DriverKit gone after installer installed activated

Question

This is really a strange situation. My application is an user agent communicates with my driverkit driver, by our design this app(named myAgent.app) activates my driver(named myDriverKit) since myAgent.app starts then communicate with myDriverKit. In our testing I load it manually by a plist, the content is:

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE plist PUBLIC "-//Apple//DTD PLIST 1.0//EN" "http://www.apple.com/DTDs/PropertyList-1.0.dtd">
<plist version="1.0">
<dict>
    <key>Label</key>
    <string>com.myCom.myApp</string>
    <key>ProgramArguments</key>
    <array>
        <string>/Applications/myApp.app/Contents/Helper/myAgent.app/Contents/MacOS/myAgent</string>
    </array>
    <key>RunAtLoad</key>
    <true/>
    <key>KeepAlive</key>                                                         
    <true/>
</dict>
</plist>

All is running perfectly (under SIP off when we are't granted entitlement yet).

Then we package it, myDriverKit looks like running well when it's activated during installing, the post-install script writes in the end:

CONSOLE_USER=$(stat -f%Su /dev/console)
su -l "$CONSOLE_USER" -c '/bin/launchctl load /Library/LaunchAgents/com.myCom.myAgent.plist' 2> /dev/null

However after reboot, the myDriverKit doesn't work anymore! It looks like survive when I using systemextensionctl list to look for it, but check console, hook it by log stream, I can't find it anymore. Unless I manually do systemextensionctl reset and restart myAgent.app to let it able to survive permanently.

I did several test:

1. Don't auto launchctl load myAgent but manually load it myself when install finished -> it works.
2. chmod 644 com.myCom.myAgent.plist then re-build package -> fail
3. Don't allow myDriverKit in Security then allow it after reboot -> works
4. use /usr/bin/sudo -u $USER /bin/launchctl load -S Aqua /Library/LaunchAgents/com.kensington.trackballworks.plist in post-install script instead->fail

Seems myAgent.app starts by install script is different with starts by myself. What's the possible root cause? Is it possibly in the post script or in myAgent.app activation process? Appreciate if any reply Orz.

Answer 1

I'd answer this question myself. The root cause of such strange situation is user activates(the moment clicking allow button in security) dext when the installer processing kextcache.

If we specify a kext to copy to /Library/Extensions/ in a .pkg, installer will do kextcache automatically during install process. That's why the installer needs so long time to finish installation.

If user activate a dext during kextcache processing, the dext seems working but after reboot the dext will not effect anything even though it shows "Activated enabled" when systemextensionctl list is issued.

This should be a bug in macOS, in my thought.