Re: [PATCH] x86/fpu: move FPU state into separate cache

[Linus Torvalds]

On Wed, Mar 29, 2017 at 2:30 PM, Linus Torvalds
<torvalds@xxxxxxxxxxxxxxxxxxxx> wrote:
>
> The trivial model might be to just declare the fpu part as an unsized
> array at the end:
>
>         /* Floating point and extended processor state */
>         struct fpu              fpu[];
>
> because there is no way in hell that any randomization code can move
> those kinds of unsized arrays around.

Side note: that approach would seem to have the added advantage that
because "fpu" now is an array, it syntactically acts like a pointer in
C, so now syntactically it's going to be equivalent to having a
"struct fpu *" pointer element, but from an allocation and code
generation standpoint it all is like allocating the fpu structure
together with the task struct.

                 Linus