Iqembu labacwaningi abavela eFree University of Amsterdam selisungule uhlobo olusha oluphambili lokuhlaselwa kweRowHammer, evumela okuqukethwe kwamabhithi ngamanye kwimemori ngokususelwa kuma-chip e-DRAM ukuthi kuguqulwe, ukuvikela ubuqotho bamakhodi wokulungisa amaphutha (ECC) asetshenziswayo.
Lokhu kuhlasela kungenziwa ukude ngokufinyelela okungelona ilungelo ohlelweniNjengoba ukuba sengozini kweRowHammer kungaphazamisa okuqukethwe kwamabhithi ngamanye kwimemori ngokufunda ngokujikeleza idatha kumaseli wememori angomakhelwane.
Buyini ubungozi beRowHammer?
Ukuthi iqembu labaphenyi lichaza ini ngobungozi beRowHammer, ukuthi lokhu se ngokuya ngesakhiwo sememori ye-DRAM, ngoba ngokuyisisekelo le yi-matrix enezinhlangothi ezimbili yamaseli lapho lawa maseli aqukethe i-capacitor ne-transistor.
Ngakho-ke ukufundwa okuqhubekayo kwendawo yememori efanayo kuholela ekushintsheni kwamandla kagesi kanye nokungafani okubanga ukulahleka okuncane kokukhokhiswa kwamaseli angomakhelwane.
Uma ukuqina kokufunda kukhulu ngokwanele, iseli lingalahlekelwa inani elanele ngokwanele lokukhokhiswa futhi umjikelezo olandelayo wokuvuselela ngeke ube nesikhathi sokubuyisa isimo sakhona sokuqala, okuholele ekuguqulweni kwenani ledatha egcinwe kuseli.
Ukuhluka okusha kweRowHammer
Kuze kube manje, ukusebenzisa i-ECC kwakuthathwa njengendlela ethembeke kunazo zonke yokuvikela ezinkingeni ezichazwe ngenhla.
Kodwa abacwaningi baphumelela ekwakheni indlela yokushintsha izingcezu zememori ezicacisiwe lokho akuzange kusebenze indlela yokulungisa iphutha.
Indlela ingasetshenziswa kumaseva anememori ye-ECC ukuguqula idatha, shintsha ikhodi enonya futhi ushintshe amalungelo okufinyelela.
Isibonelo, ekuhlaselweni kweRowHammer okuboniswe ngenhla, lapho umhlaseli ethola umshini obonakalayo, izibuyekezo zesistimu ezinonya zilandwe ngoshintsho kwinqubo ye-hostname apt yokulanda nokuguqula umqondo wokuqinisekisa wegama lomethuleli. Isiginesha yedijithali.
Ngabe lokhu kuhluka okusha kusebenza kanjani?
Lokho abacwaningi abachaza ngakho lokhu kuhlaselwa okusha ukuthi ukuhamba kwe-ECC kuncike kuzici zokulungiswa kwamaphutha- Uma kushintshwa okukodwa, i-ECC izolungisa iphutha, uma kuphakanyiswa ama-bits amabili, kuzophonswa okuhlukile futhi uhlelo luzoqedwa ngenkani, kepha uma kushintshwa izingcezu ezintathu ngasikhathi sinye, i-ECC kungenzeka ingakuboni ukuguqulwa.
Ukunquma izimo lapho ukuqinisekiswa kwe-ECC kungasebenzi khona, Indlela yokuqinisekisa efana naleyo yomjaho isakhiwe evumela ukuthi kungenzeka ukuhlaselwa kuhlolwe ikheli elithile kwimemori.
Le ndlela isuselwa eqinisweni lokuthi, lapho kulungiswa iphutha, isikhathi sokufunda siyakhuphuka futhi ukubambezeleka okuholelekile kuyalinganiswa futhi kuyabonakala.
Lokhu kuhlaselwa kuncishiselwa emizamweni elandelanayo yokuguqula into ngayinye ngawodwana, kunqunywa impumelelo yenguquko ngokubonakala kokulibaziseka okubangelwe ukusethwa kwe-ECC.
Ngakho-ke, ukuseshwa kwegama lomshini kwenziwa ngamabhithi amathathu ahlukahlukene. Esigabeni sokugcina, kuyadingeka ukuthi kuqinisekiswe ukuthi izingcezu ezintathu eziguqukayo ezindaweni ezimbili zehlukile, bese uzama ukushintsha inani lazo ngokudlula okukodwa.
Mayelana nedemo
I-Los Abaphenyi bakhombise ngempumelelo ukuthi kungenzeka kuhlaselwe amaseva amane ahlukene anememori ye-DDR3 (imemori ethembeke kalula ne-DDR4), ezintathu zazo zazinama-processor we-Intel (E3-1270 v3, Xeon E5-2650 v1, Intel Xeon E5-2620 v1), kanye ne-AMD eyodwa (Opteron 6376).
En Ukuboniswa kukhombisa ukuthi ukuthola inhlanganisela edingekayo yamabhithi kulebhu kuseva engasebenzi kuthatha imizuzu engama-32.
Ukwenza ukuhlasela kuseva esebenzayo kunzima kakhulu ngenxa yokuba khona kokuphazamiseka okuvela emsebenzini wohlelo lokusebenza.
Kuzinhlelo zokukhiqiza, kungathatha kuze kube yisonto ukuthola inhlanganisela edingekayo yamabhithi ashintshanayo.