In that referenced manual, I see the following: ============================================================= Impact of ASLR on virtual storage
The decision to enable ASLR represents a tradeoff between enhanced security and a reduction in the amounts of available 24-bit, 31-bit, and 64-bit private storage. When enabled for 24- and 31-bit virtual storage, the size of available private storage will be reduced by up to 63 pages and 255 pages, respectively. A job’s requested region size must still be satisfied from within the reduced private area in order for the job to be started. Jobs whose region size cannot be satisfied will result in an ABEND 822. If a job’s requested region size is satisfied, it is still possible that the reduced size of private storage prevents the job from completing, resulting in an ABEND 878. ============================================================= Why does ASLR require so much additional storage? 256Kb to 1Mb of "overhead" for what, exactly? Does this ASLR affect only the addresses where programs are loaded, or does it also affect the address of every GETMAINed chunk of storage in the region? What was the first release of z/OS to support this ASLR? Thanks in advance, Mark S. Waterbury ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to [email protected] with the message: INFO IBM-MAIN
