Am Donnerstag, 30. August 2018, 15:09:05 CEST schrieb Krzysztof Kozlowski: Hi Krzysztof, > Thanks Stephan for hints. Let's assume the each of init, update and > final are atomic... but how about the relation between update and > final? I have two concurrent users in user-space but only one HW: > > Process A: Process B: > init() and set_key() > init() and different key > update(some_data) > update(different_data) > final() > final() > > The final() from process A will now produce the result of hashing/CRC > of some_data and different_data (and even maybe mixed with init() for > different key). All because in the meantime process B added its own > data to the HW. The question is where is the state of the cipher operation kept that is produced with each of the init/update/final calls. Your answer implies that this state is kept in hardware. But commonly the state is kept in software. Look at ahash_request for example, the __ctx pointer is intended to point to the memory the driver needs to store its state. Pick a random driver implementation and search for ahash_request_ctx, for example. > > Best regards, > Krzysztof Ciao Stephan
