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/workqueue.h> 20 #include <linux/capability.h> 21 #include <linux/device.h> 22 #include <linux/key.h> 23 #include <linux/times.h> 24 #include <linux/posix-timers.h> 25 #include <linux/security.h> 26 #include <linux/dcookies.h> 27 #include <linux/suspend.h> 28 #include <linux/tty.h> 29 #include <linux/signal.h> 30 #include <linux/cn_proc.h> 31 #include <linux/getcpu.h> 32 #include <linux/task_io_accounting_ops.h> 33 #include <linux/seccomp.h> 34 #include <linux/cpu.h> 35 #include <linux/personality.h> 36 #include <linux/ptrace.h> 37 #include <linux/fs_struct.h> 38 #include <linux/file.h> 39 #include <linux/mount.h> 40 #include <linux/gfp.h> 41 #include <linux/syscore_ops.h> 42 #include <linux/version.h> 43 #include <linux/ctype.h> 44 45 #include <linux/compat.h> 46 #include <linux/syscalls.h> 47 #include <linux/kprobes.h> 48 #include <linux/user_namespace.h> 49 #include <linux/binfmts.h> 50 51 #include <linux/sched.h> 52 #include <linux/rcupdate.h> 53 #include <linux/uidgid.h> 54 #include <linux/cred.h> 55 56 #include <linux/kmsg_dump.h> 57 /* Move somewhere else to avoid recompiling? */ 58 #include <generated/utsrelease.h> 59 60 #include <asm/uaccess.h> 61 #include <asm/io.h> 62 #include <asm/unistd.h> 63 64 #ifndef SET_UNALIGN_CTL 65 # define SET_UNALIGN_CTL(a, b) (-EINVAL) 66 #endif 67 #ifndef GET_UNALIGN_CTL 68 # define GET_UNALIGN_CTL(a, b) (-EINVAL) 69 #endif 70 #ifndef SET_FPEMU_CTL 71 # define SET_FPEMU_CTL(a, b) (-EINVAL) 72 #endif 73 #ifndef GET_FPEMU_CTL 74 # define GET_FPEMU_CTL(a, b) (-EINVAL) 75 #endif 76 #ifndef SET_FPEXC_CTL 77 # define SET_FPEXC_CTL(a, b) (-EINVAL) 78 #endif 79 #ifndef GET_FPEXC_CTL 80 # define GET_FPEXC_CTL(a, b) (-EINVAL) 81 #endif 82 #ifndef GET_ENDIAN 83 # define GET_ENDIAN(a, b) (-EINVAL) 84 #endif 85 #ifndef SET_ENDIAN 86 # define SET_ENDIAN(a, b) (-EINVAL) 87 #endif 88 #ifndef GET_TSC_CTL 89 # define GET_TSC_CTL(a) (-EINVAL) 90 #endif 91 #ifndef SET_TSC_CTL 92 # define SET_TSC_CTL(a) (-EINVAL) 93 #endif 94 95 /* 96 * this is where the system-wide overflow UID and GID are defined, for 97 * architectures that now have 32-bit UID/GID but didn't in the past 98 */ 99 100 int overflowuid = DEFAULT_OVERFLOWUID; 101 int overflowgid = DEFAULT_OVERFLOWGID; 102 103 EXPORT_SYMBOL(overflowuid); 104 EXPORT_SYMBOL(overflowgid); 105 106 /* 107 * the same as above, but for filesystems which can only store a 16-bit 108 * UID and GID. as such, this is needed on all architectures 109 */ 110 111 int fs_overflowuid = DEFAULT_FS_OVERFLOWUID; 112 int fs_overflowgid = DEFAULT_FS_OVERFLOWUID; 113 114 EXPORT_SYMBOL(fs_overflowuid); 115 EXPORT_SYMBOL(fs_overflowgid); 116 117 /* 118 * Returns true if current's euid is same as p's uid or euid, 119 * or has CAP_SYS_NICE to p's user_ns. 120 * 121 * Called with rcu_read_lock, creds are safe 122 */ 123 static bool set_one_prio_perm(struct task_struct *p) 124 { 125 const struct cred *cred = current_cred(), *pcred = __task_cred(p); 126 127 if (uid_eq(pcred->uid, cred->euid) || 128 uid_eq(pcred->euid, cred->euid)) 129 return true; 130 if (ns_capable(pcred->user_ns, CAP_SYS_NICE)) 131 return true; 132 return false; 133 } 134 135 /* 136 * set the priority of a task 137 * - the caller must hold the RCU read lock 138 */ 139 static int set_one_prio(struct task_struct *p, int niceval, int error) 140 { 141 int no_nice; 142 143 if (!set_one_prio_perm(p)) { 144 error = -EPERM; 145 goto out; 146 } 147 if (niceval < task_nice(p) && !can_nice(p, niceval)) { 148 error = -EACCES; 149 goto out; 150 } 151 no_nice = security_task_setnice(p, niceval); 152 if (no_nice) { 153 error = no_nice; 154 goto out; 155 } 156 if (error == -ESRCH) 157 error = 0; 158 set_user_nice(p, niceval); 159 out: 160 return error; 161 } 162 163 SYSCALL_DEFINE3(setpriority, int, which, int, who, int, niceval) 164 { 165 struct task_struct *g, *p; 166 struct user_struct *user; 167 const struct cred *cred = current_cred(); 168 int error = -EINVAL; 169 struct pid *pgrp; 170 kuid_t uid; 171 172 if (which > PRIO_USER || which < PRIO_PROCESS) 173 goto out; 174 175 /* normalize: avoid signed division (rounding problems) */ 176 error = -ESRCH; 177 if (niceval < MIN_NICE) 178 niceval = MIN_NICE; 179 if (niceval > MAX_NICE) 180 niceval = MAX_NICE; 181 182 rcu_read_lock(); 183 read_lock(&tasklist_lock); 184 switch (which) { 185 case PRIO_PROCESS: 186 if (who) 187 p = find_task_by_vpid(who); 188 else 189 p = current; 190 if (p) 191 error = set_one_prio(p, niceval, error); 192 break; 193 case PRIO_PGRP: 194 if (who) 195 pgrp = find_vpid(who); 196 else 197 pgrp = task_pgrp(current); 198 do_each_pid_thread(pgrp, PIDTYPE_PGID, p) { 199 error = set_one_prio(p, niceval, error); 200 } while_each_pid_thread(pgrp, PIDTYPE_PGID, p); 201 break; 202 case PRIO_USER: 203 uid = make_kuid(cred->user_ns, who); 204 user = cred->user; 205 if (!who) 206 uid = cred->uid; 207 else if (!uid_eq(uid, cred->uid)) { 208 user = find_user(uid); 209 if (!user) 210 goto out_unlock; /* No processes for this user */ 211 } 212 do_each_thread(g, p) { 213 if (uid_eq(task_uid(p), uid)) 214 error = set_one_prio(p, niceval, error); 215 } while_each_thread(g, p); 216 if (!uid_eq(uid, cred->uid)) 217 free_uid(user); /* For find_user() */ 218 break; 219 } 220 out_unlock: 221 read_unlock(&tasklist_lock); 222 rcu_read_unlock(); 223 out: 224 return error; 225 } 226 227 /* 228 * Ugh. To avoid negative return values, "getpriority()" will 229 * not return the normal nice-value, but a negated value that 230 * has been offset by 20 (ie it returns 40..1 instead of -20..19) 231 * to stay compatible. 232 */ 233 SYSCALL_DEFINE2(getpriority, int, which, int, who) 234 { 235 struct task_struct *g, *p; 236 struct user_struct *user; 237 const struct cred *cred = current_cred(); 238 long niceval, retval = -ESRCH; 239 struct pid *pgrp; 240 kuid_t uid; 241 242 if (which > PRIO_USER || which < PRIO_PROCESS) 243 return -EINVAL; 244 245 rcu_read_lock(); 246 read_lock(&tasklist_lock); 247 switch (which) { 248 case PRIO_PROCESS: 249 if (who) 250 p = find_task_by_vpid(who); 251 else 252 p = current; 253 if (p) { 254 niceval = nice_to_rlimit(task_nice(p)); 255 if (niceval > retval) 256 retval = niceval; 257 } 258 break; 259 case PRIO_PGRP: 260 if (who) 261 pgrp = find_vpid(who); 262 else 263 pgrp = task_pgrp(current); 264 do_each_pid_thread(pgrp, PIDTYPE_PGID, p) { 265 niceval = nice_to_rlimit(task_nice(p)); 266 if (niceval > retval) 267 retval = niceval; 268 } while_each_pid_thread(pgrp, PIDTYPE_PGID, p); 269 break; 270 case PRIO_USER: 271 uid = make_kuid(cred->user_ns, who); 272 user = cred->user; 273 if (!who) 274 uid = cred->uid; 275 else if (!uid_eq(uid, cred->uid)) { 276 user = find_user(uid); 277 if (!user) 278 goto out_unlock; /* No processes for this user */ 279 } 280 do_each_thread(g, p) { 281 if (uid_eq(task_uid(p), uid)) { 282 niceval = nice_to_rlimit(task_nice(p)); 283 if (niceval > retval) 284 retval = niceval; 285 } 286 } while_each_thread(g, p); 287 if (!uid_eq(uid, 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 * Unprivileged users may change the real gid to the effective gid 300 * or vice versa. (BSD-style) 301 * 302 * If you set the real gid at all, or set the effective gid to a value not 303 * equal to the real gid, then the saved gid is set to the new effective gid. 304 * 305 * This makes it possible for a setgid program to completely drop its 306 * privileges, which is often a useful assertion to make when you are doing 307 * a security audit over a program. 308 * 309 * The general idea is that a program which uses just setregid() will be 310 * 100% compatible with BSD. A program which uses just setgid() will be 311 * 100% compatible with POSIX with saved IDs. 312 * 313 * SMP: There are not races, the GIDs are checked only by filesystem 314 * operations (as far as semantic preservation is concerned). 315 */ 316 SYSCALL_DEFINE2(setregid, gid_t, rgid, gid_t, egid) 317 { 318 struct user_namespace *ns = current_user_ns(); 319 const struct cred *old; 320 struct cred *new; 321 int retval; 322 kgid_t krgid, kegid; 323 324 krgid = make_kgid(ns, rgid); 325 kegid = make_kgid(ns, egid); 326 327 if ((rgid != (gid_t) -1) && !gid_valid(krgid)) 328 return -EINVAL; 329 if ((egid != (gid_t) -1) && !gid_valid(kegid)) 330 return -EINVAL; 331 332 new = prepare_creds(); 333 if (!new) 334 return -ENOMEM; 335 old = current_cred(); 336 337 retval = -EPERM; 338 if (rgid != (gid_t) -1) { 339 if (gid_eq(old->gid, krgid) || 340 gid_eq(old->egid, krgid) || 341 ns_capable(old->user_ns, CAP_SETGID)) 342 new->gid = krgid; 343 else 344 goto error; 345 } 346 if (egid != (gid_t) -1) { 347 if (gid_eq(old->gid, kegid) || 348 gid_eq(old->egid, kegid) || 349 gid_eq(old->sgid, kegid) || 350 ns_capable(old->user_ns, CAP_SETGID)) 351 new->egid = kegid; 352 else 353 goto error; 354 } 355 356 if (rgid != (gid_t) -1 || 357 (egid != (gid_t) -1 && !gid_eq(kegid, old->gid))) 358 new->sgid = new->egid; 359 new->fsgid = new->egid; 360 361 return commit_creds(new); 362 363 error: 364 abort_creds(new); 365 return retval; 366 } 367 368 /* 369 * setgid() is implemented like SysV w/ SAVED_IDS 370 * 371 * SMP: Same implicit races as above. 372 */ 373 SYSCALL_DEFINE1(setgid, gid_t, gid) 374 { 375 struct user_namespace *ns = current_user_ns(); 376 const struct cred *old; 377 struct cred *new; 378 int retval; 379 kgid_t kgid; 380 381 kgid = make_kgid(ns, gid); 382 if (!gid_valid(kgid)) 383 return -EINVAL; 384 385 new = prepare_creds(); 386 if (!new) 387 return -ENOMEM; 388 old = current_cred(); 389 390 retval = -EPERM; 391 if (ns_capable(old->user_ns, CAP_SETGID)) 392 new->gid = new->egid = new->sgid = new->fsgid = kgid; 393 else if (gid_eq(kgid, old->gid) || gid_eq(kgid, old->sgid)) 394 new->egid = new->fsgid = kgid; 395 else 396 goto error; 397 398 return commit_creds(new); 399 400 error: 401 abort_creds(new); 402 return retval; 403 } 404 405 /* 406 * change the user struct in a credentials set to match the new UID 407 */ 408 static int set_user(struct cred *new) 409 { 410 struct user_struct *new_user; 411 412 new_user = alloc_uid(new->uid); 413 if (!new_user) 414 return -EAGAIN; 415 416 /* 417 * We don't fail in case of NPROC limit excess here because too many 418 * poorly written programs don't check set*uid() return code, assuming 419 * it never fails if called by root. We may still enforce NPROC limit 420 * for programs doing set*uid()+execve() by harmlessly deferring the 421 * failure to the execve() stage. 422 */ 423 if (atomic_read(&new_user->processes) >= rlimit(RLIMIT_NPROC) && 424 new_user != INIT_USER) 425 current->flags |= PF_NPROC_EXCEEDED; 426 else 427 current->flags &= ~PF_NPROC_EXCEEDED; 428 429 free_uid(new->user); 430 new->user = new_user; 431 return 0; 432 } 433 434 /* 435 * Unprivileged users may change the real uid to the effective uid 436 * or vice versa. (BSD-style) 437 * 438 * If you set the real uid at all, or set the effective uid to a value not 439 * equal to the real uid, then the saved uid is set to the new effective uid. 440 * 441 * This makes it possible for a setuid program to completely drop its 442 * privileges, which is often a useful assertion to make when you are doing 443 * a security audit over a program. 444 * 445 * The general idea is that a program which uses just setreuid() will be 446 * 100% compatible with BSD. A program which uses just setuid() will be 447 * 100% compatible with POSIX with saved IDs. 448 */ 449 SYSCALL_DEFINE2(setreuid, uid_t, ruid, uid_t, euid) 450 { 451 struct user_namespace *ns = current_user_ns(); 452 const struct cred *old; 453 struct cred *new; 454 int retval; 455 kuid_t kruid, keuid; 456 457 kruid = make_kuid(ns, ruid); 458 keuid = make_kuid(ns, euid); 459 460 if ((ruid != (uid_t) -1) && !uid_valid(kruid)) 461 return -EINVAL; 462 if ((euid != (uid_t) -1) && !uid_valid(keuid)) 463 return -EINVAL; 464 465 new = prepare_creds(); 466 if (!new) 467 return -ENOMEM; 468 old = current_cred(); 469 470 retval = -EPERM; 471 if (ruid != (uid_t) -1) { 472 new->uid = kruid; 473 if (!uid_eq(old->uid, kruid) && 474 !uid_eq(old->euid, kruid) && 475 !ns_capable(old->user_ns, CAP_SETUID)) 476 goto error; 477 } 478 479 if (euid != (uid_t) -1) { 480 new->euid = keuid; 481 if (!uid_eq(old->uid, keuid) && 482 !uid_eq(old->euid, keuid) && 483 !uid_eq(old->suid, keuid) && 484 !ns_capable(old->user_ns, CAP_SETUID)) 485 goto error; 486 } 487 488 if (!uid_eq(new->uid, old->uid)) { 489 retval = set_user(new); 490 if (retval < 0) 491 goto error; 492 } 493 if (ruid != (uid_t) -1 || 494 (euid != (uid_t) -1 && !uid_eq(keuid, old->uid))) 495 new->suid = new->euid; 496 new->fsuid = new->euid; 497 498 retval = security_task_fix_setuid(new, old, LSM_SETID_RE); 499 if (retval < 0) 500 goto error; 501 502 return commit_creds(new); 503 504 error: 505 abort_creds(new); 506 return retval; 507 } 508 509 /* 510 * setuid() is implemented like SysV with SAVED_IDS 511 * 512 * Note that SAVED_ID's is deficient in that a setuid root program 513 * like sendmail, for example, cannot set its uid to be a normal 514 * user and then switch back, because if you're root, setuid() sets 515 * the saved uid too. If you don't like this, blame the bright people 516 * in the POSIX committee and/or USG. Note that the BSD-style setreuid() 517 * will allow a root program to temporarily drop privileges and be able to 518 * regain them by swapping the real and effective uid. 519 */ 520 SYSCALL_DEFINE1(setuid, uid_t, uid) 521 { 522 struct user_namespace *ns = current_user_ns(); 523 const struct cred *old; 524 struct cred *new; 525 int retval; 526 kuid_t kuid; 527 528 kuid = make_kuid(ns, uid); 529 if (!uid_valid(kuid)) 530 return -EINVAL; 531 532 new = prepare_creds(); 533 if (!new) 534 return -ENOMEM; 535 old = current_cred(); 536 537 retval = -EPERM; 538 if (ns_capable(old->user_ns, CAP_SETUID)) { 539 new->suid = new->uid = kuid; 540 if (!uid_eq(kuid, old->uid)) { 541 retval = set_user(new); 542 if (retval < 0) 543 goto error; 544 } 545 } else if (!uid_eq(kuid, old->uid) && !uid_eq(kuid, new->suid)) { 546 goto error; 547 } 548 549 new->fsuid = new->euid = kuid; 550 551 retval = security_task_fix_setuid(new, old, LSM_SETID_ID); 552 if (retval < 0) 553 goto error; 554 555 return commit_creds(new); 556 557 error: 558 abort_creds(new); 559 return retval; 560 } 561 562 563 /* 564 * This function implements a generic ability to update ruid, euid, 565 * and suid. This allows you to implement the 4.4 compatible seteuid(). 566 */ 567 SYSCALL_DEFINE3(setresuid, uid_t, ruid, uid_t, euid, uid_t, suid) 568 { 569 struct user_namespace *ns = current_user_ns(); 570 const struct cred *old; 571 struct cred *new; 572 int retval; 573 kuid_t kruid, keuid, ksuid; 574 575 kruid = make_kuid(ns, ruid); 576 keuid = make_kuid(ns, euid); 577 ksuid = make_kuid(ns, suid); 578 579 if ((ruid != (uid_t) -1) && !uid_valid(kruid)) 580 return -EINVAL; 581 582 if ((euid != (uid_t) -1) && !uid_valid(keuid)) 583 return -EINVAL; 584 585 if ((suid != (uid_t) -1) && !uid_valid(ksuid)) 586 return -EINVAL; 587 588 new = prepare_creds(); 589 if (!new) 590 return -ENOMEM; 591 592 old = current_cred(); 593 594 retval = -EPERM; 595 if (!ns_capable(old->user_ns, CAP_SETUID)) { 596 if (ruid != (uid_t) -1 && !uid_eq(kruid, old->uid) && 597 !uid_eq(kruid, old->euid) && !uid_eq(kruid, old->suid)) 598 goto error; 599 if (euid != (uid_t) -1 && !uid_eq(keuid, old->uid) && 600 !uid_eq(keuid, old->euid) && !uid_eq(keuid, old->suid)) 601 goto error; 602 if (suid != (uid_t) -1 && !uid_eq(ksuid, old->uid) && 603 !uid_eq(ksuid, old->euid) && !uid_eq(ksuid, old->suid)) 604 goto error; 605 } 606 607 if (ruid != (uid_t) -1) { 608 new->uid = kruid; 609 if (!uid_eq(kruid, old->uid)) { 610 retval = set_user(new); 611 if (retval < 0) 612 goto error; 613 } 614 } 615 if (euid != (uid_t) -1) 616 new->euid = keuid; 617 if (suid != (uid_t) -1) 618 new->suid = ksuid; 619 new->fsuid = new->euid; 620 621 retval = security_task_fix_setuid(new, old, LSM_SETID_RES); 622 if (retval < 0) 623 goto error; 624 625 return commit_creds(new); 626 627 error: 628 abort_creds(new); 629 return retval; 630 } 631 632 SYSCALL_DEFINE3(getresuid, uid_t __user *, ruidp, uid_t __user *, euidp, uid_t __user *, suidp) 633 { 634 const struct cred *cred = current_cred(); 635 int retval; 636 uid_t ruid, euid, suid; 637 638 ruid = from_kuid_munged(cred->user_ns, cred->uid); 639 euid = from_kuid_munged(cred->user_ns, cred->euid); 640 suid = from_kuid_munged(cred->user_ns, cred->suid); 641 642 retval = put_user(ruid, ruidp); 643 if (!retval) { 644 retval = put_user(euid, euidp); 645 if (!retval) 646 return put_user(suid, suidp); 647 } 648 return retval; 649 } 650 651 /* 652 * Same as above, but for rgid, egid, sgid. 653 */ 654 SYSCALL_DEFINE3(setresgid, gid_t, rgid, gid_t, egid, gid_t, sgid) 655 { 656 struct user_namespace *ns = current_user_ns(); 657 const struct cred *old; 658 struct cred *new; 659 int retval; 660 kgid_t krgid, kegid, ksgid; 661 662 krgid = make_kgid(ns, rgid); 663 kegid = make_kgid(ns, egid); 664 ksgid = make_kgid(ns, sgid); 665 666 if ((rgid != (gid_t) -1) && !gid_valid(krgid)) 667 return -EINVAL; 668 if ((egid != (gid_t) -1) && !gid_valid(kegid)) 669 return -EINVAL; 670 if ((sgid != (gid_t) -1) && !gid_valid(ksgid)) 671 return -EINVAL; 672 673 new = prepare_creds(); 674 if (!new) 675 return -ENOMEM; 676 old = current_cred(); 677 678 retval = -EPERM; 679 if (!ns_capable(old->user_ns, CAP_SETGID)) { 680 if (rgid != (gid_t) -1 && !gid_eq(krgid, old->gid) && 681 !gid_eq(krgid, old->egid) && !gid_eq(krgid, old->sgid)) 682 goto error; 683 if (egid != (gid_t) -1 && !gid_eq(kegid, old->gid) && 684 !gid_eq(kegid, old->egid) && !gid_eq(kegid, old->sgid)) 685 goto error; 686 if (sgid != (gid_t) -1 && !gid_eq(ksgid, old->gid) && 687 !gid_eq(ksgid, old->egid) && !gid_eq(ksgid, old->sgid)) 688 goto error; 689 } 690 691 if (rgid != (gid_t) -1) 692 new->gid = krgid; 693 if (egid != (gid_t) -1) 694 new->egid = kegid; 695 if (sgid != (gid_t) -1) 696 new->sgid = ksgid; 697 new->fsgid = new->egid; 698 699 return commit_creds(new); 700 701 error: 702 abort_creds(new); 703 return retval; 704 } 705 706 SYSCALL_DEFINE3(getresgid, gid_t __user *, rgidp, gid_t __user *, egidp, gid_t __user *, sgidp) 707 { 708 const struct cred *cred = current_cred(); 709 int retval; 710 gid_t rgid, egid, sgid; 711 712 rgid = from_kgid_munged(cred->user_ns, cred->gid); 713 egid = from_kgid_munged(cred->user_ns, cred->egid); 714 sgid = from_kgid_munged(cred->user_ns, cred->sgid); 715 716 retval = put_user(rgid, rgidp); 717 if (!retval) { 718 retval = put_user(egid, egidp); 719 if (!retval) 720 retval = put_user(sgid, sgidp); 721 } 722 723 return retval; 724 } 725 726 727 /* 728 * "setfsuid()" sets the fsuid - the uid used for filesystem checks. This 729 * is used for "access()" and for the NFS daemon (letting nfsd stay at 730 * whatever uid it wants to). It normally shadows "euid", except when 731 * explicitly set by setfsuid() or for access.. 732 */ 733 SYSCALL_DEFINE1(setfsuid, uid_t, uid) 734 { 735 const struct cred *old; 736 struct cred *new; 737 uid_t old_fsuid; 738 kuid_t kuid; 739 740 old = current_cred(); 741 old_fsuid = from_kuid_munged(old->user_ns, old->fsuid); 742 743 kuid = make_kuid(old->user_ns, uid); 744 if (!uid_valid(kuid)) 745 return old_fsuid; 746 747 new = prepare_creds(); 748 if (!new) 749 return old_fsuid; 750 751 if (uid_eq(kuid, old->uid) || uid_eq(kuid, old->euid) || 752 uid_eq(kuid, old->suid) || uid_eq(kuid, old->fsuid) || 753 ns_capable(old->user_ns, CAP_SETUID)) { 754 if (!uid_eq(kuid, old->fsuid)) { 755 new->fsuid = kuid; 756 if (security_task_fix_setuid(new, old, LSM_SETID_FS) == 0) 757 goto change_okay; 758 } 759 } 760 761 abort_creds(new); 762 return old_fsuid; 763 764 change_okay: 765 commit_creds(new); 766 return old_fsuid; 767 } 768 769 /* 770 * Samma på svenska.. 771 */ 772 SYSCALL_DEFINE1(setfsgid, gid_t, gid) 773 { 774 const struct cred *old; 775 struct cred *new; 776 gid_t old_fsgid; 777 kgid_t kgid; 778 779 old = current_cred(); 780 old_fsgid = from_kgid_munged(old->user_ns, old->fsgid); 781 782 kgid = make_kgid(old->user_ns, gid); 783 if (!gid_valid(kgid)) 784 return old_fsgid; 785 786 new = prepare_creds(); 787 if (!new) 788 return old_fsgid; 789 790 if (gid_eq(kgid, old->gid) || gid_eq(kgid, old->egid) || 791 gid_eq(kgid, old->sgid) || gid_eq(kgid, old->fsgid) || 792 ns_capable(old->user_ns, CAP_SETGID)) { 793 if (!gid_eq(kgid, old->fsgid)) { 794 new->fsgid = kgid; 795 goto change_okay; 796 } 797 } 798 799 abort_creds(new); 800 return old_fsgid; 801 802 change_okay: 803 commit_creds(new); 804 return old_fsgid; 805 } 806 807 /** 808 * sys_getpid - return the thread group id of the current process 809 * 810 * Note, despite the name, this returns the tgid not the pid. The tgid and 811 * the pid are identical unless CLONE_THREAD was specified on clone() in 812 * which case the tgid is the same in all threads of the same group. 813 * 814 * This is SMP safe as current->tgid does not change. 815 */ 816 SYSCALL_DEFINE0(getpid) 817 { 818 return task_tgid_vnr(current); 819 } 820 821 /* Thread ID - the internal kernel "pid" */ 822 SYSCALL_DEFINE0(gettid) 823 { 824 return task_pid_vnr(current); 825 } 826 827 /* 828 * Accessing ->real_parent is not SMP-safe, it could 829 * change from under us. However, we can use a stale 830 * value of ->real_parent under rcu_read_lock(), see 831 * release_task()->call_rcu(delayed_put_task_struct). 832 */ 833 SYSCALL_DEFINE0(getppid) 834 { 835 int pid; 836 837 rcu_read_lock(); 838 pid = task_tgid_vnr(rcu_dereference(current->real_parent)); 839 rcu_read_unlock(); 840 841 return pid; 842 } 843 844 SYSCALL_DEFINE0(getuid) 845 { 846 /* Only we change this so SMP safe */ 847 return from_kuid_munged(current_user_ns(), current_uid()); 848 } 849 850 SYSCALL_DEFINE0(geteuid) 851 { 852 /* Only we change this so SMP safe */ 853 return from_kuid_munged(current_user_ns(), current_euid()); 854 } 855 856 SYSCALL_DEFINE0(getgid) 857 { 858 /* Only we change this so SMP safe */ 859 return from_kgid_munged(current_user_ns(), current_gid()); 860 } 861 862 SYSCALL_DEFINE0(getegid) 863 { 864 /* Only we change this so SMP safe */ 865 return from_kgid_munged(current_user_ns(), current_egid()); 866 } 867 868 void do_sys_times(struct tms *tms) 869 { 870 cputime_t tgutime, tgstime, cutime, cstime; 871 872 thread_group_cputime_adjusted(current, &tgutime, &tgstime); 873 cutime = current->signal->cutime; 874 cstime = current->signal->cstime; 875 tms->tms_utime = cputime_to_clock_t(tgutime); 876 tms->tms_stime = cputime_to_clock_t(tgstime); 877 tms->tms_cutime = cputime_to_clock_t(cutime); 878 tms->tms_cstime = cputime_to_clock_t(cstime); 879 } 880 881 SYSCALL_DEFINE1(times, struct tms __user *, tbuf) 882 { 883 if (tbuf) { 884 struct tms tmp; 885 886 do_sys_times(&tmp); 887 if (copy_to_user(tbuf, &tmp, sizeof(struct tms))) 888 return -EFAULT; 889 } 890 force_successful_syscall_return(); 891 return (long) jiffies_64_to_clock_t(get_jiffies_64()); 892 } 893 894 /* 895 * This needs some heavy checking ... 896 * I just haven't the stomach for it. I also don't fully 897 * understand sessions/pgrp etc. Let somebody who does explain it. 898 * 899 * OK, I think I have the protection semantics right.... this is really 900 * only important on a multi-user system anyway, to make sure one user 901 * can't send a signal to a process owned by another. -TYT, 12/12/91 902 * 903 * !PF_FORKNOEXEC check to conform completely to POSIX. 904 */ 905 SYSCALL_DEFINE2(setpgid, pid_t, pid, pid_t, pgid) 906 { 907 struct task_struct *p; 908 struct task_struct *group_leader = current->group_leader; 909 struct pid *pgrp; 910 int err; 911 912 if (!pid) 913 pid = task_pid_vnr(group_leader); 914 if (!pgid) 915 pgid = pid; 916 if (pgid < 0) 917 return -EINVAL; 918 rcu_read_lock(); 919 920 /* From this point forward we keep holding onto the tasklist lock 921 * so that our parent does not change from under us. -DaveM 922 */ 923 write_lock_irq(&tasklist_lock); 924 925 err = -ESRCH; 926 p = find_task_by_vpid(pid); 927 if (!p) 928 goto out; 929 930 err = -EINVAL; 931 if (!thread_group_leader(p)) 932 goto out; 933 934 if (same_thread_group(p->real_parent, group_leader)) { 935 err = -EPERM; 936 if (task_session(p) != task_session(group_leader)) 937 goto out; 938 err = -EACCES; 939 if (!(p->flags & PF_FORKNOEXEC)) 940 goto out; 941 } else { 942 err = -ESRCH; 943 if (p != group_leader) 944 goto out; 945 } 946 947 err = -EPERM; 948 if (p->signal->leader) 949 goto out; 950 951 pgrp = task_pid(p); 952 if (pgid != pid) { 953 struct task_struct *g; 954 955 pgrp = find_vpid(pgid); 956 g = pid_task(pgrp, PIDTYPE_PGID); 957 if (!g || task_session(g) != task_session(group_leader)) 958 goto out; 959 } 960 961 err = security_task_setpgid(p, pgid); 962 if (err) 963 goto out; 964 965 if (task_pgrp(p) != pgrp) 966 change_pid(p, PIDTYPE_PGID, pgrp); 967 968 err = 0; 969 out: 970 /* All paths lead to here, thus we are safe. -DaveM */ 971 write_unlock_irq(&tasklist_lock); 972 rcu_read_unlock(); 973 return err; 974 } 975 976 SYSCALL_DEFINE1(getpgid, pid_t, pid) 977 { 978 struct task_struct *p; 979 struct pid *grp; 980 int retval; 981 982 rcu_read_lock(); 983 if (!pid) 984 grp = task_pgrp(current); 985 else { 986 retval = -ESRCH; 987 p = find_task_by_vpid(pid); 988 if (!p) 989 goto out; 990 grp = task_pgrp(p); 991 if (!grp) 992 goto out; 993 994 retval = security_task_getpgid(p); 995 if (retval) 996 goto out; 997 } 998 retval = pid_vnr(grp); 999 out: 1000 rcu_read_unlock(); 1001 return retval; 1002 } 1003 1004 #ifdef __ARCH_WANT_SYS_GETPGRP 1005 1006 SYSCALL_DEFINE0(getpgrp) 1007 { 1008 return sys_getpgid(0); 1009 } 1010 1011 #endif 1012 1013 SYSCALL_DEFINE1(getsid, pid_t, pid) 1014 { 1015 struct task_struct *p; 1016 struct pid *sid; 1017 int retval; 1018 1019 rcu_read_lock(); 1020 if (!pid) 1021 sid = task_session(current); 1022 else { 1023 retval = -ESRCH; 1024 p = find_task_by_vpid(pid); 1025 if (!p) 1026 goto out; 1027 sid = task_session(p); 1028 if (!sid) 1029 goto out; 1030 1031 retval = security_task_getsid(p); 1032 if (retval) 1033 goto out; 1034 } 1035 retval = pid_vnr(sid); 1036 out: 1037 rcu_read_unlock(); 1038 return retval; 1039 } 1040 1041 static void set_special_pids(struct pid *pid) 1042 { 1043 struct task_struct *curr = current->group_leader; 1044 1045 if (task_session(curr) != pid) 1046 change_pid(curr, PIDTYPE_SID, pid); 1047 1048 if (task_pgrp(curr) != pid) 1049 change_pid(curr, PIDTYPE_PGID, pid); 1050 } 1051 1052 SYSCALL_DEFINE0(setsid) 1053 { 1054 struct task_struct *group_leader = current->group_leader; 1055 struct pid *sid = task_pid(group_leader); 1056 pid_t session = pid_vnr(sid); 1057 int err = -EPERM; 1058 1059 write_lock_irq(&tasklist_lock); 1060 /* Fail if I am already a session leader */ 1061 if (group_leader->signal->leader) 1062 goto out; 1063 1064 /* Fail if a process group id already exists that equals the 1065 * proposed session id. 1066 */ 1067 if (pid_task(sid, PIDTYPE_PGID)) 1068 goto out; 1069 1070 group_leader->signal->leader = 1; 1071 set_special_pids(sid); 1072 1073 proc_clear_tty(group_leader); 1074 1075 err = session; 1076 out: 1077 write_unlock_irq(&tasklist_lock); 1078 if (err > 0) { 1079 proc_sid_connector(group_leader); 1080 sched_autogroup_create_attach(group_leader); 1081 } 1082 return err; 1083 } 1084 1085 DECLARE_RWSEM(uts_sem); 1086 1087 #ifdef COMPAT_UTS_MACHINE 1088 #define override_architecture(name) \ 1089 (personality(current->personality) == PER_LINUX32 && \ 1090 copy_to_user(name->machine, COMPAT_UTS_MACHINE, \ 1091 sizeof(COMPAT_UTS_MACHINE))) 1092 #else 1093 #define override_architecture(name) 0 1094 #endif 1095 1096 /* 1097 * Work around broken programs that cannot handle "Linux 3.0". 1098 * Instead we map 3.x to 2.6.40+x, so e.g. 3.0 would be 2.6.40 1099 */ 1100 static int override_release(char __user *release, size_t len) 1101 { 1102 int ret = 0; 1103 1104 if (current->personality & UNAME26) { 1105 const char *rest = UTS_RELEASE; 1106 char buf[65] = { 0 }; 1107 int ndots = 0; 1108 unsigned v; 1109 size_t copy; 1110 1111 while (*rest) { 1112 if (*rest == '.' && ++ndots >= 3) 1113 break; 1114 if (!isdigit(*rest) && *rest != '.') 1115 break; 1116 rest++; 1117 } 1118 v = ((LINUX_VERSION_CODE >> 8) & 0xff) + 40; 1119 copy = clamp_t(size_t, len, 1, sizeof(buf)); 1120 copy = scnprintf(buf, copy, "2.6.%u%s", v, rest); 1121 ret = copy_to_user(release, buf, copy + 1); 1122 } 1123 return ret; 1124 } 1125 1126 SYSCALL_DEFINE1(newuname, struct new_utsname __user *, name) 1127 { 1128 int errno = 0; 1129 1130 down_read(&uts_sem); 1131 if (copy_to_user(name, utsname(), sizeof *name)) 1132 errno = -EFAULT; 1133 up_read(&uts_sem); 1134 1135 if (!errno && override_release(name->release, sizeof(name->release))) 1136 errno = -EFAULT; 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_release(name->release, sizeof(name->release))) 1159 error = -EFAULT; 1160 if (!error && override_architecture(name)) 1161 error = -EFAULT; 1162 return error; 1163 } 1164 1165 SYSCALL_DEFINE1(olduname, struct oldold_utsname __user *, name) 1166 { 1167 int error; 1168 1169 if (!name) 1170 return -EFAULT; 1171 if (!access_ok(VERIFY_WRITE, name, sizeof(struct oldold_utsname))) 1172 return -EFAULT; 1173 1174 down_read(&uts_sem); 1175 error = __copy_to_user(&name->sysname, &utsname()->sysname, 1176 __OLD_UTS_LEN); 1177 error |= __put_user(0, name->sysname + __OLD_UTS_LEN); 1178 error |= __copy_to_user(&name->nodename, &utsname()->nodename, 1179 __OLD_UTS_LEN); 1180 error |= __put_user(0, name->nodename + __OLD_UTS_LEN); 1181 error |= __copy_to_user(&name->release, &utsname()->release, 1182 __OLD_UTS_LEN); 1183 error |= __put_user(0, name->release + __OLD_UTS_LEN); 1184 error |= __copy_to_user(&name->version, &utsname()->version, 1185 __OLD_UTS_LEN); 1186 error |= __put_user(0, name->version + __OLD_UTS_LEN); 1187 error |= __copy_to_user(&name->machine, &utsname()->machine, 1188 __OLD_UTS_LEN); 1189 error |= __put_user(0, name->machine + __OLD_UTS_LEN); 1190 up_read(&uts_sem); 1191 1192 if (!error && override_architecture(name)) 1193 error = -EFAULT; 1194 if (!error && override_release(name->release, sizeof(name->release))) 1195 error = -EFAULT; 1196 return error ? -EFAULT : 0; 1197 } 1198 #endif 1199 1200 SYSCALL_DEFINE2(sethostname, char __user *, name, int, len) 1201 { 1202 int errno; 1203 char tmp[__NEW_UTS_LEN]; 1204 1205 if (!ns_capable(current->nsproxy->uts_ns->user_ns, CAP_SYS_ADMIN)) 1206 return -EPERM; 1207 1208 if (len < 0 || len > __NEW_UTS_LEN) 1209 return -EINVAL; 1210 down_write(&uts_sem); 1211 errno = -EFAULT; 1212 if (!copy_from_user(tmp, name, len)) { 1213 struct new_utsname *u = utsname(); 1214 1215 memcpy(u->nodename, tmp, len); 1216 memset(u->nodename + len, 0, sizeof(u->nodename) - len); 1217 errno = 0; 1218 uts_proc_notify(UTS_PROC_HOSTNAME); 1219 } 1220 up_write(&uts_sem); 1221 return errno; 1222 } 1223 1224 #ifdef __ARCH_WANT_SYS_GETHOSTNAME 1225 1226 SYSCALL_DEFINE2(gethostname, char __user *, name, int, len) 1227 { 1228 int i, errno; 1229 struct new_utsname *u; 1230 1231 if (len < 0) 1232 return -EINVAL; 1233 down_read(&uts_sem); 1234 u = utsname(); 1235 i = 1 + strlen(u->nodename); 1236 if (i > len) 1237 i = len; 1238 errno = 0; 1239 if (copy_to_user(name, u->nodename, i)) 1240 errno = -EFAULT; 1241 up_read(&uts_sem); 1242 return errno; 1243 } 1244 1245 #endif 1246 1247 /* 1248 * Only setdomainname; getdomainname can be implemented by calling 1249 * uname() 1250 */ 1251 SYSCALL_DEFINE2(setdomainname, char __user *, name, int, len) 1252 { 1253 int errno; 1254 char tmp[__NEW_UTS_LEN]; 1255 1256 if (!ns_capable(current->nsproxy->uts_ns->user_ns, CAP_SYS_ADMIN)) 1257 return -EPERM; 1258 if (len < 0 || len > __NEW_UTS_LEN) 1259 return -EINVAL; 1260 1261 down_write(&uts_sem); 1262 errno = -EFAULT; 1263 if (!copy_from_user(tmp, name, len)) { 1264 struct new_utsname *u = utsname(); 1265 1266 memcpy(u->domainname, tmp, len); 1267 memset(u->domainname + len, 0, sizeof(u->domainname) - len); 1268 errno = 0; 1269 uts_proc_notify(UTS_PROC_DOMAINNAME); 1270 } 1271 up_write(&uts_sem); 1272 return errno; 1273 } 1274 1275 SYSCALL_DEFINE2(getrlimit, unsigned int, resource, struct rlimit __user *, rlim) 1276 { 1277 struct rlimit value; 1278 int ret; 1279 1280 ret = do_prlimit(current, resource, NULL, &value); 1281 if (!ret) 1282 ret = copy_to_user(rlim, &value, sizeof(*rlim)) ? -EFAULT : 0; 1283 1284 return ret; 1285 } 1286 1287 #ifdef __ARCH_WANT_SYS_OLD_GETRLIMIT 1288 1289 /* 1290 * Back compatibility for getrlimit. Needed for some apps. 1291 */ 1292 SYSCALL_DEFINE2(old_getrlimit, unsigned int, resource, 1293 struct rlimit __user *, rlim) 1294 { 1295 struct rlimit x; 1296 if (resource >= RLIM_NLIMITS) 1297 return -EINVAL; 1298 1299 task_lock(current->group_leader); 1300 x = current->signal->rlim[resource]; 1301 task_unlock(current->group_leader); 1302 if (x.rlim_cur > 0x7FFFFFFF) 1303 x.rlim_cur = 0x7FFFFFFF; 1304 if (x.rlim_max > 0x7FFFFFFF) 1305 x.rlim_max = 0x7FFFFFFF; 1306 return copy_to_user(rlim, &x, sizeof(x)) ? -EFAULT : 0; 1307 } 1308 1309 #endif 1310 1311 static inline bool rlim64_is_infinity(__u64 rlim64) 1312 { 1313 #if BITS_PER_LONG < 64 1314 return rlim64 >= ULONG_MAX; 1315 #else 1316 return rlim64 == RLIM64_INFINITY; 1317 #endif 1318 } 1319 1320 static void rlim_to_rlim64(const struct rlimit *rlim, struct rlimit64 *rlim64) 1321 { 1322 if (rlim->rlim_cur == RLIM_INFINITY) 1323 rlim64->rlim_cur = RLIM64_INFINITY; 1324 else 1325 rlim64->rlim_cur = rlim->rlim_cur; 1326 if (rlim->rlim_max == RLIM_INFINITY) 1327 rlim64->rlim_max = RLIM64_INFINITY; 1328 else 1329 rlim64->rlim_max = rlim->rlim_max; 1330 } 1331 1332 static void rlim64_to_rlim(const struct rlimit64 *rlim64, struct rlimit *rlim) 1333 { 1334 if (rlim64_is_infinity(rlim64->rlim_cur)) 1335 rlim->rlim_cur = RLIM_INFINITY; 1336 else 1337 rlim->rlim_cur = (unsigned long)rlim64->rlim_cur; 1338 if (rlim64_is_infinity(rlim64->rlim_max)) 1339 rlim->rlim_max = RLIM_INFINITY; 1340 else 1341 rlim->rlim_max = (unsigned long)rlim64->rlim_max; 1342 } 1343 1344 /* make sure you are allowed to change @tsk limits before calling this */ 1345 int do_prlimit(struct task_struct *tsk, unsigned int resource, 1346 struct rlimit *new_rlim, struct rlimit *old_rlim) 1347 { 1348 struct rlimit *rlim; 1349 int retval = 0; 1350 1351 if (resource >= RLIM_NLIMITS) 1352 return -EINVAL; 1353 if (new_rlim) { 1354 if (new_rlim->rlim_cur > new_rlim->rlim_max) 1355 return -EINVAL; 1356 if (resource == RLIMIT_NOFILE && 1357 new_rlim->rlim_max > sysctl_nr_open) 1358 return -EPERM; 1359 } 1360 1361 /* protect tsk->signal and tsk->sighand from disappearing */ 1362 read_lock(&tasklist_lock); 1363 if (!tsk->sighand) { 1364 retval = -ESRCH; 1365 goto out; 1366 } 1367 1368 rlim = tsk->signal->rlim + resource; 1369 task_lock(tsk->group_leader); 1370 if (new_rlim) { 1371 /* Keep the capable check against init_user_ns until 1372 cgroups can contain all limits */ 1373 if (new_rlim->rlim_max > rlim->rlim_max && 1374 !capable(CAP_SYS_RESOURCE)) 1375 retval = -EPERM; 1376 if (!retval) 1377 retval = security_task_setrlimit(tsk->group_leader, 1378 resource, new_rlim); 1379 if (resource == RLIMIT_CPU && new_rlim->rlim_cur == 0) { 1380 /* 1381 * The caller is asking for an immediate RLIMIT_CPU 1382 * expiry. But we use the zero value to mean "it was 1383 * never set". So let's cheat and make it one second 1384 * instead 1385 */ 1386 new_rlim->rlim_cur = 1; 1387 } 1388 } 1389 if (!retval) { 1390 if (old_rlim) 1391 *old_rlim = *rlim; 1392 if (new_rlim) 1393 *rlim = *new_rlim; 1394 } 1395 task_unlock(tsk->group_leader); 1396 1397 /* 1398 * RLIMIT_CPU handling. Note that the kernel fails to return an error 1399 * code if it rejected the user's attempt to set RLIMIT_CPU. This is a 1400 * very long-standing error, and fixing it now risks breakage of 1401 * applications, so we live with it 1402 */ 1403 if (!retval && new_rlim && resource == RLIMIT_CPU && 1404 new_rlim->rlim_cur != RLIM_INFINITY) 1405 update_rlimit_cpu(tsk, new_rlim->rlim_cur); 1406 out: 1407 read_unlock(&tasklist_lock); 1408 return retval; 1409 } 1410 1411 /* rcu lock must be held */ 1412 static int check_prlimit_permission(struct task_struct *task) 1413 { 1414 const struct cred *cred = current_cred(), *tcred; 1415 1416 if (current == task) 1417 return 0; 1418 1419 tcred = __task_cred(task); 1420 if (uid_eq(cred->uid, tcred->euid) && 1421 uid_eq(cred->uid, tcred->suid) && 1422 uid_eq(cred->uid, tcred->uid) && 1423 gid_eq(cred->gid, tcred->egid) && 1424 gid_eq(cred->gid, tcred->sgid) && 1425 gid_eq(cred->gid, tcred->gid)) 1426 return 0; 1427 if (ns_capable(tcred->user_ns, CAP_SYS_RESOURCE)) 1428 return 0; 1429 1430 return -EPERM; 1431 } 1432 1433 SYSCALL_DEFINE4(prlimit64, pid_t, pid, unsigned int, resource, 1434 const struct rlimit64 __user *, new_rlim, 1435 struct rlimit64 __user *, old_rlim) 1436 { 1437 struct rlimit64 old64, new64; 1438 struct rlimit old, new; 1439 struct task_struct *tsk; 1440 int ret; 1441 1442 if (new_rlim) { 1443 if (copy_from_user(&new64, new_rlim, sizeof(new64))) 1444 return -EFAULT; 1445 rlim64_to_rlim(&new64, &new); 1446 } 1447 1448 rcu_read_lock(); 1449 tsk = pid ? find_task_by_vpid(pid) : current; 1450 if (!tsk) { 1451 rcu_read_unlock(); 1452 return -ESRCH; 1453 } 1454 ret = check_prlimit_permission(tsk); 1455 if (ret) { 1456 rcu_read_unlock(); 1457 return ret; 1458 } 1459 get_task_struct(tsk); 1460 rcu_read_unlock(); 1461 1462 ret = do_prlimit(tsk, resource, new_rlim ? &new : NULL, 1463 old_rlim ? &old : NULL); 1464 1465 if (!ret && old_rlim) { 1466 rlim_to_rlim64(&old, &old64); 1467 if (copy_to_user(old_rlim, &old64, sizeof(old64))) 1468 ret = -EFAULT; 1469 } 1470 1471 put_task_struct(tsk); 1472 return ret; 1473 } 1474 1475 SYSCALL_DEFINE2(setrlimit, unsigned int, resource, struct rlimit __user *, rlim) 1476 { 1477 struct rlimit new_rlim; 1478 1479 if (copy_from_user(&new_rlim, rlim, sizeof(*rlim))) 1480 return -EFAULT; 1481 return do_prlimit(current, resource, &new_rlim, NULL); 1482 } 1483 1484 /* 1485 * It would make sense to put struct rusage in the task_struct, 1486 * except that would make the task_struct be *really big*. After 1487 * task_struct gets moved into malloc'ed memory, it would 1488 * make sense to do this. It will make moving the rest of the information 1489 * a lot simpler! (Which we're not doing right now because we're not 1490 * measuring them yet). 1491 * 1492 * When sampling multiple threads for RUSAGE_SELF, under SMP we might have 1493 * races with threads incrementing their own counters. But since word 1494 * reads are atomic, we either get new values or old values and we don't 1495 * care which for the sums. We always take the siglock to protect reading 1496 * the c* fields from p->signal from races with exit.c updating those 1497 * fields when reaping, so a sample either gets all the additions of a 1498 * given child after it's reaped, or none so this sample is before reaping. 1499 * 1500 * Locking: 1501 * We need to take the siglock for CHILDEREN, SELF and BOTH 1502 * for the cases current multithreaded, non-current single threaded 1503 * non-current multithreaded. Thread traversal is now safe with 1504 * the siglock held. 1505 * Strictly speaking, we donot need to take the siglock if we are current and 1506 * single threaded, as no one else can take our signal_struct away, no one 1507 * else can reap the children to update signal->c* counters, and no one else 1508 * can race with the signal-> fields. If we do not take any lock, the 1509 * signal-> fields could be read out of order while another thread was just 1510 * exiting. So we should place a read memory barrier when we avoid the lock. 1511 * On the writer side, write memory barrier is implied in __exit_signal 1512 * as __exit_signal releases the siglock spinlock after updating the signal-> 1513 * fields. But we don't do this yet to keep things simple. 1514 * 1515 */ 1516 1517 static void accumulate_thread_rusage(struct task_struct *t, struct rusage *r) 1518 { 1519 r->ru_nvcsw += t->nvcsw; 1520 r->ru_nivcsw += t->nivcsw; 1521 r->ru_minflt += t->min_flt; 1522 r->ru_majflt += t->maj_flt; 1523 r->ru_inblock += task_io_get_inblock(t); 1524 r->ru_oublock += task_io_get_oublock(t); 1525 } 1526 1527 static void k_getrusage(struct task_struct *p, int who, struct rusage *r) 1528 { 1529 struct task_struct *t; 1530 unsigned long flags; 1531 cputime_t tgutime, tgstime, utime, stime; 1532 unsigned long maxrss = 0; 1533 1534 memset((char *)r, 0, sizeof (*r)); 1535 utime = stime = 0; 1536 1537 if (who == RUSAGE_THREAD) { 1538 task_cputime_adjusted(current, &utime, &stime); 1539 accumulate_thread_rusage(p, r); 1540 maxrss = p->signal->maxrss; 1541 goto out; 1542 } 1543 1544 if (!lock_task_sighand(p, &flags)) 1545 return; 1546 1547 switch (who) { 1548 case RUSAGE_BOTH: 1549 case RUSAGE_CHILDREN: 1550 utime = p->signal->cutime; 1551 stime = p->signal->cstime; 1552 r->ru_nvcsw = p->signal->cnvcsw; 1553 r->ru_nivcsw = p->signal->cnivcsw; 1554 r->ru_minflt = p->signal->cmin_flt; 1555 r->ru_majflt = p->signal->cmaj_flt; 1556 r->ru_inblock = p->signal->cinblock; 1557 r->ru_oublock = p->signal->coublock; 1558 maxrss = p->signal->cmaxrss; 1559 1560 if (who == RUSAGE_CHILDREN) 1561 break; 1562 1563 case RUSAGE_SELF: 1564 thread_group_cputime_adjusted(p, &tgutime, &tgstime); 1565 utime += tgutime; 1566 stime += tgstime; 1567 r->ru_nvcsw += p->signal->nvcsw; 1568 r->ru_nivcsw += p->signal->nivcsw; 1569 r->ru_minflt += p->signal->min_flt; 1570 r->ru_majflt += p->signal->maj_flt; 1571 r->ru_inblock += p->signal->inblock; 1572 r->ru_oublock += p->signal->oublock; 1573 if (maxrss < p->signal->maxrss) 1574 maxrss = p->signal->maxrss; 1575 t = p; 1576 do { 1577 accumulate_thread_rusage(t, r); 1578 } while_each_thread(p, t); 1579 break; 1580 1581 default: 1582 BUG(); 1583 } 1584 unlock_task_sighand(p, &flags); 1585 1586 out: 1587 cputime_to_timeval(utime, &r->ru_utime); 1588 cputime_to_timeval(stime, &r->ru_stime); 1589 1590 if (who != RUSAGE_CHILDREN) { 1591 struct mm_struct *mm = get_task_mm(p); 1592 1593 if (mm) { 1594 setmax_mm_hiwater_rss(&maxrss, mm); 1595 mmput(mm); 1596 } 1597 } 1598 r->ru_maxrss = maxrss * (PAGE_SIZE / 1024); /* convert pages to KBs */ 1599 } 1600 1601 int getrusage(struct task_struct *p, int who, struct rusage __user *ru) 1602 { 1603 struct rusage r; 1604 1605 k_getrusage(p, who, &r); 1606 return copy_to_user(ru, &r, sizeof(r)) ? -EFAULT : 0; 1607 } 1608 1609 SYSCALL_DEFINE2(getrusage, int, who, struct rusage __user *, ru) 1610 { 1611 if (who != RUSAGE_SELF && who != RUSAGE_CHILDREN && 1612 who != RUSAGE_THREAD) 1613 return -EINVAL; 1614 return getrusage(current, who, ru); 1615 } 1616 1617 #ifdef CONFIG_COMPAT 1618 COMPAT_SYSCALL_DEFINE2(getrusage, int, who, struct compat_rusage __user *, ru) 1619 { 1620 struct rusage r; 1621 1622 if (who != RUSAGE_SELF && who != RUSAGE_CHILDREN && 1623 who != RUSAGE_THREAD) 1624 return -EINVAL; 1625 1626 k_getrusage(current, who, &r); 1627 return put_compat_rusage(&r, ru); 1628 } 1629 #endif 1630 1631 SYSCALL_DEFINE1(umask, int, mask) 1632 { 1633 mask = xchg(¤t->fs->umask, mask & S_IRWXUGO); 1634 return mask; 1635 } 1636 1637 static int prctl_set_mm_exe_file_locked(struct mm_struct *mm, unsigned int fd) 1638 { 1639 struct fd exe; 1640 struct inode *inode; 1641 int err; 1642 1643 VM_BUG_ON_MM(!rwsem_is_locked(&mm->mmap_sem), mm); 1644 1645 exe = fdget(fd); 1646 if (!exe.file) 1647 return -EBADF; 1648 1649 inode = file_inode(exe.file); 1650 1651 /* 1652 * Because the original mm->exe_file points to executable file, make 1653 * sure that this one is executable as well, to avoid breaking an 1654 * overall picture. 1655 */ 1656 err = -EACCES; 1657 if (!S_ISREG(inode->i_mode) || 1658 exe.file->f_path.mnt->mnt_flags & MNT_NOEXEC) 1659 goto exit; 1660 1661 err = inode_permission(inode, MAY_EXEC); 1662 if (err) 1663 goto exit; 1664 1665 /* 1666 * Forbid mm->exe_file change if old file still mapped. 1667 */ 1668 err = -EBUSY; 1669 if (mm->exe_file) { 1670 struct vm_area_struct *vma; 1671 1672 for (vma = mm->mmap; vma; vma = vma->vm_next) 1673 if (vma->vm_file && 1674 path_equal(&vma->vm_file->f_path, 1675 &mm->exe_file->f_path)) 1676 goto exit; 1677 } 1678 1679 /* 1680 * The symlink can be changed only once, just to disallow arbitrary 1681 * transitions malicious software might bring in. This means one 1682 * could make a snapshot over all processes running and monitor 1683 * /proc/pid/exe changes to notice unusual activity if needed. 1684 */ 1685 err = -EPERM; 1686 if (test_and_set_bit(MMF_EXE_FILE_CHANGED, &mm->flags)) 1687 goto exit; 1688 1689 err = 0; 1690 set_mm_exe_file(mm, exe.file); /* this grabs a reference to exe.file */ 1691 exit: 1692 fdput(exe); 1693 return err; 1694 } 1695 1696 #ifdef CONFIG_CHECKPOINT_RESTORE 1697 /* 1698 * WARNING: we don't require any capability here so be very careful 1699 * in what is allowed for modification from userspace. 1700 */ 1701 static int validate_prctl_map(struct prctl_mm_map *prctl_map) 1702 { 1703 unsigned long mmap_max_addr = TASK_SIZE; 1704 struct mm_struct *mm = current->mm; 1705 int error = -EINVAL, i; 1706 1707 static const unsigned char offsets[] = { 1708 offsetof(struct prctl_mm_map, start_code), 1709 offsetof(struct prctl_mm_map, end_code), 1710 offsetof(struct prctl_mm_map, start_data), 1711 offsetof(struct prctl_mm_map, end_data), 1712 offsetof(struct prctl_mm_map, start_brk), 1713 offsetof(struct prctl_mm_map, brk), 1714 offsetof(struct prctl_mm_map, start_stack), 1715 offsetof(struct prctl_mm_map, arg_start), 1716 offsetof(struct prctl_mm_map, arg_end), 1717 offsetof(struct prctl_mm_map, env_start), 1718 offsetof(struct prctl_mm_map, env_end), 1719 }; 1720 1721 /* 1722 * Make sure the members are not somewhere outside 1723 * of allowed address space. 1724 */ 1725 for (i = 0; i < ARRAY_SIZE(offsets); i++) { 1726 u64 val = *(u64 *)((char *)prctl_map + offsets[i]); 1727 1728 if ((unsigned long)val >= mmap_max_addr || 1729 (unsigned long)val < mmap_min_addr) 1730 goto out; 1731 } 1732 1733 /* 1734 * Make sure the pairs are ordered. 1735 */ 1736 #define __prctl_check_order(__m1, __op, __m2) \ 1737 ((unsigned long)prctl_map->__m1 __op \ 1738 (unsigned long)prctl_map->__m2) ? 0 : -EINVAL 1739 error = __prctl_check_order(start_code, <, end_code); 1740 error |= __prctl_check_order(start_data, <, end_data); 1741 error |= __prctl_check_order(start_brk, <=, brk); 1742 error |= __prctl_check_order(arg_start, <=, arg_end); 1743 error |= __prctl_check_order(env_start, <=, env_end); 1744 if (error) 1745 goto out; 1746 #undef __prctl_check_order 1747 1748 error = -EINVAL; 1749 1750 /* 1751 * @brk should be after @end_data in traditional maps. 1752 */ 1753 if (prctl_map->start_brk <= prctl_map->end_data || 1754 prctl_map->brk <= prctl_map->end_data) 1755 goto out; 1756 1757 /* 1758 * Neither we should allow to override limits if they set. 1759 */ 1760 if (check_data_rlimit(rlimit(RLIMIT_DATA), prctl_map->brk, 1761 prctl_map->start_brk, prctl_map->end_data, 1762 prctl_map->start_data)) 1763 goto out; 1764 1765 /* 1766 * Someone is trying to cheat the auxv vector. 1767 */ 1768 if (prctl_map->auxv_size) { 1769 if (!prctl_map->auxv || prctl_map->auxv_size > sizeof(mm->saved_auxv)) 1770 goto out; 1771 } 1772 1773 /* 1774 * Finally, make sure the caller has the rights to 1775 * change /proc/pid/exe link: only local root should 1776 * be allowed to. 1777 */ 1778 if (prctl_map->exe_fd != (u32)-1) { 1779 struct user_namespace *ns = current_user_ns(); 1780 const struct cred *cred = current_cred(); 1781 1782 if (!uid_eq(cred->uid, make_kuid(ns, 0)) || 1783 !gid_eq(cred->gid, make_kgid(ns, 0))) 1784 goto out; 1785 } 1786 1787 error = 0; 1788 out: 1789 return error; 1790 } 1791 1792 static int prctl_set_mm_map(int opt, const void __user *addr, unsigned long data_size) 1793 { 1794 struct prctl_mm_map prctl_map = { .exe_fd = (u32)-1, }; 1795 unsigned long user_auxv[AT_VECTOR_SIZE]; 1796 struct mm_struct *mm = current->mm; 1797 int error; 1798 1799 BUILD_BUG_ON(sizeof(user_auxv) != sizeof(mm->saved_auxv)); 1800 BUILD_BUG_ON(sizeof(struct prctl_mm_map) > 256); 1801 1802 if (opt == PR_SET_MM_MAP_SIZE) 1803 return put_user((unsigned int)sizeof(prctl_map), 1804 (unsigned int __user *)addr); 1805 1806 if (data_size != sizeof(prctl_map)) 1807 return -EINVAL; 1808 1809 if (copy_from_user(&prctl_map, addr, sizeof(prctl_map))) 1810 return -EFAULT; 1811 1812 error = validate_prctl_map(&prctl_map); 1813 if (error) 1814 return error; 1815 1816 if (prctl_map.auxv_size) { 1817 memset(user_auxv, 0, sizeof(user_auxv)); 1818 if (copy_from_user(user_auxv, 1819 (const void __user *)prctl_map.auxv, 1820 prctl_map.auxv_size)) 1821 return -EFAULT; 1822 1823 /* Last entry must be AT_NULL as specification requires */ 1824 user_auxv[AT_VECTOR_SIZE - 2] = AT_NULL; 1825 user_auxv[AT_VECTOR_SIZE - 1] = AT_NULL; 1826 } 1827 1828 down_write(&mm->mmap_sem); 1829 if (prctl_map.exe_fd != (u32)-1) 1830 error = prctl_set_mm_exe_file_locked(mm, prctl_map.exe_fd); 1831 downgrade_write(&mm->mmap_sem); 1832 if (error) 1833 goto out; 1834 1835 /* 1836 * We don't validate if these members are pointing to 1837 * real present VMAs because application may have correspond 1838 * VMAs already unmapped and kernel uses these members for statistics 1839 * output in procfs mostly, except 1840 * 1841 * - @start_brk/@brk which are used in do_brk but kernel lookups 1842 * for VMAs when updating these memvers so anything wrong written 1843 * here cause kernel to swear at userspace program but won't lead 1844 * to any problem in kernel itself 1845 */ 1846 1847 mm->start_code = prctl_map.start_code; 1848 mm->end_code = prctl_map.end_code; 1849 mm->start_data = prctl_map.start_data; 1850 mm->end_data = prctl_map.end_data; 1851 mm->start_brk = prctl_map.start_brk; 1852 mm->brk = prctl_map.brk; 1853 mm->start_stack = prctl_map.start_stack; 1854 mm->arg_start = prctl_map.arg_start; 1855 mm->arg_end = prctl_map.arg_end; 1856 mm->env_start = prctl_map.env_start; 1857 mm->env_end = prctl_map.env_end; 1858 1859 /* 1860 * Note this update of @saved_auxv is lockless thus 1861 * if someone reads this member in procfs while we're 1862 * updating -- it may get partly updated results. It's 1863 * known and acceptable trade off: we leave it as is to 1864 * not introduce additional locks here making the kernel 1865 * more complex. 1866 */ 1867 if (prctl_map.auxv_size) 1868 memcpy(mm->saved_auxv, user_auxv, sizeof(user_auxv)); 1869 1870 error = 0; 1871 out: 1872 up_read(&mm->mmap_sem); 1873 return error; 1874 } 1875 #endif /* CONFIG_CHECKPOINT_RESTORE */ 1876 1877 static int prctl_set_mm(int opt, unsigned long addr, 1878 unsigned long arg4, unsigned long arg5) 1879 { 1880 struct mm_struct *mm = current->mm; 1881 struct vm_area_struct *vma; 1882 int error; 1883 1884 if (arg5 || (arg4 && (opt != PR_SET_MM_AUXV && 1885 opt != PR_SET_MM_MAP && 1886 opt != PR_SET_MM_MAP_SIZE))) 1887 return -EINVAL; 1888 1889 #ifdef CONFIG_CHECKPOINT_RESTORE 1890 if (opt == PR_SET_MM_MAP || opt == PR_SET_MM_MAP_SIZE) 1891 return prctl_set_mm_map(opt, (const void __user *)addr, arg4); 1892 #endif 1893 1894 if (!capable(CAP_SYS_RESOURCE)) 1895 return -EPERM; 1896 1897 if (opt == PR_SET_MM_EXE_FILE) { 1898 down_write(&mm->mmap_sem); 1899 error = prctl_set_mm_exe_file_locked(mm, (unsigned int)addr); 1900 up_write(&mm->mmap_sem); 1901 return error; 1902 } 1903 1904 if (addr >= TASK_SIZE || addr < mmap_min_addr) 1905 return -EINVAL; 1906 1907 error = -EINVAL; 1908 1909 down_read(&mm->mmap_sem); 1910 vma = find_vma(mm, addr); 1911 1912 switch (opt) { 1913 case PR_SET_MM_START_CODE: 1914 mm->start_code = addr; 1915 break; 1916 case PR_SET_MM_END_CODE: 1917 mm->end_code = addr; 1918 break; 1919 case PR_SET_MM_START_DATA: 1920 mm->start_data = addr; 1921 break; 1922 case PR_SET_MM_END_DATA: 1923 mm->end_data = addr; 1924 break; 1925 1926 case PR_SET_MM_START_BRK: 1927 if (addr <= mm->end_data) 1928 goto out; 1929 1930 if (check_data_rlimit(rlimit(RLIMIT_DATA), mm->brk, addr, 1931 mm->end_data, mm->start_data)) 1932 goto out; 1933 1934 mm->start_brk = addr; 1935 break; 1936 1937 case PR_SET_MM_BRK: 1938 if (addr <= mm->end_data) 1939 goto out; 1940 1941 if (check_data_rlimit(rlimit(RLIMIT_DATA), addr, mm->start_brk, 1942 mm->end_data, mm->start_data)) 1943 goto out; 1944 1945 mm->brk = addr; 1946 break; 1947 1948 /* 1949 * If command line arguments and environment 1950 * are placed somewhere else on stack, we can 1951 * set them up here, ARG_START/END to setup 1952 * command line argumets and ENV_START/END 1953 * for environment. 1954 */ 1955 case PR_SET_MM_START_STACK: 1956 case PR_SET_MM_ARG_START: 1957 case PR_SET_MM_ARG_END: 1958 case PR_SET_MM_ENV_START: 1959 case PR_SET_MM_ENV_END: 1960 if (!vma) { 1961 error = -EFAULT; 1962 goto out; 1963 } 1964 if (opt == PR_SET_MM_START_STACK) 1965 mm->start_stack = addr; 1966 else if (opt == PR_SET_MM_ARG_START) 1967 mm->arg_start = addr; 1968 else if (opt == PR_SET_MM_ARG_END) 1969 mm->arg_end = addr; 1970 else if (opt == PR_SET_MM_ENV_START) 1971 mm->env_start = addr; 1972 else if (opt == PR_SET_MM_ENV_END) 1973 mm->env_end = addr; 1974 break; 1975 1976 /* 1977 * This doesn't move auxiliary vector itself 1978 * since it's pinned to mm_struct, but allow 1979 * to fill vector with new values. It's up 1980 * to a caller to provide sane values here 1981 * otherwise user space tools which use this 1982 * vector might be unhappy. 1983 */ 1984 case PR_SET_MM_AUXV: { 1985 unsigned long user_auxv[AT_VECTOR_SIZE]; 1986 1987 if (arg4 > sizeof(user_auxv)) 1988 goto out; 1989 up_read(&mm->mmap_sem); 1990 1991 if (copy_from_user(user_auxv, (const void __user *)addr, arg4)) 1992 return -EFAULT; 1993 1994 /* Make sure the last entry is always AT_NULL */ 1995 user_auxv[AT_VECTOR_SIZE - 2] = 0; 1996 user_auxv[AT_VECTOR_SIZE - 1] = 0; 1997 1998 BUILD_BUG_ON(sizeof(user_auxv) != sizeof(mm->saved_auxv)); 1999 2000 task_lock(current); 2001 memcpy(mm->saved_auxv, user_auxv, arg4); 2002 task_unlock(current); 2003 2004 return 0; 2005 } 2006 default: 2007 goto out; 2008 } 2009 2010 error = 0; 2011 out: 2012 up_read(&mm->mmap_sem); 2013 return error; 2014 } 2015 2016 #ifdef CONFIG_CHECKPOINT_RESTORE 2017 static int prctl_get_tid_address(struct task_struct *me, int __user **tid_addr) 2018 { 2019 return put_user(me->clear_child_tid, tid_addr); 2020 } 2021 #else 2022 static int prctl_get_tid_address(struct task_struct *me, int __user **tid_addr) 2023 { 2024 return -EINVAL; 2025 } 2026 #endif 2027 2028 SYSCALL_DEFINE5(prctl, int, option, unsigned long, arg2, unsigned long, arg3, 2029 unsigned long, arg4, unsigned long, arg5) 2030 { 2031 struct task_struct *me = current; 2032 unsigned char comm[sizeof(me->comm)]; 2033 long error; 2034 2035 error = security_task_prctl(option, arg2, arg3, arg4, arg5); 2036 if (error != -ENOSYS) 2037 return error; 2038 2039 error = 0; 2040 switch (option) { 2041 case PR_SET_PDEATHSIG: 2042 if (!valid_signal(arg2)) { 2043 error = -EINVAL; 2044 break; 2045 } 2046 me->pdeath_signal = arg2; 2047 break; 2048 case PR_GET_PDEATHSIG: 2049 error = put_user(me->pdeath_signal, (int __user *)arg2); 2050 break; 2051 case PR_GET_DUMPABLE: 2052 error = get_dumpable(me->mm); 2053 break; 2054 case PR_SET_DUMPABLE: 2055 if (arg2 != SUID_DUMP_DISABLE && arg2 != SUID_DUMP_USER) { 2056 error = -EINVAL; 2057 break; 2058 } 2059 set_dumpable(me->mm, arg2); 2060 break; 2061 2062 case PR_SET_UNALIGN: 2063 error = SET_UNALIGN_CTL(me, arg2); 2064 break; 2065 case PR_GET_UNALIGN: 2066 error = GET_UNALIGN_CTL(me, arg2); 2067 break; 2068 case PR_SET_FPEMU: 2069 error = SET_FPEMU_CTL(me, arg2); 2070 break; 2071 case PR_GET_FPEMU: 2072 error = GET_FPEMU_CTL(me, arg2); 2073 break; 2074 case PR_SET_FPEXC: 2075 error = SET_FPEXC_CTL(me, arg2); 2076 break; 2077 case PR_GET_FPEXC: 2078 error = GET_FPEXC_CTL(me, arg2); 2079 break; 2080 case PR_GET_TIMING: 2081 error = PR_TIMING_STATISTICAL; 2082 break; 2083 case PR_SET_TIMING: 2084 if (arg2 != PR_TIMING_STATISTICAL) 2085 error = -EINVAL; 2086 break; 2087 case PR_SET_NAME: 2088 comm[sizeof(me->comm) - 1] = 0; 2089 if (strncpy_from_user(comm, (char __user *)arg2, 2090 sizeof(me->comm) - 1) < 0) 2091 return -EFAULT; 2092 set_task_comm(me, comm); 2093 proc_comm_connector(me); 2094 break; 2095 case PR_GET_NAME: 2096 get_task_comm(comm, me); 2097 if (copy_to_user((char __user *)arg2, comm, sizeof(comm))) 2098 return -EFAULT; 2099 break; 2100 case PR_GET_ENDIAN: 2101 error = GET_ENDIAN(me, arg2); 2102 break; 2103 case PR_SET_ENDIAN: 2104 error = SET_ENDIAN(me, arg2); 2105 break; 2106 case PR_GET_SECCOMP: 2107 error = prctl_get_seccomp(); 2108 break; 2109 case PR_SET_SECCOMP: 2110 error = prctl_set_seccomp(arg2, (char __user *)arg3); 2111 break; 2112 case PR_GET_TSC: 2113 error = GET_TSC_CTL(arg2); 2114 break; 2115 case PR_SET_TSC: 2116 error = SET_TSC_CTL(arg2); 2117 break; 2118 case PR_TASK_PERF_EVENTS_DISABLE: 2119 error = perf_event_task_disable(); 2120 break; 2121 case PR_TASK_PERF_EVENTS_ENABLE: 2122 error = perf_event_task_enable(); 2123 break; 2124 case PR_GET_TIMERSLACK: 2125 error = current->timer_slack_ns; 2126 break; 2127 case PR_SET_TIMERSLACK: 2128 if (arg2 <= 0) 2129 current->timer_slack_ns = 2130 current->default_timer_slack_ns; 2131 else 2132 current->timer_slack_ns = arg2; 2133 break; 2134 case PR_MCE_KILL: 2135 if (arg4 | arg5) 2136 return -EINVAL; 2137 switch (arg2) { 2138 case PR_MCE_KILL_CLEAR: 2139 if (arg3 != 0) 2140 return -EINVAL; 2141 current->flags &= ~PF_MCE_PROCESS; 2142 break; 2143 case PR_MCE_KILL_SET: 2144 current->flags |= PF_MCE_PROCESS; 2145 if (arg3 == PR_MCE_KILL_EARLY) 2146 current->flags |= PF_MCE_EARLY; 2147 else if (arg3 == PR_MCE_KILL_LATE) 2148 current->flags &= ~PF_MCE_EARLY; 2149 else if (arg3 == PR_MCE_KILL_DEFAULT) 2150 current->flags &= 2151 ~(PF_MCE_EARLY|PF_MCE_PROCESS); 2152 else 2153 return -EINVAL; 2154 break; 2155 default: 2156 return -EINVAL; 2157 } 2158 break; 2159 case PR_MCE_KILL_GET: 2160 if (arg2 | arg3 | arg4 | arg5) 2161 return -EINVAL; 2162 if (current->flags & PF_MCE_PROCESS) 2163 error = (current->flags & PF_MCE_EARLY) ? 2164 PR_MCE_KILL_EARLY : PR_MCE_KILL_LATE; 2165 else 2166 error = PR_MCE_KILL_DEFAULT; 2167 break; 2168 case PR_SET_MM: 2169 error = prctl_set_mm(arg2, arg3, arg4, arg5); 2170 break; 2171 case PR_GET_TID_ADDRESS: 2172 error = prctl_get_tid_address(me, (int __user **)arg2); 2173 break; 2174 case PR_SET_CHILD_SUBREAPER: 2175 me->signal->is_child_subreaper = !!arg2; 2176 break; 2177 case PR_GET_CHILD_SUBREAPER: 2178 error = put_user(me->signal->is_child_subreaper, 2179 (int __user *)arg2); 2180 break; 2181 case PR_SET_NO_NEW_PRIVS: 2182 if (arg2 != 1 || arg3 || arg4 || arg5) 2183 return -EINVAL; 2184 2185 task_set_no_new_privs(current); 2186 break; 2187 case PR_GET_NO_NEW_PRIVS: 2188 if (arg2 || arg3 || arg4 || arg5) 2189 return -EINVAL; 2190 return task_no_new_privs(current) ? 1 : 0; 2191 case PR_GET_THP_DISABLE: 2192 if (arg2 || arg3 || arg4 || arg5) 2193 return -EINVAL; 2194 error = !!(me->mm->def_flags & VM_NOHUGEPAGE); 2195 break; 2196 case PR_SET_THP_DISABLE: 2197 if (arg3 || arg4 || arg5) 2198 return -EINVAL; 2199 down_write(&me->mm->mmap_sem); 2200 if (arg2) 2201 me->mm->def_flags |= VM_NOHUGEPAGE; 2202 else 2203 me->mm->def_flags &= ~VM_NOHUGEPAGE; 2204 up_write(&me->mm->mmap_sem); 2205 break; 2206 default: 2207 error = -EINVAL; 2208 break; 2209 } 2210 return error; 2211 } 2212 2213 SYSCALL_DEFINE3(getcpu, unsigned __user *, cpup, unsigned __user *, nodep, 2214 struct getcpu_cache __user *, unused) 2215 { 2216 int err = 0; 2217 int cpu = raw_smp_processor_id(); 2218 2219 if (cpup) 2220 err |= put_user(cpu, cpup); 2221 if (nodep) 2222 err |= put_user(cpu_to_node(cpu), nodep); 2223 return err ? -EFAULT : 0; 2224 } 2225 2226 /** 2227 * do_sysinfo - fill in sysinfo struct 2228 * @info: pointer to buffer to fill 2229 */ 2230 static int do_sysinfo(struct sysinfo *info) 2231 { 2232 unsigned long mem_total, sav_total; 2233 unsigned int mem_unit, bitcount; 2234 struct timespec tp; 2235 2236 memset(info, 0, sizeof(struct sysinfo)); 2237 2238 get_monotonic_boottime(&tp); 2239 info->uptime = tp.tv_sec + (tp.tv_nsec ? 1 : 0); 2240 2241 get_avenrun(info->loads, 0, SI_LOAD_SHIFT - FSHIFT); 2242 2243 info->procs = nr_threads; 2244 2245 si_meminfo(info); 2246 si_swapinfo(info); 2247 2248 /* 2249 * If the sum of all the available memory (i.e. ram + swap) 2250 * is less than can be stored in a 32 bit unsigned long then 2251 * we can be binary compatible with 2.2.x kernels. If not, 2252 * well, in that case 2.2.x was broken anyways... 2253 * 2254 * -Erik Andersen <andersee@debian.org> 2255 */ 2256 2257 mem_total = info->totalram + info->totalswap; 2258 if (mem_total < info->totalram || mem_total < info->totalswap) 2259 goto out; 2260 bitcount = 0; 2261 mem_unit = info->mem_unit; 2262 while (mem_unit > 1) { 2263 bitcount++; 2264 mem_unit >>= 1; 2265 sav_total = mem_total; 2266 mem_total <<= 1; 2267 if (mem_total < sav_total) 2268 goto out; 2269 } 2270 2271 /* 2272 * If mem_total did not overflow, multiply all memory values by 2273 * info->mem_unit and set it to 1. This leaves things compatible 2274 * with 2.2.x, and also retains compatibility with earlier 2.4.x 2275 * kernels... 2276 */ 2277 2278 info->mem_unit = 1; 2279 info->totalram <<= bitcount; 2280 info->freeram <<= bitcount; 2281 info->sharedram <<= bitcount; 2282 info->bufferram <<= bitcount; 2283 info->totalswap <<= bitcount; 2284 info->freeswap <<= bitcount; 2285 info->totalhigh <<= bitcount; 2286 info->freehigh <<= bitcount; 2287 2288 out: 2289 return 0; 2290 } 2291 2292 SYSCALL_DEFINE1(sysinfo, struct sysinfo __user *, info) 2293 { 2294 struct sysinfo val; 2295 2296 do_sysinfo(&val); 2297 2298 if (copy_to_user(info, &val, sizeof(struct sysinfo))) 2299 return -EFAULT; 2300 2301 return 0; 2302 } 2303 2304 #ifdef CONFIG_COMPAT 2305 struct compat_sysinfo { 2306 s32 uptime; 2307 u32 loads[3]; 2308 u32 totalram; 2309 u32 freeram; 2310 u32 sharedram; 2311 u32 bufferram; 2312 u32 totalswap; 2313 u32 freeswap; 2314 u16 procs; 2315 u16 pad; 2316 u32 totalhigh; 2317 u32 freehigh; 2318 u32 mem_unit; 2319 char _f[20-2*sizeof(u32)-sizeof(int)]; 2320 }; 2321 2322 COMPAT_SYSCALL_DEFINE1(sysinfo, struct compat_sysinfo __user *, info) 2323 { 2324 struct sysinfo s; 2325 2326 do_sysinfo(&s); 2327 2328 /* Check to see if any memory value is too large for 32-bit and scale 2329 * down if needed 2330 */ 2331 if (upper_32_bits(s.totalram) || upper_32_bits(s.totalswap)) { 2332 int bitcount = 0; 2333 2334 while (s.mem_unit < PAGE_SIZE) { 2335 s.mem_unit <<= 1; 2336 bitcount++; 2337 } 2338 2339 s.totalram >>= bitcount; 2340 s.freeram >>= bitcount; 2341 s.sharedram >>= bitcount; 2342 s.bufferram >>= bitcount; 2343 s.totalswap >>= bitcount; 2344 s.freeswap >>= bitcount; 2345 s.totalhigh >>= bitcount; 2346 s.freehigh >>= bitcount; 2347 } 2348 2349 if (!access_ok(VERIFY_WRITE, info, sizeof(struct compat_sysinfo)) || 2350 __put_user(s.uptime, &info->uptime) || 2351 __put_user(s.loads[0], &info->loads[0]) || 2352 __put_user(s.loads[1], &info->loads[1]) || 2353 __put_user(s.loads[2], &info->loads[2]) || 2354 __put_user(s.totalram, &info->totalram) || 2355 __put_user(s.freeram, &info->freeram) || 2356 __put_user(s.sharedram, &info->sharedram) || 2357 __put_user(s.bufferram, &info->bufferram) || 2358 __put_user(s.totalswap, &info->totalswap) || 2359 __put_user(s.freeswap, &info->freeswap) || 2360 __put_user(s.procs, &info->procs) || 2361 __put_user(s.totalhigh, &info->totalhigh) || 2362 __put_user(s.freehigh, &info->freehigh) || 2363 __put_user(s.mem_unit, &info->mem_unit)) 2364 return -EFAULT; 2365 2366 return 0; 2367 } 2368 #endif /* CONFIG_COMPAT */ 2369