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1 | /* |
2 | * linux/kernel/sys.c |
3 | * |
4 | * Copyright (C) 1991, 1992 Linus Torvalds |
5 | */ |
6 | |
7 | #include <linux/module.h> |
8 | #include <linux/mm.h> |
9 | #include <linux/utsname.h> |
10 | #include <linux/mman.h> |
11 | #include <linux/notifier.h> |
12 | #include <linux/reboot.h> |
13 | #include <linux/prctl.h> |
14 | #include <linux/highuid.h> |
15 | #include <linux/fs.h> |
16 | #include <linux/perf_event.h> |
17 | #include <linux/resource.h> |
18 | #include <linux/kernel.h> |
19 | #include <linux/kexec.h> |
20 | #include <linux/workqueue.h> |
21 | #include <linux/capability.h> |
22 | #include <linux/device.h> |
23 | #include <linux/key.h> |
24 | #include <linux/times.h> |
25 | #include <linux/posix-timers.h> |
26 | #include <linux/security.h> |
27 | #include <linux/dcookies.h> |
28 | #include <linux/suspend.h> |
29 | #include <linux/tty.h> |
30 | #include <linux/signal.h> |
31 | #include <linux/cn_proc.h> |
32 | #include <linux/getcpu.h> |
33 | #include <linux/task_io_accounting_ops.h> |
34 | #include <linux/seccomp.h> |
35 | #include <linux/cpu.h> |
36 | #include <linux/personality.h> |
37 | #include <linux/ptrace.h> |
38 | #include <linux/fs_struct.h> |
39 | #include <linux/gfp.h> |
40 | |
41 | #include <linux/compat.h> |
42 | #include <linux/syscalls.h> |
43 | #include <linux/kprobes.h> |
44 | #include <linux/user_namespace.h> |
45 | |
46 | #include <asm/uaccess.h> |
47 | #include <asm/io.h> |
48 | #include <asm/unistd.h> |
49 | |
50 | #ifndef SET_UNALIGN_CTL |
51 | # define SET_UNALIGN_CTL(a,b) (-EINVAL) |
52 | #endif |
53 | #ifndef GET_UNALIGN_CTL |
54 | # define GET_UNALIGN_CTL(a,b) (-EINVAL) |
55 | #endif |
56 | #ifndef SET_FPEMU_CTL |
57 | # define SET_FPEMU_CTL(a,b) (-EINVAL) |
58 | #endif |
59 | #ifndef GET_FPEMU_CTL |
60 | # define GET_FPEMU_CTL(a,b) (-EINVAL) |
61 | #endif |
62 | #ifndef SET_FPEXC_CTL |
63 | # define SET_FPEXC_CTL(a,b) (-EINVAL) |
64 | #endif |
65 | #ifndef GET_FPEXC_CTL |
66 | # define GET_FPEXC_CTL(a,b) (-EINVAL) |
67 | #endif |
68 | #ifndef GET_ENDIAN |
69 | # define GET_ENDIAN(a,b) (-EINVAL) |
70 | #endif |
71 | #ifndef SET_ENDIAN |
72 | # define SET_ENDIAN(a,b) (-EINVAL) |
73 | #endif |
74 | #ifndef GET_TSC_CTL |
75 | # define GET_TSC_CTL(a) (-EINVAL) |
76 | #endif |
77 | #ifndef SET_TSC_CTL |
78 | # define SET_TSC_CTL(a) (-EINVAL) |
79 | #endif |
80 | |
81 | /* |
82 | * this is where the system-wide overflow UID and GID are defined, for |
83 | * architectures that now have 32-bit UID/GID but didn't in the past |
84 | */ |
85 | |
86 | int overflowuid = DEFAULT_OVERFLOWUID; |
87 | int overflowgid = DEFAULT_OVERFLOWGID; |
88 | |
89 | #ifdef CONFIG_UID16 |
90 | EXPORT_SYMBOL(overflowuid); |
91 | EXPORT_SYMBOL(overflowgid); |
92 | #endif |
93 | |
94 | /* |
95 | * the same as above, but for filesystems which can only store a 16-bit |
96 | * UID and GID. as such, this is needed on all architectures |
97 | */ |
98 | |
99 | int fs_overflowuid = DEFAULT_FS_OVERFLOWUID; |
100 | int fs_overflowgid = DEFAULT_FS_OVERFLOWUID; |
101 | |
102 | EXPORT_SYMBOL(fs_overflowuid); |
103 | EXPORT_SYMBOL(fs_overflowgid); |
104 | |
105 | /* |
106 | * this indicates whether you can reboot with ctrl-alt-del: the default is yes |
107 | */ |
108 | |
109 | int C_A_D = 1; |
110 | struct pid *cad_pid; |
111 | EXPORT_SYMBOL(cad_pid); |
112 | |
113 | /* |
114 | * If set, this is used for preparing the system to power off. |
115 | */ |
116 | |
117 | void (*pm_power_off_prepare)(void); |
118 | |
119 | /* |
120 | * set the priority of a task |
121 | * - the caller must hold the RCU read lock |
122 | */ |
123 | static int set_one_prio(struct task_struct *p, int niceval, int error) |
124 | { |
125 | const struct cred *cred = current_cred(), *pcred = __task_cred(p); |
126 | int no_nice; |
127 | |
128 | if (pcred->uid != cred->euid && |
129 | pcred->euid != cred->euid && !capable(CAP_SYS_NICE)) { |
130 | error = -EPERM; |
131 | goto out; |
132 | } |
133 | if (niceval < task_nice(p) && !can_nice(p, niceval)) { |
134 | error = -EACCES; |
135 | goto out; |
136 | } |
137 | no_nice = security_task_setnice(p, niceval); |
138 | if (no_nice) { |
139 | error = no_nice; |
140 | goto out; |
141 | } |
142 | if (error == -ESRCH) |
143 | error = 0; |
144 | set_user_nice(p, niceval); |
145 | out: |
146 | return error; |
147 | } |
148 | |
149 | SYSCALL_DEFINE3(setpriority, int, which, int, who, int, niceval) |
150 | { |
151 | struct task_struct *g, *p; |
152 | struct user_struct *user; |
153 | const struct cred *cred = current_cred(); |
154 | int error = -EINVAL; |
155 | struct pid *pgrp; |
156 | |
157 | if (which > PRIO_USER || which < PRIO_PROCESS) |
158 | goto out; |
159 | |
160 | /* normalize: avoid signed division (rounding problems) */ |
161 | error = -ESRCH; |
162 | if (niceval < -20) |
163 | niceval = -20; |
164 | if (niceval > 19) |
165 | niceval = 19; |
166 | |
167 | rcu_read_lock(); |
168 | read_lock(&tasklist_lock); |
169 | switch (which) { |
170 | case PRIO_PROCESS: |
171 | if (who) |
172 | p = find_task_by_vpid(who); |
173 | else |
174 | p = current; |
175 | if (p) |
176 | error = set_one_prio(p, niceval, error); |
177 | break; |
178 | case PRIO_PGRP: |
179 | if (who) |
180 | pgrp = find_vpid(who); |
181 | else |
182 | pgrp = task_pgrp(current); |
183 | do_each_pid_thread(pgrp, PIDTYPE_PGID, p) { |
184 | error = set_one_prio(p, niceval, error); |
185 | } while_each_pid_thread(pgrp, PIDTYPE_PGID, p); |
186 | break; |
187 | case PRIO_USER: |
188 | user = (struct user_struct *) cred->user; |
189 | if (!who) |
190 | who = cred->uid; |
191 | else if ((who != cred->uid) && |
192 | !(user = find_user(who))) |
193 | goto out_unlock; /* No processes for this user */ |
194 | |
195 | do_each_thread(g, p) { |
196 | if (__task_cred(p)->uid == who) |
197 | error = set_one_prio(p, niceval, error); |
198 | } while_each_thread(g, p); |
199 | if (who != cred->uid) |
200 | free_uid(user); /* For find_user() */ |
201 | break; |
202 | } |
203 | out_unlock: |
204 | read_unlock(&tasklist_lock); |
205 | rcu_read_unlock(); |
206 | out: |
207 | return error; |
208 | } |
209 | |
210 | /* |
211 | * Ugh. To avoid negative return values, "getpriority()" will |
212 | * not return the normal nice-value, but a negated value that |
213 | * has been offset by 20 (ie it returns 40..1 instead of -20..19) |
214 | * to stay compatible. |
215 | */ |
216 | SYSCALL_DEFINE2(getpriority, int, which, int, who) |
217 | { |
218 | struct task_struct *g, *p; |
219 | struct user_struct *user; |
220 | const struct cred *cred = current_cred(); |
221 | long niceval, retval = -ESRCH; |
222 | struct pid *pgrp; |
223 | |
224 | if (which > PRIO_USER || which < PRIO_PROCESS) |
225 | return -EINVAL; |
226 | |
227 | rcu_read_lock(); |
228 | read_lock(&tasklist_lock); |
229 | switch (which) { |
230 | case PRIO_PROCESS: |
231 | if (who) |
232 | p = find_task_by_vpid(who); |
233 | else |
234 | p = current; |
235 | if (p) { |
236 | niceval = 20 - task_nice(p); |
237 | if (niceval > retval) |
238 | retval = niceval; |
239 | } |
240 | break; |
241 | case PRIO_PGRP: |
242 | if (who) |
243 | pgrp = find_vpid(who); |
244 | else |
245 | pgrp = task_pgrp(current); |
246 | do_each_pid_thread(pgrp, PIDTYPE_PGID, p) { |
247 | niceval = 20 - task_nice(p); |
248 | if (niceval > retval) |
249 | retval = niceval; |
250 | } while_each_pid_thread(pgrp, PIDTYPE_PGID, p); |
251 | break; |
252 | case PRIO_USER: |
253 | user = (struct user_struct *) cred->user; |
254 | if (!who) |
255 | who = cred->uid; |
256 | else if ((who != cred->uid) && |
257 | !(user = find_user(who))) |
258 | goto out_unlock; /* No processes for this user */ |
259 | |
260 | do_each_thread(g, p) { |
261 | if (__task_cred(p)->uid == who) { |
262 | niceval = 20 - task_nice(p); |
263 | if (niceval > retval) |
264 | retval = niceval; |
265 | } |
266 | } while_each_thread(g, p); |
267 | if (who != cred->uid) |
268 | free_uid(user); /* for find_user() */ |
269 | break; |
270 | } |
271 | out_unlock: |
272 | read_unlock(&tasklist_lock); |
273 | rcu_read_unlock(); |
274 | |
275 | return retval; |
276 | } |
277 | |
278 | /** |
279 | * emergency_restart - reboot the system |
280 | * |
281 | * Without shutting down any hardware or taking any locks |
282 | * reboot the system. This is called when we know we are in |
283 | * trouble so this is our best effort to reboot. This is |
284 | * safe to call in interrupt context. |
285 | */ |
286 | void emergency_restart(void) |
287 | { |
288 | machine_emergency_restart(); |
289 | } |
290 | EXPORT_SYMBOL_GPL(emergency_restart); |
291 | |
292 | void kernel_restart_prepare(char *cmd) |
293 | { |
294 | blocking_notifier_call_chain(&reboot_notifier_list, SYS_RESTART, cmd); |
295 | system_state = SYSTEM_RESTART; |
296 | device_shutdown(); |
297 | sysdev_shutdown(); |
298 | } |
299 | |
300 | /** |
301 | * kernel_restart - reboot the system |
302 | * @cmd: pointer to buffer containing command to execute for restart |
303 | * or %NULL |
304 | * |
305 | * Shutdown everything and perform a clean reboot. |
306 | * This is not safe to call in interrupt context. |
307 | */ |
308 | void kernel_restart(char *cmd) |
309 | { |
310 | kernel_restart_prepare(cmd); |
311 | if (!cmd) |
312 | printk(KERN_EMERG "Restarting system.\n"); |
313 | else |
314 | printk(KERN_EMERG "Restarting system with command '%s'.\n", cmd); |
315 | machine_restart(cmd); |
316 | } |
317 | EXPORT_SYMBOL_GPL(kernel_restart); |
318 | |
319 | static void kernel_shutdown_prepare(enum system_states state) |
320 | { |
321 | blocking_notifier_call_chain(&reboot_notifier_list, |
322 | (state == SYSTEM_HALT)?SYS_HALT:SYS_POWER_OFF, NULL); |
323 | system_state = state; |
324 | device_shutdown(); |
325 | } |
326 | /** |
327 | * kernel_halt - halt the system |
328 | * |
329 | * Shutdown everything and perform a clean system halt. |
330 | */ |
331 | void kernel_halt(void) |
332 | { |
333 | kernel_shutdown_prepare(SYSTEM_HALT); |
334 | sysdev_shutdown(); |
335 | printk(KERN_EMERG "System halted.\n"); |
336 | machine_halt(); |
337 | } |
338 | |
339 | EXPORT_SYMBOL_GPL(kernel_halt); |
340 | |
341 | /** |
342 | * kernel_power_off - power_off the system |
343 | * |
344 | * Shutdown everything and perform a clean system power_off. |
345 | */ |
346 | void kernel_power_off(void) |
347 | { |
348 | kernel_shutdown_prepare(SYSTEM_POWER_OFF); |
349 | if (pm_power_off_prepare) |
350 | pm_power_off_prepare(); |
351 | disable_nonboot_cpus(); |
352 | sysdev_shutdown(); |
353 | printk(KERN_EMERG "Power down.\n"); |
354 | machine_power_off(); |
355 | } |
356 | EXPORT_SYMBOL_GPL(kernel_power_off); |
357 | |
358 | static DEFINE_MUTEX(reboot_mutex); |
359 | |
360 | /* |
361 | * Reboot system call: for obvious reasons only root may call it, |
362 | * and even root needs to set up some magic numbers in the registers |
363 | * so that some mistake won't make this reboot the whole machine. |
364 | * You can also set the meaning of the ctrl-alt-del-key here. |
365 | * |
366 | * reboot doesn't sync: do that yourself before calling this. |
367 | */ |
368 | SYSCALL_DEFINE4(reboot, int, magic1, int, magic2, unsigned int, cmd, |
369 | void __user *, arg) |
370 | { |
371 | char buffer[256]; |
372 | int ret = 0; |
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 | /* Instead of trying to make the power_off code look like |
387 | * halt when pm_power_off is not set do it the easy way. |
388 | */ |
389 | if ((cmd == LINUX_REBOOT_CMD_POWER_OFF) && !pm_power_off) |
390 | cmd = LINUX_REBOOT_CMD_HALT; |
391 | |
392 | mutex_lock(&reboot_mutex); |
393 | switch (cmd) { |
394 | case LINUX_REBOOT_CMD_RESTART: |
395 | kernel_restart(NULL); |
396 | break; |
397 | |
398 | case LINUX_REBOOT_CMD_CAD_ON: |
399 | C_A_D = 1; |
400 | break; |
401 | |
402 | case LINUX_REBOOT_CMD_CAD_OFF: |
403 | C_A_D = 0; |
404 | break; |
405 | |
406 | case LINUX_REBOOT_CMD_HALT: |
407 | kernel_halt(); |
408 | do_exit(0); |
409 | panic("cannot halt"); |
410 | |
411 | case LINUX_REBOOT_CMD_POWER_OFF: |
412 | kernel_power_off(); |
413 | do_exit(0); |
414 | break; |
415 | |
416 | case LINUX_REBOOT_CMD_RESTART2: |
417 | if (strncpy_from_user(&buffer[0], arg, sizeof(buffer) - 1) < 0) { |
418 | ret = -EFAULT; |
419 | break; |
420 | } |
421 | buffer[sizeof(buffer) - 1] = '\0'; |
422 | |
423 | kernel_restart(buffer); |
424 | break; |
425 | |
426 | #ifdef CONFIG_KEXEC |
427 | case LINUX_REBOOT_CMD_KEXEC: |
428 | ret = kernel_kexec(); |
429 | break; |
430 | #endif |
431 | |
432 | #ifdef CONFIG_HIBERNATION |
433 | case LINUX_REBOOT_CMD_SW_SUSPEND: |
434 | ret = hibernate(); |
435 | break; |
436 | #endif |
437 | |
438 | default: |
439 | ret = -EINVAL; |
440 | break; |
441 | } |
442 | mutex_unlock(&reboot_mutex); |
443 | return ret; |
444 | } |
445 | |
446 | static void deferred_cad(struct work_struct *dummy) |
447 | { |
448 | kernel_restart(NULL); |
449 | } |
450 | |
451 | /* |
452 | * This function gets called by ctrl-alt-del - ie the keyboard interrupt. |
453 | * As it's called within an interrupt, it may NOT sync: the only choice |
454 | * is whether to reboot at once, or just ignore the ctrl-alt-del. |
455 | */ |
456 | void ctrl_alt_del(void) |
457 | { |
458 | static DECLARE_WORK(cad_work, deferred_cad); |
459 | |
460 | if (C_A_D) |
461 | schedule_work(&cad_work); |
462 | else |
463 | kill_cad_pid(SIGINT, 1); |
464 | } |
465 | |
466 | /* |
467 | * Unprivileged users may change the real gid to the effective gid |
468 | * or vice versa. (BSD-style) |
469 | * |
470 | * If you set the real gid at all, or set the effective gid to a value not |
471 | * equal to the real gid, then the saved gid is set to the new effective gid. |
472 | * |
473 | * This makes it possible for a setgid program to completely drop its |
474 | * privileges, which is often a useful assertion to make when you are doing |
475 | * a security audit over a program. |
476 | * |
477 | * The general idea is that a program which uses just setregid() will be |
478 | * 100% compatible with BSD. A program which uses just setgid() will be |
479 | * 100% compatible with POSIX with saved IDs. |
480 | * |
481 | * SMP: There are not races, the GIDs are checked only by filesystem |
482 | * operations (as far as semantic preservation is concerned). |
483 | */ |
484 | SYSCALL_DEFINE2(setregid, gid_t, rgid, gid_t, egid) |
485 | { |
486 | const struct cred *old; |
487 | struct cred *new; |
488 | int retval; |
489 | |
490 | new = prepare_creds(); |
491 | if (!new) |
492 | return -ENOMEM; |
493 | old = current_cred(); |
494 | |
495 | retval = -EPERM; |
496 | if (rgid != (gid_t) -1) { |
497 | if (old->gid == rgid || |
498 | old->egid == rgid || |
499 | capable(CAP_SETGID)) |
500 | new->gid = rgid; |
501 | else |
502 | goto error; |
503 | } |
504 | if (egid != (gid_t) -1) { |
505 | if (old->gid == egid || |
506 | old->egid == egid || |
507 | old->sgid == egid || |
508 | capable(CAP_SETGID)) |
509 | new->egid = egid; |
510 | else |
511 | goto error; |
512 | } |
513 | |
514 | if (rgid != (gid_t) -1 || |
515 | (egid != (gid_t) -1 && egid != old->gid)) |
516 | new->sgid = new->egid; |
517 | new->fsgid = new->egid; |
518 | |
519 | return commit_creds(new); |
520 | |
521 | error: |
522 | abort_creds(new); |
523 | return retval; |
524 | } |
525 | |
526 | /* |
527 | * setgid() is implemented like SysV w/ SAVED_IDS |
528 | * |
529 | * SMP: Same implicit races as above. |
530 | */ |
531 | SYSCALL_DEFINE1(setgid, gid_t, gid) |
532 | { |
533 | const struct cred *old; |
534 | struct cred *new; |
535 | int retval; |
536 | |
537 | new = prepare_creds(); |
538 | if (!new) |
539 | return -ENOMEM; |
540 | old = current_cred(); |
541 | |
542 | retval = -EPERM; |
543 | if (capable(CAP_SETGID)) |
544 | new->gid = new->egid = new->sgid = new->fsgid = gid; |
545 | else if (gid == old->gid || gid == old->sgid) |
546 | new->egid = new->fsgid = gid; |
547 | else |
548 | goto error; |
549 | |
550 | return commit_creds(new); |
551 | |
552 | error: |
553 | abort_creds(new); |
554 | return retval; |
555 | } |
556 | |
557 | /* |
558 | * change the user struct in a credentials set to match the new UID |
559 | */ |
560 | static int set_user(struct cred *new) |
561 | { |
562 | struct user_struct *new_user; |
563 | |
564 | new_user = alloc_uid(current_user_ns(), new->uid); |
565 | if (!new_user) |
566 | return -EAGAIN; |
567 | |
568 | if (atomic_read(&new_user->processes) >= rlimit(RLIMIT_NPROC) && |
569 | new_user != INIT_USER) { |
570 | free_uid(new_user); |
571 | return -EAGAIN; |
572 | } |
573 | |
574 | free_uid(new->user); |
575 | new->user = new_user; |
576 | return 0; |
577 | } |
578 | |
579 | /* |
580 | * Unprivileged users may change the real uid to the effective uid |
581 | * or vice versa. (BSD-style) |
582 | * |
583 | * If you set the real uid at all, or set the effective uid to a value not |
584 | * equal to the real uid, then the saved uid is set to the new effective uid. |
585 | * |
586 | * This makes it possible for a setuid program to completely drop its |
587 | * privileges, which is often a useful assertion to make when you are doing |
588 | * a security audit over a program. |
589 | * |
590 | * The general idea is that a program which uses just setreuid() will be |
591 | * 100% compatible with BSD. A program which uses just setuid() will be |
592 | * 100% compatible with POSIX with saved IDs. |
593 | */ |
594 | SYSCALL_DEFINE2(setreuid, uid_t, ruid, uid_t, euid) |
595 | { |
596 | const struct cred *old; |
597 | struct cred *new; |
598 | int retval; |
599 | |
600 | new = prepare_creds(); |
601 | if (!new) |
602 | return -ENOMEM; |
603 | old = current_cred(); |
604 | |
605 | retval = -EPERM; |
606 | if (ruid != (uid_t) -1) { |
607 | new->uid = ruid; |
608 | if (old->uid != ruid && |
609 | old->euid != ruid && |
610 | !capable(CAP_SETUID)) |
611 | goto error; |
612 | } |
613 | |
614 | if (euid != (uid_t) -1) { |
615 | new->euid = euid; |
616 | if (old->uid != euid && |
617 | old->euid != euid && |
618 | old->suid != euid && |
619 | !capable(CAP_SETUID)) |
620 | goto error; |
621 | } |
622 | |
623 | if (new->uid != old->uid) { |
624 | retval = set_user(new); |
625 | if (retval < 0) |
626 | goto error; |
627 | } |
628 | if (ruid != (uid_t) -1 || |
629 | (euid != (uid_t) -1 && euid != old->uid)) |
630 | new->suid = new->euid; |
631 | new->fsuid = new->euid; |
632 | |
633 | retval = security_task_fix_setuid(new, old, LSM_SETID_RE); |
634 | if (retval < 0) |
635 | goto error; |
636 | |
637 | return commit_creds(new); |
638 | |
639 | error: |
640 | abort_creds(new); |
641 | return retval; |
642 | } |
643 | |
644 | /* |
645 | * setuid() is implemented like SysV with SAVED_IDS |
646 | * |
647 | * Note that SAVED_ID's is deficient in that a setuid root program |
648 | * like sendmail, for example, cannot set its uid to be a normal |
649 | * user and then switch back, because if you're root, setuid() sets |
650 | * the saved uid too. If you don't like this, blame the bright people |
651 | * in the POSIX committee and/or USG. Note that the BSD-style setreuid() |
652 | * will allow a root program to temporarily drop privileges and be able to |
653 | * regain them by swapping the real and effective uid. |
654 | */ |
655 | SYSCALL_DEFINE1(setuid, uid_t, uid) |
656 | { |
657 | const struct cred *old; |
658 | struct cred *new; |
659 | int retval; |
660 | |
661 | new = prepare_creds(); |
662 | if (!new) |
663 | return -ENOMEM; |
664 | old = current_cred(); |
665 | |
666 | retval = -EPERM; |
667 | if (capable(CAP_SETUID)) { |
668 | new->suid = new->uid = uid; |
669 | if (uid != old->uid) { |
670 | retval = set_user(new); |
671 | if (retval < 0) |
672 | goto error; |
673 | } |
674 | } else if (uid != old->uid && uid != new->suid) { |
675 | goto error; |
676 | } |
677 | |
678 | new->fsuid = new->euid = uid; |
679 | |
680 | retval = security_task_fix_setuid(new, old, LSM_SETID_ID); |
681 | if (retval < 0) |
682 | goto error; |
683 | |
684 | return commit_creds(new); |
685 | |
686 | error: |
687 | abort_creds(new); |
688 | return retval; |
689 | } |
690 | |
691 | |
692 | /* |
693 | * This function implements a generic ability to update ruid, euid, |
694 | * and suid. This allows you to implement the 4.4 compatible seteuid(). |
695 | */ |
696 | SYSCALL_DEFINE3(setresuid, uid_t, ruid, uid_t, euid, uid_t, suid) |
697 | { |
698 | const struct cred *old; |
699 | struct cred *new; |
700 | int retval; |
701 | |
702 | new = prepare_creds(); |
703 | if (!new) |
704 | return -ENOMEM; |
705 | |
706 | old = current_cred(); |
707 | |
708 | retval = -EPERM; |
709 | if (!capable(CAP_SETUID)) { |
710 | if (ruid != (uid_t) -1 && ruid != old->uid && |
711 | ruid != old->euid && ruid != old->suid) |
712 | goto error; |
713 | if (euid != (uid_t) -1 && euid != old->uid && |
714 | euid != old->euid && euid != old->suid) |
715 | goto error; |
716 | if (suid != (uid_t) -1 && suid != old->uid && |
717 | suid != old->euid && suid != old->suid) |
718 | goto error; |
719 | } |
720 | |
721 | if (ruid != (uid_t) -1) { |
722 | new->uid = ruid; |
723 | if (ruid != old->uid) { |
724 | retval = set_user(new); |
725 | if (retval < 0) |
726 | goto error; |
727 | } |
728 | } |
729 | if (euid != (uid_t) -1) |
730 | new->euid = euid; |
731 | if (suid != (uid_t) -1) |
732 | new->suid = suid; |
733 | new->fsuid = new->euid; |
734 | |
735 | retval = security_task_fix_setuid(new, old, LSM_SETID_RES); |
736 | if (retval < 0) |
737 | goto error; |
738 | |
739 | return commit_creds(new); |
740 | |
741 | error: |
742 | abort_creds(new); |
743 | return retval; |
744 | } |
745 | |
746 | SYSCALL_DEFINE3(getresuid, uid_t __user *, ruid, uid_t __user *, euid, uid_t __user *, suid) |
747 | { |
748 | const struct cred *cred = current_cred(); |
749 | int retval; |
750 | |
751 | if (!(retval = put_user(cred->uid, ruid)) && |
752 | !(retval = put_user(cred->euid, euid))) |
753 | retval = put_user(cred->suid, suid); |
754 | |
755 | return retval; |
756 | } |
757 | |
758 | /* |
759 | * Same as above, but for rgid, egid, sgid. |
760 | */ |
761 | SYSCALL_DEFINE3(setresgid, gid_t, rgid, gid_t, egid, gid_t, sgid) |
762 | { |
763 | const struct cred *old; |
764 | struct cred *new; |
765 | int retval; |
766 | |
767 | new = prepare_creds(); |
768 | if (!new) |
769 | return -ENOMEM; |
770 | old = current_cred(); |
771 | |
772 | retval = -EPERM; |
773 | if (!capable(CAP_SETGID)) { |
774 | if (rgid != (gid_t) -1 && rgid != old->gid && |
775 | rgid != old->egid && rgid != old->sgid) |
776 | goto error; |
777 | if (egid != (gid_t) -1 && egid != old->gid && |
778 | egid != old->egid && egid != old->sgid) |
779 | goto error; |
780 | if (sgid != (gid_t) -1 && sgid != old->gid && |
781 | sgid != old->egid && sgid != old->sgid) |
782 | goto error; |
783 | } |
784 | |
785 | if (rgid != (gid_t) -1) |
786 | new->gid = rgid; |
787 | if (egid != (gid_t) -1) |
788 | new->egid = egid; |
789 | if (sgid != (gid_t) -1) |
790 | new->sgid = sgid; |
791 | new->fsgid = new->egid; |
792 | |
793 | return commit_creds(new); |
794 | |
795 | error: |
796 | abort_creds(new); |
797 | return retval; |
798 | } |
799 | |
800 | SYSCALL_DEFINE3(getresgid, gid_t __user *, rgid, gid_t __user *, egid, gid_t __user *, sgid) |
801 | { |
802 | const struct cred *cred = current_cred(); |
803 | int retval; |
804 | |
805 | if (!(retval = put_user(cred->gid, rgid)) && |
806 | !(retval = put_user(cred->egid, egid))) |
807 | retval = put_user(cred->sgid, sgid); |
808 | |
809 | return retval; |
810 | } |
811 | |
812 | |
813 | /* |
814 | * "setfsuid()" sets the fsuid - the uid used for filesystem checks. This |
815 | * is used for "access()" and for the NFS daemon (letting nfsd stay at |
816 | * whatever uid it wants to). It normally shadows "euid", except when |
817 | * explicitly set by setfsuid() or for access.. |
818 | */ |
819 | SYSCALL_DEFINE1(setfsuid, uid_t, uid) |
820 | { |
821 | const struct cred *old; |
822 | struct cred *new; |
823 | uid_t old_fsuid; |
824 | |
825 | new = prepare_creds(); |
826 | if (!new) |
827 | return current_fsuid(); |
828 | old = current_cred(); |
829 | old_fsuid = old->fsuid; |
830 | |
831 | if (uid == old->uid || uid == old->euid || |
832 | uid == old->suid || uid == old->fsuid || |
833 | capable(CAP_SETUID)) { |
834 | if (uid != old_fsuid) { |
835 | new->fsuid = uid; |
836 | if (security_task_fix_setuid(new, old, LSM_SETID_FS) == 0) |
837 | goto change_okay; |
838 | } |
839 | } |
840 | |
841 | abort_creds(new); |
842 | return old_fsuid; |
843 | |
844 | change_okay: |
845 | commit_creds(new); |
846 | return old_fsuid; |
847 | } |
848 | |
849 | /* |
850 | * Samma på svenska.. |
851 | */ |
852 | SYSCALL_DEFINE1(setfsgid, gid_t, gid) |
853 | { |
854 | const struct cred *old; |
855 | struct cred *new; |
856 | gid_t old_fsgid; |
857 | |
858 | new = prepare_creds(); |
859 | if (!new) |
860 | return current_fsgid(); |
861 | old = current_cred(); |
862 | old_fsgid = old->fsgid; |
863 | |
864 | if (gid == old->gid || gid == old->egid || |
865 | gid == old->sgid || gid == old->fsgid || |
866 | capable(CAP_SETGID)) { |
867 | if (gid != old_fsgid) { |
868 | new->fsgid = gid; |
869 | goto change_okay; |
870 | } |
871 | } |
872 | |
873 | abort_creds(new); |
874 | return old_fsgid; |
875 | |
876 | change_okay: |
877 | commit_creds(new); |
878 | return old_fsgid; |
879 | } |
880 | |
881 | void do_sys_times(struct tms *tms) |
882 | { |
883 | cputime_t tgutime, tgstime, cutime, cstime; |
884 | |
885 | spin_lock_irq(¤t->sighand->siglock); |
886 | thread_group_times(current, &tgutime, &tgstime); |
887 | cutime = current->signal->cutime; |
888 | cstime = current->signal->cstime; |
889 | spin_unlock_irq(¤t->sighand->siglock); |
890 | tms->tms_utime = cputime_to_clock_t(tgutime); |
891 | tms->tms_stime = cputime_to_clock_t(tgstime); |
892 | tms->tms_cutime = cputime_to_clock_t(cutime); |
893 | tms->tms_cstime = cputime_to_clock_t(cstime); |
894 | } |
895 | |
896 | SYSCALL_DEFINE1(times, struct tms __user *, tbuf) |
897 | { |
898 | if (tbuf) { |
899 | struct tms tmp; |
900 | |
901 | do_sys_times(&tmp); |
902 | if (copy_to_user(tbuf, &tmp, sizeof(struct tms))) |
903 | return -EFAULT; |
904 | } |
905 | force_successful_syscall_return(); |
906 | return (long) jiffies_64_to_clock_t(get_jiffies_64()); |
907 | } |
908 | |
909 | /* |
910 | * This needs some heavy checking ... |
911 | * I just haven't the stomach for it. I also don't fully |
912 | * understand sessions/pgrp etc. Let somebody who does explain it. |
913 | * |
914 | * OK, I think I have the protection semantics right.... this is really |
915 | * only important on a multi-user system anyway, to make sure one user |
916 | * can't send a signal to a process owned by another. -TYT, 12/12/91 |
917 | * |
918 | * Auch. Had to add the 'did_exec' flag to conform completely to POSIX. |
919 | * LBT 04.03.94 |
920 | */ |
921 | SYSCALL_DEFINE2(setpgid, pid_t, pid, pid_t, pgid) |
922 | { |
923 | struct task_struct *p; |
924 | struct task_struct *group_leader = current->group_leader; |
925 | struct pid *pgrp; |
926 | int err; |
927 | |
928 | if (!pid) |
929 | pid = task_pid_vnr(group_leader); |
930 | if (!pgid) |
931 | pgid = pid; |
932 | if (pgid < 0) |
933 | return -EINVAL; |
934 | |
935 | /* From this point forward we keep holding onto the tasklist lock |
936 | * so that our parent does not change from under us. -DaveM |
937 | */ |
938 | write_lock_irq(&tasklist_lock); |
939 | |
940 | err = -ESRCH; |
941 | p = find_task_by_vpid(pid); |
942 | if (!p) |
943 | goto out; |
944 | |
945 | err = -EINVAL; |
946 | if (!thread_group_leader(p)) |
947 | goto out; |
948 | |
949 | if (same_thread_group(p->real_parent, group_leader)) { |
950 | err = -EPERM; |
951 | if (task_session(p) != task_session(group_leader)) |
952 | goto out; |
953 | err = -EACCES; |
954 | if (p->did_exec) |
955 | goto out; |
956 | } else { |
957 | err = -ESRCH; |
958 | if (p != group_leader) |
959 | goto out; |
960 | } |
961 | |
962 | err = -EPERM; |
963 | if (p->signal->leader) |
964 | goto out; |
965 | |
966 | pgrp = task_pid(p); |
967 | if (pgid != pid) { |
968 | struct task_struct *g; |
969 | |
970 | pgrp = find_vpid(pgid); |
971 | g = pid_task(pgrp, PIDTYPE_PGID); |
972 | if (!g || task_session(g) != task_session(group_leader)) |
973 | goto out; |
974 | } |
975 | |
976 | err = security_task_setpgid(p, pgid); |
977 | if (err) |
978 | goto out; |
979 | |
980 | if (task_pgrp(p) != pgrp) |
981 | change_pid(p, PIDTYPE_PGID, pgrp); |
982 | |
983 | err = 0; |
984 | out: |
985 | /* All paths lead to here, thus we are safe. -DaveM */ |
986 | write_unlock_irq(&tasklist_lock); |
987 | return err; |
988 | } |
989 | |
990 | SYSCALL_DEFINE1(getpgid, pid_t, pid) |
991 | { |
992 | struct task_struct *p; |
993 | struct pid *grp; |
994 | int retval; |
995 | |
996 | rcu_read_lock(); |
997 | if (!pid) |
998 | grp = task_pgrp(current); |
999 | else { |
1000 | retval = -ESRCH; |
1001 | p = find_task_by_vpid(pid); |
1002 | if (!p) |
1003 | goto out; |
1004 | grp = task_pgrp(p); |
1005 | if (!grp) |
1006 | goto out; |
1007 | |
1008 | retval = security_task_getpgid(p); |
1009 | if (retval) |
1010 | goto out; |
1011 | } |
1012 | retval = pid_vnr(grp); |
1013 | out: |
1014 | rcu_read_unlock(); |
1015 | return retval; |
1016 | } |
1017 | |
1018 | #ifdef __ARCH_WANT_SYS_GETPGRP |
1019 | |
1020 | SYSCALL_DEFINE0(getpgrp) |
1021 | { |
1022 | return sys_getpgid(0); |
1023 | } |
1024 | |
1025 | #endif |
1026 | |
1027 | SYSCALL_DEFINE1(getsid, pid_t, pid) |
1028 | { |
1029 | struct task_struct *p; |
1030 | struct pid *sid; |
1031 | int retval; |
1032 | |
1033 | rcu_read_lock(); |
1034 | if (!pid) |
1035 | sid = task_session(current); |
1036 | else { |
1037 | retval = -ESRCH; |
1038 | p = find_task_by_vpid(pid); |
1039 | if (!p) |
1040 | goto out; |
1041 | sid = task_session(p); |
1042 | if (!sid) |
1043 | goto out; |
1044 | |
1045 | retval = security_task_getsid(p); |
1046 | if (retval) |
1047 | goto out; |
1048 | } |
1049 | retval = pid_vnr(sid); |
1050 | out: |
1051 | rcu_read_unlock(); |
1052 | return retval; |
1053 | } |
1054 | |
1055 | SYSCALL_DEFINE0(setsid) |
1056 | { |
1057 | struct task_struct *group_leader = current->group_leader; |
1058 | struct pid *sid = task_pid(group_leader); |
1059 | pid_t session = pid_vnr(sid); |
1060 | int err = -EPERM; |
1061 | |
1062 | write_lock_irq(&tasklist_lock); |
1063 | /* Fail if I am already a session leader */ |
1064 | if (group_leader->signal->leader) |
1065 | goto out; |
1066 | |
1067 | /* Fail if a process group id already exists that equals the |
1068 | * proposed session id. |
1069 | */ |
1070 | if (pid_task(sid, PIDTYPE_PGID)) |
1071 | goto out; |
1072 | |
1073 | group_leader->signal->leader = 1; |
1074 | __set_special_pids(sid); |
1075 | |
1076 | proc_clear_tty(group_leader); |
1077 | |
1078 | err = session; |
1079 | out: |
1080 | write_unlock_irq(&tasklist_lock); |
1081 | if (err > 0) |
1082 | proc_sid_connector(group_leader); |
1083 | return err; |
1084 | } |
1085 | |
1086 | DECLARE_RWSEM(uts_sem); |
1087 | |
1088 | #ifdef COMPAT_UTS_MACHINE |
1089 | #define override_architecture(name) \ |
1090 | (personality(current->personality) == PER_LINUX32 && \ |
1091 | copy_to_user(name->machine, COMPAT_UTS_MACHINE, \ |
1092 | sizeof(COMPAT_UTS_MACHINE))) |
1093 | #else |
1094 | #define override_architecture(name) 0 |
1095 | #endif |
1096 | |
1097 | SYSCALL_DEFINE1(newuname, struct new_utsname __user *, name) |
1098 | { |
1099 | int errno = 0; |
1100 | |
1101 | down_read(&uts_sem); |
1102 | if (copy_to_user(name, utsname(), sizeof *name)) |
1103 | errno = -EFAULT; |
1104 | up_read(&uts_sem); |
1105 | |
1106 | if (!errno && override_architecture(name)) |
1107 | errno = -EFAULT; |
1108 | return errno; |
1109 | } |
1110 | |
1111 | #ifdef __ARCH_WANT_SYS_OLD_UNAME |
1112 | /* |
1113 | * Old cruft |
1114 | */ |
1115 | SYSCALL_DEFINE1(uname, struct old_utsname __user *, name) |
1116 | { |
1117 | int error = 0; |
1118 | |
1119 | if (!name) |
1120 | return -EFAULT; |
1121 | |
1122 | down_read(&uts_sem); |
1123 | if (copy_to_user(name, utsname(), sizeof(*name))) |
1124 | error = -EFAULT; |
1125 | up_read(&uts_sem); |
1126 | |
1127 | if (!error && override_architecture(name)) |
1128 | error = -EFAULT; |
1129 | return error; |
1130 | } |
1131 | |
1132 | SYSCALL_DEFINE1(olduname, struct oldold_utsname __user *, name) |
1133 | { |
1134 | int error; |
1135 | |
1136 | if (!name) |
1137 | return -EFAULT; |
1138 | if (!access_ok(VERIFY_WRITE, name, sizeof(struct oldold_utsname))) |
1139 | return -EFAULT; |
1140 | |
1141 | down_read(&uts_sem); |
1142 | error = __copy_to_user(&name->sysname, &utsname()->sysname, |
1143 | __OLD_UTS_LEN); |
1144 | error |= __put_user(0, name->sysname + __OLD_UTS_LEN); |
1145 | error |= __copy_to_user(&name->nodename, &utsname()->nodename, |
1146 | __OLD_UTS_LEN); |
1147 | error |= __put_user(0, name->nodename + __OLD_UTS_LEN); |
1148 | error |= __copy_to_user(&name->release, &utsname()->release, |
1149 | __OLD_UTS_LEN); |
1150 | error |= __put_user(0, name->release + __OLD_UTS_LEN); |
1151 | error |= __copy_to_user(&name->version, &utsname()->version, |
1152 | __OLD_UTS_LEN); |
1153 | error |= __put_user(0, name->version + __OLD_UTS_LEN); |
1154 | error |= __copy_to_user(&name->machine, &utsname()->machine, |
1155 | __OLD_UTS_LEN); |
1156 | error |= __put_user(0, name->machine + __OLD_UTS_LEN); |
1157 | up_read(&uts_sem); |
1158 | |
1159 | if (!error && override_architecture(name)) |
1160 | error = -EFAULT; |
1161 | return error ? -EFAULT : 0; |
1162 | } |
1163 | #endif |
1164 | |
1165 | SYSCALL_DEFINE2(sethostname, char __user *, name, int, len) |
1166 | { |
1167 | int errno; |
1168 | char tmp[__NEW_UTS_LEN]; |
1169 | |
1170 | if (!capable(CAP_SYS_ADMIN)) |
1171 | return -EPERM; |
1172 | if (len < 0 || len > __NEW_UTS_LEN) |
1173 | return -EINVAL; |
1174 | down_write(&uts_sem); |
1175 | errno = -EFAULT; |
1176 | if (!copy_from_user(tmp, name, len)) { |
1177 | struct new_utsname *u = utsname(); |
1178 | |
1179 | memcpy(u->nodename, tmp, len); |
1180 | memset(u->nodename + len, 0, sizeof(u->nodename) - len); |
1181 | errno = 0; |
1182 | } |
1183 | up_write(&uts_sem); |
1184 | return errno; |
1185 | } |
1186 | |
1187 | #ifdef __ARCH_WANT_SYS_GETHOSTNAME |
1188 | |
1189 | SYSCALL_DEFINE2(gethostname, char __user *, name, int, len) |
1190 | { |
1191 | int i, errno; |
1192 | struct new_utsname *u; |
1193 | |
1194 | if (len < 0) |
1195 | return -EINVAL; |
1196 | down_read(&uts_sem); |
1197 | u = utsname(); |
1198 | i = 1 + strlen(u->nodename); |
1199 | if (i > len) |
1200 | i = len; |
1201 | errno = 0; |
1202 | if (copy_to_user(name, u->nodename, i)) |
1203 | errno = -EFAULT; |
1204 | up_read(&uts_sem); |
1205 | return errno; |
1206 | } |
1207 | |
1208 | #endif |
1209 | |
1210 | /* |
1211 | * Only setdomainname; getdomainname can be implemented by calling |
1212 | * uname() |
1213 | */ |
1214 | SYSCALL_DEFINE2(setdomainname, char __user *, name, int, len) |
1215 | { |
1216 | int errno; |
1217 | char tmp[__NEW_UTS_LEN]; |
1218 | |
1219 | if (!capable(CAP_SYS_ADMIN)) |
1220 | return -EPERM; |
1221 | if (len < 0 || len > __NEW_UTS_LEN) |
1222 | return -EINVAL; |
1223 | |
1224 | down_write(&uts_sem); |
1225 | errno = -EFAULT; |
1226 | if (!copy_from_user(tmp, name, len)) { |
1227 | struct new_utsname *u = utsname(); |
1228 | |
1229 | memcpy(u->domainname, tmp, len); |
1230 | memset(u->domainname + len, 0, sizeof(u->domainname) - len); |
1231 | errno = 0; |
1232 | } |
1233 | up_write(&uts_sem); |
1234 | return errno; |
1235 | } |
1236 | |
1237 | SYSCALL_DEFINE2(getrlimit, unsigned int, resource, struct rlimit __user *, rlim) |
1238 | { |
1239 | if (resource >= RLIM_NLIMITS) |
1240 | return -EINVAL; |
1241 | else { |
1242 | struct rlimit value; |
1243 | task_lock(current->group_leader); |
1244 | value = current->signal->rlim[resource]; |
1245 | task_unlock(current->group_leader); |
1246 | return copy_to_user(rlim, &value, sizeof(*rlim)) ? -EFAULT : 0; |
1247 | } |
1248 | } |
1249 | |
1250 | #ifdef __ARCH_WANT_SYS_OLD_GETRLIMIT |
1251 | |
1252 | /* |
1253 | * Back compatibility for getrlimit. Needed for some apps. |
1254 | */ |
1255 | |
1256 | SYSCALL_DEFINE2(old_getrlimit, unsigned int, resource, |
1257 | struct rlimit __user *, rlim) |
1258 | { |
1259 | struct rlimit x; |
1260 | if (resource >= RLIM_NLIMITS) |
1261 | return -EINVAL; |
1262 | |
1263 | task_lock(current->group_leader); |
1264 | x = current->signal->rlim[resource]; |
1265 | task_unlock(current->group_leader); |
1266 | if (x.rlim_cur > 0x7FFFFFFF) |
1267 | x.rlim_cur = 0x7FFFFFFF; |
1268 | if (x.rlim_max > 0x7FFFFFFF) |
1269 | x.rlim_max = 0x7FFFFFFF; |
1270 | return copy_to_user(rlim, &x, sizeof(x))?-EFAULT:0; |
1271 | } |
1272 | |
1273 | #endif |
1274 | |
1275 | SYSCALL_DEFINE2(setrlimit, unsigned int, resource, struct rlimit __user *, rlim) |
1276 | { |
1277 | struct rlimit new_rlim, *old_rlim; |
1278 | int retval; |
1279 | |
1280 | if (resource >= RLIM_NLIMITS) |
1281 | return -EINVAL; |
1282 | if (copy_from_user(&new_rlim, rlim, sizeof(*rlim))) |
1283 | return -EFAULT; |
1284 | if (new_rlim.rlim_cur > new_rlim.rlim_max) |
1285 | return -EINVAL; |
1286 | old_rlim = current->signal->rlim + resource; |
1287 | if ((new_rlim.rlim_max > old_rlim->rlim_max) && |
1288 | !capable(CAP_SYS_RESOURCE)) |
1289 | return -EPERM; |
1290 | if (resource == RLIMIT_NOFILE && new_rlim.rlim_max > sysctl_nr_open) |
1291 | return -EPERM; |
1292 | |
1293 | retval = security_task_setrlimit(resource, &new_rlim); |
1294 | if (retval) |
1295 | return retval; |
1296 | |
1297 | if (resource == RLIMIT_CPU && new_rlim.rlim_cur == 0) { |
1298 | /* |
1299 | * The caller is asking for an immediate RLIMIT_CPU |
1300 | * expiry. But we use the zero value to mean "it was |
1301 | * never set". So let's cheat and make it one second |
1302 | * instead |
1303 | */ |
1304 | new_rlim.rlim_cur = 1; |
1305 | } |
1306 | |
1307 | task_lock(current->group_leader); |
1308 | *old_rlim = new_rlim; |
1309 | task_unlock(current->group_leader); |
1310 | |
1311 | if (resource != RLIMIT_CPU) |
1312 | goto out; |
1313 | |
1314 | /* |
1315 | * RLIMIT_CPU handling. Note that the kernel fails to return an error |
1316 | * code if it rejected the user's attempt to set RLIMIT_CPU. This is a |
1317 | * very long-standing error, and fixing it now risks breakage of |
1318 | * applications, so we live with it |
1319 | */ |
1320 | if (new_rlim.rlim_cur == RLIM_INFINITY) |
1321 | goto out; |
1322 | |
1323 | update_rlimit_cpu(new_rlim.rlim_cur); |
1324 | out: |
1325 | return 0; |
1326 | } |
1327 | |
1328 | /* |
1329 | * It would make sense to put struct rusage in the task_struct, |
1330 | * except that would make the task_struct be *really big*. After |
1331 | * task_struct gets moved into malloc'ed memory, it would |
1332 | * make sense to do this. It will make moving the rest of the information |
1333 | * a lot simpler! (Which we're not doing right now because we're not |
1334 | * measuring them yet). |
1335 | * |
1336 | * When sampling multiple threads for RUSAGE_SELF, under SMP we might have |
1337 | * races with threads incrementing their own counters. But since word |
1338 | * reads are atomic, we either get new values or old values and we don't |
1339 | * care which for the sums. We always take the siglock to protect reading |
1340 | * the c* fields from p->signal from races with exit.c updating those |
1341 | * fields when reaping, so a sample either gets all the additions of a |
1342 | * given child after it's reaped, or none so this sample is before reaping. |
1343 | * |
1344 | * Locking: |
1345 | * We need to take the siglock for CHILDEREN, SELF and BOTH |
1346 | * for the cases current multithreaded, non-current single threaded |
1347 | * non-current multithreaded. Thread traversal is now safe with |
1348 | * the siglock held. |
1349 | * Strictly speaking, we donot need to take the siglock if we are current and |
1350 | * single threaded, as no one else can take our signal_struct away, no one |
1351 | * else can reap the children to update signal->c* counters, and no one else |
1352 | * can race with the signal-> fields. If we do not take any lock, the |
1353 | * signal-> fields could be read out of order while another thread was just |
1354 | * exiting. So we should place a read memory barrier when we avoid the lock. |
1355 | * On the writer side, write memory barrier is implied in __exit_signal |
1356 | * as __exit_signal releases the siglock spinlock after updating the signal-> |
1357 | * fields. But we don't do this yet to keep things simple. |
1358 | * |
1359 | */ |
1360 | |
1361 | static void accumulate_thread_rusage(struct task_struct *t, struct rusage *r) |
1362 | { |
1363 | r->ru_nvcsw += t->nvcsw; |
1364 | r->ru_nivcsw += t->nivcsw; |
1365 | r->ru_minflt += t->min_flt; |
1366 | r->ru_majflt += t->maj_flt; |
1367 | r->ru_inblock += task_io_get_inblock(t); |
1368 | r->ru_oublock += task_io_get_oublock(t); |
1369 | } |
1370 | |
1371 | static void k_getrusage(struct task_struct *p, int who, struct rusage *r) |
1372 | { |
1373 | struct task_struct *t; |
1374 | unsigned long flags; |
1375 | cputime_t tgutime, tgstime, utime, stime; |
1376 | unsigned long maxrss = 0; |
1377 | |
1378 | memset((char *) r, 0, sizeof *r); |
1379 | utime = stime = cputime_zero; |
1380 | |
1381 | if (who == RUSAGE_THREAD) { |
1382 | task_times(current, &utime, &stime); |
1383 | accumulate_thread_rusage(p, r); |
1384 | maxrss = p->signal->maxrss; |
1385 | goto out; |
1386 | } |
1387 | |
1388 | if (!lock_task_sighand(p, &flags)) |
1389 | return; |
1390 | |
1391 | switch (who) { |
1392 | case RUSAGE_BOTH: |
1393 | case RUSAGE_CHILDREN: |
1394 | utime = p->signal->cutime; |
1395 | stime = p->signal->cstime; |
1396 | r->ru_nvcsw = p->signal->cnvcsw; |
1397 | r->ru_nivcsw = p->signal->cnivcsw; |
1398 | r->ru_minflt = p->signal->cmin_flt; |
1399 | r->ru_majflt = p->signal->cmaj_flt; |
1400 | r->ru_inblock = p->signal->cinblock; |
1401 | r->ru_oublock = p->signal->coublock; |
1402 | maxrss = p->signal->cmaxrss; |
1403 | |
1404 | if (who == RUSAGE_CHILDREN) |
1405 | break; |
1406 | |
1407 | case RUSAGE_SELF: |
1408 | thread_group_times(p, &tgutime, &tgstime); |
1409 | utime = cputime_add(utime, tgutime); |
1410 | stime = cputime_add(stime, tgstime); |
1411 | r->ru_nvcsw += p->signal->nvcsw; |
1412 | r->ru_nivcsw += p->signal->nivcsw; |
1413 | r->ru_minflt += p->signal->min_flt; |
1414 | r->ru_majflt += p->signal->maj_flt; |
1415 | r->ru_inblock += p->signal->inblock; |
1416 | r->ru_oublock += p->signal->oublock; |
1417 | if (maxrss < p->signal->maxrss) |
1418 | maxrss = p->signal->maxrss; |
1419 | t = p; |
1420 | do { |
1421 | accumulate_thread_rusage(t, r); |
1422 | t = next_thread(t); |
1423 | } while (t != p); |
1424 | break; |
1425 | |
1426 | default: |
1427 | BUG(); |
1428 | } |
1429 | unlock_task_sighand(p, &flags); |
1430 | |
1431 | out: |
1432 | cputime_to_timeval(utime, &r->ru_utime); |
1433 | cputime_to_timeval(stime, &r->ru_stime); |
1434 | |
1435 | if (who != RUSAGE_CHILDREN) { |
1436 | struct mm_struct *mm = get_task_mm(p); |
1437 | if (mm) { |
1438 | setmax_mm_hiwater_rss(&maxrss, mm); |
1439 | mmput(mm); |
1440 | } |
1441 | } |
1442 | r->ru_maxrss = maxrss * (PAGE_SIZE / 1024); /* convert pages to KBs */ |
1443 | } |
1444 | |
1445 | int getrusage(struct task_struct *p, int who, struct rusage __user *ru) |
1446 | { |
1447 | struct rusage r; |
1448 | k_getrusage(p, who, &r); |
1449 | return copy_to_user(ru, &r, sizeof(r)) ? -EFAULT : 0; |
1450 | } |
1451 | |
1452 | SYSCALL_DEFINE2(getrusage, int, who, struct rusage __user *, ru) |
1453 | { |
1454 | if (who != RUSAGE_SELF && who != RUSAGE_CHILDREN && |
1455 | who != RUSAGE_THREAD) |
1456 | return -EINVAL; |
1457 | return getrusage(current, who, ru); |
1458 | } |
1459 | |
1460 | SYSCALL_DEFINE1(umask, int, mask) |
1461 | { |
1462 | mask = xchg(¤t->fs->umask, mask & S_IRWXUGO); |
1463 | return mask; |
1464 | } |
1465 | |
1466 | SYSCALL_DEFINE5(prctl, int, option, unsigned long, arg2, unsigned long, arg3, |
1467 | unsigned long, arg4, unsigned long, arg5) |
1468 | { |
1469 | struct task_struct *me = current; |
1470 | unsigned char comm[sizeof(me->comm)]; |
1471 | long error; |
1472 | |
1473 | error = security_task_prctl(option, arg2, arg3, arg4, arg5); |
1474 | if (error != -ENOSYS) |
1475 | return error; |
1476 | |
1477 | error = 0; |
1478 | switch (option) { |
1479 | case PR_SET_PDEATHSIG: |
1480 | if (!valid_signal(arg2)) { |
1481 | error = -EINVAL; |
1482 | break; |
1483 | } |
1484 | me->pdeath_signal = arg2; |
1485 | error = 0; |
1486 | break; |
1487 | case PR_GET_PDEATHSIG: |
1488 | error = put_user(me->pdeath_signal, (int __user *)arg2); |
1489 | break; |
1490 | case PR_GET_DUMPABLE: |
1491 | error = get_dumpable(me->mm); |
1492 | break; |
1493 | case PR_SET_DUMPABLE: |
1494 | if (arg2 < 0 || arg2 > 1) { |
1495 | error = -EINVAL; |
1496 | break; |
1497 | } |
1498 | set_dumpable(me->mm, arg2); |
1499 | error = 0; |
1500 | break; |
1501 | |
1502 | case PR_SET_UNALIGN: |
1503 | error = SET_UNALIGN_CTL(me, arg2); |
1504 | break; |
1505 | case PR_GET_UNALIGN: |
1506 | error = GET_UNALIGN_CTL(me, arg2); |
1507 | break; |
1508 | case PR_SET_FPEMU: |
1509 | error = SET_FPEMU_CTL(me, arg2); |
1510 | break; |
1511 | case PR_GET_FPEMU: |
1512 | error = GET_FPEMU_CTL(me, arg2); |
1513 | break; |
1514 | case PR_SET_FPEXC: |
1515 | error = SET_FPEXC_CTL(me, arg2); |
1516 | break; |
1517 | case PR_GET_FPEXC: |
1518 | error = GET_FPEXC_CTL(me, arg2); |
1519 | break; |
1520 | case PR_GET_TIMING: |
1521 | error = PR_TIMING_STATISTICAL; |
1522 | break; |
1523 | case PR_SET_TIMING: |
1524 | if (arg2 != PR_TIMING_STATISTICAL) |
1525 | error = -EINVAL; |
1526 | else |
1527 | error = 0; |
1528 | break; |
1529 | |
1530 | case PR_SET_NAME: |
1531 | comm[sizeof(me->comm)-1] = 0; |
1532 | if (strncpy_from_user(comm, (char __user *)arg2, |
1533 | sizeof(me->comm) - 1) < 0) |
1534 | return -EFAULT; |
1535 | set_task_comm(me, comm); |
1536 | return 0; |
1537 | case PR_GET_NAME: |
1538 | get_task_comm(comm, me); |
1539 | if (copy_to_user((char __user *)arg2, comm, |
1540 | sizeof(comm))) |
1541 | return -EFAULT; |
1542 | return 0; |
1543 | case PR_GET_ENDIAN: |
1544 | error = GET_ENDIAN(me, arg2); |
1545 | break; |
1546 | case PR_SET_ENDIAN: |
1547 | error = SET_ENDIAN(me, arg2); |
1548 | break; |
1549 | |
1550 | case PR_GET_SECCOMP: |
1551 | error = prctl_get_seccomp(); |
1552 | break; |
1553 | case PR_SET_SECCOMP: |
1554 | error = prctl_set_seccomp(arg2); |
1555 | break; |
1556 | case PR_GET_TSC: |
1557 | error = GET_TSC_CTL(arg2); |
1558 | break; |
1559 | case PR_SET_TSC: |
1560 | error = SET_TSC_CTL(arg2); |
1561 | break; |
1562 | case PR_TASK_PERF_EVENTS_DISABLE: |
1563 | error = perf_event_task_disable(); |
1564 | break; |
1565 | case PR_TASK_PERF_EVENTS_ENABLE: |
1566 | error = perf_event_task_enable(); |
1567 | break; |
1568 | case PR_GET_TIMERSLACK: |
1569 | error = current->timer_slack_ns; |
1570 | break; |
1571 | case PR_SET_TIMERSLACK: |
1572 | if (arg2 <= 0) |
1573 | current->timer_slack_ns = |
1574 | current->default_timer_slack_ns; |
1575 | else |
1576 | current->timer_slack_ns = arg2; |
1577 | error = 0; |
1578 | break; |
1579 | case PR_MCE_KILL: |
1580 | if (arg4 | arg5) |
1581 | return -EINVAL; |
1582 | switch (arg2) { |
1583 | case PR_MCE_KILL_CLEAR: |
1584 | if (arg3 != 0) |
1585 | return -EINVAL; |
1586 | current->flags &= ~PF_MCE_PROCESS; |
1587 | break; |
1588 | case PR_MCE_KILL_SET: |
1589 | current->flags |= PF_MCE_PROCESS; |
1590 | if (arg3 == PR_MCE_KILL_EARLY) |
1591 | current->flags |= PF_MCE_EARLY; |
1592 | else if (arg3 == PR_MCE_KILL_LATE) |
1593 | current->flags &= ~PF_MCE_EARLY; |
1594 | else if (arg3 == PR_MCE_KILL_DEFAULT) |
1595 | current->flags &= |
1596 | ~(PF_MCE_EARLY|PF_MCE_PROCESS); |
1597 | else |
1598 | return -EINVAL; |
1599 | break; |
1600 | default: |
1601 | return -EINVAL; |
1602 | } |
1603 | error = 0; |
1604 | break; |
1605 | case PR_MCE_KILL_GET: |
1606 | if (arg2 | arg3 | arg4 | arg5) |
1607 | return -EINVAL; |
1608 | if (current->flags & PF_MCE_PROCESS) |
1609 | error = (current->flags & PF_MCE_EARLY) ? |
1610 | PR_MCE_KILL_EARLY : PR_MCE_KILL_LATE; |
1611 | else |
1612 | error = PR_MCE_KILL_DEFAULT; |
1613 | break; |
1614 | default: |
1615 | error = -EINVAL; |
1616 | break; |
1617 | } |
1618 | return error; |
1619 | } |
1620 | |
1621 | SYSCALL_DEFINE3(getcpu, unsigned __user *, cpup, unsigned __user *, nodep, |
1622 | struct getcpu_cache __user *, unused) |
1623 | { |
1624 | int err = 0; |
1625 | int cpu = raw_smp_processor_id(); |
1626 | if (cpup) |
1627 | err |= put_user(cpu, cpup); |
1628 | if (nodep) |
1629 | err |= put_user(cpu_to_node(cpu), nodep); |
1630 | return err ? -EFAULT : 0; |
1631 | } |
1632 | |
1633 | char poweroff_cmd[POWEROFF_CMD_PATH_LEN] = "/sbin/poweroff"; |
1634 | |
1635 | static void argv_cleanup(struct subprocess_info *info) |
1636 | { |
1637 | argv_free(info->argv); |
1638 | } |
1639 | |
1640 | /** |
1641 | * orderly_poweroff - Trigger an orderly system poweroff |
1642 | * @force: force poweroff if command execution fails |
1643 | * |
1644 | * This may be called from any context to trigger a system shutdown. |
1645 | * If the orderly shutdown fails, it will force an immediate shutdown. |
1646 | */ |
1647 | int orderly_poweroff(bool force) |
1648 | { |
1649 | int argc; |
1650 | char **argv = argv_split(GFP_ATOMIC, poweroff_cmd, &argc); |
1651 | static char *envp[] = { |
1652 | "HOME=/", |
1653 | "PATH=/sbin:/bin:/usr/sbin:/usr/bin", |
1654 | NULL |
1655 | }; |
1656 | int ret = -ENOMEM; |
1657 | struct subprocess_info *info; |
1658 | |
1659 | if (argv == NULL) { |
1660 | printk(KERN_WARNING "%s failed to allocate memory for \"%s\"\n", |
1661 | __func__, poweroff_cmd); |
1662 | goto out; |
1663 | } |
1664 | |
1665 | info = call_usermodehelper_setup(argv[0], argv, envp, GFP_ATOMIC); |
1666 | if (info == NULL) { |
1667 | argv_free(argv); |
1668 | goto out; |
1669 | } |
1670 | |
1671 | call_usermodehelper_setfns(info, NULL, argv_cleanup, NULL); |
1672 | |
1673 | ret = call_usermodehelper_exec(info, UMH_NO_WAIT); |
1674 | |
1675 | out: |
1676 | if (ret && force) { |
1677 | printk(KERN_WARNING "Failed to start orderly shutdown: " |
1678 | "forcing the issue\n"); |
1679 | |
1680 | /* I guess this should try to kick off some daemon to |
1681 | sync and poweroff asap. Or not even bother syncing |
1682 | if we're doing an emergency shutdown? */ |
1683 | emergency_sync(); |
1684 | kernel_power_off(); |
1685 | } |
1686 | |
1687 | return ret; |
1688 | } |
1689 | EXPORT_SYMBOL_GPL(orderly_poweroff); |
1690 |
Branches:
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javiroman/ks7010
jz-2.6.34
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Tags:
od-2011-09-04
od-2011-09-18
v2.6.34-rc5
v2.6.34-rc6
v2.6.34-rc7
v3.9