-;;; * OpenBSD address space changes for W^X as well as malloc
-;;; randomization made the old addresses unsafe. The only range
-;;; that is really safe is between the end of the text segment (it
-;;; starts at #x3C000000) and #x7C000000. However if the -Z linker
-;;; option is used then the safe range is (probably) #x00001000 to
-;;; #x48048000, with the text and data segments at #x08048000.
+;;; * OpenBSD address space changes for W^X as well as malloc()
+;;; randomization made the old addresses unsafe.
+;;; ** By default (linked without -Z option):
+;;; The executable's text segment starts at #x1c000000 and the
+;;; data segment MAXDSIZ bytes higher, at #x3c000000. Shared
+;;; library text segments start randomly between #x00002000 and
+;;; #x10002000, with the data segment MAXDSIZ bytes after that.
+;;; ** If the -Z linker option is used:
+;;; The executable's text and data segments simply start at
+;;; #x08048000, data immediately following text. Shared library
+;;; text and data is placed as if allocated by malloc().
+;;; ** In both cases, the randomized range for malloc() starts
+;;; MAXDSIZ bytes after the end of the data segment (#x48048000
+;;; with -Z, #x7c000000 without), and extends 256 MB.
+;;; ** The read only, static, and linkage table spaces should be
+;;; safe with and without -Z if they are located just before
+;;; #x1c000000.
+;;; ** Ideally the dynamic space should be at #x94000000, 64 MB
+;;; after the end of the highest random malloc() address.
+;;; Unfortunately the dynamic space must be in the lower half
+;;; of the address space, where there are no large areas which
+;;; are unused both with and without -Z. So we break -Z by
+;;; starting at #x40000000. By only using 512 - 64 MB we can
+;;; run under the default 512 MB data size resource limit.