Re: [PATCH 1/2] sigaltstack: implement SS_AUTODISARM flag

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From	Andy Lutomirski <luto@amacapital.net>
Newsgroups	linux.kernel
Subject	Re: [PATCH 1/2] sigaltstack: implement SS_AUTODISARM flag
Date	Fri, 04 Mar 2016 23:30:01 +0100
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On Mon, Feb 29, 2016 at 1:29 PM, Stas Sergeev <stsp@list.ru> wrote:
> This patch implements the SS_AUTODISARM flag that can be ORed with
> SS_ONSTACK when forming ss_flags.
> When this flag is set, sigaltstack will be disabled when entering
> the signal handler; more precisely, after saving sas to uc_stack.
> When leaving the signal handler, the sigaltstack is restored by
> uc_stack.
> When this flag is used, it is safe to switch from sighandler with
> swapcontext(). Without this flag, the subsequent signal will corrupt
> the state of the switched-away sighandler.
>

This looks reasonable to me with one exception: how does a user
program detect the presence of this feature?  Anyone else have any
thoughts?

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Re: [PATCH 1/2] sigaltstack: implement SS_AUTODISARM flag Andy Lutomirski <luto@amacapital.net> - 2016-03-04 23:30 +0100
  Re: [PATCH 1/2] sigaltstack: implement SS_AUTODISARM flag Stas Sergeev <stsp@list.ru> - 2016-03-05 08:40 +0100
    Re: [PATCH 1/2] sigaltstack: implement SS_AUTODISARM flag Stas Sergeev <stsp@list.ru> - 2016-03-05 08:50 +0100

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