[HEADSUP] Dropping libopenssl098 from distro

Ken Brown kbrown@cornell.edu
Fri Jan 23 22:43:00 GMT 2015

On 1/23/2015 3:09 PM, Corinna Vinschen wrote:
> Hi Ken,
> On Jan 23 08:48, Ken Brown wrote:
>> On 1/14/2015 4:19 PM, Ken Brown wrote:
>>> It is.  There's a configure option "--ignore-absence-of-libsigsegv".  But there
>>> are more serious problems, affecting both the 32-bit and 64-bit versions.  (So
>>> even just rebuilding clisp for 32-bit Cygwin will take some work.)  The problem
>>> is that lisp.exe, which is built and used in the course of trying to build
>>> clisp.exe, crashes with a SEGV shortly after it's started.
>>> My reason for looking at this was that clisp is needed for building xindy, an
>>> optional component of TeX Live.  I did successfully build clisp in the 32-bit
>>> case four years ago, but I can't any more.  My guess (untested) is that this is
>>> because the location of the heap has changed since then, and maybe the source
>>> code makes unwarranted assumptions about memory layout.
>> My guess is correct.  lisp.exe uses bit 31 (counting from the LSB) as a
>> marker during garbage collection, and this is incompatible with Cygwin's use
>> of high memory for the heap.  I think I know how to fix this (by defining
>> LINUX_NOEXEC_HEAPCODES in the Cygwin build), but I haven't finished testing
>> it yet.
> Given that by default *all* addresses used for 64 bit Cygwin processes
> are beyond the 2GB border, it's kind of tricky to use bit 31 for anything.
> But even then, the same code would fail on 32 bit Windows as well, if
> it's running under WOW64 or a 32 bit kernel started with the /3GB flag
> (or it's successor).  In both cases Cygwin would happily use the
> addresses beyond 0x80000000 for the heap.
> So, from that I conclude that using bit 31 for any dubious reason is
> inherently broken.  I hope that the LINUX_NOEXEC_HEAPCODES stuff works,
> and if so, it should be used for the 32 bit build as well.

Sorry, I should have been more clear.  I was only talking about the 32-bit 
build.  I haven't yet seriously tried the 64-bit build.
>> I'd like to know Reini's intentions before investing any more time in this.
>> BTW, I am *not* qualified to take over as clisp maintainer.  I've never used
>> clisp, and I know nothing about it other than the tiny bit I've learned from
>> debugging the crash I mentioned above.
> Well, it seems you're now stuck with it.
> <slashdot>
> I, for one, welcome our new clisp overlord!
> </slashdot>

Thanks a lot.

I'll see if I can at least get version 3.48 or 3.49 built on both platforms. 
But in view of what Reini said about it being broken upstream, I don't think 
I'll try to go further.


More information about the Cygwin-apps mailing list