Commit | Line | Data |
---|---|---|
1da177e4 LT |
1 | /* |
2 | * linux/kernel/sys.c | |
3 | * | |
4 | * Copyright (C) 1991, 1992 Linus Torvalds | |
5 | */ | |
6 | ||
9984de1a | 7 | #include <linux/export.h> |
1da177e4 LT |
8 | #include <linux/mm.h> |
9 | #include <linux/utsname.h> | |
10 | #include <linux/mman.h> | |
1da177e4 LT |
11 | #include <linux/reboot.h> |
12 | #include <linux/prctl.h> | |
1da177e4 LT |
13 | #include <linux/highuid.h> |
14 | #include <linux/fs.h> | |
74da1ff7 | 15 | #include <linux/kmod.h> |
cdd6c482 | 16 | #include <linux/perf_event.h> |
3e88c553 | 17 | #include <linux/resource.h> |
dc009d92 EB |
18 | #include <linux/kernel.h> |
19 | #include <linux/kexec.h> | |
1da177e4 | 20 | #include <linux/workqueue.h> |
c59ede7b | 21 | #include <linux/capability.h> |
1da177e4 LT |
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> | |
7ed20e1a | 30 | #include <linux/signal.h> |
9f46080c | 31 | #include <linux/cn_proc.h> |
3cfc348b | 32 | #include <linux/getcpu.h> |
6eaeeaba | 33 | #include <linux/task_io_accounting_ops.h> |
1d9d02fe | 34 | #include <linux/seccomp.h> |
4047727e | 35 | #include <linux/cpu.h> |
e28cbf22 | 36 | #include <linux/personality.h> |
e3d5a27d | 37 | #include <linux/ptrace.h> |
5ad4e53b | 38 | #include <linux/fs_struct.h> |
5a0e3ad6 | 39 | #include <linux/gfp.h> |
40dc166c | 40 | #include <linux/syscore_ops.h> |
be27425d AK |
41 | #include <linux/version.h> |
42 | #include <linux/ctype.h> | |
1da177e4 LT |
43 | |
44 | #include <linux/compat.h> | |
45 | #include <linux/syscalls.h> | |
00d7c05a | 46 | #include <linux/kprobes.h> |
acce292c | 47 | #include <linux/user_namespace.h> |
1da177e4 | 48 | |
04c6862c | 49 | #include <linux/kmsg_dump.h> |
be27425d AK |
50 | /* Move somewhere else to avoid recompiling? */ |
51 | #include <generated/utsrelease.h> | |
04c6862c | 52 | |
1da177e4 LT |
53 | #include <asm/uaccess.h> |
54 | #include <asm/io.h> | |
55 | #include <asm/unistd.h> | |
56 | ||
57 | #ifndef SET_UNALIGN_CTL | |
58 | # define SET_UNALIGN_CTL(a,b) (-EINVAL) | |
59 | #endif | |
60 | #ifndef GET_UNALIGN_CTL | |
61 | # define GET_UNALIGN_CTL(a,b) (-EINVAL) | |
62 | #endif | |
63 | #ifndef SET_FPEMU_CTL | |
64 | # define SET_FPEMU_CTL(a,b) (-EINVAL) | |
65 | #endif | |
66 | #ifndef GET_FPEMU_CTL | |
67 | # define GET_FPEMU_CTL(a,b) (-EINVAL) | |
68 | #endif | |
69 | #ifndef SET_FPEXC_CTL | |
70 | # define SET_FPEXC_CTL(a,b) (-EINVAL) | |
71 | #endif | |
72 | #ifndef GET_FPEXC_CTL | |
73 | # define GET_FPEXC_CTL(a,b) (-EINVAL) | |
74 | #endif | |
651d765d AB |
75 | #ifndef GET_ENDIAN |
76 | # define GET_ENDIAN(a,b) (-EINVAL) | |
77 | #endif | |
78 | #ifndef SET_ENDIAN | |
79 | # define SET_ENDIAN(a,b) (-EINVAL) | |
80 | #endif | |
8fb402bc EB |
81 | #ifndef GET_TSC_CTL |
82 | # define GET_TSC_CTL(a) (-EINVAL) | |
83 | #endif | |
84 | #ifndef SET_TSC_CTL | |
85 | # define SET_TSC_CTL(a) (-EINVAL) | |
86 | #endif | |
1da177e4 LT |
87 | |
88 | /* | |
89 | * this is where the system-wide overflow UID and GID are defined, for | |
90 | * architectures that now have 32-bit UID/GID but didn't in the past | |
91 | */ | |
92 | ||
93 | int overflowuid = DEFAULT_OVERFLOWUID; | |
94 | int overflowgid = DEFAULT_OVERFLOWGID; | |
95 | ||
96 | #ifdef CONFIG_UID16 | |
97 | EXPORT_SYMBOL(overflowuid); | |
98 | EXPORT_SYMBOL(overflowgid); | |
99 | #endif | |
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; | |
9ec52099 CLG |
117 | struct pid *cad_pid; |
118 | EXPORT_SYMBOL(cad_pid); | |
1da177e4 | 119 | |
bd804eba RW |
120 | /* |
121 | * If set, this is used for preparing the system to power off. | |
122 | */ | |
123 | ||
124 | void (*pm_power_off_prepare)(void); | |
bd804eba | 125 | |
fc832ad3 SH |
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 (pcred->user->user_ns == cred->user->user_ns && | |
137 | (pcred->uid == cred->euid || | |
138 | pcred->euid == cred->euid)) | |
139 | return true; | |
140 | if (ns_capable(pcred->user->user_ns, CAP_SYS_NICE)) | |
141 | return true; | |
142 | return false; | |
143 | } | |
144 | ||
c69e8d9c DH |
145 | /* |
146 | * set the priority of a task | |
147 | * - the caller must hold the RCU read lock | |
148 | */ | |
1da177e4 LT |
149 | static int set_one_prio(struct task_struct *p, int niceval, int error) |
150 | { | |
151 | int no_nice; | |
152 | ||
fc832ad3 | 153 | if (!set_one_prio_perm(p)) { |
1da177e4 LT |
154 | error = -EPERM; |
155 | goto out; | |
156 | } | |
e43379f1 | 157 | if (niceval < task_nice(p) && !can_nice(p, niceval)) { |
1da177e4 LT |
158 | error = -EACCES; |
159 | goto out; | |
160 | } | |
161 | no_nice = security_task_setnice(p, niceval); | |
162 | if (no_nice) { | |
163 | error = no_nice; | |
164 | goto out; | |
165 | } | |
166 | if (error == -ESRCH) | |
167 | error = 0; | |
168 | set_user_nice(p, niceval); | |
169 | out: | |
170 | return error; | |
171 | } | |
172 | ||
754fe8d2 | 173 | SYSCALL_DEFINE3(setpriority, int, which, int, who, int, niceval) |
1da177e4 LT |
174 | { |
175 | struct task_struct *g, *p; | |
176 | struct user_struct *user; | |
86a264ab | 177 | const struct cred *cred = current_cred(); |
1da177e4 | 178 | int error = -EINVAL; |
41487c65 | 179 | struct pid *pgrp; |
1da177e4 | 180 | |
3e88c553 | 181 | if (which > PRIO_USER || which < PRIO_PROCESS) |
1da177e4 LT |
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 | ||
d4581a23 | 191 | rcu_read_lock(); |
1da177e4 LT |
192 | read_lock(&tasklist_lock); |
193 | switch (which) { | |
194 | case PRIO_PROCESS: | |
41487c65 | 195 | if (who) |
228ebcbe | 196 | p = find_task_by_vpid(who); |
41487c65 EB |
197 | else |
198 | p = current; | |
1da177e4 LT |
199 | if (p) |
200 | error = set_one_prio(p, niceval, error); | |
201 | break; | |
202 | case PRIO_PGRP: | |
41487c65 | 203 | if (who) |
b488893a | 204 | pgrp = find_vpid(who); |
41487c65 EB |
205 | else |
206 | pgrp = task_pgrp(current); | |
2d70b68d | 207 | do_each_pid_thread(pgrp, PIDTYPE_PGID, p) { |
1da177e4 | 208 | error = set_one_prio(p, niceval, error); |
2d70b68d | 209 | } while_each_pid_thread(pgrp, PIDTYPE_PGID, p); |
1da177e4 LT |
210 | break; |
211 | case PRIO_USER: | |
d84f4f99 | 212 | user = (struct user_struct *) cred->user; |
1da177e4 | 213 | if (!who) |
86a264ab DH |
214 | who = cred->uid; |
215 | else if ((who != cred->uid) && | |
216 | !(user = find_user(who))) | |
217 | goto out_unlock; /* No processes for this user */ | |
1da177e4 | 218 | |
dfc6a736 | 219 | do_each_thread(g, p) { |
86a264ab | 220 | if (__task_cred(p)->uid == who) |
1da177e4 | 221 | error = set_one_prio(p, niceval, error); |
dfc6a736 | 222 | } while_each_thread(g, p); |
86a264ab | 223 | if (who != cred->uid) |
1da177e4 LT |
224 | free_uid(user); /* For find_user() */ |
225 | break; | |
226 | } | |
227 | out_unlock: | |
228 | read_unlock(&tasklist_lock); | |
d4581a23 | 229 | rcu_read_unlock(); |
1da177e4 LT |
230 | out: |
231 | return error; | |
232 | } | |
233 | ||
234 | /* | |
235 | * Ugh. To avoid negative return values, "getpriority()" will | |
236 | * not return the normal nice-value, but a negated value that | |
237 | * has been offset by 20 (ie it returns 40..1 instead of -20..19) | |
238 | * to stay compatible. | |
239 | */ | |
754fe8d2 | 240 | SYSCALL_DEFINE2(getpriority, int, which, int, who) |
1da177e4 LT |
241 | { |
242 | struct task_struct *g, *p; | |
243 | struct user_struct *user; | |
86a264ab | 244 | const struct cred *cred = current_cred(); |
1da177e4 | 245 | long niceval, retval = -ESRCH; |
41487c65 | 246 | struct pid *pgrp; |
1da177e4 | 247 | |
3e88c553 | 248 | if (which > PRIO_USER || which < PRIO_PROCESS) |
1da177e4 LT |
249 | return -EINVAL; |
250 | ||
70118837 | 251 | rcu_read_lock(); |
1da177e4 LT |
252 | read_lock(&tasklist_lock); |
253 | switch (which) { | |
254 | case PRIO_PROCESS: | |
41487c65 | 255 | if (who) |
228ebcbe | 256 | p = find_task_by_vpid(who); |
41487c65 EB |
257 | else |
258 | p = current; | |
1da177e4 LT |
259 | if (p) { |
260 | niceval = 20 - task_nice(p); | |
261 | if (niceval > retval) | |
262 | retval = niceval; | |
263 | } | |
264 | break; | |
265 | case PRIO_PGRP: | |
41487c65 | 266 | if (who) |
b488893a | 267 | pgrp = find_vpid(who); |
41487c65 EB |
268 | else |
269 | pgrp = task_pgrp(current); | |
2d70b68d | 270 | do_each_pid_thread(pgrp, PIDTYPE_PGID, p) { |
1da177e4 LT |
271 | niceval = 20 - task_nice(p); |
272 | if (niceval > retval) | |
273 | retval = niceval; | |
2d70b68d | 274 | } while_each_pid_thread(pgrp, PIDTYPE_PGID, p); |
1da177e4 LT |
275 | break; |
276 | case PRIO_USER: | |
86a264ab | 277 | user = (struct user_struct *) cred->user; |
1da177e4 | 278 | if (!who) |
86a264ab DH |
279 | who = cred->uid; |
280 | else if ((who != cred->uid) && | |
281 | !(user = find_user(who))) | |
282 | goto out_unlock; /* No processes for this user */ | |
1da177e4 | 283 | |
dfc6a736 | 284 | do_each_thread(g, p) { |
86a264ab | 285 | if (__task_cred(p)->uid == who) { |
1da177e4 LT |
286 | niceval = 20 - task_nice(p); |
287 | if (niceval > retval) | |
288 | retval = niceval; | |
289 | } | |
dfc6a736 | 290 | } while_each_thread(g, p); |
86a264ab | 291 | if (who != cred->uid) |
1da177e4 LT |
292 | free_uid(user); /* for find_user() */ |
293 | break; | |
294 | } | |
295 | out_unlock: | |
296 | read_unlock(&tasklist_lock); | |
70118837 | 297 | rcu_read_unlock(); |
1da177e4 LT |
298 | |
299 | return retval; | |
300 | } | |
301 | ||
e4c94330 EB |
302 | /** |
303 | * emergency_restart - reboot the system | |
304 | * | |
305 | * Without shutting down any hardware or taking any locks | |
306 | * reboot the system. This is called when we know we are in | |
307 | * trouble so this is our best effort to reboot. This is | |
308 | * safe to call in interrupt context. | |
309 | */ | |
7c903473 EB |
310 | void emergency_restart(void) |
311 | { | |
04c6862c | 312 | kmsg_dump(KMSG_DUMP_EMERG); |
7c903473 EB |
313 | machine_emergency_restart(); |
314 | } | |
315 | EXPORT_SYMBOL_GPL(emergency_restart); | |
316 | ||
ca195b7f | 317 | void kernel_restart_prepare(char *cmd) |
4a00ea1e | 318 | { |
e041c683 | 319 | blocking_notifier_call_chain(&reboot_notifier_list, SYS_RESTART, cmd); |
4a00ea1e | 320 | system_state = SYSTEM_RESTART; |
b50fa7c8 | 321 | usermodehelper_disable(); |
4a00ea1e | 322 | device_shutdown(); |
40dc166c | 323 | syscore_shutdown(); |
e4c94330 | 324 | } |
1e5d5331 | 325 | |
c5f41752 AW |
326 | /** |
327 | * register_reboot_notifier - Register function to be called at reboot time | |
328 | * @nb: Info about notifier function to be called | |
329 | * | |
330 | * Registers a function with the list of functions | |
331 | * to be called at reboot time. | |
332 | * | |
333 | * Currently always returns zero, as blocking_notifier_chain_register() | |
334 | * always returns zero. | |
335 | */ | |
336 | int register_reboot_notifier(struct notifier_block *nb) | |
337 | { | |
338 | return blocking_notifier_chain_register(&reboot_notifier_list, nb); | |
339 | } | |
340 | EXPORT_SYMBOL(register_reboot_notifier); | |
341 | ||
342 | /** | |
343 | * unregister_reboot_notifier - Unregister previously registered reboot notifier | |
344 | * @nb: Hook to be unregistered | |
345 | * | |
346 | * Unregisters a previously registered reboot | |
347 | * notifier function. | |
348 | * | |
349 | * Returns zero on success, or %-ENOENT on failure. | |
350 | */ | |
351 | int unregister_reboot_notifier(struct notifier_block *nb) | |
352 | { | |
353 | return blocking_notifier_chain_unregister(&reboot_notifier_list, nb); | |
354 | } | |
355 | EXPORT_SYMBOL(unregister_reboot_notifier); | |
356 | ||
1e5d5331 RD |
357 | /** |
358 | * kernel_restart - reboot the system | |
359 | * @cmd: pointer to buffer containing command to execute for restart | |
b8887e6e | 360 | * or %NULL |
1e5d5331 RD |
361 | * |
362 | * Shutdown everything and perform a clean reboot. | |
363 | * This is not safe to call in interrupt context. | |
364 | */ | |
e4c94330 EB |
365 | void kernel_restart(char *cmd) |
366 | { | |
367 | kernel_restart_prepare(cmd); | |
756184b7 | 368 | if (!cmd) |
4a00ea1e | 369 | printk(KERN_EMERG "Restarting system.\n"); |
756184b7 | 370 | else |
4a00ea1e | 371 | printk(KERN_EMERG "Restarting system with command '%s'.\n", cmd); |
04c6862c | 372 | kmsg_dump(KMSG_DUMP_RESTART); |
4a00ea1e EB |
373 | machine_restart(cmd); |
374 | } | |
375 | EXPORT_SYMBOL_GPL(kernel_restart); | |
376 | ||
4ef7229f | 377 | static void kernel_shutdown_prepare(enum system_states state) |
729b4d4c | 378 | { |
e041c683 | 379 | blocking_notifier_call_chain(&reboot_notifier_list, |
729b4d4c AS |
380 | (state == SYSTEM_HALT)?SYS_HALT:SYS_POWER_OFF, NULL); |
381 | system_state = state; | |
b50fa7c8 | 382 | usermodehelper_disable(); |
729b4d4c AS |
383 | device_shutdown(); |
384 | } | |
e4c94330 EB |
385 | /** |
386 | * kernel_halt - halt the system | |
387 | * | |
388 | * Shutdown everything and perform a clean system halt. | |
389 | */ | |
e4c94330 EB |
390 | void kernel_halt(void) |
391 | { | |
729b4d4c | 392 | kernel_shutdown_prepare(SYSTEM_HALT); |
40dc166c | 393 | syscore_shutdown(); |
4a00ea1e | 394 | printk(KERN_EMERG "System halted.\n"); |
04c6862c | 395 | kmsg_dump(KMSG_DUMP_HALT); |
4a00ea1e EB |
396 | machine_halt(); |
397 | } | |
729b4d4c | 398 | |
4a00ea1e EB |
399 | EXPORT_SYMBOL_GPL(kernel_halt); |
400 | ||
e4c94330 EB |
401 | /** |
402 | * kernel_power_off - power_off the system | |
403 | * | |
404 | * Shutdown everything and perform a clean system power_off. | |
405 | */ | |
e4c94330 EB |
406 | void kernel_power_off(void) |
407 | { | |
729b4d4c | 408 | kernel_shutdown_prepare(SYSTEM_POWER_OFF); |
bd804eba RW |
409 | if (pm_power_off_prepare) |
410 | pm_power_off_prepare(); | |
4047727e | 411 | disable_nonboot_cpus(); |
40dc166c | 412 | syscore_shutdown(); |
4a00ea1e | 413 | printk(KERN_EMERG "Power down.\n"); |
04c6862c | 414 | kmsg_dump(KMSG_DUMP_POWEROFF); |
4a00ea1e EB |
415 | machine_power_off(); |
416 | } | |
417 | EXPORT_SYMBOL_GPL(kernel_power_off); | |
6f15fa50 TG |
418 | |
419 | static DEFINE_MUTEX(reboot_mutex); | |
420 | ||
1da177e4 LT |
421 | /* |
422 | * Reboot system call: for obvious reasons only root may call it, | |
423 | * and even root needs to set up some magic numbers in the registers | |
424 | * so that some mistake won't make this reboot the whole machine. | |
425 | * You can also set the meaning of the ctrl-alt-del-key here. | |
426 | * | |
427 | * reboot doesn't sync: do that yourself before calling this. | |
428 | */ | |
754fe8d2 HC |
429 | SYSCALL_DEFINE4(reboot, int, magic1, int, magic2, unsigned int, cmd, |
430 | void __user *, arg) | |
1da177e4 LT |
431 | { |
432 | char buffer[256]; | |
3d26dcf7 | 433 | int ret = 0; |
1da177e4 LT |
434 | |
435 | /* We only trust the superuser with rebooting the system. */ | |
436 | if (!capable(CAP_SYS_BOOT)) | |
437 | return -EPERM; | |
438 | ||
439 | /* For safety, we require "magic" arguments. */ | |
440 | if (magic1 != LINUX_REBOOT_MAGIC1 || | |
441 | (magic2 != LINUX_REBOOT_MAGIC2 && | |
442 | magic2 != LINUX_REBOOT_MAGIC2A && | |
443 | magic2 != LINUX_REBOOT_MAGIC2B && | |
444 | magic2 != LINUX_REBOOT_MAGIC2C)) | |
445 | return -EINVAL; | |
446 | ||
cf3f8921 DL |
447 | /* |
448 | * If pid namespaces are enabled and the current task is in a child | |
449 | * pid_namespace, the command is handled by reboot_pid_ns() which will | |
450 | * call do_exit(). | |
451 | */ | |
452 | ret = reboot_pid_ns(task_active_pid_ns(current), cmd); | |
453 | if (ret) | |
454 | return ret; | |
455 | ||
5e38291d EB |
456 | /* Instead of trying to make the power_off code look like |
457 | * halt when pm_power_off is not set do it the easy way. | |
458 | */ | |
459 | if ((cmd == LINUX_REBOOT_CMD_POWER_OFF) && !pm_power_off) | |
460 | cmd = LINUX_REBOOT_CMD_HALT; | |
461 | ||
6f15fa50 | 462 | mutex_lock(&reboot_mutex); |
1da177e4 LT |
463 | switch (cmd) { |
464 | case LINUX_REBOOT_CMD_RESTART: | |
4a00ea1e | 465 | kernel_restart(NULL); |
1da177e4 LT |
466 | break; |
467 | ||
468 | case LINUX_REBOOT_CMD_CAD_ON: | |
469 | C_A_D = 1; | |
470 | break; | |
471 | ||
472 | case LINUX_REBOOT_CMD_CAD_OFF: | |
473 | C_A_D = 0; | |
474 | break; | |
475 | ||
476 | case LINUX_REBOOT_CMD_HALT: | |
4a00ea1e | 477 | kernel_halt(); |
1da177e4 | 478 | do_exit(0); |
3d26dcf7 | 479 | panic("cannot halt"); |
1da177e4 LT |
480 | |
481 | case LINUX_REBOOT_CMD_POWER_OFF: | |
4a00ea1e | 482 | kernel_power_off(); |
1da177e4 LT |
483 | do_exit(0); |
484 | break; | |
485 | ||
486 | case LINUX_REBOOT_CMD_RESTART2: | |
487 | if (strncpy_from_user(&buffer[0], arg, sizeof(buffer) - 1) < 0) { | |
6f15fa50 TG |
488 | ret = -EFAULT; |
489 | break; | |
1da177e4 LT |
490 | } |
491 | buffer[sizeof(buffer) - 1] = '\0'; | |
492 | ||
4a00ea1e | 493 | kernel_restart(buffer); |
1da177e4 LT |
494 | break; |
495 | ||
3ab83521 | 496 | #ifdef CONFIG_KEXEC |
dc009d92 | 497 | case LINUX_REBOOT_CMD_KEXEC: |
3d26dcf7 AK |
498 | ret = kernel_kexec(); |
499 | break; | |
3ab83521 | 500 | #endif |
4a00ea1e | 501 | |
b0cb1a19 | 502 | #ifdef CONFIG_HIBERNATION |
1da177e4 | 503 | case LINUX_REBOOT_CMD_SW_SUSPEND: |
3d26dcf7 AK |
504 | ret = hibernate(); |
505 | break; | |
1da177e4 LT |
506 | #endif |
507 | ||
508 | default: | |
3d26dcf7 AK |
509 | ret = -EINVAL; |
510 | break; | |
1da177e4 | 511 | } |
6f15fa50 | 512 | mutex_unlock(&reboot_mutex); |
3d26dcf7 | 513 | return ret; |
1da177e4 LT |
514 | } |
515 | ||
65f27f38 | 516 | static void deferred_cad(struct work_struct *dummy) |
1da177e4 | 517 | { |
abcd9e51 | 518 | kernel_restart(NULL); |
1da177e4 LT |
519 | } |
520 | ||
521 | /* | |
522 | * This function gets called by ctrl-alt-del - ie the keyboard interrupt. | |
523 | * As it's called within an interrupt, it may NOT sync: the only choice | |
524 | * is whether to reboot at once, or just ignore the ctrl-alt-del. | |
525 | */ | |
526 | void ctrl_alt_del(void) | |
527 | { | |
65f27f38 | 528 | static DECLARE_WORK(cad_work, deferred_cad); |
1da177e4 LT |
529 | |
530 | if (C_A_D) | |
531 | schedule_work(&cad_work); | |
532 | else | |
9ec52099 | 533 | kill_cad_pid(SIGINT, 1); |
1da177e4 LT |
534 | } |
535 | ||
1da177e4 LT |
536 | /* |
537 | * Unprivileged users may change the real gid to the effective gid | |
538 | * or vice versa. (BSD-style) | |
539 | * | |
540 | * If you set the real gid at all, or set the effective gid to a value not | |
541 | * equal to the real gid, then the saved gid is set to the new effective gid. | |
542 | * | |
543 | * This makes it possible for a setgid program to completely drop its | |
544 | * privileges, which is often a useful assertion to make when you are doing | |
545 | * a security audit over a program. | |
546 | * | |
547 | * The general idea is that a program which uses just setregid() will be | |
548 | * 100% compatible with BSD. A program which uses just setgid() will be | |
549 | * 100% compatible with POSIX with saved IDs. | |
550 | * | |
551 | * SMP: There are not races, the GIDs are checked only by filesystem | |
552 | * operations (as far as semantic preservation is concerned). | |
553 | */ | |
ae1251ab | 554 | SYSCALL_DEFINE2(setregid, gid_t, rgid, gid_t, egid) |
1da177e4 | 555 | { |
d84f4f99 DH |
556 | const struct cred *old; |
557 | struct cred *new; | |
1da177e4 LT |
558 | int retval; |
559 | ||
d84f4f99 DH |
560 | new = prepare_creds(); |
561 | if (!new) | |
562 | return -ENOMEM; | |
563 | old = current_cred(); | |
564 | ||
d84f4f99 | 565 | retval = -EPERM; |
1da177e4 | 566 | if (rgid != (gid_t) -1) { |
d84f4f99 DH |
567 | if (old->gid == rgid || |
568 | old->egid == rgid || | |
fc832ad3 | 569 | nsown_capable(CAP_SETGID)) |
d84f4f99 | 570 | new->gid = rgid; |
1da177e4 | 571 | else |
d84f4f99 | 572 | goto error; |
1da177e4 LT |
573 | } |
574 | if (egid != (gid_t) -1) { | |
d84f4f99 DH |
575 | if (old->gid == egid || |
576 | old->egid == egid || | |
577 | old->sgid == egid || | |
fc832ad3 | 578 | nsown_capable(CAP_SETGID)) |
d84f4f99 | 579 | new->egid = egid; |
756184b7 | 580 | else |
d84f4f99 | 581 | goto error; |
1da177e4 | 582 | } |
d84f4f99 | 583 | |
1da177e4 | 584 | if (rgid != (gid_t) -1 || |
d84f4f99 DH |
585 | (egid != (gid_t) -1 && egid != old->gid)) |
586 | new->sgid = new->egid; | |
587 | new->fsgid = new->egid; | |
588 | ||
589 | return commit_creds(new); | |
590 | ||
591 | error: | |
592 | abort_creds(new); | |
593 | return retval; | |
1da177e4 LT |
594 | } |
595 | ||
596 | /* | |
597 | * setgid() is implemented like SysV w/ SAVED_IDS | |
598 | * | |
599 | * SMP: Same implicit races as above. | |
600 | */ | |
ae1251ab | 601 | SYSCALL_DEFINE1(setgid, gid_t, gid) |
1da177e4 | 602 | { |
d84f4f99 DH |
603 | const struct cred *old; |
604 | struct cred *new; | |
1da177e4 LT |
605 | int retval; |
606 | ||
d84f4f99 DH |
607 | new = prepare_creds(); |
608 | if (!new) | |
609 | return -ENOMEM; | |
610 | old = current_cred(); | |
611 | ||
d84f4f99 | 612 | retval = -EPERM; |
fc832ad3 | 613 | if (nsown_capable(CAP_SETGID)) |
d84f4f99 DH |
614 | new->gid = new->egid = new->sgid = new->fsgid = gid; |
615 | else if (gid == old->gid || gid == old->sgid) | |
616 | new->egid = new->fsgid = gid; | |
1da177e4 | 617 | else |
d84f4f99 | 618 | goto error; |
1da177e4 | 619 | |
d84f4f99 DH |
620 | return commit_creds(new); |
621 | ||
622 | error: | |
623 | abort_creds(new); | |
624 | return retval; | |
1da177e4 | 625 | } |
54e99124 | 626 | |
d84f4f99 DH |
627 | /* |
628 | * change the user struct in a credentials set to match the new UID | |
629 | */ | |
630 | static int set_user(struct cred *new) | |
1da177e4 LT |
631 | { |
632 | struct user_struct *new_user; | |
633 | ||
18b6e041 | 634 | new_user = alloc_uid(current_user_ns(), new->uid); |
1da177e4 LT |
635 | if (!new_user) |
636 | return -EAGAIN; | |
637 | ||
72fa5997 VK |
638 | /* |
639 | * We don't fail in case of NPROC limit excess here because too many | |
640 | * poorly written programs don't check set*uid() return code, assuming | |
641 | * it never fails if called by root. We may still enforce NPROC limit | |
642 | * for programs doing set*uid()+execve() by harmlessly deferring the | |
643 | * failure to the execve() stage. | |
644 | */ | |
78d7d407 | 645 | if (atomic_read(&new_user->processes) >= rlimit(RLIMIT_NPROC) && |
72fa5997 VK |
646 | new_user != INIT_USER) |
647 | current->flags |= PF_NPROC_EXCEEDED; | |
648 | else | |
649 | current->flags &= ~PF_NPROC_EXCEEDED; | |
1da177e4 | 650 | |
d84f4f99 DH |
651 | free_uid(new->user); |
652 | new->user = new_user; | |
1da177e4 LT |
653 | return 0; |
654 | } | |
655 | ||
656 | /* | |
657 | * Unprivileged users may change the real uid to the effective uid | |
658 | * or vice versa. (BSD-style) | |
659 | * | |
660 | * If you set the real uid at all, or set the effective uid to a value not | |
661 | * equal to the real uid, then the saved uid is set to the new effective uid. | |
662 | * | |
663 | * This makes it possible for a setuid program to completely drop its | |
664 | * privileges, which is often a useful assertion to make when you are doing | |
665 | * a security audit over a program. | |
666 | * | |
667 | * The general idea is that a program which uses just setreuid() will be | |
668 | * 100% compatible with BSD. A program which uses just setuid() will be | |
669 | * 100% compatible with POSIX with saved IDs. | |
670 | */ | |
ae1251ab | 671 | SYSCALL_DEFINE2(setreuid, uid_t, ruid, uid_t, euid) |
1da177e4 | 672 | { |
d84f4f99 DH |
673 | const struct cred *old; |
674 | struct cred *new; | |
1da177e4 LT |
675 | int retval; |
676 | ||
d84f4f99 DH |
677 | new = prepare_creds(); |
678 | if (!new) | |
679 | return -ENOMEM; | |
680 | old = current_cred(); | |
681 | ||
d84f4f99 | 682 | retval = -EPERM; |
1da177e4 | 683 | if (ruid != (uid_t) -1) { |
d84f4f99 DH |
684 | new->uid = ruid; |
685 | if (old->uid != ruid && | |
686 | old->euid != ruid && | |
fc832ad3 | 687 | !nsown_capable(CAP_SETUID)) |
d84f4f99 | 688 | goto error; |
1da177e4 LT |
689 | } |
690 | ||
691 | if (euid != (uid_t) -1) { | |
d84f4f99 DH |
692 | new->euid = euid; |
693 | if (old->uid != euid && | |
694 | old->euid != euid && | |
695 | old->suid != euid && | |
fc832ad3 | 696 | !nsown_capable(CAP_SETUID)) |
d84f4f99 | 697 | goto error; |
1da177e4 LT |
698 | } |
699 | ||
54e99124 DG |
700 | if (new->uid != old->uid) { |
701 | retval = set_user(new); | |
702 | if (retval < 0) | |
703 | goto error; | |
704 | } | |
1da177e4 | 705 | if (ruid != (uid_t) -1 || |
d84f4f99 DH |
706 | (euid != (uid_t) -1 && euid != old->uid)) |
707 | new->suid = new->euid; | |
708 | new->fsuid = new->euid; | |
1da177e4 | 709 | |
d84f4f99 DH |
710 | retval = security_task_fix_setuid(new, old, LSM_SETID_RE); |
711 | if (retval < 0) | |
712 | goto error; | |
1da177e4 | 713 | |
d84f4f99 | 714 | return commit_creds(new); |
1da177e4 | 715 | |
d84f4f99 DH |
716 | error: |
717 | abort_creds(new); | |
718 | return retval; | |
719 | } | |
1da177e4 LT |
720 | |
721 | /* | |
722 | * setuid() is implemented like SysV with SAVED_IDS | |
723 | * | |
724 | * Note that SAVED_ID's is deficient in that a setuid root program | |
725 | * like sendmail, for example, cannot set its uid to be a normal | |
726 | * user and then switch back, because if you're root, setuid() sets | |
727 | * the saved uid too. If you don't like this, blame the bright people | |
728 | * in the POSIX committee and/or USG. Note that the BSD-style setreuid() | |
729 | * will allow a root program to temporarily drop privileges and be able to | |
730 | * regain them by swapping the real and effective uid. | |
731 | */ | |
ae1251ab | 732 | SYSCALL_DEFINE1(setuid, uid_t, uid) |
1da177e4 | 733 | { |
d84f4f99 DH |
734 | const struct cred *old; |
735 | struct cred *new; | |
1da177e4 LT |
736 | int retval; |
737 | ||
d84f4f99 DH |
738 | new = prepare_creds(); |
739 | if (!new) | |
740 | return -ENOMEM; | |
741 | old = current_cred(); | |
742 | ||
d84f4f99 | 743 | retval = -EPERM; |
fc832ad3 | 744 | if (nsown_capable(CAP_SETUID)) { |
d84f4f99 | 745 | new->suid = new->uid = uid; |
54e99124 DG |
746 | if (uid != old->uid) { |
747 | retval = set_user(new); | |
748 | if (retval < 0) | |
749 | goto error; | |
d84f4f99 DH |
750 | } |
751 | } else if (uid != old->uid && uid != new->suid) { | |
752 | goto error; | |
1da177e4 | 753 | } |
1da177e4 | 754 | |
d84f4f99 DH |
755 | new->fsuid = new->euid = uid; |
756 | ||
757 | retval = security_task_fix_setuid(new, old, LSM_SETID_ID); | |
758 | if (retval < 0) | |
759 | goto error; | |
1da177e4 | 760 | |
d84f4f99 | 761 | return commit_creds(new); |
1da177e4 | 762 | |
d84f4f99 DH |
763 | error: |
764 | abort_creds(new); | |
765 | return retval; | |
1da177e4 LT |
766 | } |
767 | ||
768 | ||
769 | /* | |
770 | * This function implements a generic ability to update ruid, euid, | |
771 | * and suid. This allows you to implement the 4.4 compatible seteuid(). | |
772 | */ | |
ae1251ab | 773 | SYSCALL_DEFINE3(setresuid, uid_t, ruid, uid_t, euid, uid_t, suid) |
1da177e4 | 774 | { |
d84f4f99 DH |
775 | const struct cred *old; |
776 | struct cred *new; | |
1da177e4 LT |
777 | int retval; |
778 | ||
d84f4f99 DH |
779 | new = prepare_creds(); |
780 | if (!new) | |
781 | return -ENOMEM; | |
782 | ||
d84f4f99 | 783 | old = current_cred(); |
1da177e4 | 784 | |
d84f4f99 | 785 | retval = -EPERM; |
fc832ad3 | 786 | if (!nsown_capable(CAP_SETUID)) { |
d84f4f99 DH |
787 | if (ruid != (uid_t) -1 && ruid != old->uid && |
788 | ruid != old->euid && ruid != old->suid) | |
789 | goto error; | |
790 | if (euid != (uid_t) -1 && euid != old->uid && | |
791 | euid != old->euid && euid != old->suid) | |
792 | goto error; | |
793 | if (suid != (uid_t) -1 && suid != old->uid && | |
794 | suid != old->euid && suid != old->suid) | |
795 | goto error; | |
1da177e4 | 796 | } |
d84f4f99 | 797 | |
1da177e4 | 798 | if (ruid != (uid_t) -1) { |
d84f4f99 | 799 | new->uid = ruid; |
54e99124 DG |
800 | if (ruid != old->uid) { |
801 | retval = set_user(new); | |
802 | if (retval < 0) | |
803 | goto error; | |
804 | } | |
1da177e4 | 805 | } |
d84f4f99 DH |
806 | if (euid != (uid_t) -1) |
807 | new->euid = euid; | |
1da177e4 | 808 | if (suid != (uid_t) -1) |
d84f4f99 DH |
809 | new->suid = suid; |
810 | new->fsuid = new->euid; | |
1da177e4 | 811 | |
d84f4f99 DH |
812 | retval = security_task_fix_setuid(new, old, LSM_SETID_RES); |
813 | if (retval < 0) | |
814 | goto error; | |
1da177e4 | 815 | |
d84f4f99 | 816 | return commit_creds(new); |
1da177e4 | 817 | |
d84f4f99 DH |
818 | error: |
819 | abort_creds(new); | |
820 | return retval; | |
1da177e4 LT |
821 | } |
822 | ||
dbf040d9 | 823 | SYSCALL_DEFINE3(getresuid, uid_t __user *, ruid, uid_t __user *, euid, uid_t __user *, suid) |
1da177e4 | 824 | { |
86a264ab | 825 | const struct cred *cred = current_cred(); |
1da177e4 LT |
826 | int retval; |
827 | ||
86a264ab DH |
828 | if (!(retval = put_user(cred->uid, ruid)) && |
829 | !(retval = put_user(cred->euid, euid))) | |
b6dff3ec | 830 | retval = put_user(cred->suid, suid); |
1da177e4 LT |
831 | |
832 | return retval; | |
833 | } | |
834 | ||
835 | /* | |
836 | * Same as above, but for rgid, egid, sgid. | |
837 | */ | |
ae1251ab | 838 | SYSCALL_DEFINE3(setresgid, gid_t, rgid, gid_t, egid, gid_t, sgid) |
1da177e4 | 839 | { |
d84f4f99 DH |
840 | const struct cred *old; |
841 | struct cred *new; | |
1da177e4 LT |
842 | int retval; |
843 | ||
d84f4f99 DH |
844 | new = prepare_creds(); |
845 | if (!new) | |
846 | return -ENOMEM; | |
847 | old = current_cred(); | |
848 | ||
d84f4f99 | 849 | retval = -EPERM; |
fc832ad3 | 850 | if (!nsown_capable(CAP_SETGID)) { |
d84f4f99 DH |
851 | if (rgid != (gid_t) -1 && rgid != old->gid && |
852 | rgid != old->egid && rgid != old->sgid) | |
853 | goto error; | |
854 | if (egid != (gid_t) -1 && egid != old->gid && | |
855 | egid != old->egid && egid != old->sgid) | |
856 | goto error; | |
857 | if (sgid != (gid_t) -1 && sgid != old->gid && | |
858 | sgid != old->egid && sgid != old->sgid) | |
859 | goto error; | |
1da177e4 | 860 | } |
d84f4f99 | 861 | |
1da177e4 | 862 | if (rgid != (gid_t) -1) |
d84f4f99 DH |
863 | new->gid = rgid; |
864 | if (egid != (gid_t) -1) | |
865 | new->egid = egid; | |
1da177e4 | 866 | if (sgid != (gid_t) -1) |
d84f4f99 DH |
867 | new->sgid = sgid; |
868 | new->fsgid = new->egid; | |
1da177e4 | 869 | |
d84f4f99 DH |
870 | return commit_creds(new); |
871 | ||
872 | error: | |
873 | abort_creds(new); | |
874 | return retval; | |
1da177e4 LT |
875 | } |
876 | ||
dbf040d9 | 877 | SYSCALL_DEFINE3(getresgid, gid_t __user *, rgid, gid_t __user *, egid, gid_t __user *, sgid) |
1da177e4 | 878 | { |
86a264ab | 879 | const struct cred *cred = current_cred(); |
1da177e4 LT |
880 | int retval; |
881 | ||
86a264ab DH |
882 | if (!(retval = put_user(cred->gid, rgid)) && |
883 | !(retval = put_user(cred->egid, egid))) | |
b6dff3ec | 884 | retval = put_user(cred->sgid, sgid); |
1da177e4 LT |
885 | |
886 | return retval; | |
887 | } | |
888 | ||
889 | ||
890 | /* | |
891 | * "setfsuid()" sets the fsuid - the uid used for filesystem checks. This | |
892 | * is used for "access()" and for the NFS daemon (letting nfsd stay at | |
893 | * whatever uid it wants to). It normally shadows "euid", except when | |
894 | * explicitly set by setfsuid() or for access.. | |
895 | */ | |
ae1251ab | 896 | SYSCALL_DEFINE1(setfsuid, uid_t, uid) |
1da177e4 | 897 | { |
d84f4f99 DH |
898 | const struct cred *old; |
899 | struct cred *new; | |
900 | uid_t old_fsuid; | |
1da177e4 | 901 | |
d84f4f99 DH |
902 | new = prepare_creds(); |
903 | if (!new) | |
904 | return current_fsuid(); | |
905 | old = current_cred(); | |
906 | old_fsuid = old->fsuid; | |
1da177e4 | 907 | |
d84f4f99 DH |
908 | if (uid == old->uid || uid == old->euid || |
909 | uid == old->suid || uid == old->fsuid || | |
fc832ad3 | 910 | nsown_capable(CAP_SETUID)) { |
756184b7 | 911 | if (uid != old_fsuid) { |
d84f4f99 DH |
912 | new->fsuid = uid; |
913 | if (security_task_fix_setuid(new, old, LSM_SETID_FS) == 0) | |
914 | goto change_okay; | |
1da177e4 | 915 | } |
1da177e4 LT |
916 | } |
917 | ||
d84f4f99 DH |
918 | abort_creds(new); |
919 | return old_fsuid; | |
1da177e4 | 920 | |
d84f4f99 DH |
921 | change_okay: |
922 | commit_creds(new); | |
1da177e4 LT |
923 | return old_fsuid; |
924 | } | |
925 | ||
926 | /* | |
f42df9e6 | 927 | * Samma på svenska.. |
1da177e4 | 928 | */ |
ae1251ab | 929 | SYSCALL_DEFINE1(setfsgid, gid_t, gid) |
1da177e4 | 930 | { |
d84f4f99 DH |
931 | const struct cred *old; |
932 | struct cred *new; | |
933 | gid_t old_fsgid; | |
934 | ||
935 | new = prepare_creds(); | |
936 | if (!new) | |
937 | return current_fsgid(); | |
938 | old = current_cred(); | |
939 | old_fsgid = old->fsgid; | |
1da177e4 | 940 | |
d84f4f99 DH |
941 | if (gid == old->gid || gid == old->egid || |
942 | gid == old->sgid || gid == old->fsgid || | |
fc832ad3 | 943 | nsown_capable(CAP_SETGID)) { |
756184b7 | 944 | if (gid != old_fsgid) { |
d84f4f99 DH |
945 | new->fsgid = gid; |
946 | goto change_okay; | |
1da177e4 | 947 | } |
1da177e4 | 948 | } |
d84f4f99 | 949 | |
d84f4f99 DH |
950 | abort_creds(new); |
951 | return old_fsgid; | |
952 | ||
953 | change_okay: | |
954 | commit_creds(new); | |
1da177e4 LT |
955 | return old_fsgid; |
956 | } | |
957 | ||
f06febc9 FM |
958 | void do_sys_times(struct tms *tms) |
959 | { | |
0cf55e1e | 960 | cputime_t tgutime, tgstime, cutime, cstime; |
f06febc9 | 961 | |
2b5fe6de | 962 | spin_lock_irq(¤t->sighand->siglock); |
0cf55e1e | 963 | thread_group_times(current, &tgutime, &tgstime); |
f06febc9 FM |
964 | cutime = current->signal->cutime; |
965 | cstime = current->signal->cstime; | |
966 | spin_unlock_irq(¤t->sighand->siglock); | |
0cf55e1e HS |
967 | tms->tms_utime = cputime_to_clock_t(tgutime); |
968 | tms->tms_stime = cputime_to_clock_t(tgstime); | |
f06febc9 FM |
969 | tms->tms_cutime = cputime_to_clock_t(cutime); |
970 | tms->tms_cstime = cputime_to_clock_t(cstime); | |
971 | } | |
972 | ||
58fd3aa2 | 973 | SYSCALL_DEFINE1(times, struct tms __user *, tbuf) |
1da177e4 | 974 | { |
1da177e4 LT |
975 | if (tbuf) { |
976 | struct tms tmp; | |
f06febc9 FM |
977 | |
978 | do_sys_times(&tmp); | |
1da177e4 LT |
979 | if (copy_to_user(tbuf, &tmp, sizeof(struct tms))) |
980 | return -EFAULT; | |
981 | } | |
e3d5a27d | 982 | force_successful_syscall_return(); |
1da177e4 LT |
983 | return (long) jiffies_64_to_clock_t(get_jiffies_64()); |
984 | } | |
985 | ||
986 | /* | |
987 | * This needs some heavy checking ... | |
988 | * I just haven't the stomach for it. I also don't fully | |
989 | * understand sessions/pgrp etc. Let somebody who does explain it. | |
990 | * | |
991 | * OK, I think I have the protection semantics right.... this is really | |
992 | * only important on a multi-user system anyway, to make sure one user | |
993 | * can't send a signal to a process owned by another. -TYT, 12/12/91 | |
994 | * | |
995 | * Auch. Had to add the 'did_exec' flag to conform completely to POSIX. | |
996 | * LBT 04.03.94 | |
997 | */ | |
b290ebe2 | 998 | SYSCALL_DEFINE2(setpgid, pid_t, pid, pid_t, pgid) |
1da177e4 LT |
999 | { |
1000 | struct task_struct *p; | |
ee0acf90 | 1001 | struct task_struct *group_leader = current->group_leader; |
4e021306 ON |
1002 | struct pid *pgrp; |
1003 | int err; | |
1da177e4 LT |
1004 | |
1005 | if (!pid) | |
b488893a | 1006 | pid = task_pid_vnr(group_leader); |
1da177e4 LT |
1007 | if (!pgid) |
1008 | pgid = pid; | |
1009 | if (pgid < 0) | |
1010 | return -EINVAL; | |
950eaaca | 1011 | rcu_read_lock(); |
1da177e4 LT |
1012 | |
1013 | /* From this point forward we keep holding onto the tasklist lock | |
1014 | * so that our parent does not change from under us. -DaveM | |
1015 | */ | |
1016 | write_lock_irq(&tasklist_lock); | |
1017 | ||
1018 | err = -ESRCH; | |
4e021306 | 1019 | p = find_task_by_vpid(pid); |
1da177e4 LT |
1020 | if (!p) |
1021 | goto out; | |
1022 | ||
1023 | err = -EINVAL; | |
1024 | if (!thread_group_leader(p)) | |
1025 | goto out; | |
1026 | ||
4e021306 | 1027 | if (same_thread_group(p->real_parent, group_leader)) { |
1da177e4 | 1028 | err = -EPERM; |
41487c65 | 1029 | if (task_session(p) != task_session(group_leader)) |
1da177e4 LT |
1030 | goto out; |
1031 | err = -EACCES; | |
1032 | if (p->did_exec) | |
1033 | goto out; | |
1034 | } else { | |
1035 | err = -ESRCH; | |
ee0acf90 | 1036 | if (p != group_leader) |
1da177e4 LT |
1037 | goto out; |
1038 | } | |
1039 | ||
1040 | err = -EPERM; | |
1041 | if (p->signal->leader) | |
1042 | goto out; | |
1043 | ||
4e021306 | 1044 | pgrp = task_pid(p); |
1da177e4 | 1045 | if (pgid != pid) { |
b488893a | 1046 | struct task_struct *g; |
1da177e4 | 1047 | |
4e021306 ON |
1048 | pgrp = find_vpid(pgid); |
1049 | g = pid_task(pgrp, PIDTYPE_PGID); | |
41487c65 | 1050 | if (!g || task_session(g) != task_session(group_leader)) |
f020bc46 | 1051 | goto out; |
1da177e4 LT |
1052 | } |
1053 | ||
1da177e4 LT |
1054 | err = security_task_setpgid(p, pgid); |
1055 | if (err) | |
1056 | goto out; | |
1057 | ||
1b0f7ffd | 1058 | if (task_pgrp(p) != pgrp) |
83beaf3c | 1059 | change_pid(p, PIDTYPE_PGID, pgrp); |
1da177e4 LT |
1060 | |
1061 | err = 0; | |
1062 | out: | |
1063 | /* All paths lead to here, thus we are safe. -DaveM */ | |
1064 | write_unlock_irq(&tasklist_lock); | |
950eaaca | 1065 | rcu_read_unlock(); |
1da177e4 LT |
1066 | return err; |
1067 | } | |
1068 | ||
dbf040d9 | 1069 | SYSCALL_DEFINE1(getpgid, pid_t, pid) |
1da177e4 | 1070 | { |
12a3de0a ON |
1071 | struct task_struct *p; |
1072 | struct pid *grp; | |
1073 | int retval; | |
1074 | ||
1075 | rcu_read_lock(); | |
756184b7 | 1076 | if (!pid) |
12a3de0a | 1077 | grp = task_pgrp(current); |
756184b7 | 1078 | else { |
1da177e4 | 1079 | retval = -ESRCH; |
12a3de0a ON |
1080 | p = find_task_by_vpid(pid); |
1081 | if (!p) | |
1082 | goto out; | |
1083 | grp = task_pgrp(p); | |
1084 | if (!grp) | |
1085 | goto out; | |
1086 | ||
1087 | retval = security_task_getpgid(p); | |
1088 | if (retval) | |
1089 | goto out; | |
1da177e4 | 1090 | } |
12a3de0a ON |
1091 | retval = pid_vnr(grp); |
1092 | out: | |
1093 | rcu_read_unlock(); | |
1094 | return retval; | |
1da177e4 LT |
1095 | } |
1096 | ||
1097 | #ifdef __ARCH_WANT_SYS_GETPGRP | |
1098 | ||
dbf040d9 | 1099 | SYSCALL_DEFINE0(getpgrp) |
1da177e4 | 1100 | { |
12a3de0a | 1101 | return sys_getpgid(0); |
1da177e4 LT |
1102 | } |
1103 | ||
1104 | #endif | |
1105 | ||
dbf040d9 | 1106 | SYSCALL_DEFINE1(getsid, pid_t, pid) |
1da177e4 | 1107 | { |
1dd768c0 ON |
1108 | struct task_struct *p; |
1109 | struct pid *sid; | |
1110 | int retval; | |
1111 | ||
1112 | rcu_read_lock(); | |
756184b7 | 1113 | if (!pid) |
1dd768c0 | 1114 | sid = task_session(current); |
756184b7 | 1115 | else { |
1da177e4 | 1116 | retval = -ESRCH; |
1dd768c0 ON |
1117 | p = find_task_by_vpid(pid); |
1118 | if (!p) | |
1119 | goto out; | |
1120 | sid = task_session(p); | |
1121 | if (!sid) | |
1122 | goto out; | |
1123 | ||
1124 | retval = security_task_getsid(p); | |
1125 | if (retval) | |
1126 | goto out; | |
1da177e4 | 1127 | } |
1dd768c0 ON |
1128 | retval = pid_vnr(sid); |
1129 | out: | |
1130 | rcu_read_unlock(); | |
1131 | return retval; | |
1da177e4 LT |
1132 | } |
1133 | ||
b290ebe2 | 1134 | SYSCALL_DEFINE0(setsid) |
1da177e4 | 1135 | { |
e19f247a | 1136 | struct task_struct *group_leader = current->group_leader; |
e4cc0a9c ON |
1137 | struct pid *sid = task_pid(group_leader); |
1138 | pid_t session = pid_vnr(sid); | |
1da177e4 LT |
1139 | int err = -EPERM; |
1140 | ||
1da177e4 | 1141 | write_lock_irq(&tasklist_lock); |
390e2ff0 EB |
1142 | /* Fail if I am already a session leader */ |
1143 | if (group_leader->signal->leader) | |
1144 | goto out; | |
1145 | ||
430c6231 ON |
1146 | /* Fail if a process group id already exists that equals the |
1147 | * proposed session id. | |
390e2ff0 | 1148 | */ |
6806aac6 | 1149 | if (pid_task(sid, PIDTYPE_PGID)) |
1da177e4 LT |
1150 | goto out; |
1151 | ||
e19f247a | 1152 | group_leader->signal->leader = 1; |
8520d7c7 | 1153 | __set_special_pids(sid); |
24ec839c | 1154 | |
9c9f4ded | 1155 | proc_clear_tty(group_leader); |
24ec839c | 1156 | |
e4cc0a9c | 1157 | err = session; |
1da177e4 LT |
1158 | out: |
1159 | write_unlock_irq(&tasklist_lock); | |
5091faa4 | 1160 | if (err > 0) { |
0d0df599 | 1161 | proc_sid_connector(group_leader); |
5091faa4 MG |
1162 | sched_autogroup_create_attach(group_leader); |
1163 | } | |
1da177e4 LT |
1164 | return err; |
1165 | } | |
1166 | ||
1da177e4 LT |
1167 | DECLARE_RWSEM(uts_sem); |
1168 | ||
e28cbf22 CH |
1169 | #ifdef COMPAT_UTS_MACHINE |
1170 | #define override_architecture(name) \ | |
46da2766 | 1171 | (personality(current->personality) == PER_LINUX32 && \ |
e28cbf22 CH |
1172 | copy_to_user(name->machine, COMPAT_UTS_MACHINE, \ |
1173 | sizeof(COMPAT_UTS_MACHINE))) | |
1174 | #else | |
1175 | #define override_architecture(name) 0 | |
1176 | #endif | |
1177 | ||
be27425d AK |
1178 | /* |
1179 | * Work around broken programs that cannot handle "Linux 3.0". | |
1180 | * Instead we map 3.x to 2.6.40+x, so e.g. 3.0 would be 2.6.40 | |
1181 | */ | |
1182 | static int override_release(char __user *release, int len) | |
1183 | { | |
1184 | int ret = 0; | |
a84a79e4 | 1185 | char buf[65]; |
be27425d AK |
1186 | |
1187 | if (current->personality & UNAME26) { | |
1188 | char *rest = UTS_RELEASE; | |
1189 | int ndots = 0; | |
1190 | unsigned v; | |
1191 | ||
1192 | while (*rest) { | |
1193 | if (*rest == '.' && ++ndots >= 3) | |
1194 | break; | |
1195 | if (!isdigit(*rest) && *rest != '.') | |
1196 | break; | |
1197 | rest++; | |
1198 | } | |
1199 | v = ((LINUX_VERSION_CODE >> 8) & 0xff) + 40; | |
1200 | snprintf(buf, len, "2.6.%u%s", v, rest); | |
1201 | ret = copy_to_user(release, buf, len); | |
1202 | } | |
1203 | return ret; | |
1204 | } | |
1205 | ||
e48fbb69 | 1206 | SYSCALL_DEFINE1(newuname, struct new_utsname __user *, name) |
1da177e4 LT |
1207 | { |
1208 | int errno = 0; | |
1209 | ||
1210 | down_read(&uts_sem); | |
e9ff3990 | 1211 | if (copy_to_user(name, utsname(), sizeof *name)) |
1da177e4 LT |
1212 | errno = -EFAULT; |
1213 | up_read(&uts_sem); | |
e28cbf22 | 1214 | |
be27425d AK |
1215 | if (!errno && override_release(name->release, sizeof(name->release))) |
1216 | errno = -EFAULT; | |
e28cbf22 CH |
1217 | if (!errno && override_architecture(name)) |
1218 | errno = -EFAULT; | |
1da177e4 LT |
1219 | return errno; |
1220 | } | |
1221 | ||
5cacdb4a CH |
1222 | #ifdef __ARCH_WANT_SYS_OLD_UNAME |
1223 | /* | |
1224 | * Old cruft | |
1225 | */ | |
1226 | SYSCALL_DEFINE1(uname, struct old_utsname __user *, name) | |
1227 | { | |
1228 | int error = 0; | |
1229 | ||
1230 | if (!name) | |
1231 | return -EFAULT; | |
1232 | ||
1233 | down_read(&uts_sem); | |
1234 | if (copy_to_user(name, utsname(), sizeof(*name))) | |
1235 | error = -EFAULT; | |
1236 | up_read(&uts_sem); | |
1237 | ||
be27425d AK |
1238 | if (!error && override_release(name->release, sizeof(name->release))) |
1239 | error = -EFAULT; | |
5cacdb4a CH |
1240 | if (!error && override_architecture(name)) |
1241 | error = -EFAULT; | |
1242 | return error; | |
1243 | } | |
1244 | ||
1245 | SYSCALL_DEFINE1(olduname, struct oldold_utsname __user *, name) | |
1246 | { | |
1247 | int error; | |
1248 | ||
1249 | if (!name) | |
1250 | return -EFAULT; | |
1251 | if (!access_ok(VERIFY_WRITE, name, sizeof(struct oldold_utsname))) | |
1252 | return -EFAULT; | |
1253 | ||
1254 | down_read(&uts_sem); | |
1255 | error = __copy_to_user(&name->sysname, &utsname()->sysname, | |
1256 | __OLD_UTS_LEN); | |
1257 | error |= __put_user(0, name->sysname + __OLD_UTS_LEN); | |
1258 | error |= __copy_to_user(&name->nodename, &utsname()->nodename, | |
1259 | __OLD_UTS_LEN); | |
1260 | error |= __put_user(0, name->nodename + __OLD_UTS_LEN); | |
1261 | error |= __copy_to_user(&name->release, &utsname()->release, | |
1262 | __OLD_UTS_LEN); | |
1263 | error |= __put_user(0, name->release + __OLD_UTS_LEN); | |
1264 | error |= __copy_to_user(&name->version, &utsname()->version, | |
1265 | __OLD_UTS_LEN); | |
1266 | error |= __put_user(0, name->version + __OLD_UTS_LEN); | |
1267 | error |= __copy_to_user(&name->machine, &utsname()->machine, | |
1268 | __OLD_UTS_LEN); | |
1269 | error |= __put_user(0, name->machine + __OLD_UTS_LEN); | |
1270 | up_read(&uts_sem); | |
1271 | ||
1272 | if (!error && override_architecture(name)) | |
1273 | error = -EFAULT; | |
be27425d AK |
1274 | if (!error && override_release(name->release, sizeof(name->release))) |
1275 | error = -EFAULT; | |
5cacdb4a CH |
1276 | return error ? -EFAULT : 0; |
1277 | } | |
1278 | #endif | |
1279 | ||
5a8a82b1 | 1280 | SYSCALL_DEFINE2(sethostname, char __user *, name, int, len) |
1da177e4 LT |
1281 | { |
1282 | int errno; | |
1283 | char tmp[__NEW_UTS_LEN]; | |
1284 | ||
bb96a6f5 | 1285 | if (!ns_capable(current->nsproxy->uts_ns->user_ns, CAP_SYS_ADMIN)) |
1da177e4 | 1286 | return -EPERM; |
fc832ad3 | 1287 | |
1da177e4 LT |
1288 | if (len < 0 || len > __NEW_UTS_LEN) |
1289 | return -EINVAL; | |
1290 | down_write(&uts_sem); | |
1291 | errno = -EFAULT; | |
1292 | if (!copy_from_user(tmp, name, len)) { | |
9679e4dd AM |
1293 | struct new_utsname *u = utsname(); |
1294 | ||
1295 | memcpy(u->nodename, tmp, len); | |
1296 | memset(u->nodename + len, 0, sizeof(u->nodename) - len); | |
1da177e4 LT |
1297 | errno = 0; |
1298 | } | |
f1ecf068 | 1299 | uts_proc_notify(UTS_PROC_HOSTNAME); |
1da177e4 LT |
1300 | up_write(&uts_sem); |
1301 | return errno; | |
1302 | } | |
1303 | ||
1304 | #ifdef __ARCH_WANT_SYS_GETHOSTNAME | |
1305 | ||
5a8a82b1 | 1306 | SYSCALL_DEFINE2(gethostname, char __user *, name, int, len) |
1da177e4 LT |
1307 | { |
1308 | int i, errno; | |
9679e4dd | 1309 | struct new_utsname *u; |
1da177e4 LT |
1310 | |
1311 | if (len < 0) | |
1312 | return -EINVAL; | |
1313 | down_read(&uts_sem); | |
9679e4dd AM |
1314 | u = utsname(); |
1315 | i = 1 + strlen(u->nodename); | |
1da177e4 LT |
1316 | if (i > len) |
1317 | i = len; | |
1318 | errno = 0; | |
9679e4dd | 1319 | if (copy_to_user(name, u->nodename, i)) |
1da177e4 LT |
1320 | errno = -EFAULT; |
1321 | up_read(&uts_sem); | |
1322 | return errno; | |
1323 | } | |
1324 | ||
1325 | #endif | |
1326 | ||
1327 | /* | |
1328 | * Only setdomainname; getdomainname can be implemented by calling | |
1329 | * uname() | |
1330 | */ | |
5a8a82b1 | 1331 | SYSCALL_DEFINE2(setdomainname, char __user *, name, int, len) |
1da177e4 LT |
1332 | { |
1333 | int errno; | |
1334 | char tmp[__NEW_UTS_LEN]; | |
1335 | ||
fc832ad3 | 1336 | if (!ns_capable(current->nsproxy->uts_ns->user_ns, CAP_SYS_ADMIN)) |
1da177e4 LT |
1337 | return -EPERM; |
1338 | if (len < 0 || len > __NEW_UTS_LEN) | |
1339 | return -EINVAL; | |
1340 | ||
1341 | down_write(&uts_sem); | |
1342 | errno = -EFAULT; | |
1343 | if (!copy_from_user(tmp, name, len)) { | |
9679e4dd AM |
1344 | struct new_utsname *u = utsname(); |
1345 | ||
1346 | memcpy(u->domainname, tmp, len); | |
1347 | memset(u->domainname + len, 0, sizeof(u->domainname) - len); | |
1da177e4 LT |
1348 | errno = 0; |
1349 | } | |
f1ecf068 | 1350 | uts_proc_notify(UTS_PROC_DOMAINNAME); |
1da177e4 LT |
1351 | up_write(&uts_sem); |
1352 | return errno; | |
1353 | } | |
1354 | ||
e48fbb69 | 1355 | SYSCALL_DEFINE2(getrlimit, unsigned int, resource, struct rlimit __user *, rlim) |
1da177e4 | 1356 | { |
b9518345 JS |
1357 | struct rlimit value; |
1358 | int ret; | |
1359 | ||
1360 | ret = do_prlimit(current, resource, NULL, &value); | |
1361 | if (!ret) | |
1362 | ret = copy_to_user(rlim, &value, sizeof(*rlim)) ? -EFAULT : 0; | |
1363 | ||
1364 | return ret; | |
1da177e4 LT |
1365 | } |
1366 | ||
1367 | #ifdef __ARCH_WANT_SYS_OLD_GETRLIMIT | |
1368 | ||
1369 | /* | |
1370 | * Back compatibility for getrlimit. Needed for some apps. | |
1371 | */ | |
1372 | ||
e48fbb69 HC |
1373 | SYSCALL_DEFINE2(old_getrlimit, unsigned int, resource, |
1374 | struct rlimit __user *, rlim) | |
1da177e4 LT |
1375 | { |
1376 | struct rlimit x; | |
1377 | if (resource >= RLIM_NLIMITS) | |
1378 | return -EINVAL; | |
1379 | ||
1380 | task_lock(current->group_leader); | |
1381 | x = current->signal->rlim[resource]; | |
1382 | task_unlock(current->group_leader); | |
756184b7 | 1383 | if (x.rlim_cur > 0x7FFFFFFF) |
1da177e4 | 1384 | x.rlim_cur = 0x7FFFFFFF; |
756184b7 | 1385 | if (x.rlim_max > 0x7FFFFFFF) |
1da177e4 LT |
1386 | x.rlim_max = 0x7FFFFFFF; |
1387 | return copy_to_user(rlim, &x, sizeof(x))?-EFAULT:0; | |
1388 | } | |
1389 | ||
1390 | #endif | |
1391 | ||
c022a0ac JS |
1392 | static inline bool rlim64_is_infinity(__u64 rlim64) |
1393 | { | |
1394 | #if BITS_PER_LONG < 64 | |
1395 | return rlim64 >= ULONG_MAX; | |
1396 | #else | |
1397 | return rlim64 == RLIM64_INFINITY; | |
1398 | #endif | |
1399 | } | |
1400 | ||
1401 | static void rlim_to_rlim64(const struct rlimit *rlim, struct rlimit64 *rlim64) | |
1402 | { | |
1403 | if (rlim->rlim_cur == RLIM_INFINITY) | |
1404 | rlim64->rlim_cur = RLIM64_INFINITY; | |
1405 | else | |
1406 | rlim64->rlim_cur = rlim->rlim_cur; | |
1407 | if (rlim->rlim_max == RLIM_INFINITY) | |
1408 | rlim64->rlim_max = RLIM64_INFINITY; | |
1409 | else | |
1410 | rlim64->rlim_max = rlim->rlim_max; | |
1411 | } | |
1412 | ||
1413 | static void rlim64_to_rlim(const struct rlimit64 *rlim64, struct rlimit *rlim) | |
1414 | { | |
1415 | if (rlim64_is_infinity(rlim64->rlim_cur)) | |
1416 | rlim->rlim_cur = RLIM_INFINITY; | |
1417 | else | |
1418 | rlim->rlim_cur = (unsigned long)rlim64->rlim_cur; | |
1419 | if (rlim64_is_infinity(rlim64->rlim_max)) | |
1420 | rlim->rlim_max = RLIM_INFINITY; | |
1421 | else | |
1422 | rlim->rlim_max = (unsigned long)rlim64->rlim_max; | |
1423 | } | |
1424 | ||
1c1e618d | 1425 | /* make sure you are allowed to change @tsk limits before calling this */ |
5b41535a JS |
1426 | int do_prlimit(struct task_struct *tsk, unsigned int resource, |
1427 | struct rlimit *new_rlim, struct rlimit *old_rlim) | |
1da177e4 | 1428 | { |
5b41535a | 1429 | struct rlimit *rlim; |
86f162f4 | 1430 | int retval = 0; |
1da177e4 LT |
1431 | |
1432 | if (resource >= RLIM_NLIMITS) | |
1433 | return -EINVAL; | |
5b41535a JS |
1434 | if (new_rlim) { |
1435 | if (new_rlim->rlim_cur > new_rlim->rlim_max) | |
1436 | return -EINVAL; | |
1437 | if (resource == RLIMIT_NOFILE && | |
1438 | new_rlim->rlim_max > sysctl_nr_open) | |
1439 | return -EPERM; | |
1440 | } | |
1da177e4 | 1441 | |
1c1e618d JS |
1442 | /* protect tsk->signal and tsk->sighand from disappearing */ |
1443 | read_lock(&tasklist_lock); | |
1444 | if (!tsk->sighand) { | |
1445 | retval = -ESRCH; | |
1446 | goto out; | |
1447 | } | |
1448 | ||
5b41535a | 1449 | rlim = tsk->signal->rlim + resource; |
86f162f4 | 1450 | task_lock(tsk->group_leader); |
5b41535a | 1451 | if (new_rlim) { |
fc832ad3 SH |
1452 | /* Keep the capable check against init_user_ns until |
1453 | cgroups can contain all limits */ | |
5b41535a JS |
1454 | if (new_rlim->rlim_max > rlim->rlim_max && |
1455 | !capable(CAP_SYS_RESOURCE)) | |
1456 | retval = -EPERM; | |
1457 | if (!retval) | |
1458 | retval = security_task_setrlimit(tsk->group_leader, | |
1459 | resource, new_rlim); | |
1460 | if (resource == RLIMIT_CPU && new_rlim->rlim_cur == 0) { | |
1461 | /* | |
1462 | * The caller is asking for an immediate RLIMIT_CPU | |
1463 | * expiry. But we use the zero value to mean "it was | |
1464 | * never set". So let's cheat and make it one second | |
1465 | * instead | |
1466 | */ | |
1467 | new_rlim->rlim_cur = 1; | |
1468 | } | |
1469 | } | |
1470 | if (!retval) { | |
1471 | if (old_rlim) | |
1472 | *old_rlim = *rlim; | |
1473 | if (new_rlim) | |
1474 | *rlim = *new_rlim; | |
9926e4c7 | 1475 | } |
7855c35d | 1476 | task_unlock(tsk->group_leader); |
1da177e4 | 1477 | |
d3561f78 AM |
1478 | /* |
1479 | * RLIMIT_CPU handling. Note that the kernel fails to return an error | |
1480 | * code if it rejected the user's attempt to set RLIMIT_CPU. This is a | |
1481 | * very long-standing error, and fixing it now risks breakage of | |
1482 | * applications, so we live with it | |
1483 | */ | |
5b41535a JS |
1484 | if (!retval && new_rlim && resource == RLIMIT_CPU && |
1485 | new_rlim->rlim_cur != RLIM_INFINITY) | |
1486 | update_rlimit_cpu(tsk, new_rlim->rlim_cur); | |
ec9e16ba | 1487 | out: |
1c1e618d | 1488 | read_unlock(&tasklist_lock); |
2fb9d268 | 1489 | return retval; |
1da177e4 LT |
1490 | } |
1491 | ||
c022a0ac JS |
1492 | /* rcu lock must be held */ |
1493 | static int check_prlimit_permission(struct task_struct *task) | |
1494 | { | |
1495 | const struct cred *cred = current_cred(), *tcred; | |
1496 | ||
fc832ad3 SH |
1497 | if (current == task) |
1498 | return 0; | |
c022a0ac | 1499 | |
fc832ad3 SH |
1500 | tcred = __task_cred(task); |
1501 | if (cred->user->user_ns == tcred->user->user_ns && | |
1502 | (cred->uid == tcred->euid && | |
1503 | cred->uid == tcred->suid && | |
1504 | cred->uid == tcred->uid && | |
1505 | cred->gid == tcred->egid && | |
1506 | cred->gid == tcred->sgid && | |
1507 | cred->gid == tcred->gid)) | |
1508 | return 0; | |
1509 | if (ns_capable(tcred->user->user_ns, CAP_SYS_RESOURCE)) | |
1510 | return 0; | |
1511 | ||
1512 | return -EPERM; | |
c022a0ac JS |
1513 | } |
1514 | ||
1515 | SYSCALL_DEFINE4(prlimit64, pid_t, pid, unsigned int, resource, | |
1516 | const struct rlimit64 __user *, new_rlim, | |
1517 | struct rlimit64 __user *, old_rlim) | |
1518 | { | |
1519 | struct rlimit64 old64, new64; | |
1520 | struct rlimit old, new; | |
1521 | struct task_struct *tsk; | |
1522 | int ret; | |
1523 | ||
1524 | if (new_rlim) { | |
1525 | if (copy_from_user(&new64, new_rlim, sizeof(new64))) | |
1526 | return -EFAULT; | |
1527 | rlim64_to_rlim(&new64, &new); | |
1528 | } | |
1529 | ||
1530 | rcu_read_lock(); | |
1531 | tsk = pid ? find_task_by_vpid(pid) : current; | |
1532 | if (!tsk) { | |
1533 | rcu_read_unlock(); | |
1534 | return -ESRCH; | |
1535 | } | |
1536 | ret = check_prlimit_permission(tsk); | |
1537 | if (ret) { | |
1538 | rcu_read_unlock(); | |
1539 | return ret; | |
1540 | } | |
1541 | get_task_struct(tsk); | |
1542 | rcu_read_unlock(); | |
1543 | ||
1544 | ret = do_prlimit(tsk, resource, new_rlim ? &new : NULL, | |
1545 | old_rlim ? &old : NULL); | |
1546 | ||
1547 | if (!ret && old_rlim) { | |
1548 | rlim_to_rlim64(&old, &old64); | |
1549 | if (copy_to_user(old_rlim, &old64, sizeof(old64))) | |
1550 | ret = -EFAULT; | |
1551 | } | |
1552 | ||
1553 | put_task_struct(tsk); | |
1554 | return ret; | |
1555 | } | |
1556 | ||
7855c35d JS |
1557 | SYSCALL_DEFINE2(setrlimit, unsigned int, resource, struct rlimit __user *, rlim) |
1558 | { | |
1559 | struct rlimit new_rlim; | |
1560 | ||
1561 | if (copy_from_user(&new_rlim, rlim, sizeof(*rlim))) | |
1562 | return -EFAULT; | |
5b41535a | 1563 | return do_prlimit(current, resource, &new_rlim, NULL); |
7855c35d JS |
1564 | } |
1565 | ||
1da177e4 LT |
1566 | /* |
1567 | * It would make sense to put struct rusage in the task_struct, | |
1568 | * except that would make the task_struct be *really big*. After | |
1569 | * task_struct gets moved into malloc'ed memory, it would | |
1570 | * make sense to do this. It will make moving the rest of the information | |
1571 | * a lot simpler! (Which we're not doing right now because we're not | |
1572 | * measuring them yet). | |
1573 | * | |
1da177e4 LT |
1574 | * When sampling multiple threads for RUSAGE_SELF, under SMP we might have |
1575 | * races with threads incrementing their own counters. But since word | |
1576 | * reads are atomic, we either get new values or old values and we don't | |
1577 | * care which for the sums. We always take the siglock to protect reading | |
1578 | * the c* fields from p->signal from races with exit.c updating those | |
1579 | * fields when reaping, so a sample either gets all the additions of a | |
1580 | * given child after it's reaped, or none so this sample is before reaping. | |
2dd0ebcd | 1581 | * |
de047c1b RT |
1582 | * Locking: |
1583 | * We need to take the siglock for CHILDEREN, SELF and BOTH | |
1584 | * for the cases current multithreaded, non-current single threaded | |
1585 | * non-current multithreaded. Thread traversal is now safe with | |
1586 | * the siglock held. | |
1587 | * Strictly speaking, we donot need to take the siglock if we are current and | |
1588 | * single threaded, as no one else can take our signal_struct away, no one | |
1589 | * else can reap the children to update signal->c* counters, and no one else | |
1590 | * can race with the signal-> fields. If we do not take any lock, the | |
1591 | * signal-> fields could be read out of order while another thread was just | |
1592 | * exiting. So we should place a read memory barrier when we avoid the lock. | |
1593 | * On the writer side, write memory barrier is implied in __exit_signal | |
1594 | * as __exit_signal releases the siglock spinlock after updating the signal-> | |
1595 | * fields. But we don't do this yet to keep things simple. | |
2dd0ebcd | 1596 | * |
1da177e4 LT |
1597 | */ |
1598 | ||
f06febc9 | 1599 | static void accumulate_thread_rusage(struct task_struct *t, struct rusage *r) |
679c9cd4 | 1600 | { |
679c9cd4 SK |
1601 | r->ru_nvcsw += t->nvcsw; |
1602 | r->ru_nivcsw += t->nivcsw; | |
1603 | r->ru_minflt += t->min_flt; | |
1604 | r->ru_majflt += t->maj_flt; | |
1605 | r->ru_inblock += task_io_get_inblock(t); | |
1606 | r->ru_oublock += task_io_get_oublock(t); | |
1607 | } | |
1608 | ||
1da177e4 LT |
1609 | static void k_getrusage(struct task_struct *p, int who, struct rusage *r) |
1610 | { | |
1611 | struct task_struct *t; | |
1612 | unsigned long flags; | |
0cf55e1e | 1613 | cputime_t tgutime, tgstime, utime, stime; |
1f10206c | 1614 | unsigned long maxrss = 0; |
1da177e4 LT |
1615 | |
1616 | memset((char *) r, 0, sizeof *r); | |
64861634 | 1617 | utime = stime = 0; |
1da177e4 | 1618 | |
679c9cd4 | 1619 | if (who == RUSAGE_THREAD) { |
d180c5bc | 1620 | task_times(current, &utime, &stime); |
f06febc9 | 1621 | accumulate_thread_rusage(p, r); |
1f10206c | 1622 | maxrss = p->signal->maxrss; |
679c9cd4 SK |
1623 | goto out; |
1624 | } | |
1625 | ||
d6cf723a | 1626 | if (!lock_task_sighand(p, &flags)) |
de047c1b | 1627 | return; |
0f59cc4a | 1628 | |
1da177e4 | 1629 | switch (who) { |
0f59cc4a | 1630 | case RUSAGE_BOTH: |
1da177e4 | 1631 | case RUSAGE_CHILDREN: |
1da177e4 LT |
1632 | utime = p->signal->cutime; |
1633 | stime = p->signal->cstime; | |
1634 | r->ru_nvcsw = p->signal->cnvcsw; | |
1635 | r->ru_nivcsw = p->signal->cnivcsw; | |
1636 | r->ru_minflt = p->signal->cmin_flt; | |
1637 | r->ru_majflt = p->signal->cmaj_flt; | |
6eaeeaba ED |
1638 | r->ru_inblock = p->signal->cinblock; |
1639 | r->ru_oublock = p->signal->coublock; | |
1f10206c | 1640 | maxrss = p->signal->cmaxrss; |
0f59cc4a ON |
1641 | |
1642 | if (who == RUSAGE_CHILDREN) | |
1643 | break; | |
1644 | ||
1da177e4 | 1645 | case RUSAGE_SELF: |
0cf55e1e | 1646 | thread_group_times(p, &tgutime, &tgstime); |
64861634 MS |
1647 | utime += tgutime; |
1648 | stime += tgstime; | |
1da177e4 LT |
1649 | r->ru_nvcsw += p->signal->nvcsw; |
1650 | r->ru_nivcsw += p->signal->nivcsw; | |
1651 | r->ru_minflt += p->signal->min_flt; | |
1652 | r->ru_majflt += p->signal->maj_flt; | |
6eaeeaba ED |
1653 | r->ru_inblock += p->signal->inblock; |
1654 | r->ru_oublock += p->signal->oublock; | |
1f10206c JP |
1655 | if (maxrss < p->signal->maxrss) |
1656 | maxrss = p->signal->maxrss; | |
1da177e4 LT |
1657 | t = p; |
1658 | do { | |
f06febc9 | 1659 | accumulate_thread_rusage(t, r); |
1da177e4 LT |
1660 | t = next_thread(t); |
1661 | } while (t != p); | |
1da177e4 | 1662 | break; |
0f59cc4a | 1663 | |
1da177e4 LT |
1664 | default: |
1665 | BUG(); | |
1666 | } | |
de047c1b | 1667 | unlock_task_sighand(p, &flags); |
de047c1b | 1668 | |
679c9cd4 | 1669 | out: |
0f59cc4a ON |
1670 | cputime_to_timeval(utime, &r->ru_utime); |
1671 | cputime_to_timeval(stime, &r->ru_stime); | |
1f10206c JP |
1672 | |
1673 | if (who != RUSAGE_CHILDREN) { | |
1674 | struct mm_struct *mm = get_task_mm(p); | |
1675 | if (mm) { | |
1676 | setmax_mm_hiwater_rss(&maxrss, mm); | |
1677 | mmput(mm); | |
1678 | } | |
1679 | } | |
1680 | r->ru_maxrss = maxrss * (PAGE_SIZE / 1024); /* convert pages to KBs */ | |
1da177e4 LT |
1681 | } |
1682 | ||
1683 | int getrusage(struct task_struct *p, int who, struct rusage __user *ru) | |
1684 | { | |
1685 | struct rusage r; | |
1da177e4 | 1686 | k_getrusage(p, who, &r); |
1da177e4 LT |
1687 | return copy_to_user(ru, &r, sizeof(r)) ? -EFAULT : 0; |
1688 | } | |
1689 | ||
e48fbb69 | 1690 | SYSCALL_DEFINE2(getrusage, int, who, struct rusage __user *, ru) |
1da177e4 | 1691 | { |
679c9cd4 SK |
1692 | if (who != RUSAGE_SELF && who != RUSAGE_CHILDREN && |
1693 | who != RUSAGE_THREAD) | |
1da177e4 LT |
1694 | return -EINVAL; |
1695 | return getrusage(current, who, ru); | |
1696 | } | |
1697 | ||
e48fbb69 | 1698 | SYSCALL_DEFINE1(umask, int, mask) |
1da177e4 LT |
1699 | { |
1700 | mask = xchg(¤t->fs->umask, mask & S_IRWXUGO); | |
1701 | return mask; | |
1702 | } | |
3b7391de | 1703 | |
028ee4be CG |
1704 | #ifdef CONFIG_CHECKPOINT_RESTORE |
1705 | static int prctl_set_mm(int opt, unsigned long addr, | |
1706 | unsigned long arg4, unsigned long arg5) | |
1707 | { | |
1708 | unsigned long rlim = rlimit(RLIMIT_DATA); | |
1709 | unsigned long vm_req_flags; | |
1710 | unsigned long vm_bad_flags; | |
1711 | struct vm_area_struct *vma; | |
1712 | int error = 0; | |
1713 | struct mm_struct *mm = current->mm; | |
1714 | ||
1715 | if (arg4 | arg5) | |
1716 | return -EINVAL; | |
1717 | ||
79f0713d | 1718 | if (!capable(CAP_SYS_RESOURCE)) |
028ee4be CG |
1719 | return -EPERM; |
1720 | ||
1721 | if (addr >= TASK_SIZE) | |
1722 | return -EINVAL; | |
1723 | ||
1724 | down_read(&mm->mmap_sem); | |
1725 | vma = find_vma(mm, addr); | |
1726 | ||
1727 | if (opt != PR_SET_MM_START_BRK && opt != PR_SET_MM_BRK) { | |
1728 | /* It must be existing VMA */ | |
1729 | if (!vma || vma->vm_start > addr) | |
1730 | goto out; | |
1731 | } | |
1732 | ||
1733 | error = -EINVAL; | |
1734 | switch (opt) { | |
1735 | case PR_SET_MM_START_CODE: | |
1736 | case PR_SET_MM_END_CODE: | |
1737 | vm_req_flags = VM_READ | VM_EXEC; | |
1738 | vm_bad_flags = VM_WRITE | VM_MAYSHARE; | |
1739 | ||
1740 | if ((vma->vm_flags & vm_req_flags) != vm_req_flags || | |
1741 | (vma->vm_flags & vm_bad_flags)) | |
1742 | goto out; | |
1743 | ||
1744 | if (opt == PR_SET_MM_START_CODE) | |
1745 | mm->start_code = addr; | |
1746 | else | |
1747 | mm->end_code = addr; | |
1748 | break; | |
1749 | ||
1750 | case PR_SET_MM_START_DATA: | |
1751 | case PR_SET_MM_END_DATA: | |
1752 | vm_req_flags = VM_READ | VM_WRITE; | |
1753 | vm_bad_flags = VM_EXEC | VM_MAYSHARE; | |
1754 | ||
1755 | if ((vma->vm_flags & vm_req_flags) != vm_req_flags || | |
1756 | (vma->vm_flags & vm_bad_flags)) | |
1757 | goto out; | |
1758 | ||
1759 | if (opt == PR_SET_MM_START_DATA) | |
1760 | mm->start_data = addr; | |
1761 | else | |
1762 | mm->end_data = addr; | |
1763 | break; | |
1764 | ||
1765 | case PR_SET_MM_START_STACK: | |
1766 | ||
1767 | #ifdef CONFIG_STACK_GROWSUP | |
1768 | vm_req_flags = VM_READ | VM_WRITE | VM_GROWSUP; | |
1769 | #else | |
1770 | vm_req_flags = VM_READ | VM_WRITE | VM_GROWSDOWN; | |
1771 | #endif | |
1772 | if ((vma->vm_flags & vm_req_flags) != vm_req_flags) | |
1773 | goto out; | |
1774 | ||
1775 | mm->start_stack = addr; | |
1776 | break; | |
1777 | ||
1778 | case PR_SET_MM_START_BRK: | |
1779 | if (addr <= mm->end_data) | |
1780 | goto out; | |
1781 | ||
1782 | if (rlim < RLIM_INFINITY && | |
1783 | (mm->brk - addr) + | |
1784 | (mm->end_data - mm->start_data) > rlim) | |
1785 | goto out; | |
1786 | ||
1787 | mm->start_brk = addr; | |
1788 | break; | |
1789 | ||
1790 | case PR_SET_MM_BRK: | |
1791 | if (addr <= mm->end_data) | |
1792 | goto out; | |
1793 | ||
1794 | if (rlim < RLIM_INFINITY && | |
1795 | (addr - mm->start_brk) + | |
1796 | (mm->end_data - mm->start_data) > rlim) | |
1797 | goto out; | |
1798 | ||
1799 | mm->brk = addr; | |
1800 | break; | |
1801 | ||
1802 | default: | |
1803 | error = -EINVAL; | |
1804 | goto out; | |
1805 | } | |
1806 | ||
1807 | error = 0; | |
1808 | ||
1809 | out: | |
1810 | up_read(&mm->mmap_sem); | |
1811 | ||
1812 | return error; | |
1813 | } | |
1814 | #else /* CONFIG_CHECKPOINT_RESTORE */ | |
1815 | static int prctl_set_mm(int opt, unsigned long addr, | |
1816 | unsigned long arg4, unsigned long arg5) | |
1817 | { | |
1818 | return -EINVAL; | |
1819 | } | |
1820 | #endif | |
1821 | ||
c4ea37c2 HC |
1822 | SYSCALL_DEFINE5(prctl, int, option, unsigned long, arg2, unsigned long, arg3, |
1823 | unsigned long, arg4, unsigned long, arg5) | |
1da177e4 | 1824 | { |
b6dff3ec DH |
1825 | struct task_struct *me = current; |
1826 | unsigned char comm[sizeof(me->comm)]; | |
1827 | long error; | |
1da177e4 | 1828 | |
d84f4f99 DH |
1829 | error = security_task_prctl(option, arg2, arg3, arg4, arg5); |
1830 | if (error != -ENOSYS) | |
1da177e4 LT |
1831 | return error; |
1832 | ||
d84f4f99 | 1833 | error = 0; |
1da177e4 LT |
1834 | switch (option) { |
1835 | case PR_SET_PDEATHSIG: | |
0730ded5 | 1836 | if (!valid_signal(arg2)) { |
1da177e4 LT |
1837 | error = -EINVAL; |
1838 | break; | |
1839 | } | |
b6dff3ec DH |
1840 | me->pdeath_signal = arg2; |
1841 | error = 0; | |
1da177e4 LT |
1842 | break; |
1843 | case PR_GET_PDEATHSIG: | |
b6dff3ec | 1844 | error = put_user(me->pdeath_signal, (int __user *)arg2); |
1da177e4 LT |
1845 | break; |
1846 | case PR_GET_DUMPABLE: | |
b6dff3ec | 1847 | error = get_dumpable(me->mm); |
1da177e4 LT |
1848 | break; |
1849 | case PR_SET_DUMPABLE: | |
abf75a50 | 1850 | if (arg2 < 0 || arg2 > 1) { |
1da177e4 LT |
1851 | error = -EINVAL; |
1852 | break; | |
1853 | } | |
b6dff3ec DH |
1854 | set_dumpable(me->mm, arg2); |
1855 | error = 0; | |
1da177e4 LT |
1856 | break; |
1857 | ||
1858 | case PR_SET_UNALIGN: | |
b6dff3ec | 1859 | error = SET_UNALIGN_CTL(me, arg2); |
1da177e4 LT |
1860 | break; |
1861 | case PR_GET_UNALIGN: | |
b6dff3ec | 1862 | error = GET_UNALIGN_CTL(me, arg2); |
1da177e4 LT |
1863 | break; |
1864 | case PR_SET_FPEMU: | |
b6dff3ec | 1865 | error = SET_FPEMU_CTL(me, arg2); |
1da177e4 LT |
1866 | break; |
1867 | case PR_GET_FPEMU: | |
b6dff3ec | 1868 | error = GET_FPEMU_CTL(me, arg2); |
1da177e4 LT |
1869 | break; |
1870 | case PR_SET_FPEXC: | |
b6dff3ec | 1871 | error = SET_FPEXC_CTL(me, arg2); |
1da177e4 LT |
1872 | break; |
1873 | case PR_GET_FPEXC: | |
b6dff3ec | 1874 | error = GET_FPEXC_CTL(me, arg2); |
1da177e4 LT |
1875 | break; |
1876 | case PR_GET_TIMING: | |
1877 | error = PR_TIMING_STATISTICAL; | |
1878 | break; | |
1879 | case PR_SET_TIMING: | |
7b26655f | 1880 | if (arg2 != PR_TIMING_STATISTICAL) |
1da177e4 | 1881 | error = -EINVAL; |
b6dff3ec DH |
1882 | else |
1883 | error = 0; | |
1da177e4 LT |
1884 | break; |
1885 | ||
b6dff3ec DH |
1886 | case PR_SET_NAME: |
1887 | comm[sizeof(me->comm)-1] = 0; | |
1888 | if (strncpy_from_user(comm, (char __user *)arg2, | |
1889 | sizeof(me->comm) - 1) < 0) | |
1da177e4 | 1890 | return -EFAULT; |
b6dff3ec | 1891 | set_task_comm(me, comm); |
f786ecba | 1892 | proc_comm_connector(me); |
1da177e4 | 1893 | return 0; |
b6dff3ec DH |
1894 | case PR_GET_NAME: |
1895 | get_task_comm(comm, me); | |
1896 | if (copy_to_user((char __user *)arg2, comm, | |
1897 | sizeof(comm))) | |
1da177e4 LT |
1898 | return -EFAULT; |
1899 | return 0; | |
651d765d | 1900 | case PR_GET_ENDIAN: |
b6dff3ec | 1901 | error = GET_ENDIAN(me, arg2); |
651d765d AB |
1902 | break; |
1903 | case PR_SET_ENDIAN: | |
b6dff3ec | 1904 | error = SET_ENDIAN(me, arg2); |
651d765d AB |
1905 | break; |
1906 | ||
1d9d02fe AA |
1907 | case PR_GET_SECCOMP: |
1908 | error = prctl_get_seccomp(); | |
1909 | break; | |
1910 | case PR_SET_SECCOMP: | |
1911 | error = prctl_set_seccomp(arg2); | |
1912 | break; | |
8fb402bc EB |
1913 | case PR_GET_TSC: |
1914 | error = GET_TSC_CTL(arg2); | |
1915 | break; | |
1916 | case PR_SET_TSC: | |
1917 | error = SET_TSC_CTL(arg2); | |
1918 | break; | |
cdd6c482 IM |
1919 | case PR_TASK_PERF_EVENTS_DISABLE: |
1920 | error = perf_event_task_disable(); | |
1d1c7ddb | 1921 | break; |
cdd6c482 IM |
1922 | case PR_TASK_PERF_EVENTS_ENABLE: |
1923 | error = perf_event_task_enable(); | |
1d1c7ddb | 1924 | break; |
6976675d AV |
1925 | case PR_GET_TIMERSLACK: |
1926 | error = current->timer_slack_ns; | |
1927 | break; | |
1928 | case PR_SET_TIMERSLACK: | |
1929 | if (arg2 <= 0) | |
1930 | current->timer_slack_ns = | |
1931 | current->default_timer_slack_ns; | |
1932 | else | |
1933 | current->timer_slack_ns = arg2; | |
b6dff3ec | 1934 | error = 0; |
6976675d | 1935 | break; |
4db96cf0 AK |
1936 | case PR_MCE_KILL: |
1937 | if (arg4 | arg5) | |
1938 | return -EINVAL; | |
1939 | switch (arg2) { | |
1087e9b4 | 1940 | case PR_MCE_KILL_CLEAR: |
4db96cf0 AK |
1941 | if (arg3 != 0) |
1942 | return -EINVAL; | |
1943 | current->flags &= ~PF_MCE_PROCESS; | |
1944 | break; | |
1087e9b4 | 1945 | case PR_MCE_KILL_SET: |
4db96cf0 | 1946 | current->flags |= PF_MCE_PROCESS; |
1087e9b4 | 1947 | if (arg3 == PR_MCE_KILL_EARLY) |
4db96cf0 | 1948 | current->flags |= PF_MCE_EARLY; |
1087e9b4 | 1949 | else if (arg3 == PR_MCE_KILL_LATE) |
4db96cf0 | 1950 | current->flags &= ~PF_MCE_EARLY; |
1087e9b4 AK |
1951 | else if (arg3 == PR_MCE_KILL_DEFAULT) |
1952 | current->flags &= | |
1953 | ~(PF_MCE_EARLY|PF_MCE_PROCESS); | |
1954 | else | |
1955 | return -EINVAL; | |
4db96cf0 AK |
1956 | break; |
1957 | default: | |
1958 | return -EINVAL; | |
1959 | } | |
1960 | error = 0; | |
1961 | break; | |
1087e9b4 AK |
1962 | case PR_MCE_KILL_GET: |
1963 | if (arg2 | arg3 | arg4 | arg5) | |
1964 | return -EINVAL; | |
1965 | if (current->flags & PF_MCE_PROCESS) | |
1966 | error = (current->flags & PF_MCE_EARLY) ? | |
1967 | PR_MCE_KILL_EARLY : PR_MCE_KILL_LATE; | |
1968 | else | |
1969 | error = PR_MCE_KILL_DEFAULT; | |
1970 | break; | |
028ee4be CG |
1971 | case PR_SET_MM: |
1972 | error = prctl_set_mm(arg2, arg3, arg4, arg5); | |
1973 | break; | |
ebec18a6 LP |
1974 | case PR_SET_CHILD_SUBREAPER: |
1975 | me->signal->is_child_subreaper = !!arg2; | |
1976 | error = 0; | |
1977 | break; | |
1978 | case PR_GET_CHILD_SUBREAPER: | |
1979 | error = put_user(me->signal->is_child_subreaper, | |
1980 | (int __user *) arg2); | |
1981 | break; | |
1da177e4 LT |
1982 | default: |
1983 | error = -EINVAL; | |
1984 | break; | |
1985 | } | |
1986 | return error; | |
1987 | } | |
3cfc348b | 1988 | |
836f92ad HC |
1989 | SYSCALL_DEFINE3(getcpu, unsigned __user *, cpup, unsigned __user *, nodep, |
1990 | struct getcpu_cache __user *, unused) | |
3cfc348b AK |
1991 | { |
1992 | int err = 0; | |
1993 | int cpu = raw_smp_processor_id(); | |
1994 | if (cpup) | |
1995 | err |= put_user(cpu, cpup); | |
1996 | if (nodep) | |
1997 | err |= put_user(cpu_to_node(cpu), nodep); | |
3cfc348b AK |
1998 | return err ? -EFAULT : 0; |
1999 | } | |
10a0a8d4 JF |
2000 | |
2001 | char poweroff_cmd[POWEROFF_CMD_PATH_LEN] = "/sbin/poweroff"; | |
2002 | ||
a06a4dc3 | 2003 | static void argv_cleanup(struct subprocess_info *info) |
10a0a8d4 | 2004 | { |
a06a4dc3 | 2005 | argv_free(info->argv); |
10a0a8d4 JF |
2006 | } |
2007 | ||
2008 | /** | |
2009 | * orderly_poweroff - Trigger an orderly system poweroff | |
2010 | * @force: force poweroff if command execution fails | |
2011 | * | |
2012 | * This may be called from any context to trigger a system shutdown. | |
2013 | * If the orderly shutdown fails, it will force an immediate shutdown. | |
2014 | */ | |
2015 | int orderly_poweroff(bool force) | |
2016 | { | |
2017 | int argc; | |
2018 | char **argv = argv_split(GFP_ATOMIC, poweroff_cmd, &argc); | |
2019 | static char *envp[] = { | |
2020 | "HOME=/", | |
2021 | "PATH=/sbin:/bin:/usr/sbin:/usr/bin", | |
2022 | NULL | |
2023 | }; | |
2024 | int ret = -ENOMEM; | |
2025 | struct subprocess_info *info; | |
2026 | ||
2027 | if (argv == NULL) { | |
2028 | printk(KERN_WARNING "%s failed to allocate memory for \"%s\"\n", | |
2029 | __func__, poweroff_cmd); | |
2030 | goto out; | |
2031 | } | |
2032 | ||
ac331d15 | 2033 | info = call_usermodehelper_setup(argv[0], argv, envp, GFP_ATOMIC); |
10a0a8d4 JF |
2034 | if (info == NULL) { |
2035 | argv_free(argv); | |
2036 | goto out; | |
2037 | } | |
2038 | ||
a06a4dc3 | 2039 | call_usermodehelper_setfns(info, NULL, argv_cleanup, NULL); |
10a0a8d4 | 2040 | |
86313c48 | 2041 | ret = call_usermodehelper_exec(info, UMH_NO_WAIT); |
10a0a8d4 JF |
2042 | |
2043 | out: | |
2044 | if (ret && force) { | |
2045 | printk(KERN_WARNING "Failed to start orderly shutdown: " | |
2046 | "forcing the issue\n"); | |
2047 | ||
2048 | /* I guess this should try to kick off some daemon to | |
2049 | sync and poweroff asap. Or not even bother syncing | |
2050 | if we're doing an emergency shutdown? */ | |
2051 | emergency_sync(); | |
2052 | kernel_power_off(); | |
2053 | } | |
2054 | ||
2055 | return ret; | |
2056 | } | |
2057 | EXPORT_SYMBOL_GPL(orderly_poweroff); |