G      Guard. Enable guard pages. Each page size or larger allocation is followed by a guard page that will cause a segmentation fault upon  any accessHow can I enable guard pages to harden an OpenBSD install?Also, how can I check what is the current status of the malloc settings? In http://man.openbsd.org/malloc.conf.5 I can see: Set a systemwide reduction of the cache to a quarter of the default size and use guard pages:# ln -s 'G<<' /etc/malloc.confThis probably enabled guard pages, but what is the << and the reduction of the cache to a quarter of the default size. I just want to enable guard pages, afaik that is the most secure setting for malloc.conf. 
How to enable and check status of guard pages in OpenBSD?
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