Re: [PATCH -next 0/3] x86 insn decoder test updates (Re: linux-next: Tree for October 29 (x86 posttest))

[Masami Hiramatsu <mhiramat@redhat.com>]

Ingo Molnar wrote:
> 
> * Masami Hiramatsu <mhiramat@redhat.com> wrote:
> 
>> Here are the patches which update x86 instruction decoder build-time 
>> test. As Stephen reported on linux-next, sometimes objdump decodes bad 
>> instructions as normal. This will cause a false positive result on x86 
>> insn decoder test. This patches update the test as below;
>>
>>  - Show more information with V=1
>>  - Show in which symbol the difference places.
>>  - Just warning instead of build failure.
> 
> yes, -tip testing was showing such build bugs too:
> 
>  Error: ffffffff8104aae3:	c5 83 3d 49 80 ee    	lds    0xffffffffee80493d(%rbx),%eax
>  Error: objdump says 6 bytes, but insn_get_length() says 3 (attr:0)
> 
> it happens with older tools, such as binutils-2.17. Modern binutils 
> (2.19) is fine.

Thank you for telling me.

> We dont want to remove the build error: it helped us fix a number of 
> real bugs in the decoder - instead please try to create a make based 
> workaround based on binutils, to not run the test with binutils older 
> than 2.19 or so.

OK, that's fine for me.

Thank you,
-- 
Masami Hiramatsu

Software Engineer
Hitachi Computer Products (America), Inc.
Software Solutions Division

e-mail: mhiramat@redhat.com