Re: Keep local symbols of rump libraries

[Ryota Ozaki <ozaki-r%netbsd.org@localhost>]

I added tech-toolchain@ where is the best place to discuss this topic.

  ozaki-r


On Fri, Apr 14, 2017 at 1:19 PM, Ryota Ozaki <ozaki-r%netbsd.org@localhost> wrote:
> On Thu, Apr 13, 2017 at 12:22 PM, Ryota Ozaki <ozaki-r%netbsd.org@localhost> wrote:
>> On Wed, Apr 12, 2017 at 6:58 PM, Ryota Ozaki <ozaki-r%netbsd.org@localhost> wrote:
>>> On Wed, Apr 12, 2017 at 9:27 AM, Chuck Silvers <chuq%chuq.com@localhost> wrote:
>>>> On Mon, Apr 10, 2017 at 07:22:45PM +0900, Ryota Ozaki wrote:
>>>>> Hi,
>>>>>
>>>>> I'm using ATF tests running rump kernels (rump_server)
>>>>> for development and debugging. When a rump kernel gets
>>>>> panic, it dumps a core file from which we can obtain
>>>>> a backtrace by using gdb.
>>>>>
>>>>> Unfortunately local symbols (i.e., static functions)
>>>>> in a backtrace are unresolved because they are stripped
>>>>> by the linker (and objdump). That makes debugging a bit
>>>>> difficult.
>>>>>
>>>>> The patch introduces a compile option for rump kernels
>>>>> called RUMP_KEEPSYMBOLS to keep such symbols:
>>>>>   http://www.netbsd.org/~ozaki-r/rumplibs-keep-symbols.diff
>>>>>
>>>>> The option is disabled by default to not increase
>>>>> the size of all rump libraries.
>>>>>
>>>>> I'm not so familiar with the NetBSD build system and
>>>>> Makefiles, so the patch may be wrong or clumsy.
>>>>>
>>>>> Any comments?
>>>>
>>>> I've been meaning to ask about something similar to this
>>>> but for everything in the build (libraries and commands)
>>>> for the benefit of dtrace.  dtrace "ustack()" stack traces
>>>> are similarly less useful without the static symbols.
>>>>
>>>> my patch for that was similar to yours, but I changed the
>>>> "-Wl,-x" to "-Wl,-X" rather than removing the option entirely.
>>>> for OBJCOPYLIBFLAGS I did what you did, though I suppose using "-X"
>>>> there too would have been more consistent.
>>>
>>> Sure. Changing -x to -X works for me.
>>>
>>>>
>>>> if we had an option for preserving static symbols for everything,
>>>> would you still want a rump-library-specific option?
>>>
>>> If it's useful for other than rump libraries, having a new global
>>> option would be adequate. I don't have an idea of the name though.
>>
>> http://www.netbsd.org/~ozaki-r/libs-keep-symbols.diff
>>
>> So this is a new patch that provides a global option named MKSTRIPSYM.
>> (the name is suggested by paulg, thanks!)
>
> The patch is updated; bsd.lua.mk also applies MKSTRIPSYM. Let me know
> if the change is wrong.
>
> Thanks,
>   ozaki-r