Date: Sat, 28 Feb 2009 14:51:27 -0500
From: Christopher Faylor <cgf-use-the-mailinglist-please AT cygwin DOT com>
To: cygwin AT cygwin DOT com
Subject: Re: [1.7] rebaseall doesn't solve the problem
Message-ID: <20090228195127.GA26646@ednor.casa.cgf.cx>
Reply-To: cygwin AT cygwin DOT com
Mail-Followup-To: cygwin AT cygwin DOT com
References: <499F6682 DOT 1090204 AT cwilson DOT fastmail DOT fm> <20090224100616 DOT GC6035 AT calimero DOT vinschen DOT de> <49A85971 DOT 6070300 AT cwilson DOT fastmail DOT fm> <20090228104337 DOT GG19887 AT calimero DOT vinschen DOT de> <49A986B4 DOT 2080501 AT cwilson DOT fastmail DOT fm>
MIME-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Content-Disposition: inline
In-Reply-To: <49A986B4.2080501@cwilson.fastmail.fm>
User-Agent: Mutt/1.5.16 (2007-06-09)
Mailing-List: contact cygwin-help AT cygwin DOT com; run by ezmlm
Precedence: bulk
Sender: cygwin-owner AT cygwin DOT com
Mail-Followup-To: cygwin AT cygwin DOT com

On Sat, Feb 28, 2009 at 01:47:16PM -0500, Charles Wilson wrote:
>Corinna Vinschen wrote:
>
>> Way cool, Chuck.  Especially the fact that this tool can also mark
>> executables with the TS-aware flag (doesn't make sense for DLLs, afaik).
>> This helps to test if setting this flag in Cygwin binaries will
>> allow Cygwin to run on 2008 with TS without disabling DEP.
>
>Well, the tool would need a little tweaking I think. Right now it skips
>any image (DLL or exe) that does not contain relocations.
>
>> If so, I'm wondering if setting the TS-aware flag shouldn't become
>> default in GCC.  What do you say, Dave?  Would that be possible?
>
>I'd probably wait on that for the /next/ release (e.g. after 4.3.2-2),
>so we can get aslr integerated into rebase, and the rebaseall changes
>tested.  Should I also add a switch to rebaseall that means: ONLY alsr,
>NO rebasing.  There's already a flag that allows you to add .exe's to
>the "rebase" list -- but you can't remove dll's and .so's from the list.
>
>Maybe the aslr functionality is different enough -- and useful in enough
>contexts that differ from rebasing -- that instead of incorporating
>'call aslr TOO' into rebaseall, there should be a separate 'aslrall' script?

It should be trivial to add this to binutils.  Doesn't it ultimately
belong in ld and (maybe) objcopy?

I can add this now but I don't think it should be the default just yet.

>> That would also allow to drop the ugly TS hack I added to Cygwin 1.7.
>> All newly built binaries would have the flag set already, and older
>> binaries could be tweaked with the aslr utility.
>
>That would be nice.  However, ONLY exe's linked with cygwin1.dll should
>be marked this way, right?  Not cygcheck, strace, and whatever other few
>exes we might find in the cygwin installation lists.

Do the exes themselves need this bit as well as the dlls?

cgf

--
Unsubscribe info:      http://cygwin.com/ml/#unsubscribe-simple
Problem reports:       http://cygwin.com/problems.html
Documentation:         http://cygwin.com/docs.html
FAQ:                   http://cygwin.com/faq/