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 #ifndef MPX_ENABLE_MANAGEMENT 95 # define MPX_ENABLE_MANAGEMENT() (-EINVAL) 96 #endif 97 #ifndef MPX_DISABLE_MANAGEMENT 98 # define MPX_DISABLE_MANAGEMENT() (-EINVAL) 99 #endif 100 #ifndef GET_FP_MODE 101 # define GET_FP_MODE(a) (-EINVAL) 102 #endif 103 #ifndef SET_FP_MODE 104 # define SET_FP_MODE(a,b) (-EINVAL) 105 #endif 106 107 /* 108 * this is where the system-wide overflow UID and GID are defined, for 109 * architectures that now have 32-bit UID/GID but didn't in the past 110 */ 111 112 int overflowuid = DEFAULT_OVERFLOWUID; 113 int overflowgid = DEFAULT_OVERFLOWGID; 114 115 EXPORT_SYMBOL(overflowuid); 116 EXPORT_SYMBOL(overflowgid); 117 118 /* 119 * the same as above, but for filesystems which can only store a 16-bit 120 * UID and GID. as such, this is needed on all architectures 121 */ 122 123 int fs_overflowuid = DEFAULT_FS_OVERFLOWUID; 124 int fs_overflowgid = DEFAULT_FS_OVERFLOWUID; 125 126 EXPORT_SYMBOL(fs_overflowuid); 127 EXPORT_SYMBOL(fs_overflowgid); 128 129 /* 130 * Returns true if current's euid is same as p's uid or euid, 131 * or has CAP_SYS_NICE to p's user_ns. 132 * 133 * Called with rcu_read_lock, creds are safe 134 */ 135 static bool set_one_prio_perm(struct task_struct *p) 136 { 137 const struct cred *cred = current_cred(), *pcred = __task_cred(p); 138 139 if (uid_eq(pcred->uid, cred->euid) || 140 uid_eq(pcred->euid, cred->euid)) 141 return true; 142 if (ns_capable(pcred->user_ns, CAP_SYS_NICE)) 143 return true; 144 return false; 145 } 146 147 /* 148 * set the priority of a task 149 * - the caller must hold the RCU read lock 150 */ 151 static int set_one_prio(struct task_struct *p, int niceval, int error) 152 { 153 int no_nice; 154 155 if (!set_one_prio_perm(p)) { 156 error = -EPERM; 157 goto out; 158 } 159 if (niceval < task_nice(p) && !can_nice(p, niceval)) { 160 error = -EACCES; 161 goto out; 162 } 163 no_nice = security_task_setnice(p, niceval); 164 if (no_nice) { 165 error = no_nice; 166 goto out; 167 } 168 if (error == -ESRCH) 169 error = 0; 170 set_user_nice(p, niceval); 171 out: 172 return error; 173 } 174 175 SYSCALL_DEFINE3(setpriority, int, which, int, who, int, niceval) 176 { 177 struct task_struct *g, *p; 178 struct user_struct *user; 179 const struct cred *cred = current_cred(); 180 int error = -EINVAL; 181 struct pid *pgrp; 182 kuid_t uid; 183 184 if (which > PRIO_USER || which < PRIO_PROCESS) 185 goto out; 186 187 /* normalize: avoid signed division (rounding problems) */ 188 error = -ESRCH; 189 if (niceval < MIN_NICE) 190 niceval = MIN_NICE; 191 if (niceval > MAX_NICE) 192 niceval = MAX_NICE; 193 194 rcu_read_lock(); 195 read_lock(&tasklist_lock); 196 switch (which) { 197 case PRIO_PROCESS: 198 if (who) 199 p = find_task_by_vpid(who); 200 else 201 p = current; 202 if (p) 203 error = set_one_prio(p, niceval, error); 204 break; 205 case PRIO_PGRP: 206 if (who) 207 pgrp = find_vpid(who); 208 else 209 pgrp = task_pgrp(current); 210 do_each_pid_thread(pgrp, PIDTYPE_PGID, p) { 211 error = set_one_prio(p, niceval, error); 212 } while_each_pid_thread(pgrp, PIDTYPE_PGID, p); 213 break; 214 case PRIO_USER: 215 uid = make_kuid(cred->user_ns, who); 216 user = cred->user; 217 if (!who) 218 uid = cred->uid; 219 else if (!uid_eq(uid, cred->uid)) { 220 user = find_user(uid); 221 if (!user) 222 goto out_unlock; /* No processes for this user */ 223 } 224 do_each_thread(g, p) { 225 if (uid_eq(task_uid(p), uid)) 226 error = set_one_prio(p, niceval, error); 227 } while_each_thread(g, p); 228 if (!uid_eq(uid, cred->uid)) 229 free_uid(user); /* For find_user() */ 230 break; 231 } 232 out_unlock: 233 read_unlock(&tasklist_lock); 234 rcu_read_unlock(); 235 out: 236 return error; 237 } 238 239 /* 240 * Ugh. To avoid negative return values, "getpriority()" will 241 * not return the normal nice-value, but a negated value that 242 * has been offset by 20 (ie it returns 40..1 instead of -20..19) 243 * to stay compatible. 244 */ 245 SYSCALL_DEFINE2(getpriority, int, which, int, who) 246 { 247 struct task_struct *g, *p; 248 struct user_struct *user; 249 const struct cred *cred = current_cred(); 250 long niceval, retval = -ESRCH; 251 struct pid *pgrp; 252 kuid_t uid; 253 254 if (which > PRIO_USER || which < PRIO_PROCESS) 255 return -EINVAL; 256 257 rcu_read_lock(); 258 read_lock(&tasklist_lock); 259 switch (which) { 260 case PRIO_PROCESS: 261 if (who) 262 p = find_task_by_vpid(who); 263 else 264 p = current; 265 if (p) { 266 niceval = nice_to_rlimit(task_nice(p)); 267 if (niceval > retval) 268 retval = niceval; 269 } 270 break; 271 case PRIO_PGRP: 272 if (who) 273 pgrp = find_vpid(who); 274 else 275 pgrp = task_pgrp(current); 276 do_each_pid_thread(pgrp, PIDTYPE_PGID, p) { 277 niceval = nice_to_rlimit(task_nice(p)); 278 if (niceval > retval) 279 retval = niceval; 280 } while_each_pid_thread(pgrp, PIDTYPE_PGID, p); 281 break; 282 case PRIO_USER: 283 uid = make_kuid(cred->user_ns, who); 284 user = cred->user; 285 if (!who) 286 uid = cred->uid; 287 else if (!uid_eq(uid, cred->uid)) { 288 user = find_user(uid); 289 if (!user) 290 goto out_unlock; /* No processes for this user */ 291 } 292 do_each_thread(g, p) { 293 if (uid_eq(task_uid(p), uid)) { 294 niceval = nice_to_rlimit(task_nice(p)); 295 if (niceval > retval) 296 retval = niceval; 297 } 298 } while_each_thread(g, p); 299 if (!uid_eq(uid, cred->uid)) 300 free_uid(user); /* for find_user() */ 301 break; 302 } 303 out_unlock: 304 read_unlock(&tasklist_lock); 305 rcu_read_unlock(); 306 307 return retval; 308 } 309 310 /* 311 * Unprivileged users may change the real gid to the effective gid 312 * or vice versa. (BSD-style) 313 * 314 * If you set the real gid at all, or set the effective gid to a value not 315 * equal to the real gid, then the saved gid is set to the new effective gid. 316 * 317 * This makes it possible for a setgid program to completely drop its 318 * privileges, which is often a useful assertion to make when you are doing 319 * a security audit over a program. 320 * 321 * The general idea is that a program which uses just setregid() will be 322 * 100% compatible with BSD. A program which uses just setgid() will be 323 * 100% compatible with POSIX with saved IDs. 324 * 325 * SMP: There are not races, the GIDs are checked only by filesystem 326 * operations (as far as semantic preservation is concerned). 327 */ 328 #ifdef CONFIG_MULTIUSER 329 SYSCALL_DEFINE2(setregid, gid_t, rgid, gid_t, egid) 330 { 331 struct user_namespace *ns = current_user_ns(); 332 const struct cred *old; 333 struct cred *new; 334 int retval; 335 kgid_t krgid, kegid; 336 337 krgid = make_kgid(ns, rgid); 338 kegid = make_kgid(ns, egid); 339 340 if ((rgid != (gid_t) -1) && !gid_valid(krgid)) 341 return -EINVAL; 342 if ((egid != (gid_t) -1) && !gid_valid(kegid)) 343 return -EINVAL; 344 345 new = prepare_creds(); 346 if (!new) 347 return -ENOMEM; 348 old = current_cred(); 349 350 retval = -EPERM; 351 if (rgid != (gid_t) -1) { 352 if (gid_eq(old->gid, krgid) || 353 gid_eq(old->egid, krgid) || 354 ns_capable(old->user_ns, CAP_SETGID)) 355 new->gid = krgid; 356 else 357 goto error; 358 } 359 if (egid != (gid_t) -1) { 360 if (gid_eq(old->gid, kegid) || 361 gid_eq(old->egid, kegid) || 362 gid_eq(old->sgid, kegid) || 363 ns_capable(old->user_ns, CAP_SETGID)) 364 new->egid = kegid; 365 else 366 goto error; 367 } 368 369 if (rgid != (gid_t) -1 || 370 (egid != (gid_t) -1 && !gid_eq(kegid, old->gid))) 371 new->sgid = new->egid; 372 new->fsgid = new->egid; 373 374 return commit_creds(new); 375 376 error: 377 abort_creds(new); 378 return retval; 379 } 380 381 /* 382 * setgid() is implemented like SysV w/ SAVED_IDS 383 * 384 * SMP: Same implicit races as above. 385 */ 386 SYSCALL_DEFINE1(setgid, gid_t, gid) 387 { 388 struct user_namespace *ns = current_user_ns(); 389 const struct cred *old; 390 struct cred *new; 391 int retval; 392 kgid_t kgid; 393 394 kgid = make_kgid(ns, gid); 395 if (!gid_valid(kgid)) 396 return -EINVAL; 397 398 new = prepare_creds(); 399 if (!new) 400 return -ENOMEM; 401 old = current_cred(); 402 403 retval = -EPERM; 404 if (ns_capable(old->user_ns, CAP_SETGID)) 405 new->gid = new->egid = new->sgid = new->fsgid = kgid; 406 else if (gid_eq(kgid, old->gid) || gid_eq(kgid, old->sgid)) 407 new->egid = new->fsgid = kgid; 408 else 409 goto error; 410 411 return commit_creds(new); 412 413 error: 414 abort_creds(new); 415 return retval; 416 } 417 418 /* 419 * change the user struct in a credentials set to match the new UID 420 */ 421 static int set_user(struct cred *new) 422 { 423 struct user_struct *new_user; 424 425 new_user = alloc_uid(new->uid); 426 if (!new_user) 427 return -EAGAIN; 428 429 /* 430 * We don't fail in case of NPROC limit excess here because too many 431 * poorly written programs don't check set*uid() return code, assuming 432 * it never fails if called by root. We may still enforce NPROC limit 433 * for programs doing set*uid()+execve() by harmlessly deferring the 434 * failure to the execve() stage. 435 */ 436 if (atomic_read(&new_user->processes) >= rlimit(RLIMIT_NPROC) && 437 new_user != INIT_USER) 438 current->flags |= PF_NPROC_EXCEEDED; 439 else 440 current->flags &= ~PF_NPROC_EXCEEDED; 441 442 free_uid(new->user); 443 new->user = new_user; 444 return 0; 445 } 446 447 /* 448 * Unprivileged users may change the real uid to the effective uid 449 * or vice versa. (BSD-style) 450 * 451 * If you set the real uid at all, or set the effective uid to a value not 452 * equal to the real uid, then the saved uid is set to the new effective uid. 453 * 454 * This makes it possible for a setuid program to completely drop its 455 * privileges, which is often a useful assertion to make when you are doing 456 * a security audit over a program. 457 * 458 * The general idea is that a program which uses just setreuid() will be 459 * 100% compatible with BSD. A program which uses just setuid() will be 460 * 100% compatible with POSIX with saved IDs. 461 */ 462 SYSCALL_DEFINE2(setreuid, uid_t, ruid, uid_t, euid) 463 { 464 struct user_namespace *ns = current_user_ns(); 465 const struct cred *old; 466 struct cred *new; 467 int retval; 468 kuid_t kruid, keuid; 469 470 kruid = make_kuid(ns, ruid); 471 keuid = make_kuid(ns, euid); 472 473 if ((ruid != (uid_t) -1) && !uid_valid(kruid)) 474 return -EINVAL; 475 if ((euid != (uid_t) -1) && !uid_valid(keuid)) 476 return -EINVAL; 477 478 new = prepare_creds(); 479 if (!new) 480 return -ENOMEM; 481 old = current_cred(); 482 483 retval = -EPERM; 484 if (ruid != (uid_t) -1) { 485 new->uid = kruid; 486 if (!uid_eq(old->uid, kruid) && 487 !uid_eq(old->euid, kruid) && 488 !ns_capable(old->user_ns, CAP_SETUID)) 489 goto error; 490 } 491 492 if (euid != (uid_t) -1) { 493 new->euid = keuid; 494 if (!uid_eq(old->uid, keuid) && 495 !uid_eq(old->euid, keuid) && 496 !uid_eq(old->suid, keuid) && 497 !ns_capable(old->user_ns, CAP_SETUID)) 498 goto error; 499 } 500 501 if (!uid_eq(new->uid, old->uid)) { 502 retval = set_user(new); 503 if (retval < 0) 504 goto error; 505 } 506 if (ruid != (uid_t) -1 || 507 (euid != (uid_t) -1 && !uid_eq(keuid, old->uid))) 508 new->suid = new->euid; 509 new->fsuid = new->euid; 510 511 retval = security_task_fix_setuid(new, old, LSM_SETID_RE); 512 if (retval < 0) 513 goto error; 514 515 return commit_creds(new); 516 517 error: 518 abort_creds(new); 519 return retval; 520 } 521 522 /* 523 * setuid() is implemented like SysV with SAVED_IDS 524 * 525 * Note that SAVED_ID's is deficient in that a setuid root program 526 * like sendmail, for example, cannot set its uid to be a normal 527 * user and then switch back, because if you're root, setuid() sets 528 * the saved uid too. If you don't like this, blame the bright people 529 * in the POSIX committee and/or USG. Note that the BSD-style setreuid() 530 * will allow a root program to temporarily drop privileges and be able to 531 * regain them by swapping the real and effective uid. 532 */ 533 SYSCALL_DEFINE1(setuid, uid_t, uid) 534 { 535 struct user_namespace *ns = current_user_ns(); 536 const struct cred *old; 537 struct cred *new; 538 int retval; 539 kuid_t kuid; 540 541 kuid = make_kuid(ns, uid); 542 if (!uid_valid(kuid)) 543 return -EINVAL; 544 545 new = prepare_creds(); 546 if (!new) 547 return -ENOMEM; 548 old = current_cred(); 549 550 retval = -EPERM; 551 if (ns_capable(old->user_ns, CAP_SETUID)) { 552 new->suid = new->uid = kuid; 553 if (!uid_eq(kuid, old->uid)) { 554 retval = set_user(new); 555 if (retval < 0) 556 goto error; 557 } 558 } else if (!uid_eq(kuid, old->uid) && !uid_eq(kuid, new->suid)) { 559 goto error; 560 } 561 562 new->fsuid = new->euid = kuid; 563 564 retval = security_task_fix_setuid(new, old, LSM_SETID_ID); 565 if (retval < 0) 566 goto error; 567 568 return commit_creds(new); 569 570 error: 571 abort_creds(new); 572 return retval; 573 } 574 575 576 /* 577 * This function implements a generic ability to update ruid, euid, 578 * and suid. This allows you to implement the 4.4 compatible seteuid(). 579 */ 580 SYSCALL_DEFINE3(setresuid, uid_t, ruid, uid_t, euid, uid_t, suid) 581 { 582 struct user_namespace *ns = current_user_ns(); 583 const struct cred *old; 584 struct cred *new; 585 int retval; 586 kuid_t kruid, keuid, ksuid; 587 588 kruid = make_kuid(ns, ruid); 589 keuid = make_kuid(ns, euid); 590 ksuid = make_kuid(ns, suid); 591 592 if ((ruid != (uid_t) -1) && !uid_valid(kruid)) 593 return -EINVAL; 594 595 if ((euid != (uid_t) -1) && !uid_valid(keuid)) 596 return -EINVAL; 597 598 if ((suid != (uid_t) -1) && !uid_valid(ksuid)) 599 return -EINVAL; 600 601 new = prepare_creds(); 602 if (!new) 603 return -ENOMEM; 604 605 old = current_cred(); 606 607 retval = -EPERM; 608 if (!ns_capable(old->user_ns, CAP_SETUID)) { 609 if (ruid != (uid_t) -1 && !uid_eq(kruid, old->uid) && 610 !uid_eq(kruid, old->euid) && !uid_eq(kruid, old->suid)) 611 goto error; 612 if (euid != (uid_t) -1 && !uid_eq(keuid, old->uid) && 613 !uid_eq(keuid, old->euid) && !uid_eq(keuid, old->suid)) 614 goto error; 615 if (suid != (uid_t) -1 && !uid_eq(ksuid, old->uid) && 616 !uid_eq(ksuid, old->euid) && !uid_eq(ksuid, old->suid)) 617 goto error; 618 } 619 620 if (ruid != (uid_t) -1) { 621 new->uid = kruid; 622 if (!uid_eq(kruid, old->uid)) { 623 retval = set_user(new); 624 if (retval < 0) 625 goto error; 626 } 627 } 628 if (euid != (uid_t) -1) 629 new->euid = keuid; 630 if (suid != (uid_t) -1) 631 new->suid = ksuid; 632 new->fsuid = new->euid; 633 634 retval = security_task_fix_setuid(new, old, LSM_SETID_RES); 635 if (retval < 0) 636 goto error; 637 638 return commit_creds(new); 639 640 error: 641 abort_creds(new); 642 return retval; 643 } 644 645 SYSCALL_DEFINE3(getresuid, uid_t __user *, ruidp, uid_t __user *, euidp, uid_t __user *, suidp) 646 { 647 const struct cred *cred = current_cred(); 648 int retval; 649 uid_t ruid, euid, suid; 650 651 ruid = from_kuid_munged(cred->user_ns, cred->uid); 652 euid = from_kuid_munged(cred->user_ns, cred->euid); 653 suid = from_kuid_munged(cred->user_ns, cred->suid); 654 655 retval = put_user(ruid, ruidp); 656 if (!retval) { 657 retval = put_user(euid, euidp); 658 if (!retval) 659 return put_user(suid, suidp); 660 } 661 return retval; 662 } 663 664 /* 665 * Same as above, but for rgid, egid, sgid. 666 */ 667 SYSCALL_DEFINE3(setresgid, gid_t, rgid, gid_t, egid, gid_t, sgid) 668 { 669 struct user_namespace *ns = current_user_ns(); 670 const struct cred *old; 671 struct cred *new; 672 int retval; 673 kgid_t krgid, kegid, ksgid; 674 675 krgid = make_kgid(ns, rgid); 676 kegid = make_kgid(ns, egid); 677 ksgid = make_kgid(ns, sgid); 678 679 if ((rgid != (gid_t) -1) && !gid_valid(krgid)) 680 return -EINVAL; 681 if ((egid != (gid_t) -1) && !gid_valid(kegid)) 682 return -EINVAL; 683 if ((sgid != (gid_t) -1) && !gid_valid(ksgid)) 684 return -EINVAL; 685 686 new = prepare_creds(); 687 if (!new) 688 return -ENOMEM; 689 old = current_cred(); 690 691 retval = -EPERM; 692 if (!ns_capable(old->user_ns, CAP_SETGID)) { 693 if (rgid != (gid_t) -1 && !gid_eq(krgid, old->gid) && 694 !gid_eq(krgid, old->egid) && !gid_eq(krgid, old->sgid)) 695 goto error; 696 if (egid != (gid_t) -1 && !gid_eq(kegid, old->gid) && 697 !gid_eq(kegid, old->egid) && !gid_eq(kegid, old->sgid)) 698 goto error; 699 if (sgid != (gid_t) -1 && !gid_eq(ksgid, old->gid) && 700 !gid_eq(ksgid, old->egid) && !gid_eq(ksgid, old->sgid)) 701 goto error; 702 } 703 704 if (rgid != (gid_t) -1) 705 new->gid = krgid; 706 if (egid != (gid_t) -1) 707 new->egid = kegid; 708 if (sgid != (gid_t) -1) 709 new->sgid = ksgid; 710 new->fsgid = new->egid; 711 712 return commit_creds(new); 713 714 error: 715 abort_creds(new); 716 return retval; 717 } 718 719 SYSCALL_DEFINE3(getresgid, gid_t __user *, rgidp, gid_t __user *, egidp, gid_t __user *, sgidp) 720 { 721 const struct cred *cred = current_cred(); 722 int retval; 723 gid_t rgid, egid, sgid; 724 725 rgid = from_kgid_munged(cred->user_ns, cred->gid); 726 egid = from_kgid_munged(cred->user_ns, cred->egid); 727 sgid = from_kgid_munged(cred->user_ns, cred->sgid); 728 729 retval = put_user(rgid, rgidp); 730 if (!retval) { 731 retval = put_user(egid, egidp); 732 if (!retval) 733 retval = put_user(sgid, sgidp); 734 } 735 736 return retval; 737 } 738 739 740 /* 741 * "setfsuid()" sets the fsuid - the uid used for filesystem checks. This 742 * is used for "access()" and for the NFS daemon (letting nfsd stay at 743 * whatever uid it wants to). It normally shadows "euid", except when 744 * explicitly set by setfsuid() or for access.. 745 */ 746 SYSCALL_DEFINE1(setfsuid, uid_t, uid) 747 { 748 const struct cred *old; 749 struct cred *new; 750 uid_t old_fsuid; 751 kuid_t kuid; 752 753 old = current_cred(); 754 old_fsuid = from_kuid_munged(old->user_ns, old->fsuid); 755 756 kuid = make_kuid(old->user_ns, uid); 757 if (!uid_valid(kuid)) 758 return old_fsuid; 759 760 new = prepare_creds(); 761 if (!new) 762 return old_fsuid; 763 764 if (uid_eq(kuid, old->uid) || uid_eq(kuid, old->euid) || 765 uid_eq(kuid, old->suid) || uid_eq(kuid, old->fsuid) || 766 ns_capable(old->user_ns, CAP_SETUID)) { 767 if (!uid_eq(kuid, old->fsuid)) { 768 new->fsuid = kuid; 769 if (security_task_fix_setuid(new, old, LSM_SETID_FS) == 0) 770 goto change_okay; 771 } 772 } 773 774 abort_creds(new); 775 return old_fsuid; 776 777 change_okay: 778 commit_creds(new); 779 return old_fsuid; 780 } 781 782 /* 783 * Samma på svenska.. 784 */ 785 SYSCALL_DEFINE1(setfsgid, gid_t, gid) 786 { 787 const struct cred *old; 788 struct cred *new; 789 gid_t old_fsgid; 790 kgid_t kgid; 791 792 old = current_cred(); 793 old_fsgid = from_kgid_munged(old->user_ns, old->fsgid); 794 795 kgid = make_kgid(old->user_ns, gid); 796 if (!gid_valid(kgid)) 797 return old_fsgid; 798 799 new = prepare_creds(); 800 if (!new) 801 return old_fsgid; 802 803 if (gid_eq(kgid, old->gid) || gid_eq(kgid, old->egid) || 804 gid_eq(kgid, old->sgid) || gid_eq(kgid, old->fsgid) || 805 ns_capable(old->user_ns, CAP_SETGID)) { 806 if (!gid_eq(kgid, old->fsgid)) { 807 new->fsgid = kgid; 808 goto change_okay; 809 } 810 } 811 812 abort_creds(new); 813 return old_fsgid; 814 815 change_okay: 816 commit_creds(new); 817 return old_fsgid; 818 } 819 #endif /* CONFIG_MULTIUSER */ 820 821 /** 822 * sys_getpid - return the thread group id of the current process 823 * 824 * Note, despite the name, this returns the tgid not the pid. The tgid and 825 * the pid are identical unless CLONE_THREAD was specified on clone() in 826 * which case the tgid is the same in all threads of the same group. 827 * 828 * This is SMP safe as current->tgid does not change. 829 */ 830 SYSCALL_DEFINE0(getpid) 831 { 832 return task_tgid_vnr(current); 833 } 834 835 /* Thread ID - the internal kernel "pid" */ 836 SYSCALL_DEFINE0(gettid) 837 { 838 return task_pid_vnr(current); 839 } 840 841 /* 842 * Accessing ->real_parent is not SMP-safe, it could 843 * change from under us. However, we can use a stale 844 * value of ->real_parent under rcu_read_lock(), see 845 * release_task()->call_rcu(delayed_put_task_struct). 846 */ 847 SYSCALL_DEFINE0(getppid) 848 { 849 int pid; 850 851 rcu_read_lock(); 852 pid = task_tgid_vnr(rcu_dereference(current->real_parent)); 853 rcu_read_unlock(); 854 855 return pid; 856 } 857 858 SYSCALL_DEFINE0(getuid) 859 { 860 /* Only we change this so SMP safe */ 861 return from_kuid_munged(current_user_ns(), current_uid()); 862 } 863 864 SYSCALL_DEFINE0(geteuid) 865 { 866 /* Only we change this so SMP safe */ 867 return from_kuid_munged(current_user_ns(), current_euid()); 868 } 869 870 SYSCALL_DEFINE0(getgid) 871 { 872 /* Only we change this so SMP safe */ 873 return from_kgid_munged(current_user_ns(), current_gid()); 874 } 875 876 SYSCALL_DEFINE0(getegid) 877 { 878 /* Only we change this so SMP safe */ 879 return from_kgid_munged(current_user_ns(), current_egid()); 880 } 881 882 void do_sys_times(struct tms *tms) 883 { 884 cputime_t tgutime, tgstime, cutime, cstime; 885 886 thread_group_cputime_adjusted(current, &tgutime, &tgstime); 887 cutime = current->signal->cutime; 888 cstime = current->signal->cstime; 889 tms->tms_utime = cputime_to_clock_t(tgutime); 890 tms->tms_stime = cputime_to_clock_t(tgstime); 891 tms->tms_cutime = cputime_to_clock_t(cutime); 892 tms->tms_cstime = cputime_to_clock_t(cstime); 893 } 894 895 SYSCALL_DEFINE1(times, struct tms __user *, tbuf) 896 { 897 if (tbuf) { 898 struct tms tmp; 899 900 do_sys_times(&tmp); 901 if (copy_to_user(tbuf, &tmp, sizeof(struct tms))) 902 return -EFAULT; 903 } 904 force_successful_syscall_return(); 905 return (long) jiffies_64_to_clock_t(get_jiffies_64()); 906 } 907 908 /* 909 * This needs some heavy checking ... 910 * I just haven't the stomach for it. I also don't fully 911 * understand sessions/pgrp etc. Let somebody who does explain it. 912 * 913 * OK, I think I have the protection semantics right.... this is really 914 * only important on a multi-user system anyway, to make sure one user 915 * can't send a signal to a process owned by another. -TYT, 12/12/91 916 * 917 * !PF_FORKNOEXEC check to conform completely to POSIX. 918 */ 919 SYSCALL_DEFINE2(setpgid, pid_t, pid, pid_t, pgid) 920 { 921 struct task_struct *p; 922 struct task_struct *group_leader = current->group_leader; 923 struct pid *pgrp; 924 int err; 925 926 if (!pid) 927 pid = task_pid_vnr(group_leader); 928 if (!pgid) 929 pgid = pid; 930 if (pgid < 0) 931 return -EINVAL; 932 rcu_read_lock(); 933 934 /* From this point forward we keep holding onto the tasklist lock 935 * so that our parent does not change from under us. -DaveM 936 */ 937 write_lock_irq(&tasklist_lock); 938 939 err = -ESRCH; 940 p = find_task_by_vpid(pid); 941 if (!p) 942 goto out; 943 944 err = -EINVAL; 945 if (!thread_group_leader(p)) 946 goto out; 947 948 if (same_thread_group(p->real_parent, group_leader)) { 949 err = -EPERM; 950 if (task_session(p) != task_session(group_leader)) 951 goto out; 952 err = -EACCES; 953 if (!(p->flags & PF_FORKNOEXEC)) 954 goto out; 955 } else { 956 err = -ESRCH; 957 if (p != group_leader) 958 goto out; 959 } 960 961 err = -EPERM; 962 if (p->signal->leader) 963 goto out; 964 965 pgrp = task_pid(p); 966 if (pgid != pid) { 967 struct task_struct *g; 968 969 pgrp = find_vpid(pgid); 970 g = pid_task(pgrp, PIDTYPE_PGID); 971 if (!g || task_session(g) != task_session(group_leader)) 972 goto out; 973 } 974 975 err = security_task_setpgid(p, pgid); 976 if (err) 977 goto out; 978 979 if (task_pgrp(p) != pgrp) 980 change_pid(p, PIDTYPE_PGID, pgrp); 981 982 err = 0; 983 out: 984 /* All paths lead to here, thus we are safe. -DaveM */ 985 write_unlock_irq(&tasklist_lock); 986 rcu_read_unlock(); 987 return err; 988 } 989 990 SYSCALL_DEFINE1(getpgid, pid_t, pid) 991 { 992 struct task_struct *p; 993 struct pid *grp; 994 int retval; 995 996 rcu_read_lock(); 997 if (!pid) 998 grp = task_pgrp(current); 999 else { 1000 retval = -ESRCH; 1001 p = find_task_by_vpid(pid); 1002 if (!p) 1003 goto out; 1004 grp = task_pgrp(p); 1005 if (!grp) 1006 goto out; 1007 1008 retval = security_task_getpgid(p); 1009 if (retval) 1010 goto out; 1011 } 1012 retval = pid_vnr(grp); 1013 out: 1014 rcu_read_unlock(); 1015 return retval; 1016 } 1017 1018 #ifdef __ARCH_WANT_SYS_GETPGRP 1019 1020 SYSCALL_DEFINE0(getpgrp) 1021 { 1022 return sys_getpgid(0); 1023 } 1024 1025 #endif 1026 1027 SYSCALL_DEFINE1(getsid, pid_t, pid) 1028 { 1029 struct task_struct *p; 1030 struct pid *sid; 1031 int retval; 1032 1033 rcu_read_lock(); 1034 if (!pid) 1035 sid = task_session(current); 1036 else { 1037 retval = -ESRCH; 1038 p = find_task_by_vpid(pid); 1039 if (!p) 1040 goto out; 1041 sid = task_session(p); 1042 if (!sid) 1043 goto out; 1044 1045 retval = security_task_getsid(p); 1046 if (retval) 1047 goto out; 1048 } 1049 retval = pid_vnr(sid); 1050 out: 1051 rcu_read_unlock(); 1052 return retval; 1053 } 1054 1055 static void set_special_pids(struct pid *pid) 1056 { 1057 struct task_struct *curr = current->group_leader; 1058 1059 if (task_session(curr) != pid) 1060 change_pid(curr, PIDTYPE_SID, pid); 1061 1062 if (task_pgrp(curr) != pid) 1063 change_pid(curr, PIDTYPE_PGID, pid); 1064 } 1065 1066 SYSCALL_DEFINE0(setsid) 1067 { 1068 struct task_struct *group_leader = current->group_leader; 1069 struct pid *sid = task_pid(group_leader); 1070 pid_t session = pid_vnr(sid); 1071 int err = -EPERM; 1072 1073 write_lock_irq(&tasklist_lock); 1074 /* Fail if I am already a session leader */ 1075 if (group_leader->signal->leader) 1076 goto out; 1077 1078 /* Fail if a process group id already exists that equals the 1079 * proposed session id. 1080 */ 1081 if (pid_task(sid, PIDTYPE_PGID)) 1082 goto out; 1083 1084 group_leader->signal->leader = 1; 1085 set_special_pids(sid); 1086 1087 proc_clear_tty(group_leader); 1088 1089 err = session; 1090 out: 1091 write_unlock_irq(&tasklist_lock); 1092 if (err > 0) { 1093 proc_sid_connector(group_leader); 1094 sched_autogroup_create_attach(group_leader); 1095 } 1096 return err; 1097 } 1098 1099 DECLARE_RWSEM(uts_sem); 1100 1101 #ifdef COMPAT_UTS_MACHINE 1102 #define override_architecture(name) \ 1103 (personality(current->personality) == PER_LINUX32 && \ 1104 copy_to_user(name->machine, COMPAT_UTS_MACHINE, \ 1105 sizeof(COMPAT_UTS_MACHINE))) 1106 #else 1107 #define override_architecture(name) 0 1108 #endif 1109 1110 /* 1111 * Work around broken programs that cannot handle "Linux 3.0". 1112 * Instead we map 3.x to 2.6.40+x, so e.g. 3.0 would be 2.6.40 1113 * And we map 4.x to 2.6.60+x, so 4.0 would be 2.6.60. 1114 */ 1115 static int override_release(char __user *release, size_t len) 1116 { 1117 int ret = 0; 1118 1119 if (current->personality & UNAME26) { 1120 const char *rest = UTS_RELEASE; 1121 char buf[65] = { 0 }; 1122 int ndots = 0; 1123 unsigned v; 1124 size_t copy; 1125 1126 while (*rest) { 1127 if (*rest == '.' && ++ndots >= 3) 1128 break; 1129 if (!isdigit(*rest) && *rest != '.') 1130 break; 1131 rest++; 1132 } 1133 v = ((LINUX_VERSION_CODE >> 8) & 0xff) + 60; 1134 copy = clamp_t(size_t, len, 1, sizeof(buf)); 1135 copy = scnprintf(buf, copy, "2.6.%u%s", v, rest); 1136 ret = copy_to_user(release, buf, copy + 1); 1137 } 1138 return ret; 1139 } 1140 1141 SYSCALL_DEFINE1(newuname, struct new_utsname __user *, name) 1142 { 1143 int errno = 0; 1144 1145 down_read(&uts_sem); 1146 if (copy_to_user(name, utsname(), sizeof *name)) 1147 errno = -EFAULT; 1148 up_read(&uts_sem); 1149 1150 if (!errno && override_release(name->release, sizeof(name->release))) 1151 errno = -EFAULT; 1152 if (!errno && override_architecture(name)) 1153 errno = -EFAULT; 1154 return errno; 1155 } 1156 1157 #ifdef __ARCH_WANT_SYS_OLD_UNAME 1158 /* 1159 * Old cruft 1160 */ 1161 SYSCALL_DEFINE1(uname, struct old_utsname __user *, name) 1162 { 1163 int error = 0; 1164 1165 if (!name) 1166 return -EFAULT; 1167 1168 down_read(&uts_sem); 1169 if (copy_to_user(name, utsname(), sizeof(*name))) 1170 error = -EFAULT; 1171 up_read(&uts_sem); 1172 1173 if (!error && override_release(name->release, sizeof(name->release))) 1174 error = -EFAULT; 1175 if (!error && override_architecture(name)) 1176 error = -EFAULT; 1177 return error; 1178 } 1179 1180 SYSCALL_DEFINE1(olduname, struct oldold_utsname __user *, name) 1181 { 1182 int error; 1183 1184 if (!name) 1185 return -EFAULT; 1186 if (!access_ok(VERIFY_WRITE, name, sizeof(struct oldold_utsname))) 1187 return -EFAULT; 1188 1189 down_read(&uts_sem); 1190 error = __copy_to_user(&name->sysname, &utsname()->sysname, 1191 __OLD_UTS_LEN); 1192 error |= __put_user(0, name->sysname + __OLD_UTS_LEN); 1193 error |= __copy_to_user(&name->nodename, &utsname()->nodename, 1194 __OLD_UTS_LEN); 1195 error |= __put_user(0, name->nodename + __OLD_UTS_LEN); 1196 error |= __copy_to_user(&name->release, &utsname()->release, 1197 __OLD_UTS_LEN); 1198 error |= __put_user(0, name->release + __OLD_UTS_LEN); 1199 error |= __copy_to_user(&name->version, &utsname()->version, 1200 __OLD_UTS_LEN); 1201 error |= __put_user(0, name->version + __OLD_UTS_LEN); 1202 error |= __copy_to_user(&name->machine, &utsname()->machine, 1203 __OLD_UTS_LEN); 1204 error |= __put_user(0, name->machine + __OLD_UTS_LEN); 1205 up_read(&uts_sem); 1206 1207 if (!error && override_architecture(name)) 1208 error = -EFAULT; 1209 if (!error && override_release(name->release, sizeof(name->release))) 1210 error = -EFAULT; 1211 return error ? -EFAULT : 0; 1212 } 1213 #endif 1214 1215 SYSCALL_DEFINE2(sethostname, char __user *, name, int, len) 1216 { 1217 int errno; 1218 char tmp[__NEW_UTS_LEN]; 1219 1220 if (!ns_capable(current->nsproxy->uts_ns->user_ns, CAP_SYS_ADMIN)) 1221 return -EPERM; 1222 1223 if (len < 0 || len > __NEW_UTS_LEN) 1224 return -EINVAL; 1225 down_write(&uts_sem); 1226 errno = -EFAULT; 1227 if (!copy_from_user(tmp, name, len)) { 1228 struct new_utsname *u = utsname(); 1229 1230 memcpy(u->nodename, tmp, len); 1231 memset(u->nodename + len, 0, sizeof(u->nodename) - len); 1232 errno = 0; 1233 uts_proc_notify(UTS_PROC_HOSTNAME); 1234 } 1235 up_write(&uts_sem); 1236 return errno; 1237 } 1238 1239 #ifdef __ARCH_WANT_SYS_GETHOSTNAME 1240 1241 SYSCALL_DEFINE2(gethostname, char __user *, name, int, len) 1242 { 1243 int i, errno; 1244 struct new_utsname *u; 1245 1246 if (len < 0) 1247 return -EINVAL; 1248 down_read(&uts_sem); 1249 u = utsname(); 1250 i = 1 + strlen(u->nodename); 1251 if (i > len) 1252 i = len; 1253 errno = 0; 1254 if (copy_to_user(name, u->nodename, i)) 1255 errno = -EFAULT; 1256 up_read(&uts_sem); 1257 return errno; 1258 } 1259 1260 #endif 1261 1262 /* 1263 * Only setdomainname; getdomainname can be implemented by calling 1264 * uname() 1265 */ 1266 SYSCALL_DEFINE2(setdomainname, char __user *, name, int, len) 1267 { 1268 int errno; 1269 char tmp[__NEW_UTS_LEN]; 1270 1271 if (!ns_capable(current->nsproxy->uts_ns->user_ns, CAP_SYS_ADMIN)) 1272 return -EPERM; 1273 if (len < 0 || len > __NEW_UTS_LEN) 1274 return -EINVAL; 1275 1276 down_write(&uts_sem); 1277 errno = -EFAULT; 1278 if (!copy_from_user(tmp, name, len)) { 1279 struct new_utsname *u = utsname(); 1280 1281 memcpy(u->domainname, tmp, len); 1282 memset(u->domainname + len, 0, sizeof(u->domainname) - len); 1283 errno = 0; 1284 uts_proc_notify(UTS_PROC_DOMAINNAME); 1285 } 1286 up_write(&uts_sem); 1287 return errno; 1288 } 1289 1290 SYSCALL_DEFINE2(getrlimit, unsigned int, resource, struct rlimit __user *, rlim) 1291 { 1292 struct rlimit value; 1293 int ret; 1294 1295 ret = do_prlimit(current, resource, NULL, &value); 1296 if (!ret) 1297 ret = copy_to_user(rlim, &value, sizeof(*rlim)) ? -EFAULT : 0; 1298 1299 return ret; 1300 } 1301 1302 #ifdef __ARCH_WANT_SYS_OLD_GETRLIMIT 1303 1304 /* 1305 * Back compatibility for getrlimit. Needed for some apps. 1306 */ 1307 SYSCALL_DEFINE2(old_getrlimit, unsigned int, resource, 1308 struct rlimit __user *, rlim) 1309 { 1310 struct rlimit x; 1311 if (resource >= RLIM_NLIMITS) 1312 return -EINVAL; 1313 1314 task_lock(current->group_leader); 1315 x = current->signal->rlim[resource]; 1316 task_unlock(current->group_leader); 1317 if (x.rlim_cur > 0x7FFFFFFF) 1318 x.rlim_cur = 0x7FFFFFFF; 1319 if (x.rlim_max > 0x7FFFFFFF) 1320 x.rlim_max = 0x7FFFFFFF; 1321 return copy_to_user(rlim, &x, sizeof(x)) ? -EFAULT : 0; 1322 } 1323 1324 #endif 1325 1326 static inline bool rlim64_is_infinity(__u64 rlim64) 1327 { 1328 #if BITS_PER_LONG < 64 1329 return rlim64 >= ULONG_MAX; 1330 #else 1331 return rlim64 == RLIM64_INFINITY; 1332 #endif 1333 } 1334 1335 static void rlim_to_rlim64(const struct rlimit *rlim, struct rlimit64 *rlim64) 1336 { 1337 if (rlim->rlim_cur == RLIM_INFINITY) 1338 rlim64->rlim_cur = RLIM64_INFINITY; 1339 else 1340 rlim64->rlim_cur = rlim->rlim_cur; 1341 if (rlim->rlim_max == RLIM_INFINITY) 1342 rlim64->rlim_max = RLIM64_INFINITY; 1343 else 1344 rlim64->rlim_max = rlim->rlim_max; 1345 } 1346 1347 static void rlim64_to_rlim(const struct rlimit64 *rlim64, struct rlimit *rlim) 1348 { 1349 if (rlim64_is_infinity(rlim64->rlim_cur)) 1350 rlim->rlim_cur = RLIM_INFINITY; 1351 else 1352 rlim->rlim_cur = (unsigned long)rlim64->rlim_cur; 1353 if (rlim64_is_infinity(rlim64->rlim_max)) 1354 rlim->rlim_max = RLIM_INFINITY; 1355 else 1356 rlim->rlim_max = (unsigned long)rlim64->rlim_max; 1357 } 1358 1359 /* make sure you are allowed to change @tsk limits before calling this */ 1360 int do_prlimit(struct task_struct *tsk, unsigned int resource, 1361 struct rlimit *new_rlim, struct rlimit *old_rlim) 1362 { 1363 struct rlimit *rlim; 1364 int retval = 0; 1365 1366 if (resource >= RLIM_NLIMITS) 1367 return -EINVAL; 1368 if (new_rlim) { 1369 if (new_rlim->rlim_cur > new_rlim->rlim_max) 1370 return -EINVAL; 1371 if (resource == RLIMIT_NOFILE && 1372 new_rlim->rlim_max > sysctl_nr_open) 1373 return -EPERM; 1374 } 1375 1376 /* protect tsk->signal and tsk->sighand from disappearing */ 1377 read_lock(&tasklist_lock); 1378 if (!tsk->sighand) { 1379 retval = -ESRCH; 1380 goto out; 1381 } 1382 1383 rlim = tsk->signal->rlim + resource; 1384 task_lock(tsk->group_leader); 1385 if (new_rlim) { 1386 /* Keep the capable check against init_user_ns until 1387 cgroups can contain all limits */ 1388 if (new_rlim->rlim_max > rlim->rlim_max && 1389 !capable(CAP_SYS_RESOURCE)) 1390 retval = -EPERM; 1391 if (!retval) 1392 retval = security_task_setrlimit(tsk->group_leader, 1393 resource, new_rlim); 1394 if (resource == RLIMIT_CPU && new_rlim->rlim_cur == 0) { 1395 /* 1396 * The caller is asking for an immediate RLIMIT_CPU 1397 * expiry. But we use the zero value to mean "it was 1398 * never set". So let's cheat and make it one second 1399 * instead 1400 */ 1401 new_rlim->rlim_cur = 1; 1402 } 1403 } 1404 if (!retval) { 1405 if (old_rlim) 1406 *old_rlim = *rlim; 1407 if (new_rlim) 1408 *rlim = *new_rlim; 1409 } 1410 task_unlock(tsk->group_leader); 1411 1412 /* 1413 * RLIMIT_CPU handling. Note that the kernel fails to return an error 1414 * code if it rejected the user's attempt to set RLIMIT_CPU. This is a 1415 * very long-standing error, and fixing it now risks breakage of 1416 * applications, so we live with it 1417 */ 1418 if (!retval && new_rlim && resource == RLIMIT_CPU && 1419 new_rlim->rlim_cur != RLIM_INFINITY) 1420 update_rlimit_cpu(tsk, new_rlim->rlim_cur); 1421 out: 1422 read_unlock(&tasklist_lock); 1423 return retval; 1424 } 1425 1426 /* rcu lock must be held */ 1427 static int check_prlimit_permission(struct task_struct *task) 1428 { 1429 const struct cred *cred = current_cred(), *tcred; 1430 1431 if (current == task) 1432 return 0; 1433 1434 tcred = __task_cred(task); 1435 if (uid_eq(cred->uid, tcred->euid) && 1436 uid_eq(cred->uid, tcred->suid) && 1437 uid_eq(cred->uid, tcred->uid) && 1438 gid_eq(cred->gid, tcred->egid) && 1439 gid_eq(cred->gid, tcred->sgid) && 1440 gid_eq(cred->gid, tcred->gid)) 1441 return 0; 1442 if (ns_capable(tcred->user_ns, CAP_SYS_RESOURCE)) 1443 return 0; 1444 1445 return -EPERM; 1446 } 1447 1448 SYSCALL_DEFINE4(prlimit64, pid_t, pid, unsigned int, resource, 1449 const struct rlimit64 __user *, new_rlim, 1450 struct rlimit64 __user *, old_rlim) 1451 { 1452 struct rlimit64 old64, new64; 1453 struct rlimit old, new; 1454 struct task_struct *tsk; 1455 int ret; 1456 1457 if (new_rlim) { 1458 if (copy_from_user(&new64, new_rlim, sizeof(new64))) 1459 return -EFAULT; 1460 rlim64_to_rlim(&new64, &new); 1461 } 1462 1463 rcu_read_lock(); 1464 tsk = pid ? find_task_by_vpid(pid) : current; 1465 if (!tsk) { 1466 rcu_read_unlock(); 1467 return -ESRCH; 1468 } 1469 ret = check_prlimit_permission(tsk); 1470 if (ret) { 1471 rcu_read_unlock(); 1472 return ret; 1473 } 1474 get_task_struct(tsk); 1475 rcu_read_unlock(); 1476 1477 ret = do_prlimit(tsk, resource, new_rlim ? &new : NULL, 1478 old_rlim ? &old : NULL); 1479 1480 if (!ret && old_rlim) { 1481 rlim_to_rlim64(&old, &old64); 1482 if (copy_to_user(old_rlim, &old64, sizeof(old64))) 1483 ret = -EFAULT; 1484 } 1485 1486 put_task_struct(tsk); 1487 return ret; 1488 } 1489 1490 SYSCALL_DEFINE2(setrlimit, unsigned int, resource, struct rlimit __user *, rlim) 1491 { 1492 struct rlimit new_rlim; 1493 1494 if (copy_from_user(&new_rlim, rlim, sizeof(*rlim))) 1495 return -EFAULT; 1496 return do_prlimit(current, resource, &new_rlim, NULL); 1497 } 1498 1499 /* 1500 * It would make sense to put struct rusage in the task_struct, 1501 * except that would make the task_struct be *really big*. After 1502 * task_struct gets moved into malloc'ed memory, it would 1503 * make sense to do this. It will make moving the rest of the information 1504 * a lot simpler! (Which we're not doing right now because we're not 1505 * measuring them yet). 1506 * 1507 * When sampling multiple threads for RUSAGE_SELF, under SMP we might have 1508 * races with threads incrementing their own counters. But since word 1509 * reads are atomic, we either get new values or old values and we don't 1510 * care which for the sums. We always take the siglock to protect reading 1511 * the c* fields from p->signal from races with exit.c updating those 1512 * fields when reaping, so a sample either gets all the additions of a 1513 * given child after it's reaped, or none so this sample is before reaping. 1514 * 1515 * Locking: 1516 * We need to take the siglock for CHILDEREN, SELF and BOTH 1517 * for the cases current multithreaded, non-current single threaded 1518 * non-current multithreaded. Thread traversal is now safe with 1519 * the siglock held. 1520 * Strictly speaking, we donot need to take the siglock if we are current and 1521 * single threaded, as no one else can take our signal_struct away, no one 1522 * else can reap the children to update signal->c* counters, and no one else 1523 * can race with the signal-> fields. If we do not take any lock, the 1524 * signal-> fields could be read out of order while another thread was just 1525 * exiting. So we should place a read memory barrier when we avoid the lock. 1526 * On the writer side, write memory barrier is implied in __exit_signal 1527 * as __exit_signal releases the siglock spinlock after updating the signal-> 1528 * fields. But we don't do this yet to keep things simple. 1529 * 1530 */ 1531 1532 static void accumulate_thread_rusage(struct task_struct *t, struct rusage *r) 1533 { 1534 r->ru_nvcsw += t->nvcsw; 1535 r->ru_nivcsw += t->nivcsw; 1536 r->ru_minflt += t->min_flt; 1537 r->ru_majflt += t->maj_flt; 1538 r->ru_inblock += task_io_get_inblock(t); 1539 r->ru_oublock += task_io_get_oublock(t); 1540 } 1541 1542 static void k_getrusage(struct task_struct *p, int who, struct rusage *r) 1543 { 1544 struct task_struct *t; 1545 unsigned long flags; 1546 cputime_t tgutime, tgstime, utime, stime; 1547 unsigned long maxrss = 0; 1548 1549 memset((char *)r, 0, sizeof (*r)); 1550 utime = stime = 0; 1551 1552 if (who == RUSAGE_THREAD) { 1553 task_cputime_adjusted(current, &utime, &stime); 1554 accumulate_thread_rusage(p, r); 1555 maxrss = p->signal->maxrss; 1556 goto out; 1557 } 1558 1559 if (!lock_task_sighand(p, &flags)) 1560 return; 1561 1562 switch (who) { 1563 case RUSAGE_BOTH: 1564 case RUSAGE_CHILDREN: 1565 utime = p->signal->cutime; 1566 stime = p->signal->cstime; 1567 r->ru_nvcsw = p->signal->cnvcsw; 1568 r->ru_nivcsw = p->signal->cnivcsw; 1569 r->ru_minflt = p->signal->cmin_flt; 1570 r->ru_majflt = p->signal->cmaj_flt; 1571 r->ru_inblock = p->signal->cinblock; 1572 r->ru_oublock = p->signal->coublock; 1573 maxrss = p->signal->cmaxrss; 1574 1575 if (who == RUSAGE_CHILDREN) 1576 break; 1577 1578 case RUSAGE_SELF: 1579 thread_group_cputime_adjusted(p, &tgutime, &tgstime); 1580 utime += tgutime; 1581 stime += tgstime; 1582 r->ru_nvcsw += p->signal->nvcsw; 1583 r->ru_nivcsw += p->signal->nivcsw; 1584 r->ru_minflt += p->signal->min_flt; 1585 r->ru_majflt += p->signal->maj_flt; 1586 r->ru_inblock += p->signal->inblock; 1587 r->ru_oublock += p->signal->oublock; 1588 if (maxrss < p->signal->maxrss) 1589 maxrss = p->signal->maxrss; 1590 t = p; 1591 do { 1592 accumulate_thread_rusage(t, r); 1593 } while_each_thread(p, t); 1594 break; 1595 1596 default: 1597 BUG(); 1598 } 1599 unlock_task_sighand(p, &flags); 1600 1601 out: 1602 cputime_to_timeval(utime, &r->ru_utime); 1603 cputime_to_timeval(stime, &r->ru_stime); 1604 1605 if (who != RUSAGE_CHILDREN) { 1606 struct mm_struct *mm = get_task_mm(p); 1607 1608 if (mm) { 1609 setmax_mm_hiwater_rss(&maxrss, mm); 1610 mmput(mm); 1611 } 1612 } 1613 r->ru_maxrss = maxrss * (PAGE_SIZE / 1024); /* convert pages to KBs */ 1614 } 1615 1616 int getrusage(struct task_struct *p, int who, struct rusage __user *ru) 1617 { 1618 struct rusage r; 1619 1620 k_getrusage(p, who, &r); 1621 return copy_to_user(ru, &r, sizeof(r)) ? -EFAULT : 0; 1622 } 1623 1624 SYSCALL_DEFINE2(getrusage, int, who, struct rusage __user *, ru) 1625 { 1626 if (who != RUSAGE_SELF && who != RUSAGE_CHILDREN && 1627 who != RUSAGE_THREAD) 1628 return -EINVAL; 1629 return getrusage(current, who, ru); 1630 } 1631 1632 #ifdef CONFIG_COMPAT 1633 COMPAT_SYSCALL_DEFINE2(getrusage, int, who, struct compat_rusage __user *, ru) 1634 { 1635 struct rusage r; 1636 1637 if (who != RUSAGE_SELF && who != RUSAGE_CHILDREN && 1638 who != RUSAGE_THREAD) 1639 return -EINVAL; 1640 1641 k_getrusage(current, who, &r); 1642 return put_compat_rusage(&r, ru); 1643 } 1644 #endif 1645 1646 SYSCALL_DEFINE1(umask, int, mask) 1647 { 1648 mask = xchg(¤t->fs->umask, mask & S_IRWXUGO); 1649 return mask; 1650 } 1651 1652 static int prctl_set_mm_exe_file(struct mm_struct *mm, unsigned int fd) 1653 { 1654 struct fd exe; 1655 struct file *old_exe, *exe_file; 1656 struct inode *inode; 1657 int err; 1658 1659 exe = fdget(fd); 1660 if (!exe.file) 1661 return -EBADF; 1662 1663 inode = file_inode(exe.file); 1664 1665 /* 1666 * Because the original mm->exe_file points to executable file, make 1667 * sure that this one is executable as well, to avoid breaking an 1668 * overall picture. 1669 */ 1670 err = -EACCES; 1671 if (!S_ISREG(inode->i_mode) || path_noexec(&exe.file->f_path)) 1672 goto exit; 1673 1674 err = inode_permission(inode, MAY_EXEC); 1675 if (err) 1676 goto exit; 1677 1678 /* 1679 * Forbid mm->exe_file change if old file still mapped. 1680 */ 1681 exe_file = get_mm_exe_file(mm); 1682 err = -EBUSY; 1683 if (exe_file) { 1684 struct vm_area_struct *vma; 1685 1686 down_read(&mm->mmap_sem); 1687 for (vma = mm->mmap; vma; vma = vma->vm_next) { 1688 if (!vma->vm_file) 1689 continue; 1690 if (path_equal(&vma->vm_file->f_path, 1691 &exe_file->f_path)) 1692 goto exit_err; 1693 } 1694 1695 up_read(&mm->mmap_sem); 1696 fput(exe_file); 1697 } 1698 1699 /* 1700 * The symlink can be changed only once, just to disallow arbitrary 1701 * transitions malicious software might bring in. This means one 1702 * could make a snapshot over all processes running and monitor 1703 * /proc/pid/exe changes to notice unusual activity if needed. 1704 */ 1705 err = -EPERM; 1706 if (test_and_set_bit(MMF_EXE_FILE_CHANGED, &mm->flags)) 1707 goto exit; 1708 1709 err = 0; 1710 /* set the new file, lockless */ 1711 get_file(exe.file); 1712 old_exe = xchg(&mm->exe_file, exe.file); 1713 if (old_exe) 1714 fput(old_exe); 1715 exit: 1716 fdput(exe); 1717 return err; 1718 exit_err: 1719 up_read(&mm->mmap_sem); 1720 fput(exe_file); 1721 goto exit; 1722 } 1723 1724 /* 1725 * WARNING: we don't require any capability here so be very careful 1726 * in what is allowed for modification from userspace. 1727 */ 1728 static int validate_prctl_map(struct prctl_mm_map *prctl_map) 1729 { 1730 unsigned long mmap_max_addr = TASK_SIZE; 1731 struct mm_struct *mm = current->mm; 1732 int error = -EINVAL, i; 1733 1734 static const unsigned char offsets[] = { 1735 offsetof(struct prctl_mm_map, start_code), 1736 offsetof(struct prctl_mm_map, end_code), 1737 offsetof(struct prctl_mm_map, start_data), 1738 offsetof(struct prctl_mm_map, end_data), 1739 offsetof(struct prctl_mm_map, start_brk), 1740 offsetof(struct prctl_mm_map, brk), 1741 offsetof(struct prctl_mm_map, start_stack), 1742 offsetof(struct prctl_mm_map, arg_start), 1743 offsetof(struct prctl_mm_map, arg_end), 1744 offsetof(struct prctl_mm_map, env_start), 1745 offsetof(struct prctl_mm_map, env_end), 1746 }; 1747 1748 /* 1749 * Make sure the members are not somewhere outside 1750 * of allowed address space. 1751 */ 1752 for (i = 0; i < ARRAY_SIZE(offsets); i++) { 1753 u64 val = *(u64 *)((char *)prctl_map + offsets[i]); 1754 1755 if ((unsigned long)val >= mmap_max_addr || 1756 (unsigned long)val < mmap_min_addr) 1757 goto out; 1758 } 1759 1760 /* 1761 * Make sure the pairs are ordered. 1762 */ 1763 #define __prctl_check_order(__m1, __op, __m2) \ 1764 ((unsigned long)prctl_map->__m1 __op \ 1765 (unsigned long)prctl_map->__m2) ? 0 : -EINVAL 1766 error = __prctl_check_order(start_code, <, end_code); 1767 error |= __prctl_check_order(start_data, <, end_data); 1768 error |= __prctl_check_order(start_brk, <=, brk); 1769 error |= __prctl_check_order(arg_start, <=, arg_end); 1770 error |= __prctl_check_order(env_start, <=, env_end); 1771 if (error) 1772 goto out; 1773 #undef __prctl_check_order 1774 1775 error = -EINVAL; 1776 1777 /* 1778 * @brk should be after @end_data in traditional maps. 1779 */ 1780 if (prctl_map->start_brk <= prctl_map->end_data || 1781 prctl_map->brk <= prctl_map->end_data) 1782 goto out; 1783 1784 /* 1785 * Neither we should allow to override limits if they set. 1786 */ 1787 if (check_data_rlimit(rlimit(RLIMIT_DATA), prctl_map->brk, 1788 prctl_map->start_brk, prctl_map->end_data, 1789 prctl_map->start_data)) 1790 goto out; 1791 1792 /* 1793 * Someone is trying to cheat the auxv vector. 1794 */ 1795 if (prctl_map->auxv_size) { 1796 if (!prctl_map->auxv || prctl_map->auxv_size > sizeof(mm->saved_auxv)) 1797 goto out; 1798 } 1799 1800 /* 1801 * Finally, make sure the caller has the rights to 1802 * change /proc/pid/exe link: only local root should 1803 * be allowed to. 1804 */ 1805 if (prctl_map->exe_fd != (u32)-1) { 1806 struct user_namespace *ns = current_user_ns(); 1807 const struct cred *cred = current_cred(); 1808 1809 if (!uid_eq(cred->uid, make_kuid(ns, 0)) || 1810 !gid_eq(cred->gid, make_kgid(ns, 0))) 1811 goto out; 1812 } 1813 1814 error = 0; 1815 out: 1816 return error; 1817 } 1818 1819 #ifdef CONFIG_CHECKPOINT_RESTORE 1820 static int prctl_set_mm_map(int opt, const void __user *addr, unsigned long data_size) 1821 { 1822 struct prctl_mm_map prctl_map = { .exe_fd = (u32)-1, }; 1823 unsigned long user_auxv[AT_VECTOR_SIZE]; 1824 struct mm_struct *mm = current->mm; 1825 int error; 1826 1827 BUILD_BUG_ON(sizeof(user_auxv) != sizeof(mm->saved_auxv)); 1828 BUILD_BUG_ON(sizeof(struct prctl_mm_map) > 256); 1829 1830 if (opt == PR_SET_MM_MAP_SIZE) 1831 return put_user((unsigned int)sizeof(prctl_map), 1832 (unsigned int __user *)addr); 1833 1834 if (data_size != sizeof(prctl_map)) 1835 return -EINVAL; 1836 1837 if (copy_from_user(&prctl_map, addr, sizeof(prctl_map))) 1838 return -EFAULT; 1839 1840 error = validate_prctl_map(&prctl_map); 1841 if (error) 1842 return error; 1843 1844 if (prctl_map.auxv_size) { 1845 memset(user_auxv, 0, sizeof(user_auxv)); 1846 if (copy_from_user(user_auxv, 1847 (const void __user *)prctl_map.auxv, 1848 prctl_map.auxv_size)) 1849 return -EFAULT; 1850 1851 /* Last entry must be AT_NULL as specification requires */ 1852 user_auxv[AT_VECTOR_SIZE - 2] = AT_NULL; 1853 user_auxv[AT_VECTOR_SIZE - 1] = AT_NULL; 1854 } 1855 1856 if (prctl_map.exe_fd != (u32)-1) 1857 error = prctl_set_mm_exe_file(mm, prctl_map.exe_fd); 1858 down_read(&mm->mmap_sem); 1859 if (error) 1860 goto out; 1861 1862 /* 1863 * We don't validate if these members are pointing to 1864 * real present VMAs because application may have correspond 1865 * VMAs already unmapped and kernel uses these members for statistics 1866 * output in procfs mostly, except 1867 * 1868 * - @start_brk/@brk which are used in do_brk but kernel lookups 1869 * for VMAs when updating these memvers so anything wrong written 1870 * here cause kernel to swear at userspace program but won't lead 1871 * to any problem in kernel itself 1872 */ 1873 1874 mm->start_code = prctl_map.start_code; 1875 mm->end_code = prctl_map.end_code; 1876 mm->start_data = prctl_map.start_data; 1877 mm->end_data = prctl_map.end_data; 1878 mm->start_brk = prctl_map.start_brk; 1879 mm->brk = prctl_map.brk; 1880 mm->start_stack = prctl_map.start_stack; 1881 mm->arg_start = prctl_map.arg_start; 1882 mm->arg_end = prctl_map.arg_end; 1883 mm->env_start = prctl_map.env_start; 1884 mm->env_end = prctl_map.env_end; 1885 1886 /* 1887 * Note this update of @saved_auxv is lockless thus 1888 * if someone reads this member in procfs while we're 1889 * updating -- it may get partly updated results. It's 1890 * known and acceptable trade off: we leave it as is to 1891 * not introduce additional locks here making the kernel 1892 * more complex. 1893 */ 1894 if (prctl_map.auxv_size) 1895 memcpy(mm->saved_auxv, user_auxv, sizeof(user_auxv)); 1896 1897 error = 0; 1898 out: 1899 up_read(&mm->mmap_sem); 1900 return error; 1901 } 1902 #endif /* CONFIG_CHECKPOINT_RESTORE */ 1903 1904 static int prctl_set_auxv(struct mm_struct *mm, unsigned long addr, 1905 unsigned long len) 1906 { 1907 /* 1908 * This doesn't move the auxiliary vector itself since it's pinned to 1909 * mm_struct, but it permits filling the vector with new values. It's 1910 * up to the caller to provide sane values here, otherwise userspace 1911 * tools which use this vector might be unhappy. 1912 */ 1913 unsigned long user_auxv[AT_VECTOR_SIZE]; 1914 1915 if (len > sizeof(user_auxv)) 1916 return -EINVAL; 1917 1918 if (copy_from_user(user_auxv, (const void __user *)addr, len)) 1919 return -EFAULT; 1920 1921 /* Make sure the last entry is always AT_NULL */ 1922 user_auxv[AT_VECTOR_SIZE - 2] = 0; 1923 user_auxv[AT_VECTOR_SIZE - 1] = 0; 1924 1925 BUILD_BUG_ON(sizeof(user_auxv) != sizeof(mm->saved_auxv)); 1926 1927 task_lock(current); 1928 memcpy(mm->saved_auxv, user_auxv, len); 1929 task_unlock(current); 1930 1931 return 0; 1932 } 1933 1934 static int prctl_set_mm(int opt, unsigned long addr, 1935 unsigned long arg4, unsigned long arg5) 1936 { 1937 struct mm_struct *mm = current->mm; 1938 struct prctl_mm_map prctl_map; 1939 struct vm_area_struct *vma; 1940 int error; 1941 1942 if (arg5 || (arg4 && (opt != PR_SET_MM_AUXV && 1943 opt != PR_SET_MM_MAP && 1944 opt != PR_SET_MM_MAP_SIZE))) 1945 return -EINVAL; 1946 1947 #ifdef CONFIG_CHECKPOINT_RESTORE 1948 if (opt == PR_SET_MM_MAP || opt == PR_SET_MM_MAP_SIZE) 1949 return prctl_set_mm_map(opt, (const void __user *)addr, arg4); 1950 #endif 1951 1952 if (!capable(CAP_SYS_RESOURCE)) 1953 return -EPERM; 1954 1955 if (opt == PR_SET_MM_EXE_FILE) 1956 return prctl_set_mm_exe_file(mm, (unsigned int)addr); 1957 1958 if (opt == PR_SET_MM_AUXV) 1959 return prctl_set_auxv(mm, addr, arg4); 1960 1961 if (addr >= TASK_SIZE || addr < mmap_min_addr) 1962 return -EINVAL; 1963 1964 error = -EINVAL; 1965 1966 down_read(&mm->mmap_sem); 1967 vma = find_vma(mm, addr); 1968 1969 prctl_map.start_code = mm->start_code; 1970 prctl_map.end_code = mm->end_code; 1971 prctl_map.start_data = mm->start_data; 1972 prctl_map.end_data = mm->end_data; 1973 prctl_map.start_brk = mm->start_brk; 1974 prctl_map.brk = mm->brk; 1975 prctl_map.start_stack = mm->start_stack; 1976 prctl_map.arg_start = mm->arg_start; 1977 prctl_map.arg_end = mm->arg_end; 1978 prctl_map.env_start = mm->env_start; 1979 prctl_map.env_end = mm->env_end; 1980 prctl_map.auxv = NULL; 1981 prctl_map.auxv_size = 0; 1982 prctl_map.exe_fd = -1; 1983 1984 switch (opt) { 1985 case PR_SET_MM_START_CODE: 1986 prctl_map.start_code = addr; 1987 break; 1988 case PR_SET_MM_END_CODE: 1989 prctl_map.end_code = addr; 1990 break; 1991 case PR_SET_MM_START_DATA: 1992 prctl_map.start_data = addr; 1993 break; 1994 case PR_SET_MM_END_DATA: 1995 prctl_map.end_data = addr; 1996 break; 1997 case PR_SET_MM_START_STACK: 1998 prctl_map.start_stack = addr; 1999 break; 2000 case PR_SET_MM_START_BRK: 2001 prctl_map.start_brk = addr; 2002 break; 2003 case PR_SET_MM_BRK: 2004 prctl_map.brk = addr; 2005 break; 2006 case PR_SET_MM_ARG_START: 2007 prctl_map.arg_start = addr; 2008 break; 2009 case PR_SET_MM_ARG_END: 2010 prctl_map.arg_end = addr; 2011 break; 2012 case PR_SET_MM_ENV_START: 2013 prctl_map.env_start = addr; 2014 break; 2015 case PR_SET_MM_ENV_END: 2016 prctl_map.env_end = addr; 2017 break; 2018 default: 2019 goto out; 2020 } 2021 2022 error = validate_prctl_map(&prctl_map); 2023 if (error) 2024 goto out; 2025 2026 switch (opt) { 2027 /* 2028 * If command line arguments and environment 2029 * are placed somewhere else on stack, we can 2030 * set them up here, ARG_START/END to setup 2031 * command line argumets and ENV_START/END 2032 * for environment. 2033 */ 2034 case PR_SET_MM_START_STACK: 2035 case PR_SET_MM_ARG_START: 2036 case PR_SET_MM_ARG_END: 2037 case PR_SET_MM_ENV_START: 2038 case PR_SET_MM_ENV_END: 2039 if (!vma) { 2040 error = -EFAULT; 2041 goto out; 2042 } 2043 } 2044 2045 mm->start_code = prctl_map.start_code; 2046 mm->end_code = prctl_map.end_code; 2047 mm->start_data = prctl_map.start_data; 2048 mm->end_data = prctl_map.end_data; 2049 mm->start_brk = prctl_map.start_brk; 2050 mm->brk = prctl_map.brk; 2051 mm->start_stack = prctl_map.start_stack; 2052 mm->arg_start = prctl_map.arg_start; 2053 mm->arg_end = prctl_map.arg_end; 2054 mm->env_start = prctl_map.env_start; 2055 mm->env_end = prctl_map.env_end; 2056 2057 error = 0; 2058 out: 2059 up_read(&mm->mmap_sem); 2060 return error; 2061 } 2062 2063 #ifdef CONFIG_CHECKPOINT_RESTORE 2064 static int prctl_get_tid_address(struct task_struct *me, int __user **tid_addr) 2065 { 2066 return put_user(me->clear_child_tid, tid_addr); 2067 } 2068 #else 2069 static int prctl_get_tid_address(struct task_struct *me, int __user **tid_addr) 2070 { 2071 return -EINVAL; 2072 } 2073 #endif 2074 2075 SYSCALL_DEFINE5(prctl, int, option, unsigned long, arg2, unsigned long, arg3, 2076 unsigned long, arg4, unsigned long, arg5) 2077 { 2078 struct task_struct *me = current; 2079 unsigned char comm[sizeof(me->comm)]; 2080 long error; 2081 2082 error = security_task_prctl(option, arg2, arg3, arg4, arg5); 2083 if (error != -ENOSYS) 2084 return error; 2085 2086 error = 0; 2087 switch (option) { 2088 case PR_SET_PDEATHSIG: 2089 if (!valid_signal(arg2)) { 2090 error = -EINVAL; 2091 break; 2092 } 2093 me->pdeath_signal = arg2; 2094 break; 2095 case PR_GET_PDEATHSIG: 2096 error = put_user(me->pdeath_signal, (int __user *)arg2); 2097 break; 2098 case PR_GET_DUMPABLE: 2099 error = get_dumpable(me->mm); 2100 break; 2101 case PR_SET_DUMPABLE: 2102 if (arg2 != SUID_DUMP_DISABLE && arg2 != SUID_DUMP_USER) { 2103 error = -EINVAL; 2104 break; 2105 } 2106 set_dumpable(me->mm, arg2); 2107 break; 2108 2109 case PR_SET_UNALIGN: 2110 error = SET_UNALIGN_CTL(me, arg2); 2111 break; 2112 case PR_GET_UNALIGN: 2113 error = GET_UNALIGN_CTL(me, arg2); 2114 break; 2115 case PR_SET_FPEMU: 2116 error = SET_FPEMU_CTL(me, arg2); 2117 break; 2118 case PR_GET_FPEMU: 2119 error = GET_FPEMU_CTL(me, arg2); 2120 break; 2121 case PR_SET_FPEXC: 2122 error = SET_FPEXC_CTL(me, arg2); 2123 break; 2124 case PR_GET_FPEXC: 2125 error = GET_FPEXC_CTL(me, arg2); 2126 break; 2127 case PR_GET_TIMING: 2128 error = PR_TIMING_STATISTICAL; 2129 break; 2130 case PR_SET_TIMING: 2131 if (arg2 != PR_TIMING_STATISTICAL) 2132 error = -EINVAL; 2133 break; 2134 case PR_SET_NAME: 2135 comm[sizeof(me->comm) - 1] = 0; 2136 if (strncpy_from_user(comm, (char __user *)arg2, 2137 sizeof(me->comm) - 1) < 0) 2138 return -EFAULT; 2139 set_task_comm(me, comm); 2140 proc_comm_connector(me); 2141 break; 2142 case PR_GET_NAME: 2143 get_task_comm(comm, me); 2144 if (copy_to_user((char __user *)arg2, comm, sizeof(comm))) 2145 return -EFAULT; 2146 break; 2147 case PR_GET_ENDIAN: 2148 error = GET_ENDIAN(me, arg2); 2149 break; 2150 case PR_SET_ENDIAN: 2151 error = SET_ENDIAN(me, arg2); 2152 break; 2153 case PR_GET_SECCOMP: 2154 error = prctl_get_seccomp(); 2155 break; 2156 case PR_SET_SECCOMP: 2157 error = prctl_set_seccomp(arg2, (char __user *)arg3); 2158 break; 2159 case PR_GET_TSC: 2160 error = GET_TSC_CTL(arg2); 2161 break; 2162 case PR_SET_TSC: 2163 error = SET_TSC_CTL(arg2); 2164 break; 2165 case PR_TASK_PERF_EVENTS_DISABLE: 2166 error = perf_event_task_disable(); 2167 break; 2168 case PR_TASK_PERF_EVENTS_ENABLE: 2169 error = perf_event_task_enable(); 2170 break; 2171 case PR_GET_TIMERSLACK: 2172 error = current->timer_slack_ns; 2173 break; 2174 case PR_SET_TIMERSLACK: 2175 if (arg2 <= 0) 2176 current->timer_slack_ns = 2177 current->default_timer_slack_ns; 2178 else 2179 current->timer_slack_ns = arg2; 2180 break; 2181 case PR_MCE_KILL: 2182 if (arg4 | arg5) 2183 return -EINVAL; 2184 switch (arg2) { 2185 case PR_MCE_KILL_CLEAR: 2186 if (arg3 != 0) 2187 return -EINVAL; 2188 current->flags &= ~PF_MCE_PROCESS; 2189 break; 2190 case PR_MCE_KILL_SET: 2191 current->flags |= PF_MCE_PROCESS; 2192 if (arg3 == PR_MCE_KILL_EARLY) 2193 current->flags |= PF_MCE_EARLY; 2194 else if (arg3 == PR_MCE_KILL_LATE) 2195 current->flags &= ~PF_MCE_EARLY; 2196 else if (arg3 == PR_MCE_KILL_DEFAULT) 2197 current->flags &= 2198 ~(PF_MCE_EARLY|PF_MCE_PROCESS); 2199 else 2200 return -EINVAL; 2201 break; 2202 default: 2203 return -EINVAL; 2204 } 2205 break; 2206 case PR_MCE_KILL_GET: 2207 if (arg2 | arg3 | arg4 | arg5) 2208 return -EINVAL; 2209 if (current->flags & PF_MCE_PROCESS) 2210 error = (current->flags & PF_MCE_EARLY) ? 2211 PR_MCE_KILL_EARLY : PR_MCE_KILL_LATE; 2212 else 2213 error = PR_MCE_KILL_DEFAULT; 2214 break; 2215 case PR_SET_MM: 2216 error = prctl_set_mm(arg2, arg3, arg4, arg5); 2217 break; 2218 case PR_GET_TID_ADDRESS: 2219 error = prctl_get_tid_address(me, (int __user **)arg2); 2220 break; 2221 case PR_SET_CHILD_SUBREAPER: 2222 me->signal->is_child_subreaper = !!arg2; 2223 break; 2224 case PR_GET_CHILD_SUBREAPER: 2225 error = put_user(me->signal->is_child_subreaper, 2226 (int __user *)arg2); 2227 break; 2228 case PR_SET_NO_NEW_PRIVS: 2229 if (arg2 != 1 || arg3 || arg4 || arg5) 2230 return -EINVAL; 2231 2232 task_set_no_new_privs(current); 2233 break; 2234 case PR_GET_NO_NEW_PRIVS: 2235 if (arg2 || arg3 || arg4 || arg5) 2236 return -EINVAL; 2237 return task_no_new_privs(current) ? 1 : 0; 2238 case PR_GET_THP_DISABLE: 2239 if (arg2 || arg3 || arg4 || arg5) 2240 return -EINVAL; 2241 error = !!(me->mm->def_flags & VM_NOHUGEPAGE); 2242 break; 2243 case PR_SET_THP_DISABLE: 2244 if (arg3 || arg4 || arg5) 2245 return -EINVAL; 2246 down_write(&me->mm->mmap_sem); 2247 if (arg2) 2248 me->mm->def_flags |= VM_NOHUGEPAGE; 2249 else 2250 me->mm->def_flags &= ~VM_NOHUGEPAGE; 2251 up_write(&me->mm->mmap_sem); 2252 break; 2253 case PR_MPX_ENABLE_MANAGEMENT: 2254 if (arg2 || arg3 || arg4 || arg5) 2255 return -EINVAL; 2256 error = MPX_ENABLE_MANAGEMENT(); 2257 break; 2258 case PR_MPX_DISABLE_MANAGEMENT: 2259 if (arg2 || arg3 || arg4 || arg5) 2260 return -EINVAL; 2261 error = MPX_DISABLE_MANAGEMENT(); 2262 break; 2263 case PR_SET_FP_MODE: 2264 error = SET_FP_MODE(me, arg2); 2265 break; 2266 case PR_GET_FP_MODE: 2267 error = GET_FP_MODE(me); 2268 break; 2269 default: 2270 error = -EINVAL; 2271 break; 2272 } 2273 return error; 2274 } 2275 2276 SYSCALL_DEFINE3(getcpu, unsigned __user *, cpup, unsigned __user *, nodep, 2277 struct getcpu_cache __user *, unused) 2278 { 2279 int err = 0; 2280 int cpu = raw_smp_processor_id(); 2281 2282 if (cpup) 2283 err |= put_user(cpu, cpup); 2284 if (nodep) 2285 err |= put_user(cpu_to_node(cpu), nodep); 2286 return err ? -EFAULT : 0; 2287 } 2288 2289 /** 2290 * do_sysinfo - fill in sysinfo struct 2291 * @info: pointer to buffer to fill 2292 */ 2293 static int do_sysinfo(struct sysinfo *info) 2294 { 2295 unsigned long mem_total, sav_total; 2296 unsigned int mem_unit, bitcount; 2297 struct timespec tp; 2298 2299 memset(info, 0, sizeof(struct sysinfo)); 2300 2301 get_monotonic_boottime(&tp); 2302 info->uptime = tp.tv_sec + (tp.tv_nsec ? 1 : 0); 2303 2304 get_avenrun(info->loads, 0, SI_LOAD_SHIFT - FSHIFT); 2305 2306 info->procs = nr_threads; 2307 2308 si_meminfo(info); 2309 si_swapinfo(info); 2310 2311 /* 2312 * If the sum of all the available memory (i.e. ram + swap) 2313 * is less than can be stored in a 32 bit unsigned long then 2314 * we can be binary compatible with 2.2.x kernels. If not, 2315 * well, in that case 2.2.x was broken anyways... 2316 * 2317 * -Erik Andersen <andersee@debian.org> 2318 */ 2319 2320 mem_total = info->totalram + info->totalswap; 2321 if (mem_total < info->totalram || mem_total < info->totalswap) 2322 goto out; 2323 bitcount = 0; 2324 mem_unit = info->mem_unit; 2325 while (mem_unit > 1) { 2326 bitcount++; 2327 mem_unit >>= 1; 2328 sav_total = mem_total; 2329 mem_total <<= 1; 2330 if (mem_total < sav_total) 2331 goto out; 2332 } 2333 2334 /* 2335 * If mem_total did not overflow, multiply all memory values by 2336 * info->mem_unit and set it to 1. This leaves things compatible 2337 * with 2.2.x, and also retains compatibility with earlier 2.4.x 2338 * kernels... 2339 */ 2340 2341 info->mem_unit = 1; 2342 info->totalram <<= bitcount; 2343 info->freeram <<= bitcount; 2344 info->sharedram <<= bitcount; 2345 info->bufferram <<= bitcount; 2346 info->totalswap <<= bitcount; 2347 info->freeswap <<= bitcount; 2348 info->totalhigh <<= bitcount; 2349 info->freehigh <<= bitcount; 2350 2351 out: 2352 return 0; 2353 } 2354 2355 SYSCALL_DEFINE1(sysinfo, struct sysinfo __user *, info) 2356 { 2357 struct sysinfo val; 2358 2359 do_sysinfo(&val); 2360 2361 if (copy_to_user(info, &val, sizeof(struct sysinfo))) 2362 return -EFAULT; 2363 2364 return 0; 2365 } 2366 2367 #ifdef CONFIG_COMPAT 2368 struct compat_sysinfo { 2369 s32 uptime; 2370 u32 loads[3]; 2371 u32 totalram; 2372 u32 freeram; 2373 u32 sharedram; 2374 u32 bufferram; 2375 u32 totalswap; 2376 u32 freeswap; 2377 u16 procs; 2378 u16 pad; 2379 u32 totalhigh; 2380 u32 freehigh; 2381 u32 mem_unit; 2382 char _f[20-2*sizeof(u32)-sizeof(int)]; 2383 }; 2384 2385 COMPAT_SYSCALL_DEFINE1(sysinfo, struct compat_sysinfo __user *, info) 2386 { 2387 struct sysinfo s; 2388 2389 do_sysinfo(&s); 2390 2391 /* Check to see if any memory value is too large for 32-bit and scale 2392 * down if needed 2393 */ 2394 if (upper_32_bits(s.totalram) || upper_32_bits(s.totalswap)) { 2395 int bitcount = 0; 2396 2397 while (s.mem_unit < PAGE_SIZE) { 2398 s.mem_unit <<= 1; 2399 bitcount++; 2400 } 2401 2402 s.totalram >>= bitcount; 2403 s.freeram >>= bitcount; 2404 s.sharedram >>= bitcount; 2405 s.bufferram >>= bitcount; 2406 s.totalswap >>= bitcount; 2407 s.freeswap >>= bitcount; 2408 s.totalhigh >>= bitcount; 2409 s.freehigh >>= bitcount; 2410 } 2411 2412 if (!access_ok(VERIFY_WRITE, info, sizeof(struct compat_sysinfo)) || 2413 __put_user(s.uptime, &info->uptime) || 2414 __put_user(s.loads[0], &info->loads[0]) || 2415 __put_user(s.loads[1], &info->loads[1]) || 2416 __put_user(s.loads[2], &info->loads[2]) || 2417 __put_user(s.totalram, &info->totalram) || 2418 __put_user(s.freeram, &info->freeram) || 2419 __put_user(s.sharedram, &info->sharedram) || 2420 __put_user(s.bufferram, &info->bufferram) || 2421 __put_user(s.totalswap, &info->totalswap) || 2422 __put_user(s.freeswap, &info->freeswap) || 2423 __put_user(s.procs, &info->procs) || 2424 __put_user(s.totalhigh, &info->totalhigh) || 2425 __put_user(s.freehigh, &info->freehigh) || 2426 __put_user(s.mem_unit, &info->mem_unit)) 2427 return -EFAULT; 2428 2429 return 0; 2430 } 2431 #endif /* CONFIG_COMPAT */ 2432