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Date: Sat, 28 Feb 2009 13:47:16 -0500
From: Charles Wilson <cygwin AT cwilson DOT fastmail DOT fm>
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Subject: Re: [1.7] rebaseall doesn't solve the problem
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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?

> 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.

--
Chuck

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