Commit | Line | Data |
---|---|---|
1da177e4 LT |
1 | /* |
2 | * linux/kernel/sys.c | |
3 | * | |
4 | * Copyright (C) 1991, 1992 Linus Torvalds | |
5 | */ | |
6 | ||
1da177e4 LT |
7 | #include <linux/module.h> |
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> | |
cdd6c482 | 15 | #include <linux/perf_event.h> |
3e88c553 | 16 | #include <linux/resource.h> |
dc009d92 EB |
17 | #include <linux/kernel.h> |
18 | #include <linux/kexec.h> | |
1da177e4 | 19 | #include <linux/workqueue.h> |
c59ede7b | 20 | #include <linux/capability.h> |
1da177e4 LT |
21 | #include <linux/device.h> |
22 | #include <linux/key.h> | |
23 | #include <linux/times.h> | |
24 | #include <linux/posix-timers.h> | |
25 | #include <linux/security.h> | |
26 | #include <linux/dcookies.h> | |
27 | #include <linux/suspend.h> | |
28 | #include <linux/tty.h> | |
7ed20e1a | 29 | #include <linux/signal.h> |
9f46080c | 30 | #include <linux/cn_proc.h> |
3cfc348b | 31 | #include <linux/getcpu.h> |
6eaeeaba | 32 | #include <linux/task_io_accounting_ops.h> |
1d9d02fe | 33 | #include <linux/seccomp.h> |
4047727e | 34 | #include <linux/cpu.h> |
e28cbf22 | 35 | #include <linux/personality.h> |
e3d5a27d | 36 | #include <linux/ptrace.h> |
5ad4e53b | 37 | #include <linux/fs_struct.h> |
5a0e3ad6 | 38 | #include <linux/gfp.h> |
40dc166c | 39 | #include <linux/syscore_ops.h> |
be27425d AK |
40 | #include <linux/version.h> |
41 | #include <linux/ctype.h> | |
1da177e4 LT |
42 | |
43 | #include <linux/compat.h> | |
44 | #include <linux/syscalls.h> | |
00d7c05a | 45 | #include <linux/kprobes.h> |
acce292c | 46 | #include <linux/user_namespace.h> |
1da177e4 | 47 | |
04c6862c | 48 | #include <linux/kmsg_dump.h> |
be27425d AK |
49 | /* Move somewhere else to avoid recompiling? */ |
50 | #include <generated/utsrelease.h> | |
04c6862c | 51 | |
1da177e4 LT |
52 | #include <asm/uaccess.h> |
53 | #include <asm/io.h> | |
54 | #include <asm/unistd.h> | |
55 | ||
56 | #ifndef SET_UNALIGN_CTL | |
57 | # define SET_UNALIGN_CTL(a,b) (-EINVAL) | |
58 | #endif | |
59 | #ifndef GET_UNALIGN_CTL | |
60 | # define GET_UNALIGN_CTL(a,b) (-EINVAL) | |
61 | #endif | |
62 | #ifndef SET_FPEMU_CTL | |
63 | # define SET_FPEMU_CTL(a,b) (-EINVAL) | |
64 | #endif | |
65 | #ifndef GET_FPEMU_CTL | |
66 | # define GET_FPEMU_CTL(a,b) (-EINVAL) | |
67 | #endif | |
68 | #ifndef SET_FPEXC_CTL | |
69 | # define SET_FPEXC_CTL(a,b) (-EINVAL) | |
70 | #endif | |
71 | #ifndef GET_FPEXC_CTL | |
72 | # define GET_FPEXC_CTL(a,b) (-EINVAL) | |
73 | #endif | |
651d765d AB |
74 | #ifndef GET_ENDIAN |
75 | # define GET_ENDIAN(a,b) (-EINVAL) | |
76 | #endif | |
77 | #ifndef SET_ENDIAN | |
78 | # define SET_ENDIAN(a,b) (-EINVAL) | |
79 | #endif | |
8fb402bc EB |
80 | #ifndef GET_TSC_CTL |
81 | # define GET_TSC_CTL(a) (-EINVAL) | |
82 | #endif | |
83 | #ifndef SET_TSC_CTL | |
84 | # define SET_TSC_CTL(a) (-EINVAL) | |
85 | #endif | |
1da177e4 LT |
86 | |
87 | /* | |
88 | * this is where the system-wide overflow UID and GID are defined, for | |
89 | * architectures that now have 32-bit UID/GID but didn't in the past | |
90 | */ | |
91 | ||
92 | int overflowuid = DEFAULT_OVERFLOWUID; | |
93 | int overflowgid = DEFAULT_OVERFLOWGID; | |
94 | ||
95 | #ifdef CONFIG_UID16 | |
96 | EXPORT_SYMBOL(overflowuid); | |
97 | EXPORT_SYMBOL(overflowgid); | |
98 | #endif | |
99 | ||
100 | /* | |
101 | * the same as above, but for filesystems which can only store a 16-bit | |
102 | * UID and GID. as such, this is needed on all architectures | |
103 | */ | |
104 | ||
105 | int fs_overflowuid = DEFAULT_FS_OVERFLOWUID; | |
106 | int fs_overflowgid = DEFAULT_FS_OVERFLOWUID; | |
107 | ||
108 | EXPORT_SYMBOL(fs_overflowuid); | |
109 | EXPORT_SYMBOL(fs_overflowgid); | |
110 | ||
111 | /* | |
112 | * this indicates whether you can reboot with ctrl-alt-del: the default is yes | |
113 | */ | |
114 | ||
115 | int C_A_D = 1; | |
9ec52099 CLG |
116 | struct pid *cad_pid; |
117 | EXPORT_SYMBOL(cad_pid); | |
1da177e4 | 118 | |
bd804eba RW |
119 | /* |
120 | * If set, this is used for preparing the system to power off. | |
121 | */ | |
122 | ||
123 | void (*pm_power_off_prepare)(void); | |
bd804eba | 124 | |
fc832ad3 SH |
125 | /* |
126 | * Returns true if current's euid is same as p's uid or euid, | |
127 | * or has CAP_SYS_NICE to p's user_ns. | |
128 | * | |
129 | * Called with rcu_read_lock, creds are safe | |
130 | */ | |
131 | static bool set_one_prio_perm(struct task_struct *p) | |
132 | { | |
133 | const struct cred *cred = current_cred(), *pcred = __task_cred(p); | |
134 | ||
135 | if (pcred->user->user_ns == cred->user->user_ns && | |
136 | (pcred->uid == cred->euid || | |
137 | pcred->euid == cred->euid)) | |
138 | return true; | |
139 | if (ns_capable(pcred->user->user_ns, CAP_SYS_NICE)) | |
140 | return true; | |
141 | return false; | |
142 | } | |
143 | ||
c69e8d9c DH |
144 | /* |
145 | * set the priority of a task | |
146 | * - the caller must hold the RCU read lock | |
147 | */ | |
1da177e4 LT |
148 | static int set_one_prio(struct task_struct *p, int niceval, int error) |
149 | { | |
150 | int no_nice; | |
151 | ||
fc832ad3 | 152 | if (!set_one_prio_perm(p)) { |
1da177e4 LT |
153 | error = -EPERM; |
154 | goto out; | |
155 | } | |
e43379f1 | 156 | if (niceval < task_nice(p) && !can_nice(p, niceval)) { |
1da177e4 LT |
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 | ||
754fe8d2 | 172 | SYSCALL_DEFINE3(setpriority, int, which, int, who, int, niceval) |
1da177e4 LT |
173 | { |
174 | struct task_struct *g, *p; | |
175 | struct user_struct *user; | |
86a264ab | 176 | const struct cred *cred = current_cred(); |
1da177e4 | 177 | int error = -EINVAL; |
41487c65 | 178 | struct pid *pgrp; |
1da177e4 | 179 | |
3e88c553 | 180 | if (which > PRIO_USER || which < PRIO_PROCESS) |
1da177e4 LT |
181 | goto out; |
182 | ||
183 | /* normalize: avoid signed division (rounding problems) */ | |
184 | error = -ESRCH; | |
185 | if (niceval < -20) | |
186 | niceval = -20; | |
187 | if (niceval > 19) | |
188 | niceval = 19; | |
189 | ||
d4581a23 | 190 | rcu_read_lock(); |
1da177e4 LT |
191 | read_lock(&tasklist_lock); |
192 | switch (which) { | |
193 | case PRIO_PROCESS: | |
41487c65 | 194 | if (who) |
228ebcbe | 195 | p = find_task_by_vpid(who); |
41487c65 EB |
196 | else |
197 | p = current; | |
1da177e4 LT |
198 | if (p) |
199 | error = set_one_prio(p, niceval, error); | |
200 | break; | |
201 | case PRIO_PGRP: | |
41487c65 | 202 | if (who) |
b488893a | 203 | pgrp = find_vpid(who); |
41487c65 EB |
204 | else |
205 | pgrp = task_pgrp(current); | |
2d70b68d | 206 | do_each_pid_thread(pgrp, PIDTYPE_PGID, p) { |
1da177e4 | 207 | error = set_one_prio(p, niceval, error); |
2d70b68d | 208 | } while_each_pid_thread(pgrp, PIDTYPE_PGID, p); |
1da177e4 LT |
209 | break; |
210 | case PRIO_USER: | |
d84f4f99 | 211 | user = (struct user_struct *) cred->user; |
1da177e4 | 212 | if (!who) |
86a264ab DH |
213 | who = cred->uid; |
214 | else if ((who != cred->uid) && | |
215 | !(user = find_user(who))) | |
216 | goto out_unlock; /* No processes for this user */ | |
1da177e4 | 217 | |
dfc6a736 | 218 | do_each_thread(g, p) { |
86a264ab | 219 | if (__task_cred(p)->uid == who) |
1da177e4 | 220 | error = set_one_prio(p, niceval, error); |
dfc6a736 | 221 | } while_each_thread(g, p); |
86a264ab | 222 | if (who != cred->uid) |
1da177e4 LT |
223 | free_uid(user); /* For find_user() */ |
224 | break; | |
225 | } | |
226 | out_unlock: | |
227 | read_unlock(&tasklist_lock); | |
d4581a23 | 228 | rcu_read_unlock(); |
1da177e4 LT |
229 | out: |
230 | return error; | |
231 | } | |
232 | ||
233 | /* | |
234 | * Ugh. To avoid negative return values, "getpriority()" will | |
235 | * not return the normal nice-value, but a negated value that | |
236 | * has been offset by 20 (ie it returns 40..1 instead of -20..19) | |
237 | * to stay compatible. | |
238 | */ | |
754fe8d2 | 239 | SYSCALL_DEFINE2(getpriority, int, which, int, who) |
1da177e4 LT |
240 | { |
241 | struct task_struct *g, *p; | |
242 | struct user_struct *user; | |
86a264ab | 243 | const struct cred *cred = current_cred(); |
1da177e4 | 244 | long niceval, retval = -ESRCH; |
41487c65 | 245 | struct pid *pgrp; |
1da177e4 | 246 | |
3e88c553 | 247 | if (which > PRIO_USER || which < PRIO_PROCESS) |
1da177e4 LT |
248 | return -EINVAL; |
249 | ||
70118837 | 250 | rcu_read_lock(); |
1da177e4 LT |
251 | read_lock(&tasklist_lock); |
252 | switch (which) { | |
253 | case PRIO_PROCESS: | |
41487c65 | 254 | if (who) |
228ebcbe | 255 | p = find_task_by_vpid(who); |
41487c65 EB |
256 | else |
257 | p = current; | |
1da177e4 LT |
258 | if (p) { |
259 | niceval = 20 - task_nice(p); | |
260 | if (niceval > retval) | |
261 | retval = niceval; | |
262 | } | |
263 | break; | |
264 | case PRIO_PGRP: | |
41487c65 | 265 | if (who) |
b488893a | 266 | pgrp = find_vpid(who); |
41487c65 EB |
267 | else |
268 | pgrp = task_pgrp(current); | |
2d70b68d | 269 | do_each_pid_thread(pgrp, PIDTYPE_PGID, p) { |
1da177e4 LT |
270 | niceval = 20 - task_nice(p); |
271 | if (niceval > retval) | |
272 | retval = niceval; | |
2d70b68d | 273 | } while_each_pid_thread(pgrp, PIDTYPE_PGID, p); |
1da177e4 LT |
274 | break; |
275 | case PRIO_USER: | |
86a264ab | 276 | user = (struct user_struct *) cred->user; |
1da177e4 | 277 | if (!who) |
86a264ab DH |
278 | who = cred->uid; |
279 | else if ((who != cred->uid) && | |
280 | !(user = find_user(who))) | |
281 | goto out_unlock; /* No processes for this user */ | |
1da177e4 | 282 | |
dfc6a736 | 283 | do_each_thread(g, p) { |
86a264ab | 284 | if (__task_cred(p)->uid == who) { |
1da177e4 LT |
285 | niceval = 20 - task_nice(p); |
286 | if (niceval > retval) | |
287 | retval = niceval; | |
288 | } | |
dfc6a736 | 289 | } while_each_thread(g, p); |
86a264ab | 290 | if (who != cred->uid) |
1da177e4 LT |
291 | free_uid(user); /* for find_user() */ |
292 | break; | |
293 | } | |
294 | out_unlock: | |
295 | read_unlock(&tasklist_lock); | |
70118837 | 296 | rcu_read_unlock(); |
1da177e4 LT |
297 | |
298 | return retval; | |
299 | } | |
300 | ||
e4c94330 EB |
301 | /** |
302 | * emergency_restart - reboot the system | |
303 | * | |
304 | * Without shutting down any hardware or taking any locks | |
305 | * reboot the system. This is called when we know we are in | |
306 | * trouble so this is our best effort to reboot. This is | |
307 | * safe to call in interrupt context. | |
308 | */ | |
7c903473 EB |
309 | void emergency_restart(void) |
310 | { | |
04c6862c | 311 | kmsg_dump(KMSG_DUMP_EMERG); |
7c903473 EB |
312 | machine_emergency_restart(); |
313 | } | |
314 | EXPORT_SYMBOL_GPL(emergency_restart); | |
315 | ||
ca195b7f | 316 | void kernel_restart_prepare(char *cmd) |
4a00ea1e | 317 | { |
e041c683 | 318 | blocking_notifier_call_chain(&reboot_notifier_list, SYS_RESTART, cmd); |
4a00ea1e | 319 | system_state = SYSTEM_RESTART; |
b50fa7c8 | 320 | usermodehelper_disable(); |
4a00ea1e | 321 | device_shutdown(); |
40dc166c | 322 | syscore_shutdown(); |
e4c94330 | 323 | } |
1e5d5331 | 324 | |
c5f41752 AW |
325 | /** |
326 | * register_reboot_notifier - Register function to be called at reboot time | |
327 | * @nb: Info about notifier function to be called | |
328 | * | |
329 | * Registers a function with the list of functions | |
330 | * to be called at reboot time. | |
331 | * | |
332 | * Currently always returns zero, as blocking_notifier_chain_register() | |
333 | * always returns zero. | |
334 | */ | |
335 | int register_reboot_notifier(struct notifier_block *nb) | |
336 | { | |
337 | return blocking_notifier_chain_register(&reboot_notifier_list, nb); | |
338 | } | |
339 | EXPORT_SYMBOL(register_reboot_notifier); | |
340 | ||
341 | /** | |
342 | * unregister_reboot_notifier - Unregister previously registered reboot notifier | |
343 | * @nb: Hook to be unregistered | |
344 | * | |
345 | * Unregisters a previously registered reboot | |
346 | * notifier function. | |
347 | * | |
348 | * Returns zero on success, or %-ENOENT on failure. | |
349 | */ | |
350 | int unregister_reboot_notifier(struct notifier_block *nb) | |
351 | { | |
352 | return blocking_notifier_chain_unregister(&reboot_notifier_list, nb); | |
353 | } | |
354 | EXPORT_SYMBOL(unregister_reboot_notifier); | |
355 | ||
1e5d5331 RD |
356 | /** |
357 | * kernel_restart - reboot the system | |
358 | * @cmd: pointer to buffer containing command to execute for restart | |
b8887e6e | 359 | * or %NULL |
1e5d5331 RD |
360 | * |
361 | * Shutdown everything and perform a clean reboot. | |
362 | * This is not safe to call in interrupt context. | |
363 | */ | |
e4c94330 EB |
364 | void kernel_restart(char *cmd) |
365 | { | |
366 | kernel_restart_prepare(cmd); | |
756184b7 | 367 | if (!cmd) |
4a00ea1e | 368 | printk(KERN_EMERG "Restarting system.\n"); |
756184b7 | 369 | else |
4a00ea1e | 370 | printk(KERN_EMERG "Restarting system with command '%s'.\n", cmd); |
04c6862c | 371 | kmsg_dump(KMSG_DUMP_RESTART); |
4a00ea1e EB |
372 | machine_restart(cmd); |
373 | } | |
374 | EXPORT_SYMBOL_GPL(kernel_restart); | |
375 | ||
4ef7229f | 376 | static void kernel_shutdown_prepare(enum system_states state) |
729b4d4c | 377 | { |
e041c683 | 378 | blocking_notifier_call_chain(&reboot_notifier_list, |
729b4d4c AS |
379 | (state == SYSTEM_HALT)?SYS_HALT:SYS_POWER_OFF, NULL); |
380 | system_state = state; | |
b50fa7c8 | 381 | usermodehelper_disable(); |
729b4d4c AS |
382 | device_shutdown(); |
383 | } | |
e4c94330 EB |
384 | /** |
385 | * kernel_halt - halt the system | |
386 | * | |
387 | * Shutdown everything and perform a clean system halt. | |
388 | */ | |
e4c94330 EB |
389 | void kernel_halt(void) |
390 | { | |
729b4d4c | 391 | kernel_shutdown_prepare(SYSTEM_HALT); |
40dc166c | 392 | syscore_shutdown(); |
4a00ea1e | 393 | printk(KERN_EMERG "System halted.\n"); |
04c6862c | 394 | kmsg_dump(KMSG_DUMP_HALT); |
4a00ea1e EB |
395 | machine_halt(); |
396 | } | |
729b4d4c | 397 | |
4a00ea1e EB |
398 | EXPORT_SYMBOL_GPL(kernel_halt); |
399 | ||
e4c94330 EB |
400 | /** |
401 | * kernel_power_off - power_off the system | |
402 | * | |
403 | * Shutdown everything and perform a clean system power_off. | |
404 | */ | |
e4c94330 EB |
405 | void kernel_power_off(void) |
406 | { | |
729b4d4c | 407 | kernel_shutdown_prepare(SYSTEM_POWER_OFF); |
bd804eba RW |
408 | if (pm_power_off_prepare) |
409 | pm_power_off_prepare(); | |
4047727e | 410 | disable_nonboot_cpus(); |
40dc166c | 411 | syscore_shutdown(); |
4a00ea1e | 412 | printk(KERN_EMERG "Power down.\n"); |
04c6862c | 413 | kmsg_dump(KMSG_DUMP_POWEROFF); |
4a00ea1e EB |
414 | machine_power_off(); |
415 | } | |
416 | EXPORT_SYMBOL_GPL(kernel_power_off); | |
6f15fa50 TG |
417 | |
418 | static DEFINE_MUTEX(reboot_mutex); | |
419 | ||
1da177e4 LT |
420 | /* |
421 | * Reboot system call: for obvious reasons only root may call it, | |
422 | * and even root needs to set up some magic numbers in the registers | |
423 | * so that some mistake won't make this reboot the whole machine. | |
424 | * You can also set the meaning of the ctrl-alt-del-key here. | |
425 | * | |
426 | * reboot doesn't sync: do that yourself before calling this. | |
427 | */ | |
754fe8d2 HC |
428 | SYSCALL_DEFINE4(reboot, int, magic1, int, magic2, unsigned int, cmd, |
429 | void __user *, arg) | |
1da177e4 LT |
430 | { |
431 | char buffer[256]; | |
3d26dcf7 | 432 | int ret = 0; |
1da177e4 LT |
433 | |
434 | /* We only trust the superuser with rebooting the system. */ | |
435 | if (!capable(CAP_SYS_BOOT)) | |
436 | return -EPERM; | |
437 | ||
438 | /* For safety, we require "magic" arguments. */ | |
439 | if (magic1 != LINUX_REBOOT_MAGIC1 || | |
440 | (magic2 != LINUX_REBOOT_MAGIC2 && | |
441 | magic2 != LINUX_REBOOT_MAGIC2A && | |
442 | magic2 != LINUX_REBOOT_MAGIC2B && | |
443 | magic2 != LINUX_REBOOT_MAGIC2C)) | |
444 | return -EINVAL; | |
445 | ||
5e38291d EB |
446 | /* Instead of trying to make the power_off code look like |
447 | * halt when pm_power_off is not set do it the easy way. | |
448 | */ | |
449 | if ((cmd == LINUX_REBOOT_CMD_POWER_OFF) && !pm_power_off) | |
450 | cmd = LINUX_REBOOT_CMD_HALT; | |
451 | ||
6f15fa50 | 452 | mutex_lock(&reboot_mutex); |
1da177e4 LT |
453 | switch (cmd) { |
454 | case LINUX_REBOOT_CMD_RESTART: | |
4a00ea1e | 455 | kernel_restart(NULL); |
1da177e4 LT |
456 | break; |
457 | ||
458 | case LINUX_REBOOT_CMD_CAD_ON: | |
459 | C_A_D = 1; | |
460 | break; | |
461 | ||
462 | case LINUX_REBOOT_CMD_CAD_OFF: | |
463 | C_A_D = 0; | |
464 | break; | |
465 | ||
466 | case LINUX_REBOOT_CMD_HALT: | |
4a00ea1e | 467 | kernel_halt(); |
1da177e4 | 468 | do_exit(0); |
3d26dcf7 | 469 | panic("cannot halt"); |
1da177e4 LT |
470 | |
471 | case LINUX_REBOOT_CMD_POWER_OFF: | |
4a00ea1e | 472 | kernel_power_off(); |
1da177e4 LT |
473 | do_exit(0); |
474 | break; | |
475 | ||
476 | case LINUX_REBOOT_CMD_RESTART2: | |
477 | if (strncpy_from_user(&buffer[0], arg, sizeof(buffer) - 1) < 0) { | |
6f15fa50 TG |
478 | ret = -EFAULT; |
479 | break; | |
1da177e4 LT |
480 | } |
481 | buffer[sizeof(buffer) - 1] = '\0'; | |
482 | ||
4a00ea1e | 483 | kernel_restart(buffer); |
1da177e4 LT |
484 | break; |
485 | ||
3ab83521 | 486 | #ifdef CONFIG_KEXEC |
dc009d92 | 487 | case LINUX_REBOOT_CMD_KEXEC: |
3d26dcf7 AK |
488 | ret = kernel_kexec(); |
489 | break; | |
3ab83521 | 490 | #endif |
4a00ea1e | 491 | |
b0cb1a19 | 492 | #ifdef CONFIG_HIBERNATION |
1da177e4 | 493 | case LINUX_REBOOT_CMD_SW_SUSPEND: |
3d26dcf7 AK |
494 | ret = hibernate(); |
495 | break; | |
1da177e4 LT |
496 | #endif |
497 | ||
498 | default: | |
3d26dcf7 AK |
499 | ret = -EINVAL; |
500 | break; | |
1da177e4 | 501 | } |
6f15fa50 | 502 | mutex_unlock(&reboot_mutex); |
3d26dcf7 | 503 | return ret; |
1da177e4 LT |
504 | } |
505 | ||
65f27f38 | 506 | static void deferred_cad(struct work_struct *dummy) |
1da177e4 | 507 | { |
abcd9e51 | 508 | kernel_restart(NULL); |
1da177e4 LT |
509 | } |
510 | ||
511 | /* | |
512 | * This function gets called by ctrl-alt-del - ie the keyboard interrupt. | |
513 | * As it's called within an interrupt, it may NOT sync: the only choice | |
514 | * is whether to reboot at once, or just ignore the ctrl-alt-del. | |
515 | */ | |
516 | void ctrl_alt_del(void) | |
517 | { | |
65f27f38 | 518 | static DECLARE_WORK(cad_work, deferred_cad); |
1da177e4 LT |
519 | |
520 | if (C_A_D) | |
521 | schedule_work(&cad_work); | |
522 | else | |
9ec52099 | 523 | kill_cad_pid(SIGINT, 1); |
1da177e4 LT |
524 | } |
525 | ||
1da177e4 LT |
526 | /* |
527 | * Unprivileged users may change the real gid to the effective gid | |
528 | * or vice versa. (BSD-style) | |
529 | * | |
530 | * If you set the real gid at all, or set the effective gid to a value not | |
531 | * equal to the real gid, then the saved gid is set to the new effective gid. | |
532 | * | |
533 | * This makes it possible for a setgid program to completely drop its | |
534 | * privileges, which is often a useful assertion to make when you are doing | |
535 | * a security audit over a program. | |
536 | * | |
537 | * The general idea is that a program which uses just setregid() will be | |
538 | * 100% compatible with BSD. A program which uses just setgid() will be | |
539 | * 100% compatible with POSIX with saved IDs. | |
540 | * | |
541 | * SMP: There are not races, the GIDs are checked only by filesystem | |
542 | * operations (as far as semantic preservation is concerned). | |
543 | */ | |
ae1251ab | 544 | SYSCALL_DEFINE2(setregid, gid_t, rgid, gid_t, egid) |
1da177e4 | 545 | { |
d84f4f99 DH |
546 | const struct cred *old; |
547 | struct cred *new; | |
1da177e4 LT |
548 | int retval; |
549 | ||
d84f4f99 DH |
550 | new = prepare_creds(); |
551 | if (!new) | |
552 | return -ENOMEM; | |
553 | old = current_cred(); | |
554 | ||
d84f4f99 | 555 | retval = -EPERM; |
1da177e4 | 556 | if (rgid != (gid_t) -1) { |
d84f4f99 DH |
557 | if (old->gid == rgid || |
558 | old->egid == rgid || | |
fc832ad3 | 559 | nsown_capable(CAP_SETGID)) |
d84f4f99 | 560 | new->gid = rgid; |
1da177e4 | 561 | else |
d84f4f99 | 562 | goto error; |
1da177e4 LT |
563 | } |
564 | if (egid != (gid_t) -1) { | |
d84f4f99 DH |
565 | if (old->gid == egid || |
566 | old->egid == egid || | |
567 | old->sgid == egid || | |
fc832ad3 | 568 | nsown_capable(CAP_SETGID)) |
d84f4f99 | 569 | new->egid = egid; |
756184b7 | 570 | else |
d84f4f99 | 571 | goto error; |
1da177e4 | 572 | } |
d84f4f99 | 573 | |
1da177e4 | 574 | if (rgid != (gid_t) -1 || |
d84f4f99 DH |
575 | (egid != (gid_t) -1 && egid != old->gid)) |
576 | new->sgid = new->egid; | |
577 | new->fsgid = new->egid; | |
578 | ||
579 | return commit_creds(new); | |
580 | ||
581 | error: | |
582 | abort_creds(new); | |
583 | return retval; | |
1da177e4 LT |
584 | } |
585 | ||
586 | /* | |
587 | * setgid() is implemented like SysV w/ SAVED_IDS | |
588 | * | |
589 | * SMP: Same implicit races as above. | |
590 | */ | |
ae1251ab | 591 | SYSCALL_DEFINE1(setgid, gid_t, gid) |
1da177e4 | 592 | { |
d84f4f99 DH |
593 | const struct cred *old; |
594 | struct cred *new; | |
1da177e4 LT |
595 | int retval; |
596 | ||
d84f4f99 DH |
597 | new = prepare_creds(); |
598 | if (!new) | |
599 | return -ENOMEM; | |
600 | old = current_cred(); | |
601 | ||
d84f4f99 | 602 | retval = -EPERM; |
fc832ad3 | 603 | if (nsown_capable(CAP_SETGID)) |
d84f4f99 DH |
604 | new->gid = new->egid = new->sgid = new->fsgid = gid; |
605 | else if (gid == old->gid || gid == old->sgid) | |
606 | new->egid = new->fsgid = gid; | |
1da177e4 | 607 | else |
d84f4f99 | 608 | goto error; |
1da177e4 | 609 | |
d84f4f99 DH |
610 | return commit_creds(new); |
611 | ||
612 | error: | |
613 | abort_creds(new); | |
614 | return retval; | |
1da177e4 | 615 | } |
54e99124 | 616 | |
d84f4f99 DH |
617 | /* |
618 | * change the user struct in a credentials set to match the new UID | |
619 | */ | |
620 | static int set_user(struct cred *new) | |
1da177e4 LT |
621 | { |
622 | struct user_struct *new_user; | |
623 | ||
18b6e041 | 624 | new_user = alloc_uid(current_user_ns(), new->uid); |
1da177e4 LT |
625 | if (!new_user) |
626 | return -EAGAIN; | |
627 | ||
72fa5997 VK |
628 | /* |
629 | * We don't fail in case of NPROC limit excess here because too many | |
630 | * poorly written programs don't check set*uid() return code, assuming | |
631 | * it never fails if called by root. We may still enforce NPROC limit | |
632 | * for programs doing set*uid()+execve() by harmlessly deferring the | |
633 | * failure to the execve() stage. | |
634 | */ | |
78d7d407 | 635 | if (atomic_read(&new_user->processes) >= rlimit(RLIMIT_NPROC) && |
72fa5997 VK |
636 | new_user != INIT_USER) |
637 | current->flags |= PF_NPROC_EXCEEDED; | |
638 | else | |
639 | current->flags &= ~PF_NPROC_EXCEEDED; | |
1da177e4 | 640 | |
d84f4f99 DH |
641 | free_uid(new->user); |
642 | new->user = new_user; | |
1da177e4 LT |
643 | return 0; |
644 | } | |
645 | ||
646 | /* | |
647 | * Unprivileged users may change the real uid to the effective uid | |
648 | * or vice versa. (BSD-style) | |
649 | * | |
650 | * If you set the real uid at all, or set the effective uid to a value not | |
651 | * equal to the real uid, then the saved uid is set to the new effective uid. | |
652 | * | |
653 | * This makes it possible for a setuid program to completely drop its | |
654 | * privileges, which is often a useful assertion to make when you are doing | |
655 | * a security audit over a program. | |
656 | * | |
657 | * The general idea is that a program which uses just setreuid() will be | |
658 | * 100% compatible with BSD. A program which uses just setuid() will be | |
659 | * 100% compatible with POSIX with saved IDs. | |
660 | */ | |
ae1251ab | 661 | SYSCALL_DEFINE2(setreuid, uid_t, ruid, uid_t, euid) |
1da177e4 | 662 | { |
d84f4f99 DH |
663 | const struct cred *old; |
664 | struct cred *new; | |
1da177e4 LT |
665 | int retval; |
666 | ||
d84f4f99 DH |
667 | new = prepare_creds(); |
668 | if (!new) | |
669 | return -ENOMEM; | |
670 | old = current_cred(); | |
671 | ||
d84f4f99 | 672 | retval = -EPERM; |
1da177e4 | 673 | if (ruid != (uid_t) -1) { |
d84f4f99 DH |
674 | new->uid = ruid; |
675 | if (old->uid != ruid && | |
676 | old->euid != ruid && | |
fc832ad3 | 677 | !nsown_capable(CAP_SETUID)) |
d84f4f99 | 678 | goto error; |
1da177e4 LT |
679 | } |
680 | ||
681 | if (euid != (uid_t) -1) { | |
d84f4f99 DH |
682 | new->euid = euid; |
683 | if (old->uid != euid && | |
684 | old->euid != euid && | |
685 | old->suid != euid && | |
fc832ad3 | 686 | !nsown_capable(CAP_SETUID)) |
d84f4f99 | 687 | goto error; |
1da177e4 LT |
688 | } |
689 | ||
54e99124 DG |
690 | if (new->uid != old->uid) { |
691 | retval = set_user(new); | |
692 | if (retval < 0) | |
693 | goto error; | |
694 | } | |
1da177e4 | 695 | if (ruid != (uid_t) -1 || |
d84f4f99 DH |
696 | (euid != (uid_t) -1 && euid != old->uid)) |
697 | new->suid = new->euid; | |
698 | new->fsuid = new->euid; | |
1da177e4 | 699 | |
d84f4f99 DH |
700 | retval = security_task_fix_setuid(new, old, LSM_SETID_RE); |
701 | if (retval < 0) | |
702 | goto error; | |
1da177e4 | 703 | |
d84f4f99 | 704 | return commit_creds(new); |
1da177e4 | 705 | |
d84f4f99 DH |
706 | error: |
707 | abort_creds(new); | |
708 | return retval; | |
709 | } | |
1da177e4 LT |
710 | |
711 | /* | |
712 | * setuid() is implemented like SysV with SAVED_IDS | |
713 | * | |
714 | * Note that SAVED_ID's is deficient in that a setuid root program | |
715 | * like sendmail, for example, cannot set its uid to be a normal | |
716 | * user and then switch back, because if you're root, setuid() sets | |
717 | * the saved uid too. If you don't like this, blame the bright people | |
718 | * in the POSIX committee and/or USG. Note that the BSD-style setreuid() | |
719 | * will allow a root program to temporarily drop privileges and be able to | |
720 | * regain them by swapping the real and effective uid. | |
721 | */ | |
ae1251ab | 722 | SYSCALL_DEFINE1(setuid, uid_t, uid) |
1da177e4 | 723 | { |
d84f4f99 DH |
724 | const struct cred *old; |
725 | struct cred *new; | |
1da177e4 LT |
726 | int retval; |
727 | ||
d84f4f99 DH |
728 | new = prepare_creds(); |
729 | if (!new) | |
730 | return -ENOMEM; | |
731 | old = current_cred(); | |
732 | ||
d84f4f99 | 733 | retval = -EPERM; |
fc832ad3 | 734 | if (nsown_capable(CAP_SETUID)) { |
d84f4f99 | 735 | new->suid = new->uid = uid; |
54e99124 DG |
736 | if (uid != old->uid) { |
737 | retval = set_user(new); | |
738 | if (retval < 0) | |
739 | goto error; | |
d84f4f99 DH |
740 | } |
741 | } else if (uid != old->uid && uid != new->suid) { | |
742 | goto error; | |
1da177e4 | 743 | } |
1da177e4 | 744 | |
d84f4f99 DH |
745 | new->fsuid = new->euid = uid; |
746 | ||
747 | retval = security_task_fix_setuid(new, old, LSM_SETID_ID); | |
748 | if (retval < 0) | |
749 | goto error; | |
1da177e4 | 750 | |
d84f4f99 | 751 | return commit_creds(new); |
1da177e4 | 752 | |
d84f4f99 DH |
753 | error: |
754 | abort_creds(new); | |
755 | return retval; | |
1da177e4 LT |
756 | } |
757 | ||
758 | ||
759 | /* | |
760 | * This function implements a generic ability to update ruid, euid, | |
761 | * and suid. This allows you to implement the 4.4 compatible seteuid(). | |
762 | */ | |
ae1251ab | 763 | SYSCALL_DEFINE3(setresuid, uid_t, ruid, uid_t, euid, uid_t, suid) |
1da177e4 | 764 | { |
d84f4f99 DH |
765 | const struct cred *old; |
766 | struct cred *new; | |
1da177e4 LT |
767 | int retval; |
768 | ||
d84f4f99 DH |
769 | new = prepare_creds(); |
770 | if (!new) | |
771 | return -ENOMEM; | |
772 | ||
d84f4f99 | 773 | old = current_cred(); |
1da177e4 | 774 | |
d84f4f99 | 775 | retval = -EPERM; |
fc832ad3 | 776 | if (!nsown_capable(CAP_SETUID)) { |
d84f4f99 DH |
777 | if (ruid != (uid_t) -1 && ruid != old->uid && |
778 | ruid != old->euid && ruid != old->suid) | |
779 | goto error; | |
780 | if (euid != (uid_t) -1 && euid != old->uid && | |
781 | euid != old->euid && euid != old->suid) | |
782 | goto error; | |
783 | if (suid != (uid_t) -1 && suid != old->uid && | |
784 | suid != old->euid && suid != old->suid) | |
785 | goto error; | |
1da177e4 | 786 | } |
d84f4f99 | 787 | |
1da177e4 | 788 | if (ruid != (uid_t) -1) { |
d84f4f99 | 789 | new->uid = ruid; |
54e99124 DG |
790 | if (ruid != old->uid) { |
791 | retval = set_user(new); | |
792 | if (retval < 0) | |
793 | goto error; | |
794 | } | |
1da177e4 | 795 | } |
d84f4f99 DH |
796 | if (euid != (uid_t) -1) |
797 | new->euid = euid; | |
1da177e4 | 798 | if (suid != (uid_t) -1) |
d84f4f99 DH |
799 | new->suid = suid; |
800 | new->fsuid = new->euid; | |
1da177e4 | 801 | |
d84f4f99 DH |
802 | retval = security_task_fix_setuid(new, old, LSM_SETID_RES); |
803 | if (retval < 0) | |
804 | goto error; | |
1da177e4 | 805 | |
d84f4f99 | 806 | return commit_creds(new); |
1da177e4 | 807 | |
d84f4f99 DH |
808 | error: |
809 | abort_creds(new); | |
810 | return retval; | |
1da177e4 LT |
811 | } |
812 | ||
dbf040d9 | 813 | SYSCALL_DEFINE3(getresuid, uid_t __user *, ruid, uid_t __user *, euid, uid_t __user *, suid) |
1da177e4 | 814 | { |
86a264ab | 815 | const struct cred *cred = current_cred(); |
1da177e4 LT |
816 | int retval; |
817 | ||
86a264ab DH |
818 | if (!(retval = put_user(cred->uid, ruid)) && |
819 | !(retval = put_user(cred->euid, euid))) | |
b6dff3ec | 820 | retval = put_user(cred->suid, suid); |
1da177e4 LT |
821 | |
822 | return retval; | |
823 | } | |
824 | ||
825 | /* | |
826 | * Same as above, but for rgid, egid, sgid. | |
827 | */ | |
ae1251ab | 828 | SYSCALL_DEFINE3(setresgid, gid_t, rgid, gid_t, egid, gid_t, sgid) |
1da177e4 | 829 | { |
d84f4f99 DH |
830 | const struct cred *old; |
831 | struct cred *new; | |
1da177e4 LT |
832 | int retval; |
833 | ||
d84f4f99 DH |
834 | new = prepare_creds(); |
835 | if (!new) | |
836 | return -ENOMEM; | |
837 | old = current_cred(); | |
838 | ||
d84f4f99 | 839 | retval = -EPERM; |
fc832ad3 | 840 | if (!nsown_capable(CAP_SETGID)) { |
d84f4f99 DH |
841 | if (rgid != (gid_t) -1 && rgid != old->gid && |
842 | rgid != old->egid && rgid != old->sgid) | |
843 | goto error; | |
844 | if (egid != (gid_t) -1 && egid != old->gid && | |
845 | egid != old->egid && egid != old->sgid) | |
846 | goto error; | |
847 | if (sgid != (gid_t) -1 && sgid != old->gid && | |
848 | sgid != old->egid && sgid != old->sgid) | |
849 | goto error; | |
1da177e4 | 850 | } |
d84f4f99 | 851 | |
1da177e4 | 852 | if (rgid != (gid_t) -1) |
d84f4f99 DH |
853 | new->gid = rgid; |
854 | if (egid != (gid_t) -1) | |
855 | new->egid = egid; | |
1da177e4 | 856 | if (sgid != (gid_t) -1) |
d84f4f99 DH |
857 | new->sgid = sgid; |
858 | new->fsgid = new->egid; | |
1da177e4 | 859 | |
d84f4f99 DH |
860 | return commit_creds(new); |
861 | ||
862 | error: | |
863 | abort_creds(new); | |
864 | return retval; | |
1da177e4 LT |
865 | } |
866 | ||
dbf040d9 | 867 | SYSCALL_DEFINE3(getresgid, gid_t __user *, rgid, gid_t __user *, egid, gid_t __user *, sgid) |
1da177e4 | 868 | { |
86a264ab | 869 | const struct cred *cred = current_cred(); |
1da177e4 LT |
870 | int retval; |
871 | ||
86a264ab DH |
872 | if (!(retval = put_user(cred->gid, rgid)) && |
873 | !(retval = put_user(cred->egid, egid))) | |
b6dff3ec | 874 | retval = put_user(cred->sgid, sgid); |
1da177e4 LT |
875 | |
876 | return retval; | |
877 | } | |
878 | ||
879 | ||
880 | /* | |
881 | * "setfsuid()" sets the fsuid - the uid used for filesystem checks. This | |
882 | * is used for "access()" and for the NFS daemon (letting nfsd stay at | |
883 | * whatever uid it wants to). It normally shadows "euid", except when | |
884 | * explicitly set by setfsuid() or for access.. | |
885 | */ | |
ae1251ab | 886 | SYSCALL_DEFINE1(setfsuid, uid_t, uid) |
1da177e4 | 887 | { |
d84f4f99 DH |
888 | const struct cred *old; |
889 | struct cred *new; | |
890 | uid_t old_fsuid; | |
1da177e4 | 891 | |
d84f4f99 DH |
892 | new = prepare_creds(); |
893 | if (!new) | |
894 | return current_fsuid(); | |
895 | old = current_cred(); | |
896 | old_fsuid = old->fsuid; | |
1da177e4 | 897 | |
d84f4f99 DH |
898 | if (uid == old->uid || uid == old->euid || |
899 | uid == old->suid || uid == old->fsuid || | |
fc832ad3 | 900 | nsown_capable(CAP_SETUID)) { |
756184b7 | 901 | if (uid != old_fsuid) { |
d84f4f99 DH |
902 | new->fsuid = uid; |
903 | if (security_task_fix_setuid(new, old, LSM_SETID_FS) == 0) | |
904 | goto change_okay; | |
1da177e4 | 905 | } |
1da177e4 LT |
906 | } |
907 | ||
d84f4f99 DH |
908 | abort_creds(new); |
909 | return old_fsuid; | |
1da177e4 | 910 | |
d84f4f99 DH |
911 | change_okay: |
912 | commit_creds(new); | |
1da177e4 LT |
913 | return old_fsuid; |
914 | } | |
915 | ||
916 | /* | |
f42df9e6 | 917 | * Samma på svenska.. |
1da177e4 | 918 | */ |
ae1251ab | 919 | SYSCALL_DEFINE1(setfsgid, gid_t, gid) |
1da177e4 | 920 | { |
d84f4f99 DH |
921 | const struct cred *old; |
922 | struct cred *new; | |
923 | gid_t old_fsgid; | |
924 | ||
925 | new = prepare_creds(); | |
926 | if (!new) | |
927 | return current_fsgid(); | |
928 | old = current_cred(); | |
929 | old_fsgid = old->fsgid; | |
1da177e4 | 930 | |
d84f4f99 DH |
931 | if (gid == old->gid || gid == old->egid || |
932 | gid == old->sgid || gid == old->fsgid || | |
fc832ad3 | 933 | nsown_capable(CAP_SETGID)) { |
756184b7 | 934 | if (gid != old_fsgid) { |
d84f4f99 DH |
935 | new->fsgid = gid; |
936 | goto change_okay; | |
1da177e4 | 937 | } |
1da177e4 | 938 | } |
d84f4f99 | 939 | |
d84f4f99 DH |
940 | abort_creds(new); |
941 | return old_fsgid; | |
942 | ||
943 | change_okay: | |
944 | commit_creds(new); | |
1da177e4 LT |
945 | return old_fsgid; |
946 | } | |
947 | ||
f06febc9 FM |
948 | void do_sys_times(struct tms *tms) |
949 | { | |
0cf55e1e | 950 | cputime_t tgutime, tgstime, cutime, cstime; |
f06febc9 | 951 | |
2b5fe6de | 952 | spin_lock_irq(¤t->sighand->siglock); |
0cf55e1e | 953 | thread_group_times(current, &tgutime, &tgstime); |
f06febc9 FM |
954 | cutime = current->signal->cutime; |
955 | cstime = current->signal->cstime; | |
956 | spin_unlock_irq(¤t->sighand->siglock); | |
0cf55e1e HS |
957 | tms->tms_utime = cputime_to_clock_t(tgutime); |
958 | tms->tms_stime = cputime_to_clock_t(tgstime); | |
f06febc9 FM |
959 | tms->tms_cutime = cputime_to_clock_t(cutime); |
960 | tms->tms_cstime = cputime_to_clock_t(cstime); | |
961 | } | |
962 | ||
58fd3aa2 | 963 | SYSCALL_DEFINE1(times, struct tms __user *, tbuf) |
1da177e4 | 964 | { |
1da177e4 LT |
965 | if (tbuf) { |
966 | struct tms tmp; | |
f06febc9 FM |
967 | |
968 | do_sys_times(&tmp); | |
1da177e4 LT |
969 | if (copy_to_user(tbuf, &tmp, sizeof(struct tms))) |
970 | return -EFAULT; | |
971 | } | |
e3d5a27d | 972 | force_successful_syscall_return(); |
1da177e4 LT |
973 | return (long) jiffies_64_to_clock_t(get_jiffies_64()); |
974 | } | |
975 | ||
976 | /* | |
977 | * This needs some heavy checking ... | |
978 | * I just haven't the stomach for it. I also don't fully | |
979 | * understand sessions/pgrp etc. Let somebody who does explain it. | |
980 | * | |
981 | * OK, I think I have the protection semantics right.... this is really | |
982 | * only important on a multi-user system anyway, to make sure one user | |
983 | * can't send a signal to a process owned by another. -TYT, 12/12/91 | |
984 | * | |
985 | * Auch. Had to add the 'did_exec' flag to conform completely to POSIX. | |
986 | * LBT 04.03.94 | |
987 | */ | |
b290ebe2 | 988 | SYSCALL_DEFINE2(setpgid, pid_t, pid, pid_t, pgid) |
1da177e4 LT |
989 | { |
990 | struct task_struct *p; | |
ee0acf90 | 991 | struct task_struct *group_leader = current->group_leader; |
4e021306 ON |
992 | struct pid *pgrp; |
993 | int err; | |
1da177e4 LT |
994 | |
995 | if (!pid) | |
b488893a | 996 | pid = task_pid_vnr(group_leader); |
1da177e4 LT |
997 | if (!pgid) |
998 | pgid = pid; | |
999 | if (pgid < 0) | |
1000 | return -EINVAL; | |
950eaaca | 1001 | rcu_read_lock(); |
1da177e4 LT |
1002 | |
1003 | /* From this point forward we keep holding onto the tasklist lock | |
1004 | * so that our parent does not change from under us. -DaveM | |
1005 | */ | |
1006 | write_lock_irq(&tasklist_lock); | |
1007 | ||
1008 | err = -ESRCH; | |
4e021306 | 1009 | p = find_task_by_vpid(pid); |
1da177e4 LT |
1010 | if (!p) |
1011 | goto out; | |
1012 | ||
1013 | err = -EINVAL; | |
1014 | if (!thread_group_leader(p)) | |
1015 | goto out; | |
1016 | ||
4e021306 | 1017 | if (same_thread_group(p->real_parent, group_leader)) { |
1da177e4 | 1018 | err = -EPERM; |
41487c65 | 1019 | if (task_session(p) != task_session(group_leader)) |
1da177e4 LT |
1020 | goto out; |
1021 | err = -EACCES; | |
1022 | if (p->did_exec) | |
1023 | goto out; | |
1024 | } else { | |
1025 | err = -ESRCH; | |
ee0acf90 | 1026 | if (p != group_leader) |
1da177e4 LT |
1027 | goto out; |
1028 | } | |
1029 | ||
1030 | err = -EPERM; | |
1031 | if (p->signal->leader) | |
1032 | goto out; | |
1033 | ||
4e021306 | 1034 | pgrp = task_pid(p); |
1da177e4 | 1035 | if (pgid != pid) { |
b488893a | 1036 | struct task_struct *g; |
1da177e4 | 1037 | |
4e021306 ON |
1038 | pgrp = find_vpid(pgid); |
1039 | g = pid_task(pgrp, PIDTYPE_PGID); | |
41487c65 | 1040 | if (!g || task_session(g) != task_session(group_leader)) |
f020bc46 | 1041 | goto out; |
1da177e4 LT |
1042 | } |
1043 | ||
1da177e4 LT |
1044 | err = security_task_setpgid(p, pgid); |
1045 | if (err) | |
1046 | goto out; | |
1047 | ||
1b0f7ffd | 1048 | if (task_pgrp(p) != pgrp) |
83beaf3c | 1049 | change_pid(p, PIDTYPE_PGID, pgrp); |
1da177e4 LT |
1050 | |
1051 | err = 0; | |
1052 | out: | |
1053 | /* All paths lead to here, thus we are safe. -DaveM */ | |
1054 | write_unlock_irq(&tasklist_lock); | |
950eaaca | 1055 | rcu_read_unlock(); |
1da177e4 LT |
1056 | return err; |
1057 | } | |
1058 | ||
dbf040d9 | 1059 | SYSCALL_DEFINE1(getpgid, pid_t, pid) |
1da177e4 | 1060 | { |
12a3de0a ON |
1061 | struct task_struct *p; |
1062 | struct pid *grp; | |
1063 | int retval; | |
1064 | ||
1065 | rcu_read_lock(); | |
756184b7 | 1066 | if (!pid) |
12a3de0a | 1067 | grp = task_pgrp(current); |
756184b7 | 1068 | else { |
1da177e4 | 1069 | retval = -ESRCH; |
12a3de0a ON |
1070 | p = find_task_by_vpid(pid); |
1071 | if (!p) | |
1072 | goto out; | |
1073 | grp = task_pgrp(p); | |
1074 | if (!grp) | |
1075 | goto out; | |
1076 | ||
1077 | retval = security_task_getpgid(p); | |
1078 | if (retval) | |
1079 | goto out; | |
1da177e4 | 1080 | } |
12a3de0a ON |
1081 | retval = pid_vnr(grp); |
1082 | out: | |
1083 | rcu_read_unlock(); | |
1084 | return retval; | |
1da177e4 LT |
1085 | } |
1086 | ||
1087 | #ifdef __ARCH_WANT_SYS_GETPGRP | |
1088 | ||
dbf040d9 | 1089 | SYSCALL_DEFINE0(getpgrp) |
1da177e4 | 1090 | { |
12a3de0a | 1091 | return sys_getpgid(0); |
1da177e4 LT |
1092 | } |
1093 | ||
1094 | #endif | |
1095 | ||
dbf040d9 | 1096 | SYSCALL_DEFINE1(getsid, pid_t, pid) |
1da177e4 | 1097 | { |
1dd768c0 ON |
1098 | struct task_struct *p; |
1099 | struct pid *sid; | |
1100 | int retval; | |
1101 | ||
1102 | rcu_read_lock(); | |
756184b7 | 1103 | if (!pid) |
1dd768c0 | 1104 | sid = task_session(current); |
756184b7 | 1105 | else { |
1da177e4 | 1106 | retval = -ESRCH; |
1dd768c0 ON |
1107 | p = find_task_by_vpid(pid); |
1108 | if (!p) | |
1109 | goto out; | |
1110 | sid = task_session(p); | |
1111 | if (!sid) | |
1112 | goto out; | |
1113 | ||
1114 | retval = security_task_getsid(p); | |
1115 | if (retval) | |
1116 | goto out; | |
1da177e4 | 1117 | } |
1dd768c0 ON |
1118 | retval = pid_vnr(sid); |
1119 | out: | |
1120 | rcu_read_unlock(); | |
1121 | return retval; | |
1da177e4 LT |
1122 | } |
1123 | ||
b290ebe2 | 1124 | SYSCALL_DEFINE0(setsid) |
1da177e4 | 1125 | { |
e19f247a | 1126 | struct task_struct *group_leader = current->group_leader; |
e4cc0a9c ON |
1127 | struct pid *sid = task_pid(group_leader); |
1128 | pid_t session = pid_vnr(sid); | |
1da177e4 LT |
1129 | int err = -EPERM; |
1130 | ||
1da177e4 | 1131 | write_lock_irq(&tasklist_lock); |
390e2ff0 EB |
1132 | /* Fail if I am already a session leader */ |
1133 | if (group_leader->signal->leader) | |
1134 | goto out; | |
1135 | ||
430c6231 ON |
1136 | /* Fail if a process group id already exists that equals the |
1137 | * proposed session id. | |
390e2ff0 | 1138 | */ |
6806aac6 | 1139 | if (pid_task(sid, PIDTYPE_PGID)) |
1da177e4 LT |
1140 | goto out; |
1141 | ||
e19f247a | 1142 | group_leader->signal->leader = 1; |
8520d7c7 | 1143 | __set_special_pids(sid); |
24ec839c | 1144 | |
9c9f4ded | 1145 | proc_clear_tty(group_leader); |
24ec839c | 1146 | |
e4cc0a9c | 1147 | err = session; |
1da177e4 LT |
1148 | out: |
1149 | write_unlock_irq(&tasklist_lock); | |
5091faa4 | 1150 | if (err > 0) { |
0d0df599 | 1151 | proc_sid_connector(group_leader); |
5091faa4 MG |
1152 | sched_autogroup_create_attach(group_leader); |
1153 | } | |
1da177e4 LT |
1154 | return err; |
1155 | } | |
1156 | ||
1da177e4 LT |
1157 | DECLARE_RWSEM(uts_sem); |
1158 | ||
e28cbf22 CH |
1159 | #ifdef COMPAT_UTS_MACHINE |
1160 | #define override_architecture(name) \ | |
46da2766 | 1161 | (personality(current->personality) == PER_LINUX32 && \ |
e28cbf22 CH |
1162 | copy_to_user(name->machine, COMPAT_UTS_MACHINE, \ |
1163 | sizeof(COMPAT_UTS_MACHINE))) | |
1164 | #else | |
1165 | #define override_architecture(name) 0 | |
1166 | #endif | |
1167 | ||
be27425d AK |
1168 | /* |
1169 | * Work around broken programs that cannot handle "Linux 3.0". | |
1170 | * Instead we map 3.x to 2.6.40+x, so e.g. 3.0 would be 2.6.40 | |
1171 | */ | |
1172 | static int override_release(char __user *release, int len) | |
1173 | { | |
1174 | int ret = 0; | |
a84a79e4 | 1175 | char buf[65]; |
be27425d AK |
1176 | |
1177 | if (current->personality & UNAME26) { | |
1178 | char *rest = UTS_RELEASE; | |
1179 | int ndots = 0; | |
1180 | unsigned v; | |
1181 | ||
1182 | while (*rest) { | |
1183 | if (*rest == '.' && ++ndots >= 3) | |
1184 | break; | |
1185 | if (!isdigit(*rest) && *rest != '.') | |
1186 | break; | |
1187 | rest++; | |
1188 | } | |
1189 | v = ((LINUX_VERSION_CODE >> 8) & 0xff) + 40; | |
1190 | snprintf(buf, len, "2.6.%u%s", v, rest); | |
1191 | ret = copy_to_user(release, buf, len); | |
1192 | } | |
1193 | return ret; | |
1194 | } | |
1195 | ||
e48fbb69 | 1196 | SYSCALL_DEFINE1(newuname, struct new_utsname __user *, name) |
1da177e4 LT |
1197 | { |
1198 | int errno = 0; | |
1199 | ||
1200 | down_read(&uts_sem); | |
e9ff3990 | 1201 | if (copy_to_user(name, utsname(), sizeof *name)) |
1da177e4 LT |
1202 | errno = -EFAULT; |
1203 | up_read(&uts_sem); | |
e28cbf22 | 1204 | |
be27425d AK |
1205 | if (!errno && override_release(name->release, sizeof(name->release))) |
1206 | errno = -EFAULT; | |
e28cbf22 CH |
1207 | if (!errno && override_architecture(name)) |
1208 | errno = -EFAULT; | |
1da177e4 LT |
1209 | return errno; |
1210 | } | |
1211 | ||
5cacdb4a CH |
1212 | #ifdef __ARCH_WANT_SYS_OLD_UNAME |
1213 | /* | |
1214 | * Old cruft | |
1215 | */ | |
1216 | SYSCALL_DEFINE1(uname, struct old_utsname __user *, name) | |
1217 | { | |
1218 | int error = 0; | |
1219 | ||
1220 | if (!name) | |
1221 | return -EFAULT; | |
1222 | ||
1223 | down_read(&uts_sem); | |
1224 | if (copy_to_user(name, utsname(), sizeof(*name))) | |
1225 | error = -EFAULT; | |
1226 | up_read(&uts_sem); | |
1227 | ||
be27425d AK |
1228 | if (!error && override_release(name->release, sizeof(name->release))) |
1229 | error = -EFAULT; | |
5cacdb4a CH |
1230 | if (!error && override_architecture(name)) |
1231 | error = -EFAULT; | |
1232 | return error; | |
1233 | } | |
1234 | ||
1235 | SYSCALL_DEFINE1(olduname, struct oldold_utsname __user *, name) | |
1236 | { | |
1237 | int error; | |
1238 | ||
1239 | if (!name) | |
1240 | return -EFAULT; | |
1241 | if (!access_ok(VERIFY_WRITE, name, sizeof(struct oldold_utsname))) | |
1242 | return -EFAULT; | |
1243 | ||
1244 | down_read(&uts_sem); | |
1245 | error = __copy_to_user(&name->sysname, &utsname()->sysname, | |
1246 | __OLD_UTS_LEN); | |
1247 | error |= __put_user(0, name->sysname + __OLD_UTS_LEN); | |
1248 | error |= __copy_to_user(&name->nodename, &utsname()->nodename, | |
1249 | __OLD_UTS_LEN); | |
1250 | error |= __put_user(0, name->nodename + __OLD_UTS_LEN); | |
1251 | error |= __copy_to_user(&name->release, &utsname()->release, | |
1252 | __OLD_UTS_LEN); | |
1253 | error |= __put_user(0, name->release + __OLD_UTS_LEN); | |
1254 | error |= __copy_to_user(&name->version, &utsname()->version, | |
1255 | __OLD_UTS_LEN); | |
1256 | error |= __put_user(0, name->version + __OLD_UTS_LEN); | |
1257 | error |= __copy_to_user(&name->machine, &utsname()->machine, | |
1258 | __OLD_UTS_LEN); | |
1259 | error |= __put_user(0, name->machine + __OLD_UTS_LEN); | |
1260 | up_read(&uts_sem); | |
1261 | ||
1262 | if (!error && override_architecture(name)) | |
1263 | error = -EFAULT; | |
be27425d AK |
1264 | if (!error && override_release(name->release, sizeof(name->release))) |
1265 | error = -EFAULT; | |
5cacdb4a CH |
1266 | return error ? -EFAULT : 0; |
1267 | } | |
1268 | #endif | |
1269 | ||
5a8a82b1 | 1270 | SYSCALL_DEFINE2(sethostname, char __user *, name, int, len) |
1da177e4 LT |
1271 | { |
1272 | int errno; | |
1273 | char tmp[__NEW_UTS_LEN]; | |
1274 | ||
bb96a6f5 | 1275 | if (!ns_capable(current->nsproxy->uts_ns->user_ns, CAP_SYS_ADMIN)) |
1da177e4 | 1276 | return -EPERM; |
fc832ad3 | 1277 | |
1da177e4 LT |
1278 | if (len < 0 || len > __NEW_UTS_LEN) |
1279 | return -EINVAL; | |
1280 | down_write(&uts_sem); | |
1281 | errno = -EFAULT; | |
1282 | if (!copy_from_user(tmp, name, len)) { | |
9679e4dd AM |
1283 | struct new_utsname *u = utsname(); |
1284 | ||
1285 | memcpy(u->nodename, tmp, len); | |
1286 | memset(u->nodename + len, 0, sizeof(u->nodename) - len); | |
1da177e4 LT |
1287 | errno = 0; |
1288 | } | |
1289 | up_write(&uts_sem); | |
1290 | return errno; | |
1291 | } | |
1292 | ||
1293 | #ifdef __ARCH_WANT_SYS_GETHOSTNAME | |
1294 | ||
5a8a82b1 | 1295 | SYSCALL_DEFINE2(gethostname, char __user *, name, int, len) |
1da177e4 LT |
1296 | { |
1297 | int i, errno; | |
9679e4dd | 1298 | struct new_utsname *u; |
1da177e4 LT |
1299 | |
1300 | if (len < 0) | |
1301 | return -EINVAL; | |
1302 | down_read(&uts_sem); | |
9679e4dd AM |
1303 | u = utsname(); |
1304 | i = 1 + strlen(u->nodename); | |
1da177e4 LT |
1305 | if (i > len) |
1306 | i = len; | |
1307 | errno = 0; | |
9679e4dd | 1308 | if (copy_to_user(name, u->nodename, i)) |
1da177e4 LT |
1309 | errno = -EFAULT; |
1310 | up_read(&uts_sem); | |
1311 | return errno; | |
1312 | } | |
1313 | ||
1314 | #endif | |
1315 | ||
1316 | /* | |
1317 | * Only setdomainname; getdomainname can be implemented by calling | |
1318 | * uname() | |
1319 | */ | |
5a8a82b1 | 1320 | SYSCALL_DEFINE2(setdomainname, char __user *, name, int, len) |
1da177e4 LT |
1321 | { |
1322 | int errno; | |
1323 | char tmp[__NEW_UTS_LEN]; | |
1324 | ||
fc832ad3 | 1325 | if (!ns_capable(current->nsproxy->uts_ns->user_ns, CAP_SYS_ADMIN)) |
1da177e4 LT |
1326 | return -EPERM; |
1327 | if (len < 0 || len > __NEW_UTS_LEN) | |
1328 | return -EINVAL; | |
1329 | ||
1330 | down_write(&uts_sem); | |
1331 | errno = -EFAULT; | |
1332 | if (!copy_from_user(tmp, name, len)) { | |
9679e4dd AM |
1333 | struct new_utsname *u = utsname(); |
1334 | ||
1335 | memcpy(u->domainname, tmp, len); | |
1336 | memset(u->domainname + len, 0, sizeof(u->domainname) - len); | |
1da177e4 LT |
1337 | errno = 0; |
1338 | } | |
1339 | up_write(&uts_sem); | |
1340 | return errno; | |
1341 | } | |
1342 | ||
e48fbb69 | 1343 | SYSCALL_DEFINE2(getrlimit, unsigned int, resource, struct rlimit __user *, rlim) |
1da177e4 | 1344 | { |
b9518345 JS |
1345 | struct rlimit value; |
1346 | int ret; | |
1347 | ||
1348 | ret = do_prlimit(current, resource, NULL, &value); | |
1349 | if (!ret) | |
1350 | ret = copy_to_user(rlim, &value, sizeof(*rlim)) ? -EFAULT : 0; | |
1351 | ||
1352 | return ret; | |
1da177e4 LT |
1353 | } |
1354 | ||
1355 | #ifdef __ARCH_WANT_SYS_OLD_GETRLIMIT | |
1356 | ||
1357 | /* | |
1358 | * Back compatibility for getrlimit. Needed for some apps. | |
1359 | */ | |
1360 | ||
e48fbb69 HC |
1361 | SYSCALL_DEFINE2(old_getrlimit, unsigned int, resource, |
1362 | struct rlimit __user *, rlim) | |
1da177e4 LT |
1363 | { |
1364 | struct rlimit x; | |
1365 | if (resource >= RLIM_NLIMITS) | |
1366 | return -EINVAL; | |
1367 | ||
1368 | task_lock(current->group_leader); | |
1369 | x = current->signal->rlim[resource]; | |
1370 | task_unlock(current->group_leader); | |
756184b7 | 1371 | if (x.rlim_cur > 0x7FFFFFFF) |
1da177e4 | 1372 | x.rlim_cur = 0x7FFFFFFF; |
756184b7 | 1373 | if (x.rlim_max > 0x7FFFFFFF) |
1da177e4 LT |
1374 | x.rlim_max = 0x7FFFFFFF; |
1375 | return copy_to_user(rlim, &x, sizeof(x))?-EFAULT:0; | |
1376 | } | |
1377 | ||
1378 | #endif | |
1379 | ||
c022a0ac JS |
1380 | static inline bool rlim64_is_infinity(__u64 rlim64) |
1381 | { | |
1382 | #if BITS_PER_LONG < 64 | |
1383 | return rlim64 >= ULONG_MAX; | |
1384 | #else | |
1385 | return rlim64 == RLIM64_INFINITY; | |
1386 | #endif | |
1387 | } | |
1388 | ||
1389 | static void rlim_to_rlim64(const struct rlimit *rlim, struct rlimit64 *rlim64) | |
1390 | { | |
1391 | if (rlim->rlim_cur == RLIM_INFINITY) | |
1392 | rlim64->rlim_cur = RLIM64_INFINITY; | |
1393 | else | |
1394 | rlim64->rlim_cur = rlim->rlim_cur; | |
1395 | if (rlim->rlim_max == RLIM_INFINITY) | |
1396 | rlim64->rlim_max = RLIM64_INFINITY; | |
1397 | else | |
1398 | rlim64->rlim_max = rlim->rlim_max; | |
1399 | } | |
1400 | ||
1401 | static void rlim64_to_rlim(const struct rlimit64 *rlim64, struct rlimit *rlim) | |
1402 | { | |
1403 | if (rlim64_is_infinity(rlim64->rlim_cur)) | |
1404 | rlim->rlim_cur = RLIM_INFINITY; | |
1405 | else | |
1406 | rlim->rlim_cur = (unsigned long)rlim64->rlim_cur; | |
1407 | if (rlim64_is_infinity(rlim64->rlim_max)) | |
1408 | rlim->rlim_max = RLIM_INFINITY; | |
1409 | else | |
1410 | rlim->rlim_max = (unsigned long)rlim64->rlim_max; | |
1411 | } | |
1412 | ||
1c1e618d | 1413 | /* make sure you are allowed to change @tsk limits before calling this */ |
5b41535a JS |
1414 | int do_prlimit(struct task_struct *tsk, unsigned int resource, |
1415 | struct rlimit *new_rlim, struct rlimit *old_rlim) | |
1da177e4 | 1416 | { |
5b41535a | 1417 | struct rlimit *rlim; |
86f162f4 | 1418 | int retval = 0; |
1da177e4 LT |
1419 | |
1420 | if (resource >= RLIM_NLIMITS) | |
1421 | return -EINVAL; | |
5b41535a JS |
1422 | if (new_rlim) { |
1423 | if (new_rlim->rlim_cur > new_rlim->rlim_max) | |
1424 | return -EINVAL; | |
1425 | if (resource == RLIMIT_NOFILE && | |
1426 | new_rlim->rlim_max > sysctl_nr_open) | |
1427 | return -EPERM; | |
1428 | } | |
1da177e4 | 1429 | |
1c1e618d JS |
1430 | /* protect tsk->signal and tsk->sighand from disappearing */ |
1431 | read_lock(&tasklist_lock); | |
1432 | if (!tsk->sighand) { | |
1433 | retval = -ESRCH; | |
1434 | goto out; | |
1435 | } | |
1436 | ||
5b41535a | 1437 | rlim = tsk->signal->rlim + resource; |
86f162f4 | 1438 | task_lock(tsk->group_leader); |
5b41535a | 1439 | if (new_rlim) { |
fc832ad3 SH |
1440 | /* Keep the capable check against init_user_ns until |
1441 | cgroups can contain all limits */ | |
5b41535a JS |
1442 | if (new_rlim->rlim_max > rlim->rlim_max && |
1443 | !capable(CAP_SYS_RESOURCE)) | |
1444 | retval = -EPERM; | |
1445 | if (!retval) | |
1446 | retval = security_task_setrlimit(tsk->group_leader, | |
1447 | resource, new_rlim); | |
1448 | if (resource == RLIMIT_CPU && new_rlim->rlim_cur == 0) { | |
1449 | /* | |
1450 | * The caller is asking for an immediate RLIMIT_CPU | |
1451 | * expiry. But we use the zero value to mean "it was | |
1452 | * never set". So let's cheat and make it one second | |
1453 | * instead | |
1454 | */ | |
1455 | new_rlim->rlim_cur = 1; | |
1456 | } | |
1457 | } | |
1458 | if (!retval) { | |
1459 | if (old_rlim) | |
1460 | *old_rlim = *rlim; | |
1461 | if (new_rlim) | |
1462 | *rlim = *new_rlim; | |
9926e4c7 | 1463 | } |
7855c35d | 1464 | task_unlock(tsk->group_leader); |
1da177e4 | 1465 | |
d3561f78 AM |
1466 | /* |
1467 | * RLIMIT_CPU handling. Note that the kernel fails to return an error | |
1468 | * code if it rejected the user's attempt to set RLIMIT_CPU. This is a | |
1469 | * very long-standing error, and fixing it now risks breakage of | |
1470 | * applications, so we live with it | |
1471 | */ | |
5b41535a JS |
1472 | if (!retval && new_rlim && resource == RLIMIT_CPU && |
1473 | new_rlim->rlim_cur != RLIM_INFINITY) | |
1474 | update_rlimit_cpu(tsk, new_rlim->rlim_cur); | |
ec9e16ba | 1475 | out: |
1c1e618d | 1476 | read_unlock(&tasklist_lock); |
2fb9d268 | 1477 | return retval; |
1da177e4 LT |
1478 | } |
1479 | ||
c022a0ac JS |
1480 | /* rcu lock must be held */ |
1481 | static int check_prlimit_permission(struct task_struct *task) | |
1482 | { | |
1483 | const struct cred *cred = current_cred(), *tcred; | |
1484 | ||
fc832ad3 SH |
1485 | if (current == task) |
1486 | return 0; | |
c022a0ac | 1487 | |
fc832ad3 SH |
1488 | tcred = __task_cred(task); |
1489 | if (cred->user->user_ns == tcred->user->user_ns && | |
1490 | (cred->uid == tcred->euid && | |
1491 | cred->uid == tcred->suid && | |
1492 | cred->uid == tcred->uid && | |
1493 | cred->gid == tcred->egid && | |
1494 | cred->gid == tcred->sgid && | |
1495 | cred->gid == tcred->gid)) | |
1496 | return 0; | |
1497 | if (ns_capable(tcred->user->user_ns, CAP_SYS_RESOURCE)) | |
1498 | return 0; | |
1499 | ||
1500 | return -EPERM; | |
c022a0ac JS |
1501 | } |
1502 | ||
1503 | SYSCALL_DEFINE4(prlimit64, pid_t, pid, unsigned int, resource, | |
1504 | const struct rlimit64 __user *, new_rlim, | |
1505 | struct rlimit64 __user *, old_rlim) | |
1506 | { | |
1507 | struct rlimit64 old64, new64; | |
1508 | struct rlimit old, new; | |
1509 | struct task_struct *tsk; | |
1510 | int ret; | |
1511 | ||
1512 | if (new_rlim) { | |
1513 | if (copy_from_user(&new64, new_rlim, sizeof(new64))) | |
1514 | return -EFAULT; | |
1515 | rlim64_to_rlim(&new64, &new); | |
1516 | } | |
1517 | ||
1518 | rcu_read_lock(); | |
1519 | tsk = pid ? find_task_by_vpid(pid) : current; | |
1520 | if (!tsk) { | |
1521 | rcu_read_unlock(); | |
1522 | return -ESRCH; | |
1523 | } | |
1524 | ret = check_prlimit_permission(tsk); | |
1525 | if (ret) { | |
1526 | rcu_read_unlock(); | |
1527 | return ret; | |
1528 | } | |
1529 | get_task_struct(tsk); | |
1530 | rcu_read_unlock(); | |
1531 | ||
1532 | ret = do_prlimit(tsk, resource, new_rlim ? &new : NULL, | |
1533 | old_rlim ? &old : NULL); | |
1534 | ||
1535 | if (!ret && old_rlim) { | |
1536 | rlim_to_rlim64(&old, &old64); | |
1537 | if (copy_to_user(old_rlim, &old64, sizeof(old64))) | |
1538 | ret = -EFAULT; | |
1539 | } | |
1540 | ||
1541 | put_task_struct(tsk); | |
1542 | return ret; | |
1543 | } | |
1544 | ||
7855c35d JS |
1545 | SYSCALL_DEFINE2(setrlimit, unsigned int, resource, struct rlimit __user *, rlim) |
1546 | { | |
1547 | struct rlimit new_rlim; | |
1548 | ||
1549 | if (copy_from_user(&new_rlim, rlim, sizeof(*rlim))) | |
1550 | return -EFAULT; | |
5b41535a | 1551 | return do_prlimit(current, resource, &new_rlim, NULL); |
7855c35d JS |
1552 | } |
1553 | ||
1da177e4 LT |
1554 | /* |
1555 | * It would make sense to put struct rusage in the task_struct, | |
1556 | * except that would make the task_struct be *really big*. After | |
1557 | * task_struct gets moved into malloc'ed memory, it would | |
1558 | * make sense to do this. It will make moving the rest of the information | |
1559 | * a lot simpler! (Which we're not doing right now because we're not | |
1560 | * measuring them yet). | |
1561 | * | |
1da177e4 LT |
1562 | * When sampling multiple threads for RUSAGE_SELF, under SMP we might have |
1563 | * races with threads incrementing their own counters. But since word | |
1564 | * reads are atomic, we either get new values or old values and we don't | |
1565 | * care which for the sums. We always take the siglock to protect reading | |
1566 | * the c* fields from p->signal from races with exit.c updating those | |
1567 | * fields when reaping, so a sample either gets all the additions of a | |
1568 | * given child after it's reaped, or none so this sample is before reaping. | |
2dd0ebcd | 1569 | * |
de047c1b RT |
1570 | * Locking: |
1571 | * We need to take the siglock for CHILDEREN, SELF and BOTH | |
1572 | * for the cases current multithreaded, non-current single threaded | |
1573 | * non-current multithreaded. Thread traversal is now safe with | |
1574 | * the siglock held. | |
1575 | * Strictly speaking, we donot need to take the siglock if we are current and | |
1576 | * single threaded, as no one else can take our signal_struct away, no one | |
1577 | * else can reap the children to update signal->c* counters, and no one else | |
1578 | * can race with the signal-> fields. If we do not take any lock, the | |
1579 | * signal-> fields could be read out of order while another thread was just | |
1580 | * exiting. So we should place a read memory barrier when we avoid the lock. | |
1581 | * On the writer side, write memory barrier is implied in __exit_signal | |
1582 | * as __exit_signal releases the siglock spinlock after updating the signal-> | |
1583 | * fields. But we don't do this yet to keep things simple. | |
2dd0ebcd | 1584 | * |
1da177e4 LT |
1585 | */ |
1586 | ||
f06febc9 | 1587 | static void accumulate_thread_rusage(struct task_struct *t, struct rusage *r) |
679c9cd4 | 1588 | { |
679c9cd4 SK |
1589 | r->ru_nvcsw += t->nvcsw; |
1590 | r->ru_nivcsw += t->nivcsw; | |
1591 | r->ru_minflt += t->min_flt; | |
1592 | r->ru_majflt += t->maj_flt; | |
1593 | r->ru_inblock += task_io_get_inblock(t); | |
1594 | r->ru_oublock += task_io_get_oublock(t); | |
1595 | } | |
1596 | ||
1da177e4 LT |
1597 | static void k_getrusage(struct task_struct *p, int who, struct rusage *r) |
1598 | { | |
1599 | struct task_struct *t; | |
1600 | unsigned long flags; | |
0cf55e1e | 1601 | cputime_t tgutime, tgstime, utime, stime; |
1f10206c | 1602 | unsigned long maxrss = 0; |
1da177e4 LT |
1603 | |
1604 | memset((char *) r, 0, sizeof *r); | |
2dd0ebcd | 1605 | utime = stime = cputime_zero; |
1da177e4 | 1606 | |
679c9cd4 | 1607 | if (who == RUSAGE_THREAD) { |
d180c5bc | 1608 | task_times(current, &utime, &stime); |
f06febc9 | 1609 | accumulate_thread_rusage(p, r); |
1f10206c | 1610 | maxrss = p->signal->maxrss; |
679c9cd4 SK |
1611 | goto out; |
1612 | } | |
1613 | ||
d6cf723a | 1614 | if (!lock_task_sighand(p, &flags)) |
de047c1b | 1615 | return; |
0f59cc4a | 1616 | |
1da177e4 | 1617 | switch (who) { |
0f59cc4a | 1618 | case RUSAGE_BOTH: |
1da177e4 | 1619 | case RUSAGE_CHILDREN: |
1da177e4 LT |
1620 | utime = p->signal->cutime; |
1621 | stime = p->signal->cstime; | |
1622 | r->ru_nvcsw = p->signal->cnvcsw; | |
1623 | r->ru_nivcsw = p->signal->cnivcsw; | |
1624 | r->ru_minflt = p->signal->cmin_flt; | |
1625 | r->ru_majflt = p->signal->cmaj_flt; | |
6eaeeaba ED |
1626 | r->ru_inblock = p->signal->cinblock; |
1627 | r->ru_oublock = p->signal->coublock; | |
1f10206c | 1628 | maxrss = p->signal->cmaxrss; |
0f59cc4a ON |
1629 | |
1630 | if (who == RUSAGE_CHILDREN) | |
1631 | break; | |
1632 | ||
1da177e4 | 1633 | case RUSAGE_SELF: |
0cf55e1e HS |
1634 | thread_group_times(p, &tgutime, &tgstime); |
1635 | utime = cputime_add(utime, tgutime); | |
1636 | stime = cputime_add(stime, tgstime); | |
1da177e4 LT |
1637 | r->ru_nvcsw += p->signal->nvcsw; |
1638 | r->ru_nivcsw += p->signal->nivcsw; | |
1639 | r->ru_minflt += p->signal->min_flt; | |
1640 | r->ru_majflt += p->signal->maj_flt; | |
6eaeeaba ED |
1641 | r->ru_inblock += p->signal->inblock; |
1642 | r->ru_oublock += p->signal->oublock; | |
1f10206c JP |
1643 | if (maxrss < p->signal->maxrss) |
1644 | maxrss = p->signal->maxrss; | |
1da177e4 LT |
1645 | t = p; |
1646 | do { | |
f06febc9 | 1647 | accumulate_thread_rusage(t, r); |
1da177e4 LT |
1648 | t = next_thread(t); |
1649 | } while (t != p); | |
1da177e4 | 1650 | break; |
0f59cc4a | 1651 | |
1da177e4 LT |
1652 | default: |
1653 | BUG(); | |
1654 | } | |
de047c1b | 1655 | unlock_task_sighand(p, &flags); |
de047c1b | 1656 | |
679c9cd4 | 1657 | out: |
0f59cc4a ON |
1658 | cputime_to_timeval(utime, &r->ru_utime); |
1659 | cputime_to_timeval(stime, &r->ru_stime); | |
1f10206c JP |
1660 | |
1661 | if (who != RUSAGE_CHILDREN) { | |
1662 | struct mm_struct *mm = get_task_mm(p); | |
1663 | if (mm) { | |
1664 | setmax_mm_hiwater_rss(&maxrss, mm); | |
1665 | mmput(mm); | |
1666 | } | |
1667 | } | |
1668 | r->ru_maxrss = maxrss * (PAGE_SIZE / 1024); /* convert pages to KBs */ | |
1da177e4 LT |
1669 | } |
1670 | ||
1671 | int getrusage(struct task_struct *p, int who, struct rusage __user *ru) | |
1672 | { | |
1673 | struct rusage r; | |
1da177e4 | 1674 | k_getrusage(p, who, &r); |
1da177e4 LT |
1675 | return copy_to_user(ru, &r, sizeof(r)) ? -EFAULT : 0; |
1676 | } | |
1677 | ||
e48fbb69 | 1678 | SYSCALL_DEFINE2(getrusage, int, who, struct rusage __user *, ru) |
1da177e4 | 1679 | { |
679c9cd4 SK |
1680 | if (who != RUSAGE_SELF && who != RUSAGE_CHILDREN && |
1681 | who != RUSAGE_THREAD) | |
1da177e4 LT |
1682 | return -EINVAL; |
1683 | return getrusage(current, who, ru); | |
1684 | } | |
1685 | ||
e48fbb69 | 1686 | SYSCALL_DEFINE1(umask, int, mask) |
1da177e4 LT |
1687 | { |
1688 | mask = xchg(¤t->fs->umask, mask & S_IRWXUGO); | |
1689 | return mask; | |
1690 | } | |
3b7391de | 1691 | |
c4ea37c2 HC |
1692 | SYSCALL_DEFINE5(prctl, int, option, unsigned long, arg2, unsigned long, arg3, |
1693 | unsigned long, arg4, unsigned long, arg5) | |
1da177e4 | 1694 | { |
b6dff3ec DH |
1695 | struct task_struct *me = current; |
1696 | unsigned char comm[sizeof(me->comm)]; | |
1697 | long error; | |
1da177e4 | 1698 | |
d84f4f99 DH |
1699 | error = security_task_prctl(option, arg2, arg3, arg4, arg5); |
1700 | if (error != -ENOSYS) | |
1da177e4 LT |
1701 | return error; |
1702 | ||
d84f4f99 | 1703 | error = 0; |
1da177e4 LT |
1704 | switch (option) { |
1705 | case PR_SET_PDEATHSIG: | |
0730ded5 | 1706 | if (!valid_signal(arg2)) { |
1da177e4 LT |
1707 | error = -EINVAL; |
1708 | break; | |
1709 | } | |
b6dff3ec DH |
1710 | me->pdeath_signal = arg2; |
1711 | error = 0; | |
1da177e4 LT |
1712 | break; |
1713 | case PR_GET_PDEATHSIG: | |
b6dff3ec | 1714 | error = put_user(me->pdeath_signal, (int __user *)arg2); |
1da177e4 LT |
1715 | break; |
1716 | case PR_GET_DUMPABLE: | |
b6dff3ec | 1717 | error = get_dumpable(me->mm); |
1da177e4 LT |
1718 | break; |
1719 | case PR_SET_DUMPABLE: | |
abf75a50 | 1720 | if (arg2 < 0 || arg2 > 1) { |
1da177e4 LT |
1721 | error = -EINVAL; |
1722 | break; | |
1723 | } | |
b6dff3ec DH |
1724 | set_dumpable(me->mm, arg2); |
1725 | error = 0; | |
1da177e4 LT |
1726 | break; |
1727 | ||
1728 | case PR_SET_UNALIGN: | |
b6dff3ec | 1729 | error = SET_UNALIGN_CTL(me, arg2); |
1da177e4 LT |
1730 | break; |
1731 | case PR_GET_UNALIGN: | |
b6dff3ec | 1732 | error = GET_UNALIGN_CTL(me, arg2); |
1da177e4 LT |
1733 | break; |
1734 | case PR_SET_FPEMU: | |
b6dff3ec | 1735 | error = SET_FPEMU_CTL(me, arg2); |
1da177e4 LT |
1736 | break; |
1737 | case PR_GET_FPEMU: | |
b6dff3ec | 1738 | error = GET_FPEMU_CTL(me, arg2); |
1da177e4 LT |
1739 | break; |
1740 | case PR_SET_FPEXC: | |
b6dff3ec | 1741 | error = SET_FPEXC_CTL(me, arg2); |
1da177e4 LT |
1742 | break; |
1743 | case PR_GET_FPEXC: | |
b6dff3ec | 1744 | error = GET_FPEXC_CTL(me, arg2); |
1da177e4 LT |
1745 | break; |
1746 | case PR_GET_TIMING: | |
1747 | error = PR_TIMING_STATISTICAL; | |
1748 | break; | |
1749 | case PR_SET_TIMING: | |
7b26655f | 1750 | if (arg2 != PR_TIMING_STATISTICAL) |
1da177e4 | 1751 | error = -EINVAL; |
b6dff3ec DH |
1752 | else |
1753 | error = 0; | |
1da177e4 LT |
1754 | break; |
1755 | ||
b6dff3ec DH |
1756 | case PR_SET_NAME: |
1757 | comm[sizeof(me->comm)-1] = 0; | |
1758 | if (strncpy_from_user(comm, (char __user *)arg2, | |
1759 | sizeof(me->comm) - 1) < 0) | |
1da177e4 | 1760 | return -EFAULT; |
b6dff3ec | 1761 | set_task_comm(me, comm); |
f786ecba | 1762 | proc_comm_connector(me); |
1da177e4 | 1763 | return 0; |
b6dff3ec DH |
1764 | case PR_GET_NAME: |
1765 | get_task_comm(comm, me); | |
1766 | if (copy_to_user((char __user *)arg2, comm, | |
1767 | sizeof(comm))) | |
1da177e4 LT |
1768 | return -EFAULT; |
1769 | return 0; | |
651d765d | 1770 | case PR_GET_ENDIAN: |
b6dff3ec | 1771 | error = GET_ENDIAN(me, arg2); |
651d765d AB |
1772 | break; |
1773 | case PR_SET_ENDIAN: | |
b6dff3ec | 1774 | error = SET_ENDIAN(me, arg2); |
651d765d AB |
1775 | break; |
1776 | ||
1d9d02fe AA |
1777 | case PR_GET_SECCOMP: |
1778 | error = prctl_get_seccomp(); | |
1779 | break; | |
1780 | case PR_SET_SECCOMP: | |
1781 | error = prctl_set_seccomp(arg2); | |
1782 | break; | |
8fb402bc EB |
1783 | case PR_GET_TSC: |
1784 | error = GET_TSC_CTL(arg2); | |
1785 | break; | |
1786 | case PR_SET_TSC: | |
1787 | error = SET_TSC_CTL(arg2); | |
1788 | break; | |
cdd6c482 IM |
1789 | case PR_TASK_PERF_EVENTS_DISABLE: |
1790 | error = perf_event_task_disable(); | |
1d1c7ddb | 1791 | break; |
cdd6c482 IM |
1792 | case PR_TASK_PERF_EVENTS_ENABLE: |
1793 | error = perf_event_task_enable(); | |
1d1c7ddb | 1794 | break; |
6976675d AV |
1795 | case PR_GET_TIMERSLACK: |
1796 | error = current->timer_slack_ns; | |
1797 | break; | |
1798 | case PR_SET_TIMERSLACK: | |
1799 | if (arg2 <= 0) | |
1800 | current->timer_slack_ns = | |
1801 | current->default_timer_slack_ns; | |
1802 | else | |
1803 | current->timer_slack_ns = arg2; | |
b6dff3ec | 1804 | error = 0; |
6976675d | 1805 | break; |
4db96cf0 AK |
1806 | case PR_MCE_KILL: |
1807 | if (arg4 | arg5) | |
1808 | return -EINVAL; | |
1809 | switch (arg2) { | |
1087e9b4 | 1810 | case PR_MCE_KILL_CLEAR: |
4db96cf0 AK |
1811 | if (arg3 != 0) |
1812 | return -EINVAL; | |
1813 | current->flags &= ~PF_MCE_PROCESS; | |
1814 | break; | |
1087e9b4 | 1815 | case PR_MCE_KILL_SET: |
4db96cf0 | 1816 | current->flags |= PF_MCE_PROCESS; |
1087e9b4 | 1817 | if (arg3 == PR_MCE_KILL_EARLY) |
4db96cf0 | 1818 | current->flags |= PF_MCE_EARLY; |
1087e9b4 | 1819 | else if (arg3 == PR_MCE_KILL_LATE) |
4db96cf0 | 1820 | current->flags &= ~PF_MCE_EARLY; |
1087e9b4 AK |
1821 | else if (arg3 == PR_MCE_KILL_DEFAULT) |
1822 | current->flags &= | |
1823 | ~(PF_MCE_EARLY|PF_MCE_PROCESS); | |
1824 | else | |
1825 | return -EINVAL; | |
4db96cf0 AK |
1826 | break; |
1827 | default: | |
1828 | return -EINVAL; | |
1829 | } | |
1830 | error = 0; | |
1831 | break; | |
1087e9b4 AK |
1832 | case PR_MCE_KILL_GET: |
1833 | if (arg2 | arg3 | arg4 | arg5) | |
1834 | return -EINVAL; | |
1835 | if (current->flags & PF_MCE_PROCESS) | |
1836 | error = (current->flags & PF_MCE_EARLY) ? | |
1837 | PR_MCE_KILL_EARLY : PR_MCE_KILL_LATE; | |
1838 | else | |
1839 | error = PR_MCE_KILL_DEFAULT; | |
1840 | break; | |
1da177e4 LT |
1841 | default: |
1842 | error = -EINVAL; | |
1843 | break; | |
1844 | } | |
1845 | return error; | |
1846 | } | |
3cfc348b | 1847 | |
836f92ad HC |
1848 | SYSCALL_DEFINE3(getcpu, unsigned __user *, cpup, unsigned __user *, nodep, |
1849 | struct getcpu_cache __user *, unused) | |
3cfc348b AK |
1850 | { |
1851 | int err = 0; | |
1852 | int cpu = raw_smp_processor_id(); | |
1853 | if (cpup) | |
1854 | err |= put_user(cpu, cpup); | |
1855 | if (nodep) | |
1856 | err |= put_user(cpu_to_node(cpu), nodep); | |
3cfc348b AK |
1857 | return err ? -EFAULT : 0; |
1858 | } | |
10a0a8d4 JF |
1859 | |
1860 | char poweroff_cmd[POWEROFF_CMD_PATH_LEN] = "/sbin/poweroff"; | |
1861 | ||
a06a4dc3 | 1862 | static void argv_cleanup(struct subprocess_info *info) |
10a0a8d4 | 1863 | { |
a06a4dc3 | 1864 | argv_free(info->argv); |
10a0a8d4 JF |
1865 | } |
1866 | ||
1867 | /** | |
1868 | * orderly_poweroff - Trigger an orderly system poweroff | |
1869 | * @force: force poweroff if command execution fails | |
1870 | * | |
1871 | * This may be called from any context to trigger a system shutdown. | |
1872 | * If the orderly shutdown fails, it will force an immediate shutdown. | |
1873 | */ | |
1874 | int orderly_poweroff(bool force) | |
1875 | { | |
1876 | int argc; | |
1877 | char **argv = argv_split(GFP_ATOMIC, poweroff_cmd, &argc); | |
1878 | static char *envp[] = { | |
1879 | "HOME=/", | |
1880 | "PATH=/sbin:/bin:/usr/sbin:/usr/bin", | |
1881 | NULL | |
1882 | }; | |
1883 | int ret = -ENOMEM; | |
1884 | struct subprocess_info *info; | |
1885 | ||
1886 | if (argv == NULL) { | |
1887 | printk(KERN_WARNING "%s failed to allocate memory for \"%s\"\n", | |
1888 | __func__, poweroff_cmd); | |
1889 | goto out; | |
1890 | } | |
1891 | ||
ac331d15 | 1892 | info = call_usermodehelper_setup(argv[0], argv, envp, GFP_ATOMIC); |
10a0a8d4 JF |
1893 | if (info == NULL) { |
1894 | argv_free(argv); | |
1895 | goto out; | |
1896 | } | |
1897 | ||
a06a4dc3 | 1898 | call_usermodehelper_setfns(info, NULL, argv_cleanup, NULL); |
10a0a8d4 | 1899 | |
86313c48 | 1900 | ret = call_usermodehelper_exec(info, UMH_NO_WAIT); |
10a0a8d4 JF |
1901 | |
1902 | out: | |
1903 | if (ret && force) { | |
1904 | printk(KERN_WARNING "Failed to start orderly shutdown: " | |
1905 | "forcing the issue\n"); | |
1906 | ||
1907 | /* I guess this should try to kick off some daemon to | |
1908 | sync and poweroff asap. Or not even bother syncing | |
1909 | if we're doing an emergency shutdown? */ | |
1910 | emergency_sync(); | |
1911 | kernel_power_off(); | |
1912 | } | |
1913 | ||
1914 | return ret; | |
1915 | } | |
1916 | EXPORT_SYMBOL_GPL(orderly_poweroff); |