFINE3(getcpu, unsigned __user *, cpup, unsigned __user *, nodep, 1653 struct getcpu_cache __user *, unused) 1654 { 1655 int err = 0; 1656 int cpu = raw_smp_processor_id(); 1657 if (cpup) 1658 err |= put_user(cpu, cpup); 1659 if (nodep) 1660 err |= put_user(cpu_to_node(cpu), nodep); 1661 return err ? -EFAULT : 0; 1662 } 1663 1664 char poweroff_cmd[POWEROFF_CMD_PATH_LEN] = "/sbin/poweroff"; 1665 1666 static void argv_cleanup(char **argv, char **envp) 1667 { 1668 argv_free(argv); 1669 } 1670 1671 /** 1672 * orderly_poweroff - Trigger an orderly system poweroff 1673 * @force: force poweroff if command execution fails 1674 * 1675 * This may be called from any context to trigger a system shutdown. 1676 * If the orderly shutdown fails, it will force an immediate shutdown. 1677 */ 1678 int orderly_poweroff(bool force) 1679 { 1680 int argc; 1681 char **argv = argv_split(GFP_ATOMIC, poweroff_cmd, &argc); 1682 static char *envp[] = { 1683 "HOME=/", 1684 "PATH=/sbin:/bin:/usr/sbin:/usr/bin", 1685 NULL 1686 }; 1687 int ret = -ENOMEM; 1688 struct subprocess_info *info; 1689 1690 if (argv == NULL) { 1691 printk(KERN_WARNING "%s failed to allocate memory for \"%s\"\n", 1692 __func__, poweroff_cmd); 1693 goto out; 1694 } 1695 1696 info = call_usermodehelper_setup(argv[0], argv, envp, GFP_ATOMIC); 1697 if (info == NULL) { 1698 argv_free(argv); 1699 goto out; 1700 } 1701 1702 call_usermodehelper_setcleanup(info, argv_cleanup); 1703 1704 ret = call_usermodehelper_exec(info, UMH_NO_WAIT); 1705 1706 out: 1707 if (ret && force) { 1708 printk(KERN_WARNING "Failed to start orderly shutdown: " 1709 "forcing the issue\n"); 1710 1711 /* I guess this should try to kick off some daemon to 1712 sync and poweroff asap. Or not even bother syncing 1713 if we're doing an emergency shutdown? */ 1714 emergency_sync(); 1715 kernel_power_off(); 1716 } 1717 1718 return ret; 1719 } 1720 EXPORT_SYMBOL_GPL(orderly_poweroff); 1721