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v4.17
   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/utsname.h>
  11#include <linux/mman.h>
  12#include <linux/reboot.h>
  13#include <linux/prctl.h>
  14#include <linux/highuid.h>
  15#include <linux/fs.h>
  16#include <linux/kmod.h>
 
  17#include <linux/perf_event.h>
  18#include <linux/resource.h>
  19#include <linux/kernel.h>
  20#include <linux/workqueue.h>
  21#include <linux/capability.h>
  22#include <linux/device.h>
  23#include <linux/key.h>
  24#include <linux/times.h>
  25#include <linux/posix-timers.h>
  26#include <linux/security.h>
  27#include <linux/dcookies.h>
  28#include <linux/suspend.h>
  29#include <linux/tty.h>
  30#include <linux/signal.h>
  31#include <linux/cn_proc.h>
  32#include <linux/getcpu.h>
  33#include <linux/task_io_accounting_ops.h>
  34#include <linux/seccomp.h>
  35#include <linux/cpu.h>
  36#include <linux/personality.h>
  37#include <linux/ptrace.h>
  38#include <linux/fs_struct.h>
  39#include <linux/file.h>
  40#include <linux/mount.h>
  41#include <linux/gfp.h>
  42#include <linux/syscore_ops.h>
  43#include <linux/version.h>
  44#include <linux/ctype.h>
 
  45
  46#include <linux/compat.h>
  47#include <linux/syscalls.h>
  48#include <linux/kprobes.h>
  49#include <linux/user_namespace.h>
 
  50#include <linux/binfmts.h>
  51
  52#include <linux/sched.h>
  53#include <linux/sched/autogroup.h>
  54#include <linux/sched/loadavg.h>
  55#include <linux/sched/stat.h>
  56#include <linux/sched/mm.h>
  57#include <linux/sched/coredump.h>
  58#include <linux/sched/task.h>
  59#include <linux/sched/cputime.h>
  60#include <linux/rcupdate.h>
  61#include <linux/uidgid.h>
  62#include <linux/cred.h>
  63
  64#include <linux/nospec.h>
  65
  66#include <linux/kmsg_dump.h>
  67/* Move somewhere else to avoid recompiling? */
  68#include <generated/utsrelease.h>
  69
  70#include <linux/uaccess.h>
  71#include <asm/io.h>
  72#include <asm/unistd.h>
  73
  74/* Hardening for Spectre-v1 */
  75#include <linux/nospec.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 MPX_ENABLE_MANAGEMENT
 110# define MPX_ENABLE_MANAGEMENT()	(-EINVAL)
 111#endif
 112#ifndef MPX_DISABLE_MANAGEMENT
 113# define MPX_DISABLE_MANAGEMENT()	(-EINVAL)
 114#endif
 115#ifndef GET_FP_MODE
 116# define GET_FP_MODE(a)		(-EINVAL)
 117#endif
 118#ifndef SET_FP_MODE
 119# define SET_FP_MODE(a,b)	(-EINVAL)
 120#endif
 121#ifndef SVE_SET_VL
 122# define SVE_SET_VL(a)		(-EINVAL)
 123#endif
 124#ifndef SVE_GET_VL
 125# define SVE_GET_VL()		(-EINVAL)
 126#endif
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 127
 128/*
 129 * this is where the system-wide overflow UID and GID are defined, for
 130 * architectures that now have 32-bit UID/GID but didn't in the past
 131 */
 132
 133int overflowuid = DEFAULT_OVERFLOWUID;
 134int overflowgid = DEFAULT_OVERFLOWGID;
 135
 136EXPORT_SYMBOL(overflowuid);
 137EXPORT_SYMBOL(overflowgid);
 138
 139/*
 140 * the same as above, but for filesystems which can only store a 16-bit
 141 * UID and GID. as such, this is needed on all architectures
 142 */
 143
 144int fs_overflowuid = DEFAULT_FS_OVERFLOWUID;
 145int fs_overflowgid = DEFAULT_FS_OVERFLOWGID;
 146
 147EXPORT_SYMBOL(fs_overflowuid);
 148EXPORT_SYMBOL(fs_overflowgid);
 149
 150/*
 151 * Returns true if current's euid is same as p's uid or euid,
 152 * or has CAP_SYS_NICE to p's user_ns.
 153 *
 154 * Called with rcu_read_lock, creds are safe
 155 */
 156static bool set_one_prio_perm(struct task_struct *p)
 157{
 158	const struct cred *cred = current_cred(), *pcred = __task_cred(p);
 159
 160	if (uid_eq(pcred->uid,  cred->euid) ||
 161	    uid_eq(pcred->euid, cred->euid))
 162		return true;
 163	if (ns_capable(pcred->user_ns, CAP_SYS_NICE))
 164		return true;
 165	return false;
 166}
 167
 168/*
 169 * set the priority of a task
 170 * - the caller must hold the RCU read lock
 171 */
 172static int set_one_prio(struct task_struct *p, int niceval, int error)
 173{
 174	int no_nice;
 175
 176	if (!set_one_prio_perm(p)) {
 177		error = -EPERM;
 178		goto out;
 179	}
 180	if (niceval < task_nice(p) && !can_nice(p, niceval)) {
 181		error = -EACCES;
 182		goto out;
 183	}
 184	no_nice = security_task_setnice(p, niceval);
 185	if (no_nice) {
 186		error = no_nice;
 187		goto out;
 188	}
 189	if (error == -ESRCH)
 190		error = 0;
 191	set_user_nice(p, niceval);
 192out:
 193	return error;
 194}
 195
 196SYSCALL_DEFINE3(setpriority, int, which, int, who, int, niceval)
 197{
 198	struct task_struct *g, *p;
 199	struct user_struct *user;
 200	const struct cred *cred = current_cred();
 201	int error = -EINVAL;
 202	struct pid *pgrp;
 203	kuid_t uid;
 204
 205	if (which > PRIO_USER || which < PRIO_PROCESS)
 206		goto out;
 207
 208	/* normalize: avoid signed division (rounding problems) */
 209	error = -ESRCH;
 210	if (niceval < MIN_NICE)
 211		niceval = MIN_NICE;
 212	if (niceval > MAX_NICE)
 213		niceval = MAX_NICE;
 214
 215	rcu_read_lock();
 216	read_lock(&tasklist_lock);
 217	switch (which) {
 218	case PRIO_PROCESS:
 219		if (who)
 220			p = find_task_by_vpid(who);
 221		else
 222			p = current;
 223		if (p)
 224			error = set_one_prio(p, niceval, error);
 225		break;
 226	case PRIO_PGRP:
 227		if (who)
 228			pgrp = find_vpid(who);
 229		else
 230			pgrp = task_pgrp(current);
 
 231		do_each_pid_thread(pgrp, PIDTYPE_PGID, p) {
 232			error = set_one_prio(p, niceval, error);
 233		} while_each_pid_thread(pgrp, PIDTYPE_PGID, p);
 
 234		break;
 235	case PRIO_USER:
 236		uid = make_kuid(cred->user_ns, who);
 237		user = cred->user;
 238		if (!who)
 239			uid = cred->uid;
 240		else if (!uid_eq(uid, cred->uid)) {
 241			user = find_user(uid);
 242			if (!user)
 243				goto out_unlock;	/* No processes for this user */
 244		}
 245		do_each_thread(g, p) {
 246			if (uid_eq(task_uid(p), uid) && task_pid_vnr(p))
 247				error = set_one_prio(p, niceval, error);
 248		} while_each_thread(g, p);
 249		if (!uid_eq(uid, cred->uid))
 250			free_uid(user);		/* For find_user() */
 251		break;
 252	}
 253out_unlock:
 254	read_unlock(&tasklist_lock);
 255	rcu_read_unlock();
 256out:
 257	return error;
 258}
 259
 260/*
 261 * Ugh. To avoid negative return values, "getpriority()" will
 262 * not return the normal nice-value, but a negated value that
 263 * has been offset by 20 (ie it returns 40..1 instead of -20..19)
 264 * to stay compatible.
 265 */
 266SYSCALL_DEFINE2(getpriority, int, which, int, who)
 267{
 268	struct task_struct *g, *p;
 269	struct user_struct *user;
 270	const struct cred *cred = current_cred();
 271	long niceval, retval = -ESRCH;
 272	struct pid *pgrp;
 273	kuid_t uid;
 274
 275	if (which > PRIO_USER || which < PRIO_PROCESS)
 276		return -EINVAL;
 277
 278	rcu_read_lock();
 279	read_lock(&tasklist_lock);
 280	switch (which) {
 281	case PRIO_PROCESS:
 282		if (who)
 283			p = find_task_by_vpid(who);
 284		else
 285			p = current;
 286		if (p) {
 287			niceval = nice_to_rlimit(task_nice(p));
 288			if (niceval > retval)
 289				retval = niceval;
 290		}
 291		break;
 292	case PRIO_PGRP:
 293		if (who)
 294			pgrp = find_vpid(who);
 295		else
 296			pgrp = task_pgrp(current);
 
 297		do_each_pid_thread(pgrp, PIDTYPE_PGID, p) {
 298			niceval = nice_to_rlimit(task_nice(p));
 299			if (niceval > retval)
 300				retval = niceval;
 301		} while_each_pid_thread(pgrp, PIDTYPE_PGID, p);
 
 302		break;
 303	case PRIO_USER:
 304		uid = make_kuid(cred->user_ns, who);
 305		user = cred->user;
 306		if (!who)
 307			uid = cred->uid;
 308		else if (!uid_eq(uid, cred->uid)) {
 309			user = find_user(uid);
 310			if (!user)
 311				goto out_unlock;	/* No processes for this user */
 312		}
 313		do_each_thread(g, p) {
 314			if (uid_eq(task_uid(p), uid) && task_pid_vnr(p)) {
 315				niceval = nice_to_rlimit(task_nice(p));
 316				if (niceval > retval)
 317					retval = niceval;
 318			}
 319		} while_each_thread(g, p);
 320		if (!uid_eq(uid, cred->uid))
 321			free_uid(user);		/* for find_user() */
 322		break;
 323	}
 324out_unlock:
 325	read_unlock(&tasklist_lock);
 326	rcu_read_unlock();
 327
 328	return retval;
 329}
 330
 331/*
 332 * Unprivileged users may change the real gid to the effective gid
 333 * or vice versa.  (BSD-style)
 334 *
 335 * If you set the real gid at all, or set the effective gid to a value not
 336 * equal to the real gid, then the saved gid is set to the new effective gid.
 337 *
 338 * This makes it possible for a setgid program to completely drop its
 339 * privileges, which is often a useful assertion to make when you are doing
 340 * a security audit over a program.
 341 *
 342 * The general idea is that a program which uses just setregid() will be
 343 * 100% compatible with BSD.  A program which uses just setgid() will be
 344 * 100% compatible with POSIX with saved IDs.
 345 *
 346 * SMP: There are not races, the GIDs are checked only by filesystem
 347 *      operations (as far as semantic preservation is concerned).
 348 */
 349#ifdef CONFIG_MULTIUSER
 350long __sys_setregid(gid_t rgid, gid_t egid)
 351{
 352	struct user_namespace *ns = current_user_ns();
 353	const struct cred *old;
 354	struct cred *new;
 355	int retval;
 356	kgid_t krgid, kegid;
 357
 358	krgid = make_kgid(ns, rgid);
 359	kegid = make_kgid(ns, egid);
 360
 361	if ((rgid != (gid_t) -1) && !gid_valid(krgid))
 362		return -EINVAL;
 363	if ((egid != (gid_t) -1) && !gid_valid(kegid))
 364		return -EINVAL;
 365
 366	new = prepare_creds();
 367	if (!new)
 368		return -ENOMEM;
 369	old = current_cred();
 370
 371	retval = -EPERM;
 372	if (rgid != (gid_t) -1) {
 373		if (gid_eq(old->gid, krgid) ||
 374		    gid_eq(old->egid, krgid) ||
 375		    ns_capable(old->user_ns, CAP_SETGID))
 376			new->gid = krgid;
 377		else
 378			goto error;
 379	}
 380	if (egid != (gid_t) -1) {
 381		if (gid_eq(old->gid, kegid) ||
 382		    gid_eq(old->egid, kegid) ||
 383		    gid_eq(old->sgid, kegid) ||
 384		    ns_capable(old->user_ns, CAP_SETGID))
 385			new->egid = kegid;
 386		else
 387			goto error;
 388	}
 389
 390	if (rgid != (gid_t) -1 ||
 391	    (egid != (gid_t) -1 && !gid_eq(kegid, old->gid)))
 392		new->sgid = new->egid;
 393	new->fsgid = new->egid;
 394
 
 
 
 
 395	return commit_creds(new);
 396
 397error:
 398	abort_creds(new);
 399	return retval;
 400}
 401
 402SYSCALL_DEFINE2(setregid, gid_t, rgid, gid_t, egid)
 403{
 404	return __sys_setregid(rgid, egid);
 405}
 406
 407/*
 408 * setgid() is implemented like SysV w/ SAVED_IDS
 409 *
 410 * SMP: Same implicit races as above.
 411 */
 412long __sys_setgid(gid_t gid)
 413{
 414	struct user_namespace *ns = current_user_ns();
 415	const struct cred *old;
 416	struct cred *new;
 417	int retval;
 418	kgid_t kgid;
 419
 420	kgid = make_kgid(ns, gid);
 421	if (!gid_valid(kgid))
 422		return -EINVAL;
 423
 424	new = prepare_creds();
 425	if (!new)
 426		return -ENOMEM;
 427	old = current_cred();
 428
 429	retval = -EPERM;
 430	if (ns_capable(old->user_ns, CAP_SETGID))
 431		new->gid = new->egid = new->sgid = new->fsgid = kgid;
 432	else if (gid_eq(kgid, old->gid) || gid_eq(kgid, old->sgid))
 433		new->egid = new->fsgid = kgid;
 434	else
 435		goto error;
 436
 
 
 
 
 437	return commit_creds(new);
 438
 439error:
 440	abort_creds(new);
 441	return retval;
 442}
 443
 444SYSCALL_DEFINE1(setgid, gid_t, gid)
 445{
 446	return __sys_setgid(gid);
 447}
 448
 449/*
 450 * change the user struct in a credentials set to match the new UID
 451 */
 452static int set_user(struct cred *new)
 453{
 454	struct user_struct *new_user;
 455
 456	new_user = alloc_uid(new->uid);
 457	if (!new_user)
 458		return -EAGAIN;
 459
 
 
 
 
 
 
 
 
 
 
 460	/*
 461	 * We don't fail in case of NPROC limit excess here because too many
 462	 * poorly written programs don't check set*uid() return code, assuming
 463	 * it never fails if called by root.  We may still enforce NPROC limit
 464	 * for programs doing set*uid()+execve() by harmlessly deferring the
 465	 * failure to the execve() stage.
 466	 */
 467	if (atomic_read(&new_user->processes) >= rlimit(RLIMIT_NPROC) &&
 468			new_user != INIT_USER)
 469		current->flags |= PF_NPROC_EXCEEDED;
 470	else
 471		current->flags &= ~PF_NPROC_EXCEEDED;
 472
 473	free_uid(new->user);
 474	new->user = new_user;
 475	return 0;
 476}
 477
 478/*
 479 * Unprivileged users may change the real uid to the effective uid
 480 * or vice versa.  (BSD-style)
 481 *
 482 * If you set the real uid at all, or set the effective uid to a value not
 483 * equal to the real uid, then the saved uid is set to the new effective uid.
 484 *
 485 * This makes it possible for a setuid program to completely drop its
 486 * privileges, which is often a useful assertion to make when you are doing
 487 * a security audit over a program.
 488 *
 489 * The general idea is that a program which uses just setreuid() will be
 490 * 100% compatible with BSD.  A program which uses just setuid() will be
 491 * 100% compatible with POSIX with saved IDs.
 492 */
 493long __sys_setreuid(uid_t ruid, uid_t euid)
 494{
 495	struct user_namespace *ns = current_user_ns();
 496	const struct cred *old;
 497	struct cred *new;
 498	int retval;
 499	kuid_t kruid, keuid;
 500
 501	kruid = make_kuid(ns, ruid);
 502	keuid = make_kuid(ns, euid);
 503
 504	if ((ruid != (uid_t) -1) && !uid_valid(kruid))
 505		return -EINVAL;
 506	if ((euid != (uid_t) -1) && !uid_valid(keuid))
 507		return -EINVAL;
 508
 509	new = prepare_creds();
 510	if (!new)
 511		return -ENOMEM;
 512	old = current_cred();
 513
 514	retval = -EPERM;
 515	if (ruid != (uid_t) -1) {
 516		new->uid = kruid;
 517		if (!uid_eq(old->uid, kruid) &&
 518		    !uid_eq(old->euid, kruid) &&
 519		    !ns_capable(old->user_ns, CAP_SETUID))
 520			goto error;
 521	}
 522
 523	if (euid != (uid_t) -1) {
 524		new->euid = keuid;
 525		if (!uid_eq(old->uid, keuid) &&
 526		    !uid_eq(old->euid, keuid) &&
 527		    !uid_eq(old->suid, keuid) &&
 528		    !ns_capable(old->user_ns, CAP_SETUID))
 529			goto error;
 530	}
 531
 532	if (!uid_eq(new->uid, old->uid)) {
 533		retval = set_user(new);
 534		if (retval < 0)
 535			goto error;
 536	}
 537	if (ruid != (uid_t) -1 ||
 538	    (euid != (uid_t) -1 && !uid_eq(keuid, old->uid)))
 539		new->suid = new->euid;
 540	new->fsuid = new->euid;
 541
 542	retval = security_task_fix_setuid(new, old, LSM_SETID_RE);
 543	if (retval < 0)
 544		goto error;
 545
 
 
 
 
 
 546	return commit_creds(new);
 547
 548error:
 549	abort_creds(new);
 550	return retval;
 551}
 552
 553SYSCALL_DEFINE2(setreuid, uid_t, ruid, uid_t, euid)
 554{
 555	return __sys_setreuid(ruid, euid);
 556}
 557
 558/*
 559 * setuid() is implemented like SysV with SAVED_IDS
 560 *
 561 * Note that SAVED_ID's is deficient in that a setuid root program
 562 * like sendmail, for example, cannot set its uid to be a normal
 563 * user and then switch back, because if you're root, setuid() sets
 564 * the saved uid too.  If you don't like this, blame the bright people
 565 * in the POSIX committee and/or USG.  Note that the BSD-style setreuid()
 566 * will allow a root program to temporarily drop privileges and be able to
 567 * regain them by swapping the real and effective uid.
 568 */
 569long __sys_setuid(uid_t uid)
 570{
 571	struct user_namespace *ns = current_user_ns();
 572	const struct cred *old;
 573	struct cred *new;
 574	int retval;
 575	kuid_t kuid;
 576
 577	kuid = make_kuid(ns, uid);
 578	if (!uid_valid(kuid))
 579		return -EINVAL;
 580
 581	new = prepare_creds();
 582	if (!new)
 583		return -ENOMEM;
 584	old = current_cred();
 585
 586	retval = -EPERM;
 587	if (ns_capable(old->user_ns, CAP_SETUID)) {
 588		new->suid = new->uid = kuid;
 589		if (!uid_eq(kuid, old->uid)) {
 590			retval = set_user(new);
 591			if (retval < 0)
 592				goto error;
 593		}
 594	} else if (!uid_eq(kuid, old->uid) && !uid_eq(kuid, new->suid)) {
 595		goto error;
 596	}
 597
 598	new->fsuid = new->euid = kuid;
 599
 600	retval = security_task_fix_setuid(new, old, LSM_SETID_ID);
 601	if (retval < 0)
 602		goto error;
 603
 
 
 
 
 
 604	return commit_creds(new);
 605
 606error:
 607	abort_creds(new);
 608	return retval;
 609}
 610
 611SYSCALL_DEFINE1(setuid, uid_t, uid)
 612{
 613	return __sys_setuid(uid);
 614}
 615
 616
 617/*
 618 * This function implements a generic ability to update ruid, euid,
 619 * and suid.  This allows you to implement the 4.4 compatible seteuid().
 620 */
 621long __sys_setresuid(uid_t ruid, uid_t euid, uid_t suid)
 622{
 623	struct user_namespace *ns = current_user_ns();
 624	const struct cred *old;
 625	struct cred *new;
 626	int retval;
 627	kuid_t kruid, keuid, ksuid;
 
 628
 629	kruid = make_kuid(ns, ruid);
 630	keuid = make_kuid(ns, euid);
 631	ksuid = make_kuid(ns, suid);
 632
 633	if ((ruid != (uid_t) -1) && !uid_valid(kruid))
 634		return -EINVAL;
 635
 636	if ((euid != (uid_t) -1) && !uid_valid(keuid))
 637		return -EINVAL;
 638
 639	if ((suid != (uid_t) -1) && !uid_valid(ksuid))
 640		return -EINVAL;
 641
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 642	new = prepare_creds();
 643	if (!new)
 644		return -ENOMEM;
 645
 646	old = current_cred();
 647
 648	retval = -EPERM;
 649	if (!ns_capable(old->user_ns, CAP_SETUID)) {
 650		if (ruid != (uid_t) -1        && !uid_eq(kruid, old->uid) &&
 651		    !uid_eq(kruid, old->euid) && !uid_eq(kruid, old->suid))
 652			goto error;
 653		if (euid != (uid_t) -1        && !uid_eq(keuid, old->uid) &&
 654		    !uid_eq(keuid, old->euid) && !uid_eq(keuid, old->suid))
 655			goto error;
 656		if (suid != (uid_t) -1        && !uid_eq(ksuid, old->uid) &&
 657		    !uid_eq(ksuid, old->euid) && !uid_eq(ksuid, old->suid))
 658			goto error;
 659	}
 660
 661	if (ruid != (uid_t) -1) {
 662		new->uid = kruid;
 663		if (!uid_eq(kruid, old->uid)) {
 664			retval = set_user(new);
 665			if (retval < 0)
 666				goto error;
 667		}
 668	}
 669	if (euid != (uid_t) -1)
 670		new->euid = keuid;
 671	if (suid != (uid_t) -1)
 672		new->suid = ksuid;
 673	new->fsuid = new->euid;
 674
 675	retval = security_task_fix_setuid(new, old, LSM_SETID_RES);
 676	if (retval < 0)
 677		goto error;
 678
 
 
 
 
 
 679	return commit_creds(new);
 680
 681error:
 682	abort_creds(new);
 683	return retval;
 684}
 685
 686SYSCALL_DEFINE3(setresuid, uid_t, ruid, uid_t, euid, uid_t, suid)
 687{
 688	return __sys_setresuid(ruid, euid, suid);
 689}
 690
 691SYSCALL_DEFINE3(getresuid, uid_t __user *, ruidp, uid_t __user *, euidp, uid_t __user *, suidp)
 692{
 693	const struct cred *cred = current_cred();
 694	int retval;
 695	uid_t ruid, euid, suid;
 696
 697	ruid = from_kuid_munged(cred->user_ns, cred->uid);
 698	euid = from_kuid_munged(cred->user_ns, cred->euid);
 699	suid = from_kuid_munged(cred->user_ns, cred->suid);
 700
 701	retval = put_user(ruid, ruidp);
 702	if (!retval) {
 703		retval = put_user(euid, euidp);
 704		if (!retval)
 705			return put_user(suid, suidp);
 706	}
 707	return retval;
 708}
 709
 710/*
 711 * Same as above, but for rgid, egid, sgid.
 712 */
 713long __sys_setresgid(gid_t rgid, gid_t egid, gid_t sgid)
 714{
 715	struct user_namespace *ns = current_user_ns();
 716	const struct cred *old;
 717	struct cred *new;
 718	int retval;
 719	kgid_t krgid, kegid, ksgid;
 
 720
 721	krgid = make_kgid(ns, rgid);
 722	kegid = make_kgid(ns, egid);
 723	ksgid = make_kgid(ns, sgid);
 724
 725	if ((rgid != (gid_t) -1) && !gid_valid(krgid))
 726		return -EINVAL;
 727	if ((egid != (gid_t) -1) && !gid_valid(kegid))
 728		return -EINVAL;
 729	if ((sgid != (gid_t) -1) && !gid_valid(ksgid))
 730		return -EINVAL;
 731
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 732	new = prepare_creds();
 733	if (!new)
 734		return -ENOMEM;
 735	old = current_cred();
 736
 737	retval = -EPERM;
 738	if (!ns_capable(old->user_ns, CAP_SETGID)) {
 739		if (rgid != (gid_t) -1        && !gid_eq(krgid, old->gid) &&
 740		    !gid_eq(krgid, old->egid) && !gid_eq(krgid, old->sgid))
 741			goto error;
 742		if (egid != (gid_t) -1        && !gid_eq(kegid, old->gid) &&
 743		    !gid_eq(kegid, old->egid) && !gid_eq(kegid, old->sgid))
 744			goto error;
 745		if (sgid != (gid_t) -1        && !gid_eq(ksgid, old->gid) &&
 746		    !gid_eq(ksgid, old->egid) && !gid_eq(ksgid, old->sgid))
 747			goto error;
 748	}
 749
 750	if (rgid != (gid_t) -1)
 751		new->gid = krgid;
 752	if (egid != (gid_t) -1)
 753		new->egid = kegid;
 754	if (sgid != (gid_t) -1)
 755		new->sgid = ksgid;
 756	new->fsgid = new->egid;
 757
 
 
 
 
 758	return commit_creds(new);
 759
 760error:
 761	abort_creds(new);
 762	return retval;
 763}
 764
 765SYSCALL_DEFINE3(setresgid, gid_t, rgid, gid_t, egid, gid_t, sgid)
 766{
 767	return __sys_setresgid(rgid, egid, sgid);
 768}
 769
 770SYSCALL_DEFINE3(getresgid, gid_t __user *, rgidp, gid_t __user *, egidp, gid_t __user *, sgidp)
 771{
 772	const struct cred *cred = current_cred();
 773	int retval;
 774	gid_t rgid, egid, sgid;
 775
 776	rgid = from_kgid_munged(cred->user_ns, cred->gid);
 777	egid = from_kgid_munged(cred->user_ns, cred->egid);
 778	sgid = from_kgid_munged(cred->user_ns, cred->sgid);
 779
 780	retval = put_user(rgid, rgidp);
 781	if (!retval) {
 782		retval = put_user(egid, egidp);
 783		if (!retval)
 784			retval = put_user(sgid, sgidp);
 785	}
 786
 787	return retval;
 788}
 789
 790
 791/*
 792 * "setfsuid()" sets the fsuid - the uid used for filesystem checks. This
 793 * is used for "access()" and for the NFS daemon (letting nfsd stay at
 794 * whatever uid it wants to). It normally shadows "euid", except when
 795 * explicitly set by setfsuid() or for access..
 796 */
 797long __sys_setfsuid(uid_t uid)
 798{
 799	const struct cred *old;
 800	struct cred *new;
 801	uid_t old_fsuid;
 802	kuid_t kuid;
 803
 804	old = current_cred();
 805	old_fsuid = from_kuid_munged(old->user_ns, old->fsuid);
 806
 807	kuid = make_kuid(old->user_ns, uid);
 808	if (!uid_valid(kuid))
 809		return old_fsuid;
 810
 811	new = prepare_creds();
 812	if (!new)
 813		return old_fsuid;
 814
 815	if (uid_eq(kuid, old->uid)  || uid_eq(kuid, old->euid)  ||
 816	    uid_eq(kuid, old->suid) || uid_eq(kuid, old->fsuid) ||
 817	    ns_capable(old->user_ns, CAP_SETUID)) {
 818		if (!uid_eq(kuid, old->fsuid)) {
 819			new->fsuid = kuid;
 820			if (security_task_fix_setuid(new, old, LSM_SETID_FS) == 0)
 821				goto change_okay;
 822		}
 823	}
 824
 825	abort_creds(new);
 826	return old_fsuid;
 827
 828change_okay:
 829	commit_creds(new);
 830	return old_fsuid;
 831}
 832
 833SYSCALL_DEFINE1(setfsuid, uid_t, uid)
 834{
 835	return __sys_setfsuid(uid);
 836}
 837
 838/*
 839 * Samma på svenska..
 840 */
 841long __sys_setfsgid(gid_t gid)
 842{
 843	const struct cred *old;
 844	struct cred *new;
 845	gid_t old_fsgid;
 846	kgid_t kgid;
 847
 848	old = current_cred();
 849	old_fsgid = from_kgid_munged(old->user_ns, old->fsgid);
 850
 851	kgid = make_kgid(old->user_ns, gid);
 852	if (!gid_valid(kgid))
 853		return old_fsgid;
 854
 855	new = prepare_creds();
 856	if (!new)
 857		return old_fsgid;
 858
 859	if (gid_eq(kgid, old->gid)  || gid_eq(kgid, old->egid)  ||
 860	    gid_eq(kgid, old->sgid) || gid_eq(kgid, old->fsgid) ||
 861	    ns_capable(old->user_ns, CAP_SETGID)) {
 862		if (!gid_eq(kgid, old->fsgid)) {
 863			new->fsgid = kgid;
 864			goto change_okay;
 
 865		}
 866	}
 867
 868	abort_creds(new);
 869	return old_fsgid;
 870
 871change_okay:
 872	commit_creds(new);
 873	return old_fsgid;
 874}
 875
 876SYSCALL_DEFINE1(setfsgid, gid_t, gid)
 877{
 878	return __sys_setfsgid(gid);
 879}
 880#endif /* CONFIG_MULTIUSER */
 881
 882/**
 883 * sys_getpid - return the thread group id of the current process
 884 *
 885 * Note, despite the name, this returns the tgid not the pid.  The tgid and
 886 * the pid are identical unless CLONE_THREAD was specified on clone() in
 887 * which case the tgid is the same in all threads of the same group.
 888 *
 889 * This is SMP safe as current->tgid does not change.
 890 */
 891SYSCALL_DEFINE0(getpid)
 892{
 893	return task_tgid_vnr(current);
 894}
 895
 896/* Thread ID - the internal kernel "pid" */
 897SYSCALL_DEFINE0(gettid)
 898{
 899	return task_pid_vnr(current);
 900}
 901
 902/*
 903 * Accessing ->real_parent is not SMP-safe, it could
 904 * change from under us. However, we can use a stale
 905 * value of ->real_parent under rcu_read_lock(), see
 906 * release_task()->call_rcu(delayed_put_task_struct).
 907 */
 908SYSCALL_DEFINE0(getppid)
 909{
 910	int pid;
 911
 912	rcu_read_lock();
 913	pid = task_tgid_vnr(rcu_dereference(current->real_parent));
 914	rcu_read_unlock();
 915
 916	return pid;
 917}
 918
 919SYSCALL_DEFINE0(getuid)
 920{
 921	/* Only we change this so SMP safe */
 922	return from_kuid_munged(current_user_ns(), current_uid());
 923}
 924
 925SYSCALL_DEFINE0(geteuid)
 926{
 927	/* Only we change this so SMP safe */
 928	return from_kuid_munged(current_user_ns(), current_euid());
 929}
 930
 931SYSCALL_DEFINE0(getgid)
 932{
 933	/* Only we change this so SMP safe */
 934	return from_kgid_munged(current_user_ns(), current_gid());
 935}
 936
 937SYSCALL_DEFINE0(getegid)
 938{
 939	/* Only we change this so SMP safe */
 940	return from_kgid_munged(current_user_ns(), current_egid());
 941}
 942
 943static void do_sys_times(struct tms *tms)
 944{
 945	u64 tgutime, tgstime, cutime, cstime;
 946
 947	thread_group_cputime_adjusted(current, &tgutime, &tgstime);
 948	cutime = current->signal->cutime;
 949	cstime = current->signal->cstime;
 950	tms->tms_utime = nsec_to_clock_t(tgutime);
 951	tms->tms_stime = nsec_to_clock_t(tgstime);
 952	tms->tms_cutime = nsec_to_clock_t(cutime);
 953	tms->tms_cstime = nsec_to_clock_t(cstime);
 954}
 955
 956SYSCALL_DEFINE1(times, struct tms __user *, tbuf)
 957{
 958	if (tbuf) {
 959		struct tms tmp;
 960
 961		do_sys_times(&tmp);
 962		if (copy_to_user(tbuf, &tmp, sizeof(struct tms)))
 963			return -EFAULT;
 964	}
 965	force_successful_syscall_return();
 966	return (long) jiffies_64_to_clock_t(get_jiffies_64());
 967}
 968
 969#ifdef CONFIG_COMPAT
 970static compat_clock_t clock_t_to_compat_clock_t(clock_t x)
 971{
 972	return compat_jiffies_to_clock_t(clock_t_to_jiffies(x));
 973}
 974
 975COMPAT_SYSCALL_DEFINE1(times, struct compat_tms __user *, tbuf)
 976{
 977	if (tbuf) {
 978		struct tms tms;
 979		struct compat_tms tmp;
 980
 981		do_sys_times(&tms);
 982		/* Convert our struct tms to the compat version. */
 983		tmp.tms_utime = clock_t_to_compat_clock_t(tms.tms_utime);
 984		tmp.tms_stime = clock_t_to_compat_clock_t(tms.tms_stime);
 985		tmp.tms_cutime = clock_t_to_compat_clock_t(tms.tms_cutime);
 986		tmp.tms_cstime = clock_t_to_compat_clock_t(tms.tms_cstime);
 987		if (copy_to_user(tbuf, &tmp, sizeof(tmp)))
 988			return -EFAULT;
 989	}
 990	force_successful_syscall_return();
 991	return compat_jiffies_to_clock_t(jiffies);
 992}
 993#endif
 994
 995/*
 996 * This needs some heavy checking ...
 997 * I just haven't the stomach for it. I also don't fully
 998 * understand sessions/pgrp etc. Let somebody who does explain it.
 999 *
1000 * OK, I think I have the protection semantics right.... this is really
1001 * only important on a multi-user system anyway, to make sure one user
1002 * can't send a signal to a process owned by another.  -TYT, 12/12/91
1003 *
1004 * !PF_FORKNOEXEC check to conform completely to POSIX.
1005 */
1006SYSCALL_DEFINE2(setpgid, pid_t, pid, pid_t, pgid)
1007{
1008	struct task_struct *p;
1009	struct task_struct *group_leader = current->group_leader;
1010	struct pid *pgrp;
1011	int err;
1012
1013	if (!pid)
1014		pid = task_pid_vnr(group_leader);
1015	if (!pgid)
1016		pgid = pid;
1017	if (pgid < 0)
1018		return -EINVAL;
1019	rcu_read_lock();
1020
1021	/* From this point forward we keep holding onto the tasklist lock
1022	 * so that our parent does not change from under us. -DaveM
1023	 */
1024	write_lock_irq(&tasklist_lock);
1025
1026	err = -ESRCH;
1027	p = find_task_by_vpid(pid);
1028	if (!p)
1029		goto out;
1030
1031	err = -EINVAL;
1032	if (!thread_group_leader(p))
1033		goto out;
1034
1035	if (same_thread_group(p->real_parent, group_leader)) {
1036		err = -EPERM;
1037		if (task_session(p) != task_session(group_leader))
1038			goto out;
1039		err = -EACCES;
1040		if (!(p->flags & PF_FORKNOEXEC))
1041			goto out;
1042	} else {
1043		err = -ESRCH;
1044		if (p != group_leader)
1045			goto out;
1046	}
1047
1048	err = -EPERM;
1049	if (p->signal->leader)
1050		goto out;
1051
1052	pgrp = task_pid(p);
1053	if (pgid != pid) {
1054		struct task_struct *g;
1055
1056		pgrp = find_vpid(pgid);
1057		g = pid_task(pgrp, PIDTYPE_PGID);
1058		if (!g || task_session(g) != task_session(group_leader))
1059			goto out;
1060	}
1061
1062	err = security_task_setpgid(p, pgid);
1063	if (err)
1064		goto out;
1065
1066	if (task_pgrp(p) != pgrp)
1067		change_pid(p, PIDTYPE_PGID, pgrp);
1068
1069	err = 0;
1070out:
1071	/* All paths lead to here, thus we are safe. -DaveM */
1072	write_unlock_irq(&tasklist_lock);
1073	rcu_read_unlock();
1074	return err;
1075}
1076
1077static int do_getpgid(pid_t pid)
1078{
1079	struct task_struct *p;
1080	struct pid *grp;
1081	int retval;
1082
1083	rcu_read_lock();
1084	if (!pid)
1085		grp = task_pgrp(current);
1086	else {
1087		retval = -ESRCH;
1088		p = find_task_by_vpid(pid);
1089		if (!p)
1090			goto out;
1091		grp = task_pgrp(p);
1092		if (!grp)
1093			goto out;
1094
1095		retval = security_task_getpgid(p);
1096		if (retval)
1097			goto out;
1098	}
1099	retval = pid_vnr(grp);
1100out:
1101	rcu_read_unlock();
1102	return retval;
1103}
1104
1105SYSCALL_DEFINE1(getpgid, pid_t, pid)
1106{
1107	return do_getpgid(pid);
1108}
1109
1110#ifdef __ARCH_WANT_SYS_GETPGRP
1111
1112SYSCALL_DEFINE0(getpgrp)
1113{
1114	return do_getpgid(0);
1115}
1116
1117#endif
1118
1119SYSCALL_DEFINE1(getsid, pid_t, pid)
1120{
1121	struct task_struct *p;
1122	struct pid *sid;
1123	int retval;
1124
1125	rcu_read_lock();
1126	if (!pid)
1127		sid = task_session(current);
1128	else {
1129		retval = -ESRCH;
1130		p = find_task_by_vpid(pid);
1131		if (!p)
1132			goto out;
1133		sid = task_session(p);
1134		if (!sid)
1135			goto out;
1136
1137		retval = security_task_getsid(p);
1138		if (retval)
1139			goto out;
1140	}
1141	retval = pid_vnr(sid);
1142out:
1143	rcu_read_unlock();
1144	return retval;
1145}
1146
1147static void set_special_pids(struct pid *pid)
1148{
1149	struct task_struct *curr = current->group_leader;
1150
1151	if (task_session(curr) != pid)
1152		change_pid(curr, PIDTYPE_SID, pid);
1153
1154	if (task_pgrp(curr) != pid)
1155		change_pid(curr, PIDTYPE_PGID, pid);
1156}
1157
1158int ksys_setsid(void)
1159{
1160	struct task_struct *group_leader = current->group_leader;
1161	struct pid *sid = task_pid(group_leader);
1162	pid_t session = pid_vnr(sid);
1163	int err = -EPERM;
1164
1165	write_lock_irq(&tasklist_lock);
1166	/* Fail if I am already a session leader */
1167	if (group_leader->signal->leader)
1168		goto out;
1169
1170	/* Fail if a process group id already exists that equals the
1171	 * proposed session id.
1172	 */
1173	if (pid_task(sid, PIDTYPE_PGID))
1174		goto out;
1175
1176	group_leader->signal->leader = 1;
1177	set_special_pids(sid);
1178
1179	proc_clear_tty(group_leader);
1180
1181	err = session;
1182out:
1183	write_unlock_irq(&tasklist_lock);
1184	if (err > 0) {
1185		proc_sid_connector(group_leader);
1186		sched_autogroup_create_attach(group_leader);
1187	}
1188	return err;
1189}
1190
1191SYSCALL_DEFINE0(setsid)
1192{
1193	return ksys_setsid();
1194}
1195
1196DECLARE_RWSEM(uts_sem);
1197
1198#ifdef COMPAT_UTS_MACHINE
1199#define override_architecture(name) \
1200	(personality(current->personality) == PER_LINUX32 && \
1201	 copy_to_user(name->machine, COMPAT_UTS_MACHINE, \
1202		      sizeof(COMPAT_UTS_MACHINE)))
1203#else
1204#define override_architecture(name)	0
1205#endif
1206
1207/*
1208 * Work around broken programs that cannot handle "Linux 3.0".
1209 * Instead we map 3.x to 2.6.40+x, so e.g. 3.0 would be 2.6.40
1210 * And we map 4.x to 2.6.60+x, so 4.0 would be 2.6.60.
 
1211 */
1212static int override_release(char __user *release, size_t len)
1213{
1214	int ret = 0;
1215
1216	if (current->personality & UNAME26) {
1217		const char *rest = UTS_RELEASE;
1218		char buf[65] = { 0 };
1219		int ndots = 0;
1220		unsigned v;
1221		size_t copy;
1222
1223		while (*rest) {
1224			if (*rest == '.' && ++ndots >= 3)
1225				break;
1226			if (!isdigit(*rest) && *rest != '.')
1227				break;
1228			rest++;
1229		}
1230		v = ((LINUX_VERSION_CODE >> 8) & 0xff) + 60;
1231		copy = clamp_t(size_t, len, 1, sizeof(buf));
1232		copy = scnprintf(buf, copy, "2.6.%u%s", v, rest);
1233		ret = copy_to_user(release, buf, copy + 1);
1234	}
1235	return ret;
1236}
1237
1238SYSCALL_DEFINE1(newuname, struct new_utsname __user *, name)
1239{
1240	int errno = 0;
1241
1242	down_read(&uts_sem);
1243	if (copy_to_user(name, utsname(), sizeof *name))
1244		errno = -EFAULT;
1245	up_read(&uts_sem);
 
 
1246
1247	if (!errno && override_release(name->release, sizeof(name->release)))
1248		errno = -EFAULT;
1249	if (!errno && override_architecture(name))
1250		errno = -EFAULT;
1251	return errno;
1252}
1253
1254#ifdef __ARCH_WANT_SYS_OLD_UNAME
1255/*
1256 * Old cruft
1257 */
1258SYSCALL_DEFINE1(uname, struct old_utsname __user *, name)
1259{
1260	int error = 0;
1261
1262	if (!name)
1263		return -EFAULT;
1264
1265	down_read(&uts_sem);
1266	if (copy_to_user(name, utsname(), sizeof(*name)))
1267		error = -EFAULT;
1268	up_read(&uts_sem);
 
 
1269
1270	if (!error && override_release(name->release, sizeof(name->release)))
1271		error = -EFAULT;
1272	if (!error && override_architecture(name))
1273		error = -EFAULT;
1274	return error;
1275}
1276
1277SYSCALL_DEFINE1(olduname, struct oldold_utsname __user *, name)
1278{
1279	int error;
1280
1281	if (!name)
1282		return -EFAULT;
1283	if (!access_ok(VERIFY_WRITE, name, sizeof(struct oldold_utsname)))
1284		return -EFAULT;
1285
1286	down_read(&uts_sem);
1287	error = __copy_to_user(&name->sysname, &utsname()->sysname,
1288			       __OLD_UTS_LEN);
1289	error |= __put_user(0, name->sysname + __OLD_UTS_LEN);
1290	error |= __copy_to_user(&name->nodename, &utsname()->nodename,
1291				__OLD_UTS_LEN);
1292	error |= __put_user(0, name->nodename + __OLD_UTS_LEN);
1293	error |= __copy_to_user(&name->release, &utsname()->release,
1294				__OLD_UTS_LEN);
1295	error |= __put_user(0, name->release + __OLD_UTS_LEN);
1296	error |= __copy_to_user(&name->version, &utsname()->version,
1297				__OLD_UTS_LEN);
1298	error |= __put_user(0, name->version + __OLD_UTS_LEN);
1299	error |= __copy_to_user(&name->machine, &utsname()->machine,
1300				__OLD_UTS_LEN);
1301	error |= __put_user(0, name->machine + __OLD_UTS_LEN);
1302	up_read(&uts_sem);
 
 
1303
1304	if (!error && override_architecture(name))
1305		error = -EFAULT;
1306	if (!error && override_release(name->release, sizeof(name->release)))
1307		error = -EFAULT;
1308	return error ? -EFAULT : 0;
1309}
1310#endif
1311
1312SYSCALL_DEFINE2(sethostname, char __user *, name, int, len)
1313{
1314	int errno;
1315	char tmp[__NEW_UTS_LEN];
1316
1317	if (!ns_capable(current->nsproxy->uts_ns->user_ns, CAP_SYS_ADMIN))
1318		return -EPERM;
1319
1320	if (len < 0 || len > __NEW_UTS_LEN)
1321		return -EINVAL;
1322	down_write(&uts_sem);
1323	errno = -EFAULT;
1324	if (!copy_from_user(tmp, name, len)) {
1325		struct new_utsname *u = utsname();
1326
 
 
 
1327		memcpy(u->nodename, tmp, len);
1328		memset(u->nodename + len, 0, sizeof(u->nodename) - len);
1329		errno = 0;
1330		uts_proc_notify(UTS_PROC_HOSTNAME);
 
1331	}
1332	up_write(&uts_sem);
1333	return errno;
1334}
1335
1336#ifdef __ARCH_WANT_SYS_GETHOSTNAME
1337
1338SYSCALL_DEFINE2(gethostname, char __user *, name, int, len)
1339{
1340	int i, errno;
1341	struct new_utsname *u;
 
1342
1343	if (len < 0)
1344		return -EINVAL;
1345	down_read(&uts_sem);
1346	u = utsname();
1347	i = 1 + strlen(u->nodename);
1348	if (i > len)
1349		i = len;
1350	errno = 0;
1351	if (copy_to_user(name, u->nodename, i))
1352		errno = -EFAULT;
1353	up_read(&uts_sem);
1354	return errno;
 
 
1355}
1356
1357#endif
1358
1359/*
1360 * Only setdomainname; getdomainname can be implemented by calling
1361 * uname()
1362 */
1363SYSCALL_DEFINE2(setdomainname, char __user *, name, int, len)
1364{
1365	int errno;
1366	char tmp[__NEW_UTS_LEN];
1367
1368	if (!ns_capable(current->nsproxy->uts_ns->user_ns, CAP_SYS_ADMIN))
1369		return -EPERM;
1370	if (len < 0 || len > __NEW_UTS_LEN)
1371		return -EINVAL;
1372
1373	down_write(&uts_sem);
1374	errno = -EFAULT;
1375	if (!copy_from_user(tmp, name, len)) {
1376		struct new_utsname *u = utsname();
1377
 
 
 
1378		memcpy(u->domainname, tmp, len);
1379		memset(u->domainname + len, 0, sizeof(u->domainname) - len);
1380		errno = 0;
1381		uts_proc_notify(UTS_PROC_DOMAINNAME);
 
1382	}
1383	up_write(&uts_sem);
1384	return errno;
1385}
1386
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1387SYSCALL_DEFINE2(getrlimit, unsigned int, resource, struct rlimit __user *, rlim)
1388{
1389	struct rlimit value;
1390	int ret;
1391
1392	ret = do_prlimit(current, resource, NULL, &value);
1393	if (!ret)
1394		ret = copy_to_user(rlim, &value, sizeof(*rlim)) ? -EFAULT : 0;
1395
1396	return ret;
1397}
1398
1399#ifdef CONFIG_COMPAT
1400
1401COMPAT_SYSCALL_DEFINE2(setrlimit, unsigned int, resource,
1402		       struct compat_rlimit __user *, rlim)
1403{
1404	struct rlimit r;
1405	struct compat_rlimit r32;
1406
1407	if (copy_from_user(&r32, rlim, sizeof(struct compat_rlimit)))
1408		return -EFAULT;
1409
1410	if (r32.rlim_cur == COMPAT_RLIM_INFINITY)
1411		r.rlim_cur = RLIM_INFINITY;
1412	else
1413		r.rlim_cur = r32.rlim_cur;
1414	if (r32.rlim_max == COMPAT_RLIM_INFINITY)
1415		r.rlim_max = RLIM_INFINITY;
1416	else
1417		r.rlim_max = r32.rlim_max;
1418	return do_prlimit(current, resource, &r, NULL);
1419}
1420
1421COMPAT_SYSCALL_DEFINE2(getrlimit, unsigned int, resource,
1422		       struct compat_rlimit __user *, rlim)
1423{
1424	struct rlimit r;
1425	int ret;
1426
1427	ret = do_prlimit(current, resource, NULL, &r);
1428	if (!ret) {
1429		struct compat_rlimit r32;
1430		if (r.rlim_cur > COMPAT_RLIM_INFINITY)
1431			r32.rlim_cur = COMPAT_RLIM_INFINITY;
1432		else
1433			r32.rlim_cur = r.rlim_cur;
1434		if (r.rlim_max > COMPAT_RLIM_INFINITY)
1435			r32.rlim_max = COMPAT_RLIM_INFINITY;
1436		else
1437			r32.rlim_max = r.rlim_max;
1438
1439		if (copy_to_user(rlim, &r32, sizeof(struct compat_rlimit)))
1440			return -EFAULT;
1441	}
1442	return ret;
1443}
1444
1445#endif
1446
1447#ifdef __ARCH_WANT_SYS_OLD_GETRLIMIT
1448
1449/*
1450 *	Back compatibility for getrlimit. Needed for some apps.
1451 */
1452SYSCALL_DEFINE2(old_getrlimit, unsigned int, resource,
1453		struct rlimit __user *, rlim)
1454{
1455	struct rlimit x;
1456	if (resource >= RLIM_NLIMITS)
1457		return -EINVAL;
1458
1459	resource = array_index_nospec(resource, RLIM_NLIMITS);
1460	task_lock(current->group_leader);
1461	x = current->signal->rlim[resource];
1462	task_unlock(current->group_leader);
1463	if (x.rlim_cur > 0x7FFFFFFF)
1464		x.rlim_cur = 0x7FFFFFFF;
1465	if (x.rlim_max > 0x7FFFFFFF)
1466		x.rlim_max = 0x7FFFFFFF;
1467	return copy_to_user(rlim, &x, sizeof(x)) ? -EFAULT : 0;
1468}
1469
1470#ifdef CONFIG_COMPAT
1471COMPAT_SYSCALL_DEFINE2(old_getrlimit, unsigned int, resource,
1472		       struct compat_rlimit __user *, rlim)
1473{
1474	struct rlimit r;
1475
1476	if (resource >= RLIM_NLIMITS)
1477		return -EINVAL;
1478
1479	resource = array_index_nospec(resource, RLIM_NLIMITS);
1480	task_lock(current->group_leader);
1481	r = current->signal->rlim[resource];
1482	task_unlock(current->group_leader);
1483	if (r.rlim_cur > 0x7FFFFFFF)
1484		r.rlim_cur = 0x7FFFFFFF;
1485	if (r.rlim_max > 0x7FFFFFFF)
1486		r.rlim_max = 0x7FFFFFFF;
1487
1488	if (put_user(r.rlim_cur, &rlim->rlim_cur) ||
1489	    put_user(r.rlim_max, &rlim->rlim_max))
1490		return -EFAULT;
1491	return 0;
1492}
1493#endif
1494
1495#endif
1496
1497static inline bool rlim64_is_infinity(__u64 rlim64)
1498{
1499#if BITS_PER_LONG < 64
1500	return rlim64 >= ULONG_MAX;
1501#else
1502	return rlim64 == RLIM64_INFINITY;
1503#endif
1504}
1505
1506static void rlim_to_rlim64(const struct rlimit *rlim, struct rlimit64 *rlim64)
1507{
1508	if (rlim->rlim_cur == RLIM_INFINITY)
1509		rlim64->rlim_cur = RLIM64_INFINITY;
1510	else
1511		rlim64->rlim_cur = rlim->rlim_cur;
1512	if (rlim->rlim_max == RLIM_INFINITY)
1513		rlim64->rlim_max = RLIM64_INFINITY;
1514	else
1515		rlim64->rlim_max = rlim->rlim_max;
1516}
1517
1518static void rlim64_to_rlim(const struct rlimit64 *rlim64, struct rlimit *rlim)
1519{
1520	if (rlim64_is_infinity(rlim64->rlim_cur))
1521		rlim->rlim_cur = RLIM_INFINITY;
1522	else
1523		rlim->rlim_cur = (unsigned long)rlim64->rlim_cur;
1524	if (rlim64_is_infinity(rlim64->rlim_max))
1525		rlim->rlim_max = RLIM_INFINITY;
1526	else
1527		rlim->rlim_max = (unsigned long)rlim64->rlim_max;
1528}
1529
1530/* make sure you are allowed to change @tsk limits before calling this */
1531int do_prlimit(struct task_struct *tsk, unsigned int resource,
1532		struct rlimit *new_rlim, struct rlimit *old_rlim)
1533{
1534	struct rlimit *rlim;
1535	int retval = 0;
1536
1537	if (resource >= RLIM_NLIMITS)
1538		return -EINVAL;
1539	if (new_rlim) {
1540		if (new_rlim->rlim_cur > new_rlim->rlim_max)
1541			return -EINVAL;
1542		if (resource == RLIMIT_NOFILE &&
1543				new_rlim->rlim_max > sysctl_nr_open)
1544			return -EPERM;
1545	}
1546
1547	/* protect tsk->signal and tsk->sighand from disappearing */
1548	read_lock(&tasklist_lock);
1549	if (!tsk->sighand) {
1550		retval = -ESRCH;
1551		goto out;
1552	}
1553
1554	rlim = tsk->signal->rlim + resource;
1555	task_lock(tsk->group_leader);
1556	if (new_rlim) {
1557		/* Keep the capable check against init_user_ns until
1558		   cgroups can contain all limits */
1559		if (new_rlim->rlim_max > rlim->rlim_max &&
1560				!capable(CAP_SYS_RESOURCE))
1561			retval = -EPERM;
1562		if (!retval)
1563			retval = security_task_setrlimit(tsk, resource, new_rlim);
1564		if (resource == RLIMIT_CPU && new_rlim->rlim_cur == 0) {
1565			/*
1566			 * The caller is asking for an immediate RLIMIT_CPU
1567			 * expiry.  But we use the zero value to mean "it was
1568			 * never set".  So let's cheat and make it one second
1569			 * instead
1570			 */
1571			new_rlim->rlim_cur = 1;
1572		}
1573	}
1574	if (!retval) {
1575		if (old_rlim)
1576			*old_rlim = *rlim;
1577		if (new_rlim)
1578			*rlim = *new_rlim;
1579	}
1580	task_unlock(tsk->group_leader);
1581
1582	/*
1583	 * RLIMIT_CPU handling.   Note that the kernel fails to return an error
1584	 * code if it rejected the user's attempt to set RLIMIT_CPU.  This is a
1585	 * very long-standing error, and fixing it now risks breakage of
1586	 * applications, so we live with it
1587	 */
1588	 if (!retval && new_rlim && resource == RLIMIT_CPU &&
1589	     new_rlim->rlim_cur != RLIM_INFINITY &&
1590	     IS_ENABLED(CONFIG_POSIX_TIMERS))
1591		update_rlimit_cpu(tsk, new_rlim->rlim_cur);
1592out:
1593	read_unlock(&tasklist_lock);
1594	return retval;
1595}
1596
1597/* rcu lock must be held */
1598static int check_prlimit_permission(struct task_struct *task,
1599				    unsigned int flags)
1600{
1601	const struct cred *cred = current_cred(), *tcred;
1602	bool id_match;
1603
1604	if (current == task)
1605		return 0;
1606
1607	tcred = __task_cred(task);
1608	id_match = (uid_eq(cred->uid, tcred->euid) &&
1609		    uid_eq(cred->uid, tcred->suid) &&
1610		    uid_eq(cred->uid, tcred->uid)  &&
1611		    gid_eq(cred->gid, tcred->egid) &&
1612		    gid_eq(cred->gid, tcred->sgid) &&
1613		    gid_eq(cred->gid, tcred->gid));
1614	if (!id_match && !ns_capable(tcred->user_ns, CAP_SYS_RESOURCE))
1615		return -EPERM;
1616
1617	return security_task_prlimit(cred, tcred, flags);
1618}
1619
1620SYSCALL_DEFINE4(prlimit64, pid_t, pid, unsigned int, resource,
1621		const struct rlimit64 __user *, new_rlim,
1622		struct rlimit64 __user *, old_rlim)
1623{
1624	struct rlimit64 old64, new64;
1625	struct rlimit old, new;
1626	struct task_struct *tsk;
1627	unsigned int checkflags = 0;
1628	int ret;
1629
1630	if (old_rlim)
1631		checkflags |= LSM_PRLIMIT_READ;
1632
1633	if (new_rlim) {
1634		if (copy_from_user(&new64, new_rlim, sizeof(new64)))
1635			return -EFAULT;
1636		rlim64_to_rlim(&new64, &new);
1637		checkflags |= LSM_PRLIMIT_WRITE;
1638	}
1639
1640	rcu_read_lock();
1641	tsk = pid ? find_task_by_vpid(pid) : current;
1642	if (!tsk) {
1643		rcu_read_unlock();
1644		return -ESRCH;
1645	}
1646	ret = check_prlimit_permission(tsk, checkflags);
1647	if (ret) {
1648		rcu_read_unlock();
1649		return ret;
1650	}
1651	get_task_struct(tsk);
1652	rcu_read_unlock();
1653
1654	ret = do_prlimit(tsk, resource, new_rlim ? &new : NULL,
1655			old_rlim ? &old : NULL);
1656
1657	if (!ret && old_rlim) {
1658		rlim_to_rlim64(&old, &old64);
1659		if (copy_to_user(old_rlim, &old64, sizeof(old64)))
1660			ret = -EFAULT;
1661	}
1662
1663	put_task_struct(tsk);
1664	return ret;
1665}
1666
1667SYSCALL_DEFINE2(setrlimit, unsigned int, resource, struct rlimit __user *, rlim)
1668{
1669	struct rlimit new_rlim;
1670
1671	if (copy_from_user(&new_rlim, rlim, sizeof(*rlim)))
1672		return -EFAULT;
1673	return do_prlimit(current, resource, &new_rlim, NULL);
1674}
1675
1676/*
1677 * It would make sense to put struct rusage in the task_struct,
1678 * except that would make the task_struct be *really big*.  After
1679 * task_struct gets moved into malloc'ed memory, it would
1680 * make sense to do this.  It will make moving the rest of the information
1681 * a lot simpler!  (Which we're not doing right now because we're not
1682 * measuring them yet).
1683 *
1684 * When sampling multiple threads for RUSAGE_SELF, under SMP we might have
1685 * races with threads incrementing their own counters.  But since word
1686 * reads are atomic, we either get new values or old values and we don't
1687 * care which for the sums.  We always take the siglock to protect reading
1688 * the c* fields from p->signal from races with exit.c updating those
1689 * fields when reaping, so a sample either gets all the additions of a
1690 * given child after it's reaped, or none so this sample is before reaping.
1691 *
1692 * Locking:
1693 * We need to take the siglock for CHILDEREN, SELF and BOTH
1694 * for  the cases current multithreaded, non-current single threaded
1695 * non-current multithreaded.  Thread traversal is now safe with
1696 * the siglock held.
1697 * Strictly speaking, we donot need to take the siglock if we are current and
1698 * single threaded,  as no one else can take our signal_struct away, no one
1699 * else can  reap the  children to update signal->c* counters, and no one else
1700 * can race with the signal-> fields. If we do not take any lock, the
1701 * signal-> fields could be read out of order while another thread was just
1702 * exiting. So we should  place a read memory barrier when we avoid the lock.
1703 * On the writer side,  write memory barrier is implied in  __exit_signal
1704 * as __exit_signal releases  the siglock spinlock after updating the signal->
1705 * fields. But we don't do this yet to keep things simple.
1706 *
1707 */
1708
1709static void accumulate_thread_rusage(struct task_struct *t, struct rusage *r)
1710{
1711	r->ru_nvcsw += t->nvcsw;
1712	r->ru_nivcsw += t->nivcsw;
1713	r->ru_minflt += t->min_flt;
1714	r->ru_majflt += t->maj_flt;
1715	r->ru_inblock += task_io_get_inblock(t);
1716	r->ru_oublock += task_io_get_oublock(t);
1717}
1718
1719void getrusage(struct task_struct *p, int who, struct rusage *r)
1720{
1721	struct task_struct *t;
1722	unsigned long flags;
1723	u64 tgutime, tgstime, utime, stime;
1724	unsigned long maxrss = 0;
 
 
 
1725
1726	memset((char *)r, 0, sizeof (*r));
 
1727	utime = stime = 0;
 
1728
1729	if (who == RUSAGE_THREAD) {
1730		task_cputime_adjusted(current, &utime, &stime);
1731		accumulate_thread_rusage(p, r);
1732		maxrss = p->signal->maxrss;
1733		goto out;
1734	}
1735
1736	if (!lock_task_sighand(p, &flags))
1737		return;
1738
1739	switch (who) {
1740	case RUSAGE_BOTH:
1741	case RUSAGE_CHILDREN:
1742		utime = p->signal->cutime;
1743		stime = p->signal->cstime;
1744		r->ru_nvcsw = p->signal->cnvcsw;
1745		r->ru_nivcsw = p->signal->cnivcsw;
1746		r->ru_minflt = p->signal->cmin_flt;
1747		r->ru_majflt = p->signal->cmaj_flt;
1748		r->ru_inblock = p->signal->cinblock;
1749		r->ru_oublock = p->signal->coublock;
1750		maxrss = p->signal->cmaxrss;
1751
1752		if (who == RUSAGE_CHILDREN)
1753			break;
 
1754
1755	case RUSAGE_SELF:
1756		thread_group_cputime_adjusted(p, &tgutime, &tgstime);
1757		utime += tgutime;
1758		stime += tgstime;
1759		r->ru_nvcsw += p->signal->nvcsw;
1760		r->ru_nivcsw += p->signal->nivcsw;
1761		r->ru_minflt += p->signal->min_flt;
1762		r->ru_majflt += p->signal->maj_flt;
1763		r->ru_inblock += p->signal->inblock;
1764		r->ru_oublock += p->signal->oublock;
1765		if (maxrss < p->signal->maxrss)
1766			maxrss = p->signal->maxrss;
1767		t = p;
1768		do {
1769			accumulate_thread_rusage(t, r);
1770		} while_each_thread(p, t);
 
1771		break;
1772
1773	default:
1774		BUG();
1775	}
1776	unlock_task_sighand(p, &flags);
1777
1778out:
1779	r->ru_utime = ns_to_timeval(utime);
1780	r->ru_stime = ns_to_timeval(stime);
 
 
1781
1782	if (who != RUSAGE_CHILDREN) {
1783		struct mm_struct *mm = get_task_mm(p);
1784
1785		if (mm) {
1786			setmax_mm_hiwater_rss(&maxrss, mm);
1787			mmput(mm);
1788		}
 
 
 
 
 
1789	}
 
 
1790	r->ru_maxrss = maxrss * (PAGE_SIZE / 1024); /* convert pages to KBs */
 
 
1791}
1792
1793SYSCALL_DEFINE2(getrusage, int, who, struct rusage __user *, ru)
1794{
1795	struct rusage r;
1796
1797	if (who != RUSAGE_SELF && who != RUSAGE_CHILDREN &&
1798	    who != RUSAGE_THREAD)
1799		return -EINVAL;
1800
1801	getrusage(current, who, &r);
1802	return copy_to_user(ru, &r, sizeof(r)) ? -EFAULT : 0;
1803}
1804
1805#ifdef CONFIG_COMPAT
1806COMPAT_SYSCALL_DEFINE2(getrusage, int, who, struct compat_rusage __user *, ru)
1807{
1808	struct rusage r;
1809
1810	if (who != RUSAGE_SELF && who != RUSAGE_CHILDREN &&
1811	    who != RUSAGE_THREAD)
1812		return -EINVAL;
1813
1814	getrusage(current, who, &r);
1815	return put_compat_rusage(&r, ru);
1816}
1817#endif
1818
1819SYSCALL_DEFINE1(umask, int, mask)
1820{
1821	mask = xchg(&current->fs->umask, mask & S_IRWXUGO);
1822	return mask;
1823}
1824
1825static int prctl_set_mm_exe_file(struct mm_struct *mm, unsigned int fd)
1826{
1827	struct fd exe;
1828	struct file *old_exe, *exe_file;
1829	struct inode *inode;
1830	int err;
1831
1832	exe = fdget(fd);
1833	if (!exe.file)
1834		return -EBADF;
1835
1836	inode = file_inode(exe.file);
1837
1838	/*
1839	 * Because the original mm->exe_file points to executable file, make
1840	 * sure that this one is executable as well, to avoid breaking an
1841	 * overall picture.
1842	 */
1843	err = -EACCES;
1844	if (!S_ISREG(inode->i_mode) || path_noexec(&exe.file->f_path))
1845		goto exit;
1846
1847	err = inode_permission(inode, MAY_EXEC);
1848	if (err)
1849		goto exit;
1850
1851	/*
1852	 * Forbid mm->exe_file change if old file still mapped.
1853	 */
1854	exe_file = get_mm_exe_file(mm);
1855	err = -EBUSY;
1856	if (exe_file) {
1857		struct vm_area_struct *vma;
1858
1859		down_read(&mm->mmap_sem);
1860		for (vma = mm->mmap; vma; vma = vma->vm_next) {
1861			if (!vma->vm_file)
1862				continue;
1863			if (path_equal(&vma->vm_file->f_path,
1864				       &exe_file->f_path))
1865				goto exit_err;
1866		}
1867
1868		up_read(&mm->mmap_sem);
1869		fput(exe_file);
1870	}
1871
1872	err = 0;
1873	/* set the new file, lockless */
1874	get_file(exe.file);
1875	old_exe = xchg(&mm->exe_file, exe.file);
1876	if (old_exe)
1877		fput(old_exe);
1878exit:
1879	fdput(exe);
1880	return err;
1881exit_err:
1882	up_read(&mm->mmap_sem);
1883	fput(exe_file);
1884	goto exit;
1885}
1886
1887/*
 
 
1888 * WARNING: we don't require any capability here so be very careful
1889 * in what is allowed for modification from userspace.
1890 */
1891static int validate_prctl_map(struct prctl_mm_map *prctl_map)
1892{
1893	unsigned long mmap_max_addr = TASK_SIZE;
1894	struct mm_struct *mm = current->mm;
1895	int error = -EINVAL, i;
1896
1897	static const unsigned char offsets[] = {
1898		offsetof(struct prctl_mm_map, start_code),
1899		offsetof(struct prctl_mm_map, end_code),
1900		offsetof(struct prctl_mm_map, start_data),
1901		offsetof(struct prctl_mm_map, end_data),
1902		offsetof(struct prctl_mm_map, start_brk),
1903		offsetof(struct prctl_mm_map, brk),
1904		offsetof(struct prctl_mm_map, start_stack),
1905		offsetof(struct prctl_mm_map, arg_start),
1906		offsetof(struct prctl_mm_map, arg_end),
1907		offsetof(struct prctl_mm_map, env_start),
1908		offsetof(struct prctl_mm_map, env_end),
1909	};
1910
1911	/*
1912	 * Make sure the members are not somewhere outside
1913	 * of allowed address space.
1914	 */
1915	for (i = 0; i < ARRAY_SIZE(offsets); i++) {
1916		u64 val = *(u64 *)((char *)prctl_map + offsets[i]);
1917
1918		if ((unsigned long)val >= mmap_max_addr ||
1919		    (unsigned long)val < mmap_min_addr)
1920			goto out;
1921	}
1922
1923	/*
1924	 * Make sure the pairs are ordered.
1925	 */
1926#define __prctl_check_order(__m1, __op, __m2)				\
1927	((unsigned long)prctl_map->__m1 __op				\
1928	 (unsigned long)prctl_map->__m2) ? 0 : -EINVAL
1929	error  = __prctl_check_order(start_code, <, end_code);
1930	error |= __prctl_check_order(start_data, <, end_data);
1931	error |= __prctl_check_order(start_brk, <=, brk);
1932	error |= __prctl_check_order(arg_start, <=, arg_end);
1933	error |= __prctl_check_order(env_start, <=, env_end);
1934	if (error)
1935		goto out;
1936#undef __prctl_check_order
1937
1938	error = -EINVAL;
1939
1940	/*
1941	 * @brk should be after @end_data in traditional maps.
1942	 */
1943	if (prctl_map->start_brk <= prctl_map->end_data ||
1944	    prctl_map->brk <= prctl_map->end_data)
1945		goto out;
1946
1947	/*
1948	 * Neither we should allow to override limits if they set.
1949	 */
1950	if (check_data_rlimit(rlimit(RLIMIT_DATA), prctl_map->brk,
1951			      prctl_map->start_brk, prctl_map->end_data,
1952			      prctl_map->start_data))
1953			goto out;
1954
1955	/*
1956	 * Someone is trying to cheat the auxv vector.
1957	 */
1958	if (prctl_map->auxv_size) {
1959		if (!prctl_map->auxv || prctl_map->auxv_size > sizeof(mm->saved_auxv))
1960			goto out;
1961	}
1962
1963	/*
1964	 * Finally, make sure the caller has the rights to
1965	 * change /proc/pid/exe link: only local sys admin should
1966	 * be allowed to.
1967	 */
1968	if (prctl_map->exe_fd != (u32)-1) {
1969		if (!ns_capable(current_user_ns(), CAP_SYS_ADMIN))
1970			goto out;
1971	}
1972
1973	error = 0;
1974out:
1975	return error;
1976}
1977
1978#ifdef CONFIG_CHECKPOINT_RESTORE
1979static int prctl_set_mm_map(int opt, const void __user *addr, unsigned long data_size)
1980{
1981	struct prctl_mm_map prctl_map = { .exe_fd = (u32)-1, };
1982	unsigned long user_auxv[AT_VECTOR_SIZE];
1983	struct mm_struct *mm = current->mm;
1984	int error;
1985
1986	BUILD_BUG_ON(sizeof(user_auxv) != sizeof(mm->saved_auxv));
1987	BUILD_BUG_ON(sizeof(struct prctl_mm_map) > 256);
1988
1989	if (opt == PR_SET_MM_MAP_SIZE)
1990		return put_user((unsigned int)sizeof(prctl_map),
1991				(unsigned int __user *)addr);
1992
1993	if (data_size != sizeof(prctl_map))
1994		return -EINVAL;
1995
1996	if (copy_from_user(&prctl_map, addr, sizeof(prctl_map)))
1997		return -EFAULT;
1998
1999	error = validate_prctl_map(&prctl_map);
2000	if (error)
2001		return error;
2002
2003	if (prctl_map.auxv_size) {
 
 
 
 
 
 
 
2004		memset(user_auxv, 0, sizeof(user_auxv));
2005		if (copy_from_user(user_auxv,
2006				   (const void __user *)prctl_map.auxv,
2007				   prctl_map.auxv_size))
2008			return -EFAULT;
2009
2010		/* Last entry must be AT_NULL as specification requires */
2011		user_auxv[AT_VECTOR_SIZE - 2] = AT_NULL;
2012		user_auxv[AT_VECTOR_SIZE - 1] = AT_NULL;
2013	}
2014
2015	if (prctl_map.exe_fd != (u32)-1) {
 
 
 
 
 
 
 
 
 
 
 
2016		error = prctl_set_mm_exe_file(mm, prctl_map.exe_fd);
2017		if (error)
2018			return error;
2019	}
2020
2021	down_write(&mm->mmap_sem);
 
 
 
 
2022
2023	/*
2024	 * We don't validate if these members are pointing to
2025	 * real present VMAs because application may have correspond
2026	 * VMAs already unmapped and kernel uses these members for statistics
2027	 * output in procfs mostly, except
2028	 *
2029	 *  - @start_brk/@brk which are used in do_brk but kernel lookups
2030	 *    for VMAs when updating these memvers so anything wrong written
2031	 *    here cause kernel to swear at userspace program but won't lead
2032	 *    to any problem in kernel itself
2033	 */
2034
 
2035	mm->start_code	= prctl_map.start_code;
2036	mm->end_code	= prctl_map.end_code;
2037	mm->start_data	= prctl_map.start_data;
2038	mm->end_data	= prctl_map.end_data;
2039	mm->start_brk	= prctl_map.start_brk;
2040	mm->brk		= prctl_map.brk;
2041	mm->start_stack	= prctl_map.start_stack;
2042	mm->arg_start	= prctl_map.arg_start;
2043	mm->arg_end	= prctl_map.arg_end;
2044	mm->env_start	= prctl_map.env_start;
2045	mm->env_end	= prctl_map.env_end;
 
2046
2047	/*
2048	 * Note this update of @saved_auxv is lockless thus
2049	 * if someone reads this member in procfs while we're
2050	 * updating -- it may get partly updated results. It's
2051	 * known and acceptable trade off: we leave it as is to
2052	 * not introduce additional locks here making the kernel
2053	 * more complex.
2054	 */
2055	if (prctl_map.auxv_size)
2056		memcpy(mm->saved_auxv, user_auxv, sizeof(user_auxv));
2057
2058	up_write(&mm->mmap_sem);
2059	return 0;
2060}
2061#endif /* CONFIG_CHECKPOINT_RESTORE */
2062
2063static int prctl_set_auxv(struct mm_struct *mm, unsigned long addr,
2064			  unsigned long len)
2065{
2066	/*
2067	 * This doesn't move the auxiliary vector itself since it's pinned to
2068	 * mm_struct, but it permits filling the vector with new values.  It's
2069	 * up to the caller to provide sane values here, otherwise userspace
2070	 * tools which use this vector might be unhappy.
2071	 */
2072	unsigned long user_auxv[AT_VECTOR_SIZE];
2073
2074	if (len > sizeof(user_auxv))
2075		return -EINVAL;
2076
2077	if (copy_from_user(user_auxv, (const void __user *)addr, len))
2078		return -EFAULT;
2079
2080	/* Make sure the last entry is always AT_NULL */
2081	user_auxv[AT_VECTOR_SIZE - 2] = 0;
2082	user_auxv[AT_VECTOR_SIZE - 1] = 0;
2083
2084	BUILD_BUG_ON(sizeof(user_auxv) != sizeof(mm->saved_auxv));
2085
2086	task_lock(current);
2087	memcpy(mm->saved_auxv, user_auxv, len);
2088	task_unlock(current);
2089
2090	return 0;
2091}
2092
2093static int prctl_set_mm(int opt, unsigned long addr,
2094			unsigned long arg4, unsigned long arg5)
2095{
2096	struct mm_struct *mm = current->mm;
2097	struct prctl_mm_map prctl_map;
 
 
 
 
2098	struct vm_area_struct *vma;
2099	int error;
2100
2101	if (arg5 || (arg4 && (opt != PR_SET_MM_AUXV &&
2102			      opt != PR_SET_MM_MAP &&
2103			      opt != PR_SET_MM_MAP_SIZE)))
2104		return -EINVAL;
2105
2106#ifdef CONFIG_CHECKPOINT_RESTORE
2107	if (opt == PR_SET_MM_MAP || opt == PR_SET_MM_MAP_SIZE)
2108		return prctl_set_mm_map(opt, (const void __user *)addr, arg4);
2109#endif
2110
2111	if (!capable(CAP_SYS_RESOURCE))
2112		return -EPERM;
2113
2114	if (opt == PR_SET_MM_EXE_FILE)
2115		return prctl_set_mm_exe_file(mm, (unsigned int)addr);
2116
2117	if (opt == PR_SET_MM_AUXV)
2118		return prctl_set_auxv(mm, addr, arg4);
2119
2120	if (addr >= TASK_SIZE || addr < mmap_min_addr)
2121		return -EINVAL;
2122
2123	error = -EINVAL;
2124
2125	down_write(&mm->mmap_sem);
 
 
 
 
 
2126	vma = find_vma(mm, addr);
2127
 
2128	prctl_map.start_code	= mm->start_code;
2129	prctl_map.end_code	= mm->end_code;
2130	prctl_map.start_data	= mm->start_data;
2131	prctl_map.end_data	= mm->end_data;
2132	prctl_map.start_brk	= mm->start_brk;
2133	prctl_map.brk		= mm->brk;
2134	prctl_map.start_stack	= mm->start_stack;
2135	prctl_map.arg_start	= mm->arg_start;
2136	prctl_map.arg_end	= mm->arg_end;
2137	prctl_map.env_start	= mm->env_start;
2138	prctl_map.env_end	= mm->env_end;
2139	prctl_map.auxv		= NULL;
2140	prctl_map.auxv_size	= 0;
2141	prctl_map.exe_fd	= -1;
2142
2143	switch (opt) {
2144	case PR_SET_MM_START_CODE:
2145		prctl_map.start_code = addr;
2146		break;
2147	case PR_SET_MM_END_CODE:
2148		prctl_map.end_code = addr;
2149		break;
2150	case PR_SET_MM_START_DATA:
2151		prctl_map.start_data = addr;
2152		break;
2153	case PR_SET_MM_END_DATA:
2154		prctl_map.end_data = addr;
2155		break;
2156	case PR_SET_MM_START_STACK:
2157		prctl_map.start_stack = addr;
2158		break;
2159	case PR_SET_MM_START_BRK:
2160		prctl_map.start_brk = addr;
2161		break;
2162	case PR_SET_MM_BRK:
2163		prctl_map.brk = addr;
2164		break;
2165	case PR_SET_MM_ARG_START:
2166		prctl_map.arg_start = addr;
2167		break;
2168	case PR_SET_MM_ARG_END:
2169		prctl_map.arg_end = addr;
2170		break;
2171	case PR_SET_MM_ENV_START:
2172		prctl_map.env_start = addr;
2173		break;
2174	case PR_SET_MM_ENV_END:
2175		prctl_map.env_end = addr;
2176		break;
2177	default:
2178		goto out;
2179	}
2180
2181	error = validate_prctl_map(&prctl_map);
2182	if (error)
2183		goto out;
2184
2185	switch (opt) {
2186	/*
2187	 * If command line arguments and environment
2188	 * are placed somewhere else on stack, we can
2189	 * set them up here, ARG_START/END to setup
2190	 * command line argumets and ENV_START/END
2191	 * for environment.
2192	 */
2193	case PR_SET_MM_START_STACK:
2194	case PR_SET_MM_ARG_START:
2195	case PR_SET_MM_ARG_END:
2196	case PR_SET_MM_ENV_START:
2197	case PR_SET_MM_ENV_END:
2198		if (!vma) {
2199			error = -EFAULT;
2200			goto out;
2201		}
2202	}
2203
2204	mm->start_code	= prctl_map.start_code;
2205	mm->end_code	= prctl_map.end_code;
2206	mm->start_data	= prctl_map.start_data;
2207	mm->end_data	= prctl_map.end_data;
2208	mm->start_brk	= prctl_map.start_brk;
2209	mm->brk		= prctl_map.brk;
2210	mm->start_stack	= prctl_map.start_stack;
2211	mm->arg_start	= prctl_map.arg_start;
2212	mm->arg_end	= prctl_map.arg_end;
2213	mm->env_start	= prctl_map.env_start;
2214	mm->env_end	= prctl_map.env_end;
2215
2216	error = 0;
2217out:
2218	up_write(&mm->mmap_sem);
 
2219	return error;
2220}
2221
2222#ifdef CONFIG_CHECKPOINT_RESTORE
2223static int prctl_get_tid_address(struct task_struct *me, int __user **tid_addr)
2224{
2225	return put_user(me->clear_child_tid, tid_addr);
2226}
2227#else
2228static int prctl_get_tid_address(struct task_struct *me, int __user **tid_addr)
2229{
2230	return -EINVAL;
2231}
2232#endif
2233
2234static int propagate_has_child_subreaper(struct task_struct *p, void *data)
2235{
2236	/*
2237	 * If task has has_child_subreaper - all its decendants
2238	 * already have these flag too and new decendants will
2239	 * inherit it on fork, skip them.
2240	 *
2241	 * If we've found child_reaper - skip descendants in
2242	 * it's subtree as they will never get out pidns.
2243	 */
2244	if (p->signal->has_child_subreaper ||
2245	    is_child_reaper(task_pid(p)))
2246		return 0;
2247
2248	p->signal->has_child_subreaper = 1;
2249	return 1;
2250}
2251
2252int __weak arch_prctl_spec_ctrl_get(struct task_struct *t, unsigned long which)
2253{
2254	return -EINVAL;
2255}
2256
2257int __weak arch_prctl_spec_ctrl_set(struct task_struct *t, unsigned long which,
2258				    unsigned long ctrl)
2259{
2260	return -EINVAL;
2261}
2262
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
2263SYSCALL_DEFINE5(prctl, int, option, unsigned long, arg2, unsigned long, arg3,
2264		unsigned long, arg4, unsigned long, arg5)
2265{
2266	struct task_struct *me = current;
2267	unsigned char comm[sizeof(me->comm)];
2268	long error;
2269
2270	error = security_task_prctl(option, arg2, arg3, arg4, arg5);
2271	if (error != -ENOSYS)
2272		return error;
2273
2274	error = 0;
2275	switch (option) {
2276	case PR_SET_PDEATHSIG:
2277		if (!valid_signal(arg2)) {
2278			error = -EINVAL;
2279			break;
2280		}
2281		me->pdeath_signal = arg2;
2282		break;
2283	case PR_GET_PDEATHSIG:
2284		error = put_user(me->pdeath_signal, (int __user *)arg2);
2285		break;
2286	case PR_GET_DUMPABLE:
2287		error = get_dumpable(me->mm);
2288		break;
2289	case PR_SET_DUMPABLE:
2290		if (arg2 != SUID_DUMP_DISABLE && arg2 != SUID_DUMP_USER) {
2291			error = -EINVAL;
2292			break;
2293		}
2294		set_dumpable(me->mm, arg2);
2295		break;
2296
2297	case PR_SET_UNALIGN:
2298		error = SET_UNALIGN_CTL(me, arg2);
2299		break;
2300	case PR_GET_UNALIGN:
2301		error = GET_UNALIGN_CTL(me, arg2);
2302		break;
2303	case PR_SET_FPEMU:
2304		error = SET_FPEMU_CTL(me, arg2);
2305		break;
2306	case PR_GET_FPEMU:
2307		error = GET_FPEMU_CTL(me, arg2);
2308		break;
2309	case PR_SET_FPEXC:
2310		error = SET_FPEXC_CTL(me, arg2);
2311		break;
2312	case PR_GET_FPEXC:
2313		error = GET_FPEXC_CTL(me, arg2);
2314		break;
2315	case PR_GET_TIMING:
2316		error = PR_TIMING_STATISTICAL;
2317		break;
2318	case PR_SET_TIMING:
2319		if (arg2 != PR_TIMING_STATISTICAL)
2320			error = -EINVAL;
2321		break;
2322	case PR_SET_NAME:
2323		comm[sizeof(me->comm) - 1] = 0;
2324		if (strncpy_from_user(comm, (char __user *)arg2,
2325				      sizeof(me->comm) - 1) < 0)
2326			return -EFAULT;
2327		set_task_comm(me, comm);
2328		proc_comm_connector(me);
2329		break;
2330	case PR_GET_NAME:
2331		get_task_comm(comm, me);
2332		if (copy_to_user((char __user *)arg2, comm, sizeof(comm)))
2333			return -EFAULT;
2334		break;
2335	case PR_GET_ENDIAN:
2336		error = GET_ENDIAN(me, arg2);
2337		break;
2338	case PR_SET_ENDIAN:
2339		error = SET_ENDIAN(me, arg2);
2340		break;
2341	case PR_GET_SECCOMP:
2342		error = prctl_get_seccomp();
2343		break;
2344	case PR_SET_SECCOMP:
2345		error = prctl_set_seccomp(arg2, (char __user *)arg3);
2346		break;
2347	case PR_GET_TSC:
2348		error = GET_TSC_CTL(arg2);
2349		break;
2350	case PR_SET_TSC:
2351		error = SET_TSC_CTL(arg2);
2352		break;
2353	case PR_TASK_PERF_EVENTS_DISABLE:
2354		error = perf_event_task_disable();
2355		break;
2356	case PR_TASK_PERF_EVENTS_ENABLE:
2357		error = perf_event_task_enable();
2358		break;
2359	case PR_GET_TIMERSLACK:
2360		if (current->timer_slack_ns > ULONG_MAX)
2361			error = ULONG_MAX;
2362		else
2363			error = current->timer_slack_ns;
2364		break;
2365	case PR_SET_TIMERSLACK:
2366		if (arg2 <= 0)
2367			current->timer_slack_ns =
2368					current->default_timer_slack_ns;
2369		else
2370			current->timer_slack_ns = arg2;
2371		break;
2372	case PR_MCE_KILL:
2373		if (arg4 | arg5)
2374			return -EINVAL;
2375		switch (arg2) {
2376		case PR_MCE_KILL_CLEAR:
2377			if (arg3 != 0)
2378				return -EINVAL;
2379			current->flags &= ~PF_MCE_PROCESS;
2380			break;
2381		case PR_MCE_KILL_SET:
2382			current->flags |= PF_MCE_PROCESS;
2383			if (arg3 == PR_MCE_KILL_EARLY)
2384				current->flags |= PF_MCE_EARLY;
2385			else if (arg3 == PR_MCE_KILL_LATE)
2386				current->flags &= ~PF_MCE_EARLY;
2387			else if (arg3 == PR_MCE_KILL_DEFAULT)
2388				current->flags &=
2389						~(PF_MCE_EARLY|PF_MCE_PROCESS);
2390			else
2391				return -EINVAL;
2392			break;
2393		default:
2394			return -EINVAL;
2395		}
2396		break;
2397	case PR_MCE_KILL_GET:
2398		if (arg2 | arg3 | arg4 | arg5)
2399			return -EINVAL;
2400		if (current->flags & PF_MCE_PROCESS)
2401			error = (current->flags & PF_MCE_EARLY) ?
2402				PR_MCE_KILL_EARLY : PR_MCE_KILL_LATE;
2403		else
2404			error = PR_MCE_KILL_DEFAULT;
2405		break;
2406	case PR_SET_MM:
2407		error = prctl_set_mm(arg2, arg3, arg4, arg5);
2408		break;
2409	case PR_GET_TID_ADDRESS:
2410		error = prctl_get_tid_address(me, (int __user **)arg2);
2411		break;
2412	case PR_SET_CHILD_SUBREAPER:
2413		me->signal->is_child_subreaper = !!arg2;
2414		if (!arg2)
2415			break;
2416
2417		walk_process_tree(me, propagate_has_child_subreaper, NULL);
2418		break;
2419	case PR_GET_CHILD_SUBREAPER:
2420		error = put_user(me->signal->is_child_subreaper,
2421				 (int __user *)arg2);
2422		break;
2423	case PR_SET_NO_NEW_PRIVS:
2424		if (arg2 != 1 || arg3 || arg4 || arg5)
2425			return -EINVAL;
2426
2427		task_set_no_new_privs(current);
2428		break;
2429	case PR_GET_NO_NEW_PRIVS:
2430		if (arg2 || arg3 || arg4 || arg5)
2431			return -EINVAL;
2432		return task_no_new_privs(current) ? 1 : 0;
2433	case PR_GET_THP_DISABLE:
2434		if (arg2 || arg3 || arg4 || arg5)
2435			return -EINVAL;
2436		error = !!test_bit(MMF_DISABLE_THP, &me->mm->flags);
2437		break;
2438	case PR_SET_THP_DISABLE:
2439		if (arg3 || arg4 || arg5)
2440			return -EINVAL;
2441		if (down_write_killable(&me->mm->mmap_sem))
2442			return -EINTR;
2443		if (arg2)
2444			set_bit(MMF_DISABLE_THP, &me->mm->flags);
2445		else
2446			clear_bit(MMF_DISABLE_THP, &me->mm->flags);
2447		up_write(&me->mm->mmap_sem);
2448		break;
2449	case PR_MPX_ENABLE_MANAGEMENT:
2450		if (arg2 || arg3 || arg4 || arg5)
2451			return -EINVAL;
2452		error = MPX_ENABLE_MANAGEMENT();
2453		break;
2454	case PR_MPX_DISABLE_MANAGEMENT:
2455		if (arg2 || arg3 || arg4 || arg5)
2456			return -EINVAL;
2457		error = MPX_DISABLE_MANAGEMENT();
2458		break;
2459	case PR_SET_FP_MODE:
2460		error = SET_FP_MODE(me, arg2);
2461		break;
2462	case PR_GET_FP_MODE:
2463		error = GET_FP_MODE(me);
2464		break;
2465	case PR_SVE_SET_VL:
2466		error = SVE_SET_VL(arg2);
2467		break;
2468	case PR_SVE_GET_VL:
2469		error = SVE_GET_VL();
2470		break;
 
 
 
 
 
 
2471	case PR_GET_SPECULATION_CTRL:
2472		if (arg3 || arg4 || arg5)
2473			return -EINVAL;
2474		error = arch_prctl_spec_ctrl_get(me, arg2);
2475		break;
2476	case PR_SET_SPECULATION_CTRL:
2477		if (arg4 || arg5)
2478			return -EINVAL;
2479		error = arch_prctl_spec_ctrl_set(me, arg2, arg3);
2480		break;
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
2481	default:
2482		error = -EINVAL;
2483		break;
2484	}
2485	return error;
2486}
2487
2488SYSCALL_DEFINE3(getcpu, unsigned __user *, cpup, unsigned __user *, nodep,
2489		struct getcpu_cache __user *, unused)
2490{
2491	int err = 0;
2492	int cpu = raw_smp_processor_id();
2493
2494	if (cpup)
2495		err |= put_user(cpu, cpup);
2496	if (nodep)
2497		err |= put_user(cpu_to_node(cpu), nodep);
2498	return err ? -EFAULT : 0;
2499}
2500
2501/**
2502 * do_sysinfo - fill in sysinfo struct
2503 * @info: pointer to buffer to fill
2504 */
2505static int do_sysinfo(struct sysinfo *info)
2506{
2507	unsigned long mem_total, sav_total;
2508	unsigned int mem_unit, bitcount;
2509	struct timespec tp;
2510
2511	memset(info, 0, sizeof(struct sysinfo));
2512
2513	get_monotonic_boottime(&tp);
 
2514	info->uptime = tp.tv_sec + (tp.tv_nsec ? 1 : 0);
2515
2516	get_avenrun(info->loads, 0, SI_LOAD_SHIFT - FSHIFT);
2517
2518	info->procs = nr_threads;
2519
2520	si_meminfo(info);
2521	si_swapinfo(info);
2522
2523	/*
2524	 * If the sum of all the available memory (i.e. ram + swap)
2525	 * is less than can be stored in a 32 bit unsigned long then
2526	 * we can be binary compatible with 2.2.x kernels.  If not,
2527	 * well, in that case 2.2.x was broken anyways...
2528	 *
2529	 *  -Erik Andersen <andersee@debian.org>
2530	 */
2531
2532	mem_total = info->totalram + info->totalswap;
2533	if (mem_total < info->totalram || mem_total < info->totalswap)
2534		goto out;
2535	bitcount = 0;
2536	mem_unit = info->mem_unit;
2537	while (mem_unit > 1) {
2538		bitcount++;
2539		mem_unit >>= 1;
2540		sav_total = mem_total;
2541		mem_total <<= 1;
2542		if (mem_total < sav_total)
2543			goto out;
2544	}
2545
2546	/*
2547	 * If mem_total did not overflow, multiply all memory values by
2548	 * info->mem_unit and set it to 1.  This leaves things compatible
2549	 * with 2.2.x, and also retains compatibility with earlier 2.4.x
2550	 * kernels...
2551	 */
2552
2553	info->mem_unit = 1;
2554	info->totalram <<= bitcount;
2555	info->freeram <<= bitcount;
2556	info->sharedram <<= bitcount;
2557	info->bufferram <<= bitcount;
2558	info->totalswap <<= bitcount;
2559	info->freeswap <<= bitcount;
2560	info->totalhigh <<= bitcount;
2561	info->freehigh <<= bitcount;
2562
2563out:
2564	return 0;
2565}
2566
2567SYSCALL_DEFINE1(sysinfo, struct sysinfo __user *, info)
2568{
2569	struct sysinfo val;
2570
2571	do_sysinfo(&val);
2572
2573	if (copy_to_user(info, &val, sizeof(struct sysinfo)))
2574		return -EFAULT;
2575
2576	return 0;
2577}
2578
2579#ifdef CONFIG_COMPAT
2580struct compat_sysinfo {
2581	s32 uptime;
2582	u32 loads[3];
2583	u32 totalram;
2584	u32 freeram;
2585	u32 sharedram;
2586	u32 bufferram;
2587	u32 totalswap;
2588	u32 freeswap;
2589	u16 procs;
2590	u16 pad;
2591	u32 totalhigh;
2592	u32 freehigh;
2593	u32 mem_unit;
2594	char _f[20-2*sizeof(u32)-sizeof(int)];
2595};
2596
2597COMPAT_SYSCALL_DEFINE1(sysinfo, struct compat_sysinfo __user *, info)
2598{
2599	struct sysinfo s;
 
2600
2601	do_sysinfo(&s);
2602
2603	/* Check to see if any memory value is too large for 32-bit and scale
2604	 *  down if needed
2605	 */
2606	if (upper_32_bits(s.totalram) || upper_32_bits(s.totalswap)) {
2607		int bitcount = 0;
2608
2609		while (s.mem_unit < PAGE_SIZE) {
2610			s.mem_unit <<= 1;
2611			bitcount++;
2612		}
2613
2614		s.totalram >>= bitcount;
2615		s.freeram >>= bitcount;
2616		s.sharedram >>= bitcount;
2617		s.bufferram >>= bitcount;
2618		s.totalswap >>= bitcount;
2619		s.freeswap >>= bitcount;
2620		s.totalhigh >>= bitcount;
2621		s.freehigh >>= bitcount;
2622	}
2623
2624	if (!access_ok(VERIFY_WRITE, info, sizeof(struct compat_sysinfo)) ||
2625	    __put_user(s.uptime, &info->uptime) ||
2626	    __put_user(s.loads[0], &info->loads[0]) ||
2627	    __put_user(s.loads[1], &info->loads[1]) ||
2628	    __put_user(s.loads[2], &info->loads[2]) ||
2629	    __put_user(s.totalram, &info->totalram) ||
2630	    __put_user(s.freeram, &info->freeram) ||
2631	    __put_user(s.sharedram, &info->sharedram) ||
2632	    __put_user(s.bufferram, &info->bufferram) ||
2633	    __put_user(s.totalswap, &info->totalswap) ||
2634	    __put_user(s.freeswap, &info->freeswap) ||
2635	    __put_user(s.procs, &info->procs) ||
2636	    __put_user(s.totalhigh, &info->totalhigh) ||
2637	    __put_user(s.freehigh, &info->freehigh) ||
2638	    __put_user(s.mem_unit, &info->mem_unit))
 
2639		return -EFAULT;
2640
2641	return 0;
2642}
2643#endif /* CONFIG_COMPAT */
v6.9.4
   1// SPDX-License-Identifier: GPL-2.0
   2/*
   3 *  linux/kernel/sys.c
   4 *
   5 *  Copyright (C) 1991, 1992  Linus Torvalds
   6 */
   7
   8#include <linux/export.h>
   9#include <linux/mm.h>
  10#include <linux/mm_inline.h>
  11#include <linux/utsname.h>
  12#include <linux/mman.h>
  13#include <linux/reboot.h>
  14#include <linux/prctl.h>
  15#include <linux/highuid.h>
  16#include <linux/fs.h>
  17#include <linux/kmod.h>
  18#include <linux/ksm.h>
  19#include <linux/perf_event.h>
  20#include <linux/resource.h>
  21#include <linux/kernel.h>
  22#include <linux/workqueue.h>
  23#include <linux/capability.h>
  24#include <linux/device.h>
  25#include <linux/key.h>
  26#include <linux/times.h>
  27#include <linux/posix-timers.h>
  28#include <linux/security.h>
  29#include <linux/random.h>
  30#include <linux/suspend.h>
  31#include <linux/tty.h>
  32#include <linux/signal.h>
  33#include <linux/cn_proc.h>
  34#include <linux/getcpu.h>
  35#include <linux/task_io_accounting_ops.h>
  36#include <linux/seccomp.h>
  37#include <linux/cpu.h>
  38#include <linux/personality.h>
  39#include <linux/ptrace.h>
  40#include <linux/fs_struct.h>
  41#include <linux/file.h>
  42#include <linux/mount.h>
  43#include <linux/gfp.h>
  44#include <linux/syscore_ops.h>
  45#include <linux/version.h>
  46#include <linux/ctype.h>
  47#include <linux/syscall_user_dispatch.h>
  48
  49#include <linux/compat.h>
  50#include <linux/syscalls.h>
  51#include <linux/kprobes.h>
  52#include <linux/user_namespace.h>
  53#include <linux/time_namespace.h>
  54#include <linux/binfmts.h>
  55
  56#include <linux/sched.h>
  57#include <linux/sched/autogroup.h>
  58#include <linux/sched/loadavg.h>
  59#include <linux/sched/stat.h>
  60#include <linux/sched/mm.h>
  61#include <linux/sched/coredump.h>
  62#include <linux/sched/task.h>
  63#include <linux/sched/cputime.h>
  64#include <linux/rcupdate.h>
  65#include <linux/uidgid.h>
  66#include <linux/cred.h>
  67
  68#include <linux/nospec.h>
  69
  70#include <linux/kmsg_dump.h>
  71/* Move somewhere else to avoid recompiling? */
  72#include <generated/utsrelease.h>
  73
  74#include <linux/uaccess.h>
  75#include <asm/io.h>
  76#include <asm/unistd.h>
  77
 
 
 
  78#include "uid16.h"
  79
  80#ifndef SET_UNALIGN_CTL
  81# define SET_UNALIGN_CTL(a, b)	(-EINVAL)
  82#endif
  83#ifndef GET_UNALIGN_CTL
  84# define GET_UNALIGN_CTL(a, b)	(-EINVAL)
  85#endif
  86#ifndef SET_FPEMU_CTL
  87# define SET_FPEMU_CTL(a, b)	(-EINVAL)
  88#endif
  89#ifndef GET_FPEMU_CTL
  90# define GET_FPEMU_CTL(a, b)	(-EINVAL)
  91#endif
  92#ifndef SET_FPEXC_CTL
  93# define SET_FPEXC_CTL(a, b)	(-EINVAL)
  94#endif
  95#ifndef GET_FPEXC_CTL
  96# define GET_FPEXC_CTL(a, b)	(-EINVAL)
  97#endif
  98#ifndef GET_ENDIAN
  99# define GET_ENDIAN(a, b)	(-EINVAL)
 100#endif
 101#ifndef SET_ENDIAN
 102# define SET_ENDIAN(a, b)	(-EINVAL)
 103#endif
 104#ifndef GET_TSC_CTL
 105# define GET_TSC_CTL(a)		(-EINVAL)
 106#endif
 107#ifndef SET_TSC_CTL
 108# define SET_TSC_CTL(a)		(-EINVAL)
 109#endif
 
 
 
 
 
 
 110#ifndef GET_FP_MODE
 111# define GET_FP_MODE(a)		(-EINVAL)
 112#endif
 113#ifndef SET_FP_MODE
 114# define SET_FP_MODE(a,b)	(-EINVAL)
 115#endif
 116#ifndef SVE_SET_VL
 117# define SVE_SET_VL(a)		(-EINVAL)
 118#endif
 119#ifndef SVE_GET_VL
 120# define SVE_GET_VL()		(-EINVAL)
 121#endif
 122#ifndef SME_SET_VL
 123# define SME_SET_VL(a)		(-EINVAL)
 124#endif
 125#ifndef SME_GET_VL
 126# define SME_GET_VL()		(-EINVAL)
 127#endif
 128#ifndef PAC_RESET_KEYS
 129# define PAC_RESET_KEYS(a, b)	(-EINVAL)
 130#endif
 131#ifndef PAC_SET_ENABLED_KEYS
 132# define PAC_SET_ENABLED_KEYS(a, b, c)	(-EINVAL)
 133#endif
 134#ifndef PAC_GET_ENABLED_KEYS
 135# define PAC_GET_ENABLED_KEYS(a)	(-EINVAL)
 136#endif
 137#ifndef SET_TAGGED_ADDR_CTRL
 138# define SET_TAGGED_ADDR_CTRL(a)	(-EINVAL)
 139#endif
 140#ifndef GET_TAGGED_ADDR_CTRL
 141# define GET_TAGGED_ADDR_CTRL()		(-EINVAL)
 142#endif
 143#ifndef RISCV_V_SET_CONTROL
 144# define RISCV_V_SET_CONTROL(a)		(-EINVAL)
 145#endif
 146#ifndef RISCV_V_GET_CONTROL
 147# define RISCV_V_GET_CONTROL()		(-EINVAL)
 148#endif
 149
 150/*
 151 * this is where the system-wide overflow UID and GID are defined, for
 152 * architectures that now have 32-bit UID/GID but didn't in the past
 153 */
 154
 155int overflowuid = DEFAULT_OVERFLOWUID;
 156int overflowgid = DEFAULT_OVERFLOWGID;
 157
 158EXPORT_SYMBOL(overflowuid);
 159EXPORT_SYMBOL(overflowgid);
 160
 161/*
 162 * the same as above, but for filesystems which can only store a 16-bit
 163 * UID and GID. as such, this is needed on all architectures
 164 */
 165
 166int fs_overflowuid = DEFAULT_FS_OVERFLOWUID;
 167int fs_overflowgid = DEFAULT_FS_OVERFLOWGID;
 168
 169EXPORT_SYMBOL(fs_overflowuid);
 170EXPORT_SYMBOL(fs_overflowgid);
 171
 172/*
 173 * Returns true if current's euid is same as p's uid or euid,
 174 * or has CAP_SYS_NICE to p's user_ns.
 175 *
 176 * Called with rcu_read_lock, creds are safe
 177 */
 178static bool set_one_prio_perm(struct task_struct *p)
 179{
 180	const struct cred *cred = current_cred(), *pcred = __task_cred(p);
 181
 182	if (uid_eq(pcred->uid,  cred->euid) ||
 183	    uid_eq(pcred->euid, cred->euid))
 184		return true;
 185	if (ns_capable(pcred->user_ns, CAP_SYS_NICE))
 186		return true;
 187	return false;
 188}
 189
 190/*
 191 * set the priority of a task
 192 * - the caller must hold the RCU read lock
 193 */
 194static int set_one_prio(struct task_struct *p, int niceval, int error)
 195{
 196	int no_nice;
 197
 198	if (!set_one_prio_perm(p)) {
 199		error = -EPERM;
 200		goto out;
 201	}
 202	if (niceval < task_nice(p) && !can_nice(p, niceval)) {
 203		error = -EACCES;
 204		goto out;
 205	}
 206	no_nice = security_task_setnice(p, niceval);
 207	if (no_nice) {
 208		error = no_nice;
 209		goto out;
 210	}
 211	if (error == -ESRCH)
 212		error = 0;
 213	set_user_nice(p, niceval);
 214out:
 215	return error;
 216}
 217
 218SYSCALL_DEFINE3(setpriority, int, which, int, who, int, niceval)
 219{
 220	struct task_struct *g, *p;
 221	struct user_struct *user;
 222	const struct cred *cred = current_cred();
 223	int error = -EINVAL;
 224	struct pid *pgrp;
 225	kuid_t uid;
 226
 227	if (which > PRIO_USER || which < PRIO_PROCESS)
 228		goto out;
 229
 230	/* normalize: avoid signed division (rounding problems) */
 231	error = -ESRCH;
 232	if (niceval < MIN_NICE)
 233		niceval = MIN_NICE;
 234	if (niceval > MAX_NICE)
 235		niceval = MAX_NICE;
 236
 237	rcu_read_lock();
 
 238	switch (which) {
 239	case PRIO_PROCESS:
 240		if (who)
 241			p = find_task_by_vpid(who);
 242		else
 243			p = current;
 244		if (p)
 245			error = set_one_prio(p, niceval, error);
 246		break;
 247	case PRIO_PGRP:
 248		if (who)
 249			pgrp = find_vpid(who);
 250		else
 251			pgrp = task_pgrp(current);
 252		read_lock(&tasklist_lock);
 253		do_each_pid_thread(pgrp, PIDTYPE_PGID, p) {
 254			error = set_one_prio(p, niceval, error);
 255		} while_each_pid_thread(pgrp, PIDTYPE_PGID, p);
 256		read_unlock(&tasklist_lock);
 257		break;
 258	case PRIO_USER:
 259		uid = make_kuid(cred->user_ns, who);
 260		user = cred->user;
 261		if (!who)
 262			uid = cred->uid;
 263		else if (!uid_eq(uid, cred->uid)) {
 264			user = find_user(uid);
 265			if (!user)
 266				goto out_unlock;	/* No processes for this user */
 267		}
 268		for_each_process_thread(g, p) {
 269			if (uid_eq(task_uid(p), uid) && task_pid_vnr(p))
 270				error = set_one_prio(p, niceval, error);
 271		}
 272		if (!uid_eq(uid, cred->uid))
 273			free_uid(user);		/* For find_user() */
 274		break;
 275	}
 276out_unlock:
 
 277	rcu_read_unlock();
 278out:
 279	return error;
 280}
 281
 282/*
 283 * Ugh. To avoid negative return values, "getpriority()" will
 284 * not return the normal nice-value, but a negated value that
 285 * has been offset by 20 (ie it returns 40..1 instead of -20..19)
 286 * to stay compatible.
 287 */
 288SYSCALL_DEFINE2(getpriority, int, which, int, who)
 289{
 290	struct task_struct *g, *p;
 291	struct user_struct *user;
 292	const struct cred *cred = current_cred();
 293	long niceval, retval = -ESRCH;
 294	struct pid *pgrp;
 295	kuid_t uid;
 296
 297	if (which > PRIO_USER || which < PRIO_PROCESS)
 298		return -EINVAL;
 299
 300	rcu_read_lock();
 
 301	switch (which) {
 302	case PRIO_PROCESS:
 303		if (who)
 304			p = find_task_by_vpid(who);
 305		else
 306			p = current;
 307		if (p) {
 308			niceval = nice_to_rlimit(task_nice(p));
 309			if (niceval > retval)
 310				retval = niceval;
 311		}
 312		break;
 313	case PRIO_PGRP:
 314		if (who)
 315			pgrp = find_vpid(who);
 316		else
 317			pgrp = task_pgrp(current);
 318		read_lock(&tasklist_lock);
 319		do_each_pid_thread(pgrp, PIDTYPE_PGID, p) {
 320			niceval = nice_to_rlimit(task_nice(p));
 321			if (niceval > retval)
 322				retval = niceval;
 323		} while_each_pid_thread(pgrp, PIDTYPE_PGID, p);
 324		read_unlock(&tasklist_lock);
 325		break;
 326	case PRIO_USER:
 327		uid = make_kuid(cred->user_ns, who);
 328		user = cred->user;
 329		if (!who)
 330			uid = cred->uid;
 331		else if (!uid_eq(uid, cred->uid)) {
 332			user = find_user(uid);
 333			if (!user)
 334				goto out_unlock;	/* No processes for this user */
 335		}
 336		for_each_process_thread(g, p) {
 337			if (uid_eq(task_uid(p), uid) && task_pid_vnr(p)) {
 338				niceval = nice_to_rlimit(task_nice(p));
 339				if (niceval > retval)
 340					retval = niceval;
 341			}
 342		}
 343		if (!uid_eq(uid, cred->uid))
 344			free_uid(user);		/* for find_user() */
 345		break;
 346	}
 347out_unlock:
 
 348	rcu_read_unlock();
 349
 350	return retval;
 351}
 352
 353/*
 354 * Unprivileged users may change the real gid to the effective gid
 355 * or vice versa.  (BSD-style)
 356 *
 357 * If you set the real gid at all, or set the effective gid to a value not
 358 * equal to the real gid, then the saved gid is set to the new effective gid.
 359 *
 360 * This makes it possible for a setgid program to completely drop its
 361 * privileges, which is often a useful assertion to make when you are doing
 362 * a security audit over a program.
 363 *
 364 * The general idea is that a program which uses just setregid() will be
 365 * 100% compatible with BSD.  A program which uses just setgid() will be
 366 * 100% compatible with POSIX with saved IDs.
 367 *
 368 * SMP: There are not races, the GIDs are checked only by filesystem
 369 *      operations (as far as semantic preservation is concerned).
 370 */
 371#ifdef CONFIG_MULTIUSER
 372long __sys_setregid(gid_t rgid, gid_t egid)
 373{
 374	struct user_namespace *ns = current_user_ns();
 375	const struct cred *old;
 376	struct cred *new;
 377	int retval;
 378	kgid_t krgid, kegid;
 379
 380	krgid = make_kgid(ns, rgid);
 381	kegid = make_kgid(ns, egid);
 382
 383	if ((rgid != (gid_t) -1) && !gid_valid(krgid))
 384		return -EINVAL;
 385	if ((egid != (gid_t) -1) && !gid_valid(kegid))
 386		return -EINVAL;
 387
 388	new = prepare_creds();
 389	if (!new)
 390		return -ENOMEM;
 391	old = current_cred();
 392
 393	retval = -EPERM;
 394	if (rgid != (gid_t) -1) {
 395		if (gid_eq(old->gid, krgid) ||
 396		    gid_eq(old->egid, krgid) ||
 397		    ns_capable_setid(old->user_ns, CAP_SETGID))
 398			new->gid = krgid;
 399		else
 400			goto error;
 401	}
 402	if (egid != (gid_t) -1) {
 403		if (gid_eq(old->gid, kegid) ||
 404		    gid_eq(old->egid, kegid) ||
 405		    gid_eq(old->sgid, kegid) ||
 406		    ns_capable_setid(old->user_ns, CAP_SETGID))
 407			new->egid = kegid;
 408		else
 409			goto error;
 410	}
 411
 412	if (rgid != (gid_t) -1 ||
 413	    (egid != (gid_t) -1 && !gid_eq(kegid, old->gid)))
 414		new->sgid = new->egid;
 415	new->fsgid = new->egid;
 416
 417	retval = security_task_fix_setgid(new, old, LSM_SETID_RE);
 418	if (retval < 0)
 419		goto error;
 420
 421	return commit_creds(new);
 422
 423error:
 424	abort_creds(new);
 425	return retval;
 426}
 427
 428SYSCALL_DEFINE2(setregid, gid_t, rgid, gid_t, egid)
 429{
 430	return __sys_setregid(rgid, egid);
 431}
 432
 433/*
 434 * setgid() is implemented like SysV w/ SAVED_IDS
 435 *
 436 * SMP: Same implicit races as above.
 437 */
 438long __sys_setgid(gid_t gid)
 439{
 440	struct user_namespace *ns = current_user_ns();
 441	const struct cred *old;
 442	struct cred *new;
 443	int retval;
 444	kgid_t kgid;
 445
 446	kgid = make_kgid(ns, gid);
 447	if (!gid_valid(kgid))
 448		return -EINVAL;
 449
 450	new = prepare_creds();
 451	if (!new)
 452		return -ENOMEM;
 453	old = current_cred();
 454
 455	retval = -EPERM;
 456	if (ns_capable_setid(old->user_ns, CAP_SETGID))
 457		new->gid = new->egid = new->sgid = new->fsgid = kgid;
 458	else if (gid_eq(kgid, old->gid) || gid_eq(kgid, old->sgid))
 459		new->egid = new->fsgid = kgid;
 460	else
 461		goto error;
 462
 463	retval = security_task_fix_setgid(new, old, LSM_SETID_ID);
 464	if (retval < 0)
 465		goto error;
 466
 467	return commit_creds(new);
 468
 469error:
 470	abort_creds(new);
 471	return retval;
 472}
 473
 474SYSCALL_DEFINE1(setgid, gid_t, gid)
 475{
 476	return __sys_setgid(gid);
 477}
 478
 479/*
 480 * change the user struct in a credentials set to match the new UID
 481 */
 482static int set_user(struct cred *new)
 483{
 484	struct user_struct *new_user;
 485
 486	new_user = alloc_uid(new->uid);
 487	if (!new_user)
 488		return -EAGAIN;
 489
 490	free_uid(new->user);
 491	new->user = new_user;
 492	return 0;
 493}
 494
 495static void flag_nproc_exceeded(struct cred *new)
 496{
 497	if (new->ucounts == current_ucounts())
 498		return;
 499
 500	/*
 501	 * We don't fail in case of NPROC limit excess here because too many
 502	 * poorly written programs don't check set*uid() return code, assuming
 503	 * it never fails if called by root.  We may still enforce NPROC limit
 504	 * for programs doing set*uid()+execve() by harmlessly deferring the
 505	 * failure to the execve() stage.
 506	 */
 507	if (is_rlimit_overlimit(new->ucounts, UCOUNT_RLIMIT_NPROC, rlimit(RLIMIT_NPROC)) &&
 508			new->user != INIT_USER)
 509		current->flags |= PF_NPROC_EXCEEDED;
 510	else
 511		current->flags &= ~PF_NPROC_EXCEEDED;
 
 
 
 
 512}
 513
 514/*
 515 * Unprivileged users may change the real uid to the effective uid
 516 * or vice versa.  (BSD-style)
 517 *
 518 * If you set the real uid at all, or set the effective uid to a value not
 519 * equal to the real uid, then the saved uid is set to the new effective uid.
 520 *
 521 * This makes it possible for a setuid program to completely drop its
 522 * privileges, which is often a useful assertion to make when you are doing
 523 * a security audit over a program.
 524 *
 525 * The general idea is that a program which uses just setreuid() will be
 526 * 100% compatible with BSD.  A program which uses just setuid() will be
 527 * 100% compatible with POSIX with saved IDs.
 528 */
 529long __sys_setreuid(uid_t ruid, uid_t euid)
 530{
 531	struct user_namespace *ns = current_user_ns();
 532	const struct cred *old;
 533	struct cred *new;
 534	int retval;
 535	kuid_t kruid, keuid;
 536
 537	kruid = make_kuid(ns, ruid);
 538	keuid = make_kuid(ns, euid);
 539
 540	if ((ruid != (uid_t) -1) && !uid_valid(kruid))
 541		return -EINVAL;
 542	if ((euid != (uid_t) -1) && !uid_valid(keuid))
 543		return -EINVAL;
 544
 545	new = prepare_creds();
 546	if (!new)
 547		return -ENOMEM;
 548	old = current_cred();
 549
 550	retval = -EPERM;
 551	if (ruid != (uid_t) -1) {
 552		new->uid = kruid;
 553		if (!uid_eq(old->uid, kruid) &&
 554		    !uid_eq(old->euid, kruid) &&
 555		    !ns_capable_setid(old->user_ns, CAP_SETUID))
 556			goto error;
 557	}
 558
 559	if (euid != (uid_t) -1) {
 560		new->euid = keuid;
 561		if (!uid_eq(old->uid, keuid) &&
 562		    !uid_eq(old->euid, keuid) &&
 563		    !uid_eq(old->suid, keuid) &&
 564		    !ns_capable_setid(old->user_ns, CAP_SETUID))
 565			goto error;
 566	}
 567
 568	if (!uid_eq(new->uid, old->uid)) {
 569		retval = set_user(new);
 570		if (retval < 0)
 571			goto error;
 572	}
 573	if (ruid != (uid_t) -1 ||
 574	    (euid != (uid_t) -1 && !uid_eq(keuid, old->uid)))
 575		new->suid = new->euid;
 576	new->fsuid = new->euid;
 577
 578	retval = security_task_fix_setuid(new, old, LSM_SETID_RE);
 579	if (retval < 0)
 580		goto error;
 581
 582	retval = set_cred_ucounts(new);
 583	if (retval < 0)
 584		goto error;
 585
 586	flag_nproc_exceeded(new);
 587	return commit_creds(new);
 588
 589error:
 590	abort_creds(new);
 591	return retval;
 592}
 593
 594SYSCALL_DEFINE2(setreuid, uid_t, ruid, uid_t, euid)
 595{
 596	return __sys_setreuid(ruid, euid);
 597}
 598
 599/*
 600 * setuid() is implemented like SysV with SAVED_IDS
 601 *
 602 * Note that SAVED_ID's is deficient in that a setuid root program
 603 * like sendmail, for example, cannot set its uid to be a normal
 604 * user and then switch back, because if you're root, setuid() sets
 605 * the saved uid too.  If you don't like this, blame the bright people
 606 * in the POSIX committee and/or USG.  Note that the BSD-style setreuid()
 607 * will allow a root program to temporarily drop privileges and be able to
 608 * regain them by swapping the real and effective uid.
 609 */
 610long __sys_setuid(uid_t uid)
 611{
 612	struct user_namespace *ns = current_user_ns();
 613	const struct cred *old;
 614	struct cred *new;
 615	int retval;
 616	kuid_t kuid;
 617
 618	kuid = make_kuid(ns, uid);
 619	if (!uid_valid(kuid))
 620		return -EINVAL;
 621
 622	new = prepare_creds();
 623	if (!new)
 624		return -ENOMEM;
 625	old = current_cred();
 626
 627	retval = -EPERM;
 628	if (ns_capable_setid(old->user_ns, CAP_SETUID)) {
 629		new->suid = new->uid = kuid;
 630		if (!uid_eq(kuid, old->uid)) {
 631			retval = set_user(new);
 632			if (retval < 0)
 633				goto error;
 634		}
 635	} else if (!uid_eq(kuid, old->uid) && !uid_eq(kuid, new->suid)) {
 636		goto error;
 637	}
 638
 639	new->fsuid = new->euid = kuid;
 640
 641	retval = security_task_fix_setuid(new, old, LSM_SETID_ID);
 642	if (retval < 0)
 643		goto error;
 644
 645	retval = set_cred_ucounts(new);
 646	if (retval < 0)
 647		goto error;
 648
 649	flag_nproc_exceeded(new);
 650	return commit_creds(new);
 651
 652error:
 653	abort_creds(new);
 654	return retval;
 655}
 656
 657SYSCALL_DEFINE1(setuid, uid_t, uid)
 658{
 659	return __sys_setuid(uid);
 660}
 661
 662
 663/*
 664 * This function implements a generic ability to update ruid, euid,
 665 * and suid.  This allows you to implement the 4.4 compatible seteuid().
 666 */
 667long __sys_setresuid(uid_t ruid, uid_t euid, uid_t suid)
 668{
 669	struct user_namespace *ns = current_user_ns();
 670	const struct cred *old;
 671	struct cred *new;
 672	int retval;
 673	kuid_t kruid, keuid, ksuid;
 674	bool ruid_new, euid_new, suid_new;
 675
 676	kruid = make_kuid(ns, ruid);
 677	keuid = make_kuid(ns, euid);
 678	ksuid = make_kuid(ns, suid);
 679
 680	if ((ruid != (uid_t) -1) && !uid_valid(kruid))
 681		return -EINVAL;
 682
 683	if ((euid != (uid_t) -1) && !uid_valid(keuid))
 684		return -EINVAL;
 685
 686	if ((suid != (uid_t) -1) && !uid_valid(ksuid))
 687		return -EINVAL;
 688
 689	old = current_cred();
 690
 691	/* check for no-op */
 692	if ((ruid == (uid_t) -1 || uid_eq(kruid, old->uid)) &&
 693	    (euid == (uid_t) -1 || (uid_eq(keuid, old->euid) &&
 694				    uid_eq(keuid, old->fsuid))) &&
 695	    (suid == (uid_t) -1 || uid_eq(ksuid, old->suid)))
 696		return 0;
 697
 698	ruid_new = ruid != (uid_t) -1        && !uid_eq(kruid, old->uid) &&
 699		   !uid_eq(kruid, old->euid) && !uid_eq(kruid, old->suid);
 700	euid_new = euid != (uid_t) -1        && !uid_eq(keuid, old->uid) &&
 701		   !uid_eq(keuid, old->euid) && !uid_eq(keuid, old->suid);
 702	suid_new = suid != (uid_t) -1        && !uid_eq(ksuid, old->uid) &&
 703		   !uid_eq(ksuid, old->euid) && !uid_eq(ksuid, old->suid);
 704	if ((ruid_new || euid_new || suid_new) &&
 705	    !ns_capable_setid(old->user_ns, CAP_SETUID))
 706		return -EPERM;
 707
 708	new = prepare_creds();
 709	if (!new)
 710		return -ENOMEM;
 711
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 712	if (ruid != (uid_t) -1) {
 713		new->uid = kruid;
 714		if (!uid_eq(kruid, old->uid)) {
 715			retval = set_user(new);
 716			if (retval < 0)
 717				goto error;
 718		}
 719	}
 720	if (euid != (uid_t) -1)
 721		new->euid = keuid;
 722	if (suid != (uid_t) -1)
 723		new->suid = ksuid;
 724	new->fsuid = new->euid;
 725
 726	retval = security_task_fix_setuid(new, old, LSM_SETID_RES);
 727	if (retval < 0)
 728		goto error;
 729
 730	retval = set_cred_ucounts(new);
 731	if (retval < 0)
 732		goto error;
 733
 734	flag_nproc_exceeded(new);
 735	return commit_creds(new);
 736
 737error:
 738	abort_creds(new);
 739	return retval;
 740}
 741
 742SYSCALL_DEFINE3(setresuid, uid_t, ruid, uid_t, euid, uid_t, suid)
 743{
 744	return __sys_setresuid(ruid, euid, suid);
 745}
 746
 747SYSCALL_DEFINE3(getresuid, uid_t __user *, ruidp, uid_t __user *, euidp, uid_t __user *, suidp)
 748{
 749	const struct cred *cred = current_cred();
 750	int retval;
 751	uid_t ruid, euid, suid;
 752
 753	ruid = from_kuid_munged(cred->user_ns, cred->uid);
 754	euid = from_kuid_munged(cred->user_ns, cred->euid);
 755	suid = from_kuid_munged(cred->user_ns, cred->suid);
 756
 757	retval = put_user(ruid, ruidp);
 758	if (!retval) {
 759		retval = put_user(euid, euidp);
 760		if (!retval)
 761			return put_user(suid, suidp);
 762	}
 763	return retval;
 764}
 765
 766/*
 767 * Same as above, but for rgid, egid, sgid.
 768 */
 769long __sys_setresgid(gid_t rgid, gid_t egid, gid_t sgid)
 770{
 771	struct user_namespace *ns = current_user_ns();
 772	const struct cred *old;
 773	struct cred *new;
 774	int retval;
 775	kgid_t krgid, kegid, ksgid;
 776	bool rgid_new, egid_new, sgid_new;
 777
 778	krgid = make_kgid(ns, rgid);
 779	kegid = make_kgid(ns, egid);
 780	ksgid = make_kgid(ns, sgid);
 781
 782	if ((rgid != (gid_t) -1) && !gid_valid(krgid))
 783		return -EINVAL;
 784	if ((egid != (gid_t) -1) && !gid_valid(kegid))
 785		return -EINVAL;
 786	if ((sgid != (gid_t) -1) && !gid_valid(ksgid))
 787		return -EINVAL;
 788
 789	old = current_cred();
 790
 791	/* check for no-op */
 792	if ((rgid == (gid_t) -1 || gid_eq(krgid, old->gid)) &&
 793	    (egid == (gid_t) -1 || (gid_eq(kegid, old->egid) &&
 794				    gid_eq(kegid, old->fsgid))) &&
 795	    (sgid == (gid_t) -1 || gid_eq(ksgid, old->sgid)))
 796		return 0;
 797
 798	rgid_new = rgid != (gid_t) -1        && !gid_eq(krgid, old->gid) &&
 799		   !gid_eq(krgid, old->egid) && !gid_eq(krgid, old->sgid);
 800	egid_new = egid != (gid_t) -1        && !gid_eq(kegid, old->gid) &&
 801		   !gid_eq(kegid, old->egid) && !gid_eq(kegid, old->sgid);
 802	sgid_new = sgid != (gid_t) -1        && !gid_eq(ksgid, old->gid) &&
 803		   !gid_eq(ksgid, old->egid) && !gid_eq(ksgid, old->sgid);
 804	if ((rgid_new || egid_new || sgid_new) &&
 805	    !ns_capable_setid(old->user_ns, CAP_SETGID))
 806		return -EPERM;
 807
 808	new = prepare_creds();
 809	if (!new)
 810		return -ENOMEM;
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 811
 812	if (rgid != (gid_t) -1)
 813		new->gid = krgid;
 814	if (egid != (gid_t) -1)
 815		new->egid = kegid;
 816	if (sgid != (gid_t) -1)
 817		new->sgid = ksgid;
 818	new->fsgid = new->egid;
 819
 820	retval = security_task_fix_setgid(new, old, LSM_SETID_RES);
 821	if (retval < 0)
 822		goto error;
 823
 824	return commit_creds(new);
 825
 826error:
 827	abort_creds(new);
 828	return retval;
 829}
 830
 831SYSCALL_DEFINE3(setresgid, gid_t, rgid, gid_t, egid, gid_t, sgid)
 832{
 833	return __sys_setresgid(rgid, egid, sgid);
 834}
 835
 836SYSCALL_DEFINE3(getresgid, gid_t __user *, rgidp, gid_t __user *, egidp, gid_t __user *, sgidp)
 837{
 838	const struct cred *cred = current_cred();
 839	int retval;
 840	gid_t rgid, egid, sgid;
 841
 842	rgid = from_kgid_munged(cred->user_ns, cred->gid);
 843	egid = from_kgid_munged(cred->user_ns, cred->egid);
 844	sgid = from_kgid_munged(cred->user_ns, cred->sgid);
 845
 846	retval = put_user(rgid, rgidp);
 847	if (!retval) {
 848		retval = put_user(egid, egidp);
 849		if (!retval)
 850			retval = put_user(sgid, sgidp);
 851	}
 852
 853	return retval;
 854}
 855
 856
 857/*
 858 * "setfsuid()" sets the fsuid - the uid used for filesystem checks. This
 859 * is used for "access()" and for the NFS daemon (letting nfsd stay at
 860 * whatever uid it wants to). It normally shadows "euid", except when
 861 * explicitly set by setfsuid() or for access..
 862 */
 863long __sys_setfsuid(uid_t uid)
 864{
 865	const struct cred *old;
 866	struct cred *new;
 867	uid_t old_fsuid;
 868	kuid_t kuid;
 869
 870	old = current_cred();
 871	old_fsuid = from_kuid_munged(old->user_ns, old->fsuid);
 872
 873	kuid = make_kuid(old->user_ns, uid);
 874	if (!uid_valid(kuid))
 875		return old_fsuid;
 876
 877	new = prepare_creds();
 878	if (!new)
 879		return old_fsuid;
 880
 881	if (uid_eq(kuid, old->uid)  || uid_eq(kuid, old->euid)  ||
 882	    uid_eq(kuid, old->suid) || uid_eq(kuid, old->fsuid) ||
 883	    ns_capable_setid(old->user_ns, CAP_SETUID)) {
 884		if (!uid_eq(kuid, old->fsuid)) {
 885			new->fsuid = kuid;
 886			if (security_task_fix_setuid(new, old, LSM_SETID_FS) == 0)
 887				goto change_okay;
 888		}
 889	}
 890
 891	abort_creds(new);
 892	return old_fsuid;
 893
 894change_okay:
 895	commit_creds(new);
 896	return old_fsuid;
 897}
 898
 899SYSCALL_DEFINE1(setfsuid, uid_t, uid)
 900{
 901	return __sys_setfsuid(uid);
 902}
 903
 904/*
 905 * Samma på svenska..
 906 */
 907long __sys_setfsgid(gid_t gid)
 908{
 909	const struct cred *old;
 910	struct cred *new;
 911	gid_t old_fsgid;
 912	kgid_t kgid;
 913
 914	old = current_cred();
 915	old_fsgid = from_kgid_munged(old->user_ns, old->fsgid);
 916
 917	kgid = make_kgid(old->user_ns, gid);
 918	if (!gid_valid(kgid))
 919		return old_fsgid;
 920
 921	new = prepare_creds();
 922	if (!new)
 923		return old_fsgid;
 924
 925	if (gid_eq(kgid, old->gid)  || gid_eq(kgid, old->egid)  ||
 926	    gid_eq(kgid, old->sgid) || gid_eq(kgid, old->fsgid) ||
 927	    ns_capable_setid(old->user_ns, CAP_SETGID)) {
 928		if (!gid_eq(kgid, old->fsgid)) {
 929			new->fsgid = kgid;
 930			if (security_task_fix_setgid(new,old,LSM_SETID_FS) == 0)
 931				goto change_okay;
 932		}
 933	}
 934
 935	abort_creds(new);
 936	return old_fsgid;
 937
 938change_okay:
 939	commit_creds(new);
 940	return old_fsgid;
 941}
 942
 943SYSCALL_DEFINE1(setfsgid, gid_t, gid)
 944{
 945	return __sys_setfsgid(gid);
 946}
 947#endif /* CONFIG_MULTIUSER */
 948
 949/**
 950 * sys_getpid - return the thread group id of the current process
 951 *
 952 * Note, despite the name, this returns the tgid not the pid.  The tgid and
 953 * the pid are identical unless CLONE_THREAD was specified on clone() in
 954 * which case the tgid is the same in all threads of the same group.
 955 *
 956 * This is SMP safe as current->tgid does not change.
 957 */
 958SYSCALL_DEFINE0(getpid)
 959{
 960	return task_tgid_vnr(current);
 961}
 962
 963/* Thread ID - the internal kernel "pid" */
 964SYSCALL_DEFINE0(gettid)
 965{
 966	return task_pid_vnr(current);
 967}
 968
 969/*
 970 * Accessing ->real_parent is not SMP-safe, it could
 971 * change from under us. However, we can use a stale
 972 * value of ->real_parent under rcu_read_lock(), see
 973 * release_task()->call_rcu(delayed_put_task_struct).
 974 */
 975SYSCALL_DEFINE0(getppid)
 976{
 977	int pid;
 978
 979	rcu_read_lock();
 980	pid = task_tgid_vnr(rcu_dereference(current->real_parent));
 981	rcu_read_unlock();
 982
 983	return pid;
 984}
 985
 986SYSCALL_DEFINE0(getuid)
 987{
 988	/* Only we change this so SMP safe */
 989	return from_kuid_munged(current_user_ns(), current_uid());
 990}
 991
 992SYSCALL_DEFINE0(geteuid)
 993{
 994	/* Only we change this so SMP safe */
 995	return from_kuid_munged(current_user_ns(), current_euid());
 996}
 997
 998SYSCALL_DEFINE0(getgid)
 999{
1000	/* Only we change this so SMP safe */
1001	return from_kgid_munged(current_user_ns(), current_gid());
1002}
1003
1004SYSCALL_DEFINE0(getegid)
1005{
1006	/* Only we change this so SMP safe */
1007	return from_kgid_munged(current_user_ns(), current_egid());
1008}
1009
1010static void do_sys_times(struct tms *tms)
1011{
1012	u64 tgutime, tgstime, cutime, cstime;
1013
1014	thread_group_cputime_adjusted(current, &tgutime, &tgstime);
1015	cutime = current->signal->cutime;
1016	cstime = current->signal->cstime;
1017	tms->tms_utime = nsec_to_clock_t(tgutime);
1018	tms->tms_stime = nsec_to_clock_t(tgstime);
1019	tms->tms_cutime = nsec_to_clock_t(cutime);
1020	tms->tms_cstime = nsec_to_clock_t(cstime);
1021}
1022
1023SYSCALL_DEFINE1(times, struct tms __user *, tbuf)
1024{
1025	if (tbuf) {
1026		struct tms tmp;
1027
1028		do_sys_times(&tmp);
1029		if (copy_to_user(tbuf, &tmp, sizeof(struct tms)))
1030			return -EFAULT;
1031	}
1032	force_successful_syscall_return();
1033	return (long) jiffies_64_to_clock_t(get_jiffies_64());
1034}
1035
1036#ifdef CONFIG_COMPAT
1037static compat_clock_t clock_t_to_compat_clock_t(clock_t x)
1038{
1039	return compat_jiffies_to_clock_t(clock_t_to_jiffies(x));
1040}
1041
1042COMPAT_SYSCALL_DEFINE1(times, struct compat_tms __user *, tbuf)
1043{
1044	if (tbuf) {
1045		struct tms tms;
1046		struct compat_tms tmp;
1047
1048		do_sys_times(&tms);
1049		/* Convert our struct tms to the compat version. */
1050		tmp.tms_utime = clock_t_to_compat_clock_t(tms.tms_utime);
1051		tmp.tms_stime = clock_t_to_compat_clock_t(tms.tms_stime);
1052		tmp.tms_cutime = clock_t_to_compat_clock_t(tms.tms_cutime);
1053		tmp.tms_cstime = clock_t_to_compat_clock_t(tms.tms_cstime);
1054		if (copy_to_user(tbuf, &tmp, sizeof(tmp)))
1055			return -EFAULT;
1056	}
1057	force_successful_syscall_return();
1058	return compat_jiffies_to_clock_t(jiffies);
1059}
1060#endif
1061
1062/*
1063 * This needs some heavy checking ...
1064 * I just haven't the stomach for it. I also don't fully
1065 * understand sessions/pgrp etc. Let somebody who does explain it.
1066 *
1067 * OK, I think I have the protection semantics right.... this is really
1068 * only important on a multi-user system anyway, to make sure one user
1069 * can't send a signal to a process owned by another.  -TYT, 12/12/91
1070 *
1071 * !PF_FORKNOEXEC check to conform completely to POSIX.
1072 */
1073SYSCALL_DEFINE2(setpgid, pid_t, pid, pid_t, pgid)
1074{
1075	struct task_struct *p;
1076	struct task_struct *group_leader = current->group_leader;
1077	struct pid *pgrp;
1078	int err;
1079
1080	if (!pid)
1081		pid = task_pid_vnr(group_leader);
1082	if (!pgid)
1083		pgid = pid;
1084	if (pgid < 0)
1085		return -EINVAL;
1086	rcu_read_lock();
1087
1088	/* From this point forward we keep holding onto the tasklist lock
1089	 * so that our parent does not change from under us. -DaveM
1090	 */
1091	write_lock_irq(&tasklist_lock);
1092
1093	err = -ESRCH;
1094	p = find_task_by_vpid(pid);
1095	if (!p)
1096		goto out;
1097
1098	err = -EINVAL;
1099	if (!thread_group_leader(p))
1100		goto out;
1101
1102	if (same_thread_group(p->real_parent, group_leader)) {
1103		err = -EPERM;
1104		if (task_session(p) != task_session(group_leader))
1105			goto out;
1106		err = -EACCES;
1107		if (!(p->flags & PF_FORKNOEXEC))
1108			goto out;
1109	} else {
1110		err = -ESRCH;
1111		if (p != group_leader)
1112			goto out;
1113	}
1114
1115	err = -EPERM;
1116	if (p->signal->leader)
1117		goto out;
1118
1119	pgrp = task_pid(p);
1120	if (pgid != pid) {
1121		struct task_struct *g;
1122
1123		pgrp = find_vpid(pgid);
1124		g = pid_task(pgrp, PIDTYPE_PGID);
1125		if (!g || task_session(g) != task_session(group_leader))
1126			goto out;
1127	}
1128
1129	err = security_task_setpgid(p, pgid);
1130	if (err)
1131		goto out;
1132
1133	if (task_pgrp(p) != pgrp)
1134		change_pid(p, PIDTYPE_PGID, pgrp);
1135
1136	err = 0;
1137out:
1138	/* All paths lead to here, thus we are safe. -DaveM */
1139	write_unlock_irq(&tasklist_lock);
1140	rcu_read_unlock();
1141	return err;
1142}
1143
1144static int do_getpgid(pid_t pid)
1145{
1146	struct task_struct *p;
1147	struct pid *grp;
1148	int retval;
1149
1150	rcu_read_lock();
1151	if (!pid)
1152		grp = task_pgrp(current);
1153	else {
1154		retval = -ESRCH;
1155		p = find_task_by_vpid(pid);
1156		if (!p)
1157			goto out;
1158		grp = task_pgrp(p);
1159		if (!grp)
1160			goto out;
1161
1162		retval = security_task_getpgid(p);
1163		if (retval)
1164			goto out;
1165	}
1166	retval = pid_vnr(grp);
1167out:
1168	rcu_read_unlock();
1169	return retval;
1170}
1171
1172SYSCALL_DEFINE1(getpgid, pid_t, pid)
1173{
1174	return do_getpgid(pid);
1175}
1176
1177#ifdef __ARCH_WANT_SYS_GETPGRP
1178
1179SYSCALL_DEFINE0(getpgrp)
1180{
1181	return do_getpgid(0);
1182}
1183
1184#endif
1185
1186SYSCALL_DEFINE1(getsid, pid_t, pid)
1187{
1188	struct task_struct *p;
1189	struct pid *sid;
1190	int retval;
1191
1192	rcu_read_lock();
1193	if (!pid)
1194		sid = task_session(current);
1195	else {
1196		retval = -ESRCH;
1197		p = find_task_by_vpid(pid);
1198		if (!p)
1199			goto out;
1200		sid = task_session(p);
1201		if (!sid)
1202			goto out;
1203
1204		retval = security_task_getsid(p);
1205		if (retval)
1206			goto out;
1207	}
1208	retval = pid_vnr(sid);
1209out:
1210	rcu_read_unlock();
1211	return retval;
1212}
1213
1214static void set_special_pids(struct pid *pid)
1215{
1216	struct task_struct *curr = current->group_leader;
1217
1218	if (task_session(curr) != pid)
1219		change_pid(curr, PIDTYPE_SID, pid);
1220
1221	if (task_pgrp(curr) != pid)
1222		change_pid(curr, PIDTYPE_PGID, pid);
1223}
1224
1225int ksys_setsid(void)
1226{
1227	struct task_struct *group_leader = current->group_leader;
1228	struct pid *sid = task_pid(group_leader);
1229	pid_t session = pid_vnr(sid);
1230	int err = -EPERM;
1231
1232	write_lock_irq(&tasklist_lock);
1233	/* Fail if I am already a session leader */
1234	if (group_leader->signal->leader)
1235		goto out;
1236
1237	/* Fail if a process group id already exists that equals the
1238	 * proposed session id.
1239	 */
1240	if (pid_task(sid, PIDTYPE_PGID))
1241		goto out;
1242
1243	group_leader->signal->leader = 1;
1244	set_special_pids(sid);
1245
1246	proc_clear_tty(group_leader);
1247
1248	err = session;
1249out:
1250	write_unlock_irq(&tasklist_lock);
1251	if (err > 0) {
1252		proc_sid_connector(group_leader);
1253		sched_autogroup_create_attach(group_leader);
1254	}
1255	return err;
1256}
1257
1258SYSCALL_DEFINE0(setsid)
1259{
1260	return ksys_setsid();
1261}
1262
1263DECLARE_RWSEM(uts_sem);
1264
1265#ifdef COMPAT_UTS_MACHINE
1266#define override_architecture(name) \
1267	(personality(current->personality) == PER_LINUX32 && \
1268	 copy_to_user(name->machine, COMPAT_UTS_MACHINE, \
1269		      sizeof(COMPAT_UTS_MACHINE)))
1270#else
1271#define override_architecture(name)	0
1272#endif
1273
1274/*
1275 * Work around broken programs that cannot handle "Linux 3.0".
1276 * Instead we map 3.x to 2.6.40+x, so e.g. 3.0 would be 2.6.40
1277 * And we map 4.x and later versions to 2.6.60+x, so 4.0/5.0/6.0/... would be
1278 * 2.6.60.
1279 */
1280static int override_release(char __user *release, size_t len)
1281{
1282	int ret = 0;
1283
1284	if (current->personality & UNAME26) {
1285		const char *rest = UTS_RELEASE;
1286		char buf[65] = { 0 };
1287		int ndots = 0;
1288		unsigned v;
1289		size_t copy;
1290
1291		while (*rest) {
1292			if (*rest == '.' && ++ndots >= 3)
1293				break;
1294			if (!isdigit(*rest) && *rest != '.')
1295				break;
1296			rest++;
1297		}
1298		v = LINUX_VERSION_PATCHLEVEL + 60;
1299		copy = clamp_t(size_t, len, 1, sizeof(buf));
1300		copy = scnprintf(buf, copy, "2.6.%u%s", v, rest);
1301		ret = copy_to_user(release, buf, copy + 1);
1302	}
1303	return ret;
1304}
1305
1306SYSCALL_DEFINE1(newuname, struct new_utsname __user *, name)
1307{
1308	struct new_utsname tmp;
1309
1310	down_read(&uts_sem);
1311	memcpy(&tmp, utsname(), sizeof(tmp));
 
1312	up_read(&uts_sem);
1313	if (copy_to_user(name, &tmp, sizeof(tmp)))
1314		return -EFAULT;
1315
1316	if (override_release(name->release, sizeof(name->release)))
1317		return -EFAULT;
1318	if (override_architecture(name))
1319		return -EFAULT;
1320	return 0;
1321}
1322
1323#ifdef __ARCH_WANT_SYS_OLD_UNAME
1324/*
1325 * Old cruft
1326 */
1327SYSCALL_DEFINE1(uname, struct old_utsname __user *, name)
1328{
1329	struct old_utsname tmp;
1330
1331	if (!name)
1332		return -EFAULT;
1333
1334	down_read(&uts_sem);
1335	memcpy(&tmp, utsname(), sizeof(tmp));
 
1336	up_read(&uts_sem);
1337	if (copy_to_user(name, &tmp, sizeof(tmp)))
1338		return -EFAULT;
1339
1340	if (override_release(name->release, sizeof(name->release)))
1341		return -EFAULT;
1342	if (override_architecture(name))
1343		return -EFAULT;
1344	return 0;
1345}
1346
1347SYSCALL_DEFINE1(olduname, struct oldold_utsname __user *, name)
1348{
1349	struct oldold_utsname tmp;
1350
1351	if (!name)
1352		return -EFAULT;
1353
1354	memset(&tmp, 0, sizeof(tmp));
1355
1356	down_read(&uts_sem);
1357	memcpy(&tmp.sysname, &utsname()->sysname, __OLD_UTS_LEN);
1358	memcpy(&tmp.nodename, &utsname()->nodename, __OLD_UTS_LEN);
1359	memcpy(&tmp.release, &utsname()->release, __OLD_UTS_LEN);
1360	memcpy(&tmp.version, &utsname()->version, __OLD_UTS_LEN);
1361	memcpy(&tmp.machine, &utsname()->machine, __OLD_UTS_LEN);
 
 
 
 
 
 
 
 
 
 
1362	up_read(&uts_sem);
1363	if (copy_to_user(name, &tmp, sizeof(tmp)))
1364		return -EFAULT;
1365
1366	if (override_architecture(name))
1367		return -EFAULT;
1368	if (override_release(name->release, sizeof(name->release)))
1369		return -EFAULT;
1370	return 0;
1371}
1372#endif
1373
1374SYSCALL_DEFINE2(sethostname, char __user *, name, int, len)
1375{
1376	int errno;
1377	char tmp[__NEW_UTS_LEN];
1378
1379	if (!ns_capable(current->nsproxy->uts_ns->user_ns, CAP_SYS_ADMIN))
1380		return -EPERM;
1381
1382	if (len < 0 || len > __NEW_UTS_LEN)
1383		return -EINVAL;
 
1384	errno = -EFAULT;
1385	if (!copy_from_user(tmp, name, len)) {
1386		struct new_utsname *u;
1387
1388		add_device_randomness(tmp, len);
1389		down_write(&uts_sem);
1390		u = utsname();
1391		memcpy(u->nodename, tmp, len);
1392		memset(u->nodename + len, 0, sizeof(u->nodename) - len);
1393		errno = 0;
1394		uts_proc_notify(UTS_PROC_HOSTNAME);
1395		up_write(&uts_sem);
1396	}
 
1397	return errno;
1398}
1399
1400#ifdef __ARCH_WANT_SYS_GETHOSTNAME
1401
1402SYSCALL_DEFINE2(gethostname, char __user *, name, int, len)
1403{
1404	int i;
1405	struct new_utsname *u;
1406	char tmp[__NEW_UTS_LEN + 1];
1407
1408	if (len < 0)
1409		return -EINVAL;
1410	down_read(&uts_sem);
1411	u = utsname();
1412	i = 1 + strlen(u->nodename);
1413	if (i > len)
1414		i = len;
1415	memcpy(tmp, u->nodename, i);
 
 
1416	up_read(&uts_sem);
1417	if (copy_to_user(name, tmp, i))
1418		return -EFAULT;
1419	return 0;
1420}
1421
1422#endif
1423
1424/*
1425 * Only setdomainname; getdomainname can be implemented by calling
1426 * uname()
1427 */
1428SYSCALL_DEFINE2(setdomainname, char __user *, name, int, len)
1429{
1430	int errno;
1431	char tmp[__NEW_UTS_LEN];
1432
1433	if (!ns_capable(current->nsproxy->uts_ns->user_ns, CAP_SYS_ADMIN))
1434		return -EPERM;
1435	if (len < 0 || len > __NEW_UTS_LEN)
1436		return -EINVAL;
1437
 
1438	errno = -EFAULT;
1439	if (!copy_from_user(tmp, name, len)) {
1440		struct new_utsname *u;
1441
1442		add_device_randomness(tmp, len);
1443		down_write(&uts_sem);
1444		u = utsname();
1445		memcpy(u->domainname, tmp, len);
1446		memset(u->domainname + len, 0, sizeof(u->domainname) - len);
1447		errno = 0;
1448		uts_proc_notify(UTS_PROC_DOMAINNAME);
1449		up_write(&uts_sem);
1450	}
 
1451	return errno;
1452}
1453
1454/* make sure you are allowed to change @tsk limits before calling this */
1455static int do_prlimit(struct task_struct *tsk, unsigned int resource,
1456		      struct rlimit *new_rlim, struct rlimit *old_rlim)
1457{
1458	struct rlimit *rlim;
1459	int retval = 0;
1460
1461	if (resource >= RLIM_NLIMITS)
1462		return -EINVAL;
1463	resource = array_index_nospec(resource, RLIM_NLIMITS);
1464
1465	if (new_rlim) {
1466		if (new_rlim->rlim_cur > new_rlim->rlim_max)
1467			return -EINVAL;
1468		if (resource == RLIMIT_NOFILE &&
1469				new_rlim->rlim_max > sysctl_nr_open)
1470			return -EPERM;
1471	}
1472
1473	/* Holding a refcount on tsk protects tsk->signal from disappearing. */
1474	rlim = tsk->signal->rlim + resource;
1475	task_lock(tsk->group_leader);
1476	if (new_rlim) {
1477		/*
1478		 * Keep the capable check against init_user_ns until cgroups can
1479		 * contain all limits.
1480		 */
1481		if (new_rlim->rlim_max > rlim->rlim_max &&
1482				!capable(CAP_SYS_RESOURCE))
1483			retval = -EPERM;
1484		if (!retval)
1485			retval = security_task_setrlimit(tsk, resource, new_rlim);
1486	}
1487	if (!retval) {
1488		if (old_rlim)
1489			*old_rlim = *rlim;
1490		if (new_rlim)
1491			*rlim = *new_rlim;
1492	}
1493	task_unlock(tsk->group_leader);
1494
1495	/*
1496	 * RLIMIT_CPU handling. Arm the posix CPU timer if the limit is not
1497	 * infinite. In case of RLIM_INFINITY the posix CPU timer code
1498	 * ignores the rlimit.
1499	 */
1500	if (!retval && new_rlim && resource == RLIMIT_CPU &&
1501	    new_rlim->rlim_cur != RLIM_INFINITY &&
1502	    IS_ENABLED(CONFIG_POSIX_TIMERS)) {
1503		/*
1504		 * update_rlimit_cpu can fail if the task is exiting, but there
1505		 * may be other tasks in the thread group that are not exiting,
1506		 * and they need their cpu timers adjusted.
1507		 *
1508		 * The group_leader is the last task to be released, so if we
1509		 * cannot update_rlimit_cpu on it, then the entire process is
1510		 * exiting and we do not need to update at all.
1511		 */
1512		update_rlimit_cpu(tsk->group_leader, new_rlim->rlim_cur);
1513	}
1514
1515	return retval;
1516}
1517
1518SYSCALL_DEFINE2(getrlimit, unsigned int, resource, struct rlimit __user *, rlim)
1519{
1520	struct rlimit value;
1521	int ret;
1522
1523	ret = do_prlimit(current, resource, NULL, &value);
1524	if (!ret)
1525		ret = copy_to_user(rlim, &value, sizeof(*rlim)) ? -EFAULT : 0;
1526
1527	return ret;
1528}
1529
1530#ifdef CONFIG_COMPAT
1531
1532COMPAT_SYSCALL_DEFINE2(setrlimit, unsigned int, resource,
1533		       struct compat_rlimit __user *, rlim)
1534{
1535	struct rlimit r;
1536	struct compat_rlimit r32;
1537
1538	if (copy_from_user(&r32, rlim, sizeof(struct compat_rlimit)))
1539		return -EFAULT;
1540
1541	if (r32.rlim_cur == COMPAT_RLIM_INFINITY)
1542		r.rlim_cur = RLIM_INFINITY;
1543	else
1544		r.rlim_cur = r32.rlim_cur;
1545	if (r32.rlim_max == COMPAT_RLIM_INFINITY)
1546		r.rlim_max = RLIM_INFINITY;
1547	else
1548		r.rlim_max = r32.rlim_max;
1549	return do_prlimit(current, resource, &r, NULL);
1550}
1551
1552COMPAT_SYSCALL_DEFINE2(getrlimit, unsigned int, resource,
1553		       struct compat_rlimit __user *, rlim)
1554{
1555	struct rlimit r;
1556	int ret;
1557
1558	ret = do_prlimit(current, resource, NULL, &r);
1559	if (!ret) {
1560		struct compat_rlimit r32;
1561		if (r.rlim_cur > COMPAT_RLIM_INFINITY)
1562			r32.rlim_cur = COMPAT_RLIM_INFINITY;
1563		else
1564			r32.rlim_cur = r.rlim_cur;
1565		if (r.rlim_max > COMPAT_RLIM_INFINITY)
1566			r32.rlim_max = COMPAT_RLIM_INFINITY;
1567		else
1568			r32.rlim_max = r.rlim_max;
1569
1570		if (copy_to_user(rlim, &r32, sizeof(struct compat_rlimit)))
1571			return -EFAULT;
1572	}
1573	return ret;
1574}
1575
1576#endif
1577
1578#ifdef __ARCH_WANT_SYS_OLD_GETRLIMIT
1579
1580/*
1581 *	Back compatibility for getrlimit. Needed for some apps.
1582 */
1583SYSCALL_DEFINE2(old_getrlimit, unsigned int, resource,
1584		struct rlimit __user *, rlim)
1585{
1586	struct rlimit x;
1587	if (resource >= RLIM_NLIMITS)
1588		return -EINVAL;
1589
1590	resource = array_index_nospec(resource, RLIM_NLIMITS);
1591	task_lock(current->group_leader);
1592	x = current->signal->rlim[resource];
1593	task_unlock(current->group_leader);
1594	if (x.rlim_cur > 0x7FFFFFFF)
1595		x.rlim_cur = 0x7FFFFFFF;
1596	if (x.rlim_max > 0x7FFFFFFF)
1597		x.rlim_max = 0x7FFFFFFF;
1598	return copy_to_user(rlim, &x, sizeof(x)) ? -EFAULT : 0;
1599}
1600
1601#ifdef CONFIG_COMPAT
1602COMPAT_SYSCALL_DEFINE2(old_getrlimit, unsigned int, resource,
1603		       struct compat_rlimit __user *, rlim)
1604{
1605	struct rlimit r;
1606
1607	if (resource >= RLIM_NLIMITS)
1608		return -EINVAL;
1609
1610	resource = array_index_nospec(resource, RLIM_NLIMITS);
1611	task_lock(current->group_leader);
1612	r = current->signal->rlim[resource];
1613	task_unlock(current->group_leader);
1614	if (r.rlim_cur > 0x7FFFFFFF)
1615		r.rlim_cur = 0x7FFFFFFF;
1616	if (r.rlim_max > 0x7FFFFFFF)
1617		r.rlim_max = 0x7FFFFFFF;
1618
1619	if (put_user(r.rlim_cur, &rlim->rlim_cur) ||
1620	    put_user(r.rlim_max, &rlim->rlim_max))
1621		return -EFAULT;
1622	return 0;
1623}
1624#endif
1625
1626#endif
1627
1628static inline bool rlim64_is_infinity(__u64 rlim64)
1629{
1630#if BITS_PER_LONG < 64
1631	return rlim64 >= ULONG_MAX;
1632#else
1633	return rlim64 == RLIM64_INFINITY;
1634#endif
1635}
1636
1637static void rlim_to_rlim64(const struct rlimit *rlim, struct rlimit64 *rlim64)
1638{
1639	if (rlim->rlim_cur == RLIM_INFINITY)
1640		rlim64->rlim_cur = RLIM64_INFINITY;
1641	else
1642		rlim64->rlim_cur = rlim->rlim_cur;
1643	if (rlim->rlim_max == RLIM_INFINITY)
1644		rlim64->rlim_max = RLIM64_INFINITY;
1645	else
1646		rlim64->rlim_max = rlim->rlim_max;
1647}
1648
1649static void rlim64_to_rlim(const struct rlimit64 *rlim64, struct rlimit *rlim)
1650{
1651	if (rlim64_is_infinity(rlim64->rlim_cur))
1652		rlim->rlim_cur = RLIM_INFINITY;
1653	else
1654		rlim->rlim_cur = (unsigned long)rlim64->rlim_cur;
1655	if (rlim64_is_infinity(rlim64->rlim_max))
1656		rlim->rlim_max = RLIM_INFINITY;
1657	else
1658		rlim->rlim_max = (unsigned long)rlim64->rlim_max;
1659}
1660
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1661/* rcu lock must be held */
1662static int check_prlimit_permission(struct task_struct *task,
1663				    unsigned int flags)
1664{
1665	const struct cred *cred = current_cred(), *tcred;
1666	bool id_match;
1667
1668	if (current == task)
1669		return 0;
1670
1671	tcred = __task_cred(task);
1672	id_match = (uid_eq(cred->uid, tcred->euid) &&
1673		    uid_eq(cred->uid, tcred->suid) &&
1674		    uid_eq(cred->uid, tcred->uid)  &&
1675		    gid_eq(cred->gid, tcred->egid) &&
1676		    gid_eq(cred->gid, tcred->sgid) &&
1677		    gid_eq(cred->gid, tcred->gid));
1678	if (!id_match && !ns_capable(tcred->user_ns, CAP_SYS_RESOURCE))
1679		return -EPERM;
1680
1681	return security_task_prlimit(cred, tcred, flags);
1682}
1683
1684SYSCALL_DEFINE4(prlimit64, pid_t, pid, unsigned int, resource,
1685		const struct rlimit64 __user *, new_rlim,
1686		struct rlimit64 __user *, old_rlim)
1687{
1688	struct rlimit64 old64, new64;
1689	struct rlimit old, new;
1690	struct task_struct *tsk;
1691	unsigned int checkflags = 0;
1692	int ret;
1693
1694	if (old_rlim)
1695		checkflags |= LSM_PRLIMIT_READ;
1696
1697	if (new_rlim) {
1698		if (copy_from_user(&new64, new_rlim, sizeof(new64)))
1699			return -EFAULT;
1700		rlim64_to_rlim(&new64, &new);
1701		checkflags |= LSM_PRLIMIT_WRITE;
1702	}
1703
1704	rcu_read_lock();
1705	tsk = pid ? find_task_by_vpid(pid) : current;
1706	if (!tsk) {
1707		rcu_read_unlock();
1708		return -ESRCH;
1709	}
1710	ret = check_prlimit_permission(tsk, checkflags);
1711	if (ret) {
1712		rcu_read_unlock();
1713		return ret;
1714	}
1715	get_task_struct(tsk);
1716	rcu_read_unlock();
1717
1718	ret = do_prlimit(tsk, resource, new_rlim ? &new : NULL,
1719			old_rlim ? &old : NULL);
1720
1721	if (!ret && old_rlim) {
1722		rlim_to_rlim64(&old, &old64);
1723		if (copy_to_user(old_rlim, &old64, sizeof(old64)))
1724			ret = -EFAULT;
1725	}
1726
1727	put_task_struct(tsk);
1728	return ret;
1729}
1730
1731SYSCALL_DEFINE2(setrlimit, unsigned int, resource, struct rlimit __user *, rlim)
1732{
1733	struct rlimit new_rlim;
1734
1735	if (copy_from_user(&new_rlim, rlim, sizeof(*rlim)))
1736		return -EFAULT;
1737	return do_prlimit(current, resource, &new_rlim, NULL);
1738}
1739
1740/*
1741 * It would make sense to put struct rusage in the task_struct,
1742 * except that would make the task_struct be *really big*.  After
1743 * task_struct gets moved into malloc'ed memory, it would
1744 * make sense to do this.  It will make moving the rest of the information
1745 * a lot simpler!  (Which we're not doing right now because we're not
1746 * measuring them yet).
1747 *
1748 * When sampling multiple threads for RUSAGE_SELF, under SMP we might have
1749 * races with threads incrementing their own counters.  But since word
1750 * reads are atomic, we either get new values or old values and we don't
1751 * care which for the sums.  We always take the siglock to protect reading
1752 * the c* fields from p->signal from races with exit.c updating those
1753 * fields when reaping, so a sample either gets all the additions of a
1754 * given child after it's reaped, or none so this sample is before reaping.
1755 *
1756 * Locking:
1757 * We need to take the siglock for CHILDEREN, SELF and BOTH
1758 * for  the cases current multithreaded, non-current single threaded
1759 * non-current multithreaded.  Thread traversal is now safe with
1760 * the siglock held.
1761 * Strictly speaking, we donot need to take the siglock if we are current and
1762 * single threaded,  as no one else can take our signal_struct away, no one
1763 * else can  reap the  children to update signal->c* counters, and no one else
1764 * can race with the signal-> fields. If we do not take any lock, the
1765 * signal-> fields could be read out of order while another thread was just
1766 * exiting. So we should  place a read memory barrier when we avoid the lock.
1767 * On the writer side,  write memory barrier is implied in  __exit_signal
1768 * as __exit_signal releases  the siglock spinlock after updating the signal->
1769 * fields. But we don't do this yet to keep things simple.
1770 *
1771 */
1772
1773static void accumulate_thread_rusage(struct task_struct *t, struct rusage *r)
1774{
1775	r->ru_nvcsw += t->nvcsw;
1776	r->ru_nivcsw += t->nivcsw;
1777	r->ru_minflt += t->min_flt;
1778	r->ru_majflt += t->maj_flt;
1779	r->ru_inblock += task_io_get_inblock(t);
1780	r->ru_oublock += task_io_get_oublock(t);
1781}
1782
1783void getrusage(struct task_struct *p, int who, struct rusage *r)
1784{
1785	struct task_struct *t;
1786	unsigned long flags;
1787	u64 tgutime, tgstime, utime, stime;
1788	unsigned long maxrss;
1789	struct mm_struct *mm;
1790	struct signal_struct *sig = p->signal;
1791	unsigned int seq = 0;
1792
1793retry:
1794	memset(r, 0, sizeof(*r));
1795	utime = stime = 0;
1796	maxrss = 0;
1797
1798	if (who == RUSAGE_THREAD) {
1799		task_cputime_adjusted(current, &utime, &stime);
1800		accumulate_thread_rusage(p, r);
1801		maxrss = sig->maxrss;
1802		goto out_thread;
1803	}
1804
1805	flags = read_seqbegin_or_lock_irqsave(&sig->stats_lock, &seq);
 
1806
1807	switch (who) {
1808	case RUSAGE_BOTH:
1809	case RUSAGE_CHILDREN:
1810		utime = sig->cutime;
1811		stime = sig->cstime;
1812		r->ru_nvcsw = sig->cnvcsw;
1813		r->ru_nivcsw = sig->cnivcsw;
1814		r->ru_minflt = sig->cmin_flt;
1815		r->ru_majflt = sig->cmaj_flt;
1816		r->ru_inblock = sig->cinblock;
1817		r->ru_oublock = sig->coublock;
1818		maxrss = sig->cmaxrss;
1819
1820		if (who == RUSAGE_CHILDREN)
1821			break;
1822		fallthrough;
1823
1824	case RUSAGE_SELF:
1825		r->ru_nvcsw += sig->nvcsw;
1826		r->ru_nivcsw += sig->nivcsw;
1827		r->ru_minflt += sig->min_flt;
1828		r->ru_majflt += sig->maj_flt;
1829		r->ru_inblock += sig->inblock;
1830		r->ru_oublock += sig->oublock;
1831		if (maxrss < sig->maxrss)
1832			maxrss = sig->maxrss;
1833
1834		rcu_read_lock();
1835		__for_each_thread(sig, t)
 
 
1836			accumulate_thread_rusage(t, r);
1837		rcu_read_unlock();
1838
1839		break;
1840
1841	default:
1842		BUG();
1843	}
 
1844
1845	if (need_seqretry(&sig->stats_lock, seq)) {
1846		seq = 1;
1847		goto retry;
1848	}
1849	done_seqretry_irqrestore(&sig->stats_lock, seq, flags);
1850
1851	if (who == RUSAGE_CHILDREN)
1852		goto out_children;
1853
1854	thread_group_cputime_adjusted(p, &tgutime, &tgstime);
1855	utime += tgutime;
1856	stime += tgstime;
1857
1858out_thread:
1859	mm = get_task_mm(p);
1860	if (mm) {
1861		setmax_mm_hiwater_rss(&maxrss, mm);
1862		mmput(mm);
1863	}
1864
1865out_children:
1866	r->ru_maxrss = maxrss * (PAGE_SIZE / 1024); /* convert pages to KBs */
1867	r->ru_utime = ns_to_kernel_old_timeval(utime);
1868	r->ru_stime = ns_to_kernel_old_timeval(stime);
1869}
1870
1871SYSCALL_DEFINE2(getrusage, int, who, struct rusage __user *, ru)
1872{
1873	struct rusage r;
1874
1875	if (who != RUSAGE_SELF && who != RUSAGE_CHILDREN &&
1876	    who != RUSAGE_THREAD)
1877		return -EINVAL;
1878
1879	getrusage(current, who, &r);
1880	return copy_to_user(ru, &r, sizeof(r)) ? -EFAULT : 0;
1881}
1882
1883#ifdef CONFIG_COMPAT
1884COMPAT_SYSCALL_DEFINE2(getrusage, int, who, struct compat_rusage __user *, ru)
1885{
1886	struct rusage r;
1887
1888	if (who != RUSAGE_SELF && who != RUSAGE_CHILDREN &&
1889	    who != RUSAGE_THREAD)
1890		return -EINVAL;
1891
1892	getrusage(current, who, &r);
1893	return put_compat_rusage(&r, ru);
1894}
1895#endif
1896
1897SYSCALL_DEFINE1(umask, int, mask)
1898{
1899	mask = xchg(&current->fs->umask, mask & S_IRWXUGO);
1900	return mask;
1901}
1902
1903static int prctl_set_mm_exe_file(struct mm_struct *mm, unsigned int fd)
1904{
1905	struct fd exe;
 
1906	struct inode *inode;
1907	int err;
1908
1909	exe = fdget(fd);
1910	if (!exe.file)
1911		return -EBADF;
1912
1913	inode = file_inode(exe.file);
1914
1915	/*
1916	 * Because the original mm->exe_file points to executable file, make
1917	 * sure that this one is executable as well, to avoid breaking an
1918	 * overall picture.
1919	 */
1920	err = -EACCES;
1921	if (!S_ISREG(inode->i_mode) || path_noexec(&exe.file->f_path))
1922		goto exit;
1923
1924	err = file_permission(exe.file, MAY_EXEC);
1925	if (err)
1926		goto exit;
1927
1928	err = replace_mm_exe_file(mm, exe.file);
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1929exit:
1930	fdput(exe);
1931	return err;
 
 
 
 
1932}
1933
1934/*
1935 * Check arithmetic relations of passed addresses.
1936 *
1937 * WARNING: we don't require any capability here so be very careful
1938 * in what is allowed for modification from userspace.
1939 */
1940static int validate_prctl_map_addr(struct prctl_mm_map *prctl_map)
1941{
1942	unsigned long mmap_max_addr = TASK_SIZE;
 
1943	int error = -EINVAL, i;
1944
1945	static const unsigned char offsets[] = {
1946		offsetof(struct prctl_mm_map, start_code),
1947		offsetof(struct prctl_mm_map, end_code),
1948		offsetof(struct prctl_mm_map, start_data),
1949		offsetof(struct prctl_mm_map, end_data),
1950		offsetof(struct prctl_mm_map, start_brk),
1951		offsetof(struct prctl_mm_map, brk),
1952		offsetof(struct prctl_mm_map, start_stack),
1953		offsetof(struct prctl_mm_map, arg_start),
1954		offsetof(struct prctl_mm_map, arg_end),
1955		offsetof(struct prctl_mm_map, env_start),
1956		offsetof(struct prctl_mm_map, env_end),
1957	};
1958
1959	/*
1960	 * Make sure the members are not somewhere outside
1961	 * of allowed address space.
1962	 */
1963	for (i = 0; i < ARRAY_SIZE(offsets); i++) {
1964		u64 val = *(u64 *)((char *)prctl_map + offsets[i]);
1965
1966		if ((unsigned long)val >= mmap_max_addr ||
1967		    (unsigned long)val < mmap_min_addr)
1968			goto out;
1969	}
1970
1971	/*
1972	 * Make sure the pairs are ordered.
1973	 */
1974#define __prctl_check_order(__m1, __op, __m2)				\
1975	((unsigned long)prctl_map->__m1 __op				\
1976	 (unsigned long)prctl_map->__m2) ? 0 : -EINVAL
1977	error  = __prctl_check_order(start_code, <, end_code);
1978	error |= __prctl_check_order(start_data,<=, end_data);
1979	error |= __prctl_check_order(start_brk, <=, brk);
1980	error |= __prctl_check_order(arg_start, <=, arg_end);
1981	error |= __prctl_check_order(env_start, <=, env_end);
1982	if (error)
1983		goto out;
1984#undef __prctl_check_order
1985
1986	error = -EINVAL;
1987
1988	/*
 
 
 
 
 
 
 
1989	 * Neither we should allow to override limits if they set.
1990	 */
1991	if (check_data_rlimit(rlimit(RLIMIT_DATA), prctl_map->brk,
1992			      prctl_map->start_brk, prctl_map->end_data,
1993			      prctl_map->start_data))
1994			goto out;
1995
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1996	error = 0;
1997out:
1998	return error;
1999}
2000
2001#ifdef CONFIG_CHECKPOINT_RESTORE
2002static int prctl_set_mm_map(int opt, const void __user *addr, unsigned long data_size)
2003{
2004	struct prctl_mm_map prctl_map = { .exe_fd = (u32)-1, };
2005	unsigned long user_auxv[AT_VECTOR_SIZE];
2006	struct mm_struct *mm = current->mm;
2007	int error;
2008
2009	BUILD_BUG_ON(sizeof(user_auxv) != sizeof(mm->saved_auxv));
2010	BUILD_BUG_ON(sizeof(struct prctl_mm_map) > 256);
2011
2012	if (opt == PR_SET_MM_MAP_SIZE)
2013		return put_user((unsigned int)sizeof(prctl_map),
2014				(unsigned int __user *)addr);
2015
2016	if (data_size != sizeof(prctl_map))
2017		return -EINVAL;
2018
2019	if (copy_from_user(&prctl_map, addr, sizeof(prctl_map)))
2020		return -EFAULT;
2021
2022	error = validate_prctl_map_addr(&prctl_map);
2023	if (error)
2024		return error;
2025
2026	if (prctl_map.auxv_size) {
2027		/*
2028		 * Someone is trying to cheat the auxv vector.
2029		 */
2030		if (!prctl_map.auxv ||
2031				prctl_map.auxv_size > sizeof(mm->saved_auxv))
2032			return -EINVAL;
2033
2034		memset(user_auxv, 0, sizeof(user_auxv));
2035		if (copy_from_user(user_auxv,
2036				   (const void __user *)prctl_map.auxv,
2037				   prctl_map.auxv_size))
2038			return -EFAULT;
2039
2040		/* Last entry must be AT_NULL as specification requires */
2041		user_auxv[AT_VECTOR_SIZE - 2] = AT_NULL;
2042		user_auxv[AT_VECTOR_SIZE - 1] = AT_NULL;
2043	}
2044
2045	if (prctl_map.exe_fd != (u32)-1) {
2046		/*
2047		 * Check if the current user is checkpoint/restore capable.
2048		 * At the time of this writing, it checks for CAP_SYS_ADMIN
2049		 * or CAP_CHECKPOINT_RESTORE.
2050		 * Note that a user with access to ptrace can masquerade an
2051		 * arbitrary program as any executable, even setuid ones.
2052		 * This may have implications in the tomoyo subsystem.
2053		 */
2054		if (!checkpoint_restore_ns_capable(current_user_ns()))
2055			return -EPERM;
2056
2057		error = prctl_set_mm_exe_file(mm, prctl_map.exe_fd);
2058		if (error)
2059			return error;
2060	}
2061
2062	/*
2063	 * arg_lock protects concurrent updates but we still need mmap_lock for
2064	 * read to exclude races with sys_brk.
2065	 */
2066	mmap_read_lock(mm);
2067
2068	/*
2069	 * We don't validate if these members are pointing to
2070	 * real present VMAs because application may have correspond
2071	 * VMAs already unmapped and kernel uses these members for statistics
2072	 * output in procfs mostly, except
2073	 *
2074	 *  - @start_brk/@brk which are used in do_brk_flags but kernel lookups
2075	 *    for VMAs when updating these members so anything wrong written
2076	 *    here cause kernel to swear at userspace program but won't lead
2077	 *    to any problem in kernel itself
2078	 */
2079
2080	spin_lock(&mm->arg_lock);
2081	mm->start_code	= prctl_map.start_code;
2082	mm->end_code	= prctl_map.end_code;
2083	mm->start_data	= prctl_map.start_data;
2084	mm->end_data	= prctl_map.end_data;
2085	mm->start_brk	= prctl_map.start_brk;
2086	mm->brk		= prctl_map.brk;
2087	mm->start_stack	= prctl_map.start_stack;
2088	mm->arg_start	= prctl_map.arg_start;
2089	mm->arg_end	= prctl_map.arg_end;
2090	mm->env_start	= prctl_map.env_start;
2091	mm->env_end	= prctl_map.env_end;
2092	spin_unlock(&mm->arg_lock);
2093
2094	/*
2095	 * Note this update of @saved_auxv is lockless thus
2096	 * if someone reads this member in procfs while we're
2097	 * updating -- it may get partly updated results. It's
2098	 * known and acceptable trade off: we leave it as is to
2099	 * not introduce additional locks here making the kernel
2100	 * more complex.
2101	 */
2102	if (prctl_map.auxv_size)
2103		memcpy(mm->saved_auxv, user_auxv, sizeof(user_auxv));
2104
2105	mmap_read_unlock(mm);
2106	return 0;
2107}
2108#endif /* CONFIG_CHECKPOINT_RESTORE */
2109
2110static int prctl_set_auxv(struct mm_struct *mm, unsigned long addr,
2111			  unsigned long len)
2112{
2113	/*
2114	 * This doesn't move the auxiliary vector itself since it's pinned to
2115	 * mm_struct, but it permits filling the vector with new values.  It's
2116	 * up to the caller to provide sane values here, otherwise userspace
2117	 * tools which use this vector might be unhappy.
2118	 */
2119	unsigned long user_auxv[AT_VECTOR_SIZE] = {};
2120
2121	if (len > sizeof(user_auxv))
2122		return -EINVAL;
2123
2124	if (copy_from_user(user_auxv, (const void __user *)addr, len))
2125		return -EFAULT;
2126
2127	/* Make sure the last entry is always AT_NULL */
2128	user_auxv[AT_VECTOR_SIZE - 2] = 0;
2129	user_auxv[AT_VECTOR_SIZE - 1] = 0;
2130
2131	BUILD_BUG_ON(sizeof(user_auxv) != sizeof(mm->saved_auxv));
2132
2133	task_lock(current);
2134	memcpy(mm->saved_auxv, user_auxv, len);
2135	task_unlock(current);
2136
2137	return 0;
2138}
2139
2140static int prctl_set_mm(int opt, unsigned long addr,
2141			unsigned long arg4, unsigned long arg5)
2142{
2143	struct mm_struct *mm = current->mm;
2144	struct prctl_mm_map prctl_map = {
2145		.auxv = NULL,
2146		.auxv_size = 0,
2147		.exe_fd = -1,
2148	};
2149	struct vm_area_struct *vma;
2150	int error;
2151
2152	if (arg5 || (arg4 && (opt != PR_SET_MM_AUXV &&
2153			      opt != PR_SET_MM_MAP &&
2154			      opt != PR_SET_MM_MAP_SIZE)))
2155		return -EINVAL;
2156
2157#ifdef CONFIG_CHECKPOINT_RESTORE
2158	if (opt == PR_SET_MM_MAP || opt == PR_SET_MM_MAP_SIZE)
2159		return prctl_set_mm_map(opt, (const void __user *)addr, arg4);
2160#endif
2161
2162	if (!capable(CAP_SYS_RESOURCE))
2163		return -EPERM;
2164
2165	if (opt == PR_SET_MM_EXE_FILE)
2166		return prctl_set_mm_exe_file(mm, (unsigned int)addr);
2167
2168	if (opt == PR_SET_MM_AUXV)
2169		return prctl_set_auxv(mm, addr, arg4);
2170
2171	if (addr >= TASK_SIZE || addr < mmap_min_addr)
2172		return -EINVAL;
2173
2174	error = -EINVAL;
2175
2176	/*
2177	 * arg_lock protects concurrent updates of arg boundaries, we need
2178	 * mmap_lock for a) concurrent sys_brk, b) finding VMA for addr
2179	 * validation.
2180	 */
2181	mmap_read_lock(mm);
2182	vma = find_vma(mm, addr);
2183
2184	spin_lock(&mm->arg_lock);
2185	prctl_map.start_code	= mm->start_code;
2186	prctl_map.end_code	= mm->end_code;
2187	prctl_map.start_data	= mm->start_data;
2188	prctl_map.end_data	= mm->end_data;
2189	prctl_map.start_brk	= mm->start_brk;
2190	prctl_map.brk		= mm->brk;
2191	prctl_map.start_stack	= mm->start_stack;
2192	prctl_map.arg_start	= mm->arg_start;
2193	prctl_map.arg_end	= mm->arg_end;
2194	prctl_map.env_start	= mm->env_start;
2195	prctl_map.env_end	= mm->env_end;
 
 
 
2196
2197	switch (opt) {
2198	case PR_SET_MM_START_CODE:
2199		prctl_map.start_code = addr;
2200		break;
2201	case PR_SET_MM_END_CODE:
2202		prctl_map.end_code = addr;
2203		break;
2204	case PR_SET_MM_START_DATA:
2205		prctl_map.start_data = addr;
2206		break;
2207	case PR_SET_MM_END_DATA:
2208		prctl_map.end_data = addr;
2209		break;
2210	case PR_SET_MM_START_STACK:
2211		prctl_map.start_stack = addr;
2212		break;
2213	case PR_SET_MM_START_BRK:
2214		prctl_map.start_brk = addr;
2215		break;
2216	case PR_SET_MM_BRK:
2217		prctl_map.brk = addr;
2218		break;
2219	case PR_SET_MM_ARG_START:
2220		prctl_map.arg_start = addr;
2221		break;
2222	case PR_SET_MM_ARG_END:
2223		prctl_map.arg_end = addr;
2224		break;
2225	case PR_SET_MM_ENV_START:
2226		prctl_map.env_start = addr;
2227		break;
2228	case PR_SET_MM_ENV_END:
2229		prctl_map.env_end = addr;
2230		break;
2231	default:
2232		goto out;
2233	}
2234
2235	error = validate_prctl_map_addr(&prctl_map);
2236	if (error)
2237		goto out;
2238
2239	switch (opt) {
2240	/*
2241	 * If command line arguments and environment
2242	 * are placed somewhere else on stack, we can
2243	 * set them up here, ARG_START/END to setup
2244	 * command line arguments and ENV_START/END
2245	 * for environment.
2246	 */
2247	case PR_SET_MM_START_STACK:
2248	case PR_SET_MM_ARG_START:
2249	case PR_SET_MM_ARG_END:
2250	case PR_SET_MM_ENV_START:
2251	case PR_SET_MM_ENV_END:
2252		if (!vma) {
2253			error = -EFAULT;
2254			goto out;
2255		}
2256	}
2257
2258	mm->start_code	= prctl_map.start_code;
2259	mm->end_code	= prctl_map.end_code;
2260	mm->start_data	= prctl_map.start_data;
2261	mm->end_data	= prctl_map.end_data;
2262	mm->start_brk	= prctl_map.start_brk;
2263	mm->brk		= prctl_map.brk;
2264	mm->start_stack	= prctl_map.start_stack;
2265	mm->arg_start	= prctl_map.arg_start;
2266	mm->arg_end	= prctl_map.arg_end;
2267	mm->env_start	= prctl_map.env_start;
2268	mm->env_end	= prctl_map.env_end;
2269
2270	error = 0;
2271out:
2272	spin_unlock(&mm->arg_lock);
2273	mmap_read_unlock(mm);
2274	return error;
2275}
2276
2277#ifdef CONFIG_CHECKPOINT_RESTORE
2278static int prctl_get_tid_address(struct task_struct *me, int __user * __user *tid_addr)
2279{
2280	return put_user(me->clear_child_tid, tid_addr);
2281}
2282#else
2283static int prctl_get_tid_address(struct task_struct *me, int __user * __user *tid_addr)
2284{
2285	return -EINVAL;
2286}
2287#endif
2288
2289static int propagate_has_child_subreaper(struct task_struct *p, void *data)
2290{
2291	/*
2292	 * If task has has_child_subreaper - all its descendants
2293	 * already have these flag too and new descendants will
2294	 * inherit it on fork, skip them.
2295	 *
2296	 * If we've found child_reaper - skip descendants in
2297	 * it's subtree as they will never get out pidns.
2298	 */
2299	if (p->signal->has_child_subreaper ||
2300	    is_child_reaper(task_pid(p)))
2301		return 0;
2302
2303	p->signal->has_child_subreaper = 1;
2304	return 1;
2305}
2306
2307int __weak arch_prctl_spec_ctrl_get(struct task_struct *t, unsigned long which)
2308{
2309	return -EINVAL;
2310}
2311
2312int __weak arch_prctl_spec_ctrl_set(struct task_struct *t, unsigned long which,
2313				    unsigned long ctrl)
2314{
2315	return -EINVAL;
2316}
2317
2318#define PR_IO_FLUSHER (PF_MEMALLOC_NOIO | PF_LOCAL_THROTTLE)
2319
2320#ifdef CONFIG_ANON_VMA_NAME
2321
2322#define ANON_VMA_NAME_MAX_LEN		80
2323#define ANON_VMA_NAME_INVALID_CHARS	"\\`$[]"
2324
2325static inline bool is_valid_name_char(char ch)
2326{
2327	/* printable ascii characters, excluding ANON_VMA_NAME_INVALID_CHARS */
2328	return ch > 0x1f && ch < 0x7f &&
2329		!strchr(ANON_VMA_NAME_INVALID_CHARS, ch);
2330}
2331
2332static int prctl_set_vma(unsigned long opt, unsigned long addr,
2333			 unsigned long size, unsigned long arg)
2334{
2335	struct mm_struct *mm = current->mm;
2336	const char __user *uname;
2337	struct anon_vma_name *anon_name = NULL;
2338	int error;
2339
2340	switch (opt) {
2341	case PR_SET_VMA_ANON_NAME:
2342		uname = (const char __user *)arg;
2343		if (uname) {
2344			char *name, *pch;
2345
2346			name = strndup_user(uname, ANON_VMA_NAME_MAX_LEN);
2347			if (IS_ERR(name))
2348				return PTR_ERR(name);
2349
2350			for (pch = name; *pch != '\0'; pch++) {
2351				if (!is_valid_name_char(*pch)) {
2352					kfree(name);
2353					return -EINVAL;
2354				}
2355			}
2356			/* anon_vma has its own copy */
2357			anon_name = anon_vma_name_alloc(name);
2358			kfree(name);
2359			if (!anon_name)
2360				return -ENOMEM;
2361
2362		}
2363
2364		mmap_write_lock(mm);
2365		error = madvise_set_anon_name(mm, addr, size, anon_name);
2366		mmap_write_unlock(mm);
2367		anon_vma_name_put(anon_name);
2368		break;
2369	default:
2370		error = -EINVAL;
2371	}
2372
2373	return error;
2374}
2375
2376#else /* CONFIG_ANON_VMA_NAME */
2377static int prctl_set_vma(unsigned long opt, unsigned long start,
2378			 unsigned long size, unsigned long arg)
2379{
2380	return -EINVAL;
2381}
2382#endif /* CONFIG_ANON_VMA_NAME */
2383
2384static inline unsigned long get_current_mdwe(void)
2385{
2386	unsigned long ret = 0;
2387
2388	if (test_bit(MMF_HAS_MDWE, &current->mm->flags))
2389		ret |= PR_MDWE_REFUSE_EXEC_GAIN;
2390	if (test_bit(MMF_HAS_MDWE_NO_INHERIT, &current->mm->flags))
2391		ret |= PR_MDWE_NO_INHERIT;
2392
2393	return ret;
2394}
2395
2396static inline int prctl_set_mdwe(unsigned long bits, unsigned long arg3,
2397				 unsigned long arg4, unsigned long arg5)
2398{
2399	unsigned long current_bits;
2400
2401	if (arg3 || arg4 || arg5)
2402		return -EINVAL;
2403
2404	if (bits & ~(PR_MDWE_REFUSE_EXEC_GAIN | PR_MDWE_NO_INHERIT))
2405		return -EINVAL;
2406
2407	/* NO_INHERIT only makes sense with REFUSE_EXEC_GAIN */
2408	if (bits & PR_MDWE_NO_INHERIT && !(bits & PR_MDWE_REFUSE_EXEC_GAIN))
2409		return -EINVAL;
2410
2411	/*
2412	 * EOPNOTSUPP might be more appropriate here in principle, but
2413	 * existing userspace depends on EINVAL specifically.
2414	 */
2415	if (!arch_memory_deny_write_exec_supported())
2416		return -EINVAL;
2417
2418	current_bits = get_current_mdwe();
2419	if (current_bits && current_bits != bits)
2420		return -EPERM; /* Cannot unset the flags */
2421
2422	if (bits & PR_MDWE_NO_INHERIT)
2423		set_bit(MMF_HAS_MDWE_NO_INHERIT, &current->mm->flags);
2424	if (bits & PR_MDWE_REFUSE_EXEC_GAIN)
2425		set_bit(MMF_HAS_MDWE, &current->mm->flags);
2426
2427	return 0;
2428}
2429
2430static inline int prctl_get_mdwe(unsigned long arg2, unsigned long arg3,
2431				 unsigned long arg4, unsigned long arg5)
2432{
2433	if (arg2 || arg3 || arg4 || arg5)
2434		return -EINVAL;
2435	return get_current_mdwe();
2436}
2437
2438static int prctl_get_auxv(void __user *addr, unsigned long len)
2439{
2440	struct mm_struct *mm = current->mm;
2441	unsigned long size = min_t(unsigned long, sizeof(mm->saved_auxv), len);
2442
2443	if (size && copy_to_user(addr, mm->saved_auxv, size))
2444		return -EFAULT;
2445	return sizeof(mm->saved_auxv);
2446}
2447
2448SYSCALL_DEFINE5(prctl, int, option, unsigned long, arg2, unsigned long, arg3,
2449		unsigned long, arg4, unsigned long, arg5)
2450{
2451	struct task_struct *me = current;
2452	unsigned char comm[sizeof(me->comm)];
2453	long error;
2454
2455	error = security_task_prctl(option, arg2, arg3, arg4, arg5);
2456	if (error != -ENOSYS)
2457		return error;
2458
2459	error = 0;
2460	switch (option) {
2461	case PR_SET_PDEATHSIG:
2462		if (!valid_signal(arg2)) {
2463			error = -EINVAL;
2464			break;
2465		}
2466		me->pdeath_signal = arg2;
2467		break;
2468	case PR_GET_PDEATHSIG:
2469		error = put_user(me->pdeath_signal, (int __user *)arg2);
2470		break;
2471	case PR_GET_DUMPABLE:
2472		error = get_dumpable(me->mm);
2473		break;
2474	case PR_SET_DUMPABLE:
2475		if (arg2 != SUID_DUMP_DISABLE && arg2 != SUID_DUMP_USER) {
2476			error = -EINVAL;
2477			break;
2478		}
2479		set_dumpable(me->mm, arg2);
2480		break;
2481
2482	case PR_SET_UNALIGN:
2483		error = SET_UNALIGN_CTL(me, arg2);
2484		break;
2485	case PR_GET_UNALIGN:
2486		error = GET_UNALIGN_CTL(me, arg2);
2487		break;
2488	case PR_SET_FPEMU:
2489		error = SET_FPEMU_CTL(me, arg2);
2490		break;
2491	case PR_GET_FPEMU:
2492		error = GET_FPEMU_CTL(me, arg2);
2493		break;
2494	case PR_SET_FPEXC:
2495		error = SET_FPEXC_CTL(me, arg2);
2496		break;
2497	case PR_GET_FPEXC:
2498		error = GET_FPEXC_CTL(me, arg2);
2499		break;
2500	case PR_GET_TIMING:
2501		error = PR_TIMING_STATISTICAL;
2502		break;
2503	case PR_SET_TIMING:
2504		if (arg2 != PR_TIMING_STATISTICAL)
2505			error = -EINVAL;
2506		break;
2507	case PR_SET_NAME:
2508		comm[sizeof(me->comm) - 1] = 0;
2509		if (strncpy_from_user(comm, (char __user *)arg2,
2510				      sizeof(me->comm) - 1) < 0)
2511			return -EFAULT;
2512		set_task_comm(me, comm);
2513		proc_comm_connector(me);
2514		break;
2515	case PR_GET_NAME:
2516		get_task_comm(comm, me);
2517		if (copy_to_user((char __user *)arg2, comm, sizeof(comm)))
2518			return -EFAULT;
2519		break;
2520	case PR_GET_ENDIAN:
2521		error = GET_ENDIAN(me, arg2);
2522		break;
2523	case PR_SET_ENDIAN:
2524		error = SET_ENDIAN(me, arg2);
2525		break;
2526	case PR_GET_SECCOMP:
2527		error = prctl_get_seccomp();
2528		break;
2529	case PR_SET_SECCOMP:
2530		error = prctl_set_seccomp(arg2, (char __user *)arg3);
2531		break;
2532	case PR_GET_TSC:
2533		error = GET_TSC_CTL(arg2);
2534		break;
2535	case PR_SET_TSC:
2536		error = SET_TSC_CTL(arg2);
2537		break;
2538	case PR_TASK_PERF_EVENTS_DISABLE:
2539		error = perf_event_task_disable();
2540		break;
2541	case PR_TASK_PERF_EVENTS_ENABLE:
2542		error = perf_event_task_enable();
2543		break;
2544	case PR_GET_TIMERSLACK:
2545		if (current->timer_slack_ns > ULONG_MAX)
2546			error = ULONG_MAX;
2547		else
2548			error = current->timer_slack_ns;
2549		break;
2550	case PR_SET_TIMERSLACK:
2551		if (arg2 <= 0)
2552			current->timer_slack_ns =
2553					current->default_timer_slack_ns;
2554		else
2555			current->timer_slack_ns = arg2;
2556		break;
2557	case PR_MCE_KILL:
2558		if (arg4 | arg5)
2559			return -EINVAL;
2560		switch (arg2) {
2561		case PR_MCE_KILL_CLEAR:
2562			if (arg3 != 0)
2563				return -EINVAL;
2564			current->flags &= ~PF_MCE_PROCESS;
2565			break;
2566		case PR_MCE_KILL_SET:
2567			current->flags |= PF_MCE_PROCESS;
2568			if (arg3 == PR_MCE_KILL_EARLY)
2569				current->flags |= PF_MCE_EARLY;
2570			else if (arg3 == PR_MCE_KILL_LATE)
2571				current->flags &= ~PF_MCE_EARLY;
2572			else if (arg3 == PR_MCE_KILL_DEFAULT)
2573				current->flags &=
2574						~(PF_MCE_EARLY|PF_MCE_PROCESS);
2575			else
2576				return -EINVAL;
2577			break;
2578		default:
2579			return -EINVAL;
2580		}
2581		break;
2582	case PR_MCE_KILL_GET:
2583		if (arg2 | arg3 | arg4 | arg5)
2584			return -EINVAL;
2585		if (current->flags & PF_MCE_PROCESS)
2586			error = (current->flags & PF_MCE_EARLY) ?
2587				PR_MCE_KILL_EARLY : PR_MCE_KILL_LATE;
2588		else
2589			error = PR_MCE_KILL_DEFAULT;
2590		break;
2591	case PR_SET_MM:
2592		error = prctl_set_mm(arg2, arg3, arg4, arg5);
2593		break;
2594	case PR_GET_TID_ADDRESS:
2595		error = prctl_get_tid_address(me, (int __user * __user *)arg2);
2596		break;
2597	case PR_SET_CHILD_SUBREAPER:
2598		me->signal->is_child_subreaper = !!arg2;
2599		if (!arg2)
2600			break;
2601
2602		walk_process_tree(me, propagate_has_child_subreaper, NULL);
2603		break;
2604	case PR_GET_CHILD_SUBREAPER:
2605		error = put_user(me->signal->is_child_subreaper,
2606				 (int __user *)arg2);
2607		break;
2608	case PR_SET_NO_NEW_PRIVS:
2609		if (arg2 != 1 || arg3 || arg4 || arg5)
2610			return -EINVAL;
2611
2612		task_set_no_new_privs(current);
2613		break;
2614	case PR_GET_NO_NEW_PRIVS:
2615		if (arg2 || arg3 || arg4 || arg5)
2616			return -EINVAL;
2617		return task_no_new_privs(current) ? 1 : 0;
2618	case PR_GET_THP_DISABLE:
2619		if (arg2 || arg3 || arg4 || arg5)
2620			return -EINVAL;
2621		error = !!test_bit(MMF_DISABLE_THP, &me->mm->flags);
2622		break;
2623	case PR_SET_THP_DISABLE:
2624		if (arg3 || arg4 || arg5)
2625			return -EINVAL;
2626		if (mmap_write_lock_killable(me->mm))
2627			return -EINTR;
2628		if (arg2)
2629			set_bit(MMF_DISABLE_THP, &me->mm->flags);
2630		else
2631			clear_bit(MMF_DISABLE_THP, &me->mm->flags);
2632		mmap_write_unlock(me->mm);
2633		break;
2634	case PR_MPX_ENABLE_MANAGEMENT:
 
 
 
 
2635	case PR_MPX_DISABLE_MANAGEMENT:
2636		/* No longer implemented: */
2637		return -EINVAL;
 
 
2638	case PR_SET_FP_MODE:
2639		error = SET_FP_MODE(me, arg2);
2640		break;
2641	case PR_GET_FP_MODE:
2642		error = GET_FP_MODE(me);
2643		break;
2644	case PR_SVE_SET_VL:
2645		error = SVE_SET_VL(arg2);
2646		break;
2647	case PR_SVE_GET_VL:
2648		error = SVE_GET_VL();
2649		break;
2650	case PR_SME_SET_VL:
2651		error = SME_SET_VL(arg2);
2652		break;
2653	case PR_SME_GET_VL:
2654		error = SME_GET_VL();
2655		break;
2656	case PR_GET_SPECULATION_CTRL:
2657		if (arg3 || arg4 || arg5)
2658			return -EINVAL;
2659		error = arch_prctl_spec_ctrl_get(me, arg2);
2660		break;
2661	case PR_SET_SPECULATION_CTRL:
2662		if (arg4 || arg5)
2663			return -EINVAL;
2664		error = arch_prctl_spec_ctrl_set(me, arg2, arg3);
2665		break;
2666	case PR_PAC_RESET_KEYS:
2667		if (arg3 || arg4 || arg5)
2668			return -EINVAL;
2669		error = PAC_RESET_KEYS(me, arg2);
2670		break;
2671	case PR_PAC_SET_ENABLED_KEYS:
2672		if (arg4 || arg5)
2673			return -EINVAL;
2674		error = PAC_SET_ENABLED_KEYS(me, arg2, arg3);
2675		break;
2676	case PR_PAC_GET_ENABLED_KEYS:
2677		if (arg2 || arg3 || arg4 || arg5)
2678			return -EINVAL;
2679		error = PAC_GET_ENABLED_KEYS(me);
2680		break;
2681	case PR_SET_TAGGED_ADDR_CTRL:
2682		if (arg3 || arg4 || arg5)
2683			return -EINVAL;
2684		error = SET_TAGGED_ADDR_CTRL(arg2);
2685		break;
2686	case PR_GET_TAGGED_ADDR_CTRL:
2687		if (arg2 || arg3 || arg4 || arg5)
2688			return -EINVAL;
2689		error = GET_TAGGED_ADDR_CTRL();
2690		break;
2691	case PR_SET_IO_FLUSHER:
2692		if (!capable(CAP_SYS_RESOURCE))
2693			return -EPERM;
2694
2695		if (arg3 || arg4 || arg5)
2696			return -EINVAL;
2697
2698		if (arg2 == 1)
2699			current->flags |= PR_IO_FLUSHER;
2700		else if (!arg2)
2701			current->flags &= ~PR_IO_FLUSHER;
2702		else
2703			return -EINVAL;
2704		break;
2705	case PR_GET_IO_FLUSHER:
2706		if (!capable(CAP_SYS_RESOURCE))
2707			return -EPERM;
2708
2709		if (arg2 || arg3 || arg4 || arg5)
2710			return -EINVAL;
2711
2712		error = (current->flags & PR_IO_FLUSHER) == PR_IO_FLUSHER;
2713		break;
2714	case PR_SET_SYSCALL_USER_DISPATCH:
2715		error = set_syscall_user_dispatch(arg2, arg3, arg4,
2716						  (char __user *) arg5);
2717		break;
2718#ifdef CONFIG_SCHED_CORE
2719	case PR_SCHED_CORE:
2720		error = sched_core_share_pid(arg2, arg3, arg4, arg5);
2721		break;
2722#endif
2723	case PR_SET_MDWE:
2724		error = prctl_set_mdwe(arg2, arg3, arg4, arg5);
2725		break;
2726	case PR_GET_MDWE:
2727		error = prctl_get_mdwe(arg2, arg3, arg4, arg5);
2728		break;
2729	case PR_SET_VMA:
2730		error = prctl_set_vma(arg2, arg3, arg4, arg5);
2731		break;
2732	case PR_GET_AUXV:
2733		if (arg4 || arg5)
2734			return -EINVAL;
2735		error = prctl_get_auxv((void __user *)arg2, arg3);
2736		break;
2737#ifdef CONFIG_KSM
2738	case PR_SET_MEMORY_MERGE:
2739		if (arg3 || arg4 || arg5)
2740			return -EINVAL;
2741		if (mmap_write_lock_killable(me->mm))
2742			return -EINTR;
2743
2744		if (arg2)
2745			error = ksm_enable_merge_any(me->mm);
2746		else
2747			error = ksm_disable_merge_any(me->mm);
2748		mmap_write_unlock(me->mm);
2749		break;
2750	case PR_GET_MEMORY_MERGE:
2751		if (arg2 || arg3 || arg4 || arg5)
2752			return -EINVAL;
2753
2754		error = !!test_bit(MMF_VM_MERGE_ANY, &me->mm->flags);
2755		break;
2756#endif
2757	case PR_RISCV_V_SET_CONTROL:
2758		error = RISCV_V_SET_CONTROL(arg2);
2759		break;
2760	case PR_RISCV_V_GET_CONTROL:
2761		error = RISCV_V_GET_CONTROL();
2762		break;
2763	default:
2764		error = -EINVAL;
2765		break;
2766	}
2767	return error;
2768}
2769
2770SYSCALL_DEFINE3(getcpu, unsigned __user *, cpup, unsigned __user *, nodep,
2771		struct getcpu_cache __user *, unused)
2772{
2773	int err = 0;
2774	int cpu = raw_smp_processor_id();
2775
2776	if (cpup)
2777		err |= put_user(cpu, cpup);
2778	if (nodep)
2779		err |= put_user(cpu_to_node(cpu), nodep);
2780	return err ? -EFAULT : 0;
2781}
2782
2783/**
2784 * do_sysinfo - fill in sysinfo struct
2785 * @info: pointer to buffer to fill
2786 */
2787static int do_sysinfo(struct sysinfo *info)
2788{
2789	unsigned long mem_total, sav_total;
2790	unsigned int mem_unit, bitcount;
2791	struct timespec64 tp;
2792
2793	memset(info, 0, sizeof(struct sysinfo));
2794
2795	ktime_get_boottime_ts64(&tp);
2796	timens_add_boottime(&tp);
2797	info->uptime = tp.tv_sec + (tp.tv_nsec ? 1 : 0);
2798
2799	get_avenrun(info->loads, 0, SI_LOAD_SHIFT - FSHIFT);
2800
2801	info->procs = nr_threads;
2802
2803	si_meminfo(info);
2804	si_swapinfo(info);
2805
2806	/*
2807	 * If the sum of all the available memory (i.e. ram + swap)
2808	 * is less than can be stored in a 32 bit unsigned long then
2809	 * we can be binary compatible with 2.2.x kernels.  If not,
2810	 * well, in that case 2.2.x was broken anyways...
2811	 *
2812	 *  -Erik Andersen <andersee@debian.org>
2813	 */
2814
2815	mem_total = info->totalram + info->totalswap;
2816	if (mem_total < info->totalram || mem_total < info->totalswap)
2817		goto out;
2818	bitcount = 0;
2819	mem_unit = info->mem_unit;
2820	while (mem_unit > 1) {
2821		bitcount++;
2822		mem_unit >>= 1;
2823		sav_total = mem_total;
2824		mem_total <<= 1;
2825		if (mem_total < sav_total)
2826			goto out;
2827	}
2828
2829	/*
2830	 * If mem_total did not overflow, multiply all memory values by
2831	 * info->mem_unit and set it to 1.  This leaves things compatible
2832	 * with 2.2.x, and also retains compatibility with earlier 2.4.x
2833	 * kernels...
2834	 */
2835
2836	info->mem_unit = 1;
2837	info->totalram <<= bitcount;
2838	info->freeram <<= bitcount;
2839	info->sharedram <<= bitcount;
2840	info->bufferram <<= bitcount;
2841	info->totalswap <<= bitcount;
2842	info->freeswap <<= bitcount;
2843	info->totalhigh <<= bitcount;
2844	info->freehigh <<= bitcount;
2845
2846out:
2847	return 0;
2848}
2849
2850SYSCALL_DEFINE1(sysinfo, struct sysinfo __user *, info)
2851{
2852	struct sysinfo val;
2853
2854	do_sysinfo(&val);
2855
2856	if (copy_to_user(info, &val, sizeof(struct sysinfo)))
2857		return -EFAULT;
2858
2859	return 0;
2860}
2861
2862#ifdef CONFIG_COMPAT
2863struct compat_sysinfo {
2864	s32 uptime;
2865	u32 loads[3];
2866	u32 totalram;
2867	u32 freeram;
2868	u32 sharedram;
2869	u32 bufferram;
2870	u32 totalswap;
2871	u32 freeswap;
2872	u16 procs;
2873	u16 pad;
2874	u32 totalhigh;
2875	u32 freehigh;
2876	u32 mem_unit;
2877	char _f[20-2*sizeof(u32)-sizeof(int)];
2878};
2879
2880COMPAT_SYSCALL_DEFINE1(sysinfo, struct compat_sysinfo __user *, info)
2881{
2882	struct sysinfo s;
2883	struct compat_sysinfo s_32;
2884
2885	do_sysinfo(&s);
2886
2887	/* Check to see if any memory value is too large for 32-bit and scale
2888	 *  down if needed
2889	 */
2890	if (upper_32_bits(s.totalram) || upper_32_bits(s.totalswap)) {
2891		int bitcount = 0;
2892
2893		while (s.mem_unit < PAGE_SIZE) {
2894			s.mem_unit <<= 1;
2895			bitcount++;
2896		}
2897
2898		s.totalram >>= bitcount;
2899		s.freeram >>= bitcount;
2900		s.sharedram >>= bitcount;
2901		s.bufferram >>= bitcount;
2902		s.totalswap >>= bitcount;
2903		s.freeswap >>= bitcount;
2904		s.totalhigh >>= bitcount;
2905		s.freehigh >>= bitcount;
2906	}
2907
2908	memset(&s_32, 0, sizeof(s_32));
2909	s_32.uptime = s.uptime;
2910	s_32.loads[0] = s.loads[0];
2911	s_32.loads[1] = s.loads[1];
2912	s_32.loads[2] = s.loads[2];
2913	s_32.totalram = s.totalram;
2914	s_32.freeram = s.freeram;
2915	s_32.sharedram = s.sharedram;
2916	s_32.bufferram = s.bufferram;
2917	s_32.totalswap = s.totalswap;
2918	s_32.freeswap = s.freeswap;
2919	s_32.procs = s.procs;
2920	s_32.totalhigh = s.totalhigh;
2921	s_32.freehigh = s.freehigh;
2922	s_32.mem_unit = s.mem_unit;
2923	if (copy_to_user(info, &s_32, sizeof(s_32)))
2924		return -EFAULT;
 
2925	return 0;
2926}
2927#endif /* CONFIG_COMPAT */