From: Taylor Blau <me@ttaylorr.com>
To: phillip.wood@dunelm.org.uk
Cc: Taylor Blau <me@ttaylorr.com>, Patrick Steinhardt <ps@pks.im>,
git@vger.kernel.org, iwiedler@gitlab.com
Subject: Re: [PATCH 1/1] fetch: fix deadlock when cleaning up lockfiles in async signals
Date: Mon, 10 Jan 2022 21:11:20 -0500 [thread overview]
Message-ID: <YdznSPJCSUQwVyg8@nand.local> (raw)
In-Reply-To: <2d8c1619-74ab-62b3-3a30-8e500a16649e@gmail.com>
On Sat, Jan 08, 2022 at 10:54:35AM +0000, Phillip Wood wrote:
> > But is unlink() safe as-is? I'm not so sure. Reading signal-safety(7),
> > it's clearly on the list of functions that are OK to call. But reading
> > the errno section:
> >
> > (snip)
> >
> > We certainly not doing that, though that's nothing new, and so I wonder
> > why it doesn't seem to be an issue in practice.
>
> Because in this case we re-raise the signal and exit it does not matter if
> unlink() clobbers errno. If instead the program were to continue after
> handling the signal then we would have to save and restore errno to avoid
> interfering with the code that was running when the signal handler was
> called.
That makes perfect sense to me. Thanks for a clear explanation.
Taylor
next prev parent reply other threads:[~2022-01-11 2:11 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-01-07 10:53 [PATCH 0/1] Async-signal safety in signal handlers Patrick Steinhardt
2022-01-07 10:55 ` [PATCH 1/1] fetch: fix deadlock when cleaning up lockfiles in async signals Patrick Steinhardt
2022-01-07 11:14 ` brian m. carlson
2022-01-07 22:41 ` Taylor Blau
2022-01-08 10:54 ` Phillip Wood
2022-01-11 2:11 ` Taylor Blau [this message]
[not found] <cover.1641551066.git.ps@pks.im>
2022-01-07 10:53 ` Patrick Steinhardt
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