More robust restorecon and additional debug info.

Bug: 229129448
Test: presubmit
Change-Id: I9c71d2702ef17e852a52686f85a4ea591e83950f

core/jni/android_os_SELinux.cpp

diff --git a/core/jni/android_os_SELinux.cpp b/core/jni/android_os_SELinux.cpp
index 43c1cfd..84ca1ba 100644
--- a/core/jni/android_os_SELinux.cpp
+++ b/core/jni/android_os_SELinux.cpp
@@ -239,8 +239,12 @@
     char *tmp = const_cast<char *>(context.c_str());
     int ret = setfilecon(path.c_str(), tmp);
 
-    ALOGV("setFileCon(%s, %s) => %d", path.c_str(), context.c_str(), ret);
-    return (ret == 0) ? true : false;
+    if (ret == 0) {
+        ALOGV("setFileCon(%s, %s) => %d", path.c_str(), context.c_str(), ret);
+        return true;
+    }
+    ALOGE("setFileCon(%s, %s) => %d, err: %s", path.c_str(), context.c_str(), ret, strerror(errno));
+    return false;
 }
 
 /*

services/core/java/com/android/server/pm/PackageInstallerService.java

diff --git a/services/core/java/com/android/server/pm/PackageInstallerService.java b/services/core/java/com/android/server/pm/PackageInstallerService.java
index e406a1a..a01942d 100644
--- a/services/core/java/com/android/server/pm/PackageInstallerService.java
+++ b/services/core/java/com/android/server/pm/PackageInstallerService.java
@@ -1034,7 +1034,16 @@
         }
 
         if (!SELinux.restorecon(stageDir)) {
-            throw new IOException("Failed to restorecon session dir: " + stageDir);
+            String path = stageDir.getCanonicalPath();
+            String ctx = SELinux.fileSelabelLookup(path);
+            boolean success = SELinux.setFileContext(path, ctx);
+            Slog.e(TAG,
+                    "Failed to SELinux.restorecon session dir, path: [" + path + "], ctx: [" + ctx
+                            + "]. Retrying via SELinux.fileSelabelLookup/SELinux.setFileContext: "
+                            + (success ? "SUCCESS" : "FAILURE"));
+            if (!success) {
+                throw new IOException("Failed to restorecon session dir: " + stageDir);
+            }
         }
     }