com_android_internal_os_Zygote.cpp revision ea1831d211ea0e6b2d161c714bb0786369ef2df5
1/* 2 * Copyright (C) 2008 The Android Open Source Project 3 * 4 * Licensed under the Apache License, Version 2.0 (the "License"); 5 * you may not use this file except in compliance with the License. 6 * You may obtain a copy of the License at 7 * 8 * http://www.apache.org/licenses/LICENSE-2.0 9 * 10 * Unless required by applicable law or agreed to in writing, software 11 * distributed under the License is distributed on an "AS IS" BASIS, 12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 13 * See the License for the specific language governing permissions and 14 * limitations under the License. 15 */ 16 17#define LOG_TAG "Zygote" 18 19// sys/mount.h has to come before linux/fs.h due to redefinition of MS_RDONLY, MS_BIND, etc 20#include <sys/mount.h> 21#include <linux/fs.h> 22 23#include <list> 24#include <string> 25 26#include <fcntl.h> 27#include <grp.h> 28#include <inttypes.h> 29#include <mntent.h> 30#include <paths.h> 31#include <signal.h> 32#include <stdlib.h> 33#include <sys/capability.h> 34#include <sys/personality.h> 35#include <sys/prctl.h> 36#include <sys/resource.h> 37#include <sys/stat.h> 38#include <sys/types.h> 39#include <sys/utsname.h> 40#include <sys/wait.h> 41#include <unistd.h> 42 43#include <cutils/fs.h> 44#include <cutils/multiuser.h> 45#include <cutils/sched_policy.h> 46#include <private/android_filesystem_config.h> 47#include <utils/String8.h> 48#include <selinux/android.h> 49#include <processgroup/processgroup.h> 50 51#include "core_jni_helpers.h" 52#include "JNIHelp.h" 53#include "ScopedLocalRef.h" 54#include "ScopedPrimitiveArray.h" 55#include "ScopedUtfChars.h" 56 57#include "nativebridge/native_bridge.h" 58 59namespace { 60 61using android::String8; 62 63static pid_t gSystemServerPid = 0; 64 65static const char kZygoteClassName[] = "com/android/internal/os/Zygote"; 66static jclass gZygoteClass; 67static jmethodID gCallPostForkChildHooks; 68 69// Must match values in com.android.internal.os.Zygote. 70enum MountExternalKind { 71 MOUNT_EXTERNAL_NONE = 0, 72 MOUNT_EXTERNAL_DEFAULT = 1, 73 MOUNT_EXTERNAL_READ = 2, 74 MOUNT_EXTERNAL_WRITE = 3, 75}; 76 77static void RuntimeAbort(JNIEnv* env) { 78 env->FatalError("RuntimeAbort"); 79} 80 81// This signal handler is for zygote mode, since the zygote must reap its children 82static void SigChldHandler(int /*signal_number*/) { 83 pid_t pid; 84 int status; 85 86 // It's necessary to save and restore the errno during this function. 87 // Since errno is stored per thread, changing it here modifies the errno 88 // on the thread on which this signal handler executes. If a signal occurs 89 // between a call and an errno check, it's possible to get the errno set 90 // here. 91 // See b/23572286 for extra information. 92 int saved_errno = errno; 93 94 while ((pid = waitpid(-1, &status, WNOHANG)) > 0) { 95 // Log process-death status that we care about. In general it is 96 // not safe to call LOG(...) from a signal handler because of 97 // possible reentrancy. However, we know a priori that the 98 // current implementation of LOG() is safe to call from a SIGCHLD 99 // handler in the zygote process. If the LOG() implementation 100 // changes its locking strategy or its use of syscalls within the 101 // lazy-init critical section, its use here may become unsafe. 102 if (WIFEXITED(status)) { 103 if (WEXITSTATUS(status)) { 104 ALOGI("Process %d exited cleanly (%d)", pid, WEXITSTATUS(status)); 105 } 106 } else if (WIFSIGNALED(status)) { 107 if (WTERMSIG(status) != SIGKILL) { 108 ALOGI("Process %d exited due to signal (%d)", pid, WTERMSIG(status)); 109 } 110 if (WCOREDUMP(status)) { 111 ALOGI("Process %d dumped core.", pid); 112 } 113 } 114 115 // If the just-crashed process is the system_server, bring down zygote 116 // so that it is restarted by init and system server will be restarted 117 // from there. 118 if (pid == gSystemServerPid) { 119 ALOGE("Exit zygote because system server (%d) has terminated", pid); 120 kill(getpid(), SIGKILL); 121 } 122 } 123 124 // Note that we shouldn't consider ECHILD an error because 125 // the secondary zygote might have no children left to wait for. 126 if (pid < 0 && errno != ECHILD) { 127 ALOGW("Zygote SIGCHLD error in waitpid: %s", strerror(errno)); 128 } 129 130 errno = saved_errno; 131} 132 133// Configures the SIGCHLD handler for the zygote process. This is configured 134// very late, because earlier in the runtime we may fork() and exec() 135// other processes, and we want to waitpid() for those rather than 136// have them be harvested immediately. 137// 138// This ends up being called repeatedly before each fork(), but there's 139// no real harm in that. 140static void SetSigChldHandler() { 141 struct sigaction sa; 142 memset(&sa, 0, sizeof(sa)); 143 sa.sa_handler = SigChldHandler; 144 145 int err = sigaction(SIGCHLD, &sa, NULL); 146 if (err < 0) { 147 ALOGW("Error setting SIGCHLD handler: %s", strerror(errno)); 148 } 149} 150 151// Sets the SIGCHLD handler back to default behavior in zygote children. 152static void UnsetSigChldHandler() { 153 struct sigaction sa; 154 memset(&sa, 0, sizeof(sa)); 155 sa.sa_handler = SIG_DFL; 156 157 int err = sigaction(SIGCHLD, &sa, NULL); 158 if (err < 0) { 159 ALOGW("Error unsetting SIGCHLD handler: %s", strerror(errno)); 160 } 161} 162 163// Calls POSIX setgroups() using the int[] object as an argument. 164// A NULL argument is tolerated. 165static void SetGids(JNIEnv* env, jintArray javaGids) { 166 if (javaGids == NULL) { 167 return; 168 } 169 170 ScopedIntArrayRO gids(env, javaGids); 171 if (gids.get() == NULL) { 172 RuntimeAbort(env); 173 } 174 int rc = setgroups(gids.size(), reinterpret_cast<const gid_t*>(&gids[0])); 175 if (rc == -1) { 176 ALOGE("setgroups failed"); 177 RuntimeAbort(env); 178 } 179} 180 181// Sets the resource limits via setrlimit(2) for the values in the 182// two-dimensional array of integers that's passed in. The second dimension 183// contains a tuple of length 3: (resource, rlim_cur, rlim_max). NULL is 184// treated as an empty array. 185static void SetRLimits(JNIEnv* env, jobjectArray javaRlimits) { 186 if (javaRlimits == NULL) { 187 return; 188 } 189 190 rlimit rlim; 191 memset(&rlim, 0, sizeof(rlim)); 192 193 for (int i = 0; i < env->GetArrayLength(javaRlimits); ++i) { 194 ScopedLocalRef<jobject> javaRlimitObject(env, env->GetObjectArrayElement(javaRlimits, i)); 195 ScopedIntArrayRO javaRlimit(env, reinterpret_cast<jintArray>(javaRlimitObject.get())); 196 if (javaRlimit.size() != 3) { 197 ALOGE("rlimits array must have a second dimension of size 3"); 198 RuntimeAbort(env); 199 } 200 201 rlim.rlim_cur = javaRlimit[1]; 202 rlim.rlim_max = javaRlimit[2]; 203 204 int rc = setrlimit(javaRlimit[0], &rlim); 205 if (rc == -1) { 206 ALOGE("setrlimit(%d, {%ld, %ld}) failed", javaRlimit[0], rlim.rlim_cur, 207 rlim.rlim_max); 208 RuntimeAbort(env); 209 } 210 } 211} 212 213// The debug malloc library needs to know whether it's the zygote or a child. 214extern "C" int gMallocLeakZygoteChild; 215 216static void EnableKeepCapabilities(JNIEnv* env) { 217 int rc = prctl(PR_SET_KEEPCAPS, 1, 0, 0, 0); 218 if (rc == -1) { 219 ALOGE("prctl(PR_SET_KEEPCAPS) failed"); 220 RuntimeAbort(env); 221 } 222} 223 224static void DropCapabilitiesBoundingSet(JNIEnv* env) { 225 for (int i = 0; prctl(PR_CAPBSET_READ, i, 0, 0, 0) >= 0; i++) { 226 int rc = prctl(PR_CAPBSET_DROP, i, 0, 0, 0); 227 if (rc == -1) { 228 if (errno == EINVAL) { 229 ALOGE("prctl(PR_CAPBSET_DROP) failed with EINVAL. Please verify " 230 "your kernel is compiled with file capabilities support"); 231 } else { 232 ALOGE("prctl(PR_CAPBSET_DROP) failed"); 233 RuntimeAbort(env); 234 } 235 } 236 } 237} 238 239static void SetCapabilities(JNIEnv* env, int64_t permitted, int64_t effective) { 240 __user_cap_header_struct capheader; 241 memset(&capheader, 0, sizeof(capheader)); 242 capheader.version = _LINUX_CAPABILITY_VERSION_3; 243 capheader.pid = 0; 244 245 __user_cap_data_struct capdata[2]; 246 memset(&capdata, 0, sizeof(capdata)); 247 capdata[0].effective = effective; 248 capdata[1].effective = effective >> 32; 249 capdata[0].permitted = permitted; 250 capdata[1].permitted = permitted >> 32; 251 252 if (capset(&capheader, &capdata[0]) == -1) { 253 ALOGE("capset(%" PRId64 ", %" PRId64 ") failed", permitted, effective); 254 RuntimeAbort(env); 255 } 256} 257 258static void SetSchedulerPolicy(JNIEnv* env) { 259 errno = -set_sched_policy(0, SP_DEFAULT); 260 if (errno != 0) { 261 ALOGE("set_sched_policy(0, SP_DEFAULT) failed"); 262 RuntimeAbort(env); 263 } 264} 265 266static int UnmountTree(const char* path) { 267 size_t path_len = strlen(path); 268 269 FILE* fp = setmntent("/proc/mounts", "r"); 270 if (fp == NULL) { 271 ALOGE("Error opening /proc/mounts: %s", strerror(errno)); 272 return -errno; 273 } 274 275 // Some volumes can be stacked on each other, so force unmount in 276 // reverse order to give us the best chance of success. 277 std::list<std::string> toUnmount; 278 mntent* mentry; 279 while ((mentry = getmntent(fp)) != NULL) { 280 if (strncmp(mentry->mnt_dir, path, path_len) == 0) { 281 toUnmount.push_front(std::string(mentry->mnt_dir)); 282 } 283 } 284 endmntent(fp); 285 286 for (auto path : toUnmount) { 287 if (umount2(path.c_str(), MNT_DETACH)) { 288 ALOGW("Failed to unmount %s: %s", path.c_str(), strerror(errno)); 289 } 290 } 291 return 0; 292} 293 294// Create a private mount namespace and bind mount appropriate emulated 295// storage for the given user. 296static bool MountEmulatedStorage(uid_t uid, jint mount_mode, 297 bool force_mount_namespace) { 298 // See storage config details at http://source.android.com/tech/storage/ 299 300 // Create a second private mount namespace for our process 301 if (unshare(CLONE_NEWNS) == -1) { 302 ALOGW("Failed to unshare(): %s", strerror(errno)); 303 return false; 304 } 305 306 // Unmount storage provided by root namespace and mount requested view 307 UnmountTree("/storage"); 308 309 String8 storageSource; 310 if (mount_mode == MOUNT_EXTERNAL_DEFAULT) { 311 storageSource = "/mnt/runtime/default"; 312 } else if (mount_mode == MOUNT_EXTERNAL_READ) { 313 storageSource = "/mnt/runtime/read"; 314 } else if (mount_mode == MOUNT_EXTERNAL_WRITE) { 315 storageSource = "/mnt/runtime/write"; 316 } else { 317 // Sane default of no storage visible 318 return true; 319 } 320 if (TEMP_FAILURE_RETRY(mount(storageSource.string(), "/storage", 321 NULL, MS_BIND | MS_REC | MS_SLAVE, NULL)) == -1) { 322 ALOGW("Failed to mount %s to /storage: %s", storageSource.string(), strerror(errno)); 323 return false; 324 } 325 326 // Mount user-specific symlink helper into place 327 userid_t user_id = multiuser_get_user_id(uid); 328 const String8 userSource(String8::format("/mnt/user/%d", user_id)); 329 if (fs_prepare_dir(userSource.string(), 0751, 0, 0) == -1) { 330 return false; 331 } 332 if (TEMP_FAILURE_RETRY(mount(userSource.string(), "/storage/self", 333 NULL, MS_BIND, NULL)) == -1) { 334 ALOGW("Failed to mount %s to /storage/self: %s", userSource.string(), strerror(errno)); 335 return false; 336 } 337 338 return true; 339} 340 341static bool NeedsNoRandomizeWorkaround() { 342#if !defined(__arm__) 343 return false; 344#else 345 int major; 346 int minor; 347 struct utsname uts; 348 if (uname(&uts) == -1) { 349 return false; 350 } 351 352 if (sscanf(uts.release, "%d.%d", &major, &minor) != 2) { 353 return false; 354 } 355 356 // Kernels before 3.4.* need the workaround. 357 return (major < 3) || ((major == 3) && (minor < 4)); 358#endif 359} 360 361// Utility to close down the Zygote socket file descriptors while 362// the child is still running as root with Zygote's privileges. Each 363// descriptor (if any) is closed via dup2(), replacing it with a valid 364// (open) descriptor to /dev/null. 365 366static void DetachDescriptors(JNIEnv* env, jintArray fdsToClose) { 367 if (!fdsToClose) { 368 return; 369 } 370 jsize count = env->GetArrayLength(fdsToClose); 371 ScopedIntArrayRO ar(env, fdsToClose); 372 if (ar.get() == NULL) { 373 ALOGE("Bad fd array"); 374 RuntimeAbort(env); 375 } 376 jsize i; 377 int devnull; 378 for (i = 0; i < count; i++) { 379 devnull = open("/dev/null", O_RDWR); 380 if (devnull < 0) { 381 ALOGE("Failed to open /dev/null: %s", strerror(errno)); 382 RuntimeAbort(env); 383 continue; 384 } 385 ALOGV("Switching descriptor %d to /dev/null: %s", ar[i], strerror(errno)); 386 if (dup2(devnull, ar[i]) < 0) { 387 ALOGE("Failed dup2() on descriptor %d: %s", ar[i], strerror(errno)); 388 RuntimeAbort(env); 389 } 390 close(devnull); 391 } 392} 393 394void SetThreadName(const char* thread_name) { 395 bool hasAt = false; 396 bool hasDot = false; 397 const char* s = thread_name; 398 while (*s) { 399 if (*s == '.') { 400 hasDot = true; 401 } else if (*s == '@') { 402 hasAt = true; 403 } 404 s++; 405 } 406 const int len = s - thread_name; 407 if (len < 15 || hasAt || !hasDot) { 408 s = thread_name; 409 } else { 410 s = thread_name + len - 15; 411 } 412 // pthread_setname_np fails rather than truncating long strings. 413 char buf[16]; // MAX_TASK_COMM_LEN=16 is hard-coded into bionic 414 strlcpy(buf, s, sizeof(buf)-1); 415 errno = pthread_setname_np(pthread_self(), buf); 416 if (errno != 0) { 417 ALOGW("Unable to set the name of current thread to '%s': %s", buf, strerror(errno)); 418 } 419} 420 421#ifdef ENABLE_SCHED_BOOST 422static void SetForkLoad(bool boost) { 423 // set scheduler knob to boost forked processes 424 pid_t currentPid = getpid(); 425 // fits at most "/proc/XXXXXXX/sched_init_task_load\0" 426 char schedPath[35]; 427 snprintf(schedPath, sizeof(schedPath), "/proc/%u/sched_init_task_load", currentPid); 428 int schedBoostFile = open(schedPath, O_WRONLY); 429 if (schedBoostFile < 0) { 430 ALOGW("Unable to set zygote scheduler boost"); 431 return; 432 } 433 if (boost) { 434 write(schedBoostFile, "100\0", 4); 435 } else { 436 write(schedBoostFile, "0\0", 2); 437 } 438 close(schedBoostFile); 439} 440#endif 441 442// Utility routine to fork zygote and specialize the child process. 443static pid_t ForkAndSpecializeCommon(JNIEnv* env, uid_t uid, gid_t gid, jintArray javaGids, 444 jint debug_flags, jobjectArray javaRlimits, 445 jlong permittedCapabilities, jlong effectiveCapabilities, 446 jint mount_external, 447 jstring java_se_info, jstring java_se_name, 448 bool is_system_server, jintArray fdsToClose, 449 jstring instructionSet, jstring dataDir) { 450 SetSigChldHandler(); 451 452#ifdef ENABLE_SCHED_BOOST 453 SetForkLoad(true); 454#endif 455 456 pid_t pid = fork(); 457 458 if (pid == 0) { 459 // The child process. 460 gMallocLeakZygoteChild = 1; 461 462 // Clean up any descriptors which must be closed immediately 463 DetachDescriptors(env, fdsToClose); 464 465 // Keep capabilities across UID change, unless we're staying root. 466 if (uid != 0) { 467 EnableKeepCapabilities(env); 468 } 469 470 DropCapabilitiesBoundingSet(env); 471 472 bool use_native_bridge = !is_system_server && (instructionSet != NULL) 473 && android::NativeBridgeAvailable(); 474 if (use_native_bridge) { 475 ScopedUtfChars isa_string(env, instructionSet); 476 use_native_bridge = android::NeedsNativeBridge(isa_string.c_str()); 477 } 478 if (use_native_bridge && dataDir == NULL) { 479 // dataDir should never be null if we need to use a native bridge. 480 // In general, dataDir will never be null for normal applications. It can only happen in 481 // special cases (for isolated processes which are not associated with any app). These are 482 // launched by the framework and should not be emulated anyway. 483 use_native_bridge = false; 484 ALOGW("Native bridge will not be used because dataDir == NULL."); 485 } 486 487 if (!MountEmulatedStorage(uid, mount_external, use_native_bridge)) { 488 ALOGW("Failed to mount emulated storage: %s", strerror(errno)); 489 if (errno == ENOTCONN || errno == EROFS) { 490 // When device is actively encrypting, we get ENOTCONN here 491 // since FUSE was mounted before the framework restarted. 492 // When encrypted device is booting, we get EROFS since 493 // FUSE hasn't been created yet by init. 494 // In either case, continue without external storage. 495 } else { 496 ALOGE("Cannot continue without emulated storage"); 497 RuntimeAbort(env); 498 } 499 } 500 501 if (!is_system_server) { 502 int rc = createProcessGroup(uid, getpid()); 503 if (rc != 0) { 504 if (rc == -EROFS) { 505 ALOGW("createProcessGroup failed, kernel missing CONFIG_CGROUP_CPUACCT?"); 506 } else { 507 ALOGE("createProcessGroup(%d, %d) failed: %s", uid, pid, strerror(-rc)); 508 } 509 } 510 } 511 512 SetGids(env, javaGids); 513 514 SetRLimits(env, javaRlimits); 515 516 if (use_native_bridge) { 517 ScopedUtfChars isa_string(env, instructionSet); 518 ScopedUtfChars data_dir(env, dataDir); 519 android::PreInitializeNativeBridge(data_dir.c_str(), isa_string.c_str()); 520 } 521 522 int rc = setresgid(gid, gid, gid); 523 if (rc == -1) { 524 ALOGE("setresgid(%d) failed: %s", gid, strerror(errno)); 525 RuntimeAbort(env); 526 } 527 528 rc = setresuid(uid, uid, uid); 529 if (rc == -1) { 530 ALOGE("setresuid(%d) failed: %s", uid, strerror(errno)); 531 RuntimeAbort(env); 532 } 533 534 if (NeedsNoRandomizeWorkaround()) { 535 // Work around ARM kernel ASLR lossage (http://b/5817320). 536 int old_personality = personality(0xffffffff); 537 int new_personality = personality(old_personality | ADDR_NO_RANDOMIZE); 538 if (new_personality == -1) { 539 ALOGW("personality(%d) failed: %s", new_personality, strerror(errno)); 540 } 541 } 542 543 SetCapabilities(env, permittedCapabilities, effectiveCapabilities); 544 545 SetSchedulerPolicy(env); 546 547 const char* se_info_c_str = NULL; 548 ScopedUtfChars* se_info = NULL; 549 if (java_se_info != NULL) { 550 se_info = new ScopedUtfChars(env, java_se_info); 551 se_info_c_str = se_info->c_str(); 552 if (se_info_c_str == NULL) { 553 ALOGE("se_info_c_str == NULL"); 554 RuntimeAbort(env); 555 } 556 } 557 const char* se_name_c_str = NULL; 558 ScopedUtfChars* se_name = NULL; 559 if (java_se_name != NULL) { 560 se_name = new ScopedUtfChars(env, java_se_name); 561 se_name_c_str = se_name->c_str(); 562 if (se_name_c_str == NULL) { 563 ALOGE("se_name_c_str == NULL"); 564 RuntimeAbort(env); 565 } 566 } 567 rc = selinux_android_setcontext(uid, is_system_server, se_info_c_str, se_name_c_str); 568 if (rc == -1) { 569 ALOGE("selinux_android_setcontext(%d, %d, \"%s\", \"%s\") failed", uid, 570 is_system_server, se_info_c_str, se_name_c_str); 571 RuntimeAbort(env); 572 } 573 574 // Make it easier to debug audit logs by setting the main thread's name to the 575 // nice name rather than "app_process". 576 if (se_info_c_str == NULL && is_system_server) { 577 se_name_c_str = "system_server"; 578 } 579 if (se_info_c_str != NULL) { 580 SetThreadName(se_name_c_str); 581 } 582 583 delete se_info; 584 delete se_name; 585 586 UnsetSigChldHandler(); 587 588 env->CallStaticVoidMethod(gZygoteClass, gCallPostForkChildHooks, debug_flags, 589 is_system_server ? NULL : instructionSet); 590 if (env->ExceptionCheck()) { 591 ALOGE("Error calling post fork hooks."); 592 RuntimeAbort(env); 593 } 594 } else if (pid > 0) { 595 // the parent process 596 597#ifdef ENABLE_SCHED_BOOST 598 // unset scheduler knob 599 SetForkLoad(false); 600#endif 601 602 } 603 return pid; 604} 605} // anonymous namespace 606 607namespace android { 608 609static jint com_android_internal_os_Zygote_nativeForkAndSpecialize( 610 JNIEnv* env, jclass, jint uid, jint gid, jintArray gids, 611 jint debug_flags, jobjectArray rlimits, 612 jint mount_external, jstring se_info, jstring se_name, 613 jintArray fdsToClose, jstring instructionSet, jstring appDataDir) { 614 jlong capabilities = 0; 615 if (uid == AID_BLUETOOTH) { 616 // Grant CAP_WAKE_ALARM and CAP_BLOCK_SUSPEND to the Bluetooth process. 617 capabilities |= (1LL << CAP_WAKE_ALARM); 618 capabilities |= (1LL << CAP_BLOCK_SUSPEND); 619 620 // Add the Bluetooth process to the system group. 621 jsize length = env->GetArrayLength(reinterpret_cast<jarray>(gids)); 622 jintArray gids_with_system = env->NewIntArray(length + 1); 623 if (!gids_with_system) { 624 ALOGE("could not allocate java array for gids"); 625 RuntimeAbort(env); 626 } 627 628 jint *gids_elements = env->GetIntArrayElements(gids, NULL); 629 jint *gids_with_system_elements = env->GetIntArrayElements(gids_with_system, NULL); 630 631 if (!gids_elements || !gids_with_system_elements) { 632 ALOGE("could not allocate arrays for gids"); 633 RuntimeAbort(env); 634 } 635 636 gids_with_system_elements[0] = AID_SYSTEM; 637 memcpy(&gids_with_system_elements[1], &gids_elements[0], length * sizeof(jint)); 638 639 env->ReleaseIntArrayElements(gids, gids_elements, JNI_ABORT); 640 env->ReleaseIntArrayElements(gids_with_system, gids_with_system_elements, 0); 641 gids = gids_with_system; 642 } 643 644 return ForkAndSpecializeCommon(env, uid, gid, gids, debug_flags, 645 rlimits, capabilities, capabilities, mount_external, se_info, 646 se_name, false, fdsToClose, instructionSet, appDataDir); 647} 648 649static jint com_android_internal_os_Zygote_nativeForkSystemServer( 650 JNIEnv* env, jclass, uid_t uid, gid_t gid, jintArray gids, 651 jint debug_flags, jobjectArray rlimits, jlong permittedCapabilities, 652 jlong effectiveCapabilities) { 653 pid_t pid = ForkAndSpecializeCommon(env, uid, gid, gids, 654 debug_flags, rlimits, 655 permittedCapabilities, effectiveCapabilities, 656 MOUNT_EXTERNAL_DEFAULT, NULL, NULL, true, NULL, 657 NULL, NULL); 658 if (pid > 0) { 659 // The zygote process checks whether the child process has died or not. 660 ALOGI("System server process %d has been created", pid); 661 gSystemServerPid = pid; 662 // There is a slight window that the system server process has crashed 663 // but it went unnoticed because we haven't published its pid yet. So 664 // we recheck here just to make sure that all is well. 665 int status; 666 if (waitpid(pid, &status, WNOHANG) == pid) { 667 ALOGE("System server process %d has died. Restarting Zygote!", pid); 668 RuntimeAbort(env); 669 } 670 } 671 return pid; 672} 673 674static const JNINativeMethod gMethods[] = { 675 { "nativeForkAndSpecialize", 676 "(II[II[[IILjava/lang/String;Ljava/lang/String;[ILjava/lang/String;Ljava/lang/String;)I", 677 (void *) com_android_internal_os_Zygote_nativeForkAndSpecialize }, 678 { "nativeForkSystemServer", "(II[II[[IJJ)I", 679 (void *) com_android_internal_os_Zygote_nativeForkSystemServer } 680}; 681 682int register_com_android_internal_os_Zygote(JNIEnv* env) { 683 gZygoteClass = MakeGlobalRefOrDie(env, FindClassOrDie(env, kZygoteClassName)); 684 gCallPostForkChildHooks = GetStaticMethodIDOrDie(env, gZygoteClass, "callPostForkChildHooks", 685 "(ILjava/lang/String;)V"); 686 687 return RegisterMethodsOrDie(env, "com/android/internal/os/Zygote", gMethods, NELEM(gMethods)); 688} 689} // namespace android 690 691