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 #include <linux/syscore_ops.h> 41 42 #include <linux/compat.h> 43 #include <linux/syscalls.h> 44 #include <linux/kprobes.h> 45 #include <linux/user_namespace.h> 46 47 #include <linux/kmsg_dump.h> 48 49 #include <asm/uaccess.h> 50 #include <asm/io.h> 51 #include <asm/unistd.h> 52 53 #ifndef SET_UNALIGN_CTL 54 # define SET_UNALIGN_CTL(a,b) (-EINVAL) 55 #endif 56 #ifndef GET_UNALIGN_CTL 57 # define GET_UNALIGN_CTL(a,b) (-EINVAL) 58 #endif 59 #ifndef SET_FPEMU_CTL 60 # define SET_FPEMU_CTL(a,b) (-EINVAL) 61 #endif 62 #ifndef GET_FPEMU_CTL 63 # define GET_FPEMU_CTL(a,b) (-EINVAL) 64 #endif 65 #ifndef SET_FPEXC_CTL 66 # define SET_FPEXC_CTL(a,b) (-EINVAL) 67 #endif 68 #ifndef GET_FPEXC_CTL 69 # define GET_FPEXC_CTL(a,b) (-EINVAL) 70 #endif 71 #ifndef GET_ENDIAN 72 # define GET_ENDIAN(a,b) (-EINVAL) 73 #endif 74 #ifndef SET_ENDIAN 75 # define SET_ENDIAN(a,b) (-EINVAL) 76 #endif 77 #ifndef GET_TSC_CTL 78 # define GET_TSC_CTL(a) (-EINVAL) 79 #endif 80 #ifndef SET_TSC_CTL 81 # define SET_TSC_CTL(a) (-EINVAL) 82 #endif 83 84 /* 85 * this is where the system-wide overflow UID and GID are defined, for 86 * architectures that now have 32-bit UID/GID but didn't in the past 87 */ 88 89 int overflowuid = DEFAULT_OVERFLOWUID; 90 int overflowgid = DEFAULT_OVERFLOWGID; 91 92 #ifdef CONFIG_UID16 93 EXPORT_SYMBOL(overflowuid); 94 EXPORT_SYMBOL(overflowgid); 95 #endif 96 97 /* 98 * the same as above, but for filesystems which can only store a 16-bit 99 * UID and GID. as such, this is needed on all architectures 100 */ 101 102 int fs_overflowuid = DEFAULT_FS_OVERFLOWUID; 103 int fs_overflowgid = DEFAULT_FS_OVERFLOWUID; 104 105 EXPORT_SYMBOL(fs_overflowuid); 106 EXPORT_SYMBOL(fs_overflowgid); 107 108 /* 109 * this indicates whether you can reboot with ctrl-alt-del: the default is yes 110 */ 111 112 int C_A_D = 1; 113 struct pid *cad_pid; 114 EXPORT_SYMBOL(cad_pid); 115 116 /* 117 * If set, this is used for preparing the system to power off. 118 */ 119 120 void (*pm_power_off_prepare)(void); 121 122 /* 123 * set the priority of a task 124 * - the caller must hold the RCU read lock 125 */ 126 static int set_one_prio(struct task_struct *p, int niceval, int error) 127 { 128 const struct cred *cred = current_cred(), *pcred = __task_cred(p); 129 int no_nice; 130 131 if (pcred->uid != cred->euid && 132 pcred->euid != cred->euid && !capable(CAP_SYS_NICE)) { 133 error = -EPERM; 134 goto out; 135 } 136 if (niceval < task_nice(p) && !can_nice(p, niceval)) { 137 error = -EACCES; 138 goto out; 139 } 140 no_nice = security_task_setnice(p, niceval); 141 if (no_nice) { 142 error = no_nice; 143 goto out; 144 } 145 if (error == -ESRCH) 146 error = 0; 147 set_user_nice(p, niceval); 148 out: 149 return error; 150 } 151 152 SYSCALL_DEFINE3(setpriority, int, which, int, who, int, niceval) 153 { 154 struct task_struct *g, *p; 155 struct user_struct *user; 156 const struct cred *cred = current_cred(); 157 int error = -EINVAL; 158 struct pid *pgrp; 159 160 if (which > PRIO_USER || which < PRIO_PROCESS) 161 goto out; 162 163 /* normalize: avoid signed division (rounding problems) */ 164 error = -ESRCH; 165 if (niceval < -20) 166 niceval = -20; 167 if (niceval > 19) 168 niceval = 19; 169 170 rcu_read_lock(); 171 read_lock(&tasklist_lock); 172 switch (which) { 173 case PRIO_PROCESS: 174 if (who) 175 p = find_task_by_vpid(who); 176 else 177 p = current; 178 if (p) 179 error = set_one_prio(p, niceval, error); 180 break; 181 case PRIO_PGRP: 182 if (who) 183 pgrp = find_vpid(who); 184 else 185 pgrp = task_pgrp(current); 186 do_each_pid_thread(pgrp, PIDTYPE_PGID, p) { 187 error = set_one_prio(p, niceval, error); 188 } while_each_pid_thread(pgrp, PIDTYPE_PGID, p); 189 break; 190 case PRIO_USER: 191 user = (struct user_struct *) cred->user; 192 if (!who) 193 who = cred->uid; 194 else if ((who != cred->uid) && 195 !(user = find_user(who))) 196 goto out_unlock; /* No processes for this user */ 197 198 do_each_thread(g, p) { 199 if (__task_cred(p)->uid == who) 200 error = set_one_prio(p, niceval, error); 201 } while_each_thread(g, p); 202 if (who != cred->uid) 203 free_uid(user); /* For find_user() */ 204 break; 205 } 206 out_unlock: 207 read_unlock(&tasklist_lock); 208 rcu_read_unlock(); 209 out: 210 return error; 211 } 212 213 /* 214 * Ugh. To avoid negative return values, "getpriority()" will 215 * not return the normal nice-value, but a negated value that 216 * has been offset by 20 (ie it returns 40..1 instead of -20..19) 217 * to stay compatible. 218 */ 219 SYSCALL_DEFINE2(getpriority, int, which, int, who) 220 { 221 struct task_struct *g, *p; 222 struct user_struct *user; 223 const struct cred *cred = current_cred(); 224 long niceval, retval = -ESRCH; 225 struct pid *pgrp; 226 227 if (which > PRIO_USER || which < PRIO_PROCESS) 228 return -EINVAL; 229 230 rcu_read_lock(); 231 read_lock(&tasklist_lock); 232 switch (which) { 233 case PRIO_PROCESS: 234 if (who) 235 p = find_task_by_vpid(who); 236 else 237 p = current; 238 if (p) { 239 niceval = 20 - task_nice(p); 240 if (niceval > retval) 241 retval = niceval; 242 } 243 break; 244 case PRIO_PGRP: 245 if (who) 246 pgrp = find_vpid(who); 247 else 248 pgrp = task_pgrp(current); 249 do_each_pid_thread(pgrp, PIDTYPE_PGID, p) { 250 niceval = 20 - task_nice(p); 251 if (niceval > retval) 252 retval = niceval; 253 } while_each_pid_thread(pgrp, PIDTYPE_PGID, p); 254 break; 255 case PRIO_USER: 256 user = (struct user_struct *) cred->user; 257 if (!who) 258 who = cred->uid; 259 else if ((who != cred->uid) && 260 !(user = find_user(who))) 261 goto out_unlock; /* No processes for this user */ 262 263 do_each_thread(g, p) { 264 if (__task_cred(p)->uid == who) { 265 niceval = 20 - task_nice(p); 266 if (niceval > retval) 267 retval = niceval; 268 } 269 } while_each_thread(g, p); 270 if (who != cred->uid) 271 free_uid(user); /* for find_user() */ 272 break; 273 } 274 out_unlock: 275 read_unlock(&tasklist_lock); 276 rcu_read_unlock(); 277 278 return retval; 279 } 280 281 /** 282 * emergency_restart - reboot the system 283 * 284 * Without shutting down any hardware or taking any locks 285 * reboot the system. This is called when we know we are in 286 * trouble so this is our best effort to reboot. This is 287 * safe to call in interrupt context. 288 */ 289 void emergency_restart(void) 290 { 291 kmsg_dump(KMSG_DUMP_EMERG); 292 machine_emergency_restart(); 293 } 294 EXPORT_SYMBOL_GPL(emergency_restart); 295 296 void kernel_restart_prepare(char *cmd) 297 { 298 blocking_notifier_call_chain(&reboot_notifier_list, SYS_RESTART, cmd); 299 system_state = SYSTEM_RESTART; 300 device_shutdown(); 301 sysdev_shutdown(); 302 syscore_shutdown(); 303 } 304 305 /** 306 * kernel_restart - reboot the system 307 * @cmd: pointer to buffer containing command to execute for restart 308 * or %NULL 309 * 310 * Shutdown everything and perform a clean reboot. 311 * This is not safe to call in interrupt context. 312 */ 313 void kernel_restart(char *cmd) 314 { 315 kernel_restart_prepare(cmd); 316 if (!cmd) 317 printk(KERN_EMERG "Restarting system.\n"); 318 else 319 printk(KERN_EMERG "Restarting system with command '%s'.\n", cmd); 320 kmsg_dump(KMSG_DUMP_RESTART); 321 machine_restart(cmd); 322 } 323 EXPORT_SYMBOL_GPL(kernel_restart); 324 325 static void kernel_shutdown_prepare(enum system_states state) 326 { 327 blocking_notifier_call_chain(&reboot_notifier_list, 328 (state == SYSTEM_HALT)?SYS_HALT:SYS_POWER_OFF, NULL); 329 system_state = state; 330 device_shutdown(); 331 } 332 /** 333 * kernel_halt - halt the system 334 * 335 * Shutdown everything and perform a clean system halt. 336 */ 337 void kernel_halt(void) 338 { 339 kernel_shutdown_prepare(SYSTEM_HALT); 340 sysdev_shutdown(); 341 syscore_shutdown(); 342 printk(KERN_EMERG "System halted.\n"); 343 kmsg_dump(KMSG_DUMP_HALT); 344 machine_halt(); 345 } 346 347 EXPORT_SYMBOL_GPL(kernel_halt); 348 349 /** 350 * kernel_power_off - power_off the system 351 * 352 * Shutdown everything and perform a clean system power_off. 353 */ 354 void kernel_power_off(void) 355 { 356 kernel_shutdown_prepare(SYSTEM_POWER_OFF); 357 if (pm_power_off_prepare) 358 pm_power_off_prepare(); 359 disable_nonboot_cpus(); 360 sysdev_shutdown(); 361 syscore_shutdown(); 362 printk(KERN_EMERG "Power down.\n"); 363 kmsg_dump(KMSG_DUMP_POWEROFF); 364 machine_power_off(); 365 } 366 EXPORT_SYMBOL_GPL(kernel_power_off); 367 368 static DEFINE_MUTEX(reboot_mutex); 369 370 /* 371 * Reboot system call: for obvious reasons only root may call it, 372 * and even root needs to set up some magic numbers in the registers 373 * so that some mistake won't make this reboot the whole machine. 374 * You can also set the meaning of the ctrl-alt-del-key here. 375 * 376 * reboot doesn't sync: do that yourself before calling this. 377 */ 378 SYSCALL_DEFINE4(reboot, int, magic1, int, magic2, unsigned int, cmd, 379 void __user *, arg) 380 { 381 char buffer[256]; 382 int ret = 0; 383 384 /* We only trust the superuser with rebooting the system. */ 385 if (!capable(CAP_SYS_BOOT)) 386 return -EPERM; 387 388 /* For safety, we require "magic" arguments. */ 389 if (magic1 != LINUX_REBOOT_MAGIC1 || 390 (magic2 != LINUX_REBOOT_MAGIC2 && 391 magic2 != LINUX_REBOOT_MAGIC2A && 392 magic2 != LINUX_REBOOT_MAGIC2B && 393 magic2 != LINUX_REBOOT_MAGIC2C)) 394 return -EINVAL; 395 396 /* Instead of trying to make the power_off code look like 397 * halt when pm_power_off is not set do it the easy way. 398 */ 399 if ((cmd == LINUX_REBOOT_CMD_POWER_OFF) && !pm_power_off) 400 cmd = LINUX_REBOOT_CMD_HALT; 401 402 mutex_lock(&reboot_mutex); 403 switch (cmd) { 404 case LINUX_REBOOT_CMD_RESTART: 405 kernel_restart(NULL); 406 break; 407 408 case LINUX_REBOOT_CMD_CAD_ON: 409 C_A_D = 1; 410 break; 411 412 case LINUX_REBOOT_CMD_CAD_OFF: 413 C_A_D = 0; 414 break; 415 416 case LINUX_REBOOT_CMD_HALT: 417 kernel_halt(); 418 do_exit(0); 419 panic("cannot halt"); 420 421 case LINUX_REBOOT_CMD_POWER_OFF: 422 kernel_power_off(); 423 do_exit(0); 424 break; 425 426 case LINUX_REBOOT_CMD_RESTART2: 427 if (strncpy_from_user(&buffer[0], arg, sizeof(buffer) - 1) < 0) { 428 ret = -EFAULT; 429 break; 430 } 431 buffer[sizeof(buffer) - 1] = '\0'; 432 433 kernel_restart(buffer); 434 break; 435 436 #ifdef CONFIG_KEXEC 437 case LINUX_REBOOT_CMD_KEXEC: 438 ret = kernel_kexec(); 439 break; 440 #endif 441 442 #ifdef CONFIG_HIBERNATION 443 case LINUX_REBOOT_CMD_SW_SUSPEND: 444 ret = hibernate(); 445 break; 446 #endif 447 448 default: 449 ret = -EINVAL; 450 break; 451 } 452 mutex_unlock(&reboot_mutex); 453 return ret; 454 } 455 456 static void deferred_cad(struct work_struct *dummy) 457 { 458 kernel_restart(NULL); 459 } 460 461 /* 462 * This function gets called by ctrl-alt-del - ie the keyboard interrupt. 463 * As it's called within an interrupt, it may NOT sync: the only choice 464 * is whether to reboot at once, or just ignore the ctrl-alt-del. 465 */ 466 void ctrl_alt_del(void) 467 { 468 static DECLARE_WORK(cad_work, deferred_cad); 469 470 if (C_A_D) 471 schedule_work(&cad_work); 472 else 473 kill_cad_pid(SIGINT, 1); 474 } 475 476 /* 477 * Unprivileged users may change the real gid to the effective gid 478 * or vice versa. (BSD-style) 479 * 480 * If you set the real gid at all, or set the effective gid to a value not 481 * equal to the real gid, then the saved gid is set to the new effective gid. 482 * 483 * This makes it possible for a setgid program to completely drop its 484 * privileges, which is often a useful assertion to make when you are doing 485 * a security audit over a program. 486 * 487 * The general idea is that a program which uses just setregid() will be 488 * 100% compatible with BSD. A program which uses just setgid() will be 489 * 100% compatible with POSIX with saved IDs. 490 * 491 * SMP: There are not races, the GIDs are checked only by filesystem 492 * operations (as far as semantic preservation is concerned). 493 */ 494 SYSCALL_DEFINE2(setregid, gid_t, rgid, gid_t, egid) 495 { 496 const struct cred *old; 497 struct cred *new; 498 int retval; 499 500 new = prepare_creds(); 501 if (!new) 502 return -ENOMEM; 503 old = current_cred(); 504 505 retval = -EPERM; 506 if (rgid != (gid_t) -1) { 507 if (old->gid == rgid || 508 old->egid == rgid || 509 capable(CAP_SETGID)) 510 new->gid = rgid; 511 else 512 goto error; 513 } 514 if (egid != (gid_t) -1) { 515 if (old->gid == egid || 516 old->egid == egid || 517 old->sgid == egid || 518 capable(CAP_SETGID)) 519 new->egid = egid; 520 else 521 goto error; 522 } 523 524 if (rgid != (gid_t) -1 || 525 (egid != (gid_t) -1 && egid != old->gid)) 526 new->sgid = new->egid; 527 new->fsgid = new->egid; 528 529 return commit_creds(new); 530 531 error: 532 abort_creds(new); 533 return retval; 534 } 535 536 /* 537 * setgid() is implemented like SysV w/ SAVED_IDS 538 * 539 * SMP: Same implicit races as above. 540 */ 541 SYSCALL_DEFINE1(setgid, gid_t, gid) 542 { 543 const struct cred *old; 544 struct cred *new; 545 int retval; 546 547 new = prepare_creds(); 548 if (!new) 549 return -ENOMEM; 550 old = current_cred(); 551 552 retval = -EPERM; 553 if (capable(CAP_SETGID)) 554 new->gid = new->egid = new->sgid = new->fsgid = gid; 555 else if (gid == old->gid || gid == old->sgid) 556 new->egid = new->fsgid = gid; 557 else 558 goto error; 559 560 return commit_creds(new); 561 562 error: 563 abort_creds(new); 564 return retval; 565 } 566 567 /* 568 * change the user struct in a credentials set to match the new UID 569 */ 570 static int set_user(struct cred *new) 571 { 572 struct user_struct *new_user; 573 574 new_user = alloc_uid(current_user_ns(), new->uid); 575 if (!new_user) 576 return -EAGAIN; 577 578 if (atomic_read(&new_user->processes) >= rlimit(RLIMIT_NPROC) && 579 new_user != INIT_USER) { 580 free_uid(new_user); 581 return -EAGAIN; 582 } 583 584 free_uid(new->user); 585 new->user = new_user; 586 return 0; 587 } 588 589 /* 590 * Unprivileged users may change the real uid to the effective uid 591 * or vice versa. (BSD-style) 592 * 593 * If you set the real uid at all, or set the effective uid to a value not 594 * equal to the real uid, then the saved uid is set to the new effective uid. 595 * 596 * This makes it possible for a setuid program to completely drop its 597 * privileges, which is often a useful assertion to make when you are doing 598 * a security audit over a program. 599 * 600 * The general idea is that a program which uses just setreuid() will be 601 * 100% compatible with BSD. A program which uses just setuid() will be 602 * 100% compatible with POSIX with saved IDs. 603 */ 604 SYSCALL_DEFINE2(setreuid, uid_t, ruid, uid_t, euid) 605 { 606 const struct cred *old; 607 struct cred *new; 608 int retval; 609 610 new = prepare_creds(); 611 if (!new) 612 return -ENOMEM; 613 old = current_cred(); 614 615 retval = -EPERM; 616 if (ruid != (uid_t) -1) { 617 new->uid = ruid; 618 if (old->uid != ruid && 619 old->euid != ruid && 620 !capable(CAP_SETUID)) 621 goto error; 622 } 623 624 if (euid != (uid_t) -1) { 625 new->euid = euid; 626 if (old->uid != euid && 627 old->euid != euid && 628 old->suid != euid && 629 !capable(CAP_SETUID)) 630 goto error; 631 } 632 633 if (new->uid != old->uid) { 634 retval = set_user(new); 635 if (retval < 0) 636 goto error; 637 } 638 if (ruid != (uid_t) -1 || 639 (euid != (uid_t) -1 && euid != old->uid)) 640 new->suid = new->euid; 641 new->fsuid = new->euid; 642 643 retval = security_task_fix_setuid(new, old, LSM_SETID_RE); 644 if (retval < 0) 645 goto error; 646 647 return commit_creds(new); 648 649 error: 650 abort_creds(new); 651 return retval; 652 } 653 654 /* 655 * setuid() is implemented like SysV with SAVED_IDS 656 * 657 * Note that SAVED_ID's is deficient in that a setuid root program 658 * like sendmail, for example, cannot set its uid to be a normal 659 * user and then switch back, because if you're root, setuid() sets 660 * the saved uid too. If you don't like this, blame the bright people 661 * in the POSIX committee and/or USG. Note that the BSD-style setreuid() 662 * will allow a root program to temporarily drop privileges and be able to 663 * regain them by swapping the real and effective uid. 664 */ 665 SYSCALL_DEFINE1(setuid, uid_t, uid) 666 { 667 const struct cred *old; 668 struct cred *new; 669 int retval; 670 671 new = prepare_creds(); 672 if (!new) 673 return -ENOMEM; 674 old = current_cred(); 675 676 retval = -EPERM; 677 if (capable(CAP_SETUID)) { 678 new->suid = new->uid = uid; 679 if (uid != old->uid) { 680 retval = set_user(new); 681 if (retval < 0) 682 goto error; 683 } 684 } else if (uid != old->uid && uid != new->suid) { 685 goto error; 686 } 687 688 new->fsuid = new->euid = uid; 689 690 retval = security_task_fix_setuid(new, old, LSM_SETID_ID); 691 if (retval < 0) 692 goto error; 693 694 return commit_creds(new); 695 696 error: 697 abort_creds(new); 698 return retval; 699 } 700 701 702 /* 703 * This function implements a generic ability to update ruid, euid, 704 * and suid. This allows you to implement the 4.4 compatible seteuid(). 705 */ 706 SYSCALL_DEFINE3(setresuid, uid_t, ruid, uid_t, euid, uid_t, suid) 707 { 708 const struct cred *old; 709 struct cred *new; 710 int retval; 711 712 new = prepare_creds(); 713 if (!new) 714 return -ENOMEM; 715 716 old = current_cred(); 717 718 retval = -EPERM; 719 if (!capable(CAP_SETUID)) { 720 if (ruid != (uid_t) -1 && ruid != old->uid && 721 ruid != old->euid && ruid != old->suid) 722 goto error; 723 if (euid != (uid_t) -1 && euid != old->uid && 724 euid != old->euid && euid != old->suid) 725 goto error; 726 if (suid != (uid_t) -1 && suid != old->uid && 727 suid != old->euid && suid != old->suid) 728 goto error; 729 } 730 731 if (ruid != (uid_t) -1) { 732 new->uid = ruid; 733 if (ruid != old->uid) { 734 retval = set_user(new); 735 if (retval < 0) 736 goto error; 737 } 738 } 739 if (euid != (uid_t) -1) 740 new->euid = euid; 741 if (suid != (uid_t) -1) 742 new->suid = suid; 743 new->fsuid = new->euid; 744 745 retval = security_task_fix_setuid(new, old, LSM_SETID_RES); 746 if (retval < 0) 747 goto error; 748 749 return commit_creds(new); 750 751 error: 752 abort_creds(new); 753 return retval; 754 } 755 756 SYSCALL_DEFINE3(getresuid, uid_t __user *, ruid, uid_t __user *, euid, uid_t __user *, suid) 757 { 758 const struct cred *cred = current_cred(); 759 int retval; 760 761 if (!(retval = put_user(cred->uid, ruid)) && 762 !(retval = put_user(cred->euid, euid))) 763 retval = put_user(cred->suid, suid); 764 765 return retval; 766 } 767 768 /* 769 * Same as above, but for rgid, egid, sgid. 770 */ 771 SYSCALL_DEFINE3(setresgid, gid_t, rgid, gid_t, egid, gid_t, sgid) 772 { 773 const struct cred *old; 774 struct cred *new; 775 int retval; 776 777 new = prepare_creds(); 778 if (!new) 779 return -ENOMEM; 780 old = current_cred(); 781 782 retval = -EPERM; 783 if (!capable(CAP_SETGID)) { 784 if (rgid != (gid_t) -1 && rgid != old->gid && 785 rgid != old->egid && rgid != old->sgid) 786 goto error; 787 if (egid != (gid_t) -1 && egid != old->gid && 788 egid != old->egid && egid != old->sgid) 789 goto error; 790 if (sgid != (gid_t) -1 && sgid != old->gid && 791 sgid != old->egid && sgid != old->sgid) 792 goto error; 793 } 794 795 if (rgid != (gid_t) -1) 796 new->gid = rgid; 797 if (egid != (gid_t) -1) 798 new->egid = egid; 799 if (sgid != (gid_t) -1) 800 new->sgid = sgid; 801 new->fsgid = new->egid; 802 803 return commit_creds(new); 804 805 error: 806 abort_creds(new); 807 return retval; 808 } 809 810 SYSCALL_DEFINE3(getresgid, gid_t __user *, rgid, gid_t __user *, egid, gid_t __user *, sgid) 811 { 812 const struct cred *cred = current_cred(); 813 int retval; 814 815 if (!(retval = put_user(cred->gid, rgid)) && 816 !(retval = put_user(cred->egid, egid))) 817 retval = put_user(cred->sgid, sgid); 818 819 return retval; 820 } 821 822 823 /* 824 * "setfsuid()" sets the fsuid - the uid used for filesystem checks. This 825 * is used for "access()" and for the NFS daemon (letting nfsd stay at 826 * whatever uid it wants to). It normally shadows "euid", except when 827 * explicitly set by setfsuid() or for access.. 828 */ 829 SYSCALL_DEFINE1(setfsuid, uid_t, uid) 830 { 831 const struct cred *old; 832 struct cred *new; 833 uid_t old_fsuid; 834 835 new = prepare_creds(); 836 if (!new) 837 return current_fsuid(); 838 old = current_cred(); 839 old_fsuid = old->fsuid; 840 841 if (uid == old->uid || uid == old->euid || 842 uid == old->suid || uid == old->fsuid || 843 capable(CAP_SETUID)) { 844 if (uid != old_fsuid) { 845 new->fsuid = uid; 846 if (security_task_fix_setuid(new, old, LSM_SETID_FS) == 0) 847 goto change_okay; 848 } 849 } 850 851 abort_creds(new); 852 return old_fsuid; 853 854 change_okay: 855 commit_creds(new); 856 return old_fsuid; 857 } 858 859 /* 860 * Samma på svenska.. 861 */ 862 SYSCALL_DEFINE1(setfsgid, gid_t, gid) 863 { 864 const struct cred *old; 865 struct cred *new; 866 gid_t old_fsgid; 867 868 new = prepare_creds(); 869 if (!new) 870 return current_fsgid(); 871 old = current_cred(); 872 old_fsgid = old->fsgid; 873 874 if (gid == old->gid || gid == old->egid || 875 gid == old->sgid || gid == old->fsgid || 876 capable(CAP_SETGID)) { 877 if (gid != old_fsgid) { 878 new->fsgid = gid; 879 goto change_okay; 880 } 881 } 882 883 abort_creds(new); 884 return old_fsgid; 885 886 change_okay: 887 commit_creds(new); 888 return old_fsgid; 889 } 890 891 void do_sys_times(struct tms *tms) 892 { 893 cputime_t tgutime, tgstime, cutime, cstime; 894 895 spin_lock_irq(¤t->sighand->siglock); 896 thread_group_times(current, &tgutime, &tgstime); 897 cutime = current->signal->cutime; 898 cstime = current->signal->cstime; 899 spin_unlock_irq(¤t->sighand->siglock); 900 tms->tms_utime = cputime_to_clock_t(tgutime); 901 tms->tms_stime = cputime_to_clock_t(tgstime); 902 tms->tms_cutime = cputime_to_clock_t(cutime); 903 tms->tms_cstime = cputime_to_clock_t(cstime); 904 } 905 906 SYSCALL_DEFINE1(times, struct tms __user *, tbuf) 907 { 908 if (tbuf) { 909 struct tms tmp; 910 911 do_sys_times(&tmp); 912 if (copy_to_user(tbuf, &tmp, sizeof(struct tms))) 913 return -EFAULT; 914 } 915 force_successful_syscall_return(); 916 return (long) jiffies_64_to_clock_t(get_jiffies_64()); 917 } 918 919 /* 920 * This needs some heavy checking ... 921 * I just haven't the stomach for it. I also don't fully 922 * understand sessions/pgrp etc. Let somebody who does explain it. 923 * 924 * OK, I think I have the protection semantics right.... this is really 925 * only important on a multi-user system anyway, to make sure one user 926 * can't send a signal to a process owned by another. -TYT, 12/12/91 927 * 928 * Auch. Had to add the 'did_exec' flag to conform completely to POSIX. 929 * LBT 04.03.94 930 */ 931 SYSCALL_DEFINE2(setpgid, pid_t, pid, pid_t, pgid) 932 { 933 struct task_struct *p; 934 struct task_struct *group_leader = current->group_leader; 935 struct pid *pgrp; 936 int err; 937 938 if (!pid) 939 pid = task_pid_vnr(group_leader); 940 if (!pgid) 941 pgid = pid; 942 if (pgid < 0) 943 return -EINVAL; 944 rcu_read_lock(); 945 946 /* From this point forward we keep holding onto the tasklist lock 947 * so that our parent does not change from under us. -DaveM 948 */ 949 write_lock_irq(&tasklist_lock); 950 951 err = -ESRCH; 952 p = find_task_by_vpid(pid); 953 if (!p) 954 goto out; 955 956 err = -EINVAL; 957 if (!thread_group_leader(p)) 958 goto out; 959 960 if (same_thread_group(p->real_parent, group_leader)) { 961 err = -EPERM; 962 if (task_session(p) != task_session(group_leader)) 963 goto out; 964 err = -EACCES; 965 if (p->did_exec) 966 goto out; 967 } else { 968 err = -ESRCH; 969 if (p != group_leader) 970 goto out; 971 } 972 973 err = -EPERM; 974 if (p->signal->leader) 975 goto out; 976 977 pgrp = task_pid(p); 978 if (pgid != pid) { 979 struct task_struct *g; 980 981 pgrp = find_vpid(pgid); 982 g = pid_task(pgrp, PIDTYPE_PGID); 983 if (!g || task_session(g) != task_session(group_leader)) 984 goto out; 985 } 986 987 err = security_task_setpgid(p, pgid); 988 if (err) 989 goto out; 990 991 if (task_pgrp(p) != pgrp) 992 change_pid(p, PIDTYPE_PGID, pgrp); 993 994 err = 0; 995 out: 996 /* All paths lead to here, thus we are safe. -DaveM */ 997 write_unlock_irq(&tasklist_lock); 998 rcu_read_unlock(); 999 return err; 1000 } 1001 1002 SYSCALL_DEFINE1(getpgid, pid_t, pid) 1003 { 1004 struct task_struct *p; 1005 struct pid *grp; 1006 int retval; 1007 1008 rcu_read_lock(); 1009 if (!pid) 1010 grp = task_pgrp(current); 1011 else { 1012 retval = -ESRCH; 1013 p = find_task_by_vpid(pid); 1014 if (!p) 1015 goto out; 1016 grp = task_pgrp(p); 1017 if (!grp) 1018 goto out; 1019 1020 retval = security_task_getpgid(p); 1021 if (retval) 1022 goto out; 1023 } 1024 retval = pid_vnr(grp); 1025 out: 1026 rcu_read_unlock(); 1027 return retval; 1028 } 1029 1030 #ifdef __ARCH_WANT_SYS_GETPGRP 1031 1032 SYSCALL_DEFINE0(getpgrp) 1033 { 1034 return sys_getpgid(0); 1035 } 1036 1037 #endif 1038 1039 SYSCALL_DEFINE1(getsid, pid_t, pid) 1040 { 1041 struct task_struct *p; 1042 struct pid *sid; 1043 int retval; 1044 1045 rcu_read_lock(); 1046 if (!pid) 1047 sid = task_session(current); 1048 else { 1049 retval = -ESRCH; 1050 p = find_task_by_vpid(pid); 1051 if (!p) 1052 goto out; 1053 sid = task_session(p); 1054 if (!sid) 1055 goto out; 1056 1057 retval = security_task_getsid(p); 1058 if (retval) 1059 goto out; 1060 } 1061 retval = pid_vnr(sid); 1062 out: 1063 rcu_read_unlock(); 1064 return retval; 1065 } 1066 1067 SYSCALL_DEFINE0(setsid) 1068 { 1069 struct task_struct *group_leader = current->group_leader; 1070 struct pid *sid = task_pid(group_leader); 1071 pid_t session = pid_vnr(sid); 1072 int err = -EPERM; 1073 1074 write_lock_irq(&tasklist_lock); 1075 /* Fail if I am already a session leader */ 1076 if (group_leader->signal->leader) 1077 goto out; 1078 1079 /* Fail if a process group id already exists that equals the 1080 * proposed session id. 1081 */ 1082 if (pid_task(sid, PIDTYPE_PGID)) 1083 goto out; 1084 1085 group_leader->signal->leader = 1; 1086 __set_special_pids(sid); 1087 1088 proc_clear_tty(group_leader); 1089 1090 err = session; 1091 out: 1092 write_unlock_irq(&tasklist_lock); 1093 if (err > 0) { 1094 proc_sid_connector(group_leader); 1095 sched_autogroup_create_attach(group_leader); 1096 } 1097 return err; 1098 } 1099 1100 DECLARE_RWSEM(uts_sem); 1101 1102 #ifdef COMPAT_UTS_MACHINE 1103 #define override_architecture(name) \ 1104 (personality(current->personality) == PER_LINUX32 && \ 1105 copy_to_user(name->machine, COMPAT_UTS_MACHINE, \ 1106 sizeof(COMPAT_UTS_MACHINE))) 1107 #else 1108 #define override_architecture(name) 0 1109 #endif 1110 1111 SYSCALL_DEFINE1(newuname, struct new_utsname __user *, name) 1112 { 1113 int errno = 0; 1114 1115 down_read(&uts_sem); 1116 if (copy_to_user(name, utsname(), sizeof *name)) 1117 errno = -EFAULT; 1118 up_read(&uts_sem); 1119 1120 if (!errno && override_architecture(name)) 1121 errno = -EFAULT; 1122 return errno; 1123 } 1124 1125 #ifdef __ARCH_WANT_SYS_OLD_UNAME 1126 /* 1127 * Old cruft 1128 */ 1129 SYSCALL_DEFINE1(uname, struct old_utsname __user *, name) 1130 { 1131 int error = 0; 1132 1133 if (!name) 1134 return -EFAULT; 1135 1136 down_read(&uts_sem); 1137 if (copy_to_user(name, utsname(), sizeof(*name))) 1138 error = -EFAULT; 1139 up_read(&uts_sem); 1140 1141 if (!error && override_architecture(name)) 1142 error = -EFAULT; 1143 return error; 1144 } 1145 1146 SYSCALL_DEFINE1(olduname, struct oldold_utsname __user *, name) 1147 { 1148 int error; 1149 1150 if (!name) 1151 return -EFAULT; 1152 if (!access_ok(VERIFY_WRITE, name, sizeof(struct oldold_utsname))) 1153 return -EFAULT; 1154 1155 down_read(&uts_sem); 1156 error = __copy_to_user(&name->sysname, &utsname()->sysname, 1157 __OLD_UTS_LEN); 1158 error |= __put_user(0, name->sysname + __OLD_UTS_LEN); 1159 error |= __copy_to_user(&name->nodename, &utsname()->nodename, 1160 __OLD_UTS_LEN); 1161 error |= __put_user(0, name->nodename + __OLD_UTS_LEN); 1162 error |= __copy_to_user(&name->release, &utsname()->release, 1163 __OLD_UTS_LEN); 1164 error |= __put_user(0, name->release + __OLD_UTS_LEN); 1165 error |= __copy_to_user(&name->version, &utsname()->version, 1166 __OLD_UTS_LEN); 1167 error |= __put_user(0, name->version + __OLD_UTS_LEN); 1168 error |= __copy_to_user(&name->machine, &utsname()->machine, 1169 __OLD_UTS_LEN); 1170 error |= __put_user(0, name->machine + __OLD_UTS_LEN); 1171 up_read(&uts_sem); 1172 1173 if (!error && override_architecture(name)) 1174 error = -EFAULT; 1175 return error ? -EFAULT : 0; 1176 } 1177 #endif 1178 1179 SYSCALL_DEFINE2(sethostname, char __user *, name, int, len) 1180 { 1181 int errno; 1182 char tmp[__NEW_UTS_LEN]; 1183 1184 if (!capable(CAP_SYS_ADMIN)) 1185 return -EPERM; 1186 if (len < 0 || len > __NEW_UTS_LEN) 1187 return -EINVAL; 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->nodename, tmp, len); 1194 memset(u->nodename + len, 0, sizeof(u->nodename) - len); 1195 errno = 0; 1196 } 1197 up_write(&uts_sem); 1198 return errno; 1199 } 1200 1201 #ifdef __ARCH_WANT_SYS_GETHOSTNAME 1202 1203 SYSCALL_DEFINE2(gethostname, char __user *, name, int, len) 1204 { 1205 int i, errno; 1206 struct new_utsname *u; 1207 1208 if (len < 0) 1209 return -EINVAL; 1210 down_read(&uts_sem); 1211 u = utsname(); 1212 i = 1 + strlen(u->nodename); 1213 if (i > len) 1214 i = len; 1215 errno = 0; 1216 if (copy_to_user(name, u->nodename, i)) 1217 errno = -EFAULT; 1218 up_read(&uts_sem); 1219 return errno; 1220 } 1221 1222 #endif 1223 1224 /* 1225 * Only setdomainname; getdomainname can be implemented by calling 1226 * uname() 1227 */ 1228 SYSCALL_DEFINE2(setdomainname, char __user *, name, int, len) 1229 { 1230 int errno; 1231 char tmp[__NEW_UTS_LEN]; 1232 1233 if (!capable(CAP_SYS_ADMIN)) 1234 return -EPERM; 1235 if (len < 0 || len > __NEW_UTS_LEN) 1236 return -EINVAL; 1237 1238 down_write(&uts_sem); 1239 errno = -EFAULT; 1240 if (!copy_from_user(tmp, name, len)) { 1241 struct new_utsname *u = utsname(); 1242 1243 memcpy(u->domainname, tmp, len); 1244 memset(u->domainname + len, 0, sizeof(u->domainname) - len); 1245 errno = 0; 1246 } 1247 up_write(&uts_sem); 1248 return errno; 1249 } 1250 1251 SYSCALL_DEFINE2(getrlimit, unsigned int, resource, struct rlimit __user *, rlim) 1252 { 1253 struct rlimit value; 1254 int ret; 1255 1256 ret = do_prlimit(current, resource, NULL, &value); 1257 if (!ret) 1258 ret = copy_to_user(rlim, &value, sizeof(*rlim)) ? -EFAULT : 0; 1259 1260 return ret; 1261 } 1262 1263 #ifdef __ARCH_WANT_SYS_OLD_GETRLIMIT 1264 1265 /* 1266 * Back compatibility for getrlimit. Needed for some apps. 1267 */ 1268 1269 SYSCALL_DEFINE2(old_getrlimit, unsigned int, resource, 1270 struct rlimit __user *, rlim) 1271 { 1272 struct rlimit x; 1273 if (resource >= RLIM_NLIMITS) 1274 return -EINVAL; 1275 1276 task_lock(current->group_leader); 1277 x = current->signal->rlim[resource]; 1278 task_unlock(current->group_leader); 1279 if (x.rlim_cur > 0x7FFFFFFF) 1280 x.rlim_cur = 0x7FFFFFFF; 1281 if (x.rlim_max > 0x7FFFFFFF) 1282 x.rlim_max = 0x7FFFFFFF; 1283 return copy_to_user(rlim, &x, sizeof(x))?-EFAULT:0; 1284 } 1285 1286 #endif 1287 1288 static inline bool rlim64_is_infinity(__u64 rlim64) 1289 { 1290 #if BITS_PER_LONG < 64 1291 return rlim64 >= ULONG_MAX; 1292 #else 1293 return rlim64 == RLIM64_INFINITY; 1294 #endif 1295 } 1296 1297 static void rlim_to_rlim64(const struct rlimit *rlim, struct rlimit64 *rlim64) 1298 { 1299 if (rlim->rlim_cur == RLIM_INFINITY) 1300 rlim64->rlim_cur = RLIM64_INFINITY; 1301 else 1302 rlim64->rlim_cur = rlim->rlim_cur; 1303 if (rlim->rlim_max == RLIM_INFINITY) 1304 rlim64->rlim_max = RLIM64_INFINITY; 1305 else 1306 rlim64->rlim_max = rlim->rlim_max; 1307 } 1308 1309 static void rlim64_to_rlim(const struct rlimit64 *rlim64, struct rlimit *rlim) 1310 { 1311 if (rlim64_is_infinity(rlim64->rlim_cur)) 1312 rlim->rlim_cur = RLIM_INFINITY; 1313 else 1314 rlim->rlim_cur = (unsigned long)rlim64->rlim_cur; 1315 if (rlim64_is_infinity(rlim64->rlim_max)) 1316 rlim->rlim_max = RLIM_INFINITY; 1317 else 1318 rlim->rlim_max = (unsigned long)rlim64->rlim_max; 1319 } 1320 1321 /* make sure you are allowed to change @tsk limits before calling this */ 1322 int do_prlimit(struct task_struct *tsk, unsigned int resource, 1323 struct rlimit *new_rlim, struct rlimit *old_rlim) 1324 { 1325 struct rlimit *rlim; 1326 int retval = 0; 1327 1328 if (resource >= RLIM_NLIMITS) 1329 return -EINVAL; 1330 if (new_rlim) { 1331 if (new_rlim->rlim_cur > new_rlim->rlim_max) 1332 return -EINVAL; 1333 if (resource == RLIMIT_NOFILE && 1334 new_rlim->rlim_max > sysctl_nr_open) 1335 return -EPERM; 1336 } 1337 1338 /* protect tsk->signal and tsk->sighand from disappearing */ 1339 read_lock(&tasklist_lock); 1340 if (!tsk->sighand) { 1341 retval = -ESRCH; 1342 goto out; 1343 } 1344 1345 rlim = tsk->signal->rlim + resource; 1346 task_lock(tsk->group_leader); 1347 if (new_rlim) { 1348 if (new_rlim->rlim_max > rlim->rlim_max && 1349 !capable(CAP_SYS_RESOURCE)) 1350 retval = -EPERM; 1351 if (!retval) 1352 retval = security_task_setrlimit(tsk->group_leader, 1353 resource, new_rlim); 1354 if (resource == RLIMIT_CPU && new_rlim->rlim_cur == 0) { 1355 /* 1356 * The caller is asking for an immediate RLIMIT_CPU 1357 * expiry. But we use the zero value to mean "it was 1358 * never set". So let's cheat and make it one second 1359 * instead 1360 */ 1361 new_rlim->rlim_cur = 1; 1362 } 1363 } 1364 if (!retval) { 1365 if (old_rlim) 1366 *old_rlim = *rlim; 1367 if (new_rlim) 1368 *rlim = *new_rlim; 1369 } 1370 task_unlock(tsk->group_leader); 1371 1372 /* 1373 * RLIMIT_CPU handling. Note that the kernel fails to return an error 1374 * code if it rejected the user's attempt to set RLIMIT_CPU. This is a 1375 * very long-standing error, and fixing it now risks breakage of 1376 * applications, so we live with it 1377 */ 1378 if (!retval && new_rlim && resource == RLIMIT_CPU && 1379 new_rlim->rlim_cur != RLIM_INFINITY) 1380 update_rlimit_cpu(tsk, new_rlim->rlim_cur); 1381 out: 1382 read_unlock(&tasklist_lock); 1383 return retval; 1384 } 1385 1386 /* rcu lock must be held */ 1387 static int check_prlimit_permission(struct task_struct *task) 1388 { 1389 const struct cred *cred = current_cred(), *tcred; 1390 1391 tcred = __task_cred(task); 1392 if (current != task && 1393 (cred->uid != tcred->euid || 1394 cred->uid != tcred->suid || 1395 cred->uid != tcred->uid || 1396 cred->gid != tcred->egid || 1397 cred->gid != tcred->sgid || 1398 cred->gid != tcred->gid) && 1399 !capable(CAP_SYS_RESOURCE)) { 1400 return -EPERM; 1401 } 1402 1403 return 0; 1404 } 1405 1406 SYSCALL_DEFINE4(prlimit64, pid_t, pid, unsigned int, resource, 1407 const struct rlimit64 __user *, new_rlim, 1408 struct rlimit64 __user *, old_rlim) 1409 { 1410 struct rlimit64 old64, new64; 1411 struct rlimit old, new; 1412 struct task_struct *tsk; 1413 int ret; 1414 1415 if (new_rlim) { 1416 if (copy_from_user(&new64, new_rlim, sizeof(new64))) 1417 return -EFAULT; 1418 rlim64_to_rlim(&new64, &new); 1419 } 1420 1421 rcu_read_lock(); 1422 tsk = pid ? find_task_by_vpid(pid) : current; 1423 if (!tsk) { 1424 rcu_read_unlock(); 1425 return -ESRCH; 1426 } 1427 ret = check_prlimit_permission(tsk); 1428 if (ret) { 1429 rcu_read_unlock(); 1430 return ret; 1431 } 1432 get_task_struct(tsk); 1433 rcu_read_unlock(); 1434 1435 ret = do_prlimit(tsk, resource, new_rlim ? &new : NULL, 1436 old_rlim ? &old : NULL); 1437 1438 if (!ret && old_rlim) { 1439 rlim_to_rlim64(&old, &old64); 1440 if (copy_to_user(old_rlim, &old64, sizeof(old64))) 1441 ret = -EFAULT; 1442 } 1443 1444 put_task_struct(tsk); 1445 return ret; 1446 } 1447 1448 SYSCALL_DEFINE2(setrlimit, unsigned int, resource, struct rlimit __user *, rlim) 1449 { 1450 struct rlimit new_rlim; 1451 1452 if (copy_from_user(&new_rlim, rlim, sizeof(*rlim))) 1453 return -EFAULT; 1454 return do_prlimit(current, resource, &new_rlim, NULL); 1455 } 1456 1457 /* 1458 * It would make sense to put struct rusage in the task_struct, 1459 * except that would make the task_struct be *really big*. After 1460 * task_struct gets moved into malloc'ed memory, it would 1461 * make sense to do this. It will make moving the rest of the information 1462 * a lot simpler! (Which we're not doing right now because we're not 1463 * measuring them yet). 1464 * 1465 * When sampling multiple threads for RUSAGE_SELF, under SMP we might have 1466 * races with threads incrementing their own counters. But since word 1467 * reads are atomic, we either get new values or old values and we don't 1468 * care which for the sums. We always take the siglock to protect reading 1469 * the c* fields from p->signal from races with exit.c updating those 1470 * fields when reaping, so a sample either gets all the additions of a 1471 * given child after it's reaped, or none so this sample is before reaping. 1472 * 1473 * Locking: 1474 * We need to take the siglock for CHILDEREN, SELF and BOTH 1475 * for the cases current multithreaded, non-current single threaded 1476 * non-current multithreaded. Thread traversal is now safe with 1477 * the siglock held. 1478 * Strictly speaking, we donot need to take the siglock if we are current and 1479 * single threaded, as no one else can take our signal_struct away, no one 1480 * else can reap the children to update signal->c* counters, and no one else 1481 * can race with the signal-> fields. If we do not take any lock, the 1482 * signal-> fields could be read out of order while another thread was just 1483 * exiting. So we should place a read memory barrier when we avoid the lock. 1484 * On the writer side, write memory barrier is implied in __exit_signal 1485 * as __exit_signal releases the siglock spinlock after updating the signal-> 1486 * fields. But we don't do this yet to keep things simple. 1487 * 1488 */ 1489 1490 static void accumulate_thread_rusage(struct task_struct *t, struct rusage *r) 1491 { 1492 r->ru_nvcsw += t->nvcsw; 1493 r->ru_nivcsw += t->nivcsw; 1494 r->ru_minflt += t->min_flt; 1495 r->ru_majflt += t->maj_flt; 1496 r->ru_inblock += task_io_get_inblock(t); 1497 r->ru_oublock += task_io_get_oublock(t); 1498 } 1499 1500 static void k_getrusage(struct task_struct *p, int who, struct rusage *r) 1501 { 1502 struct task_struct *t; 1503 unsigned long flags; 1504 cputime_t tgutime, tgstime, utime, stime; 1505 unsigned long maxrss = 0; 1506 1507 memset((char *) r, 0, sizeof *r); 1508 utime = stime = cputime_zero; 1509 1510 if (who == RUSAGE_THREAD) { 1511 task_times(current, &utime, &stime); 1512 accumulate_thread_rusage(p, r); 1513 maxrss = p->signal->maxrss; 1514 goto out; 1515 } 1516 1517 if (!lock_task_sighand(p, &flags)) 1518 return; 1519 1520 switch (who) { 1521 case RUSAGE_BOTH: 1522 case RUSAGE_CHILDREN: 1523 utime = p->signal->cutime; 1524 stime = p->signal->cstime; 1525 r->ru_nvcsw = p->signal->cnvcsw; 1526 r->ru_nivcsw = p->signal->cnivcsw; 1527 r->ru_minflt = p->signal->cmin_flt; 1528 r->ru_majflt = p->signal->cmaj_flt; 1529 r->ru_inblock = p->signal->cinblock; 1530 r->ru_oublock = p->signal->coublock; 1531 maxrss = p->signal->cmaxrss; 1532 1533 if (who == RUSAGE_CHILDREN) 1534 break; 1535 1536 case RUSAGE_SELF: 1537 thread_group_times(p, &tgutime, &tgstime); 1538 utime = cputime_add(utime, tgutime); 1539 stime = cputime_add(stime, tgstime); 1540 r->ru_nvcsw += p->signal->nvcsw; 1541 r->ru_nivcsw += p->signal->nivcsw; 1542 r->ru_minflt += p->signal->min_flt; 1543 r->ru_majflt += p->signal->maj_flt; 1544 r->ru_inblock += p->signal->inblock; 1545 r->ru_oublock += p->signal->oublock; 1546 if (maxrss < p->signal->maxrss) 1547 maxrss = p->signal->maxrss; 1548 t = p; 1549 do { 1550 accumulate_thread_rusage(t, r); 1551 t = next_thread(t); 1552 } while (t != p); 1553 break; 1554 1555 default: 1556 BUG(); 1557 } 1558 unlock_task_sighand(p, &flags); 1559 1560 out: 1561 cputime_to_timeval(utime, &r->ru_utime); 1562 cputime_to_timeval(stime, &r->ru_stime); 1563 1564 if (who != RUSAGE_CHILDREN) { 1565 struct mm_struct *mm = get_task_mm(p); 1566 if (mm) { 1567 setmax_mm_hiwater_rss(&maxrss, mm); 1568 mmput(mm); 1569 } 1570 } 1571 r->ru_maxrss = maxrss * (PAGE_SIZE / 1024); /* convert pages to KBs */ 1572 } 1573 1574 int getrusage(struct task_struct *p, int who, struct rusage __user *ru) 1575 { 1576 struct rusage r; 1577 k_getrusage(p, who, &r); 1578 return copy_to_user(ru, &r, sizeof(r)) ? -EFAULT : 0; 1579 } 1580 1581 SYSCALL_DEFINE2(getrusage, int, who, struct rusage __user *, ru) 1582 { 1583 if (who != RUSAGE_SELF && who != RUSAGE_CHILDREN && 1584 who != RUSAGE_THREAD) 1585 return -EINVAL; 1586 return getrusage(current, who, ru); 1587 } 1588 1589 SYSCALL_DEFINE1(umask, int, mask) 1590 { 1591 mask = xchg(¤t->fs->umask, mask & S_IRWXUGO); 1592 return mask; 1593 } 1594 1595 SYSCALL_DEFINE5(prctl, int, option, unsigned long, arg2, unsigned long, arg3, 1596 unsigned long, arg4, unsigned long, arg5) 1597 { 1598 struct task_struct *me = current; 1599 unsigned char comm[sizeof(me->comm)]; 1600 long error; 1601 1602 error = security_task_prctl(option, arg2, arg3, arg4, arg5); 1603 if (error != -ENOSYS) 1604 return error; 1605 1606 error = 0; 1607 switch (option) { 1608 case PR_SET_PDEATHSIG: 1609 if (!valid_signal(arg2)) { 1610 error = -EINVAL; 1611 break; 1612 } 1613 me->pdeath_signal = arg2; 1614 error = 0; 1615 break; 1616 case PR_GET_PDEATHSIG: 1617 error = put_user(me->pdeath_signal, (int __user *)arg2); 1618 break; 1619 case PR_GET_DUMPABLE: 1620 error = get_dumpable(me->mm); 1621 break; 1622 case PR_SET_DUMPABLE: 1623 if (arg2 < 0 || arg2 > 1) { 1624 error = -EINVAL; 1625 break; 1626 } 1627 set_dumpable(me->mm, arg2); 1628 error = 0; 1629 break; 1630 1631 case PR_SET_UNALIGN: 1632 error = SET_UNALIGN_CTL(me, arg2); 1633 break; 1634 case PR_GET_UNALIGN: 1635 error = GET_UNALIGN_CTL(me, arg2); 1636 break; 1637 case PR_SET_FPEMU: 1638 error = SET_FPEMU_CTL(me, arg2); 1639 break; 1640 case PR_GET_FPEMU: 1641 error = GET_FPEMU_CTL(me, arg2); 1642 break; 1643 case PR_SET_FPEXC: 1644 error = SET_FPEXC_CTL(me, arg2); 1645 break; 1646 case PR_GET_FPEXC: 1647 error = GET_FPEXC_CTL(me, arg2); 1648 break; 1649 case PR_GET_TIMING: 1650 error = PR_TIMING_STATISTICAL; 1651 break; 1652 case PR_SET_TIMING: 1653 if (arg2 != PR_TIMING_STATISTICAL) 1654 error = -EINVAL; 1655 else 1656 error = 0; 1657 break; 1658 1659 case PR_SET_NAME: 1660 comm[sizeof(me->comm)-1] = 0; 1661 if (strncpy_from_user(comm, (char __user *)arg2, 1662 sizeof(me->comm) - 1) < 0) 1663 return -EFAULT; 1664 set_task_comm(me, comm); 1665 return 0; 1666 case PR_GET_NAME: 1667 get_task_comm(comm, me); 1668 if (copy_to_user((char __user *)arg2, comm, 1669 sizeof(comm))) 1670 return -EFAULT; 1671 return 0; 1672 case PR_GET_ENDIAN: 1673 error = GET_ENDIAN(me, arg2); 1674 break; 1675 case PR_SET_ENDIAN: 1676 error = SET_ENDIAN(me, arg2); 1677 break; 1678 1679 case PR_GET_SECCOMP: 1680 error = prctl_get_seccomp(); 1681 break; 1682 case PR_SET_SECCOMP: 1683 error = prctl_set_seccomp(arg2); 1684 break; 1685 case PR_GET_TSC: 1686 error = GET_TSC_CTL(arg2); 1687 break; 1688 case PR_SET_TSC: 1689 error = SET_TSC_CTL(arg2); 1690 break; 1691 case PR_TASK_PERF_EVENTS_DISABLE: 1692 error = perf_event_task_disable(); 1693 break; 1694 case PR_TASK_PERF_EVENTS_ENABLE: 1695 error = perf_event_task_enable(); 1696 break; 1697 case PR_GET_TIMERSLACK: 1698 error = current->timer_slack_ns; 1699 break; 1700 case PR_SET_TIMERSLACK: 1701 if (arg2 <= 0) 1702 current->timer_slack_ns = 1703 current->default_timer_slack_ns; 1704 else 1705 current->timer_slack_ns = arg2; 1706 error = 0; 1707 break; 1708 case PR_MCE_KILL: 1709 if (arg4 | arg5) 1710 return -EINVAL; 1711 switch (arg2) { 1712 case PR_MCE_KILL_CLEAR: 1713 if (arg3 != 0) 1714 return -EINVAL; 1715 current->flags &= ~PF_MCE_PROCESS; 1716 break; 1717 case PR_MCE_KILL_SET: 1718 current->flags |= PF_MCE_PROCESS; 1719 if (arg3 == PR_MCE_KILL_EARLY) 1720 current->flags |= PF_MCE_EARLY; 1721 else if (arg3 == PR_MCE_KILL_LATE) 1722 current->flags &= ~PF_MCE_EARLY; 1723 else if (arg3 == PR_MCE_KILL_DEFAULT) 1724 current->flags &= 1725 ~(PF_MCE_EARLY|PF_MCE_PROCESS); 1726 else 1727 return -EINVAL; 1728 break; 1729 default: 1730 return -EINVAL; 1731 } 1732 error = 0; 1733 break; 1734 case PR_MCE_KILL_GET: 1735 if (arg2 | arg3 | arg4 | arg5) 1736 return -EINVAL; 1737 if (current->flags & PF_MCE_PROCESS) 1738 error = (current->flags & PF_MCE_EARLY) ? 1739 PR_MCE_KILL_EARLY : PR_MCE_KILL_LATE; 1740 else 1741 error = PR_MCE_KILL_DEFAULT; 1742 break; 1743 default: 1744 error = -EINVAL; 1745 break; 1746 } 1747 return error; 1748 } 1749 1750 SYSCALL_DEFINE3(getcpu, unsigned __user *, cpup, unsigned __user *, nodep, 1751 struct getcpu_cache __user *, unused) 1752 { 1753 int err = 0; 1754 int cpu = raw_smp_processor_id(); 1755 if (cpup) 1756 err |= put_user(cpu, cpup); 1757 if (nodep) 1758 err |= put_user(cpu_to_node(cpu), nodep); 1759 return err ? -EFAULT : 0; 1760 } 1761 1762 char poweroff_cmd[POWEROFF_CMD_PATH_LEN] = "/sbin/poweroff"; 1763 1764 static void argv_cleanup(struct subprocess_info *info) 1765 { 1766 argv_free(info->argv); 1767 } 1768 1769 /** 1770 * orderly_poweroff - Trigger an orderly system poweroff 1771 * @force: force poweroff if command execution fails 1772 * 1773 * This may be called from any context to trigger a system shutdown. 1774 * If the orderly shutdown fails, it will force an immediate shutdown. 1775 */ 1776 int orderly_poweroff(bool force) 1777 { 1778 int argc; 1779 char **argv = argv_split(GFP_ATOMIC, poweroff_cmd, &argc); 1780 static char *envp[] = { 1781 "HOME=/", 1782 "PATH=/sbin:/bin:/usr/sbin:/usr/bin", 1783 NULL 1784 }; 1785 int ret = -ENOMEM; 1786 struct subprocess_info *info; 1787 1788 if (argv == NULL) { 1789 printk(KERN_WARNING "%s failed to allocate memory for \"%s\"\n", 1790 __func__, poweroff_cmd); 1791 goto out; 1792 } 1793 1794 info = call_usermodehelper_setup(argv[0], argv, envp, GFP_ATOMIC); 1795 if (info == NULL) { 1796 argv_free(argv); 1797 goto out; 1798 } 1799 1800 call_usermodehelper_setfns(info, NULL, argv_cleanup, NULL); 1801 1802 ret = call_usermodehelper_exec(info, UMH_NO_WAIT); 1803 1804 out: 1805 if (ret && force) { 1806 printk(KERN_WARNING "Failed to start orderly shutdown: " 1807 "forcing the issue\n"); 1808 1809 /* I guess this should try to kick off some daemon to 1810 sync and poweroff asap. Or not even bother syncing 1811 if we're doing an emergency shutdown? */ 1812 emergency_sync(); 1813 kernel_power_off(); 1814 } 1815 1816 return ret; 1817 } 1818 EXPORT_SYMBOL_GPL(orderly_poweroff); 1819