From: Pip Cet <pipcet@gmail.com>
To: Eli Zaretskii <eliz@gnu.org>
Cc: 21380@debbugs.gnu.org
Subject: bug#21380: 25.0.50; GTK-induced segfault when scheduling timer from window-configuration-change-hook
Date: Tue, 1 Sep 2015 20:48:18 +0000 [thread overview]
Message-ID: <CAOqdjBd-LLOERx78ngF_n3fQM+O6zKbF3gbEme9t8Jwb7iT3RQ@mail.gmail.com> (raw)
In-Reply-To: <83vbbuawgy.fsf@gnu.org>
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On Tue, Sep 1, 2015 at 5:19 PM, Eli Zaretskii <eliz@gnu.org> wrote:
> > The only code path that I see that's potentially dangerous is that
> atimers
> > appear to be executed even if input is blocked.
>
> Yes, that's exactly what bothered me. Not calling QUIT prevents that.
>
> Alternatively, we could turn off atimers (by calling turn_on_atimers)
> while Fcopy_sequence runs.
>
I think that would be a better solution. I've done a quick grep for the
current atimers and at first glance they appear to be okay, but obviously
that's no guarantee for the future. It might be worth thinking about
block_input_and_atimers ().
I think it's safe to assume that Lisp timers are only checked if atimers
are enabled. If it isn't, I think the best way forward is to write
block_input_and_atimers () and lock atimers with a counter just like input
is.
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From 678bdba55e4a07e3baebad204c9fe5c55c99b3d3 Mon Sep 17 00:00:00 2001
From: Philip <pipcet@gmail.com>
Date: Tue, 1 Sep 2015 20:42:44 +0000
Subject: [PATCH] Fix potential race conditions (Bug#21380)
* keyboard.c (timer_check): Call `block_input' and turn off
atimers around the creation of the temporary timer list copy.
* fns.c (concat): Don't assume argument size remains unchanged
after call to `Fmake_list'. Return incorrect results (but don't
segfault) in that case.
---
src/fns.c | 3 +++
src/keyboard.c | 4 ++++
2 files changed, 7 insertions(+)
diff --git a/src/fns.c b/src/fns.c
index 26a98ab..15d9e64 100644
--- a/src/fns.c
+++ b/src/fns.c
@@ -744,6 +744,9 @@ concat (ptrdiff_t nargs, Lisp_Object *args,
/* Store this element into the result. */
if (toindex < 0)
{
+ if (NILP (tail))
+ break;
+
XSETCAR (tail, elt);
prev = tail;
tail = XCDR (tail);
diff --git a/src/keyboard.c b/src/keyboard.c
index dab32b1..4ce830d 100644
--- a/src/keyboard.c
+++ b/src/keyboard.c
@@ -4560,6 +4560,8 @@ timer_check (void)
Lisp_Object tem = Vinhibit_quit;
Vinhibit_quit = Qt;
+ block_input ();
+ turn_on_atimers (false);
/* We use copies of the timers' lists to allow a timer to add itself
again, without locking up Emacs if the newly added timer is
@@ -4573,6 +4575,8 @@ timer_check (void)
else
idle_timers = Qnil;
+ turn_on_atimers (true);
+ unblock_input ();
Vinhibit_quit = tem;
do
--
2.5.0
next prev parent reply other threads:[~2015-09-01 20:48 UTC|newest]
Thread overview: 50+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-08-30 12:51 bug#21380: 25.0.50; GTK-induced segfault when scheduling timer from window-configuration-change-hook Pip Cet
2015-08-30 15:01 ` Eli Zaretskii
2015-08-30 15:24 ` Pip Cet
2015-08-30 15:27 ` Pip Cet
2015-08-30 16:24 ` Pip Cet
2015-08-30 18:10 ` martin rudalics
2015-08-30 18:20 ` Pip Cet
2015-08-30 19:50 ` Eli Zaretskii
2015-08-30 18:59 ` Pip Cet
2015-08-31 9:20 ` martin rudalics
2015-08-30 16:39 ` Eli Zaretskii
2015-08-30 16:42 ` Pip Cet
2015-08-30 19:44 ` Eli Zaretskii
2015-08-30 20:56 ` Pip Cet
2015-08-30 21:13 ` Pip Cet
2015-08-31 14:31 ` Eli Zaretskii
2015-09-01 10:20 ` Pip Cet
2015-09-01 15:03 ` Eli Zaretskii
2015-09-01 15:22 ` Pip Cet
2015-09-01 16:01 ` Eli Zaretskii
2015-09-01 16:02 ` Pip Cet
2015-09-01 16:23 ` Eli Zaretskii
2015-09-02 7:02 ` martin rudalics
2015-09-02 14:32 ` Eli Zaretskii
2015-09-03 15:36 ` Stefan Monnier
2015-09-05 7:38 ` Eli Zaretskii
2015-09-05 15:18 ` Stefan Monnier
2015-09-05 15:27 ` Eli Zaretskii
2015-09-06 22:11 ` Stefan Monnier
2022-04-29 12:52 ` Po Lu via Bug reports for GNU Emacs, the Swiss army knife of text editors
2022-04-29 13:40 ` Eli Zaretskii
2022-04-29 13:44 ` Po Lu via Bug reports for GNU Emacs, the Swiss army knife of text editors
2022-04-29 15:02 ` Pip Cet
2015-09-05 16:59 ` Pip Cet
2015-09-06 22:22 ` Stefan Monnier
2015-09-08 15:55 ` Pip Cet
2015-09-01 15:14 ` Pip Cet
2015-09-01 16:04 ` Eli Zaretskii
2015-09-01 16:56 ` Pip Cet
2015-09-01 17:19 ` Eli Zaretskii
2015-09-01 20:48 ` Pip Cet [this message]
2015-09-02 15:08 ` Eli Zaretskii
2015-09-02 16:09 ` Pip Cet
2015-09-02 19:13 ` Eli Zaretskii
2015-09-02 22:08 ` Pip Cet
2020-09-07 17:07 ` Lars Ingebrigtsen
2020-09-07 17:47 ` Pip Cet
2020-09-07 19:09 ` Eli Zaretskii
2020-09-08 9:57 ` Lars Ingebrigtsen
2022-04-29 12:14 ` Lars Ingebrigtsen
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