seL4 as a CPU Driver for an OS for Real Compu... Timothy Roscoe, Roman Meier, Ben Fiedler, Zikai Liu скачать в хорошем качестве

seL4 as a CPU Driver for an OS for Real Compu... Timothy Roscoe, Roman Meier, Ben Fiedler, Zikai Liu

seL4 as a CPU Driver for an OS for Real Computers - Timothy Roscoe, Roman Meier, Ben Fiedler, Zikai Liu Modern operating systems -- including seL4 -- are written to a fictional model of machine hardware from the 1960s and 1970s: a set of homogeneous cores accessing a common physical address space containing main memory, plus memory-mapped devices. However, modern SoCs and server platforms are really a complex network of heterogeneous cores and intelligent devices, many of which are running their own firmware and "operating systems''. The result is a catastrophe of system design, including a plethora of security exploits like remote over-the-air compromises due to weaknesses in WiFi modem firmware. Link: https://googleprojectzero.blogspot.co.... We are building Kirsch, a new OS that solves this problem by embracing and formally capturing the heterogeneity and multiple trust domains of modern hardware. To this end, Kirsch formally models what each hardware context can access using a decoding net representation of the platform (Link "Putting out the hardware dumpster fire", https://doi.org/10.1145/3593856.3595903), which induces a trust relationship between contexts. This trust relationship is the basis for reasoning about isolation, protection and authorization in the system. An seL4 instance can run from, and manage, a region of RAM which is explicitly isolated from untrusted contexts in the system, by using the trust an access information we formally derived. Kirsch thus recovers the power of the seL4 correctness proofs, and we can finally use the seL4 kernel to run truly isolated processes and virtual machines.