{"action":"opened","issue":{"url":"https://api.github.com/repos/eteran/edb-debugger/issues/186","labels_url":"https://api.github.com/repos/eteran/edb-debugger/issues/186/labels{/name}","comments_url":"https://api.github.com/repos/eteran/edb-debugger/issues/186/comments","events_url":"https://api.github.com/repos/eteran/edb-debugger/issues/186/events","html_url":"https://github.com/eteran/edb-debugger/issues/186","id":99513579,"number":186,"title":"ADCX with LOCK prefix is disassembled as invalid with wrong instruction length","user":{"login":"10110111","id":6376882,"avatar_url":"https://avatars.githubusercontent.com/u/6376882?v=3","gravatar_id":"","url":"https://api.github.com/users/10110111","html_url":"https://github.com/10110111","followers_url":"https://api.github.com/users/10110111/followers","following_url":"https://api.github.com/users/10110111/following{/other_user}","gists_url":"https://api.github.com/users/10110111/gists{/gist_id}","starred_url":"https://api.github.com/users/10110111/starred{/owner}{/repo}","subscriptions_url":"https://api.github.com/users/10110111/subscriptions","organizations_url":"https://api.github.com/users/10110111/orgs","repos_url":"https://api.github.com/users/10110111/repos","events_url":"https://api.github.com/users/10110111/events{/privacy}","received_events_url":"https://api.github.com/users/10110111/received_events","type":"User","site_admin":false},"labels":[],"state":"open","locked":false,"assignee":null,"milestone":null,"comments":0,"created_at":"2015-08-06T20:06:09Z","updated_at":"2015-08-06T20:06:09Z","closed_at":null,"body":"The instruction `F0 66 0F 38 F6 C1`, i.e. `lock\\nadcx eax,ecx`, is a decodable instruction, although it generates #UD. But EDB thinks that this instruction is invalid (which is somewhat correct given its behavior), but says it doesn't \"own\" the last byte.\r\n\r\nFor comparison, Capstone (testable in a [web-based disassembler based on it](http://www.cenigma.org/)), decodes the instruction fully as `lock adcx eax, ecx`.\r\nThe same is for GDB.\r\n\r\nSo, EDB should at least correctly tell its length, and it'd be best if it decoded it completely as to Capstone and GDB."}}