[PATCH] kexec: x86_64: add CONFIG_PHYSICAL_START
[deliverable/linux.git] / kernel / sys.c
CommitLineData
1da177e4
LT
1/*
2 * linux/kernel/sys.c
3 *
4 * Copyright (C) 1991, 1992 Linus Torvalds
5 */
6
7#include <linux/config.h>
8#include <linux/module.h>
9#include <linux/mm.h>
10#include <linux/utsname.h>
11#include <linux/mman.h>
12#include <linux/smp_lock.h>
13#include <linux/notifier.h>
14#include <linux/reboot.h>
15#include <linux/prctl.h>
16#include <linux/init.h>
17#include <linux/highuid.h>
18#include <linux/fs.h>
19#include <linux/workqueue.h>
20#include <linux/device.h>
21#include <linux/key.h>
22#include <linux/times.h>
23#include <linux/posix-timers.h>
24#include <linux/security.h>
25#include <linux/dcookies.h>
26#include <linux/suspend.h>
27#include <linux/tty.h>
7ed20e1a 28#include <linux/signal.h>
1da177e4
LT
29
30#include <linux/compat.h>
31#include <linux/syscalls.h>
32
33#include <asm/uaccess.h>
34#include <asm/io.h>
35#include <asm/unistd.h>
36
37#ifndef SET_UNALIGN_CTL
38# define SET_UNALIGN_CTL(a,b) (-EINVAL)
39#endif
40#ifndef GET_UNALIGN_CTL
41# define GET_UNALIGN_CTL(a,b) (-EINVAL)
42#endif
43#ifndef SET_FPEMU_CTL
44# define SET_FPEMU_CTL(a,b) (-EINVAL)
45#endif
46#ifndef GET_FPEMU_CTL
47# define GET_FPEMU_CTL(a,b) (-EINVAL)
48#endif
49#ifndef SET_FPEXC_CTL
50# define SET_FPEXC_CTL(a,b) (-EINVAL)
51#endif
52#ifndef GET_FPEXC_CTL
53# define GET_FPEXC_CTL(a,b) (-EINVAL)
54#endif
55
56/*
57 * this is where the system-wide overflow UID and GID are defined, for
58 * architectures that now have 32-bit UID/GID but didn't in the past
59 */
60
61int overflowuid = DEFAULT_OVERFLOWUID;
62int overflowgid = DEFAULT_OVERFLOWGID;
63
64#ifdef CONFIG_UID16
65EXPORT_SYMBOL(overflowuid);
66EXPORT_SYMBOL(overflowgid);
67#endif
68
69/*
70 * the same as above, but for filesystems which can only store a 16-bit
71 * UID and GID. as such, this is needed on all architectures
72 */
73
74int fs_overflowuid = DEFAULT_FS_OVERFLOWUID;
75int fs_overflowgid = DEFAULT_FS_OVERFLOWUID;
76
77EXPORT_SYMBOL(fs_overflowuid);
78EXPORT_SYMBOL(fs_overflowgid);
79
80/*
81 * this indicates whether you can reboot with ctrl-alt-del: the default is yes
82 */
83
84int C_A_D = 1;
85int cad_pid = 1;
86
87/*
88 * Notifier list for kernel code which wants to be called
89 * at shutdown. This is used to stop any idling DMA operations
90 * and the like.
91 */
92
93static struct notifier_block *reboot_notifier_list;
94static DEFINE_RWLOCK(notifier_lock);
95
96/**
97 * notifier_chain_register - Add notifier to a notifier chain
98 * @list: Pointer to root list pointer
99 * @n: New entry in notifier chain
100 *
101 * Adds a notifier to a notifier chain.
102 *
103 * Currently always returns zero.
104 */
105
106int notifier_chain_register(struct notifier_block **list, struct notifier_block *n)
107{
108 write_lock(&notifier_lock);
109 while(*list)
110 {
111 if(n->priority > (*list)->priority)
112 break;
113 list= &((*list)->next);
114 }
115 n->next = *list;
116 *list=n;
117 write_unlock(&notifier_lock);
118 return 0;
119}
120
121EXPORT_SYMBOL(notifier_chain_register);
122
123/**
124 * notifier_chain_unregister - Remove notifier from a notifier chain
125 * @nl: Pointer to root list pointer
126 * @n: New entry in notifier chain
127 *
128 * Removes a notifier from a notifier chain.
129 *
130 * Returns zero on success, or %-ENOENT on failure.
131 */
132
133int notifier_chain_unregister(struct notifier_block **nl, struct notifier_block *n)
134{
135 write_lock(&notifier_lock);
136 while((*nl)!=NULL)
137 {
138 if((*nl)==n)
139 {
140 *nl=n->next;
141 write_unlock(&notifier_lock);
142 return 0;
143 }
144 nl=&((*nl)->next);
145 }
146 write_unlock(&notifier_lock);
147 return -ENOENT;
148}
149
150EXPORT_SYMBOL(notifier_chain_unregister);
151
152/**
153 * notifier_call_chain - Call functions in a notifier chain
154 * @n: Pointer to root pointer of notifier chain
155 * @val: Value passed unmodified to notifier function
156 * @v: Pointer passed unmodified to notifier function
157 *
158 * Calls each function in a notifier chain in turn.
159 *
160 * If the return value of the notifier can be and'd
161 * with %NOTIFY_STOP_MASK, then notifier_call_chain
162 * will return immediately, with the return value of
163 * the notifier function which halted execution.
164 * Otherwise, the return value is the return value
165 * of the last notifier function called.
166 */
167
168int notifier_call_chain(struct notifier_block **n, unsigned long val, void *v)
169{
170 int ret=NOTIFY_DONE;
171 struct notifier_block *nb = *n;
172
173 while(nb)
174 {
175 ret=nb->notifier_call(nb,val,v);
176 if(ret&NOTIFY_STOP_MASK)
177 {
178 return ret;
179 }
180 nb=nb->next;
181 }
182 return ret;
183}
184
185EXPORT_SYMBOL(notifier_call_chain);
186
187/**
188 * register_reboot_notifier - Register function to be called at reboot time
189 * @nb: Info about notifier function to be called
190 *
191 * Registers a function with the list of functions
192 * to be called at reboot time.
193 *
194 * Currently always returns zero, as notifier_chain_register
195 * always returns zero.
196 */
197
198int register_reboot_notifier(struct notifier_block * nb)
199{
200 return notifier_chain_register(&reboot_notifier_list, nb);
201}
202
203EXPORT_SYMBOL(register_reboot_notifier);
204
205/**
206 * unregister_reboot_notifier - Unregister previously registered reboot notifier
207 * @nb: Hook to be unregistered
208 *
209 * Unregisters a previously registered reboot
210 * notifier function.
211 *
212 * Returns zero on success, or %-ENOENT on failure.
213 */
214
215int unregister_reboot_notifier(struct notifier_block * nb)
216{
217 return notifier_chain_unregister(&reboot_notifier_list, nb);
218}
219
220EXPORT_SYMBOL(unregister_reboot_notifier);
221
222static int set_one_prio(struct task_struct *p, int niceval, int error)
223{
224 int no_nice;
225
226 if (p->uid != current->euid &&
227 p->euid != current->euid && !capable(CAP_SYS_NICE)) {
228 error = -EPERM;
229 goto out;
230 }
e43379f1 231 if (niceval < task_nice(p) && !can_nice(p, niceval)) {
1da177e4
LT
232 error = -EACCES;
233 goto out;
234 }
235 no_nice = security_task_setnice(p, niceval);
236 if (no_nice) {
237 error = no_nice;
238 goto out;
239 }
240 if (error == -ESRCH)
241 error = 0;
242 set_user_nice(p, niceval);
243out:
244 return error;
245}
246
247asmlinkage long sys_setpriority(int which, int who, int niceval)
248{
249 struct task_struct *g, *p;
250 struct user_struct *user;
251 int error = -EINVAL;
252
253 if (which > 2 || which < 0)
254 goto out;
255
256 /* normalize: avoid signed division (rounding problems) */
257 error = -ESRCH;
258 if (niceval < -20)
259 niceval = -20;
260 if (niceval > 19)
261 niceval = 19;
262
263 read_lock(&tasklist_lock);
264 switch (which) {
265 case PRIO_PROCESS:
266 if (!who)
267 who = current->pid;
268 p = find_task_by_pid(who);
269 if (p)
270 error = set_one_prio(p, niceval, error);
271 break;
272 case PRIO_PGRP:
273 if (!who)
274 who = process_group(current);
275 do_each_task_pid(who, PIDTYPE_PGID, p) {
276 error = set_one_prio(p, niceval, error);
277 } while_each_task_pid(who, PIDTYPE_PGID, p);
278 break;
279 case PRIO_USER:
280 user = current->user;
281 if (!who)
282 who = current->uid;
283 else
284 if ((who != current->uid) && !(user = find_user(who)))
285 goto out_unlock; /* No processes for this user */
286
287 do_each_thread(g, p)
288 if (p->uid == who)
289 error = set_one_prio(p, niceval, error);
290 while_each_thread(g, p);
291 if (who != current->uid)
292 free_uid(user); /* For find_user() */
293 break;
294 }
295out_unlock:
296 read_unlock(&tasklist_lock);
297out:
298 return error;
299}
300
301/*
302 * Ugh. To avoid negative return values, "getpriority()" will
303 * not return the normal nice-value, but a negated value that
304 * has been offset by 20 (ie it returns 40..1 instead of -20..19)
305 * to stay compatible.
306 */
307asmlinkage long sys_getpriority(int which, int who)
308{
309 struct task_struct *g, *p;
310 struct user_struct *user;
311 long niceval, retval = -ESRCH;
312
313 if (which > 2 || which < 0)
314 return -EINVAL;
315
316 read_lock(&tasklist_lock);
317 switch (which) {
318 case PRIO_PROCESS:
319 if (!who)
320 who = current->pid;
321 p = find_task_by_pid(who);
322 if (p) {
323 niceval = 20 - task_nice(p);
324 if (niceval > retval)
325 retval = niceval;
326 }
327 break;
328 case PRIO_PGRP:
329 if (!who)
330 who = process_group(current);
331 do_each_task_pid(who, PIDTYPE_PGID, p) {
332 niceval = 20 - task_nice(p);
333 if (niceval > retval)
334 retval = niceval;
335 } while_each_task_pid(who, PIDTYPE_PGID, p);
336 break;
337 case PRIO_USER:
338 user = current->user;
339 if (!who)
340 who = current->uid;
341 else
342 if ((who != current->uid) && !(user = find_user(who)))
343 goto out_unlock; /* No processes for this user */
344
345 do_each_thread(g, p)
346 if (p->uid == who) {
347 niceval = 20 - task_nice(p);
348 if (niceval > retval)
349 retval = niceval;
350 }
351 while_each_thread(g, p);
352 if (who != current->uid)
353 free_uid(user); /* for find_user() */
354 break;
355 }
356out_unlock:
357 read_unlock(&tasklist_lock);
358
359 return retval;
360}
361
362
363/*
364 * Reboot system call: for obvious reasons only root may call it,
365 * and even root needs to set up some magic numbers in the registers
366 * so that some mistake won't make this reboot the whole machine.
367 * You can also set the meaning of the ctrl-alt-del-key here.
368 *
369 * reboot doesn't sync: do that yourself before calling this.
370 */
371asmlinkage long sys_reboot(int magic1, int magic2, unsigned int cmd, void __user * arg)
372{
373 char buffer[256];
374
375 /* We only trust the superuser with rebooting the system. */
376 if (!capable(CAP_SYS_BOOT))
377 return -EPERM;
378
379 /* For safety, we require "magic" arguments. */
380 if (magic1 != LINUX_REBOOT_MAGIC1 ||
381 (magic2 != LINUX_REBOOT_MAGIC2 &&
382 magic2 != LINUX_REBOOT_MAGIC2A &&
383 magic2 != LINUX_REBOOT_MAGIC2B &&
384 magic2 != LINUX_REBOOT_MAGIC2C))
385 return -EINVAL;
386
387 lock_kernel();
388 switch (cmd) {
389 case LINUX_REBOOT_CMD_RESTART:
390 notifier_call_chain(&reboot_notifier_list, SYS_RESTART, NULL);
391 system_state = SYSTEM_RESTART;
392 device_shutdown();
393 printk(KERN_EMERG "Restarting system.\n");
394 machine_restart(NULL);
395 break;
396
397 case LINUX_REBOOT_CMD_CAD_ON:
398 C_A_D = 1;
399 break;
400
401 case LINUX_REBOOT_CMD_CAD_OFF:
402 C_A_D = 0;
403 break;
404
405 case LINUX_REBOOT_CMD_HALT:
406 notifier_call_chain(&reboot_notifier_list, SYS_HALT, NULL);
407 system_state = SYSTEM_HALT;
620b0327 408 device_suspend(PMSG_SUSPEND);
1da177e4
LT
409 device_shutdown();
410 printk(KERN_EMERG "System halted.\n");
411 machine_halt();
412 unlock_kernel();
413 do_exit(0);
414 break;
415
416 case LINUX_REBOOT_CMD_POWER_OFF:
417 notifier_call_chain(&reboot_notifier_list, SYS_POWER_OFF, NULL);
418 system_state = SYSTEM_POWER_OFF;
620b0327 419 device_suspend(PMSG_SUSPEND);
1da177e4
LT
420 device_shutdown();
421 printk(KERN_EMERG "Power down.\n");
422 machine_power_off();
423 unlock_kernel();
424 do_exit(0);
425 break;
426
427 case LINUX_REBOOT_CMD_RESTART2:
428 if (strncpy_from_user(&buffer[0], arg, sizeof(buffer) - 1) < 0) {
429 unlock_kernel();
430 return -EFAULT;
431 }
432 buffer[sizeof(buffer) - 1] = '\0';
433
434 notifier_call_chain(&reboot_notifier_list, SYS_RESTART, buffer);
435 system_state = SYSTEM_RESTART;
620b0327 436 device_suspend(PMSG_FREEZE);
1da177e4
LT
437 device_shutdown();
438 printk(KERN_EMERG "Restarting system with command '%s'.\n", buffer);
439 machine_restart(buffer);
440 break;
441
442#ifdef CONFIG_SOFTWARE_SUSPEND
443 case LINUX_REBOOT_CMD_SW_SUSPEND:
444 {
445 int ret = software_suspend();
446 unlock_kernel();
447 return ret;
448 }
449#endif
450
451 default:
452 unlock_kernel();
453 return -EINVAL;
454 }
455 unlock_kernel();
456 return 0;
457}
458
459static void deferred_cad(void *dummy)
460{
461 notifier_call_chain(&reboot_notifier_list, SYS_RESTART, NULL);
462 machine_restart(NULL);
463}
464
465/*
466 * This function gets called by ctrl-alt-del - ie the keyboard interrupt.
467 * As it's called within an interrupt, it may NOT sync: the only choice
468 * is whether to reboot at once, or just ignore the ctrl-alt-del.
469 */
470void ctrl_alt_del(void)
471{
472 static DECLARE_WORK(cad_work, deferred_cad, NULL);
473
474 if (C_A_D)
475 schedule_work(&cad_work);
476 else
477 kill_proc(cad_pid, SIGINT, 1);
478}
479
480
481/*
482 * Unprivileged users may change the real gid to the effective gid
483 * or vice versa. (BSD-style)
484 *
485 * If you set the real gid at all, or set the effective gid to a value not
486 * equal to the real gid, then the saved gid is set to the new effective gid.
487 *
488 * This makes it possible for a setgid program to completely drop its
489 * privileges, which is often a useful assertion to make when you are doing
490 * a security audit over a program.
491 *
492 * The general idea is that a program which uses just setregid() will be
493 * 100% compatible with BSD. A program which uses just setgid() will be
494 * 100% compatible with POSIX with saved IDs.
495 *
496 * SMP: There are not races, the GIDs are checked only by filesystem
497 * operations (as far as semantic preservation is concerned).
498 */
499asmlinkage long sys_setregid(gid_t rgid, gid_t egid)
500{
501 int old_rgid = current->gid;
502 int old_egid = current->egid;
503 int new_rgid = old_rgid;
504 int new_egid = old_egid;
505 int retval;
506
507 retval = security_task_setgid(rgid, egid, (gid_t)-1, LSM_SETID_RE);
508 if (retval)
509 return retval;
510
511 if (rgid != (gid_t) -1) {
512 if ((old_rgid == rgid) ||
513 (current->egid==rgid) ||
514 capable(CAP_SETGID))
515 new_rgid = rgid;
516 else
517 return -EPERM;
518 }
519 if (egid != (gid_t) -1) {
520 if ((old_rgid == egid) ||
521 (current->egid == egid) ||
522 (current->sgid == egid) ||
523 capable(CAP_SETGID))
524 new_egid = egid;
525 else {
526 return -EPERM;
527 }
528 }
529 if (new_egid != old_egid)
530 {
d6e71144 531 current->mm->dumpable = suid_dumpable;
d59dd462 532 smp_wmb();
1da177e4
LT
533 }
534 if (rgid != (gid_t) -1 ||
535 (egid != (gid_t) -1 && egid != old_rgid))
536 current->sgid = new_egid;
537 current->fsgid = new_egid;
538 current->egid = new_egid;
539 current->gid = new_rgid;
540 key_fsgid_changed(current);
541 return 0;
542}
543
544/*
545 * setgid() is implemented like SysV w/ SAVED_IDS
546 *
547 * SMP: Same implicit races as above.
548 */
549asmlinkage long sys_setgid(gid_t gid)
550{
551 int old_egid = current->egid;
552 int retval;
553
554 retval = security_task_setgid(gid, (gid_t)-1, (gid_t)-1, LSM_SETID_ID);
555 if (retval)
556 return retval;
557
558 if (capable(CAP_SETGID))
559 {
560 if(old_egid != gid)
561 {
d6e71144 562 current->mm->dumpable = suid_dumpable;
d59dd462 563 smp_wmb();
1da177e4
LT
564 }
565 current->gid = current->egid = current->sgid = current->fsgid = gid;
566 }
567 else if ((gid == current->gid) || (gid == current->sgid))
568 {
569 if(old_egid != gid)
570 {
d6e71144 571 current->mm->dumpable = suid_dumpable;
d59dd462 572 smp_wmb();
1da177e4
LT
573 }
574 current->egid = current->fsgid = gid;
575 }
576 else
577 return -EPERM;
578
579 key_fsgid_changed(current);
580 return 0;
581}
582
583static int set_user(uid_t new_ruid, int dumpclear)
584{
585 struct user_struct *new_user;
586
587 new_user = alloc_uid(new_ruid);
588 if (!new_user)
589 return -EAGAIN;
590
591 if (atomic_read(&new_user->processes) >=
592 current->signal->rlim[RLIMIT_NPROC].rlim_cur &&
593 new_user != &root_user) {
594 free_uid(new_user);
595 return -EAGAIN;
596 }
597
598 switch_uid(new_user);
599
600 if(dumpclear)
601 {
d6e71144 602 current->mm->dumpable = suid_dumpable;
d59dd462 603 smp_wmb();
1da177e4
LT
604 }
605 current->uid = new_ruid;
606 return 0;
607}
608
609/*
610 * Unprivileged users may change the real uid to the effective uid
611 * or vice versa. (BSD-style)
612 *
613 * If you set the real uid at all, or set the effective uid to a value not
614 * equal to the real uid, then the saved uid is set to the new effective uid.
615 *
616 * This makes it possible for a setuid program to completely drop its
617 * privileges, which is often a useful assertion to make when you are doing
618 * a security audit over a program.
619 *
620 * The general idea is that a program which uses just setreuid() will be
621 * 100% compatible with BSD. A program which uses just setuid() will be
622 * 100% compatible with POSIX with saved IDs.
623 */
624asmlinkage long sys_setreuid(uid_t ruid, uid_t euid)
625{
626 int old_ruid, old_euid, old_suid, new_ruid, new_euid;
627 int retval;
628
629 retval = security_task_setuid(ruid, euid, (uid_t)-1, LSM_SETID_RE);
630 if (retval)
631 return retval;
632
633 new_ruid = old_ruid = current->uid;
634 new_euid = old_euid = current->euid;
635 old_suid = current->suid;
636
637 if (ruid != (uid_t) -1) {
638 new_ruid = ruid;
639 if ((old_ruid != ruid) &&
640 (current->euid != ruid) &&
641 !capable(CAP_SETUID))
642 return -EPERM;
643 }
644
645 if (euid != (uid_t) -1) {
646 new_euid = euid;
647 if ((old_ruid != euid) &&
648 (current->euid != euid) &&
649 (current->suid != euid) &&
650 !capable(CAP_SETUID))
651 return -EPERM;
652 }
653
654 if (new_ruid != old_ruid && set_user(new_ruid, new_euid != old_euid) < 0)
655 return -EAGAIN;
656
657 if (new_euid != old_euid)
658 {
d6e71144 659 current->mm->dumpable = suid_dumpable;
d59dd462 660 smp_wmb();
1da177e4
LT
661 }
662 current->fsuid = current->euid = new_euid;
663 if (ruid != (uid_t) -1 ||
664 (euid != (uid_t) -1 && euid != old_ruid))
665 current->suid = current->euid;
666 current->fsuid = current->euid;
667
668 key_fsuid_changed(current);
669
670 return security_task_post_setuid(old_ruid, old_euid, old_suid, LSM_SETID_RE);
671}
672
673
674
675/*
676 * setuid() is implemented like SysV with SAVED_IDS
677 *
678 * Note that SAVED_ID's is deficient in that a setuid root program
679 * like sendmail, for example, cannot set its uid to be a normal
680 * user and then switch back, because if you're root, setuid() sets
681 * the saved uid too. If you don't like this, blame the bright people
682 * in the POSIX committee and/or USG. Note that the BSD-style setreuid()
683 * will allow a root program to temporarily drop privileges and be able to
684 * regain them by swapping the real and effective uid.
685 */
686asmlinkage long sys_setuid(uid_t uid)
687{
688 int old_euid = current->euid;
689 int old_ruid, old_suid, new_ruid, new_suid;
690 int retval;
691
692 retval = security_task_setuid(uid, (uid_t)-1, (uid_t)-1, LSM_SETID_ID);
693 if (retval)
694 return retval;
695
696 old_ruid = new_ruid = current->uid;
697 old_suid = current->suid;
698 new_suid = old_suid;
699
700 if (capable(CAP_SETUID)) {
701 if (uid != old_ruid && set_user(uid, old_euid != uid) < 0)
702 return -EAGAIN;
703 new_suid = uid;
704 } else if ((uid != current->uid) && (uid != new_suid))
705 return -EPERM;
706
707 if (old_euid != uid)
708 {
d6e71144 709 current->mm->dumpable = suid_dumpable;
d59dd462 710 smp_wmb();
1da177e4
LT
711 }
712 current->fsuid = current->euid = uid;
713 current->suid = new_suid;
714
715 key_fsuid_changed(current);
716
717 return security_task_post_setuid(old_ruid, old_euid, old_suid, LSM_SETID_ID);
718}
719
720
721/*
722 * This function implements a generic ability to update ruid, euid,
723 * and suid. This allows you to implement the 4.4 compatible seteuid().
724 */
725asmlinkage long sys_setresuid(uid_t ruid, uid_t euid, uid_t suid)
726{
727 int old_ruid = current->uid;
728 int old_euid = current->euid;
729 int old_suid = current->suid;
730 int retval;
731
732 retval = security_task_setuid(ruid, euid, suid, LSM_SETID_RES);
733 if (retval)
734 return retval;
735
736 if (!capable(CAP_SETUID)) {
737 if ((ruid != (uid_t) -1) && (ruid != current->uid) &&
738 (ruid != current->euid) && (ruid != current->suid))
739 return -EPERM;
740 if ((euid != (uid_t) -1) && (euid != current->uid) &&
741 (euid != current->euid) && (euid != current->suid))
742 return -EPERM;
743 if ((suid != (uid_t) -1) && (suid != current->uid) &&
744 (suid != current->euid) && (suid != current->suid))
745 return -EPERM;
746 }
747 if (ruid != (uid_t) -1) {
748 if (ruid != current->uid && set_user(ruid, euid != current->euid) < 0)
749 return -EAGAIN;
750 }
751 if (euid != (uid_t) -1) {
752 if (euid != current->euid)
753 {
d6e71144 754 current->mm->dumpable = suid_dumpable;
d59dd462 755 smp_wmb();
1da177e4
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756 }
757 current->euid = euid;
758 }
759 current->fsuid = current->euid;
760 if (suid != (uid_t) -1)
761 current->suid = suid;
762
763 key_fsuid_changed(current);
764
765 return security_task_post_setuid(old_ruid, old_euid, old_suid, LSM_SETID_RES);
766}
767
768asmlinkage long sys_getresuid(uid_t __user *ruid, uid_t __user *euid, uid_t __user *suid)
769{
770 int retval;
771
772 if (!(retval = put_user(current->uid, ruid)) &&
773 !(retval = put_user(current->euid, euid)))
774 retval = put_user(current->suid, suid);
775
776 return retval;
777}
778
779/*
780 * Same as above, but for rgid, egid, sgid.
781 */
782asmlinkage long sys_setresgid(gid_t rgid, gid_t egid, gid_t sgid)
783{
784 int retval;
785
786 retval = security_task_setgid(rgid, egid, sgid, LSM_SETID_RES);
787 if (retval)
788 return retval;
789
790 if (!capable(CAP_SETGID)) {
791 if ((rgid != (gid_t) -1) && (rgid != current->gid) &&
792 (rgid != current->egid) && (rgid != current->sgid))
793 return -EPERM;
794 if ((egid != (gid_t) -1) && (egid != current->gid) &&
795 (egid != current->egid) && (egid != current->sgid))
796 return -EPERM;
797 if ((sgid != (gid_t) -1) && (sgid != current->gid) &&
798 (sgid != current->egid) && (sgid != current->sgid))
799 return -EPERM;
800 }
801 if (egid != (gid_t) -1) {
802 if (egid != current->egid)
803 {
d6e71144 804 current->mm->dumpable = suid_dumpable;
d59dd462 805 smp_wmb();
1da177e4
LT
806 }
807 current->egid = egid;
808 }
809 current->fsgid = current->egid;
810 if (rgid != (gid_t) -1)
811 current->gid = rgid;
812 if (sgid != (gid_t) -1)
813 current->sgid = sgid;
814
815 key_fsgid_changed(current);
816 return 0;
817}
818
819asmlinkage long sys_getresgid(gid_t __user *rgid, gid_t __user *egid, gid_t __user *sgid)
820{
821 int retval;
822
823 if (!(retval = put_user(current->gid, rgid)) &&
824 !(retval = put_user(current->egid, egid)))
825 retval = put_user(current->sgid, sgid);
826
827 return retval;
828}
829
830
831/*
832 * "setfsuid()" sets the fsuid - the uid used for filesystem checks. This
833 * is used for "access()" and for the NFS daemon (letting nfsd stay at
834 * whatever uid it wants to). It normally shadows "euid", except when
835 * explicitly set by setfsuid() or for access..
836 */
837asmlinkage long sys_setfsuid(uid_t uid)
838{
839 int old_fsuid;
840
841 old_fsuid = current->fsuid;
842 if (security_task_setuid(uid, (uid_t)-1, (uid_t)-1, LSM_SETID_FS))
843 return old_fsuid;
844
845 if (uid == current->uid || uid == current->euid ||
846 uid == current->suid || uid == current->fsuid ||
847 capable(CAP_SETUID))
848 {
849 if (uid != old_fsuid)
850 {
d6e71144 851 current->mm->dumpable = suid_dumpable;
d59dd462 852 smp_wmb();
1da177e4
LT
853 }
854 current->fsuid = uid;
855 }
856
857 key_fsuid_changed(current);
858
859 security_task_post_setuid(old_fsuid, (uid_t)-1, (uid_t)-1, LSM_SETID_FS);
860
861 return old_fsuid;
862}
863
864/*