Google yakaunza "Half-Double", nzira itsva yeRowHammer yekurwisa iyo inogona kushandura zviri mukati mezvimedu zvega zvega zvesimba zvekupinda memory (DRAM). Kurwiswa kwacho kunogona kudzokororwa pane mamwe mazuvano DRAM machipisi, ayo vagadziri vakadzikisa sero geometry.
Rangarira kuti RowHammer kirasi kurwiswa kunobvumidza iwe kukanganisa zviri mukati meyemunhu ndangariro bits nekutenderera kuverenga data kubva kune akavakidzana ndangariro maseru. Sezvo DRAM ndangariro iri maviri-dimensional array emaseru, rimwe nerimwe rine capacitor uye transistor, kuita kuenderera kuverenga kwenzvimbo imwechete yekurangarira kunoguma nekushanduka kwevoltage uye anomalies izvo zvinokonzeresa kurasikirwa kudiki kwechaji mumaseru akavakidzana. Kana kuverenga kwakanyanya kwakakwira zvakakwana, ipapo sero rekuvakidzani rinogona kurasikirwa nemutengo wakaringana wakawanda uye kutenderera kunotevera kwekuzvarwa patsva hakuzove nenguva yekudzorera mamiriro ayo ekutanga, izvo zvinozoita shanduko mukukosha kweiyo data yakachengetwa mu sero.
Kuchengetedza kubva kuRowHammer, vagadziri vechip vakashandisa nzira yeTRR (Target Row Refresh) inodzivirira kubva kuhuwori hwemasero mumitsara iri padyo. Iyo Half-Double nzira inokubvumira kuti upfuure chengetedzo iyi nekugadzirisa kuti kukanganisa hakuna kuganhurirwa kune mitsetse iri padyo uye kupararira kune mamwe mitsara yekurangarira, kunyangwe zvishoma. Mainjiniya eGoogle vakaratidza kuti pamitsara inoteedzana yendangariro "A", "B" uye "C", zvinokwanisika kurwisa mutsara "C" nekuremerwa kwekuwana mutsara "A" uye diki chiitiko chinokanganisa mutsara "B". Kuwana mutsara "B" panguva yekurwiswa kunomutsa nonlinear charge leak uye inobvumira mutsara "B" kushandiswa sechokufambisa kuendesa iyo Rowhammer mhedzisiro kubva mumutsara "A" kuenda "C".
Kusiyana nekurwiswa kweTRRespass, iyo inoshandura kukanganisa mukuitwa kwakasiyana-siyana kwesero huwori hwekudzivirira nzira, iyo Half-Double kurwisa kunoenderana nehunhu hweiyo silicon substrate. Half-Double inoratidza kuti zvingangoita kuti mhedzisiro inotungamira kuRowhammer inzvimbo iri kure, pane yakananga contiguity yemasero. Sezvo sero geometry mumachipisi emazuva ano inodzikira, radius yesimba rekukanganisa inowedzerawo. Zvinogoneka kuti mhedzisiro yacho ichaonekwa iri chinhambwe chemitsetse inopfuura miviri.
Zvinocherechedzwa kuti, pamwe chete nesangano reJEDEC, zvikumbiro zvakati wandei zvakagadziridzwa zvichiongorora nzira dzinogona kuvharisa kurwiswa kwakadaro. Iyo nzira iri kuburitswa nekuti Google inotenda kuti tsvakiridzo iyi inowedzera zvakanyanya kunzwisisa kwedu kweiyo Rowhammer chiitiko uye inosimbisa kukosha kwevanoongorora, chipmaker, uye vamwe vane chekuita nekushanda pamwe chete kugadzira yakakwana, yenguva refu yekuchengetedza mhinduro.
Source: opennet.ru