Messages in this thread | | | Date | Tue, 22 Jan 2019 17:15:51 +0100 | From | Oleg Nesterov <> | Subject | Re: [PATCH 05/22] x86/fpu: Remove fpu->initialized usage in copy_fpstate_to_sigframe() |
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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.
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