Hi Richard, On 2016/3/18 16:20, Richard Weinberger wrote: > I wonder how other architectures handle this case? > Ideally I'd like to avoid as much extra code as possible in userspace().
Please forgive my ignorance of other architectures. But to the best of my knowledge, FPU state is not saved and restored around a system call in x86. I agree that we should keep userspace() minimal. So what in the first place is the FPU state save/restore code for? Or, what (except for sigreturn) could possibly mess the FPU state of the ptrace'd process without it? I tried commenting out the FPU restore code in userspace() and tested with a bunch of kernel modules and userland programs. Nothing bad happened so far as I can tell. Thanks, Eli ------------------------------------------------------------------------------ Transform Data into Opportunity. Accelerate data analysis in your applications with Intel Data Analytics Acceleration Library. Click to learn more. http://pubads.g.doubleclick.net/gampad/clk?id=278785231&iu=/4140 _______________________________________________ User-mode-linux-devel mailing list User-mode-linux-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/user-mode-linux-devel
