On Wed, Mar 28, 2018 at 11:14:05AM -0400, Mathieu Desnoyers wrote: > > If at all possible I would make it SIGSEGV when issueing SYSCALL()s from > > within an RSEQ. > > What's the goal there ? rseq critical sections can technically do system calls > if they wish. Why prevent this ?
This all started as a way to do 'small' _fast_ per-cpu ops, System calls do NOT fit in that pattern. If you're willing to do a system calls the cost of atomics is not a problem. > How would you handle signal handlers that issue system calls while nested > on top of a rseq critical section in the userspace thread ? SIGSEGV on > SYSCALLs will break this case. Have the rseq thing aborted prior to delivering the signal ?
