From cfc30307a3cb7ba281e0c9964b733eb9f060dc09 Mon Sep 17 00:00:00 2001
From: desrt <unknown>
Date: Thu, 17 Feb 2005 16:58:21 +0000
Subject: [PATCH] [project @ 2005-02-17 16:58:18 by desrt] LinkerInternals.h:
 all platforms: changed 'image' pointer in ObjectCode       
                            from (void *) to (char *).

Linker.c: linux/ppc: added mremap() support to unbreak the build when
                     USE_MMAP is defined on linux/ppc (as it now is.)
---
 ghc/rts/Linker.c          |   46 ++++++++++++++++++++++++++++++++++++++-------
 ghc/rts/LinkerInternals.h |    2 +-
 2 files changed, 40 insertions(+), 8 deletions(-)

diff --git a/ghc/rts/Linker.c b/ghc/rts/Linker.c
index 8aed286..7b9df7f 100644
--- a/ghc/rts/Linker.c
+++ b/ghc/rts/Linker.c
@@ -10,7 +10,9 @@
 #include "PosixSource.h"
 #endif
 
-//  Linux needs _GNU_SOURCE to get RTLD_DEFAULT from <dlfcn.h>.
+/* Linux needs _GNU_SOURCE to get RTLD_DEFAULT from <dlfcn.h> and 
+   MREMAP_MAYMOVE from <sys/mman.h>.
+ */
 #ifdef __linux__
 #define _GNU_SOURCE
 #endif
@@ -1307,21 +1309,51 @@ static void addSection ( ObjectCode* oc, SectionKind kind,
 
 static int ocAllocateJumpIslands( ObjectCode* oc, int count, int first )
 {
+#ifdef USE_MMAP
+  int pagesize, n, m;
+#endif
   int aligned;
 
   if( count > 0 )
   {
-#ifdef USE_MMAP
-    #error ocAllocateJumpIslands doesnt want USE_MMAP to be defined
-#endif
     // round up to the nearest 4
     aligned = (oc->fileSize + 3) & ~3;
 
+#ifdef USE_MMAP
+    #ifndef linux_HOST_OS /* mremap is a linux extension */
+        #error ocAllocateJumpIslands doesnt want USE_MMAP to be defined
+    #endif
+
+    pagesize = getpagesize();
+    n = ROUND_UP( oc->fileSize, pagesize );
+    m = ROUND_UP( aligned + sizeof (ppcJumpIsland) * count, pagesize );
+
+    /* The effect of this mremap() call is only the ensure that we have
+     * a sufficient number of virtually contiguous pages.  As returned from
+     * mremap, the pages past the end of the file are not backed.  We give
+     * them a backing by using MAP_FIXED to map in anonymous pages.
+     */
+    if( (oc->image = mremap( oc->image, n, m, MREMAP_MAYMOVE )) == MAP_FAILED )
+    {
+      errorBelch( "Unable to mremap for Jump Islands\n" );
+      return 0;
+    }
+
+    if( mmap( oc->image + n, m - n, PROT_READ | PROT_WRITE | PROT_EXEC,
+              MAP_PRIVATE | MAP_ANONYMOUS | MAP_FIXED, 0, 0 ) == MAP_FAILED )
+    {
+      errorBelch( "Unable to mmap( MAP_FIXED ) for Jump Islands\n" );
+      return 0;
+    }
+
+#else
     oc->image = stgReallocBytes( oc->image,
-                                 aligned + sizeof( ppcJumpIsland ) * count,
+                                 aligned + sizeof (ppcJumpIsland) * count,
                                  "ocAllocateJumpIslands" );
-    oc->jump_islands = (ppcJumpIsland *) (((char *) oc->image) + aligned);
-    memset( oc->jump_islands, 0, sizeof( ppcJumpIsland ) * count );
+#endif /* USE_MMAP */
+
+    oc->jump_islands = (ppcJumpIsland *) (oc->image + aligned);
+    memset( oc->jump_islands, 0, sizeof (ppcJumpIsland) * count );
   }
   else
     oc->jump_islands = NULL;
diff --git a/ghc/rts/LinkerInternals.h b/ghc/rts/LinkerInternals.h
index f1e2677..3f7653f 100644
--- a/ghc/rts/LinkerInternals.h
+++ b/ghc/rts/LinkerInternals.h
@@ -65,7 +65,7 @@ typedef struct _ObjectCode {
     int        n_symbols;
 
     /* ptr to malloc'd lump of memory holding the obj file */
-    void*      image;
+    char*      image;
 
     /* The section-kind entries for this object module.  Linked
        list. */
-- 
1.7.10.4