Re: FreeBSD and wine mmap

From: Anish Mistry <mistry.7_at_osu.edu>
Date: Mon, 6 Sep 2004 01:39:31 -0400
On Sunday 05 September 2004 05:46 pm, you wrote:
> On Sun, Sep 05, 2004 at 01:15:15PM -0400, Anish Mistry wrote:
> > On Sunday 29 August 2004 12:59 am, you wrote:
> > > On Tue, Aug 10, 2004 at 01:53:14PM -0400, Anish Mistry wrote:
> > > > -----BEGIN PGP SIGNED MESSAGE-----
> > > > Hash: SHA1
> > > >
> > > > On Wednesday 04 August 2004 06:39 pm, you wrote:
> > > > > On Wed, Aug 04, 2004 at 06:28:02PM -0400, Anish Mistry wrote:
> > > > > > Ok, so we need something like vm_map_findspace(), but for process
> > > > > > address mapping?  ie. pmap_findspace() that will return an
> > > > > > address to a large enough free chunk?
> > > > >
> > > > > That's a good start, just to get something to work with. How this
> > > > > fits in with the vm code and whether it is ultimately suitable in
> > > > > the long run is probably up to Alan Cox. For now, just get
> > > > > something that (a) doesn't break anything else; and (b) lets Wine
> > > > > behave the way it needs to.
> > > > >
> > > > > AFAIK, there are still pthread issues with Wine, but those can't be
> > > > > addressed until the mmap issue has a work-around.
> > > >
> > > > I've got a small patch that gets by the initial problem about not
> > > > being to mmap the memory for the libraries, but the addresses that
> > > > are mmap'ed seem to seem to overlap with memory that the current
> > > > pthread implementation want to mmap for the "red zone" when wine
> > > > tries to create a thread.  It can't mmap the "red zone" addresses
> > > > since all those address mapping where gobbled up before the thread
> > > > launched.
> > > > I'll try to figure out a way to maybe leave a space for the "red
> > > > zone" and see if that works.
> > > > Someone who actually knows what they are doing should probably take a
> > > > look.
> > >
> > > The red pages are implemented by leaving the memory space unallocated;
> > > I don't like that one bit -- this will cause those spaces to be
> > > allocated but given no protection, which should provide the crash
> > > feature that the guard pages are there for, but be less bogus (and it
> > > doesn't use more "memory," but it will use a few more vm_map_entrys.
> > >
> > > Index: lib/libpthread/thread/thr_stack.c
> > > ===================================================================
> > > RCS file: /usr/ncvs/src/lib/libpthread/thread/thr_stack.c,v
> > > retrieving revision 1.8
> > > diff -u -r1.8 thr_stack.c
> > > --- lib/libpthread/thread/thr_stack.c 14 Sep 2003 22:39:44 -0000 1.8
> > > +++ lib/libpthread/thread/thr_stack.c 29 Aug 2004 04:50:28 -0000
> > > _at__at_ -214,6 +214,17 _at__at_
> > >         stacksize, PROT_READ | PROT_WRITE, MAP_STACK,
> > >         -1, 0)) == MAP_FAILED)
> > >     attr->stackaddr_attr = NULL;
> > > +  if (attr->stackaddr_attr != NULL) {
> > > +   void *red;
> > > +
> > > +   red = mmap((char *)attr->stackaddr_attr + stacksize,
> > > +       _thr_guard_default, PROT_NONE,
> > > +       MAP_ANON | MAP_FIXED | MAP_PRIVATE, -1, 0);
> > > +   if (red == MAP_FAILED) {
> > > +    (void)munmap(attr->stackaddr_attr, stacksize);
> > > +    attr->stackaddr_attr = NULL;
> > > +   }
> > > +  }
> > >   }
> > >   if (attr->stackaddr_attr != NULL)
> > >    return (0);
> >
> > This is good.  Can this be committed?
>
> Probably; can you verify it fixes the problem as you observe it?
Hmmm...well I can't seem to reproduce this problem anymore with my latest 
cvsup Saturday night, so I guess this doesn't need to be committed.

-- 
Anish Mistry

Received on Mon Sep 06 2004 - 03:37:37 UTC

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