I-Google ivuliwe ezinsukwini eziningana ezedlule izindlela zokuxhaphaza ezahlukahlukene lokho kukhombisa ukuthi kungenzeka kusizakale ubungozi wesigaba seSpecter lapho wenza ikhodi yeJavaScript kusiphequluli, ngaphandle kokuya ngezindlela zokuphepha ezingezwe ngenhla.
Ukuxhaphaza kungasetshenziselwa ukufinyelela kwimemori yenqubo ecubungula okuqukethwe kwewebhu kuthebhu yamanje. Ukuhlola ukusebenza kwalokhu kuxhashazwa, kwasungulwa iwebhusayithi yekhasi elivuzayo futhi ikhodi echaza umqondo wokusebenza ithunyelwe ku-GitHub.
Uhlobo oluhlongozwayo lwenzelwe uku izinhlelo zokuhlasela nge Amaprosesa we-Intel Core i7-6500U endaweni ye-Linux ne-Chrome 88, yize lokhu kungafaki ngaphandle kokuthi izinguquko zingenziwa ukusebenzisa ukuxhashazwa kwezinye izindawo.
Indlela yokusebenza ayicacisiwe ku- amaprosesa I-Intel: ngemuva kokujwayela kahle, Ukuxhashazwa sekuqinisekisiwe ukuthi kuzosebenza ezinhlelweni ezinama-CPU wesithathu, kufaka phakathi i-Apple M1 ngokususelwa ekwakhiweni kwe-ARM. Ngemuva kwama-tweaks amancane, ukuxhashazwa nakho kusebenza kwezinye izinhlelo zokusebenza nezinye iziphequluli ngokususelwa kunjini yeChromium.
Emvelweni osuselwa kunqubo ejwayelekile ye-Chrome 88 ne-Intel Skylake, sithole ukuvuza kwedatha kusuka kwinqubo ebhekele ukunikezela okuqukethwe kwewebhu kuthebhu yamanje ye-Chrome (inqubo yokunikezela) ngejubane le-1 kilobyte ngomzuzwana. Ngaphezu kwalokho, ezinye izindlela ezivelayo zakhiwe, ngokwesibonelo, ukuxhaphaza okuvumela, ngentengo yokuncipha kokuzinza, ukukhuphula izinga lokuvuza kuye ku-8kB / s lapho usebenzisa i-performance.now () timer ngokunemba kwama-microseconds ama-5 (ama-0.005 millisecond ). Kwasungulwa okwahlukile okwakusebenza ngokunemba kwesilinganiso se-millisecond eyodwa, okungasetshenziswa ukuhlela ukufinyelela kwimemori yenye inqubo ngenani lama-byte angama-60 ngomzuzwana.
Ikhodi yedemo eshicilelwe iqukethe izingxenye ezintathu:
- Ingxenye yokuqala Linganisa isibali sikhathi ukulinganisa isikhathi sokusebenza yokusebenza okudingekayo ukubuyisa idatha ehlala kusilondolozi seprosesa njengomphumela wokuqagela kokucabanga kwemiyalo ye-CPU.
- Ingxenye yesibili Ichaza ukwakheka kwememori okusetshenzisiwe lapho kwabiwa uhlu lweJavaScript.
- Ingxenye yesithathu kuxhaphaza ngqo ukuba sengozini kweSpecter ukuthola okuqukethwe kwememori kwenqubo yamanje njengomphumela wokwenziwa kwezimo zokwenza imisebenzi ethile yokuqagela, umphumela wayo ulahlwa yiprosesa ngemuva kokuthola isibikezelo esihlulekile, kepha imikhondo yokubulawa ixazululwa kunqolobane eyabiwe futhi ingabuyiselwa kusetshenziswa izindlela zokunquma okuqukethwe kwesilondolozi usebenzisa iziteshi ezivela eceleni ezihlaziya ushintsho esikhathini sokufinyelela kudatha efakwe kunqolobane nengagciniwe.
Inqubo ehlongozwayo yokuxhashazwa iqeda izibali sikhathi esinemba kakhulu itholakala nge-performance.now () API futhi ngaphandle kokusekelwa kohlobo lweSharedArrayBuffer, olukuvumela ukuthi udale ukuhlelwa kwememori okwabiwe ngayo.
Ukuxhashazwa kufaka phakathi idivaysi yeSpecter, edala ukwenziwa kwekhodi yokuqagela elawulwayo, kanye ne-analyzer evuzayo yesiteshi eseceleni, enquma ukuthi iyiphi idatha efakwe kunqolobane ngesikhathi sokuqagela.
Igajethi isetshenziswa kusetshenziswa uhlu lweJavaScript, lapho kwenziwa umzamo wokufinyelela endaweni engaphandle kwemikhawulo ye-buffer, ethinta isimo sebhulokhi yokubikezela igatsha ngenxa yobukhona besheke lesilinganiso se-buffer esingezwe umhlanganisi (iprosesa yenza ukufinyelela ngokukhanyayo ngaphambi kwesikhathi, kepha ibuyisela isimo ngemuva kokuhlola).
Ukuhlaziya okuqukethwe okulondolozwe okwesikhashana ngaphansi kwezimo zokunemba kwesikhathi okunganele, kwaphakanyiswa indlela yokukhohlisa isu lokukhishwa kwedatha ye-Tree-PLRU elisetshenziswa kuma-processor futhi livumela, ngokwandisa inani lemijikelezo, ukwandisa kakhulu isikhathi sokwehluka lapho inani libuyiselwa kusuka kunqolobane nasekungabikho kwenani kunqolobane.
I-Google ishicilele uhlobo oluthile lokuxhaphaza ukukhombisa ukuthi kungenzeka yini ukuhlaselwa kusetshenziswa ubungozi besigaba seSpecter futhi ukhuthaze abathuthukisi bewebhu ukuthi basebenzise amasu anciphisa ubungozi bokuhlaselwa okunjalo.
Ngasikhathi sinye, iGoogle ikholelwa ukuthi ngaphandle kokubuyekezwa okuphawulekayo kohlobo lwesiphakamiso oluhlongozwayo, akunakwenzeka ukudala ukuxhaphazwa kwendawo yonke okulungele hhayi kuphela ukuboniswa, kepha nokusetshenziswa kabanzi.
Umthombo: https://security.googleblog.com