1// SPDX-License-Identifier: GPL-2.0 2/* 3 * linux/kernel/sys.c 4 * 5 * Copyright (C) 1991, 1992 Linus Torvalds 6 */ 7 8#include <linux/export.h> 9#include <linux/mm.h> 10#include <linux/mm_inline.h> 11#include <linux/utsname.h> 12#include <linux/mman.h> 13#include <linux/reboot.h> 14#include <linux/prctl.h> 15#include <linux/highuid.h> 16#include <linux/fs.h> 17#include <linux/kmod.h> 18#include <linux/ksm.h> 19#include <linux/perf_event.h> 20#include <linux/resource.h> 21#include <linux/kernel.h> 22#include <linux/workqueue.h> 23#include <linux/capability.h> 24#include <linux/device.h> 25#include <linux/key.h> 26#include <linux/times.h> 27#include <linux/posix-timers.h> 28#include <linux/security.h> 29#include <linux/random.h> 30#include <linux/suspend.h> 31#include <linux/tty.h> 32#include <linux/signal.h> 33#include <linux/cn_proc.h> 34#include <linux/getcpu.h> 35#include <linux/task_io_accounting_ops.h> 36#include <linux/seccomp.h> 37#include <linux/cpu.h> 38#include <linux/personality.h> 39#include <linux/ptrace.h> 40#include <linux/fs_struct.h> 41#include <linux/file.h> 42#include <linux/mount.h> 43#include <linux/gfp.h> 44#include <linux/syscore_ops.h> 45#include <linux/version.h> 46#include <linux/ctype.h> 47#include <linux/syscall_user_dispatch.h> 48 49#include <linux/compat.h> 50#include <linux/syscalls.h> 51#include <linux/kprobes.h> 52#include <linux/user_namespace.h> 53#include <linux/time_namespace.h> 54#include <linux/binfmts.h> 55 56#include <linux/sched.h> 57#include <linux/sched/autogroup.h> 58#include <linux/sched/loadavg.h> 59#include <linux/sched/stat.h> 60#include <linux/sched/mm.h> 61#include <linux/sched/coredump.h> 62#include <linux/sched/task.h> 63#include <linux/sched/cputime.h> 64#include <linux/rcupdate.h> 65#include <linux/uidgid.h> 66#include <linux/cred.h> 67 68#include <linux/nospec.h> 69 70#include <linux/kmsg_dump.h> 71/* Move somewhere else to avoid recompiling? */ 72#include <generated/utsrelease.h> 73 74#include <linux/uaccess.h> 75#include <asm/io.h> 76#include <asm/unistd.h> 77 78#include "uid16.h" 79 80#ifndef SET_UNALIGN_CTL 81# define SET_UNALIGN_CTL(a, b) (-EINVAL) 82#endif 83#ifndef GET_UNALIGN_CTL 84# define GET_UNALIGN_CTL(a, b) (-EINVAL) 85#endif 86#ifndef SET_FPEMU_CTL 87# define SET_FPEMU_CTL(a, b) (-EINVAL) 88#endif 89#ifndef GET_FPEMU_CTL 90# define GET_FPEMU_CTL(a, b) (-EINVAL) 91#endif 92#ifndef SET_FPEXC_CTL 93# define SET_FPEXC_CTL(a, b) (-EINVAL) 94#endif 95#ifndef GET_FPEXC_CTL 96# define GET_FPEXC_CTL(a, b) (-EINVAL) 97#endif 98#ifndef GET_ENDIAN 99# define GET_ENDIAN(a, b) (-EINVAL) 100#endif 101#ifndef SET_ENDIAN 102# define SET_ENDIAN(a, b) (-EINVAL) 103#endif 104#ifndef GET_TSC_CTL 105# define GET_TSC_CTL(a) (-EINVAL) 106#endif 107#ifndef SET_TSC_CTL 108# define SET_TSC_CTL(a) (-EINVAL) 109#endif 110#ifndef GET_FP_MODE 111# define GET_FP_MODE(a) (-EINVAL) 112#endif 113#ifndef SET_FP_MODE 114# define SET_FP_MODE(a,b) (-EINVAL) 115#endif 116#ifndef SVE_SET_VL 117# define SVE_SET_VL(a) (-EINVAL) 118#endif 119#ifndef SVE_GET_VL 120# define SVE_GET_VL() (-EINVAL) 121#endif 122#ifndef SME_SET_VL 123# define SME_SET_VL(a) (-EINVAL) 124#endif 125#ifndef SME_GET_VL 126# define SME_GET_VL() (-EINVAL) 127#endif 128#ifndef PAC_RESET_KEYS 129# define PAC_RESET_KEYS(a, b) (-EINVAL) 130#endif 131#ifndef PAC_SET_ENABLED_KEYS 132# define PAC_SET_ENABLED_KEYS(a, b, c) (-EINVAL) 133#endif 134#ifndef PAC_GET_ENABLED_KEYS 135# define PAC_GET_ENABLED_KEYS(a) (-EINVAL) 136#endif 137#ifndef SET_TAGGED_ADDR_CTRL 138# define SET_TAGGED_ADDR_CTRL(a) (-EINVAL) 139#endif 140#ifndef GET_TAGGED_ADDR_CTRL 141# define GET_TAGGED_ADDR_CTRL() (-EINVAL) 142#endif 143#ifndef RISCV_V_SET_CONTROL 144# define RISCV_V_SET_CONTROL(a) (-EINVAL) 145#endif 146#ifndef RISCV_V_GET_CONTROL 147# define RISCV_V_GET_CONTROL() (-EINVAL) 148#endif 149 150/* 151 * this is where the system-wide overflow UID and GID are defined, for 152 * architectures that now have 32-bit UID/GID but didn't in the past 153 */ 154 155int overflowuid = DEFAULT_OVERFLOWUID; 156int overflowgid = DEFAULT_OVERFLOWGID; 157 158EXPORT_SYMBOL(overflowuid); 159EXPORT_SYMBOL(overflowgid); 160 161/* 162 * the same as above, but for filesystems which can only store a 16-bit 163 * UID and GID. as such, this is needed on all architectures 164 */ 165 166int fs_overflowuid = DEFAULT_FS_OVERFLOWUID; 167int fs_overflowgid = DEFAULT_FS_OVERFLOWGID; 168 169EXPORT_SYMBOL(fs_overflowuid); 170EXPORT_SYMBOL(fs_overflowgid); 171 172/* 173 * Returns true if current's euid is same as p's uid or euid, 174 * or has CAP_SYS_NICE to p's user_ns. 175 * 176 * Called with rcu_read_lock, creds are safe 177 */ 178static bool set_one_prio_perm(struct task_struct *p) 179{ 180 const struct cred *cred = current_cred(), *pcred = __task_cred(p); 181 182 if (uid_eq(pcred->uid, cred->euid) || 183 uid_eq(pcred->euid, cred->euid)) 184 return true; 185 if (ns_capable(pcred->user_ns, CAP_SYS_NICE)) 186 return true; 187 return false; 188} 189 190/* 191 * set the priority of a task 192 * - the caller must hold the RCU read lock 193 */ 194static int set_one_prio(struct task_struct *p, int niceval, int error) 195{ 196 int no_nice; 197 198 if (!set_one_prio_perm(p)) { 199 error = -EPERM; 200 goto out; 201 } 202 if (niceval < task_nice(p) && !can_nice(p, niceval)) { 203 error = -EACCES; 204 goto out; 205 } 206 no_nice = security_task_setnice(p, niceval); 207 if (no_nice) { 208 error = no_nice; 209 goto out; 210 } 211 if (error == -ESRCH) 212 error = 0; 213 set_user_nice(p, niceval); 214out: 215 return error; 216} 217 218SYSCALL_DEFINE3(setpriority, int, which, int, who, int, niceval) 219{ 220 struct task_struct *g, *p; 221 struct user_struct *user; 222 const struct cred *cred = current_cred(); 223 int error = -EINVAL; 224 struct pid *pgrp; 225 kuid_t uid; 226 227 if (which > PRIO_USER || which < PRIO_PROCESS) 228 goto out; 229 230 /* normalize: avoid signed division (rounding problems) */ 231 error = -ESRCH; 232 if (niceval < MIN_NICE) 233 niceval = MIN_NICE; 234 if (niceval > MAX_NICE) 235 niceval = MAX_NICE; 236 237 rcu_read_lock(); 238 switch (which) { 239 case PRIO_PROCESS: 240 if (who) 241 p = find_task_by_vpid(who); 242 else 243 p = current; 244 if (p) 245 error = set_one_prio(p, niceval, error); 246 break; 247 case PRIO_PGRP: 248 if (who) 249 pgrp = find_vpid(who); 250 else 251 pgrp = task_pgrp(current); 252 read_lock(&tasklist_lock); 253 do_each_pid_thread(pgrp, PIDTYPE_PGID, p) { 254 error = set_one_prio(p, niceval, error); 255 } while_each_pid_thread(pgrp, PIDTYPE_PGID, p); 256 read_unlock(&tasklist_lock); 257 break; 258 case PRIO_USER: 259 uid = make_kuid(cred->user_ns, who); 260 user = cred->user; 261 if (!who) 262 uid = cred->uid; 263 else if (!uid_eq(uid, cred->uid)) { 264 user = find_user(uid); 265 if (!user) 266 goto out_unlock; /* No processes for this user */ 267 } 268 for_each_process_thread(g, p) { 269 if (uid_eq(task_uid(p), uid) && task_pid_vnr(p)) 270 error = set_one_prio(p, niceval, error); 271 } 272 if (!uid_eq(uid, cred->uid)) 273 free_uid(user); /* For find_user() */ 274 break; 275 } 276out_unlock: 277 rcu_read_unlock(); 278out: 279 return error; 280} 281 282/* 283 * Ugh. To avoid negative return values, "getpriority()" will 284 * not return the normal nice-value, but a negated value that 285 * has been offset by 20 (ie it returns 40..1 instead of -20..19) 286 * to stay compatible. 287 */ 288SYSCALL_DEFINE2(getpriority, int, which, int, who) 289{ 290 struct task_struct *g, *p; 291 struct user_struct *user; 292 const struct cred *cred = current_cred(); 293 long niceval, retval = -ESRCH; 294 struct pid *pgrp; 295 kuid_t uid; 296 297 if (which > PRIO_USER || which < PRIO_PROCESS) 298 return -EINVAL; 299 300 rcu_read_lock(); 301 switch (which) { 302 case PRIO_PROCESS: 303 if (who) 304 p = find_task_by_vpid(who); 305 else 306 p = current; 307 if (p) { 308 niceval = nice_to_rlimit(task_nice(p)); 309 if (niceval > retval) 310 retval = niceval; 311 } 312 break; 313 case PRIO_PGRP: 314 if (who) 315 pgrp = find_vpid(who); 316 else 317 pgrp = task_pgrp(current); 318 read_lock(&tasklist_lock); 319 do_each_pid_thread(pgrp, PIDTYPE_PGID, p) { 320 niceval = nice_to_rlimit(task_nice(p)); 321 if (niceval > retval) 322 retval = niceval; 323 } while_each_pid_thread(pgrp, PIDTYPE_PGID, p); 324 read_unlock(&tasklist_lock); 325 break; 326 case PRIO_USER: 327 uid = make_kuid(cred->user_ns, who); 328 user = cred->user; 329 if (!who) 330 uid = cred->uid; 331 else if (!uid_eq(uid, cred->uid)) { 332 user = find_user(uid); 333 if (!user) 334 goto out_unlock; /* No processes for this user */ 335 } 336 for_each_process_thread(g, p) { 337 if (uid_eq(task_uid(p), uid) && task_pid_vnr(p)) { 338 niceval = nice_to_rlimit(task_nice(p)); 339 if (niceval > retval) 340 retval = niceval; 341 } 342 } 343 if (!uid_eq(uid, cred->uid)) 344 free_uid(user); /* for find_user() */ 345 break; 346 } 347out_unlock: 348 rcu_read_unlock(); 349 350 return retval; 351} 352 353/* 354 * Unprivileged users may change the real gid to the effective gid 355 * or vice versa. (BSD-style) 356 * 357 * If you set the real gid at all, or set the effective gid to a value not 358 * equal to the real gid, then the saved gid is set to the new effective gid. 359 * 360 * This makes it possible for a setgid program to completely drop its 361 * privileges, which is often a useful assertion to make when you are doing 362 * a security audit over a program. 363 * 364 * The general idea is that a program which uses just setregid() will be 365 * 100% compatible with BSD. A program which uses just setgid() will be 366 * 100% compatible with POSIX with saved IDs. 367 * 368 * SMP: There are not races, the GIDs are checked only by filesystem 369 * operations (as far as semantic preservation is concerned). 370 */ 371#ifdef CONFIG_MULTIUSER 372long __sys_setregid(gid_t rgid, gid_t egid) 373{ 374 struct user_namespace *ns = current_user_ns(); 375 const struct cred *old; 376 struct cred *new; 377 int retval; 378 kgid_t krgid, kegid; 379 380 krgid = make_kgid(ns, rgid); 381 kegid = make_kgid(ns, egid); 382 383 if ((rgid != (gid_t) -1) && !gid_valid(krgid)) 384 return -EINVAL; 385 if ((egid != (gid_t) -1) && !gid_valid(kegid)) 386 return -EINVAL; 387 388 new = prepare_creds(); 389 if (!new) 390 return -ENOMEM; 391 old = current_cred(); 392 393 retval = -EPERM; 394 if (rgid != (gid_t) -1) { 395 if (gid_eq(old->gid, krgid) || 396 gid_eq(old->egid, krgid) || 397 ns_capable_setid(old->user_ns, CAP_SETGID)) 398 new->gid = krgid; 399 else 400 goto error; 401 } 402 if (egid != (gid_t) -1) { 403 if (gid_eq(old->gid, kegid) || 404 gid_eq(old->egid, kegid) || 405 gid_eq(old->sgid, kegid) || 406 ns_capable_setid(old->user_ns, CAP_SETGID)) 407 new->egid = kegid; 408 else 409 goto error; 410 } 411 412 if (rgid != (gid_t) -1 || 413 (egid != (gid_t) -1 && !gid_eq(kegid, old->gid))) 414 new->sgid = new->egid; 415 new->fsgid = new->egid; 416 417 retval = security_task_fix_setgid(new, old, LSM_SETID_RE); 418 if (retval < 0) 419 goto error; 420 421 return commit_creds(new); 422 423error: 424 abort_creds(new); 425 return retval; 426} 427 428SYSCALL_DEFINE2(setregid, gid_t, rgid, gid_t, egid) 429{ 430 return __sys_setregid(rgid, egid); 431} 432 433/* 434 * setgid() is implemented like SysV w/ SAVED_IDS 435 * 436 * SMP: Same implicit races as above. 437 */ 438long __sys_setgid(gid_t gid) 439{ 440 struct user_namespace *ns = current_user_ns(); 441 const struct cred *old; 442 struct cred *new; 443 int retval; 444 kgid_t kgid; 445 446 kgid = make_kgid(ns, gid); 447 if (!gid_valid(kgid)) 448 return -EINVAL; 449 450 new = prepare_creds(); 451 if (!new) 452 return -ENOMEM; 453 old = current_cred(); 454 455 retval = -EPERM; 456 if (ns_capable_setid(old->user_ns, CAP_SETGID)) 457 new->gid = new->egid = new->sgid = new->fsgid = kgid; 458 else if (gid_eq(kgid, old->gid) || gid_eq(kgid, old->sgid)) 459 new->egid = new->fsgid = kgid; 460 else 461 goto error; 462 463 retval = security_task_fix_setgid(new, old, LSM_SETID_ID); 464 if (retval < 0) 465 goto error; 466 467 return commit_creds(new); 468 469error: 470 abort_creds(new); 471 return retval; 472} 473 474SYSCALL_DEFINE1(setgid, gid_t, gid) 475{ 476 return __sys_setgid(gid); 477} 478 479/* 480 * change the user struct in a credentials set to match the new UID 481 */ 482static int set_user(struct cred *new) 483{ 484 struct user_struct *new_user; 485 486 new_user = alloc_uid(new->uid); 487 if (!new_user) 488 return -EAGAIN; 489 490 free_uid(new->user); 491 new->user = new_user; 492 return 0; 493} 494 495static void flag_nproc_exceeded(struct cred *new) 496{ 497 if (new->ucounts == current_ucounts()) 498 return; 499 500 /* 501 * We don't fail in case of NPROC limit excess here because too many 502 * poorly written programs don't check set*uid() return code, assuming 503 * it never fails if called by root. We may still enforce NPROC limit 504 * for programs doing set*uid()+execve() by harmlessly deferring the 505 * failure to the execve() stage. 506 */ 507 if (is_rlimit_overlimit(new->ucounts, UCOUNT_RLIMIT_NPROC, rlimit(RLIMIT_NPROC)) && 508 new->user != INIT_USER) 509 current->flags |= PF_NPROC_EXCEEDED; 510 else 511 current->flags &= ~PF_NPROC_EXCEEDED; 512} 513 514/* 515 * Unprivileged users may change the real uid to the effective uid 516 * or vice versa. (BSD-style) 517 * 518 * If you set the real uid at all, or set the effective uid to a value not 519 * equal to the real uid, then the saved uid is set to the new effective uid. 520 * 521 * This makes it possible for a setuid program to completely drop its 522 * privileges, which is often a useful assertion to make when you are doing 523 * a security audit over a program. 524 * 525 * The general idea is that a program which uses just setreuid() will be 526 * 100% compatible with BSD. A program which uses just setuid() will be 527 * 100% compatible with POSIX with saved IDs. 528 */ 529long __sys_setreuid(uid_t ruid, uid_t euid) 530{ 531 struct user_namespace *ns = current_user_ns(); 532 const struct cred *old; 533 struct cred *new; 534 int retval; 535 kuid_t kruid, keuid; 536 537 kruid = make_kuid(ns, ruid); 538 keuid = make_kuid(ns, euid); 539 540 if ((ruid != (uid_t) -1) && !uid_valid(kruid)) 541 return -EINVAL; 542 if ((euid != (uid_t) -1) && !uid_valid(keuid)) 543 return -EINVAL; 544 545 new = prepare_creds(); 546 if (!new) 547 return -ENOMEM; 548 old = current_cred(); 549 550 retval = -EPERM; 551 if (ruid != (uid_t) -1) { 552 new->uid = kruid; 553 if (!uid_eq(old->uid, kruid) && 554 !uid_eq(old->euid, kruid) && 555 !ns_capable_setid(old->user_ns, CAP_SETUID)) 556 goto error; 557 } 558 559 if (euid != (uid_t) -1) { 560 new->euid = keuid; 561 if (!uid_eq(old->uid, keuid) && 562 !uid_eq(old->euid, keuid) && 563 !uid_eq(old->suid, keuid) && 564 !ns_capable_setid(old->user_ns, CAP_SETUID)) 565 goto error; 566 } 567 568 if (!uid_eq(new->uid, old->uid)) { 569 retval = set_user(new); 570 if (retval < 0) 571 goto error; 572 } 573 if (ruid != (uid_t) -1 || 574 (euid != (uid_t) -1 && !uid_eq(keuid, old->uid))) 575 new->suid = new->euid; 576 new->fsuid = new->euid; 577 578 retval = security_task_fix_setuid(new, old, LSM_SETID_RE); 579 if (retval < 0) 580 goto error; 581 582 retval = set_cred_ucounts(new); 583 if (retval < 0) 584 goto error; 585 586 flag_nproc_exceeded(new); 587 return commit_creds(new); 588 589error: 590 abort_creds(new); 591 return retval; 592} 593 594SYSCALL_DEFINE2(setreuid, uid_t, ruid, uid_t, euid) 595{ 596 return __sys_setreuid(ruid, euid); 597} 598 599/* 600 * setuid() is implemented like SysV with SAVED_IDS 601 * 602 * Note that SAVED_ID's is deficient in that a setuid root program 603 * like sendmail, for example, cannot set its uid to be a normal 604 * user and then switch back, because if you're root, setuid() sets 605 * the saved uid too. If you don't like this, blame the bright people 606 * in the POSIX committee and/or USG. Note that the BSD-style setreuid() 607 * will allow a root program to temporarily drop privileges and be able to 608 * regain them by swapping the real and effective uid. 609 */ 610long __sys_setuid(uid_t uid) 611{ 612 struct user_namespace *ns = current_user_ns(); 613 const struct cred *old; 614 struct cred *new; 615 int retval; 616 kuid_t kuid; 617 618 kuid = make_kuid(ns, uid); 619 if (!uid_valid(kuid)) 620 return -EINVAL; 621 622 new = prepare_creds(); 623 if (!new) 624 return -ENOMEM; 625 old = current_cred(); 626 627 retval = -EPERM; 628 if (ns_capable_setid(old->user_ns, CAP_SETUID)) { 629 new->suid = new->uid = kuid; 630 if (!uid_eq(kuid, old->uid)) { 631 retval = set_user(new); 632 if (retval < 0) 633 goto error; 634 } 635 } else if (!uid_eq(kuid, old->uid) && !uid_eq(kuid, new->suid)) { 636 goto error; 637 } 638 639 new->fsuid = new->euid = kuid; 640 641 retval = security_task_fix_setuid(new, old, LSM_SETID_ID); 642 if (retval < 0) 643 goto error; 644 645 retval = set_cred_ucounts(new); 646 if (retval < 0) 647 goto error; 648 649 flag_nproc_exceeded(new); 650 return commit_creds(new); 651 652error: 653 abort_creds(new); 654 return retval; 655} 656 657SYSCALL_DEFINE1(setuid, uid_t, uid) 658{ 659 return __sys_setuid(uid); 660} 661 662 663/* 664 * This function implements a generic ability to update ruid, euid, 665 * and suid. This allows you to implement the 4.4 compatible seteuid(). 666 */ 667long __sys_setresuid(uid_t ruid, uid_t euid, uid_t suid) 668{ 669 struct user_namespace *ns = current_user_ns(); 670 const struct cred *old; 671 struct cred *new; 672 int retval; 673 kuid_t kruid, keuid, ksuid; 674 bool ruid_new, euid_new, suid_new; 675 676 kruid = make_kuid(ns, ruid); 677 keuid = make_kuid(ns, euid); 678 ksuid = make_kuid(ns, suid); 679 680 if ((ruid != (uid_t) -1) && !uid_valid(kruid)) 681 return -EINVAL; 682 683 if ((euid != (uid_t) -1) && !uid_valid(keuid)) 684 return -EINVAL; 685 686 if ((suid != (uid_t) -1) && !uid_valid(ksuid)) 687 return -EINVAL; 688 689 old = current_cred(); 690 691 /* check for no-op */ 692 if ((ruid == (uid_t) -1 || uid_eq(kruid, old->uid)) && 693 (euid == (uid_t) -1 || (uid_eq(keuid, old->euid) && 694 uid_eq(keuid, old->fsuid))) && 695 (suid == (uid_t) -1 || uid_eq(ksuid, old->suid))) 696 return 0; 697 698 ruid_new = ruid != (uid_t) -1 && !uid_eq(kruid, old->uid) && 699 !uid_eq(kruid, old->euid) && !uid_eq(kruid, old->suid); 700 euid_new = euid != (uid_t) -1 && !uid_eq(keuid, old->uid) && 701 !uid_eq(keuid, old->euid) && !uid_eq(keuid, old->suid); 702 suid_new = suid != (uid_t) -1 && !uid_eq(ksuid, old->uid) && 703 !uid_eq(ksuid, old->euid) && !uid_eq(ksuid, old->suid); 704 if ((ruid_new || euid_new || suid_new) && 705 !ns_capable_setid(old->user_ns, CAP_SETUID)) 706 return -EPERM; 707 708 new = prepare_creds(); 709 if (!new) 710 return -ENOMEM; 711 712 if (ruid != (uid_t) -1) { 713 new->uid = kruid; 714 if (!uid_eq(kruid, old->uid)) { 715 retval = set_user(new); 716 if (retval < 0) 717 goto error; 718 } 719 } 720 if (euid != (uid_t) -1) 721 new->euid = keuid; 722 if (suid != (uid_t) -1) 723 new->suid = ksuid; 724 new->fsuid = new->euid; 725 726 retval = security_task_fix_setuid(new, old, LSM_SETID_RES); 727 if (retval < 0) 728 goto error; 729 730 retval = set_cred_ucounts(new); 731 if (retval < 0) 732 goto error; 733 734 flag_nproc_exceeded(new); 735 return commit_creds(new); 736 737error: 738 abort_creds(new); 739 return retval; 740} 741 742SYSCALL_DEFINE3(setresuid, uid_t, ruid, uid_t, euid, uid_t, suid) 743{ 744 return __sys_setresuid(ruid, euid, suid); 745} 746 747SYSCALL_DEFINE3(getresuid, uid_t __user *, ruidp, uid_t __user *, euidp, uid_t __user *, suidp) 748{ 749 const struct cred *cred = current_cred(); 750 int retval; 751 uid_t ruid, euid, suid; 752 753 ruid = from_kuid_munged(cred->user_ns, cred->uid); 754 euid = from_kuid_munged(cred->user_ns, cred->euid); 755 suid = from_kuid_munged(cred->user_ns, cred->suid); 756 757 retval = put_user(ruid, ruidp); 758 if (!retval) { 759 retval = put_user(euid, euidp); 760 if (!retval) 761 return put_user(suid, suidp); 762 } 763 return retval; 764} 765 766/* 767 * Same as above, but for rgid, egid, sgid. 768 */ 769long __sys_setresgid(gid_t rgid, gid_t egid, gid_t sgid) 770{ 771 struct user_namespace *ns = current_user_ns(); 772 const struct cred *old; 773 struct cred *new; 774 int retval; 775 kgid_t krgid, kegid, ksgid; 776 bool rgid_new, egid_new, sgid_new; 777 778 krgid = make_kgid(ns, rgid); 779 kegid = make_kgid(ns, egid); 780 ksgid = make_kgid(ns, sgid); 781 782 if ((rgid != (gid_t) -1) && !gid_valid(krgid)) 783 return -EINVAL; 784 if ((egid != (gid_t) -1) && !gid_valid(kegid)) 785 return -EINVAL; 786 if ((sgid != (gid_t) -1) && !gid_valid(ksgid)) 787 return -EINVAL; 788 789 old = current_cred(); 790 791 /* check for no-op */ 792 if ((rgid == (gid_t) -1 || gid_eq(krgid, old->gid)) && 793 (egid == (gid_t) -1 || (gid_eq(kegid, old->egid) && 794 gid_eq(kegid, old->fsgid))) && 795 (sgid == (gid_t) -1 || gid_eq(ksgid, old->sgid))) 796 return 0; 797 798 rgid_new = rgid != (gid_t) -1 && !gid_eq(krgid, old->gid) && 799 !gid_eq(krgid, old->egid) && !gid_eq(krgid, old->sgid); 800 egid_new = egid != (gid_t) -1 && !gid_eq(kegid, old->gid) && 801 !gid_eq(kegid, old->egid) && !gid_eq(kegid, old->sgid); 802 sgid_new = sgid != (gid_t) -1 && !gid_eq(ksgid, old->gid) && 803 !gid_eq(ksgid, old->egid) && !gid_eq(ksgid, old->sgid); 804 if ((rgid_new || egid_new || sgid_new) && 805 !ns_capable_setid(old->user_ns, CAP_SETGID)) 806 return -EPERM; 807 808 new = prepare_creds(); 809 if (!new) 810 return -ENOMEM; 811 812 if (rgid != (gid_t) -1) 813 new->gid = krgid; 814 if (egid != (gid_t) -1) 815 new->egid = kegid; 816 if (sgid != (gid_t) -1) 817 new->sgid = ksgid; 818 new->fsgid = new->egid; 819 820 retval = security_task_fix_setgid(new, old, LSM_SETID_RES); 821 if (retval < 0) 822 goto error; 823 824 return commit_creds(new); 825 826error: 827 abort_creds(new); 828 return retval; 829} 830 831SYSCALL_DEFINE3(setresgid, gid_t, rgid, gid_t, egid, gid_t, sgid) 832{ 833 return __sys_setresgid(rgid, egid, sgid); 834} 835 836SYSCALL_DEFINE3(getresgid, gid_t __user *, rgidp, gid_t __user *, egidp, gid_t __user *, sgidp) 837{ 838 const struct cred *cred = current_cred(); 839 int retval; 840 gid_t rgid, egid, sgid; 841 842 rgid = from_kgid_munged(cred->user_ns, cred->gid); 843 egid = from_kgid_munged(cred->user_ns, cred->egid); 844 sgid = from_kgid_munged(cred->user_ns, cred->sgid); 845 846 retval = put_user(rgid, rgidp); 847 if (!retval) { 848 retval = put_user(egid, egidp); 849 if (!retval) 850 retval = put_user(sgid, sgidp); 851 } 852 853 return retval; 854} 855 856 857/* 858 * "setfsuid()" sets the fsuid - the uid used for filesystem checks. This 859 * is used for "access()" and for the NFS daemon (letting nfsd stay at 860 * whatever uid it wants to). It normally shadows "euid", except when 861 * explicitly set by setfsuid() or for access.. 862 */ 863long __sys_setfsuid(uid_t uid) 864{ 865 const struct cred *old; 866 struct cred *new; 867 uid_t old_fsuid; 868 kuid_t kuid; 869 870 old = current_cred(); 871 old_fsuid = from_kuid_munged(old->user_ns, old->fsuid); 872 873 kuid = make_kuid(old->user_ns, uid); 874 if (!uid_valid(kuid)) 875 return old_fsuid; 876 877 new = prepare_creds(); 878 if (!new) 879 return old_fsuid; 880 881 if (uid_eq(kuid, old->uid) || uid_eq(kuid, old->euid) || 882 uid_eq(kuid, old->suid) || uid_eq(kuid, old->fsuid) || 883 ns_capable_setid(old->user_ns, CAP_SETUID)) { 884 if (!uid_eq(kuid, old->fsuid)) { 885 new->fsuid = kuid; 886 if (security_task_fix_setuid(new, old, LSM_SETID_FS) == 0) 887 goto change_okay; 888 } 889 } 890 891 abort_creds(new); 892 return old_fsuid; 893 894change_okay: 895 commit_creds(new); 896 return old_fsuid; 897} 898 899SYSCALL_DEFINE1(setfsuid, uid_t, uid) 900{ 901 return __sys_setfsuid(uid); 902} 903 904/* 905 * Samma p�� svenska.. 906 */ 907long __sys_setfsgid(gid_t gid) 908{ 909 const struct cred *old; 910 struct cred *new; 911 gid_t old_fsgid; 912 kgid_t kgid; 913 914 old = current_cred(); 915 old_fsgid = from_kgid_munged(old->user_ns, old->fsgid); 916 917 kgid = make_kgid(old->user_ns, gid); 918 if (!gid_valid(kgid)) 919 return old_fsgid; 920 921 new = prepare_creds(); 922 if (!new) 923 return old_fsgid; 924 925 if (gid_eq(kgid, old->gid) || gid_eq(kgid, old->egid) || 926 gid_eq(kgid, old->sgid) || gid_eq(kgid, old->fsgid) || 927 ns_capable_setid(old->user_ns, CAP_SETGID)) { 928 if (!gid_eq(kgid, old->fsgid)) { 929 new->fsgid = kgid; 930 if (security_task_fix_setgid(new,old,LSM_SETID_FS) == 0) 931 goto change_okay; 932 } 933 } 934 935 abort_creds(new); 936 return old_fsgid; 937 938change_okay: 939 commit_creds(new); 940 return old_fsgid; 941} 942 943SYSCALL_DEFINE1(setfsgid, gid_t, gid) 944{ 945 return __sys_setfsgid(gid); 946} 947#endif /* CONFIG_MULTIUSER */ 948 949/** 950 * sys_getpid - return the thread group id of the current process 951 * 952 * Note, despite the name, this returns the tgid not the pid. The tgid and 953 * the pid are identical unless CLONE_THREAD was specified on clone() in 954 * which case the tgid is the same in all threads of the same group. 955 * 956 * This is SMP safe as current->tgid does not change. 957 */ 958SYSCALL_DEFINE0(getpid) 959{ 960 return task_tgid_vnr(current); 961} 962 963/* Thread ID - the internal kernel "pid" */ 964SYSCALL_DEFINE0(gettid) 965{ 966 return task_pid_vnr(current); 967} 968 969/* 970 * Accessing ->real_parent is not SMP-safe, it could 971 * change from under us. However, we can use a stale 972 * value of ->real_parent under rcu_read_lock(), see 973 * release_task()->call_rcu(delayed_put_task_struct). 974 */ 975SYSCALL_DEFINE0(getppid) 976{ 977 int pid; 978 979 rcu_read_lock(); 980 pid = task_tgid_vnr(rcu_dereference(current->real_parent)); 981 rcu_read_unlock(); 982 983 return pid; 984} 985 986SYSCALL_DEFINE0(getuid) 987{ 988 /* Only we change this so SMP safe */ 989 return from_kuid_munged(current_user_ns(), current_uid()); 990} 991 992SYSCALL_DEFINE0(geteuid) 993{ 994 /* Only we change this so SMP safe */ 995 return from_kuid_munged(current_user_ns(), current_euid()); 996} 997 998SYSCALL_DEFINE0(getgid) 999{ 1000 /* Only we change this so SMP safe */ 1001 return from_kgid_munged(current_user_ns(), current_gid()); 1002} 1003 1004SYSCALL_DEFINE0(getegid) 1005{ 1006 /* Only we change this so SMP safe */ 1007 return from_kgid_munged(current_user_ns(), current_egid()); 1008} 1009 1010static void do_sys_times(struct tms *tms) 1011{ 1012 u64 tgutime, tgstime, cutime, cstime; 1013 1014 thread_group_cputime_adjusted(current, &tgutime, &tgstime); 1015 cutime = current->signal->cutime; 1016 cstime = current->signal->cstime; 1017 tms->tms_utime = nsec_to_clock_t(tgutime); 1018 tms->tms_stime = nsec_to_clock_t(tgstime); 1019 tms->tms_cutime = nsec_to_clock_t(cutime); 1020 tms->tms_cstime = nsec_to_clock_t(cstime); 1021} 1022 1023SYSCALL_DEFINE1(times, struct tms __user *, tbuf) 1024{ 1025 if (tbuf) { 1026 struct tms tmp; 1027 1028 do_sys_times(&tmp); 1029 if (copy_to_user(tbuf, &tmp, sizeof(struct tms))) 1030 return -EFAULT; 1031 } 1032 force_successful_syscall_return(); 1033 return (long) jiffies_64_to_clock_t(get_jiffies_64()); 1034} 1035 1036#ifdef CONFIG_COMPAT 1037static compat_clock_t clock_t_to_compat_clock_t(clock_t x) 1038{ 1039 return compat_jiffies_to_clock_t(clock_t_to_jiffies(x)); 1040} 1041 1042COMPAT_SYSCALL_DEFINE1(times, struct compat_tms __user *, tbuf) 1043{ 1044 if (tbuf) { 1045 struct tms tms; 1046 struct compat_tms tmp; 1047 1048 do_sys_times(&tms); 1049 /* Convert our struct tms to the compat version. */ 1050 tmp.tms_utime = clock_t_to_compat_clock_t(tms.tms_utime); 1051 tmp.tms_stime = clock_t_to_compat_clock_t(tms.tms_stime); 1052 tmp.tms_cutime = clock_t_to_compat_clock_t(tms.tms_cutime); 1053 tmp.tms_cstime = clock_t_to_compat_clock_t(tms.tms_cstime); 1054 if (copy_to_user(tbuf, &tmp, sizeof(tmp))) 1055 return -EFAULT; 1056 } 1057 force_successful_syscall_return(); 1058 return compat_jiffies_to_clock_t(jiffies); 1059} 1060#endif 1061 1062/* 1063 * This needs some heavy checking ... 1064 * I just haven't the stomach for it. I also don't fully 1065 * understand sessions/pgrp etc. Let somebody who does explain it. 1066 * 1067 * OK, I think I have the protection semantics right.... this is really 1068 * only important on a multi-user system anyway, to make sure one user 1069 * can't send a signal to a process owned by another. -TYT, 12/12/91 1070 * 1071 * !PF_FORKNOEXEC check to conform completely to POSIX. 1072 */ 1073SYSCALL_DEFINE2(setpgid, pid_t, pid, pid_t, pgid) 1074{ 1075 struct task_struct *p; 1076 struct task_struct *group_leader = current->group_leader; 1077 struct pid *pgrp; 1078 int err; 1079 1080 if (!pid) 1081 pid = task_pid_vnr(group_leader); 1082 if (!pgid) 1083 pgid = pid; 1084 if (pgid < 0) 1085 return -EINVAL; 1086 rcu_read_lock(); 1087 1088 /* From this point forward we keep holding onto the tasklist lock 1089 * so that our parent does not change from under us. -DaveM 1090 */ 1091 write_lock_irq(&tasklist_lock); 1092 1093 err = -ESRCH; 1094 p = find_task_by_vpid(pid); 1095 if (!p) 1096 goto out; 1097 1098 err = -EINVAL; 1099 if (!thread_group_leader(p)) 1100 goto out; 1101 1102 if (same_thread_group(p->real_parent, group_leader)) { 1103 err = -EPERM; 1104 if (task_session(p) != task_session(group_leader)) 1105 goto out; 1106 err = -EACCES; 1107 if (!(p->flags & PF_FORKNOEXEC)) 1108 goto out; 1109 } else { 1110 err = -ESRCH; 1111 if (p != group_leader) 1112 goto out; 1113 } 1114 1115 err = -EPERM; 1116 if (p->signal->leader) 1117 goto out; 1118 1119 pgrp = task_pid(p); 1120 if (pgid != pid) { 1121 struct task_struct *g; 1122 1123 pgrp = find_vpid(pgid); 1124 g = pid_task(pgrp, PIDTYPE_PGID); 1125 if (!g || task_session(g) != task_session(group_leader)) 1126 goto out; 1127 } 1128 1129 err = security_task_setpgid(p, pgid); 1130 if (err) 1131 goto out; 1132 1133 if (task_pgrp(p) != pgrp) 1134 change_pid(p, PIDTYPE_PGID, pgrp); 1135 1136 err = 0; 1137out: 1138 /* All paths lead to here, thus we are safe. -DaveM */ 1139 write_unlock_irq(&tasklist_lock); 1140 rcu_read_unlock(); 1141 return err; 1142} 1143 1144static int do_getpgid(pid_t pid) 1145{ 1146 struct task_struct *p; 1147 struct pid *grp; 1148 int retval; 1149 1150 rcu_read_lock(); 1151 if (!pid) 1152 grp = task_pgrp(current); 1153 else { 1154 retval = -ESRCH; 1155 p = find_task_by_vpid(pid); 1156 if (!p) 1157 goto out; 1158 grp = task_pgrp(p); 1159 if (!grp) 1160 goto out; 1161 1162 retval = security_task_getpgid(p); 1163 if (retval) 1164 goto out; 1165 } 1166 retval = pid_vnr(grp); 1167out: 1168 rcu_read_unlock(); 1169 return retval; 1170} 1171 1172SYSCALL_DEFINE1(getpgid, pid_t, pid) 1173{ 1174 return do_getpgid(pid); 1175} 1176 1177#ifdef __ARCH_WANT_SYS_GETPGRP 1178 1179SYSCALL_DEFINE0(getpgrp) 1180{ 1181 return do_getpgid(0); 1182} 1183 1184#endif 1185 1186SYSCALL_DEFINE1(getsid, pid_t, pid) 1187{ 1188 struct task_struct *p; 1189 struct pid *sid; 1190 int retval; 1191 1192 rcu_read_lock(); 1193 if (!pid) 1194 sid = task_session(current); 1195 else { 1196 retval = -ESRCH; 1197 p = find_task_by_vpid(pid); 1198 if (!p) 1199 goto out; 1200 sid = task_session(p); 1201 if (!sid) 1202 goto out; 1203 1204 retval = security_task_getsid(p); 1205 if (retval) 1206 goto out; 1207 } 1208 retval = pid_vnr(sid); 1209out: 1210 rcu_read_unlock(); 1211 return retval; 1212} 1213 1214static void set_special_pids(struct pid *pid) 1215{ 1216 struct task_struct *curr = current->group_leader; 1217 1218 if (task_session(curr) != pid) 1219 change_pid(curr, PIDTYPE_SID, pid); 1220 1221 if (task_pgrp(curr) != pid) 1222 change_pid(curr, PIDTYPE_PGID, pid); 1223} 1224 1225int ksys_setsid(void) 1226{ 1227 struct task_struct *group_leader = current->group_leader; 1228 struct pid *sid = task_pid(group_leader); 1229 pid_t session = pid_vnr(sid); 1230 int err = -EPERM; 1231 1232 write_lock_irq(&tasklist_lock); 1233 /* Fail if I am already a session leader */ 1234 if (group_leader->signal->leader) 1235 goto out; 1236 1237 /* Fail if a process group id already exists that equals the 1238 * proposed session id. 1239 */ 1240 if (pid_task(sid, PIDTYPE_PGID)) 1241 goto out; 1242 1243 group_leader->signal->leader = 1; 1244 set_special_pids(sid); 1245 1246 proc_clear_tty(group_leader); 1247 1248 err = session; 1249out: 1250 write_unlock_irq(&tasklist_lock); 1251 if (err > 0) { 1252 proc_sid_connector(group_leader); 1253 sched_autogroup_create_attach(group_leader); 1254 } 1255 return err; 1256} 1257 1258SYSCALL_DEFINE0(setsid) 1259{ 1260 return ksys_setsid(); 1261} 1262 1263DECLARE_RWSEM(uts_sem); 1264 1265#ifdef COMPAT_UTS_MACHINE 1266#define override_architecture(name) \ 1267 (personality(current->personality) == PER_LINUX32 && \ 1268 copy_to_user(name->machine, COMPAT_UTS_MACHINE, \ 1269 sizeof(COMPAT_UTS_MACHINE))) 1270#else 1271#define override_architecture(name) 0 1272#endif 1273 1274/* 1275 * Work around broken programs that cannot handle "Linux 3.0". 1276 * Instead we map 3.x to 2.6.40+x, so e.g. 3.0 would be 2.6.40 1277 * And we map 4.x and later versions to 2.6.60+x, so 4.0/5.0/6.0/... would be 1278 * 2.6.60. 1279 */ 1280static int override_release(char __user *release, size_t len) 1281{ 1282 int ret = 0; 1283 1284 if (current->personality & UNAME26) { 1285 const char *rest = UTS_RELEASE; 1286 char buf[65] = { 0 }; 1287 int ndots = 0; 1288 unsigned v; 1289 size_t copy; 1290 1291 while (*rest) { 1292 if (*rest == '.' && ++ndots >= 3) 1293 break; 1294 if (!isdigit(*rest) && *rest != '.') 1295 break; 1296 rest++; 1297 } 1298 v = LINUX_VERSION_PATCHLEVEL + 60; 1299 copy = clamp_t(size_t, len, 1, sizeof(buf)); 1300 copy = scnprintf(buf, copy, "2.6.%u%s", v, rest); 1301 ret = copy_to_user(release, buf, copy + 1); 1302 } 1303 return ret; 1304} 1305 1306SYSCALL_DEFINE1(newuname, struct new_utsname __user *, name) 1307{ 1308 struct new_utsname tmp; 1309 1310 down_read(&uts_sem); 1311 memcpy(&tmp, utsname(), sizeof(tmp)); 1312 up_read(&uts_sem); 1313 if (copy_to_user(name, &tmp, sizeof(tmp))) 1314 return -EFAULT; 1315 1316 if (override_release(name->release, sizeof(name->release))) 1317 return -EFAULT; 1318 if (override_architecture(name)) 1319 return -EFAULT; 1320 return 0; 1321} 1322 1323#ifdef __ARCH_WANT_SYS_OLD_UNAME 1324/* 1325 * Old cruft 1326 */ 1327SYSCALL_DEFINE1(uname, struct old_utsname __user *, name) 1328{ 1329 struct old_utsname tmp; 1330 1331 if (!name) 1332 return -EFAULT; 1333 1334 down_read(&uts_sem); 1335 memcpy(&tmp, utsname(), sizeof(tmp)); 1336 up_read(&uts_sem); 1337 if (copy_to_user(name, &tmp, sizeof(tmp))) 1338 return -EFAULT; 1339 1340 if (override_release(name->release, sizeof(name->release))) 1341 return -EFAULT; 1342 if (override_architecture(name)) 1343 return -EFAULT; 1344 return 0; 1345} 1346 1347SYSCALL_DEFINE1(olduname, struct oldold_utsname __user *, name) 1348{ 1349 struct oldold_utsname tmp; 1350 1351 if (!name) 1352 return -EFAULT; 1353 1354 memset(&tmp, 0, sizeof(tmp)); 1355 1356 down_read(&uts_sem); 1357 memcpy(&tmp.sysname, &utsname()->sysname, __OLD_UTS_LEN); 1358 memcpy(&tmp.nodename, &utsname()->nodename, __OLD_UTS_LEN); 1359 memcpy(&tmp.release, &utsname()->release, __OLD_UTS_LEN); 1360 memcpy(&tmp.version, &utsname()->version, __OLD_UTS_LEN); 1361 memcpy(&tmp.machine, &utsname()->machine, __OLD_UTS_LEN); 1362 up_read(&uts_sem); 1363 if (copy_to_user(name, &tmp, sizeof(tmp))) 1364 return -EFAULT; 1365 1366 if (override_architecture(name)) 1367 return -EFAULT; 1368 if (override_release(name->release, sizeof(name->release))) 1369 return -EFAULT; 1370 return 0; 1371} 1372#endif 1373 1374SYSCALL_DEFINE2(sethostname, char __user *, name, int, len) 1375{ 1376 int errno; 1377 char tmp[__NEW_UTS_LEN]; 1378 1379 if (!ns_capable(current->nsproxy->uts_ns->user_ns, CAP_SYS_ADMIN)) 1380 return -EPERM; 1381 1382 if (len < 0 || len > __NEW_UTS_LEN) 1383 return -EINVAL; 1384 errno = -EFAULT; 1385 if (!copy_from_user(tmp, name, len)) { 1386 struct new_utsname *u; 1387 1388 add_device_randomness(tmp, len); 1389 down_write(&uts_sem); 1390 u = utsname(); 1391 memcpy(u->nodename, tmp, len); 1392 memset(u->nodename + len, 0, sizeof(u->nodename) - len); 1393 errno = 0; 1394 uts_proc_notify(UTS_PROC_HOSTNAME); 1395 up_write(&uts_sem); 1396 } 1397 return errno; 1398} 1399 1400#ifdef __ARCH_WANT_SYS_GETHOSTNAME 1401 1402SYSCALL_DEFINE2(gethostname, char __user *, name, int, len) 1403{ 1404 int i; 1405 struct new_utsname *u; 1406 char tmp[__NEW_UTS_LEN + 1]; 1407 1408 if (len < 0) 1409 return -EINVAL; 1410 down_read(&uts_sem); 1411 u = utsname(); 1412 i = 1 + strlen(u->nodename); 1413 if (i > len) 1414 i = len; 1415 memcpy(tmp, u->nodename, i); 1416 up_read(&uts_sem); 1417 if (copy_to_user(name, tmp, i)) 1418 return -EFAULT; 1419 return 0; 1420} 1421 1422#endif 1423 1424/* 1425 * Only setdomainname; getdomainname can be implemented by calling 1426 * uname() 1427 */ 1428SYSCALL_DEFINE2(setdomainname, char __user *, name, int, len) 1429{ 1430 int errno; 1431 char tmp[__NEW_UTS_LEN]; 1432 1433 if (!ns_capable(current->nsproxy->uts_ns->user_ns, CAP_SYS_ADMIN)) 1434 return -EPERM; 1435 if (len < 0 || len > __NEW_UTS_LEN) 1436 return -EINVAL; 1437 1438 errno = -EFAULT; 1439 if (!copy_from_user(tmp, name, len)) { 1440 struct new_utsname *u; 1441 1442 add_device_randomness(tmp, len); 1443 down_write(&uts_sem); 1444 u = utsname(); 1445 memcpy(u->domainname, tmp, len); 1446 memset(u->domainname + len, 0, sizeof(u->domainname) - len); 1447 errno = 0; 1448 uts_proc_notify(UTS_PROC_DOMAINNAME); 1449 up_write(&uts_sem); 1450 } 1451 return errno; 1452} 1453 1454/* make sure you are allowed to change @tsk limits before calling this */ 1455static int do_prlimit(struct task_struct *tsk, unsigned int resource, 1456 struct rlimit *new_rlim, struct rlimit *old_rlim) 1457{ 1458 struct rlimit *rlim; 1459 int retval = 0; 1460 1461 if (resource >= RLIM_NLIMITS) 1462 return -EINVAL; 1463 resource = array_index_nospec(resource, RLIM_NLIMITS); 1464 1465 if (new_rlim) { 1466 if (new_rlim->rlim_cur > new_rlim->rlim_max) 1467 return -EINVAL; 1468 if (resource == RLIMIT_NOFILE && 1469 new_rlim->rlim_max > sysctl_nr_open) 1470 return -EPERM; 1471 } 1472 1473 /* Holding a refcount on tsk protects tsk->signal from disappearing. */ 1474 rlim = tsk->signal->rlim + resource; 1475 task_lock(tsk->group_leader); 1476 if (new_rlim) { 1477 /* 1478 * Keep the capable check against init_user_ns until cgroups can 1479 * contain all limits. 1480 */ 1481 if (new_rlim->rlim_max > rlim->rlim_max && 1482 !capable(CAP_SYS_RESOURCE)) 1483 retval = -EPERM; 1484 if (!retval) 1485 retval = security_task_setrlimit(tsk, resource, new_rlim); 1486 } 1487 if (!retval) { 1488 if (old_rlim) 1489 *old_rlim = *rlim; 1490 if (new_rlim) 1491 *rlim = *new_rlim; 1492 } 1493 task_unlock(tsk->group_leader); 1494 1495 /* 1496 * RLIMIT_CPU handling. Arm the posix CPU timer if the limit is not 1497 * infinite. In case of RLIM_INFINITY the posix CPU timer code 1498 * ignores the rlimit. 1499 */ 1500 if (!retval && new_rlim && resource == RLIMIT_CPU && 1501 new_rlim->rlim_cur != RLIM_INFINITY && 1502 IS_ENABLED(CONFIG_POSIX_TIMERS)) { 1503 /* 1504 * update_rlimit_cpu can fail if the task is exiting, but there 1505 * may be other tasks in the thread group that are not exiting, 1506 * and they need their cpu timers adjusted. 1507 * 1508 * The group_leader is the last task to be released, so if we 1509 * cannot update_rlimit_cpu on it, then the entire process is 1510 * exiting and we do not need to update at all. 1511 */ 1512 update_rlimit_cpu(tsk->group_leader, new_rlim->rlim_cur); 1513 } 1514 1515 return retval; 1516} 1517 1518SYSCALL_DEFINE2(getrlimit, unsigned int, resource, struct rlimit __user *, rlim) 1519{ 1520 struct rlimit value; 1521 int ret; 1522 1523 ret = do_prlimit(current, resource, NULL, &value); 1524 if (!ret) 1525 ret = copy_to_user(rlim, &value, sizeof(*rlim)) ? -EFAULT : 0; 1526 1527 return ret; 1528} 1529 1530#ifdef CONFIG_COMPAT 1531 1532COMPAT_SYSCALL_DEFINE2(setrlimit, unsigned int, resource, 1533 struct compat_rlimit __user *, rlim) 1534{ 1535 struct rlimit r; 1536 struct compat_rlimit r32; 1537 1538 if (copy_from_user(&r32, rlim, sizeof(struct compat_rlimit))) 1539 return -EFAULT; 1540 1541 if (r32.rlim_cur == COMPAT_RLIM_INFINITY) 1542 r.rlim_cur = RLIM_INFINITY; 1543 else 1544 r.rlim_cur = r32.rlim_cur; 1545 if (r32.rlim_max == COMPAT_RLIM_INFINITY) 1546 r.rlim_max = RLIM_INFINITY; 1547 else 1548 r.rlim_max = r32.rlim_max; 1549 return do_prlimit(current, resource, &r, NULL); 1550} 1551 1552COMPAT_SYSCALL_DEFINE2(getrlimit, unsigned int, resource, 1553 struct compat_rlimit __user *, rlim) 1554{ 1555 struct rlimit r; 1556 int ret; 1557 1558 ret = do_prlimit(current, resource, NULL, &r); 1559 if (!ret) { 1560 struct compat_rlimit r32; 1561 if (r.rlim_cur > COMPAT_RLIM_INFINITY) 1562 r32.rlim_cur = COMPAT_RLIM_INFINITY; 1563 else 1564 r32.rlim_cur = r.rlim_cur; 1565 if (r.rlim_max > COMPAT_RLIM_INFINITY) 1566 r32.rlim_max = COMPAT_RLIM_INFINITY; 1567 else 1568 r32.rlim_max = r.rlim_max; 1569 1570 if (copy_to_user(rlim, &r32, sizeof(struct compat_rlimit))) 1571 return -EFAULT; 1572 } 1573 return ret; 1574} 1575 1576#endif 1577 1578#ifdef __ARCH_WANT_SYS_OLD_GETRLIMIT 1579 1580/* 1581 * Back compatibility for getrlimit. Needed for some apps. 1582 */ 1583SYSCALL_DEFINE2(old_getrlimit, unsigned int, resource, 1584 struct rlimit __user *, rlim) 1585{ 1586 struct rlimit x; 1587 if (resource >= RLIM_NLIMITS) 1588 return -EINVAL; 1589 1590 resource = array_index_nospec(resource, RLIM_NLIMITS); 1591 task_lock(current->group_leader); 1592 x = current->signal->rlim[resource]; 1593 task_unlock(current->group_leader); 1594 if (x.rlim_cur > 0x7FFFFFFF) 1595 x.rlim_cur = 0x7FFFFFFF; 1596 if (x.rlim_max > 0x7FFFFFFF) 1597 x.rlim_max = 0x7FFFFFFF; 1598 return copy_to_user(rlim, &x, sizeof(x)) ? -EFAULT : 0; 1599} 1600 1601#ifdef CONFIG_COMPAT 1602COMPAT_SYSCALL_DEFINE2(old_getrlimit, unsigned int, resource, 1603 struct compat_rlimit __user *, rlim) 1604{ 1605 struct rlimit r; 1606 1607 if (resource >= RLIM_NLIMITS) 1608 return -EINVAL; 1609 1610 resource = array_index_nospec(resource, RLIM_NLIMITS); 1611 task_lock(current->group_leader); 1612 r = current->signal->rlim[resource]; 1613 task_unlock(current->group_leader); 1614 if (r.rlim_cur > 0x7FFFFFFF) 1615 r.rlim_cur = 0x7FFFFFFF; 1616 if (r.rlim_max > 0x7FFFFFFF) 1617 r.rlim_max = 0x7FFFFFFF; 1618 1619 if (put_user(r.rlim_cur, &rlim->rlim_cur) || 1620 put_user(r.rlim_max, &rlim->rlim_max)) 1621 return -EFAULT; 1622 return 0; 1623} 1624#endif 1625 1626#endif 1627 1628static inline bool rlim64_is_infinity(__u64 rlim64) 1629{ 1630#if BITS_PER_LONG < 64 1631 return rlim64 >= ULONG_MAX; 1632#else 1633 return rlim64 == RLIM64_INFINITY; 1634#endif 1635} 1636 1637static void rlim_to_rlim64(const struct rlimit *rlim, struct rlimit64 *rlim64) 1638{ 1639 if (rlim->rlim_cur == RLIM_INFINITY) 1640 rlim64->rlim_cur = RLIM64_INFINITY; 1641 else 1642 rlim64->rlim_cur = rlim->rlim_cur; 1643 if (rlim->rlim_max == RLIM_INFINITY) 1644 rlim64->rlim_max = RLIM64_INFINITY; 1645 else 1646 rlim64->rlim_max = rlim->rlim_max; 1647} 1648 1649static void rlim64_to_rlim(const struct rlimit64 *rlim64, struct rlimit *rlim) 1650{ 1651 if (rlim64_is_infinity(rlim64->rlim_cur)) 1652 rlim->rlim_cur = RLIM_INFINITY; 1653 else 1654 rlim->rlim_cur = (unsigned long)rlim64->rlim_cur; 1655 if (rlim64_is_infinity(rlim64->rlim_max)) 1656 rlim->rlim_max = RLIM_INFINITY; 1657 else 1658 rlim->rlim_max = (unsigned long)rlim64->rlim_max; 1659} 1660 1661/* rcu lock must be held */ 1662static int check_prlimit_permission(struct task_struct *task, 1663 unsigned int flags) 1664{ 1665 const struct cred *cred = current_cred(), *tcred; 1666 bool id_match; 1667 1668 if (current == task) 1669 return 0; 1670 1671 tcred = __task_cred(task); 1672 id_match = (uid_eq(cred->uid, tcred->euid) && 1673 uid_eq(cred->uid, tcred->suid) && 1674 uid_eq(cred->uid, tcred->uid) && 1675 gid_eq(cred->gid, tcred->egid) && 1676 gid_eq(cred->gid, tcred->sgid) && 1677 gid_eq(cred->gid, tcred->gid)); 1678 if (!id_match && !ns_capable(tcred->user_ns, CAP_SYS_RESOURCE)) 1679 return -EPERM; 1680 1681 return security_task_prlimit(cred, tcred, flags); 1682} 1683 1684SYSCALL_DEFINE4(prlimit64, pid_t, pid, unsigned int, resource, 1685 const struct rlimit64 __user *, new_rlim, 1686 struct rlimit64 __user *, old_rlim) 1687{ 1688 struct rlimit64 old64, new64; 1689 struct rlimit old, new; 1690 struct task_struct *tsk; 1691 unsigned int checkflags = 0; 1692 int ret; 1693 1694 if (old_rlim) 1695 checkflags |= LSM_PRLIMIT_READ; 1696 1697 if (new_rlim) { 1698 if (copy_from_user(&new64, new_rlim, sizeof(new64))) 1699 return -EFAULT; 1700 rlim64_to_rlim(&new64, &new); 1701 checkflags |= LSM_PRLIMIT_WRITE; 1702 } 1703 1704 rcu_read_lock(); 1705 tsk = pid ? find_task_by_vpid(pid) : current; 1706 if (!tsk) { 1707 rcu_read_unlock(); 1708 return -ESRCH; 1709 } 1710 ret = check_prlimit_permission(tsk, checkflags); 1711 if (ret) { 1712 rcu_read_unlock(); 1713 return ret; 1714 } 1715 get_task_struct(tsk); 1716 rcu_read_unlock(); 1717 1718 ret = do_prlimit(tsk, resource, new_rlim ? &new : NULL, 1719 old_rlim ? &old : NULL); 1720 1721 if (!ret && old_rlim) { 1722 rlim_to_rlim64(&old, &old64); 1723 if (copy_to_user(old_rlim, &old64, sizeof(old64))) 1724 ret = -EFAULT; 1725 } 1726 1727 put_task_struct(tsk); 1728 return ret; 1729} 1730 1731SYSCALL_DEFINE2(setrlimit, unsigned int, resource, struct rlimit __user *, rlim) 1732{ 1733 struct rlimit new_rlim; 1734 1735 if (copy_from_user(&new_rlim, rlim, sizeof(*rlim))) 1736 return -EFAULT; 1737 return do_prlimit(current, resource, &new_rlim, NULL); 1738} 1739 1740/* 1741 * It would make sense to put struct rusage in the task_struct, 1742 * except that would make the task_struct be *really big*. After 1743 * task_struct gets moved into malloc'ed memory, it would 1744 * make sense to do this. It will make moving the rest of the information 1745 * a lot simpler! (Which we're not doing right now because we're not 1746 * measuring them yet). 1747 * 1748 * When sampling multiple threads for RUSAGE_SELF, under SMP we might have 1749 * races with threads incrementing their own counters. But since word 1750 * reads are atomic, we either get new values or old values and we don't 1751 * care which for the sums. We always take the siglock to protect reading 1752 * the c* fields from p->signal from races with exit.c updating those 1753 * fields when reaping, so a sample either gets all the additions of a 1754 * given child after it's reaped, or none so this sample is before reaping. 1755 * 1756 * Locking: 1757 * We need to take the siglock for CHILDEREN, SELF and BOTH 1758 * for the cases current multithreaded, non-current single threaded 1759 * non-current multithreaded. Thread traversal is now safe with 1760 * the siglock held. 1761 * Strictly speaking, we donot need to take the siglock if we are current and 1762 * single threaded, as no one else can take our signal_struct away, no one 1763 * else can reap the children to update signal->c* counters, and no one else 1764 * can race with the signal-> fields. If we do not take any lock, the 1765 * signal-> fields could be read out of order while another thread was just 1766 * exiting. So we should place a read memory barrier when we avoid the lock. 1767 * On the writer side, write memory barrier is implied in __exit_signal 1768 * as __exit_signal releases the siglock spinlock after updating the signal-> 1769 * fields. But we don't do this yet to keep things simple. 1770 * 1771 */ 1772 1773static void accumulate_thread_rusage(struct task_struct *t, struct rusage *r) 1774{ 1775 r->ru_nvcsw += t->nvcsw; 1776 r->ru_nivcsw += t->nivcsw; 1777 r->ru_minflt += t->min_flt; 1778 r->ru_majflt += t->maj_flt; 1779 r->ru_inblock += task_io_get_inblock(t); 1780 r->ru_oublock += task_io_get_oublock(t); 1781} 1782 1783void getrusage(struct task_struct *p, int who, struct rusage *r) 1784{ 1785 struct task_struct *t; 1786 unsigned long flags; 1787 u64 tgutime, tgstime, utime, stime; 1788 unsigned long maxrss; 1789 struct mm_struct *mm; 1790 struct signal_struct *sig = p->signal; 1791 unsigned int seq = 0; 1792 1793retry: 1794 memset(r, 0, sizeof(*r)); 1795 utime = stime = 0; 1796 maxrss = 0; 1797 1798 if (who == RUSAGE_THREAD) { 1799 task_cputime_adjusted(current, &utime, &stime); 1800 accumulate_thread_rusage(p, r); 1801 maxrss = sig->maxrss; 1802 goto out_thread; 1803 } 1804 1805 flags = read_seqbegin_or_lock_irqsave(&sig->stats_lock, &seq); 1806 1807 switch (who) { 1808 case RUSAGE_BOTH: 1809 case RUSAGE_CHILDREN: 1810 utime = sig->cutime; 1811 stime = sig->cstime; 1812 r->ru_nvcsw = sig->cnvcsw; 1813 r->ru_nivcsw = sig->cnivcsw; 1814 r->ru_minflt = sig->cmin_flt; 1815 r->ru_majflt = sig->cmaj_flt; 1816 r->ru_inblock = sig->cinblock; 1817 r->ru_oublock = sig->coublock; 1818 maxrss = sig->cmaxrss; 1819 1820 if (who == RUSAGE_CHILDREN) 1821 break; 1822 fallthrough; 1823 1824 case RUSAGE_SELF: 1825 r->ru_nvcsw += sig->nvcsw; 1826 r->ru_nivcsw += sig->nivcsw; 1827 r->ru_minflt += sig->min_flt; 1828 r->ru_majflt += sig->maj_flt; 1829 r->ru_inblock += sig->inblock; 1830 r->ru_oublock += sig->oublock; 1831 if (maxrss < sig->maxrss) 1832 maxrss = sig->maxrss; 1833 1834 rcu_read_lock(); 1835 __for_each_thread(sig, t) 1836 accumulate_thread_rusage(t, r); 1837 rcu_read_unlock(); 1838 1839 break; 1840 1841 default: 1842 BUG(); 1843 } 1844 1845 if (need_seqretry(&sig->stats_lock, seq)) { 1846 seq = 1; 1847 goto retry; 1848 } 1849 done_seqretry_irqrestore(&sig->stats_lock, seq, flags); 1850 1851 if (who == RUSAGE_CHILDREN) 1852 goto out_children; 1853 1854 thread_group_cputime_adjusted(p, &tgutime, &tgstime); 1855 utime += tgutime; 1856 stime += tgstime; 1857 1858out_thread: 1859 mm = get_task_mm(p); 1860 if (mm) { 1861 setmax_mm_hiwater_rss(&maxrss, mm); 1862 mmput(mm); 1863 } 1864 1865out_children: 1866 r->ru_maxrss = maxrss * (PAGE_SIZE / 1024); /* convert pages to KBs */ 1867 r->ru_utime = ns_to_kernel_old_timeval(utime); 1868 r->ru_stime = ns_to_kernel_old_timeval(stime); 1869} 1870 1871SYSCALL_DEFINE2(getrusage, int, who, struct rusage __user *, ru) 1872{ 1873 struct rusage r; 1874 1875 if (who != RUSAGE_SELF && who != RUSAGE_CHILDREN && 1876 who != RUSAGE_THREAD) 1877 return -EINVAL; 1878 1879 getrusage(current, who, &r); 1880 return copy_to_user(ru, &r, sizeof(r)) ? -EFAULT : 0; 1881} 1882 1883#ifdef CONFIG_COMPAT 1884COMPAT_SYSCALL_DEFINE2(getrusage, int, who, struct compat_rusage __user *, ru) 1885{ 1886 struct rusage r; 1887 1888 if (who != RUSAGE_SELF && who != RUSAGE_CHILDREN && 1889 who != RUSAGE_THREAD) 1890 return -EINVAL; 1891 1892 getrusage(current, who, &r); 1893 return put_compat_rusage(&r, ru); 1894} 1895#endif 1896 1897SYSCALL_DEFINE1(umask, int, mask) 1898{ 1899 mask = xchg(¤t->fs->umask, mask & S_IRWXUGO); 1900 return mask; 1901} 1902 1903static int prctl_set_mm_exe_file(struct mm_struct *mm, unsigned int fd) 1904{ 1905 struct fd exe; 1906 struct inode *inode; 1907 int err; 1908 1909 exe = fdget(fd); 1910 if (!exe.file) 1911 return -EBADF; 1912 1913 inode = file_inode(exe.file); 1914 1915 /* 1916 * Because the original mm->exe_file points to executable file, make 1917 * sure that this one is executable as well, to avoid breaking an 1918 * overall picture. 1919 */ 1920 err = -EACCES; 1921 if (!S_ISREG(inode->i_mode) || path_noexec(&exe.file->f_path)) 1922 goto exit; 1923 1924 err = file_permission(exe.file, MAY_EXEC); 1925 if (err) 1926 goto exit; 1927 1928 err = replace_mm_exe_file(mm, exe.file); 1929exit: 1930 fdput(exe); 1931 return err; 1932} 1933 1934/* 1935 * Check arithmetic relations of passed addresses. 1936 * 1937 * WARNING: we don't require any capability here so be very careful 1938 * in what is allowed for modification from userspace. 1939 */ 1940static int validate_prctl_map_addr(struct prctl_mm_map *prctl_map) 1941{ 1942 unsigned long mmap_max_addr = TASK_SIZE; 1943 int error = -EINVAL, i; 1944 1945 static const unsigned char offsets[] = { 1946 offsetof(struct prctl_mm_map, start_code), 1947 offsetof(struct prctl_mm_map, end_code), 1948 offsetof(struct prctl_mm_map, start_data), 1949 offsetof(struct prctl_mm_map, end_data), 1950 offsetof(struct prctl_mm_map, start_brk), 1951 offsetof(struct prctl_mm_map, brk), 1952 offsetof(struct prctl_mm_map, start_stack), 1953 offsetof(struct prctl_mm_map, arg_start), 1954 offsetof(struct prctl_mm_map, arg_end), 1955 offsetof(struct prctl_mm_map, env_start), 1956 offsetof(struct prctl_mm_map, env_end), 1957 }; 1958 1959 /* 1960 * Make sure the members are not somewhere outside 1961 * of allowed address space. 1962 */ 1963 for (i = 0; i < ARRAY_SIZE(offsets); i++) { 1964 u64 val = *(u64 *)((char *)prctl_map + offsets[i]); 1965 1966 if ((unsigned long)val >= mmap_max_addr || 1967 (unsigned long)val < mmap_min_addr) 1968 goto out; 1969 } 1970 1971 /* 1972 * Make sure the pairs are ordered. 1973 */ 1974#define __prctl_check_order(__m1, __op, __m2) \ 1975 ((unsigned long)prctl_map->__m1 __op \ 1976 (unsigned long)prctl_map->__m2) ? 0 : -EINVAL 1977 error = __prctl_check_order(start_code, <, end_code); 1978 error |= __prctl_check_order(start_data,<=, end_data); 1979 error |= __prctl_check_order(start_brk, <=, brk); 1980 error |= __prctl_check_order(arg_start, <=, arg_end); 1981 error |= __prctl_check_order(env_start, <=, env_end); 1982 if (error) 1983 goto out; 1984#undef __prctl_check_order 1985 1986 error = -EINVAL; 1987 1988 /* 1989 * Neither we should allow to override limits if they set. 1990 */ 1991 if (check_data_rlimit(rlimit(RLIMIT_DATA), prctl_map->brk, 1992 prctl_map->start_brk, prctl_map->end_data, 1993 prctl_map->start_data)) 1994 goto out; 1995 1996 error = 0; 1997out: 1998 return error; 1999} 2000 2001#ifdef CONFIG_CHECKPOINT_RESTORE 2002static int prctl_set_mm_map(int opt, const void __user *addr, unsigned long data_size) 2003{ 2004 struct prctl_mm_map prctl_map = { .exe_fd = (u32)-1, }; 2005 unsigned long user_auxv[AT_VECTOR_SIZE]; 2006 struct mm_struct *mm = current->mm; 2007 int error; 2008 2009 BUILD_BUG_ON(sizeof(user_auxv) != sizeof(mm->saved_auxv)); 2010 BUILD_BUG_ON(sizeof(struct prctl_mm_map) > 256); 2011 2012 if (opt == PR_SET_MM_MAP_SIZE) 2013 return put_user((unsigned int)sizeof(prctl_map), 2014 (unsigned int __user *)addr); 2015 2016 if (data_size != sizeof(prctl_map)) 2017 return -EINVAL; 2018 2019 if (copy_from_user(&prctl_map, addr, sizeof(prctl_map))) 2020 return -EFAULT; 2021 2022 error = validate_prctl_map_addr(&prctl_map); 2023 if (error) 2024 return error; 2025 2026 if (prctl_map.auxv_size) { 2027 /* 2028 * Someone is trying to cheat the auxv vector. 2029 */ 2030 if (!prctl_map.auxv || 2031 prctl_map.auxv_size > sizeof(mm->saved_auxv)) 2032 return -EINVAL; 2033 2034 memset(user_auxv, 0, sizeof(user_auxv)); 2035 if (copy_from_user(user_auxv, 2036 (const void __user *)prctl_map.auxv, 2037 prctl_map.auxv_size)) 2038 return -EFAULT; 2039 2040 /* Last entry must be AT_NULL as specification requires */ 2041 user_auxv[AT_VECTOR_SIZE - 2] = AT_NULL; 2042 user_auxv[AT_VECTOR_SIZE - 1] = AT_NULL; 2043 } 2044 2045 if (prctl_map.exe_fd != (u32)-1) { 2046 /* 2047 * Check if the current user is checkpoint/restore capable. 2048 * At the time of this writing, it checks for CAP_SYS_ADMIN 2049 * or CAP_CHECKPOINT_RESTORE. 2050 * Note that a user with access to ptrace can masquerade an 2051 * arbitrary program as any executable, even setuid ones. 2052 * This may have implications in the tomoyo subsystem. 2053 */ 2054 if (!checkpoint_restore_ns_capable(current_user_ns())) 2055 return -EPERM; 2056 2057 error = prctl_set_mm_exe_file(mm, prctl_map.exe_fd); 2058 if (error) 2059 return error; 2060 } 2061 2062 /* 2063 * arg_lock protects concurrent updates but we still need mmap_lock for 2064 * read to exclude races with sys_brk. 2065 */ 2066 mmap_read_lock(mm); 2067 2068 /* 2069 * We don't validate if these members are pointing to 2070 * real present VMAs because application may have correspond 2071 * VMAs already unmapped and kernel uses these members for statistics 2072 * output in procfs mostly, except 2073 * 2074 * - @start_brk/@brk which are used in do_brk_flags but kernel lookups 2075 * for VMAs when updating these members so anything wrong written 2076 * here cause kernel to swear at userspace program but won't lead 2077 * to any problem in kernel itself 2078 */ 2079 2080 spin_lock(&mm->arg_lock); 2081 mm->start_code = prctl_map.start_code; 2082 mm->end_code = prctl_map.end_code; 2083 mm->start_data = prctl_map.start_data; 2084 mm->end_data = prctl_map.end_data; 2085 mm->start_brk = prctl_map.start_brk; 2086 mm->brk = prctl_map.brk; 2087 mm->start_stack = prctl_map.start_stack; 2088 mm->arg_start = prctl_map.arg_start; 2089 mm->arg_end = prctl_map.arg_end; 2090 mm->env_start = prctl_map.env_start; 2091 mm->env_end = prctl_map.env_end; 2092 spin_unlock(&mm->arg_lock); 2093 2094 /* 2095 * Note this update of @saved_auxv is lockless thus 2096 * if someone reads this member in procfs while we're 2097 * updating -- it may get partly updated results. It's 2098 * known and acceptable trade off: we leave it as is to 2099 * not introduce additional locks here making the kernel 2100 * more complex. 2101 */ 2102 if (prctl_map.auxv_size) 2103 memcpy(mm->saved_auxv, user_auxv, sizeof(user_auxv)); 2104 2105 mmap_read_unlock(mm); 2106 return 0; 2107} 2108#endif /* CONFIG_CHECKPOINT_RESTORE */ 2109 2110static int prctl_set_auxv(struct mm_struct *mm, unsigned long addr, 2111 unsigned long len) 2112{ 2113 /* 2114 * This doesn't move the auxiliary vector itself since it's pinned to 2115 * mm_struct, but it permits filling the vector with new values. It's 2116 * up to the caller to provide sane values here, otherwise userspace 2117 * tools which use this vector might be unhappy. 2118 */ 2119 unsigned long user_auxv[AT_VECTOR_SIZE] = {}; 2120 2121 if (len > sizeof(user_auxv)) 2122 return -EINVAL; 2123 2124 if (copy_from_user(user_auxv, (const void __user *)addr, len)) 2125 return -EFAULT; 2126 2127 /* Make sure the last entry is always AT_NULL */ 2128 user_auxv[AT_VECTOR_SIZE - 2] = 0; 2129 user_auxv[AT_VECTOR_SIZE - 1] = 0; 2130 2131 BUILD_BUG_ON(sizeof(user_auxv) != sizeof(mm->saved_auxv)); 2132 2133 task_lock(current); 2134 memcpy(mm->saved_auxv, user_auxv, len); 2135 task_unlock(current); 2136 2137 return 0; 2138} 2139 2140static int prctl_set_mm(int opt, unsigned long addr, 2141 unsigned long arg4, unsigned long arg5) 2142{ 2143 struct mm_struct *mm = current->mm; 2144 struct prctl_mm_map prctl_map = { 2145 .auxv = NULL, 2146 .auxv_size = 0, 2147 .exe_fd = -1, 2148 }; 2149 struct vm_area_struct *vma; 2150 int error; 2151 2152 if (arg5 || (arg4 && (opt != PR_SET_MM_AUXV && 2153 opt != PR_SET_MM_MAP && 2154 opt != PR_SET_MM_MAP_SIZE))) 2155 return -EINVAL; 2156 2157#ifdef CONFIG_CHECKPOINT_RESTORE 2158 if (opt == PR_SET_MM_MAP || opt == PR_SET_MM_MAP_SIZE) 2159 return prctl_set_mm_map(opt, (const void __user *)addr, arg4); 2160#endif 2161 2162 if (!capable(CAP_SYS_RESOURCE)) 2163 return -EPERM; 2164 2165 if (opt == PR_SET_MM_EXE_FILE) 2166 return prctl_set_mm_exe_file(mm, (unsigned int)addr); 2167 2168 if (opt == PR_SET_MM_AUXV) 2169 return prctl_set_auxv(mm, addr, arg4); 2170 2171 if (addr >= TASK_SIZE || addr < mmap_min_addr) 2172 return -EINVAL; 2173 2174 error = -EINVAL; 2175 2176 /* 2177 * arg_lock protects concurrent updates of arg boundaries, we need 2178 * mmap_lock for a) concurrent sys_brk, b) finding VMA for addr 2179 * validation. 2180 */ 2181 mmap_read_lock(mm); 2182 vma = find_vma(mm, addr); 2183 2184 spin_lock(&mm->arg_lock); 2185 prctl_map.start_code = mm->start_code; 2186 prctl_map.end_code = mm->end_code; 2187 prctl_map.start_data = mm->start_data; 2188 prctl_map.end_data = mm->end_data; 2189 prctl_map.start_brk = mm->start_brk; 2190 prctl_map.brk = mm->brk; 2191 prctl_map.start_stack = mm->start_stack; 2192 prctl_map.arg_start = mm->arg_start; 2193 prctl_map.arg_end = mm->arg_end; 2194 prctl_map.env_start = mm->env_start; 2195 prctl_map.env_end = mm->env_end; 2196 2197 switch (opt) { 2198 case PR_SET_MM_START_CODE: 2199 prctl_map.start_code = addr; 2200 break; 2201 case PR_SET_MM_END_CODE: 2202 prctl_map.end_code = addr; 2203 break; 2204 case PR_SET_MM_START_DATA: 2205 prctl_map.start_data = addr; 2206 break; 2207 case PR_SET_MM_END_DATA: 2208 prctl_map.end_data = addr; 2209 break; 2210 case PR_SET_MM_START_STACK: 2211 prctl_map.start_stack = addr; 2212 break; 2213 case PR_SET_MM_START_BRK: 2214 prctl_map.start_brk = addr; 2215 break; 2216 case PR_SET_MM_BRK: 2217 prctl_map.brk = addr; 2218 break; 2219 case PR_SET_MM_ARG_START: 2220 prctl_map.arg_start = addr; 2221 break; 2222 case PR_SET_MM_ARG_END: 2223 prctl_map.arg_end = addr; 2224 break; 2225 case PR_SET_MM_ENV_START: 2226 prctl_map.env_start = addr; 2227 break; 2228 case PR_SET_MM_ENV_END: 2229 prctl_map.env_end = addr; 2230 break; 2231 default: 2232 goto out; 2233 } 2234 2235 error = validate_prctl_map_addr(&prctl_map); 2236 if (error) 2237 goto out; 2238 2239 switch (opt) { 2240 /* 2241 * If command line arguments and environment 2242 * are placed somewhere else on stack, we can 2243 * set them up here, ARG_START/END to setup 2244 * command line arguments and ENV_START/END 2245 * for environment. 2246 */ 2247 case PR_SET_MM_START_STACK: 2248 case PR_SET_MM_ARG_START: 2249 case PR_SET_MM_ARG_END: 2250 case PR_SET_MM_ENV_START: 2251 case PR_SET_MM_ENV_END: 2252 if (!vma) { 2253 error = -EFAULT; 2254 goto out; 2255 } 2256 } 2257 2258 mm->start_code = prctl_map.start_code; 2259 mm->end_code = prctl_map.end_code; 2260 mm->start_data = prctl_map.start_data; 2261 mm->end_data = prctl_map.end_data; 2262 mm->start_brk = prctl_map.start_brk; 2263 mm->brk = prctl_map.brk; 2264 mm->start_stack = prctl_map.start_stack; 2265 mm->arg_start = prctl_map.arg_start; 2266 mm->arg_end = prctl_map.arg_end; 2267 mm->env_start = prctl_map.env_start; 2268 mm->env_end = prctl_map.env_end; 2269 2270 error = 0; 2271out: 2272 spin_unlock(&mm->arg_lock); 2273 mmap_read_unlock(mm); 2274 return error; 2275} 2276 2277#ifdef CONFIG_CHECKPOINT_RESTORE 2278static int prctl_get_tid_address(struct task_struct *me, int __user * __user *tid_addr) 2279{ 2280 return put_user(me->clear_child_tid, tid_addr); 2281} 2282#else 2283static int prctl_get_tid_address(struct task_struct *me, int __user * __user *tid_addr) 2284{ 2285 return -EINVAL; 2286} 2287#endif 2288 2289static int propagate_has_child_subreaper(struct task_struct *p, void *data) 2290{ 2291 /* 2292 * If task has has_child_subreaper - all its descendants 2293 * already have these flag too and new descendants will 2294 * inherit it on fork, skip them. 2295 * 2296 * If we've found child_reaper - skip descendants in 2297 * it's subtree as they will never get out pidns. 2298 */ 2299 if (p->signal->has_child_subreaper || 2300 is_child_reaper(task_pid(p))) 2301 return 0; 2302 2303 p->signal->has_child_subreaper = 1; 2304 return 1; 2305} 2306 2307int __weak arch_prctl_spec_ctrl_get(struct task_struct *t, unsigned long which) 2308{ 2309 return -EINVAL; 2310} 2311 2312int __weak arch_prctl_spec_ctrl_set(struct task_struct *t, unsigned long which, 2313 unsigned long ctrl) 2314{ 2315 return -EINVAL; 2316} 2317 2318#define PR_IO_FLUSHER (PF_MEMALLOC_NOIO | PF_LOCAL_THROTTLE) 2319 2320#ifdef CONFIG_ANON_VMA_NAME 2321 2322#define ANON_VMA_NAME_MAX_LEN 80 2323#define ANON_VMA_NAME_INVALID_CHARS "\\`$[]" 2324 2325static inline bool is_valid_name_char(char ch) 2326{ 2327 /* printable ascii characters, excluding ANON_VMA_NAME_INVALID_CHARS */ 2328 return ch > 0x1f && ch < 0x7f && 2329 !strchr(ANON_VMA_NAME_INVALID_CHARS, ch); 2330} 2331 2332static int prctl_set_vma(unsigned long opt, unsigned long addr, 2333 unsigned long size, unsigned long arg) 2334{ 2335 struct mm_struct *mm = current->mm; 2336 const char __user *uname; 2337 struct anon_vma_name *anon_name = NULL; 2338 int error; 2339 2340 switch (opt) { 2341 case PR_SET_VMA_ANON_NAME: 2342 uname = (const char __user *)arg; 2343 if (uname) { 2344 char *name, *pch; 2345 2346 name = strndup_user(uname, ANON_VMA_NAME_MAX_LEN); 2347 if (IS_ERR(name)) 2348 return PTR_ERR(name); 2349 2350 for (pch = name; *pch != '\0'; pch++) { 2351 if (!is_valid_name_char(*pch)) { 2352 kfree(name); 2353 return -EINVAL; 2354 } 2355 } 2356 /* anon_vma has its own copy */ 2357 anon_name = anon_vma_name_alloc(name); 2358 kfree(name); 2359 if (!anon_name) 2360 return -ENOMEM; 2361 2362 } 2363 2364 mmap_write_lock(mm); 2365 error = madvise_set_anon_name(mm, addr, size, anon_name); 2366 mmap_write_unlock(mm); 2367 anon_vma_name_put(anon_name); 2368 break; 2369 default: 2370 error = -EINVAL; 2371 } 2372 2373 return error; 2374} 2375 2376#else /* CONFIG_ANON_VMA_NAME */ 2377static int prctl_set_vma(unsigned long opt, unsigned long start, 2378 unsigned long size, unsigned long arg) 2379{ 2380 return -EINVAL; 2381} 2382#endif /* CONFIG_ANON_VMA_NAME */ 2383 2384static inline unsigned long get_current_mdwe(void) 2385{ 2386 unsigned long ret = 0; 2387 2388 if (test_bit(MMF_HAS_MDWE, ¤t->mm->flags)) 2389 ret |= PR_MDWE_REFUSE_EXEC_GAIN; 2390 if (test_bit(MMF_HAS_MDWE_NO_INHERIT, ¤t->mm->flags)) 2391 ret |= PR_MDWE_NO_INHERIT; 2392 2393 return ret; 2394} 2395 2396static inline int prctl_set_mdwe(unsigned long bits, unsigned long arg3, 2397 unsigned long arg4, unsigned long arg5) 2398{ 2399 unsigned long current_bits; 2400 2401 if (arg3 || arg4 || arg5) 2402 return -EINVAL; 2403 2404 if (bits & ~(PR_MDWE_REFUSE_EXEC_GAIN | PR_MDWE_NO_INHERIT)) 2405 return -EINVAL; 2406 2407 /* NO_INHERIT only makes sense with REFUSE_EXEC_GAIN */ 2408 if (bits & PR_MDWE_NO_INHERIT && !(bits & PR_MDWE_REFUSE_EXEC_GAIN)) 2409 return -EINVAL; 2410 2411 /* 2412 * EOPNOTSUPP might be more appropriate here in principle, but 2413 * existing userspace depends on EINVAL specifically. 2414 */ 2415 if (!arch_memory_deny_write_exec_supported()) 2416 return -EINVAL; 2417 2418 current_bits = get_current_mdwe(); 2419 if (current_bits && current_bits != bits) 2420 return -EPERM; /* Cannot unset the flags */ 2421 2422 if (bits & PR_MDWE_NO_INHERIT) 2423 set_bit(MMF_HAS_MDWE_NO_INHERIT, ¤t->mm->flags); 2424 if (bits & PR_MDWE_REFUSE_EXEC_GAIN) 2425 set_bit(MMF_HAS_MDWE, ¤t->mm->flags); 2426 2427 return 0; 2428} 2429 2430static inline int prctl_get_mdwe(unsigned long arg2, unsigned long arg3, 2431 unsigned long arg4, unsigned long arg5) 2432{ 2433 if (arg2 || arg3 || arg4 || arg5) 2434 return -EINVAL; 2435 return get_current_mdwe(); 2436} 2437 2438static int prctl_get_auxv(void __user *addr, unsigned long len) 2439{ 2440 struct mm_struct *mm = current->mm; 2441 unsigned long size = min_t(unsigned long, sizeof(mm->saved_auxv), len); 2442 2443 if (size && copy_to_user(addr, mm->saved_auxv, size)) 2444 return -EFAULT; 2445 return sizeof(mm->saved_auxv); 2446} 2447 2448SYSCALL_DEFINE5(prctl, int, option, unsigned long, arg2, unsigned long, arg3, 2449 unsigned long, arg4, unsigned long, arg5) 2450{ 2451 struct task_struct *me = current; 2452 unsigned char comm[sizeof(me->comm)]; 2453 long error; 2454 2455 error = security_task_prctl(option, arg2, arg3, arg4, arg5); 2456 if (error != -ENOSYS) 2457 return error; 2458 2459 error = 0; 2460 switch (option) { 2461 case PR_SET_PDEATHSIG: 2462 if (!valid_signal(arg2)) { 2463 error = -EINVAL; 2464 break; 2465 } 2466 me->pdeath_signal = arg2; 2467 break; 2468 case PR_GET_PDEATHSIG: 2469 error = put_user(me->pdeath_signal, (int __user *)arg2); 2470 break; 2471 case PR_GET_DUMPABLE: 2472 error = get_dumpable(me->mm); 2473 break; 2474 case PR_SET_DUMPABLE: 2475 if (arg2 != SUID_DUMP_DISABLE && arg2 != SUID_DUMP_USER) { 2476 error = -EINVAL; 2477 break; 2478 } 2479 set_dumpable(me->mm, arg2); 2480 break; 2481 2482 case PR_SET_UNALIGN: 2483 error = SET_UNALIGN_CTL(me, arg2); 2484 break; 2485 case PR_GET_UNALIGN: 2486 error = GET_UNALIGN_CTL(me, arg2); 2487 break; 2488 case PR_SET_FPEMU: 2489 error = SET_FPEMU_CTL(me, arg2); 2490 break; 2491 case PR_GET_FPEMU: 2492 error = GET_FPEMU_CTL(me, arg2); 2493 break; 2494 case PR_SET_FPEXC: 2495 error = SET_FPEXC_CTL(me, arg2); 2496 break; 2497 case PR_GET_FPEXC: 2498 error = GET_FPEXC_CTL(me, arg2); 2499 break; 2500 case PR_GET_TIMING: 2501 error = PR_TIMING_STATISTICAL; 2502 break; 2503 case PR_SET_TIMING: 2504 if (arg2 != PR_TIMING_STATISTICAL) 2505 error = -EINVAL; 2506 break; 2507 case PR_SET_NAME: 2508 comm[sizeof(me->comm) - 1] = 0; 2509 if (strncpy_from_user(comm, (char __user *)arg2, 2510 sizeof(me->comm) - 1) < 0) 2511 return -EFAULT; 2512 set_task_comm(me, comm); 2513 proc_comm_connector(me); 2514 break; 2515 case PR_GET_NAME: 2516 get_task_comm(comm, me); 2517 if (copy_to_user((char __user *)arg2, comm, sizeof(comm))) 2518 return -EFAULT; 2519 break; 2520 case PR_GET_ENDIAN: 2521 error = GET_ENDIAN(me, arg2); 2522 break; 2523 case PR_SET_ENDIAN: 2524 error = SET_ENDIAN(me, arg2); 2525 break; 2526 case PR_GET_SECCOMP: 2527 error = prctl_get_seccomp(); 2528 break; 2529 case PR_SET_SECCOMP: 2530 error = prctl_set_seccomp(arg2, (char __user *)arg3); 2531 break; 2532 case PR_GET_TSC: 2533 error = GET_TSC_CTL(arg2); 2534 break; 2535 case PR_SET_TSC: 2536 error = SET_TSC_CTL(arg2); 2537 break; 2538 case PR_TASK_PERF_EVENTS_DISABLE: 2539 error = perf_event_task_disable(); 2540 break; 2541 case PR_TASK_PERF_EVENTS_ENABLE: 2542 error = perf_event_task_enable(); 2543 break; 2544 case PR_GET_TIMERSLACK: 2545 if (current->timer_slack_ns > ULONG_MAX) 2546 error = ULONG_MAX; 2547 else 2548 error = current->timer_slack_ns; 2549 break; 2550 case PR_SET_TIMERSLACK: 2551 if (arg2 <= 0) 2552 current->timer_slack_ns = 2553 current->default_timer_slack_ns; 2554 else 2555 current->timer_slack_ns = arg2; 2556 break; 2557 case PR_MCE_KILL: 2558 if (arg4 | arg5) 2559 return -EINVAL; 2560 switch (arg2) { 2561 case PR_MCE_KILL_CLEAR: 2562 if (arg3 != 0) 2563 return -EINVAL; 2564 current->flags &= ~PF_MCE_PROCESS; 2565 break; 2566 case PR_MCE_KILL_SET: 2567 current->flags |= PF_MCE_PROCESS; 2568 if (arg3 == PR_MCE_KILL_EARLY) 2569 current->flags |= PF_MCE_EARLY; 2570 else if (arg3 == PR_MCE_KILL_LATE) 2571 current->flags &= ~PF_MCE_EARLY; 2572 else if (arg3 == PR_MCE_KILL_DEFAULT) 2573 current->flags &= 2574 ~(PF_MCE_EARLY|PF_MCE_PROCESS); 2575 else 2576 return -EINVAL; 2577 break; 2578 default: 2579 return -EINVAL; 2580 } 2581 break; 2582 case PR_MCE_KILL_GET: 2583 if (arg2 | arg3 | arg4 | arg5) 2584 return -EINVAL; 2585 if (current->flags & PF_MCE_PROCESS) 2586 error = (current->flags & PF_MCE_EARLY) ? 2587 PR_MCE_KILL_EARLY : PR_MCE_KILL_LATE; 2588 else 2589 error = PR_MCE_KILL_DEFAULT; 2590 break; 2591 case PR_SET_MM: 2592 error = prctl_set_mm(arg2, arg3, arg4, arg5); 2593 break; 2594 case PR_GET_TID_ADDRESS: 2595 error = prctl_get_tid_address(me, (int __user * __user *)arg2); 2596 break; 2597 case PR_SET_CHILD_SUBREAPER: 2598 me->signal->is_child_subreaper = !!arg2; 2599 if (!arg2) 2600 break; 2601 2602 walk_process_tree(me, propagate_has_child_subreaper, NULL); 2603 break; 2604 case PR_GET_CHILD_SUBREAPER: 2605 error = put_user(me->signal->is_child_subreaper, 2606 (int __user *)arg2); 2607 break; 2608 case PR_SET_NO_NEW_PRIVS: 2609 if (arg2 != 1 || arg3 || arg4 || arg5) 2610 return -EINVAL; 2611 2612 task_set_no_new_privs(current); 2613 break; 2614 case PR_GET_NO_NEW_PRIVS: 2615 if (arg2 || arg3 || arg4 || arg5) 2616 return -EINVAL; 2617 return task_no_new_privs(current) ? 1 : 0; 2618 case PR_GET_THP_DISABLE: 2619 if (arg2 || arg3 || arg4 || arg5) 2620 return -EINVAL; 2621 error = !!test_bit(MMF_DISABLE_THP, &me->mm->flags); 2622 break; 2623 case PR_SET_THP_DISABLE: 2624 if (arg3 || arg4 || arg5) 2625 return -EINVAL; 2626 if (mmap_write_lock_killable(me->mm)) 2627 return -EINTR; 2628 if (arg2) 2629 set_bit(MMF_DISABLE_THP, &me->mm->flags); 2630 else 2631 clear_bit(MMF_DISABLE_THP, &me->mm->flags); 2632 mmap_write_unlock(me->mm); 2633 break; 2634 case PR_MPX_ENABLE_MANAGEMENT: 2635 case PR_MPX_DISABLE_MANAGEMENT: 2636 /* No longer implemented: */ 2637 return -EINVAL; 2638 case PR_SET_FP_MODE: 2639 error = SET_FP_MODE(me, arg2); 2640 break; 2641 case PR_GET_FP_MODE: 2642 error = GET_FP_MODE(me); 2643 break; 2644 case PR_SVE_SET_VL: 2645 error = SVE_SET_VL(arg2); 2646 break; 2647 case PR_SVE_GET_VL: 2648 error = SVE_GET_VL(); 2649 break; 2650 case PR_SME_SET_VL: 2651 error = SME_SET_VL(arg2); 2652 break; 2653 case PR_SME_GET_VL: 2654 error = SME_GET_VL(); 2655 break; 2656 case PR_GET_SPECULATION_CTRL: 2657 if (arg3 || arg4 || arg5) 2658 return -EINVAL; 2659 error = arch_prctl_spec_ctrl_get(me, arg2); 2660 break; 2661 case PR_SET_SPECULATION_CTRL: 2662 if (arg4 || arg5) 2663 return -EINVAL; 2664 error = arch_prctl_spec_ctrl_set(me, arg2, arg3); 2665 break; 2666 case PR_PAC_RESET_KEYS: 2667 if (arg3 || arg4 || arg5) 2668 return -EINVAL; 2669 error = PAC_RESET_KEYS(me, arg2); 2670 break; 2671 case PR_PAC_SET_ENABLED_KEYS: 2672 if (arg4 || arg5) 2673 return -EINVAL; 2674 error = PAC_SET_ENABLED_KEYS(me, arg2, arg3); 2675 break; 2676 case PR_PAC_GET_ENABLED_KEYS: 2677 if (arg2 || arg3 || arg4 || arg5) 2678 return -EINVAL; 2679 error = PAC_GET_ENABLED_KEYS(me); 2680 break; 2681 case PR_SET_TAGGED_ADDR_CTRL: 2682 if (arg3 || arg4 || arg5) 2683 return -EINVAL; 2684 error = SET_TAGGED_ADDR_CTRL(arg2); 2685 break; 2686 case PR_GET_TAGGED_ADDR_CTRL: 2687 if (arg2 || arg3 || arg4 || arg5) 2688 return -EINVAL; 2689 error = GET_TAGGED_ADDR_CTRL(); 2690 break; 2691 case PR_SET_IO_FLUSHER: 2692 if (!capable(CAP_SYS_RESOURCE)) 2693 return -EPERM; 2694 2695 if (arg3 || arg4 || arg5) 2696 return -EINVAL; 2697 2698 if (arg2 == 1) 2699 current->flags |= PR_IO_FLUSHER; 2700 else if (!arg2) 2701 current->flags &= ~PR_IO_FLUSHER; 2702 else 2703 return -EINVAL; 2704 break; 2705 case PR_GET_IO_FLUSHER: 2706 if (!capable(CAP_SYS_RESOURCE)) 2707 return -EPERM; 2708 2709 if (arg2 || arg3 || arg4 || arg5) 2710 return -EINVAL; 2711 2712 error = (current->flags & PR_IO_FLUSHER) == PR_IO_FLUSHER; 2713 break; 2714 case PR_SET_SYSCALL_USER_DISPATCH: 2715 error = set_syscall_user_dispatch(arg2, arg3, arg4, 2716 (char __user *) arg5); 2717 break; 2718#ifdef CONFIG_SCHED_CORE 2719 case PR_SCHED_CORE: 2720 error = sched_core_share_pid(arg2, arg3, arg4, arg5); 2721 break; 2722#endif 2723 case PR_SET_MDWE: 2724 error = prctl_set_mdwe(arg2, arg3, arg4, arg5); 2725 break; 2726 case PR_GET_MDWE: 2727 error = prctl_get_mdwe(arg2, arg3, arg4, arg5); 2728 break; 2729 case PR_SET_VMA: 2730 error = prctl_set_vma(arg2, arg3, arg4, arg5); 2731 break; 2732 case PR_GET_AUXV: 2733 if (arg4 || arg5) 2734 return -EINVAL; 2735 error = prctl_get_auxv((void __user *)arg2, arg3); 2736 break; 2737#ifdef CONFIG_KSM 2738 case PR_SET_MEMORY_MERGE: 2739 if (arg3 || arg4 || arg5) 2740 return -EINVAL; 2741 if (mmap_write_lock_killable(me->mm)) 2742 return -EINTR; 2743 2744 if (arg2) 2745 error = ksm_enable_merge_any(me->mm); 2746 else 2747 error = ksm_disable_merge_any(me->mm); 2748 mmap_write_unlock(me->mm); 2749 break; 2750 case PR_GET_MEMORY_MERGE: 2751 if (arg2 || arg3 || arg4 || arg5) 2752 return -EINVAL; 2753 2754 error = !!test_bit(MMF_VM_MERGE_ANY, &me->mm->flags); 2755 break; 2756#endif 2757 case PR_RISCV_V_SET_CONTROL: 2758 error = RISCV_V_SET_CONTROL(arg2); 2759 break; 2760 case PR_RISCV_V_GET_CONTROL: 2761 error = RISCV_V_GET_CONTROL(); 2762 break; 2763 default: 2764 error = -EINVAL; 2765 break; 2766 } 2767 return error; 2768} 2769 2770SYSCALL_DEFINE3(getcpu, unsigned __user *, cpup, unsigned __user *, nodep, 2771 struct getcpu_cache __user *, unused) 2772{ 2773 int err = 0; 2774 int cpu = raw_smp_processor_id(); 2775 2776 if (cpup) 2777 err |= put_user(cpu, cpup); 2778 if (nodep) 2779 err |= put_user(cpu_to_node(cpu), nodep); 2780 return err ? -EFAULT : 0; 2781} 2782 2783/** 2784 * do_sysinfo - fill in sysinfo struct 2785 * @info: pointer to buffer to fill 2786 */ 2787static int do_sysinfo(struct sysinfo *info) 2788{ 2789 unsigned long mem_total, sav_total; 2790 unsigned int mem_unit, bitcount; 2791 struct timespec64 tp; 2792 2793 memset(info, 0, sizeof(struct sysinfo)); 2794 2795 ktime_get_boottime_ts64(&tp); 2796 timens_add_boottime(&tp); 2797 info->uptime = tp.tv_sec + (tp.tv_nsec ? 1 : 0); 2798 2799 get_avenrun(info->loads, 0, SI_LOAD_SHIFT - FSHIFT); 2800 2801 info->procs = nr_threads; 2802 2803 si_meminfo(info); 2804 si_swapinfo(info); 2805 2806 /* 2807 * If the sum of all the available memory (i.e. ram + swap) 2808 * is less than can be stored in a 32 bit unsigned long then 2809 * we can be binary compatible with 2.2.x kernels. If not, 2810 * well, in that case 2.2.x was broken anyways... 2811 * 2812 * -Erik Andersen <andersee@debian.org> 2813 */ 2814 2815 mem_total = info->totalram + info->totalswap; 2816 if (mem_total < info->totalram || mem_total < info->totalswap) 2817 goto out; 2818 bitcount = 0; 2819 mem_unit = info->mem_unit; 2820 while (mem_unit > 1) { 2821 bitcount++; 2822 mem_unit >>= 1; 2823 sav_total = mem_total; 2824 mem_total <<= 1; 2825 if (mem_total < sav_total) 2826 goto out; 2827 } 2828 2829 /* 2830 * If mem_total did not overflow, multiply all memory values by 2831 * info->mem_unit and set it to 1. This leaves things compatible 2832 * with 2.2.x, and also retains compatibility with earlier 2.4.x 2833 * kernels... 2834 */ 2835 2836 info->mem_unit = 1; 2837 info->totalram <<= bitcount; 2838 info->freeram <<= bitcount; 2839 info->sharedram <<= bitcount; 2840 info->bufferram <<= bitcount; 2841 info->totalswap <<= bitcount; 2842 info->freeswap <<= bitcount; 2843 info->totalhigh <<= bitcount; 2844 info->freehigh <<= bitcount; 2845 2846out: 2847 return 0; 2848} 2849 2850SYSCALL_DEFINE1(sysinfo, struct sysinfo __user *, info) 2851{ 2852 struct sysinfo val; 2853 2854 do_sysinfo(&val); 2855 2856 if (copy_to_user(info, &val, sizeof(struct sysinfo))) 2857 return -EFAULT; 2858 2859 return 0; 2860} 2861 2862#ifdef CONFIG_COMPAT 2863struct compat_sysinfo { 2864 s32 uptime; 2865 u32 loads[3]; 2866 u32 totalram; 2867 u32 freeram; 2868 u32 sharedram; 2869 u32 bufferram; 2870 u32 totalswap; 2871 u32 freeswap; 2872 u16 procs; 2873 u16 pad; 2874 u32 totalhigh; 2875 u32 freehigh; 2876 u32 mem_unit; 2877 char _f[20-2*sizeof(u32)-sizeof(int)]; 2878}; 2879 2880COMPAT_SYSCALL_DEFINE1(sysinfo, struct compat_sysinfo __user *, info) 2881{ 2882 struct sysinfo s; 2883 struct compat_sysinfo s_32; 2884 2885 do_sysinfo(&s); 2886 2887 /* Check to see if any memory value is too large for 32-bit and scale 2888 * down if needed 2889 */ 2890 if (upper_32_bits(s.totalram) || upper_32_bits(s.totalswap)) { 2891 int bitcount = 0; 2892 2893 while (s.mem_unit < PAGE_SIZE) { 2894 s.mem_unit <<= 1; 2895 bitcount++; 2896 } 2897 2898 s.totalram >>= bitcount; 2899 s.freeram >>= bitcount; 2900 s.sharedram >>= bitcount; 2901 s.bufferram >>= bitcount; 2902 s.totalswap >>= bitcount; 2903 s.freeswap >>= bitcount; 2904 s.totalhigh >>= bitcount; 2905 s.freehigh >>= bitcount; 2906 } 2907 2908 memset(&s_32, 0, sizeof(s_32)); 2909 s_32.uptime = s.uptime; 2910 s_32.loads[0] = s.loads[0]; 2911 s_32.loads[1] = s.loads[1]; 2912 s_32.loads[2] = s.loads[2]; 2913 s_32.totalram = s.totalram; 2914 s_32.freeram = s.freeram; 2915 s_32.sharedram = s.sharedram; 2916 s_32.bufferram = s.bufferram; 2917 s_32.totalswap = s.totalswap; 2918 s_32.freeswap = s.freeswap; 2919 s_32.procs = s.procs; 2920 s_32.totalhigh = s.totalhigh; 2921 s_32.freehigh = s.freehigh; 2922 s_32.mem_unit = s.mem_unit; 2923 if (copy_to_user(info, &s_32, sizeof(s_32))) 2924 return -EFAULT; 2925 return 0; 2926} 2927#endif /* CONFIG_COMPAT */ 2928