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 */ 154 155 int overflowuid = DEFAULT_OVERFLOWUID; 156 int overflowgid = DEFAULT_OVERFLOWGID; 157 158 EXPORT_SYMBOL(overflowuid); 159 EXPORT_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 */ 165 166 int fs_overflowuid = DEFAULT_FS_OVERFLOWUID; 167 int fs_overflowgid = DEFAULT_FS_OVERFLOWGID; 168 169 EXPORT_SYMBOL(fs_overflowuid); 170 EXPORT_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 */ 178 static 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 */ 194 static 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); 214 out: 215 return error; 216 } 217 218 SYSCALL_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 } 276 out_unlock: 277 rcu_read_unlock(); 278 out: 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 */ 288 SYSCALL_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 } 347 out_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 372 long __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); 422 423 error: 424 abort_creds(new); 425 return retval; 426 } 427 428 SYSCALL_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 */ 438 long __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); 468 469 error: 470 abort_creds(new); 471 return retval; 472 } 473 474 SYSCALL_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 */ 482 static 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 } 494 495 static 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 */ 529 long __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); 588 589 error: 590 abort_creds(new); 591 return retval; 592 } 593 594 SYSCALL_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 */ 610 long __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); 651 652 error: 653 abort_creds(new); 654 return retval; 655 } 656 657 SYSCALL_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 */ 667 long __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); 736 737 error: 738 abort_creds(new); 739 return retval; 740 } 741 742 SYSCALL_DEFINE3(setresuid, uid_t, ruid, uid_t, euid, uid_t, suid) 743 { 744 return __sys_setresuid(ruid, euid, suid); 745 } 746 747 SYSCALL_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 */ 769 long __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); 825 826 error: 827 abort_creds(new); 828 return retval; 829 } 830 831 SYSCALL_DEFINE3(setresgid, gid_t, rgid, gid_t, egid, gid_t, sgid) 832 { 833 return __sys_setresgid(rgid, egid, sgid); 834 } 835 836 SYSCALL_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 */ 863 long __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; 893 894 change_okay: 895 commit_creds(new); 896 return old_fsuid; 897 } 898 899 SYSCALL_DEFINE1(setfsuid, uid_t, uid) 900 { 901 return __sys_setfsuid(uid); 902 } 903 904 /* 905 * Samma på svenska.. 906 */ 907 long __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; 937 938 change_okay: 939 commit_creds(new); 940 return old_fsgid; 941 } 942 943 SYSCALL_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 */ 958 SYSCALL_DEFINE0(getpid) 959 { 960 return task_tgid_vnr(current); 961 } 962 963 /* Thread ID - the internal kernel "pid" */ 964 SYSCALL_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 */ 975 SYSCALL_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 } 985 986 SYSCALL_DEFINE0(getuid) 987 { 988 /* Only we change this so SMP safe */ 989 return from_kuid_munged(current_user_ns(), current_uid()); 990 } 991 992 SYSCALL_DEFINE0(geteuid) 993 { 994 /* Only we change this so SMP safe */ 995 return from_kuid_munged(current_user_ns(), current_euid()); 996 } 997 998 SYSCALL_DEFINE0(getgid) 999 { 1000 /* Only we change this so SMP safe */ 1001 return from_kgid_munged(current_user_ns(), current_gid()); 1002 } 1003 1004 SYSCALL_DEFINE0(getegid) 1005 { 1006 /* Only we change this so SMP safe */ 1007 return from_kgid_munged(current_user_ns(), current_egid()); 1008 } 1009 1010 static 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 1023 SYSCALL_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 1037 static 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 1042 COMPAT_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 */ 1073 SYSCALL_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; 1137 out: 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 1144 static 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); 1167 out: 1168 rcu_read_unlock(); 1169 return retval; 1170 } 1171 1172 SYSCALL_DEFINE1(getpgid, pid_t, pid) 1173 { 1174 return do_getpgid(pid); 1175 } 1176 1177 #ifdef __ARCH_WANT_SYS_GETPGRP 1178 1179 SYSCALL_DEFINE0(getpgrp) 1180 { 1181 return do_getpgid(0); 1182 } 1183 1184 #endif 1185 1186 SYSCALL_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); 1209 out: 1210 rcu_read_unlock(); 1211 return retval; 1212 } 1213 1214 static 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 1225 int 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; 1249 out: 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 1258 SYSCALL_DEFINE0(setsid) 1259 { 1260 return ksys_setsid(); 1261 } 1262 1263 DECLARE_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 */ 1280 static 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 1306 SYSCALL_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 */ 1327 SYSCALL_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 1347 SYSCALL_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 1374 SYSCALL_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 1402 SYSCALL_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 */ 1428 SYSCALL_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 */ 1455 static 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 1518 SYSCALL_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 1532 COMPAT_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 1552 COMPAT_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 */ 1583 SYSCALL_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 1602 COMPAT_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 1628 static 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 1637 static 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 1649 static 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 */ 1662 static 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 1684 SYSCALL_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 1731 SYSCALL_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 1773 static 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 1783 void 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 = 0; 1789 1790 memset((char *)r, 0, sizeof (*r)); 1791 utime = stime = 0; 1792 1793 if (who == RUSAGE_THREAD) { 1794 task_cputime_adjusted(current, &utime, &stime); 1795 accumulate_thread_rusage(p, r); 1796 maxrss = p->signal->maxrss; 1797 goto out; 1798 } 1799 1800 if (!lock_task_sighand(p, &flags)) 1801 return; 1802 1803 switch (who) { 1804 case RUSAGE_BOTH: 1805 case RUSAGE_CHILDREN: 1806 utime = p->signal->cutime; 1807 stime = p->signal->cstime; 1808 r->ru_nvcsw = p->signal->cnvcsw; 1809 r->ru_nivcsw = p->signal->cnivcsw; 1810 r->ru_minflt = p->signal->cmin_flt; 1811 r->ru_majflt = p->signal->cmaj_flt; 1812 r->ru_inblock = p->signal->cinblock; 1813 r->ru_oublock = p->signal->coublock; 1814 maxrss = p->signal->cmaxrss; 1815 1816 if (who == RUSAGE_CHILDREN) 1817 break; 1818 fallthrough; 1819 1820 case RUSAGE_SELF: 1821 thread_group_cputime_adjusted(p, &tgutime, &tgstime); 1822 utime += tgutime; 1823 stime += tgstime; 1824 r->ru_nvcsw += p->signal->nvcsw; 1825 r->ru_nivcsw += p->signal->nivcsw; 1826 r->ru_minflt += p->signal->min_flt; 1827 r->ru_majflt += p->signal->maj_flt; 1828 r->ru_inblock += p->signal->inblock; 1829 r->ru_oublock += p->signal->oublock; 1830 if (maxrss < p->signal->maxrss) 1831 maxrss = p->signal->maxrss; 1832 t = p; 1833 do { 1834 accumulate_thread_rusage(t, r); 1835 } while_each_thread(p, t); 1836 break; 1837 1838 default: 1839 BUG(); 1840 } 1841 unlock_task_sighand(p, &flags); 1842 1843 out: 1844 r->ru_utime = ns_to_kernel_old_timeval(utime); 1845 r->ru_stime = ns_to_kernel_old_timeval(stime); 1846 1847 if (who != RUSAGE_CHILDREN) { 1848 struct mm_struct *mm = get_task_mm(p); 1849 1850 if (mm) { 1851 setmax_mm_hiwater_rss(&maxrss, mm); 1852 mmput(mm); 1853 } 1854 } 1855 r->ru_maxrss = maxrss * (PAGE_SIZE / 1024); /* convert pages to KBs */ 1856 } 1857 1858 SYSCALL_DEFINE2(getrusage, int, who, struct rusage __user *, ru) 1859 { 1860 struct rusage r; 1861 1862 if (who != RUSAGE_SELF && who != RUSAGE_CHILDREN && 1863 who != RUSAGE_THREAD) 1864 return -EINVAL; 1865 1866 getrusage(current, who, &r); 1867 return copy_to_user(ru, &r, sizeof(r)) ? -EFAULT : 0; 1868 } 1869 1870 #ifdef CONFIG_COMPAT 1871 COMPAT_SYSCALL_DEFINE2(getrusage, int, who, struct compat_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 put_compat_rusage(&r, ru); 1881 } 1882 #endif 1883 1884 SYSCALL_DEFINE1(umask, int, mask) 1885 { 1886 mask = xchg(¤t->fs->umask, mask & S_IRWXUGO); 1887 return mask; 1888 } 1889 1890 static int prctl_set_mm_exe_file(struct mm_struct *mm, unsigned int fd) 1891 { 1892 struct fd exe; 1893 struct inode *inode; 1894 int err; 1895 1896 exe = fdget(fd); 1897 if (!exe.file) 1898 return -EBADF; 1899 1900 inode = file_inode(exe.file); 1901 1902 /* 1903 * Because the original mm->exe_file points to executable file, make 1904 * sure that this one is executable as well, to avoid breaking an 1905 * overall picture. 1906 */ 1907 err = -EACCES; 1908 if (!S_ISREG(inode->i_mode) || path_noexec(&exe.file->f_path)) 1909 goto exit; 1910 1911 err = file_permission(exe.file, MAY_EXEC); 1912 if (err) 1913 goto exit; 1914 1915 err = replace_mm_exe_file(mm, exe.file); 1916 exit: 1917 fdput(exe); 1918 return err; 1919 } 1920 1921 /* 1922 * Check arithmetic relations of passed addresses. 1923 * 1924 * WARNING: we don't require any capability here so be very careful 1925 * in what is allowed for modification from userspace. 1926 */ 1927 static int validate_prctl_map_addr(struct prctl_mm_map *prctl_map) 1928 { 1929 unsigned long mmap_max_addr = TASK_SIZE; 1930 int error = -EINVAL, i; 1931 1932 static const unsigned char offsets[] = { 1933 offsetof(struct prctl_mm_map, start_code), 1934 offsetof(struct prctl_mm_map, end_code), 1935 offsetof(struct prctl_mm_map, start_data), 1936 offsetof(struct prctl_mm_map, end_data), 1937 offsetof(struct prctl_mm_map, start_brk), 1938 offsetof(struct prctl_mm_map, brk), 1939 offsetof(struct prctl_mm_map, start_stack), 1940 offsetof(struct prctl_mm_map, arg_start), 1941 offsetof(struct prctl_mm_map, arg_end), 1942 offsetof(struct prctl_mm_map, env_start), 1943 offsetof(struct prctl_mm_map, env_end), 1944 }; 1945 1946 /* 1947 * Make sure the members are not somewhere outside 1948 * of allowed address space. 1949 */ 1950 for (i = 0; i < ARRAY_SIZE(offsets); i++) { 1951 u64 val = *(u64 *)((char *)prctl_map + offsets[i]); 1952 1953 if ((unsigned long)val >= mmap_max_addr || 1954 (unsigned long)val < mmap_min_addr) 1955 goto out; 1956 } 1957 1958 /* 1959 * Make sure the pairs are ordered. 1960 */ 1961 #define __prctl_check_order(__m1, __op, __m2) \ 1962 ((unsigned long)prctl_map->__m1 __op \ 1963 (unsigned long)prctl_map->__m2) ? 0 : -EINVAL 1964 error = __prctl_check_order(start_code, <, end_code); 1965 error |= __prctl_check_order(start_data,<=, end_data); 1966 error |= __prctl_check_order(start_brk, <=, brk); 1967 error |= __prctl_check_order(arg_start, <=, arg_end); 1968 error |= __prctl_check_order(env_start, <=, env_end); 1969 if (error) 1970 goto out; 1971 #undef __prctl_check_order 1972 1973 error = -EINVAL; 1974 1975 /* 1976 * Neither we should allow to override limits if they set. 1977 */ 1978 if (check_data_rlimit(rlimit(RLIMIT_DATA), prctl_map->brk, 1979 prctl_map->start_brk, prctl_map->end_data, 1980 prctl_map->start_data)) 1981 goto out; 1982 1983 error = 0; 1984 out: 1985 return error; 1986 } 1987 1988 #ifdef CONFIG_CHECKPOINT_RESTORE 1989 static int prctl_set_mm_map(int opt, const void __user *addr, unsigned long data_size) 1990 { 1991 struct prctl_mm_map prctl_map = { .exe_fd = (u32)-1, }; 1992 unsigned long user_auxv[AT_VECTOR_SIZE]; 1993 struct mm_struct *mm = current->mm; 1994 int error; 1995 1996 BUILD_BUG_ON(sizeof(user_auxv) != sizeof(mm->saved_auxv)); 1997 BUILD_BUG_ON(sizeof(struct prctl_mm_map) > 256); 1998 1999 if (opt == PR_SET_MM_MAP_SIZE) 2000 return put_user((unsigned int)sizeof(prctl_map), 2001 (unsigned int __user *)addr); 2002 2003 if (data_size != sizeof(prctl_map)) 2004 return -EINVAL; 2005 2006 if (copy_from_user(&prctl_map, addr, sizeof(prctl_map))) 2007 return -EFAULT; 2008 2009 error = validate_prctl_map_addr(&prctl_map); 2010 if (error) 2011 return error; 2012 2013 if (prctl_map.auxv_size) { 2014 /* 2015 * Someone is trying to cheat the auxv vector. 2016 */ 2017 if (!prctl_map.auxv || 2018 prctl_map.auxv_size > sizeof(mm->saved_auxv)) 2019 return -EINVAL; 2020 2021 memset(user_auxv, 0, sizeof(user_auxv)); 2022 if (copy_from_user(user_auxv, 2023 (const void __user *)prctl_map.auxv, 2024 prctl_map.auxv_size)) 2025 return -EFAULT; 2026 2027 /* Last entry must be AT_NULL as specification requires */ 2028 user_auxv[AT_VECTOR_SIZE - 2] = AT_NULL; 2029 user_auxv[AT_VECTOR_SIZE - 1] = AT_NULL; 2030 } 2031 2032 if (prctl_map.exe_fd != (u32)-1) { 2033 /* 2034 * Check if the current user is checkpoint/restore capable. 2035 * At the time of this writing, it checks for CAP_SYS_ADMIN 2036 * or CAP_CHECKPOINT_RESTORE. 2037 * Note that a user with access to ptrace can masquerade an 2038 * arbitrary program as any executable, even setuid ones. 2039 * This may have implications in the tomoyo subsystem. 2040 */ 2041 if (!checkpoint_restore_ns_capable(current_user_ns())) 2042 return -EPERM; 2043 2044 error = prctl_set_mm_exe_file(mm, prctl_map.exe_fd); 2045 if (error) 2046 return error; 2047 } 2048 2049 /* 2050 * arg_lock protects concurrent updates but we still need mmap_lock for 2051 * read to exclude races with sys_brk. 2052 */ 2053 mmap_read_lock(mm); 2054 2055 /* 2056 * We don't validate if these members are pointing to 2057 * real present VMAs because application may have correspond 2058 * VMAs already unmapped and kernel uses these members for statistics 2059 * output in procfs mostly, except 2060 * 2061 * - @start_brk/@brk which are used in do_brk_flags but kernel lookups 2062 * for VMAs when updating these members so anything wrong written 2063 * here cause kernel to swear at userspace program but won't lead 2064 * to any problem in kernel itself 2065 */ 2066 2067 spin_lock(&mm->arg_lock); 2068 mm->start_code = prctl_map.start_code; 2069 mm->end_code = prctl_map.end_code; 2070 mm->start_data = prctl_map.start_data; 2071 mm->end_data = prctl_map.end_data; 2072 mm->start_brk = prctl_map.start_brk; 2073 mm->brk = prctl_map.brk; 2074 mm->start_stack = prctl_map.start_stack; 2075 mm->arg_start = prctl_map.arg_start; 2076 mm->arg_end = prctl_map.arg_end; 2077 mm->env_start = prctl_map.env_start; 2078 mm->env_end = prctl_map.env_end; 2079 spin_unlock(&mm->arg_lock); 2080 2081 /* 2082 * Note this update of @saved_auxv is lockless thus 2083 * if someone reads this member in procfs while we're 2084 * updating -- it may get partly updated results. It's 2085 * known and acceptable trade off: we leave it as is to 2086 * not introduce additional locks here making the kernel 2087 * more complex. 2088 */ 2089 if (prctl_map.auxv_size) 2090 memcpy(mm->saved_auxv, user_auxv, sizeof(user_auxv)); 2091 2092 mmap_read_unlock(mm); 2093 return 0; 2094 } 2095 #endif /* CONFIG_CHECKPOINT_RESTORE */ 2096 2097 static int prctl_set_auxv(struct mm_struct *mm, unsigned long addr, 2098 unsigned long len) 2099 { 2100 /* 2101 * This doesn't move the auxiliary vector itself since it's pinned to 2102 * mm_struct, but it permits filling the vector with new values. It's 2103 * up to the caller to provide sane values here, otherwise userspace 2104 * tools which use this vector might be unhappy. 2105 */ 2106 unsigned long user_auxv[AT_VECTOR_SIZE] = {}; 2107 2108 if (len > sizeof(user_auxv)) 2109 return -EINVAL; 2110 2111 if (copy_from_user(user_auxv, (const void __user *)addr, len)) 2112 return -EFAULT; 2113 2114 /* Make sure the last entry is always AT_NULL */ 2115 user_auxv[AT_VECTOR_SIZE - 2] = 0; 2116 user_auxv[AT_VECTOR_SIZE - 1] = 0; 2117 2118 BUILD_BUG_ON(sizeof(user_auxv) != sizeof(mm->saved_auxv)); 2119 2120 task_lock(current); 2121 memcpy(mm->saved_auxv, user_auxv, len); 2122 task_unlock(current); 2123 2124 return 0; 2125 } 2126 2127 static int prctl_set_mm(int opt, unsigned long addr, 2128 unsigned long arg4, unsigned long arg5) 2129 { 2130 struct mm_struct *mm = current->mm; 2131 struct prctl_mm_map prctl_map = { 2132 .auxv = NULL, 2133 .auxv_size = 0, 2134 .exe_fd = -1, 2135 }; 2136 struct vm_area_struct *vma; 2137 int error; 2138 2139 if (arg5 || (arg4 && (opt != PR_SET_MM_AUXV && 2140 opt != PR_SET_MM_MAP && 2141 opt != PR_SET_MM_MAP_SIZE))) 2142 return -EINVAL; 2143 2144 #ifdef CONFIG_CHECKPOINT_RESTORE 2145 if (opt == PR_SET_MM_MAP || opt == PR_SET_MM_MAP_SIZE) 2146 return prctl_set_mm_map(opt, (const void __user *)addr, arg4); 2147 #endif 2148 2149 if (!capable(CAP_SYS_RESOURCE)) 2150 return -EPERM; 2151 2152 if (opt == PR_SET_MM_EXE_FILE) 2153 return prctl_set_mm_exe_file(mm, (unsigned int)addr); 2154 2155 if (opt == PR_SET_MM_AUXV) 2156 return prctl_set_auxv(mm, addr, arg4); 2157 2158 if (addr >= TASK_SIZE || addr < mmap_min_addr) 2159 return -EINVAL; 2160 2161 error = -EINVAL; 2162 2163 /* 2164 * arg_lock protects concurrent updates of arg boundaries, we need 2165 * mmap_lock for a) concurrent sys_brk, b) finding VMA for addr 2166 * validation. 2167 */ 2168 mmap_read_lock(mm); 2169 vma = find_vma(mm, addr); 2170 2171 spin_lock(&mm->arg_lock); 2172 prctl_map.start_code = mm->start_code; 2173 prctl_map.end_code = mm->end_code; 2174 prctl_map.start_data = mm->start_data; 2175 prctl_map.end_data = mm->end_data; 2176 prctl_map.start_brk = mm->start_brk; 2177 prctl_map.brk = mm->brk; 2178 prctl_map.start_stack = mm->start_stack; 2179 prctl_map.arg_start = mm->arg_start; 2180 prctl_map.arg_end = mm->arg_end; 2181 prctl_map.env_start = mm->env_start; 2182 prctl_map.env_end = mm->env_end; 2183 2184 switch (opt) { 2185 case PR_SET_MM_START_CODE: 2186 prctl_map.start_code = addr; 2187 break; 2188 case PR_SET_MM_END_CODE: 2189 prctl_map.end_code = addr; 2190 break; 2191 case PR_SET_MM_START_DATA: 2192 prctl_map.start_data = addr; 2193 break; 2194 case PR_SET_MM_END_DATA: 2195 prctl_map.end_data = addr; 2196 break; 2197 case PR_SET_MM_START_STACK: 2198 prctl_map.start_stack = addr; 2199 break; 2200 case PR_SET_MM_START_BRK: 2201 prctl_map.start_brk = addr; 2202 break; 2203 case PR_SET_MM_BRK: 2204 prctl_map.brk = addr; 2205 break; 2206 case PR_SET_MM_ARG_START: 2207 prctl_map.arg_start = addr; 2208 break; 2209 case PR_SET_MM_ARG_END: 2210 prctl_map.arg_end = addr; 2211 break; 2212 case PR_SET_MM_ENV_START: 2213 prctl_map.env_start = addr; 2214 break; 2215 case PR_SET_MM_ENV_END: 2216 prctl_map.env_end = addr; 2217 break; 2218 default: 2219 goto out; 2220 } 2221 2222 error = validate_prctl_map_addr(&prctl_map); 2223 if (error) 2224 goto out; 2225 2226 switch (opt) { 2227 /* 2228 * If command line arguments and environment 2229 * are placed somewhere else on stack, we can 2230 * set them up here, ARG_START/END to setup 2231 * command line arguments and ENV_START/END 2232 * for environment. 2233 */ 2234 case PR_SET_MM_START_STACK: 2235 case PR_SET_MM_ARG_START: 2236 case PR_SET_MM_ARG_END: 2237 case PR_SET_MM_ENV_START: 2238 case PR_SET_MM_ENV_END: 2239 if (!vma) { 2240 error = -EFAULT; 2241 goto out; 2242 } 2243 } 2244 2245 mm->start_code = prctl_map.start_code; 2246 mm->end_code = prctl_map.end_code; 2247 mm->start_data = prctl_map.start_data; 2248 mm->end_data = prctl_map.end_data; 2249 mm->start_brk = prctl_map.start_brk; 2250 mm->brk = prctl_map.brk; 2251 mm->start_stack = prctl_map.start_stack; 2252 mm->arg_start = prctl_map.arg_start; 2253 mm->arg_end = prctl_map.arg_end; 2254 mm->env_start = prctl_map.env_start; 2255 mm->env_end = prctl_map.env_end; 2256 2257 error = 0; 2258 out: 2259 spin_unlock(&mm->arg_lock); 2260 mmap_read_unlock(mm); 2261 return error; 2262 } 2263 2264 #ifdef CONFIG_CHECKPOINT_RESTORE 2265 static int prctl_get_tid_address(struct task_struct *me, int __user * __user *tid_addr) 2266 { 2267 return put_user(me->clear_child_tid, tid_addr); 2268 } 2269 #else 2270 static int prctl_get_tid_address(struct task_struct *me, int __user * __user *tid_addr) 2271 { 2272 return -EINVAL; 2273 } 2274 #endif 2275 2276 static int propagate_has_child_subreaper(struct task_struct *p, void *data) 2277 { 2278 /* 2279 * If task has has_child_subreaper - all its descendants 2280 * already have these flag too and new descendants will 2281 * inherit it on fork, skip them. 2282 * 2283 * If we've found child_reaper - skip descendants in 2284 * it's subtree as they will never get out pidns. 2285 */ 2286 if (p->signal->has_child_subreaper || 2287 is_child_reaper(task_pid(p))) 2288 return 0; 2289 2290 p->signal->has_child_subreaper = 1; 2291 return 1; 2292 } 2293 2294 int __weak arch_prctl_spec_ctrl_get(struct task_struct *t, unsigned long which) 2295 { 2296 return -EINVAL; 2297 } 2298 2299 int __weak arch_prctl_spec_ctrl_set(struct task_struct *t, unsigned long which, 2300 unsigned long ctrl) 2301 { 2302 return -EINVAL; 2303 } 2304 2305 #define PR_IO_FLUSHER (PF_MEMALLOC_NOIO | PF_LOCAL_THROTTLE) 2306 2307 #ifdef CONFIG_ANON_VMA_NAME 2308 2309 #define ANON_VMA_NAME_MAX_LEN 80 2310 #define ANON_VMA_NAME_INVALID_CHARS "\\`$[]" 2311 2312 static inline bool is_valid_name_char(char ch) 2313 { 2314 /* printable ascii characters, excluding ANON_VMA_NAME_INVALID_CHARS */ 2315 return ch > 0x1f && ch < 0x7f && 2316 !strchr(ANON_VMA_NAME_INVALID_CHARS, ch); 2317 } 2318 2319 static int prctl_set_vma(unsigned long opt, unsigned long addr, 2320 unsigned long size, unsigned long arg) 2321 { 2322 struct mm_struct *mm = current->mm; 2323 const char __user *uname; 2324 struct anon_vma_name *anon_name = NULL; 2325 int error; 2326 2327 switch (opt) { 2328 case PR_SET_VMA_ANON_NAME: 2329 uname = (const char __user *)arg; 2330 if (uname) { 2331 char *name, *pch; 2332 2333 name = strndup_user(uname, ANON_VMA_NAME_MAX_LEN); 2334 if (IS_ERR(name)) 2335 return PTR_ERR(name); 2336 2337 for (pch = name; *pch != '\0'; pch++) { 2338 if (!is_valid_name_char(*pch)) { 2339 kfree(name); 2340 return -EINVAL; 2341 } 2342 } 2343 /* anon_vma has its own copy */ 2344 anon_name = anon_vma_name_alloc(name); 2345 kfree(name); 2346 if (!anon_name) 2347 return -ENOMEM; 2348 2349 } 2350 2351 mmap_write_lock(mm); 2352 error = madvise_set_anon_name(mm, addr, size, anon_name); 2353 mmap_write_unlock(mm); 2354 anon_vma_name_put(anon_name); 2355 break; 2356 default: 2357 error = -EINVAL; 2358 } 2359 2360 return error; 2361 } 2362 2363 #else /* CONFIG_ANON_VMA_NAME */ 2364 static int prctl_set_vma(unsigned long opt, unsigned long start, 2365 unsigned long size, unsigned long arg) 2366 { 2367 return -EINVAL; 2368 } 2369 #endif /* CONFIG_ANON_VMA_NAME */ 2370 2371 static inline int prctl_set_mdwe(unsigned long bits, unsigned long arg3, 2372 unsigned long arg4, unsigned long arg5) 2373 { 2374 if (arg3 || arg4 || arg5) 2375 return -EINVAL; 2376 2377 if (bits & ~(PR_MDWE_REFUSE_EXEC_GAIN)) 2378 return -EINVAL; 2379 2380 if (bits & PR_MDWE_REFUSE_EXEC_GAIN) 2381 set_bit(MMF_HAS_MDWE, ¤t->mm->flags); 2382 else if (test_bit(MMF_HAS_MDWE, ¤t->mm->flags)) 2383 return -EPERM; /* Cannot unset the flag */ 2384 2385 return 0; 2386 } 2387 2388 static inline int prctl_get_mdwe(unsigned long arg2, unsigned long arg3, 2389 unsigned long arg4, unsigned long arg5) 2390 { 2391 if (arg2 || arg3 || arg4 || arg5) 2392 return -EINVAL; 2393 2394 return test_bit(MMF_HAS_MDWE, ¤t->mm->flags) ? 2395 PR_MDWE_REFUSE_EXEC_GAIN : 0; 2396 } 2397 2398 static int prctl_get_auxv(void __user *addr, unsigned long len) 2399 { 2400 struct mm_struct *mm = current->mm; 2401 unsigned long size = min_t(unsigned long, sizeof(mm->saved_auxv), len); 2402 2403 if (size && copy_to_user(addr, mm->saved_auxv, size)) 2404 return -EFAULT; 2405 return sizeof(mm->saved_auxv); 2406 } 2407 2408 SYSCALL_DEFINE5(prctl, int, option, unsigned long, arg2, unsigned long, arg3, 2409 unsigned long, arg4, unsigned long, arg5) 2410 { 2411 struct task_struct *me = current; 2412 unsigned char comm[sizeof(me->comm)]; 2413 long error; 2414 2415 error = security_task_prctl(option, arg2, arg3, arg4, arg5); 2416 if (error != -ENOSYS) 2417 return error; 2418 2419 error = 0; 2420 switch (option) { 2421 case PR_SET_PDEATHSIG: 2422 if (!valid_signal(arg2)) { 2423 error = -EINVAL; 2424 break; 2425 } 2426 me->pdeath_signal = arg2; 2427 break; 2428 case PR_GET_PDEATHSIG: 2429 error = put_user(me->pdeath_signal, (int __user *)arg2); 2430 break; 2431 case PR_GET_DUMPABLE: 2432 error = get_dumpable(me->mm); 2433 break; 2434 case PR_SET_DUMPABLE: 2435 if (arg2 != SUID_DUMP_DISABLE && arg2 != SUID_DUMP_USER) { 2436 error = -EINVAL; 2437 break; 2438 } 2439 set_dumpable(me->mm, arg2); 2440 break; 2441 2442 case PR_SET_UNALIGN: 2443 error = SET_UNALIGN_CTL(me, arg2); 2444 break; 2445 case PR_GET_UNALIGN: 2446 error = GET_UNALIGN_CTL(me, arg2); 2447 break; 2448 case PR_SET_FPEMU: 2449 error = SET_FPEMU_CTL(me, arg2); 2450 break; 2451 case PR_GET_FPEMU: 2452 error = GET_FPEMU_CTL(me, arg2); 2453 break; 2454 case PR_SET_FPEXC: 2455 error = SET_FPEXC_CTL(me, arg2); 2456 break; 2457 case PR_GET_FPEXC: 2458 error = GET_FPEXC_CTL(me, arg2); 2459 break; 2460 case PR_GET_TIMING: 2461 error = PR_TIMING_STATISTICAL; 2462 break; 2463 case PR_SET_TIMING: 2464 if (arg2 != PR_TIMING_STATISTICAL) 2465 error = -EINVAL; 2466 break; 2467 case PR_SET_NAME: 2468 comm[sizeof(me->comm) - 1] = 0; 2469 if (strncpy_from_user(comm, (char __user *)arg2, 2470 sizeof(me->comm) - 1) < 0) 2471 return -EFAULT; 2472 set_task_comm(me, comm); 2473 proc_comm_connector(me); 2474 break; 2475 case PR_GET_NAME: 2476 get_task_comm(comm, me); 2477 if (copy_to_user((char __user *)arg2, comm, sizeof(comm))) 2478 return -EFAULT; 2479 break; 2480 case PR_GET_ENDIAN: 2481 error = GET_ENDIAN(me, arg2); 2482 break; 2483 case PR_SET_ENDIAN: 2484 error = SET_ENDIAN(me, arg2); 2485 break; 2486 case PR_GET_SECCOMP: 2487 error = prctl_get_seccomp(); 2488 break; 2489 case PR_SET_SECCOMP: 2490 error = prctl_set_seccomp(arg2, (char __user *)arg3); 2491 break; 2492 case PR_GET_TSC: 2493 error = GET_TSC_CTL(arg2); 2494 break; 2495 case PR_SET_TSC: 2496 error = SET_TSC_CTL(arg2); 2497 break; 2498 case PR_TASK_PERF_EVENTS_DISABLE: 2499 error = perf_event_task_disable(); 2500 break; 2501 case PR_TASK_PERF_EVENTS_ENABLE: 2502 error = perf_event_task_enable(); 2503 break; 2504 case PR_GET_TIMERSLACK: 2505 if (current->timer_slack_ns > ULONG_MAX) 2506 error = ULONG_MAX; 2507 else 2508 error = current->timer_slack_ns; 2509 break; 2510 case PR_SET_TIMERSLACK: 2511 if (arg2 <= 0) 2512 current->timer_slack_ns = 2513 current->default_timer_slack_ns; 2514 else 2515 current->timer_slack_ns = arg2; 2516 break; 2517 case PR_MCE_KILL: 2518 if (arg4 | arg5) 2519 return -EINVAL; 2520 switch (arg2) { 2521 case PR_MCE_KILL_CLEAR: 2522 if (arg3 != 0) 2523 return -EINVAL; 2524 current->flags &= ~PF_MCE_PROCESS; 2525 break; 2526 case PR_MCE_KILL_SET: 2527 current->flags |= PF_MCE_PROCESS; 2528 if (arg3 == PR_MCE_KILL_EARLY) 2529 current->flags |= PF_MCE_EARLY; 2530 else if (arg3 == PR_MCE_KILL_LATE) 2531 current->flags &= ~PF_MCE_EARLY; 2532 else if (arg3 == PR_MCE_KILL_DEFAULT) 2533 current->flags &= 2534 ~(PF_MCE_EARLY|PF_MCE_PROCESS); 2535 else 2536 return -EINVAL; 2537 break; 2538 default: 2539 return -EINVAL; 2540 } 2541 break; 2542 case PR_MCE_KILL_GET: 2543 if (arg2 | arg3 | arg4 | arg5) 2544 return -EINVAL; 2545 if (current->flags & PF_MCE_PROCESS) 2546 error = (current->flags & PF_MCE_EARLY) ? 2547 PR_MCE_KILL_EARLY : PR_MCE_KILL_LATE; 2548 else 2549 error = PR_MCE_KILL_DEFAULT; 2550 break; 2551 case PR_SET_MM: 2552 error = prctl_set_mm(arg2, arg3, arg4, arg5); 2553 break; 2554 case PR_GET_TID_ADDRESS: 2555 error = prctl_get_tid_address(me, (int __user * __user *)arg2); 2556 break; 2557 case PR_SET_CHILD_SUBREAPER: 2558 me->signal->is_child_subreaper = !!arg2; 2559 if (!arg2) 2560 break; 2561 2562 walk_process_tree(me, propagate_has_child_subreaper, NULL); 2563 break; 2564 case PR_GET_CHILD_SUBREAPER: 2565 error = put_user(me->signal->is_child_subreaper, 2566 (int __user *)arg2); 2567 break; 2568 case PR_SET_NO_NEW_PRIVS: 2569 if (arg2 != 1 || arg3 || arg4 || arg5) 2570 return -EINVAL; 2571 2572 task_set_no_new_privs(current); 2573 break; 2574 case PR_GET_NO_NEW_PRIVS: 2575 if (arg2 || arg3 || arg4 || arg5) 2576 return -EINVAL; 2577 return task_no_new_privs(current) ? 1 : 0; 2578 case PR_GET_THP_DISABLE: 2579 if (arg2 || arg3 || arg4 || arg5) 2580 return -EINVAL; 2581 error = !!test_bit(MMF_DISABLE_THP, &me->mm->flags); 2582 break; 2583 case PR_SET_THP_DISABLE: 2584 if (arg3 || arg4 || arg5) 2585 return -EINVAL; 2586 if (mmap_write_lock_killable(me->mm)) 2587 return -EINTR; 2588 if (arg2) 2589 set_bit(MMF_DISABLE_THP, &me->mm->flags); 2590 else 2591 clear_bit(MMF_DISABLE_THP, &me->mm->flags); 2592 mmap_write_unlock(me->mm); 2593 break; 2594 case PR_MPX_ENABLE_MANAGEMENT: 2595 case PR_MPX_DISABLE_MANAGEMENT: 2596 /* No longer implemented: */ 2597 return -EINVAL; 2598 case PR_SET_FP_MODE: 2599 error = SET_FP_MODE(me, arg2); 2600 break; 2601 case PR_GET_FP_MODE: 2602 error = GET_FP_MODE(me); 2603 break; 2604 case PR_SVE_SET_VL: 2605 error = SVE_SET_VL(arg2); 2606 break; 2607 case PR_SVE_GET_VL: 2608 error = SVE_GET_VL(); 2609 break; 2610 case PR_SME_SET_VL: 2611 error = SME_SET_VL(arg2); 2612 break; 2613 case PR_SME_GET_VL: 2614 error = SME_GET_VL(); 2615 break; 2616 case PR_GET_SPECULATION_CTRL: 2617 if (arg3 || arg4 || arg5) 2618 return -EINVAL; 2619 error = arch_prctl_spec_ctrl_get(me, arg2); 2620 break; 2621 case PR_SET_SPECULATION_CTRL: 2622 if (arg4 || arg5) 2623 return -EINVAL; 2624 error = arch_prctl_spec_ctrl_set(me, arg2, arg3); 2625 break; 2626 case PR_PAC_RESET_KEYS: 2627 if (arg3 || arg4 || arg5) 2628 return -EINVAL; 2629 error = PAC_RESET_KEYS(me, arg2); 2630 break; 2631 case PR_PAC_SET_ENABLED_KEYS: 2632 if (arg4 || arg5) 2633 return -EINVAL; 2634 error = PAC_SET_ENABLED_KEYS(me, arg2, arg3); 2635 break; 2636 case PR_PAC_GET_ENABLED_KEYS: 2637 if (arg2 || arg3 || arg4 || arg5) 2638 return -EINVAL; 2639 error = PAC_GET_ENABLED_KEYS(me); 2640 break; 2641 case PR_SET_TAGGED_ADDR_CTRL: 2642 if (arg3 || arg4 || arg5) 2643 return -EINVAL; 2644 error = SET_TAGGED_ADDR_CTRL(arg2); 2645 break; 2646 case PR_GET_TAGGED_ADDR_CTRL: 2647 if (arg2 || arg3 || arg4 || arg5) 2648 return -EINVAL; 2649 error = GET_TAGGED_ADDR_CTRL(); 2650 break; 2651 case PR_SET_IO_FLUSHER: 2652 if (!capable(CAP_SYS_RESOURCE)) 2653 return -EPERM; 2654 2655 if (arg3 || arg4 || arg5) 2656 return -EINVAL; 2657 2658 if (arg2 == 1) 2659 current->flags |= PR_IO_FLUSHER; 2660 else if (!arg2) 2661 current->flags &= ~PR_IO_FLUSHER; 2662 else 2663 return -EINVAL; 2664 break; 2665 case PR_GET_IO_FLUSHER: 2666 if (!capable(CAP_SYS_RESOURCE)) 2667 return -EPERM; 2668 2669 if (arg2 || arg3 || arg4 || arg5) 2670 return -EINVAL; 2671 2672 error = (current->flags & PR_IO_FLUSHER) == PR_IO_FLUSHER; 2673 break; 2674 case PR_SET_SYSCALL_USER_DISPATCH: 2675 error = set_syscall_user_dispatch(arg2, arg3, arg4, 2676 (char __user *) arg5); 2677 break; 2678 #ifdef CONFIG_SCHED_CORE 2679 case PR_SCHED_CORE: 2680 error = sched_core_share_pid(arg2, arg3, arg4, arg5); 2681 break; 2682 #endif 2683 case PR_SET_MDWE: 2684 error = prctl_set_mdwe(arg2, arg3, arg4, arg5); 2685 break; 2686 case PR_GET_MDWE: 2687 error = prctl_get_mdwe(arg2, arg3, arg4, arg5); 2688 break; 2689 case PR_SET_VMA: 2690 error = prctl_set_vma(arg2, arg3, arg4, arg5); 2691 break; 2692 case PR_GET_AUXV: 2693 if (arg4 || arg5) 2694 return -EINVAL; 2695 error = prctl_get_auxv((void __user *)arg2, arg3); 2696 break; 2697 #ifdef CONFIG_KSM 2698 case PR_SET_MEMORY_MERGE: 2699 if (arg3 || arg4 || arg5) 2700 return -EINVAL; 2701 if (mmap_write_lock_killable(me->mm)) 2702 return -EINTR; 2703 2704 if (arg2) 2705 error = ksm_enable_merge_any(me->mm); 2706 else 2707 error = ksm_disable_merge_any(me->mm); 2708 mmap_write_unlock(me->mm); 2709 break; 2710 case PR_GET_MEMORY_MERGE: 2711 if (arg2 || arg3 || arg4 || arg5) 2712 return -EINVAL; 2713 2714 error = !!test_bit(MMF_VM_MERGE_ANY, &me->mm->flags); 2715 break; 2716 #endif 2717 case PR_RISCV_V_SET_CONTROL: 2718 error = RISCV_V_SET_CONTROL(arg2); 2719 break; 2720 case PR_RISCV_V_GET_CONTROL: 2721 error = RISCV_V_GET_CONTROL(); 2722 break; 2723 default: 2724 error = -EINVAL; 2725 break; 2726 } 2727 return error; 2728 } 2729 2730 SYSCALL_DEFINE3(getcpu, unsigned __user *, cpup, unsigned __user *, nodep, 2731 struct getcpu_cache __user *, unused) 2732 { 2733 int err = 0; 2734 int cpu = raw_smp_processor_id(); 2735 2736 if (cpup) 2737 err |= put_user(cpu, cpup); 2738 if (nodep) 2739 err |= put_user(cpu_to_node(cpu), nodep); 2740 return err ? -EFAULT : 0; 2741 } 2742 2743 /** 2744 * do_sysinfo - fill in sysinfo struct 2745 * @info: pointer to buffer to fill 2746 */ 2747 static int do_sysinfo(struct sysinfo *info) 2748 { 2749 unsigned long mem_total, sav_total; 2750 unsigned int mem_unit, bitcount; 2751 struct timespec64 tp; 2752 2753 memset(info, 0, sizeof(struct sysinfo)); 2754 2755 ktime_get_boottime_ts64(&tp); 2756 timens_add_boottime(&tp); 2757 info->uptime = tp.tv_sec + (tp.tv_nsec ? 1 : 0); 2758 2759 get_avenrun(info->loads, 0, SI_LOAD_SHIFT - FSHIFT); 2760 2761 info->procs = nr_threads; 2762 2763 si_meminfo(info); 2764 si_swapinfo(info); 2765 2766 /* 2767 * If the sum of all the available memory (i.e. ram + swap) 2768 * is less than can be stored in a 32 bit unsigned long then 2769 * we can be binary compatible with 2.2.x kernels. If not, 2770 * well, in that case 2.2.x was broken anyways... 2771 * 2772 * -Erik Andersen <andersee@debian.org> 2773 */ 2774 2775 mem_total = info->totalram + info->totalswap; 2776 if (mem_total < info->totalram || mem_total < info->totalswap) 2777 goto out; 2778 bitcount = 0; 2779 mem_unit = info->mem_unit; 2780 while (mem_unit > 1) { 2781 bitcount++; 2782 mem_unit >>= 1; 2783 sav_total = mem_total; 2784 mem_total <<= 1; 2785 if (mem_total < sav_total) 2786 goto out; 2787 } 2788 2789 /* 2790 * If mem_total did not overflow, multiply all memory values by 2791 * info->mem_unit and set it to 1. This leaves things compatible 2792 * with 2.2.x, and also retains compatibility with earlier 2.4.x 2793 * kernels... 2794 */ 2795 2796 info->mem_unit = 1; 2797 info->totalram <<= bitcount; 2798 info->freeram <<= bitcount; 2799 info->sharedram <<= bitcount; 2800 info->bufferram <<= bitcount; 2801 info->totalswap <<= bitcount; 2802 info->freeswap <<= bitcount; 2803 info->totalhigh <<= bitcount; 2804 info->freehigh <<= bitcount; 2805 2806 out: 2807 return 0; 2808 } 2809 2810 SYSCALL_DEFINE1(sysinfo, struct sysinfo __user *, info) 2811 { 2812 struct sysinfo val; 2813 2814 do_sysinfo(&val); 2815 2816 if (copy_to_user(info, &val, sizeof(struct sysinfo))) 2817 return -EFAULT; 2818 2819 return 0; 2820 } 2821 2822 #ifdef CONFIG_COMPAT 2823 struct compat_sysinfo { 2824 s32 uptime; 2825 u32 loads[3]; 2826 u32 totalram; 2827 u32 freeram; 2828 u32 sharedram; 2829 u32 bufferram; 2830 u32 totalswap; 2831 u32 freeswap; 2832 u16 procs; 2833 u16 pad; 2834 u32 totalhigh; 2835 u32 freehigh; 2836 u32 mem_unit; 2837 char _f[20-2*sizeof(u32)-sizeof(int)]; 2838 }; 2839 2840 COMPAT_SYSCALL_DEFINE1(sysinfo, struct compat_sysinfo __user *, info) 2841 { 2842 struct sysinfo s; 2843 struct compat_sysinfo s_32; 2844 2845 do_sysinfo(&s); 2846 2847 /* Check to see if any memory value is too large for 32-bit and scale 2848 * down if needed 2849 */ 2850 if (upper_32_bits(s.totalram) || upper_32_bits(s.totalswap)) { 2851 int bitcount = 0; 2852 2853 while (s.mem_unit < PAGE_SIZE) { 2854 s.mem_unit <<= 1; 2855 bitcount++; 2856 } 2857 2858 s.totalram >>= bitcount; 2859 s.freeram >>= bitcount; 2860 s.sharedram >>= bitcount; 2861 s.bufferram >>= bitcount; 2862 s.totalswap >>= bitcount; 2863 s.freeswap >>= bitcount; 2864 s.totalhigh >>= bitcount; 2865 s.freehigh >>= bitcount; 2866 } 2867 2868 memset(&s_32, 0, sizeof(s_32)); 2869 s_32.uptime = s.uptime; 2870 s_32.loads[0] = s.loads[0]; 2871 s_32.loads[1] = s.loads[1]; 2872 s_32.loads[2] = s.loads[2]; 2873 s_32.totalram = s.totalram; 2874 s_32.freeram = s.freeram; 2875 s_32.sharedram = s.sharedram; 2876 s_32.bufferram = s.bufferram; 2877 s_32.totalswap = s.totalswap; 2878 s_32.freeswap = s.freeswap; 2879 s_32.procs = s.procs; 2880 s_32.totalhigh = s.totalhigh; 2881 s_32.freehigh = s.freehigh; 2882 s_32.mem_unit = s.mem_unit; 2883 if (copy_to_user(info, &s_32, sizeof(s_32))) 2884 return -EFAULT; 2885 return 0; 2886 } 2887 #endif /* CONFIG_COMPAT */ 2888