Re: [PATCH x86/mm 6/6] x86-64 ia32 ptrace get/putreg32 current task

Roland McGrath
2007-11-29T22:25:49Z

> But the ones that do the same thing for fs/es/ds are *not*. Those three
> registers are kernel mode registers (ds/es are the regular kernel data
> segment, fs is the per-cpu data segment), and restored on return to user
> space from the stack.

Um, really? This is x86-64 code. AIUI those values don't have any effect
at all in 64-bit mode (as the kernel is). I haven't found any code in
entry_64.S or ia32entry.S that touches them. __switch_to uses direct
access to the segment registers just as I've done.

Thanks,
Roland