[PATCH] pwc-uncompress warning fix
[linux-2.6] / kernel / sys.c
1 /*
2  *  linux/kernel/sys.c
3  *
4  *  Copyright (C) 1991, 1992  Linus Torvalds
5  */
6
7 #include <linux/config.h>
8 #include <linux/module.h>
9 #include <linux/mm.h>
10 #include <linux/utsname.h>
11 #include <linux/mman.h>
12 #include <linux/smp_lock.h>
13 #include <linux/notifier.h>
14 #include <linux/reboot.h>
15 #include <linux/prctl.h>
16 #include <linux/init.h>
17 #include <linux/highuid.h>
18 #include <linux/fs.h>
19 #include <linux/workqueue.h>
20 #include <linux/device.h>
21 #include <linux/key.h>
22 #include <linux/times.h>
23 #include <linux/posix-timers.h>
24 #include <linux/security.h>
25 #include <linux/dcookies.h>
26 #include <linux/suspend.h>
27 #include <linux/tty.h>
28 #include <linux/signal.h>
29
30 #include <linux/compat.h>
31 #include <linux/syscalls.h>
32
33 #include <asm/uaccess.h>
34 #include <asm/io.h>
35 #include <asm/unistd.h>
36
37 #ifndef SET_UNALIGN_CTL
38 # define SET_UNALIGN_CTL(a,b)   (-EINVAL)
39 #endif
40 #ifndef GET_UNALIGN_CTL
41 # define GET_UNALIGN_CTL(a,b)   (-EINVAL)
42 #endif
43 #ifndef SET_FPEMU_CTL
44 # define SET_FPEMU_CTL(a,b)     (-EINVAL)
45 #endif
46 #ifndef GET_FPEMU_CTL
47 # define GET_FPEMU_CTL(a,b)     (-EINVAL)
48 #endif
49 #ifndef SET_FPEXC_CTL
50 # define SET_FPEXC_CTL(a,b)     (-EINVAL)
51 #endif
52 #ifndef GET_FPEXC_CTL
53 # define GET_FPEXC_CTL(a,b)     (-EINVAL)
54 #endif
55
56 /*
57  * this is where the system-wide overflow UID and GID are defined, for
58  * architectures that now have 32-bit UID/GID but didn't in the past
59  */
60
61 int overflowuid = DEFAULT_OVERFLOWUID;
62 int overflowgid = DEFAULT_OVERFLOWGID;
63
64 #ifdef CONFIG_UID16
65 EXPORT_SYMBOL(overflowuid);
66 EXPORT_SYMBOL(overflowgid);
67 #endif
68
69 /*
70  * the same as above, but for filesystems which can only store a 16-bit
71  * UID and GID. as such, this is needed on all architectures
72  */
73
74 int fs_overflowuid = DEFAULT_FS_OVERFLOWUID;
75 int fs_overflowgid = DEFAULT_FS_OVERFLOWUID;
76
77 EXPORT_SYMBOL(fs_overflowuid);
78 EXPORT_SYMBOL(fs_overflowgid);
79
80 /*
81  * this indicates whether you can reboot with ctrl-alt-del: the default is yes
82  */
83
84 int C_A_D = 1;
85 int cad_pid = 1;
86
87 /*
88  *      Notifier list for kernel code which wants to be called
89  *      at shutdown. This is used to stop any idling DMA operations
90  *      and the like. 
91  */
92
93 static struct notifier_block *reboot_notifier_list;
94 static DEFINE_RWLOCK(notifier_lock);
95
96 /**
97  *      notifier_chain_register - Add notifier to a notifier chain
98  *      @list: Pointer to root list pointer
99  *      @n: New entry in notifier chain
100  *
101  *      Adds a notifier to a notifier chain.
102  *
103  *      Currently always returns zero.
104  */
105  
106 int notifier_chain_register(struct notifier_block **list, struct notifier_block *n)
107 {
108         write_lock(&notifier_lock);
109         while(*list)
110         {
111                 if(n->priority > (*list)->priority)
112                         break;
113                 list= &((*list)->next);
114         }
115         n->next = *list;
116         *list=n;
117         write_unlock(&notifier_lock);
118         return 0;
119 }
120
121 EXPORT_SYMBOL(notifier_chain_register);
122
123 /**
124  *      notifier_chain_unregister - Remove notifier from a notifier chain
125  *      @nl: Pointer to root list pointer
126  *      @n: New entry in notifier chain
127  *
128  *      Removes a notifier from a notifier chain.
129  *
130  *      Returns zero on success, or %-ENOENT on failure.
131  */
132  
133 int notifier_chain_unregister(struct notifier_block **nl, struct notifier_block *n)
134 {
135         write_lock(&notifier_lock);
136         while((*nl)!=NULL)
137         {
138                 if((*nl)==n)
139                 {
140                         *nl=n->next;
141                         write_unlock(&notifier_lock);
142                         return 0;
143                 }
144                 nl=&((*nl)->next);
145         }
146         write_unlock(&notifier_lock);
147         return -ENOENT;
148 }
149
150 EXPORT_SYMBOL(notifier_chain_unregister);
151
152 /**
153  *      notifier_call_chain - Call functions in a notifier chain
154  *      @n: Pointer to root pointer of notifier chain
155  *      @val: Value passed unmodified to notifier function
156  *      @v: Pointer passed unmodified to notifier function
157  *
158  *      Calls each function in a notifier chain in turn.
159  *
160  *      If the return value of the notifier can be and'd
161  *      with %NOTIFY_STOP_MASK, then notifier_call_chain
162  *      will return immediately, with the return value of
163  *      the notifier function which halted execution.
164  *      Otherwise, the return value is the return value
165  *      of the last notifier function called.
166  */
167  
168 int notifier_call_chain(struct notifier_block **n, unsigned long val, void *v)
169 {
170         int ret=NOTIFY_DONE;
171         struct notifier_block *nb = *n;
172
173         while(nb)
174         {
175                 ret=nb->notifier_call(nb,val,v);
176                 if(ret&NOTIFY_STOP_MASK)
177                 {
178                         return ret;
179                 }
180                 nb=nb->next;
181         }
182         return ret;
183 }
184
185 EXPORT_SYMBOL(notifier_call_chain);
186
187 /**
188  *      register_reboot_notifier - Register function to be called at reboot time
189  *      @nb: Info about notifier function to be called
190  *
191  *      Registers a function with the list of functions
192  *      to be called at reboot time.
193  *
194  *      Currently always returns zero, as notifier_chain_register
195  *      always returns zero.
196  */
197  
198 int register_reboot_notifier(struct notifier_block * nb)
199 {
200         return notifier_chain_register(&reboot_notifier_list, nb);
201 }
202
203 EXPORT_SYMBOL(register_reboot_notifier);
204
205 /**
206  *      unregister_reboot_notifier - Unregister previously registered reboot notifier
207  *      @nb: Hook to be unregistered
208  *
209  *      Unregisters a previously registered reboot
210  *      notifier function.
211  *
212  *      Returns zero on success, or %-ENOENT on failure.
213  */
214  
215 int unregister_reboot_notifier(struct notifier_block * nb)
216 {
217         return notifier_chain_unregister(&reboot_notifier_list, nb);
218 }
219
220 EXPORT_SYMBOL(unregister_reboot_notifier);
221
222 static int set_one_prio(struct task_struct *p, int niceval, int error)
223 {
224         int no_nice;
225
226         if (p->uid != current->euid &&
227                 p->euid != current->euid && !capable(CAP_SYS_NICE)) {
228                 error = -EPERM;
229                 goto out;
230         }
231         if (niceval < task_nice(p) && !can_nice(p, niceval)) {
232                 error = -EACCES;
233                 goto out;
234         }
235         no_nice = security_task_setnice(p, niceval);
236         if (no_nice) {
237                 error = no_nice;
238                 goto out;
239         }
240         if (error == -ESRCH)
241                 error = 0;
242         set_user_nice(p, niceval);
243 out:
244         return error;
245 }
246
247 asmlinkage long sys_setpriority(int which, int who, int niceval)
248 {
249         struct task_struct *g, *p;
250         struct user_struct *user;
251         int error = -EINVAL;
252
253         if (which > 2 || which < 0)
254                 goto out;
255
256         /* normalize: avoid signed division (rounding problems) */
257         error = -ESRCH;
258         if (niceval < -20)
259                 niceval = -20;
260         if (niceval > 19)
261                 niceval = 19;
262
263         read_lock(&tasklist_lock);
264         switch (which) {
265                 case PRIO_PROCESS:
266                         if (!who)
267                                 who = current->pid;
268                         p = find_task_by_pid(who);
269                         if (p)
270                                 error = set_one_prio(p, niceval, error);
271                         break;
272                 case PRIO_PGRP:
273                         if (!who)
274                                 who = process_group(current);
275                         do_each_task_pid(who, PIDTYPE_PGID, p) {
276                                 error = set_one_prio(p, niceval, error);
277                         } while_each_task_pid(who, PIDTYPE_PGID, p);
278                         break;
279                 case PRIO_USER:
280                         user = current->user;
281                         if (!who)
282                                 who = current->uid;
283                         else
284                                 if ((who != current->uid) && !(user = find_user(who)))
285                                         goto out_unlock;        /* No processes for this user */
286
287                         do_each_thread(g, p)
288                                 if (p->uid == who)
289                                         error = set_one_prio(p, niceval, error);
290                         while_each_thread(g, p);
291                         if (who != current->uid)
292                                 free_uid(user);         /* For find_user() */
293                         break;
294         }
295 out_unlock:
296         read_unlock(&tasklist_lock);
297 out:
298         return error;
299 }
300
301 /*
302  * Ugh. To avoid negative return values, "getpriority()" will
303  * not return the normal nice-value, but a negated value that
304  * has been offset by 20 (ie it returns 40..1 instead of -20..19)
305  * to stay compatible.
306  */
307 asmlinkage long sys_getpriority(int which, int who)
308 {
309         struct task_struct *g, *p;
310         struct user_struct *user;
311         long niceval, retval = -ESRCH;
312
313         if (which > 2 || which < 0)
314                 return -EINVAL;
315
316         read_lock(&tasklist_lock);
317         switch (which) {
318                 case PRIO_PROCESS:
319                         if (!who)
320                                 who = current->pid;
321                         p = find_task_by_pid(who);
322                         if (p) {
323                                 niceval = 20 - task_nice(p);
324                                 if (niceval > retval)
325                                         retval = niceval;
326                         }
327                         break;
328                 case PRIO_PGRP:
329                         if (!who)
330                                 who = process_group(current);
331                         do_each_task_pid(who, PIDTYPE_PGID, p) {
332                                 niceval = 20 - task_nice(p);
333                                 if (niceval > retval)
334                                         retval = niceval;
335                         } while_each_task_pid(who, PIDTYPE_PGID, p);
336                         break;
337                 case PRIO_USER:
338                         user = current->user;
339                         if (!who)
340                                 who = current->uid;
341                         else
342                                 if ((who != current->uid) && !(user = find_user(who)))
343                                         goto out_unlock;        /* No processes for this user */
344
345                         do_each_thread(g, p)
346                                 if (p->uid == who) {
347                                         niceval = 20 - task_nice(p);
348                                         if (niceval > retval)
349                                                 retval = niceval;
350                                 }
351                         while_each_thread(g, p);
352                         if (who != current->uid)
353                                 free_uid(user);         /* for find_user() */
354                         break;
355         }
356 out_unlock:
357         read_unlock(&tasklist_lock);
358
359         return retval;
360 }
361
362
363 /*
364  * Reboot system call: for obvious reasons only root may call it,
365  * and even root needs to set up some magic numbers in the registers
366  * so that some mistake won't make this reboot the whole machine.
367  * You can also set the meaning of the ctrl-alt-del-key here.
368  *
369  * reboot doesn't sync: do that yourself before calling this.
370  */
371 asmlinkage long sys_reboot(int magic1, int magic2, unsigned int cmd, void __user * arg)
372 {
373         char buffer[256];
374
375         /* We only trust the superuser with rebooting the system. */
376         if (!capable(CAP_SYS_BOOT))
377                 return -EPERM;
378
379         /* For safety, we require "magic" arguments. */
380         if (magic1 != LINUX_REBOOT_MAGIC1 ||
381             (magic2 != LINUX_REBOOT_MAGIC2 &&
382                         magic2 != LINUX_REBOOT_MAGIC2A &&
383                         magic2 != LINUX_REBOOT_MAGIC2B &&
384                         magic2 != LINUX_REBOOT_MAGIC2C))
385                 return -EINVAL;
386
387         lock_kernel();
388         switch (cmd) {
389         case LINUX_REBOOT_CMD_RESTART:
390                 notifier_call_chain(&reboot_notifier_list, SYS_RESTART, NULL);
391                 system_state = SYSTEM_RESTART;
392                 device_shutdown();
393                 printk(KERN_EMERG "Restarting system.\n");
394                 machine_restart(NULL);
395                 break;
396
397         case LINUX_REBOOT_CMD_CAD_ON:
398                 C_A_D = 1;
399                 break;
400
401         case LINUX_REBOOT_CMD_CAD_OFF:
402                 C_A_D = 0;
403                 break;
404
405         case LINUX_REBOOT_CMD_HALT:
406                 notifier_call_chain(&reboot_notifier_list, SYS_HALT, NULL);
407                 system_state = SYSTEM_HALT;
408                 device_shutdown();
409                 printk(KERN_EMERG "System halted.\n");
410                 machine_halt();
411                 unlock_kernel();
412                 do_exit(0);
413                 break;
414
415         case LINUX_REBOOT_CMD_POWER_OFF:
416                 notifier_call_chain(&reboot_notifier_list, SYS_POWER_OFF, NULL);
417                 system_state = SYSTEM_POWER_OFF;
418                 device_shutdown();
419                 printk(KERN_EMERG "Power down.\n");
420                 machine_power_off();
421                 unlock_kernel();
422                 do_exit(0);
423                 break;
424
425         case LINUX_REBOOT_CMD_RESTART2:
426                 if (strncpy_from_user(&buffer[0], arg, sizeof(buffer) - 1) < 0) {
427                         unlock_kernel();
428                         return -EFAULT;
429                 }
430                 buffer[sizeof(buffer) - 1] = '\0';
431
432                 notifier_call_chain(&reboot_notifier_list, SYS_RESTART, buffer);
433                 system_state = SYSTEM_RESTART;
434                 device_shutdown();
435                 printk(KERN_EMERG "Restarting system with command '%s'.\n", buffer);
436                 machine_restart(buffer);
437                 break;
438
439 #ifdef CONFIG_SOFTWARE_SUSPEND
440         case LINUX_REBOOT_CMD_SW_SUSPEND:
441                 {
442                         int ret = software_suspend();
443                         unlock_kernel();
444                         return ret;
445                 }
446 #endif
447
448         default:
449                 unlock_kernel();
450                 return -EINVAL;
451         }
452         unlock_kernel();
453         return 0;
454 }
455
456 static void deferred_cad(void *dummy)
457 {
458         notifier_call_chain(&reboot_notifier_list, SYS_RESTART, NULL);
459         machine_restart(NULL);
460 }
461
462 /*
463  * This function gets called by ctrl-alt-del - ie the keyboard interrupt.
464  * As it's called within an interrupt, it may NOT sync: the only choice
465  * is whether to reboot at once, or just ignore the ctrl-alt-del.
466  */
467 void ctrl_alt_del(void)
468 {
469         static DECLARE_WORK(cad_work, deferred_cad, NULL);
470
471         if (C_A_D)
472                 schedule_work(&cad_work);
473         else
474                 kill_proc(cad_pid, SIGINT, 1);
475 }
476         
477
478 /*
479  * Unprivileged users may change the real gid to the effective gid
480  * or vice versa.  (BSD-style)
481  *
482  * If you set the real gid at all, or set the effective gid to a value not
483  * equal to the real gid, then the saved gid is set to the new effective gid.
484  *
485  * This makes it possible for a setgid program to completely drop its
486  * privileges, which is often a useful assertion to make when you are doing
487  * a security audit over a program.
488  *
489  * The general idea is that a program which uses just setregid() will be
490  * 100% compatible with BSD.  A program which uses just setgid() will be
491  * 100% compatible with POSIX with saved IDs. 
492  *
493  * SMP: There are not races, the GIDs are checked only by filesystem
494  *      operations (as far as semantic preservation is concerned).
495  */
496 asmlinkage long sys_setregid(gid_t rgid, gid_t egid)
497 {
498         int old_rgid = current->gid;
499         int old_egid = current->egid;
500         int new_rgid = old_rgid;
501         int new_egid = old_egid;
502         int retval;
503
504         retval = security_task_setgid(rgid, egid, (gid_t)-1, LSM_SETID_RE);
505         if (retval)
506                 return retval;
507
508         if (rgid != (gid_t) -1) {
509                 if ((old_rgid == rgid) ||
510                     (current->egid==rgid) ||
511                     capable(CAP_SETGID))
512                         new_rgid = rgid;
513                 else
514                         return -EPERM;
515         }
516         if (egid != (gid_t) -1) {
517                 if ((old_rgid == egid) ||
518                     (current->egid == egid) ||
519                     (current->sgid == egid) ||
520                     capable(CAP_SETGID))
521                         new_egid = egid;
522                 else {
523                         return -EPERM;
524                 }
525         }
526         if (new_egid != old_egid)
527         {
528                 current->mm->dumpable = suid_dumpable;
529                 smp_wmb();
530         }
531         if (rgid != (gid_t) -1 ||
532             (egid != (gid_t) -1 && egid != old_rgid))
533                 current->sgid = new_egid;
534         current->fsgid = new_egid;
535         current->egid = new_egid;
536         current->gid = new_rgid;
537         key_fsgid_changed(current);
538         return 0;
539 }
540
541 /*
542  * setgid() is implemented like SysV w/ SAVED_IDS 
543  *
544  * SMP: Same implicit races as above.
545  */
546 asmlinkage long sys_setgid(gid_t gid)
547 {
548         int old_egid = current->egid;
549         int retval;
550
551         retval = security_task_setgid(gid, (gid_t)-1, (gid_t)-1, LSM_SETID_ID);
552         if (retval)
553                 return retval;
554
555         if (capable(CAP_SETGID))
556         {
557                 if(old_egid != gid)
558                 {
559                         current->mm->dumpable = suid_dumpable;
560                         smp_wmb();
561                 }
562                 current->gid = current->egid = current->sgid = current->fsgid = gid;
563         }
564         else if ((gid == current->gid) || (gid == current->sgid))
565         {
566                 if(old_egid != gid)
567                 {
568                         current->mm->dumpable = suid_dumpable;
569                         smp_wmb();
570                 }
571                 current->egid = current->fsgid = gid;
572         }
573         else
574                 return -EPERM;
575
576         key_fsgid_changed(current);
577         return 0;
578 }
579   
580 static int set_user(uid_t new_ruid, int dumpclear)
581 {
582         struct user_struct *new_user;
583
584         new_user = alloc_uid(new_ruid);
585         if (!new_user)
586                 return -EAGAIN;
587
588         if (atomic_read(&new_user->processes) >=
589                                 current->signal->rlim[RLIMIT_NPROC].rlim_cur &&
590                         new_user != &root_user) {
591                 free_uid(new_user);
592                 return -EAGAIN;
593         }
594
595         switch_uid(new_user);
596
597         if(dumpclear)
598         {
599                 current->mm->dumpable = suid_dumpable;
600                 smp_wmb();
601         }
602         current->uid = new_ruid;
603         return 0;
604 }
605
606 /*
607  * Unprivileged users may change the real uid to the effective uid
608  * or vice versa.  (BSD-style)
609  *
610  * If you set the real uid at all, or set the effective uid to a value not
611  * equal to the real uid, then the saved uid is set to the new effective uid.
612  *
613  * This makes it possible for a setuid program to completely drop its
614  * privileges, which is often a useful assertion to make when you are doing
615  * a security audit over a program.
616  *
617  * The general idea is that a program which uses just setreuid() will be
618  * 100% compatible with BSD.  A program which uses just setuid() will be
619  * 100% compatible with POSIX with saved IDs. 
620  */
621 asmlinkage long sys_setreuid(uid_t ruid, uid_t euid)
622 {
623         int old_ruid, old_euid, old_suid, new_ruid, new_euid;
624         int retval;
625
626         retval = security_task_setuid(ruid, euid, (uid_t)-1, LSM_SETID_RE);
627         if (retval)
628                 return retval;
629
630         new_ruid = old_ruid = current->uid;
631         new_euid = old_euid = current->euid;
632         old_suid = current->suid;
633
634         if (ruid != (uid_t) -1) {
635                 new_ruid = ruid;
636                 if ((old_ruid != ruid) &&
637                     (current->euid != ruid) &&
638                     !capable(CAP_SETUID))
639                         return -EPERM;
640         }
641
642         if (euid != (uid_t) -1) {
643                 new_euid = euid;
644                 if ((old_ruid != euid) &&
645                     (current->euid != euid) &&
646                     (current->suid != euid) &&
647                     !capable(CAP_SETUID))
648                         return -EPERM;
649         }
650
651         if (new_ruid != old_ruid && set_user(new_ruid, new_euid != old_euid) < 0)
652                 return -EAGAIN;
653
654         if (new_euid != old_euid)
655         {
656                 current->mm->dumpable = suid_dumpable;
657                 smp_wmb();
658         }
659         current->fsuid = current->euid = new_euid;
660         if (ruid != (uid_t) -1 ||
661             (euid != (uid_t) -1 && euid != old_ruid))
662                 current->suid = current->euid;
663         current->fsuid = current->euid;
664
665         key_fsuid_changed(current);
666
667         return security_task_post_setuid(old_ruid, old_euid, old_suid, LSM_SETID_RE);
668 }
669
670
671                 
672 /*
673  * setuid() is implemented like SysV with SAVED_IDS 
674  * 
675  * Note that SAVED_ID's is deficient in that a setuid root program
676  * like sendmail, for example, cannot set its uid to be a normal 
677  * user and then switch back, because if you're root, setuid() sets
678  * the saved uid too.  If you don't like this, blame the bright people
679  * in the POSIX committee and/or USG.  Note that the BSD-style setreuid()
680  * will allow a root program to temporarily drop privileges and be able to
681  * regain them by swapping the real and effective uid.  
682  */
683 asmlinkage long sys_setuid(uid_t uid)
684 {
685         int old_euid = current->euid;
686         int old_ruid, old_suid, new_ruid, new_suid;
687         int retval;
688
689         retval = security_task_setuid(uid, (uid_t)-1, (uid_t)-1, LSM_SETID_ID);
690         if (retval)
691                 return retval;
692
693         old_ruid = new_ruid = current->uid;
694         old_suid = current->suid;
695         new_suid = old_suid;
696         
697         if (capable(CAP_SETUID)) {
698                 if (uid != old_ruid && set_user(uid, old_euid != uid) < 0)
699                         return -EAGAIN;
700                 new_suid = uid;
701         } else if ((uid != current->uid) && (uid != new_suid))
702                 return -EPERM;
703
704         if (old_euid != uid)
705         {
706                 current->mm->dumpable = suid_dumpable;
707                 smp_wmb();
708         }
709         current->fsuid = current->euid = uid;
710         current->suid = new_suid;
711
712         key_fsuid_changed(current);
713
714         return security_task_post_setuid(old_ruid, old_euid, old_suid, LSM_SETID_ID);
715 }
716
717
718 /*
719  * This function implements a generic ability to update ruid, euid,
720  * and suid.  This allows you to implement the 4.4 compatible seteuid().
721  */
722 asmlinkage long sys_setresuid(uid_t ruid, uid_t euid, uid_t suid)
723 {
724         int old_ruid = current->uid;
725         int old_euid = current->euid;
726         int old_suid = current->suid;
727         int retval;
728
729         retval = security_task_setuid(ruid, euid, suid, LSM_SETID_RES);
730         if (retval)
731                 return retval;
732
733         if (!capable(CAP_SETUID)) {
734                 if ((ruid != (uid_t) -1) && (ruid != current->uid) &&
735                     (ruid != current->euid) && (ruid != current->suid))
736                         return -EPERM;
737                 if ((euid != (uid_t) -1) && (euid != current->uid) &&
738                     (euid != current->euid) && (euid != current->suid))
739                         return -EPERM;
740                 if ((suid != (uid_t) -1) && (suid != current->uid) &&
741                     (suid != current->euid) && (suid != current->suid))
742                         return -EPERM;
743         }
744         if (ruid != (uid_t) -1) {
745                 if (ruid != current->uid && set_user(ruid, euid != current->euid) < 0)
746                         return -EAGAIN;
747         }
748         if (euid != (uid_t) -1) {
749                 if (euid != current->euid)
750                 {
751                         current->mm->dumpable = suid_dumpable;
752                         smp_wmb();
753                 }
754                 current->euid = euid;
755         }
756         current->fsuid = current->euid;
757         if (suid != (uid_t) -1)
758                 current->suid = suid;
759
760         key_fsuid_changed(current);
761
762         return security_task_post_setuid(old_ruid, old_euid, old_suid, LSM_SETID_RES);
763 }
764
765 asmlinkage long sys_getresuid(uid_t __user *ruid, uid_t __user *euid, uid_t __user *suid)
766 {
767         int retval;
768
769         if (!(retval = put_user(current->uid, ruid)) &&
770             !(retval = put_user(current->euid, euid)))
771                 retval = put_user(current->suid, suid);
772
773         return retval;
774 }
775
776 /*
777  * Same as above, but for rgid, egid, sgid.
778  */
779 asmlinkage long sys_setresgid(gid_t rgid, gid_t egid, gid_t sgid)
780 {
781         int retval;
782
783         retval = security_task_setgid(rgid, egid, sgid, LSM_SETID_RES);
784         if (retval)
785                 return retval;
786
787         if (!capable(CAP_SETGID)) {
788                 if ((rgid != (gid_t) -1) && (rgid != current->gid) &&
789                     (rgid != current->egid) && (rgid != current->sgid))
790                         return -EPERM;
791                 if ((egid != (gid_t) -1) && (egid != current->gid) &&
792                     (egid != current->egid) && (egid != current->sgid))
793                         return -EPERM;
794                 if ((sgid != (gid_t) -1) && (sgid != current->gid) &&
795                     (sgid != current->egid) && (sgid != current->sgid))
796                         return -EPERM;
797         }
798         if (egid != (gid_t) -1) {
799                 if (egid != current->egid)
800                 {
801                         current->mm->dumpable = suid_dumpable;
802                         smp_wmb();
803                 }
804                 current->egid = egid;
805         }
806         current->fsgid = current->egid;
807         if (rgid != (gid_t) -1)
808                 current->gid = rgid;
809         if (sgid != (gid_t) -1)
810                 current->sgid = sgid;
811
812         key_fsgid_changed(current);
813         return 0;
814 }
815
816 asmlinkage long sys_getresgid(gid_t __user *rgid, gid_t __user *egid, gid_t __user *sgid)
817 {
818         int retval;
819
820         if (!(retval = put_user(current->gid, rgid)) &&
821             !(retval = put_user(current->egid, egid)))
822                 retval = put_user(current->sgid, sgid);
823
824         return retval;
825 }
826
827
828 /*
829  * "setfsuid()" sets the fsuid - the uid used for filesystem checks. This
830  * is used for "access()" and for the NFS daemon (letting nfsd stay at
831  * whatever uid it wants to). It normally shadows "euid", except when
832  * explicitly set by setfsuid() or for access..
833  */
834 asmlinkage long sys_setfsuid(uid_t uid)
835 {
836         int old_fsuid;
837
838         old_fsuid = current->fsuid;
839         if (security_task_setuid(uid, (uid_t)-1, (uid_t)-1, LSM_SETID_FS))
840                 return old_fsuid;
841
842         if (uid == current->uid || uid == current->euid ||
843             uid == current->suid || uid == current->fsuid || 
844             capable(CAP_SETUID))
845         {
846                 if (uid != old_fsuid)
847                 {
848                         current->mm->dumpable = suid_dumpable;
849                         smp_wmb();
850                 }
851                 current->fsuid = uid;
852         }
853
854         key_fsuid_changed(current);
855
856         security_task_post_setuid(old_fsuid, (uid_t)-1, (uid_t)-1, LSM_SETID_FS);
857
858         return old_fsuid;
859 }
860
861 /*
862  * Samma pÃ¥ svenska..
863  */
864 asmlinkage long sys_setfsgid(gid_t gid)
865 {
866         int old_fsgid;
867
868         old_fsgid = current->fsgid;
869         if (security_task_setgid(gid, (gid_t)-1, (gid_t)-1, LSM_SETID_FS))
870                 return old_fsgid;
871
872         if (gid == current->gid || gid == current->egid ||
873             gid == current->sgid || gid == current->fsgid || 
874             capable(CAP_SETGID))
875         {
876                 if (gid != old_fsgid)
877                 {
878                         current->mm->dumpable = suid_dumpable;
879                         smp_wmb();
880                 }
881                 current->fsgid = gid;
882                 key_fsgid_changed(current);
883         }
884         return old_fsgid;
885 }
886
887 asmlinkage long sys_times(struct tms __user * tbuf)
888 {
889         /*
890          *      In the SMP world we might just be unlucky and have one of
891          *      the times increment as we use it. Since the value is an
892          *      atomically safe type this is just fine. Conceptually its
893          *      as if the syscall took an instant longer to occur.
894          */
895         if (tbuf) {
896                 struct tms tmp;
897                 cputime_t utime, stime, cutime, cstime;
898
899 #ifdef CONFIG_SMP
900                 if (thread_group_empty(current)) {
901                         /*
902                          * Single thread case without the use of any locks.
903                          *
904                          * We may race with release_task if two threads are
905                          * executing. However, release task first adds up the
906                          * counters (__exit_signal) before  removing the task
907                          * from the process tasklist (__unhash_process).
908                          * __exit_signal also acquires and releases the
909                          * siglock which results in the proper memory ordering
910                          * so that the list modifications are always visible
911                          * after the counters have been updated.
912                          *
913                          * If the counters have been updated by the second thread
914                          * but the thread has not yet been removed from the list
915                          * then the other branch will be executing which will
916                          * block on tasklist_lock until the exit handling of the
917                          * other task is finished.
918                          *
919                          * This also implies that the sighand->siglock cannot
920                          * be held by another processor. So we can also
921                          * skip acquiring that lock.
922                          */
923                         utime = cputime_add(current->signal->utime, current->utime);
924                         stime = cputime_add(current->signal->utime, current->stime);
925                         cutime = current->signal->cutime;
926                         cstime = current->signal->cstime;
927                 } else
928 #endif
929                 {
930
931                         /* Process with multiple threads */
932                         struct task_struct *tsk = current;
933                         struct task_struct *t;
934
935                         read_lock(&tasklist_lock);
936                         utime = tsk->signal->utime;
937                         stime = tsk->signal->stime;
938                         t = tsk;
939                         do {
940                                 utime = cputime_add(utime, t->utime);
941                                 stime = cputime_add(stime, t->stime);
942                                 t = next_thread(t);
943                         } while (t != tsk);
944
945                         /*
946                          * While we have tasklist_lock read-locked, no dying thread
947                          * can be updating current->signal->[us]time.  Instead,
948                          * we got their counts included in the live thread loop.
949                          * However, another thread can come in right now and
950                          * do a wait call that updates current->signal->c[us]time.
951                          * To make sure we always see that pair updated atomically,
952                          * we take the siglock around fetching them.
953                          */
954                         spin_lock_irq(&tsk->sighand->siglock);
955                         cutime = tsk->signal->cutime;
956                         cstime = tsk->signal->cstime;
957                         spin_unlock_irq(&tsk->sighand->siglock);
958                         read_unlock(&tasklist_lock);
959                 }
960                 tmp.tms_utime = cputime_to_clock_t(utime);
961                 tmp.tms_stime = cputime_to_clock_t(stime);
962                 tmp.tms_cutime = cputime_to_clock_t(cutime);
963                 tmp.tms_cstime = cputime_to_clock_t(cstime);
964                 if (copy_to_user(tbuf, &tmp, sizeof(struct tms)))
965                         return -EFAULT;
966         }
967         return (long) jiffies_64_to_clock_t(get_jiffies_64());
968 }
969
970 /*
971  * This needs some heavy checking ...
972  * I just haven't the stomach for it. I also don't fully
973  * understand sessions/pgrp etc. Let somebody who does explain it.
974  *
975  * OK, I think I have the protection semantics right.... this is really
976  * only important on a multi-user system anyway, to make sure one user
977  * can't send a signal to a process owned by another.  -TYT, 12/12/91
978  *
979  * Auch. Had to add the 'did_exec' flag to conform completely to POSIX.
980  * LBT 04.03.94
981  */
982
983 asmlinkage long sys_setpgid(pid_t pid, pid_t pgid)
984 {
985         struct task_struct *p;
986         int err = -EINVAL;
987
988         if (!pid)
989                 pid = current->pid;
990         if (!pgid)
991                 pgid = pid;
992         if (pgid < 0)
993                 return -EINVAL;
994
995         /* From this point forward we keep holding onto the tasklist lock
996          * so that our parent does not change from under us. -DaveM
997          */
998         write_lock_irq(&tasklist_lock);
999
1000         err = -ESRCH;
1001         p = find_task_by_pid(pid);
1002         if (!p)
1003                 goto out;
1004
1005         err = -EINVAL;
1006         if (!thread_group_leader(p))
1007                 goto out;
1008
1009         if (p->parent == current || p->real_parent == current) {
1010                 err = -EPERM;
1011                 if (p->signal->session != current->signal->session)
1012                         goto out;
1013                 err = -EACCES;
1014                 if (p->did_exec)
1015                         goto out;
1016         } else {
1017                 err = -ESRCH;
1018                 if (p != current)
1019                         goto out;
1020         }
1021
1022         err = -EPERM;
1023         if (p->signal->leader)
1024                 goto out;
1025
1026         if (pgid != pid) {
1027                 struct task_struct *p;
1028
1029                 do_each_task_pid(pgid, PIDTYPE_PGID, p) {
1030                         if (p->signal->session == current->signal->session)
1031                                 goto ok_pgid;
1032                 } while_each_task_pid(pgid, PIDTYPE_PGID, p);
1033                 goto out;
1034         }
1035
1036 ok_pgid:
1037         err = security_task_setpgid(p, pgid);
1038         if (err)
1039                 goto out;
1040
1041         if (process_group(p) != pgid) {
1042                 detach_pid(p, PIDTYPE_PGID);
1043                 p->signal->pgrp = pgid;
1044                 attach_pid(p, PIDTYPE_PGID, pgid);
1045         }
1046
1047         err = 0;
1048 out:
1049         /* All paths lead to here, thus we are safe. -DaveM */
1050         write_unlock_irq(&tasklist_lock);
1051         return err;
1052 }
1053
1054 asmlinkage long sys_getpgid(pid_t pid)
1055 {
1056         if (!pid) {
1057                 return process_group(current);
1058         } else {
1059                 int retval;
1060                 struct task_struct *p;
1061
1062                 read_lock(&tasklist_lock);
1063                 p = find_task_by_pid(pid);
1064
1065                 retval = -ESRCH;
1066                 if (p) {
1067                         retval = security_task_getpgid(p);
1068                         if (!retval)
1069                                 retval = process_group(p);
1070                 }
1071                 read_unlock(&tasklist_lock);
1072                 return retval;
1073         }
1074 }
1075
1076 #ifdef __ARCH_WANT_SYS_GETPGRP
1077
1078 asmlinkage long sys_getpgrp(void)
1079 {
1080         /* SMP - assuming writes are word atomic this is fine */
1081         return process_group(current);
1082 }
1083
1084 #endif
1085
1086 asmlinkage long sys_getsid(pid_t pid)
1087 {
1088         if (!pid) {
1089                 return current->signal->session;
1090         } else {
1091                 int retval;
1092                 struct task_struct *p;
1093
1094                 read_lock(&tasklist_lock);
1095                 p = find_task_by_pid(pid);
1096
1097                 retval = -ESRCH;
1098                 if(p) {
1099                         retval = security_task_getsid(p);
1100                         if (!retval)
1101                                 retval = p->signal->session;
1102                 }
1103                 read_unlock(&tasklist_lock);
1104                 return retval;
1105         }
1106 }
1107
1108 asmlinkage long sys_setsid(void)
1109 {
1110         struct pid *pid;
1111         int err = -EPERM;
1112
1113         if (!thread_group_leader(current))
1114                 return -EINVAL;
1115
1116         down(&tty_sem);
1117         write_lock_irq(&tasklist_lock);
1118
1119         pid = find_pid(PIDTYPE_PGID, current->pid);
1120         if (pid)
1121                 goto out;
1122
1123         current->signal->leader = 1;
1124         __set_special_pids(current->pid, current->pid);
1125         current->signal->tty = NULL;
1126         current->signal->tty_old_pgrp = 0;
1127         err = process_group(current);
1128 out:
1129         write_unlock_irq(&tasklist_lock);
1130         up(&tty_sem);
1131         return err;
1132 }
1133
1134 /*
1135  * Supplementary group IDs
1136  */
1137
1138 /* init to 2 - one for init_task, one to ensure it is never freed */
1139 struct group_info init_groups = { .usage = ATOMIC_INIT(2) };
1140
1141 struct group_info *groups_alloc(int gidsetsize)
1142 {
1143         struct group_info *group_info;
1144         int nblocks;
1145         int i;
1146
1147         nblocks = (gidsetsize + NGROUPS_PER_BLOCK - 1) / NGROUPS_PER_BLOCK;
1148         /* Make sure we always allocate at least one indirect block pointer */
1149         nblocks = nblocks ? : 1;
1150         group_info = kmalloc(sizeof(*group_info) + nblocks*sizeof(gid_t *), GFP_USER);
1151         if (!group_info)
1152                 return NULL;
1153         group_info->ngroups = gidsetsize;
1154         group_info->nblocks = nblocks;
1155         atomic_set(&group_info->usage, 1);
1156
1157         if (gidsetsize <= NGROUPS_SMALL) {
1158                 group_info->blocks[0] = group_info->small_block;
1159         } else {
1160                 for (i = 0; i < nblocks; i++) {
1161                         gid_t *b;
1162                         b = (void *)__get_free_page(GFP_USER);
1163                         if (!b)
1164                                 goto out_undo_partial_alloc;
1165                         group_info->blocks[i] = b;
1166                 }
1167         }
1168         return group_info;
1169
1170 out_undo_partial_alloc:
1171         while (--i >= 0) {
1172                 free_page((unsigned long)group_info->blocks[i]);
1173         }
1174         kfree(group_info);
1175         return NULL;
1176 }
1177
1178 EXPORT_SYMBOL(groups_alloc);
1179
1180 void groups_free(struct group_info *group_info)
1181 {
1182         if (group_info->blocks[0] != group_info->small_block) {
1183                 int i;
1184                 for (i = 0; i < group_info->nblocks; i++)
1185                         free_page((unsigned long)group_info->blocks[i]);
1186         }
1187         kfree(group_info);
1188 }
1189
1190 EXPORT_SYMBOL(groups_free);
1191
1192 /* export the group_info to a user-space array */
1193 static int groups_to_user(gid_t __user *grouplist,
1194     struct group_info *group_info)
1195 {
1196         int i;
1197         int count = group_info->ngroups;
1198
1199         for (i = 0; i < group_info->nblocks; i++) {
1200                 int cp_count = min(NGROUPS_PER_BLOCK, count);
1201                 int off = i * NGROUPS_PER_BLOCK;
1202                 int len = cp_count * sizeof(*grouplist);
1203
1204                 if (copy_to_user(grouplist+off, group_info->blocks[i], len))
1205                         return -EFAULT;
1206
1207                 count -= cp_count;
1208         }
1209         return 0;
1210 }
1211
1212 /* fill a group_info from a user-space array - it must be allocated already */
1213 static int groups_from_user(struct group_info *group_info,
1214     gid_t __user *grouplist)
1215  {
1216         int i;
1217         int count = group_info->ngroups;
1218
1219         for (i = 0; i < group_info->nblocks; i++) {
1220                 int cp_count = min(NGROUPS_PER_BLOCK, count);
1221                 int off = i * NGROUPS_PER_BLOCK;
1222                 int len = cp_count * sizeof(*grouplist);
1223
1224                 if (copy_from_user(group_info->blocks[i], grouplist+off, len))
1225                         return -EFAULT;
1226
1227                 count -= cp_count;
1228         }
1229         return 0;
1230 }
1231
1232 /* a simple Shell sort */
1233 static void groups_sort(struct group_info *group_info)
1234 {
1235         int base, max, stride;
1236         int gidsetsize = group_info->ngroups;
1237
1238         for (stride = 1; stride < gidsetsize; stride = 3 * stride + 1)
1239                 ; /* nothing */
1240         stride /= 3;
1241
1242         while (stride) {
1243                 max = gidsetsize - stride;
1244                 for (base = 0; base < max; base++) {
1245                         int left = base;
1246                         int right = left + stride;
1247                         gid_t tmp = GROUP_AT(group_info, right);
1248
1249                         while (left >= 0 && GROUP_AT(group_info, left) > tmp) {
1250                                 GROUP_AT(group_info, right) =
1251                                     GROUP_AT(group_info, left);
1252                                 right = left;
1253                                 left -= stride;
1254                         }
1255                         GROUP_AT(group_info, right) = tmp;
1256                 }
1257                 stride /= 3;
1258         }
1259 }
1260
1261 /* a simple bsearch */
1262 static int groups_search(struct group_info *group_info, gid_t grp)
1263 {
1264         int left, right;
1265
1266         if (!group_info)
1267                 return 0;
1268
1269         left = 0;
1270         right = group_info->ngroups;
1271         while (left < right) {
1272                 int mid = (left+right)/2;
1273                 int cmp = grp - GROUP_AT(group_info, mid);
1274                 if (cmp > 0)
1275                         left = mid + 1;
1276                 else if (cmp < 0)
1277                         right = mid;
1278                 else
1279                         return 1;
1280         }
1281         return 0;
1282 }
1283
1284 /* validate and set current->group_info */
1285 int set_current_groups(struct group_info *group_info)
1286 {
1287         int retval;
1288         struct group_info *old_info;
1289
1290         retval = security_task_setgroups(group_info);
1291         if (retval)
1292                 return retval;
1293
1294         groups_sort(group_info);
1295         get_group_info(group_info);
1296
1297         task_lock(current);
1298         old_info = current->group_info;
1299         current->group_info = group_info;
1300         task_unlock(current);
1301
1302         put_group_info(old_info);
1303
1304         return 0;
1305 }
1306
1307 EXPORT_SYMBOL(set_current_groups);
1308
1309 asmlinkage long sys_getgroups(int gidsetsize, gid_t __user *grouplist)
1310 {
1311         int i = 0;
1312
1313         /*
1314          *      SMP: Nobody else can change our grouplist. Thus we are
1315          *      safe.
1316          */
1317
1318         if (gidsetsize < 0)
1319                 return -EINVAL;
1320
1321         /* no need to grab task_lock here; it cannot change */
1322         get_group_info(current->group_info);
1323         i = current->group_info->ngroups;
1324         if (gidsetsize) {
1325                 if (i > gidsetsize) {
1326                         i = -EINVAL;
1327                         goto out;
1328                 }
1329                 if (groups_to_user(grouplist, current->group_info)) {
1330                         i = -EFAULT;
1331                         goto out;
1332                 }
1333         }
1334 out:
1335         put_group_info(current->group_info);
1336         return i;
1337 }
1338
1339 /*
1340  *      SMP: Our groups are copy-on-write. We can set them safely
1341  *      without another task interfering.
1342  */
1343  
1344 asmlinkage long sys_setgroups(int gidsetsize, gid_t __user *grouplist)
1345 {
1346         struct group_info *group_info;
1347         int retval;
1348
1349         if (!capable(CAP_SETGID))
1350                 return -EPERM;
1351         if ((unsigned)gidsetsize > NGROUPS_MAX)
1352                 return -EINVAL;
1353
1354         group_info = groups_alloc(gidsetsize);
1355         if (!group_info)
1356                 return -ENOMEM;
1357         retval = groups_from_user(group_info, grouplist);
1358         if (retval) {
1359                 put_group_info(group_info);
1360                 return retval;
1361         }
1362
1363         retval = set_current_groups(group_info);
1364         put_group_info(group_info);
1365
1366         return retval;
1367 }
1368
1369 /*
1370  * Check whether we're fsgid/egid or in the supplemental group..
1371  */
1372 int in_group_p(gid_t grp)
1373 {
1374         int retval = 1;
1375         if (grp != current->fsgid) {
1376                 get_group_info(current->group_info);
1377                 retval = groups_search(current->group_info, grp);
1378                 put_group_info(current->group_info);
1379         }
1380         return retval;
1381 }
1382
1383 EXPORT_SYMBOL(in_group_p);
1384
1385 int in_egroup_p(gid_t grp)
1386 {
1387         int retval = 1;
1388         if (grp != current->egid) {
1389                 get_group_info(current->group_info);
1390                 retval = groups_search(current->group_info, grp);
1391                 put_group_info(current->group_info);
1392         }
1393         return retval;
1394 }
1395
1396 EXPORT_SYMBOL(in_egroup_p);
1397
1398 DECLARE_RWSEM(uts_sem);
1399
1400 EXPORT_SYMBOL(uts_sem);
1401
1402 asmlinkage long sys_newuname(struct new_utsname __user * name)
1403 {
1404         int errno = 0;
1405
1406         down_read(&uts_sem);
1407         if (copy_to_user(name,&system_utsname,sizeof *name))
1408                 errno = -EFAULT;
1409         up_read(&uts_sem);
1410         return errno;
1411 }
1412
1413 asmlinkage long sys_sethostname(char __user *name, int len)
1414 {
1415         int errno;
1416         char tmp[__NEW_UTS_LEN];
1417
1418         if (!capable(CAP_SYS_ADMIN))
1419                 return -EPERM;
1420         if (len < 0 || len > __NEW_UTS_LEN)
1421                 return -EINVAL;
1422         down_write(&uts_sem);
1423         errno = -EFAULT;
1424         if (!copy_from_user(tmp, name, len)) {
1425                 memcpy(system_utsname.nodename, tmp, len);
1426                 system_utsname.nodename[len] = 0;
1427                 errno = 0;
1428         }
1429         up_write(&uts_sem);
1430         return errno;
1431 }
1432
1433 #ifdef __ARCH_WANT_SYS_GETHOSTNAME
1434
1435 asmlinkage long sys_gethostname(char __user *name, int len)
1436 {
1437         int i, errno;
1438
1439         if (len < 0)
1440                 return -EINVAL;
1441         down_read(&uts_sem);
1442         i = 1 + strlen(system_utsname.nodename);
1443         if (i > len)
1444                 i = len;
1445         errno = 0;
1446         if (copy_to_user(name, system_utsname.nodename, i))
1447                 errno = -EFAULT;
1448         up_read(&uts_sem);
1449         return errno;
1450 }
1451
1452 #endif
1453
1454 /*
1455  * Only setdomainname; getdomainname can be implemented by calling
1456  * uname()
1457  */
1458 asmlinkage long sys_setdomainname(char __user *name, int len)
1459 {
1460         int errno;
1461         char tmp[__NEW_UTS_LEN];
1462
1463         if (!capable(CAP_SYS_ADMIN))
1464                 return -EPERM;
1465         if (len < 0 || len > __NEW_UTS_LEN)
1466                 return -EINVAL;
1467
1468         down_write(&uts_sem);
1469         errno = -EFAULT;
1470         if (!copy_from_user(tmp, name, len)) {
1471                 memcpy(system_utsname.domainname, tmp, len);
1472                 system_utsname.domainname[len] = 0;
1473                 errno = 0;
1474         }
1475         up_write(&uts_sem);
1476         return errno;
1477 }
1478
1479 asmlinkage long sys_getrlimit(unsigned int resource, struct rlimit __user *rlim)
1480 {
1481         if (resource >= RLIM_NLIMITS)
1482                 return -EINVAL;
1483         else {
1484                 struct rlimit value;
1485                 task_lock(current->group_leader);
1486                 value = current->signal->rlim[resource];
1487                 task_unlock(current->group_leader);
1488                 return copy_to_user(rlim, &value, sizeof(*rlim)) ? -EFAULT : 0;
1489         }
1490 }
1491
1492 #ifdef __ARCH_WANT_SYS_OLD_GETRLIMIT
1493
1494 /*
1495  *      Back compatibility for getrlimit. Needed for some apps.
1496  */
1497  
1498 asmlinkage long sys_old_getrlimit(unsigned int resource, struct rlimit __user *rlim)
1499 {
1500         struct rlimit x;
1501         if (resource >= RLIM_NLIMITS)
1502                 return -EINVAL;
1503
1504         task_lock(current->group_leader);
1505         x = current->signal->rlim[resource];
1506         task_unlock(current->group_leader);
1507         if(x.rlim_cur > 0x7FFFFFFF)
1508                 x.rlim_cur = 0x7FFFFFFF;
1509         if(x.rlim_max > 0x7FFFFFFF)
1510                 x.rlim_max = 0x7FFFFFFF;
1511         return copy_to_user(rlim, &x, sizeof(x))?-EFAULT:0;
1512 }
1513
1514 #endif
1515
1516 asmlinkage long sys_setrlimit(unsigned int resource, struct rlimit __user *rlim)
1517 {
1518         struct rlimit new_rlim, *old_rlim;
1519         int retval;
1520
1521         if (resource >= RLIM_NLIMITS)
1522                 return -EINVAL;
1523         if(copy_from_user(&new_rlim, rlim, sizeof(*rlim)))
1524                 return -EFAULT;
1525        if (new_rlim.rlim_cur > new_rlim.rlim_max)
1526                return -EINVAL;
1527         old_rlim = current->signal->rlim + resource;
1528         if ((new_rlim.rlim_max > old_rlim->rlim_max) &&
1529             !capable(CAP_SYS_RESOURCE))
1530                 return -EPERM;
1531         if (resource == RLIMIT_NOFILE && new_rlim.rlim_max > NR_OPEN)
1532                         return -EPERM;
1533
1534         retval = security_task_setrlimit(resource, &new_rlim);
1535         if (retval)
1536                 return retval;
1537
1538         task_lock(current->group_leader);
1539         *old_rlim = new_rlim;
1540         task_unlock(current->group_leader);
1541
1542         if (resource == RLIMIT_CPU && new_rlim.rlim_cur != RLIM_INFINITY &&
1543             (cputime_eq(current->signal->it_prof_expires, cputime_zero) ||
1544              new_rlim.rlim_cur <= cputime_to_secs(
1545                      current->signal->it_prof_expires))) {
1546                 cputime_t cputime = secs_to_cputime(new_rlim.rlim_cur);
1547                 read_lock(&tasklist_lock);
1548                 spin_lock_irq(&current->sighand->siglock);
1549                 set_process_cpu_timer(current, CPUCLOCK_PROF,
1550                                       &cputime, NULL);
1551                 spin_unlock_irq(&current->sighand->siglock);
1552                 read_unlock(&tasklist_lock);
1553         }
1554
1555         return 0;
1556 }
1557
1558 /*
1559  * It would make sense to put struct rusage in the task_struct,
1560  * except that would make the task_struct be *really big*.  After
1561  * task_struct gets moved into malloc'ed memory, it would
1562  * make sense to do this.  It will make moving the rest of the information
1563  * a lot simpler!  (Which we're not doing right now because we're not
1564  * measuring them yet).
1565  *
1566  * This expects to be called with tasklist_lock read-locked or better,
1567  * and the siglock not locked.  It may momentarily take the siglock.
1568  *
1569  * When sampling multiple threads for RUSAGE_SELF, under SMP we might have
1570  * races with threads incrementing their own counters.  But since word
1571  * reads are atomic, we either get new values or old values and we don't
1572  * care which for the sums.  We always take the siglock to protect reading
1573  * the c* fields from p->signal from races with exit.c updating those
1574  * fields when reaping, so a sample either gets all the additions of a
1575  * given child after it's reaped, or none so this sample is before reaping.
1576  */
1577
1578 static void k_getrusage(struct task_struct *p, int who, struct rusage *r)
1579 {
1580         struct task_struct *t;
1581         unsigned long flags;
1582         cputime_t utime, stime;
1583
1584         memset((char *) r, 0, sizeof *r);
1585
1586         if (unlikely(!p->signal))
1587                 return;
1588
1589         switch (who) {
1590                 case RUSAGE_CHILDREN:
1591                         spin_lock_irqsave(&p->sighand->siglock, flags);
1592                         utime = p->signal->cutime;
1593                         stime = p->signal->cstime;
1594                         r->ru_nvcsw = p->signal->cnvcsw;
1595                         r->ru_nivcsw = p->signal->cnivcsw;
1596                         r->ru_minflt = p->signal->cmin_flt;
1597                         r->ru_majflt = p->signal->cmaj_flt;
1598                         spin_unlock_irqrestore(&p->sighand->siglock, flags);
1599                         cputime_to_timeval(utime, &r->ru_utime);
1600                         cputime_to_timeval(stime, &r->ru_stime);
1601                         break;
1602                 case RUSAGE_SELF:
1603                         spin_lock_irqsave(&p->sighand->siglock, flags);
1604                         utime = stime = cputime_zero;
1605                         goto sum_group;
1606                 case RUSAGE_BOTH:
1607                         spin_lock_irqsave(&p->sighand->siglock, flags);
1608                         utime = p->signal->cutime;
1609                         stime = p->signal->cstime;
1610                         r->ru_nvcsw = p->signal->cnvcsw;
1611                         r->ru_nivcsw = p->signal->cnivcsw;
1612                         r->ru_minflt = p->signal->cmin_flt;
1613                         r->ru_majflt = p->signal->cmaj_flt;
1614                 sum_group:
1615                         utime = cputime_add(utime, p->signal->utime);
1616                         stime = cputime_add(stime, p->signal->stime);
1617                         r->ru_nvcsw += p->signal->nvcsw;
1618                         r->ru_nivcsw += p->signal->nivcsw;
1619                         r->ru_minflt += p->signal->min_flt;
1620                         r->ru_majflt += p->signal->maj_flt;
1621                         t = p;
1622                         do {
1623                                 utime = cputime_add(utime, t->utime);
1624                                 stime = cputime_add(stime, t->stime);
1625                                 r->ru_nvcsw += t->nvcsw;
1626                                 r->ru_nivcsw += t->nivcsw;
1627                                 r->ru_minflt += t->min_flt;
1628                                 r->ru_majflt += t->maj_flt;
1629                                 t = next_thread(t);
1630                         } while (t != p);
1631                         spin_unlock_irqrestore(&p->sighand->siglock, flags);
1632                         cputime_to_timeval(utime, &r->ru_utime);
1633                         cputime_to_timeval(stime, &r->ru_stime);
1634                         break;
1635                 default:
1636                         BUG();
1637         }
1638 }
1639
1640 int getrusage(struct task_struct *p, int who, struct rusage __user *ru)
1641 {
1642         struct rusage r;
1643         read_lock(&tasklist_lock);
1644         k_getrusage(p, who, &r);
1645         read_unlock(&tasklist_lock);
1646         return copy_to_user(ru, &r, sizeof(r)) ? -EFAULT : 0;
1647 }
1648
1649 asmlinkage long sys_getrusage(int who, struct rusage __user *ru)
1650 {
1651         if (who != RUSAGE_SELF && who != RUSAGE_CHILDREN)
1652                 return -EINVAL;
1653         return getrusage(current, who, ru);
1654 }
1655
1656 asmlinkage long sys_umask(int mask)
1657 {
1658         mask = xchg(&current->fs->umask, mask & S_IRWXUGO);
1659         return mask;
1660 }
1661     
1662 asmlinkage long sys_prctl(int option, unsigned long arg2, unsigned long arg3,
1663                           unsigned long arg4, unsigned long arg5)
1664 {
1665         long error;
1666         int sig;
1667
1668         error = security_task_prctl(option, arg2, arg3, arg4, arg5);
1669         if (error)
1670                 return error;
1671
1672         switch (option) {
1673                 case PR_SET_PDEATHSIG:
1674                         sig = arg2;
1675                         if (!valid_signal(sig)) {
1676                                 error = -EINVAL;
1677                                 break;
1678                         }
1679                         current->pdeath_signal = sig;
1680                         break;
1681                 case PR_GET_PDEATHSIG:
1682                         error = put_user(current->pdeath_signal, (int __user *)arg2);
1683                         break;
1684                 case PR_GET_DUMPABLE:
1685                         if (current->mm->dumpable)
1686                                 error = 1;
1687                         break;
1688                 case PR_SET_DUMPABLE:
1689                         if (arg2 < 0 || arg2 > 2) {
1690                                 error = -EINVAL;
1691                                 break;
1692                         }
1693                         current->mm->dumpable = arg2;
1694                         break;
1695
1696                 case PR_SET_UNALIGN:
1697                         error = SET_UNALIGN_CTL(current, arg2);
1698                         break;
1699                 case PR_GET_UNALIGN:
1700                         error = GET_UNALIGN_CTL(current, arg2);
1701                         break;
1702                 case PR_SET_FPEMU:
1703                         error = SET_FPEMU_CTL(current, arg2);
1704                         break;
1705                 case PR_GET_FPEMU:
1706                         error = GET_FPEMU_CTL(current, arg2);
1707                         break;
1708                 case PR_SET_FPEXC:
1709                         error = SET_FPEXC_CTL(current, arg2);
1710                         break;
1711                 case PR_GET_FPEXC:
1712                         error = GET_FPEXC_CTL(current, arg2);
1713                         break;
1714                 case PR_GET_TIMING:
1715                         error = PR_TIMING_STATISTICAL;
1716                         break;
1717                 case PR_SET_TIMING:
1718                         if (arg2 == PR_TIMING_STATISTICAL)
1719                                 error = 0;
1720                         else
1721                                 error = -EINVAL;
1722                         break;
1723
1724                 case PR_GET_KEEPCAPS:
1725                         if (current->keep_capabilities)
1726                                 error = 1;
1727                         break;
1728                 case PR_SET_KEEPCAPS:
1729                         if (arg2 != 0 && arg2 != 1) {
1730                                 error = -EINVAL;
1731                                 break;
1732                         }
1733                         current->keep_capabilities = arg2;
1734                         break;
1735                 case PR_SET_NAME: {
1736                         struct task_struct *me = current;
1737                         unsigned char ncomm[sizeof(me->comm)];
1738
1739                         ncomm[sizeof(me->comm)-1] = 0;
1740                         if (strncpy_from_user(ncomm, (char __user *)arg2,
1741                                                 sizeof(me->comm)-1) < 0)
1742                                 return -EFAULT;
1743                         set_task_comm(me, ncomm);
1744                         return 0;
1745                 }
1746                 case PR_GET_NAME: {
1747                         struct task_struct *me = current;
1748                         unsigned char tcomm[sizeof(me->comm)];
1749
1750                         get_task_comm(tcomm, me);
1751                         if (copy_to_user((char __user *)arg2, tcomm, sizeof(tcomm)))
1752                                 return -EFAULT;
1753                         return 0;
1754                 }
1755                 default:
1756                         error = -EINVAL;
1757                         break;
1758         }
1759         return error;
1760 }