Re: Documenting sigaltstack SS_AUTODISRM

[Stas Sergeev]

30.10.2017 13:50, Michael Kerrisk (man-pages) ÐÐÑÐÑ:
> I see what you mean. The point is back then that SS_ONSTACK was
> the only flag that could (on Linux) be specified in ss.ss_flags,
> so that "SS_ONSTACK | SOMETHING_FLAG" was a nonexistent case.
> These days, it's possible to specify the new SS_AUTODISARM
> flag in ss.ss_flags, which I think is why you are doubtful
> about the new page text. How about this, as a tightened-up
> version:
>
>      BUGS
>         In Linux 2.2 and earlier, the only flag that could be specified in
>         ss.sa_flags  was SS_DISABLE.  In the lead up to the release of the
>         Linux 2.4 kernel, a change was  made  to  allow  sigaltstack()  to
>         allow   ss.ss_flags==SS_ONSTACK   with   the   same   meaning   as
>         ss.ss_flags==0 (i.e., the inclusion of SS_ONSTACK  in  ss.ss_flags
>         is  a no-op).  On other implementations, and according to POSIX.1,
>         SS_ONSTACK appears only as a reported flag in old_ss.ss_flags.  On
>         Linux, there is no need ever to specify SS_ONSTACK in ss.ss_flags,
>         and indeed doing so should be avoided on portability grounds: varâ
>         ious  other  systems  give  an error if SS_ONSTACK is specified in
>         ss.ss_flags.
And after all these amendments it seems to
no longer belong to BUGS section but to NOTES.