Commit 1d153a33 authored by Peter Maydell's avatar Peter Maydell
Browse files

disas/microblaze: Avoid unintended sign extension 



In read_insn_microblaze() we assemble 4 bytes into an 'unsigned
long'.  If 'unsigned long' is 64 bits and the high byte has its top
bit set, then C's implicit conversion from 'unsigned char' to 'int'
for the shift will result in an unintended sign extension which sets
the top 32 bits in 'inst'.  Add casts to prevent this.  (Spotted by
Coverity, CID 10054016.)

Signed-off-by: default avatarPeter Maydell <peter.maydell@linaro.org>
Reviewed-by: default avatarEdgar E. Iglesias <edgar.iglesias@xilinx.com>
Message-id: 1488556233-31246-5-git-send-email-peter.maydell@linaro.org
parent 2e3883d0

disas/microblaze.c

+4 −2
Original line number Diff line number Diff line
@@ -748,9 +748,11 @@ read_insn_microblaze (bfd_vma memaddr, 
    }



  if (info->endian == BFD_ENDIAN_BIG)

    inst = (ibytes[0] << 24) | (ibytes[1] << 16) | (ibytes[2] << 8) | ibytes[3];

    inst = ((unsigned)ibytes[0] << 24) | (ibytes[1] << 16)

      | (ibytes[2] << 8) | ibytes[3];

  else if (info->endian == BFD_ENDIAN_LITTLE)

    inst = (ibytes[3] << 24) | (ibytes[2] << 16) | (ibytes[1] << 8) | ibytes[0];

    inst = ((unsigned)ibytes[3] << 24) | (ibytes[2] << 16)

      | (ibytes[1] << 8) | ibytes[0];

  else

    abort ();