* hookapi.cc (rvadelta): Add parameter to return maximum available

	size from start of import RVA table to end of section.
	(find_first_notloaded_dll): Take big executables into account.  Use
	offset and size computation as in hook_or_detect_cygwin, just simpler.
	(hook_or_detect_cygwin): Return NULL rather than false througout.
	Change computation of required mapping size to take non-gcc compilers
	into account.  Explain the differences and what we do against them.
	Don't alloca buf if fn is NULL.  Never use buf if fn is NULL.

	Fix name and address in previous ChangeLog entry.

1 files changed, 98 insertions, 17 deletions

diff --git a/winsup/cygwin/hookapi.cc b/winsup/cygwin/hookapi.cc
index 8137b85d2..6c4d38fa3 100644
--- a/winsup/cygwin/hookapi.cc
+++ b/winsup/cygwin/hookapi.cc
@@ -1,6 +1,6 @@
 /* hookapi.cc
 
-   Copyright 2005, 2006, 2007, 2008, 2011 Red Hat, Inc.
+   Copyright 2005, 2006, 2007, 2008, 2011, 2012 Red Hat, Inc.
 
 This file is part of Cygwin.
 
@@ -49,14 +49,18 @@ PEHeaderFromHModule (HMODULE hModule)
 }
 
 static long
-rvadelta (PIMAGE_NT_HEADERS pnt, DWORD import_rva)
+rvadelta (PIMAGE_NT_HEADERS pnt, DWORD import_rva, DWORD &max_size)
 {
   PIMAGE_SECTION_HEADER section = (PIMAGE_SECTION_HEADER) (pnt + 1);
   for (int i = 0; i < pnt->FileHeader.NumberOfSections; i++)
     if (section[i].VirtualAddress <= import_rva
 	&& (section[i].VirtualAddress + section[i].Misc.VirtualSize) > import_rva)
     // if (ascii_strncasematch ((char *) section[i].Name, ".idata", IMAGE_SIZEOF_SHORT_NAME))
-      return section[i].VirtualAddress - section[i].PointerToRawData;
+      {
+	max_size = section[i].Misc.VirtualSize
+		   - (import_rva - section[i].VirtualAddress);
+	return section[i].VirtualAddress - section[i].PointerToRawData;
+      }
   return -1;
 }
 
@@ -172,6 +176,7 @@ find_first_notloaded_dll (path_conv& pc)
   IO_STATUS_BLOCK io;
   HANDLE h;
   NTSTATUS status;
+  LARGE_INTEGER size;
 
   status = NtOpenFile (&h, SYNCHRONIZE | GENERIC_READ,
 		       pc.get_object_attr (attr, sec_none_nih),
@@ -181,13 +186,27 @@ find_first_notloaded_dll (path_conv& pc)
 		       | FILE_NON_DIRECTORY_FILE);
   if (!NT_SUCCESS (status))
     goto out;
-
+  /* Just as in hook_or_detect_cygwin below, we have to take big executables
+     into account.  That means, we must not try to map the entire file, since
+     there's no guarantee that the current process has enough VM in one block
+     left for this mapping.  The offset computation below ignores very big
+     executables for now.  In theory, since the import RVA table appears to
+     be more or less at the end of the data section, independent of the used
+     compiler, that shouldn't matter. */
+  if (!GetFileSizeEx (h, &size))
+    {
+      NtClose (h);
+      goto out;
+    }
+  if (size.QuadPart > wincap.allocation_granularity ())
+    size.LowPart = wincap.allocation_granularity ();
   hc = CreateFileMapping (h, &sec_none_nih, PAGE_READONLY, 0, 0, NULL);
   NtClose (h);
   if (!hc)
     goto out;
-  hm = (HMODULE) MapViewOfFile(hc, FILE_MAP_READ, 0, 0, 0);
-  CloseHandle (hc);
+  hm = (HMODULE) MapViewOfFile(hc, FILE_MAP_READ, 0, 0, size.LowPart);
+  if (!hm)
+    goto out;
 
   PIMAGE_NT_HEADERS pExeNTHdr;
   pExeNTHdr = PEHeaderFromHModule (hm);
@@ -195,19 +214,36 @@ find_first_notloaded_dll (path_conv& pc)
   if (pExeNTHdr)
     {
       DWORD importRVA;
+      DWORD importRVASize;
+      DWORD importRVAMaxSize;
       importRVA = pExeNTHdr->OptionalHeader.DataDirectory[IMAGE_DIRECTORY_ENTRY_IMPORT].VirtualAddress;
+      importRVASize = pExeNTHdr->OptionalHeader.DataDirectory[IMAGE_DIRECTORY_ENTRY_IMPORT].Size;
       if (importRVA)
 	{
-	  long delta = rvadelta (pExeNTHdr, importRVA);
+	  long delta = rvadelta (pExeNTHdr, importRVA, importRVAMaxSize);
+	  if (delta < 0)
+	    goto out;
+	  importRVA -= delta;
+
+	  DWORD offset = 0;
+	  char *map;
+	  if (importRVA + importRVAMaxSize > wincap.allocation_granularity ())
+	    {
+	      offset = rounddown (importRVA, wincap.allocation_granularity ());
+	      DWORD size = importRVA - offset + importRVAMaxSize;
+	      map = (char *) MapViewOfFile (hc, FILE_MAP_READ, 0, offset, size);
+	      if (!map)
+		goto out;
+	    }
 
 	  // Convert imports RVA to a usable pointer
 	  PIMAGE_IMPORT_DESCRIPTOR pdfirst;
-	  pdfirst = rva (PIMAGE_IMPORT_DESCRIPTOR, hm, importRVA - delta);
+	  pdfirst = rva (PIMAGE_IMPORT_DESCRIPTOR, hm, importRVA - offset);
 
 	  // Iterate through each import descriptor, and redirect if appropriate
 	  for (PIMAGE_IMPORT_DESCRIPTOR pd = pdfirst; pd->FirstThunk; pd++)
 	    {
-	      const char *lib = rva (PSTR, hm, pd->Name - delta);
+	      const char *lib = rva (PSTR, hm, pd->Name - delta - offset);
 	      if (!LoadLibraryEx (lib, NULL, DONT_RESOLVE_DLL_REFERENCES
 					     | LOAD_LIBRARY_AS_DATAFILE))
 		{
@@ -215,12 +251,15 @@ find_first_notloaded_dll (path_conv& pc)
 		  res = strcpy (buf, lib);
 		}
 	    }
+	  UnmapViewOfFile (map);
 	}
     }
 
 out:
   if (hm)
     UnmapViewOfFile (hm);
+  if (hc)
+    CloseHandle (hc);
 
   return res;
 }
@@ -233,7 +272,11 @@ hook_or_detect_cygwin (const char *name, const void *fn, WORD& subsys, HANDLE h)
   PIMAGE_NT_HEADERS pExeNTHdr = PEHeaderFromHModule (hm);
 
   if (!pExeNTHdr)
-    return false;
+    return NULL;
+
+  /* FIXME: This code has to be made 64 bit capable. */
+  if (pExeNTHdr->FileHeader.Machine != IMAGE_FILE_MACHINE_I386)
+    return NULL;
 
   subsys =  pExeNTHdr->OptionalHeader.Subsystem;
 
@@ -242,18 +285,19 @@ hook_or_detect_cygwin (const char *name, const void *fn, WORD& subsys, HANDLE h)
   DWORD importRVASize = pExeNTHdr->OptionalHeader.DataDirectory
 			[IMAGE_DIRECTORY_ENTRY_IMPORT].Size;
   if (!importRVA)
-    return false;
+    return NULL;
 
-  long delta = fn ? 0 : rvadelta (pExeNTHdr, importRVA);
+  DWORD importRVAMaxSize;
+  long delta = fn ? 0 : rvadelta (pExeNTHdr, importRVA, importRVAMaxSize);
   if (delta < 0)
-    return false;
+    return NULL;
   importRVA -= delta;
 
   // Convert imports RVA to a usable pointer
   PIMAGE_IMPORT_DESCRIPTOR pdfirst;
   char *map = NULL;
   DWORD offset = 0;
-  if (h && importRVA + importRVASize > wincap.allocation_granularity ())
+  if (h && importRVA + importRVAMaxSize > wincap.allocation_granularity ())
     {
       /* If h is not NULL, the calling function only mapped at most the first
 	 64K of the image.  The IAT is usually at the end of the image, so
@@ -261,11 +305,44 @@ hook_or_detect_cygwin (const char *name, const void *fn, WORD& subsys, HANDLE h)
 	 reside in the first 64K anyway.  The offset must be a multiple of the
 	 allocation granularity, though, so we have to map a bit more. */
       offset = rounddown (importRVA, wincap.allocation_granularity ());
-      DWORD size = importRVA - offset + importRVASize;
+      /* But that's not all, unfortunately.  Apparently there's a difference
+	 between the importRVASize of applications built with gcc and those
+	 built with Visual Studio.  When built with gcc, importRVASize contains
+	 the size of the import RVA table plus the size of the referenced
+	 string table with the DLL names.  When built with VS, it only contains
+	 the size of the naked import RVA table.  importRVAMaxSize contains the
+	 size of the reminder of the section.  If that's less than 64K, we're
+	 good.  Otherwise the executable is potentially *very* big.  In that
+	 case we only map the naked import RVA table and ... */
+      DWORD size = importRVA - offset
+		   + ((importRVA - offset + importRVAMaxSize
+		       <= wincap.allocation_granularity ())
+		      ? importRVAMaxSize : importRVASize);
       map = (char *) MapViewOfFile (h, FILE_MAP_READ, 0, offset, size);
       if (!map)
-	return false;
+	return NULL;
       pdfirst = rva (PIMAGE_IMPORT_DESCRIPTOR, map, importRVA - offset);
+      /* ... carefully check the required size to fit the string table into
+         the map as well.  Allow NAME_MAX bytes for the DLL name.  There's a
+	 slim chance that the allocation will fail, if the string table is
+	 right at the end of the last section in the file, but that's very
+	 unlikely. */
+      if (importRVA - offset + importRVAMaxSize > wincap.allocation_granularity ())
+	{
+	  DWORD newsize = size;
+	  for (PIMAGE_IMPORT_DESCRIPTOR pd = pdfirst; pd->FirstThunk; pd++)
+	    if (pd->Name - delta - offset + (NAME_MAX + 1) > newsize)
+	      newsize = pd->Name - delta - offset + (NAME_MAX + 1);
+	  if (newsize > size )
+	    {
+	      UnmapViewOfFile (map);
+	      map = (char *) MapViewOfFile (h, FILE_MAP_READ, 0, offset,
+					    newsize);
+	      if (!map)
+		return NULL;
+	      pdfirst = rva (PIMAGE_IMPORT_DESCRIPTOR, map, importRVA - offset);
+	    }
+	}
     }
   else
     pdfirst = rva (PIMAGE_IMPORT_DESCRIPTOR, hm, importRVA);
@@ -273,7 +350,9 @@ hook_or_detect_cygwin (const char *name, const void *fn, WORD& subsys, HANDLE h)
   function_hook fh;
   fh.origfn = NULL;
   fh.hookfn = fn;
-  char *buf = (char *) alloca (strlen (name) + sizeof ("_64"));
+  char *buf = NULL;
+  if (fn)
+    buf = (char *) alloca (strlen (name) + sizeof ("_64"));
   int i = 0;
   // Iterate through each import descriptor, and redirect if appropriate
   for (PIMAGE_IMPORT_DESCRIPTOR pd = pdfirst; pd->FirstThunk; pd++)
@@ -296,6 +375,8 @@ hook_or_detect_cygwin (const char *name, const void *fn, WORD& subsys, HANDLE h)
 
   if (map)
     UnmapViewOfFile (map);
+  if (!fn)
+    return NULL;
 
   while (!fh.origfn && (fh.name = makename (name, buf, i, -1)))
     get_export (fh);