On 8/5/21 11:29 PM, Andres Freund wrote: > Hi, > > When testing EXEC_BACKEND on linux I see occasional test failures as long as I > don't disable ASLR. There's a code comment to that effect: > > * If testing EXEC_BACKEND on Linux, you should run this as root before > * starting the postmaster: > * > * echo 0 >/proc/sys/kernel/randomize_va_space > > but I don't like doing that on a system wide basis. > > Linux allows disabling ASLR on a per-process basis using > personality(ADDR_NO_RANDOMIZE). There's a wrapper binary to do that as well, > setarch --addr-no-randomize. > > I was wondering if we should have postmaster do personality(ADDR_NO_RANDOMIZE) > for EXEC_BACKEND builds? It seems nicer to make it automatically work than > have people remember that they need to call "setarch --addr-no-randomize make > check". > > Not that it actually matters for EXEC_BACKEND, but theoretically doing > personality(ADDR_NO_RANDOMIZE) in postmaster is a tad more secure than doing > it via setarch, as in the personality() case postmaster's layout itself is > still randomized... > > > Or perhaps we should just add a comment mentioning setarch. >
If we can set it conveniently then that seems worth doing. (Thinks: do we have non-Windows buildfarm members doing EXEC_BACKEND?) cheers andrew -- Andrew Dunstan EDB: https://www.enterprisedb.com
