Ngexesha elidlulileyo, kuye kwaziwa malunga nokuba sesichengeni okutsha kuyilo lwentelekelelo ye-Intel processors, eyayibizwa ngokuba yi-Intel. (LVI). I-Intel inombono wayo malunga neengozi ze-LVI kunye neengcebiso zokuyinciphisa. Uguqulelo lwakho lokhuseleko kuhlaselo olunjalo injineli kuGoogle. Kodwa kuya kufuneka uhlawulele ukhuseleko ngokunciphisa ukusebenza kweprosesa ngomyinge we-7%.
Siye saphawula ngaphambili ukuba ingozi ye-LVI ayikho kwindlela ethile efunyenwe ngabaphandi, kodwa kumgaqo-siseko we-LVI uhlaselo lwe-channel side-channel, eyaboniswa okokuqala. Ngaloo ndlela, isikhokelo esitsha savulwa kwizisongelo ekungekho mntu wayekrokrela ngaphambili (ubuncinci, oku akuzange kuxoxwe kwindawo yoluntu). Ke ngoko, ixabiso lophuhliso lwengcaphephe kaGoogle uZola Bridges ilele kwinto yokuba isiziba sakhe sinciphisa ubungozi bohlaselo olutsha olungaziwayo olusekwe kumgaqo weLVI.
Ngaphambili kwi-GNU Project Assembler () utshintsho lwenziwe olunciphisa umngcipheko wokuba sesichengeni se-LVI. Olu tshintsho lubandakanya ukongeza I-LFENCE, eyaseka ulandelelwano olungqongqo phakathi kokufikelela kwimemori ngaphambi nangemva komqobo. Ukuvavanya isiqwenga kwenye yeeprosesa ze-Intel's Kaby Lake zibonise ukwehla kokusebenza ukuya kuthi ga kwi-22%.
Umphuhlisi weGoogle ucebise isiqwenga sakhe kunye nokongezwa kwe-LFENCE imiyalelo kwisethi ye-LLVM compiler, kwaye wabiza ukhuseleko lwe-SESES (I-Speculative Executive Side Effect Suppression). Ukhetho lokukhusela alucetyisayo lunciphisa zombini izisongelo ze-LVI kunye nezinye ezifanayo, umzekelo, i-Specter V1 / V4. Ukuphunyezwa kwe-SESES kuvumela umqambi ukuba afake imiyalelo ye-LFENCE kwiindawo ezifanelekileyo ngexesha lokuvelisa ikhowudi yomatshini. Umzekelo, zifake phambi komyalelo ngamnye wokufunda kwinkumbulo okanye ukubhala kwimemori.
Imiyalelo ye-LFENCE inqanda ukukhutshwa kwayo yonke imiyalelo elandelayo de ufundo lwenkumbulo yangaphambili lugqitywe. Ngokucacileyo, oku kuchaphazela ukusebenza kweeprosesa. Umphandi wafumanisa ukuba ngokomyinge, ukukhuselwa kwe-SESES kunciphise isantya sokugqiba imisebenzi usebenzisa ithala leencwadi elikhuselweyo nge-7,1%. Uluhlu lokunciphisa imveliso kule meko lusuka kwi-4 ukuya kwi-23%. Uqikelelo lokuqala lwabaphandi lwalungenathemba ngakumbi, lubiza ukuhla okuphindwe ka-19 ekusebenzeni.
umthombo: 3dnews.ru