rtems-addr2line not working on ARM?

[Sebastian Huber]

On 09/09/2019 07:31, Sebastian Huber wrote:
> On 07/09/2019 16:25, Sebastian Huber wrote:
>> ----- Am 6. Sep 2019 um 18:06 schrieb Sebastian Huber 
>> sebastian.huber at embedded-brains.de:
>>
>>> ----- Am 6. Sep 2019 um 11:09 schrieb Sebastian Huber
>>> sebastian.huber at embedded-brains.de:
>>>
>>>> On 06/09/2019 09:26, Sebastian Huber wrote:
>>>>> On 06/09/2019 09:01, Chris Johns wrote:
>>>>>> On 6/9/19 4:20 pm, Sebastian Huber wrote:
>>>>>>> Hello,
>>>>>>>
>>>>>>> I tried the rtems-addr2line on ARM and SPARC. On SPARC it seems to
>>>>>>> work fine,
>>>>>>> however, on ARM I get this:
>>>>>>>
>>>>>>> rtems-addr2line -e
>>>>>>> build/arm-rtems5-xilinx_zynq_a9_qemu-everything/media01.exe
>>>>>>> 0x0000135a
>>>>>>> /home/EB/sebastian_h/git-rtems-5/c/src/lib/libbsp/arm/xilinx-zynq/../../../../../../bsps/arm/shared/irq/irq-gic.c:264 
>>>>>>>
>>>>>>>
>>>>>>>
>>>>>>>
>>>>>>> addr2line -e
>>>>>>> build/arm-rtems5-xilinx_zynq_a9_qemu-everything/media01.exe 0000135a
>>>>>>> /scratch/git-rtems-libbsd/build/arm-rtems5-xilinx_zynq_a9_qemu-everything/../../testsuite/include/rtems/bsd/test/default-network-init.h:179 
>>>>>>>
>>>>>>>
>>>>>>>
>>>>>>>
>>>>>>> The GNU tool is right. It is also considerably faster.
>>>>>> I would hope it is faster and exact. It has had many years of work 
>>>>>> on it,
>>>>>> written in C and not a means to test a C++ framework so we can 
>>>>>> grow an
>>>>>> ecosystem. I have stated its purpose before. I am perplexed by the
>>>>>> intent of
>>>>>> this statement.
>>>>>>
>>>>>> If you want to compare performance I suggest you try the elftools 
>>>>>> one?
>>>>>> There is
>>>>>> one. It is not built because GNU provides one and good one.
>>>>>>
>>>>>> Also be-careful as the exec call is not as fast as Linux on all the
>>>>>> hosts we
>>>>>> support.
>>>>>
>>>>> That the GNU tool is faster was just an observation.
>>>>>
>>>>> Do we have a working library solution to get from an address to the
>>>>> source line/function? I don't have time to debug the DWARF support 
>>>>> code
>>>>> at the moment.
>>>>>
>>>>> I have a working solution using "addr2line" and 
>>>>> rld::process::execute().
>>>>
>>>> Thanks for the hint to the elftoolchain:
>>>>
>>>> https://github.com/elftoolchain/elftoolchain/blob/trunk/addr2line/addr2line.c 
>>>>
>>>>
>>>> To me it looks pretty complicated. It should be possible to refactor
>>>> this code to use it as a library, e.g. call translate() for each 
>>>> address
>>>> you need the source information.
>>>>
>>>> I tried to debug the rld get_source() problem for more than two hours
>>>> and the elftoolchain code looks similar. I am not sure what to do.
>>>
>>> Another option is to use the LLVM infrastructure:
>>>
>>> https://github.com/llvm-mirror/llvm/blob/master/tools/llvm-symbolizer/llvm-symbolizer.cpp 
>>>
>>>
>>>  From a first glance, this looks like the way to go.
>>
>> Attached is a patch which uses the LLVM library to get an addr2line 
>> functionality. The code to resolve an address is very easy (item.data 
>> is the address):
>>
>>      auto res_or_err = symbolizer_.symbolizeCode(elf_file_, item.data);
>>
>>      if (res_or_err) {
>>        auto info = res_or_err.get();
>>        std::string fn = info.FunctionName;
>>        std::string str;
>>
>>        if (fn != "<invalid>") {
>>          str += fn;
>>          str += " at ";
>>        }
>>
>>        str += llvm::sys::path::filename(info.FileName);
>>        str += ":";
>>        str += std::to_string(info.Line);
>>
>> LLVM has also support for command line arguments, file handling, etc.
> 
> The LLVM solution is also the fastest so far:
> 
> time ../build/trace/rtems-record-lttng -e media01.exe records.bin
> 
> real    0m0.425s
> user    0m0.293s
> sys     0m0.132s
> 
> addr2line based solution on Linux:
> 
> real    0m11.944s
> user    0m5.334s
> sys     0m6.593s

Compiling this on Windows using mingw64 was a bit difficult. I had to 
install:

mingw-w64-x86_64-llvm
mingw-w64-x86_64-clang

I used clang to build the tool by hand. I had to remove the use of the 
POSIX open/connect/socket/etc. and replace it with fopen().

The CTF stream files generated on Linux and Windows were identical using 
LLVM.

-- 
Sebastian Huber, embedded brains GmbH

Address : Dornierstr. 4, D-82178 Puchheim, Germany
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E-Mail  : sebastian.huber at embedded-brains.de
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