[llvm-dev] llvm-bjdump and ELF-ARM/Thumb

[Johan Wehrli via llvm-dev]

I found the problem, my libraries contains both ARM and Thumb instructions.

When I specified the triple for thumb, all the arm function where not correctly disassemble.

This creates a shift that has repercussion into the thumb function.

You can simply disassemble function per function and used the triple : thumbv7-unknown-unknown-macho or armv7-unknown-unknown-macho

> On 20 Jun 2016, at 08:47, Johan Wehrli via llvm-dev <llvm-dev at lists.llvm.org> wrote:
> 
> After some digging, I found people with the same problem:
> 
> https://llvm.org/bugs/show_bug.cgi?id=15795 <https://llvm.org/bugs/show_bug.cgi?id=15795>
> https://groups.google.com/forum/#!topic/llvm-dev/Kf3jXQLUJtM <https://groups.google.com/forum/#!topic/llvm-dev/Kf3jXQLUJtM>
> 
> Does anyone know if there is a solution now? I can’t find anything.
> 
>> On 20 Jun 2016, at 07:37, Johan Wehrli via llvm-dev <llvm-dev at lists.llvm.org <mailto:llvm-dev at lists.llvm.org>> wrote:
>> 
>> The standard objdump does not recognised the format.
>> 
>> It works if I used an arm-linux-androideabi-objdump from the Android ndk but I am using the clang API to read binary inside my soft.
>> 
>> This is why I was only working with llvm-objdump.
>> 
>>> On 19 Jun 2016, at 15:03, Bruce Hoult <bruce at hoult.org <mailto:bruce at hoult.org>> wrote:
>>> 
>>> What happens if you use the standard bunutils objdump e.g. from macports package arm-elf-binutils (if you're on a Mac)?
>>> 
>>> 
>>> On Mon, Jun 20, 2016 at 12:45 AM, Johan Wehrli via llvm-dev <llvm-dev at lists.llvm.org <mailto:llvm-dev at lists.llvm.org>> wrote:
>>> Hi Everyone,
>>> 
>>> When I used llvm-objdump to disassemble an ELF armv7 or thumb I have this error message:
>>> 
>>> llvm-objdump: warning: invalid instruction encoding
>>> 
>>> This message appears directly into the output and the output is mostly wrong (the invalid instruction create a shift in the addresses) :
>>> 
>>> 
>>>     1a6d:       ff 2f e1 08     stmeq   r1!, {r0, r1, r2, r3, r4, r5, r6, r7, r8, r9, r10, r11, sp} ^
>>>     1a71:       30 90 e5 00     rsceq   r9, r5, r0, lsr r0
>>>     1a75:       10 a0 e1 00     rsceq   r10, r1, r0, lsl r0
>>>     1a79:       00 53 e3 1e     cdpne   p3, #14, c5, c3, c0, #0
>>> llvm-objdump: warning: invalid instruction encoding
>>>     1a7e:       2f 01 01 00     andeq   r0, r1, pc, lsr #2
>>> llvm-objdump: warning: invalid instruction encoding
>>>     1a83:       e3 13 ff 2f     svchs   #16716771
>>> llvm-objdump: warning: invalid instruction encoding
>>> 
>>> The binaries I try to read are c++ dynamic libraries for Android.
>>> 
>>> I have used the following parameters:
>>> 
>>> -llvm-objcdump mylib.so -d -arch=arm
>>> -llvm-objcdump mylib.so -d -arch=armv7
>>> -llvm-objcdump mylib.so -d -arch=thumb
>>> 
>>> or with the following triples:
>>> 
>>> armv7-none-linux-android
>>> thumbv7-none-linux-android
>>> 
>>> Does anyone know why I have this error? Am I missing some input parameters?
>>> 
>>> This is strange because it works great on iOS binaries (both thumb or arm).
>>> 
>>> Greetings,
>>> 
>>> Johan
>>> _______________________________________________
>>> LLVM Developers mailing list
>>> llvm-dev at lists.llvm.org <mailto:llvm-dev at lists.llvm.org>
>>> http://lists.llvm.org/cgi-bin/mailman/listinfo/llvm-dev <http://lists.llvm.org/cgi-bin/mailman/listinfo/llvm-dev>
>>> 
>> 
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