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 * Returns true if current's euid is same as p's uid or euid, 124 * or has CAP_SYS_NICE to p's user_ns. 125 * 126 * Called with rcu_read_lock, creds are safe 127 */ 128 static bool set_one_prio_perm(struct task_struct *p) 129 { 130 const struct cred *cred = current_cred(), *pcred = __task_cred(p); 131 132 if (pcred->user->user_ns == cred->user->user_ns && 133 (pcred->uid == cred->euid || 134 pcred->euid == cred->euid)) 135 return true; 136 if (ns_capable(pcred->user->user_ns, CAP_SYS_NICE)) 137 return true; 138 return false; 139 } 140 141 /* 142 * set the priority of a task 143 * - the caller must hold the RCU read lock 144 */ 145 static int set_one_prio(struct task_struct *p, int niceval, int error) 146 { 147 int no_nice; 148 149 if (!set_one_prio_perm(p)) { 150 error = -EPERM; 151 goto out; 152 } 153 if (niceval < task_nice(p) && !can_nice(p, niceval)) { 154 error = -EACCES; 155 goto out; 156 } 157 no_nice = security_task_setnice(p, niceval); 158 if (no_nice) { 159 error = no_nice; 160 goto out; 161 } 162 if (error == -ESRCH) 163 error = 0; 164 set_user_nice(p, niceval); 165 out: 166 return error; 167 } 168 169 SYSCALL_DEFINE3(setpriority, int, which, int, who, int, niceval) 170 { 171 struct task_struct *g, *p; 172 struct user_struct *user; 173 const struct cred *cred = current_cred(); 174 int error = -EINVAL; 175 struct pid *pgrp; 176 177 if (which > PRIO_USER || which < PRIO_PROCESS) 178 goto out; 179 180 /* normalize: avoid signed division (rounding problems) */ 181 error = -ESRCH; 182 if (niceval < -20) 183 niceval = -20; 184 if (niceval > 19) 185 niceval = 19; 186 187 rcu_read_lock(); 188 read_lock(&tasklist_lock); 189 switch (which) { 190 case PRIO_PROCESS: 191 if (who) 192 p = find_task_by_vpid(who); 193 else 194 p = current; 195 if (p) 196 error = set_one_prio(p, niceval, error); 197 break; 198 case PRIO_PGRP: 199 if (who) 200 pgrp = find_vpid(who); 201 else 202 pgrp = task_pgrp(current); 203 do_each_pid_thread(pgrp, PIDTYPE_PGID, p) { 204 error = set_one_prio(p, niceval, error); 205 } while_each_pid_thread(pgrp, PIDTYPE_PGID, p); 206 break; 207 case PRIO_USER: 208 user = (struct user_struct *) cred->user; 209 if (!who) 210 who = cred->uid; 211 else if ((who != cred->uid) && 212 !(user = find_user(who))) 213 goto out_unlock; /* No processes for this user */ 214 215 do_each_thread(g, p) { 216 if (__task_cred(p)->uid == who) 217 error = set_one_prio(p, niceval, error); 218 } while_each_thread(g, p); 219 if (who != cred->uid) 220 free_uid(user); /* For find_user() */ 221 break; 222 } 223 out_unlock: 224 read_unlock(&tasklist_lock); 225 rcu_read_unlock(); 226 out: 227 return error; 228 } 229 230 /* 231 * Ugh. To avoid negative return values, "getpriority()" will 232 * not return the normal nice-value, but a negated value that 233 * has been offset by 20 (ie it returns 40..1 instead of -20..19) 234 * to stay compatible. 235 */ 236 SYSCALL_DEFINE2(getpriority, int, which, int, who) 237 { 238 struct task_struct *g, *p; 239 struct user_struct *user; 240 const struct cred *cred = current_cred(); 241 long niceval, retval = -ESRCH; 242 struct pid *pgrp; 243 244 if (which > PRIO_USER || which < PRIO_PROCESS) 245 return -EINVAL; 246 247 rcu_read_lock(); 248 read_lock(&tasklist_lock); 249 switch (which) { 250 case PRIO_PROCESS: 251 if (who) 252 p = find_task_by_vpid(who); 253 else 254 p = current; 255 if (p) { 256 niceval = 20 - task_nice(p); 257 if (niceval > retval) 258 retval = niceval; 259 } 260 break; 261 case PRIO_PGRP: 262 if (who) 263 pgrp = find_vpid(who); 264 else 265 pgrp = task_pgrp(current); 266 do_each_pid_thread(pgrp, PIDTYPE_PGID, p) { 267 niceval = 20 - task_nice(p); 268 if (niceval > retval) 269 retval = niceval; 270 } while_each_pid_thread(pgrp, PIDTYPE_PGID, p); 271 break; 272 case PRIO_USER: 273 user = (struct user_struct *) cred->user; 274 if (!who) 275 who = cred->uid; 276 else if ((who != cred->uid) && 277 !(user = find_user(who))) 278 goto out_unlock; /* No processes for this user */ 279 280 do_each_thread(g, p) { 281 if (__task_cred(p)->uid == who) { 282 niceval = 20 - task_nice(p); 283 if (niceval > retval) 284 retval = niceval; 285 } 286 } while_each_thread(g, p); 287 if (who != cred->uid) 288 free_uid(user); /* for find_user() */ 289 break; 290 } 291 out_unlock: 292 read_unlock(&tasklist_lock); 293 rcu_read_unlock(); 294 295 return retval; 296 } 297 298 /** 299 * emergency_restart - reboot the system 300 * 301 * Without shutting down any hardware or taking any locks 302 * reboot the system. This is called when we know we are in 303 * trouble so this is our best effort to reboot. This is 304 * safe to call in interrupt context. 305 */ 306 void emergency_restart(void) 307 { 308 kmsg_dump(KMSG_DUMP_EMERG); 309 machine_emergency_restart(); 310 } 311 EXPORT_SYMBOL_GPL(emergency_restart); 312 313 void kernel_restart_prepare(char *cmd) 314 { 315 blocking_notifier_call_chain(&reboot_notifier_list, SYS_RESTART, cmd); 316 system_state = SYSTEM_RESTART; 317 device_shutdown(); 318 sysdev_shutdown(); 319 syscore_shutdown(); 320 } 321 322 /** 323 * kernel_restart - reboot the system 324 * @cmd: pointer to buffer containing command to execute for restart 325 * or %NULL 326 * 327 * Shutdown everything and perform a clean reboot. 328 * This is not safe to call in interrupt context. 329 */ 330 void kernel_restart(char *cmd) 331 { 332 kernel_restart_prepare(cmd); 333 if (!cmd) 334 printk(KERN_EMERG "Restarting system.\n"); 335 else 336 printk(KERN_EMERG "Restarting system with command '%s'.\n", cmd); 337 kmsg_dump(KMSG_DUMP_RESTART); 338 machine_restart(cmd); 339 } 340 EXPORT_SYMBOL_GPL(kernel_restart); 341 342 static void kernel_shutdown_prepare(enum system_states state) 343 { 344 blocking_notifier_call_chain(&reboot_notifier_list, 345 (state == SYSTEM_HALT)?SYS_HALT:SYS_POWER_OFF, NULL); 346 system_state = state; 347 device_shutdown(); 348 } 349 /** 350 * kernel_halt - halt the system 351 * 352 * Shutdown everything and perform a clean system halt. 353 */ 354 void kernel_halt(void) 355 { 356 kernel_shutdown_prepare(SYSTEM_HALT); 357 sysdev_shutdown(); 358 syscore_shutdown(); 359 printk(KERN_EMERG "System halted.\n"); 360 kmsg_dump(KMSG_DUMP_HALT); 361 machine_halt(); 362 } 363 364 EXPORT_SYMBOL_GPL(kernel_halt); 365 366 /** 367 * kernel_power_off - power_off the system 368 * 369 * Shutdown everything and perform a clean system power_off. 370 */ 371 void kernel_power_off(void) 372 { 373 kernel_shutdown_prepare(SYSTEM_POWER_OFF); 374 if (pm_power_off_prepare) 375 pm_power_off_prepare(); 376 disable_nonboot_cpus(); 377 sysdev_shutdown(); 378 syscore_shutdown(); 379 printk(KERN_EMERG "Power down.\n"); 380 kmsg_dump(KMSG_DUMP_POWEROFF); 381 machine_power_off(); 382 } 383 EXPORT_SYMBOL_GPL(kernel_power_off); 384 385 static DEFINE_MUTEX(reboot_mutex); 386 387 /* 388 * Reboot system call: for obvious reasons only root may call it, 389 * and even root needs to set up some magic numbers in the registers 390 * so that some mistake won't make this reboot the whole machine. 391 * You can also set the meaning of the ctrl-alt-del-key here. 392 * 393 * reboot doesn't sync: do that yourself before calling this. 394 */ 395 SYSCALL_DEFINE4(reboot, int, magic1, int, magic2, unsigned int, cmd, 396 void __user *, arg) 397 { 398 char buffer[256]; 399 int ret = 0; 400 401 /* We only trust the superuser with rebooting the system. */ 402 if (!capable(CAP_SYS_BOOT)) 403 return -EPERM; 404 405 /* For safety, we require "magic" arguments. */ 406 if (magic1 != LINUX_REBOOT_MAGIC1 || 407 (magic2 != LINUX_REBOOT_MAGIC2 && 408 magic2 != LINUX_REBOOT_MAGIC2A && 409 magic2 != LINUX_REBOOT_MAGIC2B && 410 magic2 != LINUX_REBOOT_MAGIC2C)) 411 return -EINVAL; 412 413 /* Instead of trying to make the power_off code look like 414 * halt when pm_power_off is not set do it the easy way. 415 */ 416 if ((cmd == LINUX_REBOOT_CMD_POWER_OFF) && !pm_power_off) 417 cmd = LINUX_REBOOT_CMD_HALT; 418 419 mutex_lock(&reboot_mutex); 420 switch (cmd) { 421 case LINUX_REBOOT_CMD_RESTART: 422 kernel_restart(NULL); 423 break; 424 425 case LINUX_REBOOT_CMD_CAD_ON: 426 C_A_D = 1; 427 break; 428 429 case LINUX_REBOOT_CMD_CAD_OFF: 430 C_A_D = 0; 431 break; 432 433 case LINUX_REBOOT_CMD_HALT: 434 kernel_halt(); 435 do_exit(0); 436 panic("cannot halt"); 437 438 case LINUX_REBOOT_CMD_POWER_OFF: 439 kernel_power_off(); 440 do_exit(0); 441 break; 442 443 case LINUX_REBOOT_CMD_RESTART2: 444 if (strncpy_from_user(&buffer[0], arg, sizeof(buffer) - 1) < 0) { 445 ret = -EFAULT; 446 break; 447 } 448 buffer[sizeof(buffer) - 1] = '\0'; 449 450 kernel_restart(buffer); 451 break; 452 453 #ifdef CONFIG_KEXEC 454 case LINUX_REBOOT_CMD_KEXEC: 455 ret = kernel_kexec(); 456 break; 457 #endif 458 459 #ifdef CONFIG_HIBERNATION 460 case LINUX_REBOOT_CMD_SW_SUSPEND: 461 ret = hibernate(); 462 break; 463 #endif 464 465 default: 466 ret = -EINVAL; 467 break; 468 } 469 mutex_unlock(&reboot_mutex); 470 return ret; 471 } 472 473 static void deferred_cad(struct work_struct *dummy) 474 { 475 kernel_restart(NULL); 476 } 477 478 /* 479 * This function gets called by ctrl-alt-del - ie the keyboard interrupt. 480 * As it's called within an interrupt, it may NOT sync: the only choice 481 * is whether to reboot at once, or just ignore the ctrl-alt-del. 482 */ 483 void ctrl_alt_del(void) 484 { 485 static DECLARE_WORK(cad_work, deferred_cad); 486 487 if (C_A_D) 488 schedule_work(&cad_work); 489 else 490 kill_cad_pid(SIGINT, 1); 491 } 492 493 /* 494 * Unprivileged users may change the real gid to the effective gid 495 * or vice versa. (BSD-style) 496 * 497 * If you set the real gid at all, or set the effective gid to a value not 498 * equal to the real gid, then the saved gid is set to the new effective gid. 499 * 500 * This makes it possible for a setgid program to completely drop its 501 * privileges, which is often a useful assertion to make when you are doing 502 * a security audit over a program. 503 * 504 * The general idea is that a program which uses just setregid() will be 505 * 100% compatible with BSD. A program which uses just setgid() will be 506 * 100% compatible with POSIX with saved IDs. 507 * 508 * SMP: There are not races, the GIDs are checked only by filesystem 509 * operations (as far as semantic preservation is concerned). 510 */ 511 SYSCALL_DEFINE2(setregid, gid_t, rgid, gid_t, egid) 512 { 513 const struct cred *old; 514 struct cred *new; 515 int retval; 516 517 new = prepare_creds(); 518 if (!new) 519 return -ENOMEM; 520 old = current_cred(); 521 522 retval = -EPERM; 523 if (rgid != (gid_t) -1) { 524 if (old->gid == rgid || 525 old->egid == rgid || 526 nsown_capable(CAP_SETGID)) 527 new->gid = rgid; 528 else 529 goto error; 530 } 531 if (egid != (gid_t) -1) { 532 if (old->gid == egid || 533 old->egid == egid || 534 old->sgid == egid || 535 nsown_capable(CAP_SETGID)) 536 new->egid = egid; 537 else 538 goto error; 539 } 540 541 if (rgid != (gid_t) -1 || 542 (egid != (gid_t) -1 && egid != old->gid)) 543 new->sgid = new->egid; 544 new->fsgid = new->egid; 545 546 return commit_creds(new); 547 548 error: 549 abort_creds(new); 550 return retval; 551 } 552 553 /* 554 * setgid() is implemented like SysV w/ SAVED_IDS 555 * 556 * SMP: Same implicit races as above. 557 */ 558 SYSCALL_DEFINE1(setgid, gid_t, gid) 559 { 560 const struct cred *old; 561 struct cred *new; 562 int retval; 563 564 new = prepare_creds(); 565 if (!new) 566 return -ENOMEM; 567 old = current_cred(); 568 569 retval = -EPERM; 570 if (nsown_capable(CAP_SETGID)) 571 new->gid = new->egid = new->sgid = new->fsgid = gid; 572 else if (gid == old->gid || gid == old->sgid) 573 new->egid = new->fsgid = gid; 574 else 575 goto error; 576 577 return commit_creds(new); 578 579 error: 580 abort_creds(new); 581 return retval; 582 } 583 584 /* 585 * change the user struct in a credentials set to match the new UID 586 */ 587 static int set_user(struct cred *new) 588 { 589 struct user_struct *new_user; 590 591 new_user = alloc_uid(current_user_ns(), new->uid); 592 if (!new_user) 593 return -EAGAIN; 594 595 if (atomic_read(&new_user->processes) >= rlimit(RLIMIT_NPROC) && 596 new_user != INIT_USER) { 597 free_uid(new_user); 598 return -EAGAIN; 599 } 600 601 free_uid(new->user); 602 new->user = new_user; 603 return 0; 604 } 605 606 /* 607 * Unprivileged users may change the real uid to the effective uid 608 * or vice versa. (BSD-style) 609 * 610 * If you set the real uid at all, or set the effective uid to a value not 611 * equal to the real uid, then the saved uid is set to the new effective uid. 612 * 613 * This makes it possible for a setuid program to completely drop its 614 * privileges, which is often a useful assertion to make when you are doing 615 * a security audit over a program. 616 * 617 * The general idea is that a program which uses just setreuid() will be 618 * 100% compatible with BSD. A program which uses just setuid() will be 619 * 100% compatible with POSIX with saved IDs. 620 */ 621 SYSCALL_DEFINE2(setreuid, uid_t, ruid, uid_t, euid) 622 { 623 const struct cred *old; 624 struct cred *new; 625 int retval; 626 627 new = prepare_creds(); 628 if (!new) 629 return -ENOMEM; 630 old = current_cred(); 631 632 retval = -EPERM; 633 if (ruid != (uid_t) -1) { 634 new->uid = ruid; 635 if (old->uid != ruid && 636 old->euid != ruid && 637 !nsown_capable(CAP_SETUID)) 638 goto error; 639 } 640 641 if (euid != (uid_t) -1) { 642 new->euid = euid; 643 if (old->uid != euid && 644 old->euid != euid && 645 old->suid != euid && 646 !nsown_capable(CAP_SETUID)) 647 goto error; 648 } 649 650 if (new->uid != old->uid) { 651 retval = set_user(new); 652 if (retval < 0) 653 goto error; 654 } 655 if (ruid != (uid_t) -1 || 656 (euid != (uid_t) -1 && euid != old->uid)) 657 new->suid = new->euid; 658 new->fsuid = new->euid; 659 660 retval = security_task_fix_setuid(new, old, LSM_SETID_RE); 661 if (retval < 0) 662 goto error; 663 664 return commit_creds(new); 665 666 error: 667 abort_creds(new); 668 return retval; 669 } 670 671 /* 672 * setuid() is implemented like SysV with SAVED_IDS 673 * 674 * Note that SAVED_ID's is deficient in that a setuid root program 675 * like sendmail, for example, cannot set its uid to be a normal 676 * user and then switch back, because if you're root, setuid() sets 677 * the saved uid too. If you don't like this, blame the bright people 678 * in the POSIX committee and/or USG. Note that the BSD-style setreuid() 679 * will allow a root program to temporarily drop privileges and be able to 680 * regain them by swapping the real and effective uid. 681 */ 682 SYSCALL_DEFINE1(setuid, uid_t, uid) 683 { 684 const struct cred *old; 685 struct cred *new; 686 int retval; 687 688 new = prepare_creds(); 689 if (!new) 690 return -ENOMEM; 691 old = current_cred(); 692 693 retval = -EPERM; 694 if (nsown_capable(CAP_SETUID)) { 695 new->suid = new->uid = uid; 696 if (uid != old->uid) { 697 retval = set_user(new); 698 if (retval < 0) 699 goto error; 700 } 701 } else if (uid != old->uid && uid != new->suid) { 702 goto error; 703 } 704 705 new->fsuid = new->euid = uid; 706 707 retval = security_task_fix_setuid(new, old, LSM_SETID_ID); 708 if (retval < 0) 709 goto error; 710 711 return commit_creds(new); 712 713 error: 714 abort_creds(new); 715 return retval; 716 } 717 718 719 /* 720 * This function implements a generic ability to update ruid, euid, 721 * and suid. This allows you to implement the 4.4 compatible seteuid(). 722 */ 723 SYSCALL_DEFINE3(setresuid, uid_t, ruid, uid_t, euid, uid_t, suid) 724 { 725 const struct cred *old; 726 struct cred *new; 727 int retval; 728 729 new = prepare_creds(); 730 if (!new) 731 return -ENOMEM; 732 733 old = current_cred(); 734 735 retval = -EPERM; 736 if (!nsown_capable(CAP_SETUID)) { 737 if (ruid != (uid_t) -1 && ruid != old->uid && 738 ruid != old->euid && ruid != old->suid) 739 goto error; 740 if (euid != (uid_t) -1 && euid != old->uid && 741 euid != old->euid && euid != old->suid) 742 goto error; 743 if (suid != (uid_t) -1 && suid != old->uid && 744 suid != old->euid && suid != old->suid) 745 goto error; 746 } 747 748 if (ruid != (uid_t) -1) { 749 new->uid = ruid; 750 if (ruid != old->uid) { 751 retval = set_user(new); 752 if (retval < 0) 753 goto error; 754 } 755 } 756 if (euid != (uid_t) -1) 757 new->euid = euid; 758 if (suid != (uid_t) -1) 759 new->suid = suid; 760 new->fsuid = new->euid; 761 762 retval = security_task_fix_setuid(new, old, LSM_SETID_RES); 763 if (retval < 0) 764 goto error; 765 766 return commit_creds(new); 767 768 error: 769 abort_creds(new); 770 return retval; 771 } 772 773 SYSCALL_DEFINE3(getresuid, uid_t __user *, ruid, uid_t __user *, euid, uid_t __user *, suid) 774 { 775 const struct cred *cred = current_cred(); 776 int retval; 777 778 if (!(retval = put_user(cred->uid, ruid)) && 779 !(retval = put_user(cred->euid, euid))) 780 retval = put_user(cred->suid, suid); 781 782 return retval; 783 } 784 785 /* 786 * Same as above, but for rgid, egid, sgid. 787 */ 788 SYSCALL_DEFINE3(setresgid, gid_t, rgid, gid_t, egid, gid_t, sgid) 789 { 790 const struct cred *old; 791 struct cred *new; 792 int retval; 793 794 new = prepare_creds(); 795 if (!new) 796 return -ENOMEM; 797 old = current_cred(); 798 799 retval = -EPERM; 800 if (!nsown_capable(CAP_SETGID)) { 801 if (rgid != (gid_t) -1 && rgid != old->gid && 802 rgid != old->egid && rgid != old->sgid) 803 goto error; 804 if (egid != (gid_t) -1 && egid != old->gid && 805 egid != old->egid && egid != old->sgid) 806 goto error; 807 if (sgid != (gid_t) -1 && sgid != old->gid && 808 sgid != old->egid && sgid != old->sgid) 809 goto error; 810 } 811 812 if (rgid != (gid_t) -1) 813 new->gid = rgid; 814 if (egid != (gid_t) -1) 815 new->egid = egid; 816 if (sgid != (gid_t) -1) 817 new->sgid = sgid; 818 new->fsgid = new->egid; 819 820 return commit_creds(new); 821 822 error: 823 abort_creds(new); 824 return retval; 825 } 826 827 SYSCALL_DEFINE3(getresgid, gid_t __user *, rgid, gid_t __user *, egid, gid_t __user *, sgid) 828 { 829 const struct cred *cred = current_cred(); 830 int retval; 831 832 if (!(retval = put_user(cred->gid, rgid)) && 833 !(retval = put_user(cred->egid, egid))) 834 retval = put_user(cred->sgid, sgid); 835 836 return retval; 837 } 838 839 840 /* 841 * "setfsuid()" sets the fsuid - the uid used for filesystem checks. This 842 * is used for "access()" and for the NFS daemon (letting nfsd stay at 843 * whatever uid it wants to). It normally shadows "euid", except when 844 * explicitly set by setfsuid() or for access.. 845 */ 846 SYSCALL_DEFINE1(setfsuid, uid_t, uid) 847 { 848 const struct cred *old; 849 struct cred *new; 850 uid_t old_fsuid; 851 852 new = prepare_creds(); 853 if (!new) 854 return current_fsuid(); 855 old = current_cred(); 856 old_fsuid = old->fsuid; 857 858 if (uid == old->uid || uid == old->euid || 859 uid == old->suid || uid == old->fsuid || 860 nsown_capable(CAP_SETUID)) { 861 if (uid != old_fsuid) { 862 new->fsuid = uid; 863 if (security_task_fix_setuid(new, old, LSM_SETID_FS) == 0) 864 goto change_okay; 865 } 866 } 867 868 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 (gid == old->gid || gid == old->egid || 892 gid == old->sgid || gid == old->fsgid || 893 nsown_capable(CAP_SETGID)) { 894 if (gid != old_fsgid) { 895 new->fsgid = gid; 896 goto change_okay; 897 } 898 } 899 900 abort_creds(new); 901 return old_fsgid; 902 903 change_okay: 904 commit_creds(new); 905 return old_fsgid; 906 } 907 908 void do_sys_times(struct tms *tms) 909 { 910 cputime_t tgutime, tgstime, cutime, cstime; 911 912 spin_lock_irq(¤t->sighand->siglock); 913 thread_group_times(current, &tgutime, &tgstime); 914 cutime = current->signal->cutime; 915 cstime = current->signal->cstime; 916 spin_unlock_irq(¤t->sighand->siglock); 917 tms->tms_utime = cputime_to_clock_t(tgutime); 918 tms->tms_stime = cputime_to_clock_t(tgstime); 919 tms->tms_cutime = cputime_to_clock_t(cutime); 920 tms->tms_cstime = cputime_to_clock_t(cstime); 921 } 922 923 SYSCALL_DEFINE1(times, struct tms __user *, tbuf) 924 { 925 if (tbuf) { 926 struct tms tmp; 927 928 do_sys_times(&tmp); 929 if (copy_to_user(tbuf, &tmp, sizeof(struct tms))) 930 return -EFAULT; 931 } 932 force_successful_syscall_return(); 933 return (long) jiffies_64_to_clock_t(get_jiffies_64()); 934 } 935 936 /* 937 * This needs some heavy checking ... 938 * I just haven't the stomach for it. I also don't fully 939 * understand sessions/pgrp etc. Let somebody who does explain it. 940 * 941 * OK, I think I have the protection semantics right.... this is really 942 * only important on a multi-user system anyway, to make sure one user 943 * can't send a signal to a process owned by another. -TYT, 12/12/91 944 * 945 * Auch. Had to add the 'did_exec' flag to conform completely to POSIX. 946 * LBT 04.03.94 947 */ 948 SYSCALL_DEFINE2(setpgid, pid_t, pid, pid_t, pgid) 949 { 950 struct task_struct *p; 951 struct task_struct *group_leader = current->group_leader; 952 struct pid *pgrp; 953 int err; 954 955 if (!pid) 956 pid = task_pid_vnr(group_leader); 957 if (!pgid) 958 pgid = pid; 959 if (pgid < 0) 960 return -EINVAL; 961 rcu_read_lock(); 962 963 /* From this point forward we keep holding onto the tasklist lock 964 * so that our parent does not change from under us. -DaveM 965 */ 966 write_lock_irq(&tasklist_lock); 967 968 err = -ESRCH; 969 p = find_task_by_vpid(pid); 970 if (!p) 971 goto out; 972 973 err = -EINVAL; 974 if (!thread_group_leader(p)) 975 goto out; 976 977 if (same_thread_group(p->real_parent, group_leader)) { 978 err = -EPERM; 979 if (task_session(p) != task_session(group_leader)) 980 goto out; 981 err = -EACCES; 982 if (p->did_exec) 983 goto out; 984 } else { 985 err = -ESRCH; 986 if (p != group_leader) 987 goto out; 988 } 989 990 err = -EPERM; 991 if (p->signal->leader) 992 goto out; 993 994 pgrp = task_pid(p); 995 if (pgid != pid) { 996 struct task_struct *g; 997 998 pgrp = find_vpid(pgid); 999 g = pid_task(pgrp, PIDTYPE_PGID); 1000 if (!g || task_session(g) != task_session(group_leader)) 1001 goto out; 1002 } 1003 1004 err = security_task_setpgid(p, pgid); 1005 if (err) 1006 goto out; 1007 1008 if (task_pgrp(p) != pgrp) 1009 change_pid(p, PIDTYPE_PGID, pgrp); 1010 1011 err = 0; 1012 out: 1013 /* All paths lead to here, thus we are safe. -DaveM */ 1014 write_unlock_irq(&tasklist_lock); 1015 rcu_read_unlock(); 1016 return err; 1017 } 1018 1019 SYSCALL_DEFINE1(getpgid, pid_t, pid) 1020 { 1021 struct task_struct *p; 1022 struct pid *grp; 1023 int retval; 1024 1025 rcu_read_lock(); 1026 if (!pid) 1027 grp = task_pgrp(current); 1028 else { 1029 retval = -ESRCH; 1030 p = find_task_by_vpid(pid); 1031 if (!p) 1032 goto out; 1033 grp = task_pgrp(p); 1034 if (!grp) 1035 goto out; 1036 1037 retval = security_task_getpgid(p); 1038 if (retval) 1039 goto out; 1040 } 1041 retval = pid_vnr(grp); 1042 out: 1043 rcu_read_unlock(); 1044 return retval; 1045 } 1046 1047 #ifdef __ARCH_WANT_SYS_GETPGRP 1048 1049 SYSCALL_DEFINE0(getpgrp) 1050 { 1051 return sys_getpgid(0); 1052 } 1053 1054 #endif 1055 1056 SYSCALL_DEFINE1(getsid, pid_t, pid) 1057 { 1058 struct task_struct *p; 1059 struct pid *sid; 1060 int retval; 1061 1062 rcu_read_lock(); 1063 if (!pid) 1064 sid = task_session(current); 1065 else { 1066 retval = -ESRCH; 1067 p = find_task_by_vpid(pid); 1068 if (!p) 1069 goto out; 1070 sid = task_session(p); 1071 if (!sid) 1072 goto out; 1073 1074 retval = security_task_getsid(p); 1075 if (retval) 1076 goto out; 1077 } 1078 retval = pid_vnr(sid); 1079 out: 1080 rcu_read_unlock(); 1081 return retval; 1082 } 1083 1084 SYSCALL_DEFINE0(setsid) 1085 { 1086 struct task_struct *group_leader = current->group_leader; 1087 struct pid *sid = task_pid(group_leader); 1088 pid_t session = pid_vnr(sid); 1089 int err = -EPERM; 1090 1091 write_lock_irq(&tasklist_lock); 1092 /* Fail if I am already a session leader */ 1093 if (group_leader->signal->leader) 1094 goto out; 1095 1096 /* Fail if a process group id already exists that equals the 1097 * proposed session id. 1098 */ 1099 if (pid_task(sid, PIDTYPE_PGID)) 1100 goto out; 1101 1102 group_leader->signal->leader = 1; 1103 __set_special_pids(sid); 1104 1105 proc_clear_tty(group_leader); 1106 1107 err = session; 1108 out: 1109 write_unlock_irq(&tasklist_lock); 1110 if (err > 0) { 1111 proc_sid_connector(group_leader); 1112 sched_autogroup_create_attach(group_leader); 1113 } 1114 return err; 1115 } 1116 1117 DECLARE_RWSEM(uts_sem); 1118 1119 #ifdef COMPAT_UTS_MACHINE 1120 #define override_architecture(name) \ 1121 (personality(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 (!ns_capable(current->nsproxy->uts_ns->user_ns, CAP_SYS_ADMIN)) 1202 return -EPERM; 1203 1204 if (len < 0 || len > __NEW_UTS_LEN) 1205 return -EINVAL; 1206 down_write(&uts_sem); 1207 errno = -EFAULT; 1208 if (!copy_from_user(tmp, name, len)) { 1209 struct new_utsname *u = utsname(); 1210 1211 memcpy(u->nodename, tmp, len); 1212 memset(u->nodename + len, 0, sizeof(u->nodename) - len); 1213 errno = 0; 1214 } 1215 up_write(&uts_sem); 1216 return errno; 1217 } 1218 1219 #ifdef __ARCH_WANT_SYS_GETHOSTNAME 1220 1221 SYSCALL_DEFINE2(gethostname, char __user *, name, int, len) 1222 { 1223 int i, errno; 1224 struct new_utsname *u; 1225 1226 if (len < 0) 1227 return -EINVAL; 1228 down_read(&uts_sem); 1229 u = utsname(); 1230 i = 1 + strlen(u->nodename); 1231 if (i > len) 1232 i = len; 1233 errno = 0; 1234 if (copy_to_user(name, u->nodename, i)) 1235 errno = -EFAULT; 1236 up_read(&uts_sem); 1237 return errno; 1238 } 1239 1240 #endif 1241 1242 /* 1243 * Only setdomainname; getdomainname can be implemented by calling 1244 * uname() 1245 */ 1246 SYSCALL_DEFINE2(setdomainname, char __user *, name, int, len) 1247 { 1248 int errno; 1249 char tmp[__NEW_UTS_LEN]; 1250 1251 if (!ns_capable(current->nsproxy->uts_ns->user_ns, CAP_SYS_ADMIN)) 1252 return -EPERM; 1253 if (len < 0 || len > __NEW_UTS_LEN) 1254 return -EINVAL; 1255 1256 down_write(&uts_sem); 1257 errno = -EFAULT; 1258 if (!copy_from_user(tmp, name, len)) { 1259 struct new_utsname *u = utsname(); 1260 1261 memcpy(u->domainname, tmp, len); 1262 memset(u->domainname + len, 0, sizeof(u->domainname) - len); 1263 errno = 0; 1264 } 1265 up_write(&uts_sem); 1266 return errno; 1267 } 1268 1269 SYSCALL_DEFINE2(getrlimit, unsigned int, resource, struct rlimit __user *, rlim) 1270 { 1271 struct rlimit value; 1272 int ret; 1273 1274 ret = do_prlimit(current, resource, NULL, &value); 1275 if (!ret) 1276 ret = copy_to_user(rlim, &value, sizeof(*rlim)) ? -EFAULT : 0; 1277 1278 return ret; 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 static inline bool rlim64_is_infinity(__u64 rlim64) 1307 { 1308 #if BITS_PER_LONG < 64 1309 return rlim64 >= ULONG_MAX; 1310 #else 1311 return rlim64 == RLIM64_INFINITY; 1312 #endif 1313 } 1314 1315 static void rlim_to_rlim64(const struct rlimit *rlim, struct rlimit64 *rlim64) 1316 { 1317 if (rlim->rlim_cur == RLIM_INFINITY) 1318 rlim64->rlim_cur = RLIM64_INFINITY; 1319 else 1320 rlim64->rlim_cur = rlim->rlim_cur; 1321 if (rlim->rlim_max == RLIM_INFINITY) 1322 rlim64->rlim_max = RLIM64_INFINITY; 1323 else 1324 rlim64->rlim_max = rlim->rlim_max; 1325 } 1326 1327 static void rlim64_to_rlim(const struct rlimit64 *rlim64, struct rlimit *rlim) 1328 { 1329 if (rlim64_is_infinity(rlim64->rlim_cur)) 1330 rlim->rlim_cur = RLIM_INFINITY; 1331 else 1332 rlim->rlim_cur = (unsigned long)rlim64->rlim_cur; 1333 if (rlim64_is_infinity(rlim64->rlim_max)) 1334 rlim->rlim_max = RLIM_INFINITY; 1335 else 1336 rlim->rlim_max = (unsigned long)rlim64->rlim_max; 1337 } 1338 1339 /* make sure you are allowed to change @tsk limits before calling this */ 1340 int do_prlimit(struct task_struct *tsk, unsigned int resource, 1341 struct rlimit *new_rlim, struct rlimit *old_rlim) 1342 { 1343 struct rlimit *rlim; 1344 int retval = 0; 1345 1346 if (resource >= RLIM_NLIMITS) 1347 return -EINVAL; 1348 if (new_rlim) { 1349 if (new_rlim->rlim_cur > new_rlim->rlim_max) 1350 return -EINVAL; 1351 if (resource == RLIMIT_NOFILE && 1352 new_rlim->rlim_max > sysctl_nr_open) 1353 return -EPERM; 1354 } 1355 1356 /* protect tsk->signal and tsk->sighand from disappearing */ 1357 read_lock(&tasklist_lock); 1358 if (!tsk->sighand) { 1359 retval = -ESRCH; 1360 goto out; 1361 } 1362 1363 rlim = tsk->signal->rlim + resource; 1364 task_lock(tsk->group_leader); 1365 if (new_rlim) { 1366 /* Keep the capable check against init_user_ns until 1367 cgroups can contain all limits */ 1368 if (new_rlim->rlim_max > rlim->rlim_max && 1369 !capable(CAP_SYS_RESOURCE)) 1370 retval = -EPERM; 1371 if (!retval) 1372 retval = security_task_setrlimit(tsk->group_leader, 1373 resource, new_rlim); 1374 if (resource == RLIMIT_CPU && new_rlim->rlim_cur == 0) { 1375 /* 1376 * The caller is asking for an immediate RLIMIT_CPU 1377 * expiry. But we use the zero value to mean "it was 1378 * never set". So let's cheat and make it one second 1379 * instead 1380 */ 1381 new_rlim->rlim_cur = 1; 1382 } 1383 } 1384 if (!retval) { 1385 if (old_rlim) 1386 *old_rlim = *rlim; 1387 if (new_rlim) 1388 *rlim = *new_rlim; 1389 } 1390 task_unlock(tsk->group_leader); 1391 1392 /* 1393 * RLIMIT_CPU handling. Note that the kernel fails to return an error 1394 * code if it rejected the user's attempt to set RLIMIT_CPU. This is a 1395 * very long-standing error, and fixing it now risks breakage of 1396 * applications, so we live with it 1397 */ 1398 if (!retval && new_rlim && resource == RLIMIT_CPU && 1399 new_rlim->rlim_cur != RLIM_INFINITY) 1400 update_rlimit_cpu(tsk, new_rlim->rlim_cur); 1401 out: 1402 read_unlock(&tasklist_lock); 1403 return retval; 1404 } 1405 1406 /* rcu lock must be held */ 1407 static int check_prlimit_permission(struct task_struct *task) 1408 { 1409 const struct cred *cred = current_cred(), *tcred; 1410 1411 if (current == task) 1412 return 0; 1413 1414 tcred = __task_cred(task); 1415 if (cred->user->user_ns == tcred->user->user_ns && 1416 (cred->uid == tcred->euid && 1417 cred->uid == tcred->suid && 1418 cred->uid == tcred->uid && 1419 cred->gid == tcred->egid && 1420 cred->gid == tcred->sgid && 1421 cred->gid == tcred->gid)) 1422 return 0; 1423 if (ns_capable(tcred->user->user_ns, CAP_SYS_RESOURCE)) 1424 return 0; 1425 1426 return -EPERM; 1427 } 1428 1429 SYSCALL_DEFINE4(prlimit64, pid_t, pid, unsigned int, resource, 1430 const struct rlimit64 __user *, new_rlim, 1431 struct rlimit64 __user *, old_rlim) 1432 { 1433 struct rlimit64 old64, new64; 1434 struct rlimit old, new; 1435 struct task_struct *tsk; 1436 int ret; 1437 1438 if (new_rlim) { 1439 if (copy_from_user(&new64, new_rlim, sizeof(new64))) 1440 return -EFAULT; 1441 rlim64_to_rlim(&new64, &new); 1442 } 1443 1444 rcu_read_lock(); 1445 tsk = pid ? find_task_by_vpid(pid) : current; 1446 if (!tsk) { 1447 rcu_read_unlock(); 1448 return -ESRCH; 1449 } 1450 ret = check_prlimit_permission(tsk); 1451 if (ret) { 1452 rcu_read_unlock(); 1453 return ret; 1454 } 1455 get_task_struct(tsk); 1456 rcu_read_unlock(); 1457 1458 ret = do_prlimit(tsk, resource, new_rlim ? &new : NULL, 1459 old_rlim ? &old : NULL); 1460 1461 if (!ret && old_rlim) { 1462 rlim_to_rlim64(&old, &old64); 1463 if (copy_to_user(old_rlim, &old64, sizeof(old64))) 1464 ret = -EFAULT; 1465 } 1466 1467 put_task_struct(tsk); 1468 return ret; 1469 } 1470 1471 SYSCALL_DEFINE2(setrlimit, unsigned int, resource, struct rlimit __user *, rlim) 1472 { 1473 struct rlimit new_rlim; 1474 1475 if (copy_from_user(&new_rlim, rlim, sizeof(*rlim))) 1476 return -EFAULT; 1477 return do_prlimit(current, resource, &new_rlim, NULL); 1478 } 1479 1480 /* 1481 * It would make sense to put struct rusage in the task_struct, 1482 * except that would make the task_struct be *really big*. After 1483 * task_struct gets moved into malloc'ed memory, it would 1484 * make sense to do this. It will make moving the rest of the information 1485 * a lot simpler! (Which we're not doing right now because we're not 1486 * measuring them yet). 1487 * 1488 * When sampling multiple threads for RUSAGE_SELF, under SMP we might have 1489 * races with threads incrementing their own counters. But since word 1490 * reads are atomic, we either get new values or old values and we don't 1491 * care which for the sums. We always take the siglock to protect reading 1492 * the c* fields from p->signal from races with exit.c updating those 1493 * fields when reaping, so a sample either gets all the additions of a 1494 * given child after it's reaped, or none so this sample is before reaping. 1495 * 1496 * Locking: 1497 * We need to take the siglock for CHILDEREN, SELF and BOTH 1498 * for the cases current multithreaded, non-current single threaded 1499 * non-current multithreaded. Thread traversal is now safe with 1500 * the siglock held. 1501 * Strictly speaking, we donot need to take the siglock if we are current and 1502 * single threaded, as no one else can take our signal_struct away, no one 1503 * else can reap the children to update signal->c* counters, and no one else 1504 * can race with the signal-> fields. If we do not take any lock, the 1505 * signal-> fields could be read out of order while another thread was just 1506 * exiting. So we should place a read memory barrier when we avoid the lock. 1507 * On the writer side, write memory barrier is implied in __exit_signal 1508 * as __exit_signal releases the siglock spinlock after updating the signal-> 1509 * fields. But we don't do this yet to keep things simple. 1510 * 1511 */ 1512 1513 static void accumulate_thread_rusage(struct task_struct *t, struct rusage *r) 1514 { 1515 r->ru_nvcsw += t->nvcsw; 1516 r->ru_nivcsw += t->nivcsw; 1517 r->ru_minflt += t->min_flt; 1518 r->ru_majflt += t->maj_flt; 1519 r->ru_inblock += task_io_get_inblock(t); 1520 r->ru_oublock += task_io_get_oublock(t); 1521 } 1522 1523 static void k_getrusage(struct task_struct *p, int who, struct rusage *r) 1524 { 1525 struct task_struct *t; 1526 unsigned long flags; 1527 cputime_t tgutime, tgstime, utime, stime; 1528 unsigned long maxrss = 0; 1529 1530 memset((char *) r, 0, sizeof *r); 1531 utime = stime = cputime_zero; 1532 1533 if (who == RUSAGE_THREAD) { 1534 task_times(current, &utime, &stime); 1535 accumulate_thread_rusage(p, r); 1536 maxrss = p->signal->maxrss; 1537 goto out; 1538 } 1539 1540 if (!lock_task_sighand(p, &flags)) 1541 return; 1542 1543 switch (who) { 1544 case RUSAGE_BOTH: 1545 case RUSAGE_CHILDREN: 1546 utime = p->signal->cutime; 1547 stime = p->signal->cstime; 1548 r->ru_nvcsw = p->signal->cnvcsw; 1549 r->ru_nivcsw = p->signal->cnivcsw; 1550 r->ru_minflt = p->signal->cmin_flt; 1551 r->ru_majflt = p->signal->cmaj_flt; 1552 r->ru_inblock = p->signal->cinblock; 1553 r->ru_oublock = p->signal->coublock; 1554 maxrss = p->signal->cmaxrss; 1555 1556 if (who == RUSAGE_CHILDREN) 1557 break; 1558 1559 case RUSAGE_SELF: 1560 thread_group_times(p, &tgutime, &tgstime); 1561 utime = cputime_add(utime, tgutime); 1562 stime = cputime_add(stime, tgstime); 1563 r->ru_nvcsw += p->signal->nvcsw; 1564 r->ru_nivcsw += p->signal->nivcsw; 1565 r->ru_minflt += p->signal->min_flt; 1566 r->ru_majflt += p->signal->maj_flt; 1567 r->ru_inblock += p->signal->inblock; 1568 r->ru_oublock += p->signal->oublock; 1569 if (maxrss < p->signal->maxrss) 1570 maxrss = p->signal->maxrss; 1571 t = p; 1572 do { 1573 accumulate_thread_rusage(t, r); 1574 t = next_thread(t); 1575 } while (t != p); 1576 break; 1577 1578 default: 1579 BUG(); 1580 } 1581 unlock_task_sighand(p, &flags); 1582 1583 out: 1584 cputime_to_timeval(utime, &r->ru_utime); 1585 cputime_to_timeval(stime, &r->ru_stime); 1586 1587 if (who != RUSAGE_CHILDREN) { 1588 struct mm_struct *mm = get_task_mm(p); 1589 if (mm) { 1590 setmax_mm_hiwater_rss(&maxrss, mm); 1591 mmput(mm); 1592 } 1593 } 1594 r->ru_maxrss = maxrss * (PAGE_SIZE / 1024); /* convert pages to KBs */ 1595 } 1596 1597 int getrusage(struct task_struct *p, int who, struct rusage __user *ru) 1598 { 1599 struct rusage r; 1600 k_getrusage(p, who, &r); 1601 return copy_to_user(ru, &r, sizeof(r)) ? -EFAULT : 0; 1602 } 1603 1604 SYSCALL_DEFINE2(getrusage, int, who, struct rusage __user *, ru) 1605 { 1606 if (who != RUSAGE_SELF && who != RUSAGE_CHILDREN && 1607 who != RUSAGE_THREAD) 1608 return -EINVAL; 1609 return getrusage(current, who, ru); 1610 } 1611 1612 SYSCALL_DEFINE1(umask, int, mask) 1613 { 1614 mask = xchg(¤t->fs->umask, mask & S_IRWXUGO); 1615 return mask; 1616 } 1617 1618 SYSCALL_DEFINE5(prctl, int, option, unsigned long, arg2, unsigned long, arg3, 1619 unsigned long, arg4, unsigned long, arg5) 1620 { 1621 struct task_struct *me = current; 1622 unsigned char comm[sizeof(me->comm)]; 1623 long error; 1624 1625 error = security_task_prctl(option, arg2, arg3, arg4, arg5); 1626 if (error != -ENOSYS) 1627 return error; 1628 1629 error = 0; 1630 switch (option) { 1631 case PR_SET_PDEATHSIG: 1632 if (!valid_signal(arg2)) { 1633 error = -EINVAL; 1634 break; 1635 } 1636 me->pdeath_signal = arg2; 1637 error = 0; 1638 break; 1639 case PR_GET_PDEATHSIG: 1640 error = put_user(me->pdeath_signal, (int __user *)arg2); 1641 break; 1642 case PR_GET_DUMPABLE: 1643 error = get_dumpable(me->mm); 1644 break; 1645 case PR_SET_DUMPABLE: 1646 if (arg2 < 0 || arg2 > 1) { 1647 error = -EINVAL; 1648 break; 1649 } 1650 set_dumpable(me->mm, arg2); 1651 error = 0; 1652 break; 1653 1654 case PR_SET_UNALIGN: 1655 error = SET_UNALIGN_CTL(me, arg2); 1656 break; 1657 case PR_GET_UNALIGN: 1658 error = GET_UNALIGN_CTL(me, arg2); 1659 break; 1660 case PR_SET_FPEMU: 1661 error = SET_FPEMU_CTL(me, arg2); 1662 break; 1663 case PR_GET_FPEMU: 1664 error = GET_FPEMU_CTL(me, arg2); 1665 break; 1666 case PR_SET_FPEXC: 1667 error = SET_FPEXC_CTL(me, arg2); 1668 break; 1669 case PR_GET_FPEXC: 1670 error = GET_FPEXC_CTL(me, arg2); 1671 break; 1672 case PR_GET_TIMING: 1673 error = PR_TIMING_STATISTICAL; 1674 break; 1675 case PR_SET_TIMING: 1676 if (arg2 != PR_TIMING_STATISTICAL) 1677 error = -EINVAL; 1678 else 1679 error = 0; 1680 break; 1681 1682 case PR_SET_NAME: 1683 comm[sizeof(me->comm)-1] = 0; 1684 if (strncpy_from_user(comm, (char __user *)arg2, 1685 sizeof(me->comm) - 1) < 0) 1686 return -EFAULT; 1687 set_task_comm(me, comm); 1688 return 0; 1689 case PR_GET_NAME: 1690 get_task_comm(comm, me); 1691 if (copy_to_user((char __user *)arg2, comm, 1692 sizeof(comm))) 1693 return -EFAULT; 1694 return 0; 1695 case PR_GET_ENDIAN: 1696 error = GET_ENDIAN(me, arg2); 1697 break; 1698 case PR_SET_ENDIAN: 1699 error = SET_ENDIAN(me, arg2); 1700 break; 1701 1702 case PR_GET_SECCOMP: 1703 error = prctl_get_seccomp(); 1704 break; 1705 case PR_SET_SECCOMP: 1706 error = prctl_set_seccomp(arg2); 1707 break; 1708 case PR_GET_TSC: 1709 error = GET_TSC_CTL(arg2); 1710 break; 1711 case PR_SET_TSC: 1712 error = SET_TSC_CTL(arg2); 1713 break; 1714 case PR_TASK_PERF_EVENTS_DISABLE: 1715 error = perf_event_task_disable(); 1716 break; 1717 case PR_TASK_PERF_EVENTS_ENABLE: 1718 error = perf_event_task_enable(); 1719 break; 1720 case PR_GET_TIMERSLACK: 1721 error = current->timer_slack_ns; 1722 break; 1723 case PR_SET_TIMERSLACK: 1724 if (arg2 <= 0) 1725 current->timer_slack_ns = 1726 current->default_timer_slack_ns; 1727 else 1728 current->timer_slack_ns = arg2; 1729 error = 0; 1730 break; 1731 case PR_MCE_KILL: 1732 if (arg4 | arg5) 1733 return -EINVAL; 1734 switch (arg2) { 1735 case PR_MCE_KILL_CLEAR: 1736 if (arg3 != 0) 1737 return -EINVAL; 1738 current->flags &= ~PF_MCE_PROCESS; 1739 break; 1740 case PR_MCE_KILL_SET: 1741 current->flags |= PF_MCE_PROCESS; 1742 if (arg3 == PR_MCE_KILL_EARLY) 1743 current->flags |= PF_MCE_EARLY; 1744 else if (arg3 == PR_MCE_KILL_LATE) 1745 current->flags &= ~PF_MCE_EARLY; 1746 else if (arg3 == PR_MCE_KILL_DEFAULT) 1747 current->flags &= 1748 ~(PF_MCE_EARLY|PF_MCE_PROCESS); 1749 else 1750 return -EINVAL; 1751 break; 1752 default: 1753 return -EINVAL; 1754 } 1755 error = 0; 1756 break; 1757 case PR_MCE_KILL_GET: 1758 if (arg2 | arg3 | arg4 | arg5) 1759 return -EINVAL; 1760 if (current->flags & PF_MCE_PROCESS) 1761 error = (current->flags & PF_MCE_EARLY) ? 1762 PR_MCE_KILL_EARLY : PR_MCE_KILL_LATE; 1763 else 1764 error = PR_MCE_KILL_DEFAULT; 1765 break; 1766 default: 1767 error = -EINVAL; 1768 break; 1769 } 1770 return error; 1771 } 1772 1773 SYSCALL_DEFINE3(getcpu, unsigned __user *, cpup, unsigned __user *, nodep, 1774 struct getcpu_cache __user *, unused) 1775 { 1776 int err = 0; 1777 int cpu = raw_smp_processor_id(); 1778 if (cpup) 1779 err |= put_user(cpu, cpup); 1780 if (nodep) 1781 err |= put_user(cpu_to_node(cpu), nodep); 1782 return err ? -EFAULT : 0; 1783 } 1784 1785 char poweroff_cmd[POWEROFF_CMD_PATH_LEN] = "/sbin/poweroff"; 1786 1787 static void argv_cleanup(struct subprocess_info *info) 1788 { 1789 argv_free(info->argv); 1790 } 1791 1792 /** 1793 * orderly_poweroff - Trigger an orderly system poweroff 1794 * @force: force poweroff if command execution fails 1795 * 1796 * This may be called from any context to trigger a system shutdown. 1797 * If the orderly shutdown fails, it will force an immediate shutdown. 1798 */ 1799 int orderly_poweroff(bool force) 1800 { 1801 int argc; 1802 char **argv = argv_split(GFP_ATOMIC, poweroff_cmd, &argc); 1803 static char *envp[] = { 1804 "HOME=/", 1805 "PATH=/sbin:/bin:/usr/sbin:/usr/bin", 1806 NULL 1807 }; 1808 int ret = -ENOMEM; 1809 struct subprocess_info *info; 1810 1811 if (argv == NULL) { 1812 printk(KERN_WARNING "%s failed to allocate memory for \"%s\"\n", 1813 __func__, poweroff_cmd); 1814 goto out; 1815 } 1816 1817 info = call_usermodehelper_setup(argv[0], argv, envp, GFP_ATOMIC); 1818 if (info == NULL) { 1819 argv_free(argv); 1820 goto out; 1821 } 1822 1823 call_usermodehelper_setfns(info, NULL, argv_cleanup, NULL); 1824 1825 ret = call_usermodehelper_exec(info, UMH_NO_WAIT); 1826 1827 out: 1828 if (ret && force) { 1829 printk(KERN_WARNING "Failed to start orderly shutdown: " 1830 "forcing the issue\n"); 1831 1832 /* I guess this should try to kick off some daemon to 1833 sync and poweroff asap. Or not even bother syncing 1834 if we're doing an emergency shutdown? */ 1835 emergency_sync(); 1836 kernel_power_off(); 1837 } 1838 1839 return ret; 1840 } 1841 EXPORT_SYMBOL_GPL(orderly_poweroff); 1842