1 /* 2 * linux/kernel/sys.c 3 * 4 * Copyright (C) 1991, 1992 Linus Torvalds 5 */ 6 7 #include <linux/export.h> 8 #include <linux/mm.h> 9 #include <linux/utsname.h> 10 #include <linux/mman.h> 11 #include <linux/reboot.h> 12 #include <linux/prctl.h> 13 #include <linux/highuid.h> 14 #include <linux/fs.h> 15 #include <linux/kmod.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/file.h> 40 #include <linux/mount.h> 41 #include <linux/gfp.h> 42 #include <linux/syscore_ops.h> 43 #include <linux/version.h> 44 #include <linux/ctype.h> 45 46 #include <linux/compat.h> 47 #include <linux/syscalls.h> 48 #include <linux/kprobes.h> 49 #include <linux/user_namespace.h> 50 #include <linux/binfmts.h> 51 52 #include <linux/sched.h> 53 #include <linux/rcupdate.h> 54 #include <linux/uidgid.h> 55 #include <linux/cred.h> 56 57 #include <linux/kmsg_dump.h> 58 /* Move somewhere else to avoid recompiling? */ 59 #include <generated/utsrelease.h> 60 61 #include <asm/uaccess.h> 62 #include <asm/io.h> 63 #include <asm/unistd.h> 64 65 #ifndef SET_UNALIGN_CTL 66 # define SET_UNALIGN_CTL(a,b) (-EINVAL) 67 #endif 68 #ifndef GET_UNALIGN_CTL 69 # define GET_UNALIGN_CTL(a,b) (-EINVAL) 70 #endif 71 #ifndef SET_FPEMU_CTL 72 # define SET_FPEMU_CTL(a,b) (-EINVAL) 73 #endif 74 #ifndef GET_FPEMU_CTL 75 # define GET_FPEMU_CTL(a,b) (-EINVAL) 76 #endif 77 #ifndef SET_FPEXC_CTL 78 # define SET_FPEXC_CTL(a,b) (-EINVAL) 79 #endif 80 #ifndef GET_FPEXC_CTL 81 # define GET_FPEXC_CTL(a,b) (-EINVAL) 82 #endif 83 #ifndef GET_ENDIAN 84 # define GET_ENDIAN(a,b) (-EINVAL) 85 #endif 86 #ifndef SET_ENDIAN 87 # define SET_ENDIAN(a,b) (-EINVAL) 88 #endif 89 #ifndef GET_TSC_CTL 90 # define GET_TSC_CTL(a) (-EINVAL) 91 #endif 92 #ifndef SET_TSC_CTL 93 # define SET_TSC_CTL(a) (-EINVAL) 94 #endif 95 96 /* 97 * this is where the system-wide overflow UID and GID are defined, for 98 * architectures that now have 32-bit UID/GID but didn't in the past 99 */ 100 101 int overflowuid = DEFAULT_OVERFLOWUID; 102 int overflowgid = DEFAULT_OVERFLOWGID; 103 104 EXPORT_SYMBOL(overflowuid); 105 EXPORT_SYMBOL(overflowgid); 106 107 /* 108 * the same as above, but for filesystems which can only store a 16-bit 109 * UID and GID. as such, this is needed on all architectures 110 */ 111 112 int fs_overflowuid = DEFAULT_FS_OVERFLOWUID; 113 int fs_overflowgid = DEFAULT_FS_OVERFLOWUID; 114 115 EXPORT_SYMBOL(fs_overflowuid); 116 EXPORT_SYMBOL(fs_overflowgid); 117 118 /* 119 * this indicates whether you can reboot with ctrl-alt-del: the default is yes 120 */ 121 122 int C_A_D = 1; 123 struct pid *cad_pid; 124 EXPORT_SYMBOL(cad_pid); 125 126 /* 127 * If set, this is used for preparing the system to power off. 128 */ 129 130 void (*pm_power_off_prepare)(void); 131 132 /* 133 * Returns true if current's euid is same as p's uid or euid, 134 * or has CAP_SYS_NICE to p's user_ns. 135 * 136 * Called with rcu_read_lock, creds are safe 137 */ 138 static bool set_one_prio_perm(struct task_struct *p) 139 { 140 const struct cred *cred = current_cred(), *pcred = __task_cred(p); 141 142 if (uid_eq(pcred->uid, cred->euid) || 143 uid_eq(pcred->euid, cred->euid)) 144 return true; 145 if (ns_capable(pcred->user_ns, CAP_SYS_NICE)) 146 return true; 147 return false; 148 } 149 150 /* 151 * set the priority of a task 152 * - the caller must hold the RCU read lock 153 */ 154 static int set_one_prio(struct task_struct *p, int niceval, int error) 155 { 156 int no_nice; 157 158 if (!set_one_prio_perm(p)) { 159 error = -EPERM; 160 goto out; 161 } 162 if (niceval < task_nice(p) && !can_nice(p, niceval)) { 163 error = -EACCES; 164 goto out; 165 } 166 no_nice = security_task_setnice(p, niceval); 167 if (no_nice) { 168 error = no_nice; 169 goto out; 170 } 171 if (error == -ESRCH) 172 error = 0; 173 set_user_nice(p, niceval); 174 out: 175 return error; 176 } 177 178 SYSCALL_DEFINE3(setpriority, int, which, int, who, int, niceval) 179 { 180 struct task_struct *g, *p; 181 struct user_struct *user; 182 const struct cred *cred = current_cred(); 183 int error = -EINVAL; 184 struct pid *pgrp; 185 kuid_t uid; 186 187 if (which > PRIO_USER || which < PRIO_PROCESS) 188 goto out; 189 190 /* normalize: avoid signed division (rounding problems) */ 191 error = -ESRCH; 192 if (niceval < -20) 193 niceval = -20; 194 if (niceval > 19) 195 niceval = 19; 196 197 rcu_read_lock(); 198 read_lock(&tasklist_lock); 199 switch (which) { 200 case PRIO_PROCESS: 201 if (who) 202 p = find_task_by_vpid(who); 203 else 204 p = current; 205 if (p) 206 error = set_one_prio(p, niceval, error); 207 break; 208 case PRIO_PGRP: 209 if (who) 210 pgrp = find_vpid(who); 211 else 212 pgrp = task_pgrp(current); 213 do_each_pid_thread(pgrp, PIDTYPE_PGID, p) { 214 error = set_one_prio(p, niceval, error); 215 } while_each_pid_thread(pgrp, PIDTYPE_PGID, p); 216 break; 217 case PRIO_USER: 218 uid = make_kuid(cred->user_ns, who); 219 user = cred->user; 220 if (!who) 221 uid = cred->uid; 222 else if (!uid_eq(uid, cred->uid) && 223 !(user = find_user(uid))) 224 goto out_unlock; /* No processes for this user */ 225 226 do_each_thread(g, p) { 227 if (uid_eq(task_uid(p), uid)) 228 error = set_one_prio(p, niceval, error); 229 } while_each_thread(g, p); 230 if (!uid_eq(uid, cred->uid)) 231 free_uid(user); /* For find_user() */ 232 break; 233 } 234 out_unlock: 235 read_unlock(&tasklist_lock); 236 rcu_read_unlock(); 237 out: 238 return error; 239 } 240 241 /* 242 * Ugh. To avoid negative return values, "getpriority()" will 243 * not return the normal nice-value, but a negated value that 244 * has been offset by 20 (ie it returns 40..1 instead of -20..19) 245 * to stay compatible. 246 */ 247 SYSCALL_DEFINE2(getpriority, int, which, int, who) 248 { 249 struct task_struct *g, *p; 250 struct user_struct *user; 251 const struct cred *cred = current_cred(); 252 long niceval, retval = -ESRCH; 253 struct pid *pgrp; 254 kuid_t uid; 255 256 if (which > PRIO_USER || which < PRIO_PROCESS) 257 return -EINVAL; 258 259 rcu_read_lock(); 260 read_lock(&tasklist_lock); 261 switch (which) { 262 case PRIO_PROCESS: 263 if (who) 264 p = find_task_by_vpid(who); 265 else 266 p = current; 267 if (p) { 268 niceval = 20 - task_nice(p); 269 if (niceval > retval) 270 retval = niceval; 271 } 272 break; 273 case PRIO_PGRP: 274 if (who) 275 pgrp = find_vpid(who); 276 else 277 pgrp = task_pgrp(current); 278 do_each_pid_thread(pgrp, PIDTYPE_PGID, p) { 279 niceval = 20 - task_nice(p); 280 if (niceval > retval) 281 retval = niceval; 282 } while_each_pid_thread(pgrp, PIDTYPE_PGID, p); 283 break; 284 case PRIO_USER: 285 uid = make_kuid(cred->user_ns, who); 286 user = cred->user; 287 if (!who) 288 uid = cred->uid; 289 else if (!uid_eq(uid, cred->uid) && 290 !(user = find_user(uid))) 291 goto out_unlock; /* No processes for this user */ 292 293 do_each_thread(g, p) { 294 if (uid_eq(task_uid(p), uid)) { 295 niceval = 20 - task_nice(p); 296 if (niceval > retval) 297 retval = niceval; 298 } 299 } while_each_thread(g, p); 300 if (!uid_eq(uid, cred->uid)) 301 free_uid(user); /* for find_user() */ 302 break; 303 } 304 out_unlock: 305 read_unlock(&tasklist_lock); 306 rcu_read_unlock(); 307 308 return retval; 309 } 310 311 /** 312 * emergency_restart - reboot the system 313 * 314 * Without shutting down any hardware or taking any locks 315 * reboot the system. This is called when we know we are in 316 * trouble so this is our best effort to reboot. This is 317 * safe to call in interrupt context. 318 */ 319 void emergency_restart(void) 320 { 321 kmsg_dump(KMSG_DUMP_EMERG); 322 machine_emergency_restart(); 323 } 324 EXPORT_SYMBOL_GPL(emergency_restart); 325 326 void kernel_restart_prepare(char *cmd) 327 { 328 blocking_notifier_call_chain(&reboot_notifier_list, SYS_RESTART, cmd); 329 system_state = SYSTEM_RESTART; 330 usermodehelper_disable(); 331 device_shutdown(); 332 } 333 334 /** 335 * register_reboot_notifier - Register function to be called at reboot time 336 * @nb: Info about notifier function to be called 337 * 338 * Registers a function with the list of functions 339 * to be called at reboot time. 340 * 341 * Currently always returns zero, as blocking_notifier_chain_register() 342 * always returns zero. 343 */ 344 int register_reboot_notifier(struct notifier_block *nb) 345 { 346 return blocking_notifier_chain_register(&reboot_notifier_list, nb); 347 } 348 EXPORT_SYMBOL(register_reboot_notifier); 349 350 /** 351 * unregister_reboot_notifier - Unregister previously registered reboot notifier 352 * @nb: Hook to be unregistered 353 * 354 * Unregisters a previously registered reboot 355 * notifier function. 356 * 357 * Returns zero on success, or %-ENOENT on failure. 358 */ 359 int unregister_reboot_notifier(struct notifier_block *nb) 360 { 361 return blocking_notifier_chain_unregister(&reboot_notifier_list, nb); 362 } 363 EXPORT_SYMBOL(unregister_reboot_notifier); 364 365 /* Add backwards compatibility for stable trees. */ 366 #ifndef PF_NO_SETAFFINITY 367 #define PF_NO_SETAFFINITY PF_THREAD_BOUND 368 #endif 369 370 static void migrate_to_reboot_cpu(void) 371 { 372 /* The boot cpu is always logical cpu 0 */ 373 int cpu = 0; 374 375 cpu_hotplug_disable(); 376 377 /* Make certain the cpu I'm about to reboot on is online */ 378 if (!cpu_online(cpu)) 379 cpu = cpumask_first(cpu_online_mask); 380 381 /* Prevent races with other tasks migrating this task */ 382 current->flags |= PF_NO_SETAFFINITY; 383 384 /* Make certain I only run on the appropriate processor */ 385 set_cpus_allowed_ptr(current, cpumask_of(cpu)); 386 } 387 388 /** 389 * kernel_restart - reboot the system 390 * @cmd: pointer to buffer containing command to execute for restart 391 * or %NULL 392 * 393 * Shutdown everything and perform a clean reboot. 394 * This is not safe to call in interrupt context. 395 */ 396 void kernel_restart(char *cmd) 397 { 398 kernel_restart_prepare(cmd); 399 migrate_to_reboot_cpu(); 400 syscore_shutdown(); 401 if (!cmd) 402 printk(KERN_EMERG "Restarting system.\n"); 403 else 404 printk(KERN_EMERG "Restarting system with command '%s'.\n", cmd); 405 kmsg_dump(KMSG_DUMP_RESTART); 406 machine_restart(cmd); 407 } 408 EXPORT_SYMBOL_GPL(kernel_restart); 409 410 static void kernel_shutdown_prepare(enum system_states state) 411 { 412 blocking_notifier_call_chain(&reboot_notifier_list, 413 (state == SYSTEM_HALT)?SYS_HALT:SYS_POWER_OFF, NULL); 414 system_state = state; 415 usermodehelper_disable(); 416 device_shutdown(); 417 } 418 /** 419 * kernel_halt - halt the system 420 * 421 * Shutdown everything and perform a clean system halt. 422 */ 423 void kernel_halt(void) 424 { 425 kernel_shutdown_prepare(SYSTEM_HALT); 426 migrate_to_reboot_cpu(); 427 syscore_shutdown(); 428 printk(KERN_EMERG "System halted.\n"); 429 kmsg_dump(KMSG_DUMP_HALT); 430 machine_halt(); 431 } 432 433 EXPORT_SYMBOL_GPL(kernel_halt); 434 435 /** 436 * kernel_power_off - power_off the system 437 * 438 * Shutdown everything and perform a clean system power_off. 439 */ 440 void kernel_power_off(void) 441 { 442 kernel_shutdown_prepare(SYSTEM_POWER_OFF); 443 if (pm_power_off_prepare) 444 pm_power_off_prepare(); 445 migrate_to_reboot_cpu(); 446 syscore_shutdown(); 447 printk(KERN_EMERG "Power down.\n"); 448 kmsg_dump(KMSG_DUMP_POWEROFF); 449 machine_power_off(); 450 } 451 EXPORT_SYMBOL_GPL(kernel_power_off); 452 453 static DEFINE_MUTEX(reboot_mutex); 454 455 /* 456 * Reboot system call: for obvious reasons only root may call it, 457 * and even root needs to set up some magic numbers in the registers 458 * so that some mistake won't make this reboot the whole machine. 459 * You can also set the meaning of the ctrl-alt-del-key here. 460 * 461 * reboot doesn't sync: do that yourself before calling this. 462 */ 463 SYSCALL_DEFINE4(reboot, int, magic1, int, magic2, unsigned int, cmd, 464 void __user *, arg) 465 { 466 struct pid_namespace *pid_ns = task_active_pid_ns(current); 467 char buffer[256]; 468 int ret = 0; 469 470 /* We only trust the superuser with rebooting the system. */ 471 if (!ns_capable(pid_ns->user_ns, CAP_SYS_BOOT)) 472 return -EPERM; 473 474 /* For safety, we require "magic" arguments. */ 475 if (magic1 != LINUX_REBOOT_MAGIC1 || 476 (magic2 != LINUX_REBOOT_MAGIC2 && 477 magic2 != LINUX_REBOOT_MAGIC2A && 478 magic2 != LINUX_REBOOT_MAGIC2B && 479 magic2 != LINUX_REBOOT_MAGIC2C)) 480 return -EINVAL; 481 482 /* 483 * If pid namespaces are enabled and the current task is in a child 484 * pid_namespace, the command is handled by reboot_pid_ns() which will 485 * call do_exit(). 486 */ 487 ret = reboot_pid_ns(pid_ns, cmd); 488 if (ret) 489 return ret; 490 491 /* Instead of trying to make the power_off code look like 492 * halt when pm_power_off is not set do it the easy way. 493 */ 494 if ((cmd == LINUX_REBOOT_CMD_POWER_OFF) && !pm_power_off) 495 cmd = LINUX_REBOOT_CMD_HALT; 496 497 mutex_lock(&reboot_mutex); 498 switch (cmd) { 499 case LINUX_REBOOT_CMD_RESTART: 500 kernel_restart(NULL); 501 break; 502 503 case LINUX_REBOOT_CMD_CAD_ON: 504 C_A_D = 1; 505 break; 506 507 case LINUX_REBOOT_CMD_CAD_OFF: 508 C_A_D = 0; 509 break; 510 511 case LINUX_REBOOT_CMD_HALT: 512 kernel_halt(); 513 do_exit(0); 514 panic("cannot halt.\n"); 515 516 case LINUX_REBOOT_CMD_POWER_OFF: 517 kernel_power_off(); 518 do_exit(0); 519 break; 520 521 case LINUX_REBOOT_CMD_RESTART2: 522 if (strncpy_from_user(&buffer[0], arg, sizeof(buffer) - 1) < 0) { 523 ret = -EFAULT; 524 break; 525 } 526 buffer[sizeof(buffer) - 1] = '\0'; 527 528 kernel_restart(buffer); 529 break; 530 531 #ifdef CONFIG_KEXEC 532 case LINUX_REBOOT_CMD_KEXEC: 533 ret = kernel_kexec(); 534 break; 535 #endif 536 537 #ifdef CONFIG_HIBERNATION 538 case LINUX_REBOOT_CMD_SW_SUSPEND: 539 ret = hibernate(); 540 break; 541 #endif 542 543 default: 544 ret = -EINVAL; 545 break; 546 } 547 mutex_unlock(&reboot_mutex); 548 return ret; 549 } 550 551 static void deferred_cad(struct work_struct *dummy) 552 { 553 kernel_restart(NULL); 554 } 555 556 /* 557 * This function gets called by ctrl-alt-del - ie the keyboard interrupt. 558 * As it's called within an interrupt, it may NOT sync: the only choice 559 * is whether to reboot at once, or just ignore the ctrl-alt-del. 560 */ 561 void ctrl_alt_del(void) 562 { 563 static DECLARE_WORK(cad_work, deferred_cad); 564 565 if (C_A_D) 566 schedule_work(&cad_work); 567 else 568 kill_cad_pid(SIGINT, 1); 569 } 570 571 /* 572 * Unprivileged users may change the real gid to the effective gid 573 * or vice versa. (BSD-style) 574 * 575 * If you set the real gid at all, or set the effective gid to a value not 576 * equal to the real gid, then the saved gid is set to the new effective gid. 577 * 578 * This makes it possible for a setgid program to completely drop its 579 * privileges, which is often a useful assertion to make when you are doing 580 * a security audit over a program. 581 * 582 * The general idea is that a program which uses just setregid() will be 583 * 100% compatible with BSD. A program which uses just setgid() will be 584 * 100% compatible with POSIX with saved IDs. 585 * 586 * SMP: There are not races, the GIDs are checked only by filesystem 587 * operations (as far as semantic preservation is concerned). 588 */ 589 SYSCALL_DEFINE2(setregid, gid_t, rgid, gid_t, egid) 590 { 591 struct user_namespace *ns = current_user_ns(); 592 const struct cred *old; 593 struct cred *new; 594 int retval; 595 kgid_t krgid, kegid; 596 597 krgid = make_kgid(ns, rgid); 598 kegid = make_kgid(ns, egid); 599 600 if ((rgid != (gid_t) -1) && !gid_valid(krgid)) 601 return -EINVAL; 602 if ((egid != (gid_t) -1) && !gid_valid(kegid)) 603 return -EINVAL; 604 605 new = prepare_creds(); 606 if (!new) 607 return -ENOMEM; 608 old = current_cred(); 609 610 retval = -EPERM; 611 if (rgid != (gid_t) -1) { 612 if (gid_eq(old->gid, krgid) || 613 gid_eq(old->egid, krgid) || 614 nsown_capable(CAP_SETGID)) 615 new->gid = krgid; 616 else 617 goto error; 618 } 619 if (egid != (gid_t) -1) { 620 if (gid_eq(old->gid, kegid) || 621 gid_eq(old->egid, kegid) || 622 gid_eq(old->sgid, kegid) || 623 nsown_capable(CAP_SETGID)) 624 new->egid = kegid; 625 else 626 goto error; 627 } 628 629 if (rgid != (gid_t) -1 || 630 (egid != (gid_t) -1 && !gid_eq(kegid, old->gid))) 631 new->sgid = new->egid; 632 new->fsgid = new->egid; 633 634 return commit_creds(new); 635 636 error: 637 abort_creds(new); 638 return retval; 639 } 640 641 /* 642 * setgid() is implemented like SysV w/ SAVED_IDS 643 * 644 * SMP: Same implicit races as above. 645 */ 646 SYSCALL_DEFINE1(setgid, gid_t, gid) 647 { 648 struct user_namespace *ns = current_user_ns(); 649 const struct cred *old; 650 struct cred *new; 651 int retval; 652 kgid_t kgid; 653 654 kgid = make_kgid(ns, gid); 655 if (!gid_valid(kgid)) 656 return -EINVAL; 657 658 new = prepare_creds(); 659 if (!new) 660 return -ENOMEM; 661 old = current_cred(); 662 663 retval = -EPERM; 664 if (nsown_capable(CAP_SETGID)) 665 new->gid = new->egid = new->sgid = new->fsgid = kgid; 666 else if (gid_eq(kgid, old->gid) || gid_eq(kgid, old->sgid)) 667 new->egid = new->fsgid = kgid; 668 else 669 goto error; 670 671 return commit_creds(new); 672 673 error: 674 abort_creds(new); 675 return retval; 676 } 677 678 /* 679 * change the user struct in a credentials set to match the new UID 680 */ 681 static int set_user(struct cred *new) 682 { 683 struct user_struct *new_user; 684 685 new_user = alloc_uid(new->uid); 686 if (!new_user) 687 return -EAGAIN; 688 689 /* 690 * We don't fail in case of NPROC limit excess here because too many 691 * poorly written programs don't check set*uid() return code, assuming 692 * it never fails if called by root. We may still enforce NPROC limit 693 * for programs doing set*uid()+execve() by harmlessly deferring the 694 * failure to the execve() stage. 695 */ 696 if (atomic_read(&new_user->processes) >= rlimit(RLIMIT_NPROC) && 697 new_user != INIT_USER) 698 current->flags |= PF_NPROC_EXCEEDED; 699 else 700 current->flags &= ~PF_NPROC_EXCEEDED; 701 702 free_uid(new->user); 703 new->user = new_user; 704 return 0; 705 } 706 707 /* 708 * Unprivileged users may change the real uid to the effective uid 709 * or vice versa. (BSD-style) 710 * 711 * If you set the real uid at all, or set the effective uid to a value not 712 * equal to the real uid, then the saved uid is set to the new effective uid. 713 * 714 * This makes it possible for a setuid program to completely drop its 715 * privileges, which is often a useful assertion to make when you are doing 716 * a security audit over a program. 717 * 718 * The general idea is that a program which uses just setreuid() will be 719 * 100% compatible with BSD. A program which uses just setuid() will be 720 * 100% compatible with POSIX with saved IDs. 721 */ 722 SYSCALL_DEFINE2(setreuid, uid_t, ruid, uid_t, euid) 723 { 724 struct user_namespace *ns = current_user_ns(); 725 const struct cred *old; 726 struct cred *new; 727 int retval; 728 kuid_t kruid, keuid; 729 730 kruid = make_kuid(ns, ruid); 731 keuid = make_kuid(ns, euid); 732 733 if ((ruid != (uid_t) -1) && !uid_valid(kruid)) 734 return -EINVAL; 735 if ((euid != (uid_t) -1) && !uid_valid(keuid)) 736 return -EINVAL; 737 738 new = prepare_creds(); 739 if (!new) 740 return -ENOMEM; 741 old = current_cred(); 742 743 retval = -EPERM; 744 if (ruid != (uid_t) -1) { 745 new->uid = kruid; 746 if (!uid_eq(old->uid, kruid) && 747 !uid_eq(old->euid, kruid) && 748 !nsown_capable(CAP_SETUID)) 749 goto error; 750 } 751 752 if (euid != (uid_t) -1) { 753 new->euid = keuid; 754 if (!uid_eq(old->uid, keuid) && 755 !uid_eq(old->euid, keuid) && 756 !uid_eq(old->suid, keuid) && 757 !nsown_capable(CAP_SETUID)) 758 goto error; 759 } 760 761 if (!uid_eq(new->uid, old->uid)) { 762 retval = set_user(new); 763 if (retval < 0) 764 goto error; 765 } 766 if (ruid != (uid_t) -1 || 767 (euid != (uid_t) -1 && !uid_eq(keuid, old->uid))) 768 new->suid = new->euid; 769 new->fsuid = new->euid; 770 771 retval = security_task_fix_setuid(new, old, LSM_SETID_RE); 772 if (retval < 0) 773 goto error; 774 775 return commit_creds(new); 776 777 error: 778 abort_creds(new); 779 return retval; 780 } 781 782 /* 783 * setuid() is implemented like SysV with SAVED_IDS 784 * 785 * Note that SAVED_ID's is deficient in that a setuid root program 786 * like sendmail, for example, cannot set its uid to be a normal 787 * user and then switch back, because if you're root, setuid() sets 788 * the saved uid too. If you don't like this, blame the bright people 789 * in the POSIX committee and/or USG. Note that the BSD-style setreuid() 790 * will allow a root program to temporarily drop privileges and be able to 791 * regain them by swapping the real and effective uid. 792 */ 793 SYSCALL_DEFINE1(setuid, uid_t, uid) 794 { 795 struct user_namespace *ns = current_user_ns(); 796 const struct cred *old; 797 struct cred *new; 798 int retval; 799 kuid_t kuid; 800 801 kuid = make_kuid(ns, uid); 802 if (!uid_valid(kuid)) 803 return -EINVAL; 804 805 new = prepare_creds(); 806 if (!new) 807 return -ENOMEM; 808 old = current_cred(); 809 810 retval = -EPERM; 811 if (nsown_capable(CAP_SETUID)) { 812 new->suid = new->uid = kuid; 813 if (!uid_eq(kuid, old->uid)) { 814 retval = set_user(new); 815 if (retval < 0) 816 goto error; 817 } 818 } else if (!uid_eq(kuid, old->uid) && !uid_eq(kuid, new->suid)) { 819 goto error; 820 } 821 822 new->fsuid = new->euid = kuid; 823 824 retval = security_task_fix_setuid(new, old, LSM_SETID_ID); 825 if (retval < 0) 826 goto error; 827 828 return commit_creds(new); 829 830 error: 831 abort_creds(new); 832 return retval; 833 } 834 835 836 /* 837 * This function implements a generic ability to update ruid, euid, 838 * and suid. This allows you to implement the 4.4 compatible seteuid(). 839 */ 840 SYSCALL_DEFINE3(setresuid, uid_t, ruid, uid_t, euid, uid_t, suid) 841 { 842 struct user_namespace *ns = current_user_ns(); 843 const struct cred *old; 844 struct cred *new; 845 int retval; 846 kuid_t kruid, keuid, ksuid; 847 848 kruid = make_kuid(ns, ruid); 849 keuid = make_kuid(ns, euid); 850 ksuid = make_kuid(ns, suid); 851 852 if ((ruid != (uid_t) -1) && !uid_valid(kruid)) 853 return -EINVAL; 854 855 if ((euid != (uid_t) -1) && !uid_valid(keuid)) 856 return -EINVAL; 857 858 if ((suid != (uid_t) -1) && !uid_valid(ksuid)) 859 return -EINVAL; 860 861 new = prepare_creds(); 862 if (!new) 863 return -ENOMEM; 864 865 old = current_cred(); 866 867 retval = -EPERM; 868 if (!nsown_capable(CAP_SETUID)) { 869 if (ruid != (uid_t) -1 && !uid_eq(kruid, old->uid) && 870 !uid_eq(kruid, old->euid) && !uid_eq(kruid, old->suid)) 871 goto error; 872 if (euid != (uid_t) -1 && !uid_eq(keuid, old->uid) && 873 !uid_eq(keuid, old->euid) && !uid_eq(keuid, old->suid)) 874 goto error; 875 if (suid != (uid_t) -1 && !uid_eq(ksuid, old->uid) && 876 !uid_eq(ksuid, old->euid) && !uid_eq(ksuid, old->suid)) 877 goto error; 878 } 879 880 if (ruid != (uid_t) -1) { 881 new->uid = kruid; 882 if (!uid_eq(kruid, old->uid)) { 883 retval = set_user(new); 884 if (retval < 0) 885 goto error; 886 } 887 } 888 if (euid != (uid_t) -1) 889 new->euid = keuid; 890 if (suid != (uid_t) -1) 891 new->suid = ksuid; 892 new->fsuid = new->euid; 893 894 retval = security_task_fix_setuid(new, old, LSM_SETID_RES); 895 if (retval < 0) 896 goto error; 897 898 return commit_creds(new); 899 900 error: 901 abort_creds(new); 902 return retval; 903 } 904 905 SYSCALL_DEFINE3(getresuid, uid_t __user *, ruidp, uid_t __user *, euidp, uid_t __user *, suidp) 906 { 907 const struct cred *cred = current_cred(); 908 int retval; 909 uid_t ruid, euid, suid; 910 911 ruid = from_kuid_munged(cred->user_ns, cred->uid); 912 euid = from_kuid_munged(cred->user_ns, cred->euid); 913 suid = from_kuid_munged(cred->user_ns, cred->suid); 914 915 if (!(retval = put_user(ruid, ruidp)) && 916 !(retval = put_user(euid, euidp))) 917 retval = put_user(suid, suidp); 918 919 return retval; 920 } 921 922 /* 923 * Same as above, but for rgid, egid, sgid. 924 */ 925 SYSCALL_DEFINE3(setresgid, gid_t, rgid, gid_t, egid, gid_t, sgid) 926 { 927 struct user_namespace *ns = current_user_ns(); 928 const struct cred *old; 929 struct cred *new; 930 int retval; 931 kgid_t krgid, kegid, ksgid; 932 933 krgid = make_kgid(ns, rgid); 934 kegid = make_kgid(ns, egid); 935 ksgid = make_kgid(ns, sgid); 936 937 if ((rgid != (gid_t) -1) && !gid_valid(krgid)) 938 return -EINVAL; 939 if ((egid != (gid_t) -1) && !gid_valid(kegid)) 940 return -EINVAL; 941 if ((sgid != (gid_t) -1) && !gid_valid(ksgid)) 942 return -EINVAL; 943 944 new = prepare_creds(); 945 if (!new) 946 return -ENOMEM; 947 old = current_cred(); 948 949 retval = -EPERM; 950 if (!nsown_capable(CAP_SETGID)) { 951 if (rgid != (gid_t) -1 && !gid_eq(krgid, old->gid) && 952 !gid_eq(krgid, old->egid) && !gid_eq(krgid, old->sgid)) 953 goto error; 954 if (egid != (gid_t) -1 && !gid_eq(kegid, old->gid) && 955 !gid_eq(kegid, old->egid) && !gid_eq(kegid, old->sgid)) 956 goto error; 957 if (sgid != (gid_t) -1 && !gid_eq(ksgid, old->gid) && 958 !gid_eq(ksgid, old->egid) && !gid_eq(ksgid, old->sgid)) 959 goto error; 960 } 961 962 if (rgid != (gid_t) -1) 963 new->gid = krgid; 964 if (egid != (gid_t) -1) 965 new->egid = kegid; 966 if (sgid != (gid_t) -1) 967 new->sgid = ksgid; 968 new->fsgid = new->egid; 969 970 return commit_creds(new); 971 972 error: 973 abort_creds(new); 974 return retval; 975 } 976 977 SYSCALL_DEFINE3(getresgid, gid_t __user *, rgidp, gid_t __user *, egidp, gid_t __user *, sgidp) 978 { 979 const struct cred *cred = current_cred(); 980 int retval; 981 gid_t rgid, egid, sgid; 982 983 rgid = from_kgid_munged(cred->user_ns, cred->gid); 984 egid = from_kgid_munged(cred->user_ns, cred->egid); 985 sgid = from_kgid_munged(cred->user_ns, cred->sgid); 986 987 if (!(retval = put_user(rgid, rgidp)) && 988 !(retval = put_user(egid, egidp))) 989 retval = put_user(sgid, sgidp); 990 991 return retval; 992 } 993 994 995 /* 996 * "setfsuid()" sets the fsuid - the uid used for filesystem checks. This 997 * is used for "access()" and for the NFS daemon (letting nfsd stay at 998 * whatever uid it wants to). It normally shadows "euid", except when 999 * explicitly set by setfsuid() or for access.. 1000 */ 1001 SYSCALL_DEFINE1(setfsuid, uid_t, uid) 1002 { 1003 const struct cred *old; 1004 struct cred *new; 1005 uid_t old_fsuid; 1006 kuid_t kuid; 1007 1008 old = current_cred(); 1009 old_fsuid = from_kuid_munged(old->user_ns, old->fsuid); 1010 1011 kuid = make_kuid(old->user_ns, uid); 1012 if (!uid_valid(kuid)) 1013 return old_fsuid; 1014 1015 new = prepare_creds(); 1016 if (!new) 1017 return old_fsuid; 1018 1019 if (uid_eq(kuid, old->uid) || uid_eq(kuid, old->euid) || 1020 uid_eq(kuid, old->suid) || uid_eq(kuid, old->fsuid) || 1021 nsown_capable(CAP_SETUID)) { 1022 if (!uid_eq(kuid, old->fsuid)) { 1023 new->fsuid = kuid; 1024 if (security_task_fix_setuid(new, old, LSM_SETID_FS) == 0) 1025 goto change_okay; 1026 } 1027 } 1028 1029 abort_creds(new); 1030 return old_fsuid; 1031 1032 change_okay: 1033 commit_creds(new); 1034 return old_fsuid; 1035 } 1036 1037 /* 1038 * Samma på svenska.. 1039 */ 1040 SYSCALL_DEFINE1(setfsgid, gid_t, gid) 1041 { 1042 const struct cred *old; 1043 struct cred *new; 1044 gid_t old_fsgid; 1045 kgid_t kgid; 1046 1047 old = current_cred(); 1048 old_fsgid = from_kgid_munged(old->user_ns, old->fsgid); 1049 1050 kgid = make_kgid(old->user_ns, gid); 1051 if (!gid_valid(kgid)) 1052 return old_fsgid; 1053 1054 new = prepare_creds(); 1055 if (!new) 1056 return old_fsgid; 1057 1058 if (gid_eq(kgid, old->gid) || gid_eq(kgid, old->egid) || 1059 gid_eq(kgid, old->sgid) || gid_eq(kgid, old->fsgid) || 1060 nsown_capable(CAP_SETGID)) { 1061 if (!gid_eq(kgid, old->fsgid)) { 1062 new->fsgid = kgid; 1063 goto change_okay; 1064 } 1065 } 1066 1067 abort_creds(new); 1068 return old_fsgid; 1069 1070 change_okay: 1071 commit_creds(new); 1072 return old_fsgid; 1073 } 1074 1075 /** 1076 * sys_getpid - return the thread group id of the current process 1077 * 1078 * Note, despite the name, this returns the tgid not the pid. The tgid and 1079 * the pid are identical unless CLONE_THREAD was specified on clone() in 1080 * which case the tgid is the same in all threads of the same group. 1081 * 1082 * This is SMP safe as current->tgid does not change. 1083 */ 1084 SYSCALL_DEFINE0(getpid) 1085 { 1086 return task_tgid_vnr(current); 1087 } 1088 1089 /* Thread ID - the internal kernel "pid" */ 1090 SYSCALL_DEFINE0(gettid) 1091 { 1092 return task_pid_vnr(current); 1093 } 1094 1095 /* 1096 * Accessing ->real_parent is not SMP-safe, it could 1097 * change from under us. However, we can use a stale 1098 * value of ->real_parent under rcu_read_lock(), see 1099 * release_task()->call_rcu(delayed_put_task_struct). 1100 */ 1101 SYSCALL_DEFINE0(getppid) 1102 { 1103 int pid; 1104 1105 rcu_read_lock(); 1106 pid = task_tgid_vnr(rcu_dereference(current->real_parent)); 1107 rcu_read_unlock(); 1108 1109 return pid; 1110 } 1111 1112 SYSCALL_DEFINE0(getuid) 1113 { 1114 /* Only we change this so SMP safe */ 1115 return from_kuid_munged(current_user_ns(), current_uid()); 1116 } 1117 1118 SYSCALL_DEFINE0(geteuid) 1119 { 1120 /* Only we change this so SMP safe */ 1121 return from_kuid_munged(current_user_ns(), current_euid()); 1122 } 1123 1124 SYSCALL_DEFINE0(getgid) 1125 { 1126 /* Only we change this so SMP safe */ 1127 return from_kgid_munged(current_user_ns(), current_gid()); 1128 } 1129 1130 SYSCALL_DEFINE0(getegid) 1131 { 1132 /* Only we change this so SMP safe */ 1133 return from_kgid_munged(current_user_ns(), current_egid()); 1134 } 1135 1136 void do_sys_times(struct tms *tms) 1137 { 1138 cputime_t tgutime, tgstime, cutime, cstime; 1139 1140 spin_lock_irq(¤t->sighand->siglock); 1141 thread_group_cputime_adjusted(current, &tgutime, &tgstime); 1142 cutime = current->signal->cutime; 1143 cstime = current->signal->cstime; 1144 spin_unlock_irq(¤t->sighand->siglock); 1145 tms->tms_utime = cputime_to_clock_t(tgutime); 1146 tms->tms_stime = cputime_to_clock_t(tgstime); 1147 tms->tms_cutime = cputime_to_clock_t(cutime); 1148 tms->tms_cstime = cputime_to_clock_t(cstime); 1149 } 1150 1151 SYSCALL_DEFINE1(times, struct tms __user *, tbuf) 1152 { 1153 if (tbuf) { 1154 struct tms tmp; 1155 1156 do_sys_times(&tmp); 1157 if (copy_to_user(tbuf, &tmp, sizeof(struct tms))) 1158 return -EFAULT; 1159 } 1160 force_successful_syscall_return(); 1161 return (long) jiffies_64_to_clock_t(get_jiffies_64()); 1162 } 1163 1164 /* 1165 * This needs some heavy checking ... 1166 * I just haven't the stomach for it. I also don't fully 1167 * understand sessions/pgrp etc. Let somebody who does explain it. 1168 * 1169 * OK, I think I have the protection semantics right.... this is really 1170 * only important on a multi-user system anyway, to make sure one user 1171 * can't send a signal to a process owned by another. -TYT, 12/12/91 1172 * 1173 * Auch. Had to add the 'did_exec' flag to conform completely to POSIX. 1174 * LBT 04.03.94 1175 */ 1176 SYSCALL_DEFINE2(setpgid, pid_t, pid, pid_t, pgid) 1177 { 1178 struct task_struct *p; 1179 struct task_struct *group_leader = current->group_leader; 1180 struct pid *pgrp; 1181 int err; 1182 1183 if (!pid) 1184 pid = task_pid_vnr(group_leader); 1185 if (!pgid) 1186 pgid = pid; 1187 if (pgid < 0) 1188 return -EINVAL; 1189 rcu_read_lock(); 1190 1191 /* From this point forward we keep holding onto the tasklist lock 1192 * so that our parent does not change from under us. -DaveM 1193 */ 1194 write_lock_irq(&tasklist_lock); 1195 1196 err = -ESRCH; 1197 p = find_task_by_vpid(pid); 1198 if (!p) 1199 goto out; 1200 1201 err = -EINVAL; 1202 if (!thread_group_leader(p)) 1203 goto out; 1204 1205 if (same_thread_group(p->real_parent, group_leader)) { 1206 err = -EPERM; 1207 if (task_session(p) != task_session(group_leader)) 1208 goto out; 1209 err = -EACCES; 1210 if (p->did_exec) 1211 goto out; 1212 } else { 1213 err = -ESRCH; 1214 if (p != group_leader) 1215 goto out; 1216 } 1217 1218 err = -EPERM; 1219 if (p->signal->leader) 1220 goto out; 1221 1222 pgrp = task_pid(p); 1223 if (pgid != pid) { 1224 struct task_struct *g; 1225 1226 pgrp = find_vpid(pgid); 1227 g = pid_task(pgrp, PIDTYPE_PGID); 1228 if (!g || task_session(g) != task_session(group_leader)) 1229 goto out; 1230 } 1231 1232 err = security_task_setpgid(p, pgid); 1233 if (err) 1234 goto out; 1235 1236 if (task_pgrp(p) != pgrp) 1237 change_pid(p, PIDTYPE_PGID, pgrp); 1238 1239 err = 0; 1240 out: 1241 /* All paths lead to here, thus we are safe. -DaveM */ 1242 write_unlock_irq(&tasklist_lock); 1243 rcu_read_unlock(); 1244 return err; 1245 } 1246 1247 SYSCALL_DEFINE1(getpgid, pid_t, pid) 1248 { 1249 struct task_struct *p; 1250 struct pid *grp; 1251 int retval; 1252 1253 rcu_read_lock(); 1254 if (!pid) 1255 grp = task_pgrp(current); 1256 else { 1257 retval = -ESRCH; 1258 p = find_task_by_vpid(pid); 1259 if (!p) 1260 goto out; 1261 grp = task_pgrp(p); 1262 if (!grp) 1263 goto out; 1264 1265 retval = security_task_getpgid(p); 1266 if (retval) 1267 goto out; 1268 } 1269 retval = pid_vnr(grp); 1270 out: 1271 rcu_read_unlock(); 1272 return retval; 1273 } 1274 1275 #ifdef __ARCH_WANT_SYS_GETPGRP 1276 1277 SYSCALL_DEFINE0(getpgrp) 1278 { 1279 return sys_getpgid(0); 1280 } 1281 1282 #endif 1283 1284 SYSCALL_DEFINE1(getsid, pid_t, pid) 1285 { 1286 struct task_struct *p; 1287 struct pid *sid; 1288 int retval; 1289 1290 rcu_read_lock(); 1291 if (!pid) 1292 sid = task_session(current); 1293 else { 1294 retval = -ESRCH; 1295 p = find_task_by_vpid(pid); 1296 if (!p) 1297 goto out; 1298 sid = task_session(p); 1299 if (!sid) 1300 goto out; 1301 1302 retval = security_task_getsid(p); 1303 if (retval) 1304 goto out; 1305 } 1306 retval = pid_vnr(sid); 1307 out: 1308 rcu_read_unlock(); 1309 return retval; 1310 } 1311 1312 static void set_special_pids(struct pid *pid) 1313 { 1314 struct task_struct *curr = current->group_leader; 1315 1316 if (task_session(curr) != pid) 1317 change_pid(curr, PIDTYPE_SID, pid); 1318 1319 if (task_pgrp(curr) != pid) 1320 change_pid(curr, PIDTYPE_PGID, pid); 1321 } 1322 1323 SYSCALL_DEFINE0(setsid) 1324 { 1325 struct task_struct *group_leader = current->group_leader; 1326 struct pid *sid = task_pid(group_leader); 1327 pid_t session = pid_vnr(sid); 1328 int err = -EPERM; 1329 1330 write_lock_irq(&tasklist_lock); 1331 /* Fail if I am already a session leader */ 1332 if (group_leader->signal->leader) 1333 goto out; 1334 1335 /* Fail if a process group id already exists that equals the 1336 * proposed session id. 1337 */ 1338 if (pid_task(sid, PIDTYPE_PGID)) 1339 goto out; 1340 1341 group_leader->signal->leader = 1; 1342 set_special_pids(sid); 1343 1344 proc_clear_tty(group_leader); 1345 1346 err = session; 1347 out: 1348 write_unlock_irq(&tasklist_lock); 1349 if (err > 0) { 1350 proc_sid_connector(group_leader); 1351 sched_autogroup_create_attach(group_leader); 1352 } 1353 return err; 1354 } 1355 1356 DECLARE_RWSEM(uts_sem); 1357 1358 #ifdef COMPAT_UTS_MACHINE 1359 #define override_architecture(name) \ 1360 (personality(current->personality) == PER_LINUX32 && \ 1361 copy_to_user(name->machine, COMPAT_UTS_MACHINE, \ 1362 sizeof(COMPAT_UTS_MACHINE))) 1363 #else 1364 #define override_architecture(name) 0 1365 #endif 1366 1367 /* 1368 * Work around broken programs that cannot handle "Linux 3.0". 1369 * Instead we map 3.x to 2.6.40+x, so e.g. 3.0 would be 2.6.40 1370 */ 1371 static int override_release(char __user *release, size_t len) 1372 { 1373 int ret = 0; 1374 1375 if (current->personality & UNAME26) { 1376 const char *rest = UTS_RELEASE; 1377 char buf[65] = { 0 }; 1378 int ndots = 0; 1379 unsigned v; 1380 size_t copy; 1381 1382 while (*rest) { 1383 if (*rest == '.' && ++ndots >= 3) 1384 break; 1385 if (!isdigit(*rest) && *rest != '.') 1386 break; 1387 rest++; 1388 } 1389 v = ((LINUX_VERSION_CODE >> 8) & 0xff) + 40; 1390 copy = clamp_t(size_t, len, 1, sizeof(buf)); 1391 copy = scnprintf(buf, copy, "2.6.%u%s", v, rest); 1392 ret = copy_to_user(release, buf, copy + 1); 1393 } 1394 return ret; 1395 } 1396 1397 SYSCALL_DEFINE1(newuname, struct new_utsname __user *, name) 1398 { 1399 int errno = 0; 1400 1401 down_read(&uts_sem); 1402 if (copy_to_user(name, utsname(), sizeof *name)) 1403 errno = -EFAULT; 1404 up_read(&uts_sem); 1405 1406 if (!errno && override_release(name->release, sizeof(name->release))) 1407 errno = -EFAULT; 1408 if (!errno && override_architecture(name)) 1409 errno = -EFAULT; 1410 return errno; 1411 } 1412 1413 #ifdef __ARCH_WANT_SYS_OLD_UNAME 1414 /* 1415 * Old cruft 1416 */ 1417 SYSCALL_DEFINE1(uname, struct old_utsname __user *, name) 1418 { 1419 int error = 0; 1420 1421 if (!name) 1422 return -EFAULT; 1423 1424 down_read(&uts_sem); 1425 if (copy_to_user(name, utsname(), sizeof(*name))) 1426 error = -EFAULT; 1427 up_read(&uts_sem); 1428 1429 if (!error && override_release(name->release, sizeof(name->release))) 1430 error = -EFAULT; 1431 if (!error && override_architecture(name)) 1432 error = -EFAULT; 1433 return error; 1434 } 1435 1436 SYSCALL_DEFINE1(olduname, struct oldold_utsname __user *, name) 1437 { 1438 int error; 1439 1440 if (!name) 1441 return -EFAULT; 1442 if (!access_ok(VERIFY_WRITE, name, sizeof(struct oldold_utsname))) 1443 return -EFAULT; 1444 1445 down_read(&uts_sem); 1446 error = __copy_to_user(&name->sysname, &utsname()->sysname, 1447 __OLD_UTS_LEN); 1448 error |= __put_user(0, name->sysname + __OLD_UTS_LEN); 1449 error |= __copy_to_user(&name->nodename, &utsname()->nodename, 1450 __OLD_UTS_LEN); 1451 error |= __put_user(0, name->nodename + __OLD_UTS_LEN); 1452 error |= __copy_to_user(&name->release, &utsname()->release, 1453 __OLD_UTS_LEN); 1454 error |= __put_user(0, name->release + __OLD_UTS_LEN); 1455 error |= __copy_to_user(&name->version, &utsname()->version, 1456 __OLD_UTS_LEN); 1457 error |= __put_user(0, name->version + __OLD_UTS_LEN); 1458 error |= __copy_to_user(&name->machine, &utsname()->machine, 1459 __OLD_UTS_LEN); 1460 error |= __put_user(0, name->machine + __OLD_UTS_LEN); 1461 up_read(&uts_sem); 1462 1463 if (!error && override_architecture(name)) 1464 error = -EFAULT; 1465 if (!error && override_release(name->release, sizeof(name->release))) 1466 error = -EFAULT; 1467 return error ? -EFAULT : 0; 1468 } 1469 #endif 1470 1471 SYSCALL_DEFINE2(sethostname, char __user *, name, int, len) 1472 { 1473 int errno; 1474 char tmp[__NEW_UTS_LEN]; 1475 1476 if (!ns_capable(current->nsproxy->uts_ns->user_ns, CAP_SYS_ADMIN)) 1477 return -EPERM; 1478 1479 if (len < 0 || len > __NEW_UTS_LEN) 1480 return -EINVAL; 1481 down_write(&uts_sem); 1482 errno = -EFAULT; 1483 if (!copy_from_user(tmp, name, len)) { 1484 struct new_utsname *u = utsname(); 1485 1486 memcpy(u->nodename, tmp, len); 1487 memset(u->nodename + len, 0, sizeof(u->nodename) - len); 1488 errno = 0; 1489 uts_proc_notify(UTS_PROC_HOSTNAME); 1490 } 1491 up_write(&uts_sem); 1492 return errno; 1493 } 1494 1495 #ifdef __ARCH_WANT_SYS_GETHOSTNAME 1496 1497 SYSCALL_DEFINE2(gethostname, char __user *, name, int, len) 1498 { 1499 int i, errno; 1500 struct new_utsname *u; 1501 1502 if (len < 0) 1503 return -EINVAL; 1504 down_read(&uts_sem); 1505 u = utsname(); 1506 i = 1 + strlen(u->nodename); 1507 if (i > len) 1508 i = len; 1509 errno = 0; 1510 if (copy_to_user(name, u->nodename, i)) 1511 errno = -EFAULT; 1512 up_read(&uts_sem); 1513 return errno; 1514 } 1515 1516 #endif 1517 1518 /* 1519 * Only setdomainname; getdomainname can be implemented by calling 1520 * uname() 1521 */ 1522 SYSCALL_DEFINE2(setdomainname, char __user *, name, int, len) 1523 { 1524 int errno; 1525 char tmp[__NEW_UTS_LEN]; 1526 1527 if (!ns_capable(current->nsproxy->uts_ns->user_ns, CAP_SYS_ADMIN)) 1528 return -EPERM; 1529 if (len < 0 || len > __NEW_UTS_LEN) 1530 return -EINVAL; 1531 1532 down_write(&uts_sem); 1533 errno = -EFAULT; 1534 if (!copy_from_user(tmp, name, len)) { 1535 struct new_utsname *u = utsname(); 1536 1537 memcpy(u->domainname, tmp, len); 1538 memset(u->domainname + len, 0, sizeof(u->domainname) - len); 1539 errno = 0; 1540 uts_proc_notify(UTS_PROC_DOMAINNAME); 1541 } 1542 up_write(&uts_sem); 1543 return errno; 1544 } 1545 1546 SYSCALL_DEFINE2(getrlimit, unsigned int, resource, struct rlimit __user *, rlim) 1547 { 1548 struct rlimit value; 1549 int ret; 1550 1551 ret = do_prlimit(current, resource, NULL, &value); 1552 if (!ret) 1553 ret = copy_to_user(rlim, &value, sizeof(*rlim)) ? -EFAULT : 0; 1554 1555 return ret; 1556 } 1557 1558 #ifdef __ARCH_WANT_SYS_OLD_GETRLIMIT 1559 1560 /* 1561 * Back compatibility for getrlimit. Needed for some apps. 1562 */ 1563 1564 SYSCALL_DEFINE2(old_getrlimit, unsigned int, resource, 1565 struct rlimit __user *, rlim) 1566 { 1567 struct rlimit x; 1568 if (resource >= RLIM_NLIMITS) 1569 return -EINVAL; 1570 1571 task_lock(current->group_leader); 1572 x = current->signal->rlim[resource]; 1573 task_unlock(current->group_leader); 1574 if (x.rlim_cur > 0x7FFFFFFF) 1575 x.rlim_cur = 0x7FFFFFFF; 1576 if (x.rlim_max > 0x7FFFFFFF) 1577 x.rlim_max = 0x7FFFFFFF; 1578 return copy_to_user(rlim, &x, sizeof(x))?-EFAULT:0; 1579 } 1580 1581 #endif 1582 1583 static inline bool rlim64_is_infinity(__u64 rlim64) 1584 { 1585 #if BITS_PER_LONG < 64 1586 return rlim64 >= ULONG_MAX; 1587 #else 1588 return rlim64 == RLIM64_INFINITY; 1589 #endif 1590 } 1591 1592 static void rlim_to_rlim64(const struct rlimit *rlim, struct rlimit64 *rlim64) 1593 { 1594 if (rlim->rlim_cur == RLIM_INFINITY) 1595 rlim64->rlim_cur = RLIM64_INFINITY; 1596 else 1597 rlim64->rlim_cur = rlim->rlim_cur; 1598 if (rlim->rlim_max == RLIM_INFINITY) 1599 rlim64->rlim_max = RLIM64_INFINITY; 1600 else 1601 rlim64->rlim_max = rlim->rlim_max; 1602 } 1603 1604 static void rlim64_to_rlim(const struct rlimit64 *rlim64, struct rlimit *rlim) 1605 { 1606 if (rlim64_is_infinity(rlim64->rlim_cur)) 1607 rlim->rlim_cur = RLIM_INFINITY; 1608 else 1609 rlim->rlim_cur = (unsigned long)rlim64->rlim_cur; 1610 if (rlim64_is_infinity(rlim64->rlim_max)) 1611 rlim->rlim_max = RLIM_INFINITY; 1612 else 1613 rlim->rlim_max = (unsigned long)rlim64->rlim_max; 1614 } 1615 1616 /* make sure you are allowed to change @tsk limits before calling this */ 1617 int do_prlimit(struct task_struct *tsk, unsigned int resource, 1618 struct rlimit *new_rlim, struct rlimit *old_rlim) 1619 { 1620 struct rlimit *rlim; 1621 int retval = 0; 1622 1623 if (resource >= RLIM_NLIMITS) 1624 return -EINVAL; 1625 if (new_rlim) { 1626 if (new_rlim->rlim_cur > new_rlim->rlim_max) 1627 return -EINVAL; 1628 if (resource == RLIMIT_NOFILE && 1629 new_rlim->rlim_max > sysctl_nr_open) 1630 return -EPERM; 1631 } 1632 1633 /* protect tsk->signal and tsk->sighand from disappearing */ 1634 read_lock(&tasklist_lock); 1635 if (!tsk->sighand) { 1636 retval = -ESRCH; 1637 goto out; 1638 } 1639 1640 rlim = tsk->signal->rlim + resource; 1641 task_lock(tsk->group_leader); 1642 if (new_rlim) { 1643 /* Keep the capable check against init_user_ns until 1644 cgroups can contain all limits */ 1645 if (new_rlim->rlim_max > rlim->rlim_max && 1646 !capable(CAP_SYS_RESOURCE)) 1647 retval = -EPERM; 1648 if (!retval) 1649 retval = security_task_setrlimit(tsk->group_leader, 1650 resource, new_rlim); 1651 if (resource == RLIMIT_CPU && new_rlim->rlim_cur == 0) { 1652 /* 1653 * The caller is asking for an immediate RLIMIT_CPU 1654 * expiry. But we use the zero value to mean "it was 1655 * never set". So let's cheat and make it one second 1656 * instead 1657 */ 1658 new_rlim->rlim_cur = 1; 1659 } 1660 } 1661 if (!retval) { 1662 if (old_rlim) 1663 *old_rlim = *rlim; 1664 if (new_rlim) 1665 *rlim = *new_rlim; 1666 } 1667 task_unlock(tsk->group_leader); 1668 1669 /* 1670 * RLIMIT_CPU handling. Note that the kernel fails to return an error 1671 * code if it rejected the user's attempt to set RLIMIT_CPU. This is a 1672 * very long-standing error, and fixing it now risks breakage of 1673 * applications, so we live with it 1674 */ 1675 if (!retval && new_rlim && resource == RLIMIT_CPU && 1676 new_rlim->rlim_cur != RLIM_INFINITY) 1677 update_rlimit_cpu(tsk, new_rlim->rlim_cur); 1678 out: 1679 read_unlock(&tasklist_lock); 1680 return retval; 1681 } 1682 1683 /* rcu lock must be held */ 1684 static int check_prlimit_permission(struct task_struct *task) 1685 { 1686 const struct cred *cred = current_cred(), *tcred; 1687 1688 if (current == task) 1689 return 0; 1690 1691 tcred = __task_cred(task); 1692 if (uid_eq(cred->uid, tcred->euid) && 1693 uid_eq(cred->uid, tcred->suid) && 1694 uid_eq(cred->uid, tcred->uid) && 1695 gid_eq(cred->gid, tcred->egid) && 1696 gid_eq(cred->gid, tcred->sgid) && 1697 gid_eq(cred->gid, tcred->gid)) 1698 return 0; 1699 if (ns_capable(tcred->user_ns, CAP_SYS_RESOURCE)) 1700 return 0; 1701 1702 return -EPERM; 1703 } 1704 1705 SYSCALL_DEFINE4(prlimit64, pid_t, pid, unsigned int, resource, 1706 const struct rlimit64 __user *, new_rlim, 1707 struct rlimit64 __user *, old_rlim) 1708 { 1709 struct rlimit64 old64, new64; 1710 struct rlimit old, new; 1711 struct task_struct *tsk; 1712 int ret; 1713 1714 if (new_rlim) { 1715 if (copy_from_user(&new64, new_rlim, sizeof(new64))) 1716 return -EFAULT; 1717 rlim64_to_rlim(&new64, &new); 1718 } 1719 1720 rcu_read_lock(); 1721 tsk = pid ? find_task_by_vpid(pid) : current; 1722 if (!tsk) { 1723 rcu_read_unlock(); 1724 return -ESRCH; 1725 } 1726 ret = check_prlimit_permission(tsk); 1727 if (ret) { 1728 rcu_read_unlock(); 1729 return ret; 1730 } 1731 get_task_struct(tsk); 1732 rcu_read_unlock(); 1733 1734 ret = do_prlimit(tsk, resource, new_rlim ? &new : NULL, 1735 old_rlim ? &old : NULL); 1736 1737 if (!ret && old_rlim) { 1738 rlim_to_rlim64(&old, &old64); 1739 if (copy_to_user(old_rlim, &old64, sizeof(old64))) 1740 ret = -EFAULT; 1741 } 1742 1743 put_task_struct(tsk); 1744 return ret; 1745 } 1746 1747 SYSCALL_DEFINE2(setrlimit, unsigned int, resource, struct rlimit __user *, rlim) 1748 { 1749 struct rlimit new_rlim; 1750 1751 if (copy_from_user(&new_rlim, rlim, sizeof(*rlim))) 1752 return -EFAULT; 1753 return do_prlimit(current, resource, &new_rlim, NULL); 1754 } 1755 1756 /* 1757 * It would make sense to put struct rusage in the task_struct, 1758 * except that would make the task_struct be *really big*. After 1759 * task_struct gets moved into malloc'ed memory, it would 1760 * make sense to do this. It will make moving the rest of the information 1761 * a lot simpler! (Which we're not doing right now because we're not 1762 * measuring them yet). 1763 * 1764 * When sampling multiple threads for RUSAGE_SELF, under SMP we might have 1765 * races with threads incrementing their own counters. But since word 1766 * reads are atomic, we either get new values or old values and we don't 1767 * care which for the sums. We always take the siglock to protect reading 1768 * the c* fields from p->signal from races with exit.c updating those 1769 * fields when reaping, so a sample either gets all the additions of a 1770 * given child after it's reaped, or none so this sample is before reaping. 1771 * 1772 * Locking: 1773 * We need to take the siglock for CHILDEREN, SELF and BOTH 1774 * for the cases current multithreaded, non-current single threaded 1775 * non-current multithreaded. Thread traversal is now safe with 1776 * the siglock held. 1777 * Strictly speaking, we donot need to take the siglock if we are current and 1778 * single threaded, as no one else can take our signal_struct away, no one 1779 * else can reap the children to update signal->c* counters, and no one else 1780 * can race with the signal-> fields. If we do not take any lock, the 1781 * signal-> fields could be read out of order while another thread was just 1782 * exiting. So we should place a read memory barrier when we avoid the lock. 1783 * On the writer side, write memory barrier is implied in __exit_signal 1784 * as __exit_signal releases the siglock spinlock after updating the signal-> 1785 * fields. But we don't do this yet to keep things simple. 1786 * 1787 */ 1788 1789 static void accumulate_thread_rusage(struct task_struct *t, struct rusage *r) 1790 { 1791 r->ru_nvcsw += t->nvcsw; 1792 r->ru_nivcsw += t->nivcsw; 1793 r->ru_minflt += t->min_flt; 1794 r->ru_majflt += t->maj_flt; 1795 r->ru_inblock += task_io_get_inblock(t); 1796 r->ru_oublock += task_io_get_oublock(t); 1797 } 1798 1799 static void k_getrusage(struct task_struct *p, int who, struct rusage *r) 1800 { 1801 struct task_struct *t; 1802 unsigned long flags; 1803 cputime_t tgutime, tgstime, utime, stime; 1804 unsigned long maxrss = 0; 1805 1806 memset((char *) r, 0, sizeof *r); 1807 utime = stime = 0; 1808 1809 if (who == RUSAGE_THREAD) { 1810 task_cputime_adjusted(current, &utime, &stime); 1811 accumulate_thread_rusage(p, r); 1812 maxrss = p->signal->maxrss; 1813 goto out; 1814 } 1815 1816 if (!lock_task_sighand(p, &flags)) 1817 return; 1818 1819 switch (who) { 1820 case RUSAGE_BOTH: 1821 case RUSAGE_CHILDREN: 1822 utime = p->signal->cutime; 1823 stime = p->signal->cstime; 1824 r->ru_nvcsw = p->signal->cnvcsw; 1825 r->ru_nivcsw = p->signal->cnivcsw; 1826 r->ru_minflt = p->signal->cmin_flt; 1827 r->ru_majflt = p->signal->cmaj_flt; 1828 r->ru_inblock = p->signal->cinblock; 1829 r->ru_oublock = p->signal->coublock; 1830 maxrss = p->signal->cmaxrss; 1831 1832 if (who == RUSAGE_CHILDREN) 1833 break; 1834 1835 case RUSAGE_SELF: 1836 thread_group_cputime_adjusted(p, &tgutime, &tgstime); 1837 utime += tgutime; 1838 stime += tgstime; 1839 r->ru_nvcsw += p->signal->nvcsw; 1840 r->ru_nivcsw += p->signal->nivcsw; 1841 r->ru_minflt += p->signal->min_flt; 1842 r->ru_majflt += p->signal->maj_flt; 1843 r->ru_inblock += p->signal->inblock; 1844 r->ru_oublock += p->signal->oublock; 1845 if (maxrss < p->signal->maxrss) 1846 maxrss = p->signal->maxrss; 1847 t = p; 1848 do { 1849 accumulate_thread_rusage(t, r); 1850 t = next_thread(t); 1851 } while (t != p); 1852 break; 1853 1854 default: 1855 BUG(); 1856 } 1857 unlock_task_sighand(p, &flags); 1858 1859 out: 1860 cputime_to_timeval(utime, &r->ru_utime); 1861 cputime_to_timeval(stime, &r->ru_stime); 1862 1863 if (who != RUSAGE_CHILDREN) { 1864 struct mm_struct *mm = get_task_mm(p); 1865 if (mm) { 1866 setmax_mm_hiwater_rss(&maxrss, mm); 1867 mmput(mm); 1868 } 1869 } 1870 r->ru_maxrss = maxrss * (PAGE_SIZE / 1024); /* convert pages to KBs */ 1871 } 1872 1873 int getrusage(struct task_struct *p, int who, struct rusage __user *ru) 1874 { 1875 struct rusage r; 1876 k_getrusage(p, who, &r); 1877 return copy_to_user(ru, &r, sizeof(r)) ? -EFAULT : 0; 1878 } 1879 1880 SYSCALL_DEFINE2(getrusage, int, who, struct rusage __user *, ru) 1881 { 1882 if (who != RUSAGE_SELF && who != RUSAGE_CHILDREN && 1883 who != RUSAGE_THREAD) 1884 return -EINVAL; 1885 return getrusage(current, who, ru); 1886 } 1887 1888 #ifdef CONFIG_COMPAT 1889 COMPAT_SYSCALL_DEFINE2(getrusage, int, who, struct compat_rusage __user *, ru) 1890 { 1891 struct rusage r; 1892 1893 if (who != RUSAGE_SELF && who != RUSAGE_CHILDREN && 1894 who != RUSAGE_THREAD) 1895 return -EINVAL; 1896 1897 k_getrusage(current, who, &r); 1898 return put_compat_rusage(&r, ru); 1899 } 1900 #endif 1901 1902 SYSCALL_DEFINE1(umask, int, mask) 1903 { 1904 mask = xchg(¤t->fs->umask, mask & S_IRWXUGO); 1905 return mask; 1906 } 1907 1908 static int prctl_set_mm_exe_file(struct mm_struct *mm, unsigned int fd) 1909 { 1910 struct fd exe; 1911 struct inode *inode; 1912 int err; 1913 1914 exe = fdget(fd); 1915 if (!exe.file) 1916 return -EBADF; 1917 1918 inode = file_inode(exe.file); 1919 1920 /* 1921 * Because the original mm->exe_file points to executable file, make 1922 * sure that this one is executable as well, to avoid breaking an 1923 * overall picture. 1924 */ 1925 err = -EACCES; 1926 if (!S_ISREG(inode->i_mode) || 1927 exe.file->f_path.mnt->mnt_flags & MNT_NOEXEC) 1928 goto exit; 1929 1930 err = inode_permission(inode, MAY_EXEC); 1931 if (err) 1932 goto exit; 1933 1934 down_write(&mm->mmap_sem); 1935 1936 /* 1937 * Forbid mm->exe_file change if old file still mapped. 1938 */ 1939 err = -EBUSY; 1940 if (mm->exe_file) { 1941 struct vm_area_struct *vma; 1942 1943 for (vma = mm->mmap; vma; vma = vma->vm_next) 1944 if (vma->vm_file && 1945 path_equal(&vma->vm_file->f_path, 1946 &mm->exe_file->f_path)) 1947 goto exit_unlock; 1948 } 1949 1950 /* 1951 * The symlink can be changed only once, just to disallow arbitrary 1952 * transitions malicious software might bring in. This means one 1953 * could make a snapshot over all processes running and monitor 1954 * /proc/pid/exe changes to notice unusual activity if needed. 1955 */ 1956 err = -EPERM; 1957 if (test_and_set_bit(MMF_EXE_FILE_CHANGED, &mm->flags)) 1958 goto exit_unlock; 1959 1960 err = 0; 1961 set_mm_exe_file(mm, exe.file); /* this grabs a reference to exe.file */ 1962 exit_unlock: 1963 up_write(&mm->mmap_sem); 1964 1965 exit: 1966 fdput(exe); 1967 return err; 1968 } 1969 1970 static int prctl_set_mm(int opt, unsigned long addr, 1971 unsigned long arg4, unsigned long arg5) 1972 { 1973 unsigned long rlim = rlimit(RLIMIT_DATA); 1974 struct mm_struct *mm = current->mm; 1975 struct vm_area_struct *vma; 1976 int error; 1977 1978 if (arg5 || (arg4 && opt != PR_SET_MM_AUXV)) 1979 return -EINVAL; 1980 1981 if (!capable(CAP_SYS_RESOURCE)) 1982 return -EPERM; 1983 1984 if (opt == PR_SET_MM_EXE_FILE) 1985 return prctl_set_mm_exe_file(mm, (unsigned int)addr); 1986 1987 if (addr >= TASK_SIZE || addr < mmap_min_addr) 1988 return -EINVAL; 1989 1990 error = -EINVAL; 1991 1992 down_read(&mm->mmap_sem); 1993 vma = find_vma(mm, addr); 1994 1995 switch (opt) { 1996 case PR_SET_MM_START_CODE: 1997 mm->start_code = addr; 1998 break; 1999 case PR_SET_MM_END_CODE: 2000 mm->end_code = addr; 2001 break; 2002 case PR_SET_MM_START_DATA: 2003 mm->start_data = addr; 2004 break; 2005 case PR_SET_MM_END_DATA: 2006 mm->end_data = addr; 2007 break; 2008 2009 case PR_SET_MM_START_BRK: 2010 if (addr <= mm->end_data) 2011 goto out; 2012 2013 if (rlim < RLIM_INFINITY && 2014 (mm->brk - addr) + 2015 (mm->end_data - mm->start_data) > rlim) 2016 goto out; 2017 2018 mm->start_brk = addr; 2019 break; 2020 2021 case PR_SET_MM_BRK: 2022 if (addr <= mm->end_data) 2023 goto out; 2024 2025 if (rlim < RLIM_INFINITY && 2026 (addr - mm->start_brk) + 2027 (mm->end_data - mm->start_data) > rlim) 2028 goto out; 2029 2030 mm->brk = addr; 2031 break; 2032 2033 /* 2034 * If command line arguments and environment 2035 * are placed somewhere else on stack, we can 2036 * set them up here, ARG_START/END to setup 2037 * command line argumets and ENV_START/END 2038 * for environment. 2039 */ 2040 case PR_SET_MM_START_STACK: 2041 case PR_SET_MM_ARG_START: 2042 case PR_SET_MM_ARG_END: 2043 case PR_SET_MM_ENV_START: 2044 case PR_SET_MM_ENV_END: 2045 if (!vma) { 2046 error = -EFAULT; 2047 goto out; 2048 } 2049 if (opt == PR_SET_MM_START_STACK) 2050 mm->start_stack = addr; 2051 else if (opt == PR_SET_MM_ARG_START) 2052 mm->arg_start = addr; 2053 else if (opt == PR_SET_MM_ARG_END) 2054 mm->arg_end = addr; 2055 else if (opt == PR_SET_MM_ENV_START) 2056 mm->env_start = addr; 2057 else if (opt == PR_SET_MM_ENV_END) 2058 mm->env_end = addr; 2059 break; 2060 2061 /* 2062 * This doesn't move auxiliary vector itself 2063 * since it's pinned to mm_struct, but allow 2064 * to fill vector with new values. It's up 2065 * to a caller to provide sane values here 2066 * otherwise user space tools which use this 2067 * vector might be unhappy. 2068 */ 2069 case PR_SET_MM_AUXV: { 2070 unsigned long user_auxv[AT_VECTOR_SIZE]; 2071 2072 if (arg4 > sizeof(user_auxv)) 2073 goto out; 2074 up_read(&mm->mmap_sem); 2075 2076 if (copy_from_user(user_auxv, (const void __user *)addr, arg4)) 2077 return -EFAULT; 2078 2079 /* Make sure the last entry is always AT_NULL */ 2080 user_auxv[AT_VECTOR_SIZE - 2] = 0; 2081 user_auxv[AT_VECTOR_SIZE - 1] = 0; 2082 2083 BUILD_BUG_ON(sizeof(user_auxv) != sizeof(mm->saved_auxv)); 2084 2085 task_lock(current); 2086 memcpy(mm->saved_auxv, user_auxv, arg4); 2087 task_unlock(current); 2088 2089 return 0; 2090 } 2091 default: 2092 goto out; 2093 } 2094 2095 error = 0; 2096 out: 2097 up_read(&mm->mmap_sem); 2098 return error; 2099 } 2100 2101 #ifdef CONFIG_CHECKPOINT_RESTORE 2102 static int prctl_get_tid_address(struct task_struct *me, int __user **tid_addr) 2103 { 2104 return put_user(me->clear_child_tid, tid_addr); 2105 } 2106 #else 2107 static int prctl_get_tid_address(struct task_struct *me, int __user **tid_addr) 2108 { 2109 return -EINVAL; 2110 } 2111 #endif 2112 2113 SYSCALL_DEFINE5(prctl, int, option, unsigned long, arg2, unsigned long, arg3, 2114 unsigned long, arg4, unsigned long, arg5) 2115 { 2116 struct task_struct *me = current; 2117 unsigned char comm[sizeof(me->comm)]; 2118 long error; 2119 2120 error = security_task_prctl(option, arg2, arg3, arg4, arg5); 2121 if (error != -ENOSYS) 2122 return error; 2123 2124 error = 0; 2125 switch (option) { 2126 case PR_SET_PDEATHSIG: 2127 if (!valid_signal(arg2)) { 2128 error = -EINVAL; 2129 break; 2130 } 2131 me->pdeath_signal = arg2; 2132 break; 2133 case PR_GET_PDEATHSIG: 2134 error = put_user(me->pdeath_signal, (int __user *)arg2); 2135 break; 2136 case PR_GET_DUMPABLE: 2137 error = get_dumpable(me->mm); 2138 break; 2139 case PR_SET_DUMPABLE: 2140 if (arg2 != SUID_DUMP_DISABLE && arg2 != SUID_DUMP_USER) { 2141 error = -EINVAL; 2142 break; 2143 } 2144 set_dumpable(me->mm, arg2); 2145 break; 2146 2147 case PR_SET_UNALIGN: 2148 error = SET_UNALIGN_CTL(me, arg2); 2149 break; 2150 case PR_GET_UNALIGN: 2151 error = GET_UNALIGN_CTL(me, arg2); 2152 break; 2153 case PR_SET_FPEMU: 2154 error = SET_FPEMU_CTL(me, arg2); 2155 break; 2156 case PR_GET_FPEMU: 2157 error = GET_FPEMU_CTL(me, arg2); 2158 break; 2159 case PR_SET_FPEXC: 2160 error = SET_FPEXC_CTL(me, arg2); 2161 break; 2162 case PR_GET_FPEXC: 2163 error = GET_FPEXC_CTL(me, arg2); 2164 break; 2165 case PR_GET_TIMING: 2166 error = PR_TIMING_STATISTICAL; 2167 break; 2168 case PR_SET_TIMING: 2169 if (arg2 != PR_TIMING_STATISTICAL) 2170 error = -EINVAL; 2171 break; 2172 case PR_SET_NAME: 2173 comm[sizeof(me->comm) - 1] = 0; 2174 if (strncpy_from_user(comm, (char __user *)arg2, 2175 sizeof(me->comm) - 1) < 0) 2176 return -EFAULT; 2177 set_task_comm(me, comm); 2178 proc_comm_connector(me); 2179 break; 2180 case PR_GET_NAME: 2181 get_task_comm(comm, me); 2182 if (copy_to_user((char __user *)arg2, comm, sizeof(comm))) 2183 return -EFAULT; 2184 break; 2185 case PR_GET_ENDIAN: 2186 error = GET_ENDIAN(me, arg2); 2187 break; 2188 case PR_SET_ENDIAN: 2189 error = SET_ENDIAN(me, arg2); 2190 break; 2191 case PR_GET_SECCOMP: 2192 error = prctl_get_seccomp(); 2193 break; 2194 case PR_SET_SECCOMP: 2195 error = prctl_set_seccomp(arg2, (char __user *)arg3); 2196 break; 2197 case PR_GET_TSC: 2198 error = GET_TSC_CTL(arg2); 2199 break; 2200 case PR_SET_TSC: 2201 error = SET_TSC_CTL(arg2); 2202 break; 2203 case PR_TASK_PERF_EVENTS_DISABLE: 2204 error = perf_event_task_disable(); 2205 break; 2206 case PR_TASK_PERF_EVENTS_ENABLE: 2207 error = perf_event_task_enable(); 2208 break; 2209 case PR_GET_TIMERSLACK: 2210 error = current->timer_slack_ns; 2211 break; 2212 case PR_SET_TIMERSLACK: 2213 if (arg2 <= 0) 2214 current->timer_slack_ns = 2215 current->default_timer_slack_ns; 2216 else 2217 current->timer_slack_ns = arg2; 2218 break; 2219 case PR_MCE_KILL: 2220 if (arg4 | arg5) 2221 return -EINVAL; 2222 switch (arg2) { 2223 case PR_MCE_KILL_CLEAR: 2224 if (arg3 != 0) 2225 return -EINVAL; 2226 current->flags &= ~PF_MCE_PROCESS; 2227 break; 2228 case PR_MCE_KILL_SET: 2229 current->flags |= PF_MCE_PROCESS; 2230 if (arg3 == PR_MCE_KILL_EARLY) 2231 current->flags |= PF_MCE_EARLY; 2232 else if (arg3 == PR_MCE_KILL_LATE) 2233 current->flags &= ~PF_MCE_EARLY; 2234 else if (arg3 == PR_MCE_KILL_DEFAULT) 2235 current->flags &= 2236 ~(PF_MCE_EARLY|PF_MCE_PROCESS); 2237 else 2238 return -EINVAL; 2239 break; 2240 default: 2241 return -EINVAL; 2242 } 2243 break; 2244 case PR_MCE_KILL_GET: 2245 if (arg2 | arg3 | arg4 | arg5) 2246 return -EINVAL; 2247 if (current->flags & PF_MCE_PROCESS) 2248 error = (current->flags & PF_MCE_EARLY) ? 2249 PR_MCE_KILL_EARLY : PR_MCE_KILL_LATE; 2250 else 2251 error = PR_MCE_KILL_DEFAULT; 2252 break; 2253 case PR_SET_MM: 2254 error = prctl_set_mm(arg2, arg3, arg4, arg5); 2255 break; 2256 case PR_GET_TID_ADDRESS: 2257 error = prctl_get_tid_address(me, (int __user **)arg2); 2258 break; 2259 case PR_SET_CHILD_SUBREAPER: 2260 me->signal->is_child_subreaper = !!arg2; 2261 break; 2262 case PR_GET_CHILD_SUBREAPER: 2263 error = put_user(me->signal->is_child_subreaper, 2264 (int __user *)arg2); 2265 break; 2266 case PR_SET_NO_NEW_PRIVS: 2267 if (arg2 != 1 || arg3 || arg4 || arg5) 2268 return -EINVAL; 2269 2270 current->no_new_privs = 1; 2271 break; 2272 case PR_GET_NO_NEW_PRIVS: 2273 if (arg2 || arg3 || arg4 || arg5) 2274 return -EINVAL; 2275 return current->no_new_privs ? 1 : 0; 2276 default: 2277 error = -EINVAL; 2278 break; 2279 } 2280 return error; 2281 } 2282 2283 SYSCALL_DEFINE3(getcpu, unsigned __user *, cpup, unsigned __user *, nodep, 2284 struct getcpu_cache __user *, unused) 2285 { 2286 int err = 0; 2287 int cpu = raw_smp_processor_id(); 2288 if (cpup) 2289 err |= put_user(cpu, cpup); 2290 if (nodep) 2291 err |= put_user(cpu_to_node(cpu), nodep); 2292 return err ? -EFAULT : 0; 2293 } 2294 2295 char poweroff_cmd[POWEROFF_CMD_PATH_LEN] = "/sbin/poweroff"; 2296 2297 static int __orderly_poweroff(bool force) 2298 { 2299 char **argv; 2300 static char *envp[] = { 2301 "HOME=/", 2302 "PATH=/sbin:/bin:/usr/sbin:/usr/bin", 2303 NULL 2304 }; 2305 int ret; 2306 2307 argv = argv_split(GFP_KERNEL, poweroff_cmd, NULL); 2308 if (argv) { 2309 ret = call_usermodehelper(argv[0], argv, envp, UMH_WAIT_EXEC); 2310 argv_free(argv); 2311 } else { 2312 printk(KERN_WARNING "%s failed to allocate memory for \"%s\"\n", 2313 __func__, poweroff_cmd); 2314 ret = -ENOMEM; 2315 } 2316 2317 if (ret && force) { 2318 printk(KERN_WARNING "Failed to start orderly shutdown: " 2319 "forcing the issue\n"); 2320 /* 2321 * I guess this should try to kick off some daemon to sync and 2322 * poweroff asap. Or not even bother syncing if we're doing an 2323 * emergency shutdown? 2324 */ 2325 emergency_sync(); 2326 kernel_power_off(); 2327 } 2328 2329 return ret; 2330 } 2331 2332 static bool poweroff_force; 2333 2334 static void poweroff_work_func(struct work_struct *work) 2335 { 2336 __orderly_poweroff(poweroff_force); 2337 } 2338 2339 static DECLARE_WORK(poweroff_work, poweroff_work_func); 2340 2341 /** 2342 * orderly_poweroff - Trigger an orderly system poweroff 2343 * @force: force poweroff if command execution fails 2344 * 2345 * This may be called from any context to trigger a system shutdown. 2346 * If the orderly shutdown fails, it will force an immediate shutdown. 2347 */ 2348 int orderly_poweroff(bool force) 2349 { 2350 if (force) /* do not override the pending "true" */ 2351 poweroff_force = true; 2352 schedule_work(&poweroff_work); 2353 return 0; 2354 } 2355 EXPORT_SYMBOL_GPL(orderly_poweroff); 2356 2357 /** 2358 * do_sysinfo - fill in sysinfo struct 2359 * @info: pointer to buffer to fill 2360 */ 2361 static int do_sysinfo(struct sysinfo *info) 2362 { 2363 unsigned long mem_total, sav_total; 2364 unsigned int mem_unit, bitcount; 2365 struct timespec tp; 2366 2367 memset(info, 0, sizeof(struct sysinfo)); 2368 2369 get_monotonic_boottime(&tp); 2370 info->uptime = tp.tv_sec + (tp.tv_nsec ? 1 : 0); 2371 2372 get_avenrun(info->loads, 0, SI_LOAD_SHIFT - FSHIFT); 2373 2374 info->procs = nr_threads; 2375 2376 si_meminfo(info); 2377 si_swapinfo(info); 2378 2379 /* 2380 * If the sum of all the available memory (i.e. ram + swap) 2381 * is less than can be stored in a 32 bit unsigned long then 2382 * we can be binary compatible with 2.2.x kernels. If not, 2383 * well, in that case 2.2.x was broken anyways... 2384 * 2385 * -Erik Andersen <andersee@debian.org> 2386 */ 2387 2388 mem_total = info->totalram + info->totalswap; 2389 if (mem_total < info->totalram || mem_total < info->totalswap) 2390 goto out; 2391 bitcount = 0; 2392 mem_unit = info->mem_unit; 2393 while (mem_unit > 1) { 2394 bitcount++; 2395 mem_unit >>= 1; 2396 sav_total = mem_total; 2397 mem_total <<= 1; 2398 if (mem_total < sav_total) 2399 goto out; 2400 } 2401 2402 /* 2403 * If mem_total did not overflow, multiply all memory values by 2404 * info->mem_unit and set it to 1. This leaves things compatible 2405 * with 2.2.x, and also retains compatibility with earlier 2.4.x 2406 * kernels... 2407 */ 2408 2409 info->mem_unit = 1; 2410 info->totalram <<= bitcount; 2411 info->freeram <<= bitcount; 2412 info->sharedram <<= bitcount; 2413 info->bufferram <<= bitcount; 2414 info->totalswap <<= bitcount; 2415 info->freeswap <<= bitcount; 2416 info->totalhigh <<= bitcount; 2417 info->freehigh <<= bitcount; 2418 2419 out: 2420 return 0; 2421 } 2422 2423 SYSCALL_DEFINE1(sysinfo, struct sysinfo __user *, info) 2424 { 2425 struct sysinfo val; 2426 2427 do_sysinfo(&val); 2428 2429 if (copy_to_user(info, &val, sizeof(struct sysinfo))) 2430 return -EFAULT; 2431 2432 return 0; 2433 } 2434 2435 #ifdef CONFIG_COMPAT 2436 struct compat_sysinfo { 2437 s32 uptime; 2438 u32 loads[3]; 2439 u32 totalram; 2440 u32 freeram; 2441 u32 sharedram; 2442 u32 bufferram; 2443 u32 totalswap; 2444 u32 freeswap; 2445 u16 procs; 2446 u16 pad; 2447 u32 totalhigh; 2448 u32 freehigh; 2449 u32 mem_unit; 2450 char _f[20-2*sizeof(u32)-sizeof(int)]; 2451 }; 2452 2453 COMPAT_SYSCALL_DEFINE1(sysinfo, struct compat_sysinfo __user *, info) 2454 { 2455 struct sysinfo s; 2456 2457 do_sysinfo(&s); 2458 2459 /* Check to see if any memory value is too large for 32-bit and scale 2460 * down if needed 2461 */ 2462 if ((s.totalram >> 32) || (s.totalswap >> 32)) { 2463 int bitcount = 0; 2464 2465 while (s.mem_unit < PAGE_SIZE) { 2466 s.mem_unit <<= 1; 2467 bitcount++; 2468 } 2469 2470 s.totalram >>= bitcount; 2471 s.freeram >>= bitcount; 2472 s.sharedram >>= bitcount; 2473 s.bufferram >>= bitcount; 2474 s.totalswap >>= bitcount; 2475 s.freeswap >>= bitcount; 2476 s.totalhigh >>= bitcount; 2477 s.freehigh >>= bitcount; 2478 } 2479 2480 if (!access_ok(VERIFY_WRITE, info, sizeof(struct compat_sysinfo)) || 2481 __put_user(s.uptime, &info->uptime) || 2482 __put_user(s.loads[0], &info->loads[0]) || 2483 __put_user(s.loads[1], &info->loads[1]) || 2484 __put_user(s.loads[2], &info->loads[2]) || 2485 __put_user(s.totalram, &info->totalram) || 2486 __put_user(s.freeram, &info->freeram) || 2487 __put_user(s.sharedram, &info->sharedram) || 2488 __put_user(s.bufferram, &info->bufferram) || 2489 __put_user(s.totalswap, &info->totalswap) || 2490 __put_user(s.freeswap, &info->freeswap) || 2491 __put_user(s.procs, &info->procs) || 2492 __put_user(s.totalhigh, &info->totalhigh) || 2493 __put_user(s.freehigh, &info->freehigh) || 2494 __put_user(s.mem_unit, &info->mem_unit)) 2495 return -EFAULT; 2496 2497 return 0; 2498 } 2499 #endif /* CONFIG_COMPAT */ 2500