GNU bug report logs - #25178
26.0.50; Crash when pressing C-g in TTY mode

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Package: emacs;

Reported by: Elias Martenson <elias.martenson <at> murex.com>

Date: Mon, 12 Dec 2016 04:34:01 UTC

Severity: normal

Tags: fixed

Found in version 26.0.50

Done: npostavs <at> users.sourceforge.net

Bug is archived. No further changes may be made.

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From: eliz <at> gnu.org
Subject: bug#25178: (no subject)
Date: Mon, 19 Dec 2016 12:17:37 -0500
þÿDate: Mon, 19 Dec 2016 19:17:02 +0200
þÿMessage-Id: <83r3534z5d.fsf@gnu.org>
þÿFrom: Eli Zaretskii <eliz@gnu.org>
þÿTo: Elias Martenson <elias.martenson@murex.com>
þÿCC: 25178@debbugs.gnu.org
þÿIn-reply-to: <yxd837hkocrb.fsf@murex.com> (message from Elias Martenson on
þÿ	Mon, 19 Dec 2016 10:48:08 +0800)
þÿSubject: Re: bug#25178: 26.0.50; Crash when pressing C-g in TTY mode
þÿReply-to: Eli Zaretskii <eliz@gnu.org>
þÿReferences: <yxd8twa9g41u.fsf@murex.com> <83bmwhccib.fsf@gnu.org>
þÿ	<yxd8wpf4msrn.fsf@murex.com> <838trjbrcq.fsf@gnu.org>
þÿ	<yxd8oa0fmckn.fsf@murex.com> <83eg167j31.fsf@gnu.org> <yxd837hkocrb.fsf@murex.com>
þÿ
þÿ> From: Elias Martenson <elias.martenson@murex.com>
þÿ> CC: <25178@debbugs.gnu.org>
þÿ> Date: Mon, 19 Dec 2016 10:48:08 +0800
þÿ> 
þÿ> > Eli Zaretskii <eliz@gnu.org> writes:
þÿ> > 
þÿ> > > From: Elias Martenson <elias.martenson@murex.com>
þÿ> > > CC: <25178@debbugs.gnu.org>
þÿ> > > Date: Wed, 14 Dec 2016 11:09:12 +0800
þÿ> > > 
þÿ> > > Calling pthread_mutex_unlock() twice has to be undefined behaviour. In
þÿ> > > fact, it can never work. Imagine what would happen if a different thread
þÿ> > > called pthread_mutex_lock() on the mutex between two the two unlock
þÿ> > > calls. In that case, you'd be unlocking a mutex help by a different
þÿ> > > thread which is obviously very dangerous.
þÿ> > 
þÿ> > Can you try the patch below and see if it stops the crashes?  With
þÿ> > this patch, I no longer see two calls to pthread_mutex_unlock in a
þÿ> > row.
þÿ> 
þÿ> I've tried it, and I am now unable to reproduce the problem. Thanks a
þÿ> lot!
þÿ
þÿThanks, pushed.  Please test.
þÿ
þÿ> > Would people who know about signals and threads please eyeball this
þÿ> > patch and comment on whether it is correct, safe, etc.?  TIA.
þÿ> 
þÿ> I'm quite well-versed on the topic of threading, but not so much in the
þÿ> internals of Emacs, but I'm looking at it now.
þÿ
þÿThanks.
þÿ
þÿ> I do have a non-technical comment though, about the function
þÿ> unblock_interrupt_signal(). As far as I can tell, it doesn't do what the
þÿ> function name suggests it does. I'd rather name it set_signal_mask(),
þÿ> since that's what it does.
þÿ
þÿI renamed it to restore_signal_mask.
þÿ
þÿP.S. your mailer does something weird: it appends a disclaimer
þÿencoded in UTF-16, which marks your entire mail as encoded in UTF-16,
þÿand that makes the body unreadable gibberish.  I needed some juggling
þÿto restore the payload.




This bug report was last modified 8 years and 139 days ago.

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