Commit 6b1992bc authored by Stephen Rothwell's avatar Stephen Rothwell Committed by Michael Ellerman
Browse files

powerpc: unrel_branch_check.sh: enable the use of llvm-objdump v9, 10 or 11 



Currently, using llvm-objtool, this script just silently succeeds without
actually do the intended checking.  So this updates it to work properly.

Firstly, llvm-objdump does not add target symbol names to the end
of branches in its asm output, so we have to drop the branch to
__start_initialization_multiplatform using its address.

Secondly, v9 and 10 specify branch targets as .+<offset>, so we convert
those to actual addresses.

Thirdly, v10 and 11 error out on a vmlinux if given the -R option
complaining that it is "not a dynamic object".  The -R does not make
any difference to the asm output, so remove it.

Lastly, v11 produces asm that is very similar to Gnu objtool (at least
as far as branches are concerned), so no further changes are necessary
to make it work.

Signed-off-by: default avatarStephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: default avatarMichael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200812081036.7969-3-sfr@canb.auug.org.au
parent b71dca98

arch/powerpc/tools/unrel_branch_check.sh

+29 −5
Original line number Diff line number Diff line
@@ -18,12 +18,16 @@ if [ "$end_intr" = "0x" ]; then 
	exit 0

fi



$objdump -R -D --no-show-raw-insn --start-address="$kstart" --stop-address="$end_intr" "$vmlinux" |

# we know that there is a correct branch to

# __start_initialization_multiplatform, so find its address

# so we can exclude it.

sim=0x$($nm -p "$vmlinux" |

	sed -E -n '/\s+[[:alpha:]]\s+__start_initialization_multiplatform\s*$/{s///p;q}')



$objdump -D --no-show-raw-insn --start-address="$kstart" --stop-address="$end_intr" "$vmlinux" |

sed -E -n '

# match lines that start with a kernel address

/^c[0-9a-f]*:\s*b/ {

	# drop a target that we do not care about

	/\<__start_initialization_multiplatform>/d

	# drop branches via ctr or lr

	/\<b.?.?(ct|l)r/d

	# cope with some differences between Clang and GNU objdumps
@@ -33,14 +37,34 @@ sed -E -n ' 
	s/\s0x/ /

	s/://

	# format for the loop below

	s/^(\S+)\s+(\S+)\s+(\S+)\s*(\S*).*$/\1:\2:0x\3:\4/

	s/^(\S+)\s+(\S+)\s+(\S+)\s*(\S*).*$/\1:\2:\3:\4/

	# strip out condition registers

	s/:0xcr[0-7],/:0x/

	s/:cr[0-7],/:/

	p

}' | {



all_good=true

while IFS=: read -r from branch to sym; do

	case "$to" in

	c*)	to="0x$to"

		;;

	.+*)

		to=${to#.+}

		if [ "$branch" = 'b' ]; then

			if (( to >= 0x2000000 )); then

				to=$(( to - 0x4000000 ))

			fi

		elif (( to >= 0x8000 )); then

			to=$(( to - 0x10000 ))

		fi

		printf -v to '0x%x' $(( "0x$from" + to ))

		;;

	*)	printf 'Unkown branch format\n'

		;;

	esac

	if [ "$to" = "$sim" ]; then

		continue

	fi

	if (( to > end_intr )); then

		if $all_good; then

			printf '%s\n' 'WARNING: Unrelocated relative branches'

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