Align and pad code segments to 64k

nacl/dyn-link/ldscripts/elf64_nacl.xs

Index: nacl/dyn-link/ldscripts/elf64_nacl.xs
diff --git a/nacl/dyn-link/ldscripts/elf64_nacl.xs b/nacl/dyn-link/ldscripts/elf64_nacl.xs
index 5925cf95c87989d322a053fbedf589b4ba9bfebf..e92865bf1c9858b2c4ce9d53b14e40d841ec527e 100644
--- a/nacl/dyn-link/ldscripts/elf64_nacl.xs
+++ b/nacl/dyn-link/ldscripts/elf64_nacl.xs
@@ -16,12 +16,9 @@ PHDRS
 }
 SECTIONS
 {
-  /* NaCl runtime treats ld.so as an executable.  NaCl executables must have
-     page-aligned code and data segments, so linker script for ld.so is patched
-     to remove SIZEOF_HEADERS below and make code segment aligned to page
-     boundary. */
-  . = SEGMENT_START("text", 0) + SIZEOF_HEADERS;
+  . = SEGMENT_START("text", 0);
   _begin = .;
+
   /* The ALIGN(32) instructions below are workarounds.
      TODO(mseaborn): Get the object files to include the correct
      alignments and padding themselves.
@@ -43,21 +40,13 @@ SECTIONS
     KEEP (*(.fini))
     *(__libc_freeres_fn)
     *(__libc_thread_freeres_fn)
-    . = ALIGN(32); /* ensure nop padding */
+    . = ALIGN(CONSTANT (MAXPAGESIZE)); /* ensures NOP fill */
   } =0x90909090
   PROVIDE (__etext = .);
   PROVIDE (_etext = .);
   PROVIDE (etext = .);
 
-  /* Adjust data segment so that is has the same position within the page as
-     the end of code segment.  In this case linker can store them without any
-     zeros in between.
-     
-     NaCl runtime treats ld.so as an executable which must have page-aligned
-     read-only data segment.  So the last term is replaced with 0 while patching
-     linker script for ld.so. */
-  . = SEGMENT_START("text", 0) + 0x10000000 +
-      (. & (CONSTANT (MAXPAGESIZE) - 1));
+  . = ALIGN(SEGMENT_START("text", 0) + 0x10000000, CONSTANT (MAXPAGESIZE));
   .note.gnu.build-id : { *(.note.gnu.build-id) } :seg_rodata
   .hash           : { *(.hash) }
   .gnu.hash       : { *(.gnu.hash) }
@@ -102,7 +91,7 @@ SECTIONS
   . = ALIGN (CONSTANT (MAXPAGESIZE)) - ((CONSTANT (MAXPAGESIZE) - .) & (CONSTANT (MAXPAGESIZE) - 1)); . = DATA_SEGMENT_ALIGN (CONSTANT (MAXPAGESIZE), CONSTANT (COMMONPAGESIZE));
   /* Executables loaded by sel_ldr are not required to have seg_rwdata aligned
      to page boundary.  So we can omit alignment here both for ld.so and normal
-     libraries. */      
+     libraries. */
   /* Exception handling  */
   .eh_frame       : ONLY_IF_RW { KEEP (*(.eh_frame)) } :seg_rwdata
   .gcc_except_table   : ONLY_IF_RW { *(.gcc_except_table .gcc_except_table.*) }