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