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sched: Inherit task cookie on fork()
[linux-block.git] / kernel / sys.c
CommitLineData
b2441318 1// SPDX-License-Identifier: GPL-2.0
1da177e4
LT		 2/*
3 * linux/kernel/sys.c
4 *
5 * Copyright (C) 1991, 1992 Linus Torvalds
6 */
7
9984de1a 8#include <linux/export.h>
1da177e4
LT		 9#include <linux/mm.h>
10#include <linux/utsname.h>
11#include <linux/mman.h>
1da177e4
LT		 12#include <linux/reboot.h>
13#include <linux/prctl.h>
1da177e4
LT		 14#include <linux/highuid.h>
15#include <linux/fs.h>
74da1ff7 16#include <linux/kmod.h>
cdd6c482 17#include <linux/perf_event.h>
3e88c553 18#include <linux/resource.h>
dc009d92 19#include <linux/kernel.h>
1da177e4 20#include <linux/workqueue.h>
c59ede7b 21#include <linux/capability.h>
1da177e4
LT		 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>
1da177e4
LT		 27#include <linux/suspend.h>
28#include <linux/tty.h>
7ed20e1a 29#include <linux/signal.h>
9f46080c 30#include <linux/cn_proc.h>
3cfc348b 31#include <linux/getcpu.h>
6eaeeaba 32#include <linux/task_io_accounting_ops.h>
1d9d02fe 33#include <linux/seccomp.h>
4047727e 34#include <linux/cpu.h>
e28cbf22 35#include <linux/personality.h>
e3d5a27d 36#include <linux/ptrace.h>
5ad4e53b 37#include <linux/fs_struct.h>
b32dfe37
CG		 38#include <linux/file.h>
39#include <linux/mount.h>
5a0e3ad6 40#include <linux/gfp.h>
40dc166c 41#include <linux/syscore_ops.h>
be27425d
AK		 42#include <linux/version.h>
43#include <linux/ctype.h>
1446e1df 44#include <linux/syscall_user_dispatch.h>
1da177e4
LT		 45
46#include <linux/compat.h>
47#include <linux/syscalls.h>
00d7c05a 48#include <linux/kprobes.h>
acce292c 49#include <linux/user_namespace.h>
ecc421e0 50#include <linux/time_namespace.h>
7fe5e042 51#include <linux/binfmts.h>
1da177e4 52
4a22f166 53#include <linux/sched.h>
4eb5aaa3 54#include <linux/sched/autogroup.h>
4f17722c 55#include <linux/sched/loadavg.h>
03441a34 56#include <linux/sched/stat.h>
6e84f315 57#include <linux/sched/mm.h>
f7ccbae4 58#include <linux/sched/coredump.h>
29930025 59#include <linux/sched/task.h>
32ef5517 60#include <linux/sched/cputime.h>
4a22f166
SR		 61#include <linux/rcupdate.h>
62#include <linux/uidgid.h>
63#include <linux/cred.h>
64
b617cfc8
TG		 65#include <linux/nospec.h>
66
04c6862c 67#include <linux/kmsg_dump.h>
be27425d
AK		 68/* Move somewhere else to avoid recompiling? */
69#include <generated/utsrelease.h>
04c6862c 70
7c0f6ba6 71#include <linux/uaccess.h>
1da177e4
LT		 72#include <asm/io.h>
73#include <asm/unistd.h>
74
e530dca5
DB		 75#include "uid16.h"
76
1da177e4 77#ifndef SET_UNALIGN_CTL
ec94fc3d 78# define SET_UNALIGN_CTL(a, b) (-EINVAL)
1da177e4
LT		 79#endif
80#ifndef GET_UNALIGN_CTL
ec94fc3d 81# define GET_UNALIGN_CTL(a, b) (-EINVAL)
1da177e4
LT		 82#endif
83#ifndef SET_FPEMU_CTL
ec94fc3d 84# define SET_FPEMU_CTL(a, b) (-EINVAL)
1da177e4
LT		 85#endif
86#ifndef GET_FPEMU_CTL
ec94fc3d 87# define GET_FPEMU_CTL(a, b) (-EINVAL)
1da177e4
LT		 88#endif
89#ifndef SET_FPEXC_CTL
ec94fc3d 90# define SET_FPEXC_CTL(a, b) (-EINVAL)
1da177e4
LT		 91#endif
92#ifndef GET_FPEXC_CTL
ec94fc3d 93# define GET_FPEXC_CTL(a, b) (-EINVAL)
1da177e4 94#endif
651d765d 95#ifndef GET_ENDIAN
ec94fc3d 96# define GET_ENDIAN(a, b) (-EINVAL)
651d765d
AB		 97#endif
98#ifndef SET_ENDIAN
ec94fc3d 99# define SET_ENDIAN(a, b) (-EINVAL)
651d765d 100#endif
8fb402bc
EB		 101#ifndef GET_TSC_CTL
102# define GET_TSC_CTL(a) (-EINVAL)
103#endif
104#ifndef SET_TSC_CTL
105# define SET_TSC_CTL(a) (-EINVAL)
106#endif
9791554b
PB		 107#ifndef GET_FP_MODE
108# define GET_FP_MODE(a) (-EINVAL)
109#endif
110#ifndef SET_FP_MODE
111# define SET_FP_MODE(a,b) (-EINVAL)
112#endif
2d2123bc
DM		 113#ifndef SVE_SET_VL
114# define SVE_SET_VL(a) (-EINVAL)
115#endif
116#ifndef SVE_GET_VL
117# define SVE_GET_VL() (-EINVAL)
118#endif
ba830885
KM		 119#ifndef PAC_RESET_KEYS
120# define PAC_RESET_KEYS(a, b) (-EINVAL)
121#endif
20169862
PC		 122#ifndef PAC_SET_ENABLED_KEYS
123# define PAC_SET_ENABLED_KEYS(a, b, c) (-EINVAL)
124#endif
125#ifndef PAC_GET_ENABLED_KEYS
126# define PAC_GET_ENABLED_KEYS(a) (-EINVAL)
127#endif
63f0c603
CM		 128#ifndef SET_TAGGED_ADDR_CTRL
129# define SET_TAGGED_ADDR_CTRL(a) (-EINVAL)
130#endif
131#ifndef GET_TAGGED_ADDR_CTRL
132# define GET_TAGGED_ADDR_CTRL() (-EINVAL)
133#endif
1da177e4
LT		 134
135/*
136 * this is where the system-wide overflow UID and GID are defined, for
137 * architectures that now have 32-bit UID/GID but didn't in the past
138 */
139
140int overflowuid = DEFAULT_OVERFLOWUID;
141int overflowgid = DEFAULT_OVERFLOWGID;
142
1da177e4
LT		 143EXPORT_SYMBOL(overflowuid);
144EXPORT_SYMBOL(overflowgid);
1da177e4
LT		 145
146/*
147 * the same as above, but for filesystems which can only store a 16-bit
148 * UID and GID. as such, this is needed on all architectures
149 */
150
151int fs_overflowuid = DEFAULT_FS_OVERFLOWUID;
8b2770a4 152int fs_overflowgid = DEFAULT_FS_OVERFLOWGID;
1da177e4
LT		 153
154EXPORT_SYMBOL(fs_overflowuid);
155EXPORT_SYMBOL(fs_overflowgid);
156
fc832ad3
SH		 157/*
158 * Returns true if current's euid is same as p's uid or euid,
159 * or has CAP_SYS_NICE to p's user_ns.
160 *
161 * Called with rcu_read_lock, creds are safe
162 */
163static bool set_one_prio_perm(struct task_struct *p)
164{
165 const struct cred *cred = current_cred(), *pcred = __task_cred(p);
166
5af66203
EB		 167 if (uid_eq(pcred->uid, cred->euid) ||
168 uid_eq(pcred->euid, cred->euid))
fc832ad3 169 return true;
c4a4d603 170 if (ns_capable(pcred->user_ns, CAP_SYS_NICE))
fc832ad3
SH		 171 return true;
172 return false;
173}
174
c69e8d9c
DH		 175/*
176 * set the priority of a task
177 * - the caller must hold the RCU read lock
178 */
1da177e4
LT		 179static int set_one_prio(struct task_struct *p, int niceval, int error)
180{
181 int no_nice;
182
fc832ad3 183 if (!set_one_prio_perm(p)) {
1da177e4
LT		 184 error = -EPERM;
185 goto out;
186 }
e43379f1 187 if (niceval < task_nice(p) && !can_nice(p, niceval)) {
1da177e4
LT		 188 error = -EACCES;
189 goto out;
190 }
191 no_nice = security_task_setnice(p, niceval);
192 if (no_nice) {
193 error = no_nice;
194 goto out;
195 }
196 if (error == -ESRCH)
197 error = 0;
198 set_user_nice(p, niceval);
199out:
200 return error;
201}
202
754fe8d2 203SYSCALL_DEFINE3(setpriority, int, which, int, who, int, niceval)
1da177e4
LT		 204{
205 struct task_struct *g, *p;
206 struct user_struct *user;
86a264ab 207 const struct cred *cred = current_cred();
1da177e4 208 int error = -EINVAL;
41487c65 209 struct pid *pgrp;
7b44ab97 210 kuid_t uid;
1da177e4 211
3e88c553 212 if (which > PRIO_USER || which < PRIO_PROCESS)
1da177e4
LT		 213 goto out;
214
215 /* normalize: avoid signed division (rounding problems) */
216 error = -ESRCH;
c4a4d2f4
DY		 217 if (niceval < MIN_NICE)
218 niceval = MIN_NICE;
219 if (niceval > MAX_NICE)
220 niceval = MAX_NICE;
1da177e4 221
d4581a23 222 rcu_read_lock();
1da177e4
LT		 223 read_lock(&tasklist_lock);
224 switch (which) {
ec94fc3d 225 case PRIO_PROCESS:
226 if (who)
227 p = find_task_by_vpid(who);
228 else
229 p = current;
230 if (p)
231 error = set_one_prio(p, niceval, error);
232 break;
233 case PRIO_PGRP:
234 if (who)
235 pgrp = find_vpid(who);
236 else
237 pgrp = task_pgrp(current);
238 do_each_pid_thread(pgrp, PIDTYPE_PGID, p) {
239 error = set_one_prio(p, niceval, error);
240 } while_each_pid_thread(pgrp, PIDTYPE_PGID, p);
241 break;
242 case PRIO_USER:
243 uid = make_kuid(cred->user_ns, who);
244 user = cred->user;
245 if (!who)
246 uid = cred->uid;
247 else if (!uid_eq(uid, cred->uid)) {
248 user = find_user(uid);
249 if (!user)
86a264ab 250 goto out_unlock; /* No processes for this user */
ec94fc3d 251 }
252 do_each_thread(g, p) {
8639b461 253 if (uid_eq(task_uid(p), uid) && task_pid_vnr(p))
ec94fc3d 254 error = set_one_prio(p, niceval, error);
255 } while_each_thread(g, p);
256 if (!uid_eq(uid, cred->uid))
257 free_uid(user); /* For find_user() */
258 break;
1da177e4
LT		 259 }
260out_unlock:
261 read_unlock(&tasklist_lock);
d4581a23 262 rcu_read_unlock();
1da177e4
LT		 263out:
264 return error;
265}
266
267/*
268 * Ugh. To avoid negative return values, "getpriority()" will
269 * not return the normal nice-value, but a negated value that
270 * has been offset by 20 (ie it returns 40..1 instead of -20..19)
271 * to stay compatible.
272 */
754fe8d2 273SYSCALL_DEFINE2(getpriority, int, which, int, who)
1da177e4
LT		 274{
275 struct task_struct *g, *p;
276 struct user_struct *user;
86a264ab 277 const struct cred *cred = current_cred();
1da177e4 278 long niceval, retval = -ESRCH;
41487c65 279 struct pid *pgrp;
7b44ab97 280 kuid_t uid;
1da177e4 281
3e88c553 282 if (which > PRIO_USER || which < PRIO_PROCESS)
1da177e4
LT		 283 return -EINVAL;
284
70118837 285 rcu_read_lock();
1da177e4
LT		 286 read_lock(&tasklist_lock);
287 switch (which) {
ec94fc3d 288 case PRIO_PROCESS:
289 if (who)
290 p = find_task_by_vpid(who);
291 else
292 p = current;
293 if (p) {
294 niceval = nice_to_rlimit(task_nice(p));
295 if (niceval > retval)
296 retval = niceval;
297 }
298 break;
299 case PRIO_PGRP:
300 if (who)
301 pgrp = find_vpid(who);
302 else
303 pgrp = task_pgrp(current);
304 do_each_pid_thread(pgrp, PIDTYPE_PGID, p) {
305 niceval = nice_to_rlimit(task_nice(p));
306 if (niceval > retval)
307 retval = niceval;
308 } while_each_pid_thread(pgrp, PIDTYPE_PGID, p);
309 break;
310 case PRIO_USER:
311 uid = make_kuid(cred->user_ns, who);
312 user = cred->user;
313 if (!who)
314 uid = cred->uid;
315 else if (!uid_eq(uid, cred->uid)) {
316 user = find_user(uid);
317 if (!user)
318 goto out_unlock; /* No processes for this user */
319 }
320 do_each_thread(g, p) {
8639b461 321 if (uid_eq(task_uid(p), uid) && task_pid_vnr(p)) {
7aa2c016 322 niceval = nice_to_rlimit(task_nice(p));
1da177e4
LT		 323 if (niceval > retval)
324 retval = niceval;
325 }
ec94fc3d 326 } while_each_thread(g, p);
327 if (!uid_eq(uid, cred->uid))
328 free_uid(user); /* for find_user() */
329 break;
1da177e4
LT		 330 }
331out_unlock:
332 read_unlock(&tasklist_lock);
70118837 333 rcu_read_unlock();
1da177e4
LT		 334
335 return retval;
336}
337
1da177e4
LT		 338/*
339 * Unprivileged users may change the real gid to the effective gid
340 * or vice versa. (BSD-style)
341 *
342 * If you set the real gid at all, or set the effective gid to a value not
343 * equal to the real gid, then the saved gid is set to the new effective gid.
344 *
345 * This makes it possible for a setgid program to completely drop its
346 * privileges, which is often a useful assertion to make when you are doing
347 * a security audit over a program.
348 *
349 * The general idea is that a program which uses just setregid() will be
350 * 100% compatible with BSD. A program which uses just setgid() will be
ec94fc3d 351 * 100% compatible with POSIX with saved IDs.
1da177e4
LT		 352 *
353 * SMP: There are not races, the GIDs are checked only by filesystem
354 * operations (as far as semantic preservation is concerned).
355 */
2813893f 356#ifdef CONFIG_MULTIUSER
e530dca5 357long __sys_setregid(gid_t rgid, gid_t egid)
1da177e4 358{
a29c33f4 359 struct user_namespace *ns = current_user_ns();
d84f4f99
DH		 360 const struct cred *old;
361 struct cred *new;
1da177e4 362 int retval;
a29c33f4
EB		 363 kgid_t krgid, kegid;
364
365 krgid = make_kgid(ns, rgid);
366 kegid = make_kgid(ns, egid);
367
368 if ((rgid != (gid_t) -1) && !gid_valid(krgid))
369 return -EINVAL;
370 if ((egid != (gid_t) -1) && !gid_valid(kegid))
371 return -EINVAL;
1da177e4 372
d84f4f99
DH		 373 new = prepare_creds();
374 if (!new)
375 return -ENOMEM;
376 old = current_cred();
377
d84f4f99 378 retval = -EPERM;
1da177e4 379 if (rgid != (gid_t) -1) {
a29c33f4
EB		 380 if (gid_eq(old->gid, krgid) ||
381 gid_eq(old->egid, krgid) ||
111767c1 382 ns_capable_setid(old->user_ns, CAP_SETGID))
a29c33f4 383 new->gid = krgid;
1da177e4 384 else
d84f4f99 385 goto error;
1da177e4
LT		 386 }
387 if (egid != (gid_t) -1) {
a29c33f4
EB		 388 if (gid_eq(old->gid, kegid) ||
389 gid_eq(old->egid, kegid) ||
390 gid_eq(old->sgid, kegid) ||
111767c1 391 ns_capable_setid(old->user_ns, CAP_SETGID))
a29c33f4 392 new->egid = kegid;
756184b7 393 else
d84f4f99 394 goto error;
1da177e4 395 }
d84f4f99 396
1da177e4 397 if (rgid != (gid_t) -1 ||
a29c33f4 398 (egid != (gid_t) -1 && !gid_eq(kegid, old->gid)))
d84f4f99
DH		 399 new->sgid = new->egid;
400 new->fsgid = new->egid;
401
39030e13
TC		 402 retval = security_task_fix_setgid(new, old, LSM_SETID_RE);
403 if (retval < 0)
404 goto error;
405
d84f4f99
DH		 406 return commit_creds(new);
407
408error:
409 abort_creds(new);
410 return retval;
1da177e4
LT		 411}
412
e530dca5
DB		 413SYSCALL_DEFINE2(setregid, gid_t, rgid, gid_t, egid)
414{
415 return __sys_setregid(rgid, egid);
416}
417
1da177e4 418/*
ec94fc3d 419 * setgid() is implemented like SysV w/ SAVED_IDS
1da177e4
LT		 420 *
421 * SMP: Same implicit races as above.
422 */
e530dca5 423long __sys_setgid(gid_t gid)
1da177e4 424{
a29c33f4 425 struct user_namespace *ns = current_user_ns();
d84f4f99
DH		 426 const struct cred *old;
427 struct cred *new;
1da177e4 428 int retval;
a29c33f4
EB		 429 kgid_t kgid;
430
431 kgid = make_kgid(ns, gid);
432 if (!gid_valid(kgid))
433 return -EINVAL;
1da177e4 434
d84f4f99
DH		 435 new = prepare_creds();
436 if (!new)
437 return -ENOMEM;
438 old = current_cred();
439
d84f4f99 440 retval = -EPERM;
111767c1 441 if (ns_capable_setid(old->user_ns, CAP_SETGID))
a29c33f4
EB		 442 new->gid = new->egid = new->sgid = new->fsgid = kgid;
443 else if (gid_eq(kgid, old->gid) || gid_eq(kgid, old->sgid))
444 new->egid = new->fsgid = kgid;
1da177e4 445 else
d84f4f99 446 goto error;
1da177e4 447
39030e13
TC		 448 retval = security_task_fix_setgid(new, old, LSM_SETID_ID);
449 if (retval < 0)
450 goto error;
451
d84f4f99
DH		 452 return commit_creds(new);
453
454error:
455 abort_creds(new);
456 return retval;
1da177e4 457}
54e99124 458
e530dca5
DB		 459SYSCALL_DEFINE1(setgid, gid_t, gid)
460{
461 return __sys_setgid(gid);
462}
463
d84f4f99
DH		 464/*
465 * change the user struct in a credentials set to match the new UID
466 */
467static int set_user(struct cred *new)
1da177e4
LT		 468{
469 struct user_struct *new_user;
470
078de5f7 471 new_user = alloc_uid(new->uid);
1da177e4
LT		 472 if (!new_user)
473 return -EAGAIN;
474
72fa5997
VK		 475 /*
476 * We don't fail in case of NPROC limit excess here because too many
477 * poorly written programs don't check set*uid() return code, assuming
478 * it never fails if called by root. We may still enforce NPROC limit
479 * for programs doing set*uid()+execve() by harmlessly deferring the
480 * failure to the execve() stage.
481 */
78d7d407 482 if (atomic_read(&new_user->processes) >= rlimit(RLIMIT_NPROC) &&
72fa5997
VK		 483 new_user != INIT_USER)
484 current->flags |= PF_NPROC_EXCEEDED;
485 else
486 current->flags &= ~PF_NPROC_EXCEEDED;
1da177e4 487
d84f4f99
DH		 488 free_uid(new->user);
489 new->user = new_user;
1da177e4
LT		 490 return 0;
491}
492
493/*
494 * Unprivileged users may change the real uid to the effective uid
495 * or vice versa. (BSD-style)
496 *
497 * If you set the real uid at all, or set the effective uid to a value not
498 * equal to the real uid, then the saved uid is set to the new effective uid.
499 *
500 * This makes it possible for a setuid program to completely drop its
501 * privileges, which is often a useful assertion to make when you are doing
502 * a security audit over a program.
503 *
504 * The general idea is that a program which uses just setreuid() will be
505 * 100% compatible with BSD. A program which uses just setuid() will be
ec94fc3d 506 * 100% compatible with POSIX with saved IDs.
1da177e4 507 */
e530dca5 508long __sys_setreuid(uid_t ruid, uid_t euid)
1da177e4 509{
a29c33f4 510 struct user_namespace *ns = current_user_ns();
d84f4f99
DH		 511 const struct cred *old;
512 struct cred *new;
1da177e4 513 int retval;
a29c33f4
EB		 514 kuid_t kruid, keuid;
515
516 kruid = make_kuid(ns, ruid);
517 keuid = make_kuid(ns, euid);
518
519 if ((ruid != (uid_t) -1) && !uid_valid(kruid))
520 return -EINVAL;
521 if ((euid != (uid_t) -1) && !uid_valid(keuid))
522 return -EINVAL;
1da177e4 523
d84f4f99
DH		 524 new = prepare_creds();
525 if (!new)
526 return -ENOMEM;
527 old = current_cred();
528
d84f4f99 529 retval = -EPERM;
1da177e4 530 if (ruid != (uid_t) -1) {
a29c33f4
EB		 531 new->uid = kruid;
532 if (!uid_eq(old->uid, kruid) &&
533 !uid_eq(old->euid, kruid) &&
40852275 534 !ns_capable_setid(old->user_ns, CAP_SETUID))
d84f4f99 535 goto error;
1da177e4
LT		 536 }
537
538 if (euid != (uid_t) -1) {
a29c33f4
EB		 539 new->euid = keuid;
540 if (!uid_eq(old->uid, keuid) &&
541 !uid_eq(old->euid, keuid) &&
542 !uid_eq(old->suid, keuid) &&
40852275 543 !ns_capable_setid(old->user_ns, CAP_SETUID))
d84f4f99 544 goto error;
1da177e4
LT		 545 }
546
a29c33f4 547 if (!uid_eq(new->uid, old->uid)) {
54e99124
DG		 548 retval = set_user(new);
549 if (retval < 0)
550 goto error;
551 }
1da177e4 552 if (ruid != (uid_t) -1 ||
a29c33f4 553 (euid != (uid_t) -1 && !uid_eq(keuid, old->uid)))
d84f4f99
DH		 554 new->suid = new->euid;
555 new->fsuid = new->euid;
1da177e4 556
d84f4f99
DH		 557 retval = security_task_fix_setuid(new, old, LSM_SETID_RE);
558 if (retval < 0)
559 goto error;
1da177e4 560
d84f4f99 561 return commit_creds(new);
1da177e4 562
d84f4f99
DH		 563error:
564 abort_creds(new);
565 return retval;
566}
ec94fc3d 567
e530dca5
DB		 568SYSCALL_DEFINE2(setreuid, uid_t, ruid, uid_t, euid)
569{
570 return __sys_setreuid(ruid, euid);
571}
572
1da177e4 573/*
ec94fc3d 574 * setuid() is implemented like SysV with SAVED_IDS
575 *
1da177e4 576 * Note that SAVED_ID's is deficient in that a setuid root program
ec94fc3d 577 * like sendmail, for example, cannot set its uid to be a normal
1da177e4
LT		 578 * user and then switch back, because if you're root, setuid() sets
579 * the saved uid too. If you don't like this, blame the bright people
580 * in the POSIX committee and/or USG. Note that the BSD-style setreuid()
581 * will allow a root program to temporarily drop privileges and be able to
ec94fc3d 582 * regain them by swapping the real and effective uid.
1da177e4 583 */
e530dca5 584long __sys_setuid(uid_t uid)
1da177e4 585{
a29c33f4 586 struct user_namespace *ns = current_user_ns();
d84f4f99
DH		 587 const struct cred *old;
588 struct cred *new;
1da177e4 589 int retval;
a29c33f4
EB		 590 kuid_t kuid;
591
592 kuid = make_kuid(ns, uid);
593 if (!uid_valid(kuid))
594 return -EINVAL;
1da177e4 595
d84f4f99
DH		 596 new = prepare_creds();
597 if (!new)
598 return -ENOMEM;
599 old = current_cred();
600
d84f4f99 601 retval = -EPERM;
40852275 602 if (ns_capable_setid(old->user_ns, CAP_SETUID)) {
a29c33f4
EB		 603 new->suid = new->uid = kuid;
604 if (!uid_eq(kuid, old->uid)) {
54e99124
DG		 605 retval = set_user(new);
606 if (retval < 0)
607 goto error;
d84f4f99 608 }
a29c33f4 609 } else if (!uid_eq(kuid, old->uid) && !uid_eq(kuid, new->suid)) {
d84f4f99 610 goto error;
1da177e4 611 }
1da177e4 612
a29c33f4 613 new->fsuid = new->euid = kuid;
d84f4f99
DH		 614
615 retval = security_task_fix_setuid(new, old, LSM_SETID_ID);
616 if (retval < 0)
617 goto error;
1da177e4 618
d84f4f99 619 return commit_creds(new);
1da177e4 620
d84f4f99
DH		 621error:
622 abort_creds(new);
623 return retval;
1da177e4
LT		 624}
625
e530dca5
DB		 626SYSCALL_DEFINE1(setuid, uid_t, uid)
627{
628 return __sys_setuid(uid);
629}
630
1da177e4
LT		 631
632/*
633 * This function implements a generic ability to update ruid, euid,
634 * and suid. This allows you to implement the 4.4 compatible seteuid().
635 */
e530dca5 636long __sys_setresuid(uid_t ruid, uid_t euid, uid_t suid)
1da177e4 637{
a29c33f4 638 struct user_namespace *ns = current_user_ns();
d84f4f99
DH		 639 const struct cred *old;
640 struct cred *new;
1da177e4 641 int retval;
a29c33f4
EB		 642 kuid_t kruid, keuid, ksuid;
643
644 kruid = make_kuid(ns, ruid);
645 keuid = make_kuid(ns, euid);
646 ksuid = make_kuid(ns, suid);
647
648 if ((ruid != (uid_t) -1) && !uid_valid(kruid))
649 return -EINVAL;
650
651 if ((euid != (uid_t) -1) && !uid_valid(keuid))
652 return -EINVAL;
653
654 if ((suid != (uid_t) -1) && !uid_valid(ksuid))
655 return -EINVAL;
1da177e4 656
d84f4f99
DH		 657 new = prepare_creds();
658 if (!new)
659 return -ENOMEM;
660
d84f4f99 661 old = current_cred();
1da177e4 662
d84f4f99 663 retval = -EPERM;
40852275 664 if (!ns_capable_setid(old->user_ns, CAP_SETUID)) {
a29c33f4
EB		 665 if (ruid != (uid_t) -1 && !uid_eq(kruid, old->uid) &&
666 !uid_eq(kruid, old->euid) && !uid_eq(kruid, old->suid))
d84f4f99 667 goto error;
a29c33f4
EB		 668 if (euid != (uid_t) -1 && !uid_eq(keuid, old->uid) &&
669 !uid_eq(keuid, old->euid) && !uid_eq(keuid, old->suid))
d84f4f99 670 goto error;
a29c33f4
EB		 671 if (suid != (uid_t) -1 && !uid_eq(ksuid, old->uid) &&
672 !uid_eq(ksuid, old->euid) && !uid_eq(ksuid, old->suid))
d84f4f99 673 goto error;
1da177e4 674 }
d84f4f99 675
1da177e4 676 if (ruid != (uid_t) -1) {
a29c33f4
EB		 677 new->uid = kruid;
678 if (!uid_eq(kruid, old->uid)) {
54e99124
DG		 679 retval = set_user(new);
680 if (retval < 0)
681 goto error;
682 }
1da177e4 683 }
d84f4f99 684 if (euid != (uid_t) -1)
a29c33f4 685 new->euid = keuid;
1da177e4 686 if (suid != (uid_t) -1)
a29c33f4 687 new->suid = ksuid;
d84f4f99 688 new->fsuid = new->euid;
1da177e4 689
d84f4f99
DH		 690 retval = security_task_fix_setuid(new, old, LSM_SETID_RES);
691 if (retval < 0)
692 goto error;
1da177e4 693
d84f4f99 694 return commit_creds(new);
1da177e4 695
d84f4f99
DH		 696error:
697 abort_creds(new);
698 return retval;
1da177e4
LT		 699}
700
e530dca5
DB		 701SYSCALL_DEFINE3(setresuid, uid_t, ruid, uid_t, euid, uid_t, suid)
702{
703 return __sys_setresuid(ruid, euid, suid);
704}
705
a29c33f4 706SYSCALL_DEFINE3(getresuid, uid_t __user *, ruidp, uid_t __user *, euidp, uid_t __user *, suidp)
1da177e4 707{
86a264ab 708 const struct cred *cred = current_cred();
1da177e4 709 int retval;
a29c33f4
EB		 710 uid_t ruid, euid, suid;
711
712 ruid = from_kuid_munged(cred->user_ns, cred->uid);
713 euid = from_kuid_munged(cred->user_ns, cred->euid);
714 suid = from_kuid_munged(cred->user_ns, cred->suid);
1da177e4 715
ec94fc3d 716 retval = put_user(ruid, ruidp);
717 if (!retval) {
718 retval = put_user(euid, euidp);
719 if (!retval)
720 return put_user(suid, suidp);
721 }
1da177e4
LT		 722 return retval;
723}
724
725/*
726 * Same as above, but for rgid, egid, sgid.
727 */
e530dca5 728long __sys_setresgid(gid_t rgid, gid_t egid, gid_t sgid)
1da177e4 729{
a29c33f4 730 struct user_namespace *ns = current_user_ns();
d84f4f99
DH		 731 const struct cred *old;
732 struct cred *new;
1da177e4 733 int retval;
a29c33f4
EB		 734 kgid_t krgid, kegid, ksgid;
735
736 krgid = make_kgid(ns, rgid);
737 kegid = make_kgid(ns, egid);
738 ksgid = make_kgid(ns, sgid);
739
740 if ((rgid != (gid_t) -1) && !gid_valid(krgid))
741 return -EINVAL;
742 if ((egid != (gid_t) -1) && !gid_valid(kegid))
743 return -EINVAL;
744 if ((sgid != (gid_t) -1) && !gid_valid(ksgid))
745 return -EINVAL;
1da177e4 746
d84f4f99
DH		 747 new = prepare_creds();
748 if (!new)
749 return -ENOMEM;
750 old = current_cred();
751
d84f4f99 752 retval = -EPERM;
111767c1 753 if (!ns_capable_setid(old->user_ns, CAP_SETGID)) {
a29c33f4
EB		 754 if (rgid != (gid_t) -1 && !gid_eq(krgid, old->gid) &&
755 !gid_eq(krgid, old->egid) && !gid_eq(krgid, old->sgid))
d84f4f99 756 goto error;
a29c33f4
EB		 757 if (egid != (gid_t) -1 && !gid_eq(kegid, old->gid) &&
758 !gid_eq(kegid, old->egid) && !gid_eq(kegid, old->sgid))
d84f4f99 759 goto error;
a29c33f4
EB		 760 if (sgid != (gid_t) -1 && !gid_eq(ksgid, old->gid) &&
761 !gid_eq(ksgid, old->egid) && !gid_eq(ksgid, old->sgid))
d84f4f99 762 goto error;
1da177e4 763 }
d84f4f99 764
1da177e4 765 if (rgid != (gid_t) -1)
a29c33f4 766 new->gid = krgid;
d84f4f99 767 if (egid != (gid_t) -1)
a29c33f4 768 new->egid = kegid;
1da177e4 769 if (sgid != (gid_t) -1)
a29c33f4 770 new->sgid = ksgid;
d84f4f99 771 new->fsgid = new->egid;
1da177e4 772
39030e13
TC		 773 retval = security_task_fix_setgid(new, old, LSM_SETID_RES);
774 if (retval < 0)
775 goto error;
776
d84f4f99
DH		 777 return commit_creds(new);
778
779error:
780 abort_creds(new);
781 return retval;
1da177e4
LT		 782}
783
e530dca5
DB		 784SYSCALL_DEFINE3(setresgid, gid_t, rgid, gid_t, egid, gid_t, sgid)
785{
786 return __sys_setresgid(rgid, egid, sgid);
787}
788
a29c33f4 789SYSCALL_DEFINE3(getresgid, gid_t __user *, rgidp, gid_t __user *, egidp, gid_t __user *, sgidp)
1da177e4 790{
86a264ab 791 const struct cred *cred = current_cred();
1da177e4 792 int retval;
a29c33f4
EB		 793 gid_t rgid, egid, sgid;
794
795 rgid = from_kgid_munged(cred->user_ns, cred->gid);
796 egid = from_kgid_munged(cred->user_ns, cred->egid);
797 sgid = from_kgid_munged(cred->user_ns, cred->sgid);
1da177e4 798
ec94fc3d 799 retval = put_user(rgid, rgidp);
800 if (!retval) {
801 retval = put_user(egid, egidp);
802 if (!retval)
803 retval = put_user(sgid, sgidp);
804 }
1da177e4
LT		 805
806 return retval;
807}
808
809
810/*
811 * "setfsuid()" sets the fsuid - the uid used for filesystem checks. This
812 * is used for "access()" and for the NFS daemon (letting nfsd stay at
813 * whatever uid it wants to). It normally shadows "euid", except when
814 * explicitly set by setfsuid() or for access..
815 */
e530dca5 816long __sys_setfsuid(uid_t uid)
1da177e4 817{
d84f4f99
DH		 818 const struct cred *old;
819 struct cred *new;
820 uid_t old_fsuid;
a29c33f4
EB		 821 kuid_t kuid;
822
823 old = current_cred();
824 old_fsuid = from_kuid_munged(old->user_ns, old->fsuid);
825
826 kuid = make_kuid(old->user_ns, uid);
827 if (!uid_valid(kuid))
828 return old_fsuid;
1da177e4 829
d84f4f99
DH		 830 new = prepare_creds();
831 if (!new)
a29c33f4 832 return old_fsuid;
1da177e4 833
a29c33f4
EB		 834 if (uid_eq(kuid, old->uid) || uid_eq(kuid, old->euid) ||
835 uid_eq(kuid, old->suid) || uid_eq(kuid, old->fsuid) ||
40852275 836 ns_capable_setid(old->user_ns, CAP_SETUID)) {
a29c33f4
EB		 837 if (!uid_eq(kuid, old->fsuid)) {
838 new->fsuid = kuid;
d84f4f99
DH		 839 if (security_task_fix_setuid(new, old, LSM_SETID_FS) == 0)
840 goto change_okay;
1da177e4 841 }
1da177e4
LT		 842 }
843
d84f4f99
DH		 844 abort_creds(new);
845 return old_fsuid;
1da177e4 846
d84f4f99
DH		 847change_okay:
848 commit_creds(new);
1da177e4
LT		 849 return old_fsuid;
850}
851
e530dca5
DB		 852SYSCALL_DEFINE1(setfsuid, uid_t, uid)
853{
854 return __sys_setfsuid(uid);
855}
856
1da177e4 857/*
f42df9e6 858 * Samma på svenska..
1da177e4 859 */
e530dca5 860long __sys_setfsgid(gid_t gid)
1da177e4 861{
d84f4f99
DH		 862 const struct cred *old;
863 struct cred *new;
864 gid_t old_fsgid;
a29c33f4
EB		 865 kgid_t kgid;
866
867 old = current_cred();
868 old_fsgid = from_kgid_munged(old->user_ns, old->fsgid);
869
870 kgid = make_kgid(old->user_ns, gid);
871 if (!gid_valid(kgid))
872 return old_fsgid;
d84f4f99
DH		 873
874 new = prepare_creds();
875 if (!new)
a29c33f4 876 return old_fsgid;
1da177e4 877
a29c33f4
EB		 878 if (gid_eq(kgid, old->gid) || gid_eq(kgid, old->egid) ||
879 gid_eq(kgid, old->sgid) || gid_eq(kgid, old->fsgid) ||
111767c1 880 ns_capable_setid(old->user_ns, CAP_SETGID)) {
a29c33f4
EB		 881 if (!gid_eq(kgid, old->fsgid)) {
882 new->fsgid = kgid;
39030e13
TC		 883 if (security_task_fix_setgid(new,old,LSM_SETID_FS) == 0)
884 goto change_okay;
1da177e4 885 }
1da177e4 886 }
d84f4f99 887
d84f4f99
DH		 888 abort_creds(new);
889 return old_fsgid;
890
891change_okay:
892 commit_creds(new);
1da177e4
LT		 893 return old_fsgid;
894}
e530dca5
DB		 895
896SYSCALL_DEFINE1(setfsgid, gid_t, gid)
897{
898 return __sys_setfsgid(gid);
899}
2813893f 900#endif /* CONFIG_MULTIUSER */
1da177e4 901
4a22f166
SR		 902/**
903 * sys_getpid - return the thread group id of the current process
904 *
905 * Note, despite the name, this returns the tgid not the pid. The tgid and
906 * the pid are identical unless CLONE_THREAD was specified on clone() in
907 * which case the tgid is the same in all threads of the same group.
908 *
909 * This is SMP safe as current->tgid does not change.
910 */
911SYSCALL_DEFINE0(getpid)
912{
913 return task_tgid_vnr(current);
914}
915
916/* Thread ID - the internal kernel "pid" */
917SYSCALL_DEFINE0(gettid)
918{
919 return task_pid_vnr(current);
920}
921
922/*
923 * Accessing ->real_parent is not SMP-safe, it could
924 * change from under us. However, we can use a stale
925 * value of ->real_parent under rcu_read_lock(), see
926 * release_task()->call_rcu(delayed_put_task_struct).
927 */
928SYSCALL_DEFINE0(getppid)
929{
930 int pid;
931
932 rcu_read_lock();
933 pid = task_tgid_vnr(rcu_dereference(current->real_parent));
934 rcu_read_unlock();
935
936 return pid;
937}
938
939SYSCALL_DEFINE0(getuid)
940{
941 /* Only we change this so SMP safe */
942 return from_kuid_munged(current_user_ns(), current_uid());
943}
944
945SYSCALL_DEFINE0(geteuid)
946{
947 /* Only we change this so SMP safe */
948 return from_kuid_munged(current_user_ns(), current_euid());
949}
950
951SYSCALL_DEFINE0(getgid)
952{
953 /* Only we change this so SMP safe */
954 return from_kgid_munged(current_user_ns(), current_gid());
955}
956
957SYSCALL_DEFINE0(getegid)
958{
959 /* Only we change this so SMP safe */
960 return from_kgid_munged(current_user_ns(), current_egid());
961}
962
ca2406ed 963static void do_sys_times(struct tms *tms)
f06febc9 964{
5613fda9 965 u64 tgutime, tgstime, cutime, cstime;
f06febc9 966
e80d0a1a 967 thread_group_cputime_adjusted(current, &tgutime, &tgstime);
f06febc9
FM		 968 cutime = current->signal->cutime;
969 cstime = current->signal->cstime;
5613fda9
FW		 970 tms->tms_utime = nsec_to_clock_t(tgutime);
971 tms->tms_stime = nsec_to_clock_t(tgstime);
972 tms->tms_cutime = nsec_to_clock_t(cutime);
973 tms->tms_cstime = nsec_to_clock_t(cstime);
f06febc9
FM		 974}
975
58fd3aa2 976SYSCALL_DEFINE1(times, struct tms __user *, tbuf)
1da177e4 977{
1da177e4
LT		 978 if (tbuf) {
979 struct tms tmp;
f06febc9
FM		 980
981 do_sys_times(&tmp);
1da177e4
LT		 982 if (copy_to_user(tbuf, &tmp, sizeof(struct tms)))
983 return -EFAULT;
984 }
e3d5a27d 985 force_successful_syscall_return();
1da177e4
LT		 986 return (long) jiffies_64_to_clock_t(get_jiffies_64());
987}
988
ca2406ed
AV		 989#ifdef CONFIG_COMPAT
990static compat_clock_t clock_t_to_compat_clock_t(clock_t x)
991{
992 return compat_jiffies_to_clock_t(clock_t_to_jiffies(x));
993}
994
995COMPAT_SYSCALL_DEFINE1(times, struct compat_tms __user *, tbuf)
996{
997 if (tbuf) {
998 struct tms tms;
999 struct compat_tms tmp;
1000
1001 do_sys_times(&tms);
1002 /* Convert our struct tms to the compat version. */
1003 tmp.tms_utime = clock_t_to_compat_clock_t(tms.tms_utime);
1004 tmp.tms_stime = clock_t_to_compat_clock_t(tms.tms_stime);
1005 tmp.tms_cutime = clock_t_to_compat_clock_t(tms.tms_cutime);
1006 tmp.tms_cstime = clock_t_to_compat_clock_t(tms.tms_cstime);
1007 if (copy_to_user(tbuf, &tmp, sizeof(tmp)))
1008 return -EFAULT;
1009 }
1010 force_successful_syscall_return();
1011 return compat_jiffies_to_clock_t(jiffies);
1012}
1013#endif
1014
1da177e4
LT		 1015/*
1016 * This needs some heavy checking ...
1017 * I just haven't the stomach for it. I also don't fully
1018 * understand sessions/pgrp etc. Let somebody who does explain it.
1019 *
1020 * OK, I think I have the protection semantics right.... this is really
1021 * only important on a multi-user system anyway, to make sure one user
1022 * can't send a signal to a process owned by another. -TYT, 12/12/91
1023 *
98611e4e 1024 * !PF_FORKNOEXEC check to conform completely to POSIX.
1da177e4 1025 */
b290ebe2 1026SYSCALL_DEFINE2(setpgid, pid_t, pid, pid_t, pgid)
1da177e4
LT		 1027{
1028 struct task_struct *p;
ee0acf90 1029 struct task_struct *group_leader = current->group_leader;
4e021306
ON		 1030 struct pid *pgrp;
1031 int err;
1da177e4
LT		 1032
1033 if (!pid)
b488893a 1034 pid = task_pid_vnr(group_leader);
1da177e4
LT		 1035 if (!pgid)
1036 pgid = pid;
1037 if (pgid < 0)
1038 return -EINVAL;
950eaaca 1039 rcu_read_lock();
1da177e4
LT		 1040
1041 /* From this point forward we keep holding onto the tasklist lock
1042 * so that our parent does not change from under us. -DaveM
1043 */
1044 write_lock_irq(&tasklist_lock);
1045
1046 err = -ESRCH;
4e021306 1047 p = find_task_by_vpid(pid);
1da177e4
LT		 1048 if (!p)
1049 goto out;
1050
1051 err = -EINVAL;
1052 if (!thread_group_leader(p))
1053 goto out;
1054
4e021306 1055 if (same_thread_group(p->real_parent, group_leader)) {
1da177e4 1056 err = -EPERM;
41487c65 1057 if (task_session(p) != task_session(group_leader))
1da177e4
LT		 1058 goto out;
1059 err = -EACCES;
98611e4e 1060 if (!(p->flags & PF_FORKNOEXEC))
1da177e4
LT		 1061 goto out;
1062 } else {
1063 err = -ESRCH;
ee0acf90 1064 if (p != group_leader)
1da177e4
LT		 1065 goto out;
1066 }
1067
1068 err = -EPERM;
1069 if (p->signal->leader)
1070 goto out;
1071
4e021306 1072 pgrp = task_pid(p);
1da177e4 1073 if (pgid != pid) {
b488893a 1074 struct task_struct *g;
1da177e4 1075
4e021306
ON		 1076 pgrp = find_vpid(pgid);
1077 g = pid_task(pgrp, PIDTYPE_PGID);
41487c65 1078 if (!g || task_session(g) != task_session(group_leader))
f020bc46 1079 goto out;
1da177e4
LT		 1080 }
1081
1da177e4
LT		 1082 err = security_task_setpgid(p, pgid);
1083 if (err)
1084 goto out;
1085
1b0f7ffd 1086 if (task_pgrp(p) != pgrp)
83beaf3c 1087 change_pid(p, PIDTYPE_PGID, pgrp);
1da177e4
LT		 1088
1089 err = 0;
1090out:
1091 /* All paths lead to here, thus we are safe. -DaveM */
1092 write_unlock_irq(&tasklist_lock);
950eaaca 1093 rcu_read_unlock();
1da177e4
LT		 1094 return err;
1095}
1096
192c5807 1097static int do_getpgid(pid_t pid)
1da177e4 1098{
12a3de0a
ON		 1099 struct task_struct *p;
1100 struct pid *grp;
1101 int retval;
1102
1103 rcu_read_lock();
756184b7 1104 if (!pid)
12a3de0a 1105 grp = task_pgrp(current);
756184b7 1106 else {
1da177e4 1107 retval = -ESRCH;
12a3de0a
ON		 1108 p = find_task_by_vpid(pid);
1109 if (!p)
1110 goto out;
1111 grp = task_pgrp(p);
1112 if (!grp)
1113 goto out;
1114
1115 retval = security_task_getpgid(p);
1116 if (retval)
1117 goto out;
1da177e4 1118 }
12a3de0a
ON		 1119 retval = pid_vnr(grp);
1120out:
1121 rcu_read_unlock();
1122 return retval;
1da177e4
LT		 1123}
1124
192c5807
DB		 1125SYSCALL_DEFINE1(getpgid, pid_t, pid)
1126{
1127 return do_getpgid(pid);
1128}
1129
1da177e4
LT		 1130#ifdef __ARCH_WANT_SYS_GETPGRP
1131
dbf040d9 1132SYSCALL_DEFINE0(getpgrp)
1da177e4 1133{
192c5807 1134 return do_getpgid(0);
1da177e4
LT		 1135}
1136
1137#endif
1138
dbf040d9 1139SYSCALL_DEFINE1(getsid, pid_t, pid)
1da177e4 1140{
1dd768c0
ON		 1141 struct task_struct *p;
1142 struct pid *sid;
1143 int retval;
1144
1145 rcu_read_lock();
756184b7 1146 if (!pid)
1dd768c0 1147 sid = task_session(current);
756184b7 1148 else {
1da177e4 1149 retval = -ESRCH;
1dd768c0
ON		 1150 p = find_task_by_vpid(pid);
1151 if (!p)
1152 goto out;
1153 sid = task_session(p);
1154 if (!sid)
1155 goto out;
1156
1157 retval = security_task_getsid(p);
1158 if (retval)
1159 goto out;
1da177e4 1160 }
1dd768c0
ON		 1161 retval = pid_vnr(sid);
1162out:
1163 rcu_read_unlock();
1164 return retval;
1da177e4
LT		 1165}
1166
81dabb46
ON		 1167static void set_special_pids(struct pid *pid)
1168{
1169 struct task_struct *curr = current->group_leader;
1170
1171 if (task_session(curr) != pid)
1172 change_pid(curr, PIDTYPE_SID, pid);
1173
1174 if (task_pgrp(curr) != pid)
1175 change_pid(curr, PIDTYPE_PGID, pid);
1176}
1177
e2aaa9f4 1178int ksys_setsid(void)
1da177e4 1179{
e19f247a 1180 struct task_struct *group_leader = current->group_leader;
e4cc0a9c
ON		 1181 struct pid *sid = task_pid(group_leader);
1182 pid_t session = pid_vnr(sid);
1da177e4
LT		 1183 int err = -EPERM;
1184
1da177e4 1185 write_lock_irq(&tasklist_lock);
390e2ff0
EB		 1186 /* Fail if I am already a session leader */
1187 if (group_leader->signal->leader)
1188 goto out;
1189
430c6231
ON		 1190 /* Fail if a process group id already exists that equals the
1191 * proposed session id.
390e2ff0 1192 */
6806aac6 1193 if (pid_task(sid, PIDTYPE_PGID))
1da177e4
LT		 1194 goto out;
1195
e19f247a 1196 group_leader->signal->leader = 1;
81dabb46 1197 set_special_pids(sid);
24ec839c 1198
9c9f4ded 1199 proc_clear_tty(group_leader);
24ec839c 1200
e4cc0a9c 1201 err = session;
1da177e4
LT		 1202out:
1203 write_unlock_irq(&tasklist_lock);
5091faa4 1204 if (err > 0) {
0d0df599 1205 proc_sid_connector(group_leader);
5091faa4
MG		 1206 sched_autogroup_create_attach(group_leader);
1207 }
1da177e4
LT		 1208 return err;
1209}
1210
e2aaa9f4
DB		 1211SYSCALL_DEFINE0(setsid)
1212{
1213 return ksys_setsid();
1214}
1215
1da177e4
LT		 1216DECLARE_RWSEM(uts_sem);
1217
e28cbf22
CH		 1218#ifdef COMPAT_UTS_MACHINE
1219#define override_architecture(name) \
46da2766 1220 (personality(current->personality) == PER_LINUX32 && \
e28cbf22
CH		 1221 copy_to_user(name->machine, COMPAT_UTS_MACHINE, \
1222 sizeof(COMPAT_UTS_MACHINE)))
1223#else
1224#define override_architecture(name) 0
1225#endif
1226
be27425d
AK		 1227/*
1228 * Work around broken programs that cannot handle "Linux 3.0".
1229 * Instead we map 3.x to 2.6.40+x, so e.g. 3.0 would be 2.6.40
b7285b42
JN		 1230 * And we map 4.x and later versions to 2.6.60+x, so 4.0/5.0/6.0/... would be
1231 * 2.6.60.
be27425d 1232 */
2702b152 1233static int override_release(char __user *release, size_t len)
be27425d
AK		 1234{
1235 int ret = 0;
be27425d
AK		 1236
1237 if (current->personality & UNAME26) {
2702b152
KC		 1238 const char *rest = UTS_RELEASE;
1239 char buf[65] = { 0 };
be27425d
AK		 1240 int ndots = 0;
1241 unsigned v;
2702b152 1242 size_t copy;
be27425d
AK		 1243
1244 while (*rest) {
1245 if (*rest == '.' && ++ndots >= 3)
1246 break;
1247 if (!isdigit(*rest) && *rest != '.')
1248 break;
1249 rest++;
1250 }
88a68672 1251 v = LINUX_VERSION_PATCHLEVEL + 60;
31fd84b9 1252 copy = clamp_t(size_t, len, 1, sizeof(buf));
2702b152
KC		 1253 copy = scnprintf(buf, copy, "2.6.%u%s", v, rest);
1254 ret = copy_to_user(release, buf, copy + 1);
be27425d
AK		 1255 }
1256 return ret;
1257}
1258
e48fbb69 1259SYSCALL_DEFINE1(newuname, struct new_utsname __user *, name)
1da177e4 1260{
42a0cc34 1261 struct new_utsname tmp;
1da177e4
LT		 1262
1263 down_read(&uts_sem);
42a0cc34 1264 memcpy(&tmp, utsname(), sizeof(tmp));
1da177e4 1265 up_read(&uts_sem);
42a0cc34
JH		 1266 if (copy_to_user(name, &tmp, sizeof(tmp)))
1267 return -EFAULT;
e28cbf22 1268
42a0cc34
JH		 1269 if (override_release(name->release, sizeof(name->release)))
1270 return -EFAULT;
1271 if (override_architecture(name))
1272 return -EFAULT;
1273 return 0;
1da177e4
LT		 1274}
1275
5cacdb4a
CH		 1276#ifdef __ARCH_WANT_SYS_OLD_UNAME
1277/*
1278 * Old cruft
1279 */
1280SYSCALL_DEFINE1(uname, struct old_utsname __user *, name)
1281{
42a0cc34 1282 struct old_utsname tmp;
5cacdb4a
CH		 1283
1284 if (!name)
1285 return -EFAULT;
1286
1287 down_read(&uts_sem);
42a0cc34 1288 memcpy(&tmp, utsname(), sizeof(tmp));
5cacdb4a 1289 up_read(&uts_sem);
42a0cc34
JH		 1290 if (copy_to_user(name, &tmp, sizeof(tmp)))
1291 return -EFAULT;
5cacdb4a 1292
42a0cc34
JH		 1293 if (override_release(name->release, sizeof(name->release)))
1294 return -EFAULT;
1295 if (override_architecture(name))
1296 return -EFAULT;
1297 return 0;
5cacdb4a
CH		 1298}
1299
1300SYSCALL_DEFINE1(olduname, struct oldold_utsname __user *, name)
1301{
5e1aada0 1302 struct oldold_utsname tmp;
5cacdb4a
CH		 1303
1304 if (!name)
1305 return -EFAULT;
5cacdb4a 1306
5e1aada0
JP		 1307 memset(&tmp, 0, sizeof(tmp));
1308
5cacdb4a 1309 down_read(&uts_sem);
42a0cc34
JH		 1310 memcpy(&tmp.sysname, &utsname()->sysname, __OLD_UTS_LEN);
1311 memcpy(&tmp.nodename, &utsname()->nodename, __OLD_UTS_LEN);
1312 memcpy(&tmp.release, &utsname()->release, __OLD_UTS_LEN);
1313 memcpy(&tmp.version, &utsname()->version, __OLD_UTS_LEN);
1314 memcpy(&tmp.machine, &utsname()->machine, __OLD_UTS_LEN);
5cacdb4a 1315 up_read(&uts_sem);
42a0cc34
JH		 1316 if (copy_to_user(name, &tmp, sizeof(tmp)))
1317 return -EFAULT;
5cacdb4a 1318
42a0cc34
JH		 1319 if (override_architecture(name))
1320 return -EFAULT;
1321 if (override_release(name->release, sizeof(name->release)))
1322 return -EFAULT;
1323 return 0;
5cacdb4a
CH		 1324}
1325#endif
1326
5a8a82b1 1327SYSCALL_DEFINE2(sethostname, char __user *, name, int, len)
1da177e4
LT		 1328{
1329 int errno;
1330 char tmp[__NEW_UTS_LEN];
1331
bb96a6f5 1332 if (!ns_capable(current->nsproxy->uts_ns->user_ns, CAP_SYS_ADMIN))
1da177e4 1333 return -EPERM;
fc832ad3 1334
1da177e4
LT		 1335 if (len < 0 || len > __NEW_UTS_LEN)
1336 return -EINVAL;
1da177e4
LT		 1337 errno = -EFAULT;
1338 if (!copy_from_user(tmp, name, len)) {
42a0cc34 1339 struct new_utsname *u;
9679e4dd 1340
42a0cc34
JH		 1341 down_write(&uts_sem);
1342 u = utsname();
9679e4dd
AM		 1343 memcpy(u->nodename, tmp, len);
1344 memset(u->nodename + len, 0, sizeof(u->nodename) - len);
1da177e4 1345 errno = 0;
499eea6b 1346 uts_proc_notify(UTS_PROC_HOSTNAME);
42a0cc34 1347 up_write(&uts_sem);
1da177e4 1348 }
1da177e4
LT		 1349 return errno;
1350}
1351
1352#ifdef __ARCH_WANT_SYS_GETHOSTNAME
1353
5a8a82b1 1354SYSCALL_DEFINE2(gethostname, char __user *, name, int, len)
1da177e4 1355{
42a0cc34 1356 int i;
9679e4dd 1357 struct new_utsname *u;
42a0cc34 1358 char tmp[__NEW_UTS_LEN + 1];
1da177e4
LT		 1359
1360 if (len < 0)
1361 return -EINVAL;
1362 down_read(&uts_sem);
9679e4dd
AM		 1363 u = utsname();
1364 i = 1 + strlen(u->nodename);
1da177e4
LT		 1365 if (i > len)
1366 i = len;
42a0cc34 1367 memcpy(tmp, u->nodename, i);
1da177e4 1368 up_read(&uts_sem);
42a0cc34
JH		 1369 if (copy_to_user(name, tmp, i))
1370 return -EFAULT;
1371 return 0;
1da177e4
LT		 1372}
1373
1374#endif
1375
1376/*
1377 * Only setdomainname; getdomainname can be implemented by calling
1378 * uname()
1379 */
5a8a82b1 1380SYSCALL_DEFINE2(setdomainname, char __user *, name, int, len)
1da177e4
LT		 1381{
1382 int errno;
1383 char tmp[__NEW_UTS_LEN];
1384
fc832ad3 1385 if (!ns_capable(current->nsproxy->uts_ns->user_ns, CAP_SYS_ADMIN))
1da177e4
LT		 1386 return -EPERM;
1387 if (len < 0 || len > __NEW_UTS_LEN)
1388 return -EINVAL;
1389
1da177e4
LT		 1390 errno = -EFAULT;
1391 if (!copy_from_user(tmp, name, len)) {
42a0cc34 1392 struct new_utsname *u;
9679e4dd 1393
42a0cc34
JH		 1394 down_write(&uts_sem);
1395 u = utsname();
9679e4dd
AM		 1396 memcpy(u->domainname, tmp, len);
1397 memset(u->domainname + len, 0, sizeof(u->domainname) - len);
1da177e4 1398 errno = 0;
499eea6b 1399 uts_proc_notify(UTS_PROC_DOMAINNAME);
42a0cc34 1400 up_write(&uts_sem);
1da177e4 1401 }
1da177e4
LT		 1402 return errno;
1403}
1404
e48fbb69 1405SYSCALL_DEFINE2(getrlimit, unsigned int, resource, struct rlimit __user *, rlim)
1da177e4 1406{
b9518345
JS		 1407 struct rlimit value;
1408 int ret;
1409
1410 ret = do_prlimit(current, resource, NULL, &value);
1411 if (!ret)
1412 ret = copy_to_user(rlim, &value, sizeof(*rlim)) ? -EFAULT : 0;
1413
1414 return ret;
1da177e4
LT		 1415}
1416
d9e968cb
AV		 1417#ifdef CONFIG_COMPAT
1418
1419COMPAT_SYSCALL_DEFINE2(setrlimit, unsigned int, resource,
1420 struct compat_rlimit __user *, rlim)
1421{
1422 struct rlimit r;
1423 struct compat_rlimit r32;
1424
1425 if (copy_from_user(&r32, rlim, sizeof(struct compat_rlimit)))
1426 return -EFAULT;
1427
1428 if (r32.rlim_cur == COMPAT_RLIM_INFINITY)
1429 r.rlim_cur = RLIM_INFINITY;
1430 else
1431 r.rlim_cur = r32.rlim_cur;
1432 if (r32.rlim_max == COMPAT_RLIM_INFINITY)
1433 r.rlim_max = RLIM_INFINITY;
1434 else
1435 r.rlim_max = r32.rlim_max;
1436 return do_prlimit(current, resource, &r, NULL);
1437}
1438
1439COMPAT_SYSCALL_DEFINE2(getrlimit, unsigned int, resource,
1440 struct compat_rlimit __user *, rlim)
1441{
1442 struct rlimit r;
1443 int ret;
1444
1445 ret = do_prlimit(current, resource, NULL, &r);
1446 if (!ret) {
58c7ffc0 1447 struct compat_rlimit r32;
d9e968cb
AV		 1448 if (r.rlim_cur > COMPAT_RLIM_INFINITY)
1449 r32.rlim_cur = COMPAT_RLIM_INFINITY;
1450 else
1451 r32.rlim_cur = r.rlim_cur;
1452 if (r.rlim_max > COMPAT_RLIM_INFINITY)
1453 r32.rlim_max = COMPAT_RLIM_INFINITY;
1454 else
1455 r32.rlim_max = r.rlim_max;
1456
1457 if (copy_to_user(rlim, &r32, sizeof(struct compat_rlimit)))
1458 return -EFAULT;
1459 }
1460 return ret;
1461}
1462
1463#endif
1464
1da177e4
LT		 1465#ifdef __ARCH_WANT_SYS_OLD_GETRLIMIT
1466
1467/*
1468 * Back compatibility for getrlimit. Needed for some apps.
1469 */
e48fbb69
HC		 1470SYSCALL_DEFINE2(old_getrlimit, unsigned int, resource,
1471 struct rlimit __user *, rlim)
1da177e4
LT		 1472{
1473 struct rlimit x;
1474 if (resource >= RLIM_NLIMITS)
1475 return -EINVAL;
1476
23d6aef7 1477 resource = array_index_nospec(resource, RLIM_NLIMITS);
1da177e4
LT		 1478 task_lock(current->group_leader);
1479 x = current->signal->rlim[resource];
1480 task_unlock(current->group_leader);
756184b7 1481 if (x.rlim_cur > 0x7FFFFFFF)
1da177e4 1482 x.rlim_cur = 0x7FFFFFFF;
756184b7 1483 if (x.rlim_max > 0x7FFFFFFF)
1da177e4 1484 x.rlim_max = 0x7FFFFFFF;
ec94fc3d 1485 return copy_to_user(rlim, &x, sizeof(x)) ? -EFAULT : 0;
1da177e4
LT		 1486}
1487
613763a1
AV		 1488#ifdef CONFIG_COMPAT
1489COMPAT_SYSCALL_DEFINE2(old_getrlimit, unsigned int, resource,
1490 struct compat_rlimit __user *, rlim)
1491{
1492 struct rlimit r;
1493
1494 if (resource >= RLIM_NLIMITS)
1495 return -EINVAL;
1496
23d6aef7 1497 resource = array_index_nospec(resource, RLIM_NLIMITS);
613763a1
AV		 1498 task_lock(current->group_leader);
1499 r = current->signal->rlim[resource];
1500 task_unlock(current->group_leader);
1501 if (r.rlim_cur > 0x7FFFFFFF)
1502 r.rlim_cur = 0x7FFFFFFF;
1503 if (r.rlim_max > 0x7FFFFFFF)
1504 r.rlim_max = 0x7FFFFFFF;
1505
1506 if (put_user(r.rlim_cur, &rlim->rlim_cur) ||
1507 put_user(r.rlim_max, &rlim->rlim_max))
1508 return -EFAULT;
1509 return 0;
1510}
1511#endif
1512
1da177e4
LT		 1513#endif
1514
c022a0ac
JS		 1515static inline bool rlim64_is_infinity(__u64 rlim64)
1516{
1517#if BITS_PER_LONG < 64
1518 return rlim64 >= ULONG_MAX;
1519#else
1520 return rlim64 == RLIM64_INFINITY;
1521#endif
1522}
1523
1524static void rlim_to_rlim64(const struct rlimit *rlim, struct rlimit64 *rlim64)
1525{
1526 if (rlim->rlim_cur == RLIM_INFINITY)
1527 rlim64->rlim_cur = RLIM64_INFINITY;
1528 else
1529 rlim64->rlim_cur = rlim->rlim_cur;
1530 if (rlim->rlim_max == RLIM_INFINITY)
1531 rlim64->rlim_max = RLIM64_INFINITY;
1532 else
1533 rlim64->rlim_max = rlim->rlim_max;
1534}
1535
1536static void rlim64_to_rlim(const struct rlimit64 *rlim64, struct rlimit *rlim)
1537{
1538 if (rlim64_is_infinity(rlim64->rlim_cur))
1539 rlim->rlim_cur = RLIM_INFINITY;
1540 else
1541 rlim->rlim_cur = (unsigned long)rlim64->rlim_cur;
1542 if (rlim64_is_infinity(rlim64->rlim_max))
1543 rlim->rlim_max = RLIM_INFINITY;
1544 else
1545 rlim->rlim_max = (unsigned long)rlim64->rlim_max;
1546}
1547
1c1e618d 1548/* make sure you are allowed to change @tsk limits before calling this */
5b41535a
JS		 1549int do_prlimit(struct task_struct *tsk, unsigned int resource,
1550 struct rlimit *new_rlim, struct rlimit *old_rlim)
1da177e4 1551{
5b41535a 1552 struct rlimit *rlim;
86f162f4 1553 int retval = 0;
1da177e4
LT		 1554
1555 if (resource >= RLIM_NLIMITS)
1556 return -EINVAL;
5b41535a
JS		 1557 if (new_rlim) {
1558 if (new_rlim->rlim_cur > new_rlim->rlim_max)
1559 return -EINVAL;
1560 if (resource == RLIMIT_NOFILE &&
1561 new_rlim->rlim_max > sysctl_nr_open)
1562 return -EPERM;
1563 }
1da177e4 1564
1c1e618d
JS		 1565 /* protect tsk->signal and tsk->sighand from disappearing */
1566 read_lock(&tasklist_lock);
1567 if (!tsk->sighand) {
1568 retval = -ESRCH;
1569 goto out;
1570 }
1571
5b41535a 1572 rlim = tsk->signal->rlim + resource;
86f162f4 1573 task_lock(tsk->group_leader);
5b41535a 1574 if (new_rlim) {
fc832ad3
SH		 1575 /* Keep the capable check against init_user_ns until
1576 cgroups can contain all limits */
5b41535a
JS		 1577 if (new_rlim->rlim_max > rlim->rlim_max &&
1578 !capable(CAP_SYS_RESOURCE))
1579 retval = -EPERM;
1580 if (!retval)
cad4ea54 1581 retval = security_task_setrlimit(tsk, resource, new_rlim);
5b41535a
JS		 1582 }
1583 if (!retval) {
1584 if (old_rlim)
1585 *old_rlim = *rlim;
1586 if (new_rlim)
1587 *rlim = *new_rlim;
9926e4c7 1588 }
7855c35d 1589 task_unlock(tsk->group_leader);
1da177e4 1590
d3561f78 1591 /*
24db4dd9 1592 * RLIMIT_CPU handling. Arm the posix CPU timer if the limit is not
5afe69c2 1593 * infinite. In case of RLIM_INFINITY the posix CPU timer code
24db4dd9 1594 * ignores the rlimit.
d3561f78 1595 */
5b41535a 1596 if (!retval && new_rlim && resource == RLIMIT_CPU &&
baa73d9e
NP		 1597 new_rlim->rlim_cur != RLIM_INFINITY &&
1598 IS_ENABLED(CONFIG_POSIX_TIMERS))
5b41535a 1599 update_rlimit_cpu(tsk, new_rlim->rlim_cur);
ec9e16ba 1600out:
1c1e618d 1601 read_unlock(&tasklist_lock);
2fb9d268 1602 return retval;
1da177e4
LT		 1603}
1604
c022a0ac 1605/* rcu lock must be held */
791ec491
SS		 1606static int check_prlimit_permission(struct task_struct *task,
1607 unsigned int flags)
c022a0ac
JS		 1608{
1609 const struct cred *cred = current_cred(), *tcred;
791ec491 1610 bool id_match;
c022a0ac 1611
fc832ad3
SH		 1612 if (current == task)
1613 return 0;
c022a0ac 1614
fc832ad3 1615 tcred = __task_cred(task);
791ec491
SS		 1616 id_match = (uid_eq(cred->uid, tcred->euid) &&
1617 uid_eq(cred->uid, tcred->suid) &&
1618 uid_eq(cred->uid, tcred->uid) &&
1619 gid_eq(cred->gid, tcred->egid) &&
1620 gid_eq(cred->gid, tcred->sgid) &&
1621 gid_eq(cred->gid, tcred->gid));
1622 if (!id_match && !ns_capable(tcred->user_ns, CAP_SYS_RESOURCE))
1623 return -EPERM;
fc832ad3 1624
791ec491 1625 return security_task_prlimit(cred, tcred, flags);
c022a0ac
JS		 1626}
1627
1628SYSCALL_DEFINE4(prlimit64, pid_t, pid, unsigned int, resource,
1629 const struct rlimit64 __user *, new_rlim,
1630 struct rlimit64 __user *, old_rlim)
1631{
1632 struct rlimit64 old64, new64;
1633 struct rlimit old, new;
1634 struct task_struct *tsk;
791ec491 1635 unsigned int checkflags = 0;
c022a0ac
JS		 1636 int ret;
1637
791ec491
SS		 1638 if (old_rlim)
1639 checkflags |= LSM_PRLIMIT_READ;
1640
c022a0ac
JS		 1641 if (new_rlim) {
1642 if (copy_from_user(&new64, new_rlim, sizeof(new64)))
1643 return -EFAULT;
1644 rlim64_to_rlim(&new64, &new);
791ec491 1645 checkflags |= LSM_PRLIMIT_WRITE;
c022a0ac
JS		 1646 }
1647
1648 rcu_read_lock();
1649 tsk = pid ? find_task_by_vpid(pid) : current;
1650 if (!tsk) {
1651 rcu_read_unlock();
1652 return -ESRCH;
1653 }
791ec491 1654 ret = check_prlimit_permission(tsk, checkflags);
c022a0ac
JS		 1655 if (ret) {
1656 rcu_read_unlock();
1657 return ret;
1658 }
1659 get_task_struct(tsk);
1660 rcu_read_unlock();
1661
1662 ret = do_prlimit(tsk, resource, new_rlim ? &new : NULL,
1663 old_rlim ? &old : NULL);
1664
1665 if (!ret && old_rlim) {
1666 rlim_to_rlim64(&old, &old64);
1667 if (copy_to_user(old_rlim, &old64, sizeof(old64)))
1668 ret = -EFAULT;
1669 }
1670
1671 put_task_struct(tsk);
1672 return ret;
1673}
1674
7855c35d
JS		 1675SYSCALL_DEFINE2(setrlimit, unsigned int, resource, struct rlimit __user *, rlim)
1676{
1677 struct rlimit new_rlim;
1678
1679 if (copy_from_user(&new_rlim, rlim, sizeof(*rlim)))
1680 return -EFAULT;
5b41535a 1681 return do_prlimit(current, resource, &new_rlim, NULL);
7855c35d
JS		 1682}
1683
1da177e4
LT		 1684/*
1685 * It would make sense to put struct rusage in the task_struct,
1686 * except that would make the task_struct be *really big*. After
1687 * task_struct gets moved into malloc'ed memory, it would
1688 * make sense to do this. It will make moving the rest of the information
1689 * a lot simpler! (Which we're not doing right now because we're not
1690 * measuring them yet).
1691 *
1da177e4
LT		 1692 * When sampling multiple threads for RUSAGE_SELF, under SMP we might have
1693 * races with threads incrementing their own counters. But since word
1694 * reads are atomic, we either get new values or old values and we don't
1695 * care which for the sums. We always take the siglock to protect reading
1696 * the c* fields from p->signal from races with exit.c updating those
1697 * fields when reaping, so a sample either gets all the additions of a
1698 * given child after it's reaped, or none so this sample is before reaping.
2dd0ebcd 1699 *
de047c1b
RT		 1700 * Locking:
1701 * We need to take the siglock for CHILDEREN, SELF and BOTH
1702 * for the cases current multithreaded, non-current single threaded
1703 * non-current multithreaded. Thread traversal is now safe with
1704 * the siglock held.
1705 * Strictly speaking, we donot need to take the siglock if we are current and
1706 * single threaded, as no one else can take our signal_struct away, no one
1707 * else can reap the children to update signal->c* counters, and no one else
1708 * can race with the signal-> fields. If we do not take any lock, the
1709 * signal-> fields could be read out of order while another thread was just
1710 * exiting. So we should place a read memory barrier when we avoid the lock.
1711 * On the writer side, write memory barrier is implied in __exit_signal
1712 * as __exit_signal releases the siglock spinlock after updating the signal->
1713 * fields. But we don't do this yet to keep things simple.
2dd0ebcd 1714 *
1da177e4
LT		 1715 */
1716
f06febc9 1717static void accumulate_thread_rusage(struct task_struct *t, struct rusage *r)
679c9cd4 1718{
679c9cd4
SK		 1719 r->ru_nvcsw += t->nvcsw;
1720 r->ru_nivcsw += t->nivcsw;
1721 r->ru_minflt += t->min_flt;
1722 r->ru_majflt += t->maj_flt;
1723 r->ru_inblock += task_io_get_inblock(t);
1724 r->ru_oublock += task_io_get_oublock(t);
1725}
1726
ce72a16f 1727void getrusage(struct task_struct *p, int who, struct rusage *r)
1da177e4
LT		 1728{
1729 struct task_struct *t;
1730 unsigned long flags;
5613fda9 1731 u64 tgutime, tgstime, utime, stime;
1f10206c 1732 unsigned long maxrss = 0;
1da177e4 1733
ec94fc3d 1734 memset((char *)r, 0, sizeof (*r));
64861634 1735 utime = stime = 0;
1da177e4 1736
679c9cd4 1737 if (who == RUSAGE_THREAD) {
e80d0a1a 1738 task_cputime_adjusted(current, &utime, &stime);
f06febc9 1739 accumulate_thread_rusage(p, r);
1f10206c 1740 maxrss = p->signal->maxrss;
679c9cd4
SK		 1741 goto out;
1742 }
1743
d6cf723a 1744 if (!lock_task_sighand(p, &flags))
de047c1b 1745 return;
0f59cc4a 1746
1da177e4 1747 switch (who) {
ec94fc3d 1748 case RUSAGE_BOTH:
1749 case RUSAGE_CHILDREN:
1750 utime = p->signal->cutime;
1751 stime = p->signal->cstime;
1752 r->ru_nvcsw = p->signal->cnvcsw;
1753 r->ru_nivcsw = p->signal->cnivcsw;
1754 r->ru_minflt = p->signal->cmin_flt;
1755 r->ru_majflt = p->signal->cmaj_flt;
1756 r->ru_inblock = p->signal->cinblock;
1757 r->ru_oublock = p->signal->coublock;
1758 maxrss = p->signal->cmaxrss;
1759
1760 if (who == RUSAGE_CHILDREN)
1da177e4 1761 break;
df561f66 1762 fallthrough;
0f59cc4a 1763
ec94fc3d 1764 case RUSAGE_SELF:
1765 thread_group_cputime_adjusted(p, &tgutime, &tgstime);
1766 utime += tgutime;
1767 stime += tgstime;
1768 r->ru_nvcsw += p->signal->nvcsw;
1769 r->ru_nivcsw += p->signal->nivcsw;
1770 r->ru_minflt += p->signal->min_flt;
1771 r->ru_majflt += p->signal->maj_flt;
1772 r->ru_inblock += p->signal->inblock;
1773 r->ru_oublock += p->signal->oublock;
1774 if (maxrss < p->signal->maxrss)
1775 maxrss = p->signal->maxrss;
1776 t = p;
1777 do {
1778 accumulate_thread_rusage(t, r);
1779 } while_each_thread(p, t);
1780 break;
1781
1782 default:
1783 BUG();
1da177e4 1784 }
de047c1b 1785 unlock_task_sighand(p, &flags);
de047c1b 1786
679c9cd4 1787out:
bdd565f8
AB		 1788 r->ru_utime = ns_to_kernel_old_timeval(utime);
1789 r->ru_stime = ns_to_kernel_old_timeval(stime);
1f10206c
JP		 1790
1791 if (who != RUSAGE_CHILDREN) {
1792 struct mm_struct *mm = get_task_mm(p);
ec94fc3d 1793
1f10206c
JP		 1794 if (mm) {
1795 setmax_mm_hiwater_rss(&maxrss, mm);
1796 mmput(mm);
1797 }
1798 }
1799 r->ru_maxrss = maxrss * (PAGE_SIZE / 1024); /* convert pages to KBs */
1da177e4
LT		 1800}
1801
ce72a16f 1802SYSCALL_DEFINE2(getrusage, int, who, struct rusage __user *, ru)
1da177e4
LT		 1803{
1804 struct rusage r;
ec94fc3d 1805
679c9cd4
SK		 1806 if (who != RUSAGE_SELF && who != RUSAGE_CHILDREN &&
1807 who != RUSAGE_THREAD)
1da177e4 1808 return -EINVAL;
ce72a16f
AV		 1809
1810 getrusage(current, who, &r);
1811 return copy_to_user(ru, &r, sizeof(r)) ? -EFAULT : 0;
1da177e4
LT		 1812}
1813
8d2d5c4a
AV		 1814#ifdef CONFIG_COMPAT
1815COMPAT_SYSCALL_DEFINE2(getrusage, int, who, struct compat_rusage __user *, ru)
1816{
1817 struct rusage r;
1818
1819 if (who != RUSAGE_SELF && who != RUSAGE_CHILDREN &&
1820 who != RUSAGE_THREAD)
1821 return -EINVAL;
1822
ce72a16f 1823 getrusage(current, who, &r);
8d2d5c4a
AV		 1824 return put_compat_rusage(&r, ru);
1825}
1826#endif
1827
e48fbb69 1828SYSCALL_DEFINE1(umask, int, mask)
1da177e4
LT		 1829{
1830 mask = xchg(&current->fs->umask, mask & S_IRWXUGO);
1831 return mask;
1832}
3b7391de 1833
6e399cd1 1834static int prctl_set_mm_exe_file(struct mm_struct *mm, unsigned int fd)
b32dfe37 1835{
2903ff01 1836 struct fd exe;
6e399cd1 1837 struct file *old_exe, *exe_file;
496ad9aa 1838 struct inode *inode;
2903ff01 1839 int err;
b32dfe37 1840
2903ff01
AV		 1841 exe = fdget(fd);
1842 if (!exe.file)
b32dfe37
CG		 1843 return -EBADF;
1844
496ad9aa 1845 inode = file_inode(exe.file);
b32dfe37
CG		 1846
1847 /*
1848 * Because the original mm->exe_file points to executable file, make
1849 * sure that this one is executable as well, to avoid breaking an
1850 * overall picture.
1851 */
1852 err = -EACCES;
90f8572b 1853 if (!S_ISREG(inode->i_mode) || path_noexec(&exe.file->f_path))
b32dfe37
CG		 1854 goto exit;
1855
02f92b38 1856 err = file_permission(exe.file, MAY_EXEC);
b32dfe37
CG		 1857 if (err)
1858 goto exit;
1859
bafb282d 1860 /*
4229fb1d 1861 * Forbid mm->exe_file change if old file still mapped.
bafb282d 1862 */
6e399cd1 1863 exe_file = get_mm_exe_file(mm);
bafb282d 1864 err = -EBUSY;
6e399cd1 1865 if (exe_file) {
4229fb1d
KK		 1866 struct vm_area_struct *vma;
1867
d8ed45c5 1868 mmap_read_lock(mm);
6e399cd1
DB		 1869 for (vma = mm->mmap; vma; vma = vma->vm_next) {
1870 if (!vma->vm_file)
1871 continue;
1872 if (path_equal(&vma->vm_file->f_path,
1873 &exe_file->f_path))
1874 goto exit_err;
1875 }
1876
d8ed45c5 1877 mmap_read_unlock(mm);
6e399cd1 1878 fput(exe_file);
bafb282d
KK		 1879 }
1880
4229fb1d 1881 err = 0;
6e399cd1
DB		 1882 /* set the new file, lockless */
1883 get_file(exe.file);
1884 old_exe = xchg(&mm->exe_file, exe.file);
1885 if (old_exe)
1886 fput(old_exe);
b32dfe37 1887exit:
2903ff01 1888 fdput(exe);
b32dfe37 1889 return err;
6e399cd1 1890exit_err:
d8ed45c5 1891 mmap_read_unlock(mm);
6e399cd1
DB		 1892 fput(exe_file);
1893 goto exit;
b32dfe37
CG		 1894}
1895
f606b77f 1896/*
11bbd8b4
MK		 1897 * Check arithmetic relations of passed addresses.
1898 *
f606b77f
CG		 1899 * WARNING: we don't require any capability here so be very careful
1900 * in what is allowed for modification from userspace.
1901 */
11bbd8b4 1902static int validate_prctl_map_addr(struct prctl_mm_map *prctl_map)
f606b77f
CG		 1903{
1904 unsigned long mmap_max_addr = TASK_SIZE;
f606b77f
CG		 1905 int error = -EINVAL, i;
1906
1907 static const unsigned char offsets[] = {
1908 offsetof(struct prctl_mm_map, start_code),
1909 offsetof(struct prctl_mm_map, end_code),
1910 offsetof(struct prctl_mm_map, start_data),
1911 offsetof(struct prctl_mm_map, end_data),
1912 offsetof(struct prctl_mm_map, start_brk),
1913 offsetof(struct prctl_mm_map, brk),
1914 offsetof(struct prctl_mm_map, start_stack),
1915 offsetof(struct prctl_mm_map, arg_start),
1916 offsetof(struct prctl_mm_map, arg_end),
1917 offsetof(struct prctl_mm_map, env_start),
1918 offsetof(struct prctl_mm_map, env_end),
1919 };
1920
1921 /*
1922 * Make sure the members are not somewhere outside
1923 * of allowed address space.
1924 */
1925 for (i = 0; i < ARRAY_SIZE(offsets); i++) {
1926 u64 val = *(u64 *)((char *)prctl_map + offsets[i]);
1927
1928 if ((unsigned long)val >= mmap_max_addr ||
1929 (unsigned long)val < mmap_min_addr)
1930 goto out;
1931 }
1932
1933 /*
1934 * Make sure the pairs are ordered.
1935 */
1936#define __prctl_check_order(__m1, __op, __m2) \
1937 ((unsigned long)prctl_map->__m1 __op \
1938 (unsigned long)prctl_map->__m2) ? 0 : -EINVAL
1939 error = __prctl_check_order(start_code, <, end_code);
a9e73998 1940 error |= __prctl_check_order(start_data,<=, end_data);
f606b77f
CG		 1941 error |= __prctl_check_order(start_brk, <=, brk);
1942 error |= __prctl_check_order(arg_start, <=, arg_end);
1943 error |= __prctl_check_order(env_start, <=, env_end);
1944 if (error)
1945 goto out;
1946#undef __prctl_check_order
1947
1948 error = -EINVAL;
1949
1950 /*
1951 * @brk should be after @end_data in traditional maps.
1952 */
1953 if (prctl_map->start_brk <= prctl_map->end_data ||
1954 prctl_map->brk <= prctl_map->end_data)
1955 goto out;
1956
1957 /*
1958 * Neither we should allow to override limits if they set.
1959 */
1960 if (check_data_rlimit(rlimit(RLIMIT_DATA), prctl_map->brk,
1961 prctl_map->start_brk, prctl_map->end_data,
1962 prctl_map->start_data))
1963 goto out;
1964
f606b77f
CG		 1965 error = 0;
1966out:
1967 return error;
1968}
1969
4a00e9df 1970#ifdef CONFIG_CHECKPOINT_RESTORE
f606b77f
CG		 1971static int prctl_set_mm_map(int opt, const void __user *addr, unsigned long data_size)
1972{
1973 struct prctl_mm_map prctl_map = { .exe_fd = (u32)-1, };
1974 unsigned long user_auxv[AT_VECTOR_SIZE];
1975 struct mm_struct *mm = current->mm;
1976 int error;
1977
1978 BUILD_BUG_ON(sizeof(user_auxv) != sizeof(mm->saved_auxv));
1979 BUILD_BUG_ON(sizeof(struct prctl_mm_map) > 256);
1980
1981 if (opt == PR_SET_MM_MAP_SIZE)
1982 return put_user((unsigned int)sizeof(prctl_map),
1983 (unsigned int __user *)addr);
1984
1985 if (data_size != sizeof(prctl_map))
1986 return -EINVAL;
1987
1988 if (copy_from_user(&prctl_map, addr, sizeof(prctl_map)))
1989 return -EFAULT;
1990
11bbd8b4 1991 error = validate_prctl_map_addr(&prctl_map);
f606b77f
CG		 1992 if (error)
1993 return error;
1994
1995 if (prctl_map.auxv_size) {
11bbd8b4
MK		 1996 /*
1997 * Someone is trying to cheat the auxv vector.
1998 */
1999 if (!prctl_map.auxv ||
2000 prctl_map.auxv_size > sizeof(mm->saved_auxv))
2001 return -EINVAL;
2002
f606b77f
CG		 2003 memset(user_auxv, 0, sizeof(user_auxv));
2004 if (copy_from_user(user_auxv,
2005 (const void __user *)prctl_map.auxv,
2006 prctl_map.auxv_size))
2007 return -EFAULT;
2008
2009 /* Last entry must be AT_NULL as specification requires */
2010 user_auxv[AT_VECTOR_SIZE - 2] = AT_NULL;
2011 user_auxv[AT_VECTOR_SIZE - 1] = AT_NULL;
2012 }
2013
ddf1d398 2014 if (prctl_map.exe_fd != (u32)-1) {
11bbd8b4 2015 /*
ebd6de68
NV		 2016 * Check if the current user is checkpoint/restore capable.
2017 * At the time of this writing, it checks for CAP_SYS_ADMIN
2018 * or CAP_CHECKPOINT_RESTORE.
2019 * Note that a user with access to ptrace can masquerade an
2020 * arbitrary program as any executable, even setuid ones.
2021 * This may have implications in the tomoyo subsystem.
11bbd8b4 2022 */
ebd6de68 2023 if (!checkpoint_restore_ns_capable(current_user_ns()))
227175b2 2024 return -EPERM;
11bbd8b4 2025
6e399cd1 2026 error = prctl_set_mm_exe_file(mm, prctl_map.exe_fd);
ddf1d398
MG		 2027 if (error)
2028 return error;
2029 }
2030
88aa7cc6 2031 /*
5afe69c2 2032 * arg_lock protects concurrent updates but we still need mmap_lock for
88aa7cc6
YS		 2033 * read to exclude races with sys_brk.
2034 */
d8ed45c5 2035 mmap_read_lock(mm);
f606b77f
CG		 2036
2037 /*
2038 * We don't validate if these members are pointing to
2039 * real present VMAs because application may have correspond
2040 * VMAs already unmapped and kernel uses these members for statistics
2041 * output in procfs mostly, except
2042 *
15ec0fcf 2043 * - @start_brk/@brk which are used in do_brk_flags but kernel lookups
5afe69c2 2044 * for VMAs when updating these members so anything wrong written
f606b77f
CG		 2045 * here cause kernel to swear at userspace program but won't lead
2046 * to any problem in kernel itself
2047 */
2048
88aa7cc6 2049 spin_lock(&mm->arg_lock);
f606b77f
CG		 2050 mm->start_code = prctl_map.start_code;
2051 mm->end_code = prctl_map.end_code;
2052 mm->start_data = prctl_map.start_data;
2053 mm->end_data = prctl_map.end_data;
2054 mm->start_brk = prctl_map.start_brk;
2055 mm->brk = prctl_map.brk;
2056 mm->start_stack = prctl_map.start_stack;
2057 mm->arg_start = prctl_map.arg_start;
2058 mm->arg_end = prctl_map.arg_end;
2059 mm->env_start = prctl_map.env_start;
2060 mm->env_end = prctl_map.env_end;
88aa7cc6 2061 spin_unlock(&mm->arg_lock);
f606b77f
CG		 2062
2063 /*
2064 * Note this update of @saved_auxv is lockless thus
2065 * if someone reads this member in procfs while we're
2066 * updating -- it may get partly updated results. It's
2067 * known and acceptable trade off: we leave it as is to
2068 * not introduce additional locks here making the kernel
2069 * more complex.
2070 */
2071 if (prctl_map.auxv_size)
2072 memcpy(mm->saved_auxv, user_auxv, sizeof(user_auxv));
2073
d8ed45c5 2074 mmap_read_unlock(mm);
ddf1d398 2075 return 0;
f606b77f
CG		 2076}
2077#endif /* CONFIG_CHECKPOINT_RESTORE */
2078
4a00e9df
AD		 2079static int prctl_set_auxv(struct mm_struct *mm, unsigned long addr,
2080 unsigned long len)
2081{
2082 /*
2083 * This doesn't move the auxiliary vector itself since it's pinned to
2084 * mm_struct, but it permits filling the vector with new values. It's
2085 * up to the caller to provide sane values here, otherwise userspace
2086 * tools which use this vector might be unhappy.
2087 */
c995f12a 2088 unsigned long user_auxv[AT_VECTOR_SIZE] = {};
4a00e9df
AD		 2089
2090 if (len > sizeof(user_auxv))
2091 return -EINVAL;
2092
2093 if (copy_from_user(user_auxv, (const void __user *)addr, len))
2094 return -EFAULT;
2095
2096 /* Make sure the last entry is always AT_NULL */
2097 user_auxv[AT_VECTOR_SIZE - 2] = 0;
2098 user_auxv[AT_VECTOR_SIZE - 1] = 0;
2099
2100 BUILD_BUG_ON(sizeof(user_auxv) != sizeof(mm->saved_auxv));
2101
2102 task_lock(current);
2103 memcpy(mm->saved_auxv, user_auxv, len);
2104 task_unlock(current);
2105
2106 return 0;
2107}
2108
028ee4be
CG		 2109static int prctl_set_mm(int opt, unsigned long addr,
2110 unsigned long arg4, unsigned long arg5)
2111{
028ee4be 2112 struct mm_struct *mm = current->mm;
11bbd8b4
MK		 2113 struct prctl_mm_map prctl_map = {
2114 .auxv = NULL,
2115 .auxv_size = 0,
2116 .exe_fd = -1,
2117 };
fe8c7f5c
CG		 2118 struct vm_area_struct *vma;
2119 int error;
028ee4be 2120
f606b77f
CG		 2121 if (arg5 || (arg4 && (opt != PR_SET_MM_AUXV &&
2122 opt != PR_SET_MM_MAP &&
2123 opt != PR_SET_MM_MAP_SIZE)))
028ee4be
CG		 2124 return -EINVAL;
2125
f606b77f
CG		 2126#ifdef CONFIG_CHECKPOINT_RESTORE
2127 if (opt == PR_SET_MM_MAP || opt == PR_SET_MM_MAP_SIZE)
2128 return prctl_set_mm_map(opt, (const void __user *)addr, arg4);
2129#endif
2130
79f0713d 2131 if (!capable(CAP_SYS_RESOURCE))
028ee4be
CG		 2132 return -EPERM;
2133
6e399cd1
DB		 2134 if (opt == PR_SET_MM_EXE_FILE)
2135 return prctl_set_mm_exe_file(mm, (unsigned int)addr);
b32dfe37 2136
4a00e9df
AD		 2137 if (opt == PR_SET_MM_AUXV)
2138 return prctl_set_auxv(mm, addr, arg4);
2139
1ad75b9e 2140 if (addr >= TASK_SIZE || addr < mmap_min_addr)
028ee4be
CG		 2141 return -EINVAL;
2142
fe8c7f5c
CG		 2143 error = -EINVAL;
2144
bc81426f 2145 /*
5afe69c2 2146 * arg_lock protects concurrent updates of arg boundaries, we need
c1e8d7c6 2147 * mmap_lock for a) concurrent sys_brk, b) finding VMA for addr
bc81426f
MK		 2148 * validation.
2149 */
d8ed45c5 2150 mmap_read_lock(mm);
028ee4be
CG		 2151 vma = find_vma(mm, addr);
2152
bc81426f 2153 spin_lock(&mm->arg_lock);
4a00e9df
AD		 2154 prctl_map.start_code = mm->start_code;
2155 prctl_map.end_code = mm->end_code;
2156 prctl_map.start_data = mm->start_data;
2157 prctl_map.end_data = mm->end_data;
2158 prctl_map.start_brk = mm->start_brk;
2159 prctl_map.brk = mm->brk;
2160 prctl_map.start_stack = mm->start_stack;
2161 prctl_map.arg_start = mm->arg_start;
2162 prctl_map.arg_end = mm->arg_end;
2163 prctl_map.env_start = mm->env_start;
2164 prctl_map.env_end = mm->env_end;
4a00e9df 2165
028ee4be
CG		 2166 switch (opt) {
2167 case PR_SET_MM_START_CODE:
4a00e9df 2168 prctl_map.start_code = addr;
fe8c7f5c 2169 break;
028ee4be 2170 case PR_SET_MM_END_CODE:
4a00e9df 2171 prctl_map.end_code = addr;
028ee4be 2172 break;
028ee4be 2173 case PR_SET_MM_START_DATA:
4a00e9df 2174 prctl_map.start_data = addr;
028ee4be 2175 break;
fe8c7f5c 2176 case PR_SET_MM_END_DATA:
4a00e9df
AD		 2177 prctl_map.end_data = addr;
2178 break;
2179 case PR_SET_MM_START_STACK:
2180 prctl_map.start_stack = addr;
028ee4be 2181 break;
028ee4be 2182 case PR_SET_MM_START_BRK:
4a00e9df 2183 prctl_map.start_brk = addr;
028ee4be 2184 break;
028ee4be 2185 case PR_SET_MM_BRK:
4a00e9df 2186 prctl_map.brk = addr;
028ee4be 2187 break;
4a00e9df
AD		 2188 case PR_SET_MM_ARG_START:
2189 prctl_map.arg_start = addr;
2190 break;
2191 case PR_SET_MM_ARG_END:
2192 prctl_map.arg_end = addr;
2193 break;
2194 case PR_SET_MM_ENV_START:
2195 prctl_map.env_start = addr;
2196 break;
2197 case PR_SET_MM_ENV_END:
2198 prctl_map.env_end = addr;
2199 break;
2200 default:
2201 goto out;
2202 }
2203
11bbd8b4 2204 error = validate_prctl_map_addr(&prctl_map);
4a00e9df
AD		 2205 if (error)
2206 goto out;
028ee4be 2207
4a00e9df 2208 switch (opt) {
fe8c7f5c
CG		 2209 /*
2210 * If command line arguments and environment
2211 * are placed somewhere else on stack, we can
2212 * set them up here, ARG_START/END to setup
5afe69c2 2213 * command line arguments and ENV_START/END
fe8c7f5c
CG		 2214 * for environment.
2215 */
2216 case PR_SET_MM_START_STACK:
2217 case PR_SET_MM_ARG_START:
2218 case PR_SET_MM_ARG_END:
2219 case PR_SET_MM_ENV_START:
2220 case PR_SET_MM_ENV_END:
2221 if (!vma) {
2222 error = -EFAULT;
2223 goto out;
2224 }
028ee4be
CG		 2225 }
2226
4a00e9df
AD		 2227 mm->start_code = prctl_map.start_code;
2228 mm->end_code = prctl_map.end_code;
2229 mm->start_data = prctl_map.start_data;
2230 mm->end_data = prctl_map.end_data;
2231 mm->start_brk = prctl_map.start_brk;
2232 mm->brk = prctl_map.brk;
2233 mm->start_stack = prctl_map.start_stack;
2234 mm->arg_start = prctl_map.arg_start;
2235 mm->arg_end = prctl_map.arg_end;
2236 mm->env_start = prctl_map.env_start;
2237 mm->env_end = prctl_map.env_end;
2238
028ee4be 2239 error = 0;
028ee4be 2240out:
bc81426f 2241 spin_unlock(&mm->arg_lock);
d8ed45c5 2242 mmap_read_unlock(mm);
028ee4be
CG		 2243 return error;
2244}
300f786b 2245
52b36941 2246#ifdef CONFIG_CHECKPOINT_RESTORE
986b9eac 2247static int prctl_get_tid_address(struct task_struct *me, int __user * __user *tid_addr)
300f786b
CG		 2248{
2249 return put_user(me->clear_child_tid, tid_addr);
2250}
52b36941 2251#else
986b9eac 2252static int prctl_get_tid_address(struct task_struct *me, int __user * __user *tid_addr)
300f786b
CG		 2253{
2254 return -EINVAL;
2255}
028ee4be
CG		 2256#endif
2257
749860ce
PT		 2258static int propagate_has_child_subreaper(struct task_struct *p, void *data)
2259{
2260 /*
5afe69c2
XC		 2261 * If task has has_child_subreaper - all its descendants
2262 * already have these flag too and new descendants will
749860ce
PT		 2263 * inherit it on fork, skip them.
2264 *
2265 * If we've found child_reaper - skip descendants in
2266 * it's subtree as they will never get out pidns.
2267 */
2268 if (p->signal->has_child_subreaper ||
2269 is_child_reaper(task_pid(p)))
2270 return 0;
2271
2272 p->signal->has_child_subreaper = 1;
2273 return 1;
2274}
2275
7bbf1373 2276int __weak arch_prctl_spec_ctrl_get(struct task_struct *t, unsigned long which)
b617cfc8
TG		 2277{
2278 return -EINVAL;
2279}
2280
7bbf1373
KC		 2281int __weak arch_prctl_spec_ctrl_set(struct task_struct *t, unsigned long which,
2282 unsigned long ctrl)
b617cfc8
TG		 2283{
2284 return -EINVAL;
2285}
2286
a37b0715 2287#define PR_IO_FLUSHER (PF_MEMALLOC_NOIO | PF_LOCAL_THROTTLE)
8d19f1c8 2288
c4ea37c2
HC		 2289SYSCALL_DEFINE5(prctl, int, option, unsigned long, arg2, unsigned long, arg3,
2290 unsigned long, arg4, unsigned long, arg5)
1da177e4 2291{
b6dff3ec
DH		 2292 struct task_struct *me = current;
2293 unsigned char comm[sizeof(me->comm)];
2294 long error;
1da177e4 2295
d84f4f99
DH		 2296 error = security_task_prctl(option, arg2, arg3, arg4, arg5);
2297 if (error != -ENOSYS)
1da177e4
LT		 2298 return error;
2299
d84f4f99 2300 error = 0;
1da177e4 2301 switch (option) {
f3cbd435
AM		 2302 case PR_SET_PDEATHSIG:
2303 if (!valid_signal(arg2)) {
2304 error = -EINVAL;
1da177e4 2305 break;
f3cbd435
AM		 2306 }
2307 me->pdeath_signal = arg2;
2308 break;
2309 case PR_GET_PDEATHSIG:
2310 error = put_user(me->pdeath_signal, (int __user *)arg2);
2311 break;
2312 case PR_GET_DUMPABLE:
2313 error = get_dumpable(me->mm);
2314 break;
2315 case PR_SET_DUMPABLE:
2316 if (arg2 != SUID_DUMP_DISABLE && arg2 != SUID_DUMP_USER) {
2317 error = -EINVAL;
1da177e4 2318 break;
f3cbd435
AM		 2319 }
2320 set_dumpable(me->mm, arg2);
2321 break;
1da177e4 2322
f3cbd435
AM		 2323 case PR_SET_UNALIGN:
2324 error = SET_UNALIGN_CTL(me, arg2);
2325 break;
2326 case PR_GET_UNALIGN:
2327 error = GET_UNALIGN_CTL(me, arg2);
2328 break;
2329 case PR_SET_FPEMU:
2330 error = SET_FPEMU_CTL(me, arg2);
2331 break;
2332 case PR_GET_FPEMU:
2333 error = GET_FPEMU_CTL(me, arg2);
2334 break;
2335 case PR_SET_FPEXC:
2336 error = SET_FPEXC_CTL(me, arg2);
2337 break;
2338 case PR_GET_FPEXC:
2339 error = GET_FPEXC_CTL(me, arg2);
2340 break;
2341 case PR_GET_TIMING:
2342 error = PR_TIMING_STATISTICAL;
2343 break;
2344 case PR_SET_TIMING:
2345 if (arg2 != PR_TIMING_STATISTICAL)
2346 error = -EINVAL;
2347 break;
2348 case PR_SET_NAME:
2349 comm[sizeof(me->comm) - 1] = 0;
2350 if (strncpy_from_user(comm, (char __user *)arg2,
2351 sizeof(me->comm) - 1) < 0)
2352 return -EFAULT;
2353 set_task_comm(me, comm);
2354 proc_comm_connector(me);
2355 break;
2356 case PR_GET_NAME:
2357 get_task_comm(comm, me);
2358 if (copy_to_user((char __user *)arg2, comm, sizeof(comm)))
2359 return -EFAULT;
2360 break;
2361 case PR_GET_ENDIAN:
2362 error = GET_ENDIAN(me, arg2);
2363 break;
2364 case PR_SET_ENDIAN:
2365 error = SET_ENDIAN(me, arg2);
2366 break;
2367 case PR_GET_SECCOMP:
2368 error = prctl_get_seccomp();
2369 break;
2370 case PR_SET_SECCOMP:
2371 error = prctl_set_seccomp(arg2, (char __user *)arg3);
2372 break;
2373 case PR_GET_TSC:
2374 error = GET_TSC_CTL(arg2);
2375 break;
2376 case PR_SET_TSC:
2377 error = SET_TSC_CTL(arg2);
2378 break;
2379 case PR_TASK_PERF_EVENTS_DISABLE:
2380 error = perf_event_task_disable();
2381 break;
2382 case PR_TASK_PERF_EVENTS_ENABLE:
2383 error = perf_event_task_enable();
2384 break;
2385 case PR_GET_TIMERSLACK:
da8b44d5
JS		 2386 if (current->timer_slack_ns > ULONG_MAX)
2387 error = ULONG_MAX;
2388 else
2389 error = current->timer_slack_ns;
f3cbd435
AM		 2390 break;
2391 case PR_SET_TIMERSLACK:
2392 if (arg2 <= 0)
2393 current->timer_slack_ns =
6976675d 2394 current->default_timer_slack_ns;
f3cbd435
AM		 2395 else
2396 current->timer_slack_ns = arg2;
2397 break;
2398 case PR_MCE_KILL:
2399 if (arg4 | arg5)
2400 return -EINVAL;
2401 switch (arg2) {
2402 case PR_MCE_KILL_CLEAR:
2403 if (arg3 != 0)
4db96cf0 2404 return -EINVAL;
f3cbd435 2405 current->flags &= ~PF_MCE_PROCESS;
4db96cf0 2406 break;
f3cbd435
AM		 2407 case PR_MCE_KILL_SET:
2408 current->flags |= PF_MCE_PROCESS;
2409 if (arg3 == PR_MCE_KILL_EARLY)
2410 current->flags |= PF_MCE_EARLY;
2411 else if (arg3 == PR_MCE_KILL_LATE)
2412 current->flags &= ~PF_MCE_EARLY;
2413 else if (arg3 == PR_MCE_KILL_DEFAULT)
2414 current->flags &=
2415 ~(PF_MCE_EARLY|PF_MCE_PROCESS);
1087e9b4 2416 else
259e5e6c 2417 return -EINVAL;
259e5e6c 2418 break;
1da177e4 2419 default:
f3cbd435
AM		 2420 return -EINVAL;
2421 }
2422 break;
2423 case PR_MCE_KILL_GET:
2424 if (arg2 | arg3 | arg4 | arg5)
2425 return -EINVAL;
2426 if (current->flags & PF_MCE_PROCESS)
2427 error = (current->flags & PF_MCE_EARLY) ?
2428 PR_MCE_KILL_EARLY : PR_MCE_KILL_LATE;
2429 else
2430 error = PR_MCE_KILL_DEFAULT;
2431 break;
2432 case PR_SET_MM:
2433 error = prctl_set_mm(arg2, arg3, arg4, arg5);
2434 break;
2435 case PR_GET_TID_ADDRESS:
986b9eac 2436 error = prctl_get_tid_address(me, (int __user * __user *)arg2);
f3cbd435
AM		 2437 break;
2438 case PR_SET_CHILD_SUBREAPER:
2439 me->signal->is_child_subreaper = !!arg2;
749860ce
PT		 2440 if (!arg2)
2441 break;
2442
2443 walk_process_tree(me, propagate_has_child_subreaper, NULL);
f3cbd435
AM		 2444 break;
2445 case PR_GET_CHILD_SUBREAPER:
2446 error = put_user(me->signal->is_child_subreaper,
2447 (int __user *)arg2);
2448 break;
2449 case PR_SET_NO_NEW_PRIVS:
2450 if (arg2 != 1 || arg3 || arg4 || arg5)
2451 return -EINVAL;
2452
1d4457f9 2453 task_set_no_new_privs(current);
f3cbd435
AM		 2454 break;
2455 case PR_GET_NO_NEW_PRIVS:
2456 if (arg2 || arg3 || arg4 || arg5)
2457 return -EINVAL;
1d4457f9 2458 return task_no_new_privs(current) ? 1 : 0;
a0715cc2
AT		 2459 case PR_GET_THP_DISABLE:
2460 if (arg2 || arg3 || arg4 || arg5)
2461 return -EINVAL;
18600332 2462 error = !!test_bit(MMF_DISABLE_THP, &me->mm->flags);
a0715cc2
AT		 2463 break;
2464 case PR_SET_THP_DISABLE:
2465 if (arg3 || arg4 || arg5)
2466 return -EINVAL;
d8ed45c5 2467 if (mmap_write_lock_killable(me->mm))
17b0573d 2468 return -EINTR;
a0715cc2 2469 if (arg2)
18600332 2470 set_bit(MMF_DISABLE_THP, &me->mm->flags);
a0715cc2 2471 else
18600332 2472 clear_bit(MMF_DISABLE_THP, &me->mm->flags);
d8ed45c5 2473 mmap_write_unlock(me->mm);
a0715cc2 2474 break;
fe3d197f 2475 case PR_MPX_ENABLE_MANAGEMENT:
fe3d197f 2476 case PR_MPX_DISABLE_MANAGEMENT:
f240652b
DH		 2477 /* No longer implemented: */
2478 return -EINVAL;
9791554b
PB		 2479 case PR_SET_FP_MODE:
2480 error = SET_FP_MODE(me, arg2);
2481 break;
2482 case PR_GET_FP_MODE:
2483 error = GET_FP_MODE(me);
2484 break;
2d2123bc
DM		 2485 case PR_SVE_SET_VL:
2486 error = SVE_SET_VL(arg2);
2487 break;
2488 case PR_SVE_GET_VL:
2489 error = SVE_GET_VL();
2490 break;
b617cfc8
TG		 2491 case PR_GET_SPECULATION_CTRL:
2492 if (arg3 || arg4 || arg5)
2493 return -EINVAL;
7bbf1373 2494 error = arch_prctl_spec_ctrl_get(me, arg2);
b617cfc8
TG		 2495 break;
2496 case PR_SET_SPECULATION_CTRL:
2497 if (arg4 || arg5)
2498 return -EINVAL;
7bbf1373 2499 error = arch_prctl_spec_ctrl_set(me, arg2, arg3);
b617cfc8 2500 break;
ba830885
KM		 2501 case PR_PAC_RESET_KEYS:
2502 if (arg3 || arg4 || arg5)
2503 return -EINVAL;
2504 error = PAC_RESET_KEYS(me, arg2);
2505 break;
20169862
PC		 2506 case PR_PAC_SET_ENABLED_KEYS:
2507 if (arg4 || arg5)
2508 return -EINVAL;
2509 error = PAC_SET_ENABLED_KEYS(me, arg2, arg3);
2510 break;
2511 case PR_PAC_GET_ENABLED_KEYS:
2512 if (arg2 || arg3 || arg4 || arg5)
2513 return -EINVAL;
2514 error = PAC_GET_ENABLED_KEYS(me);
2515 break;
63f0c603 2516 case PR_SET_TAGGED_ADDR_CTRL:
3e91ec89
CM		 2517 if (arg3 || arg4 || arg5)
2518 return -EINVAL;
63f0c603
CM		 2519 error = SET_TAGGED_ADDR_CTRL(arg2);
2520 break;
2521 case PR_GET_TAGGED_ADDR_CTRL:
3e91ec89
CM		 2522 if (arg2 || arg3 || arg4 || arg5)
2523 return -EINVAL;
63f0c603
CM		 2524 error = GET_TAGGED_ADDR_CTRL();
2525 break;
8d19f1c8
MC		 2526 case PR_SET_IO_FLUSHER:
2527 if (!capable(CAP_SYS_RESOURCE))
2528 return -EPERM;
2529
2530 if (arg3 || arg4 || arg5)
2531 return -EINVAL;
2532
2533 if (arg2 == 1)
2534 current->flags |= PR_IO_FLUSHER;
2535 else if (!arg2)
2536 current->flags &= ~PR_IO_FLUSHER;
2537 else
2538 return -EINVAL;
2539 break;
2540 case PR_GET_IO_FLUSHER:
2541 if (!capable(CAP_SYS_RESOURCE))
2542 return -EPERM;
2543
2544 if (arg2 || arg3 || arg4 || arg5)
2545 return -EINVAL;
2546
2547 error = (current->flags & PR_IO_FLUSHER) == PR_IO_FLUSHER;
2548 break;
1446e1df
GKB		 2549 case PR_SET_SYSCALL_USER_DISPATCH:
2550 error = set_syscall_user_dispatch(arg2, arg3, arg4,
2551 (char __user *) arg5);
2552 break;
f3cbd435
AM		 2553 default:
2554 error = -EINVAL;
2555 break;
1da177e4
LT		 2556 }
2557 return error;
2558}
3cfc348b 2559
836f92ad
HC		 2560SYSCALL_DEFINE3(getcpu, unsigned __user *, cpup, unsigned __user *, nodep,
2561 struct getcpu_cache __user *, unused)
3cfc348b
AK		 2562{
2563 int err = 0;
2564 int cpu = raw_smp_processor_id();
ec94fc3d 2565
3cfc348b
AK		 2566 if (cpup)
2567 err |= put_user(cpu, cpup);
2568 if (nodep)
2569 err |= put_user(cpu_to_node(cpu), nodep);
3cfc348b
AK		 2570 return err ? -EFAULT : 0;
2571}
10a0a8d4 2572
4a22f166
SR		 2573/**
2574 * do_sysinfo - fill in sysinfo struct
2575 * @info: pointer to buffer to fill
2576 */
2577static int do_sysinfo(struct sysinfo *info)
2578{
2579 unsigned long mem_total, sav_total;
2580 unsigned int mem_unit, bitcount;
dc1b7b6c 2581 struct timespec64 tp;
4a22f166
SR		 2582
2583 memset(info, 0, sizeof(struct sysinfo));
2584
dc1b7b6c 2585 ktime_get_boottime_ts64(&tp);
ecc421e0 2586 timens_add_boottime(&tp);
4a22f166
SR		 2587 info->uptime = tp.tv_sec + (tp.tv_nsec ? 1 : 0);
2588
2589 get_avenrun(info->loads, 0, SI_LOAD_SHIFT - FSHIFT);
2590
2591 info->procs = nr_threads;
2592
2593 si_meminfo(info);
2594 si_swapinfo(info);
2595
2596 /*
2597 * If the sum of all the available memory (i.e. ram + swap)
2598 * is less than can be stored in a 32 bit unsigned long then
2599 * we can be binary compatible with 2.2.x kernels. If not,
2600 * well, in that case 2.2.x was broken anyways...
2601 *
2602 * -Erik Andersen <andersee@debian.org>
2603 */
2604
2605 mem_total = info->totalram + info->totalswap;
2606 if (mem_total < info->totalram || mem_total < info->totalswap)
2607 goto out;
2608 bitcount = 0;
2609 mem_unit = info->mem_unit;
2610 while (mem_unit > 1) {
2611 bitcount++;
2612 mem_unit >>= 1;
2613 sav_total = mem_total;
2614 mem_total <<= 1;
2615 if (mem_total < sav_total)
2616 goto out;
2617 }
2618
2619 /*
2620 * If mem_total did not overflow, multiply all memory values by
2621 * info->mem_unit and set it to 1. This leaves things compatible
2622 * with 2.2.x, and also retains compatibility with earlier 2.4.x
2623 * kernels...
2624 */
2625
2626 info->mem_unit = 1;
2627 info->totalram <<= bitcount;
2628 info->freeram <<= bitcount;
2629 info->sharedram <<= bitcount;
2630 info->bufferram <<= bitcount;
2631 info->totalswap <<= bitcount;
2632 info->freeswap <<= bitcount;
2633 info->totalhigh <<= bitcount;
2634 info->freehigh <<= bitcount;
2635
2636out:
2637 return 0;
2638}
2639
2640SYSCALL_DEFINE1(sysinfo, struct sysinfo __user *, info)
2641{
2642 struct sysinfo val;
2643
2644 do_sysinfo(&val);
2645
2646 if (copy_to_user(info, &val, sizeof(struct sysinfo)))
2647 return -EFAULT;
2648
2649 return 0;
2650}
2651
2652#ifdef CONFIG_COMPAT
2653struct compat_sysinfo {
2654 s32 uptime;
2655 u32 loads[3];
2656 u32 totalram;
2657 u32 freeram;
2658 u32 sharedram;
2659 u32 bufferram;
2660 u32 totalswap;
2661 u32 freeswap;
2662 u16 procs;
2663 u16 pad;
2664 u32 totalhigh;
2665 u32 freehigh;
2666 u32 mem_unit;
2667 char _f[20-2*sizeof(u32)-sizeof(int)];
2668};
2669
2670COMPAT_SYSCALL_DEFINE1(sysinfo, struct compat_sysinfo __user *, info)
2671{
2672 struct sysinfo s;
ce5155c4 2673 struct compat_sysinfo s_32;
4a22f166
SR		 2674
2675 do_sysinfo(&s);
2676
2677 /* Check to see if any memory value is too large for 32-bit and scale
2678 * down if needed
2679 */
0baae41e 2680 if (upper_32_bits(s.totalram) || upper_32_bits(s.totalswap)) {
4a22f166
SR		 2681 int bitcount = 0;
2682
2683 while (s.mem_unit < PAGE_SIZE) {
2684 s.mem_unit <<= 1;
2685 bitcount++;
2686 }
2687
2688 s.totalram >>= bitcount;
2689 s.freeram >>= bitcount;
2690 s.sharedram >>= bitcount;
2691 s.bufferram >>= bitcount;
2692 s.totalswap >>= bitcount;
2693 s.freeswap >>= bitcount;
2694 s.totalhigh >>= bitcount;
2695 s.freehigh >>= bitcount;
2696 }
2697
ce5155c4
AV		 2698 memset(&s_32, 0, sizeof(s_32));
2699 s_32.uptime = s.uptime;
2700 s_32.loads[0] = s.loads[0];
2701 s_32.loads[1] = s.loads[1];
2702 s_32.loads[2] = s.loads[2];
2703 s_32.totalram = s.totalram;
2704 s_32.freeram = s.freeram;
2705 s_32.sharedram = s.sharedram;
2706 s_32.bufferram = s.bufferram;
2707 s_32.totalswap = s.totalswap;
2708 s_32.freeswap = s.freeswap;
2709 s_32.procs = s.procs;
2710 s_32.totalhigh = s.totalhigh;
2711 s_32.freehigh = s.freehigh;
2712 s_32.mem_unit = s.mem_unit;
2713 if (copy_to_user(info, &s_32, sizeof(s_32)))
4a22f166 2714 return -EFAULT;
4a22f166
SR		 2715 return 0;
2716}
2717#endif /* CONFIG_COMPAT */
Linux 6.x block layer and io_uring tree(s)