From: Eric W. Biederman
Sent: 30 May 2019 16:38 ebiederm@xmission.com (Eric W. Biederman) writes:
Which means I believe we have a semantically valid change in behavior that is causing a regression.
I haven't made a survey of all of the functions yet but fucntions return -ENORESTARTNOHAND will never return -EINTR and are immune from this problem.
Eh? ERESTARTNOHAND just makes the system call restart if there is no signal handler, EINTR should still be returned if there is a handler.
All the functions that have a temporary signal mask are likely to be expected to work the same way and thus have the same bugs.
http://pubs.opengroup.org/onlinepubs/9699919799/functions/pselect.html# isn't overly helpful. But I think it should return EINTR even if there is no handler unless SA_RESTART is set:
[EINTR] The function was interrupted while blocked waiting for any of the selected descriptors to become ready and before the timeout interval expired.
If SA_RESTART has been set for the interrupting signal, it is implementation-defined whether the function restarts or returns with [EINTR].
David
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