2013/12/1 Ingo Weinhold <ingo_weinhold@xxxxxx>:
I'd suggest to replace B_RANDOMIZED_{ANY,BASE}_ADDRESS by
B_{ANY,BASE}_ADDRESS_DETERMINISTIC, make B_{ANY,BASE}_ADDRESS randomize by
default, and don't map the address spec constants in _user_create_area()
anymore. The advantages would be consistency and a simple way to avoid
randomization, if needed.
We are not able to guarantee that an area will be created at
deterministic location once at least one randomized area (e.g. main
thread stack) has been created. If an application for some reason
needs deterministic addresses then all areas have to be created with
ASLR disabled.
However, the possibility to disable ASLR for a specific team makes
things much easier. If it is enabled then even if we don't perform any
explicit randomization for an area its address is non-deterministic
due to randomized locations of already created areas. When, it is
disabled, well, then we have all locations deterministic. That's why I
think we don't need neither B_RANDOMIZED_{ANY,BASE}_ADDRESS nor
B_{ANY,BASE}_ADDRESS_DETERMINISTIC, disabling ASLR for specific team
should suffice.
