On Wed, Aug 11, 2021 at 6:24 PM Thomas Munro <thomas.mu...@gmail.com> wrote: > On Thu, Aug 12, 2021 at 1:45 AM Robert Haas <robertmh...@gmail.com> wrote: > > I think that worked for me on older macOS releases, and then it > > stopped working at some point after some update or reinstall or > > something. Unfortunately I don't know any more precisely than that, > > but it does seem like we have to find some other approach to work on > > modern systems. > > I gave up on trying to make that work once I realised that > /usr/lib/dyld doesn't seem to obey the flag, so although other > segments become deterministic and the success rate is fairly high, > there's still a 600kb wrecking ball swinging around. I wondered what > the "slide" range could be... it appears to be fairly small > (vm_map_get_max_aslr_slide_pages() seems to be the place that's > determined and it's a 16MB or 256MB window, depending on architecture, > if I read that right). Given that, the death of 32 bit processes > since Catalina, and the typical layout we see, I think just doing > something like (/me rolls dice) export PG_SHMEM_ADDR=0x80000000000 is > a good candidate for something that works on both architectures, being > many TB away from everything else (above everything on ARM, between > heap etc and libs on Intel but with 8TB of space below it and 120TB > above). That gets the tests passing consistently with unpatched > master, -DEXEC_BACKEND, on both flavours of silicon.
Ugh, OK. So, is there a way that we can get an "easy button" committed to the tree? -- Robert Haas EDB: http://www.enterprisedb.com