[llvm-dev] Hardware ASan Generating Unknown Instruction

[Derrick McKee via llvm-dev]

Using lld fixes this issue.

On Mon, Jun 22, 2020 at 4:51 PM Peter Collingbourne <peter at pcc.me.uk> wrote:
>
> I suspect that this is hitting the issue that I mentioned here:
> https://reviews.llvm.org/D65857#1621335
>
> We may need to do what I suggested there and restrict global tag entropy on non-Android Linux to 7 bits. You can try working around this issue for now by using lld as the linker (-fuse-ld=lld).
>
> Peter
>
> On Mon, Jun 22, 2020 at 1:37 PM Mitch Phillips via llvm-dev <llvm-dev at lists.llvm.org> wrote:
>>
>> Hi Derrick,
>>
>> Can you send through `test.c`? What does clang's assembly say (`path/to/compiled/clang --target=aarch64-linux-gnu -march=armv8.5-a -fsanitize=hwaddress -S test.c; cat test.s`)?
>>
>> - Mitch
>>
>> On Mon, Jun 22, 2020 at 12:04 PM Derrick McKee via llvm-dev <llvm-dev at lists.llvm.org> wrote:
>>>
>>> Hi,
>>>
>>> I am trying to execute a simple hello world program compiled like so:
>>>
>>> path/to/compiled/clang -o test --target=aarch64-linux-gnu
>>> -march=armv8.5-a -fsanitize=hwaddress
>>> --sysroot=/usr/aarch64-linux-gnu/
>>> -L/usr/lib/gcc/aarch64-linux-gnu/10.1.0/ -g test.c
>>>
>>> However, when I look at the disassembly, there is an unknown
>>> instruction listed at 0x2d51c:
>>>
>>> 000000000002d4c0 main:
>>>    2d4c0: ff c3 00 d1                      sub    sp, sp, #48
>>>    2d4c4: fd 7b 02 a9                      stp    x29, x30, [sp, #32]
>>>    2d4c8: fd 83 00 91                      add    x29, sp, #32
>>>    2d4cc: 08 01 00 d0                      adrp    x8, #139264
>>>    2d4d0: 08 49 47 f9                      ldr    x8, [x8, #3728]
>>>    2d4d4: 49 d0 3b d5                      mrs    x9, TPIDR_EL0
>>>    2d4d8: 28 69 68 f8                      ldr    x8, [x9, x8]
>>>    2d4dc: 08 7d 40 b2                      orr    x8, x8, #0xffffffff
>>>    2d4e0: 08 05 00 91                      add    x8, x8, #1
>>>    2d4e4: a2 13 00 d1                      sub    x2, x29, #4
>>>    2d4e8: e9 03 08 aa                      mov    x9, x8
>>>    2d4ec: df 64 ff 97                      bl    #-158852
>>> <__hwasan_check_x2_18_short>
>>>    2d4f0: ea 03 1f 2a                      mov    w10, wzr
>>>    2d4f4: aa c3 1f b8                      stur    w10, [x29, #-4]
>>>    2d4f8: a2 23 00 d1                      sub    x2, x29, #8
>>>    2d4fc: e9 03 08 aa                      mov    x9, x8
>>>    2d500: da 64 ff 97                      bl    #-158872
>>> <__hwasan_check_x2_18_short>
>>>    2d504: a0 83 1f b8                      stur    w0, [x29, #-8]
>>>    2d508: e2 43 00 91                      add    x2, sp, #16
>>>    2d50c: e9 03 08 aa                      mov    x9, x8
>>>    2d510: ec 64 ff 97                      bl    #-158800
>>> <__hwasan_check_x2_19_short>
>>>    2d514: e1 0b 00 f9                      str    x1, [sp, #16]
>>>    2d518: 40 00 00 d0                      adrp    x0, #40960
>>>    2d51c: e0 ff e5 b2                      <unknown>
>>>    2d520: 00 40 35 91                      add    x0, x0, #3408
>>>    2d524: ea 0f 00 b9                      str    w10, [sp, #12]
>>>    2d528: c2 64 ff 97                      bl    #-158968 <printf at plt>
>>>    2d52c: ea 0f 40 b9                      ldr    w10, [sp, #12]
>>>    2d530: e0 0b 00 b9                      str    w0, [sp, #8]
>>>    2d534: e0 03 0a 2a                      mov    w0, w10
>>>    2d538: fd 7b 42 a9                      ldp    x29, x30, [sp, #32]
>>>    2d53c: ff c3 00 91                      add    sp, sp, #48
>>>    2d540: c0 03 5f d6                      ret
>>>
>>>
>>> Am I compiling the program incorrectly?  For reference, here's my clang version
>>>
>>> # llvm-project/build-10.x/install/bin/clang --version
>>>                                              [1]
>>> clang version 10.0.1 (git at github.com:llvm/llvm-project.git
>>> a634a80615b1e012f1a61aa0cd1e2e67ef77d0bd)
>>> Target: x86_64-unknown-linux-gnu
>>> Thread model: posix
>>>
>>> --
>>> Derrick McKee
>>> Phone: (703) 957-9362
>>> Email: derrick.mckee at gmail.com
>>> _______________________________________________
>>> LLVM Developers mailing list
>>> llvm-dev at lists.llvm.org
>>> https://lists.llvm.org/cgi-bin/mailman/listinfo/llvm-dev
>>
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>
>
>
> --
> --
> Peter



-- 
Derrick McKee
Phone: (703) 957-9362
Email: derrick.mckee at gmail.com