Reverting nacl_fixup_ldso.py sections change.

elf/nacl_fixup_ldso.py

 
 # Modifies ld.so's ELF Program Headers to get a version that NaCl's
 # sel_ldr will run.
 #
 # For a discussion, see:
 # http://code.google.com/p/nativeclient/issues/detail?id=156
 # http://code.google.com/p/nativeclient/issues/detail?id=558
 
 import struct
 import sys
@@ skipping 25 matching lines @@
             raise AssertionError("Expected %s, got %s" % (expected, got))
 
     def replace(ty, offset, value):
         fh.seek(offset)
         fh.write(struct.pack(ty, value))
 
     # sel_ldr only accepts ELF objects with e_type=ET_EXEC.
     check("B", offset_e_type, ET_DYN)
     replace("B", offset_e_type, ET_EXEC)
 
+    # sel_ldr rejects ELF Program Headers other than PT_LOAD.
+    # Drop PT_DYNAMIC, PT_GNU_STACK and PT_TLS.
+    fh.seek(offset_ei_class)
+    elfclass = fh.read(1)
+    if elfclass == elfclass32:
+        check("H", offset_e_phnum32, 7)
+        replace("H", offset_e_phnum32, 3)
+    elif elfclass == elfclass64:
+        check("H", offset_e_phnum64, 7)
+        replace("H", offset_e_phnum64, 3)
+    else:
+        raise AssertionError("Unknown ELF class in file %s." % filename)
+
     fh.close()
 
 
 if __name__ == "__main__":
     main(sys.argv[1:])