Android/frameworks_base
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

Don't hold lock calling into PackageMgr

Browse Source 
There's a subtle deadlock; when dumping state, we obtain the package manager
lock before trying to obtain the package installer session lock. Meanwhile,
creating a new session obtains the locks in the reverse -- the package
installer takes the package installer session lock and then tries to obtain
the package manager lock.

Here, we avoid holding the package installer session lock before we call
into the package manager. Alternatively, we could consider not holding the
package manager lock when dumping package installer state. But, given the
scope of the dumping logic, that's a bigger change with other, unknown
side effects.

Change-Id: I11f08484cd335bb7ad3bc557808eb48d14bd29cf
Fixes: 30089638
This commit is contained in:
Todd Kennedy
2016-07-12 14:07:40 -07:00
parent 0e792f567a
commit 04918fe027
1 changed files with 17 additions and 14 deletions
Download Patch File Download Diff File Expand all files Collapse all files

31
services/core/java/com/android/server/pm/PackageInstallerService.java
View File

@@ -666,23 +666,26 @@ public class PackageInstallerService extends IPackageInstaller.Stub {
"Too many historical sessions for UID " + callingUid);
}
final long createdMillis = System.currentTimeMillis();
sessionId = allocateSessionIdLocked();
}
// We're staging to exactly one location
File stageDir = null;
String stageCid = null;
if ((params.installFlags & PackageManager.INSTALL_INTERNAL) != 0) {
final boolean isEphemeral =
(params.installFlags & PackageManager.INSTALL_EPHEMERAL) != 0;
stageDir = buildStageDir(params.volumeUuid, sessionId, isEphemeral);
} else {
stageCid = buildExternalStageCid(sessionId);
}
final long createdMillis = System.currentTimeMillis();
// We're staging to exactly one location
File stageDir = null;
String stageCid = null;
if ((params.installFlags & PackageManager.INSTALL_INTERNAL) != 0) {
final boolean isEphemeral =
(params.installFlags & PackageManager.INSTALL_EPHEMERAL) != 0;
stageDir = buildStageDir(params.volumeUuid, sessionId, isEphemeral);
} else {
stageCid = buildExternalStageCid(sessionId);
}
session = new PackageInstallerSession(mInternalCallback, mContext, mPm,
mInstallThread.getLooper(), sessionId, userId, installerPackageName, callingUid,
params, createdMillis, stageDir, stageCid, false, false);
session = new PackageInstallerSession(mInternalCallback, mContext, mPm,
mInstallThread.getLooper(), sessionId, userId, installerPackageName, callingUid,
params, createdMillis, stageDir, stageCid, false, false);
synchronized (mSessions) {
mSessions.put(sessionId, session);
}