On Mon, 11 Nov 2002, Post, Mark K wrote: > Linas, > > No. Either your storage key matches, or it doesn't. If it matches, you get > read and write access, if it doesn't match, you get neither. (You _do_ get > a S0C4 abend.) >
I am looking at http://www.share.org/proceedings/SH98/data/S2826.PDF The stroage key is 7 bits. 0-3 Protect key, 0-15 4 F Fetch 5 R 6 C A program may fetch if its PDW key matches, or the F bit is zero. I'm having difficulty reading it; it's a slide presentation, landscape format and Mozilla's running xpdf inside the browser window. I turned the image round, but it's cropped. Actually, gets cropped both ways;-( My recollection, from over 20 years ago, that the page can be ro and it can be changed, but I don't see how that fits R. > Mark Post > > -----Original Message----- > From: Linas Vepstas [mailto:linas@;linas.org] > Sent: Monday, November 11, 2002 12:57 PM > To: [EMAIL PROTECTED] > Subject: Re: CPU Arch Security [was: Re: Probably the first published > shell code] > > > -snip- > It has been years since I last looked at the 390 instruction set. Can't one > set a read-only mode for selected PSW keys? > -- Cheers John. Please, no off-list mail. You will fall foul of my spam treatment. Join the "Linux Support by Small Businesses" list at http://mail.computerdatasafe.com.au/mailman/listinfo/lssb
