Re: stopgap fix for signal handling during restore_command

Hi,

On 2023-10-10 22:29:34 -0500, Nathan Bossart wrote:
> On Tue, Oct 10, 2023 at 09:54:18PM -0500, Nathan Bossart wrote:
> > On Tue, Oct 10, 2023 at 04:40:28PM -0700, Andres Freund wrote:
> >> I'd make these elog(PANIC), I think. The paths are not performance critical
> >> enough that a single branch hurts, so the overhead of the check is irrelevant,
> >> and the consequences of calling ProcKill() twice for the same process are very
> >> severe.
> > 
> > Right.  Should we write_stderr_signal_safe() and then abort() to keep these
> > paths async-signal-safe?
> 
> Hm.  I see that elog() is called elsewhere in proc_exit(), and it does not
> appear to be async-signal-safe.  Am I missing something?

We shouldn't call proc_exit() in a signal handler. We perhaps have a few
remaining calls left, but we should (and I think in some cases are) working on
removing those.

Greetings,

Andres Freund