From: Tom Lane <tgl@sss.pgh.pa.us>
To: Heikki Linnakangas <heikki.linnakangas@iki.fi>
Cc: pgsql-committers@lists.postgresql.org, Andres Freund <andres@anarazel.de>
Subject: Re: pgsql: Fix double-release of spinlock
Date: Mon, 29 Jul 2024 11:31:56 -0400
Message-ID: <2600757.1722267116@sss.pgh.pa.us> (raw)
In-Reply-To: <E1sYSF2-001lEB-D1@gemulon.postgresql.org>
References: <E1sYSF2-001lEB-D1@gemulon.postgresql.org>
Heikki Linnakangas <heikki.linnakangas@iki.fi> writes:
> Commit 9d9b9d46f3 added spinlocks to protect the fields in ProcSignal
> flags, but in EmitProcSignalBarrier(), the spinlock was released
> twice. With most spinlock implementations, releasing a lock that's not
> held is not easy to notice, because most of the time it does nothing,
> but if the spinlock was concurrently acquired by another process, it
> could lead to more serious issues. Fortunately, with the
> --disable-spinlocks emulation implementation, it caused more visible
> failures.
There was some recent discussion about getting rid of
--disable-spinlocks on the grounds that nobody would use
hardware that lacked native spinlocks. But now I wonder
if there is a testing/debugging reason to keep it.
regards, tom lane
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To: pgsql-committers@postgresql.org
Cc: tgl@sss.pgh.pa.us, heikki.linnakangas@iki.fi, andres@anarazel.de
Subject: Re: pgsql: Fix double-release of spinlock
In-Reply-To: <2600757.1722267116@sss.pgh.pa.us>
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