Re: SIGINT, longjmp, getaddrinfo

["Carlos O'Donell" <carlos at systemhalted dot org>]

On Tue, Feb 16, 2016 at 10:00 AM, Michael Kerrisk
<mtk.manpages@gmail.com> wrote:
>> I'm still surprised that there isn't some web page that documents and
>> discusses this whole area.
>
> <Blush> Well, I know there's a book that covers it...
>
> And now I've added this text to the completely revamped setjmp(2) man page[1]:
>
>        POSIX.1-2008  Technical  Corrigendum  2  adds  longjmp() and sigâ
>        longjmp() to the list of async-signal-safe  functions.   However,
>        the  standard recommends avoiding the use of these functions from
>        signal handlers and goes on to point out that if these  functions
>        are  called  from  a  signal handler that interrupted a call to a
>        non-async-signal-safe function (or some equivalent, such  as  the
>        steps  equivalent  to  exit(3)  that occur upon a return from the
>        initial call to main()), the behavior is undefined if the program
>        subsequently  makes  a call to a non-async-signal-safe.  The only
>        way of avoiding undefined behavior is to ensure one of  the  folâ
>        lowing:
>
>        *  After  long  jumping from the signal handler, the program does
>           not call any  non-async-signal-safe  functions  and  does  not
>           return from the initial call to main().
>
>        *  Any  signal whose handler performs a long jump must be blocked
>           during every call to a non-async-signal-safe function  and  no
>           non-async-signal-safe  functions  are  called  after returning
>           from the initial call to main().
>
> Hopefully that covers everyone's concerns.

Very well worded. Thanks for the update.

Cheers,
Carlos.