From: Florian Weimer <fw@deneb.enyo.de>
To: Rich Felker <dalias@libc.org>
Cc: Carlos O'Donell via Libc-alpha <libc-alpha@sourceware.org>
Subject: Re: [PATCH] Make abort() AS-safe (Bug 26275).
Date: Tue, 29 Sep 2020 08:54:59 +0200 [thread overview]
Message-ID: <87d025jcn0.fsf@mid.deneb.enyo.de> (raw)
In-Reply-To: <20200928234833.GC17637@brightrain.aerifal.cx> (Rich Felker's message of "Mon, 28 Sep 2020 19:48:33 -0400")
* Rich Felker:
> Is there a reason to take the lock across fork rather than just
> resetting it in the child? After seeing this I'm working on fixing the
> same issue in musl and was about to take the lock, but realized ours
> isn't actually protecting any userspace data state, just excluding
> sigaction on SIGABRT during abort.
It's also necessary to stop the fork because the subprocess could
otherwise observe the impossible SIG_DFL state. In case the signal
handler returns, the implementation needs to produce a termination
status with SIGABRT as the termination signal, and the only way I can
see to achieve that is to remove the signal handler and send the
signal again. This suggests that a lock in sigaction is needed as
well.
But for the fork case, restting the lock in the new subprocess should
be sufficient.
next prev parent reply other threads:[~2020-09-29 6:55 UTC|newest]
Thread overview: 13+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-09-27 14:19 [PATCH] Make abort() AS-safe (Bug 26275) Carlos O'Donell via Libc-alpha
2020-09-27 20:04 ` Florian Weimer
2020-09-28 23:48 ` Rich Felker
2020-09-29 6:54 ` Florian Weimer [this message]
2020-09-29 14:42 ` Rich Felker
2020-10-01 2:30 ` Rich Felker
2020-10-01 6:08 ` Florian Weimer
2020-10-01 14:39 ` [musl] " Rich Felker
2020-10-01 15:11 ` Florian Weimer via Libc-alpha
2020-10-01 15:28 ` Rich Felker
2020-10-01 14:49 ` Carlos O'Donell via Libc-alpha
2020-10-01 14:55 ` [musl] " Rich Felker
2020-10-10 0:26 ` Rich Felker
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