Message-ID: <855a1b16-0dc0-42b2-8f90-79eb49cf2893@technowledgy.de>
Date: Sun, 17 Mar 2024 14:11:19 +0100
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From: Wolfgang Walther <walther@technowledgy.de>
Subject: Re: Regression tests fail with musl libc because libpq.so can't be
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To: Christophe Pettus <xof@thebuild.com>
Cc: Thomas Munro <thomas.munro@gmail.com>, Tom Lane <tgl@sss.pgh.pa.us>,
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Christophe Pettus:
> Given the musl (still?) does not define a preprocessor macro specific to it, is there a way of improving the test in pg_status.c to catch this case?  It seems wrong that the current test passes a case that doesn't actually work.

The missing macro is on purpose and unlikely to change: 
https://openwall.com/lists/musl/2013/03/29/13

I also found this thread, which discusses exactly our case: 
https://www.openwall.com/lists/musl/2022/08/17/1

Some quotes from that thread:

> I understand that what Postgres et al are doing is a nasty hack.

And:

> Applications that *really* want setproctitle type functionality can
> presumably do something like re-exec themselves with a suitably large
> argv[0] to give them safe space to overwrite with their preferred
> message, rather than UB trying to relocate the environment (and auxv?
> how? they can't tell libc they moved it) to some other location.

Could that be a more portable way of doing this?

Best,

Wolfgang