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[bpt/emacs.git] / src / unexmacosx.c

diff --git a/src/unexmacosx.c b/src/unexmacosx.c
index c84e5c9..b41c586 100644 (file)
--- a/src/unexmacosx.c
+++ b/src/unexmacosx.c
@@ -95,6 +95,10 @@ Boston, MA 02111-1307, USA.  */
 #include <unistd.h>
 #include <mach/mach.h>
 #include <mach-o/loader.h>
+#include <mach-o/reloc.h>
+#if defined (__ppc__)
+#include <mach-o/ppc/reloc.h>
+#endif
 #include <objc/malloc.h>
 
 #define VERBOSE 1
@@ -158,6 +162,11 @@ int in_dumped_exec = 0;
 
 malloc_zone_t *emacs_zone;
 
+/* file offset of input file's data segment */
+off_t data_segment_old_fileoff;
+
+struct segment_command *data_segment_scp;
+
 /* Read n bytes from infd into memory starting at address dest.
    Return true if successful, false otherwise.  */
 static int
@@ -183,6 +192,7 @@ static int
 unexec_copy (off_t dest, off_t src, ssize_t count)
 {
   ssize_t bytes_read;
+  ssize_t bytes_to_read;
 
   char buf[UNEXEC_COPY_BUFSZ];
 
@@ -194,7 +204,8 @@ unexec_copy (off_t dest, off_t src, ssize_t count)
 
   while (count > 0)
     {
-      bytes_read = read (infd, buf, UNEXEC_COPY_BUFSZ);
+      bytes_to_read = count > UNEXEC_COPY_BUFSZ ? UNEXEC_COPY_BUFSZ : count;
+      bytes_read = read (infd, buf, bytes_to_read);
       if (bytes_read <= 0)
        return 0;
       if (write (outfd, buf, bytes_read) != bytes_read)
@@ -763,6 +774,65 @@ copy_symtab (struct load_command *lc)
   curr_header_offset += lc->cmdsize;
 }
 
+/* Fix up relocation entries. */
+static void
+unrelocate (const char *name, off_t reloff, int nrel)
+{
+  int i, unreloc_count;
+  struct relocation_info reloc_info;
+  struct scattered_relocation_info *sc_reloc_info
+    = (struct scattered_relocation_info *) &reloc_info;
+
+  for (unreloc_count = 0, i = 0; i < nrel; i++)
+    {
+      if (lseek (infd, reloff, L_SET) != reloff)
+       unexec_error ("unrelocate: %s:%d cannot seek to reloc_info", name, i);
+      if (!unexec_read (&reloc_info, sizeof (reloc_info)))
+       unexec_error ("unrelocate: %s:%d cannot read reloc_info", name, i);
+      reloff += sizeof (reloc_info);
+
+      if (sc_reloc_info->r_scattered == 0)
+       switch (reloc_info.r_type)
+         {
+         case GENERIC_RELOC_VANILLA:
+           if (reloc_info.r_address >= data_segment_scp->vmaddr
+               && reloc_info.r_address < (data_segment_scp->vmaddr
+                                          + data_segment_scp->vmsize))
+             {
+               off_t src_off = data_segment_old_fileoff
+                 + reloc_info.r_address - data_segment_scp->vmaddr;
+               off_t dst_off = data_segment_scp->fileoff
+                 + reloc_info.r_address - data_segment_scp->vmaddr;
+
+               if (!unexec_copy (dst_off, src_off, 1 << reloc_info.r_length))
+                 unexec_error ("unrelocate: %s:%d cannot copy original value",
+                               name, i);
+               unreloc_count++;
+             }
+           break;
+         default:
+           unexec_error ("unrelocate: %s:%d cannot handle type = %d",
+                         name, i, reloc_info.r_type);
+         }
+      else
+       switch (sc_reloc_info->r_type)
+         {
+#if defined (__ppc__)
+         case PPC_RELOC_PB_LA_PTR:
+           /* nothing to do for prebound lazy pointer */
+           break;
+#endif
+         default:
+           unexec_error ("unrelocate: %s:%d cannot handle scattered type = %d",
+                         name, i, sc_reloc_info->r_type);
+         }
+    }
+
+  if (nrel > 0)
+    printf ("Fixed up %d/%d %s relocation entries in data segment.\n",
+           unreloc_count, nrel, name);
+}
+
 /* Copy a LC_DYSYMTAB load command from the input file to the output
    file, adjusting the file offset fields.  */
 static void
@@ -770,10 +840,8 @@ copy_dysymtab (struct load_command *lc)
 {
   struct dysymtab_command *dstp = (struct dysymtab_command *) lc;
 
-  /* If Mach-O executable is not prebound, relocation entries need
-     fixing up.  This is not supported currently.  */
-  if (!(mh.flags & MH_PREBOUND) && (dstp->nextrel != 0 || dstp->nlocrel != 0))
-    unexec_error ("cannot handle LC_DYSYMTAB with relocation entries");
+  unrelocate ("local", dstp->locreloff, dstp->nlocrel);
+  unrelocate ("external", dstp->extreloff, dstp->nextrel);
 
   if (dstp->nextrel > 0) {
     dstp->extreloff += delta;
@@ -845,6 +913,11 @@ dump_it ()
          struct segment_command *scp = (struct segment_command *) lca[i];
          if (strncmp (scp->segname, SEG_DATA, 16) == 0)
            {
+             /* save data segment file offset and segment_command for
+                unrelocate */
+             data_segment_old_fileoff = scp->fileoff;
+             data_segment_scp = scp;
+
              copy_data_segment (lca[i]);
            }
          else
@@ -976,3 +1049,6 @@ unexec_free (void *ptr)
   else
     malloc_zone_free (emacs_zone, ptr);
 }
+
+/* arch-tag: 1a784f7b-a184-4c4f-9544-da8619593d72
+   (do not change this comment) */