Hi Guys,

  The code to implement the .nop directive calls the md_assemble() function 
  with an allocated string, rather than input_line_pointer.  This is supposed
  to work, but there are some targets that assume that md_assemble()'s 
  argument is input_line_pointer, and that they are free to update it.  Even 
  worse some of them assign input_line_pointer to the string argument and
  leave it there.  So when s_nop() finishes and frees the string pointer,
  input_line_pointer is left pointing at freed memory.

  At first I though that it was just the S12Z port that behaved in this way
  but now I have found that the MN10300 port does too.  There may be others
  as well, since the symptom is hard to trace.  So I am applying the attached
  patch to fix s_nop() so that it explicitly preserves input_line_pointer
  instead.

Cheers
  Nick

gas/ChangeLog
2020-09-15  Nick Clifton  <nickc@redhat.com>

	* read.c (s_nop): Preserve the input_line_pointer around the call
	to md_assemble.
	* config/tc-s12z.c (md_assemble): Revert previous delta.