Iyo AMD EPYC 2018 ("Rome") yakatevedzana sevha processors yakavakirwa pa "Zen 7002" microarchitecture yakatumirwa kubva 2 ine bug inokonzeresa kuti processor irembera mushure memazuva zana nemakumi mana ekushanda pasina kugadziridzwa kwenyika (system reboot). Sekushanda kuvharisa nyaya, zvinokurudzirwa kudzima CC1044 simba rekuchengetedza modhi rutsigiro kana kutangazve sevha kanopfuura kamwe chete mazuva 6 (anenge makore maviri nemwedzi gumi).
Zvinoenderana neruzivo rwakaburitswa ne AMD, kusungirirwa kunokonzerwa nekupunzika kunoitika kana processor core ichiedza kumuka kubva kuCC6 simba-saving mode (core-C6, inodzikisa voltage kana isina basa) kana timer yasvika kukosha kwemazuva 1044. mushure mekupedzisira CPU state reset (nguva yekuratidzwa inogona kusiyana zvichienderana neREFCLK frequency).
AMD haipe imwe tsananguro yakadzama yechikonzero chekutadza. Tichitarisa nefungidziro yakadhindwa paReddit, kusungirirwa kunoitika kana kaunda muTSC (Time Stamp Counter) rejista, iyo inoverenga nhamba yekushanda kutenderera mushure mekugadzirisazve, pafrequency ye2800 MHz inosvika kukosha 0x380000000000000 (2800 MHz * 10* * 6 * 1042.5, i.e. mushure memazuva 1042 nemaawa gumi nemaviri).
Iyo bug kugadzirisa haisi kuzoburitswa. Dambudziko rakaramba risingaonekwe kwenguva yakareba, sezvo kukwidziridzwa kwemakore akawanda kusiri kwakajairwa kumaseva ayo, kuitira kuti arambe aripo, nguva nenguva anofanirwa kutangwazve kuisa kernel zvigadziriso kana kushandura kune kuburitswa kutsva kweiyo inoshanda sisitimu. Nekudaro, Linux kugovera 'isina-reboot kernel yekusimudzira nzira uye marefu ekugadzirisa matenderera (Ubuntu, RHEL, uye SUSE anotsigirwa nemakore gumi) anogona kutungamira kunguva refu yekumirira maseva pasina kutangazve.
Source: opennet.ru