From: Ulrich Mueller <ulm@gentoo.org>
To: Eli Zaretskii <eliz@gnu.org>
Cc: 18784@debbugs.gnu.org
Subject: bug#18784: Coultdn't compile emacs-24.4
Date: Mon, 16 Mar 2015 21:04:08 +0100 [thread overview]
Message-ID: <21767.14136.316805.481531@a1i15.kph.uni-mainz.de> (raw)
In-Reply-To: <83pp88zqgl.fsf@gnu.org>
>>>>> On Mon, 16 Mar 2015, Eli Zaretskii wrote:
>> I guess if PIE is used in order to place Emacs's code at randomized
>> addresses (different address every time an Emacs process is launched),
>> it can break the dump because our subr objects will end up with pointers
>> to addresses that aren't valid any more (might be other such problems,
>> but that's the first that comes to my mind).
> Then this is only an issue on systems where PIE == address
> randomization, isn't it?
That would be my guess too. Here are some gdb backtraces showing that
the problem occurs in unexelf.c:
https://bugs.gentoo.org/494316#c13
https://bugs.gentoo.org/526948#c9
http://debbugs.gnu.org/13847#5
There is a long history of Emacs catching up with kernel hardening
in this area. It started with setting ADDR_NO_RANDOMIZE via Linux
personality(2), then setting the NORANDEXEC flag with paxctl(1) or
setfattr(1). Now it seems that we need -nopie in addition.
My impression is that these are all workarounds that don't address the
real issue.
next prev parent reply other threads:[~2015-03-16 20:04 UTC|newest]
Thread overview: 19+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-10-21 11:52 bug#18784: Coultdn't compile emacs-24.4 Gangræna Gorgeous
2014-10-21 15:16 ` Eli Zaretskii
2014-10-21 15:49 ` David Engster
2015-03-13 19:54 ` Glenn Morris
2015-03-13 20:43 ` Ulrich Mueller
2015-03-13 21:09 ` Ulrich Mueller
2015-03-13 23:25 ` Stefan Monnier
2015-03-16 9:16 ` Ulrich Mueller
2015-03-16 13:09 ` Stefan Monnier
2015-03-16 16:18 ` Eli Zaretskii
2015-03-16 18:19 ` Stefan Monnier
2015-03-16 18:29 ` Eli Zaretskii
2015-03-16 19:06 ` Stefan Monnier
2015-03-16 19:34 ` Eli Zaretskii
2015-03-16 20:04 ` Ulrich Mueller [this message]
2015-03-16 20:29 ` Stefan Monnier
2015-03-29 12:19 ` Ulrich Mueller
2015-04-03 11:45 ` Ulrich Mueller
2015-03-16 16:26 ` Ulrich Mueller
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
List information: https://www.gnu.org/software/emacs/
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=21767.14136.316805.481531@a1i15.kph.uni-mainz.de \
--to=ulm@gentoo.org \
--cc=18784@debbugs.gnu.org \
--cc=eliz@gnu.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
Code repositories for project(s) associated with this public inbox
https://git.savannah.gnu.org/cgit/emacs.git
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for read-only IMAP folder(s) and NNTP newsgroup(s).