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bug#24764: 25.1.50; Another crash in automatic gc
From: |
Eli Zaretskii |
Subject: |
bug#24764: 25.1.50; Another crash in automatic gc |
Date: |
Sat, 22 Oct 2016 15:01:25 +0300 |
> From: Andreas Schwab <schwab@linux-m68k.org>
> Cc: Michael Heerdegen <michael_heerdegen@web.de>, 24764@debbugs.gnu.org
> Date: Sat, 22 Oct 2016 13:41:15 +0200
>
> >> (gdb) bt full
> >> #0 0x000000000058aae0 in unchain_marker (marker=0x88e9968) at marker.c:605
> >> tail = 0x2020200020202020 <<<<<<<<<<<<<<<<<<<<<<<<
> >> prev = 0x2020200020202030 <<<<<<<<<<<<<<<<<<<<<<<<
> >
> > Your marker pointers are actually full of blank (and other ASCII)
> > characters. So some code somewhere either writes past the end of some
> > stack-based array or otherwise overwrites the stack.
>
> More likely, BUF_MARKERS is already overwritten.
Could be, perhaps because of this:
> Or maybe your system, too, uses ralloc.c, and this is one more
> manifestation of some buffer or string relocated while some code hangs
> to the C pointers of the original contents.
> Finding the place where a member of a struct buffer is overwritten
> can be done with a watchpoint.
Yes. But IME just a watchpoint with no conditions gets triggered too
frequently to be useful, which is why a more-or-less specific recipe
for reproducing the problem would be beneficial, because then you
could activate the watchpoint only when it matters, or specify a
condition for it to trigger only when that matters.
For starters, I'd try to see whether 'tail' and 'prev' always have
these values when GC crashes.
- bug#24764: 25.1.50; Another crash in automatic gc, Michael Heerdegen, 2016/10/22
- bug#24764: 25.1.50; Another crash in automatic gc, Eli Zaretskii, 2016/10/22
- bug#24764: 25.1.50; Another crash in automatic gc, Andreas Schwab, 2016/10/22
- bug#24764: 25.1.50; Another crash in automatic gc,
Eli Zaretskii <=
- bug#24764: 25.1.50; Another crash in automatic gc, Eli Zaretskii, 2016/10/22
- bug#24764: 25.1.50; Another crash in automatic gc, Michael Heerdegen, 2016/10/22
- bug#24764: 25.1.50; Another crash in automatic gc, Eli Zaretskii, 2016/10/22
- bug#24764: 25.1.50; Another crash in automatic gc, Michael Heerdegen, 2016/10/22
- bug#24764: 25.1.50; Another crash in automatic gc, Eli Zaretskii, 2016/10/22
- bug#24764: 25.1.50; Another crash in automatic gc, Michael Heerdegen, 2016/10/22
- bug#24764: 25.1.50; Another crash in automatic gc, Eli Zaretskii, 2016/10/22
- bug#24764: 25.1.50; Another crash in automatic gc, Michael Heerdegen, 2016/10/23
- bug#24764: 25.1.50; Another crash in automatic gc, Eli Zaretskii, 2016/10/23
- bug#24764: 25.1.50; Another crash in automatic gc, Eli Zaretskii, 2016/10/23