update_engine: Added ability to retrieve old version via DBus
Now it is possible to retrieve an old OS version that was in use
before the last reboot, provided that we are now booted into
an updated version. This is to be used by crash reporter in case
the reboot was caused by a crash in kernel while reboot was pending
for an update. In such a scenario, the crash would be attributed
to the current (updated) version, which is wrong.
Also added additional parameter, --old_version, to
update_engine_client to retrieve the old version number, if any,
from the update engine.
BUG=chrome-os-partner:26518
TEST=cros deploy and tested via update_engine_client
Change-Id: I84e2322c5698b44b4c77f25c8f4211cdb367e5dc
Reviewed-on: https://chromium-review.googlesource.com/190149
Reviewed-by: Chris Sosa <sosa@chromium.org>
Tested-by: Alex Vakulenko <avakulenko@chromium.org>
Commit-Queue: Alex Vakulenko <avakulenko@chromium.org>
diff --git a/update_attempter.cc b/update_attempter.cc
index 9cb7a25..5ab8e1a 100644
--- a/update_attempter.cc
+++ b/update_attempter.cc
@@ -1456,6 +1456,20 @@
void UpdateAttempter::UpdateEngineStarted() {
+ // If we just booted into a new update, keep the previous OS version
+ // in case we rebooted because of a crash of the old version, so we
+ // can do a proper crash report with correcy information.
+ // This must be done before calling
+ // system_state_->payload_state()->UpdateEngineStarted() since it will
+ // delete SystemUpdated marker file.
+ if (system_state_->system_rebooted() &&
+ prefs_->Exists(kPrefsSystemUpdatedMarker)) {
+ if (!prefs_->GetString(kPrefsPreviousVersion, &prev_version_)) {
+ // If we fail to get the version string, make sure it stays empty.
+ prev_version_.clear();
+ }
+ }
+
system_state_->payload_state()->UpdateEngineStarted();
StartP2PAtStartup();
}