ActivityManagerService: stay away from zombie content providers (d90350b9) · Commits · e / os / android_frameworks_base

core/java/android/os/Process.java

+25 −0

Original line number	Diff line number	Diff line
		@@ -829,4 +829,29 @@ public class Process {
		* @hide
		*/
		public static final native long getPss(int pid);

		private static final int[] PROCESS_STATE_FORMAT = new int[] {
		PROC_SPACE_TERM,
		PROC_SPACE_TERM\|PROC_PARENS, // 1: name
		PROC_SPACE_TERM\|PROC_OUT_STRING, // 2: state
		};

		/**
		* Returns true if the process can be found and is not a zombie
		* @param pid the process id
		* @hide
		*/
		public static final boolean isAlive(int pid) {
		boolean ret = false;
		String[] processStateString = new String[1];
		if (Process.readProcFile("/proc/" + pid + "/stat",
		PROCESS_STATE_FORMAT, processStateString, null, null)) {
		ret = true;
		// Log.i(LOG_TAG,"State of process " + pid + " is " + processStateString[0]);
		if (processStateString[0].equals("Z")) {
		ret = false;
		}
		}
		return ret;
		}
		}

services/java/com/android/server/am/ActivityManagerService.java

+68 −42

Original line number	Diff line number	Diff line
		@@ -5260,6 +5260,48 @@ public final class ActivityManagerService extends ActivityManagerNative
		return msg;
		}

		boolean incProviderCount(ProcessRecord r, ContentProviderRecord cpr) {
		if (r != null) {
		Integer cnt = r.conProviders.get(cpr);
		if (DEBUG_PROVIDER) Slog.v(TAG,
		"Adding provider requested by "
		+ r.processName + " from process "
		+ cpr.info.processName + ": " + cpr.name.flattenToShortString()
		+ " cnt=" + (cnt == null ? 1 : cnt));
		if (cnt == null) {
		cpr.clients.add(r);
		r.conProviders.put(cpr, new Integer(1));
		return true;
		} else {
		r.conProviders.put(cpr, new Integer(cnt.intValue()+1));
		}
		} else {
		cpr.externals++;
		}
		return false;
		}

		boolean decProviderCount(ProcessRecord r, ContentProviderRecord cpr) {
		if (r != null) {
		Integer cnt = r.conProviders.get(cpr);
		if (DEBUG_PROVIDER) Slog.v(TAG,
		"Removing provider requested by "
		+ r.processName + " from process "
		+ cpr.info.processName + ": " + cpr.name.flattenToShortString()
		+ " cnt=" + cnt);
		if (cnt == null \|\| cnt.intValue() <= 1) {
		cpr.clients.remove(r);
		r.conProviders.remove(cpr);
		return true;
		} else {
		r.conProviders.put(cpr, new Integer(cnt.intValue()-1));
		}
		} else {
		cpr.externals++;
		}
		return false;
		}

		private final ContentProviderHolder getContentProviderImpl(
		IApplicationThread caller, String name) {
		ContentProviderRecord cpr;
		@@ -5279,7 +5321,8 @@ public final class ActivityManagerService extends ActivityManagerNative

		// First check if this content provider has been published...
		cpr = mProvidersByName.get(name);
		if (cpr != null) {
		boolean providerRunning = cpr != null;
		if (providerRunning) {
		cpi = cpr.info;
		String msg;
		if ((msg=checkContentProviderPermissionLocked(cpi, r)) != null) {
		@@ -5303,18 +5346,8 @@ public final class ActivityManagerService extends ActivityManagerNative

		// In this case the provider instance already exists, so we can
		// return it right away.
		if (r != null) {
		if (DEBUG_PROVIDER) Slog.v(TAG,
		"Adding provider requested by "
		+ r.processName + " from process "
		+ cpr.info.processName);
		Integer cnt = r.conProviders.get(cpr);
		if (cnt == null) {
		r.conProviders.put(cpr, new Integer(1));
		} else {
		r.conProviders.put(cpr, new Integer(cnt.intValue()+1));
		}
		cpr.clients.add(r);
		final boolean countChanged = incProviderCount(r, cpr);
		if (countChanged) {
		if (cpr.app != null && r.setAdj <= PERCEPTIBLE_APP_ADJ) {
		// If this is a perceptible app accessing the provider,
		// make sure to count it as being accessed and thus
		@@ -5322,17 +5355,33 @@ public final class ActivityManagerService extends ActivityManagerNative
		// content providers are often expensive to start.
		updateLruProcessLocked(cpr.app, false, true);
		}
		} else {
		cpr.externals++;
		}

		if (cpr.app != null) {
		updateOomAdjLocked(cpr.app);
		if (!Process.isAlive(cpr.app.pid)) {
		// Uh oh... it looks like the provider's process
		// has been killed on us. We need to wait for a new
		// process to be started, and make sure its death
		// doesn't kill our process.
		Slog.i(TAG,
		"Existing provider " + cpr.name.flattenToShortString()
		+ " is crashing; detaching " + r);
		boolean lastRef = decProviderCount(r, cpr);
		//appDiedLocked(cpr.app, cpr.app.pid, cpr.app.thread);
		if (!lastRef) {
		// This wasn't the last ref our process had on
		// the provider... we have now been killed, bail.
		return null;
		}
		providerRunning = false;
		}
		}

		Binder.restoreCallingIdentity(origId);
		}

		} else {
		if (!providerRunning) {
		try {
		cpi = AppGlobals.getPackageManager().
		resolveContentProvider(name,
		@@ -5428,22 +5477,7 @@ public final class ActivityManagerService extends ActivityManagerNative
		mProvidersByClass.put(cpi.name, cpr);
		}
		mProvidersByName.put(name, cpr);

		if (r != null) {
		if (DEBUG_PROVIDER) Slog.v(TAG,
		"Adding provider requested by "
		+ r.processName + " from process "
		+ cpr.info.processName);
		Integer cnt = r.conProviders.get(cpr);
		if (cnt == null) {
		r.conProviders.put(cpr, new Integer(1));
		} else {
		r.conProviders.put(cpr, new Integer(cnt.intValue()+1));
		}
		cpr.clients.add(r);
		} else {
		cpr.externals++;
		}
		incProviderCount(r, cpr);
		}
		}

		@@ -5506,24 +5540,16 @@ public final class ActivityManagerService extends ActivityManagerNative
		}
		//update content provider record entry info
		ContentProviderRecord localCpr = mProvidersByClass.get(cpr.info.name);
		if (DEBUG_PROVIDER) Slog.v(TAG, "Removing provider requested by "
		+ r.info.processName + " from process "
		+ localCpr.appInfo.processName);
		if (localCpr.app == r) {
		//should not happen. taken care of as a local provider
		Slog.w(TAG, "removeContentProvider called on local provider: "
		+ cpr.info.name + " in process " + r.processName);
		return;
		} else {
		Integer cnt = r.conProviders.get(localCpr);
		if (cnt == null \|\| cnt.intValue() <= 1) {
		localCpr.clients.remove(r);
		r.conProviders.remove(localCpr);
		} else {
		r.conProviders.put(localCpr, new Integer(cnt.intValue()-1));
		if (decProviderCount(r, localCpr)) {
		updateOomAdjLocked();
		}
		}
		updateOomAdjLocked();
		}
		}