On Tue, Dec 01, 2020 at 01:48:30AM +0800, Rongwei Wang wrote: > MSR ARM driver aims to provide interfacs for user to read or write > data to all system registers.
Just a warranty from x86 land: if I were an ARM arch maintainer, I would never never *ever* take such driver exposing naked hw registers to userspace. We have been fighting with this on x86 for years: a7e1f67ed29f ("x86/msr: Filter MSR writes") with userspace tools poking at random MSRs. Read the commit message for what can happen. And taking that thing is like opening a huge can'o'worms that can't be closed anymore. Currently, we're trying to move userspace tools to proper sysfs interfaces but it is a huuuge pain. It is a lot easier to have people define proper interfaces from the get-go where the kernel can control and synchronize access. HTH. -- Regards/Gruss, Boris. https://people.kernel.org/tglx/notes-about-netiquette