Horton

Re: BUG #19095: Test if function exit() is used fail when linked static

Andres Freund <andres@anarazel.de>

View thread
From: Andres Freund <andres@anarazel.de>
To: Daniel Gustafsson <daniel@yesql.se>
Cc: Michael Paquier <michael@paquier.xyz>, Tom Lane <tgl@sss.pgh.pa.us>, BharatDB <bharatdbpg@gmail.com>, torsten.rupp@gmx.net, pgsql-bugs@lists.postgresql.org, VASUKI M <vasukim1992002@gmail.com>
Date: 2025-11-14T14:01:06Z
Lists: pgsql-bugs, pgsql-hackers

Commits

Same data as JSON: GET /api/v1/messages/:b64id/commits the thread's linked commits as JSON, with link sources. API reference →

  1. libpq: Authorize pthread_exit() in libpq_check

  2. Fix meson warning due to missing declaration of NM

  3. libpq: Refactor logic checking for exit() in shared library builds

Hi,
On 2025-11-14 13:11:15 +0100, Daniel Gustafsson wrote:
> > On 12 Nov 2025, at 09:15, Michael Paquier <michael@paquier.xyz> wrote:
> > 
> > On Wed, Nov 12, 2025 at 09:13:09AM +0100, Daniel Gustafsson wrote:
> >> On 12 Nov 2025, at 07:38, Tom Lane <tgl@sss.pgh.pa.us> wrote:
> >>> Personally I'm okay with whitelisting pthread_exit() as
> >>> Torsten suggested.
> >> 
> >> +1, we already have a few whitelisted entries and pthread_exit seems perfectly
> >> reasonable to add to that list.
> > 
> > WFM.
> 
> The attached trivial diff adds this to the whitelist clause in the Makefile.  I
> experimented with adding this to Meson, and while it's trivial enough to do the
> run_command with libpq_so.full_path, it's less clear to me exactly where in the
> build it should be added.  I've pinged my colleague Bilal who is much better at
> Meson than me to collaborate on that as a separate fix.

For meson we'll have to filter where we test this more strictly - it'll
e.g. not work on windows, because there's no nm, perhaps no grep, etc.

But more generally: If we allow pthread_exit(), what's the point of this test?
That's one of the functions we better avoid calling, no?


ISTM that if we do want to continue having this test, the issue is that we're
testing the shared library - which will have already linked against static
libraries like the sanitizer ones or in this case libcrypto. What we ought to
do is to test the .o files constituting libpq.so, rather than the already
linked .so. That way we will find our own calls to exit etc, but not ones in
static libraries.

Greetings,

Andres Freund