Article View: rec.games.programmer
Article #2255Re: Writing code at run-time
From: John Wilson
Date: Tue, 07 Jun 1994 04:18
Date: Tue, 07 Jun 1994 04:18
14 lines
2174 bytes
2174 bytes
Don't forget that there *have* to be limits to how far the cache can chase you as far as getting bitten by self-modifying-code bugs go, since the LOADER itself loads the program (which may be done using DMA and/or copied out of disk buffers by the CPU), patches up the places that need relocation (i.e. writes to what may well be code segments) and then jumps to your program. Not to mention compressed executables where the whole program is munged by the decompressor before being jumped to. All they've ever told us to do is do any jump to clear the prefetch queue (and this has been true since day 1, although the size of the queue varies widely). If they change the spec in future processors to have an I and a D cache which are totally unaware of each other, then that's a bug and everybody will justifiably burn in hell. John Wilson
Technical Details
Message-ID:
<2t0seg$kdc@usenet.rpi.edu>Path:
arc1-ca.pugleaf.net!nntp.gmd.de!xlink.net!howland.reston.ans.net!europa.eng.gtefsd.com!sundog.tiac.net!usenet.elf.com!rpi!wilsonjReferences:
<2suogv$s60@harbinger.cc.monash.edu.au> <1994Jun6.115625.10787@uk.ac.swan.pyr> <telnet.770945312@sfu.ca>Show Full Headers
Complete Article Headers
X-Google-Language: ENGLISH,ASCII-7-bit X-Google-Thread: 10f6aa,e6b2b5751c2b9056 X-Google-Attributes: gid10f6aa,public X-Google-Thread: fe306,e6b2b5751c2b9056 X-Google-Attributes: gidfe306,public X-Google-Thread: 1103af,e6b2b5751c2b9056 X-Google-Attributes: gid1103af,public X-Google-Thread: f9382,e6b2b5751c2b9056 X-Google-Attributes: gidf9382,public X-Google-Thread: 10a997,e6b2b5751c2b9056 X-Google-Attributes: gid10a997,public X-Google-Thread: 102bfa,e6b2b5751c2b9056 X-Google-Attributes: gid102bfa,public X-Google-Thread: 102983,e6b2b5751c2b9056 X-Google-Attributes: gid102983,public X-Google-ArrivalTime: 1994-06-06 21:26:06 PST Path: arc1-ca.pugleaf.net!nntp.gmd.de!xlink.net!howland.reston.ans.net!europa.eng.gtefsd.com!sundog.tiac.net!usenet.elf.com!rpi!wilsonj From: wilsonj@alum01.its.rpi.edu (John Wilson) Newsgroups: rec.games.programmer,alt.uu.comp.os.linux.questions,aus.computers.linux,comp.os.linux,comp.os.linux.misc,alt.msdos.programmer,comp.os.msdos.programmer Subject: Re: Writing code at run-time Date: 7 Jun 1994 04:18:24 GMT Organization: Rensselaer Polytechnic Institute, Troy NY Lines: 14 Message-ID: <2t0seg$kdc@usenet.rpi.edu> References: <2suogv$s60@harbinger.cc.monash.edu.au> <1994Jun6.115625.10787@uk.ac.swan.pyr> <telnet.770945312@sfu.ca> NNTP-Posting-Host: alum01.its.rpi.edu