Zygote: Add fdsToIgnore (8dfa178e) · Commits · e / os / android_frameworks_base

core/java/com/android/internal/os/Zygote.java

+6 −3

Original line number	Diff line number	Diff line
		@@ -85,6 +85,9 @@ public final class Zygote {
		* file descriptor numbers that are to be closed by the child
		* (and replaced by /dev/null) after forking. An integer value
		* of -1 in any entry in the array means "ignore this one".
		* @param fdsToIgnore null-ok an array of ints, either null or holding
		* one or more POSIX file descriptor numbers that are to be ignored
		* in the file descriptor table check.
		* @param instructionSet null-ok the instruction set to use.
		* @param appDataDir null-ok the data directory of the app.
		*
		@@ -93,11 +96,11 @@ public final class Zygote {
		*/
		public static int forkAndSpecialize(int uid, int gid, int[] gids, int debugFlags,
		int[][] rlimits, int mountExternal, String seInfo, String niceName, int[] fdsToClose,
		String instructionSet, String appDataDir) {
		int[] fdsToIgnore, String instructionSet, String appDataDir) {
		VM_HOOKS.preFork();
		int pid = nativeForkAndSpecialize(
		uid, gid, gids, debugFlags, rlimits, mountExternal, seInfo, niceName, fdsToClose,
		instructionSet, appDataDir);
		fdsToIgnore, instructionSet, appDataDir);
		// Enable tracing as soon as possible for the child process.
		if (pid == 0) {
		Trace.setTracingEnabled(true);
		@@ -111,7 +114,7 @@ public final class Zygote {

		native private static int nativeForkAndSpecialize(int uid, int gid, int[] gids,int debugFlags,
		int[][] rlimits, int mountExternal, String seInfo, String niceName, int[] fdsToClose,
		String instructionSet, String appDataDir);
		int[] fdsToIgnore, String instructionSet, String appDataDir);

		/**
		* Special method to start the system server process. In addition to the

core/java/com/android/internal/os/ZygoteConnection.java

+4 −1

Original line number	Diff line number	Diff line
		@@ -193,11 +193,14 @@ class ZygoteConnection {
		rlimits = parsedArgs.rlimits.toArray(intArray2d);
		}

		int[] fdsToIgnore = null;

		if (parsedArgs.invokeWith != null) {
		FileDescriptor[] pipeFds = Os.pipe2(O_CLOEXEC);
		childPipeFd = pipeFds[1];
		serverPipeFd = pipeFds[0];
		Os.fcntlInt(childPipeFd, F_SETFD, 0);
		fdsToIgnore = new int[] { childPipeFd.getInt$(), serverPipeFd.getInt$() };
		}

		/**
		@@ -230,7 +233,7 @@ class ZygoteConnection {

		pid = Zygote.forkAndSpecialize(parsedArgs.uid, parsedArgs.gid, parsedArgs.gids,
		parsedArgs.debugFlags, rlimits, parsedArgs.mountExternal, parsedArgs.seInfo,
		parsedArgs.niceName, fdsToClose, parsedArgs.instructionSet,
		parsedArgs.niceName, fdsToClose, fdsToIgnore, parsedArgs.instructionSet,
		parsedArgs.appDataDir);
		} catch (ErrnoException ex) {
		logAndPrintError(newStderr, "Exception creating pipe", ex);

core/jni/com_android_internal_os_Zygote.cpp

+28 −6

Original line number	Diff line number	Diff line
		@@ -43,6 +43,7 @@
		#include <sys/wait.h>
		#include <unistd.h>

		#include "android-base/logging.h"
		#include <cutils/fs.h>
		#include <cutils/multiuser.h>
		#include <cutils/sched_policy.h>
		@@ -440,6 +441,22 @@ void SetThreadName(const char* thread_name) {
		// The list of open zygote file descriptors.
		static FileDescriptorTable* gOpenFdTable = NULL;

		static void FillFileDescriptorVector(JNIEnv* env,
		jintArray java_fds,
		std::vector<int>* fds) {
		CHECK(fds != nullptr);
		if (java_fds != nullptr) {
		ScopedIntArrayRO ar(env, java_fds);
		if (ar.get() == nullptr) {
		RuntimeAbort(env, __LINE__, "Bad fd array");
		}
		fds->reserve(ar.size());
		for (size_t i = 0; i < ar.size(); ++i) {
		fds->push_back(ar[i]);
		}
		}
		}

		// Utility routine to fork zygote and specialize the child process.
		static pid_t ForkAndSpecializeCommon(JNIEnv* env, uid_t uid, gid_t gid, jintArray javaGids,
		jint debug_flags, jobjectArray javaRlimits,
		@@ -447,6 +464,7 @@ static pid_t ForkAndSpecializeCommon(JNIEnv* env, uid_t uid, gid_t gid, jintArra
		jint mount_external,
		jstring java_se_info, jstring java_se_name,
		bool is_system_server, jintArray fdsToClose,
		jintArray fdsToIgnore,
		jstring instructionSet, jstring dataDir) {
		SetSigChldHandler();

		@@ -457,12 +475,14 @@ static pid_t ForkAndSpecializeCommon(JNIEnv* env, uid_t uid, gid_t gid, jintArra
		// If this is the first fork for this zygote, create the open FD table.
		// If it isn't, we just need to check whether the list of open files has
		// changed (and it shouldn't in the normal case).
		std::vector<int> fds_to_ignore;
		FillFileDescriptorVector(env, fdsToIgnore, &fds_to_ignore);
		if (gOpenFdTable == NULL) {
		gOpenFdTable = FileDescriptorTable::Create();
		gOpenFdTable = FileDescriptorTable::Create(fds_to_ignore);
		if (gOpenFdTable == NULL) {
		RuntimeAbort(env, __LINE__, "Unable to construct file descriptor table.");
		}
		} else if (!gOpenFdTable->Restat()) {
		} else if (!gOpenFdTable->Restat(fds_to_ignore)) {
		RuntimeAbort(env, __LINE__, "Unable to restat file descriptor table.");
		}

		@@ -621,7 +641,9 @@ static jint com_android_internal_os_Zygote_nativeForkAndSpecialize(
		JNIEnv* env, jclass, jint uid, jint gid, jintArray gids,
		jint debug_flags, jobjectArray rlimits,
		jint mount_external, jstring se_info, jstring se_name,
		jintArray fdsToClose, jstring instructionSet, jstring appDataDir) {
		jintArray fdsToClose,
		jintArray fdsToIgnore,
		jstring instructionSet, jstring appDataDir) {
		jlong capabilities = 0;

		// Grant CAP_WAKE_ALARM to the Bluetooth process.
		@@ -656,7 +678,7 @@ static jint com_android_internal_os_Zygote_nativeForkAndSpecialize(

		return ForkAndSpecializeCommon(env, uid, gid, gids, debug_flags,
		rlimits, capabilities, capabilities, mount_external, se_info,
		se_name, false, fdsToClose, instructionSet, appDataDir);
		se_name, false, fdsToClose, fdsToIgnore, instructionSet, appDataDir);
		}

		static jint com_android_internal_os_Zygote_nativeForkSystemServer(
		@@ -667,7 +689,7 @@ static jint com_android_internal_os_Zygote_nativeForkSystemServer(
		debug_flags, rlimits,
		permittedCapabilities, effectiveCapabilities,
		MOUNT_EXTERNAL_DEFAULT, NULL, NULL, true, NULL,
		NULL, NULL);
		NULL, NULL, NULL);
		if (pid > 0) {
		// The zygote process checks whether the child process has died or not.
		ALOGI("System server process %d has been created", pid);
		@@ -734,7 +756,7 @@ static void com_android_internal_os_Zygote_nativeUnmountStorageOnInit(JNIEnv* en

		static const JNINativeMethod gMethods[] = {
		{ "nativeForkAndSpecialize",
		"(II[II[[IILjava/lang/String;Ljava/lang/String;[ILjava/lang/String;Ljava/lang/String;)I",
		"(II[II[[IILjava/lang/String;Ljava/lang/String;[I[ILjava/lang/String;Ljava/lang/String;)I",
		(void *) com_android_internal_os_Zygote_nativeForkAndSpecialize },
		{ "nativeForkSystemServer", "(II[II[[IJJ)I",
		(void *) com_android_internal_os_Zygote_nativeForkSystemServer },

core/jni/fd_utils.cpp

+10 −2

Original line number	Diff line number	Diff line
		@@ -381,7 +381,7 @@ bool FileDescriptorInfo::DetachSocket() const {
		}

		// static
		FileDescriptorTable* FileDescriptorTable::Create() {
		FileDescriptorTable* FileDescriptorTable::Create(const std::vector<int>& fds_to_ignore) {
		DIR* d = opendir(kFdPath);
		if (d == NULL) {
		ALOGE("Unable to open directory %s: %s", kFdPath, strerror(errno));
		@@ -396,6 +396,10 @@ FileDescriptorTable* FileDescriptorTable::Create() {
		if (fd == -1) {
		continue;
		}
		if (std::find(fds_to_ignore.begin(), fds_to_ignore.end(), fd) != fds_to_ignore.end()) {
		ALOGI("Ignoring open file descriptor %d", fd);
		continue;
		}

		FileDescriptorInfo* info = FileDescriptorInfo::CreateFromFd(fd);
		if (info == NULL) {
		@@ -414,7 +418,7 @@ FileDescriptorTable* FileDescriptorTable::Create() {
		return new FileDescriptorTable(open_fd_map);
		}

		bool FileDescriptorTable::Restat() {
		bool FileDescriptorTable::Restat(const std::vector<int>& fds_to_ignore) {
		std::set<int> open_fds;

		// First get the list of open descriptors.
		@@ -431,6 +435,10 @@ bool FileDescriptorTable::Restat() {
		if (fd == -1) {
		continue;
		}
		if (std::find(fds_to_ignore.begin(), fds_to_ignore.end(), fd) != fds_to_ignore.end()) {
		ALOGI("Ignoring open file descriptor %d", fd);
		continue;
		}

		open_fds.insert(fd);
		}

core/jni/fd_utils.h

+2 −2

Original line number	Diff line number	Diff line
		@@ -122,9 +122,9 @@ class FileDescriptorTable {
		// Creates a new FileDescriptorTable. This function scans
		// /proc/self/fd for the list of open file descriptors and collects
		// information about them. Returns NULL if an error occurs.
		static FileDescriptorTable* Create();
		static FileDescriptorTable* Create(const std::vector<int>& fds_to_ignore);

		bool Restat();
		bool Restat(const std::vector<int>& fds_to_ignore);

		// Reopens all file descriptors that are contained in the table. Returns true
		// if all descriptors were successfully re-opened or detached, and false if an