PR 21274, ld segfaults linking PE DLL

[deliverable/binutils-gdb.git] / ld / emultempl / pe.em

diff --git a/ld/emultempl/pe.em b/ld/emultempl/pe.em
index 8f41f27709a11c5b3bc4f028c05f7915ce540a86..e835404479fb5c19b04f63bfdaf4c57afb6d9bba 100644 (file)
--- a/ld/emultempl/pe.em
+++ b/ld/emultempl/pe.em
@@ -1130,7 +1130,7 @@ pe_fixup_stdcalls (void)
 }
 
 static int
-make_import_fixup (arelent *rel, asection *s)
+make_import_fixup (arelent *rel, asection *s, char *name)
 {
   struct bfd_symbol *sym = *rel->sym_ptr_ptr;
   char addend[4];
@@ -1143,7 +1143,7 @@ make_import_fixup (arelent *rel, asection *s)
     einfo (_("%C: Cannot get section contents - auto-import exception\n"),
           s->owner, s, rel->address);
 
-  pe_create_import_fixup (rel, s, bfd_get_32 (s->owner, addend));
+  pe_create_import_fixup (rel, s, bfd_get_32 (s->owner, addend), name);
 
   return 1;
 }
@@ -1152,32 +1152,46 @@ static void
 pe_find_data_imports (void)
 {
   struct bfd_link_hash_entry *undef, *sym;
+  size_t namelen;
+  char *buf, *name;
 
   if (link_info.pei386_auto_import == 0)
     return;
 
-  for (undef = link_info.hash->undefs; undef; undef=undef->u.undef.next)
+  namelen = 0;
+  for (undef = link_info.hash->undefs; undef; undef = undef->u.undef.next)
+    {
+      if (undef->type == bfd_link_hash_undefined)
+       {
+         size_t len = strlen (undef->root.string);
+         if (namelen < len)
+           namelen = len;
+       }
+    }
+  if (namelen == 0)
+    return;
+
+  /* We are being a bit cunning here.  The buffer will have space for
+     prefixes at the beginning.  The prefix is modified here and in a
+     number of functions called from this function.  */
+#define PREFIX_LEN 32
+  buf = xmalloc (PREFIX_LEN + namelen + 1);
+  name = buf + PREFIX_LEN;
+
+  for (undef = link_info.hash->undefs; undef; undef = undef->u.undef.next)
     {
       if (undef->type == bfd_link_hash_undefined)
        {
-         /* C++ symbols are *long*.  */
-#define BUF_SIZE 4096
-         char buf[BUF_SIZE];
+         char *impname;
 
          if (pe_dll_extra_pe_debug)
            printf ("%s:%s\n", __FUNCTION__, undef->root.string);
 
-         if (strlen (undef->root.string) > (BUF_SIZE - 6))
-           {
-             /* PR linker/18466.  */
-             einfo (_("%P: internal error: symbol too long: %s\n"),
-                    undef->root.string);
-             return;
-           }
-
-         sprintf (buf, "__imp_%s", undef->root.string);
+         strcpy (name, undef->root.string);
+         impname = name - (sizeof "__imp_" - 1);
+         memcpy (impname, "__imp_", sizeof "__imp_" - 1);
 
-         sym = bfd_link_hash_lookup (link_info.hash, buf, 0, 0, 1);
+         sym = bfd_link_hash_lookup (link_info.hash, impname, 0, 0, 1);
 
          if (sym && sym->type == bfd_link_hash_defined)
            {
@@ -1189,15 +1203,18 @@ pe_find_data_imports (void)
                {
                  static bfd_boolean warned = FALSE;
 
-                 info_msg (_("Info: resolving %s by linking to %s (auto-import)\n"),
-                           undef->root.string, buf);
+                 info_msg (_("Info: resolving %s by linking to %s "
+                             "(auto-import)\n"), name, impname);
 
                  /* PR linker/4844.  */
                  if (! warned)
                    {
                      warned = TRUE;
-                     einfo (_("%P: warning: auto-importing has been activated without --enable-auto-import specified on the command line.\n\
-This should work unless it involves constant data structures referencing symbols from auto-imported DLLs.\n"));
+                     einfo (_("%P: warning: auto-importing has been activated "
+                              "without --enable-auto-import specified on the "
+                              "command line.\nThis should work unless it "
+                              "involves constant data structures referencing "
+                              "symbols from auto-imported DLLs.\n"));
                    }
                }
 
@@ -1212,8 +1229,7 @@ This should work unless it involves constant data structures referencing symbols
 
              for (i = 0; i < nsyms; i++)
                {
-                 if (! CONST_STRNEQ (symbols[i]->name,
-                                     U ("_head_")))
+                 if (! CONST_STRNEQ (symbols[i]->name, U ("_head_")))
                    continue;
 
                  if (pe_dll_extra_pe_debug)
@@ -1224,8 +1240,7 @@ This should work unless it involves constant data structures referencing symbols
                  break;
                }
 
-             pe_walk_relocs_of_symbol (&link_info, undef->root.string,
-                                       make_import_fixup);
+             pe_walk_relocs_of_symbol (&link_info, name, make_import_fixup);
 
              /* Let's differentiate it somehow from defined.  */
              undef->type = bfd_link_hash_defweak;
@@ -1238,6 +1253,7 @@ This should work unless it involves constant data structures referencing symbols
            }
        }
     }
+  free (buf);
 }
 
 static bfd_boolean