[RFA] fix for intel disassembly, truncated BFD_VMA

H.J. Lu hjl.tools@gmail.com
Tue Feb 16 00:07:00 GMT 2016


On Wed, Feb 9, 2011 at 10:43 AM, Michael Snyder <msnyder@vmware.com> wrote:
> H.J. Lu wrote:
>>
>> On Wed, Feb 9, 2011 at 10:36 AM, Michael Snyder <msnyder@vmware.com>
>> wrote:
>>>
>>> This expression needed parentheses.  Without them, it was truncating the
>>> target address of jumps and calls from BFD_VMA to 32-bits.
>>>
>>> Disassembly at high addresses is vastly improved.
>>>
>>>
>>> 2011-02-09  Michael Snyder  <msnyder@vmware.com>
>>>
>>>        * i386-dis.c (OP_J): Parenthesize expression to prevent
>>>        truncated addresses.
>>>        (print_insn): Fix indentation off-by-one.
>>>
>>> Index: i386-dis.c
>>> ===================================================================
>>> RCS file: /cvs/src/src/opcodes/i386-dis.c,v
>>> retrieving revision 1.257
>>> diff -u -p -u -p -r1.257 i386-dis.c
>>> --- i386-dis.c  18 Jan 2011 17:08:13 -0000      1.257
>>> +++ i386-dis.c  9 Feb 2011 18:28:02 -0000
>>> @@ -1,6 +1,6 @@
>>>  /* Print i386 instructions for GDB, the GNU debugger.
>>>    Copyright 1988, 1989, 1991, 1993, 1994, 1995, 1996, 1997, 1998, 1999,
>>> -   2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009, 2010
>>> +   2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009, 2010, 2011
>>>    Free Software Foundation, Inc.
>>>
>>>    This file is part of the GNU opcodes library.
>>> @@ -11702,9 +11702,9 @@ print_insn (bfd_vma pc, disassemble_info
>>>       modrm.rm = *codep & 7;
>>>     }
>>>
>>> -   need_vex = 0;
>>> -   need_vex_reg = 0;
>>> -   vex_w_done = 0;
>>> +  need_vex = 0;
>>> +  need_vex_reg = 0;
>>> +  vex_w_done = 0;
>>>
>>>   if (dp->name == NULL && dp->op[0].bytemode == FLOATCODE)
>>>     {
>>> @@ -13817,7 +13817,7 @@ OP_J (int bytemode, int sizeflag)
>>>       oappend (INTERNAL_DISASSEMBLER_ERROR);
>>>       return;
>>>     }
>>> -  disp = ((start_pc + codep - start_codep + disp) & mask) | segment;
>>> +  disp = ((start_pc + (codep - start_codep) + disp) & mask) | segment;
>>>   set_op (disp, 0);
>>>   print_operand_value (scratchbuf, 1, disp);
>>>   oappend (scratchbuf);
>>>
>>>
>>
>> OK.
>
>
> Thanks, committed.

I got a hit with a similar case.  I checked this patch into trunk
and 2.26 branch.

-- 
H.J.
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