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Clever Hack Finds Mystery CPU Instructions
- Gys 6y agoOn x86. The linked article loaded very, very slow. Original (?) bloppost: https://blog.can.ac/2021/03/22/speculating-x86-64-isa-with-one-weird-trick/ https://blog.can.ac/2021/03/22/speculating-x86-64-isa-with-o...
- rdpintqogeogsaa 6y agoPreviously for that link (208 points / 65 comments): https://news.ycombinator.com/item?id=26584118 https://news.ycombinator.com/item?id=26584118
- tomcam 6y agoThank you. Said blog post loads very, very fast!
- pabs3 6y agoThis reminds me of sandsifter, the x86 processor fuzzer: https://github.com/xoreaxeaxeax/sandsifter https://github.com/xoreaxeaxeax/sandsifter
- justinclift 6y agoArchive.today cached version: https://archive.ph/wi3Hp https://archive.ph/wi3Hp
- BruceEel 6y agothanks
- BruceEel 6y agoHN'dotted?
- simcop2387 6y agoI like the phrase "hugged to death" as a more generic version of "slashdotted" personally. It's a shame but /. is no longer the web powerhouse that it used to be, though I still read it regularly just because it will sometimes have stories and things I don't otherwise find in places like reddit or hn.
- BruceEel 6y agoagreed!
- anaganisk 6y agoContrary to popular belief, HN traffic is not as huge as people think for the hug of death. Its the reddit traffic, when people either repost or post at both places. HN can barely send 5 users per second, which can surely be handled by a potato.
- jshmrsn 6y agoWhile I certainly have no need to find undocumented x86 instructions, I do find this style of explanation great learning a bit about how processors work (something I would like to learn more about).
- crdotson 6y agoI know very little about this field, but I guess I’m surprised that the table of instructions can’t be found by looking at a microcode update file.
- dboreham 6y agoAren't those encrypted?
- colejohnson66 6y agoYes, but also: the update file doesn’t contain everything, but just what needs changing. So if these undocumented ones aren’t in the file, that doesn’t mean they don’t exist.
- billytetrud 6y agoIsn't having undocumented opcodes a huge red flag for security?