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1 | /* | |
2 | * linux/kernel/sys.c | |
3 | * | |
4 | * Copyright (C) 1991, 1992 Linus Torvalds | |
5 | */ | |
6 | ||
7 | #include <linux/export.h> | |
8 | #include <linux/mm.h> | |
9 | #include <linux/utsname.h> | |
10 | #include <linux/mman.h> | |
11 | #include <linux/reboot.h> | |
12 | #include <linux/prctl.h> | |
13 | #include <linux/highuid.h> | |
14 | #include <linux/fs.h> | |
15 | #include <linux/kmod.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/file.h> | |
40 | #include <linux/mount.h> | |
41 | #include <linux/gfp.h> | |
42 | #include <linux/syscore_ops.h> | |
43 | #include <linux/version.h> | |
44 | #include <linux/ctype.h> | |
45 | ||
46 | #include <linux/compat.h> | |
47 | #include <linux/syscalls.h> | |
48 | #include <linux/kprobes.h> | |
49 | #include <linux/user_namespace.h> | |
50 | ||
51 | #include <linux/kmsg_dump.h> | |
52 | /* Move somewhere else to avoid recompiling? */ | |
53 | #include <generated/utsrelease.h> | |
54 | ||
55 | #include <asm/uaccess.h> | |
56 | #include <asm/io.h> | |
57 | #include <asm/unistd.h> | |
58 | ||
59 | #ifndef SET_UNALIGN_CTL | |
60 | # define SET_UNALIGN_CTL(a,b) (-EINVAL) | |
61 | #endif | |
62 | #ifndef GET_UNALIGN_CTL | |
63 | # define GET_UNALIGN_CTL(a,b) (-EINVAL) | |
64 | #endif | |
65 | #ifndef SET_FPEMU_CTL | |
66 | # define SET_FPEMU_CTL(a,b) (-EINVAL) | |
67 | #endif | |
68 | #ifndef GET_FPEMU_CTL | |
69 | # define GET_FPEMU_CTL(a,b) (-EINVAL) | |
70 | #endif | |
71 | #ifndef SET_FPEXC_CTL | |
72 | # define SET_FPEXC_CTL(a,b) (-EINVAL) | |
73 | #endif | |
74 | #ifndef GET_FPEXC_CTL | |
75 | # define GET_FPEXC_CTL(a,b) (-EINVAL) | |
76 | #endif | |
77 | #ifndef GET_ENDIAN | |
78 | # define GET_ENDIAN(a,b) (-EINVAL) | |
79 | #endif | |
80 | #ifndef SET_ENDIAN | |
81 | # define SET_ENDIAN(a,b) (-EINVAL) | |
82 | #endif | |
83 | #ifndef GET_TSC_CTL | |
84 | # define GET_TSC_CTL(a) (-EINVAL) | |
85 | #endif | |
86 | #ifndef SET_TSC_CTL | |
87 | # define SET_TSC_CTL(a) (-EINVAL) | |
88 | #endif | |
89 | ||
90 | /* | |
91 | * this is where the system-wide overflow UID and GID are defined, for | |
92 | * architectures that now have 32-bit UID/GID but didn't in the past | |
93 | */ | |
94 | ||
95 | int overflowuid = DEFAULT_OVERFLOWUID; | |
96 | int overflowgid = DEFAULT_OVERFLOWGID; | |
97 | ||
98 | EXPORT_SYMBOL(overflowuid); | |
99 | EXPORT_SYMBOL(overflowgid); | |
100 | ||
101 | /* | |
102 | * the same as above, but for filesystems which can only store a 16-bit | |
103 | * UID and GID. as such, this is needed on all architectures | |
104 | */ | |
105 | ||
106 | int fs_overflowuid = DEFAULT_FS_OVERFLOWUID; | |
107 | int fs_overflowgid = DEFAULT_FS_OVERFLOWUID; | |
108 | ||
109 | EXPORT_SYMBOL(fs_overflowuid); | |
110 | EXPORT_SYMBOL(fs_overflowgid); | |
111 | ||
112 | /* | |
113 | * this indicates whether you can reboot with ctrl-alt-del: the default is yes | |
114 | */ | |
115 | ||
116 | int C_A_D = 1; | |
117 | struct pid *cad_pid; | |
118 | EXPORT_SYMBOL(cad_pid); | |
119 | ||
120 | /* | |
121 | * If set, this is used for preparing the system to power off. | |
122 | */ | |
123 | ||
124 | void (*pm_power_off_prepare)(void); | |
125 | ||
126 | /* | |
127 | * Returns true if current's euid is same as p's uid or euid, | |
128 | * or has CAP_SYS_NICE to p's user_ns. | |
129 | * | |
130 | * Called with rcu_read_lock, creds are safe | |
131 | */ | |
132 | static bool set_one_prio_perm(struct task_struct *p) | |
133 | { | |
134 | const struct cred *cred = current_cred(), *pcred = __task_cred(p); | |
135 | ||
136 | if (uid_eq(pcred->uid, cred->euid) || | |
137 | uid_eq(pcred->euid, cred->euid)) | |
138 | return true; | |
139 | if (ns_capable(pcred->user_ns, CAP_SYS_NICE)) | |
140 | return true; | |
141 | return false; | |
142 | } | |
143 | ||
144 | /* | |
145 | * set the priority of a task | |
146 | * - the caller must hold the RCU read lock | |
147 | */ | |
148 | static int set_one_prio(struct task_struct *p, int niceval, int error) | |
149 | { | |
150 | int no_nice; | |
151 | ||
152 | if (!set_one_prio_perm(p)) { | |
153 | error = -EPERM; | |
154 | goto out; | |
155 | } | |
156 | if (niceval < task_nice(p) && !can_nice(p, niceval)) { | |
157 | error = -EACCES; | |
158 | goto out; | |
159 | } | |
160 | no_nice = security_task_setnice(p, niceval); | |
161 | if (no_nice) { | |
162 | error = no_nice; | |
163 | goto out; | |
164 | } | |
165 | if (error == -ESRCH) | |
166 | error = 0; | |
167 | set_user_nice(p, niceval); | |
168 | out: | |
169 | return error; | |
170 | } | |
171 | ||
172 | SYSCALL_DEFINE3(setpriority, int, which, int, who, int, niceval) | |
173 | { | |
174 | struct task_struct *g, *p; | |
175 | struct user_struct *user; | |
176 | const struct cred *cred = current_cred(); | |
177 | int error = -EINVAL; | |
178 | struct pid *pgrp; | |
179 | kuid_t uid; | |
180 | ||
181 | if (which > PRIO_USER || which < PRIO_PROCESS) | |
182 | goto out; | |
183 | ||
184 | /* normalize: avoid signed division (rounding problems) */ | |
185 | error = -ESRCH; | |
186 | if (niceval < -20) | |
187 | niceval = -20; | |
188 | if (niceval > 19) | |
189 | niceval = 19; | |
190 | ||
191 | rcu_read_lock(); | |
192 | read_lock(&tasklist_lock); | |
193 | switch (which) { | |
194 | case PRIO_PROCESS: | |
195 | if (who) | |
196 | p = find_task_by_vpid(who); | |
197 | else | |
198 | p = current; | |
199 | if (p) | |
200 | error = set_one_prio(p, niceval, error); | |
201 | break; | |
202 | case PRIO_PGRP: | |
203 | if (who) | |
204 | pgrp = find_vpid(who); | |
205 | else | |
206 | pgrp = task_pgrp(current); | |
207 | do_each_pid_thread(pgrp, PIDTYPE_PGID, p) { | |
208 | error = set_one_prio(p, niceval, error); | |
209 | } while_each_pid_thread(pgrp, PIDTYPE_PGID, p); | |
210 | break; | |
211 | case PRIO_USER: | |
212 | uid = make_kuid(cred->user_ns, who); | |
213 | user = cred->user; | |
214 | if (!who) | |
215 | uid = cred->uid; | |
216 | else if (!uid_eq(uid, cred->uid) && | |
217 | !(user = find_user(uid))) | |
218 | goto out_unlock; /* No processes for this user */ | |
219 | ||
220 | do_each_thread(g, p) { | |
221 | if (uid_eq(task_uid(p), uid)) | |
222 | error = set_one_prio(p, niceval, error); | |
223 | } while_each_thread(g, p); | |
224 | if (!uid_eq(uid, cred->uid)) | |
225 | free_uid(user); /* For find_user() */ | |
226 | break; | |
227 | } | |
228 | out_unlock: | |
229 | read_unlock(&tasklist_lock); | |
230 | rcu_read_unlock(); | |
231 | out: | |
232 | return error; | |
233 | } | |
234 | ||
235 | /* | |
236 | * Ugh. To avoid negative return values, "getpriority()" will | |
237 | * not return the normal nice-value, but a negated value that | |
238 | * has been offset by 20 (ie it returns 40..1 instead of -20..19) | |
239 | * to stay compatible. | |
240 | */ | |
241 | SYSCALL_DEFINE2(getpriority, int, which, int, who) | |
242 | { | |
243 | struct task_struct *g, *p; | |
244 | struct user_struct *user; | |
245 | const struct cred *cred = current_cred(); | |
246 | long niceval, retval = -ESRCH; | |
247 | struct pid *pgrp; | |
248 | kuid_t uid; | |
249 | ||
250 | if (which > PRIO_USER || which < PRIO_PROCESS) | |
251 | return -EINVAL; | |
252 | ||
253 | rcu_read_lock(); | |
254 | read_lock(&tasklist_lock); | |
255 | switch (which) { | |
256 | case PRIO_PROCESS: | |
257 | if (who) | |
258 | p = find_task_by_vpid(who); | |
259 | else | |
260 | p = current; | |
261 | if (p) { | |
262 | niceval = 20 - task_nice(p); | |
263 | if (niceval > retval) | |
264 | retval = niceval; | |
265 | } | |
266 | break; | |
267 | case PRIO_PGRP: | |
268 | if (who) | |
269 | pgrp = find_vpid(who); | |
270 | else | |
271 | pgrp = task_pgrp(current); | |
272 | do_each_pid_thread(pgrp, PIDTYPE_PGID, p) { | |
273 | niceval = 20 - task_nice(p); | |
274 | if (niceval > retval) | |
275 | retval = niceval; | |
276 | } while_each_pid_thread(pgrp, PIDTYPE_PGID, p); | |
277 | break; | |
278 | case PRIO_USER: | |
279 | uid = make_kuid(cred->user_ns, who); | |
280 | user = cred->user; | |
281 | if (!who) | |
282 | uid = cred->uid; | |
283 | else if (!uid_eq(uid, cred->uid) && | |
284 | !(user = find_user(uid))) | |
285 | goto out_unlock; /* No processes for this user */ | |
286 | ||
287 | do_each_thread(g, p) { | |
288 | if (uid_eq(task_uid(p), uid)) { | |
289 | niceval = 20 - task_nice(p); | |
290 | if (niceval > retval) | |
291 | retval = niceval; | |
292 | } | |
293 | } while_each_thread(g, p); | |
294 | if (!uid_eq(uid, cred->uid)) | |
295 | free_uid(user); /* for find_user() */ | |
296 | break; | |
297 | } | |
298 | out_unlock: | |
299 | read_unlock(&tasklist_lock); | |
300 | rcu_read_unlock(); | |
301 | ||
302 | return retval; | |
303 | } | |
304 | ||
305 | /** | |
306 | * emergency_restart - reboot the system | |
307 | * | |
308 | * Without shutting down any hardware or taking any locks | |
309 | * reboot the system. This is called when we know we are in | |
310 | * trouble so this is our best effort to reboot. This is | |
311 | * safe to call in interrupt context. | |
312 | */ | |
313 | void emergency_restart(void) | |
314 | { | |
315 | kmsg_dump(KMSG_DUMP_EMERG); | |
316 | machine_emergency_restart(); | |
317 | } | |
318 | EXPORT_SYMBOL_GPL(emergency_restart); | |
319 | ||
320 | void kernel_restart_prepare(char *cmd) | |
321 | { | |
322 | blocking_notifier_call_chain(&reboot_notifier_list, SYS_RESTART, cmd); | |
323 | system_state = SYSTEM_RESTART; | |
324 | usermodehelper_disable(); | |
325 | device_shutdown(); | |
326 | syscore_shutdown(); | |
327 | } | |
328 | ||
329 | /** | |
330 | * register_reboot_notifier - Register function to be called at reboot time | |
331 | * @nb: Info about notifier function to be called | |
332 | * | |
333 | * Registers a function with the list of functions | |
334 | * to be called at reboot time. | |
335 | * | |
336 | * Currently always returns zero, as blocking_notifier_chain_register() | |
337 | * always returns zero. | |
338 | */ | |
339 | int register_reboot_notifier(struct notifier_block *nb) | |
340 | { | |
341 | return blocking_notifier_chain_register(&reboot_notifier_list, nb); | |
342 | } | |
343 | EXPORT_SYMBOL(register_reboot_notifier); | |
344 | ||
345 | /** | |
346 | * unregister_reboot_notifier - Unregister previously registered reboot notifier | |
347 | * @nb: Hook to be unregistered | |
348 | * | |
349 | * Unregisters a previously registered reboot | |
350 | * notifier function. | |
351 | * | |
352 | * Returns zero on success, or %-ENOENT on failure. | |
353 | */ | |
354 | int unregister_reboot_notifier(struct notifier_block *nb) | |
355 | { | |
356 | return blocking_notifier_chain_unregister(&reboot_notifier_list, nb); | |
357 | } | |
358 | EXPORT_SYMBOL(unregister_reboot_notifier); | |
359 | ||
360 | /** | |
361 | * kernel_restart - reboot the system | |
362 | * @cmd: pointer to buffer containing command to execute for restart | |
363 | * or %NULL | |
364 | * | |
365 | * Shutdown everything and perform a clean reboot. | |
366 | * This is not safe to call in interrupt context. | |
367 | */ | |
368 | void kernel_restart(char *cmd) | |
369 | { | |
370 | kernel_restart_prepare(cmd); | |
371 | disable_nonboot_cpus(); | |
372 | if (!cmd) | |
373 | printk(KERN_EMERG "Restarting system.\n"); | |
374 | else | |
375 | printk(KERN_EMERG "Restarting system with command '%s'.\n", cmd); | |
376 | kmsg_dump(KMSG_DUMP_RESTART); | |
377 | machine_restart(cmd); | |
378 | } | |
379 | EXPORT_SYMBOL_GPL(kernel_restart); | |
380 | ||
381 | static void kernel_shutdown_prepare(enum system_states state) | |
382 | { | |
383 | blocking_notifier_call_chain(&reboot_notifier_list, | |
384 | (state == SYSTEM_HALT)?SYS_HALT:SYS_POWER_OFF, NULL); | |
385 | system_state = state; | |
386 | usermodehelper_disable(); | |
387 | device_shutdown(); | |
388 | } | |
389 | /** | |
390 | * kernel_halt - halt the system | |
391 | * | |
392 | * Shutdown everything and perform a clean system halt. | |
393 | */ | |
394 | void kernel_halt(void) | |
395 | { | |
396 | kernel_shutdown_prepare(SYSTEM_HALT); | |
397 | syscore_shutdown(); | |
398 | printk(KERN_EMERG "System halted.\n"); | |
399 | kmsg_dump(KMSG_DUMP_HALT); | |
400 | machine_halt(); | |
401 | } | |
402 | ||
403 | EXPORT_SYMBOL_GPL(kernel_halt); | |
404 | ||
405 | /** | |
406 | * kernel_power_off - power_off the system | |
407 | * | |
408 | * Shutdown everything and perform a clean system power_off. | |
409 | */ | |
410 | void kernel_power_off(void) | |
411 | { | |
412 | kernel_shutdown_prepare(SYSTEM_POWER_OFF); | |
413 | if (pm_power_off_prepare) | |
414 | pm_power_off_prepare(); | |
415 | disable_nonboot_cpus(); | |
416 | syscore_shutdown(); | |
417 | printk(KERN_EMERG "Power down.\n"); | |
418 | kmsg_dump(KMSG_DUMP_POWEROFF); | |
419 | machine_power_off(); | |
420 | } | |
421 | EXPORT_SYMBOL_GPL(kernel_power_off); | |
422 | ||
423 | static DEFINE_MUTEX(reboot_mutex); | |
424 | ||
425 | /* | |
426 | * Reboot system call: for obvious reasons only root may call it, | |
427 | * and even root needs to set up some magic numbers in the registers | |
428 | * so that some mistake won't make this reboot the whole machine. | |
429 | * You can also set the meaning of the ctrl-alt-del-key here. | |
430 | * | |
431 | * reboot doesn't sync: do that yourself before calling this. | |
432 | */ | |
433 | SYSCALL_DEFINE4(reboot, int, magic1, int, magic2, unsigned int, cmd, | |
434 | void __user *, arg) | |
435 | { | |
436 | char buffer[256]; | |
437 | int ret = 0; | |
438 | ||
439 | /* We only trust the superuser with rebooting the system. */ | |
440 | if (!capable(CAP_SYS_BOOT)) | |
441 | return -EPERM; | |
442 | ||
443 | /* For safety, we require "magic" arguments. */ | |
444 | if (magic1 != LINUX_REBOOT_MAGIC1 || | |
445 | (magic2 != LINUX_REBOOT_MAGIC2 && | |
446 | magic2 != LINUX_REBOOT_MAGIC2A && | |
447 | magic2 != LINUX_REBOOT_MAGIC2B && | |
448 | magic2 != LINUX_REBOOT_MAGIC2C)) | |
449 | return -EINVAL; | |
450 | ||
451 | /* | |
452 | * If pid namespaces are enabled and the current task is in a child | |
453 | * pid_namespace, the command is handled by reboot_pid_ns() which will | |
454 | * call do_exit(). | |
455 | */ | |
456 | ret = reboot_pid_ns(task_active_pid_ns(current), cmd); | |
457 | if (ret) | |
458 | return ret; | |
459 | ||
460 | /* Instead of trying to make the power_off code look like | |
461 | * halt when pm_power_off is not set do it the easy way. | |
462 | */ | |
463 | if ((cmd == LINUX_REBOOT_CMD_POWER_OFF) && !pm_power_off) | |
464 | cmd = LINUX_REBOOT_CMD_HALT; | |
465 | ||
466 | mutex_lock(&reboot_mutex); | |
467 | switch (cmd) { | |
468 | case LINUX_REBOOT_CMD_RESTART: | |
469 | kernel_restart(NULL); | |
470 | break; | |
471 | ||
472 | case LINUX_REBOOT_CMD_CAD_ON: | |
473 | C_A_D = 1; | |
474 | break; | |
475 | ||
476 | case LINUX_REBOOT_CMD_CAD_OFF: | |
477 | C_A_D = 0; | |
478 | break; | |
479 | ||
480 | case LINUX_REBOOT_CMD_HALT: | |
481 | kernel_halt(); | |
482 | do_exit(0); | |
483 | panic("cannot halt"); | |
484 | ||
485 | case LINUX_REBOOT_CMD_POWER_OFF: | |
486 | kernel_power_off(); | |
487 | do_exit(0); | |
488 | break; | |
489 | ||
490 | case LINUX_REBOOT_CMD_RESTART2: | |
491 | if (strncpy_from_user(&buffer[0], arg, sizeof(buffer) - 1) < 0) { | |
492 | ret = -EFAULT; | |
493 | break; | |
494 | } | |
495 | buffer[sizeof(buffer) - 1] = '\0'; | |
496 | ||
497 | kernel_restart(buffer); | |
498 | break; | |
499 | ||
500 | #ifdef CONFIG_KEXEC | |
501 | case LINUX_REBOOT_CMD_KEXEC: | |
502 | ret = kernel_kexec(); | |
503 | break; | |
504 | #endif | |
505 | ||
506 | #ifdef CONFIG_HIBERNATION | |
507 | case LINUX_REBOOT_CMD_SW_SUSPEND: | |
508 | ret = hibernate(); | |
509 | break; | |
510 | #endif | |
511 | ||
512 | default: | |
513 | ret = -EINVAL; | |
514 | break; | |
515 | } | |
516 | mutex_unlock(&reboot_mutex); | |
517 | return ret; | |
518 | } | |
519 | ||
520 | static void deferred_cad(struct work_struct *dummy) | |
521 | { | |
522 | kernel_restart(NULL); | |
523 | } | |
524 | ||
525 | /* | |
526 | * This function gets called by ctrl-alt-del - ie the keyboard interrupt. | |
527 | * As it's called within an interrupt, it may NOT sync: the only choice | |
528 | * is whether to reboot at once, or just ignore the ctrl-alt-del. | |
529 | */ | |
530 | void ctrl_alt_del(void) | |
531 | { | |
532 | static DECLARE_WORK(cad_work, deferred_cad); | |
533 | ||
534 | if (C_A_D) | |
535 | schedule_work(&cad_work); | |
536 | else | |
537 | kill_cad_pid(SIGINT, 1); | |
538 | } | |
539 | ||
540 | /* | |
541 | * Unprivileged users may change the real gid to the effective gid | |
542 | * or vice versa. (BSD-style) | |
543 | * | |
544 | * If you set the real gid at all, or set the effective gid to a value not | |
545 | * equal to the real gid, then the saved gid is set to the new effective gid. | |
546 | * | |
547 | * This makes it possible for a setgid program to completely drop its | |
548 | * privileges, which is often a useful assertion to make when you are doing | |
549 | * a security audit over a program. | |
550 | * | |
551 | * The general idea is that a program which uses just setregid() will be | |
552 | * 100% compatible with BSD. A program which uses just setgid() will be | |
553 | * 100% compatible with POSIX with saved IDs. | |
554 | * | |
555 | * SMP: There are not races, the GIDs are checked only by filesystem | |
556 | * operations (as far as semantic preservation is concerned). | |
557 | */ | |
558 | SYSCALL_DEFINE2(setregid, gid_t, rgid, gid_t, egid) | |
559 | { | |
560 | struct user_namespace *ns = current_user_ns(); | |
561 | const struct cred *old; | |
562 | struct cred *new; | |
563 | int retval; | |
564 | kgid_t krgid, kegid; | |
565 | ||
566 | krgid = make_kgid(ns, rgid); | |
567 | kegid = make_kgid(ns, egid); | |
568 | ||
569 | if ((rgid != (gid_t) -1) && !gid_valid(krgid)) | |
570 | return -EINVAL; | |
571 | if ((egid != (gid_t) -1) && !gid_valid(kegid)) | |
572 | return -EINVAL; | |
573 | ||
574 | new = prepare_creds(); | |
575 | if (!new) | |
576 | return -ENOMEM; | |
577 | old = current_cred(); | |
578 | ||
579 | retval = -EPERM; | |
580 | if (rgid != (gid_t) -1) { | |
581 | if (gid_eq(old->gid, krgid) || | |
582 | gid_eq(old->egid, krgid) || | |
583 | nsown_capable(CAP_SETGID)) | |
584 | new->gid = krgid; | |
585 | else | |
586 | goto error; | |
587 | } | |
588 | if (egid != (gid_t) -1) { | |
589 | if (gid_eq(old->gid, kegid) || | |
590 | gid_eq(old->egid, kegid) || | |
591 | gid_eq(old->sgid, kegid) || | |
592 | nsown_capable(CAP_SETGID)) | |
593 | new->egid = kegid; | |
594 | else | |
595 | goto error; | |
596 | } | |
597 | ||
598 | if (rgid != (gid_t) -1 || | |
599 | (egid != (gid_t) -1 && !gid_eq(kegid, old->gid))) | |
600 | new->sgid = new->egid; | |
601 | new->fsgid = new->egid; | |
602 | ||
603 | return commit_creds(new); | |
604 | ||
605 | error: | |
606 | abort_creds(new); | |
607 | return retval; | |
608 | } | |
609 | ||
610 | /* | |
611 | * setgid() is implemented like SysV w/ SAVED_IDS | |
612 | * | |
613 | * SMP: Same implicit races as above. | |
614 | */ | |
615 | SYSCALL_DEFINE1(setgid, gid_t, gid) | |
616 | { | |
617 | struct user_namespace *ns = current_user_ns(); | |
618 | const struct cred *old; | |
619 | struct cred *new; | |
620 | int retval; | |
621 | kgid_t kgid; | |
622 | ||
623 | kgid = make_kgid(ns, gid); | |
624 | if (!gid_valid(kgid)) | |
625 | return -EINVAL; | |
626 | ||
627 | new = prepare_creds(); | |
628 | if (!new) | |
629 | return -ENOMEM; | |
630 | old = current_cred(); | |
631 | ||
632 | retval = -EPERM; | |
633 | if (nsown_capable(CAP_SETGID)) | |
634 | new->gid = new->egid = new->sgid = new->fsgid = kgid; | |
635 | else if (gid_eq(kgid, old->gid) || gid_eq(kgid, old->sgid)) | |
636 | new->egid = new->fsgid = kgid; | |
637 | else | |
638 | goto error; | |
639 | ||
640 | return commit_creds(new); | |
641 | ||
642 | error: | |
643 | abort_creds(new); | |
644 | return retval; | |
645 | } | |
646 | ||
647 | /* | |
648 | * change the user struct in a credentials set to match the new UID | |
649 | */ | |
650 | static int set_user(struct cred *new) | |
651 | { | |
652 | struct user_struct *new_user; | |
653 | ||
654 | new_user = alloc_uid(new->uid); | |
655 | if (!new_user) | |
656 | return -EAGAIN; | |
657 | ||
658 | /* | |
659 | * We don't fail in case of NPROC limit excess here because too many | |
660 | * poorly written programs don't check set*uid() return code, assuming | |
661 | * it never fails if called by root. We may still enforce NPROC limit | |
662 | * for programs doing set*uid()+execve() by harmlessly deferring the | |
663 | * failure to the execve() stage. | |
664 | */ | |
665 | if (atomic_read(&new_user->processes) >= rlimit(RLIMIT_NPROC) && | |
666 | new_user != INIT_USER) | |
667 | current->flags |= PF_NPROC_EXCEEDED; | |
668 | else | |
669 | current->flags &= ~PF_NPROC_EXCEEDED; | |
670 | ||
671 | free_uid(new->user); | |
672 | new->user = new_user; | |
673 | return 0; | |
674 | } | |
675 | ||
676 | /* | |
677 | * Unprivileged users may change the real uid to the effective uid | |
678 | * or vice versa. (BSD-style) | |
679 | * | |
680 | * If you set the real uid at all, or set the effective uid to a value not | |
681 | * equal to the real uid, then the saved uid is set to the new effective uid. | |
682 | * | |
683 | * This makes it possible for a setuid program to completely drop its | |
684 | * privileges, which is often a useful assertion to make when you are doing | |
685 | * a security audit over a program. | |
686 | * | |
687 | * The general idea is that a program which uses just setreuid() will be | |
688 | * 100% compatible with BSD. A program which uses just setuid() will be | |
689 | * 100% compatible with POSIX with saved IDs. | |
690 | */ | |
691 | SYSCALL_DEFINE2(setreuid, uid_t, ruid, uid_t, euid) | |
692 | { | |
693 | struct user_namespace *ns = current_user_ns(); | |
694 | const struct cred *old; | |
695 | struct cred *new; | |
696 | int retval; | |
697 | kuid_t kruid, keuid; | |
698 | ||
699 | kruid = make_kuid(ns, ruid); | |
700 | keuid = make_kuid(ns, euid); | |
701 | ||
702 | if ((ruid != (uid_t) -1) && !uid_valid(kruid)) | |
703 | return -EINVAL; | |
704 | if ((euid != (uid_t) -1) && !uid_valid(keuid)) | |
705 | return -EINVAL; | |
706 | ||
707 | new = prepare_creds(); | |
708 | if (!new) | |
709 | return -ENOMEM; | |
710 | old = current_cred(); | |
711 | ||
712 | retval = -EPERM; | |
713 | if (ruid != (uid_t) -1) { | |
714 | new->uid = kruid; | |
715 | if (!uid_eq(old->uid, kruid) && | |
716 | !uid_eq(old->euid, kruid) && | |
717 | !nsown_capable(CAP_SETUID)) | |
718 | goto error; | |
719 | } | |
720 | ||
721 | if (euid != (uid_t) -1) { | |
722 | new->euid = keuid; | |
723 | if (!uid_eq(old->uid, keuid) && | |
724 | !uid_eq(old->euid, keuid) && | |
725 | !uid_eq(old->suid, keuid) && | |
726 | !nsown_capable(CAP_SETUID)) | |
727 | goto error; | |
728 | } | |
729 | ||
730 | if (!uid_eq(new->uid, old->uid)) { | |
731 | retval = set_user(new); | |
732 | if (retval < 0) | |
733 | goto error; | |
734 | } | |
735 | if (ruid != (uid_t) -1 || | |
736 | (euid != (uid_t) -1 && !uid_eq(keuid, old->uid))) | |
737 | new->suid = new->euid; | |
738 | new->fsuid = new->euid; | |
739 | ||
740 | retval = security_task_fix_setuid(new, old, LSM_SETID_RE); | |
741 | if (retval < 0) | |
742 | goto error; | |
743 | ||
744 | return commit_creds(new); | |
745 | ||
746 | error: | |
747 | abort_creds(new); | |
748 | return retval; | |
749 | } | |
750 | ||
751 | /* | |
752 | * setuid() is implemented like SysV with SAVED_IDS | |
753 | * | |
754 | * Note that SAVED_ID's is deficient in that a setuid root program | |
755 | * like sendmail, for example, cannot set its uid to be a normal | |
756 | * user and then switch back, because if you're root, setuid() sets | |
757 | * the saved uid too. If you don't like this, blame the bright people | |
758 | * in the POSIX committee and/or USG. Note that the BSD-style setreuid() | |
759 | * will allow a root program to temporarily drop privileges and be able to | |
760 | * regain them by swapping the real and effective uid. | |
761 | */ | |
762 | SYSCALL_DEFINE1(setuid, uid_t, uid) | |
763 | { | |
764 | struct user_namespace *ns = current_user_ns(); | |
765 | const struct cred *old; | |
766 | struct cred *new; | |
767 | int retval; | |
768 | kuid_t kuid; | |
769 | ||
770 | kuid = make_kuid(ns, uid); | |
771 | if (!uid_valid(kuid)) | |
772 | return -EINVAL; | |
773 | ||
774 | new = prepare_creds(); | |
775 | if (!new) | |
776 | return -ENOMEM; | |
777 | old = current_cred(); | |
778 | ||
779 | retval = -EPERM; | |
780 | if (nsown_capable(CAP_SETUID)) { | |
781 | new->suid = new->uid = kuid; | |
782 | if (!uid_eq(kuid, old->uid)) { | |
783 | retval = set_user(new); | |
784 | if (retval < 0) | |
785 | goto error; | |
786 | } | |
787 | } else if (!uid_eq(kuid, old->uid) && !uid_eq(kuid, new->suid)) { | |
788 | goto error; | |
789 | } | |
790 | ||
791 | new->fsuid = new->euid = kuid; | |
792 | ||
793 | retval = security_task_fix_setuid(new, old, LSM_SETID_ID); | |
794 | if (retval < 0) | |
795 | goto error; | |
796 | ||
797 | return commit_creds(new); | |
798 | ||
799 | error: | |
800 | abort_creds(new); | |
801 | return retval; | |
802 | } | |
803 | ||
804 | ||
805 | /* | |
806 | * This function implements a generic ability to update ruid, euid, | |
807 | * and suid. This allows you to implement the 4.4 compatible seteuid(). | |
808 | */ | |
809 | SYSCALL_DEFINE3(setresuid, uid_t, ruid, uid_t, euid, uid_t, suid) | |
810 | { | |
811 | struct user_namespace *ns = current_user_ns(); | |
812 | const struct cred *old; | |
813 | struct cred *new; | |
814 | int retval; | |
815 | kuid_t kruid, keuid, ksuid; | |
816 | ||
817 | kruid = make_kuid(ns, ruid); | |
818 | keuid = make_kuid(ns, euid); | |
819 | ksuid = make_kuid(ns, suid); | |
820 | ||
821 | if ((ruid != (uid_t) -1) && !uid_valid(kruid)) | |
822 | return -EINVAL; | |
823 | ||
824 | if ((euid != (uid_t) -1) && !uid_valid(keuid)) | |
825 | return -EINVAL; | |
826 | ||
827 | if ((suid != (uid_t) -1) && !uid_valid(ksuid)) | |
828 | return -EINVAL; | |
829 | ||
830 | new = prepare_creds(); | |
831 | if (!new) | |
832 | return -ENOMEM; | |
833 | ||
834 | old = current_cred(); | |
835 | ||
836 | retval = -EPERM; | |
837 | if (!nsown_capable(CAP_SETUID)) { | |
838 | if (ruid != (uid_t) -1 && !uid_eq(kruid, old->uid) && | |
839 | !uid_eq(kruid, old->euid) && !uid_eq(kruid, old->suid)) | |
840 | goto error; | |
841 | if (euid != (uid_t) -1 && !uid_eq(keuid, old->uid) && | |
842 | !uid_eq(keuid, old->euid) && !uid_eq(keuid, old->suid)) | |
843 | goto error; | |
844 | if (suid != (uid_t) -1 && !uid_eq(ksuid, old->uid) && | |
845 | !uid_eq(ksuid, old->euid) && !uid_eq(ksuid, old->suid)) | |
846 | goto error; | |
847 | } | |
848 | ||
849 | if (ruid != (uid_t) -1) { | |
850 | new->uid = kruid; | |
851 | if (!uid_eq(kruid, old->uid)) { | |
852 | retval = set_user(new); | |
853 | if (retval < 0) | |
854 | goto error; | |
855 | } | |
856 | } | |
857 | if (euid != (uid_t) -1) | |
858 | new->euid = keuid; | |
859 | if (suid != (uid_t) -1) | |
860 | new->suid = ksuid; | |
861 | new->fsuid = new->euid; | |
862 | ||
863 | retval = security_task_fix_setuid(new, old, LSM_SETID_RES); | |
864 | if (retval < 0) | |
865 | goto error; | |
866 | ||
867 | return commit_creds(new); | |
868 | ||
869 | error: | |
870 | abort_creds(new); | |
871 | return retval; | |
872 | } | |
873 | ||
874 | SYSCALL_DEFINE3(getresuid, uid_t __user *, ruidp, uid_t __user *, euidp, uid_t __user *, suidp) | |
875 | { | |
876 | const struct cred *cred = current_cred(); | |
877 | int retval; | |
878 | uid_t ruid, euid, suid; | |
879 | ||
880 | ruid = from_kuid_munged(cred->user_ns, cred->uid); | |
881 | euid = from_kuid_munged(cred->user_ns, cred->euid); | |
882 | suid = from_kuid_munged(cred->user_ns, cred->suid); | |
883 | ||
884 | if (!(retval = put_user(ruid, ruidp)) && | |
885 | !(retval = put_user(euid, euidp))) | |
886 | retval = put_user(suid, suidp); | |
887 | ||
888 | return retval; | |
889 | } | |
890 | ||
891 | /* | |
892 | * Same as above, but for rgid, egid, sgid. | |
893 | */ | |
894 | SYSCALL_DEFINE3(setresgid, gid_t, rgid, gid_t, egid, gid_t, sgid) | |
895 | { | |
896 | struct user_namespace *ns = current_user_ns(); | |
897 | const struct cred *old; | |
898 | struct cred *new; | |
899 | int retval; | |
900 | kgid_t krgid, kegid, ksgid; | |
901 | ||
902 | krgid = make_kgid(ns, rgid); | |
903 | kegid = make_kgid(ns, egid); | |
904 | ksgid = make_kgid(ns, sgid); | |
905 | ||
906 | if ((rgid != (gid_t) -1) && !gid_valid(krgid)) | |
907 | return -EINVAL; | |
908 | if ((egid != (gid_t) -1) && !gid_valid(kegid)) | |
909 | return -EINVAL; | |
910 | if ((sgid != (gid_t) -1) && !gid_valid(ksgid)) | |
911 | return -EINVAL; | |
912 | ||
913 | new = prepare_creds(); | |
914 | if (!new) | |
915 | return -ENOMEM; | |
916 | old = current_cred(); | |
917 | ||
918 | retval = -EPERM; | |
919 | if (!nsown_capable(CAP_SETGID)) { | |
920 | if (rgid != (gid_t) -1 && !gid_eq(krgid, old->gid) && | |
921 | !gid_eq(krgid, old->egid) && !gid_eq(krgid, old->sgid)) | |
922 | goto error; | |
923 | if (egid != (gid_t) -1 && !gid_eq(kegid, old->gid) && | |
924 | !gid_eq(kegid, old->egid) && !gid_eq(kegid, old->sgid)) | |
925 | goto error; | |
926 | if (sgid != (gid_t) -1 && !gid_eq(ksgid, old->gid) && | |
927 | !gid_eq(ksgid, old->egid) && !gid_eq(ksgid, old->sgid)) | |
928 | goto error; | |
929 | } | |
930 | ||
931 | if (rgid != (gid_t) -1) | |
932 | new->gid = krgid; | |
933 | if (egid != (gid_t) -1) | |
934 | new->egid = kegid; | |
935 | if (sgid != (gid_t) -1) | |
936 | new->sgid = ksgid; | |
937 | new->fsgid = new->egid; | |
938 | ||
939 | return commit_creds(new); | |
940 | ||
941 | error: | |
942 | abort_creds(new); | |
943 | return retval; | |
944 | } | |
945 | ||
946 | SYSCALL_DEFINE3(getresgid, gid_t __user *, rgidp, gid_t __user *, egidp, gid_t __user *, sgidp) | |
947 | { | |
948 | const struct cred *cred = current_cred(); | |
949 | int retval; | |
950 | gid_t rgid, egid, sgid; | |
951 | ||
952 | rgid = from_kgid_munged(cred->user_ns, cred->gid); | |
953 | egid = from_kgid_munged(cred->user_ns, cred->egid); | |
954 | sgid = from_kgid_munged(cred->user_ns, cred->sgid); | |
955 | ||
956 | if (!(retval = put_user(rgid, rgidp)) && | |
957 | !(retval = put_user(egid, egidp))) | |
958 | retval = put_user(sgid, sgidp); | |
959 | ||
960 | return retval; | |
961 | } | |
962 | ||
963 | ||
964 | /* | |
965 | * "setfsuid()" sets the fsuid - the uid used for filesystem checks. This | |
966 | * is used for "access()" and for the NFS daemon (letting nfsd stay at | |
967 | * whatever uid it wants to). It normally shadows "euid", except when | |
968 | * explicitly set by setfsuid() or for access.. | |
969 | */ | |
970 | SYSCALL_DEFINE1(setfsuid, uid_t, uid) | |
971 | { | |
972 | const struct cred *old; | |
973 | struct cred *new; | |
974 | uid_t old_fsuid; | |
975 | kuid_t kuid; | |
976 | ||
977 | old = current_cred(); | |
978 | old_fsuid = from_kuid_munged(old->user_ns, old->fsuid); | |
979 | ||
980 | kuid = make_kuid(old->user_ns, uid); | |
981 | if (!uid_valid(kuid)) | |
982 | return old_fsuid; | |
983 | ||
984 | new = prepare_creds(); | |
985 | if (!new) | |
986 | return old_fsuid; | |
987 | ||
988 | if (uid_eq(kuid, old->uid) || uid_eq(kuid, old->euid) || | |
989 | uid_eq(kuid, old->suid) || uid_eq(kuid, old->fsuid) || | |
990 | nsown_capable(CAP_SETUID)) { | |
991 | if (!uid_eq(kuid, old->fsuid)) { | |
992 | new->fsuid = kuid; | |
993 | if (security_task_fix_setuid(new, old, LSM_SETID_FS) == 0) | |
994 | goto change_okay; | |
995 | } | |
996 | } | |
997 | ||
998 | abort_creds(new); | |
999 | return old_fsuid; | |
1000 | ||
1001 | change_okay: | |
1002 | commit_creds(new); | |
1003 | return old_fsuid; | |
1004 | } | |
1005 | ||
1006 | /* | |
1007 | * Samma på svenska.. | |
1008 | */ | |
1009 | SYSCALL_DEFINE1(setfsgid, gid_t, gid) | |
1010 | { | |
1011 | const struct cred *old; | |
1012 | struct cred *new; | |
1013 | gid_t old_fsgid; | |
1014 | kgid_t kgid; | |
1015 | ||
1016 | old = current_cred(); | |
1017 | old_fsgid = from_kgid_munged(old->user_ns, old->fsgid); | |
1018 | ||
1019 | kgid = make_kgid(old->user_ns, gid); | |
1020 | if (!gid_valid(kgid)) | |
1021 | return old_fsgid; | |
1022 | ||
1023 | new = prepare_creds(); | |
1024 | if (!new) | |
1025 | return old_fsgid; | |
1026 | ||
1027 | if (gid_eq(kgid, old->gid) || gid_eq(kgid, old->egid) || | |
1028 | gid_eq(kgid, old->sgid) || gid_eq(kgid, old->fsgid) || | |
1029 | nsown_capable(CAP_SETGID)) { | |
1030 | if (!gid_eq(kgid, old->fsgid)) { | |
1031 | new->fsgid = kgid; | |
1032 | goto change_okay; | |
1033 | } | |
1034 | } | |
1035 | ||
1036 | abort_creds(new); | |
1037 | return old_fsgid; | |
1038 | ||
1039 | change_okay: | |
1040 | commit_creds(new); | |
1041 | return old_fsgid; | |
1042 | } | |
1043 | ||
1044 | void do_sys_times(struct tms *tms) | |
1045 | { | |
1046 | cputime_t tgutime, tgstime, cutime, cstime; | |
1047 | ||
1048 | spin_lock_irq(¤t->sighand->siglock); | |
1049 | thread_group_cputime_adjusted(current, &tgutime, &tgstime); | |
1050 | cutime = current->signal->cutime; | |
1051 | cstime = current->signal->cstime; | |
1052 | spin_unlock_irq(¤t->sighand->siglock); | |
1053 | tms->tms_utime = cputime_to_clock_t(tgutime); | |
1054 | tms->tms_stime = cputime_to_clock_t(tgstime); | |
1055 | tms->tms_cutime = cputime_to_clock_t(cutime); | |
1056 | tms->tms_cstime = cputime_to_clock_t(cstime); | |
1057 | } | |
1058 | ||
1059 | SYSCALL_DEFINE1(times, struct tms __user *, tbuf) | |
1060 | { | |
1061 | if (tbuf) { | |
1062 | struct tms tmp; | |
1063 | ||
1064 | do_sys_times(&tmp); | |
1065 | if (copy_to_user(tbuf, &tmp, sizeof(struct tms))) | |
1066 | return -EFAULT; | |
1067 | } | |
1068 | force_successful_syscall_return(); | |
1069 | return (long) jiffies_64_to_clock_t(get_jiffies_64()); | |
1070 | } | |
1071 | ||
1072 | /* | |
1073 | * This needs some heavy checking ... | |
1074 | * I just haven't the stomach for it. I also don't fully | |
1075 | * understand sessions/pgrp etc. Let somebody who does explain it. | |
1076 | * | |
1077 | * OK, I think I have the protection semantics right.... this is really | |
1078 | * only important on a multi-user system anyway, to make sure one user | |
1079 | * can't send a signal to a process owned by another. -TYT, 12/12/91 | |
1080 | * | |
1081 | * Auch. Had to add the 'did_exec' flag to conform completely to POSIX. | |
1082 | * LBT 04.03.94 | |
1083 | */ | |
1084 | SYSCALL_DEFINE2(setpgid, pid_t, pid, pid_t, pgid) | |
1085 | { | |
1086 | struct task_struct *p; | |
1087 | struct task_struct *group_leader = current->group_leader; | |
1088 | struct pid *pgrp; | |
1089 | int err; | |
1090 | ||
1091 | if (!pid) | |
1092 | pid = task_pid_vnr(group_leader); | |
1093 | if (!pgid) | |
1094 | pgid = pid; | |
1095 | if (pgid < 0) | |
1096 | return -EINVAL; | |
1097 | rcu_read_lock(); | |
1098 | ||
1099 | /* From this point forward we keep holding onto the tasklist lock | |
1100 | * so that our parent does not change from under us. -DaveM | |
1101 | */ | |
1102 | write_lock_irq(&tasklist_lock); | |
1103 | ||
1104 | err = -ESRCH; | |
1105 | p = find_task_by_vpid(pid); | |
1106 | if (!p) | |
1107 | goto out; | |
1108 | ||
1109 | err = -EINVAL; | |
1110 | if (!thread_group_leader(p)) | |
1111 | goto out; | |
1112 | ||
1113 | if (same_thread_group(p->real_parent, group_leader)) { | |
1114 | err = -EPERM; | |
1115 | if (task_session(p) != task_session(group_leader)) | |
1116 | goto out; | |
1117 | err = -EACCES; | |
1118 | if (p->did_exec) | |
1119 | goto out; | |
1120 | } else { | |
1121 | err = -ESRCH; | |
1122 | if (p != group_leader) | |
1123 | goto out; | |
1124 | } | |
1125 | ||
1126 | err = -EPERM; | |
1127 | if (p->signal->leader) | |
1128 | goto out; | |
1129 | ||
1130 | pgrp = task_pid(p); | |
1131 | if (pgid != pid) { | |
1132 | struct task_struct *g; | |
1133 | ||
1134 | pgrp = find_vpid(pgid); | |
1135 | g = pid_task(pgrp, PIDTYPE_PGID); | |
1136 | if (!g || task_session(g) != task_session(group_leader)) | |
1137 | goto out; | |
1138 | } | |
1139 | ||
1140 | err = security_task_setpgid(p, pgid); | |
1141 | if (err) | |
1142 | goto out; | |
1143 | ||
1144 | if (task_pgrp(p) != pgrp) | |
1145 | change_pid(p, PIDTYPE_PGID, pgrp); | |
1146 | ||
1147 | err = 0; | |
1148 | out: | |
1149 | /* All paths lead to here, thus we are safe. -DaveM */ | |
1150 | write_unlock_irq(&tasklist_lock); | |
1151 | rcu_read_unlock(); | |
1152 | return err; | |
1153 | } | |
1154 | ||
1155 | SYSCALL_DEFINE1(getpgid, pid_t, pid) | |
1156 | { | |
1157 | struct task_struct *p; | |
1158 | struct pid *grp; | |
1159 | int retval; | |
1160 | ||
1161 | rcu_read_lock(); | |
1162 | if (!pid) | |
1163 | grp = task_pgrp(current); | |
1164 | else { | |
1165 | retval = -ESRCH; | |
1166 | p = find_task_by_vpid(pid); | |
1167 | if (!p) | |
1168 | goto out; | |
1169 | grp = task_pgrp(p); | |
1170 | if (!grp) | |
1171 | goto out; | |
1172 | ||
1173 | retval = security_task_getpgid(p); | |
1174 | if (retval) | |
1175 | goto out; | |
1176 | } | |
1177 | retval = pid_vnr(grp); | |
1178 | out: | |
1179 | rcu_read_unlock(); | |
1180 | return retval; | |
1181 | } | |
1182 | ||
1183 | #ifdef __ARCH_WANT_SYS_GETPGRP | |
1184 | ||
1185 | SYSCALL_DEFINE0(getpgrp) | |
1186 | { | |
1187 | return sys_getpgid(0); | |
1188 | } | |
1189 | ||
1190 | #endif | |
1191 | ||
1192 | SYSCALL_DEFINE1(getsid, pid_t, pid) | |
1193 | { | |
1194 | struct task_struct *p; | |
1195 | struct pid *sid; | |
1196 | int retval; | |
1197 | ||
1198 | rcu_read_lock(); | |
1199 | if (!pid) | |
1200 | sid = task_session(current); | |
1201 | else { | |
1202 | retval = -ESRCH; | |
1203 | p = find_task_by_vpid(pid); | |
1204 | if (!p) | |
1205 | goto out; | |
1206 | sid = task_session(p); | |
1207 | if (!sid) | |
1208 | goto out; | |
1209 | ||
1210 | retval = security_task_getsid(p); | |
1211 | if (retval) | |
1212 | goto out; | |
1213 | } | |
1214 | retval = pid_vnr(sid); | |
1215 | out: | |
1216 | rcu_read_unlock(); | |
1217 | return retval; | |
1218 | } | |
1219 | ||
1220 | SYSCALL_DEFINE0(setsid) | |
1221 | { | |
1222 | struct task_struct *group_leader = current->group_leader; | |
1223 | struct pid *sid = task_pid(group_leader); | |
1224 | pid_t session = pid_vnr(sid); | |
1225 | int err = -EPERM; | |
1226 | ||
1227 | write_lock_irq(&tasklist_lock); | |
1228 | /* Fail if I am already a session leader */ | |
1229 | if (group_leader->signal->leader) | |
1230 | goto out; | |
1231 | ||
1232 | /* Fail if a process group id already exists that equals the | |
1233 | * proposed session id. | |
1234 | */ | |
1235 | if (pid_task(sid, PIDTYPE_PGID)) | |
1236 | goto out; | |
1237 | ||
1238 | group_leader->signal->leader = 1; | |
1239 | __set_special_pids(sid); | |
1240 | ||
1241 | proc_clear_tty(group_leader); | |
1242 | ||
1243 | err = session; | |
1244 | out: | |
1245 | write_unlock_irq(&tasklist_lock); | |
1246 | if (err > 0) { | |
1247 | proc_sid_connector(group_leader); | |
1248 | sched_autogroup_create_attach(group_leader); | |
1249 | } | |
1250 | return err; | |
1251 | } | |
1252 | ||
1253 | DECLARE_RWSEM(uts_sem); | |
1254 | ||
1255 | #ifdef COMPAT_UTS_MACHINE | |
1256 | #define override_architecture(name) \ | |
1257 | (personality(current->personality) == PER_LINUX32 && \ | |
1258 | copy_to_user(name->machine, COMPAT_UTS_MACHINE, \ | |
1259 | sizeof(COMPAT_UTS_MACHINE))) | |
1260 | #else | |
1261 | #define override_architecture(name) 0 | |
1262 | #endif | |
1263 | ||
1264 | /* | |
1265 | * Work around broken programs that cannot handle "Linux 3.0". | |
1266 | * Instead we map 3.x to 2.6.40+x, so e.g. 3.0 would be 2.6.40 | |
1267 | */ | |
1268 | static int override_release(char __user *release, size_t len) | |
1269 | { | |
1270 | int ret = 0; | |
1271 | ||
1272 | if (current->personality & UNAME26) { | |
1273 | const char *rest = UTS_RELEASE; | |
1274 | char buf[65] = { 0 }; | |
1275 | int ndots = 0; | |
1276 | unsigned v; | |
1277 | size_t copy; | |
1278 | ||
1279 | while (*rest) { | |
1280 | if (*rest == '.' && ++ndots >= 3) | |
1281 | break; | |
1282 | if (!isdigit(*rest) && *rest != '.') | |
1283 | break; | |
1284 | rest++; | |
1285 | } | |
1286 | v = ((LINUX_VERSION_CODE >> 8) & 0xff) + 40; | |
1287 | copy = clamp_t(size_t, len, 1, sizeof(buf)); | |
1288 | copy = scnprintf(buf, copy, "2.6.%u%s", v, rest); | |
1289 | ret = copy_to_user(release, buf, copy + 1); | |
1290 | } | |
1291 | return ret; | |
1292 | } | |
1293 | ||
1294 | SYSCALL_DEFINE1(newuname, struct new_utsname __user *, name) | |
1295 | { | |
1296 | int errno = 0; | |
1297 | ||
1298 | down_read(&uts_sem); | |
1299 | if (copy_to_user(name, utsname(), sizeof *name)) | |
1300 | errno = -EFAULT; | |
1301 | up_read(&uts_sem); | |
1302 | ||
1303 | if (!errno && override_release(name->release, sizeof(name->release))) | |
1304 | errno = -EFAULT; | |
1305 | if (!errno && override_architecture(name)) | |
1306 | errno = -EFAULT; | |
1307 | return errno; | |
1308 | } | |
1309 | ||
1310 | #ifdef __ARCH_WANT_SYS_OLD_UNAME | |
1311 | /* | |
1312 | * Old cruft | |
1313 | */ | |
1314 | SYSCALL_DEFINE1(uname, struct old_utsname __user *, name) | |
1315 | { | |
1316 | int error = 0; | |
1317 | ||
1318 | if (!name) | |
1319 | return -EFAULT; | |
1320 | ||
1321 | down_read(&uts_sem); | |
1322 | if (copy_to_user(name, utsname(), sizeof(*name))) | |
1323 | error = -EFAULT; | |
1324 | up_read(&uts_sem); | |
1325 | ||
1326 | if (!error && override_release(name->release, sizeof(name->release))) | |
1327 | error = -EFAULT; | |
1328 | if (!error && override_architecture(name)) | |
1329 | error = -EFAULT; | |
1330 | return error; | |
1331 | } | |
1332 | ||
1333 | SYSCALL_DEFINE1(olduname, struct oldold_utsname __user *, name) | |
1334 | { | |
1335 | int error; | |
1336 | ||
1337 | if (!name) | |
1338 | return -EFAULT; | |
1339 | if (!access_ok(VERIFY_WRITE, name, sizeof(struct oldold_utsname))) | |
1340 | return -EFAULT; | |
1341 | ||
1342 | down_read(&uts_sem); | |
1343 | error = __copy_to_user(&name->sysname, &utsname()->sysname, | |
1344 | __OLD_UTS_LEN); | |
1345 | error |= __put_user(0, name->sysname + __OLD_UTS_LEN); | |
1346 | error |= __copy_to_user(&name->nodename, &utsname()->nodename, | |
1347 | __OLD_UTS_LEN); | |
1348 | error |= __put_user(0, name->nodename + __OLD_UTS_LEN); | |
1349 | error |= __copy_to_user(&name->release, &utsname()->release, | |
1350 | __OLD_UTS_LEN); | |
1351 | error |= __put_user(0, name->release + __OLD_UTS_LEN); | |
1352 | error |= __copy_to_user(&name->version, &utsname()->version, | |
1353 | __OLD_UTS_LEN); | |
1354 | error |= __put_user(0, name->version + __OLD_UTS_LEN); | |
1355 | error |= __copy_to_user(&name->machine, &utsname()->machine, | |
1356 | __OLD_UTS_LEN); | |
1357 | error |= __put_user(0, name->machine + __OLD_UTS_LEN); | |
1358 | up_read(&uts_sem); | |
1359 | ||
1360 | if (!error && override_architecture(name)) | |
1361 | error = -EFAULT; | |
1362 | if (!error && override_release(name->release, sizeof(name->release))) | |
1363 | error = -EFAULT; | |
1364 | return error ? -EFAULT : 0; | |
1365 | } | |
1366 | #endif | |
1367 | ||
1368 | SYSCALL_DEFINE2(sethostname, char __user *, name, int, len) | |
1369 | { | |
1370 | int errno; | |
1371 | char tmp[__NEW_UTS_LEN]; | |
1372 | ||
1373 | if (!ns_capable(current->nsproxy->uts_ns->user_ns, CAP_SYS_ADMIN)) | |
1374 | return -EPERM; | |
1375 | ||
1376 | if (len < 0 || len > __NEW_UTS_LEN) | |
1377 | return -EINVAL; | |
1378 | down_write(&uts_sem); | |
1379 | errno = -EFAULT; | |
1380 | if (!copy_from_user(tmp, name, len)) { | |
1381 | struct new_utsname *u = utsname(); | |
1382 | ||
1383 | memcpy(u->nodename, tmp, len); | |
1384 | memset(u->nodename + len, 0, sizeof(u->nodename) - len); | |
1385 | errno = 0; | |
1386 | uts_proc_notify(UTS_PROC_HOSTNAME); | |
1387 | } | |
1388 | up_write(&uts_sem); | |
1389 | return errno; | |
1390 | } | |
1391 | ||
1392 | #ifdef __ARCH_WANT_SYS_GETHOSTNAME | |
1393 | ||
1394 | SYSCALL_DEFINE2(gethostname, char __user *, name, int, len) | |
1395 | { | |
1396 | int i, errno; | |
1397 | struct new_utsname *u; | |
1398 | ||
1399 | if (len < 0) | |
1400 | return -EINVAL; | |
1401 | down_read(&uts_sem); | |
1402 | u = utsname(); | |
1403 | i = 1 + strlen(u->nodename); | |
1404 | if (i > len) | |
1405 | i = len; | |
1406 | errno = 0; | |
1407 | if (copy_to_user(name, u->nodename, i)) | |
1408 | errno = -EFAULT; | |
1409 | up_read(&uts_sem); | |
1410 | return errno; | |
1411 | } | |
1412 | ||
1413 | #endif | |
1414 | ||
1415 | /* | |
1416 | * Only setdomainname; getdomainname can be implemented by calling | |
1417 | * uname() | |
1418 | */ | |
1419 | SYSCALL_DEFINE2(setdomainname, char __user *, name, int, len) | |
1420 | { | |
1421 | int errno; | |
1422 | char tmp[__NEW_UTS_LEN]; | |
1423 | ||
1424 | if (!ns_capable(current->nsproxy->uts_ns->user_ns, CAP_SYS_ADMIN)) | |
1425 | return -EPERM; | |
1426 | if (len < 0 || len > __NEW_UTS_LEN) | |
1427 | return -EINVAL; | |
1428 | ||
1429 | down_write(&uts_sem); | |
1430 | errno = -EFAULT; | |
1431 | if (!copy_from_user(tmp, name, len)) { | |
1432 | struct new_utsname *u = utsname(); | |
1433 | ||
1434 | memcpy(u->domainname, tmp, len); | |
1435 | memset(u->domainname + len, 0, sizeof(u->domainname) - len); | |
1436 | errno = 0; | |
1437 | uts_proc_notify(UTS_PROC_DOMAINNAME); | |
1438 | } | |
1439 | up_write(&uts_sem); | |
1440 | return errno; | |
1441 | } | |
1442 | ||
1443 | SYSCALL_DEFINE2(getrlimit, unsigned int, resource, struct rlimit __user *, rlim) | |
1444 | { | |
1445 | struct rlimit value; | |
1446 | int ret; | |
1447 | ||
1448 | ret = do_prlimit(current, resource, NULL, &value); | |
1449 | if (!ret) | |
1450 | ret = copy_to_user(rlim, &value, sizeof(*rlim)) ? -EFAULT : 0; | |
1451 | ||
1452 | return ret; | |
1453 | } | |
1454 | ||
1455 | #ifdef __ARCH_WANT_SYS_OLD_GETRLIMIT | |
1456 | ||
1457 | /* | |
1458 | * Back compatibility for getrlimit. Needed for some apps. | |
1459 | */ | |
1460 | ||
1461 | SYSCALL_DEFINE2(old_getrlimit, unsigned int, resource, | |
1462 | struct rlimit __user *, rlim) | |
1463 | { | |
1464 | struct rlimit x; | |
1465 | if (resource >= RLIM_NLIMITS) | |
1466 | return -EINVAL; | |
1467 | ||
1468 | task_lock(current->group_leader); | |
1469 | x = current->signal->rlim[resource]; | |
1470 | task_unlock(current->group_leader); | |
1471 | if (x.rlim_cur > 0x7FFFFFFF) | |
1472 | x.rlim_cur = 0x7FFFFFFF; | |
1473 | if (x.rlim_max > 0x7FFFFFFF) | |
1474 | x.rlim_max = 0x7FFFFFFF; | |
1475 | return copy_to_user(rlim, &x, sizeof(x))?-EFAULT:0; | |
1476 | } | |
1477 | ||
1478 | #endif | |
1479 | ||
1480 | static inline bool rlim64_is_infinity(__u64 rlim64) | |
1481 | { | |
1482 | #if BITS_PER_LONG < 64 | |
1483 | return rlim64 >= ULONG_MAX; | |
1484 | #else | |
1485 | return rlim64 == RLIM64_INFINITY; | |
1486 | #endif | |
1487 | } | |
1488 | ||
1489 | static void rlim_to_rlim64(const struct rlimit *rlim, struct rlimit64 *rlim64) | |
1490 | { | |
1491 | if (rlim->rlim_cur == RLIM_INFINITY) | |
1492 | rlim64->rlim_cur = RLIM64_INFINITY; | |
1493 | else | |
1494 | rlim64->rlim_cur = rlim->rlim_cur; | |
1495 | if (rlim->rlim_max == RLIM_INFINITY) | |
1496 | rlim64->rlim_max = RLIM64_INFINITY; | |
1497 | else | |
1498 | rlim64->rlim_max = rlim->rlim_max; | |
1499 | } | |
1500 | ||
1501 | static void rlim64_to_rlim(const struct rlimit64 *rlim64, struct rlimit *rlim) | |
1502 | { | |
1503 | if (rlim64_is_infinity(rlim64->rlim_cur)) | |
1504 | rlim->rlim_cur = RLIM_INFINITY; | |
1505 | else | |
1506 | rlim->rlim_cur = (unsigned long)rlim64->rlim_cur; | |
1507 | if (rlim64_is_infinity(rlim64->rlim_max)) | |
1508 | rlim->rlim_max = RLIM_INFINITY; | |
1509 | else | |
1510 | rlim->rlim_max = (unsigned long)rlim64->rlim_max; | |
1511 | } | |
1512 | ||
1513 | /* make sure you are allowed to change @tsk limits before calling this */ | |
1514 | int do_prlimit(struct task_struct *tsk, unsigned int resource, | |
1515 | struct rlimit *new_rlim, struct rlimit *old_rlim) | |
1516 | { | |
1517 | struct rlimit *rlim; | |
1518 | int retval = 0; | |
1519 | ||
1520 | if (resource >= RLIM_NLIMITS) | |
1521 | return -EINVAL; | |
1522 | if (new_rlim) { | |
1523 | if (new_rlim->rlim_cur > new_rlim->rlim_max) | |
1524 | return -EINVAL; | |
1525 | if (resource == RLIMIT_NOFILE && | |
1526 | new_rlim->rlim_max > sysctl_nr_open) | |
1527 | return -EPERM; | |
1528 | } | |
1529 | ||
1530 | /* protect tsk->signal and tsk->sighand from disappearing */ | |
1531 | read_lock(&tasklist_lock); | |
1532 | if (!tsk->sighand) { | |
1533 | retval = -ESRCH; | |
1534 | goto out; | |
1535 | } | |
1536 | ||
1537 | rlim = tsk->signal->rlim + resource; | |
1538 | task_lock(tsk->group_leader); | |
1539 | if (new_rlim) { | |
1540 | /* Keep the capable check against init_user_ns until | |
1541 | cgroups can contain all limits */ | |
1542 | if (new_rlim->rlim_max > rlim->rlim_max && | |
1543 | !capable(CAP_SYS_RESOURCE)) | |
1544 | retval = -EPERM; | |
1545 | if (!retval) | |
1546 | retval = security_task_setrlimit(tsk->group_leader, | |
1547 | resource, new_rlim); | |
1548 | if (resource == RLIMIT_CPU && new_rlim->rlim_cur == 0) { | |
1549 | /* | |
1550 | * The caller is asking for an immediate RLIMIT_CPU | |
1551 | * expiry. But we use the zero value to mean "it was | |
1552 | * never set". So let's cheat and make it one second | |
1553 | * instead | |
1554 | */ | |
1555 | new_rlim->rlim_cur = 1; | |
1556 | } | |
1557 | } | |
1558 | if (!retval) { | |
1559 | if (old_rlim) | |
1560 | *old_rlim = *rlim; | |
1561 | if (new_rlim) | |
1562 | *rlim = *new_rlim; | |
1563 | } | |
1564 | task_unlock(tsk->group_leader); | |
1565 | ||
1566 | /* | |
1567 | * RLIMIT_CPU handling. Note that the kernel fails to return an error | |
1568 | * code if it rejected the user's attempt to set RLIMIT_CPU. This is a | |
1569 | * very long-standing error, and fixing it now risks breakage of | |
1570 | * applications, so we live with it | |
1571 | */ | |
1572 | if (!retval && new_rlim && resource == RLIMIT_CPU && | |
1573 | new_rlim->rlim_cur != RLIM_INFINITY) | |
1574 | update_rlimit_cpu(tsk, new_rlim->rlim_cur); | |
1575 | out: | |
1576 | read_unlock(&tasklist_lock); | |
1577 | return retval; | |
1578 | } | |
1579 | ||
1580 | /* rcu lock must be held */ | |
1581 | static int check_prlimit_permission(struct task_struct *task) | |
1582 | { | |
1583 | const struct cred *cred = current_cred(), *tcred; | |
1584 | ||
1585 | if (current == task) | |
1586 | return 0; | |
1587 | ||
1588 | tcred = __task_cred(task); | |
1589 | if (uid_eq(cred->uid, tcred->euid) && | |
1590 | uid_eq(cred->uid, tcred->suid) && | |
1591 | uid_eq(cred->uid, tcred->uid) && | |
1592 | gid_eq(cred->gid, tcred->egid) && | |
1593 | gid_eq(cred->gid, tcred->sgid) && | |
1594 | gid_eq(cred->gid, tcred->gid)) | |
1595 | return 0; | |
1596 | if (ns_capable(tcred->user_ns, CAP_SYS_RESOURCE)) | |
1597 | return 0; | |
1598 | ||
1599 | return -EPERM; | |
1600 | } | |
1601 | ||
1602 | SYSCALL_DEFINE4(prlimit64, pid_t, pid, unsigned int, resource, | |
1603 | const struct rlimit64 __user *, new_rlim, | |
1604 | struct rlimit64 __user *, old_rlim) | |
1605 | { | |
1606 | struct rlimit64 old64, new64; | |
1607 | struct rlimit old, new; | |
1608 | struct task_struct *tsk; | |
1609 | int ret; | |
1610 | ||
1611 | if (new_rlim) { | |
1612 | if (copy_from_user(&new64, new_rlim, sizeof(new64))) | |
1613 | return -EFAULT; | |
1614 | rlim64_to_rlim(&new64, &new); | |
1615 | } | |
1616 | ||
1617 | rcu_read_lock(); | |
1618 | tsk = pid ? find_task_by_vpid(pid) : current; | |
1619 | if (!tsk) { | |
1620 | rcu_read_unlock(); | |
1621 | return -ESRCH; | |
1622 | } | |
1623 | ret = check_prlimit_permission(tsk); | |
1624 | if (ret) { | |
1625 | rcu_read_unlock(); | |
1626 | return ret; | |
1627 | } | |
1628 | get_task_struct(tsk); | |
1629 | rcu_read_unlock(); | |
1630 | ||
1631 | ret = do_prlimit(tsk, resource, new_rlim ? &new : NULL, | |
1632 | old_rlim ? &old : NULL); | |
1633 | ||
1634 | if (!ret && old_rlim) { | |
1635 | rlim_to_rlim64(&old, &old64); | |
1636 | if (copy_to_user(old_rlim, &old64, sizeof(old64))) | |
1637 | ret = -EFAULT; | |
1638 | } | |
1639 | ||
1640 | put_task_struct(tsk); | |
1641 | return ret; | |
1642 | } | |
1643 | ||
1644 | SYSCALL_DEFINE2(setrlimit, unsigned int, resource, struct rlimit __user *, rlim) | |
1645 | { | |
1646 | struct rlimit new_rlim; | |
1647 | ||
1648 | if (copy_from_user(&new_rlim, rlim, sizeof(*rlim))) | |
1649 | return -EFAULT; | |
1650 | return do_prlimit(current, resource, &new_rlim, NULL); | |
1651 | } | |
1652 | ||
1653 | /* | |
1654 | * It would make sense to put struct rusage in the task_struct, | |
1655 | * except that would make the task_struct be *really big*. After | |
1656 | * task_struct gets moved into malloc'ed memory, it would | |
1657 | * make sense to do this. It will make moving the rest of the information | |
1658 | * a lot simpler! (Which we're not doing right now because we're not | |
1659 | * measuring them yet). | |
1660 | * | |
1661 | * When sampling multiple threads for RUSAGE_SELF, under SMP we might have | |
1662 | * races with threads incrementing their own counters. But since word | |
1663 | * reads are atomic, we either get new values or old values and we don't | |
1664 | * care which for the sums. We always take the siglock to protect reading | |
1665 | * the c* fields from p->signal from races with exit.c updating those | |
1666 | * fields when reaping, so a sample either gets all the additions of a | |
1667 | * given child after it's reaped, or none so this sample is before reaping. | |
1668 | * | |
1669 | * Locking: | |
1670 | * We need to take the siglock for CHILDEREN, SELF and BOTH | |
1671 | * for the cases current multithreaded, non-current single threaded | |
1672 | * non-current multithreaded. Thread traversal is now safe with | |
1673 | * the siglock held. | |
1674 | * Strictly speaking, we donot need to take the siglock if we are current and | |
1675 | * single threaded, as no one else can take our signal_struct away, no one | |
1676 | * else can reap the children to update signal->c* counters, and no one else | |
1677 | * can race with the signal-> fields. If we do not take any lock, the | |
1678 | * signal-> fields could be read out of order while another thread was just | |
1679 | * exiting. So we should place a read memory barrier when we avoid the lock. | |
1680 | * On the writer side, write memory barrier is implied in __exit_signal | |
1681 | * as __exit_signal releases the siglock spinlock after updating the signal-> | |
1682 | * fields. But we don't do this yet to keep things simple. | |
1683 | * | |
1684 | */ | |
1685 | ||
1686 | static void accumulate_thread_rusage(struct task_struct *t, struct rusage *r) | |
1687 | { | |
1688 | r->ru_nvcsw += t->nvcsw; | |
1689 | r->ru_nivcsw += t->nivcsw; | |
1690 | r->ru_minflt += t->min_flt; | |
1691 | r->ru_majflt += t->maj_flt; | |
1692 | r->ru_inblock += task_io_get_inblock(t); | |
1693 | r->ru_oublock += task_io_get_oublock(t); | |
1694 | } | |
1695 | ||
1696 | static void k_getrusage(struct task_struct *p, int who, struct rusage *r) | |
1697 | { | |
1698 | struct task_struct *t; | |
1699 | unsigned long flags; | |
1700 | cputime_t tgutime, tgstime, utime, stime; | |
1701 | unsigned long maxrss = 0; | |
1702 | ||
1703 | memset((char *) r, 0, sizeof *r); | |
1704 | utime = stime = 0; | |
1705 | ||
1706 | if (who == RUSAGE_THREAD) { | |
1707 | task_cputime_adjusted(current, &utime, &stime); | |
1708 | accumulate_thread_rusage(p, r); | |
1709 | maxrss = p->signal->maxrss; | |
1710 | goto out; | |
1711 | } | |
1712 | ||
1713 | if (!lock_task_sighand(p, &flags)) | |
1714 | return; | |
1715 | ||
1716 | switch (who) { | |
1717 | case RUSAGE_BOTH: | |
1718 | case RUSAGE_CHILDREN: | |
1719 | utime = p->signal->cutime; | |
1720 | stime = p->signal->cstime; | |
1721 | r->ru_nvcsw = p->signal->cnvcsw; | |
1722 | r->ru_nivcsw = p->signal->cnivcsw; | |
1723 | r->ru_minflt = p->signal->cmin_flt; | |
1724 | r->ru_majflt = p->signal->cmaj_flt; | |
1725 | r->ru_inblock = p->signal->cinblock; | |
1726 | r->ru_oublock = p->signal->coublock; | |
1727 | maxrss = p->signal->cmaxrss; | |
1728 | ||
1729 | if (who == RUSAGE_CHILDREN) | |
1730 | break; | |
1731 | ||
1732 | case RUSAGE_SELF: | |
1733 | thread_group_cputime_adjusted(p, &tgutime, &tgstime); | |
1734 | utime += tgutime; | |
1735 | stime += tgstime; | |
1736 | r->ru_nvcsw += p->signal->nvcsw; | |
1737 | r->ru_nivcsw += p->signal->nivcsw; | |
1738 | r->ru_minflt += p->signal->min_flt; | |
1739 | r->ru_majflt += p->signal->maj_flt; | |
1740 | r->ru_inblock += p->signal->inblock; | |
1741 | r->ru_oublock += p->signal->oublock; | |
1742 | if (maxrss < p->signal->maxrss) | |
1743 | maxrss = p->signal->maxrss; | |
1744 | t = p; | |
1745 | do { | |
1746 | accumulate_thread_rusage(t, r); | |
1747 | t = next_thread(t); | |
1748 | } while (t != p); | |
1749 | break; | |
1750 | ||
1751 | default: | |
1752 | BUG(); | |
1753 | } | |
1754 | unlock_task_sighand(p, &flags); | |
1755 | ||
1756 | out: | |
1757 | cputime_to_timeval(utime, &r->ru_utime); | |
1758 | cputime_to_timeval(stime, &r->ru_stime); | |
1759 | ||
1760 | if (who != RUSAGE_CHILDREN) { | |
1761 | struct mm_struct *mm = get_task_mm(p); | |
1762 | if (mm) { | |
1763 | setmax_mm_hiwater_rss(&maxrss, mm); | |
1764 | mmput(mm); | |
1765 | } | |
1766 | } | |
1767 | r->ru_maxrss = maxrss * (PAGE_SIZE / 1024); /* convert pages to KBs */ | |
1768 | } | |
1769 | ||
1770 | int getrusage(struct task_struct *p, int who, struct rusage __user *ru) | |
1771 | { | |
1772 | struct rusage r; | |
1773 | k_getrusage(p, who, &r); | |
1774 | return copy_to_user(ru, &r, sizeof(r)) ? -EFAULT : 0; | |
1775 | } | |
1776 | ||
1777 | SYSCALL_DEFINE2(getrusage, int, who, struct rusage __user *, ru) | |
1778 | { | |
1779 | if (who != RUSAGE_SELF && who != RUSAGE_CHILDREN && | |
1780 | who != RUSAGE_THREAD) | |
1781 | return -EINVAL; | |
1782 | return getrusage(current, who, ru); | |
1783 | } | |
1784 | ||
1785 | SYSCALL_DEFINE1(umask, int, mask) | |
1786 | { | |
1787 | mask = xchg(¤t->fs->umask, mask & S_IRWXUGO); | |
1788 | return mask; | |
1789 | } | |
1790 | ||
1791 | #ifdef CONFIG_CHECKPOINT_RESTORE | |
1792 | static int prctl_set_mm_exe_file(struct mm_struct *mm, unsigned int fd) | |
1793 | { | |
1794 | struct fd exe; | |
1795 | struct dentry *dentry; | |
1796 | int err; | |
1797 | ||
1798 | exe = fdget(fd); | |
1799 | if (!exe.file) | |
1800 | return -EBADF; | |
1801 | ||
1802 | dentry = exe.file->f_path.dentry; | |
1803 | ||
1804 | /* | |
1805 | * Because the original mm->exe_file points to executable file, make | |
1806 | * sure that this one is executable as well, to avoid breaking an | |
1807 | * overall picture. | |
1808 | */ | |
1809 | err = -EACCES; | |
1810 | if (!S_ISREG(dentry->d_inode->i_mode) || | |
1811 | exe.file->f_path.mnt->mnt_flags & MNT_NOEXEC) | |
1812 | goto exit; | |
1813 | ||
1814 | err = inode_permission(dentry->d_inode, MAY_EXEC); | |
1815 | if (err) | |
1816 | goto exit; | |
1817 | ||
1818 | down_write(&mm->mmap_sem); | |
1819 | ||
1820 | /* | |
1821 | * Forbid mm->exe_file change if old file still mapped. | |
1822 | */ | |
1823 | err = -EBUSY; | |
1824 | if (mm->exe_file) { | |
1825 | struct vm_area_struct *vma; | |
1826 | ||
1827 | for (vma = mm->mmap; vma; vma = vma->vm_next) | |
1828 | if (vma->vm_file && | |
1829 | path_equal(&vma->vm_file->f_path, | |
1830 | &mm->exe_file->f_path)) | |
1831 | goto exit_unlock; | |
1832 | } | |
1833 | ||
1834 | /* | |
1835 | * The symlink can be changed only once, just to disallow arbitrary | |
1836 | * transitions malicious software might bring in. This means one | |
1837 | * could make a snapshot over all processes running and monitor | |
1838 | * /proc/pid/exe changes to notice unusual activity if needed. | |
1839 | */ | |
1840 | err = -EPERM; | |
1841 | if (test_and_set_bit(MMF_EXE_FILE_CHANGED, &mm->flags)) | |
1842 | goto exit_unlock; | |
1843 | ||
1844 | err = 0; | |
1845 | set_mm_exe_file(mm, exe.file); /* this grabs a reference to exe.file */ | |
1846 | exit_unlock: | |
1847 | up_write(&mm->mmap_sem); | |
1848 | ||
1849 | exit: | |
1850 | fdput(exe); | |
1851 | return err; | |
1852 | } | |
1853 | ||
1854 | static int prctl_set_mm(int opt, unsigned long addr, | |
1855 | unsigned long arg4, unsigned long arg5) | |
1856 | { | |
1857 | unsigned long rlim = rlimit(RLIMIT_DATA); | |
1858 | struct mm_struct *mm = current->mm; | |
1859 | struct vm_area_struct *vma; | |
1860 | int error; | |
1861 | ||
1862 | if (arg5 || (arg4 && opt != PR_SET_MM_AUXV)) | |
1863 | return -EINVAL; | |
1864 | ||
1865 | if (!capable(CAP_SYS_RESOURCE)) | |
1866 | return -EPERM; | |
1867 | ||
1868 | if (opt == PR_SET_MM_EXE_FILE) | |
1869 | return prctl_set_mm_exe_file(mm, (unsigned int)addr); | |
1870 | ||
1871 | if (addr >= TASK_SIZE || addr < mmap_min_addr) | |
1872 | return -EINVAL; | |
1873 | ||
1874 | error = -EINVAL; | |
1875 | ||
1876 | down_read(&mm->mmap_sem); | |
1877 | vma = find_vma(mm, addr); | |
1878 | ||
1879 | switch (opt) { | |
1880 | case PR_SET_MM_START_CODE: | |
1881 | mm->start_code = addr; | |
1882 | break; | |
1883 | case PR_SET_MM_END_CODE: | |
1884 | mm->end_code = addr; | |
1885 | break; | |
1886 | case PR_SET_MM_START_DATA: | |
1887 | mm->start_data = addr; | |
1888 | break; | |
1889 | case PR_SET_MM_END_DATA: | |
1890 | mm->end_data = addr; | |
1891 | break; | |
1892 | ||
1893 | case PR_SET_MM_START_BRK: | |
1894 | if (addr <= mm->end_data) | |
1895 | goto out; | |
1896 | ||
1897 | if (rlim < RLIM_INFINITY && | |
1898 | (mm->brk - addr) + | |
1899 | (mm->end_data - mm->start_data) > rlim) | |
1900 | goto out; | |
1901 | ||
1902 | mm->start_brk = addr; | |
1903 | break; | |
1904 | ||
1905 | case PR_SET_MM_BRK: | |
1906 | if (addr <= mm->end_data) | |
1907 | goto out; | |
1908 | ||
1909 | if (rlim < RLIM_INFINITY && | |
1910 | (addr - mm->start_brk) + | |
1911 | (mm->end_data - mm->start_data) > rlim) | |
1912 | goto out; | |
1913 | ||
1914 | mm->brk = addr; | |
1915 | break; | |
1916 | ||
1917 | /* | |
1918 | * If command line arguments and environment | |
1919 | * are placed somewhere else on stack, we can | |
1920 | * set them up here, ARG_START/END to setup | |
1921 | * command line argumets and ENV_START/END | |
1922 | * for environment. | |
1923 | */ | |
1924 | case PR_SET_MM_START_STACK: | |
1925 | case PR_SET_MM_ARG_START: | |
1926 | case PR_SET_MM_ARG_END: | |
1927 | case PR_SET_MM_ENV_START: | |
1928 | case PR_SET_MM_ENV_END: | |
1929 | if (!vma) { | |
1930 | error = -EFAULT; | |
1931 | goto out; | |
1932 | } | |
1933 | if (opt == PR_SET_MM_START_STACK) | |
1934 | mm->start_stack = addr; | |
1935 | else if (opt == PR_SET_MM_ARG_START) | |
1936 | mm->arg_start = addr; | |
1937 | else if (opt == PR_SET_MM_ARG_END) | |
1938 | mm->arg_end = addr; | |
1939 | else if (opt == PR_SET_MM_ENV_START) | |
1940 | mm->env_start = addr; | |
1941 | else if (opt == PR_SET_MM_ENV_END) | |
1942 | mm->env_end = addr; | |
1943 | break; | |
1944 | ||
1945 | /* | |
1946 | * This doesn't move auxiliary vector itself | |
1947 | * since it's pinned to mm_struct, but allow | |
1948 | * to fill vector with new values. It's up | |
1949 | * to a caller to provide sane values here | |
1950 | * otherwise user space tools which use this | |
1951 | * vector might be unhappy. | |
1952 | */ | |
1953 | case PR_SET_MM_AUXV: { | |
1954 | unsigned long user_auxv[AT_VECTOR_SIZE]; | |
1955 | ||
1956 | if (arg4 > sizeof(user_auxv)) | |
1957 | goto out; | |
1958 | up_read(&mm->mmap_sem); | |
1959 | ||
1960 | if (copy_from_user(user_auxv, (const void __user *)addr, arg4)) | |
1961 | return -EFAULT; | |
1962 | ||
1963 | /* Make sure the last entry is always AT_NULL */ | |
1964 | user_auxv[AT_VECTOR_SIZE - 2] = 0; | |
1965 | user_auxv[AT_VECTOR_SIZE - 1] = 0; | |
1966 | ||
1967 | BUILD_BUG_ON(sizeof(user_auxv) != sizeof(mm->saved_auxv)); | |
1968 | ||
1969 | task_lock(current); | |
1970 | memcpy(mm->saved_auxv, user_auxv, arg4); | |
1971 | task_unlock(current); | |
1972 | ||
1973 | return 0; | |
1974 | } | |
1975 | default: | |
1976 | goto out; | |
1977 | } | |
1978 | ||
1979 | error = 0; | |
1980 | out: | |
1981 | up_read(&mm->mmap_sem); | |
1982 | return error; | |
1983 | } | |
1984 | ||
1985 | static int prctl_get_tid_address(struct task_struct *me, int __user **tid_addr) | |
1986 | { | |
1987 | return put_user(me->clear_child_tid, tid_addr); | |
1988 | } | |
1989 | ||
1990 | #else /* CONFIG_CHECKPOINT_RESTORE */ | |
1991 | static int prctl_set_mm(int opt, unsigned long addr, | |
1992 | unsigned long arg4, unsigned long arg5) | |
1993 | { | |
1994 | return -EINVAL; | |
1995 | } | |
1996 | static int prctl_get_tid_address(struct task_struct *me, int __user **tid_addr) | |
1997 | { | |
1998 | return -EINVAL; | |
1999 | } | |
2000 | #endif | |
2001 | ||
2002 | SYSCALL_DEFINE5(prctl, int, option, unsigned long, arg2, unsigned long, arg3, | |
2003 | unsigned long, arg4, unsigned long, arg5) | |
2004 | { | |
2005 | struct task_struct *me = current; | |
2006 | unsigned char comm[sizeof(me->comm)]; | |
2007 | long error; | |
2008 | ||
2009 | error = security_task_prctl(option, arg2, arg3, arg4, arg5); | |
2010 | if (error != -ENOSYS) | |
2011 | return error; | |
2012 | ||
2013 | error = 0; | |
2014 | switch (option) { | |
2015 | case PR_SET_PDEATHSIG: | |
2016 | if (!valid_signal(arg2)) { | |
2017 | error = -EINVAL; | |
2018 | break; | |
2019 | } | |
2020 | me->pdeath_signal = arg2; | |
2021 | break; | |
2022 | case PR_GET_PDEATHSIG: | |
2023 | error = put_user(me->pdeath_signal, (int __user *)arg2); | |
2024 | break; | |
2025 | case PR_GET_DUMPABLE: | |
2026 | error = get_dumpable(me->mm); | |
2027 | break; | |
2028 | case PR_SET_DUMPABLE: | |
2029 | if (arg2 < 0 || arg2 > 1) { | |
2030 | error = -EINVAL; | |
2031 | break; | |
2032 | } | |
2033 | set_dumpable(me->mm, arg2); | |
2034 | break; | |
2035 | ||
2036 | case PR_SET_UNALIGN: | |
2037 | error = SET_UNALIGN_CTL(me, arg2); | |
2038 | break; | |
2039 | case PR_GET_UNALIGN: | |
2040 | error = GET_UNALIGN_CTL(me, arg2); | |
2041 | break; | |
2042 | case PR_SET_FPEMU: | |
2043 | error = SET_FPEMU_CTL(me, arg2); | |
2044 | break; | |
2045 | case PR_GET_FPEMU: | |
2046 | error = GET_FPEMU_CTL(me, arg2); | |
2047 | break; | |
2048 | case PR_SET_FPEXC: | |
2049 | error = SET_FPEXC_CTL(me, arg2); | |
2050 | break; | |
2051 | case PR_GET_FPEXC: | |
2052 | error = GET_FPEXC_CTL(me, arg2); | |
2053 | break; | |
2054 | case PR_GET_TIMING: | |
2055 | error = PR_TIMING_STATISTICAL; | |
2056 | break; | |
2057 | case PR_SET_TIMING: | |
2058 | if (arg2 != PR_TIMING_STATISTICAL) | |
2059 | error = -EINVAL; | |
2060 | break; | |
2061 | case PR_SET_NAME: | |
2062 | comm[sizeof(me->comm)-1] = 0; | |
2063 | if (strncpy_from_user(comm, (char __user *)arg2, | |
2064 | sizeof(me->comm) - 1) < 0) | |
2065 | return -EFAULT; | |
2066 | set_task_comm(me, comm); | |
2067 | proc_comm_connector(me); | |
2068 | break; | |
2069 | case PR_GET_NAME: | |
2070 | get_task_comm(comm, me); | |
2071 | if (copy_to_user((char __user *)arg2, comm, | |
2072 | sizeof(comm))) | |
2073 | return -EFAULT; | |
2074 | break; | |
2075 | case PR_GET_ENDIAN: | |
2076 | error = GET_ENDIAN(me, arg2); | |
2077 | break; | |
2078 | case PR_SET_ENDIAN: | |
2079 | error = SET_ENDIAN(me, arg2); | |
2080 | break; | |
2081 | case PR_GET_SECCOMP: | |
2082 | error = prctl_get_seccomp(); | |
2083 | break; | |
2084 | case PR_SET_SECCOMP: | |
2085 | error = prctl_set_seccomp(arg2, (char __user *)arg3); | |
2086 | break; | |
2087 | case PR_GET_TSC: | |
2088 | error = GET_TSC_CTL(arg2); | |
2089 | break; | |
2090 | case PR_SET_TSC: | |
2091 | error = SET_TSC_CTL(arg2); | |
2092 | break; | |
2093 | case PR_TASK_PERF_EVENTS_DISABLE: | |
2094 | error = perf_event_task_disable(); | |
2095 | break; | |
2096 | case PR_TASK_PERF_EVENTS_ENABLE: | |
2097 | error = perf_event_task_enable(); | |
2098 | break; | |
2099 | case PR_GET_TIMERSLACK: | |
2100 | error = current->timer_slack_ns; | |
2101 | break; | |
2102 | case PR_SET_TIMERSLACK: | |
2103 | if (arg2 <= 0) | |
2104 | current->timer_slack_ns = | |
2105 | current->default_timer_slack_ns; | |
2106 | else | |
2107 | current->timer_slack_ns = arg2; | |
2108 | break; | |
2109 | case PR_MCE_KILL: | |
2110 | if (arg4 | arg5) | |
2111 | return -EINVAL; | |
2112 | switch (arg2) { | |
2113 | case PR_MCE_KILL_CLEAR: | |
2114 | if (arg3 != 0) | |
2115 | return -EINVAL; | |
2116 | current->flags &= ~PF_MCE_PROCESS; | |
2117 | break; | |
2118 | case PR_MCE_KILL_SET: | |
2119 | current->flags |= PF_MCE_PROCESS; | |
2120 | if (arg3 == PR_MCE_KILL_EARLY) | |
2121 | current->flags |= PF_MCE_EARLY; | |
2122 | else if (arg3 == PR_MCE_KILL_LATE) | |
2123 | current->flags &= ~PF_MCE_EARLY; | |
2124 | else if (arg3 == PR_MCE_KILL_DEFAULT) | |
2125 | current->flags &= | |
2126 | ~(PF_MCE_EARLY|PF_MCE_PROCESS); | |
2127 | else | |
2128 | return -EINVAL; | |
2129 | break; | |
2130 | default: | |
2131 | return -EINVAL; | |
2132 | } | |
2133 | break; | |
2134 | case PR_MCE_KILL_GET: | |
2135 | if (arg2 | arg3 | arg4 | arg5) | |
2136 | return -EINVAL; | |
2137 | if (current->flags & PF_MCE_PROCESS) | |
2138 | error = (current->flags & PF_MCE_EARLY) ? | |
2139 | PR_MCE_KILL_EARLY : PR_MCE_KILL_LATE; | |
2140 | else | |
2141 | error = PR_MCE_KILL_DEFAULT; | |
2142 | break; | |
2143 | case PR_SET_MM: | |
2144 | error = prctl_set_mm(arg2, arg3, arg4, arg5); | |
2145 | break; | |
2146 | case PR_GET_TID_ADDRESS: | |
2147 | error = prctl_get_tid_address(me, (int __user **)arg2); | |
2148 | break; | |
2149 | case PR_SET_CHILD_SUBREAPER: | |
2150 | me->signal->is_child_subreaper = !!arg2; | |
2151 | break; | |
2152 | case PR_GET_CHILD_SUBREAPER: | |
2153 | error = put_user(me->signal->is_child_subreaper, | |
2154 | (int __user *) arg2); | |
2155 | break; | |
2156 | case PR_SET_NO_NEW_PRIVS: | |
2157 | if (arg2 != 1 || arg3 || arg4 || arg5) | |
2158 | return -EINVAL; | |
2159 | ||
2160 | current->no_new_privs = 1; | |
2161 | break; | |
2162 | case PR_GET_NO_NEW_PRIVS: | |
2163 | if (arg2 || arg3 || arg4 || arg5) | |
2164 | return -EINVAL; | |
2165 | return current->no_new_privs ? 1 : 0; | |
2166 | default: | |
2167 | error = -EINVAL; | |
2168 | break; | |
2169 | } | |
2170 | return error; | |
2171 | } | |
2172 | ||
2173 | SYSCALL_DEFINE3(getcpu, unsigned __user *, cpup, unsigned __user *, nodep, | |
2174 | struct getcpu_cache __user *, unused) | |
2175 | { | |
2176 | int err = 0; | |
2177 | int cpu = raw_smp_processor_id(); | |
2178 | if (cpup) | |
2179 | err |= put_user(cpu, cpup); | |
2180 | if (nodep) | |
2181 | err |= put_user(cpu_to_node(cpu), nodep); | |
2182 | return err ? -EFAULT : 0; | |
2183 | } | |
2184 | ||
2185 | char poweroff_cmd[POWEROFF_CMD_PATH_LEN] = "/sbin/poweroff"; | |
2186 | ||
2187 | static void argv_cleanup(struct subprocess_info *info) | |
2188 | { | |
2189 | argv_free(info->argv); | |
2190 | } | |
2191 | ||
2192 | static int __orderly_poweroff(void) | |
2193 | { | |
2194 | int argc; | |
2195 | char **argv; | |
2196 | static char *envp[] = { | |
2197 | "HOME=/", | |
2198 | "PATH=/sbin:/bin:/usr/sbin:/usr/bin", | |
2199 | NULL | |
2200 | }; | |
2201 | int ret; | |
2202 | ||
2203 | argv = argv_split(GFP_ATOMIC, poweroff_cmd, &argc); | |
2204 | if (argv == NULL) { | |
2205 | printk(KERN_WARNING "%s failed to allocate memory for \"%s\"\n", | |
2206 | __func__, poweroff_cmd); | |
2207 | return -ENOMEM; | |
2208 | } | |
2209 | ||
2210 | ret = call_usermodehelper_fns(argv[0], argv, envp, UMH_WAIT_EXEC, | |
2211 | NULL, argv_cleanup, NULL); | |
2212 | if (ret == -ENOMEM) | |
2213 | argv_free(argv); | |
2214 | ||
2215 | return ret; | |
2216 | } | |
2217 | ||
2218 | /** | |
2219 | * orderly_poweroff - Trigger an orderly system poweroff | |
2220 | * @force: force poweroff if command execution fails | |
2221 | * | |
2222 | * This may be called from any context to trigger a system shutdown. | |
2223 | * If the orderly shutdown fails, it will force an immediate shutdown. | |
2224 | */ | |
2225 | int orderly_poweroff(bool force) | |
2226 | { | |
2227 | int ret = __orderly_poweroff(); | |
2228 | ||
2229 | if (ret && force) { | |
2230 | printk(KERN_WARNING "Failed to start orderly shutdown: " | |
2231 | "forcing the issue\n"); | |
2232 | ||
2233 | /* | |
2234 | * I guess this should try to kick off some daemon to sync and | |
2235 | * poweroff asap. Or not even bother syncing if we're doing an | |
2236 | * emergency shutdown? | |
2237 | */ | |
2238 | emergency_sync(); | |
2239 | kernel_power_off(); | |
2240 | } | |
2241 | ||
2242 | return ret; | |
2243 | } | |
2244 | EXPORT_SYMBOL_GPL(orderly_poweroff); |