On 01/22, Borislav Petkov wrote: > > On Mon, Jan 21, 2019 at 12:21:17PM +0100, Oleg Nesterov wrote: > > And in any case I do not understand the idea to use the second > > in-kernel struct fpu. A signal handler can be interrupted by another > > signal, this will need to save/restore the FPU state again. > > Well, we were just speculating whether doing that would simplify the > code around get_sigframe() et al. But if that is an ABI, then we can't > really touch it. > > Btw, where is that whole ABI deal about saving FPU regs on the user > signal stack documented? I don't know... tried to google, found nothing. the comment in /usr/include/sys/ucontext.h mentions SysV/i386 ABI + historical reasons, this didn't help. Oleg.
