Okay, so likely Widevine *did* get an update that makes it do an extra call to the linker, and changes in October 2019 mean that ld.so will use pread64 to implement the functionality being called. Anyway we should be able to just whitelist pread64 in the common policy I think.
Bug 1614535 Comment 7 Edit History
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Okay, so likely Widevine *did* get an update that makes it do an extra call to the linker, and changes in October 2019 mean that ld.so will use pread64 to implement the functionality being called. (This means not everyone who gets the Widevine update will see this problem!) Anyway we should be able to just whitelist pread64 in the common policy I think.