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[PATCH] forcedeth: rewritten tx irq handling
[linux-2.6/sactl.git] / kernel / sys.c
blob000e81ad2c1d8320d6b5609e87baccba6a07ad52
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_suspend(PMSG_SUSPEND);
408 device_shutdown();
409 printk(KERN_EMERG "System halted.\n");
410 machine_halt();
411 }
412 EXPORT_SYMBOL_GPL(kernel_halt);
413
414 void kernel_power_off(void)
415 {
416 notifier_call_chain(&reboot_notifier_list, SYS_POWER_OFF, NULL);
417 system_state = SYSTEM_POWER_OFF;
418 device_suspend(PMSG_SUSPEND);
419 device_shutdown();
420 printk(KERN_EMERG "Power down.\n");
421 machine_power_off();
422 }
423 EXPORT_SYMBOL_GPL(kernel_power_off);
424
425 /*
426 * Reboot system call: for obvious reasons only root may call it,
427 * and even root needs to set up some magic numbers in the registers
428 * so that some mistake won't make this reboot the whole machine.
429 * You can also set the meaning of the ctrl-alt-del-key here.
430 *
431 * reboot doesn't sync: do that yourself before calling this.
432 */
433 asmlinkage long sys_reboot(int magic1, int magic2, unsigned int cmd, void __user * arg)
434 {
435 char buffer[256];
436
437 /* We only trust the superuser with rebooting the system. */
438 if (!capable(CAP_SYS_BOOT))
439 return -EPERM;
440
441 /* For safety, we require "magic" arguments. */
442 if (magic1 != LINUX_REBOOT_MAGIC1 ||
443 (magic2 != LINUX_REBOOT_MAGIC2 &&
444 magic2 != LINUX_REBOOT_MAGIC2A &&
445 magic2 != LINUX_REBOOT_MAGIC2B &&
446 magic2 != LINUX_REBOOT_MAGIC2C))
447 return -EINVAL;
448
449 lock_kernel();
450 switch (cmd) {
451 case LINUX_REBOOT_CMD_RESTART:
452 kernel_restart(NULL);
453 break;
454
455 case LINUX_REBOOT_CMD_CAD_ON:
456 C_A_D = 1;
457 break;
458
459 case LINUX_REBOOT_CMD_CAD_OFF:
460 C_A_D = 0;
461 break;
462
463 case LINUX_REBOOT_CMD_HALT:
464 kernel_halt();
465 unlock_kernel();
466 do_exit(0);
467 break;
468
469 case LINUX_REBOOT_CMD_POWER_OFF:
470 kernel_power_off();
471 unlock_kernel();
472 do_exit(0);
473 break;
474
475 case LINUX_REBOOT_CMD_RESTART2:
476 if (strncpy_from_user(&buffer[0], arg, sizeof(buffer) - 1) < 0) {
477 unlock_kernel();
478 return -EFAULT;
479 }
480 buffer[sizeof(buffer) - 1] = '\0';
481
482 kernel_restart(buffer);
483 break;
484
485 case LINUX_REBOOT_CMD_KEXEC:
486 kernel_kexec();
487 unlock_kernel();
488 return -EINVAL;
489
490 #ifdef CONFIG_SOFTWARE_SUSPEND
491 case LINUX_REBOOT_CMD_SW_SUSPEND:
492 {
493 int ret = software_suspend();
494 unlock_kernel();
495 return ret;
496 }
497 #endif
498
499 default:
500 unlock_kernel();
501 return -EINVAL;
502 }
503 unlock_kernel();
504 return 0;
505 }
506
507 static void deferred_cad(void *dummy)
508 {
509 kernel_restart(NULL);
510 }
511
512 /*
513 * This function gets called by ctrl-alt-del - ie the keyboard interrupt.
514 * As it's called within an interrupt, it may NOT sync: the only choice
515 * is whether to reboot at once, or just ignore the ctrl-alt-del.
516 */
517 void ctrl_alt_del(void)
518 {
519 static DECLARE_WORK(cad_work, deferred_cad, NULL);
520
521 if (C_A_D)
522 schedule_work(&cad_work);
523 else
524 kill_proc(cad_pid, SIGINT, 1);
525 }
526
527
528 /*
529 * Unprivileged users may change the real gid to the effective gid
530 * or vice versa. (BSD-style)
531 *
532 * If you set the real gid at all, or set the effective gid to a value not
533 * equal to the real gid, then the saved gid is set to the new effective gid.
534 *
535 * This makes it possible for a setgid program to completely drop its
536 * privileges, which is often a useful assertion to make when you are doing
537 * a security audit over a program.
538 *
539 * The general idea is that a program which uses just setregid() will be
540 * 100% compatible with BSD. A program which uses just setgid() will be
541 * 100% compatible with POSIX with saved IDs.
542 *
543 * SMP: There are not races, the GIDs are checked only by filesystem
544 * operations (as far as semantic preservation is concerned).
545 */
546 asmlinkage long sys_setregid(gid_t rgid, gid_t egid)
547 {
548 int old_rgid = current->gid;
549 int old_egid = current->egid;
550 int new_rgid = old_rgid;
551 int new_egid = old_egid;
552 int retval;
553
554 retval = security_task_setgid(rgid, egid, (gid_t)-1, LSM_SETID_RE);
555 if (retval)
556 return retval;
557
558 if (rgid != (gid_t) -1) {
559 if ((old_rgid == rgid) ||
560 (current->egid==rgid) ||
561 capable(CAP_SETGID))
562 new_rgid = rgid;
563 else
564 return -EPERM;
565 }
566 if (egid != (gid_t) -1) {
567 if ((old_rgid == egid) ||
568 (current->egid == egid) ||
569 (current->sgid == egid) ||
570 capable(CAP_SETGID))
571 new_egid = egid;
572 else {
573 return -EPERM;
574 }
575 }
576 if (new_egid != old_egid)
577 {
578 current->mm->dumpable = suid_dumpable;
579 smp_wmb();
580 }
581 if (rgid != (gid_t) -1 ||
582 (egid != (gid_t) -1 && egid != old_rgid))
583 current->sgid = new_egid;
584 current->fsgid = new_egid;
585 current->egid = new_egid;
586 current->gid = new_rgid;
587 key_fsgid_changed(current);
588 return 0;
589 }
590
591 /*
592 * setgid() is implemented like SysV w/ SAVED_IDS
593 *
594 * SMP: Same implicit races as above.
595 */
596 asmlinkage long sys_setgid(gid_t gid)
597 {
598 int old_egid = current->egid;
599 int retval;
600
601 retval = security_task_setgid(gid, (gid_t)-1, (gid_t)-1, LSM_SETID_ID);
602 if (retval)
603 return retval;
604
605 if (capable(CAP_SETGID))
606 {
607 if(old_egid != gid)
608 {
609 current->mm->dumpable = suid_dumpable;
610 smp_wmb();
611 }
612 current->gid = current->egid = current->sgid = current->fsgid = gid;
613 }
614 else if ((gid == current->gid) || (gid == current->sgid))
615 {
616 if(old_egid != gid)
617 {
618 current->mm->dumpable = suid_dumpable;
619 smp_wmb();
620 }
621 current->egid = current->fsgid = gid;
622 }
623 else
624 return -EPERM;
625
626 key_fsgid_changed(current);
627 return 0;
628 }
629
630 static int set_user(uid_t new_ruid, int dumpclear)
631 {
632 struct user_struct *new_user;
633
634 new_user = alloc_uid(new_ruid);
635 if (!new_user)
636 return -EAGAIN;
637
638 if (atomic_read(&new_user->processes) >=
639 current->signal->rlim[RLIMIT_NPROC].rlim_cur &&
640 new_user != &root_user) {
641 free_uid(new_user);
642 return -EAGAIN;
643 }
644
645 switch_uid(new_user);
646
647 if(dumpclear)
648 {
649 current->mm->dumpable = suid_dumpable;
650 smp_wmb();
651 }
652 current->uid = new_ruid;
653 return 0;
654 }
655
656 /*
657 * Unprivileged users may change the real uid to the effective uid
658 * or vice versa. (BSD-style)
659 *
660 * If you set the real uid at all, or set the effective uid to a value not
661 * equal to the real uid, then the saved uid is set to the new effective uid.
662 *
663 * This makes it possible for a setuid program to completely drop its
664 * privileges, which is often a useful assertion to make when you are doing
665 * a security audit over a program.
666 *
667 * The general idea is that a program which uses just setreuid() will be
668 * 100% compatible with BSD. A program which uses just setuid() will be
669 * 100% compatible with POSIX with saved IDs.
670 */
671 asmlinkage long sys_setreuid(uid_t ruid, uid_t euid)
672 {
673 int old_ruid, old_euid, old_suid, new_ruid, new_euid;
674 int retval;
675
676 retval = security_task_setuid(ruid, euid, (uid_t)-1, LSM_SETID_RE);
677 if (retval)
678 return retval;
679
680 new_ruid = old_ruid = current->uid;
681 new_euid = old_euid = current->euid;
682 old_suid = current->suid;
683
684 if (ruid != (uid_t) -1) {
685 new_ruid = ruid;
686 if ((old_ruid != ruid) &&
687 (current->euid != ruid) &&
688 !capable(CAP_SETUID))
689 return -EPERM;
690 }
691
692 if (euid != (uid_t) -1) {
693 new_euid = euid;
694 if ((old_ruid != euid) &&
695 (current->euid != euid) &&
696 (current->suid != euid) &&
697 !capable(CAP_SETUID))
698 return -EPERM;
699 }
700
701 if (new_ruid != old_ruid && set_user(new_ruid, new_euid != old_euid) < 0)
702 return -EAGAIN;
703
704 if (new_euid != old_euid)
705 {
706 current->mm->dumpable = suid_dumpable;
707 smp_wmb();
708 }
709 current->fsuid = current->euid = new_euid;
710 if (ruid != (uid_t) -1 ||
711 (euid != (uid_t) -1 && euid != old_ruid))
712 current->suid = current->euid;
713 current->fsuid = current->euid;
714
715 key_fsuid_changed(current);
716
717 return security_task_post_setuid(old_ruid, old_euid, old_suid, LSM_SETID_RE);
718 }
719
720
721
722 /*
723 * setuid() is implemented like SysV with SAVED_IDS
724 *
725 * Note that SAVED_ID's is deficient in that a setuid root program
726 * like sendmail, for example, cannot set its uid to be a normal
727 * user and then switch back, because if you're root, setuid() sets
728 * the saved uid too. If you don't like this, blame the bright people
729 * in the POSIX committee and/or USG. Note that the BSD-style setreuid()
730 * will allow a root program to temporarily drop privileges and be able to
731 * regain them by swapping the real and effective uid.
732 */
733 asmlinkage long sys_setuid(uid_t uid)
734 {
735 int old_euid = current->euid;
736 int old_ruid, old_suid, new_ruid, new_suid;
737 int retval;
738
739 retval = security_task_setuid(uid, (uid_t)-1, (uid_t)-1, LSM_SETID_ID);
740 if (retval)
741 return retval;
742
743 old_ruid = new_ruid = current->uid;
744 old_suid = current->suid;
745 new_suid = old_suid;
746
747 if (capable(CAP_SETUID)) {
748 if (uid != old_ruid && set_user(uid, old_euid != uid) < 0)
749 return -EAGAIN;
750 new_suid = uid;
751 } else if ((uid != current->uid) && (uid != new_suid))
752 return -EPERM;
753
754 if (old_euid != uid)
755 {
756 current->mm->dumpable = suid_dumpable;
757 smp_wmb();
758 }
759 current->fsuid = current->euid = uid;
760 current->suid = new_suid;
761
762 key_fsuid_changed(current);
763
764 return security_task_post_setuid(old_ruid, old_euid, old_suid, LSM_SETID_ID);
765 }
766
767
768 /*
769 * This function implements a generic ability to update ruid, euid,
770 * and suid. This allows you to implement the 4.4 compatible seteuid().
771 */
772 asmlinkage long sys_setresuid(uid_t ruid, uid_t euid, uid_t suid)
773 {
774 int old_ruid = current->uid;
775 int old_euid = current->euid;
776 int old_suid = current->suid;
777 int retval;
778
779 retval = security_task_setuid(ruid, euid, suid, LSM_SETID_RES);
780 if (retval)
781 return retval;
782
783 if (!capable(CAP_SETUID)) {
784 if ((ruid != (uid_t) -1) && (ruid != current->uid) &&
785 (ruid != current->euid) && (ruid != current->suid))
786 return -EPERM;
787 if ((euid != (uid_t) -1) && (euid != current->uid) &&
788 (euid != current->euid) && (euid != current->suid))
789 return -EPERM;
790 if ((suid != (uid_t) -1) && (suid != current->uid) &&
791 (suid != current->euid) && (suid != current->suid))
792 return -EPERM;
793 }
794 if (ruid != (uid_t) -1) {
795 if (ruid != current->uid && set_user(ruid, euid != current->euid) < 0)
796 return -EAGAIN;
797 }
798 if (euid != (uid_t) -1) {
799 if (euid != current->euid)
800 {
801 current->mm->dumpable = suid_dumpable;
802 smp_wmb();
803 }
804 current->euid = euid;
805 }
806 current->fsuid = current->euid;
807 if (suid != (uid_t) -1)
808 current->suid = suid;
809
810 key_fsuid_changed(current);
811
812 return security_task_post_setuid(old_ruid, old_euid, old_suid, LSM_SETID_RES);
813 }
814
815 asmlinkage long sys_getresuid(uid_t __user *ruid, uid_t __user *euid, uid_t __user *suid)
816 {
817 int retval;
818
819 if (!(retval = put_user(current->uid, ruid)) &&
820 !(retval = put_user(current->euid, euid)))
821 retval = put_user(current->suid, suid);
822
823 return retval;
824 }
825
826 /*
827 * Same as above, but for rgid, egid, sgid.
828 */
829 asmlinkage long sys_setresgid(gid_t rgid, gid_t egid, gid_t sgid)
830 {
831 int retval;
832
833 retval = security_task_setgid(rgid, egid, sgid, LSM_SETID_RES);
834 if (retval)
835 return retval;
836
837 if (!capable(CAP_SETGID)) {
838 if ((rgid != (gid_t) -1) && (rgid != current->gid) &&
839 (rgid != current->egid) && (rgid != current->sgid))
840 return -EPERM;
841 if ((egid != (gid_t) -1) && (egid != current->gid) &&
842 (egid != current->egid) && (egid != current->sgid))
843 return -EPERM;
844 if ((sgid != (gid_t) -1) && (sgid != current->gid) &&
845 (sgid != current->egid) && (sgid != current->sgid))
846 return -EPERM;
847 }
848 if (egid != (gid_t) -1) {
849 if (egid != current->egid)
850 {
851 current->mm->dumpable = suid_dumpable;
852 smp_wmb();
853 }
854 current->egid = egid;
855 }
856 current->fsgid = current->egid;
857 if (rgid != (gid_t) -1)
858 current->gid = rgid;
859 if (sgid != (gid_t) -1)
860 current->sgid = sgid;
861
862 key_fsgid_changed(current);
863 return 0;
864 }
865
866 asmlinkage long sys_getresgid(gid_t __user *rgid, gid_t __user *egid, gid_t __user *sgid)
867 {
868 int retval;
869
870 if (!(retval = put_user(current->gid, rgid)) &&
871 !(retval = put_user(current->egid, egid)))
872 retval = put_user(current->sgid, sgid);
873
874 return retval;
875 }
876
877
878 /*
879 * "setfsuid()" sets the fsuid - the uid used for filesystem checks. This
880 * is used for "access()" and for the NFS daemon (letting nfsd stay at
881 * whatever uid it wants to). It normally shadows "euid", except when
882 * explicitly set by setfsuid() or for access..
883 */
884 asmlinkage long sys_setfsuid(uid_t uid)
885 {
886 int old_fsuid;
887
888 old_fsuid = current->fsuid;
889 if (security_task_setuid(uid, (uid_t)-1, (uid_t)-1, LSM_SETID_FS))
890 return old_fsuid;
891
892 if (uid == current->uid || uid == current->euid ||
893 uid == current->suid || uid == current->fsuid ||
894 capable(CAP_SETUID))
895 {
896 if (uid != old_fsuid)
897 {
898 current->mm->dumpable = suid_dumpable;
899 smp_wmb();
900 }
901 current->fsuid = uid;
902 }
903
904 key_fsuid_changed(current);
905
906 security_task_post_setuid(old_fsuid, (uid_t)-1, (uid_t)-1, LSM_SETID_FS);
907
908 return old_fsuid;
909 }
910
911 /*
912 * Samma på svenska..
913 */
914 asmlinkage long sys_setfsgid(gid_t gid)
915 {
916 int old_fsgid;
917
918 old_fsgid = current->fsgid;
919 if (security_task_setgid(gid, (gid_t)-1, (gid_t)-1, LSM_SETID_FS))
920 return old_fsgid;
921
922 if (gid == current->gid || gid == current->egid ||
923 gid == current->sgid || gid == current->fsgid ||
924 capable(CAP_SETGID))
925 {
926 if (gid != old_fsgid)
927 {
928 current->mm->dumpable = suid_dumpable;
929 smp_wmb();
930 }
931 current->fsgid = gid;
932 key_fsgid_changed(current);
933 }
934 return old_fsgid;
935 }
936
937 asmlinkage long sys_times(struct tms __user * tbuf)
938 {
939 /*
940 * In the SMP world we might just be unlucky and have one of
941 * the times increment as we use it. Since the value is an
942 * atomically safe type this is just fine. Conceptually its
943 * as if the syscall took an instant longer to occur.
944 */
945 if (tbuf) {
946 struct tms tmp;
947 cputime_t utime, stime, cutime, cstime;
948
949 #ifdef CONFIG_SMP
950 if (thread_group_empty(current)) {
951 /*
952 * Single thread case without the use of any locks.
953 *
954 * We may race with release_task if two threads are
955 * executing. However, release task first adds up the
956 * counters (__exit_signal) before removing the task
957 * from the process tasklist (__unhash_process).
958 * __exit_signal also acquires and releases the
959 * siglock which results in the proper memory ordering
960 * so that the list modifications are always visible
961 * after the counters have been updated.
962 *
963 * If the counters have been updated by the second thread
964 * but the thread has not yet been removed from the list
965 * then the other branch will be executing which will
966 * block on tasklist_lock until the exit handling of the
967 * other task is finished.
968 *
969 * This also implies that the sighand->siglock cannot
970 * be held by another processor. So we can also
971 * skip acquiring that lock.
972 */
973 utime = cputime_add(current->signal->utime, current->utime);
974 stime = cputime_add(current->signal->utime, current->stime);
975 cutime = current->signal->cutime;
976 cstime = current->signal->cstime;
977 } else
978 #endif
979 {
980
981 /* Process with multiple threads */
982 struct task_struct *tsk = current;
983 struct task_struct *t;
984
985 read_lock(&tasklist_lock);
986 utime = tsk->signal->utime;
987 stime = tsk->signal->stime;
988 t = tsk;
989 do {
990 utime = cputime_add(utime, t->utime);
991 stime = cputime_add(stime, t->stime);
992 t = next_thread(t);
993 } while (t != tsk);
994
995 /*
996 * While we have tasklist_lock read-locked, no dying thread
997 * can be updating current->signal->[us]time. Instead,
998 * we got their counts included in the live thread loop.
999 * However, another thread can come in right now and
1000 * do a wait call that updates current->signal->c[us]time.
1001 * To make sure we always see that pair updated atomically,
1002 * we take the siglock around fetching them.
1003 */
1004 spin_lock_irq(&tsk->sighand->siglock);
1005 cutime = tsk->signal->cutime;
1006 cstime = tsk->signal->cstime;
1007 spin_unlock_irq(&tsk->sighand->siglock);
1008 read_unlock(&tasklist_lock);
1009 }
1010 tmp.tms_utime = cputime_to_clock_t(utime);
1011 tmp.tms_stime = cputime_to_clock_t(stime);
1012 tmp.tms_cutime = cputime_to_clock_t(cutime);
1013 tmp.tms_cstime = cputime_to_clock_t(cstime);
1014 if (copy_to_user(tbuf, &tmp, sizeof(struct tms)))
1015 return -EFAULT;
1016 }
1017 return (long) jiffies_64_to_clock_t(get_jiffies_64());
1018 }
1019
1020 /*
1021 * This needs some heavy checking ...
1022 * I just haven't the stomach for it. I also don't fully
1023 * understand sessions/pgrp etc. Let somebody who does explain it.
1024 *
1025 * OK, I think I have the protection semantics right.... this is really
1026 * only important on a multi-user system anyway, to make sure one user
1027 * can't send a signal to a process owned by another. -TYT, 12/12/91
1028 *
1029 * Auch. Had to add the 'did_exec' flag to conform completely to POSIX.
1030 * LBT 04.03.94
1031 */
1032
1033 asmlinkage long sys_setpgid(pid_t pid, pid_t pgid)
1034 {
1035 struct task_struct *p;
1036 int err = -EINVAL;
1037
1038 if (!pid)
1039 pid = current->pid;
1040 if (!pgid)
1041 pgid = pid;
1042 if (pgid < 0)
1043 return -EINVAL;
1044
1045 /* From this point forward we keep holding onto the tasklist lock
1046 * so that our parent does not change from under us. -DaveM
1047 */
1048 write_lock_irq(&tasklist_lock);
1049
1050 err = -ESRCH;
1051 p = find_task_by_pid(pid);
1052 if (!p)
1053 goto out;
1054
1055 err = -EINVAL;
1056 if (!thread_group_leader(p))
1057 goto out;
1058
1059 if (p->parent == current || p->real_parent == current) {
1060 err = -EPERM;
1061 if (p->signal->session != current->signal->session)
1062 goto out;
1063 err = -EACCES;
1064 if (p->did_exec)
1065 goto out;
1066 } else {
1067 err = -ESRCH;
1068 if (p != current)
1069 goto out;
1070 }
1071
1072 err = -EPERM;
1073 if (p->signal->leader)
1074 goto out;
1075
1076 if (pgid != pid) {
1077 struct task_struct *p;
1078
1079 do_each_task_pid(pgid, PIDTYPE_PGID, p) {
1080 if (p->signal->session == current->signal->session)
1081 goto ok_pgid;
1082 } while_each_task_pid(pgid, PIDTYPE_PGID, p);
1083 goto out;
1084 }
1085
1086 ok_pgid:
1087 err = security_task_setpgid(p, pgid);
1088 if (err)
1089 goto out;
1090
1091 if (process_group(p) != pgid) {
1092 detach_pid(p, PIDTYPE_PGID);
1093 p->signal->pgrp = pgid;
1094 attach_pid(p, PIDTYPE_PGID, pgid);
1095 }
1096
1097 err = 0;
1098 out:
1099 /* All paths lead to here, thus we are safe. -DaveM */
1100 write_unlock_irq(&tasklist_lock);
1101 return err;
1102 }
1103
1104 asmlinkage long sys_getpgid(pid_t pid)
1105 {
1106 if (!pid) {
1107 return process_group(current);
1108 } else {
1109 int retval;
1110 struct task_struct *p;
1111
1112 read_lock(&tasklist_lock);
1113 p = find_task_by_pid(pid);
1114
1115 retval = -ESRCH;
1116 if (p) {
1117 retval = security_task_getpgid(p);
1118 if (!retval)
1119 retval = process_group(p);
1120 }
1121 read_unlock(&tasklist_lock);
1122 return retval;
1123 }
1124 }
1125
1126 #ifdef __ARCH_WANT_SYS_GETPGRP
1127
1128 asmlinkage long sys_getpgrp(void)
1129 {
1130 /* SMP - assuming writes are word atomic this is fine */
1131 return process_group(current);
1132 }
1133
1134 #endif
1135
1136 asmlinkage long sys_getsid(pid_t pid)
1137 {
1138 if (!pid) {
1139 return current->signal->session;
1140 } else {
1141 int retval;
1142 struct task_struct *p;
1143
1144 read_lock(&tasklist_lock);
1145 p = find_task_by_pid(pid);
1146
1147 retval = -ESRCH;
1148 if(p) {
1149 retval = security_task_getsid(p);
1150 if (!retval)
1151 retval = p->signal->session;
1152 }
1153 read_unlock(&tasklist_lock);
1154 return retval;
1155 }
1156 }
1157
1158 asmlinkage long sys_setsid(void)
1159 {
1160 struct pid *pid;
1161 int err = -EPERM;
1162
1163 if (!thread_group_leader(current))
1164 return -EINVAL;
1165
1166 down(&tty_sem);
1167 write_lock_irq(&tasklist_lock);
1168
1169 pid = find_pid(PIDTYPE_PGID, current->pid);
1170 if (pid)
1171 goto out;
1172
1173 current->signal->leader = 1;
1174 __set_special_pids(current->pid, current->pid);
1175 current->signal->tty = NULL;
1176 current->signal->tty_old_pgrp = 0;
1177 err = process_group(current);
1178 out:
1179 write_unlock_irq(&tasklist_lock);
1180 up(&tty_sem);
1181 return err;
1182 }
1183
1184 /*
1185 * Supplementary group IDs
1186 */
1187
1188 /* init to 2 - one for init_task, one to ensure it is never freed */
1189 struct group_info init_groups = { .usage = ATOMIC_INIT(2) };
1190
1191 struct group_info *groups_alloc(int gidsetsize)
1192 {
1193 struct group_info *group_info;
1194 int nblocks;
1195 int i;
1196
1197 nblocks = (gidsetsize + NGROUPS_PER_BLOCK - 1) / NGROUPS_PER_BLOCK;
1198 /* Make sure we always allocate at least one indirect block pointer */
1199 nblocks = nblocks ? : 1;
1200 group_info = kmalloc(sizeof(*group_info) + nblocks*sizeof(gid_t *), GFP_USER);
1201 if (!group_info)
1202 return NULL;
1203 group_info->ngroups = gidsetsize;
1204 group_info->nblocks = nblocks;
1205 atomic_set(&group_info->usage, 1);
1206
1207 if (gidsetsize <= NGROUPS_SMALL) {
1208 group_info->blocks[0] = group_info->small_block;
1209 } else {
1210 for (i = 0; i < nblocks; i++) {
1211 gid_t *b;
1212 b = (void *)__get_free_page(GFP_USER);
1213 if (!b)
1214 goto out_undo_partial_alloc;
1215 group_info->blocks[i] = b;
1216 }
1217 }
1218 return group_info;
1219
1220 out_undo_partial_alloc:
1221 while (--i >= 0) {
1222 free_page((unsigned long)group_info->blocks[i]);
1223 }
1224 kfree(group_info);
1225 return NULL;
1226 }
1227
1228 EXPORT_SYMBOL(groups_alloc);
1229
1230 void groups_free(struct group_info *group_info)
1231 {
1232 if (group_info->blocks[0] != group_info->small_block) {
1233 int i;
1234 for (i = 0; i < group_info->nblocks; i++)
1235 free_page((unsigned long)group_info->blocks[i]);
1236 }
1237 kfree(group_info);
1238 }
1239
1240 EXPORT_SYMBOL(groups_free);
1241
1242 /* export the group_info to a user-space array */
1243 static int groups_to_user(gid_t __user *grouplist,
1244 struct group_info *group_info)
1245 {
1246 int i;
1247 int count = group_info->ngroups;
1248
1249 for (i = 0; i < group_info->nblocks; i++) {
1250 int cp_count = min(NGROUPS_PER_BLOCK, count);
1251 int off = i * NGROUPS_PER_BLOCK;
1252 int len = cp_count * sizeof(*grouplist);
1253
1254 if (copy_to_user(grouplist+off, group_info->blocks[i], len))
1255 return -EFAULT;
1256
1257 count -= cp_count;
1258 }
1259 return 0;
1260 }
1261
1262 /* fill a group_info from a user-space array - it must be allocated already */
1263 static int groups_from_user(struct group_info *group_info,
1264 gid_t __user *grouplist)
1265 {
1266 int i;
1267 int count = group_info->ngroups;
1268
1269 for (i = 0; i < group_info->nblocks; i++) {
1270 int cp_count = min(NGROUPS_PER_BLOCK, count);
1271 int off = i * NGROUPS_PER_BLOCK;
1272 int len = cp_count * sizeof(*grouplist);
1273
1274 if (copy_from_user(group_info->blocks[i], grouplist+off, len))
1275 return -EFAULT;
1276
1277 count -= cp_count;
1278 }
1279 return 0;
1280 }
1281
1282 /* a simple Shell sort */
1283 static void groups_sort(struct group_info *group_info)
1284 {
1285 int base, max, stride;
1286 int gidsetsize = group_info->ngroups;
1287
1288 for (stride = 1; stride < gidsetsize; stride = 3 * stride + 1)
1289 ; /* nothing */
1290 stride /= 3;
1291
1292 while (stride) {
1293 max = gidsetsize - stride;
1294 for (base = 0; base < max; base++) {
1295 int left = base;
1296 int right = left + stride;
1297 gid_t tmp = GROUP_AT(group_info, right);
1298
1299 while (left >= 0 && GROUP_AT(group_info, left) > tmp) {
1300 GROUP_AT(group_info, right) =
1301 GROUP_AT(group_info, left);
1302 right = left;
1303 left -= stride;
1304 }
1305 GROUP_AT(group_info, right) = tmp;
1306 }
1307 stride /= 3;
1308 }
1309 }
1310
1311 /* a simple bsearch */
1312 int groups_search(struct group_info *group_info, gid_t grp)
1313 {
1314 int left, right;
1315
1316 if (!group_info)
1317 return 0;
1318
1319 left = 0;
1320 right = group_info->ngroups;
1321 while (left < right) {
1322 int mid = (left+right)/2;
1323 int cmp = grp - GROUP_AT(group_info, mid);
1324 if (cmp > 0)
1325 left = mid + 1;
1326 else if (cmp < 0)
1327 right = mid;
1328 else
1329 return 1;
1330 }
1331 return 0;
1332 }
1333
1334 /* validate and set current->group_info */
1335 int set_current_groups(struct group_info *group_info)
1336 {
1337 int retval;
1338 struct group_info *old_info;
1339
1340 retval = security_task_setgroups(group_info);
1341 if (retval)
1342 return retval;
1343
1344 groups_sort(group_info);
1345 get_group_info(group_info);
1346
1347 task_lock(current);
1348 old_info = current->group_info;
1349 current->group_info = group_info;
1350 task_unlock(current);
1351
1352 put_group_info(old_info);
1353
1354 return 0;
1355 }
1356
1357 EXPORT_SYMBOL(set_current_groups);
1358
1359 asmlinkage long sys_getgroups(int gidsetsize, gid_t __user *grouplist)
1360 {
1361 int i = 0;
1362
1363 /*
1364 * SMP: Nobody else can change our grouplist. Thus we are
1365 * safe.
1366 */
1367
1368 if (gidsetsize < 0)
1369 return -EINVAL;
1370
1371 /* no need to grab task_lock here; it cannot change */
1372 get_group_info(current->group_info);
1373 i = current->group_info->ngroups;
1374 if (gidsetsize) {
1375 if (i > gidsetsize) {
1376 i = -EINVAL;
1377 goto out;
1378 }
1379 if (groups_to_user(grouplist, current->group_info)) {
1380 i = -EFAULT;
1381 goto out;
1382 }
1383 }
1384 out:
1385 put_group_info(current->group_info);
1386 return i;
1387 }
1388
1389 /*
1390 * SMP: Our groups are copy-on-write. We can set them safely
1391 * without another task interfering.
1392 */
1393
1394 asmlinkage long sys_setgroups(int gidsetsize, gid_t __user *grouplist)
1395 {
1396 struct group_info *group_info;
1397 int retval;
1398
1399 if (!capable(CAP_SETGID))
1400 return -EPERM;
1401 if ((unsigned)gidsetsize > NGROUPS_MAX)
1402 return -EINVAL;
1403
1404 group_info = groups_alloc(gidsetsize);
1405 if (!group_info)
1406 return -ENOMEM;
1407 retval = groups_from_user(group_info, grouplist);
1408 if (retval) {
1409 put_group_info(group_info);
1410 return retval;
1411 }
1412
1413 retval = set_current_groups(group_info);
1414 put_group_info(group_info);
1415
1416 return retval;
1417 }
1418
1419 /*
1420 * Check whether we're fsgid/egid or in the supplemental group..
1421 */
1422 int in_group_p(gid_t grp)
1423 {
1424 int retval = 1;
1425 if (grp != current->fsgid) {
1426 get_group_info(current->group_info);
1427 retval = groups_search(current->group_info, grp);
1428 put_group_info(current->group_info);
1429 }
1430 return retval;
1431 }
1432
1433 EXPORT_SYMBOL(in_group_p);
1434
1435 int in_egroup_p(gid_t grp)
1436 {
1437 int retval = 1;
1438 if (grp != current->egid) {
1439 get_group_info(current->group_info);
1440 retval = groups_search(current->group_info, grp);
1441 put_group_info(current->group_info);
1442 }
1443 return retval;
1444 }
1445
1446 EXPORT_SYMBOL(in_egroup_p);
1447
1448 DECLARE_RWSEM(uts_sem);
1449
1450 EXPORT_SYMBOL(uts_sem);
1451
1452 asmlinkage long sys_newuname(struct new_utsname __user * name)
1453 {
1454 int errno = 0;
1455
1456 down_read(&uts_sem);
1457 if (copy_to_user(name,&system_utsname,sizeof *name))
1458 errno = -EFAULT;
1459 up_read(&uts_sem);
1460 return errno;
1461 }
1462
1463 asmlinkage long sys_sethostname(char __user *name, int len)
1464 {
1465 int errno;
1466 char tmp[__NEW_UTS_LEN];
1467
1468 if (!capable(CAP_SYS_ADMIN))
1469 return -EPERM;
1470 if (len < 0 || len > __NEW_UTS_LEN)
1471 return -EINVAL;
1472 down_write(&uts_sem);
1473 errno = -EFAULT;
1474 if (!copy_from_user(tmp, name, len)) {
1475 memcpy(system_utsname.nodename, tmp, len);
1476 system_utsname.nodename[len] = 0;
1477 errno = 0;
1478 }
1479 up_write(&uts_sem);
1480 return errno;
1481 }
1482
1483 #ifdef __ARCH_WANT_SYS_GETHOSTNAME
1484
1485 asmlinkage long sys_gethostname(char __user *name, int len)
1486 {
1487 int i, errno;
1488
1489 if (len < 0)
1490 return -EINVAL;
1491 down_read(&uts_sem);
1492 i = 1 + strlen(system_utsname.nodename);
1493 if (i > len)
1494 i = len;
1495 errno = 0;
1496 if (copy_to_user(name, system_utsname.nodename, i))
1497 errno = -EFAULT;
1498 up_read(&uts_sem);
1499 return errno;
1500 }
1501
1502 #endif
1503
1504 /*
1505 * Only setdomainname; getdomainname can be implemented by calling
1506 * uname()
1507 */
1508 asmlinkage long sys_setdomainname(char __user *name, int len)
1509 {
1510 int errno;
1511 char tmp[__NEW_UTS_LEN];
1512
1513 if (!capable(CAP_SYS_ADMIN))
1514 return -EPERM;
1515 if (len < 0 || len > __NEW_UTS_LEN)
1516 return -EINVAL;
1517
1518 down_write(&uts_sem);
1519 errno = -EFAULT;
1520 if (!copy_from_user(tmp, name, len)) {
1521 memcpy(system_utsname.domainname, tmp, len);
1522 system_utsname.domainname[len] = 0;
1523 errno = 0;
1524 }
1525 up_write(&uts_sem);
1526 return errno;
1527 }
1528
1529 asmlinkage long sys_getrlimit(unsigned int resource, struct rlimit __user *rlim)
1530 {
1531 if (resource >= RLIM_NLIMITS)
1532 return -EINVAL;
1533 else {
1534 struct rlimit value;
1535 task_lock(current->group_leader);
1536 value = current->signal->rlim[resource];
1537 task_unlock(current->group_leader);
1538 return copy_to_user(rlim, &value, sizeof(*rlim)) ? -EFAULT : 0;
1539 }
1540 }
1541
1542 #ifdef __ARCH_WANT_SYS_OLD_GETRLIMIT
1543
1544 /*
1545 * Back compatibility for getrlimit. Needed for some apps.
1546 */
1547
1548 asmlinkage long sys_old_getrlimit(unsigned int resource, struct rlimit __user *rlim)
1549 {
1550 struct rlimit x;
1551 if (resource >= RLIM_NLIMITS)
1552 return -EINVAL;
1553
1554 task_lock(current->group_leader);
1555 x = current->signal->rlim[resource];
1556 task_unlock(current->group_leader);
1557 if(x.rlim_cur > 0x7FFFFFFF)
1558 x.rlim_cur = 0x7FFFFFFF;
1559 if(x.rlim_max > 0x7FFFFFFF)
1560 x.rlim_max = 0x7FFFFFFF;
1561 return copy_to_user(rlim, &x, sizeof(x))?-EFAULT:0;
1562 }
1563
1564 #endif
1565
1566 asmlinkage long sys_setrlimit(unsigned int resource, struct rlimit __user *rlim)
1567 {
1568 struct rlimit new_rlim, *old_rlim;
1569 int retval;
1570
1571 if (resource >= RLIM_NLIMITS)
1572 return -EINVAL;
1573 if(copy_from_user(&new_rlim, rlim, sizeof(*rlim)))
1574 return -EFAULT;
1575 if (new_rlim.rlim_cur > new_rlim.rlim_max)
1576 return -EINVAL;
1577 old_rlim = current->signal->rlim + resource;
1578 if ((new_rlim.rlim_max > old_rlim->rlim_max) &&
1579 !capable(CAP_SYS_RESOURCE))
1580 return -EPERM;
1581 if (resource == RLIMIT_NOFILE && new_rlim.rlim_max > NR_OPEN)
1582 return -EPERM;
1583
1584 retval = security_task_setrlimit(resource, &new_rlim);
1585 if (retval)
1586 return retval;
1587
1588 task_lock(current->group_leader);
1589 *old_rlim = new_rlim;
1590 task_unlock(current->group_leader);
1591
1592 if (resource == RLIMIT_CPU && new_rlim.rlim_cur != RLIM_INFINITY &&
1593 (cputime_eq(current->signal->it_prof_expires, cputime_zero) ||
1594 new_rlim.rlim_cur <= cputime_to_secs(
1595 current->signal->it_prof_expires))) {
1596 cputime_t cputime = secs_to_cputime(new_rlim.rlim_cur);
1597 read_lock(&tasklist_lock);
1598 spin_lock_irq(&current->sighand->siglock);
1599 set_process_cpu_timer(current, CPUCLOCK_PROF,
1600 &cputime, NULL);
1601 spin_unlock_irq(&current->sighand->siglock);
1602 read_unlock(&tasklist_lock);
1603 }
1604
1605 return 0;
1606 }
1607
1608 /*
1609 * It would make sense to put struct rusage in the task_struct,
1610 * except that would make the task_struct be *really big*. After
1611 * task_struct gets moved into malloc'ed memory, it would
1612 * make sense to do this. It will make moving the rest of the information
1613 * a lot simpler! (Which we're not doing right now because we're not
1614 * measuring them yet).
1615 *
1616 * This expects to be called with tasklist_lock read-locked or better,
1617 * and the siglock not locked. It may momentarily take the siglock.
1618 *
1619 * When sampling multiple threads for RUSAGE_SELF, under SMP we might have
1620 * races with threads incrementing their own counters. But since word
1621 * reads are atomic, we either get new values or old values and we don't
1622 * care which for the sums. We always take the siglock to protect reading
1623 * the c* fields from p->signal from races with exit.c updating those
1624 * fields when reaping, so a sample either gets all the additions of a
1625 * given child after it's reaped, or none so this sample is before reaping.
1626 */
1627
1628 static void k_getrusage(struct task_struct *p, int who, struct rusage *r)
1629 {
1630 struct task_struct *t;
1631 unsigned long flags;
1632 cputime_t utime, stime;
1633
1634 memset((char *) r, 0, sizeof *r);
1635
1636 if (unlikely(!p->signal))
1637 return;
1638
1639 switch (who) {
1640 case RUSAGE_CHILDREN:
1641 spin_lock_irqsave(&p->sighand->siglock, flags);
1642 utime = p->signal->cutime;
1643 stime = p->signal->cstime;
1644 r->ru_nvcsw = p->signal->cnvcsw;
1645 r->ru_nivcsw = p->signal->cnivcsw;
1646 r->ru_minflt = p->signal->cmin_flt;
1647 r->ru_majflt = p->signal->cmaj_flt;
1648 spin_unlock_irqrestore(&p->sighand->siglock, flags);
1649 cputime_to_timeval(utime, &r->ru_utime);
1650 cputime_to_timeval(stime, &r->ru_stime);
1651 break;
1652 case RUSAGE_SELF:
1653 spin_lock_irqsave(&p->sighand->siglock, flags);
1654 utime = stime = cputime_zero;
1655 goto sum_group;
1656 case RUSAGE_BOTH:
1657 spin_lock_irqsave(&p->sighand->siglock, flags);
1658 utime = p->signal->cutime;
1659 stime = p->signal->cstime;
1660 r->ru_nvcsw = p->signal->cnvcsw;
1661 r->ru_nivcsw = p->signal->cnivcsw;
1662 r->ru_minflt = p->signal->cmin_flt;
1663 r->ru_majflt = p->signal->cmaj_flt;
1664 sum_group:
1665 utime = cputime_add(utime, p->signal->utime);
1666 stime = cputime_add(stime, p->signal->stime);
1667 r->ru_nvcsw += p->signal->nvcsw;
1668 r->ru_nivcsw += p->signal->nivcsw;
1669 r->ru_minflt += p->signal->min_flt;
1670 r->ru_majflt += p->signal->maj_flt;
1671 t = p;
1672 do {
1673 utime = cputime_add(utime, t->utime);
1674 stime = cputime_add(stime, t->stime);
1675 r->ru_nvcsw += t->nvcsw;
1676 r->ru_nivcsw += t->nivcsw;
1677 r->ru_minflt += t->min_flt;
1678 r->ru_majflt += t->maj_flt;
1679 t = next_thread(t);
1680 } while (t != p);
1681 spin_unlock_irqrestore(&p->sighand->siglock, flags);
1682 cputime_to_timeval(utime, &r->ru_utime);
1683 cputime_to_timeval(stime, &r->ru_stime);
1684 break;
1685 default:
1686 BUG();
1687 }
1688 }
1689
1690 int getrusage(struct task_struct *p, int who, struct rusage __user *ru)
1691 {
1692 struct rusage r;
1693 read_lock(&tasklist_lock);
1694 k_getrusage(p, who, &r);
1695 read_unlock(&tasklist_lock);
1696 return copy_to_user(ru, &r, sizeof(r)) ? -EFAULT : 0;
1697 }
1698
1699 asmlinkage long sys_getrusage(int who, struct rusage __user *ru)
1700 {
1701 if (who != RUSAGE_SELF && who != RUSAGE_CHILDREN)
1702 return -EINVAL;
1703 return getrusage(current, who, ru);
1704 }
1705
1706 asmlinkage long sys_umask(int mask)
1707 {
1708 mask = xchg(&current->fs->umask, mask & S_IRWXUGO);
1709 return mask;
1710 }
1711
1712 asmlinkage long sys_prctl(int option, unsigned long arg2, unsigned long arg3,
1713 unsigned long arg4, unsigned long arg5)
1714 {
1715 long error;
1716 int sig;
1717
1718 error = security_task_prctl(option, arg2, arg3, arg4, arg5);
1719 if (error)
1720 return error;
1721
1722 switch (option) {
1723 case PR_SET_PDEATHSIG:
1724 sig = arg2;
1725 if (!valid_signal(sig)) {
1726 error = -EINVAL;
1727 break;
1728 }
1729 current->pdeath_signal = sig;
1730 break;
1731 case PR_GET_PDEATHSIG:
1732 error = put_user(current->pdeath_signal, (int __user *)arg2);
1733 break;
1734 case PR_GET_DUMPABLE:
1735 if (current->mm->dumpable)
1736 error = 1;
1737 break;
1738 case PR_SET_DUMPABLE:
1739 if (arg2 < 0 || arg2 > 2) {
1740 error = -EINVAL;
1741 break;
1742 }
1743 current->mm->dumpable = arg2;
1744 break;
1745
1746 case PR_SET_UNALIGN:
1747 error = SET_UNALIGN_CTL(current, arg2);
1748 break;
1749 case PR_GET_UNALIGN:
1750 error = GET_UNALIGN_CTL(current, arg2);
1751 break;
1752 case PR_SET_FPEMU:
1753 error = SET_FPEMU_CTL(current, arg2);
1754 break;
1755 case PR_GET_FPEMU:
1756 error = GET_FPEMU_CTL(current, arg2);
1757 break;
1758 case PR_SET_FPEXC:
1759 error = SET_FPEXC_CTL(current, arg2);
1760 break;
1761 case PR_GET_FPEXC:
1762 error = GET_FPEXC_CTL(current, arg2);
1763 break;
1764 case PR_GET_TIMING:
1765 error = PR_TIMING_STATISTICAL;
1766 break;
1767 case PR_SET_TIMING:
1768 if (arg2 == PR_TIMING_STATISTICAL)
1769 error = 0;
1770 else
1771 error = -EINVAL;
1772 break;
1773
1774 case PR_GET_KEEPCAPS:
1775 if (current->keep_capabilities)
1776 error = 1;
1777 break;
1778 case PR_SET_KEEPCAPS:
1779 if (arg2 != 0 && arg2 != 1) {
1780 error = -EINVAL;
1781 break;
1782 }
1783 current->keep_capabilities = arg2;
1784 break;
1785 case PR_SET_NAME: {
1786 struct task_struct *me = current;
1787 unsigned char ncomm[sizeof(me->comm)];
1788
1789 ncomm[sizeof(me->comm)-1] = 0;
1790 if (strncpy_from_user(ncomm, (char __user *)arg2,
1791 sizeof(me->comm)-1) < 0)
1792 return -EFAULT;
1793 set_task_comm(me, ncomm);
1794 return 0;
1795 }
1796 case PR_GET_NAME: {
1797 struct task_struct *me = current;
1798 unsigned char tcomm[sizeof(me->comm)];
1799
1800 get_task_comm(tcomm, me);
1801 if (copy_to_user((char __user *)arg2, tcomm, sizeof(tcomm)))
1802 return -EFAULT;
1803 return 0;
1804 }
1805 default:
1806 error = -EINVAL;
1807 break;
1808 }
1809 return error;
1810 }
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