Re: [RFC 3/4] x86/signal/64: Re-add support for SS in the 64-bit signal context

Cyrill Gorcunov
2015-10-14T16:40:26Z

On Mon, Oct 12, 2015 at 06:04:07PM -0700, Andy Lutomirski wrote:
...
>
> For the benefit of new 64-bit software that uses segmentation (new
> versions of DOSEMU might), the new behavior can be detected with a
> new ucontext flag UC_SIGCONTEXT_SS.
>
> To avoid compilation issues, __pad0 is left as an alias for ss in
> ucontext.
>
> The nitty-gritty details are documented in the header file.
>
> Cc: Stas Sergeev <stsp@list.ru>
> Cc: Linus Torvalds <torvalds@linux-foundation.org>
> Cc: Cyrill Gorcunov <gorcunov@gmail.com>
> Cc: Pavel Emelyanov <xemul@parallels.com>
> Signed-off-by: Andy Lutomirski <luto@kernel.org>

Andy, so for old criu versions (prior the 1.5.1 which is Mar 2015,
in next versions we already write proper ss into the images)
we've been providing __pad = 0, which is ss in a new meaning,
and the kernel will overwrite it with @user-ds after this series,
correct? This should work for us. Stas, mind to refresh my memory,
which ss value doesmu setups here?