diff options
author | Linus Torvalds <torvalds@ppc970.osdl.org> | 2005-04-16 18:20:36 -0400 |
---|---|---|
committer | Linus Torvalds <torvalds@ppc970.osdl.org> | 2005-04-16 18:20:36 -0400 |
commit | 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 (patch) | |
tree | 0bba044c4ce775e45a88a51686b5d9f90697ea9d /kernel/sys.c |
Linux-2.6.12-rc2v2.6.12-rc2
Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.
Let it rip!
Diffstat (limited to 'kernel/sys.c')
-rw-r--r-- | kernel/sys.c | 1725 |
1 files changed, 1725 insertions, 0 deletions
diff --git a/kernel/sys.c b/kernel/sys.c new file mode 100644 index 000000000000..462d78d55895 --- /dev/null +++ b/kernel/sys.c | |||
@@ -0,0 +1,1725 @@ | |||
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 | |||
29 | #include <linux/compat.h> | ||
30 | #include <linux/syscalls.h> | ||
31 | |||
32 | #include <asm/uaccess.h> | ||
33 | #include <asm/io.h> | ||
34 | #include <asm/unistd.h> | ||
35 | |||
36 | #ifndef SET_UNALIGN_CTL | ||
37 | # define SET_UNALIGN_CTL(a,b) (-EINVAL) | ||
38 | #endif | ||
39 | #ifndef GET_UNALIGN_CTL | ||
40 | # define GET_UNALIGN_CTL(a,b) (-EINVAL) | ||
41 | #endif | ||
42 | #ifndef SET_FPEMU_CTL | ||
43 | # define SET_FPEMU_CTL(a,b) (-EINVAL) | ||
44 | #endif | ||
45 | #ifndef GET_FPEMU_CTL | ||
46 | # define GET_FPEMU_CTL(a,b) (-EINVAL) | ||
47 | #endif | ||
48 | #ifndef SET_FPEXC_CTL | ||
49 | # define SET_FPEXC_CTL(a,b) (-EINVAL) | ||
50 | #endif | ||
51 | #ifndef GET_FPEXC_CTL | ||
52 | # define GET_FPEXC_CTL(a,b) (-EINVAL) | ||
53 | #endif | ||
54 | |||
55 | /* | ||
56 | * this is where the system-wide overflow UID and GID are defined, for | ||
57 | * architectures that now have 32-bit UID/GID but didn't in the past | ||
58 | */ | ||
59 | |||
60 | int overflowuid = DEFAULT_OVERFLOWUID; | ||
61 | int overflowgid = DEFAULT_OVERFLOWGID; | ||
62 | |||
63 | #ifdef CONFIG_UID16 | ||
64 | EXPORT_SYMBOL(overflowuid); | ||
65 | EXPORT_SYMBOL(overflowgid); | ||
66 | #endif | ||
67 | |||
68 | /* | ||
69 | * the same as above, but for filesystems which can only store a 16-bit | ||
70 | * UID and GID. as such, this is needed on all architectures | ||
71 | */ | ||
72 | |||
73 | int fs_overflowuid = DEFAULT_FS_OVERFLOWUID; | ||
74 | int fs_overflowgid = DEFAULT_FS_OVERFLOWUID; | ||
75 | |||
76 | EXPORT_SYMBOL(fs_overflowuid); | ||
77 | EXPORT_SYMBOL(fs_overflowgid); | ||
78 | |||
79 | /* | ||
80 | * this indicates whether you can reboot with ctrl-alt-del: the default is yes | ||
81 | */ | ||
82 | |||
83 | int C_A_D = 1; | ||
84 | int cad_pid = 1; | ||
85 | |||
86 | /* | ||
87 | * Notifier list for kernel code which wants to be called | ||
88 | * at shutdown. This is used to stop any idling DMA operations | ||
89 | * and the like. | ||
90 | */ | ||
91 | |||
92 | static struct notifier_block *reboot_notifier_list; | ||
93 | static DEFINE_RWLOCK(notifier_lock); | ||
94 | |||
95 | /** | ||
96 | * notifier_chain_register - Add notifier to a notifier chain | ||
97 | * @list: Pointer to root list pointer | ||
98 | * @n: New entry in notifier chain | ||
99 | * | ||
100 | * Adds a notifier to a notifier chain. | ||
101 | * | ||
102 | * Currently always returns zero. | ||
103 | */ | ||
104 | |||
105 | int notifier_chain_register(struct notifier_block **list, struct notifier_block *n) | ||
106 | { | ||
107 | write_lock(¬ifier_lock); | ||
108 | while(*list) | ||
109 | { | ||
110 | if(n->priority > (*list)->priority) | ||
111 | break; | ||
112 | list= &((*list)->next); | ||
113 | } | ||
114 | n->next = *list; | ||
115 | *list=n; | ||
116 | write_unlock(¬ifier_lock); | ||
117 | return 0; | ||
118 | } | ||
119 | |||
120 | EXPORT_SYMBOL(notifier_chain_register); | ||
121 | |||
122 | /** | ||
123 | * notifier_chain_unregister - Remove notifier from a notifier chain | ||
124 | * @nl: Pointer to root list pointer | ||
125 | * @n: New entry in notifier chain | ||
126 | * | ||
127 | * Removes a notifier from a notifier chain. | ||
128 | * | ||
129 | * Returns zero on success, or %-ENOENT on failure. | ||
130 | */ | ||
131 | |||
132 | int notifier_chain_unregister(struct notifier_block **nl, struct notifier_block *n) | ||
133 | { | ||
134 | write_lock(¬ifier_lock); | ||
135 | while((*nl)!=NULL) | ||
136 | { | ||
137 | if((*nl)==n) | ||
138 | { | ||
139 | *nl=n->next; | ||
140 | write_unlock(¬ifier_lock); | ||
141 | return 0; | ||
142 | } | ||
143 | nl=&((*nl)->next); | ||
144 | } | ||
145 | write_unlock(¬ifier_lock); | ||
146 | return -ENOENT; | ||
147 | } | ||
148 | |||
149 | EXPORT_SYMBOL(notifier_chain_unregister); | ||
150 | |||
151 | /** | ||
152 | * notifier_call_chain - Call functions in a notifier chain | ||
153 | * @n: Pointer to root pointer of notifier chain | ||
154 | * @val: Value passed unmodified to notifier function | ||
155 | * @v: Pointer passed unmodified to notifier function | ||
156 | * | ||
157 | * Calls each function in a notifier chain in turn. | ||
158 | * | ||
159 | * If the return value of the notifier can be and'd | ||
160 | * with %NOTIFY_STOP_MASK, then notifier_call_chain | ||
161 | * will return immediately, with the return value of | ||
162 | * the notifier function which halted execution. | ||
163 | * Otherwise, the return value is the return value | ||
164 | * of the last notifier function called. | ||
165 | */ | ||
166 | |||
167 | int notifier_call_chain(struct notifier_block **n, unsigned long val, void *v) | ||
168 | { | ||
169 | int ret=NOTIFY_DONE; | ||
170 | struct notifier_block *nb = *n; | ||
171 | |||
172 | while(nb) | ||
173 | { | ||
174 | ret=nb->notifier_call(nb,val,v); | ||
175 | if(ret&NOTIFY_STOP_MASK) | ||
176 | { | ||
177 | return ret; | ||
178 | } | ||
179 | nb=nb->next; | ||
180 | } | ||
181 | return ret; | ||
182 | } | ||
183 | |||
184 | EXPORT_SYMBOL(notifier_call_chain); | ||
185 | |||
186 | /** | ||
187 | * register_reboot_notifier - Register function to be called at reboot time | ||
188 | * @nb: Info about notifier function to be called | ||
189 | * | ||
190 | * Registers a function with the list of functions | ||
191 | * to be called at reboot time. | ||
192 | * | ||
193 | * Currently always returns zero, as notifier_chain_register | ||
194 | * always returns zero. | ||
195 | */ | ||
196 | |||
197 | int register_reboot_notifier(struct notifier_block * nb) | ||
198 | { | ||
199 | return notifier_chain_register(&reboot_notifier_list, nb); | ||
200 | } | ||
201 | |||
202 | EXPORT_SYMBOL(register_reboot_notifier); | ||
203 | |||
204 | /** | ||
205 | * unregister_reboot_notifier - Unregister previously registered reboot notifier | ||
206 | * @nb: Hook to be unregistered | ||
207 | * | ||
208 | * Unregisters a previously registered reboot | ||
209 | * notifier function. | ||
210 | * | ||
211 | * Returns zero on success, or %-ENOENT on failure. | ||
212 | */ | ||
213 | |||
214 | int unregister_reboot_notifier(struct notifier_block * nb) | ||
215 | { | ||
216 | return notifier_chain_unregister(&reboot_notifier_list, nb); | ||
217 | } | ||
218 | |||
219 | EXPORT_SYMBOL(unregister_reboot_notifier); | ||
220 | |||
221 | static int set_one_prio(struct task_struct *p, int niceval, int error) | ||
222 | { | ||
223 | int no_nice; | ||
224 | |||
225 | if (p->uid != current->euid && | ||
226 | p->euid != current->euid && !capable(CAP_SYS_NICE)) { | ||
227 | error = -EPERM; | ||
228 | goto out; | ||
229 | } | ||
230 | if (niceval < task_nice(p) && !capable(CAP_SYS_NICE)) { | ||
231 | error = -EACCES; | ||
232 | goto out; | ||
233 | } | ||
234 | no_nice = security_task_setnice(p, niceval); | ||
235 | if (no_nice) { | ||
236 | error = no_nice; | ||
237 | goto out; | ||
238 | } | ||
239 | if (error == -ESRCH) | ||
240 | error = 0; | ||
241 | set_user_nice(p, niceval); | ||
242 | out: | ||
243 | return error; | ||
244 | } | ||
245 | |||
246 | asmlinkage long sys_setpriority(int which, int who, int niceval) | ||
247 | { | ||
248 | struct task_struct *g, *p; | ||
249 | struct user_struct *user; | ||
250 | int error = -EINVAL; | ||
251 | |||
252 | if (which > 2 || which < 0) | ||
253 | goto out; | ||
254 | |||
255 | /* normalize: avoid signed division (rounding problems) */ | ||
256 | error = -ESRCH; | ||
257 | if (niceval < -20) | ||
258 | niceval = -20; | ||
259 | if (niceval > 19) | ||
260 | niceval = 19; | ||
261 | |||
262 | read_lock(&tasklist_lock); | ||
263 | switch (which) { | ||
264 | case PRIO_PROCESS: | ||
265 | if (!who) | ||
266 | who = current->pid; | ||
267 | p = find_task_by_pid(who); | ||
268 | if (p) | ||
269 | error = set_one_prio(p, niceval, error); | ||
270 | break; | ||
271 | case PRIO_PGRP: | ||
272 | if (!who) | ||
273 | who = process_group(current); | ||
274 | do_each_task_pid(who, PIDTYPE_PGID, p) { | ||
275 | error = set_one_prio(p, niceval, error); | ||
276 | } while_each_task_pid(who, PIDTYPE_PGID, p); | ||
277 | break; | ||
278 | case PRIO_USER: | ||
279 | user = current->user; | ||
280 | if (!who) | ||
281 | who = current->uid; | ||
282 | else | ||
283 | if ((who != current->uid) && !(user = find_user(who))) | ||
284 | goto out_unlock; /* No processes for this user */ | ||
285 | |||
286 | do_each_thread(g, p) | ||
287 | if (p->uid == who) | ||
288 | error = set_one_prio(p, niceval, error); | ||
289 | while_each_thread(g, p); | ||
290 | if (who != current->uid) | ||
291 | free_uid(user); /* For find_user() */ | ||
292 | break; | ||
293 | } | ||
294 | out_unlock: | ||
295 | read_unlock(&tasklist_lock); | ||
296 | out: | ||
297 | return error; | ||
298 | } | ||
299 | |||
300 | /* | ||
301 | * Ugh. To avoid negative return values, "getpriority()" will | ||
302 | * not return the normal nice-value, but a negated value that | ||
303 | * has been offset by 20 (ie it returns 40..1 instead of -20..19) | ||
304 | * to stay compatible. | ||
305 | */ | ||
306 | asmlinkage long sys_getpriority(int which, int who) | ||
307 | { | ||
308 | struct task_struct *g, *p; | ||
309 | struct user_struct *user; | ||
310 | long niceval, retval = -ESRCH; | ||
311 | |||
312 | if (which > 2 || which < 0) | ||
313 | return -EINVAL; | ||
314 | |||
315 | read_lock(&tasklist_lock); | ||
316 | switch (which) { | ||
317 | case PRIO_PROCESS: | ||
318 | if (!who) | ||
319 | who = current->pid; | ||
320 | p = find_task_by_pid(who); | ||
321 | if (p) { | ||
322 | niceval = 20 - task_nice(p); | ||
323 | if (niceval > retval) | ||
324 | retval = niceval; | ||
325 | } | ||
326 | break; | ||
327 | case PRIO_PGRP: | ||
328 | if (!who) | ||
329 | who = process_group(current); | ||
330 | do_each_task_pid(who, PIDTYPE_PGID, p) { | ||
331 | niceval = 20 - task_nice(p); | ||
332 | if (niceval > retval) | ||
333 | retval = niceval; | ||
334 | } while_each_task_pid(who, PIDTYPE_PGID, p); | ||
335 | break; | ||
336 | case PRIO_USER: | ||
337 | user = current->user; | ||
338 | if (!who) | ||
339 | who = current->uid; | ||
340 | else | ||
341 | if ((who != current->uid) && !(user = find_user(who))) | ||
342 | goto out_unlock; /* No processes for this user */ | ||
343 | |||
344 | do_each_thread(g, p) | ||
345 | if (p->uid == who) { | ||
346 | niceval = 20 - task_nice(p); | ||
347 | if (niceval > retval) | ||
348 | retval = niceval; | ||
349 | } | ||
350 | while_each_thread(g, p); | ||
351 | if (who != current->uid) | ||
352 | free_uid(user); /* for find_user() */ | ||
353 | break; | ||
354 | } | ||
355 | out_unlock: | ||
356 | read_unlock(&tasklist_lock); | ||
357 | |||
358 | return retval; | ||
359 | } | ||
360 | |||
361 | |||
362 | /* | ||
363 | * Reboot system call: for obvious reasons only root may call it, | ||
364 | * and even root needs to set up some magic numbers in the registers | ||
365 | * so that some mistake won't make this reboot the whole machine. | ||
366 | * You can also set the meaning of the ctrl-alt-del-key here. | ||
367 | * | ||
368 | * reboot doesn't sync: do that yourself before calling this. | ||
369 | */ | ||
370 | asmlinkage long sys_reboot(int magic1, int magic2, unsigned int cmd, void __user * arg) | ||
371 | { | ||
372 | char buffer[256]; | ||
373 | |||
374 | /* We only trust the superuser with rebooting the system. */ | ||
375 | if (!capable(CAP_SYS_BOOT)) | ||
376 | return -EPERM; | ||
377 | |||
378 | /* For safety, we require "magic" arguments. */ | ||
379 | if (magic1 != LINUX_REBOOT_MAGIC1 || | ||
380 | (magic2 != LINUX_REBOOT_MAGIC2 && | ||
381 | magic2 != LINUX_REBOOT_MAGIC2A && | ||
382 | magic2 != LINUX_REBOOT_MAGIC2B && | ||
383 | magic2 != LINUX_REBOOT_MAGIC2C)) | ||
384 | return -EINVAL; | ||
385 | |||
386 | lock_kernel(); | ||
387 | switch (cmd) { | ||
388 | case LINUX_REBOOT_CMD_RESTART: | ||
389 | notifier_call_chain(&reboot_notifier_list, SYS_RESTART, NULL); | ||
390 | system_state = SYSTEM_RESTART; | ||
391 | device_shutdown(); | ||
392 | printk(KERN_EMERG "Restarting system.\n"); | ||
393 | machine_restart(NULL); | ||
394 | break; | ||
395 | |||
396 | case LINUX_REBOOT_CMD_CAD_ON: | ||
397 | C_A_D = 1; | ||
398 | break; | ||
399 | |||
400 | case LINUX_REBOOT_CMD_CAD_OFF: | ||
401 | C_A_D = 0; | ||
402 | break; | ||
403 | |||
404 | case LINUX_REBOOT_CMD_HALT: | ||
405 | notifier_call_chain(&reboot_notifier_list, SYS_HALT, NULL); | ||
406 | system_state = SYSTEM_HALT; | ||
407 | device_shutdown(); | ||
408 | printk(KERN_EMERG "System halted.\n"); | ||
409 | machine_halt(); | ||
410 | unlock_kernel(); | ||
411 | do_exit(0); | ||
412 | break; | ||
413 | |||
414 | case LINUX_REBOOT_CMD_POWER_OFF: | ||
415 | notifier_call_chain(&reboot_notifier_list, SYS_POWER_OFF, NULL); | ||
416 | system_state = SYSTEM_POWER_OFF; | ||
417 | device_shutdown(); | ||
418 | printk(KERN_EMERG "Power down.\n"); | ||
419 | machine_power_off(); | ||
420 | unlock_kernel(); | ||
421 | do_exit(0); | ||
422 | break; | ||
423 | |||
424 | case LINUX_REBOOT_CMD_RESTART2: | ||
425 | if (strncpy_from_user(&buffer[0], arg, sizeof(buffer) - 1) < 0) { | ||
426 | unlock_kernel(); | ||
427 | return -EFAULT; | ||
428 | } | ||
429 | buffer[sizeof(buffer) - 1] = '\0'; | ||
430 | |||
431 | notifier_call_chain(&reboot_notifier_list, SYS_RESTART, buffer); | ||
432 | system_state = SYSTEM_RESTART; | ||
433 | device_shutdown(); | ||
434 | printk(KERN_EMERG "Restarting system with command '%s'.\n", buffer); | ||
435 | machine_restart(buffer); | ||
436 | break; | ||
437 | |||
438 | #ifdef CONFIG_SOFTWARE_SUSPEND | ||
439 | case LINUX_REBOOT_CMD_SW_SUSPEND: | ||
440 | { | ||
441 | int ret = software_suspend(); | ||
442 | unlock_kernel(); | ||
443 | return ret; | ||
444 | } | ||
445 | #endif | ||
446 | |||
447 | default: | ||
448 | unlock_kernel(); | ||
449 | return -EINVAL; | ||
450 | } | ||
451 | unlock_kernel(); | ||
452 | return 0; | ||
453 | } | ||
454 | |||
455 | static void deferred_cad(void *dummy) | ||
456 | { | ||
457 | notifier_call_chain(&reboot_notifier_list, SYS_RESTART, NULL); | ||
458 | machine_restart(NULL); | ||
459 | } | ||
460 | |||
461 | /* | ||
462 | * This function gets called by ctrl-alt-del - ie the keyboard interrupt. | ||
463 | * As it's called within an interrupt, it may NOT sync: the only choice | ||
464 | * is whether to reboot at once, or just ignore the ctrl-alt-del. | ||
465 | */ | ||
466 | void ctrl_alt_del(void) | ||
467 | { | ||
468 | static DECLARE_WORK(cad_work, deferred_cad, NULL); | ||
469 | |||
470 | if (C_A_D) | ||
471 | schedule_work(&cad_work); | ||
472 | else | ||
473 | kill_proc(cad_pid, SIGINT, 1); | ||
474 | } | ||
475 | |||
476 | |||
477 | /* | ||
478 | * Unprivileged users may change the real gid to the effective gid | ||
479 | * or vice versa. (BSD-style) | ||
480 | * | ||
481 | * If you set the real gid at all, or set the effective gid to a value not | ||
482 | * equal to the real gid, then the saved gid is set to the new effective gid. | ||
483 | * | ||
484 | * This makes it possible for a setgid program to completely drop its | ||
485 | * privileges, which is often a useful assertion to make when you are doing | ||
486 | * a security audit over a program. | ||
487 | * | ||
488 | * The general idea is that a program which uses just setregid() will be | ||
489 | * 100% compatible with BSD. A program which uses just setgid() will be | ||
490 | * 100% compatible with POSIX with saved IDs. | ||
491 | * | ||
492 | * SMP: There are not races, the GIDs are checked only by filesystem | ||
493 | * operations (as far as semantic preservation is concerned). | ||
494 | */ | ||
495 | asmlinkage long sys_setregid(gid_t rgid, gid_t egid) | ||
496 | { | ||
497 | int old_rgid = current->gid; | ||
498 | int old_egid = current->egid; | ||
499 | int new_rgid = old_rgid; | ||
500 | int new_egid = old_egid; | ||
501 | int retval; | ||
502 | |||
503 | retval = security_task_setgid(rgid, egid, (gid_t)-1, LSM_SETID_RE); | ||
504 | if (retval) | ||
505 | return retval; | ||
506 | |||
507 | if (rgid != (gid_t) -1) { | ||
508 | if ((old_rgid == rgid) || | ||
509 | (current->egid==rgid) || | ||
510 | capable(CAP_SETGID)) | ||
511 | new_rgid = rgid; | ||
512 | else | ||
513 | return -EPERM; | ||
514 | } | ||
515 | if (egid != (gid_t) -1) { | ||
516 | if ((old_rgid == egid) || | ||
517 | (current->egid == egid) || | ||
518 | (current->sgid == egid) || | ||
519 | capable(CAP_SETGID)) | ||
520 | new_egid = egid; | ||
521 | else { | ||
522 | return -EPERM; | ||
523 | } | ||
524 | } | ||
525 | if (new_egid != old_egid) | ||
526 | { | ||
527 | current->mm->dumpable = 0; | ||
528 | wmb(); | ||
529 | } | ||
530 | if (rgid != (gid_t) -1 || | ||
531 | (egid != (gid_t) -1 && egid != old_rgid)) | ||
532 | current->sgid = new_egid; | ||
533 | current->fsgid = new_egid; | ||
534 | current->egid = new_egid; | ||
535 | current->gid = new_rgid; | ||
536 | key_fsgid_changed(current); | ||
537 | return 0; | ||
538 | } | ||
539 | |||
540 | /* | ||
541 | * setgid() is implemented like SysV w/ SAVED_IDS | ||
542 | * | ||
543 | * SMP: Same implicit races as above. | ||
544 | */ | ||
545 | asmlinkage long sys_setgid(gid_t gid) | ||
546 | { | ||
547 | int old_egid = current->egid; | ||
548 | int retval; | ||
549 | |||
550 | retval = security_task_setgid(gid, (gid_t)-1, (gid_t)-1, LSM_SETID_ID); | ||
551 | if (retval) | ||
552 | return retval; | ||
553 | |||
554 | if (capable(CAP_SETGID)) | ||
555 | { | ||
556 | if(old_egid != gid) | ||
557 | { | ||
558 | current->mm->dumpable=0; | ||
559 | wmb(); | ||
560 | } | ||
561 | current->gid = current->egid = current->sgid = current->fsgid = gid; | ||
562 | } | ||
563 | else if ((gid == current->gid) || (gid == current->sgid)) | ||
564 | { | ||
565 | if(old_egid != gid) | ||
566 | { | ||
567 | current->mm->dumpable=0; | ||
568 | wmb(); | ||
569 | } | ||
570 | current->egid = current->fsgid = gid; | ||
571 | } | ||
572 | else | ||
573 | return -EPERM; | ||
574 | |||
575 | key_fsgid_changed(current); | ||
576 | return 0; | ||
577 | } | ||
578 | |||
579 | static int set_user(uid_t new_ruid, int dumpclear) | ||
580 | { | ||
581 | struct user_struct *new_user; | ||
582 | |||
583 | new_user = alloc_uid(new_ruid); | ||
584 | if (!new_user) | ||
585 | return -EAGAIN; | ||
586 | |||
587 | if (atomic_read(&new_user->processes) >= | ||
588 | current->signal->rlim[RLIMIT_NPROC].rlim_cur && | ||
589 | new_user != &root_user) { | ||
590 | free_uid(new_user); | ||
591 | return -EAGAIN; | ||
592 | } | ||
593 | |||
594 | switch_uid(new_user); | ||
595 | |||
596 | if(dumpclear) | ||
597 | { | ||
598 | current->mm->dumpable = 0; | ||
599 | wmb(); | ||
600 | } | ||
601 | current->uid = new_ruid; | ||
602 | return 0; | ||
603 | } | ||
604 | |||
605 | /* | ||
606 | * Unprivileged users may change the real uid to the effective uid | ||
607 | * or vice versa. (BSD-style) | ||
608 | * | ||
609 | * If you set the real uid at all, or set the effective uid to a value not | ||
610 | * equal to the real uid, then the saved uid is set to the new effective uid. | ||
611 | * | ||
612 | * This makes it possible for a setuid program to completely drop its | ||
613 | * privileges, which is often a useful assertion to make when you are doing | ||
614 | * a security audit over a program. | ||
615 | * | ||
616 | * The general idea is that a program which uses just setreuid() will be | ||
617 | * 100% compatible with BSD. A program which uses just setuid() will be | ||
618 | * 100% compatible with POSIX with saved IDs. | ||
619 | */ | ||
620 | asmlinkage long sys_setreuid(uid_t ruid, uid_t euid) | ||
621 | { | ||
622 | int old_ruid, old_euid, old_suid, new_ruid, new_euid; | ||
623 | int retval; | ||
624 | |||
625 | retval = security_task_setuid(ruid, euid, (uid_t)-1, LSM_SETID_RE); | ||
626 | if (retval) | ||
627 | return retval; | ||
628 | |||
629 | new_ruid = old_ruid = current->uid; | ||
630 | new_euid = old_euid = current->euid; | ||
631 | old_suid = current->suid; | ||
632 | |||
633 | if (ruid != (uid_t) -1) { | ||
634 | new_ruid = ruid; | ||
635 | if ((old_ruid != ruid) && | ||
636 | (current->euid != ruid) && | ||
637 | !capable(CAP_SETUID)) | ||
638 | return -EPERM; | ||
639 | } | ||
640 | |||
641 | if (euid != (uid_t) -1) { | ||
642 | new_euid = euid; | ||
643 | if ((old_ruid != euid) && | ||
644 | (current->euid != euid) && | ||
645 | (current->suid != euid) && | ||
646 | !capable(CAP_SETUID)) | ||
647 | return -EPERM; | ||
648 | } | ||
649 | |||
650 | if (new_ruid != old_ruid && set_user(new_ruid, new_euid != old_euid) < 0) | ||
651 | return -EAGAIN; | ||
652 | |||
653 | if (new_euid != old_euid) | ||
654 | { | ||
655 | current->mm->dumpable=0; | ||
656 | wmb(); | ||
657 | } | ||
658 | current->fsuid = current->euid = new_euid; | ||
659 | if (ruid != (uid_t) -1 || | ||
660 | (euid != (uid_t) -1 && euid != old_ruid)) | ||
661 | current->suid = current->euid; | ||
662 | current->fsuid = current->euid; | ||
663 | |||
664 | key_fsuid_changed(current); | ||
665 | |||
666 | return security_task_post_setuid(old_ruid, old_euid, old_suid, LSM_SETID_RE); | ||
667 | } | ||
668 | |||
669 | |||
670 | |||
671 | /* | ||
672 | * setuid() is implemented like SysV with SAVED_IDS | ||
673 | * | ||
674 | * Note that SAVED_ID's is deficient in that a setuid root program | ||
675 | * like sendmail, for example, cannot set its uid to be a normal | ||
676 | * user and then switch back, because if you're root, setuid() sets | ||
677 | * the saved uid too. If you don't like this, blame the bright people | ||
678 | * in the POSIX committee and/or USG. Note that the BSD-style setreuid() | ||
679 | * will allow a root program to temporarily drop privileges and be able to | ||
680 | * regain them by swapping the real and effective uid. | ||
681 | */ | ||
682 | asmlinkage long sys_setuid(uid_t uid) | ||
683 | { | ||
684 | int old_euid = current->euid; | ||
685 | int old_ruid, old_suid, new_ruid, new_suid; | ||
686 | int retval; | ||
687 | |||
688 | retval = security_task_setuid(uid, (uid_t)-1, (uid_t)-1, LSM_SETID_ID); | ||
689 | if (retval) | ||
690 | return retval; | ||
691 | |||
692 | old_ruid = new_ruid = current->uid; | ||
693 | old_suid = current->suid; | ||
694 | new_suid = old_suid; | ||
695 | |||
696 | if (capable(CAP_SETUID)) { | ||
697 | if (uid != old_ruid && set_user(uid, old_euid != uid) < 0) | ||
698 | return -EAGAIN; | ||
699 | new_suid = uid; | ||
700 | } else if ((uid != current->uid) && (uid != new_suid)) | ||
701 | return -EPERM; | ||
702 | |||
703 | if (old_euid != uid) | ||
704 | { | ||
705 | current->mm->dumpable = 0; | ||
706 | wmb(); | ||
707 | } | ||
708 | current->fsuid = current->euid = uid; | ||
709 | current->suid = new_suid; | ||
710 | |||
711 | key_fsuid_changed(current); | ||
712 | |||
713 | return security_task_post_setuid(old_ruid, old_euid, old_suid, LSM_SETID_ID); | ||
714 | } | ||
715 | |||
716 | |||
717 | /* | ||
718 | * This function implements a generic ability to update ruid, euid, | ||
719 | * and suid. This allows you to implement the 4.4 compatible seteuid(). | ||
720 | */ | ||
721 | asmlinkage long sys_setresuid(uid_t ruid, uid_t euid, uid_t suid) | ||
722 | { | ||
723 | int old_ruid = current->uid; | ||
724 | int old_euid = current->euid; | ||
725 | int old_suid = current->suid; | ||
726 | int retval; | ||
727 | |||
728 | retval = security_task_setuid(ruid, euid, suid, LSM_SETID_RES); | ||
729 | if (retval) | ||
730 | return retval; | ||
731 | |||
732 | if (!capable(CAP_SETUID)) { | ||
733 | if ((ruid != (uid_t) -1) && (ruid != current->uid) && | ||
734 | (ruid != current->euid) && (ruid != current->suid)) | ||
735 | return -EPERM; | ||
736 | if ((euid != (uid_t) -1) && (euid != current->uid) && | ||
737 | (euid != current->euid) && (euid != current->suid)) | ||
738 | return -EPERM; | ||
739 | if ((suid != (uid_t) -1) && (suid != current->uid) && | ||
740 | (suid != current->euid) && (suid != current->suid)) | ||
741 | return -EPERM; | ||
742 | } | ||
743 | if (ruid != (uid_t) -1) { | ||
744 | if (ruid != current->uid && set_user(ruid, euid != current->euid) < 0) | ||
745 | return -EAGAIN; | ||
746 | } | ||
747 | if (euid != (uid_t) -1) { | ||
748 | if (euid != current->euid) | ||
749 | { | ||
750 | current->mm->dumpable = 0; | ||
751 | wmb(); | ||
752 | } | ||
753 | current->euid = euid; | ||
754 | } | ||
755 | current->fsuid = current->euid; | ||
756 | if (suid != (uid_t) -1) | ||
757 | current->suid = suid; | ||
758 | |||
759 | key_fsuid_changed(current); | ||
760 | |||
761 | return security_task_post_setuid(old_ruid, old_euid, old_suid, LSM_SETID_RES); | ||
762 | } | ||
763 | |||
764 | asmlinkage long sys_getresuid(uid_t __user *ruid, uid_t __user *euid, uid_t __user *suid) | ||
765 | { | ||
766 | int retval; | ||
767 | |||
768 | if (!(retval = put_user(current->uid, ruid)) && | ||
769 | !(retval = put_user(current->euid, euid))) | ||
770 | retval = put_user(current->suid, suid); | ||
771 | |||
772 | return retval; | ||
773 | } | ||
774 | |||
775 | /* | ||
776 | * Same as above, but for rgid, egid, sgid. | ||
777 | */ | ||
778 | asmlinkage long sys_setresgid(gid_t rgid, gid_t egid, gid_t sgid) | ||
779 | { | ||
780 | int retval; | ||
781 | |||
782 | retval = security_task_setgid(rgid, egid, sgid, LSM_SETID_RES); | ||
783 | if (retval) | ||
784 | return retval; | ||
785 | |||
786 | if (!capable(CAP_SETGID)) { | ||
787 | if ((rgid != (gid_t) -1) && (rgid != current->gid) && | ||
788 | (rgid != current->egid) && (rgid != current->sgid)) | ||
789 | return -EPERM; | ||
790 | if ((egid != (gid_t) -1) && (egid != current->gid) && | ||
791 | (egid != current->egid) && (egid != current->sgid)) | ||
792 | return -EPERM; | ||
793 | if ((sgid != (gid_t) -1) && (sgid != current->gid) && | ||
794 | (sgid != current->egid) && (sgid != current->sgid)) | ||
795 | return -EPERM; | ||
796 | } | ||
797 | if (egid != (gid_t) -1) { | ||
798 | if (egid != current->egid) | ||
799 | { | ||
800 | current->mm->dumpable = 0; | ||
801 | wmb(); | ||
802 | } | ||
803 | current->egid = egid; | ||
804 | } | ||
805 | current->fsgid = current->egid; | ||
806 | if (rgid != (gid_t) -1) | ||
807 | current->gid = rgid; | ||
808 | if (sgid != (gid_t) -1) | ||
809 | current->sgid = sgid; | ||
810 | |||
811 | key_fsgid_changed(current); | ||
812 | return 0; | ||
813 | } | ||
814 | |||
815 | asmlinkage long sys_getresgid(gid_t __user *rgid, gid_t __user *egid, gid_t __user *sgid) | ||
816 | { | ||
817 | int retval; | ||
818 | |||
819 | if (!(retval = put_user(current->gid, rgid)) && | ||
820 | !(retval = put_user(current->egid, egid))) | ||
821 | retval = put_user(current->sgid, sgid); | ||
822 | |||
823 | return retval; | ||
824 | } | ||
825 | |||
826 | |||
827 | /* | ||
828 | * "setfsuid()" sets the fsuid - the uid used for filesystem checks. This | ||
829 | * is used for "access()" and for the NFS daemon (letting nfsd stay at | ||
830 | * whatever uid it wants to). It normally shadows "euid", except when | ||
831 | * explicitly set by setfsuid() or for access.. | ||
832 | */ | ||
833 | asmlinkage long sys_setfsuid(uid_t uid) | ||
834 | { | ||
835 | int old_fsuid; | ||
836 | |||
837 | old_fsuid = current->fsuid; | ||
838 | if (security_task_setuid(uid, (uid_t)-1, (uid_t)-1, LSM_SETID_FS)) | ||
839 | return old_fsuid; | ||
840 | |||
841 | if (uid == current->uid || uid == current->euid || | ||
842 | uid == current->suid || uid == current->fsuid || | ||
843 | capable(CAP_SETUID)) | ||
844 | { | ||
845 | if (uid != old_fsuid) | ||
846 | { | ||
847 | current->mm->dumpable = 0; | ||
848 | wmb(); | ||
849 | } | ||
850 | current->fsuid = uid; | ||
851 | } | ||
852 | |||
853 | key_fsuid_changed(current); | ||
854 | |||
855 | security_task_post_setuid(old_fsuid, (uid_t)-1, (uid_t)-1, LSM_SETID_FS); | ||
856 | |||
857 | return old_fsuid; | ||
858 | } | ||
859 | |||
860 | /* | ||
861 | * Samma på svenska.. | ||
862 | */ | ||
863 | asmlinkage long sys_setfsgid(gid_t gid) | ||
864 | { | ||
865 | int old_fsgid; | ||
866 | |||
867 | old_fsgid = current->fsgid; | ||
868 | if (security_task_setgid(gid, (gid_t)-1, (gid_t)-1, LSM_SETID_FS)) | ||
869 | return old_fsgid; | ||
870 | |||
871 | if (gid == current->gid || gid == current->egid || | ||
872 | gid == current->sgid || gid == current->fsgid || | ||
873 | capable(CAP_SETGID)) | ||
874 | { | ||
875 | if (gid != old_fsgid) | ||
876 | { | ||
877 | current->mm->dumpable = 0; | ||
878 | wmb(); | ||
879 | } | ||
880 | current->fsgid = gid; | ||
881 | key_fsgid_changed(current); | ||
882 | } | ||
883 | return old_fsgid; | ||
884 | } | ||
885 | |||
886 | asmlinkage long sys_times(struct tms __user * tbuf) | ||
887 | { | ||
888 | /* | ||
889 | * In the SMP world we might just be unlucky and have one of | ||
890 | * the times increment as we use it. Since the value is an | ||
891 | * atomically safe type this is just fine. Conceptually its | ||
892 | * as if the syscall took an instant longer to occur. | ||
893 | */ | ||
894 | if (tbuf) { | ||
895 | struct tms tmp; | ||
896 | struct task_struct *tsk = current; | ||
897 | struct task_struct *t; | ||
898 | cputime_t utime, stime, cutime, cstime; | ||
899 | |||
900 | read_lock(&tasklist_lock); | ||
901 | utime = tsk->signal->utime; | ||
902 | stime = tsk->signal->stime; | ||
903 | t = tsk; | ||
904 | do { | ||
905 | utime = cputime_add(utime, t->utime); | ||
906 | stime = cputime_add(stime, t->stime); | ||
907 | t = next_thread(t); | ||
908 | } while (t != tsk); | ||
909 | |||
910 | /* | ||
911 | * While we have tasklist_lock read-locked, no dying thread | ||
912 | * can be updating current->signal->[us]time. Instead, | ||
913 | * we got their counts included in the live thread loop. | ||
914 | * However, another thread can come in right now and | ||
915 | * do a wait call that updates current->signal->c[us]time. | ||
916 | * To make sure we always see that pair updated atomically, | ||
917 | * we take the siglock around fetching them. | ||
918 | */ | ||
919 | spin_lock_irq(&tsk->sighand->siglock); | ||
920 | cutime = tsk->signal->cutime; | ||
921 | cstime = tsk->signal->cstime; | ||
922 | spin_unlock_irq(&tsk->sighand->siglock); | ||
923 | read_unlock(&tasklist_lock); | ||
924 | |||
925 | tmp.tms_utime = cputime_to_clock_t(utime); | ||
926 | tmp.tms_stime = cputime_to_clock_t(stime); | ||
927 | tmp.tms_cutime = cputime_to_clock_t(cutime); | ||
928 | tmp.tms_cstime = cputime_to_clock_t(cstime); | ||
929 | if (copy_to_user(tbuf, &tmp, sizeof(struct tms))) | ||
930 | return -EFAULT; | ||
931 | } | ||
932 | return (long) jiffies_64_to_clock_t(get_jiffies_64()); | ||
933 | } | ||
934 | |||
935 | /* | ||
936 | * This needs some heavy checking ... | ||
937 | * I just haven't the stomach for it. I also don't fully | ||
938 | * understand sessions/pgrp etc. Let somebody who does explain it. | ||
939 | * | ||
940 | * OK, I think I have the protection semantics right.... this is really | ||
941 | * only important on a multi-user system anyway, to make sure one user | ||
942 | * can't send a signal to a process owned by another. -TYT, 12/12/91 | ||
943 | * | ||
944 | * Auch. Had to add the 'did_exec' flag to conform completely to POSIX. | ||
945 | * LBT 04.03.94 | ||
946 | */ | ||
947 | |||
948 | asmlinkage long sys_setpgid(pid_t pid, pid_t pgid) | ||
949 | { | ||
950 | struct task_struct *p; | ||
951 | int err = -EINVAL; | ||
952 | |||
953 | if (!pid) | ||
954 | pid = current->pid; | ||
955 | if (!pgid) | ||
956 | pgid = pid; | ||
957 | if (pgid < 0) | ||
958 | return -EINVAL; | ||
959 | |||
960 | /* From this point forward we keep holding onto the tasklist lock | ||
961 | * so that our parent does not change from under us. -DaveM | ||
962 | */ | ||
963 | write_lock_irq(&tasklist_lock); | ||
964 | |||
965 | err = -ESRCH; | ||
966 | p = find_task_by_pid(pid); | ||
967 | if (!p) | ||
968 | goto out; | ||
969 | |||
970 | err = -EINVAL; | ||
971 | if (!thread_group_leader(p)) | ||
972 | goto out; | ||
973 | |||
974 | if (p->parent == current || p->real_parent == current) { | ||
975 | err = -EPERM; | ||
976 | if (p->signal->session != current->signal->session) | ||
977 | goto out; | ||
978 | err = -EACCES; | ||
979 | if (p->did_exec) | ||
980 | goto out; | ||
981 | } else { | ||
982 | err = -ESRCH; | ||
983 | if (p != current) | ||
984 | goto out; | ||
985 | } | ||
986 | |||
987 | err = -EPERM; | ||
988 | if (p->signal->leader) | ||
989 | goto out; | ||
990 | |||
991 | if (pgid != pid) { | ||
992 | struct task_struct *p; | ||
993 | |||
994 | do_each_task_pid(pgid, PIDTYPE_PGID, p) { | ||
995 | if (p->signal->session == current->signal->session) | ||
996 | goto ok_pgid; | ||
997 | } while_each_task_pid(pgid, PIDTYPE_PGID, p); | ||
998 | goto out; | ||
999 | } | ||
1000 | |||
1001 | ok_pgid: | ||
1002 | err = security_task_setpgid(p, pgid); | ||
1003 | if (err) | ||
1004 | goto out; | ||
1005 | |||
1006 | if (process_group(p) != pgid) { | ||
1007 | detach_pid(p, PIDTYPE_PGID); | ||
1008 | p->signal->pgrp = pgid; | ||
1009 | attach_pid(p, PIDTYPE_PGID, pgid); | ||
1010 | } | ||
1011 | |||
1012 | err = 0; | ||
1013 | out: | ||
1014 | /* All paths lead to here, thus we are safe. -DaveM */ | ||
1015 | write_unlock_irq(&tasklist_lock); | ||
1016 | return err; | ||
1017 | } | ||
1018 | |||
1019 | asmlinkage long sys_getpgid(pid_t pid) | ||
1020 | { | ||
1021 | if (!pid) { | ||
1022 | return process_group(current); | ||
1023 | } else { | ||
1024 | int retval; | ||
1025 | struct task_struct *p; | ||
1026 | |||
1027 | read_lock(&tasklist_lock); | ||
1028 | p = find_task_by_pid(pid); | ||
1029 | |||
1030 | retval = -ESRCH; | ||
1031 | if (p) { | ||
1032 | retval = security_task_getpgid(p); | ||
1033 | if (!retval) | ||
1034 | retval = process_group(p); | ||
1035 | } | ||
1036 | read_unlock(&tasklist_lock); | ||
1037 | return retval; | ||
1038 | } | ||
1039 | } | ||
1040 | |||
1041 | #ifdef __ARCH_WANT_SYS_GETPGRP | ||
1042 | |||
1043 | asmlinkage long sys_getpgrp(void) | ||
1044 | { | ||
1045 | /* SMP - assuming writes are word atomic this is fine */ | ||
1046 | return process_group(current); | ||
1047 | } | ||
1048 | |||
1049 | #endif | ||
1050 | |||
1051 | asmlinkage long sys_getsid(pid_t pid) | ||
1052 | { | ||
1053 | if (!pid) { | ||
1054 | return current->signal->session; | ||
1055 | } else { | ||
1056 | int retval; | ||
1057 | struct task_struct *p; | ||
1058 | |||
1059 | read_lock(&tasklist_lock); | ||
1060 | p = find_task_by_pid(pid); | ||
1061 | |||
1062 | retval = -ESRCH; | ||
1063 | if(p) { | ||
1064 | retval = security_task_getsid(p); | ||
1065 | if (!retval) | ||
1066 | retval = p->signal->session; | ||
1067 | } | ||
1068 | read_unlock(&tasklist_lock); | ||
1069 | return retval; | ||
1070 | } | ||
1071 | } | ||
1072 | |||
1073 | asmlinkage long sys_setsid(void) | ||
1074 | { | ||
1075 | struct pid *pid; | ||
1076 | int err = -EPERM; | ||
1077 | |||
1078 | if (!thread_group_leader(current)) | ||
1079 | return -EINVAL; | ||
1080 | |||
1081 | down(&tty_sem); | ||
1082 | write_lock_irq(&tasklist_lock); | ||
1083 | |||
1084 | pid = find_pid(PIDTYPE_PGID, current->pid); | ||
1085 | if (pid) | ||
1086 | goto out; | ||
1087 | |||
1088 | current->signal->leader = 1; | ||
1089 | __set_special_pids(current->pid, current->pid); | ||
1090 | current->signal->tty = NULL; | ||
1091 | current->signal->tty_old_pgrp = 0; | ||
1092 | err = process_group(current); | ||
1093 | out: | ||
1094 | write_unlock_irq(&tasklist_lock); | ||
1095 | up(&tty_sem); | ||
1096 | return err; | ||
1097 | } | ||
1098 | |||
1099 | /* | ||
1100 | * Supplementary group IDs | ||
1101 | */ | ||
1102 | |||
1103 | /* init to 2 - one for init_task, one to ensure it is never freed */ | ||
1104 | struct group_info init_groups = { .usage = ATOMIC_INIT(2) }; | ||
1105 | |||
1106 | struct group_info *groups_alloc(int gidsetsize) | ||
1107 | { | ||
1108 | struct group_info *group_info; | ||
1109 | int nblocks; | ||
1110 | int i; | ||
1111 | |||
1112 | nblocks = (gidsetsize + NGROUPS_PER_BLOCK - 1) / NGROUPS_PER_BLOCK; | ||
1113 | /* Make sure we always allocate at least one indirect block pointer */ | ||
1114 | nblocks = nblocks ? : 1; | ||
1115 | group_info = kmalloc(sizeof(*group_info) + nblocks*sizeof(gid_t *), GFP_USER); | ||
1116 | if (!group_info) | ||
1117 | return NULL; | ||
1118 | group_info->ngroups = gidsetsize; | ||
1119 | group_info->nblocks = nblocks; | ||
1120 | atomic_set(&group_info->usage, 1); | ||
1121 | |||
1122 | if (gidsetsize <= NGROUPS_SMALL) { | ||
1123 | group_info->blocks[0] = group_info->small_block; | ||
1124 | } else { | ||
1125 | for (i = 0; i < nblocks; i++) { | ||
1126 | gid_t *b; | ||
1127 | b = (void *)__get_free_page(GFP_USER); | ||
1128 | if (!b) | ||
1129 | goto out_undo_partial_alloc; | ||
1130 | group_info->blocks[i] = b; | ||
1131 | } | ||
1132 | } | ||
1133 | return group_info; | ||
1134 | |||
1135 | out_undo_partial_alloc: | ||
1136 | while (--i >= 0) { | ||
1137 | free_page((unsigned long)group_info->blocks[i]); | ||
1138 | } | ||
1139 | kfree(group_info); | ||
1140 | return NULL; | ||
1141 | } | ||
1142 | |||
1143 | EXPORT_SYMBOL(groups_alloc); | ||
1144 | |||
1145 | void groups_free(struct group_info *group_info) | ||
1146 | { | ||
1147 | if (group_info->blocks[0] != group_info->small_block) { | ||
1148 | int i; | ||
1149 | for (i = 0; i < group_info->nblocks; i++) | ||
1150 | free_page((unsigned long)group_info->blocks[i]); | ||
1151 | } | ||
1152 | kfree(group_info); | ||
1153 | } | ||
1154 | |||
1155 | EXPORT_SYMBOL(groups_free); | ||
1156 | |||
1157 | /* export the group_info to a user-space array */ | ||
1158 | static int groups_to_user(gid_t __user *grouplist, | ||
1159 | struct group_info *group_info) | ||
1160 | { | ||
1161 | int i; | ||
1162 | int count = group_info->ngroups; | ||
1163 | |||
1164 | for (i = 0; i < group_info->nblocks; i++) { | ||
1165 | int cp_count = min(NGROUPS_PER_BLOCK, count); | ||
1166 | int off = i * NGROUPS_PER_BLOCK; | ||
1167 | int len = cp_count * sizeof(*grouplist); | ||
1168 | |||
1169 | if (copy_to_user(grouplist+off, group_info->blocks[i], len)) | ||
1170 | return -EFAULT; | ||
1171 | |||
1172 | count -= cp_count; | ||
1173 | } | ||
1174 | return 0; | ||
1175 | } | ||
1176 | |||
1177 | /* fill a group_info from a user-space array - it must be allocated already */ | ||
1178 | static int groups_from_user(struct group_info *group_info, | ||
1179 | gid_t __user *grouplist) | ||
1180 | { | ||
1181 | int i; | ||
1182 | int count = group_info->ngroups; | ||
1183 | |||
1184 | for (i = 0; i < group_info->nblocks; i++) { | ||
1185 | int cp_count = min(NGROUPS_PER_BLOCK, count); | ||
1186 | int off = i * NGROUPS_PER_BLOCK; | ||
1187 | int len = cp_count * sizeof(*grouplist); | ||
1188 | |||
1189 | if (copy_from_user(group_info->blocks[i], grouplist+off, len)) | ||
1190 | return -EFAULT; | ||
1191 | |||
1192 | count -= cp_count; | ||
1193 | } | ||
1194 | return 0; | ||
1195 | } | ||
1196 | |||
1197 | /* a simple shell-metzner sort */ | ||
1198 | static void groups_sort(struct group_info *group_info) | ||
1199 | { | ||
1200 | int base, max, stride; | ||
1201 | int gidsetsize = group_info->ngroups; | ||
1202 | |||
1203 | for (stride = 1; stride < gidsetsize; stride = 3 * stride + 1) | ||
1204 | ; /* nothing */ | ||
1205 | stride /= 3; | ||
1206 | |||
1207 | while (stride) { | ||
1208 | max = gidsetsize - stride; | ||
1209 | for (base = 0; base < max; base++) { | ||
1210 | int left = base; | ||
1211 | int right = left + stride; | ||
1212 | gid_t tmp = GROUP_AT(group_info, right); | ||
1213 | |||
1214 | while (left >= 0 && GROUP_AT(group_info, left) > tmp) { | ||
1215 | GROUP_AT(group_info, right) = | ||
1216 | GROUP_AT(group_info, left); | ||
1217 | right = left; | ||
1218 | left -= stride; | ||
1219 | } | ||
1220 | GROUP_AT(group_info, right) = tmp; | ||
1221 | } | ||
1222 | stride /= 3; | ||
1223 | } | ||
1224 | } | ||
1225 | |||
1226 | /* a simple bsearch */ | ||
1227 | static int groups_search(struct group_info *group_info, gid_t grp) | ||
1228 | { | ||
1229 | int left, right; | ||
1230 | |||
1231 | if (!group_info) | ||
1232 | return 0; | ||
1233 | |||
1234 | left = 0; | ||
1235 | right = group_info->ngroups; | ||
1236 | while (left < right) { | ||
1237 | int mid = (left+right)/2; | ||
1238 | int cmp = grp - GROUP_AT(group_info, mid); | ||
1239 | if (cmp > 0) | ||
1240 | left = mid + 1; | ||
1241 | else if (cmp < 0) | ||
1242 | right = mid; | ||
1243 | else | ||
1244 | return 1; | ||
1245 | } | ||
1246 | return 0; | ||
1247 | } | ||
1248 | |||
1249 | /* validate and set current->group_info */ | ||
1250 | int set_current_groups(struct group_info *group_info) | ||
1251 | { | ||
1252 | int retval; | ||
1253 | struct group_info *old_info; | ||
1254 | |||
1255 | retval = security_task_setgroups(group_info); | ||
1256 | if (retval) | ||
1257 | return retval; | ||
1258 | |||
1259 | groups_sort(group_info); | ||
1260 | get_group_info(group_info); | ||
1261 | |||
1262 | task_lock(current); | ||
1263 | old_info = current->group_info; | ||
1264 | current->group_info = group_info; | ||
1265 | task_unlock(current); | ||
1266 | |||
1267 | put_group_info(old_info); | ||
1268 | |||
1269 | return 0; | ||
1270 | } | ||
1271 | |||
1272 | EXPORT_SYMBOL(set_current_groups); | ||
1273 | |||
1274 | asmlinkage long sys_getgroups(int gidsetsize, gid_t __user *grouplist) | ||
1275 | { | ||
1276 | int i = 0; | ||
1277 | |||
1278 | /* | ||
1279 | * SMP: Nobody else can change our grouplist. Thus we are | ||
1280 | * safe. | ||
1281 | */ | ||
1282 | |||
1283 | if (gidsetsize < 0) | ||
1284 | return -EINVAL; | ||
1285 | |||
1286 | /* no need to grab task_lock here; it cannot change */ | ||
1287 | get_group_info(current->group_info); | ||
1288 | i = current->group_info->ngroups; | ||
1289 | if (gidsetsize) { | ||
1290 | if (i > gidsetsize) { | ||
1291 | i = -EINVAL; | ||
1292 | goto out; | ||
1293 | } | ||
1294 | if (groups_to_user(grouplist, current->group_info)) { | ||
1295 | i = -EFAULT; | ||
1296 | goto out; | ||
1297 | } | ||
1298 | } | ||
1299 | out: | ||
1300 | put_group_info(current->group_info); | ||
1301 | return i; | ||
1302 | } | ||
1303 | |||
1304 | /* | ||
1305 | * SMP: Our groups are copy-on-write. We can set them safely | ||
1306 | * without another task interfering. | ||
1307 | */ | ||
1308 | |||
1309 | asmlinkage long sys_setgroups(int gidsetsize, gid_t __user *grouplist) | ||
1310 | { | ||
1311 | struct group_info *group_info; | ||
1312 | int retval; | ||
1313 | |||
1314 | if (!capable(CAP_SETGID)) | ||
1315 | return -EPERM; | ||
1316 | if ((unsigned)gidsetsize > NGROUPS_MAX) | ||
1317 | return -EINVAL; | ||
1318 | |||
1319 | group_info = groups_alloc(gidsetsize); | ||
1320 | if (!group_info) | ||
1321 | return -ENOMEM; | ||
1322 | retval = groups_from_user(group_info, grouplist); | ||
1323 | if (retval) { | ||
1324 | put_group_info(group_info); | ||
1325 | return retval; | ||
1326 | } | ||
1327 | |||
1328 | retval = set_current_groups(group_info); | ||
1329 | put_group_info(group_info); | ||
1330 | |||
1331 | return retval; | ||
1332 | } | ||
1333 | |||
1334 | /* | ||
1335 | * Check whether we're fsgid/egid or in the supplemental group.. | ||
1336 | */ | ||
1337 | int in_group_p(gid_t grp) | ||
1338 | { | ||
1339 | int retval = 1; | ||
1340 | if (grp != current->fsgid) { | ||
1341 | get_group_info(current->group_info); | ||
1342 | retval = groups_search(current->group_info, grp); | ||
1343 | put_group_info(current->group_info); | ||
1344 | } | ||
1345 | return retval; | ||
1346 | } | ||
1347 | |||
1348 | EXPORT_SYMBOL(in_group_p); | ||
1349 | |||
1350 | int in_egroup_p(gid_t grp) | ||
1351 | { | ||
1352 | int retval = 1; | ||
1353 | if (grp != current->egid) { | ||
1354 | get_group_info(current->group_info); | ||
1355 | retval = groups_search(current->group_info, grp); | ||
1356 | put_group_info(current->group_info); | ||
1357 | } | ||
1358 | return retval; | ||
1359 | } | ||
1360 | |||
1361 | EXPORT_SYMBOL(in_egroup_p); | ||
1362 | |||
1363 | DECLARE_RWSEM(uts_sem); | ||
1364 | |||
1365 | EXPORT_SYMBOL(uts_sem); | ||
1366 | |||
1367 | asmlinkage long sys_newuname(struct new_utsname __user * name) | ||
1368 | { | ||
1369 | int errno = 0; | ||
1370 | |||
1371 | down_read(&uts_sem); | ||
1372 | if (copy_to_user(name,&system_utsname,sizeof *name)) | ||
1373 | errno = -EFAULT; | ||
1374 | up_read(&uts_sem); | ||
1375 | return errno; | ||
1376 | } | ||
1377 | |||
1378 | asmlinkage long sys_sethostname(char __user *name, int len) | ||
1379 | { | ||
1380 | int errno; | ||
1381 | char tmp[__NEW_UTS_LEN]; | ||
1382 | |||
1383 | if (!capable(CAP_SYS_ADMIN)) | ||
1384 | return -EPERM; | ||
1385 | if (len < 0 || len > __NEW_UTS_LEN) | ||
1386 | return -EINVAL; | ||
1387 | down_write(&uts_sem); | ||
1388 | errno = -EFAULT; | ||
1389 | if (!copy_from_user(tmp, name, len)) { | ||
1390 | memcpy(system_utsname.nodename, tmp, len); | ||
1391 | system_utsname.nodename[len] = 0; | ||
1392 | errno = 0; | ||
1393 | } | ||
1394 | up_write(&uts_sem); | ||
1395 | return errno; | ||
1396 | } | ||
1397 | |||
1398 | #ifdef __ARCH_WANT_SYS_GETHOSTNAME | ||
1399 | |||
1400 | asmlinkage long sys_gethostname(char __user *name, int len) | ||
1401 | { | ||
1402 | int i, errno; | ||
1403 | |||
1404 | if (len < 0) | ||
1405 | return -EINVAL; | ||
1406 | down_read(&uts_sem); | ||
1407 | i = 1 + strlen(system_utsname.nodename); | ||
1408 | if (i > len) | ||
1409 | i = len; | ||
1410 | errno = 0; | ||
1411 | if (copy_to_user(name, system_utsname.nodename, i)) | ||
1412 | errno = -EFAULT; | ||
1413 | up_read(&uts_sem); | ||
1414 | return errno; | ||
1415 | } | ||
1416 | |||
1417 | #endif | ||
1418 | |||
1419 | /* | ||
1420 | * Only setdomainname; getdomainname can be implemented by calling | ||
1421 | * uname() | ||
1422 | */ | ||
1423 | asmlinkage long sys_setdomainname(char __user *name, int len) | ||
1424 | { | ||
1425 | int errno; | ||
1426 | char tmp[__NEW_UTS_LEN]; | ||
1427 | |||
1428 | if (!capable(CAP_SYS_ADMIN)) | ||
1429 | return -EPERM; | ||
1430 | if (len < 0 || len > __NEW_UTS_LEN) | ||
1431 | return -EINVAL; | ||
1432 | |||
1433 | down_write(&uts_sem); | ||
1434 | errno = -EFAULT; | ||
1435 | if (!copy_from_user(tmp, name, len)) { | ||
1436 | memcpy(system_utsname.domainname, tmp, len); | ||
1437 | system_utsname.domainname[len] = 0; | ||
1438 | errno = 0; | ||
1439 | } | ||
1440 | up_write(&uts_sem); | ||
1441 | return errno; | ||
1442 | } | ||
1443 | |||
1444 | asmlinkage long sys_getrlimit(unsigned int resource, struct rlimit __user *rlim) | ||
1445 | { | ||
1446 | if (resource >= RLIM_NLIMITS) | ||
1447 | return -EINVAL; | ||
1448 | else { | ||
1449 | struct rlimit value; | ||
1450 | task_lock(current->group_leader); | ||
1451 | value = current->signal->rlim[resource]; | ||
1452 | task_unlock(current->group_leader); | ||
1453 | return copy_to_user(rlim, &value, sizeof(*rlim)) ? -EFAULT : 0; | ||
1454 | } | ||
1455 | } | ||
1456 | |||
1457 | #ifdef __ARCH_WANT_SYS_OLD_GETRLIMIT | ||
1458 | |||
1459 | /* | ||
1460 | * Back compatibility for getrlimit. Needed for some apps. | ||
1461 | */ | ||
1462 | |||
1463 | asmlinkage long sys_old_getrlimit(unsigned int resource, struct rlimit __user *rlim) | ||
1464 | { | ||
1465 | struct rlimit x; | ||
1466 | if (resource >= RLIM_NLIMITS) | ||
1467 | return -EINVAL; | ||
1468 | |||
1469 | task_lock(current->group_leader); | ||
1470 | x = current->signal->rlim[resource]; | ||
1471 | task_unlock(current->group_leader); | ||
1472 | if(x.rlim_cur > 0x7FFFFFFF) | ||
1473 | x.rlim_cur = 0x7FFFFFFF; | ||
1474 | if(x.rlim_max > 0x7FFFFFFF) | ||
1475 | x.rlim_max = 0x7FFFFFFF; | ||
1476 | return copy_to_user(rlim, &x, sizeof(x))?-EFAULT:0; | ||
1477 | } | ||
1478 | |||
1479 | #endif | ||
1480 | |||
1481 | asmlinkage long sys_setrlimit(unsigned int resource, struct rlimit __user *rlim) | ||
1482 | { | ||
1483 | struct rlimit new_rlim, *old_rlim; | ||
1484 | int retval; | ||
1485 | |||
1486 | if (resource >= RLIM_NLIMITS) | ||
1487 | return -EINVAL; | ||
1488 | if(copy_from_user(&new_rlim, rlim, sizeof(*rlim))) | ||
1489 | return -EFAULT; | ||
1490 | if (new_rlim.rlim_cur > new_rlim.rlim_max) | ||
1491 | return -EINVAL; | ||
1492 | old_rlim = current->signal->rlim + resource; | ||
1493 | if ((new_rlim.rlim_max > old_rlim->rlim_max) && | ||
1494 | !capable(CAP_SYS_RESOURCE)) | ||
1495 | return -EPERM; | ||
1496 | if (resource == RLIMIT_NOFILE && new_rlim.rlim_max > NR_OPEN) | ||
1497 | return -EPERM; | ||
1498 | |||
1499 | retval = security_task_setrlimit(resource, &new_rlim); | ||
1500 | if (retval) | ||
1501 | return retval; | ||
1502 | |||
1503 | task_lock(current->group_leader); | ||
1504 | *old_rlim = new_rlim; | ||
1505 | task_unlock(current->group_leader); | ||
1506 | |||
1507 | if (resource == RLIMIT_CPU && new_rlim.rlim_cur != RLIM_INFINITY && | ||
1508 | (cputime_eq(current->signal->it_prof_expires, cputime_zero) || | ||
1509 | new_rlim.rlim_cur <= cputime_to_secs( | ||
1510 | current->signal->it_prof_expires))) { | ||
1511 | cputime_t cputime = secs_to_cputime(new_rlim.rlim_cur); | ||
1512 | read_lock(&tasklist_lock); | ||
1513 | spin_lock_irq(¤t->sighand->siglock); | ||
1514 | set_process_cpu_timer(current, CPUCLOCK_PROF, | ||
1515 | &cputime, NULL); | ||
1516 | spin_unlock_irq(¤t->sighand->siglock); | ||
1517 | read_unlock(&tasklist_lock); | ||
1518 | } | ||
1519 | |||
1520 | return 0; | ||
1521 | } | ||
1522 | |||
1523 | /* | ||
1524 | * It would make sense to put struct rusage in the task_struct, | ||
1525 | * except that would make the task_struct be *really big*. After | ||
1526 | * task_struct gets moved into malloc'ed memory, it would | ||
1527 | * make sense to do this. It will make moving the rest of the information | ||
1528 | * a lot simpler! (Which we're not doing right now because we're not | ||
1529 | * measuring them yet). | ||
1530 | * | ||
1531 | * This expects to be called with tasklist_lock read-locked or better, | ||
1532 | * and the siglock not locked. It may momentarily take the siglock. | ||
1533 | * | ||
1534 | * When sampling multiple threads for RUSAGE_SELF, under SMP we might have | ||
1535 | * races with threads incrementing their own counters. But since word | ||
1536 | * reads are atomic, we either get new values or old values and we don't | ||
1537 | * care which for the sums. We always take the siglock to protect reading | ||
1538 | * the c* fields from p->signal from races with exit.c updating those | ||
1539 | * fields when reaping, so a sample either gets all the additions of a | ||
1540 | * given child after it's reaped, or none so this sample is before reaping. | ||
1541 | */ | ||
1542 | |||
1543 | static void k_getrusage(struct task_struct *p, int who, struct rusage *r) | ||
1544 | { | ||
1545 | struct task_struct *t; | ||
1546 | unsigned long flags; | ||
1547 | cputime_t utime, stime; | ||
1548 | |||
1549 | memset((char *) r, 0, sizeof *r); | ||
1550 | |||
1551 | if (unlikely(!p->signal)) | ||
1552 | return; | ||
1553 | |||
1554 | switch (who) { | ||
1555 | case RUSAGE_CHILDREN: | ||
1556 | spin_lock_irqsave(&p->sighand->siglock, flags); | ||
1557 | utime = p->signal->cutime; | ||
1558 | stime = p->signal->cstime; | ||
1559 | r->ru_nvcsw = p->signal->cnvcsw; | ||
1560 | r->ru_nivcsw = p->signal->cnivcsw; | ||
1561 | r->ru_minflt = p->signal->cmin_flt; | ||
1562 | r->ru_majflt = p->signal->cmaj_flt; | ||
1563 | spin_unlock_irqrestore(&p->sighand->siglock, flags); | ||
1564 | cputime_to_timeval(utime, &r->ru_utime); | ||
1565 | cputime_to_timeval(stime, &r->ru_stime); | ||
1566 | break; | ||
1567 | case RUSAGE_SELF: | ||
1568 | spin_lock_irqsave(&p->sighand->siglock, flags); | ||
1569 | utime = stime = cputime_zero; | ||
1570 | goto sum_group; | ||
1571 | case RUSAGE_BOTH: | ||
1572 | spin_lock_irqsave(&p->sighand->siglock, flags); | ||
1573 | utime = p->signal->cutime; | ||
1574 | stime = p->signal->cstime; | ||
1575 | r->ru_nvcsw = p->signal->cnvcsw; | ||
1576 | r->ru_nivcsw = p->signal->cnivcsw; | ||
1577 | r->ru_minflt = p->signal->cmin_flt; | ||
1578 | r->ru_majflt = p->signal->cmaj_flt; | ||
1579 | sum_group: | ||
1580 | utime = cputime_add(utime, p->signal->utime); | ||
1581 | stime = cputime_add(stime, p->signal->stime); | ||
1582 | r->ru_nvcsw += p->signal->nvcsw; | ||
1583 | r->ru_nivcsw += p->signal->nivcsw; | ||
1584 | r->ru_minflt += p->signal->min_flt; | ||
1585 | r->ru_majflt += p->signal->maj_flt; | ||
1586 | t = p; | ||
1587 | do { | ||
1588 | utime = cputime_add(utime, t->utime); | ||
1589 | stime = cputime_add(stime, t->stime); | ||
1590 | r->ru_nvcsw += t->nvcsw; | ||
1591 | r->ru_nivcsw += t->nivcsw; | ||
1592 | r->ru_minflt += t->min_flt; | ||
1593 | r->ru_majflt += t->maj_flt; | ||
1594 | t = next_thread(t); | ||
1595 | } while (t != p); | ||
1596 | spin_unlock_irqrestore(&p->sighand->siglock, flags); | ||
1597 | cputime_to_timeval(utime, &r->ru_utime); | ||
1598 | cputime_to_timeval(stime, &r->ru_stime); | ||
1599 | break; | ||
1600 | default: | ||
1601 | BUG(); | ||
1602 | } | ||
1603 | } | ||
1604 | |||
1605 | int getrusage(struct task_struct *p, int who, struct rusage __user *ru) | ||
1606 | { | ||
1607 | struct rusage r; | ||
1608 | read_lock(&tasklist_lock); | ||
1609 | k_getrusage(p, who, &r); | ||
1610 | read_unlock(&tasklist_lock); | ||
1611 | return copy_to_user(ru, &r, sizeof(r)) ? -EFAULT : 0; | ||
1612 | } | ||
1613 | |||
1614 | asmlinkage long sys_getrusage(int who, struct rusage __user *ru) | ||
1615 | { | ||
1616 | if (who != RUSAGE_SELF && who != RUSAGE_CHILDREN) | ||
1617 | return -EINVAL; | ||
1618 | return getrusage(current, who, ru); | ||
1619 | } | ||
1620 | |||
1621 | asmlinkage long sys_umask(int mask) | ||
1622 | { | ||
1623 | mask = xchg(¤t->fs->umask, mask & S_IRWXUGO); | ||
1624 | return mask; | ||
1625 | } | ||
1626 | |||
1627 | asmlinkage long sys_prctl(int option, unsigned long arg2, unsigned long arg3, | ||
1628 | unsigned long arg4, unsigned long arg5) | ||
1629 | { | ||
1630 | long error; | ||
1631 | int sig; | ||
1632 | |||
1633 | error = security_task_prctl(option, arg2, arg3, arg4, arg5); | ||
1634 | if (error) | ||
1635 | return error; | ||
1636 | |||
1637 | switch (option) { | ||
1638 | case PR_SET_PDEATHSIG: | ||
1639 | sig = arg2; | ||
1640 | if (sig < 0 || sig > _NSIG) { | ||
1641 | error = -EINVAL; | ||
1642 | break; | ||
1643 | } | ||
1644 | current->pdeath_signal = sig; | ||
1645 | break; | ||
1646 | case PR_GET_PDEATHSIG: | ||
1647 | error = put_user(current->pdeath_signal, (int __user *)arg2); | ||
1648 | break; | ||
1649 | case PR_GET_DUMPABLE: | ||
1650 | if (current->mm->dumpable) | ||
1651 | error = 1; | ||
1652 | break; | ||
1653 | case PR_SET_DUMPABLE: | ||
1654 | if (arg2 != 0 && arg2 != 1) { | ||
1655 | error = -EINVAL; | ||
1656 | break; | ||
1657 | } | ||
1658 | current->mm->dumpable = arg2; | ||
1659 | break; | ||
1660 | |||
1661 | case PR_SET_UNALIGN: | ||
1662 | error = SET_UNALIGN_CTL(current, arg2); | ||
1663 | break; | ||
1664 | case PR_GET_UNALIGN: | ||
1665 | error = GET_UNALIGN_CTL(current, arg2); | ||
1666 | break; | ||
1667 | case PR_SET_FPEMU: | ||
1668 | error = SET_FPEMU_CTL(current, arg2); | ||
1669 | break; | ||
1670 | case PR_GET_FPEMU: | ||
1671 | error = GET_FPEMU_CTL(current, arg2); | ||
1672 | break; | ||
1673 | case PR_SET_FPEXC: | ||
1674 | error = SET_FPEXC_CTL(current, arg2); | ||
1675 | break; | ||
1676 | case PR_GET_FPEXC: | ||
1677 | error = GET_FPEXC_CTL(current, arg2); | ||
1678 | break; | ||
1679 | case PR_GET_TIMING: | ||
1680 | error = PR_TIMING_STATISTICAL; | ||
1681 | break; | ||
1682 | case PR_SET_TIMING: | ||
1683 | if (arg2 == PR_TIMING_STATISTICAL) | ||
1684 | error = 0; | ||
1685 | else | ||
1686 | error = -EINVAL; | ||
1687 | break; | ||
1688 | |||
1689 | case PR_GET_KEEPCAPS: | ||
1690 | if (current->keep_capabilities) | ||
1691 | error = 1; | ||
1692 | break; | ||
1693 | case PR_SET_KEEPCAPS: | ||
1694 | if (arg2 != 0 && arg2 != 1) { | ||
1695 | error = -EINVAL; | ||
1696 | break; | ||
1697 | } | ||
1698 | current->keep_capabilities = arg2; | ||
1699 | break; | ||
1700 | case PR_SET_NAME: { | ||
1701 | struct task_struct *me = current; | ||
1702 | unsigned char ncomm[sizeof(me->comm)]; | ||
1703 | |||
1704 | ncomm[sizeof(me->comm)-1] = 0; | ||
1705 | if (strncpy_from_user(ncomm, (char __user *)arg2, | ||
1706 | sizeof(me->comm)-1) < 0) | ||
1707 | return -EFAULT; | ||
1708 | set_task_comm(me, ncomm); | ||
1709 | return 0; | ||
1710 | } | ||
1711 | case PR_GET_NAME: { | ||
1712 | struct task_struct *me = current; | ||
1713 | unsigned char tcomm[sizeof(me->comm)]; | ||
1714 | |||
1715 | get_task_comm(tcomm, me); | ||
1716 | if (copy_to_user((char __user *)arg2, tcomm, sizeof(tcomm))) | ||
1717 | return -EFAULT; | ||
1718 | return 0; | ||
1719 | } | ||
1720 | default: | ||
1721 | error = -EINVAL; | ||
1722 | break; | ||
1723 | } | ||
1724 | return error; | ||
1725 | } | ||