| 1 | /* |
| 2 | * linux/kernel/sys.c |
| 3 | * |
| 4 | * Copyright (C) 1991, 1992 Linus Torvalds |
| 5 | */ |
| 6 | |
| 7 | #include <linux/export.h> |
| 8 | #include <linux/mm.h> |
| 9 | #include <linux/utsname.h> |
| 10 | #include <linux/mman.h> |
| 11 | #include <linux/reboot.h> |
| 12 | #include <linux/prctl.h> |
| 13 | #include <linux/highuid.h> |
| 14 | #include <linux/fs.h> |
| 15 | #include <linux/kmod.h> |
| 16 | #include <linux/perf_event.h> |
| 17 | #include <linux/resource.h> |
| 18 | #include <linux/kernel.h> |
| 19 | #include <linux/kexec.h> |
| 20 | #include <linux/workqueue.h> |
| 21 | #include <linux/capability.h> |
| 22 | #include <linux/device.h> |
| 23 | #include <linux/key.h> |
| 24 | #include <linux/times.h> |
| 25 | #include <linux/posix-timers.h> |
| 26 | #include <linux/security.h> |
| 27 | #include <linux/dcookies.h> |
| 28 | #include <linux/suspend.h> |
| 29 | #include <linux/tty.h> |
| 30 | #include <linux/signal.h> |
| 31 | #include <linux/cn_proc.h> |
| 32 | #include <linux/getcpu.h> |
| 33 | #include <linux/task_io_accounting_ops.h> |
| 34 | #include <linux/seccomp.h> |
| 35 | #include <linux/cpu.h> |
| 36 | #include <linux/personality.h> |
| 37 | #include <linux/ptrace.h> |
| 38 | #include <linux/fs_struct.h> |
| 39 | #include <linux/file.h> |
| 40 | #include <linux/mount.h> |
| 41 | #include <linux/gfp.h> |
| 42 | #include <linux/syscore_ops.h> |
| 43 | #include <linux/version.h> |
| 44 | #include <linux/ctype.h> |
| 45 | #include <linux/mm.h> |
| 46 | #include <linux/mempolicy.h> |
| 47 | #include <linux/sched.h> |
| 48 | |
| 49 | #include <linux/compat.h> |
| 50 | #include <linux/syscalls.h> |
| 51 | #include <linux/kprobes.h> |
| 52 | #include <linux/user_namespace.h> |
| 53 | #include <linux/binfmts.h> |
| 54 | |
| 55 | #include <linux/sched.h> |
| 56 | #include <linux/rcupdate.h> |
| 57 | #include <linux/uidgid.h> |
| 58 | #include <linux/cred.h> |
| 59 | |
| 60 | #include <linux/kmsg_dump.h> |
| 61 | /* Move somewhere else to avoid recompiling? */ |
| 62 | #include <generated/utsrelease.h> |
| 63 | |
| 64 | #include <asm/uaccess.h> |
| 65 | #include <asm/io.h> |
| 66 | #include <asm/unistd.h> |
| 67 | |
| 68 | #ifdef CONFIG_MT_PRIO_TRACER |
| 69 | # include <linux/prio_tracer.h> |
| 70 | #endif |
| 71 | |
| 72 | #ifndef SET_UNALIGN_CTL |
| 73 | # define SET_UNALIGN_CTL(a,b) (-EINVAL) |
| 74 | #endif |
| 75 | #ifndef GET_UNALIGN_CTL |
| 76 | # define GET_UNALIGN_CTL(a,b) (-EINVAL) |
| 77 | #endif |
| 78 | #ifndef SET_FPEMU_CTL |
| 79 | # define SET_FPEMU_CTL(a,b) (-EINVAL) |
| 80 | #endif |
| 81 | #ifndef GET_FPEMU_CTL |
| 82 | # define GET_FPEMU_CTL(a,b) (-EINVAL) |
| 83 | #endif |
| 84 | #ifndef SET_FPEXC_CTL |
| 85 | # define SET_FPEXC_CTL(a,b) (-EINVAL) |
| 86 | #endif |
| 87 | #ifndef GET_FPEXC_CTL |
| 88 | # define GET_FPEXC_CTL(a,b) (-EINVAL) |
| 89 | #endif |
| 90 | #ifndef GET_ENDIAN |
| 91 | # define GET_ENDIAN(a,b) (-EINVAL) |
| 92 | #endif |
| 93 | #ifndef SET_ENDIAN |
| 94 | # define SET_ENDIAN(a,b) (-EINVAL) |
| 95 | #endif |
| 96 | #ifndef GET_TSC_CTL |
| 97 | # define GET_TSC_CTL(a) (-EINVAL) |
| 98 | #endif |
| 99 | #ifndef SET_TSC_CTL |
| 100 | # define SET_TSC_CTL(a) (-EINVAL) |
| 101 | #endif |
| 102 | |
| 103 | /* |
| 104 | * this is where the system-wide overflow UID and GID are defined, for |
| 105 | * architectures that now have 32-bit UID/GID but didn't in the past |
| 106 | */ |
| 107 | |
| 108 | int overflowuid = DEFAULT_OVERFLOWUID; |
| 109 | int overflowgid = DEFAULT_OVERFLOWGID; |
| 110 | |
| 111 | EXPORT_SYMBOL(overflowuid); |
| 112 | EXPORT_SYMBOL(overflowgid); |
| 113 | |
| 114 | /* |
| 115 | * the same as above, but for filesystems which can only store a 16-bit |
| 116 | * UID and GID. as such, this is needed on all architectures |
| 117 | */ |
| 118 | |
| 119 | int fs_overflowuid = DEFAULT_FS_OVERFLOWUID; |
| 120 | int fs_overflowgid = DEFAULT_FS_OVERFLOWUID; |
| 121 | |
| 122 | EXPORT_SYMBOL(fs_overflowuid); |
| 123 | EXPORT_SYMBOL(fs_overflowgid); |
| 124 | |
| 125 | /* |
| 126 | * this indicates whether you can reboot with ctrl-alt-del: the default is yes |
| 127 | */ |
| 128 | |
| 129 | int C_A_D = 1; |
| 130 | struct pid *cad_pid; |
| 131 | EXPORT_SYMBOL(cad_pid); |
| 132 | |
| 133 | /* |
| 134 | * If set, this is used for preparing the system to power off. |
| 135 | */ |
| 136 | |
| 137 | void (*pm_power_off_prepare)(void); |
| 138 | |
| 139 | /* |
| 140 | * Returns true if current's euid is same as p's uid or euid, |
| 141 | * or has CAP_SYS_NICE to p's user_ns. |
| 142 | * |
| 143 | * Called with rcu_read_lock, creds are safe |
| 144 | */ |
| 145 | static bool set_one_prio_perm(struct task_struct *p) |
| 146 | { |
| 147 | const struct cred *cred = current_cred(), *pcred = __task_cred(p); |
| 148 | |
| 149 | if (uid_eq(pcred->uid, cred->euid) || |
| 150 | uid_eq(pcred->euid, cred->euid)) |
| 151 | return true; |
| 152 | if (ns_capable(pcred->user_ns, CAP_SYS_NICE)) |
| 153 | return true; |
| 154 | return false; |
| 155 | } |
| 156 | |
| 157 | /* |
| 158 | * set the priority of a task |
| 159 | * - the caller must hold the RCU read lock |
| 160 | */ |
| 161 | static int set_one_prio(struct task_struct *p, int niceval, int error) |
| 162 | { |
| 163 | int no_nice; |
| 164 | |
| 165 | if (!set_one_prio_perm(p)) { |
| 166 | error = -EPERM; |
| 167 | goto out; |
| 168 | } |
| 169 | if (niceval < task_nice(p) && !can_nice(p, niceval)) { |
| 170 | error = -EACCES; |
| 171 | goto out; |
| 172 | } |
| 173 | no_nice = security_task_setnice(p, niceval); |
| 174 | if (no_nice) { |
| 175 | error = no_nice; |
| 176 | goto out; |
| 177 | } |
| 178 | if (error == -ESRCH) |
| 179 | error = 0; |
| 180 | #ifdef CONFIG_MT_PRIO_TRACER |
| 181 | set_user_nice_syscall(p, niceval); |
| 182 | #else |
| 183 | set_user_nice(p, niceval); |
| 184 | #endif |
| 185 | out: |
| 186 | return error; |
| 187 | } |
| 188 | |
| 189 | SYSCALL_DEFINE3(setpriority, int, which, int, who, int, niceval) |
| 190 | { |
| 191 | struct task_struct *g, *p; |
| 192 | struct user_struct *user; |
| 193 | const struct cred *cred = current_cred(); |
| 194 | int error = -EINVAL; |
| 195 | struct pid *pgrp; |
| 196 | kuid_t uid; |
| 197 | |
| 198 | if (which > PRIO_USER || which < PRIO_PROCESS) |
| 199 | goto out; |
| 200 | |
| 201 | /* normalize: avoid signed division (rounding problems) */ |
| 202 | error = -ESRCH; |
| 203 | if (niceval < -20) |
| 204 | niceval = -20; |
| 205 | if (niceval > 19) |
| 206 | niceval = 19; |
| 207 | |
| 208 | rcu_read_lock(); |
| 209 | read_lock(&tasklist_lock); |
| 210 | switch (which) { |
| 211 | case PRIO_PROCESS: |
| 212 | if (who) |
| 213 | p = find_task_by_vpid(who); |
| 214 | else |
| 215 | p = current; |
| 216 | if (p) |
| 217 | error = set_one_prio(p, niceval, error); |
| 218 | break; |
| 219 | case PRIO_PGRP: |
| 220 | if (who) |
| 221 | pgrp = find_vpid(who); |
| 222 | else |
| 223 | pgrp = task_pgrp(current); |
| 224 | do_each_pid_thread(pgrp, PIDTYPE_PGID, p) { |
| 225 | error = set_one_prio(p, niceval, error); |
| 226 | } while_each_pid_thread(pgrp, PIDTYPE_PGID, p); |
| 227 | break; |
| 228 | case PRIO_USER: |
| 229 | uid = make_kuid(cred->user_ns, who); |
| 230 | user = cred->user; |
| 231 | if (!who) |
| 232 | uid = cred->uid; |
| 233 | else if (!uid_eq(uid, cred->uid) && |
| 234 | !(user = find_user(uid))) |
| 235 | goto out_unlock; /* No processes for this user */ |
| 236 | |
| 237 | do_each_thread(g, p) { |
| 238 | if (uid_eq(task_uid(p), uid)) |
| 239 | error = set_one_prio(p, niceval, error); |
| 240 | } while_each_thread(g, p); |
| 241 | if (!uid_eq(uid, cred->uid)) |
| 242 | free_uid(user); /* For find_user() */ |
| 243 | break; |
| 244 | } |
| 245 | out_unlock: |
| 246 | read_unlock(&tasklist_lock); |
| 247 | rcu_read_unlock(); |
| 248 | out: |
| 249 | return error; |
| 250 | } |
| 251 | |
| 252 | /* |
| 253 | * Ugh. To avoid negative return values, "getpriority()" will |
| 254 | * not return the normal nice-value, but a negated value that |
| 255 | * has been offset by 20 (ie it returns 40..1 instead of -20..19) |
| 256 | * to stay compatible. |
| 257 | */ |
| 258 | SYSCALL_DEFINE2(getpriority, int, which, int, who) |
| 259 | { |
| 260 | struct task_struct *g, *p; |
| 261 | struct user_struct *user; |
| 262 | const struct cred *cred = current_cred(); |
| 263 | long niceval, retval = -ESRCH; |
| 264 | struct pid *pgrp; |
| 265 | kuid_t uid; |
| 266 | |
| 267 | if (which > PRIO_USER || which < PRIO_PROCESS) |
| 268 | return -EINVAL; |
| 269 | |
| 270 | rcu_read_lock(); |
| 271 | read_lock(&tasklist_lock); |
| 272 | switch (which) { |
| 273 | case PRIO_PROCESS: |
| 274 | if (who) |
| 275 | p = find_task_by_vpid(who); |
| 276 | else |
| 277 | p = current; |
| 278 | if (p) { |
| 279 | niceval = 20 - task_nice(p); |
| 280 | if (niceval > retval) |
| 281 | retval = niceval; |
| 282 | } |
| 283 | break; |
| 284 | case PRIO_PGRP: |
| 285 | if (who) |
| 286 | pgrp = find_vpid(who); |
| 287 | else |
| 288 | pgrp = task_pgrp(current); |
| 289 | do_each_pid_thread(pgrp, PIDTYPE_PGID, p) { |
| 290 | niceval = 20 - task_nice(p); |
| 291 | if (niceval > retval) |
| 292 | retval = niceval; |
| 293 | } while_each_pid_thread(pgrp, PIDTYPE_PGID, p); |
| 294 | break; |
| 295 | case PRIO_USER: |
| 296 | uid = make_kuid(cred->user_ns, who); |
| 297 | user = cred->user; |
| 298 | if (!who) |
| 299 | uid = cred->uid; |
| 300 | else if (!uid_eq(uid, cred->uid) && |
| 301 | !(user = find_user(uid))) |
| 302 | goto out_unlock; /* No processes for this user */ |
| 303 | |
| 304 | do_each_thread(g, p) { |
| 305 | if (uid_eq(task_uid(p), uid)) { |
| 306 | niceval = 20 - task_nice(p); |
| 307 | if (niceval > retval) |
| 308 | retval = niceval; |
| 309 | } |
| 310 | } while_each_thread(g, p); |
| 311 | if (!uid_eq(uid, cred->uid)) |
| 312 | free_uid(user); /* for find_user() */ |
| 313 | break; |
| 314 | } |
| 315 | out_unlock: |
| 316 | read_unlock(&tasklist_lock); |
| 317 | rcu_read_unlock(); |
| 318 | |
| 319 | return retval; |
| 320 | } |
| 321 | |
| 322 | /** |
| 323 | * emergency_restart - reboot the system |
| 324 | * |
| 325 | * Without shutting down any hardware or taking any locks |
| 326 | * reboot the system. This is called when we know we are in |
| 327 | * trouble so this is our best effort to reboot. This is |
| 328 | * safe to call in interrupt context. |
| 329 | */ |
| 330 | void emergency_restart(void) |
| 331 | { |
| 332 | kmsg_dump(KMSG_DUMP_EMERG); |
| 333 | machine_emergency_restart(); |
| 334 | } |
| 335 | EXPORT_SYMBOL_GPL(emergency_restart); |
| 336 | |
| 337 | void kernel_restart_prepare(char *cmd) |
| 338 | { |
| 339 | blocking_notifier_call_chain(&reboot_notifier_list, SYS_RESTART, cmd); |
| 340 | system_state = SYSTEM_RESTART; |
| 341 | usermodehelper_disable(); |
| 342 | device_shutdown(); |
| 343 | } |
| 344 | |
| 345 | /** |
| 346 | * register_reboot_notifier - Register function to be called at reboot time |
| 347 | * @nb: Info about notifier function to be called |
| 348 | * |
| 349 | * Registers a function with the list of functions |
| 350 | * to be called at reboot time. |
| 351 | * |
| 352 | * Currently always returns zero, as blocking_notifier_chain_register() |
| 353 | * always returns zero. |
| 354 | */ |
| 355 | int register_reboot_notifier(struct notifier_block *nb) |
| 356 | { |
| 357 | return blocking_notifier_chain_register(&reboot_notifier_list, nb); |
| 358 | } |
| 359 | EXPORT_SYMBOL(register_reboot_notifier); |
| 360 | |
| 361 | /** |
| 362 | * unregister_reboot_notifier - Unregister previously registered reboot notifier |
| 363 | * @nb: Hook to be unregistered |
| 364 | * |
| 365 | * Unregisters a previously registered reboot |
| 366 | * notifier function. |
| 367 | * |
| 368 | * Returns zero on success, or %-ENOENT on failure. |
| 369 | */ |
| 370 | int unregister_reboot_notifier(struct notifier_block *nb) |
| 371 | { |
| 372 | return blocking_notifier_chain_unregister(&reboot_notifier_list, nb); |
| 373 | } |
| 374 | EXPORT_SYMBOL(unregister_reboot_notifier); |
| 375 | |
| 376 | /* Add backwards compatibility for stable trees. */ |
| 377 | #ifndef PF_NO_SETAFFINITY |
| 378 | #define PF_NO_SETAFFINITY PF_THREAD_BOUND |
| 379 | #endif |
| 380 | |
| 381 | static void migrate_to_reboot_cpu(void) |
| 382 | { |
| 383 | /* The boot cpu is always logical cpu 0 */ |
| 384 | int cpu = 0; |
| 385 | |
| 386 | cpu_hotplug_disable(); |
| 387 | |
| 388 | /* Make certain the cpu I'm about to reboot on is online */ |
| 389 | if (!cpu_online(cpu)) |
| 390 | cpu = cpumask_first(cpu_online_mask); |
| 391 | |
| 392 | /* Prevent races with other tasks migrating this task */ |
| 393 | current->flags |= PF_NO_SETAFFINITY; |
| 394 | |
| 395 | /* Make certain I only run on the appropriate processor */ |
| 396 | set_cpus_allowed_ptr(current, cpumask_of(cpu)); |
| 397 | } |
| 398 | |
| 399 | /** |
| 400 | * kernel_restart - reboot the system |
| 401 | * @cmd: pointer to buffer containing command to execute for restart |
| 402 | * or %NULL |
| 403 | * |
| 404 | * Shutdown everything and perform a clean reboot. |
| 405 | * This is not safe to call in interrupt context. |
| 406 | */ |
| 407 | void kernel_restart(char *cmd) |
| 408 | { |
| 409 | kernel_restart_prepare(cmd); |
| 410 | migrate_to_reboot_cpu(); |
| 411 | syscore_shutdown(); |
| 412 | if (!cmd) |
| 413 | printk(KERN_EMERG "Restarting system.\n"); |
| 414 | else |
| 415 | printk(KERN_EMERG "Restarting system with command '%s'.\n", cmd); |
| 416 | kmsg_dump(KMSG_DUMP_RESTART); |
| 417 | machine_restart(cmd); |
| 418 | } |
| 419 | EXPORT_SYMBOL_GPL(kernel_restart); |
| 420 | |
| 421 | static void kernel_shutdown_prepare(enum system_states state) |
| 422 | { |
| 423 | blocking_notifier_call_chain(&reboot_notifier_list, |
| 424 | (state == SYSTEM_HALT)?SYS_HALT:SYS_POWER_OFF, NULL); |
| 425 | system_state = state; |
| 426 | usermodehelper_disable(); |
| 427 | device_shutdown(); |
| 428 | } |
| 429 | /** |
| 430 | * kernel_halt - halt the system |
| 431 | * |
| 432 | * Shutdown everything and perform a clean system halt. |
| 433 | */ |
| 434 | void kernel_halt(void) |
| 435 | { |
| 436 | kernel_shutdown_prepare(SYSTEM_HALT); |
| 437 | migrate_to_reboot_cpu(); |
| 438 | syscore_shutdown(); |
| 439 | printk(KERN_EMERG "System halted.\n"); |
| 440 | kmsg_dump(KMSG_DUMP_HALT); |
| 441 | machine_halt(); |
| 442 | } |
| 443 | |
| 444 | EXPORT_SYMBOL_GPL(kernel_halt); |
| 445 | |
| 446 | /** |
| 447 | * kernel_power_off - power_off the system |
| 448 | * |
| 449 | * Shutdown everything and perform a clean system power_off. |
| 450 | */ |
| 451 | void kernel_power_off(void) |
| 452 | { |
| 453 | kernel_shutdown_prepare(SYSTEM_POWER_OFF); |
| 454 | if (pm_power_off_prepare) |
| 455 | pm_power_off_prepare(); |
| 456 | migrate_to_reboot_cpu(); |
| 457 | syscore_shutdown(); |
| 458 | printk(KERN_EMERG "Power down.\n"); |
| 459 | kmsg_dump(KMSG_DUMP_POWEROFF); |
| 460 | machine_power_off(); |
| 461 | } |
| 462 | EXPORT_SYMBOL_GPL(kernel_power_off); |
| 463 | |
| 464 | static DEFINE_MUTEX(reboot_mutex); |
| 465 | |
| 466 | /* |
| 467 | * Reboot system call: for obvious reasons only root may call it, |
| 468 | * and even root needs to set up some magic numbers in the registers |
| 469 | * so that some mistake won't make this reboot the whole machine. |
| 470 | * You can also set the meaning of the ctrl-alt-del-key here. |
| 471 | * |
| 472 | * reboot doesn't sync: do that yourself before calling this. |
| 473 | */ |
| 474 | SYSCALL_DEFINE4(reboot, int, magic1, int, magic2, unsigned int, cmd, |
| 475 | void __user *, arg) |
| 476 | { |
| 477 | struct pid_namespace *pid_ns = task_active_pid_ns(current); |
| 478 | char buffer[256]; |
| 479 | int ret = 0; |
| 480 | |
| 481 | /* We only trust the superuser with rebooting the system. */ |
| 482 | if (!ns_capable(pid_ns->user_ns, CAP_SYS_BOOT)) |
| 483 | return -EPERM; |
| 484 | |
| 485 | /* For safety, we require "magic" arguments. */ |
| 486 | if (magic1 != LINUX_REBOOT_MAGIC1 || |
| 487 | (magic2 != LINUX_REBOOT_MAGIC2 && |
| 488 | magic2 != LINUX_REBOOT_MAGIC2A && |
| 489 | magic2 != LINUX_REBOOT_MAGIC2B && |
| 490 | magic2 != LINUX_REBOOT_MAGIC2C)) |
| 491 | return -EINVAL; |
| 492 | |
| 493 | /* |
| 494 | * If pid namespaces are enabled and the current task is in a child |
| 495 | * pid_namespace, the command is handled by reboot_pid_ns() which will |
| 496 | * call do_exit(). |
| 497 | */ |
| 498 | ret = reboot_pid_ns(pid_ns, cmd); |
| 499 | if (ret) |
| 500 | return ret; |
| 501 | |
| 502 | /* Instead of trying to make the power_off code look like |
| 503 | * halt when pm_power_off is not set do it the easy way. |
| 504 | */ |
| 505 | if ((cmd == LINUX_REBOOT_CMD_POWER_OFF) && !pm_power_off) |
| 506 | cmd = LINUX_REBOOT_CMD_HALT; |
| 507 | |
| 508 | mutex_lock(&reboot_mutex); |
| 509 | switch (cmd) { |
| 510 | case LINUX_REBOOT_CMD_RESTART: |
| 511 | kernel_restart(NULL); |
| 512 | break; |
| 513 | |
| 514 | case LINUX_REBOOT_CMD_CAD_ON: |
| 515 | C_A_D = 1; |
| 516 | break; |
| 517 | |
| 518 | case LINUX_REBOOT_CMD_CAD_OFF: |
| 519 | C_A_D = 0; |
| 520 | break; |
| 521 | |
| 522 | case LINUX_REBOOT_CMD_HALT: |
| 523 | kernel_halt(); |
| 524 | do_exit(0); |
| 525 | panic("cannot halt"); |
| 526 | |
| 527 | case LINUX_REBOOT_CMD_POWER_OFF: |
| 528 | kernel_power_off(); |
| 529 | do_exit(0); |
| 530 | break; |
| 531 | |
| 532 | case LINUX_REBOOT_CMD_RESTART2: |
| 533 | if (strncpy_from_user(&buffer[0], arg, sizeof(buffer) - 1) < 0) { |
| 534 | ret = -EFAULT; |
| 535 | break; |
| 536 | } |
| 537 | buffer[sizeof(buffer) - 1] = '\0'; |
| 538 | |
| 539 | kernel_restart(buffer); |
| 540 | break; |
| 541 | |
| 542 | #ifdef CONFIG_KEXEC |
| 543 | case LINUX_REBOOT_CMD_KEXEC: |
| 544 | ret = kernel_kexec(); |
| 545 | break; |
| 546 | #endif |
| 547 | |
| 548 | #ifdef CONFIG_HIBERNATION |
| 549 | case LINUX_REBOOT_CMD_SW_SUSPEND: |
| 550 | ret = hibernate(); |
| 551 | break; |
| 552 | #endif |
| 553 | |
| 554 | default: |
| 555 | ret = -EINVAL; |
| 556 | break; |
| 557 | } |
| 558 | mutex_unlock(&reboot_mutex); |
| 559 | return ret; |
| 560 | } |
| 561 | |
| 562 | static void deferred_cad(struct work_struct *dummy) |
| 563 | { |
| 564 | kernel_restart(NULL); |
| 565 | } |
| 566 | |
| 567 | /* |
| 568 | * This function gets called by ctrl-alt-del - ie the keyboard interrupt. |
| 569 | * As it's called within an interrupt, it may NOT sync: the only choice |
| 570 | * is whether to reboot at once, or just ignore the ctrl-alt-del. |
| 571 | */ |
| 572 | void ctrl_alt_del(void) |
| 573 | { |
| 574 | static DECLARE_WORK(cad_work, deferred_cad); |
| 575 | |
| 576 | if (C_A_D) |
| 577 | schedule_work(&cad_work); |
| 578 | else |
| 579 | kill_cad_pid(SIGINT, 1); |
| 580 | } |
| 581 | |
| 582 | /* |
| 583 | * Unprivileged users may change the real gid to the effective gid |
| 584 | * or vice versa. (BSD-style) |
| 585 | * |
| 586 | * If you set the real gid at all, or set the effective gid to a value not |
| 587 | * equal to the real gid, then the saved gid is set to the new effective gid. |
| 588 | * |
| 589 | * This makes it possible for a setgid program to completely drop its |
| 590 | * privileges, which is often a useful assertion to make when you are doing |
| 591 | * a security audit over a program. |
| 592 | * |
| 593 | * The general idea is that a program which uses just setregid() will be |
| 594 | * 100% compatible with BSD. A program which uses just setgid() will be |
| 595 | * 100% compatible with POSIX with saved IDs. |
| 596 | * |
| 597 | * SMP: There are not races, the GIDs are checked only by filesystem |
| 598 | * operations (as far as semantic preservation is concerned). |
| 599 | */ |
| 600 | SYSCALL_DEFINE2(setregid, gid_t, rgid, gid_t, egid) |
| 601 | { |
| 602 | struct user_namespace *ns = current_user_ns(); |
| 603 | const struct cred *old; |
| 604 | struct cred *new; |
| 605 | int retval; |
| 606 | kgid_t krgid, kegid; |
| 607 | |
| 608 | krgid = make_kgid(ns, rgid); |
| 609 | kegid = make_kgid(ns, egid); |
| 610 | |
| 611 | if ((rgid != (gid_t) -1) && !gid_valid(krgid)) |
| 612 | return -EINVAL; |
| 613 | if ((egid != (gid_t) -1) && !gid_valid(kegid)) |
| 614 | return -EINVAL; |
| 615 | |
| 616 | new = prepare_creds(); |
| 617 | if (!new) |
| 618 | return -ENOMEM; |
| 619 | old = current_cred(); |
| 620 | |
| 621 | retval = -EPERM; |
| 622 | if (rgid != (gid_t) -1) { |
| 623 | if (gid_eq(old->gid, krgid) || |
| 624 | gid_eq(old->egid, krgid) || |
| 625 | nsown_capable(CAP_SETGID)) |
| 626 | new->gid = krgid; |
| 627 | else |
| 628 | goto error; |
| 629 | } |
| 630 | if (egid != (gid_t) -1) { |
| 631 | if (gid_eq(old->gid, kegid) || |
| 632 | gid_eq(old->egid, kegid) || |
| 633 | gid_eq(old->sgid, kegid) || |
| 634 | nsown_capable(CAP_SETGID)) |
| 635 | new->egid = kegid; |
| 636 | else |
| 637 | goto error; |
| 638 | } |
| 639 | |
| 640 | if (rgid != (gid_t) -1 || |
| 641 | (egid != (gid_t) -1 && !gid_eq(kegid, old->gid))) |
| 642 | new->sgid = new->egid; |
| 643 | new->fsgid = new->egid; |
| 644 | |
| 645 | return commit_creds(new); |
| 646 | |
| 647 | error: |
| 648 | abort_creds(new); |
| 649 | return retval; |
| 650 | } |
| 651 | |
| 652 | /* |
| 653 | * setgid() is implemented like SysV w/ SAVED_IDS |
| 654 | * |
| 655 | * SMP: Same implicit races as above. |
| 656 | */ |
| 657 | SYSCALL_DEFINE1(setgid, gid_t, gid) |
| 658 | { |
| 659 | struct user_namespace *ns = current_user_ns(); |
| 660 | const struct cred *old; |
| 661 | struct cred *new; |
| 662 | int retval; |
| 663 | kgid_t kgid; |
| 664 | |
| 665 | kgid = make_kgid(ns, gid); |
| 666 | if (!gid_valid(kgid)) |
| 667 | return -EINVAL; |
| 668 | |
| 669 | new = prepare_creds(); |
| 670 | if (!new) |
| 671 | return -ENOMEM; |
| 672 | old = current_cred(); |
| 673 | |
| 674 | retval = -EPERM; |
| 675 | if (nsown_capable(CAP_SETGID)) |
| 676 | new->gid = new->egid = new->sgid = new->fsgid = kgid; |
| 677 | else if (gid_eq(kgid, old->gid) || gid_eq(kgid, old->sgid)) |
| 678 | new->egid = new->fsgid = kgid; |
| 679 | else |
| 680 | goto error; |
| 681 | |
| 682 | return commit_creds(new); |
| 683 | |
| 684 | error: |
| 685 | abort_creds(new); |
| 686 | return retval; |
| 687 | } |
| 688 | |
| 689 | /* |
| 690 | * change the user struct in a credentials set to match the new UID |
| 691 | */ |
| 692 | static int set_user(struct cred *new) |
| 693 | { |
| 694 | struct user_struct *new_user; |
| 695 | |
| 696 | new_user = alloc_uid(new->uid); |
| 697 | if (!new_user) |
| 698 | return -EAGAIN; |
| 699 | |
| 700 | /* |
| 701 | * We don't fail in case of NPROC limit excess here because too many |
| 702 | * poorly written programs don't check set*uid() return code, assuming |
| 703 | * it never fails if called by root. We may still enforce NPROC limit |
| 704 | * for programs doing set*uid()+execve() by harmlessly deferring the |
| 705 | * failure to the execve() stage. |
| 706 | */ |
| 707 | if (atomic_read(&new_user->processes) >= rlimit(RLIMIT_NPROC) && |
| 708 | new_user != INIT_USER) |
| 709 | current->flags |= PF_NPROC_EXCEEDED; |
| 710 | else |
| 711 | current->flags &= ~PF_NPROC_EXCEEDED; |
| 712 | |
| 713 | free_uid(new->user); |
| 714 | new->user = new_user; |
| 715 | return 0; |
| 716 | } |
| 717 | |
| 718 | /* |
| 719 | * Unprivileged users may change the real uid to the effective uid |
| 720 | * or vice versa. (BSD-style) |
| 721 | * |
| 722 | * If you set the real uid at all, or set the effective uid to a value not |
| 723 | * equal to the real uid, then the saved uid is set to the new effective uid. |
| 724 | * |
| 725 | * This makes it possible for a setuid program to completely drop its |
| 726 | * privileges, which is often a useful assertion to make when you are doing |
| 727 | * a security audit over a program. |
| 728 | * |
| 729 | * The general idea is that a program which uses just setreuid() will be |
| 730 | * 100% compatible with BSD. A program which uses just setuid() will be |
| 731 | * 100% compatible with POSIX with saved IDs. |
| 732 | */ |
| 733 | SYSCALL_DEFINE2(setreuid, uid_t, ruid, uid_t, euid) |
| 734 | { |
| 735 | struct user_namespace *ns = current_user_ns(); |
| 736 | const struct cred *old; |
| 737 | struct cred *new; |
| 738 | int retval; |
| 739 | kuid_t kruid, keuid; |
| 740 | |
| 741 | kruid = make_kuid(ns, ruid); |
| 742 | keuid = make_kuid(ns, euid); |
| 743 | |
| 744 | if ((ruid != (uid_t) -1) && !uid_valid(kruid)) |
| 745 | return -EINVAL; |
| 746 | if ((euid != (uid_t) -1) && !uid_valid(keuid)) |
| 747 | return -EINVAL; |
| 748 | |
| 749 | new = prepare_creds(); |
| 750 | if (!new) |
| 751 | return -ENOMEM; |
| 752 | old = current_cred(); |
| 753 | |
| 754 | retval = -EPERM; |
| 755 | if (ruid != (uid_t) -1) { |
| 756 | new->uid = kruid; |
| 757 | if (!uid_eq(old->uid, kruid) && |
| 758 | !uid_eq(old->euid, kruid) && |
| 759 | !nsown_capable(CAP_SETUID)) |
| 760 | goto error; |
| 761 | } |
| 762 | |
| 763 | if (euid != (uid_t) -1) { |
| 764 | new->euid = keuid; |
| 765 | if (!uid_eq(old->uid, keuid) && |
| 766 | !uid_eq(old->euid, keuid) && |
| 767 | !uid_eq(old->suid, keuid) && |
| 768 | !nsown_capable(CAP_SETUID)) |
| 769 | goto error; |
| 770 | } |
| 771 | |
| 772 | if (!uid_eq(new->uid, old->uid)) { |
| 773 | retval = set_user(new); |
| 774 | if (retval < 0) |
| 775 | goto error; |
| 776 | } |
| 777 | if (ruid != (uid_t) -1 || |
| 778 | (euid != (uid_t) -1 && !uid_eq(keuid, old->uid))) |
| 779 | new->suid = new->euid; |
| 780 | new->fsuid = new->euid; |
| 781 | |
| 782 | retval = security_task_fix_setuid(new, old, LSM_SETID_RE); |
| 783 | if (retval < 0) |
| 784 | goto error; |
| 785 | |
| 786 | return commit_creds(new); |
| 787 | |
| 788 | error: |
| 789 | abort_creds(new); |
| 790 | return retval; |
| 791 | } |
| 792 | |
| 793 | /* |
| 794 | * setuid() is implemented like SysV with SAVED_IDS |
| 795 | * |
| 796 | * Note that SAVED_ID's is deficient in that a setuid root program |
| 797 | * like sendmail, for example, cannot set its uid to be a normal |
| 798 | * user and then switch back, because if you're root, setuid() sets |
| 799 | * the saved uid too. If you don't like this, blame the bright people |
| 800 | * in the POSIX committee and/or USG. Note that the BSD-style setreuid() |
| 801 | * will allow a root program to temporarily drop privileges and be able to |
| 802 | * regain them by swapping the real and effective uid. |
| 803 | */ |
| 804 | SYSCALL_DEFINE1(setuid, uid_t, uid) |
| 805 | { |
| 806 | struct user_namespace *ns = current_user_ns(); |
| 807 | const struct cred *old; |
| 808 | struct cred *new; |
| 809 | int retval; |
| 810 | kuid_t kuid; |
| 811 | |
| 812 | kuid = make_kuid(ns, uid); |
| 813 | if (!uid_valid(kuid)) |
| 814 | return -EINVAL; |
| 815 | |
| 816 | new = prepare_creds(); |
| 817 | if (!new) |
| 818 | return -ENOMEM; |
| 819 | old = current_cred(); |
| 820 | |
| 821 | retval = -EPERM; |
| 822 | if (nsown_capable(CAP_SETUID)) { |
| 823 | new->suid = new->uid = kuid; |
| 824 | if (!uid_eq(kuid, old->uid)) { |
| 825 | retval = set_user(new); |
| 826 | if (retval < 0) |
| 827 | goto error; |
| 828 | } |
| 829 | } else if (!uid_eq(kuid, old->uid) && !uid_eq(kuid, new->suid)) { |
| 830 | goto error; |
| 831 | } |
| 832 | |
| 833 | new->fsuid = new->euid = kuid; |
| 834 | |
| 835 | retval = security_task_fix_setuid(new, old, LSM_SETID_ID); |
| 836 | if (retval < 0) |
| 837 | goto error; |
| 838 | |
| 839 | return commit_creds(new); |
| 840 | |
| 841 | error: |
| 842 | abort_creds(new); |
| 843 | return retval; |
| 844 | } |
| 845 | |
| 846 | |
| 847 | /* |
| 848 | * This function implements a generic ability to update ruid, euid, |
| 849 | * and suid. This allows you to implement the 4.4 compatible seteuid(). |
| 850 | */ |
| 851 | SYSCALL_DEFINE3(setresuid, uid_t, ruid, uid_t, euid, uid_t, suid) |
| 852 | { |
| 853 | struct user_namespace *ns = current_user_ns(); |
| 854 | const struct cred *old; |
| 855 | struct cred *new; |
| 856 | int retval; |
| 857 | kuid_t kruid, keuid, ksuid; |
| 858 | |
| 859 | kruid = make_kuid(ns, ruid); |
| 860 | keuid = make_kuid(ns, euid); |
| 861 | ksuid = make_kuid(ns, suid); |
| 862 | |
| 863 | if ((ruid != (uid_t) -1) && !uid_valid(kruid)) |
| 864 | return -EINVAL; |
| 865 | |
| 866 | if ((euid != (uid_t) -1) && !uid_valid(keuid)) |
| 867 | return -EINVAL; |
| 868 | |
| 869 | if ((suid != (uid_t) -1) && !uid_valid(ksuid)) |
| 870 | return -EINVAL; |
| 871 | |
| 872 | new = prepare_creds(); |
| 873 | if (!new) |
| 874 | return -ENOMEM; |
| 875 | |
| 876 | old = current_cred(); |
| 877 | |
| 878 | retval = -EPERM; |
| 879 | if (!nsown_capable(CAP_SETUID)) { |
| 880 | if (ruid != (uid_t) -1 && !uid_eq(kruid, old->uid) && |
| 881 | !uid_eq(kruid, old->euid) && !uid_eq(kruid, old->suid)) |
| 882 | goto error; |
| 883 | if (euid != (uid_t) -1 && !uid_eq(keuid, old->uid) && |
| 884 | !uid_eq(keuid, old->euid) && !uid_eq(keuid, old->suid)) |
| 885 | goto error; |
| 886 | if (suid != (uid_t) -1 && !uid_eq(ksuid, old->uid) && |
| 887 | !uid_eq(ksuid, old->euid) && !uid_eq(ksuid, old->suid)) |
| 888 | goto error; |
| 889 | } |
| 890 | |
| 891 | if (ruid != (uid_t) -1) { |
| 892 | new->uid = kruid; |
| 893 | if (!uid_eq(kruid, old->uid)) { |
| 894 | retval = set_user(new); |
| 895 | if (retval < 0) |
| 896 | goto error; |
| 897 | } |
| 898 | } |
| 899 | if (euid != (uid_t) -1) |
| 900 | new->euid = keuid; |
| 901 | if (suid != (uid_t) -1) |
| 902 | new->suid = ksuid; |
| 903 | new->fsuid = new->euid; |
| 904 | |
| 905 | retval = security_task_fix_setuid(new, old, LSM_SETID_RES); |
| 906 | if (retval < 0) |
| 907 | goto error; |
| 908 | |
| 909 | return commit_creds(new); |
| 910 | |
| 911 | error: |
| 912 | abort_creds(new); |
| 913 | return retval; |
| 914 | } |
| 915 | |
| 916 | SYSCALL_DEFINE3(getresuid, uid_t __user *, ruidp, uid_t __user *, euidp, uid_t __user *, suidp) |
| 917 | { |
| 918 | const struct cred *cred = current_cred(); |
| 919 | int retval; |
| 920 | uid_t ruid, euid, suid; |
| 921 | |
| 922 | ruid = from_kuid_munged(cred->user_ns, cred->uid); |
| 923 | euid = from_kuid_munged(cred->user_ns, cred->euid); |
| 924 | suid = from_kuid_munged(cred->user_ns, cred->suid); |
| 925 | |
| 926 | if (!(retval = put_user(ruid, ruidp)) && |
| 927 | !(retval = put_user(euid, euidp))) |
| 928 | retval = put_user(suid, suidp); |
| 929 | |
| 930 | return retval; |
| 931 | } |
| 932 | |
| 933 | /* |
| 934 | * Same as above, but for rgid, egid, sgid. |
| 935 | */ |
| 936 | SYSCALL_DEFINE3(setresgid, gid_t, rgid, gid_t, egid, gid_t, sgid) |
| 937 | { |
| 938 | struct user_namespace *ns = current_user_ns(); |
| 939 | const struct cred *old; |
| 940 | struct cred *new; |
| 941 | int retval; |
| 942 | kgid_t krgid, kegid, ksgid; |
| 943 | |
| 944 | krgid = make_kgid(ns, rgid); |
| 945 | kegid = make_kgid(ns, egid); |
| 946 | ksgid = make_kgid(ns, sgid); |
| 947 | |
| 948 | if ((rgid != (gid_t) -1) && !gid_valid(krgid)) |
| 949 | return -EINVAL; |
| 950 | if ((egid != (gid_t) -1) && !gid_valid(kegid)) |
| 951 | return -EINVAL; |
| 952 | if ((sgid != (gid_t) -1) && !gid_valid(ksgid)) |
| 953 | return -EINVAL; |
| 954 | |
| 955 | new = prepare_creds(); |
| 956 | if (!new) |
| 957 | return -ENOMEM; |
| 958 | old = current_cred(); |
| 959 | |
| 960 | retval = -EPERM; |
| 961 | if (!nsown_capable(CAP_SETGID)) { |
| 962 | if (rgid != (gid_t) -1 && !gid_eq(krgid, old->gid) && |
| 963 | !gid_eq(krgid, old->egid) && !gid_eq(krgid, old->sgid)) |
| 964 | goto error; |
| 965 | if (egid != (gid_t) -1 && !gid_eq(kegid, old->gid) && |
| 966 | !gid_eq(kegid, old->egid) && !gid_eq(kegid, old->sgid)) |
| 967 | goto error; |
| 968 | if (sgid != (gid_t) -1 && !gid_eq(ksgid, old->gid) && |
| 969 | !gid_eq(ksgid, old->egid) && !gid_eq(ksgid, old->sgid)) |
| 970 | goto error; |
| 971 | } |
| 972 | |
| 973 | if (rgid != (gid_t) -1) |
| 974 | new->gid = krgid; |
| 975 | if (egid != (gid_t) -1) |
| 976 | new->egid = kegid; |
| 977 | if (sgid != (gid_t) -1) |
| 978 | new->sgid = ksgid; |
| 979 | new->fsgid = new->egid; |
| 980 | |
| 981 | return commit_creds(new); |
| 982 | |
| 983 | error: |
| 984 | abort_creds(new); |
| 985 | return retval; |
| 986 | } |
| 987 | |
| 988 | SYSCALL_DEFINE3(getresgid, gid_t __user *, rgidp, gid_t __user *, egidp, gid_t __user *, sgidp) |
| 989 | { |
| 990 | const struct cred *cred = current_cred(); |
| 991 | int retval; |
| 992 | gid_t rgid, egid, sgid; |
| 993 | |
| 994 | rgid = from_kgid_munged(cred->user_ns, cred->gid); |
| 995 | egid = from_kgid_munged(cred->user_ns, cred->egid); |
| 996 | sgid = from_kgid_munged(cred->user_ns, cred->sgid); |
| 997 | |
| 998 | if (!(retval = put_user(rgid, rgidp)) && |
| 999 | !(retval = put_user(egid, egidp))) |
| 1000 | retval = put_user(sgid, sgidp); |
| 1001 | |
| 1002 | return retval; |
| 1003 | } |
| 1004 | |
| 1005 | |
| 1006 | /* |
| 1007 | * "setfsuid()" sets the fsuid - the uid used for filesystem checks. This |
| 1008 | * is used for "access()" and for the NFS daemon (letting nfsd stay at |
| 1009 | * whatever uid it wants to). It normally shadows "euid", except when |
| 1010 | * explicitly set by setfsuid() or for access.. |
| 1011 | */ |
| 1012 | SYSCALL_DEFINE1(setfsuid, uid_t, uid) |
| 1013 | { |
| 1014 | const struct cred *old; |
| 1015 | struct cred *new; |
| 1016 | uid_t old_fsuid; |
| 1017 | kuid_t kuid; |
| 1018 | |
| 1019 | old = current_cred(); |
| 1020 | old_fsuid = from_kuid_munged(old->user_ns, old->fsuid); |
| 1021 | |
| 1022 | kuid = make_kuid(old->user_ns, uid); |
| 1023 | if (!uid_valid(kuid)) |
| 1024 | return old_fsuid; |
| 1025 | |
| 1026 | new = prepare_creds(); |
| 1027 | if (!new) |
| 1028 | return old_fsuid; |
| 1029 | |
| 1030 | if (uid_eq(kuid, old->uid) || uid_eq(kuid, old->euid) || |
| 1031 | uid_eq(kuid, old->suid) || uid_eq(kuid, old->fsuid) || |
| 1032 | nsown_capable(CAP_SETUID)) { |
| 1033 | if (!uid_eq(kuid, old->fsuid)) { |
| 1034 | new->fsuid = kuid; |
| 1035 | if (security_task_fix_setuid(new, old, LSM_SETID_FS) == 0) |
| 1036 | goto change_okay; |
| 1037 | } |
| 1038 | } |
| 1039 | |
| 1040 | abort_creds(new); |
| 1041 | return old_fsuid; |
| 1042 | |
| 1043 | change_okay: |
| 1044 | commit_creds(new); |
| 1045 | return old_fsuid; |
| 1046 | } |
| 1047 | |
| 1048 | /* |
| 1049 | * Samma pa svenska.. |
| 1050 | */ |
| 1051 | SYSCALL_DEFINE1(setfsgid, gid_t, gid) |
| 1052 | { |
| 1053 | const struct cred *old; |
| 1054 | struct cred *new; |
| 1055 | gid_t old_fsgid; |
| 1056 | kgid_t kgid; |
| 1057 | |
| 1058 | old = current_cred(); |
| 1059 | old_fsgid = from_kgid_munged(old->user_ns, old->fsgid); |
| 1060 | |
| 1061 | kgid = make_kgid(old->user_ns, gid); |
| 1062 | if (!gid_valid(kgid)) |
| 1063 | return old_fsgid; |
| 1064 | |
| 1065 | new = prepare_creds(); |
| 1066 | if (!new) |
| 1067 | return old_fsgid; |
| 1068 | |
| 1069 | if (gid_eq(kgid, old->gid) || gid_eq(kgid, old->egid) || |
| 1070 | gid_eq(kgid, old->sgid) || gid_eq(kgid, old->fsgid) || |
| 1071 | nsown_capable(CAP_SETGID)) { |
| 1072 | if (!gid_eq(kgid, old->fsgid)) { |
| 1073 | new->fsgid = kgid; |
| 1074 | goto change_okay; |
| 1075 | } |
| 1076 | } |
| 1077 | |
| 1078 | abort_creds(new); |
| 1079 | return old_fsgid; |
| 1080 | |
| 1081 | change_okay: |
| 1082 | commit_creds(new); |
| 1083 | return old_fsgid; |
| 1084 | } |
| 1085 | |
| 1086 | /** |
| 1087 | * sys_getpid - return the thread group id of the current process |
| 1088 | * |
| 1089 | * Note, despite the name, this returns the tgid not the pid. The tgid and |
| 1090 | * the pid are identical unless CLONE_THREAD was specified on clone() in |
| 1091 | * which case the tgid is the same in all threads of the same group. |
| 1092 | * |
| 1093 | * This is SMP safe as current->tgid does not change. |
| 1094 | */ |
| 1095 | SYSCALL_DEFINE0(getpid) |
| 1096 | { |
| 1097 | return task_tgid_vnr(current); |
| 1098 | } |
| 1099 | |
| 1100 | /* Thread ID - the internal kernel "pid" */ |
| 1101 | SYSCALL_DEFINE0(gettid) |
| 1102 | { |
| 1103 | return task_pid_vnr(current); |
| 1104 | } |
| 1105 | |
| 1106 | /* |
| 1107 | * Accessing ->real_parent is not SMP-safe, it could |
| 1108 | * change from under us. However, we can use a stale |
| 1109 | * value of ->real_parent under rcu_read_lock(), see |
| 1110 | * release_task()->call_rcu(delayed_put_task_struct). |
| 1111 | */ |
| 1112 | SYSCALL_DEFINE0(getppid) |
| 1113 | { |
| 1114 | int pid; |
| 1115 | |
| 1116 | rcu_read_lock(); |
| 1117 | pid = task_tgid_vnr(rcu_dereference(current->real_parent)); |
| 1118 | rcu_read_unlock(); |
| 1119 | |
| 1120 | return pid; |
| 1121 | } |
| 1122 | |
| 1123 | SYSCALL_DEFINE0(getuid) |
| 1124 | { |
| 1125 | /* Only we change this so SMP safe */ |
| 1126 | return from_kuid_munged(current_user_ns(), current_uid()); |
| 1127 | } |
| 1128 | |
| 1129 | SYSCALL_DEFINE0(geteuid) |
| 1130 | { |
| 1131 | /* Only we change this so SMP safe */ |
| 1132 | return from_kuid_munged(current_user_ns(), current_euid()); |
| 1133 | } |
| 1134 | |
| 1135 | SYSCALL_DEFINE0(getgid) |
| 1136 | { |
| 1137 | /* Only we change this so SMP safe */ |
| 1138 | return from_kgid_munged(current_user_ns(), current_gid()); |
| 1139 | } |
| 1140 | |
| 1141 | SYSCALL_DEFINE0(getegid) |
| 1142 | { |
| 1143 | /* Only we change this so SMP safe */ |
| 1144 | return from_kgid_munged(current_user_ns(), current_egid()); |
| 1145 | } |
| 1146 | |
| 1147 | void do_sys_times(struct tms *tms) |
| 1148 | { |
| 1149 | cputime_t tgutime, tgstime, cutime, cstime; |
| 1150 | |
| 1151 | spin_lock_irq(¤t->sighand->siglock); |
| 1152 | thread_group_cputime_adjusted(current, &tgutime, &tgstime); |
| 1153 | cutime = current->signal->cutime; |
| 1154 | cstime = current->signal->cstime; |
| 1155 | spin_unlock_irq(¤t->sighand->siglock); |
| 1156 | tms->tms_utime = cputime_to_clock_t(tgutime); |
| 1157 | tms->tms_stime = cputime_to_clock_t(tgstime); |
| 1158 | tms->tms_cutime = cputime_to_clock_t(cutime); |
| 1159 | tms->tms_cstime = cputime_to_clock_t(cstime); |
| 1160 | } |
| 1161 | |
| 1162 | SYSCALL_DEFINE1(times, struct tms __user *, tbuf) |
| 1163 | { |
| 1164 | if (tbuf) { |
| 1165 | struct tms tmp; |
| 1166 | |
| 1167 | do_sys_times(&tmp); |
| 1168 | if (copy_to_user(tbuf, &tmp, sizeof(struct tms))) |
| 1169 | return -EFAULT; |
| 1170 | } |
| 1171 | force_successful_syscall_return(); |
| 1172 | return (long) jiffies_64_to_clock_t(get_jiffies_64()); |
| 1173 | } |
| 1174 | |
| 1175 | /* |
| 1176 | * This needs some heavy checking ... |
| 1177 | * I just haven't the stomach for it. I also don't fully |
| 1178 | * understand sessions/pgrp etc. Let somebody who does explain it. |
| 1179 | * |
| 1180 | * OK, I think I have the protection semantics right.... this is really |
| 1181 | * only important on a multi-user system anyway, to make sure one user |
| 1182 | * can't send a signal to a process owned by another. -TYT, 12/12/91 |
| 1183 | * |
| 1184 | * Auch. Had to add the 'did_exec' flag to conform completely to POSIX. |
| 1185 | * LBT 04.03.94 |
| 1186 | */ |
| 1187 | SYSCALL_DEFINE2(setpgid, pid_t, pid, pid_t, pgid) |
| 1188 | { |
| 1189 | struct task_struct *p; |
| 1190 | struct task_struct *group_leader = current->group_leader; |
| 1191 | struct pid *pgrp; |
| 1192 | int err; |
| 1193 | |
| 1194 | if (!pid) |
| 1195 | pid = task_pid_vnr(group_leader); |
| 1196 | if (!pgid) |
| 1197 | pgid = pid; |
| 1198 | if (pgid < 0) |
| 1199 | return -EINVAL; |
| 1200 | rcu_read_lock(); |
| 1201 | |
| 1202 | /* From this point forward we keep holding onto the tasklist lock |
| 1203 | * so that our parent does not change from under us. -DaveM |
| 1204 | */ |
| 1205 | write_lock_irq(&tasklist_lock); |
| 1206 | |
| 1207 | err = -ESRCH; |
| 1208 | p = find_task_by_vpid(pid); |
| 1209 | if (!p) |
| 1210 | goto out; |
| 1211 | |
| 1212 | err = -EINVAL; |
| 1213 | if (!thread_group_leader(p)) |
| 1214 | goto out; |
| 1215 | |
| 1216 | if (same_thread_group(p->real_parent, group_leader)) { |
| 1217 | err = -EPERM; |
| 1218 | if (task_session(p) != task_session(group_leader)) |
| 1219 | goto out; |
| 1220 | err = -EACCES; |
| 1221 | if (p->did_exec) |
| 1222 | goto out; |
| 1223 | } else { |
| 1224 | err = -ESRCH; |
| 1225 | if (p != group_leader) |
| 1226 | goto out; |
| 1227 | } |
| 1228 | |
| 1229 | err = -EPERM; |
| 1230 | if (p->signal->leader) |
| 1231 | goto out; |
| 1232 | |
| 1233 | pgrp = task_pid(p); |
| 1234 | if (pgid != pid) { |
| 1235 | struct task_struct *g; |
| 1236 | |
| 1237 | pgrp = find_vpid(pgid); |
| 1238 | g = pid_task(pgrp, PIDTYPE_PGID); |
| 1239 | if (!g || task_session(g) != task_session(group_leader)) |
| 1240 | goto out; |
| 1241 | } |
| 1242 | |
| 1243 | err = security_task_setpgid(p, pgid); |
| 1244 | if (err) |
| 1245 | goto out; |
| 1246 | |
| 1247 | if (task_pgrp(p) != pgrp) |
| 1248 | change_pid(p, PIDTYPE_PGID, pgrp); |
| 1249 | |
| 1250 | err = 0; |
| 1251 | out: |
| 1252 | /* All paths lead to here, thus we are safe. -DaveM */ |
| 1253 | write_unlock_irq(&tasklist_lock); |
| 1254 | rcu_read_unlock(); |
| 1255 | return err; |
| 1256 | } |
| 1257 | |
| 1258 | SYSCALL_DEFINE1(getpgid, pid_t, pid) |
| 1259 | { |
| 1260 | struct task_struct *p; |
| 1261 | struct pid *grp; |
| 1262 | int retval; |
| 1263 | |
| 1264 | rcu_read_lock(); |
| 1265 | if (!pid) |
| 1266 | grp = task_pgrp(current); |
| 1267 | else { |
| 1268 | retval = -ESRCH; |
| 1269 | p = find_task_by_vpid(pid); |
| 1270 | if (!p) |
| 1271 | goto out; |
| 1272 | grp = task_pgrp(p); |
| 1273 | if (!grp) |
| 1274 | goto out; |
| 1275 | |
| 1276 | retval = security_task_getpgid(p); |
| 1277 | if (retval) |
| 1278 | goto out; |
| 1279 | } |
| 1280 | retval = pid_vnr(grp); |
| 1281 | out: |
| 1282 | rcu_read_unlock(); |
| 1283 | return retval; |
| 1284 | } |
| 1285 | |
| 1286 | #ifdef __ARCH_WANT_SYS_GETPGRP |
| 1287 | |
| 1288 | SYSCALL_DEFINE0(getpgrp) |
| 1289 | { |
| 1290 | return sys_getpgid(0); |
| 1291 | } |
| 1292 | |
| 1293 | #endif |
| 1294 | |
| 1295 | SYSCALL_DEFINE1(getsid, pid_t, pid) |
| 1296 | { |
| 1297 | struct task_struct *p; |
| 1298 | struct pid *sid; |
| 1299 | int retval; |
| 1300 | |
| 1301 | rcu_read_lock(); |
| 1302 | if (!pid) |
| 1303 | sid = task_session(current); |
| 1304 | else { |
| 1305 | retval = -ESRCH; |
| 1306 | p = find_task_by_vpid(pid); |
| 1307 | if (!p) |
| 1308 | goto out; |
| 1309 | sid = task_session(p); |
| 1310 | if (!sid) |
| 1311 | goto out; |
| 1312 | |
| 1313 | retval = security_task_getsid(p); |
| 1314 | if (retval) |
| 1315 | goto out; |
| 1316 | } |
| 1317 | retval = pid_vnr(sid); |
| 1318 | out: |
| 1319 | rcu_read_unlock(); |
| 1320 | return retval; |
| 1321 | } |
| 1322 | |
| 1323 | SYSCALL_DEFINE0(setsid) |
| 1324 | { |
| 1325 | struct task_struct *group_leader = current->group_leader; |
| 1326 | struct pid *sid = task_pid(group_leader); |
| 1327 | pid_t session = pid_vnr(sid); |
| 1328 | int err = -EPERM; |
| 1329 | |
| 1330 | write_lock_irq(&tasklist_lock); |
| 1331 | /* Fail if I am already a session leader */ |
| 1332 | if (group_leader->signal->leader) |
| 1333 | goto out; |
| 1334 | |
| 1335 | /* Fail if a process group id already exists that equals the |
| 1336 | * proposed session id. |
| 1337 | */ |
| 1338 | if (pid_task(sid, PIDTYPE_PGID)) |
| 1339 | goto out; |
| 1340 | |
| 1341 | group_leader->signal->leader = 1; |
| 1342 | __set_special_pids(sid); |
| 1343 | |
| 1344 | proc_clear_tty(group_leader); |
| 1345 | |
| 1346 | err = session; |
| 1347 | out: |
| 1348 | write_unlock_irq(&tasklist_lock); |
| 1349 | if (err > 0) { |
| 1350 | proc_sid_connector(group_leader); |
| 1351 | sched_autogroup_create_attach(group_leader); |
| 1352 | } |
| 1353 | return err; |
| 1354 | } |
| 1355 | |
| 1356 | DECLARE_RWSEM(uts_sem); |
| 1357 | |
| 1358 | #ifdef COMPAT_UTS_MACHINE |
| 1359 | #define override_architecture(name) \ |
| 1360 | (personality(current->personality) == PER_LINUX32 && \ |
| 1361 | copy_to_user(name->machine, COMPAT_UTS_MACHINE, \ |
| 1362 | sizeof(COMPAT_UTS_MACHINE))) |
| 1363 | #else |
| 1364 | #define override_architecture(name) 0 |
| 1365 | #endif |
| 1366 | |
| 1367 | /* |
| 1368 | * Work around broken programs that cannot handle "Linux 3.0". |
| 1369 | * Instead we map 3.x to 2.6.40+x, so e.g. 3.0 would be 2.6.40 |
| 1370 | */ |
| 1371 | static int override_release(char __user *release, size_t len) |
| 1372 | { |
| 1373 | int ret = 0; |
| 1374 | |
| 1375 | if (current->personality & UNAME26) { |
| 1376 | const char *rest = UTS_RELEASE; |
| 1377 | char buf[65] = { 0 }; |
| 1378 | int ndots = 0; |
| 1379 | unsigned v; |
| 1380 | size_t copy; |
| 1381 | |
| 1382 | while (*rest) { |
| 1383 | if (*rest == '.' && ++ndots >= 3) |
| 1384 | break; |
| 1385 | if (!isdigit(*rest) && *rest != '.') |
| 1386 | break; |
| 1387 | rest++; |
| 1388 | } |
| 1389 | v = ((LINUX_VERSION_CODE >> 8) & 0xff) + 40; |
| 1390 | copy = clamp_t(size_t, len, 1, sizeof(buf)); |
| 1391 | copy = scnprintf(buf, copy, "2.6.%u%s", v, rest); |
| 1392 | ret = copy_to_user(release, buf, copy + 1); |
| 1393 | } |
| 1394 | return ret; |
| 1395 | } |
| 1396 | |
| 1397 | SYSCALL_DEFINE1(newuname, struct new_utsname __user *, name) |
| 1398 | { |
| 1399 | int errno = 0; |
| 1400 | |
| 1401 | down_read(&uts_sem); |
| 1402 | if (copy_to_user(name, utsname(), sizeof *name)) |
| 1403 | errno = -EFAULT; |
| 1404 | up_read(&uts_sem); |
| 1405 | |
| 1406 | if (!errno && override_release(name->release, sizeof(name->release))) |
| 1407 | errno = -EFAULT; |
| 1408 | if (!errno && override_architecture(name)) |
| 1409 | errno = -EFAULT; |
| 1410 | return errno; |
| 1411 | } |
| 1412 | |
| 1413 | #ifdef __ARCH_WANT_SYS_OLD_UNAME |
| 1414 | /* |
| 1415 | * Old cruft |
| 1416 | */ |
| 1417 | SYSCALL_DEFINE1(uname, struct old_utsname __user *, name) |
| 1418 | { |
| 1419 | int error = 0; |
| 1420 | |
| 1421 | if (!name) |
| 1422 | return -EFAULT; |
| 1423 | |
| 1424 | down_read(&uts_sem); |
| 1425 | if (copy_to_user(name, utsname(), sizeof(*name))) |
| 1426 | error = -EFAULT; |
| 1427 | up_read(&uts_sem); |
| 1428 | |
| 1429 | if (!error && override_release(name->release, sizeof(name->release))) |
| 1430 | error = -EFAULT; |
| 1431 | if (!error && override_architecture(name)) |
| 1432 | error = -EFAULT; |
| 1433 | return error; |
| 1434 | } |
| 1435 | |
| 1436 | SYSCALL_DEFINE1(olduname, struct oldold_utsname __user *, name) |
| 1437 | { |
| 1438 | int error; |
| 1439 | |
| 1440 | if (!name) |
| 1441 | return -EFAULT; |
| 1442 | if (!access_ok(VERIFY_WRITE, name, sizeof(struct oldold_utsname))) |
| 1443 | return -EFAULT; |
| 1444 | |
| 1445 | down_read(&uts_sem); |
| 1446 | error = __copy_to_user(&name->sysname, &utsname()->sysname, |
| 1447 | __OLD_UTS_LEN); |
| 1448 | error |= __put_user(0, name->sysname + __OLD_UTS_LEN); |
| 1449 | error |= __copy_to_user(&name->nodename, &utsname()->nodename, |
| 1450 | __OLD_UTS_LEN); |
| 1451 | error |= __put_user(0, name->nodename + __OLD_UTS_LEN); |
| 1452 | error |= __copy_to_user(&name->release, &utsname()->release, |
| 1453 | __OLD_UTS_LEN); |
| 1454 | error |= __put_user(0, name->release + __OLD_UTS_LEN); |
| 1455 | error |= __copy_to_user(&name->version, &utsname()->version, |
| 1456 | __OLD_UTS_LEN); |
| 1457 | error |= __put_user(0, name->version + __OLD_UTS_LEN); |
| 1458 | error |= __copy_to_user(&name->machine, &utsname()->machine, |
| 1459 | __OLD_UTS_LEN); |
| 1460 | error |= __put_user(0, name->machine + __OLD_UTS_LEN); |
| 1461 | up_read(&uts_sem); |
| 1462 | |
| 1463 | if (!error && override_architecture(name)) |
| 1464 | error = -EFAULT; |
| 1465 | if (!error && override_release(name->release, sizeof(name->release))) |
| 1466 | error = -EFAULT; |
| 1467 | return error ? -EFAULT : 0; |
| 1468 | } |
| 1469 | #endif |
| 1470 | |
| 1471 | SYSCALL_DEFINE2(sethostname, char __user *, name, int, len) |
| 1472 | { |
| 1473 | int errno; |
| 1474 | char tmp[__NEW_UTS_LEN]; |
| 1475 | |
| 1476 | if (!ns_capable(current->nsproxy->uts_ns->user_ns, CAP_SYS_ADMIN)) |
| 1477 | return -EPERM; |
| 1478 | |
| 1479 | if (len < 0 || len > __NEW_UTS_LEN) |
| 1480 | return -EINVAL; |
| 1481 | down_write(&uts_sem); |
| 1482 | errno = -EFAULT; |
| 1483 | if (!copy_from_user(tmp, name, len)) { |
| 1484 | struct new_utsname *u = utsname(); |
| 1485 | |
| 1486 | memcpy(u->nodename, tmp, len); |
| 1487 | memset(u->nodename + len, 0, sizeof(u->nodename) - len); |
| 1488 | errno = 0; |
| 1489 | uts_proc_notify(UTS_PROC_HOSTNAME); |
| 1490 | } |
| 1491 | up_write(&uts_sem); |
| 1492 | return errno; |
| 1493 | } |
| 1494 | |
| 1495 | #ifdef __ARCH_WANT_SYS_GETHOSTNAME |
| 1496 | |
| 1497 | SYSCALL_DEFINE2(gethostname, char __user *, name, int, len) |
| 1498 | { |
| 1499 | int i, errno; |
| 1500 | struct new_utsname *u; |
| 1501 | |
| 1502 | if (len < 0) |
| 1503 | return -EINVAL; |
| 1504 | down_read(&uts_sem); |
| 1505 | u = utsname(); |
| 1506 | i = 1 + strlen(u->nodename); |
| 1507 | if (i > len) |
| 1508 | i = len; |
| 1509 | errno = 0; |
| 1510 | if (copy_to_user(name, u->nodename, i)) |
| 1511 | errno = -EFAULT; |
| 1512 | up_read(&uts_sem); |
| 1513 | return errno; |
| 1514 | } |
| 1515 | |
| 1516 | #endif |
| 1517 | |
| 1518 | /* |
| 1519 | * Only setdomainname; getdomainname can be implemented by calling |
| 1520 | * uname() |
| 1521 | */ |
| 1522 | SYSCALL_DEFINE2(setdomainname, char __user *, name, int, len) |
| 1523 | { |
| 1524 | int errno; |
| 1525 | char tmp[__NEW_UTS_LEN]; |
| 1526 | |
| 1527 | if (!ns_capable(current->nsproxy->uts_ns->user_ns, CAP_SYS_ADMIN)) |
| 1528 | return -EPERM; |
| 1529 | if (len < 0 || len > __NEW_UTS_LEN) |
| 1530 | return -EINVAL; |
| 1531 | |
| 1532 | down_write(&uts_sem); |
| 1533 | errno = -EFAULT; |
| 1534 | if (!copy_from_user(tmp, name, len)) { |
| 1535 | struct new_utsname *u = utsname(); |
| 1536 | |
| 1537 | memcpy(u->domainname, tmp, len); |
| 1538 | memset(u->domainname + len, 0, sizeof(u->domainname) - len); |
| 1539 | errno = 0; |
| 1540 | uts_proc_notify(UTS_PROC_DOMAINNAME); |
| 1541 | } |
| 1542 | up_write(&uts_sem); |
| 1543 | return errno; |
| 1544 | } |
| 1545 | |
| 1546 | SYSCALL_DEFINE2(getrlimit, unsigned int, resource, struct rlimit __user *, rlim) |
| 1547 | { |
| 1548 | struct rlimit value; |
| 1549 | int ret; |
| 1550 | |
| 1551 | ret = do_prlimit(current, resource, NULL, &value); |
| 1552 | if (!ret) |
| 1553 | ret = copy_to_user(rlim, &value, sizeof(*rlim)) ? -EFAULT : 0; |
| 1554 | |
| 1555 | return ret; |
| 1556 | } |
| 1557 | |
| 1558 | #ifdef __ARCH_WANT_SYS_OLD_GETRLIMIT |
| 1559 | |
| 1560 | /* |
| 1561 | * Back compatibility for getrlimit. Needed for some apps. |
| 1562 | */ |
| 1563 | |
| 1564 | SYSCALL_DEFINE2(old_getrlimit, unsigned int, resource, |
| 1565 | struct rlimit __user *, rlim) |
| 1566 | { |
| 1567 | struct rlimit x; |
| 1568 | if (resource >= RLIM_NLIMITS) |
| 1569 | return -EINVAL; |
| 1570 | |
| 1571 | task_lock(current->group_leader); |
| 1572 | x = current->signal->rlim[resource]; |
| 1573 | task_unlock(current->group_leader); |
| 1574 | if (x.rlim_cur > 0x7FFFFFFF) |
| 1575 | x.rlim_cur = 0x7FFFFFFF; |
| 1576 | if (x.rlim_max > 0x7FFFFFFF) |
| 1577 | x.rlim_max = 0x7FFFFFFF; |
| 1578 | return copy_to_user(rlim, &x, sizeof(x))?-EFAULT:0; |
| 1579 | } |
| 1580 | |
| 1581 | #endif |
| 1582 | |
| 1583 | static inline bool rlim64_is_infinity(__u64 rlim64) |
| 1584 | { |
| 1585 | #if BITS_PER_LONG < 64 |
| 1586 | return rlim64 >= ULONG_MAX; |
| 1587 | #else |
| 1588 | return rlim64 == RLIM64_INFINITY; |
| 1589 | #endif |
| 1590 | } |
| 1591 | |
| 1592 | static void rlim_to_rlim64(const struct rlimit *rlim, struct rlimit64 *rlim64) |
| 1593 | { |
| 1594 | if (rlim->rlim_cur == RLIM_INFINITY) |
| 1595 | rlim64->rlim_cur = RLIM64_INFINITY; |
| 1596 | else |
| 1597 | rlim64->rlim_cur = rlim->rlim_cur; |
| 1598 | if (rlim->rlim_max == RLIM_INFINITY) |
| 1599 | rlim64->rlim_max = RLIM64_INFINITY; |
| 1600 | else |
| 1601 | rlim64->rlim_max = rlim->rlim_max; |
| 1602 | } |
| 1603 | |
| 1604 | static void rlim64_to_rlim(const struct rlimit64 *rlim64, struct rlimit *rlim) |
| 1605 | { |
| 1606 | if (rlim64_is_infinity(rlim64->rlim_cur)) |
| 1607 | rlim->rlim_cur = RLIM_INFINITY; |
| 1608 | else |
| 1609 | rlim->rlim_cur = (unsigned long)rlim64->rlim_cur; |
| 1610 | if (rlim64_is_infinity(rlim64->rlim_max)) |
| 1611 | rlim->rlim_max = RLIM_INFINITY; |
| 1612 | else |
| 1613 | rlim->rlim_max = (unsigned long)rlim64->rlim_max; |
| 1614 | } |
| 1615 | |
| 1616 | /* make sure you are allowed to change @tsk limits before calling this */ |
| 1617 | int do_prlimit(struct task_struct *tsk, unsigned int resource, |
| 1618 | struct rlimit *new_rlim, struct rlimit *old_rlim) |
| 1619 | { |
| 1620 | struct rlimit *rlim; |
| 1621 | int retval = 0; |
| 1622 | |
| 1623 | if (resource >= RLIM_NLIMITS) |
| 1624 | return -EINVAL; |
| 1625 | if (new_rlim) { |
| 1626 | if (new_rlim->rlim_cur > new_rlim->rlim_max) |
| 1627 | return -EINVAL; |
| 1628 | if (resource == RLIMIT_NOFILE && |
| 1629 | new_rlim->rlim_max > sysctl_nr_open) |
| 1630 | return -EPERM; |
| 1631 | } |
| 1632 | |
| 1633 | /* protect tsk->signal and tsk->sighand from disappearing */ |
| 1634 | read_lock(&tasklist_lock); |
| 1635 | if (!tsk->sighand) { |
| 1636 | retval = -ESRCH; |
| 1637 | goto out; |
| 1638 | } |
| 1639 | |
| 1640 | rlim = tsk->signal->rlim + resource; |
| 1641 | task_lock(tsk->group_leader); |
| 1642 | if (new_rlim) { |
| 1643 | /* Keep the capable check against init_user_ns until |
| 1644 | cgroups can contain all limits */ |
| 1645 | if (new_rlim->rlim_max > rlim->rlim_max && |
| 1646 | !capable(CAP_SYS_RESOURCE)) |
| 1647 | retval = -EPERM; |
| 1648 | if (!retval) |
| 1649 | retval = security_task_setrlimit(tsk->group_leader, |
| 1650 | resource, new_rlim); |
| 1651 | if (resource == RLIMIT_CPU && new_rlim->rlim_cur == 0) { |
| 1652 | /* |
| 1653 | * The caller is asking for an immediate RLIMIT_CPU |
| 1654 | * expiry. But we use the zero value to mean "it was |
| 1655 | * never set". So let's cheat and make it one second |
| 1656 | * instead |
| 1657 | */ |
| 1658 | new_rlim->rlim_cur = 1; |
| 1659 | } |
| 1660 | } |
| 1661 | if (!retval) { |
| 1662 | if (old_rlim) |
| 1663 | *old_rlim = *rlim; |
| 1664 | if (new_rlim) |
| 1665 | *rlim = *new_rlim; |
| 1666 | } |
| 1667 | task_unlock(tsk->group_leader); |
| 1668 | |
| 1669 | /* |
| 1670 | * RLIMIT_CPU handling. Note that the kernel fails to return an error |
| 1671 | * code if it rejected the user's attempt to set RLIMIT_CPU. This is a |
| 1672 | * very long-standing error, and fixing it now risks breakage of |
| 1673 | * applications, so we live with it |
| 1674 | */ |
| 1675 | if (!retval && new_rlim && resource == RLIMIT_CPU && |
| 1676 | new_rlim->rlim_cur != RLIM_INFINITY) |
| 1677 | update_rlimit_cpu(tsk, new_rlim->rlim_cur); |
| 1678 | out: |
| 1679 | read_unlock(&tasklist_lock); |
| 1680 | return retval; |
| 1681 | } |
| 1682 | |
| 1683 | /* rcu lock must be held */ |
| 1684 | static int check_prlimit_permission(struct task_struct *task) |
| 1685 | { |
| 1686 | const struct cred *cred = current_cred(), *tcred; |
| 1687 | |
| 1688 | if (current == task) |
| 1689 | return 0; |
| 1690 | |
| 1691 | tcred = __task_cred(task); |
| 1692 | if (uid_eq(cred->uid, tcred->euid) && |
| 1693 | uid_eq(cred->uid, tcred->suid) && |
| 1694 | uid_eq(cred->uid, tcred->uid) && |
| 1695 | gid_eq(cred->gid, tcred->egid) && |
| 1696 | gid_eq(cred->gid, tcred->sgid) && |
| 1697 | gid_eq(cred->gid, tcred->gid)) |
| 1698 | return 0; |
| 1699 | if (ns_capable(tcred->user_ns, CAP_SYS_RESOURCE)) |
| 1700 | return 0; |
| 1701 | |
| 1702 | return -EPERM; |
| 1703 | } |
| 1704 | |
| 1705 | SYSCALL_DEFINE4(prlimit64, pid_t, pid, unsigned int, resource, |
| 1706 | const struct rlimit64 __user *, new_rlim, |
| 1707 | struct rlimit64 __user *, old_rlim) |
| 1708 | { |
| 1709 | struct rlimit64 old64, new64; |
| 1710 | struct rlimit old, new; |
| 1711 | struct task_struct *tsk; |
| 1712 | int ret; |
| 1713 | |
| 1714 | if (new_rlim) { |
| 1715 | if (copy_from_user(&new64, new_rlim, sizeof(new64))) |
| 1716 | return -EFAULT; |
| 1717 | rlim64_to_rlim(&new64, &new); |
| 1718 | } |
| 1719 | |
| 1720 | rcu_read_lock(); |
| 1721 | tsk = pid ? find_task_by_vpid(pid) : current; |
| 1722 | if (!tsk) { |
| 1723 | rcu_read_unlock(); |
| 1724 | return -ESRCH; |
| 1725 | } |
| 1726 | ret = check_prlimit_permission(tsk); |
| 1727 | if (ret) { |
| 1728 | rcu_read_unlock(); |
| 1729 | return ret; |
| 1730 | } |
| 1731 | get_task_struct(tsk); |
| 1732 | rcu_read_unlock(); |
| 1733 | |
| 1734 | ret = do_prlimit(tsk, resource, new_rlim ? &new : NULL, |
| 1735 | old_rlim ? &old : NULL); |
| 1736 | |
| 1737 | if (!ret && old_rlim) { |
| 1738 | rlim_to_rlim64(&old, &old64); |
| 1739 | if (copy_to_user(old_rlim, &old64, sizeof(old64))) |
| 1740 | ret = -EFAULT; |
| 1741 | } |
| 1742 | |
| 1743 | put_task_struct(tsk); |
| 1744 | return ret; |
| 1745 | } |
| 1746 | |
| 1747 | SYSCALL_DEFINE2(setrlimit, unsigned int, resource, struct rlimit __user *, rlim) |
| 1748 | { |
| 1749 | struct rlimit new_rlim; |
| 1750 | |
| 1751 | if (copy_from_user(&new_rlim, rlim, sizeof(*rlim))) |
| 1752 | return -EFAULT; |
| 1753 | return do_prlimit(current, resource, &new_rlim, NULL); |
| 1754 | } |
| 1755 | |
| 1756 | /* |
| 1757 | * It would make sense to put struct rusage in the task_struct, |
| 1758 | * except that would make the task_struct be *really big*. After |
| 1759 | * task_struct gets moved into malloc'ed memory, it would |
| 1760 | * make sense to do this. It will make moving the rest of the information |
| 1761 | * a lot simpler! (Which we're not doing right now because we're not |
| 1762 | * measuring them yet). |
| 1763 | * |
| 1764 | * When sampling multiple threads for RUSAGE_SELF, under SMP we might have |
| 1765 | * races with threads incrementing their own counters. But since word |
| 1766 | * reads are atomic, we either get new values or old values and we don't |
| 1767 | * care which for the sums. We always take the siglock to protect reading |
| 1768 | * the c* fields from p->signal from races with exit.c updating those |
| 1769 | * fields when reaping, so a sample either gets all the additions of a |
| 1770 | * given child after it's reaped, or none so this sample is before reaping. |
| 1771 | * |
| 1772 | * Locking: |
| 1773 | * We need to take the siglock for CHILDEREN, SELF and BOTH |
| 1774 | * for the cases current multithreaded, non-current single threaded |
| 1775 | * non-current multithreaded. Thread traversal is now safe with |
| 1776 | * the siglock held. |
| 1777 | * Strictly speaking, we donot need to take the siglock if we are current and |
| 1778 | * single threaded, as no one else can take our signal_struct away, no one |
| 1779 | * else can reap the children to update signal->c* counters, and no one else |
| 1780 | * can race with the signal-> fields. If we do not take any lock, the |
| 1781 | * signal-> fields could be read out of order while another thread was just |
| 1782 | * exiting. So we should place a read memory barrier when we avoid the lock. |
| 1783 | * On the writer side, write memory barrier is implied in __exit_signal |
| 1784 | * as __exit_signal releases the siglock spinlock after updating the signal-> |
| 1785 | * fields. But we don't do this yet to keep things simple. |
| 1786 | * |
| 1787 | */ |
| 1788 | |
| 1789 | static void accumulate_thread_rusage(struct task_struct *t, struct rusage *r) |
| 1790 | { |
| 1791 | r->ru_nvcsw += t->nvcsw; |
| 1792 | r->ru_nivcsw += t->nivcsw; |
| 1793 | r->ru_minflt += t->min_flt; |
| 1794 | r->ru_majflt += t->maj_flt; |
| 1795 | r->ru_inblock += task_io_get_inblock(t); |
| 1796 | r->ru_oublock += task_io_get_oublock(t); |
| 1797 | } |
| 1798 | |
| 1799 | static void k_getrusage(struct task_struct *p, int who, struct rusage *r) |
| 1800 | { |
| 1801 | struct task_struct *t; |
| 1802 | unsigned long flags; |
| 1803 | cputime_t tgutime, tgstime, utime, stime; |
| 1804 | unsigned long maxrss = 0; |
| 1805 | |
| 1806 | memset((char *) r, 0, sizeof *r); |
| 1807 | utime = stime = 0; |
| 1808 | |
| 1809 | if (who == RUSAGE_THREAD) { |
| 1810 | task_cputime_adjusted(current, &utime, &stime); |
| 1811 | accumulate_thread_rusage(p, r); |
| 1812 | maxrss = p->signal->maxrss; |
| 1813 | goto out; |
| 1814 | } |
| 1815 | |
| 1816 | if (!lock_task_sighand(p, &flags)) |
| 1817 | return; |
| 1818 | |
| 1819 | switch (who) { |
| 1820 | case RUSAGE_BOTH: |
| 1821 | case RUSAGE_CHILDREN: |
| 1822 | utime = p->signal->cutime; |
| 1823 | stime = p->signal->cstime; |
| 1824 | r->ru_nvcsw = p->signal->cnvcsw; |
| 1825 | r->ru_nivcsw = p->signal->cnivcsw; |
| 1826 | r->ru_minflt = p->signal->cmin_flt; |
| 1827 | r->ru_majflt = p->signal->cmaj_flt; |
| 1828 | r->ru_inblock = p->signal->cinblock; |
| 1829 | r->ru_oublock = p->signal->coublock; |
| 1830 | maxrss = p->signal->cmaxrss; |
| 1831 | |
| 1832 | if (who == RUSAGE_CHILDREN) |
| 1833 | break; |
| 1834 | |
| 1835 | case RUSAGE_SELF: |
| 1836 | thread_group_cputime_adjusted(p, &tgutime, &tgstime); |
| 1837 | utime += tgutime; |
| 1838 | stime += tgstime; |
| 1839 | r->ru_nvcsw += p->signal->nvcsw; |
| 1840 | r->ru_nivcsw += p->signal->nivcsw; |
| 1841 | r->ru_minflt += p->signal->min_flt; |
| 1842 | r->ru_majflt += p->signal->maj_flt; |
| 1843 | r->ru_inblock += p->signal->inblock; |
| 1844 | r->ru_oublock += p->signal->oublock; |
| 1845 | if (maxrss < p->signal->maxrss) |
| 1846 | maxrss = p->signal->maxrss; |
| 1847 | t = p; |
| 1848 | do { |
| 1849 | accumulate_thread_rusage(t, r); |
| 1850 | t = next_thread(t); |
| 1851 | } while (t != p); |
| 1852 | break; |
| 1853 | |
| 1854 | default: |
| 1855 | BUG(); |
| 1856 | } |
| 1857 | unlock_task_sighand(p, &flags); |
| 1858 | |
| 1859 | out: |
| 1860 | cputime_to_timeval(utime, &r->ru_utime); |
| 1861 | cputime_to_timeval(stime, &r->ru_stime); |
| 1862 | |
| 1863 | if (who != RUSAGE_CHILDREN) { |
| 1864 | struct mm_struct *mm = get_task_mm(p); |
| 1865 | if (mm) { |
| 1866 | setmax_mm_hiwater_rss(&maxrss, mm); |
| 1867 | mmput(mm); |
| 1868 | } |
| 1869 | } |
| 1870 | r->ru_maxrss = maxrss * (PAGE_SIZE / 1024); /* convert pages to KBs */ |
| 1871 | } |
| 1872 | |
| 1873 | int getrusage(struct task_struct *p, int who, struct rusage __user *ru) |
| 1874 | { |
| 1875 | struct rusage r; |
| 1876 | k_getrusage(p, who, &r); |
| 1877 | return copy_to_user(ru, &r, sizeof(r)) ? -EFAULT : 0; |
| 1878 | } |
| 1879 | |
| 1880 | SYSCALL_DEFINE2(getrusage, int, who, struct rusage __user *, ru) |
| 1881 | { |
| 1882 | if (who != RUSAGE_SELF && who != RUSAGE_CHILDREN && |
| 1883 | who != RUSAGE_THREAD) |
| 1884 | return -EINVAL; |
| 1885 | return getrusage(current, who, ru); |
| 1886 | } |
| 1887 | |
| 1888 | #ifdef CONFIG_COMPAT |
| 1889 | COMPAT_SYSCALL_DEFINE2(getrusage, int, who, struct compat_rusage __user *, ru) |
| 1890 | { |
| 1891 | struct rusage r; |
| 1892 | |
| 1893 | if (who != RUSAGE_SELF && who != RUSAGE_CHILDREN && |
| 1894 | who != RUSAGE_THREAD) |
| 1895 | return -EINVAL; |
| 1896 | |
| 1897 | k_getrusage(current, who, &r); |
| 1898 | return put_compat_rusage(&r, ru); |
| 1899 | } |
| 1900 | #endif |
| 1901 | |
| 1902 | SYSCALL_DEFINE1(umask, int, mask) |
| 1903 | { |
| 1904 | mask = xchg(¤t->fs->umask, mask & S_IRWXUGO); |
| 1905 | return mask; |
| 1906 | } |
| 1907 | |
| 1908 | static int prctl_set_mm_exe_file(struct mm_struct *mm, unsigned int fd) |
| 1909 | { |
| 1910 | struct fd exe; |
| 1911 | struct inode *inode; |
| 1912 | int err; |
| 1913 | |
| 1914 | exe = fdget(fd); |
| 1915 | if (!exe.file) |
| 1916 | return -EBADF; |
| 1917 | |
| 1918 | inode = file_inode(exe.file); |
| 1919 | |
| 1920 | /* |
| 1921 | * Because the original mm->exe_file points to executable file, make |
| 1922 | * sure that this one is executable as well, to avoid breaking an |
| 1923 | * overall picture. |
| 1924 | */ |
| 1925 | err = -EACCES; |
| 1926 | if (!S_ISREG(inode->i_mode) || |
| 1927 | exe.file->f_path.mnt->mnt_flags & MNT_NOEXEC) |
| 1928 | goto exit; |
| 1929 | |
| 1930 | err = inode_permission(inode, MAY_EXEC); |
| 1931 | if (err) |
| 1932 | goto exit; |
| 1933 | |
| 1934 | down_write(&mm->mmap_sem); |
| 1935 | |
| 1936 | /* |
| 1937 | * Forbid mm->exe_file change if old file still mapped. |
| 1938 | */ |
| 1939 | err = -EBUSY; |
| 1940 | if (mm->exe_file) { |
| 1941 | struct vm_area_struct *vma; |
| 1942 | |
| 1943 | for (vma = mm->mmap; vma; vma = vma->vm_next) |
| 1944 | if (vma->vm_file && |
| 1945 | path_equal(&vma->vm_file->f_path, |
| 1946 | &mm->exe_file->f_path)) |
| 1947 | goto exit_unlock; |
| 1948 | } |
| 1949 | |
| 1950 | /* |
| 1951 | * The symlink can be changed only once, just to disallow arbitrary |
| 1952 | * transitions malicious software might bring in. This means one |
| 1953 | * could make a snapshot over all processes running and monitor |
| 1954 | * /proc/pid/exe changes to notice unusual activity if needed. |
| 1955 | */ |
| 1956 | err = -EPERM; |
| 1957 | if (test_and_set_bit(MMF_EXE_FILE_CHANGED, &mm->flags)) |
| 1958 | goto exit_unlock; |
| 1959 | |
| 1960 | err = 0; |
| 1961 | set_mm_exe_file(mm, exe.file); /* this grabs a reference to exe.file */ |
| 1962 | exit_unlock: |
| 1963 | up_write(&mm->mmap_sem); |
| 1964 | |
| 1965 | exit: |
| 1966 | fdput(exe); |
| 1967 | return err; |
| 1968 | } |
| 1969 | |
| 1970 | static int prctl_set_mm(int opt, unsigned long addr, |
| 1971 | unsigned long arg4, unsigned long arg5) |
| 1972 | { |
| 1973 | unsigned long rlim = rlimit(RLIMIT_DATA); |
| 1974 | struct mm_struct *mm = current->mm; |
| 1975 | struct vm_area_struct *vma; |
| 1976 | int error; |
| 1977 | |
| 1978 | if (arg5 || (arg4 && opt != PR_SET_MM_AUXV)) |
| 1979 | return -EINVAL; |
| 1980 | |
| 1981 | if (!capable(CAP_SYS_RESOURCE)) |
| 1982 | return -EPERM; |
| 1983 | |
| 1984 | if (opt == PR_SET_MM_EXE_FILE) |
| 1985 | return prctl_set_mm_exe_file(mm, (unsigned int)addr); |
| 1986 | |
| 1987 | if (addr >= TASK_SIZE || addr < mmap_min_addr) |
| 1988 | return -EINVAL; |
| 1989 | |
| 1990 | error = -EINVAL; |
| 1991 | |
| 1992 | down_read(&mm->mmap_sem); |
| 1993 | vma = find_vma(mm, addr); |
| 1994 | |
| 1995 | switch (opt) { |
| 1996 | case PR_SET_MM_START_CODE: |
| 1997 | mm->start_code = addr; |
| 1998 | break; |
| 1999 | case PR_SET_MM_END_CODE: |
| 2000 | mm->end_code = addr; |
| 2001 | break; |
| 2002 | case PR_SET_MM_START_DATA: |
| 2003 | mm->start_data = addr; |
| 2004 | break; |
| 2005 | case PR_SET_MM_END_DATA: |
| 2006 | mm->end_data = addr; |
| 2007 | break; |
| 2008 | |
| 2009 | case PR_SET_MM_START_BRK: |
| 2010 | if (addr <= mm->end_data) |
| 2011 | goto out; |
| 2012 | |
| 2013 | if (rlim < RLIM_INFINITY && |
| 2014 | (mm->brk - addr) + |
| 2015 | (mm->end_data - mm->start_data) > rlim) |
| 2016 | goto out; |
| 2017 | |
| 2018 | mm->start_brk = addr; |
| 2019 | break; |
| 2020 | |
| 2021 | case PR_SET_MM_BRK: |
| 2022 | if (addr <= mm->end_data) |
| 2023 | goto out; |
| 2024 | |
| 2025 | if (rlim < RLIM_INFINITY && |
| 2026 | (addr - mm->start_brk) + |
| 2027 | (mm->end_data - mm->start_data) > rlim) |
| 2028 | goto out; |
| 2029 | |
| 2030 | mm->brk = addr; |
| 2031 | break; |
| 2032 | |
| 2033 | /* |
| 2034 | * If command line arguments and environment |
| 2035 | * are placed somewhere else on stack, we can |
| 2036 | * set them up here, ARG_START/END to setup |
| 2037 | * command line argumets and ENV_START/END |
| 2038 | * for environment. |
| 2039 | */ |
| 2040 | case PR_SET_MM_START_STACK: |
| 2041 | case PR_SET_MM_ARG_START: |
| 2042 | case PR_SET_MM_ARG_END: |
| 2043 | case PR_SET_MM_ENV_START: |
| 2044 | case PR_SET_MM_ENV_END: |
| 2045 | if (!vma) { |
| 2046 | error = -EFAULT; |
| 2047 | goto out; |
| 2048 | } |
| 2049 | if (opt == PR_SET_MM_START_STACK) |
| 2050 | mm->start_stack = addr; |
| 2051 | else if (opt == PR_SET_MM_ARG_START) |
| 2052 | mm->arg_start = addr; |
| 2053 | else if (opt == PR_SET_MM_ARG_END) |
| 2054 | mm->arg_end = addr; |
| 2055 | else if (opt == PR_SET_MM_ENV_START) |
| 2056 | mm->env_start = addr; |
| 2057 | else if (opt == PR_SET_MM_ENV_END) |
| 2058 | mm->env_end = addr; |
| 2059 | break; |
| 2060 | |
| 2061 | /* |
| 2062 | * This doesn't move auxiliary vector itself |
| 2063 | * since it's pinned to mm_struct, but allow |
| 2064 | * to fill vector with new values. It's up |
| 2065 | * to a caller to provide sane values here |
| 2066 | * otherwise user space tools which use this |
| 2067 | * vector might be unhappy. |
| 2068 | */ |
| 2069 | case PR_SET_MM_AUXV: { |
| 2070 | unsigned long user_auxv[AT_VECTOR_SIZE]; |
| 2071 | |
| 2072 | if (arg4 > sizeof(user_auxv)) |
| 2073 | goto out; |
| 2074 | up_read(&mm->mmap_sem); |
| 2075 | |
| 2076 | if (copy_from_user(user_auxv, (const void __user *)addr, arg4)) |
| 2077 | return -EFAULT; |
| 2078 | |
| 2079 | /* Make sure the last entry is always AT_NULL */ |
| 2080 | user_auxv[AT_VECTOR_SIZE - 2] = 0; |
| 2081 | user_auxv[AT_VECTOR_SIZE - 1] = 0; |
| 2082 | |
| 2083 | BUILD_BUG_ON(sizeof(user_auxv) != sizeof(mm->saved_auxv)); |
| 2084 | |
| 2085 | task_lock(current); |
| 2086 | memcpy(mm->saved_auxv, user_auxv, arg4); |
| 2087 | task_unlock(current); |
| 2088 | |
| 2089 | return 0; |
| 2090 | } |
| 2091 | default: |
| 2092 | goto out; |
| 2093 | } |
| 2094 | |
| 2095 | error = 0; |
| 2096 | out: |
| 2097 | up_read(&mm->mmap_sem); |
| 2098 | return error; |
| 2099 | } |
| 2100 | |
| 2101 | #ifdef CONFIG_CHECKPOINT_RESTORE |
| 2102 | static int prctl_get_tid_address(struct task_struct *me, int __user **tid_addr) |
| 2103 | { |
| 2104 | return put_user(me->clear_child_tid, tid_addr); |
| 2105 | } |
| 2106 | #else |
| 2107 | static int prctl_get_tid_address(struct task_struct *me, int __user **tid_addr) |
| 2108 | { |
| 2109 | return -EINVAL; |
| 2110 | } |
| 2111 | #endif |
| 2112 | |
| 2113 | #ifdef CONFIG_MMU |
| 2114 | static int prctl_update_vma_anon_name(struct vm_area_struct *vma, |
| 2115 | struct vm_area_struct **prev, |
| 2116 | unsigned long start, unsigned long end, |
| 2117 | const char __user *name_addr) |
| 2118 | { |
| 2119 | struct mm_struct * mm = vma->vm_mm; |
| 2120 | int error = 0; |
| 2121 | pgoff_t pgoff; |
| 2122 | |
| 2123 | if (name_addr == vma_get_anon_name(vma)) { |
| 2124 | *prev = vma; |
| 2125 | goto out; |
| 2126 | } |
| 2127 | |
| 2128 | pgoff = vma->vm_pgoff + ((start - vma->vm_start) >> PAGE_SHIFT); |
| 2129 | *prev = vma_merge(mm, *prev, start, end, vma->vm_flags, vma->anon_vma, |
| 2130 | vma->vm_file, pgoff, vma_policy(vma), |
| 2131 | name_addr); |
| 2132 | if (*prev) { |
| 2133 | vma = *prev; |
| 2134 | goto success; |
| 2135 | } |
| 2136 | |
| 2137 | *prev = vma; |
| 2138 | |
| 2139 | if (start != vma->vm_start) { |
| 2140 | error = split_vma(mm, vma, start, 1); |
| 2141 | if (error) |
| 2142 | goto out; |
| 2143 | } |
| 2144 | |
| 2145 | if (end != vma->vm_end) { |
| 2146 | error = split_vma(mm, vma, end, 0); |
| 2147 | if (error) |
| 2148 | goto out; |
| 2149 | } |
| 2150 | |
| 2151 | success: |
| 2152 | if (!vma->vm_file) |
| 2153 | vma->shared.anon_name = name_addr; |
| 2154 | |
| 2155 | out: |
| 2156 | if (error == -ENOMEM) |
| 2157 | error = -EAGAIN; |
| 2158 | return error; |
| 2159 | } |
| 2160 | |
| 2161 | static int prctl_set_vma_anon_name(unsigned long start, unsigned long end, |
| 2162 | unsigned long arg) |
| 2163 | { |
| 2164 | unsigned long tmp; |
| 2165 | struct vm_area_struct * vma, *prev; |
| 2166 | int unmapped_error = 0; |
| 2167 | int error = -EINVAL; |
| 2168 | |
| 2169 | /* |
| 2170 | * If the interval [start,end) covers some unmapped address |
| 2171 | * ranges, just ignore them, but return -ENOMEM at the end. |
| 2172 | * - this matches the handling in madvise. |
| 2173 | */ |
| 2174 | vma = find_vma_prev(current->mm, start, &prev); |
| 2175 | if (vma && start > vma->vm_start) |
| 2176 | prev = vma; |
| 2177 | |
| 2178 | for (;;) { |
| 2179 | /* Still start < end. */ |
| 2180 | error = -ENOMEM; |
| 2181 | if (!vma) |
| 2182 | return error; |
| 2183 | |
| 2184 | /* Here start < (end|vma->vm_end). */ |
| 2185 | if (start < vma->vm_start) { |
| 2186 | unmapped_error = -ENOMEM; |
| 2187 | start = vma->vm_start; |
| 2188 | if (start >= end) |
| 2189 | return error; |
| 2190 | } |
| 2191 | |
| 2192 | /* Here vma->vm_start <= start < (end|vma->vm_end) */ |
| 2193 | tmp = vma->vm_end; |
| 2194 | if (end < tmp) |
| 2195 | tmp = end; |
| 2196 | |
| 2197 | /* Here vma->vm_start <= start < tmp <= (end|vma->vm_end). */ |
| 2198 | error = prctl_update_vma_anon_name(vma, &prev, start, tmp, |
| 2199 | (const char __user *)arg); |
| 2200 | if (error) |
| 2201 | return error; |
| 2202 | start = tmp; |
| 2203 | if (prev && start < prev->vm_end) |
| 2204 | start = prev->vm_end; |
| 2205 | error = unmapped_error; |
| 2206 | if (start >= end) |
| 2207 | return error; |
| 2208 | if (prev) |
| 2209 | vma = prev->vm_next; |
| 2210 | else /* madvise_remove dropped mmap_sem */ |
| 2211 | vma = find_vma(current->mm, start); |
| 2212 | } |
| 2213 | } |
| 2214 | |
| 2215 | static int prctl_set_vma(unsigned long opt, unsigned long start, |
| 2216 | unsigned long len_in, unsigned long arg) |
| 2217 | { |
| 2218 | struct mm_struct *mm = current->mm; |
| 2219 | int error; |
| 2220 | unsigned long len; |
| 2221 | unsigned long end; |
| 2222 | |
| 2223 | #ifndef CONFIG_MT_ENG_BUILD |
| 2224 | /* Do not do prctl_set_vma in !eng load */ |
| 2225 | return 0; |
| 2226 | #endif |
| 2227 | |
| 2228 | if (start & ~PAGE_MASK) |
| 2229 | return -EINVAL; |
| 2230 | len = (len_in + ~PAGE_MASK) & PAGE_MASK; |
| 2231 | |
| 2232 | /* Check to see whether len was rounded up from small -ve to zero */ |
| 2233 | if (len_in && !len) |
| 2234 | return -EINVAL; |
| 2235 | |
| 2236 | end = start + len; |
| 2237 | if (end < start) |
| 2238 | return -EINVAL; |
| 2239 | |
| 2240 | if (end == start) |
| 2241 | return 0; |
| 2242 | |
| 2243 | down_write(&mm->mmap_sem); |
| 2244 | |
| 2245 | switch (opt) { |
| 2246 | case PR_SET_VMA_ANON_NAME: |
| 2247 | error = prctl_set_vma_anon_name(start, end, arg); |
| 2248 | break; |
| 2249 | default: |
| 2250 | error = -EINVAL; |
| 2251 | } |
| 2252 | |
| 2253 | up_write(&mm->mmap_sem); |
| 2254 | |
| 2255 | return error; |
| 2256 | } |
| 2257 | #else /* CONFIG_MMU */ |
| 2258 | static int prctl_set_vma(unsigned long opt, unsigned long start, |
| 2259 | unsigned long len_in, unsigned long arg) |
| 2260 | { |
| 2261 | return -EINVAL; |
| 2262 | } |
| 2263 | #endif |
| 2264 | |
| 2265 | SYSCALL_DEFINE5(prctl, int, option, unsigned long, arg2, unsigned long, arg3, |
| 2266 | unsigned long, arg4, unsigned long, arg5) |
| 2267 | { |
| 2268 | struct task_struct *me = current; |
| 2269 | struct task_struct *tsk; |
| 2270 | unsigned char comm[sizeof(me->comm)]; |
| 2271 | long error; |
| 2272 | |
| 2273 | error = security_task_prctl(option, arg2, arg3, arg4, arg5); |
| 2274 | if (error != -ENOSYS) |
| 2275 | return error; |
| 2276 | |
| 2277 | error = 0; |
| 2278 | switch (option) { |
| 2279 | case PR_SET_PDEATHSIG: |
| 2280 | if (!valid_signal(arg2)) { |
| 2281 | error = -EINVAL; |
| 2282 | break; |
| 2283 | } |
| 2284 | me->pdeath_signal = arg2; |
| 2285 | break; |
| 2286 | case PR_GET_PDEATHSIG: |
| 2287 | error = put_user(me->pdeath_signal, (int __user *)arg2); |
| 2288 | break; |
| 2289 | case PR_GET_DUMPABLE: |
| 2290 | error = get_dumpable(me->mm); |
| 2291 | break; |
| 2292 | case PR_SET_DUMPABLE: |
| 2293 | if (arg2 != SUID_DUMP_DISABLE && arg2 != SUID_DUMP_USER) { |
| 2294 | error = -EINVAL; |
| 2295 | break; |
| 2296 | } |
| 2297 | set_dumpable(me->mm, arg2); |
| 2298 | break; |
| 2299 | |
| 2300 | case PR_SET_UNALIGN: |
| 2301 | error = SET_UNALIGN_CTL(me, arg2); |
| 2302 | break; |
| 2303 | case PR_GET_UNALIGN: |
| 2304 | error = GET_UNALIGN_CTL(me, arg2); |
| 2305 | break; |
| 2306 | case PR_SET_FPEMU: |
| 2307 | error = SET_FPEMU_CTL(me, arg2); |
| 2308 | break; |
| 2309 | case PR_GET_FPEMU: |
| 2310 | error = GET_FPEMU_CTL(me, arg2); |
| 2311 | break; |
| 2312 | case PR_SET_FPEXC: |
| 2313 | error = SET_FPEXC_CTL(me, arg2); |
| 2314 | break; |
| 2315 | case PR_GET_FPEXC: |
| 2316 | error = GET_FPEXC_CTL(me, arg2); |
| 2317 | break; |
| 2318 | case PR_GET_TIMING: |
| 2319 | error = PR_TIMING_STATISTICAL; |
| 2320 | break; |
| 2321 | case PR_SET_TIMING: |
| 2322 | if (arg2 != PR_TIMING_STATISTICAL) |
| 2323 | error = -EINVAL; |
| 2324 | break; |
| 2325 | case PR_SET_NAME: |
| 2326 | comm[sizeof(me->comm) - 1] = 0; |
| 2327 | if (strncpy_from_user(comm, (char __user *)arg2, |
| 2328 | sizeof(me->comm) - 1) < 0) |
| 2329 | return -EFAULT; |
| 2330 | set_task_comm(me, comm); |
| 2331 | proc_comm_connector(me); |
| 2332 | break; |
| 2333 | case PR_GET_NAME: |
| 2334 | get_task_comm(comm, me); |
| 2335 | if (copy_to_user((char __user *)arg2, comm, sizeof(comm))) |
| 2336 | return -EFAULT; |
| 2337 | break; |
| 2338 | case PR_GET_ENDIAN: |
| 2339 | error = GET_ENDIAN(me, arg2); |
| 2340 | break; |
| 2341 | case PR_SET_ENDIAN: |
| 2342 | error = SET_ENDIAN(me, arg2); |
| 2343 | break; |
| 2344 | case PR_GET_SECCOMP: |
| 2345 | error = prctl_get_seccomp(); |
| 2346 | break; |
| 2347 | case PR_SET_SECCOMP: |
| 2348 | error = prctl_set_seccomp(arg2, (char __user *)arg3); |
| 2349 | break; |
| 2350 | case PR_GET_TSC: |
| 2351 | error = GET_TSC_CTL(arg2); |
| 2352 | break; |
| 2353 | case PR_SET_TSC: |
| 2354 | error = SET_TSC_CTL(arg2); |
| 2355 | break; |
| 2356 | case PR_TASK_PERF_EVENTS_DISABLE: |
| 2357 | error = perf_event_task_disable(); |
| 2358 | break; |
| 2359 | case PR_TASK_PERF_EVENTS_ENABLE: |
| 2360 | error = perf_event_task_enable(); |
| 2361 | break; |
| 2362 | case PR_GET_TIMERSLACK: |
| 2363 | error = current->timer_slack_ns; |
| 2364 | break; |
| 2365 | case PR_SET_TIMERSLACK: |
| 2366 | if (arg2 <= 0) |
| 2367 | current->timer_slack_ns = |
| 2368 | current->default_timer_slack_ns; |
| 2369 | else |
| 2370 | current->timer_slack_ns = arg2; |
| 2371 | break; |
| 2372 | case PR_MCE_KILL: |
| 2373 | if (arg4 | arg5) |
| 2374 | return -EINVAL; |
| 2375 | switch (arg2) { |
| 2376 | case PR_MCE_KILL_CLEAR: |
| 2377 | if (arg3 != 0) |
| 2378 | return -EINVAL; |
| 2379 | current->flags &= ~PF_MCE_PROCESS; |
| 2380 | break; |
| 2381 | case PR_MCE_KILL_SET: |
| 2382 | current->flags |= PF_MCE_PROCESS; |
| 2383 | if (arg3 == PR_MCE_KILL_EARLY) |
| 2384 | current->flags |= PF_MCE_EARLY; |
| 2385 | else if (arg3 == PR_MCE_KILL_LATE) |
| 2386 | current->flags &= ~PF_MCE_EARLY; |
| 2387 | else if (arg3 == PR_MCE_KILL_DEFAULT) |
| 2388 | current->flags &= |
| 2389 | ~(PF_MCE_EARLY|PF_MCE_PROCESS); |
| 2390 | else |
| 2391 | return -EINVAL; |
| 2392 | break; |
| 2393 | case PR_SET_TIMERSLACK_PID: |
| 2394 | if (current->pid != (pid_t)arg3 && |
| 2395 | !capable(CAP_SYS_NICE)) |
| 2396 | return -EPERM; |
| 2397 | rcu_read_lock(); |
| 2398 | tsk = find_task_by_pid_ns((pid_t)arg3, &init_pid_ns); |
| 2399 | if (tsk == NULL) { |
| 2400 | rcu_read_unlock(); |
| 2401 | return -EINVAL; |
| 2402 | } |
| 2403 | get_task_struct(tsk); |
| 2404 | rcu_read_unlock(); |
| 2405 | if (arg2 <= 0) |
| 2406 | tsk->timer_slack_ns = |
| 2407 | tsk->default_timer_slack_ns; |
| 2408 | else |
| 2409 | tsk->timer_slack_ns = arg2; |
| 2410 | put_task_struct(tsk); |
| 2411 | error = 0; |
| 2412 | break; |
| 2413 | default: |
| 2414 | return -EINVAL; |
| 2415 | } |
| 2416 | break; |
| 2417 | case PR_MCE_KILL_GET: |
| 2418 | if (arg2 | arg3 | arg4 | arg5) |
| 2419 | return -EINVAL; |
| 2420 | if (current->flags & PF_MCE_PROCESS) |
| 2421 | error = (current->flags & PF_MCE_EARLY) ? |
| 2422 | PR_MCE_KILL_EARLY : PR_MCE_KILL_LATE; |
| 2423 | else |
| 2424 | error = PR_MCE_KILL_DEFAULT; |
| 2425 | break; |
| 2426 | case PR_SET_MM: |
| 2427 | error = prctl_set_mm(arg2, arg3, arg4, arg5); |
| 2428 | break; |
| 2429 | case PR_GET_TID_ADDRESS: |
| 2430 | error = prctl_get_tid_address(me, (int __user **)arg2); |
| 2431 | break; |
| 2432 | case PR_SET_CHILD_SUBREAPER: |
| 2433 | me->signal->is_child_subreaper = !!arg2; |
| 2434 | break; |
| 2435 | case PR_GET_CHILD_SUBREAPER: |
| 2436 | error = put_user(me->signal->is_child_subreaper, |
| 2437 | (int __user *)arg2); |
| 2438 | break; |
| 2439 | case PR_SET_NO_NEW_PRIVS: |
| 2440 | if (arg2 != 1 || arg3 || arg4 || arg5) |
| 2441 | return -EINVAL; |
| 2442 | |
| 2443 | task_set_no_new_privs(current); |
| 2444 | break; |
| 2445 | case PR_GET_NO_NEW_PRIVS: |
| 2446 | if (arg2 || arg3 || arg4 || arg5) |
| 2447 | return -EINVAL; |
| 2448 | return task_no_new_privs(current) ? 1 : 0; |
| 2449 | case PR_SET_VMA: |
| 2450 | error = prctl_set_vma(arg2, arg3, arg4, arg5); |
| 2451 | break; |
| 2452 | default: |
| 2453 | error = -EINVAL; |
| 2454 | break; |
| 2455 | } |
| 2456 | return error; |
| 2457 | } |
| 2458 | |
| 2459 | SYSCALL_DEFINE3(getcpu, unsigned __user *, cpup, unsigned __user *, nodep, |
| 2460 | struct getcpu_cache __user *, unused) |
| 2461 | { |
| 2462 | int err = 0; |
| 2463 | int cpu = raw_smp_processor_id(); |
| 2464 | if (cpup) |
| 2465 | err |= put_user(cpu, cpup); |
| 2466 | if (nodep) |
| 2467 | err |= put_user(cpu_to_node(cpu), nodep); |
| 2468 | return err ? -EFAULT : 0; |
| 2469 | } |
| 2470 | |
| 2471 | char poweroff_cmd[POWEROFF_CMD_PATH_LEN] = "/sbin/poweroff"; |
| 2472 | |
| 2473 | static int __orderly_poweroff(bool force) |
| 2474 | { |
| 2475 | char **argv; |
| 2476 | static char *envp[] = { |
| 2477 | "HOME=/", |
| 2478 | "PATH=/sbin:/bin:/usr/sbin:/usr/bin", |
| 2479 | NULL |
| 2480 | }; |
| 2481 | int ret; |
| 2482 | |
| 2483 | argv = argv_split(GFP_KERNEL, poweroff_cmd, NULL); |
| 2484 | if (argv) { |
| 2485 | ret = call_usermodehelper(argv[0], argv, envp, UMH_WAIT_EXEC); |
| 2486 | argv_free(argv); |
| 2487 | } else { |
| 2488 | printk(KERN_WARNING "%s failed to allocate memory for \"%s\"\n", |
| 2489 | __func__, poweroff_cmd); |
| 2490 | ret = -ENOMEM; |
| 2491 | } |
| 2492 | |
| 2493 | if (ret && force) { |
| 2494 | printk(KERN_WARNING "Failed to start orderly shutdown: " |
| 2495 | "forcing the issue\n"); |
| 2496 | /* |
| 2497 | * I guess this should try to kick off some daemon to sync and |
| 2498 | * poweroff asap. Or not even bother syncing if we're doing an |
| 2499 | * emergency shutdown? |
| 2500 | */ |
| 2501 | emergency_sync(); |
| 2502 | kernel_power_off(); |
| 2503 | } |
| 2504 | |
| 2505 | return ret; |
| 2506 | } |
| 2507 | |
| 2508 | static bool poweroff_force; |
| 2509 | |
| 2510 | static void poweroff_work_func(struct work_struct *work) |
| 2511 | { |
| 2512 | __orderly_poweroff(poweroff_force); |
| 2513 | } |
| 2514 | |
| 2515 | static DECLARE_WORK(poweroff_work, poweroff_work_func); |
| 2516 | |
| 2517 | /** |
| 2518 | * orderly_poweroff - Trigger an orderly system poweroff |
| 2519 | * @force: force poweroff if command execution fails |
| 2520 | * |
| 2521 | * This may be called from any context to trigger a system shutdown. |
| 2522 | * If the orderly shutdown fails, it will force an immediate shutdown. |
| 2523 | */ |
| 2524 | int orderly_poweroff(bool force) |
| 2525 | { |
| 2526 | if (force) /* do not override the pending "true" */ |
| 2527 | poweroff_force = true; |
| 2528 | schedule_work(&poweroff_work); |
| 2529 | return 0; |
| 2530 | } |
| 2531 | EXPORT_SYMBOL_GPL(orderly_poweroff); |
| 2532 | |
| 2533 | /** |
| 2534 | * do_sysinfo - fill in sysinfo struct |
| 2535 | * @info: pointer to buffer to fill |
| 2536 | */ |
| 2537 | static int do_sysinfo(struct sysinfo *info) |
| 2538 | { |
| 2539 | unsigned long mem_total, sav_total; |
| 2540 | unsigned int mem_unit, bitcount; |
| 2541 | struct timespec tp; |
| 2542 | |
| 2543 | memset(info, 0, sizeof(struct sysinfo)); |
| 2544 | |
| 2545 | ktime_get_ts(&tp); |
| 2546 | monotonic_to_bootbased(&tp); |
| 2547 | info->uptime = tp.tv_sec + (tp.tv_nsec ? 1 : 0); |
| 2548 | |
| 2549 | get_avenrun(info->loads, 0, SI_LOAD_SHIFT - FSHIFT); |
| 2550 | |
| 2551 | info->procs = nr_threads; |
| 2552 | |
| 2553 | si_meminfo(info); |
| 2554 | si_swapinfo(info); |
| 2555 | |
| 2556 | /* |
| 2557 | * If the sum of all the available memory (i.e. ram + swap) |
| 2558 | * is less than can be stored in a 32 bit unsigned long then |
| 2559 | * we can be binary compatible with 2.2.x kernels. If not, |
| 2560 | * well, in that case 2.2.x was broken anyways... |
| 2561 | * |
| 2562 | * -Erik Andersen <andersee@debian.org> |
| 2563 | */ |
| 2564 | |
| 2565 | mem_total = info->totalram + info->totalswap; |
| 2566 | if (mem_total < info->totalram || mem_total < info->totalswap) |
| 2567 | goto out; |
| 2568 | bitcount = 0; |
| 2569 | mem_unit = info->mem_unit; |
| 2570 | while (mem_unit > 1) { |
| 2571 | bitcount++; |
| 2572 | mem_unit >>= 1; |
| 2573 | sav_total = mem_total; |
| 2574 | mem_total <<= 1; |
| 2575 | if (mem_total < sav_total) |
| 2576 | goto out; |
| 2577 | } |
| 2578 | |
| 2579 | /* |
| 2580 | * If mem_total did not overflow, multiply all memory values by |
| 2581 | * info->mem_unit and set it to 1. This leaves things compatible |
| 2582 | * with 2.2.x, and also retains compatibility with earlier 2.4.x |
| 2583 | * kernels... |
| 2584 | */ |
| 2585 | |
| 2586 | info->mem_unit = 1; |
| 2587 | info->totalram <<= bitcount; |
| 2588 | info->freeram <<= bitcount; |
| 2589 | info->sharedram <<= bitcount; |
| 2590 | info->bufferram <<= bitcount; |
| 2591 | info->totalswap <<= bitcount; |
| 2592 | info->freeswap <<= bitcount; |
| 2593 | info->totalhigh <<= bitcount; |
| 2594 | info->freehigh <<= bitcount; |
| 2595 | |
| 2596 | out: |
| 2597 | return 0; |
| 2598 | } |
| 2599 | |
| 2600 | SYSCALL_DEFINE1(sysinfo, struct sysinfo __user *, info) |
| 2601 | { |
| 2602 | struct sysinfo val; |
| 2603 | |
| 2604 | do_sysinfo(&val); |
| 2605 | |
| 2606 | if (copy_to_user(info, &val, sizeof(struct sysinfo))) |
| 2607 | return -EFAULT; |
| 2608 | |
| 2609 | return 0; |
| 2610 | } |
| 2611 | |
| 2612 | #ifdef CONFIG_COMPAT |
| 2613 | struct compat_sysinfo { |
| 2614 | s32 uptime; |
| 2615 | u32 loads[3]; |
| 2616 | u32 totalram; |
| 2617 | u32 freeram; |
| 2618 | u32 sharedram; |
| 2619 | u32 bufferram; |
| 2620 | u32 totalswap; |
| 2621 | u32 freeswap; |
| 2622 | u16 procs; |
| 2623 | u16 pad; |
| 2624 | u32 totalhigh; |
| 2625 | u32 freehigh; |
| 2626 | u32 mem_unit; |
| 2627 | char _f[20-2*sizeof(u32)-sizeof(int)]; |
| 2628 | }; |
| 2629 | |
| 2630 | COMPAT_SYSCALL_DEFINE1(sysinfo, struct compat_sysinfo __user *, info) |
| 2631 | { |
| 2632 | struct sysinfo s; |
| 2633 | |
| 2634 | do_sysinfo(&s); |
| 2635 | |
| 2636 | /* Check to see if any memory value is too large for 32-bit and scale |
| 2637 | * down if needed |
| 2638 | */ |
| 2639 | if ((s.totalram >> 32) || (s.totalswap >> 32)) { |
| 2640 | int bitcount = 0; |
| 2641 | |
| 2642 | while (s.mem_unit < PAGE_SIZE) { |
| 2643 | s.mem_unit <<= 1; |
| 2644 | bitcount++; |
| 2645 | } |
| 2646 | |
| 2647 | s.totalram >>= bitcount; |
| 2648 | s.freeram >>= bitcount; |
| 2649 | s.sharedram >>= bitcount; |
| 2650 | s.bufferram >>= bitcount; |
| 2651 | s.totalswap >>= bitcount; |
| 2652 | s.freeswap >>= bitcount; |
| 2653 | s.totalhigh >>= bitcount; |
| 2654 | s.freehigh >>= bitcount; |
| 2655 | } |
| 2656 | |
| 2657 | if (!access_ok(VERIFY_WRITE, info, sizeof(struct compat_sysinfo)) || |
| 2658 | __put_user(s.uptime, &info->uptime) || |
| 2659 | __put_user(s.loads[0], &info->loads[0]) || |
| 2660 | __put_user(s.loads[1], &info->loads[1]) || |
| 2661 | __put_user(s.loads[2], &info->loads[2]) || |
| 2662 | __put_user(s.totalram, &info->totalram) || |
| 2663 | __put_user(s.freeram, &info->freeram) || |
| 2664 | __put_user(s.sharedram, &info->sharedram) || |
| 2665 | __put_user(s.bufferram, &info->bufferram) || |
| 2666 | __put_user(s.totalswap, &info->totalswap) || |
| 2667 | __put_user(s.freeswap, &info->freeswap) || |
| 2668 | __put_user(s.procs, &info->procs) || |
| 2669 | __put_user(s.totalhigh, &info->totalhigh) || |
| 2670 | __put_user(s.freehigh, &info->freehigh) || |
| 2671 | __put_user(s.mem_unit, &info->mem_unit)) |
| 2672 | return -EFAULT; |
| 2673 | |
| 2674 | return 0; |
| 2675 | } |
| 2676 | #endif /* CONFIG_COMPAT */ |