x86 process memory map

[Paul FLOYD]

> It is the stack grow area and the guard, combined. Read the mmap(2), in> particular explanation of MAP_STACK and MAP_GUARD.
I see from the mmap man page that this appeared in FreeBSD 11.1.
 
Do you know where the size of the stack guard gets defined? I tried searching on google for stuff like 'stack MAP_GUARD size' but didn't find anything.
 
(I need this to fix setting up the client stack on Valgrind x86, which is currently broken)
 
A+
Paul