Re: [Linux-stable-mirror] [PATCH] arm: ensure symbol is a thumb symbol in new binutils

Hi Russell,

On Tue, Nov 21, 2017 at 6:38 PM, Russell King - ARM Linux linux@armlinux.org.uk wrote:

+toolcheck:

•   @$(CONFIG_SHELL) '$(srctree)/$(src)/toolcheck'
  

Perhaps faster to put the check for THUMB2_KERNEL around the make target, instead of doing it in the code?

+if grep -q 'CONFIG_THUMB2_KERNEL=y' .config; then

See above.

• tmp=$(mktemp -d /tmp/binutils-test.XXXXXXXXXX)
• cat <<EOF | $AS $ASFLAGS -o $tmp/test.o

•   .syntax unified
  

•   .thumb
  

•   .macro  badr, reg, sym
  

•   adr     \reg, \sym + 1
  

•   .endm
  

+test:

•   mov     r0, #0
  

•   badr    lr, test
  

+EOF

• if ! $OBJDUMP -d $tmp/test.o | grep -q '4:\s*f2af 0e07'; then

•  echo "Error: your assembler version produces buggy kernels" >&2
  

•  $AS --version | head -n1 >&2
  

•  rm $tmp/*.o
  

•  rmdir $tmp
  

•  exit 1
  

• fi
• rm $tmp/*.o
• rmdir $tmp

+fi

This doesn't actually catch the issues. In the buggy binutils, it appears that sometimes adr grabs the right symbol and sometimes it doesn't. I'm not yet able to figure out a minimal condition for it going one way or the other.

Jason