ARM Thumb instruction SUB may decode wrong in ADR situation

[yakamoz423]

I have an ARM Thumb instruction:

 80001a6:   f2af 0e09   subw    lr, pc, #9

In bits view:

The Capstone decoded it as a SUB instruction:

But according to the Arm Architecture Reference Manual for A-profile architecture document, when Rn is PC (15) in T4 format, it should be regarded as ADR instruction.

Capstone says it insn-mnem is sub. I think it's a mistake. It matters because ADR is 4-byte aligning the PC value, while SUB is not.

The Capstone instance is configured by:

    cs_open(CS_ARCH_ARM, CS_MODE_THUMB, &handle);
    cs_option(handle, CS_OPT_DETAIL, CS_OPT_ON);

[Rot127]

It seems to be fixed in the next branch:

./cstool thumbbe f2af0e09
 0  f2 af 0e 09  adr.w  lr, #-9

[Rot127]

@yakamoz423 Please check for yourself and close the issue if it works as expected.

[yakamoz423]

@Rot127 Hi, I encountered some issues while compiling the latest next version d3eb79c2aa6511675c2f80eb185cb41bfd61e5ea

$ CC=gcc ./make.sh
  LINK    capstone.
./arch/AArch64/AArch64DisassemblerExtension.o:AArch64DisassemblerExtension.c:(.text+0x0): multiple definition of `llabs'
./arch/ARM/ARMDisassemblerExtension.o:ARMDisassemblerExtension.c:(.text+0x0): first defined here
./arch/AArch64/AArch64DisassemblerExtension.o:AArch64DisassemblerExtension.c:(.text+0x44): multiple definition of `wcscmpi'
./arch/ARM/ARMDisassemblerExtension.o:ARMDisassemblerExtension.c:(.text+0x40c): first defined here
./arch/AArch64/AArch64DisassemblerExtension.o:AArch64DisassemblerExtension.c:(.text+0x50): multiple definition of `strncasecmp'
./arch/ARM/ARMDisassemblerExtension.o:ARMDisassemblerExtension.c:(.text+0x418): first defined here
./arch/AArch64/AArch64DisassemblerExtension.o:AArch64DisassemblerExtension.c:(.text+0x5c): multiple definition of `strcasecmp'
./arch/ARM/ARMDisassemblerExtension.o:ARMDisassemblerExtension.c:(.text+0x424): first defined here
./arch/AArch64/AArch64DisassemblerExtension.o:AArch64DisassemblerExtension.c:(.text+0x68): multiple definition of `vsnwprintf'
./arch/ARM/ARMDisassemblerExtension.o:ARMDisassemblerExtension.c:(.text+0x430): first defined here
./arch/AArch64/AArch64DisassemblerExtension.o:AArch64DisassemblerExtension.c:(.text+0x74): multiple definition of `ftello64'
./arch/ARM/ARMDisassemblerExtension.o:ARMDisassemblerExtension.c:(.text+0x43c): first defined here
./arch/AArch64/AArch64DisassemblerExtension.o:AArch64DisassemblerExtension.c:(.text+0xa4): multiple definition of `fopen64'
./arch/ARM/ARMDisassemblerExtension.o:ARMDisassemblerExtension.c:(.text+0x46c): first defined here
./arch/AArch64/AArch64DisassemblerExtension.o:AArch64DisassemblerExtension.c:(.text+0xb0): multiple definition of `putchar'
./arch/ARM/ARMDisassemblerExtension.o:ARMDisassemblerExtension.c:(.text+0x478): first defined here
./arch/AArch64/AArch64DisassemblerExtension.o:AArch64DisassemblerExtension.c:(.text+0xf4): multiple definition of `putc'
./arch/ARM/ARMDisassemblerExtension.o:ARMDisassemblerExtension.c:(.text+0x4bc): first defined here
./arch/AArch64/AArch64DisassemblerExtension.o:AArch64DisassemblerExtension.c:(.text+0x128): multiple definition of `getchar'
./arch/ARM/ARMDisassemblerExtension.o:ARMDisassemblerExtension.c:(.text+0x4f0): first defined here
./arch/AArch64/AArch64DisassemblerExtension.o:AArch64DisassemblerExtension.c:(.text+0x160): multiple definition of `getc'
./arch/ARM/ARMDisassemblerExtension.o:ARMDisassemblerExtension.c:(.text+0x528): first defined here
./arch/AArch64/AArch64DisassemblerExtension.o:AArch64DisassemblerExtension.c:(.text+0x188): multiple definition of `ulltow'
./arch/ARM/ARMDisassemblerExtension.o:ARMDisassemblerExtension.c:(.text+0x550): first defined here
./arch/AArch64/AArch64DisassemblerExtension.o:AArch64DisassemblerExtension.c:(.text+0x194): multiple definition of `lltow'
./arch/ARM/ARMDisassemblerExtension.o:ARMDisassemblerExtension.c:(.text+0x55c): first defined here
./arch/AArch64/AArch64DisassemblerExtension.o:AArch64DisassemblerExtension.c:(.text+0x1a0): multiple definition of `wtoll'
./arch/ARM/ARMDisassemblerExtension.o:ARMDisassemblerExtension.c:(.text+0x568): first defined here
./arch/AArch64/AArch64DisassemblerExtension.o:AArch64DisassemblerExtension.c:(.text+0x1ac): multiple definition of `ulltoa'
./arch/ARM/ARMDisassemblerExtension.o:ARMDisassemblerExtension.c:(.text+0x574): first defined here
./arch/AArch64/AArch64DisassemblerExtension.o:AArch64DisassemblerExtension.c:(.text+0x1b8): multiple definition of `lltoa'
./arch/ARM/ARMDisassemblerExtension.o:ARMDisassemblerExtension.c:(.text+0x580): first defined here
./arch/AArch64/AArch64DisassemblerExtension.o:AArch64DisassemblerExtension.c:(.text+0x1c4): multiple definition of `atoll'
./arch/ARM/ARMDisassemblerExtension.o:ARMDisassemblerExtension.c:(.text+0x58c): first defined here
./arch/AArch64/AArch64DisassemblerExtension.o:AArch64DisassemblerExtension.c:(.text+0x1d0): multiple definition of `_Exit'
./arch/ARM/ARMDisassemblerExtension.o:ARMDisassemblerExtension.c:(.text+0x598): first defined here
collect2: ld returned 1 exit status
make: *** [capstone.] Error 1

Compiler (seems too old):

$ gcc -v
Using built-in specs.
Target: mingw32
Configured with: ../gcc-4.3.3/configure --prefix=/mingw --build=mingw32 --enable-languages=c,c++ --with-bugurl=http://www.simics.net --disable-nls --disable-win32-registry --enable-threads --disable-symvers --enable-cxx-flags='-fno-function-sections -fno-data-sections' --enable-fully-dynamic-string --enable-version-specific-runtime-libs --enable-sjlj-exceptions --with-pkgversion='4.3.3-vt-1 mingw32'
Thread model: win32
gcc version 4.3.3 (4.3.3-vt-1 mingw32)

5.x wasn't like this.

[Rot127]

Please use cmake (see docs). The make build is deprecated and only there until the bindings are update as well (some when in the future) But yes. gcc is very old in your case. Better use some version >10