1 files changed, 72 insertions, 53 deletions
diff --git a/arch/powerpc/tools/unrel_branch_check.sh b/arch/powerpc/tools/unrel_branch_check.sh
index 6e6a30aea3ed..8301efee1e6c 100755
--- a/arch/powerpc/tools/unrel_branch_check.sh
+++ b/arch/powerpc/tools/unrel_branch_check.sh
@@ -1,60 +1,79 @@
-# Copyright © 2016 IBM Corporation
+#!/bin/bash
+# SPDX-License-Identifier: GPL-2.0+
+# Copyright © 2016,2020 IBM Corporation
 #
-# This program is free software; you can redistribute it and/or
-# modify it under the terms of the GNU General Public License
-# as published by the Free Software Foundation; either version
-# 2 of the License, or (at your option) any later version.
-#
-# This script checks the relocations of a vmlinux for "suspicious"
-# branches from unrelocated code (head_64.S code).
-
-# Turn this on if you want more debug output:
-# set -x
+# This script checks the unrelocated code of a vmlinux for "suspicious"
+# branches to relocated code (head_64.S code).
 
-# Have Kbuild supply the path to objdump so we handle cross compilation.
+# Have Kbuild supply the path to objdump and nm so we handle cross compilation.
 objdump="$1"
-vmlinux="$2"
-
-#__end_interrupts should be located within the first 64K
-
-end_intr=0x$(
-$objdump -R "$vmlinux" -d --start-address=0xc000000000000000           \
-		 --stop-address=0xc000000000010000 |
-grep '\<__end_interrupts>:' |
-awk '{print $1}'
-)
-
-BRANCHES=$(
-$objdump -R "$vmlinux" -D --start-address=0xc000000000000000           \
-		--stop-address=${end_intr} |
-grep -e "^c[0-9a-f]*:[[:space:]]*\([0-9a-f][0-9a-f][[:space:]]\)\{4\}[[:space:]]*b" |
-grep -v '\<__start_initialization_multiplatform>' |
-grep -v -e 'b.\?.\?ctr' |
-grep -v -e 'b.\?.\?lr' |
-sed -e 's/\bbt.\?[[:space:]]*[[:digit:]][[:digit:]]*,/beq/' \
-	-e 's/\bbf.\?[[:space:]]*[[:digit:]][[:digit:]]*,/bne/' \
-	-e 's/[[:space:]]0x/ /' \
-	-e 's/://' |
-awk '{ print $1 ":" $6 ":0x" $7 ":" $8 " "}'
-)
-
-for tuple in $BRANCHES
-do
-	from=`echo $tuple | cut -d':' -f1`
-	branch=`echo $tuple | cut -d':' -f2`
-	to=`echo $tuple | cut -d':' -f3 | sed 's/cr[0-7],//'`
-	sym=`echo $tuple | cut -d':' -f4`
-
-	if (( $to > $end_intr ))
-	then
-		if [ -z "$bad_branches" ]; then
-			echo "WARNING: Unrelocated relative branches"
-			bad_branches="yes"
+nm="$2"
+vmlinux="$3"
+
+kstart=0xc000000000000000
+
+end_intr=0x$($nm -p "$vmlinux" |
+	sed -E -n '/\s+[[:alpha:]]\s+__end_interrupts\s*$/{s///p;q}')
+if [ "$end_intr" = "0x" ]; then
+	exit 0
+fi
+
+# 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 branches via ctr or lr
+	/\<b.?.?(ct|l)r/d
+	# cope with some differences between Clang and GNU objdumps
+	s/\<bt.?\s*[[:digit:]]+,/beq/
+	s/\<bf.?\s*[[:digit:]]+,/bne/
+	# tidy up
+	s/\s0x/ /
+	s/://
+	# format for the loop below
+	s/^(\S+)\s+(\S+)\s+(\S+)\s*(\S*).*$/\1:\2:\3:\4/
+	# strip out condition registers
+	s/:cr[0-7],/:/
+	p
+}' | {
+
+all_good=true
+while IFS=: read -r from branch to sym; do
+	case "$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 $all_good; then
+			printf '%s\n' 'WARNING: Unrelocated relative branches'
+			all_good=false
 		fi
-		echo "$from $branch-> $to $sym"
+		printf '%s %s-> %s %s\n' "$from" "$branch" "$to" "$sym"
 	fi
 done
 
-if [ -z "$bad_branches" ]; then
-	exit 0
-fi
+$all_good
+
+}