public inbox for [email protected]  

help / color / mirror / Atom feed

From: Nathan Bossart <[email protected]>
To: [email protected]
Subject: pgsql: Check that MyProcPid == getpid() in backend signal handlers.
Date: Wed, 14 Feb 2024 20:53:17 +0000
Message-ID: <[email protected]> (raw)

Check that MyProcPid == getpid() in backend signal handlers.

In commit 97550c0711, we added a similar check to the SIGTERM
handler for the startup process.  This commit adds this check to
backend signal handlers installed with pqsignal().  This is done by
using a wrapper function that performs the check before calling the
actual handler.

The hope is that this will offer more general protection against
child processes of Postgres backends inadvertently modifying shared
memory due to inherited signal handlers.  Another potential
follow-up improvement is to use this wrapper handler function to
restore errno instead of relying on each individual handler
function to do so.

This commit makes the changes in commit 97550c0711 obsolete but
leaves reverting it for a follow-up commit.

Reviewed-by: Andres Freund, Noah Misch
Discussion: https://postgr.es/m/20231121212008.GA3742740%40nathanxps13

Branch
------
master

Details
-------
https://git.postgresql.org/pg/commitdiff/3b00fdba9f20b641d5d3c2b781cd435b23540e61

Modified Files
--------------
src/port/pqsignal.c | 86 +++++++++++++++++++++++++++++++++++++++++++++++++++--
1 file changed, 84 insertions(+), 2 deletions(-)

reply

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Reply to all the recipients using the --to and --cc options:
  reply via email

  To: [email protected]
  Cc: [email protected], [email protected]
  Subject: Re: pgsql: Check that MyProcPid == getpid() in backend signal handlers.
  In-Reply-To: <[email protected]>

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

This inbox is served by agora; see mirroring instructions
for how to clone and mirror all data and code used for this inbox