Tops-20 had mapped memory segments before VMS was born. It was called PMAP back then (for Page Map). I don't know if it had the same vulnerability. Howie Kaye "Dick St.Peters" wrote: > > Mike Perry writes: > > > So as it turns out that it is in fact possible to create a DoS condition by > > requesting a truckload of shared mem, then triggering pagefaults in the entire > > shared region. > > Mapped memory segments have been susceptible to this since at least > the early days of VMS, which AFAIK was the first OS to implement > mapped memory (VMS used the term "mapped section"). I ran into this > by accident no later than 1982 while doing image processing on a VMS > system. My processes run at the lowest possible priority (equivalent > to the highest possible niceness), would effectively shut down the > system until they completed. > > VMS didn't have a lot of tools for analyzing what was happening, but a > few experiments quickly showed the culprit was page faulting. Image > processing tends to step through memory sparsely. > > Sorry - I no longer have an exploit :) > > -- > Dick St.Peters, stpetersat_private > Gatekeeper, NetHeaven, Saratoga Springs, NY > Saratoga/Albany/Amsterdam/BoltonLanding/Cobleskill/Greenwich/ > GlensFalls/LakePlacid/NorthCreek/Plattsburgh/... > Oldest Internet service based in the Adirondack-Albany region
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