WindowsDllBlocklist installs a callback function that fires whenever a DLL
is loaded. The installer function shares an SRWLock with the callback
function.
SRWLock is not re-entrant, so if the installer function accidently causes a
DLL load before releasing the lock, the callback function will deadlock.
This occured trying to solve Bug 1402282, where the installer function used
"new" to allocate memory, which called the Win32 "RtlGenRandom()" function,
which loaded bcrypt.dll, which caused the callback to fire off, which tried
to lock the mutex that was already locked by the installer function.
Hopefully this will save another developer lots of debug time in the future by
turning a difficult-to-debug deadlock into a nice, loud assertion.
Differential Revision: https://phabricator.services.mozilla.com/D15840
--HG--
extra : moz-landing-system : lando
We now record DLL load events along with stack trace and other data so we can
later determine trustworthiness and report the DLL via telemetry.
Differential Revision: https://phabricator.services.mozilla.com/D7175
--HG--
extra : moz-landing-system : lando
Chris Martin
Sylvestre Ledru
Carl Corcoran