From 21863a0cb74c7a4b5d2ace787d3dc979e11e3dd0 Mon Sep 17 00:00:00 2001 From: Christopher Tate Date: Tue, 11 Dec 2018 14:55:19 -0800 Subject: Be more comprehensive about boot time RTC check If we detect that the RTC is uninitialized at boot time, we advance to the nearest safe estimated time that we can determine. We can't necessarily touch read/write filesystems at this point, so we have been using the timestamp of the root filesystem. Unfortunately, on retail devices that timestamp is often artificial, and quite far in the past by today's standards (e.g. some time in 2009). We now consult a variety of milestones to get a better estimate for the latest possible "the current date cannot be earlier than this" reference point: the root filesystem timestamp, the Build.TIME system variable, and the [ro.build.date.utc] system property if available. The latter two, in particular, are typically within at most two years of the current real time/date, rather than the eight or nine years of offset that we see with the root filesystem timestamp. This is a cherrypick of a later change back to Android P. Test: manually boot with system time forced to the 0 epoch Test: CTS Bug: 65354678 Bug: 63711349 Bug: 122883482 Merged-In: I36bbe6dfebba79ad83ce536917d6893427a026dd Change-Id: I36bbe6dfebba79ad83ce536917d6893427a026dd (cherry picked from commit bfbd98868e56064f1c4813dcdbaedf87ced526ea) --- services/core/java/com/android/server/AlarmManagerService.java | 9 +++++++-- 1 file changed, 7 insertions(+), 2 deletions(-) diff --git a/services/core/java/com/android/server/AlarmManagerService.java b/services/core/java/com/android/server/AlarmManagerService.java index f79a51b13afd..47b646c1a667 100644 --- a/services/core/java/com/android/server/AlarmManagerService.java +++ b/services/core/java/com/android/server/AlarmManagerService.java @@ -48,6 +48,7 @@ import android.content.pm.PermissionInfo; import android.database.ContentObserver; import android.net.Uri; import android.os.Binder; +import android.os.Build; import android.os.Bundle; import android.os.Environment; import android.os.Handler; @@ -1288,9 +1289,13 @@ class AlarmManagerService extends SystemService { // because kernel doesn't keep this after reboot setTimeZoneImpl(SystemProperties.get(TIMEZONE_PROPERTY)); - // Also sure that we're booting with a halfway sensible current time if (mNativeData != 0) { - final long systemBuildTime = Environment.getRootDirectory().lastModified(); + // Ensure that we're booting with a halfway sensible current time. Use the + // most recent of Build.TIME, the root file system's timestamp, and the + // value of the ro.build.date.utc system property (which is in seconds). + final long systemBuildTime = Long.max( + 1000L * SystemProperties.getLong("ro.build.date.utc", -1L), + Long.max(Environment.getRootDirectory().lastModified(), Build.TIME)); if (System.currentTimeMillis() < systemBuildTime) { Slog.i(TAG, "Current time only " + System.currentTimeMillis() + ", advancing to build time " + systemBuildTime); -- cgit v1.2.3