Revert previous checkins as they introduced a bug when running zsh.

winsup/cygwin/ChangeLog

@@ -1,41 +1,5 @@
 2011-05-28  Christopher Faylor  <me.cygwin2011@cgf.cx>
-
+	    Ryan Johnson  <ryan.johnson@cs.utoronto.ca>
-	* dll_init.cc (reserve_upto): Remove.
-	(release_upto): Ditto.
-	(dll_list::reserve_space): New function to reserve space needed by
-	DLL_LOAD dlls early in the fork process.
-	(dll_list::load_after_fork): Rewrite to use recursion for tracking
-	reservations made while trying to make dlls land where they belong.
-	(dll_list::load_after_fork_impl): Ditto.
-	(dll_list::alloc): Initialize image base field.
-	* dll_init.h (struct dll_list): declare new functions.
-	(dll::image_size): New member.
-
-2011-05-28  Ryan Johnson  <ryan.johnson@cs.utoronto.ca>
-
-	* dll_init.cc (dll_list::find_by_modname): New function to search the
-	dll list for a module name only (no path).
-	(dll_list::alloc): Initialize newly-added members of struct dll.
-	(dll_list::append): New function to factor out the append operation
-	(used by dll_list::topsort).
-	(dll_list::populate_deps): New function to identify dll dependencies.
-	(dll_list::topsort): New function to sort the dll list topologically by
-	dependencies.
-	(dll_list::topsort_visit): New helper function for the above.
-	* dll_init.h (dll::ndeps): New class member.
-	(dll::deps): Ditto.
-	(dll::modname): Ditto.
-	(dll_list::find_by_modname): New function related to topsort.
-	(dll_list::populate_all_deps): Ditto.
-	(dll_list::populate_deps): Ditto.
-	(dll_list::topsort): Ditto.
-	(dll_list::topsort_visit): Ditto.
-	(dll_list::append): Ditto.
-	(pefile): New struct allowing simple introspection of dll images.
-	* fork.cc (fork): Topologically sort the dll list before forking.
-
-2011-05-28  Christopher Faylor  <me.cygwin2011@cgf.cx>
-	    
 
 	* dll_init.c (dll_list::load_after_fork): Don't clear in_forkee here.
 	* fork.cc (frok::errmsg): Rename from 'error'.

winsup/cygwin/dll_init.cc

@@ -116,18 +116,6 @@ dll_list::operator[] (const PWCHAR name)
   return NULL;
 }
 
-/* Look for a dll based on is short name only (no path) */
-dll *
-dll_list::find_by_modname (const PWCHAR name)
-{
-  dll *d = &start;
-  while ((d = d->next) != NULL)
-    if (!wcscasecmp (name, d->modname))
-      return d;
-
-  return NULL;
-}
-
 #define RETRIES 1000
 
 /* Allocate space for a dll struct. */
@@ -173,25 +161,7 @@ dll_list::alloc (HINSTANCE h, per_process *p, dll_type type)
       d->handle = h;
       d->has_dtors = true;
       d->p = p;
-      d->image_size = ((pefile*)h)->optional_hdr ()->SizeOfImage;
-      d->ndeps = 0;
-      d->deps = NULL;
-      d->modname = wcsrchr (d->name, L'\\');
-      if (d->modname)
-	d->modname++;
       d->type = type;
-      append (d);
-      if (type == DLL_LOAD)
-	loaded_dlls++;
-    }
-  guard (false);
-  assert (p->envptr != NULL);
-  return d;
-}
-
-void
-dll_list::append (dll* d)
-{
       if (end == NULL)
 	end = &start;	/* Point to "end" of dll chain. */
       end->next = d;	/* Standard linked list stuff. */
@@ -199,108 +169,13 @@ dll_list::append (dll* d)
       d->prev = end;
       end = d;
       tot++;
+      if (type == DLL_LOAD)
+	loaded_dlls++;
     }
-
+  guard (false);
-void dll_list::populate_deps (dll* d)
+  assert (p->envptr != NULL);
-{
+  return d;
-  WCHAR wmodname[NT_MAX_PATH];
-  pefile* pef = (pefile*) d->handle;
-  PIMAGE_DATA_DIRECTORY dd = pef->idata_dir (IMAGE_DIRECTORY_ENTRY_IMPORT);
-  /* Annoyance: calling crealloc with a NULL pointer will use the
-     wrong heap and crash, so we have to replicate some code */
-  long maxdeps = 4;
-  d->deps = (dll**) cmalloc (HEAP_2_DLL, maxdeps*sizeof (dll*));
-  d->ndeps = 0;
-  for (PIMAGE_IMPORT_DESCRIPTOR id=
-	(PIMAGE_IMPORT_DESCRIPTOR) pef->rva (dd->VirtualAddress);
-      dd->Size && id->Name;
-      id++)
-    {
-      char* modname = pef->rva (id->Name);
-      sys_mbstowcs (wmodname, NT_MAX_PATH, modname);
-      if (dll* dep = find_by_modname (wmodname))
-	{
-	  if (d->ndeps >= maxdeps)
-	    {
-	      maxdeps = 2*(1+maxdeps);
-	      d->deps = (dll**) crealloc (d->deps, maxdeps*sizeof (dll*));
 }
-	  d->deps[d->ndeps++] = dep;
-	}
-    }
-  
-  /* add one to differentiate no deps from unknown */
-  d->ndeps++;
-}
-
-
-void
-dll_list::topsort ()
-{
-  /* Anything to do? */
-  if (!end)
-    return;
-  
-  /* make sure we have all the deps available */
-  dll* d = &start;
-  while ((d = d->next))
-    if (!d->ndeps)
-      populate_deps (d);
-  
-  /* unlink head and tail pointers so the sort can rebuild the list */
-  d = start.next;
-  start.next = end = NULL;
-  topsort_visit (d, true);
-
-  /* clear node markings made by the sort */
-  d = &start;
-  while ((d = d->next))
-    {
-      debug_printf ("%W", d->modname);
-      for (int i=1; i < -d->ndeps; i++)
-	debug_printf ("-> %W", d->deps[i-1]->modname);
-
-      /* It would be really nice to be able to keep this information
-	 around for next time, but we don't have an easy way to
-	 invalidate cached dependencies when a module unloads. */
-      d->ndeps = 0;
-      cfree (d->deps);
-      d->deps = NULL;
-    }
-}
-
-/* A recursive in-place topological sort. The result is ordered so that
-   dependencies of a dll appear before it in the list.
-
-   NOTE: this algorithm is guaranteed to terminate with a "partial
-   order" of dlls but does not do anything smart about cycles: an
-   arbitrary dependent dll will necessarily appear first. Perhaps not
-   surprisingly, Windows ships several dlls containing dependency
-   cycles, including SspiCli/RPCRT4.dll and a lovely tangle involving
-   USP10/LPK/GDI32/USER32.dll). Fortunately, we don't care about
-   Windows DLLs here, and cygwin dlls should behave better */
-void
-dll_list::topsort_visit (dll* d, bool seek_tail)
-{
-  /* Recurse to the end of the dll chain, then visit nodes as we
-     unwind. We do this because once we start visiting nodes we can no
-     longer trust any _next_ pointers.
-
-     We "mark" visited nodes (to avoid revisiting them) by negating
-     ndeps (undone once the sort completes). */
-  if (seek_tail && d->next)
-    topsort_visit (d->next, true);
-  
-  if (d->ndeps > 0)
-    {
-      d->ndeps = -d->ndeps;
-      for (long i=1; i < -d->ndeps; i++)
-	topsort_visit (d->deps[i-1], false);
-
-      append (d);
-    }
-}
-
 
 dll *
 dll_list::find (void *retaddr)
@@ -417,33 +292,21 @@ release_upto (const PWCHAR name, DWORD here)
       }
 }
 
-/* Reserve the chunk of free address space starting _here_ and (usually)
+/* Mark one page at "here" as reserved.  This may force
-   covering at least _dll_size_ bytes. However, we must take care not
+   Windows NT to load a DLL elsewhere. */
-   to clobber the dll's target address range because it often overlaps.
- */
 static DWORD
-reserve_at (const PWCHAR name, DWORD here, DWORD dll_base, DWORD dll_size)
+reserve_at (const PWCHAR name, DWORD here)
 {
   DWORD size;
   MEMORY_BASIC_INFORMATION mb;
 
   if (!VirtualQuery ((void *) here, &mb, sizeof (mb)))
-    api_fatal ("couldn't examine memory at %08lx while mapping %W, %E",
+    size = 64 * 1024;
-	       here, name);
+
   if (mb.State != MEM_FREE)
     return 0;
 
   size = mb.RegionSize;
-  
-  // don't clobber the space where we want the dll to land
-  DWORD end = here + size;
-  DWORD dll_end = dll_base + dll_size;
-  if (dll_base < here && dll_end > here)
-      here = dll_end; // the dll straddles our left edge
-  else if (dll_base >= here && dll_base < end)
-      end = dll_base; // the dll overlaps partly or fully to our right
-  
-  size = end - here;
   if (!VirtualAlloc ((void *) here, size, MEM_RESERVE, PAGE_NOACCESS))
     api_fatal ("couldn't allocate memory %p(%d) for '%W' alignment, %E\n",
                here, size, name);
@@ -521,8 +384,7 @@ dll_list::load_after_fork (HANDLE parent)
              can in the child, due to differences in the load ordering.
              Block memory at it's preferred address and try again. */
           if ((DWORD) h > (DWORD) d->handle)
-            preferred_block = reserve_at (d->name, (DWORD) h,
+            preferred_block = reserve_at (d->name, (DWORD) h);
-					  (DWORD) d->handle, d->image_size);
 
 	}
 }

winsup/cygwin/dll_init.h

@@ -52,10 +52,6 @@ struct dll
   int count;
   bool has_dtors;
   dll_type type;
-  DWORD image_size;
-  long ndeps;
-  dll** deps;
-  PWCHAR modname;
   WCHAR name[1];
   void detach ();
   int init ();
@@ -88,13 +84,6 @@ public:
   void detach (void *);
   void init ();
   void load_after_fork (HANDLE);
-  dll *find_by_modname (const PWCHAR name);
-  void populate_all_deps ();
-  void populate_deps (dll* d);
-  void topsort ();
-  void topsort_visit (dll* d, bool goto_tail);
-  void append (dll* d);
-  
   dll *inext ()
   {
     while ((hold = hold->next))
@@ -120,25 +109,6 @@ public:
   dll_list () { protect.init ("dll_list"); }
 };
 
-/* References:
-   http://msdn.microsoft.com/en-us/windows/hardware/gg463125
-   http://msdn.microsoft.com/en-us/library/ms809762.aspx
-*/
-/* FIXME: Integrate with other similar uses in source. */
-struct pefile
-{
-  IMAGE_DOS_HEADER dos_hdr;
-
-  char* rva (long offset) { return (char*) this + offset; }
-  PIMAGE_NT_HEADERS32 pe_hdr () { return (PIMAGE_NT_HEADERS32) rva (dos_hdr.e_lfanew); }
-  PIMAGE_OPTIONAL_HEADER32 optional_hdr () { return &pe_hdr ()->OptionalHeader; }
-  PIMAGE_DATA_DIRECTORY idata_dir (DWORD which)
-  {
-    PIMAGE_OPTIONAL_HEADER32 oh = optional_hdr ();
-    return (which < oh->NumberOfRvaAndSizes)? oh->DataDirectory + which : 0;
-  }
-};
-
 extern dll_list dlls;
 void dll_global_dtors ();
 

winsup/cygwin/fork.cc

@@ -634,12 +634,6 @@ fork ()
 	return -1;
       }
 
-    /* Put the dll list in topological dependency ordering, in
-       hopes that the child will have a better shot at loading dlls
-       properly if it only has to deal with one at a time.
-    */
-    dlls.topsort ();
-
     ischild = !!setjmp (grouped.ch.jmp);
 
     volatile char * volatile esp;