bsd/kern/process_policy.c

   1 /*
   2  * Copyright (c) 2005-2016 Apple Computer, Inc. All rights reserved.
   3  *
   4  * @APPLE_OSREFERENCE_LICENSE_HEADER_START@
   5  *
   6  * This file contains Original Code and/or Modifications of Original Code
   7  * as defined in and that are subject to the Apple Public Source License
   8  * Version 2.0 (the 'License'). You may not use this file except in
   9  * compliance with the License. The rights granted to you under the License
  10  * may not be used to create, or enable the creation or redistribution of,
  11  * unlawful or unlicensed copies of an Apple operating system, or to
  12  * circumvent, violate, or enable the circumvention or violation of, any
  13  * terms of an Apple operating system software license agreement.
  14  *
  15  * Please obtain a copy of the License at
  16  * http://www.opensource.apple.com/apsl/ and read it before using this file.
  17  *
  18  * The Original Code and all software distributed under the License are
  19  * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
  20  * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
  21  * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
  22  * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
  23  * Please see the License for the specific language governing rights and
  24  * limitations under the License.
  25  *
  26  * @APPLE_OSREFERENCE_LICENSE_HEADER_END@
  27  */
  28
  29 /*
  30  * process policy syscall implementation
  31  */
  32
  33 #include <sys/param.h>
  34 #include <sys/systm.h>
  35 #include <sys/kernel.h>
  36 #include <sys/malloc.h>
  37 #include <sys/proc_internal.h>
  38 #include <sys/proc.h>
  39 #include <sys/kauth.h>
  40 #include <sys/unistd.h>
  41 #include <sys/buf.h>
  42 #include <sys/ioctl.h>
  43 #include <sys/vm.h>
  44 #include <sys/user.h>
  45
  46 #include <security/audit/audit.h>
  47
  48 #include <mach/machine.h>
  49 #include <mach/mach_types.h>
  50 #include <mach/vm_param.h>
  51 #include <kern/task.h>
  52 #include <kern/kalloc.h>
  53 #include <kern/assert.h>
  54 #include <kern/policy_internal.h>
  55
  56 #include <vm/vm_kern.h>
  57 #include <vm/vm_map.h>
  58 #include <mach/host_info.h>
  59 #include <mach/task_info.h>
  60 #include <mach/thread_info.h>
  61 #include <mach/vm_region.h>
  62
  63 #include <sys/process_policy.h>
  64 #include <sys/proc_info.h>
  65 #include <sys/bsdtask_info.h>
  66 #include <sys/kdebug.h>
  67 #include <sys/sysproto.h>
  68 #include <sys/msgbuf.h>
  69
  70 #include <machine/machine_routines.h>
  71
  72 #include <kern/ipc_misc.h>
  73 #include <vm/vm_protos.h>
  74
  75 static int handle_lowresource(int scope, int action, int policy, int policy_subtype, user_addr_t attrp, proc_t proc, uint64_t target_threadid);
  76 static int handle_cpuuse(int action, user_addr_t attrp, proc_t proc, uint64_t target_threadid);
  77 static int handle_apptype(int scope, int action, int policy, int policy_subtype, user_addr_t attrp, proc_t proc, uint64_t target_threadid);
  78 static int handle_boost(int scope, int action, int policy, int policy_subtype, user_addr_t attrp, proc_t proc, uint64_t target_threadid);
  79
  80 extern kern_return_t task_suspend(task_t);
  81 extern kern_return_t task_resume(task_t);
  82
  83
  84 /***************************** process_policy ********************/
  85
  86 /*
  87  *int process_policy(int scope, int action, int policy, int policy_subtype,
  88  *                   proc_policy_attribute_t * attrp, pid_t target_pid,
  89  *                   uint64_t target_threadid)
  90  *{ int process_policy(int scope, int action, int policy, int policy_subtype,
  91  * user_addr_t attrp, pid_t target_pid, uint64_t target_threadid); }
  92  */
  93
  94 /* system call implementation */
  95 int
  96 process_policy(__unused struct proc *p, struct process_policy_args * uap, __unused int32_t *retval)
  97 {
  98         int error = 0;
  99         int scope = uap->scope;
 100         int policy = uap->policy;
 101         int action = uap->action;
 102         int policy_subtype = uap->policy_subtype;
 103         user_addr_t attrp = uap->attrp;
 104         pid_t target_pid = uap->target_pid;
 105         uint64_t target_threadid = uap->target_threadid;
 106         proc_t target_proc = PROC_NULL;
 107         proc_t curp = current_proc();
 108         kauth_cred_t my_cred;
 109
 110         if ((scope != PROC_POLICY_SCOPE_PROCESS) && (scope != PROC_POLICY_SCOPE_THREAD)) {
 111                 return(EINVAL);
 112         }
 113
 114         if (target_pid == 0 || target_pid == proc_selfpid())
 115                 target_proc = proc_self();
 116         else
 117                 target_proc = proc_find(target_pid);
 118
 119         if (target_proc == PROC_NULL)
 120                 return(ESRCH);
 121
 122         my_cred = kauth_cred_get();
 123
 124         /*
 125          * Resoure starvation control can be used by unpriv resource owner but priv at the time of ownership claim. This is
 126          * checked in low resource handle routine. So bypass the checks here.
 127          */
 128         if ((policy != PROC_POLICY_RESOURCE_STARVATION) &&
 129                 (policy != PROC_POLICY_APPTYPE) &&
 130                 (!kauth_cred_issuser(my_cred) && curp != p))
 131         {
 132                 error = EPERM;
 133                 goto out;
 134         }
 135
 136 #if CONFIG_MACF
 137         switch (policy) {
 138                 case PROC_POLICY_BOOST:
 139                 case PROC_POLICY_RESOURCE_USAGE:
 140                         /* These policies do their own appropriate mac checks */
 141                         break;
 142                 default:
 143                         error = mac_proc_check_sched(curp, target_proc);
 144                         if (error) goto out;
 145                         break;
 146         }
 147 #endif /* CONFIG_MACF */
 148
 149         switch(policy) {
 150                 case PROC_POLICY_BACKGROUND:
 151                         error = ENOTSUP;
 152                         break;
 153                 case PROC_POLICY_HARDWARE_ACCESS:
 154                         error = ENOTSUP;
 155                         break;
 156                 case PROC_POLICY_RESOURCE_STARVATION:
 157                         error = handle_lowresource(scope, action, policy, policy_subtype, attrp, target_proc, target_threadid);
 158                         break;
 159                 case PROC_POLICY_RESOURCE_USAGE:
 160                         switch(policy_subtype) {
 161                                 case PROC_POLICY_RUSAGE_NONE:
 162                                 case PROC_POLICY_RUSAGE_WIREDMEM:
 163                                 case PROC_POLICY_RUSAGE_VIRTMEM:
 164                                 case PROC_POLICY_RUSAGE_DISK:
 165                                 case PROC_POLICY_RUSAGE_NETWORK:
 166                                 case PROC_POLICY_RUSAGE_POWER:
 167                                         return(ENOTSUP);
 168                                 default:
 169                                         return(EINVAL);
 170                                 case PROC_POLICY_RUSAGE_CPU:
 171                                         break;
 172                         }
 173
 174                         error = handle_cpuuse(action, attrp, target_proc, target_threadid);
 175                         break;
 176                 case PROC_POLICY_APPTYPE:
 177                         error = handle_apptype(scope, action, policy, policy_subtype, attrp, target_proc, target_threadid);
 178                         break;
 179                 case PROC_POLICY_BOOST:
 180                         error = handle_boost(scope, action, policy, policy_subtype, attrp, target_proc, target_threadid);
 181                         break;
 182                 default:
 183                         error = EINVAL;
 184                         break;
 185         }
 186
 187 out:
 188         proc_rele(target_proc);
 189         return(error);
 190 }
 191
 192 static int
 193 handle_lowresource(__unused int scope, int action, __unused int policy, int policy_subtype, __unused user_addr_t attrp, proc_t proc, __unused uint64_t target_threadid)
 194 {
 195         int error = 0;
 196
 197         switch(policy_subtype) {
 198                 case PROC_POLICY_RS_NONE:
 199                 case PROC_POLICY_RS_VIRTUALMEM:
 200                         break;
 201                 default:
 202                         return(EINVAL);
 203         }
 204
 205         if (action == PROC_POLICY_ACTION_RESTORE)
 206                 error = proc_resetpcontrol(proc_pid(proc));
 207         else
 208                 error = EINVAL;
 209
 210         return(error);
 211 }
 212
 213
 214 static int
 215 handle_cpuuse(int action, user_addr_t attrp, proc_t proc, __unused uint64_t target_threadid)
 216 {
 217         proc_policy_cpuusage_attr_t     cpuattr;
 218 #if CONFIG_MACF
 219         proc_t                          curp = current_proc();
 220 #endif
 221         int                             entitled = FALSE;
 222         Boolean                         canEnable = FALSE;
 223         uint64_t                        interval = -1ULL;
 224         int                             error = 0;
 225         uint8_t                         percentage;
 226
 227 #if CONFIG_MACF
 228         /*
 229          * iOS only allows processes to override their own CPU usage monitor
 230          * parameters if they have com.apple.private.kernel.override-cpumon.
 231          *
 232          * Until rdar://24799462 improves our scheme, we are also using the
 233          * same entitlement to indicate which processes can resume monitoring
 234          * when they otherwise wouldn't be able to.
 235          */
 236         entitled = (mac_proc_check_cpumon(curp) == 0) ? TRUE : FALSE;
 237         canEnable = (entitled && action == PROC_POLICY_ACTION_ENABLE);
 238
 239         if (!canEnable && curp != proc) {
 240                 /* can the current process change scheduling parameters? */
 241                 error = mac_proc_check_sched(curp, proc);
 242                 if (error)      return error;
 243         }
 244 #endif
 245
 246         // on macOS tasks can only set and clear their own CPU limits
 247         if ((action == PROC_POLICY_ACTION_APPLY || action == PROC_POLICY_ACTION_RESTORE)
 248              && proc != current_proc()) {
 249                 return (EPERM);
 250         }
 251
 252         switch (action) {
 253                 case PROC_POLICY_ACTION_GET:
 254                         error = proc_get_task_ruse_cpu(proc->task, &cpuattr.ppattr_cpu_attr,
 255                                         &percentage,
 256                                         &cpuattr.ppattr_cpu_attr_interval,
 257                                         &cpuattr.ppattr_cpu_attr_deadline);
 258                         if (error == 0) {
 259                                 cpuattr.ppattr_cpu_percentage = percentage;
 260                                 cpuattr.ppattr_cpu_attr_interval /= NSEC_PER_SEC;
 261                                 error = copyout((proc_policy_cpuusage_attr_t *)&cpuattr, (user_addr_t)attrp, sizeof(proc_policy_cpuusage_attr_t));
 262                         }
 263                         break;
 264
 265                 case PROC_POLICY_ACTION_APPLY:
 266                 case PROC_POLICY_ACTION_SET:
 267                         error = copyin((user_addr_t)attrp, (proc_policy_cpuusage_attr_t *)&cpuattr, sizeof(proc_policy_cpuusage_attr_t));
 268                         if (error != 0) {
 269                                 return (error);
 270                         }
 271
 272                         /*
 273                          * The process_policy API uses seconds as the units for the interval,
 274                          * but the mach task policy SPI uses nanoseconds. Do the conversion,
 275                          * but preserve -1 as it has special meaning.
 276                          */
 277                         if (cpuattr.ppattr_cpu_attr_interval != -1ULL) {
 278                                 interval = cpuattr.ppattr_cpu_attr_interval * NSEC_PER_SEC;
 279                         } else {
 280                                 interval = -1ULL;
 281                         }
 282
 283                         error = proc_set_task_ruse_cpu(proc->task, cpuattr.ppattr_cpu_attr,
 284                                         cpuattr.ppattr_cpu_percentage,
 285                                         interval,
 286                                         cpuattr.ppattr_cpu_attr_deadline,
 287                                         entitled);
 288                         break;
 289
 290                 /* restore process to prior state */
 291                 case PROC_POLICY_ACTION_RESTORE:
 292                         error = proc_clear_task_ruse_cpu(proc->task, entitled);
 293                         break;
 294
 295                 /* re-enable suspended monitor */
 296                 case PROC_POLICY_ACTION_ENABLE:
 297                         error = task_resume_cpumon(proc->task);
 298                         break;
 299
 300                 case PROC_POLICY_ACTION_REMOVE:
 301
 302                 default:
 303                         error = EINVAL;
 304                         break;
 305
 306         }
 307
 308         return(error);
 309 }
 310
 311
 312 static int
 313 handle_apptype(         int scope,
 314                         int action,
 315                __unused int policy,
 316                         int policy_subtype,
 317                __unused user_addr_t attrp,
 318                         proc_t target_proc,
 319                __unused uint64_t target_threadid)
 320 {
 321         int error = 0;
 322
 323         if (scope != PROC_POLICY_SCOPE_PROCESS)
 324                 return (EINVAL);
 325
 326         /* Temporary compatibility with old importance donation interface until libproc is moved to new boost calls */
 327         switch (policy_subtype) {
 328                 case PROC_POLICY_IOS_DONATEIMP:
 329                         if (action != PROC_POLICY_ACTION_ENABLE)
 330                                 return (EINVAL);
 331                         if (target_proc != current_proc())
 332                                 return (EINVAL);
 333
 334                         /* PROCESS ENABLE APPTYPE DONATEIMP */
 335                         task_importance_mark_donor(target_proc->task, TRUE);
 336
 337                         return(0);
 338
 339                 case PROC_POLICY_IOS_HOLDIMP:
 340                         if (action != PROC_POLICY_ACTION_ENABLE)
 341                                 return (EINVAL);
 342                         if (target_proc != current_proc())
 343                                 return (EINVAL);
 344
 345                         /* PROCESS ENABLE APPTYPE HOLDIMP */
 346                         error = task_importance_hold_legacy_external_assertion(current_task(), 1);
 347
 348                         return(error);
 349
 350                 case PROC_POLICY_IOS_DROPIMP:
 351                         if (action != PROC_POLICY_ACTION_ENABLE)
 352                                 return (EINVAL);
 353                         if (target_proc != current_proc())
 354                                 return (EINVAL);
 355
 356                         /* PROCESS ENABLE APPTYPE DROPIMP */
 357                         error = task_importance_drop_legacy_external_assertion(current_task(), 1);
 358
 359                         return(error);
 360
 361                 default:
 362                         /* continue to TAL handling */
 363                         break;
 364         }
 365
 366         if (policy_subtype != PROC_POLICY_OSX_APPTYPE_TAL)
 367                 return (EINVAL);
 368
 369         /* need to be super user to do this */
 370         if (kauth_cred_issuser(kauth_cred_get()) == 0)
 371                 return (EPERM);
 372
 373         if (proc_task_is_tal(target_proc->task) == FALSE)
 374                 return (EINVAL);
 375
 376         switch (action) {
 377                 case PROC_POLICY_ACTION_ENABLE:
 378                         /* PROCESS ENABLE APPTYPE TAL */
 379                         proc_set_task_policy(target_proc->task,
 380                                              TASK_POLICY_ATTRIBUTE, TASK_POLICY_TAL,
 381                                              TASK_POLICY_ENABLE);
 382                         break;
 383                 case PROC_POLICY_ACTION_DISABLE:
 384                         /* PROCESS DISABLE APPTYPE TAL */
 385                         proc_set_task_policy(target_proc->task,
 386                                              TASK_POLICY_ATTRIBUTE, TASK_POLICY_TAL,
 387                                              TASK_POLICY_DISABLE);
 388                         break;
 389                 default:
 390                         return (EINVAL);
 391         }
 392
 393         return(0);
 394 }
 395
 396 static int
 397 handle_boost(int scope,
 398              int action,
 399     __unused int policy,
 400              int policy_subtype,
 401     __unused user_addr_t attrp,
 402              proc_t target_proc,
 403     __unused uint64_t target_threadid)
 404 {
 405         int error = 0;
 406
 407         assert(policy == PROC_POLICY_BOOST);
 408
 409         if (scope != PROC_POLICY_SCOPE_PROCESS)
 410                 return (EINVAL);
 411
 412         if (target_proc != current_proc())
 413                 return (EINVAL);
 414
 415         switch(policy_subtype) {
 416                 case PROC_POLICY_IMP_IMPORTANT:
 417                         if (task_is_importance_receiver_type(target_proc->task) == FALSE)
 418                                 return (EINVAL);
 419
 420                         switch (action) {
 421                                 case PROC_POLICY_ACTION_HOLD:
 422                                         /* PROCESS HOLD BOOST IMPORTANT */
 423                                         error = task_importance_hold_legacy_external_assertion(current_task(), 1);
 424                                         break;
 425                                 case PROC_POLICY_ACTION_DROP:
 426                                         /* PROCESS DROP BOOST IMPORTANT */
 427                                         error = task_importance_drop_legacy_external_assertion(current_task(), 1);
 428                                         break;
 429                                 default:
 430                                         error = (EINVAL);
 431                                         break;
 432                         }
 433                         break;
 434
 435                 case PROC_POLICY_IMP_DONATION:
 436 #if CONFIG_MACF
 437                         error = mac_proc_check_sched(current_proc(), target_proc);
 438                         if (error) return error;
 439 #endif
 440                         switch (action) {
 441                                 case PROC_POLICY_ACTION_SET:
 442                                         /* PROCESS SET BOOST DONATION */
 443                                         task_importance_mark_donor(target_proc->task, TRUE);
 444                                         break;
 445                                 default:
 446                                         error = (EINVAL);
 447                                         break;
 448                         }
 449                         break;
 450
 451                 default:
 452                         error = (EINVAL);
 453                         break;
 454         }
 455
 456         return(error);
 457 }
 458
 459
 460 /*
 461  * KPI to determine if a pid is currently backgrounded.
 462  * Returns ESRCH if pid cannot be found or has started exiting.
 463  * Returns EINVAL if state is NULL.
 464  * Sets *state to 1 if pid is backgrounded, and 0 otherwise.
 465  */
 466 int
 467 proc_pidbackgrounded(pid_t pid, uint32_t* state)
 468 {
 469         proc_t target_proc = PROC_NULL;
 470
 471         if (state == NULL)
 472                 return(EINVAL);
 473
 474         target_proc = proc_find(pid);
 475
 476         if (target_proc == PROC_NULL)
 477                 return(ESRCH);
 478
 479         if ( proc_get_effective_task_policy(target_proc->task, TASK_POLICY_DARWIN_BG) ) {
 480                 *state = 1;
 481         } else {
 482                 *state = 0;
 483         }
 484
 485         proc_rele(target_proc);
 486         return (0);
 487 }
 488
 489 /*
 490  * Get the darwin background state of the originator. If the current
 491  * process app type is App, then it is the originator, else if it is
 492  * a Daemon, then creator of the Resource Accounting attribute of
 493  * the current thread voucher is the originator of the work.
 494  */
 495 int
 496 proc_get_originatorbgstate(uint32_t *is_backgrounded)
 497 {
 498         uint32_t bgstate;
 499         proc_t p = current_proc();
 500         uint32_t flagsp;
 501         kern_return_t kr;
 502         pid_t pid;
 503         int ret;
 504         thread_t thread = current_thread();
 505
 506         bgstate = proc_get_effective_thread_policy(thread, TASK_POLICY_DARWIN_BG);
 507
 508         /* If current thread or task backgrounded, return background */
 509         if (bgstate) {
 510                 *is_backgrounded = 1;
 511                 return 0;
 512         }
 513
 514         /* Check if current process app type is App, then return foreground */
 515         proc_get_darwinbgstate(p->task, &flagsp);
 516         if ((flagsp & PROC_FLAG_APPLICATION) == PROC_FLAG_APPLICATION) {
 517                 *is_backgrounded = 0;
 518                 return 0;
 519         }
 520
 521         /*
 522          * Get the current voucher origin pid and it's bgstate.The pid
 523          * returned here might not be valid or may have been recycled.
 524          */
 525         kr = thread_get_current_voucher_origin_pid(&pid);
 526         if (kr != KERN_SUCCESS) {
 527                 if (kr == KERN_INVALID_TASK)
 528                         return ESRCH;
 529                 else if (kr == KERN_INVALID_VALUE)
 530                         return ENOATTR;
 531                 else
 532                         return EINVAL;
 533         }
 534
 535         ret = proc_pidbackgrounded(pid, is_backgrounded);
 536         return ret;
 537 }
 538
 539 int
 540 proc_apply_resource_actions(void * bsdinfo, __unused int type, int action)
 541 {
 542         proc_t p = (proc_t)bsdinfo;
 543
 544         switch(action) {
 545                 case PROC_POLICY_RSRCACT_THROTTLE:
 546                         /* no need to do anything */
 547                         break;
 548
 549                 case PROC_POLICY_RSRCACT_SUSPEND:
 550                         task_suspend(p->task);
 551                         break;
 552
 553                 case PROC_POLICY_RSRCACT_TERMINATE:
 554                         psignal(p, SIGKILL);
 555                         break;
 556
 557                 case PROC_POLICY_RSRCACT_NOTIFY_KQ:
 558                         /* not implemented */
 559                         break;
 560
 561                 case PROC_POLICY_RSRCACT_NOTIFY_EXC:
 562                         panic("shouldn't be applying exception notification to process!");
 563                         break;
 564         }
 565
 566         return(0);
 567 }
 568
 569 int
 570 proc_restore_resource_actions(void * bsdinfo, __unused int type, int action)
 571 {
 572         proc_t p = (proc_t)bsdinfo;
 573
 574         switch(action) {
 575                 case PROC_POLICY_RSRCACT_THROTTLE:
 576                 case PROC_POLICY_RSRCACT_TERMINATE:
 577                 case PROC_POLICY_RSRCACT_NOTIFY_KQ:
 578                 case PROC_POLICY_RSRCACT_NOTIFY_EXC:
 579                         /* no need to do anything */
 580                         break;
 581
 582                 case PROC_POLICY_RSRCACT_SUSPEND:
 583                         task_resume(p->task);
 584                         break;
 585
 586         }
 587
 588         return(0);
 589 }
 590