Perhaps I did not make it clear enough, but these issues still exist as far as I can tell. I have clean Windows 7 and Windows XP virtual machines, and a clean install of Cygwin that was updated at the time I sent my original message. Both issues I described still exist. This is why I wrote the message. If the issues weren't existing on an up-to-date Cygwin installation, I would not write to this mailing list and waste anyone's time - I am usually not that dumb!
Just this morning, I turned on my Cygwin installation in the Windows 7 VM. This time, cygreadline7.dll decided to relocate to 0x70030000 - different from the original location I mentioned in my original e-mail. This DLL is not locating itself in a stable location. And there are still system DLLs located very close to the Cygwin DLLs. If having Windows randomly rebase cygreadline7.dll in a child process via ASLR is not a problem, I'd simply be interested to know why. I thought *any* Cygwin DLL relocating itself would cause fork to fail. If having Cygwin DLLs conflict with system DLLs in the address space is not a potential problem, I'd also be interested to know why. Because I am observing both of these on an *up-to-date Cygwin installation* - not just the Cygwin 1.7.9 setup. According to the users guide at http://cygwin.com/cygwin-ug-net/highlights.html#ov-hi-process - section "Problems with process creation" - having Cygwin DLLs conflict with system DLLs is a problem, and having cygreadline7.dll randomly based via ASLR is a problem - so is my logic faulty in this case or not? As far as I can tell, I'm up-to-date... Setup says I have libreadline7 6.1.2-2 installed - the latest according to http://cygwin.com/packages/libreadline7/. My file size and date matches what is shown at that URL. Yet: c:\cygwin\bin>dumpbin /headers cygreadline7.dll | more <snip> 8040 DLL characteristics Dynamic base Terminal Server Aware Notice the "Dynamic base" flag set. -----Original Message----- Sent: Friday, April 20, 2012 20:50 Subject: Re: Two probable basing issues causing fork failures: (1) cygreadline7.dll has ASLR enabled, (2) default base address conflicts with ASLR-relocated/system DLLs On Fri, Apr 20, 2012 at 05:44:38PM -0000, James Johnston wrote: >[snip] >... Today this issue came >to a head on one installation of Cygwin 1.7.9,... >[snip] >Thoughts, anyone? Yep. Update your Cygwin installation. You're four revisions out of date. It should come not too great a surprise that we've had extensive discussions about this issue and have made some changes in recent releases. -- Problem reports: http://cygwin.com/problems.html FAQ: http://cygwin.com/faq/ Documentation: http://cygwin.com/docs.html Unsubscribe info: http://cygwin.com/ml/#unsubscribe-simple -- Problem reports: http://cygwin.com/problems.html FAQ: http://cygwin.com/faq/ Documentation: http://cygwin.com/docs.html Unsubscribe info: http://cygwin.com/ml/#unsubscribe-simple