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[PATCH] Make PE images deterministic by default.


Use --insert-timestamp to restore previous behavior.

binutils/Changelog
2013-11-20  Cory Fields  <cory@coryfields.com>
    * bfd/libcoff-in.h: Add insert_timestamp flag to the pe_data struct.
    * bfd/libcoff.h: Update after change to bfd/libcoff-in.h.
    * bfd/peXXigen.c (_bfd_XXi_only_swap_filehdr_out): Only use a real
      timestamp if --insert-timestamp was used.
    * ld/pe-dll.c (fill_edata): Likewise.
    * ld/emultempl/pe.em: Add the --insert-timestamp option.
    * ld/emultempl/pep.em: Likewise for 64bit.
    * ld/ld.texinfo:  Document the --insert-timestamp option.
---
 bfd/libcoff-in.h    |  1 +
 bfd/libcoff.h       |  1 +
 bfd/peXXigen.c      |  5 ++++-
 binutils/ChangeLog  | 10 ++++++++++
 ld/emultempl/pe.em  | 12 +++++++++++-
 ld/emultempl/pep.em | 11 ++++++++++-
 ld/ld.texinfo       |  6 ++++++
 ld/pe-dll.c         |  7 +++----
 8 files changed, 46 insertions(+), 7 deletions(-)

diff --git a/bfd/libcoff-in.h b/bfd/libcoff-in.h
index 6efbc52..17617d6 100644
--- a/bfd/libcoff-in.h
+++ b/bfd/libcoff-in.h
@@ -118,6 +118,7 @@ typedef struct pe_tdata
   int dll;
   int has_reloc_section;
   int dont_strip_reloc;
+  bfd_boolean insert_timestamp;
   bfd_boolean (*in_reloc_p) (bfd *, reloc_howto_type *);
   flagword real_flags;
 } pe_data_type;
diff --git a/bfd/libcoff.h b/bfd/libcoff.h
index 6270bab..d0959a9 100644
--- a/bfd/libcoff.h
+++ b/bfd/libcoff.h
@@ -122,6 +122,7 @@ typedef struct pe_tdata
   int dll;
   int has_reloc_section;
   int dont_strip_reloc;
+  bfd_boolean insert_timestamp;
   bfd_boolean (*in_reloc_p) (bfd *, reloc_howto_type *);
   flagword real_flags;
 } pe_data_type;
diff --git a/bfd/peXXigen.c b/bfd/peXXigen.c
index d0f7a96..e1bde2a 100644
--- a/bfd/peXXigen.c
+++ b/bfd/peXXigen.c
@@ -793,7 +793,10 @@ _bfd_XXi_only_swap_filehdr_out (bfd * abfd, void * in, void * out)
   H_PUT_16 (abfd, filehdr_in->f_magic, filehdr_out->f_magic);
   H_PUT_16 (abfd, filehdr_in->f_nscns, filehdr_out->f_nscns);
 
-  H_PUT_32 (abfd, time (0), filehdr_out->f_timdat);
+  // Only use a real timestamp if the option was chosen
+  if ((pe_data (abfd)->insert_timestamp))
+    H_PUT_32 (abfd, time(0), filehdr_out->f_timdat);
+
   PUT_FILEHDR_SYMPTR (abfd, filehdr_in->f_symptr,
 		      filehdr_out->f_symptr);
   H_PUT_32 (abfd, filehdr_in->f_nsyms, filehdr_out->f_nsyms);
diff --git a/binutils/ChangeLog b/binutils/ChangeLog
index cc9c6f9..1aea955 100644
--- a/binutils/ChangeLog
+++ b/binutils/ChangeLog
@@ -1,3 +1,13 @@
+2013-11-20  Cory Fields  <cory@coryfields.com>
+	* bfd/libcoff-in.h: Add insert_timestamp flag to the pe_data struct.
+	* bfd/libcoff.h: Update after change to bfd/libcoff-in.h.
+	* bfd/peXXigen.c (_bfd_XXi_only_swap_filehdr_out): Only use a real
+	  timestamp if --insert-timestamp was used.
+	* ld/pe-dll.c (fill_edata): Likewise.
+	* ld/emultempl/pe.em: Add the --insert-timestamp option.
+	* ld/emultempl/pep.em: Likewise for 64bit.
+	* ld/ld.texinfo: Document the --insert-timestamp option.
+
 2013-11-13  Martin Mitas  <mity@morous.org>
 
 	* rescoff.c (write_coff_file): Use 64-bit alignment for resource
diff --git a/ld/emultempl/pe.em b/ld/emultempl/pe.em
index 4df7753..bb25e53 100644
--- a/ld/emultempl/pe.em
+++ b/ld/emultempl/pe.em
@@ -130,6 +130,7 @@ static int support_old_code = 0;
 static char * thumb_entry_symbol = NULL;
 static lang_assignment_statement_type *image_base_statement = 0;
 static unsigned short pe_dll_characteristics = 0;
+static bfd_boolean insert_timestamp = FALSE;
 
 #ifdef DLL_SUPPORT
 static int pe_enable_stdcall_fixup = -1; /* 0=disable 1=enable.  */
@@ -259,8 +260,10 @@ fragment <<EOF
 					(OPTION_LEADING_UNDERSCORE + 1)
 #define OPTION_DISABLE_LONG_SECTION_NAMES \
 					(OPTION_ENABLE_LONG_SECTION_NAMES + 1)
+#define OPTION_INSERT_TIMESTAMP \
+                                        (OPTION_DISABLE_LONG_SECTION_NAMES + 1)
 /* DLLCharacteristics flags */
-#define OPTION_DYNAMIC_BASE		(OPTION_DISABLE_LONG_SECTION_NAMES + 1)
+#define OPTION_DYNAMIC_BASE		(OPTION_INSERT_TIMESTAMP + 1)
 #define OPTION_FORCE_INTEGRITY		(OPTION_DYNAMIC_BASE + 1)
 #define OPTION_NX_COMPAT		(OPTION_FORCE_INTEGRITY + 1)
 #define OPTION_NO_ISOLATION		(OPTION_NX_COMPAT + 1)
@@ -301,6 +304,7 @@ gld${EMULATION_NAME}_add_options
      OPTION_USE_NUL_PREFIXED_IMPORT_TABLES},
     {"no-leading-underscore", no_argument, NULL, OPTION_NO_LEADING_UNDERSCORE},
     {"leading-underscore", no_argument, NULL, OPTION_LEADING_UNDERSCORE},
+    {"insert-timestamp", no_argument, NULL, OPTION_INSERT_TIMESTAMP},
 #ifdef DLL_SUPPORT
     /* getopt allows abbreviations, so we do this to stop it
        from treating -o as an abbreviation for this option.  */
@@ -438,6 +442,8 @@ gld_${EMULATION_NAME}_list_options (FILE *file)
   fprintf (file, _("  --support-old-code                 Support interworking with old code\n"));
   fprintf (file, _("  --[no-]leading-underscore          Set explicit symbol underscore prefix mode\n"));
   fprintf (file, _("  --thumb-entry=<symbol>             Set the entry point to be Thumb <symbol>\n"));
+  fprintf (file, _("  --insert-timestamp                 Use a real timestamp rather than zero.\n"));
+  fprintf (file, _("                                     This makes binaries non-deterministic\n"));
 #ifdef DLL_SUPPORT
   fprintf (file, _("  --add-stdcall-alias                Export symbols with and without @nn\n"));
   fprintf (file, _("  --disable-stdcall-fixup            Don't link _sym to _sym@nn\n"));
@@ -754,6 +760,9 @@ gld${EMULATION_NAME}_handle_option (int optc)
     case OPTION_LEADING_UNDERSCORE:
       pe_leading_underscore = 1;
       break;
+    case OPTION_INSERT_TIMESTAMP:
+      insert_timestamp = TRUE;
+      break;
 #ifdef DLL_SUPPORT
     case OPTION_OUT_DEF:
       pe_out_def_filename = xstrdup (optarg);
@@ -1255,6 +1264,7 @@ gld_${EMULATION_NAME}_after_open (void)
   pe_data (link_info.output_bfd)->pe_opthdr = pe;
   pe_data (link_info.output_bfd)->dll = init[DLLOFF].value;
   pe_data (link_info.output_bfd)->real_flags |= real_flags;
+  pe_data (link_info.output_bfd)->insert_timestamp = insert_timestamp;
 
   /* At this point we must decide whether to use long section names
      in the output or not.  If the user hasn't explicitly specified
diff --git a/ld/emultempl/pep.em b/ld/emultempl/pep.em
index 3e8b65e..c6cb626 100644
--- a/ld/emultempl/pep.em
+++ b/ld/emultempl/pep.em
@@ -146,6 +146,7 @@ static flagword real_flags = IMAGE_FILE_LARGE_ADDRESS_AWARE;
 static int support_old_code = 0;
 static lang_assignment_statement_type *image_base_statement = 0;
 static unsigned short pe_dll_characteristics = 0;
+static bfd_boolean insert_timestamp = FALSE;
 
 #ifdef DLL_SUPPORT
 static int    pep_enable_stdcall_fixup = 1; /* 0=disable 1=enable (default).  */
@@ -241,7 +242,8 @@ enum options
   OPTION_NO_SEH,
   OPTION_NO_BIND,
   OPTION_WDM_DRIVER,
-  OPTION_TERMINAL_SERVER_AWARE
+  OPTION_TERMINAL_SERVER_AWARE,
+  OPTION_INSERT_TIMESTAMP,
 };
 
 static void
@@ -316,6 +318,7 @@ gld${EMULATION_NAME}_add_options
     {"no-bind", no_argument, NULL, OPTION_NO_BIND},
     {"wdmdriver", no_argument, NULL, OPTION_WDM_DRIVER},
     {"tsaware", no_argument, NULL, OPTION_TERMINAL_SERVER_AWARE},
+    {"insert-timestamp", no_argument, NULL, OPTION_INSERT_TIMESTAMP},
     {NULL, no_argument, NULL, 0}
   };
 
@@ -402,6 +405,8 @@ gld_${EMULATION_NAME}_list_options (FILE *file)
   fprintf (file, _("  --subsystem <name>[:<version>]     Set required OS subsystem [& version]\n"));
   fprintf (file, _("  --support-old-code                 Support interworking with old code\n"));
   fprintf (file, _("  --[no-]leading-underscore          Set explicit symbol underscore prefix mode\n"));
+  fprintf (file, _("  --insert-timestamp                 Use a real timestamp rather than zero.\n"));
+  fprintf (file, _("                                     This makes binaries non-deterministic\n"));
 #ifdef DLL_SUPPORT
   fprintf (file, _("  --add-stdcall-alias                Export symbols with and without @nn\n"));
   fprintf (file, _("  --disable-stdcall-fixup            Don't link _sym to _sym@nn\n"));
@@ -707,6 +712,9 @@ gld${EMULATION_NAME}_handle_option (int optc)
     case OPTION_LEADING_UNDERSCORE:
       pep_leading_underscore = 1;
       break;
+    case OPTION_INSERT_TIMESTAMP:
+      insert_timestamp = TRUE;
+      break;
 #ifdef DLL_SUPPORT
     case OPTION_OUT_DEF:
       pep_out_def_filename = xstrdup (optarg);
@@ -1219,6 +1227,7 @@ gld_${EMULATION_NAME}_after_open (void)
   pe_data (link_info.output_bfd)->pe_opthdr = pep;
   pe_data (link_info.output_bfd)->dll = init[DLLOFF].value;
   pe_data (link_info.output_bfd)->real_flags |= real_flags;
+  pe_data (link_info.output_bfd)->insert_timestamp = insert_timestamp;
 
   /* At this point we must decide whether to use long section names
      in the output or not.  If the user hasn't explicitly specified
diff --git a/ld/ld.texinfo b/ld/ld.texinfo
index e4788f6..04325c6 100644
--- a/ld/ld.texinfo
+++ b/ld/ld.texinfo
@@ -2657,6 +2657,12 @@ The driver uses the MS Windows Driver Model.
 @item --tsaware
 The image is Terminal Server aware.
 
+@kindex --insert-timestamp
+@item --insert-timestamp
+Insert a real timestamp into the image, rather than the default value of zero.
+This will result in a slightly different results with each invocation, which
+could be helpful for distributing unique images.
+
 @end table
 
 @c man end
diff --git a/ld/pe-dll.c b/ld/pe-dll.c
index bd3195f..843be7a 100644
--- a/ld/pe-dll.c
+++ b/ld/pe-dll.c
@@ -1170,9 +1170,6 @@ fill_edata (bfd *abfd, struct bfd_link_info *info ATTRIBUTE_UNUSED)
   unsigned char *enameptrs;
   unsigned char *eordinals;
   char *enamestr;
-  time_t now;
-
-  time (&now);
 
   edata_d = xmalloc (edata_sz);
 
@@ -1187,7 +1184,9 @@ fill_edata (bfd *abfd, struct bfd_link_info *info ATTRIBUTE_UNUSED)
 		   + edata_s->output_section->vma - image_base)
 
   memset (edata_d, 0, edata_sz);
-  bfd_put_32 (abfd, now, edata_d + 4);
+  if (pe_data (abfd)->insert_timestamp)
+    H_PUT_32 (abfd, time(0), edata_d + 4);
+
   if (pe_def_file->version_major != -1)
     {
       bfd_put_16 (abfd, pe_def_file->version_major, edata_d + 8);
-- 
1.8.1.2


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