4 ms·

Debugging launchd on OS X 10.10.3

• pschastain 12y ago
  So I don't know much at all about kernel debugging, but when the author mentioned not being able to attach a debugger to launchd since it's PID 1 I got to wondering if it would be possible to use a debugger by launching OS X in a VM instead.
  • feld 12y ago
    Well at that point you have to sift through the noise of the hypervisor and understand an entire OS you can't really see. Sort of...
    • alphonse23 12y ago
      Test
  • comex 12y ago
    The author does end up using a VM, although via native kernel debugging over a virtual network rather than the VM's built-in debug stub. Neither one is going to isolate a single user process from other activity, though.
• deleted 12y ago
  [deleted]
• chris_wot 12y ago
  I initially thought this was some anti-debug trick Apple introduced to prevent debugging of the service. However, I got to thinking - if launchd is PID 1, and everything is spawned off of it, then if lldb was able to break lauchd, then lldb should be halted as well - something like the “chicken or the egg” problem. It would be like if you spawned a thread, and then put a breakpoint in the parent, but the thread still was running. It is just not possible. Hold on... So if you break on a parent process the children stop? However, the error is that the connection is lost to the debug server. I don't think you are having the problem for the reason you are saying.