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Linux v2.6.13
[linux-2.6/next.git] / kernel / sys.c
blob0bcaed6560ac19f72ab308b2fe92839238e9ba70
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/kernel.h>
20 #include <linux/kexec.h>
21 #include <linux/workqueue.h>
22 #include <linux/device.h>
23 #include <linux/key.h>
24 #include <linux/times.h>
25 #include <linux/posix-timers.h>
26 #include <linux/security.h>
27 #include <linux/dcookies.h>
28 #include <linux/suspend.h>
29 #include <linux/tty.h>
30 #include <linux/signal.h>
31
32 #include <linux/compat.h>
33 #include <linux/syscalls.h>
34
35 #include <asm/uaccess.h>
36 #include <asm/io.h>
37 #include <asm/unistd.h>
38
39 #ifndef SET_UNALIGN_CTL
40 # define SET_UNALIGN_CTL(a,b) (-EINVAL)
41 #endif
42 #ifndef GET_UNALIGN_CTL
43 # define GET_UNALIGN_CTL(a,b) (-EINVAL)
44 #endif
45 #ifndef SET_FPEMU_CTL
46 # define SET_FPEMU_CTL(a,b) (-EINVAL)
47 #endif
48 #ifndef GET_FPEMU_CTL
49 # define GET_FPEMU_CTL(a,b) (-EINVAL)
50 #endif
51 #ifndef SET_FPEXC_CTL
52 # define SET_FPEXC_CTL(a,b) (-EINVAL)
53 #endif
54 #ifndef GET_FPEXC_CTL
55 # define GET_FPEXC_CTL(a,b) (-EINVAL)
56 #endif
57
58 /*
59 * this is where the system-wide overflow UID and GID are defined, for
60 * architectures that now have 32-bit UID/GID but didn't in the past
61 */
62
63 int overflowuid = DEFAULT_OVERFLOWUID;
64 int overflowgid = DEFAULT_OVERFLOWGID;
65
66 #ifdef CONFIG_UID16
67 EXPORT_SYMBOL(overflowuid);
68 EXPORT_SYMBOL(overflowgid);
69 #endif
70
71 /*
72 * the same as above, but for filesystems which can only store a 16-bit
73 * UID and GID. as such, this is needed on all architectures
74 */
75
76 int fs_overflowuid = DEFAULT_FS_OVERFLOWUID;
77 int fs_overflowgid = DEFAULT_FS_OVERFLOWUID;
78
79 EXPORT_SYMBOL(fs_overflowuid);
80 EXPORT_SYMBOL(fs_overflowgid);
81
82 /*
83 * this indicates whether you can reboot with ctrl-alt-del: the default is yes
84 */
85
86 int C_A_D = 1;
87 int cad_pid = 1;
88
89 /*
90 * Notifier list for kernel code which wants to be called
91 * at shutdown. This is used to stop any idling DMA operations
92 * and the like.
93 */
94
95 static struct notifier_block *reboot_notifier_list;
96 static DEFINE_RWLOCK(notifier_lock);
97
98 /**
99 * notifier_chain_register - Add notifier to a notifier chain
100 * @list: Pointer to root list pointer
101 * @n: New entry in notifier chain
102 *
103 * Adds a notifier to a notifier chain.
104 *
105 * Currently always returns zero.
106 */
107
108 int notifier_chain_register(struct notifier_block **list, struct notifier_block *n)
109 {
110 write_lock(&notifier_lock);
111 while(*list)
112 {
113 if(n->priority > (*list)->priority)
114 break;
115 list= &((*list)->next);
116 }
117 n->next = *list;
118 *list=n;
119 write_unlock(&notifier_lock);
120 return 0;
121 }
122
123 EXPORT_SYMBOL(notifier_chain_register);
124
125 /**
126 * notifier_chain_unregister - Remove notifier from a notifier chain
127 * @nl: Pointer to root list pointer
128 * @n: New entry in notifier chain
129 *
130 * Removes a notifier from a notifier chain.
131 *
132 * Returns zero on success, or %-ENOENT on failure.
133 */
134
135 int notifier_chain_unregister(struct notifier_block **nl, struct notifier_block *n)
136 {
137 write_lock(&notifier_lock);
138 while((*nl)!=NULL)
139 {
140 if((*nl)==n)
141 {
142 *nl=n->next;
143 write_unlock(&notifier_lock);
144 return 0;
145 }
146 nl=&((*nl)->next);
147 }
148 write_unlock(&notifier_lock);
149 return -ENOENT;
150 }
151
152 EXPORT_SYMBOL(notifier_chain_unregister);
153
154 /**
155 * notifier_call_chain - Call functions in a notifier chain
156 * @n: Pointer to root pointer of notifier chain
157 * @val: Value passed unmodified to notifier function
158 * @v: Pointer passed unmodified to notifier function
159 *
160 * Calls each function in a notifier chain in turn.
161 *
162 * If the return value of the notifier can be and'd
163 * with %NOTIFY_STOP_MASK, then notifier_call_chain
164 * will return immediately, with the return value of
165 * the notifier function which halted execution.
166 * Otherwise, the return value is the return value
167 * of the last notifier function called.
168 */
169
170 int notifier_call_chain(struct notifier_block **n, unsigned long val, void *v)
171 {
172 int ret=NOTIFY_DONE;
173 struct notifier_block *nb = *n;
174
175 while(nb)
176 {
177 ret=nb->notifier_call(nb,val,v);
178 if(ret&NOTIFY_STOP_MASK)
179 {
180 return ret;
181 }
182 nb=nb->next;
183 }
184 return ret;
185 }
186
187 EXPORT_SYMBOL(notifier_call_chain);
188
189 /**
190 * register_reboot_notifier - Register function to be called at reboot time
191 * @nb: Info about notifier function to be called
192 *
193 * Registers a function with the list of functions
194 * to be called at reboot time.
195 *
196 * Currently always returns zero, as notifier_chain_register
197 * always returns zero.
198 */
199
200 int register_reboot_notifier(struct notifier_block * nb)
201 {
202 return notifier_chain_register(&reboot_notifier_list, nb);
203 }
204
205 EXPORT_SYMBOL(register_reboot_notifier);
206
207 /**
208 * unregister_reboot_notifier - Unregister previously registered reboot notifier
209 * @nb: Hook to be unregistered
210 *
211 * Unregisters a previously registered reboot
212 * notifier function.
213 *
214 * Returns zero on success, or %-ENOENT on failure.
215 */
216
217 int unregister_reboot_notifier(struct notifier_block * nb)
218 {
219 return notifier_chain_unregister(&reboot_notifier_list, nb);
220 }
221
222 EXPORT_SYMBOL(unregister_reboot_notifier);
223
224 static int set_one_prio(struct task_struct *p, int niceval, int error)
225 {
226 int no_nice;
227
228 if (p->uid != current->euid &&
229 p->euid != current->euid && !capable(CAP_SYS_NICE)) {
230 error = -EPERM;
231 goto out;
232 }
233 if (niceval < task_nice(p) && !can_nice(p, niceval)) {
234 error = -EACCES;
235 goto out;
236 }
237 no_nice = security_task_setnice(p, niceval);
238 if (no_nice) {
239 error = no_nice;
240 goto out;
241 }
242 if (error == -ESRCH)
243 error = 0;
244 set_user_nice(p, niceval);
245 out:
246 return error;
247 }
248
249 asmlinkage long sys_setpriority(int which, int who, int niceval)
250 {
251 struct task_struct *g, *p;
252 struct user_struct *user;
253 int error = -EINVAL;
254
255 if (which > 2 || which < 0)
256 goto out;
257
258 /* normalize: avoid signed division (rounding problems) */
259 error = -ESRCH;
260 if (niceval < -20)
261 niceval = -20;
262 if (niceval > 19)
263 niceval = 19;
264
265 read_lock(&tasklist_lock);
266 switch (which) {
267 case PRIO_PROCESS:
268 if (!who)
269 who = current->pid;
270 p = find_task_by_pid(who);
271 if (p)
272 error = set_one_prio(p, niceval, error);
273 break;
274 case PRIO_PGRP:
275 if (!who)
276 who = process_group(current);
277 do_each_task_pid(who, PIDTYPE_PGID, p) {
278 error = set_one_prio(p, niceval, error);
279 } while_each_task_pid(who, PIDTYPE_PGID, p);
280 break;
281 case PRIO_USER:
282 user = current->user;
283 if (!who)
284 who = current->uid;
285 else
286 if ((who != current->uid) && !(user = find_user(who)))
287 goto out_unlock; /* No processes for this user */
288
289 do_each_thread(g, p)
290 if (p->uid == who)
291 error = set_one_prio(p, niceval, error);
292 while_each_thread(g, p);
293 if (who != current->uid)
294 free_uid(user); /* For find_user() */
295 break;
296 }
297 out_unlock:
298 read_unlock(&tasklist_lock);
299 out:
300 return error;
301 }
302
303 /*
304 * Ugh. To avoid negative return values, "getpriority()" will
305 * not return the normal nice-value, but a negated value that
306 * has been offset by 20 (ie it returns 40..1 instead of -20..19)
307 * to stay compatible.
308 */
309 asmlinkage long sys_getpriority(int which, int who)
310 {
311 struct task_struct *g, *p;
312 struct user_struct *user;
313 long niceval, retval = -ESRCH;
314
315 if (which > 2 || which < 0)
316 return -EINVAL;
317
318 read_lock(&tasklist_lock);
319 switch (which) {
320 case PRIO_PROCESS:
321 if (!who)
322 who = current->pid;
323 p = find_task_by_pid(who);
324 if (p) {
325 niceval = 20 - task_nice(p);
326 if (niceval > retval)
327 retval = niceval;
328 }
329 break;
330 case PRIO_PGRP:
331 if (!who)
332 who = process_group(current);
333 do_each_task_pid(who, PIDTYPE_PGID, p) {
334 niceval = 20 - task_nice(p);
335 if (niceval > retval)
336 retval = niceval;
337 } while_each_task_pid(who, PIDTYPE_PGID, p);
338 break;
339 case PRIO_USER:
340 user = current->user;
341 if (!who)
342 who = current->uid;
343 else
344 if ((who != current->uid) && !(user = find_user(who)))
345 goto out_unlock; /* No processes for this user */
346
347 do_each_thread(g, p)
348 if (p->uid == who) {
349 niceval = 20 - task_nice(p);
350 if (niceval > retval)
351 retval = niceval;
352 }
353 while_each_thread(g, p);
354 if (who != current->uid)
355 free_uid(user); /* for find_user() */
356 break;
357 }
358 out_unlock:
359 read_unlock(&tasklist_lock);
360
361 return retval;
362 }
363
364 void emergency_restart(void)
365 {
366 machine_emergency_restart();
367 }
368 EXPORT_SYMBOL_GPL(emergency_restart);
369
370 void kernel_restart(char *cmd)
371 {
372 notifier_call_chain(&reboot_notifier_list, SYS_RESTART, cmd);
373 system_state = SYSTEM_RESTART;
374 device_shutdown();
375 if (!cmd) {
376 printk(KERN_EMERG "Restarting system.\n");
377 } else {
378 printk(KERN_EMERG "Restarting system with command '%s'.\n", cmd);
379 }
380 printk(".\n");
381 machine_restart(cmd);
382 }
383 EXPORT_SYMBOL_GPL(kernel_restart);
384
385 void kernel_kexec(void)
386 {
387 #ifdef CONFIG_KEXEC
388 struct kimage *image;
389 image = xchg(&kexec_image, 0);
390 if (!image) {
391 return;
392 }
393 notifier_call_chain(&reboot_notifier_list, SYS_RESTART, NULL);
394 system_state = SYSTEM_RESTART;
395 device_shutdown();
396 printk(KERN_EMERG "Starting new kernel\n");
397 machine_shutdown();
398 machine_kexec(image);
399 #endif
400 }
401 EXPORT_SYMBOL_GPL(kernel_kexec);
402
403 void kernel_halt(void)
404 {
405 notifier_call_chain(&reboot_notifier_list, SYS_HALT, NULL);
406 system_state = SYSTEM_HALT;
407 device_shutdown();
408 printk(KERN_EMERG "System halted.\n");
409 machine_halt();
410 }
411 EXPORT_SYMBOL_GPL(kernel_halt);
412
413 void kernel_power_off(void)
414 {
415 notifier_call_chain(&reboot_notifier_list, SYS_POWER_OFF, NULL);
416 system_state = SYSTEM_POWER_OFF;
417 device_shutdown();
418 printk(KERN_EMERG "Power down.\n");
419 machine_power_off();
420 }
421 EXPORT_SYMBOL_GPL(kernel_power_off);
422
423 /*
424 * Reboot system call: for obvious reasons only root may call it,
425 * and even root needs to set up some magic numbers in the registers
426 * so that some mistake won't make this reboot the whole machine.
427 * You can also set the meaning of the ctrl-alt-del-key here.
428 *
429 * reboot doesn't sync: do that yourself before calling this.
430 */
431 asmlinkage long sys_reboot(int magic1, int magic2, unsigned int cmd, void __user * arg)
432 {
433 char buffer[256];
434
435 /* We only trust the superuser with rebooting the system. */
436 if (!capable(CAP_SYS_BOOT))
437 return -EPERM;
438
439 /* For safety, we require "magic" arguments. */
440 if (magic1 != LINUX_REBOOT_MAGIC1 ||
441 (magic2 != LINUX_REBOOT_MAGIC2 &&
442 magic2 != LINUX_REBOOT_MAGIC2A &&
443 magic2 != LINUX_REBOOT_MAGIC2B &&
444 magic2 != LINUX_REBOOT_MAGIC2C))
445 return -EINVAL;
446
447 lock_kernel();
448 switch (cmd) {
449 case LINUX_REBOOT_CMD_RESTART:
450 kernel_restart(NULL);
451 break;
452
453 case LINUX_REBOOT_CMD_CAD_ON:
454 C_A_D = 1;
455 break;
456
457 case LINUX_REBOOT_CMD_CAD_OFF:
458 C_A_D = 0;
459 break;
460
461 case LINUX_REBOOT_CMD_HALT:
462 kernel_halt();
463 unlock_kernel();
464 do_exit(0);
465 break;
466
467 case LINUX_REBOOT_CMD_POWER_OFF:
468 kernel_power_off();
469 unlock_kernel();
470 do_exit(0);
471 break;
472
473 case LINUX_REBOOT_CMD_RESTART2:
474 if (strncpy_from_user(&buffer[0], arg, sizeof(buffer) - 1) < 0) {
475 unlock_kernel();
476 return -EFAULT;
477 }
478 buffer[sizeof(buffer) - 1] = '\0';
479
480 kernel_restart(buffer);
481 break;
482
483 case LINUX_REBOOT_CMD_KEXEC:
484 kernel_kexec();
485 unlock_kernel();
486 return -EINVAL;
487
488 #ifdef CONFIG_SOFTWARE_SUSPEND
489 case LINUX_REBOOT_CMD_SW_SUSPEND:
490 {
491 int ret = software_suspend();
492 unlock_kernel();
493 return ret;
494 }
495 #endif
496
497 default:
498 unlock_kernel();
499 return -EINVAL;
500 }
501 unlock_kernel();
502 return 0;
503 }
504
505 static void deferred_cad(void *dummy)
506 {
507 kernel_restart(NULL);
508 }
509
510 /*
511 * This function gets called by ctrl-alt-del - ie the keyboard interrupt.
512 * As it's called within an interrupt, it may NOT sync: the only choice
513 * is whether to reboot at once, or just ignore the ctrl-alt-del.
514 */
515 void ctrl_alt_del(void)
516 {
517 static DECLARE_WORK(cad_work, deferred_cad, NULL);
518
519 if (C_A_D)
520 schedule_work(&cad_work);
521 else
522 kill_proc(cad_pid, SIGINT, 1);
523 }
524
525
526 /*
527 * Unprivileged users may change the real gid to the effective gid
528 * or vice versa. (BSD-style)
529 *
530 * If you set the real gid at all, or set the effective gid to a value not
531 * equal to the real gid, then the saved gid is set to the new effective gid.
532 *
533 * This makes it possible for a setgid program to completely drop its
534 * privileges, which is often a useful assertion to make when you are doing
535 * a security audit over a program.
536 *
537 * The general idea is that a program which uses just setregid() will be
538 * 100% compatible with BSD. A program which uses just setgid() will be
539 * 100% compatible with POSIX with saved IDs.
540 *
541 * SMP: There are not races, the GIDs are checked only by filesystem
542 * operations (as far as semantic preservation is concerned).
543 */
544 asmlinkage long sys_setregid(gid_t rgid, gid_t egid)
545 {
546 int old_rgid = current->gid;
547 int old_egid = current->egid;
548 int new_rgid = old_rgid;
549 int new_egid = old_egid;
550 int retval;
551
552 retval = security_task_setgid(rgid, egid, (gid_t)-1, LSM_SETID_RE);
553 if (retval)
554 return retval;
555
556 if (rgid != (gid_t) -1) {
557 if ((old_rgid == rgid) ||
558 (current->egid==rgid) ||
559 capable(CAP_SETGID))
560 new_rgid = rgid;
561 else
562 return -EPERM;
563 }
564 if (egid != (gid_t) -1) {
565 if ((old_rgid == egid) ||
566 (current->egid == egid) ||
567 (current->sgid == egid) ||
568 capable(CAP_SETGID))
569 new_egid = egid;
570 else {
571 return -EPERM;
572 }
573 }
574 if (new_egid != old_egid)
575 {
576 current->mm->dumpable = suid_dumpable;
577 smp_wmb();
578 }
579 if (rgid != (gid_t) -1 ||
580 (egid != (gid_t) -1 && egid != old_rgid))
581 current->sgid = new_egid;
582 current->fsgid = new_egid;
583 current->egid = new_egid;
584 current->gid = new_rgid;
585 key_fsgid_changed(current);
586 return 0;
587 }
588
589 /*
590 * setgid() is implemented like SysV w/ SAVED_IDS
591 *
592 * SMP: Same implicit races as above.
593 */
594 asmlinkage long sys_setgid(gid_t gid)
595 {
596 int old_egid = current->egid;
597 int retval;
598
599 retval = security_task_setgid(gid, (gid_t)-1, (gid_t)-1, LSM_SETID_ID);
600 if (retval)
601 return retval;
602
603 if (capable(CAP_SETGID))
604 {
605 if(old_egid != gid)
606 {
607 current->mm->dumpable = suid_dumpable;
608 smp_wmb();
609 }
610 current->gid = current->egid = current->sgid = current->fsgid = gid;
611 }
612 else if ((gid == current->gid) || (gid == current->sgid))
613 {
614 if(old_egid != gid)
615 {
616 current->mm->dumpable = suid_dumpable;
617 smp_wmb();
618 }
619 current->egid = current->fsgid = gid;
620 }
621 else
622 return -EPERM;
623
624 key_fsgid_changed(current);
625 return 0;
626 }
627
628 static int set_user(uid_t new_ruid, int dumpclear)
629 {
630 struct user_struct *new_user;
631
632 new_user = alloc_uid(new_ruid);
633 if (!new_user)
634 return -EAGAIN;
635
636 if (atomic_read(&new_user->processes) >=
637 current->signal->rlim[RLIMIT_NPROC].rlim_cur &&
638 new_user != &root_user) {
639 free_uid(new_user);
640 return -EAGAIN;
641 }
642
643 switch_uid(new_user);
644
645 if(dumpclear)
646 {
647 current->mm->dumpable = suid_dumpable;
648 smp_wmb();
649 }
650 current->uid = new_ruid;
651 return 0;
652 }
653
654 /*
655 * Unprivileged users may change the real uid to the effective uid
656 * or vice versa. (BSD-style)
657 *
658 * If you set the real uid at all, or set the effective uid to a value not
659 * equal to the real uid, then the saved uid is set to the new effective uid.
660 *
661 * This makes it possible for a setuid program to completely drop its
662 * privileges, which is often a useful assertion to make when you are doing
663 * a security audit over a program.
664 *
665 * The general idea is that a program which uses just setreuid() will be
666 * 100% compatible with BSD. A program which uses just setuid() will be
667 * 100% compatible with POSIX with saved IDs.
668 */
669 asmlinkage long sys_setreuid(uid_t ruid, uid_t euid)
670 {
671 int old_ruid, old_euid, old_suid, new_ruid, new_euid;
672 int retval;
673
674 retval = security_task_setuid(ruid, euid, (uid_t)-1, LSM_SETID_RE);
675 if (retval)
676 return retval;
677
678 new_ruid = old_ruid = current->uid;
679 new_euid = old_euid = current->euid;
680 old_suid = current->suid;
681
682 if (ruid != (uid_t) -1) {
683 new_ruid = ruid;
684 if ((old_ruid != ruid) &&
685 (current->euid != ruid) &&
686 !capable(CAP_SETUID))
687 return -EPERM;
688 }
689
690 if (euid != (uid_t) -1) {
691 new_euid = euid;
692 if ((old_ruid != euid) &&
693 (current->euid != euid) &&
694 (current->suid != euid) &&
695 !capable(CAP_SETUID))
696 return -EPERM;
697 }
698
699 if (new_ruid != old_ruid && set_user(new_ruid, new_euid != old_euid) < 0)
700 return -EAGAIN;
701
702 if (new_euid != old_euid)
703 {
704 current->mm->dumpable = suid_dumpable;
705 smp_wmb();
706 }
707 current->fsuid = current->euid = new_euid;
708 if (ruid != (uid_t) -1 ||
709 (euid != (uid_t) -1 && euid != old_ruid))
710 current->suid = current->euid;
711 current->fsuid = current->euid;
712
713 key_fsuid_changed(current);
714
715 return security_task_post_setuid(old_ruid, old_euid, old_suid, LSM_SETID_RE);
716 }
717
718
719
720 /*
721 * setuid() is implemented like SysV with SAVED_IDS
722 *
723 * Note that SAVED_ID's is deficient in that a setuid root program
724 * like sendmail, for example, cannot set its uid to be a normal
725 * user and then switch back, because if you're root, setuid() sets
726 * the saved uid too. If you don't like this, blame the bright people
727 * in the POSIX committee and/or USG. Note that the BSD-style setreuid()
728 * will allow a root program to temporarily drop privileges and be able to
729 * regain them by swapping the real and effective uid.
730 */
731 asmlinkage long sys_setuid(uid_t uid)
732 {
733 int old_euid = current->euid;
734 int old_ruid, old_suid, new_ruid, new_suid;
735 int retval;
736
737 retval = security_task_setuid(uid, (uid_t)-1, (uid_t)-1, LSM_SETID_ID);
738 if (retval)
739 return retval;
740
741 old_ruid = new_ruid = current->uid;
742 old_suid = current->suid;
743 new_suid = old_suid;
744
745 if (capable(CAP_SETUID)) {
746 if (uid != old_ruid && set_user(uid, old_euid != uid) < 0)
747 return -EAGAIN;
748 new_suid = uid;
749 } else if ((uid != current->uid) && (uid != new_suid))
750 return -EPERM;
751
752 if (old_euid != uid)
753 {
754 current->mm->dumpable = suid_dumpable;
755 smp_wmb();
756 }
757 current->fsuid = current->euid = uid;
758 current->suid = new_suid;
759
760 key_fsuid_changed(current);
761
762 return security_task_post_setuid(old_ruid, old_euid, old_suid, LSM_SETID_ID);
763 }
764
765
766 /*
767 * This function implements a generic ability to update ruid, euid,
768 * and suid. This allows you to implement the 4.4 compatible seteuid().
769 */
770 asmlinkage long sys_setresuid(uid_t ruid, uid_t euid, uid_t suid)
771 {
772 int old_ruid = current->uid;
773 int old_euid = current->euid;
774 int old_suid = current->suid;
775 int retval;
776
777 retval = security_task_setuid(ruid, euid, suid, LSM_SETID_RES);
778 if (retval)
779 return retval;
780
781 if (!capable(CAP_SETUID)) {
782 if ((ruid != (uid_t) -1) && (ruid != current->uid) &&
783 (ruid != current->euid) && (ruid != current->suid))
784 return -EPERM;
785 if ((euid != (uid_t) -1) && (euid != current->uid) &&
786 (euid != current->euid) && (euid != current->suid))
787 return -EPERM;
788 if ((suid != (uid_t) -1) && (suid != current->uid) &&
789 (suid != current->euid) && (suid != current->suid))
790 return -EPERM;
791 }
792 if (ruid != (uid_t) -1) {
793 if (ruid != current->uid && set_user(ruid, euid != current->euid) < 0)
794 return -EAGAIN;
795 }
796 if (euid != (uid_t) -1) {
797 if (euid != current->euid)
798 {
799 current->mm->dumpable = suid_dumpable;
800 smp_wmb();
801 }
802 current->euid = euid;
803 }
804 current->fsuid = current->euid;
805 if (suid != (uid_t) -1)
806 current->suid = suid;
807
808 key_fsuid_changed(current);
809
810 return security_task_post_setuid(old_ruid, old_euid, old_suid, LSM_SETID_RES);
811 }
812
813 asmlinkage long sys_getresuid(uid_t __user *ruid, uid_t __user *euid, uid_t __user *suid)
814 {
815 int retval;
816
817 if (!(retval = put_user(current->uid, ruid)) &&
818 !(retval = put_user(current->euid, euid)))
819 retval = put_user(current->suid, suid);
820
821 return retval;
822 }
823
824 /*
825 * Same as above, but for rgid, egid, sgid.
826 */
827 asmlinkage long sys_setresgid(gid_t rgid, gid_t egid, gid_t sgid)
828 {
829 int retval;
830
831 retval = security_task_setgid(rgid, egid, sgid, LSM_SETID_RES);
832 if (retval)
833 return retval;
834
835 if (!capable(CAP_SETGID)) {
836 if ((rgid != (gid_t) -1) && (rgid != current->gid) &&
837 (rgid != current->egid) && (rgid != current->sgid))
838 return -EPERM;
839 if ((egid != (gid_t) -1) && (egid != current->gid) &&
840 (egid != current->egid) && (egid != current->sgid))
841 return -EPERM;
842 if ((sgid != (gid_t) -1) && (sgid != current->gid) &&
843 (sgid != current->egid) && (sgid != current->sgid))
844 return -EPERM;
845 }
846 if (egid != (gid_t) -1) {
847 if (egid != current->egid)
848 {
849 current->mm->dumpable = suid_dumpable;
850 smp_wmb();
851 }
852 current->egid = egid;
853 }
854 current->fsgid = current->egid;
855 if (rgid != (gid_t) -1)
856 current->gid = rgid;
857 if (sgid != (gid_t) -1)
858 current->sgid = sgid;
859
860 key_fsgid_changed(current);
861 return 0;
862 }
863
864 asmlinkage long sys_getresgid(gid_t __user *rgid, gid_t __user *egid, gid_t __user *sgid)
865 {
866 int retval;
867
868 if (!(retval = put_user(current->gid, rgid)) &&
869 !(retval = put_user(current->egid, egid)))
870 retval = put_user(current->sgid, sgid);
871
872 return retval;
873 }
874
875
876 /*
877 * "setfsuid()" sets the fsuid - the uid used for filesystem checks. This
878 * is used for "access()" and for the NFS daemon (letting nfsd stay at
879 * whatever uid it wants to). It normally shadows "euid", except when
880 * explicitly set by setfsuid() or for access..
881 */
882 asmlinkage long sys_setfsuid(uid_t uid)
883 {
884 int old_fsuid;
885
886 old_fsuid = current->fsuid;
887 if (security_task_setuid(uid, (uid_t)-1, (uid_t)-1, LSM_SETID_FS))
888 return old_fsuid;
889
890 if (uid == current->uid || uid == current->euid ||
891 uid == current->suid || uid == current->fsuid ||
892 capable(CAP_SETUID))
893 {
894 if (uid != old_fsuid)
895 {
896 current->mm->dumpable = suid_dumpable;
897 smp_wmb();
898 }
899 current->fsuid = uid;
900 }
901
902 key_fsuid_changed(current);
903
904 security_task_post_setuid(old_fsuid, (uid_t)-1, (uid_t)-1, LSM_SETID_FS);
905
906 return old_fsuid;
907 }
908
909 /*
910 * Samma på svenska..
911 */
912 asmlinkage long sys_setfsgid(gid_t gid)
913 {
914 int old_fsgid;
915
916 old_fsgid = current->fsgid;
917 if (security_task_setgid(gid, (gid_t)-1, (gid_t)-1, LSM_SETID_FS))
918 return old_fsgid;
919
920 if (gid == current->gid || gid == current->egid ||
921 gid == current->sgid || gid == current->fsgid ||
922 capable(CAP_SETGID))
923 {
924 if (gid != old_fsgid)
925 {
926 current->mm->dumpable = suid_dumpable;
927 smp_wmb();
928 }
929 current->fsgid = gid;
930 key_fsgid_changed(current);
931 }
932 return old_fsgid;
933 }
934
935 asmlinkage long sys_times(struct tms __user * tbuf)
936 {
937 /*
938 * In the SMP world we might just be unlucky and have one of
939 * the times increment as we use it. Since the value is an
940 * atomically safe type this is just fine. Conceptually its
941 * as if the syscall took an instant longer to occur.
942 */
943 if (tbuf) {
944 struct tms tmp;
945 cputime_t utime, stime, cutime, cstime;
946
947 #ifdef CONFIG_SMP
948 if (thread_group_empty(current)) {
949 /*
950 * Single thread case without the use of any locks.
951 *
952 * We may race with release_task if two threads are
953 * executing. However, release task first adds up the
954 * counters (__exit_signal) before removing the task
955 * from the process tasklist (__unhash_process).
956 * __exit_signal also acquires and releases the
957 * siglock which results in the proper memory ordering
958 * so that the list modifications are always visible
959 * after the counters have been updated.
960 *
961 * If the counters have been updated by the second thread
962 * but the thread has not yet been removed from the list
963 * then the other branch will be executing which will
964 * block on tasklist_lock until the exit handling of the
965 * other task is finished.
966 *
967 * This also implies that the sighand->siglock cannot
968 * be held by another processor. So we can also
969 * skip acquiring that lock.
970 */
971 utime = cputime_add(current->signal->utime, current->utime);
972 stime = cputime_add(current->signal->utime, current->stime);
973 cutime = current->signal->cutime;
974 cstime = current->signal->cstime;
975 } else
976 #endif
977 {
978
979 /* Process with multiple threads */
980 struct task_struct *tsk = current;
981 struct task_struct *t;
982
983 read_lock(&tasklist_lock);
984 utime = tsk->signal->utime;
985 stime = tsk->signal->stime;
986 t = tsk;
987 do {
988 utime = cputime_add(utime, t->utime);
989 stime = cputime_add(stime, t->stime);
990 t = next_thread(t);
991 } while (t != tsk);
992
993 /*
994 * While we have tasklist_lock read-locked, no dying thread
995 * can be updating current->signal->[us]time. Instead,
996 * we got their counts included in the live thread loop.
997 * However, another thread can come in right now and
998 * do a wait call that updates current->signal->c[us]time.
999 * To make sure we always see that pair updated atomically,
1000 * we take the siglock around fetching them.
1001 */
1002 spin_lock_irq(&tsk->sighand->siglock);
1003 cutime = tsk->signal->cutime;
1004 cstime = tsk->signal->cstime;
1005 spin_unlock_irq(&tsk->sighand->siglock);
1006 read_unlock(&tasklist_lock);
1007 }
1008 tmp.tms_utime = cputime_to_clock_t(utime);
1009 tmp.tms_stime = cputime_to_clock_t(stime);
1010 tmp.tms_cutime = cputime_to_clock_t(cutime);
1011 tmp.tms_cstime = cputime_to_clock_t(cstime);
1012 if (copy_to_user(tbuf, &tmp, sizeof(struct tms)))
1013 return -EFAULT;
1014 }
1015 return (long) jiffies_64_to_clock_t(get_jiffies_64());
1016 }
1017
1018 /*
1019 * This needs some heavy checking ...
1020 * I just haven't the stomach for it. I also don't fully
1021 * understand sessions/pgrp etc. Let somebody who does explain it.
1022 *
1023 * OK, I think I have the protection semantics right.... this is really
1024 * only important on a multi-user system anyway, to make sure one user
1025 * can't send a signal to a process owned by another. -TYT, 12/12/91
1026 *
1027 * Auch. Had to add the 'did_exec' flag to conform completely to POSIX.
1028 * LBT 04.03.94
1029 */
1030
1031 asmlinkage long sys_setpgid(pid_t pid, pid_t pgid)
1032 {
1033 struct task_struct *p;
1034 int err = -EINVAL;
1035
1036 if (!pid)
1037 pid = current->pid;
1038 if (!pgid)
1039 pgid = pid;
1040 if (pgid < 0)
1041 return -EINVAL;
1042
1043 /* From this point forward we keep holding onto the tasklist lock
1044 * so that our parent does not change from under us. -DaveM
1045 */
1046 write_lock_irq(&tasklist_lock);
1047
1048 err = -ESRCH;
1049 p = find_task_by_pid(pid);
1050 if (!p)
1051 goto out;
1052
1053 err = -EINVAL;
1054 if (!thread_group_leader(p))
1055 goto out;
1056
1057 if (p->parent == current || p->real_parent == current) {
1058 err = -EPERM;
1059 if (p->signal->session != current->signal->session)
1060 goto out;
1061 err = -EACCES;
1062 if (p->did_exec)
1063 goto out;
1064 } else {
1065 err = -ESRCH;
1066 if (p != current)
1067 goto out;
1068 }
1069
1070 err = -EPERM;
1071 if (p->signal->leader)
1072 goto out;
1073
1074 if (pgid != pid) {
1075 struct task_struct *p;
1076
1077 do_each_task_pid(pgid, PIDTYPE_PGID, p) {
1078 if (p->signal->session == current->signal->session)
1079 goto ok_pgid;
1080 } while_each_task_pid(pgid, PIDTYPE_PGID, p);
1081 goto out;
1082 }
1083
1084 ok_pgid:
1085 err = security_task_setpgid(p, pgid);
1086 if (err)
1087 goto out;
1088
1089 if (process_group(p) != pgid) {
1090 detach_pid(p, PIDTYPE_PGID);
1091 p->signal->pgrp = pgid;
1092 attach_pid(p, PIDTYPE_PGID, pgid);
1093 }
1094
1095 err = 0;
1096 out:
1097 /* All paths lead to here, thus we are safe. -DaveM */
1098 write_unlock_irq(&tasklist_lock);
1099 return err;
1100 }
1101
1102 asmlinkage long sys_getpgid(pid_t pid)
1103 {
1104 if (!pid) {
1105 return process_group(current);
1106 } else {
1107 int retval;
1108 struct task_struct *p;
1109
1110 read_lock(&tasklist_lock);
1111 p = find_task_by_pid(pid);
1112
1113 retval = -ESRCH;
1114 if (p) {
1115 retval = security_task_getpgid(p);
1116 if (!retval)
1117 retval = process_group(p);
1118 }
1119 read_unlock(&tasklist_lock);
1120 return retval;
1121 }
1122 }
1123
1124 #ifdef __ARCH_WANT_SYS_GETPGRP
1125
1126 asmlinkage long sys_getpgrp(void)
1127 {
1128 /* SMP - assuming writes are word atomic this is fine */
1129 return process_group(current);
1130 }
1131
1132 #endif
1133
1134 asmlinkage long sys_getsid(pid_t pid)
1135 {
1136 if (!pid) {
1137 return current->signal->session;
1138 } else {
1139 int retval;
1140 struct task_struct *p;
1141
1142 read_lock(&tasklist_lock);
1143 p = find_task_by_pid(pid);
1144
1145 retval = -ESRCH;
1146 if(p) {
1147 retval = security_task_getsid(p);
1148 if (!retval)
1149 retval = p->signal->session;
1150 }
1151 read_unlock(&tasklist_lock);
1152 return retval;
1153 }
1154 }
1155
1156 asmlinkage long sys_setsid(void)
1157 {
1158 struct pid *pid;
1159 int err = -EPERM;
1160
1161 if (!thread_group_leader(current))
1162 return -EINVAL;
1163
1164 down(&tty_sem);
1165 write_lock_irq(&tasklist_lock);
1166
1167 pid = find_pid(PIDTYPE_PGID, current->pid);
1168 if (pid)
1169 goto out;
1170
1171 current->signal->leader = 1;
1172 __set_special_pids(current->pid, current->pid);
1173 current->signal->tty = NULL;
1174 current->signal->tty_old_pgrp = 0;
1175 err = process_group(current);
1176 out:
1177 write_unlock_irq(&tasklist_lock);
1178 up(&tty_sem);
1179 return err;
1180 }
1181
1182 /*
1183 * Supplementary group IDs
1184 */
1185
1186 /* init to 2 - one for init_task, one to ensure it is never freed */
1187 struct group_info init_groups = { .usage = ATOMIC_INIT(2) };
1188
1189 struct group_info *groups_alloc(int gidsetsize)
1190 {
1191 struct group_info *group_info;
1192 int nblocks;
1193 int i;
1194
1195 nblocks = (gidsetsize + NGROUPS_PER_BLOCK - 1) / NGROUPS_PER_BLOCK;
1196 /* Make sure we always allocate at least one indirect block pointer */
1197 nblocks = nblocks ? : 1;
1198 group_info = kmalloc(sizeof(*group_info) + nblocks*sizeof(gid_t *), GFP_USER);
1199 if (!group_info)
1200 return NULL;
1201 group_info->ngroups = gidsetsize;
1202 group_info->nblocks = nblocks;
1203 atomic_set(&group_info->usage, 1);
1204
1205 if (gidsetsize <= NGROUPS_SMALL) {
1206 group_info->blocks[0] = group_info->small_block;
1207 } else {
1208 for (i = 0; i < nblocks; i++) {
1209 gid_t *b;
1210 b = (void *)__get_free_page(GFP_USER);
1211 if (!b)
1212 goto out_undo_partial_alloc;
1213 group_info->blocks[i] = b;
1214 }
1215 }
1216 return group_info;
1217
1218 out_undo_partial_alloc:
1219 while (--i >= 0) {
1220 free_page((unsigned long)group_info->blocks[i]);
1221 }
1222 kfree(group_info);
1223 return NULL;
1224 }
1225
1226 EXPORT_SYMBOL(groups_alloc);
1227
1228 void groups_free(struct group_info *group_info)
1229 {
1230 if (group_info->blocks[0] != group_info->small_block) {
1231 int i;
1232 for (i = 0; i < group_info->nblocks; i++)
1233 free_page((unsigned long)group_info->blocks[i]);
1234 }
1235 kfree(group_info);
1236 }
1237
1238 EXPORT_SYMBOL(groups_free);
1239
1240 /* export the group_info to a user-space array */
1241 static int groups_to_user(gid_t __user *grouplist,
1242 struct group_info *group_info)
1243 {
1244 int i;
1245 int count = group_info->ngroups;
1246
1247 for (i = 0; i < group_info->nblocks; i++) {
1248 int cp_count = min(NGROUPS_PER_BLOCK, count);
1249 int off = i * NGROUPS_PER_BLOCK;
1250 int len = cp_count * sizeof(*grouplist);
1251
1252 if (copy_to_user(grouplist+off, group_info->blocks[i], len))
1253 return -EFAULT;
1254
1255 count -= cp_count;
1256 }
1257 return 0;
1258 }
1259
1260 /* fill a group_info from a user-space array - it must be allocated already */
1261 static int groups_from_user(struct group_info *group_info,
1262 gid_t __user *grouplist)
1263 {
1264 int i;
1265 int count = group_info->ngroups;
1266
1267 for (i = 0; i < group_info->nblocks; i++) {
1268 int cp_count = min(NGROUPS_PER_BLOCK, count);
1269 int off = i * NGROUPS_PER_BLOCK;
1270 int len = cp_count * sizeof(*grouplist);
1271
1272 if (copy_from_user(group_info->blocks[i], grouplist+off, len))
1273 return -EFAULT;
1274
1275 count -= cp_count;
1276 }
1277 return 0;
1278 }
1279
1280 /* a simple Shell sort */
1281 static void groups_sort(struct group_info *group_info)
1282 {
1283 int base, max, stride;
1284 int gidsetsize = group_info->ngroups;
1285
1286 for (stride = 1; stride < gidsetsize; stride = 3 * stride + 1)
1287 ; /* nothing */
1288 stride /= 3;
1289
1290 while (stride) {
1291 max = gidsetsize - stride;
1292 for (base = 0; base < max; base++) {
1293 int left = base;
1294 int right = left + stride;
1295 gid_t tmp = GROUP_AT(group_info, right);
1296
1297 while (left >= 0 && GROUP_AT(group_info, left) > tmp) {
1298 GROUP_AT(group_info, right) =
1299 GROUP_AT(group_info, left);
1300 right = left;
1301 left -= stride;
1302 }
1303 GROUP_AT(group_info, right) = tmp;
1304 }
1305 stride /= 3;
1306 }
1307 }
1308
1309 /* a simple bsearch */
1310 int groups_search(struct group_info *group_info, gid_t grp)
1311 {
1312 int left, right;
1313
1314 if (!group_info)
1315 return 0;
1316
1317 left = 0;
1318 right = group_info->ngroups;
1319 while (left < right) {
1320 int mid = (left+right)/2;
1321 int cmp = grp - GROUP_AT(group_info, mid);
1322 if (cmp > 0)
1323 left = mid + 1;
1324 else if (cmp < 0)
1325 right = mid;
1326 else
1327 return 1;
1328 }
1329 return 0;
1330 }
1331
1332 /* validate and set current->group_info */
1333 int set_current_groups(struct group_info *group_info)
1334 {
1335 int retval;
1336 struct group_info *old_info;
1337
1338 retval = security_task_setgroups(group_info);
1339 if (retval)
1340 return retval;
1341
1342 groups_sort(group_info);
1343 get_group_info(group_info);
1344
1345 task_lock(current);
1346 old_info = current->group_info;
1347 current->group_info = group_info;
1348 task_unlock(current);
1349
1350 put_group_info(old_info);
1351
1352 return 0;
1353 }
1354
1355 EXPORT_SYMBOL(set_current_groups);
1356
1357 asmlinkage long sys_getgroups(int gidsetsize, gid_t __user *grouplist)
1358 {
1359 int i = 0;
1360
1361 /*
1362 * SMP: Nobody else can change our grouplist. Thus we are
1363 * safe.
1364 */
1365
1366 if (gidsetsize < 0)
1367 return -EINVAL;
1368
1369 /* no need to grab task_lock here; it cannot change */
1370 get_group_info(current->group_info);
1371 i = current->group_info->ngroups;
1372 if (gidsetsize) {
1373 if (i > gidsetsize) {
1374 i = -EINVAL;
1375 goto out;
1376 }
1377 if (groups_to_user(grouplist, current->group_info)) {
1378 i = -EFAULT;
1379 goto out;
1380 }
1381 }
1382 out:
1383 put_group_info(current->group_info);
1384 return i;
1385 }
1386
1387 /*
1388 * SMP: Our groups are copy-on-write. We can set them safely
1389 * without another task interfering.
1390 */
1391
1392 asmlinkage long sys_setgroups(int gidsetsize, gid_t __user *grouplist)
1393 {
1394 struct group_info *group_info;
1395 int retval;
1396
1397 if (!capable(CAP_SETGID))
1398 return -EPERM;
1399 if ((unsigned)gidsetsize > NGROUPS_MAX)
1400 return -EINVAL;
1401
1402 group_info = groups_alloc(gidsetsize);
1403 if (!group_info)
1404 return -ENOMEM;
1405 retval = groups_from_user(group_info, grouplist);
1406 if (retval) {
1407 put_group_info(group_info);
1408 return retval;
1409 }
1410
1411 retval = set_current_groups(group_info);
1412 put_group_info(group_info);
1413
1414 return retval;
1415 }
1416
1417 /*
1418 * Check whether we're fsgid/egid or in the supplemental group..
1419 */
1420 int in_group_p(gid_t grp)
1421 {
1422 int retval = 1;
1423 if (grp != current->fsgid) {
1424 get_group_info(current->group_info);
1425 retval = groups_search(current->group_info, grp);
1426 put_group_info(current->group_info);
1427 }
1428 return retval;
1429 }
1430
1431 EXPORT_SYMBOL(in_group_p);
1432
1433 int in_egroup_p(gid_t grp)
1434 {
1435 int retval = 1;
1436 if (grp != current->egid) {
1437 get_group_info(current->group_info);
1438 retval = groups_search(current->group_info, grp);
1439 put_group_info(current->group_info);
1440 }
1441 return retval;
1442 }
1443
1444 EXPORT_SYMBOL(in_egroup_p);
1445
1446 DECLARE_RWSEM(uts_sem);
1447
1448 EXPORT_SYMBOL(uts_sem);
1449
1450 asmlinkage long sys_newuname(struct new_utsname __user * name)
1451 {
1452 int errno = 0;
1453
1454 down_read(&uts_sem);
1455 if (copy_to_user(name,&system_utsname,sizeof *name))
1456 errno = -EFAULT;
1457 up_read(&uts_sem);
1458 return errno;
1459 }
1460
1461 asmlinkage long sys_sethostname(char __user *name, int len)
1462 {
1463 int errno;
1464 char tmp[__NEW_UTS_LEN];
1465
1466 if (!capable(CAP_SYS_ADMIN))
1467 return -EPERM;
1468 if (len < 0 || len > __NEW_UTS_LEN)
1469 return -EINVAL;
1470 down_write(&uts_sem);
1471 errno = -EFAULT;
1472 if (!copy_from_user(tmp, name, len)) {
1473 memcpy(system_utsname.nodename, tmp, len);
1474 system_utsname.nodename[len] = 0;
1475 errno = 0;
1476 }
1477 up_write(&uts_sem);
1478 return errno;
1479 }
1480
1481 #ifdef __ARCH_WANT_SYS_GETHOSTNAME
1482
1483 asmlinkage long sys_gethostname(char __user *name, int len)
1484 {
1485 int i, errno;
1486
1487 if (len < 0)
1488 return -EINVAL;
1489 down_read(&uts_sem);
1490 i = 1 + strlen(system_utsname.nodename);
1491 if (i > len)
1492 i = len;
1493 errno = 0;
1494 if (copy_to_user(name, system_utsname.nodename, i))
1495 errno = -EFAULT;
1496 up_read(&uts_sem);
1497 return errno;
1498 }
1499
1500 #endif
1501
1502 /*
1503 * Only setdomainname; getdomainname can be implemented by calling
1504 * uname()
1505 */
1506 asmlinkage long sys_setdomainname(char __user *name, int len)
1507 {
1508 int errno;
1509 char tmp[__NEW_UTS_LEN];
1510
1511 if (!capable(CAP_SYS_ADMIN))
1512 return -EPERM;
1513 if (len < 0 || len > __NEW_UTS_LEN)
1514 return -EINVAL;
1515
1516 down_write(&uts_sem);
1517 errno = -EFAULT;
1518 if (!copy_from_user(tmp, name, len)) {
1519 memcpy(system_utsname.domainname, tmp, len);
1520 system_utsname.domainname[len] = 0;
1521 errno = 0;
1522 }
1523 up_write(&uts_sem);
1524 return errno;
1525 }
1526
1527 asmlinkage long sys_getrlimit(unsigned int resource, struct rlimit __user *rlim)
1528 {
1529 if (resource >= RLIM_NLIMITS)
1530 return -EINVAL;
1531 else {
1532 struct rlimit value;
1533 task_lock(current->group_leader);
1534 value = current->signal->rlim[resource];
1535 task_unlock(current->group_leader);
1536 return copy_to_user(rlim, &value, sizeof(*rlim)) ? -EFAULT : 0;
1537 }
1538 }
1539
1540 #ifdef __ARCH_WANT_SYS_OLD_GETRLIMIT
1541
1542 /*
1543 * Back compatibility for getrlimit. Needed for some apps.
1544 */
1545
1546 asmlinkage long sys_old_getrlimit(unsigned int resource, struct rlimit __user *rlim)
1547 {
1548 struct rlimit x;
1549 if (resource >= RLIM_NLIMITS)
1550 return -EINVAL;
1551
1552 task_lock(current->group_leader);
1553 x = current->signal->rlim[resource];
1554 task_unlock(current->group_leader);
1555 if(x.rlim_cur > 0x7FFFFFFF)
1556 x.rlim_cur = 0x7FFFFFFF;
1557 if(x.rlim_max > 0x7FFFFFFF)
1558 x.rlim_max = 0x7FFFFFFF;
1559 return copy_to_user(rlim, &x, sizeof(x))?-EFAULT:0;
1560 }
1561
1562 #endif
1563
1564 asmlinkage long sys_setrlimit(unsigned int resource, struct rlimit __user *rlim)
1565 {
1566 struct rlimit new_rlim, *old_rlim;
1567 int retval;
1568
1569 if (resource >= RLIM_NLIMITS)
1570 return -EINVAL;
1571 if(copy_from_user(&new_rlim, rlim, sizeof(*rlim)))
1572 return -EFAULT;
1573 if (new_rlim.rlim_cur > new_rlim.rlim_max)
1574 return -EINVAL;
1575 old_rlim = current->signal->rlim + resource;
1576 if ((new_rlim.rlim_max > old_rlim->rlim_max) &&
1577 !capable(CAP_SYS_RESOURCE))
1578 return -EPERM;
1579 if (resource == RLIMIT_NOFILE && new_rlim.rlim_max > NR_OPEN)
1580 return -EPERM;
1581
1582 retval = security_task_setrlimit(resource, &new_rlim);
1583 if (retval)
1584 return retval;
1585
1586 task_lock(current->group_leader);
1587 *old_rlim = new_rlim;
1588 task_unlock(current->group_leader);
1589
1590 if (resource == RLIMIT_CPU && new_rlim.rlim_cur != RLIM_INFINITY &&
1591 (cputime_eq(current->signal->it_prof_expires, cputime_zero) ||
1592 new_rlim.rlim_cur <= cputime_to_secs(
1593 current->signal->it_prof_expires))) {
1594 cputime_t cputime = secs_to_cputime(new_rlim.rlim_cur);
1595 read_lock(&tasklist_lock);
1596 spin_lock_irq(&current->sighand->siglock);
1597 set_process_cpu_timer(current, CPUCLOCK_PROF,
1598 &cputime, NULL);
1599 spin_unlock_irq(&current->sighand->siglock);
1600 read_unlock(&tasklist_lock);
1601 }
1602
1603 return 0;
1604 }
1605
1606 /*
1607 * It would make sense to put struct rusage in the task_struct,
1608 * except that would make the task_struct be *really big*. After
1609 * task_struct gets moved into malloc'ed memory, it would
1610 * make sense to do this. It will make moving the rest of the information
1611 * a lot simpler! (Which we're not doing right now because we're not
1612 * measuring them yet).
1613 *
1614 * This expects to be called with tasklist_lock read-locked or better,
1615 * and the siglock not locked. It may momentarily take the siglock.
1616 *
1617 * When sampling multiple threads for RUSAGE_SELF, under SMP we might have
1618 * races with threads incrementing their own counters. But since word
1619 * reads are atomic, we either get new values or old values and we don't
1620 * care which for the sums. We always take the siglock to protect reading
1621 * the c* fields from p->signal from races with exit.c updating those
1622 * fields when reaping, so a sample either gets all the additions of a
1623 * given child after it's reaped, or none so this sample is before reaping.
1624 */
1625
1626 static void k_getrusage(struct task_struct *p, int who, struct rusage *r)
1627 {
1628 struct task_struct *t;
1629 unsigned long flags;
1630 cputime_t utime, stime;
1631
1632 memset((char *) r, 0, sizeof *r);
1633
1634 if (unlikely(!p->signal))
1635 return;
1636
1637 switch (who) {
1638 case RUSAGE_CHILDREN:
1639 spin_lock_irqsave(&p->sighand->siglock, flags);
1640 utime = p->signal->cutime;
1641 stime = p->signal->cstime;
1642 r->ru_nvcsw = p->signal->cnvcsw;
1643 r->ru_nivcsw = p->signal->cnivcsw;
1644 r->ru_minflt = p->signal->cmin_flt;
1645 r->ru_majflt = p->signal->cmaj_flt;
1646 spin_unlock_irqrestore(&p->sighand->siglock, flags);
1647 cputime_to_timeval(utime, &r->ru_utime);
1648 cputime_to_timeval(stime, &r->ru_stime);
1649 break;
1650 case RUSAGE_SELF:
1651 spin_lock_irqsave(&p->sighand->siglock, flags);
1652 utime = stime = cputime_zero;
1653 goto sum_group;
1654 case RUSAGE_BOTH:
1655 spin_lock_irqsave(&p->sighand->siglock, flags);
1656 utime = p->signal->cutime;
1657 stime = p->signal->cstime;
1658 r->ru_nvcsw = p->signal->cnvcsw;
1659 r->ru_nivcsw = p->signal->cnivcsw;
1660 r->ru_minflt = p->signal->cmin_flt;
1661 r->ru_majflt = p->signal->cmaj_flt;
1662 sum_group:
1663 utime = cputime_add(utime, p->signal->utime);
1664 stime = cputime_add(stime, p->signal->stime);
1665 r->ru_nvcsw += p->signal->nvcsw;
1666 r->ru_nivcsw += p->signal->nivcsw;
1667 r->ru_minflt += p->signal->min_flt;
1668 r->ru_majflt += p->signal->maj_flt;
1669 t = p;
1670 do {
1671 utime = cputime_add(utime, t->utime);
1672 stime = cputime_add(stime, t->stime);
1673 r->ru_nvcsw += t->nvcsw;
1674 r->ru_nivcsw += t->nivcsw;
1675 r->ru_minflt += t->min_flt;
1676 r->ru_majflt += t->maj_flt;
1677 t = next_thread(t);
1678 } while (t != p);
1679 spin_unlock_irqrestore(&p->sighand->siglock, flags);
1680 cputime_to_timeval(utime, &r->ru_utime);
1681 cputime_to_timeval(stime, &r->ru_stime);
1682 break;
1683 default:
1684 BUG();
1685 }
1686 }
1687
1688 int getrusage(struct task_struct *p, int who, struct rusage __user *ru)
1689 {
1690 struct rusage r;
1691 read_lock(&tasklist_lock);
1692 k_getrusage(p, who, &r);
1693 read_unlock(&tasklist_lock);
1694 return copy_to_user(ru, &r, sizeof(r)) ? -EFAULT : 0;
1695 }
1696
1697 asmlinkage long sys_getrusage(int who, struct rusage __user *ru)
1698 {
1699 if (who != RUSAGE_SELF && who != RUSAGE_CHILDREN)
1700 return -EINVAL;
1701 return getrusage(current, who, ru);
1702 }
1703
1704 asmlinkage long sys_umask(int mask)
1705 {
1706 mask = xchg(&current->fs->umask, mask & S_IRWXUGO);
1707 return mask;
1708 }
1709
1710 asmlinkage long sys_prctl(int option, unsigned long arg2, unsigned long arg3,
1711 unsigned long arg4, unsigned long arg5)
1712 {
1713 long error;
1714 int sig;
1715
1716 error = security_task_prctl(option, arg2, arg3, arg4, arg5);
1717 if (error)
1718 return error;
1719
1720 switch (option) {
1721 case PR_SET_PDEATHSIG:
1722 sig = arg2;
1723 if (!valid_signal(sig)) {
1724 error = -EINVAL;
1725 break;
1726 }
1727 current->pdeath_signal = sig;
1728 break;
1729 case PR_GET_PDEATHSIG:
1730 error = put_user(current->pdeath_signal, (int __user *)arg2);
1731 break;
1732 case PR_GET_DUMPABLE:
1733 if (current->mm->dumpable)
1734 error = 1;
1735 break;
1736 case PR_SET_DUMPABLE:
1737 if (arg2 < 0 || arg2 > 2) {
1738 error = -EINVAL;
1739 break;
1740 }
1741 current->mm->dumpable = arg2;
1742 break;
1743
1744 case PR_SET_UNALIGN:
1745 error = SET_UNALIGN_CTL(current, arg2);
1746 break;
1747 case PR_GET_UNALIGN:
1748 error = GET_UNALIGN_CTL(current, arg2);
1749 break;
1750 case PR_SET_FPEMU:
1751 error = SET_FPEMU_CTL(current, arg2);
1752 break;
1753 case PR_GET_FPEMU:
1754 error = GET_FPEMU_CTL(current, arg2);
1755 break;
1756 case PR_SET_FPEXC:
1757 error = SET_FPEXC_CTL(current, arg2);
1758 break;
1759 case PR_GET_FPEXC:
1760 error = GET_FPEXC_CTL(current, arg2);
1761 break;
1762 case PR_GET_TIMING:
1763 error = PR_TIMING_STATISTICAL;
1764 break;
1765 case PR_SET_TIMING:
1766 if (arg2 == PR_TIMING_STATISTICAL)
1767 error = 0;
1768 else
1769 error = -EINVAL;
1770 break;
1771
1772 case PR_GET_KEEPCAPS:
1773 if (current->keep_capabilities)
1774 error = 1;
1775 break;
1776 case PR_SET_KEEPCAPS:
1777 if (arg2 != 0 && arg2 != 1) {
1778 error = -EINVAL;
1779 break;
1780 }
1781 current->keep_capabilities = arg2;
1782 break;
1783 case PR_SET_NAME: {
1784 struct task_struct *me = current;
1785 unsigned char ncomm[sizeof(me->comm)];
1786
1787 ncomm[sizeof(me->comm)-1] = 0;
1788 if (strncpy_from_user(ncomm, (char __user *)arg2,
1789 sizeof(me->comm)-1) < 0)
1790 return -EFAULT;
1791 set_task_comm(me, ncomm);
1792 return 0;
1793 }
1794 case PR_GET_NAME: {
1795 struct task_struct *me = current;
1796 unsigned char tcomm[sizeof(me->comm)];
1797
1798 get_task_comm(tcomm, me);
1799 if (copy_to_user((char __user *)arg2, tcomm, sizeof(tcomm)))
1800 return -EFAULT;
1801 return 0;
1802 }
1803 default:
1804 error = -EINVAL;
1805 break;
1806 }
1807 return error;
1808 }
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