PPC: Invalid assembly code

[Rot127]

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Binaries which are compiled with the cross-compiler available for Ubuntu are not decompiled correctly.

Running

> cstool -d ppc64be <bin>
ERROR: invalid assembly code

Reproduce

src

int main() {
  int a = 0;
  int b = -1;
  a = b + b;
  return 0;
}

Build

> sudo apt install g++-10-multilib-powerpc64-linux-gnu
> powerpc64-linux-gnu-g++-10 -m64 -mbig -o add_bin add_bin.c
> readelf -h add_bin
ELF Header:
  Magic:   7f 45 4c 46 02 02 01 00 00 00 00 00 00 00 00 00 
  Class:                             ELF64
  Data:                              2's complement, big endian
  Version:                           1 (current)
  OS/ABI:                            UNIX - System V
  ABI Version:                       0
  Type:                              EXEC (Executable file)
  Machine:                           PowerPC64
  Version:                           0x1
  Entry point address:               0x1001fdf8
  Start of program headers:          64 (bytes into file)
  Start of section headers:          67944 (bytes into file)
  Flags:                             0x1, abiv1
  Size of this header:               64 (bytes)
  Size of program headers:           56 (bytes)
  Number of program headers:         8
  Size of section headers:           64 (bytes)
  Number of section headers:         29
  Section header string table index: 28

Disassemble with objdump

> powerpc64-linux-gnu-objdump -d add_bin
<Valid assembly>

Capstone

> cstool -d ppc64be <bin>
ERROR: invalid assembly code

Versions

Capstone: v5.0.0 g++: (Ubuntu 10.3.0-1ubuntu1~20.04) 10.3.0

[Rot127]

I am able to compile asm files with powerpc64-linux-gnu-as, link them with powerpc64-linux-gnu-ld and they are disassembled correctly in rizin. But not by the command cstool

> powerpc64-linux-gnu-as -a64 -mregnames src.S -o asm_bin.o
> powerpc64-linux-gnu-ld -b elf64-powerpc  asm_bin.o -o asm_bin
> cstool -d ppc64be asm_bin
ERROR: invalid assembly code
> rizin -qq -c 'pd 10' tracetest
            ;-- entry0:
            ;-- _start:
            0x1000047c      bl    loc.add_insns
            0x10000480      li    r0, 0
            0x10000484      blr
            0x10000488      invalid
...

In the former case rizin does not decompile the binary neither.