UGoogle uye wazisa i-"Half-Double", indlela entsha yohlaselo yeRowHammer enokutshintsha imixholo yeebits zememori yokufikelela okungahleliweyo (DRAM). Uhlaselo lunokuphinda luveliswe kwezinye iitshiphusi ze-DRAM zanamhlanje, abavelisi bazo banciphise ijometri yeeseli.
Khumbula ukuba uhlaselo lweklasi yeRowHammer lukuvumela ukuba ugqwethe imixholo yeememori zeememori zomntu ngamnye ngokufunda idatha ngebhayisekile kwiiseli zememori ezingabamelwane. Kuba inkumbulo ye-DRAM iluluhlu olunamacala amabini eeseli, nganye ibandakanya i-capacitor kunye ne-transistor, ukwenza ufundo oluqhubekayo lommandla wememori efanayo kubangela ukuguquguquka kombane kunye nokungahambi kakuhle okubangela ilahleko encinci yentlawulo kwiiseli ezingabamelwane. Ukuba ubungakanani bokufunda buphezulu ngokwaneleyo, ngoko iseli engummelwane inokulahlekelwa inani elikhulu ngokwaneleyo lentlawulo kwaye umjikelo wokuhlaziya olandelayo awuyi kuba nexesha lokubuyisela imeko yayo yokuqala, eya kubangela utshintsho kwixabiso ledatha egcinwe kwi iseli.
Ukukhusela kwi-RowHammer, abavelisi beetshiphu baphumeze indlela yeTRR (Target Row Refresh) ekhusela kurhwaphilizo lweeseli ezikwimiqolo ekufutshane. Indlela ye-Half-Double ikuvumela ukuba udlule olu khuselo ngokulawula ukuba ukuguqulwa akukhawulelwanga kwimigca ekufutshane kwaye isasazeke kweminye imigca yememori, nangona kuncinci. Iinjineli zikaGoogle zibonise ukuba kwimiqolo elandelelanayo yememori "A", "B" kunye ne "C", kunokwenzeka ukuhlasela umqolo "C" ngokufikelela okunzima kakhulu kumqolo "A" kunye nomsebenzi omncinci ochaphazela umqolo "B". Ukungena kumqolo "B" ngexesha lohlaselo kuvula ukuvuza kwentlawulo engaqhelekanga kwaye ivumela umqolo "B" usetyenziswe njengothutho lokudlulisa umphumo weRowhammer ukusuka kumqolo "A" ukuya "C".
Ngokungafaniyo nohlaselo lwe-TRRespass, olulawula iziphene ekuphunyezweni okuhlukeneyo kwendlela yokuthintela urhwaphilizo lweseli, uhlaselo lweHalf-Double lusekwe kwiipropathi ezibonakalayo ze-silicon substrate. I-Half-Double ibonisa ukuba kunokwenzeka ukuba imiphumo ekhokelela kwi-Rowhammer yipropati yomgama, kunokuba i-contiguity ngqo yeeseli. Njengoko i-geometry yeseli kwiitshiphusi zanamhlanje iyancipha, iradiyasi yempembelelo yokugqwetheka nayo iyanda. Kungenzeka ukuba umphumo uya kubonwa kumgama wemigca engaphezu kwemibini.
Kuqatshelwe ukuba, kunye nombutho we-JEDEC, izindululo ezininzi ziye zaphuhliswa ukuhlalutya iindlela ezinokuthi zithintele uhlaselo olunjalo. Le ndlela ichazwa kuba iGoogle ikholelwa ukuba uphando lukhulisa kakhulu ukuqonda kwethu i-Rowhammer phenomenon kwaye igxininisa ukubaluleka kwabaphandi, abenzi be-chip, kunye nabanye abachaphazelekayo abasebenza kunye ukuphuhlisa isisombululo esibanzi, sokhuseleko lwexesha elide.
umthombo: opennet.ru