Kukhutshwe abaphandi bakaGoogle Zimbalwa iintsuku ezidlulileyo Inkqubo entsha yokuhlaselwa kweRowHammer ebizwa ngokuba yi "Half-Double", que iguqula umxholo wezinto ezizimeleyo zememori eguqukayo ukufikelela ngokungaqhelekanga (DRAM). Olu hlaselo luphinde lwenziwa kwakhona kwiitshiphusi zanamhlanje zeDRAM, abavelisi babo abakwazileyo ukunciphisa ijiyometri yeseli.
Kulabo abangalwaziyo uhlobo lohlaselo oluyiRowHammer, kuya kufuneka uyazi ukuba ivumela ukugqwetha umxholo weebhithi ezithile ze-RAM Ukufunda ngokujikeleza idatha kwiiseli zememori ezingabamelwane.
Kuba i-DRAM iludidi lwesibini lweeseli, nganye nganye ine-capacitor kunye ne-transistor, ukuthatha ukufundwa okuqhubekayo kwindawo enye yenkumbulo kukhokelela kuguquguquko lwevolthi kunye nokungahambi kakuhle, kubangela ilahleko encinci yentlawulo kwiiseli ezingabamelwane. Ukuba ubungakanani bokufunda buphezulu ngokwaneleyo, iseli engummelwane inokuphulukana nesixa esikhulu sentlawulo kwaye umjikelo wokuphinda uzalwe ngokutsha awuyi kuba nalo ixesha lokubuyisela imeko yayo, eya kuthi ikhokelele kutshintsho kwixabiso ledatha egciniweyo.
Ukukhusela ngokuchasene neRowHammer, abenzi beetshiphu baphumeze indlela yeTRR (Target Row Refresh), ekhusela ekugqwethweni kweeseli kwimiqolo ekufuphi.
Njengoko i-DDR4 yamkelwa ngokubanzi, kwabonakala ngathi iRowhammer iphele enkosi kwinxalenye yezi ndlela zokhuselo zakhelwe ngaphakathi. Nangona kunjalo, ngo-2020, uxwebhu lwe-TRRespass lubonise indlela yokubuyisela umva kunjineli kunye nokuthomalalisa ukhuselo ngokusasaza ukufikelela, kubonisa ukuba iindlela zikaRowhammer zisasebenza. Kwangoko kulo nyaka, uphando lwe-SMASH lwaya kwelinye inyathelo kwaye lwabonisa ukuxhaphazwa kweJavaScript, ngaphandle kokufaka isimemo solawulo lwe-cache okanye inkqubo yeefowuni.
Abaphandi bakaGoogle bakhankanya ukuba ngokwesiko, iRowHammer yayiqondwa ukuba isebenza kumgama womqolo omnye: xa umqolo weDRAM ufikeleleka kaninzi ("umhlaseli"), utshintsho oluncinci lufumaneka kuphela kwimiqolo emibini emelene (i "Amaxhoba") .
Kodwa oku kutshintshile njengoko ezinye iindlela zokuhlaselwa kweRowHammer zibonakele kwaye oku kungenxa yokuba ingxaki yile akukho ndlela imanyeneyo yokuphunyezwa kwe-TRR kwaye umenzi ngamnye utolika i-TRR ngendlela yakhe, esebenzisa ezabo iindlela zokuzikhusela ngaphandle kokuchaza iinkcukacha zomiliselo.
Kwaye oku kuyaboniswa ngendlela yesiqingatha se-Double evumela ukunqanda olu khuselo ngokubaphatha ukuze ukuphambuka kungapheleli kwimigca emelene nayo kwaye kunwenwele kweminye imigca yememori, nangona kungaphantsi.
Iinjineli zikaGoogle bonisile ukuba:
Kwimigca yememori elandelelanayo "A", "B kunye C", kunokwenzeka ukuba uhlasele umgca "C" ngokufikelela kakhulu kumgca "A" kunye nomsebenzi omncinci ochaphazela umgca "B". Ukufikelela kumgca «B» «ngexesha lohlaselo, kusebenze ukungasebenzi komthwalo ongahambelaniyo kunye nokuvumela ukusetyenziswa kwentambo» B «njengezothutho ukuguqulela umphumo weRowhammer wentambo» A «ukuya» C «.
Ngokungafaniyo nohlaselo lweTrRespass, elijongana neziphene kulwenziwo olwahlukeneyo yendlela yokuthintela ukuphazamiseka kweselula, uhlaselo Isiqingatha esiphindwe kabini sisekwe kwiipropathi ezibonakalayo ze-silicon substrate. Isiqingatha esiphindwe kabini sibonisa ukuba iziphumo zokuhlawulwa kwentlawulo ezikhokelela kwiRowHammer zixhomekeke kumgama, endaweni yokunamathela ngokuthe ngqo kwiseli.
Ngokwehla kwejometri yeseli kwiichips zale mihla, irediyasi yempembelelo yokugqwetha iyonyuka, ke kunokwenzeka ukuba umphumo unokujongwa kumgama ongaphezulu kwemigca emibini. Kuyajongwa ukuba, ngokudibeneyo noMbutho weJEDEC, izindululo ezininzi ziye zaphuhliswa zokuhlalutya iindlela ezinokubakho zokuthintela olu hlobo lokuhlaselwa.
Indlela ityhiliwe kuba UGoogle ukholelwa ukuba uphononongo luqhube kakhulu lwandisa ukuqonda kwento yeRowhammer kwaye igxininisa ukubaluleka kokudibanisa abaphandi, abenzi be-chipm, kunye nabanye abathathi-nxaxheba ekuphuhliseni isisombululo esibanzi, sexesha elide sokhuseleko.
Gqibela Ukuba unomdla wokwazi okungakumbi ngayo, ungajonga iinkcukacha Kule khonkco ilandelayo.