* Andy Lutomirski <[email protected]> wrote:
> From: Andy Lutomirski <[email protected]>
>
> The comment in the signal code says that apps can save/restore other
> segments on their own. It's true that apps can *save* SS on their
> own, but there's no way for apps to restore it: SYSCALL effectively
> resets SS to __USER_DS, so any value that user code tries to load
> into SS gets lost on entry to sigreturn.
>
> This recycles two padding bytes in the segment selector area for SS.
>
> While we're at it, we need a second change to make this useful. If
> the signal we're delivering is caused by a bad SS value, saving that
> value isn't enough. We need to remove that bad value from the regs
> before we try to deliver the signal. Oddly, x32 already got this
> right.
Note, it's the original i386 code that got this right, not the
(relatively new) x32 code. I fixed this in the commit that I applied.
Thanks,
Ingo
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