* mmap.cc: Do bookkeeping in 4K pages, rather than in 64K chunks.

1 files changed, 22 insertions, 18 deletions

diff --git a/winsup/cygwin/mmap.cc b/winsup/cygwin/mmap.cc
index 31bac5869..14a09b5bd 100644
--- a/winsup/cygwin/mmap.cc
+++ b/winsup/cygwin/mmap.cc
@@ -1,7 +1,7 @@
 /* mmap.cc
 
    Copyright 1996, 1997, 1998, 2000, 2001, 2002, 2003, 2004, 2005,
-   2006 Red Hat, Inc.
+   2006, 2007 Red Hat, Inc.
 
 This file is part of Cygwin.
 
@@ -36,7 +36,9 @@ details. */
    expect to be able to access this part the same way as the file pages. */
 #define __PROT_FILLER   0x4000000
 
-#define PAGE_CNT(bytes) howmany((bytes),getpagesize())
+/* Stick with 4K pages for bookkeeping, otherwise we just get confused
+   when trying to do file mappings with trailing filler pages correctly. */
+#define PAGE_CNT(bytes) howmany((bytes),getsystempagesize())
 
 #define PGBITS		(sizeof (DWORD)*8)
 #define MAPSIZE(pages)	howmany ((pages), PGBITS)
@@ -602,8 +604,9 @@ mmap_record::map_pages (_off64_t off, DWORD len)
   if ((off = find_unused_pages (len)) == (DWORD)-1)
     return 0L;
   if (!noreserve ()
-      && !VirtualProtect (get_address () + off * getpagesize (),
-			  len * getpagesize (), gen_protect (), &old_prot))
+      && !VirtualProtect (get_address () + off * getsystempagesize (),
+			  len * getsystempagesize (), gen_protect (),
+			  &old_prot))
     {
       __seterrno ();
       return (_off64_t)-1;
@@ -611,7 +614,7 @@ mmap_record::map_pages (_off64_t off, DWORD len)
 
   while (len-- > 0)
     MAP_SET (off + len);
-  return off * getpagesize ();
+  return off * getsystempagesize ();
 }
 
 bool
@@ -620,7 +623,7 @@ mmap_record::map_pages (caddr_t addr, DWORD len)
   debug_printf ("map_pages (addr=%x, len=%u)", addr, len);
   DWORD old_prot;
   DWORD off = addr - get_address ();
-  off /= getpagesize ();
+  off /= getsystempagesize ();
   len = PAGE_CNT (len);
   /* First check if the area is unused right now. */
   for (DWORD l = 0; l < len; ++l)
@@ -630,8 +633,9 @@ mmap_record::map_pages (caddr_t addr, DWORD len)
 	return false;
       }
   if (!noreserve ()
-      && !VirtualProtect (get_address () + off * getpagesize (),
-			  len * getpagesize (), gen_protect (), &old_prot))
+      && !VirtualProtect (get_address () + off * getsystempagesize (),
+			  len * getsystempagesize (), gen_protect (),
+			  &old_prot))
     {
       __seterrno ();
       return false;
@@ -646,16 +650,15 @@ mmap_record::unmap_pages (caddr_t addr, DWORD len)
 {
   DWORD old_prot;
   DWORD off = addr - get_address ();
-  off /= getpagesize ();
-  len = PAGE_CNT (len);
   if (noreserve ()
-      && !VirtualFree (get_address () + off * getpagesize (),
-		       len * getpagesize (), MEM_DECOMMIT))
+      && !VirtualFree (get_address () + off, len, MEM_DECOMMIT))
     debug_printf ("VirtualFree in unmap_pages () failed, %E");
-  else if (!VirtualProtect (get_address () + off * getpagesize (),
-			    len * getpagesize (), PAGE_NOACCESS, &old_prot))
+  else if (!VirtualProtect (get_address () + off, len, PAGE_NOACCESS,
+			    &old_prot))
     debug_printf ("VirtualProtect in unmap_pages () failed, %E");
 
+  off /= getsystempagesize ();
+  len = PAGE_CNT (len);
   for (; len-- > 0; ++off)
     MAP_CLR (off);
   /* Return TRUE if all pages are free'd which may result in unmapping
@@ -671,7 +674,7 @@ mmap_record::access (caddr_t address)
 {
   if (address < get_address () || address >= get_address () + get_len ())
     return 0;
-  DWORD off = (address - get_address ()) / getpagesize ();
+  DWORD off = (address - get_address ()) / getsystempagesize ();
   return MAP_ISSET (off);
 }
 
@@ -740,8 +743,9 @@ list::search_record (_off64_t off, DWORD len)
     {
       for (int i = 0; i < nrecs; ++i)
 	if (off >= recs[i].get_offset ()
-	    && off + len <= recs[i].get_offset ()
-			 + (PAGE_CNT (recs[i].get_len ()) * getpagesize ()))
+	    && off + len
+	       <= recs[i].get_offset ()
+		  + (PAGE_CNT (recs[i].get_len ()) * getsystempagesize ()))
 	  return recs + i;
     }
   return NULL;
@@ -761,7 +765,7 @@ list::search_record (caddr_t addr, DWORD len, caddr_t &m_addr, DWORD &m_len,
       if (recs[i].filler ())
 	high += recs[i].get_len ();
       else
-	high += (PAGE_CNT (recs[i].get_len ()) * getpagesize ());
+	high += (PAGE_CNT (recs[i].get_len ()) * getsystempagesize ());
       high = (addr + len < high) ? addr + len : high;
       if (low < high)
 	{