Re: Worth using personality(ADDR_NO_RANDOMIZE) for EXEC_BACKEND on linux?

Hi,

On Tue, Aug 10, 2021, at 15:19, Thomas Munro wrote:
> On Tue, Aug 10, 2021 at 5:43 AM Robert Haas <robertmhaas@gmail.com> wrote:
> > On Mon, Aug 9, 2021 at 1:30 PM Alvaro Herrera <alvherre@alvh.no-ip.org> wrote:
> > > How common is to get a failure?  I know I've run tests under
> > > EXEC_BACKEND and not seen any failures.  Not many runs though.
> >
> > On macOS, failures are extremely common. Sometimes I have to run
> > simple tests many times to get even one success. The proposal on the
> > table won't help with that problem since it's Linux-specific, but if
> > there's any way to do something similar on macOS it would be a _huge_
> > help.
> 
> Yeah, make check always fails for me on macOS 11.  With the attached
> experimental hack, it fails only occasionally (1 in 8 runs or so).  I
> don't know why.

I suspect you'd need to use the hack in pg_ctl to make it reliable. The layout of normally stayed position independent
postmastercan be incompatible with the non ASLR spawned child.
 

Andres