1 files changed, 295 insertions, 0 deletions
diff --git a/scripts/faddr2line b/scripts/faddr2line
new file mode 100755
index 000000000..0e73aca4f
--- /dev/null
+++ b/scripts/faddr2line
@@ -0,0 +1,295 @@
+#!/bin/bash
+# SPDX-License-Identifier: GPL-2.0
+#
+# Translate stack dump function offsets.
+#
+# addr2line doesn't work with KASLR addresses.  This works similarly to
+# addr2line, but instead takes the 'func+0x123' format as input:
+#
+#   $ ./scripts/faddr2line ~/k/vmlinux meminfo_proc_show+0x5/0x568
+#   meminfo_proc_show+0x5/0x568:
+#   meminfo_proc_show at fs/proc/meminfo.c:27
+#
+# If the address is part of an inlined function, the full inline call chain is
+# printed:
+#
+#   $ ./scripts/faddr2line ~/k/vmlinux native_write_msr+0x6/0x27
+#   native_write_msr+0x6/0x27:
+#   arch_static_branch at arch/x86/include/asm/msr.h:121
+#    (inlined by) static_key_false at include/linux/jump_label.h:125
+#    (inlined by) native_write_msr at arch/x86/include/asm/msr.h:125
+#
+# The function size after the '/' in the input is optional, but recommended.
+# It's used to help disambiguate any duplicate symbol names, which can occur
+# rarely.  If the size is omitted for a duplicate symbol then it's possible for
+# multiple code sites to be printed:
+#
+#   $ ./scripts/faddr2line ~/k/vmlinux raw_ioctl+0x5
+#   raw_ioctl+0x5/0x20:
+#   raw_ioctl at drivers/char/raw.c:122
+#
+#   raw_ioctl+0x5/0xb1:
+#   raw_ioctl at net/ipv4/raw.c:876
+#
+# Multiple addresses can be specified on a single command line:
+#
+#   $ ./scripts/faddr2line ~/k/vmlinux type_show+0x10/45 free_reserved_area+0x90
+#   type_show+0x10/0x2d:
+#   type_show at drivers/video/backlight/backlight.c:213
+#
+#   free_reserved_area+0x90/0x123:
+#   free_reserved_area at mm/page_alloc.c:6429 (discriminator 2)
+
+
+set -o errexit
+set -o nounset
+
+usage() {
+	echo "usage: faddr2line [--list] <object file> <func+offset> <func+offset>..." >&2
+	exit 1
+}
+
+warn() {
+	echo "$1" >&2
+}
+
+die() {
+	echo "ERROR: $1" >&2
+	exit 1
+}
+
+READELF="${CROSS_COMPILE:-}readelf"
+ADDR2LINE="${CROSS_COMPILE:-}addr2line"
+AWK="awk"
+GREP="grep"
+
+command -v ${AWK} >/dev/null 2>&1 || die "${AWK} isn't installed"
+command -v ${READELF} >/dev/null 2>&1 || die "${READELF} isn't installed"
+command -v ${ADDR2LINE} >/dev/null 2>&1 || die "${ADDR2LINE} isn't installed"
+
+# Try to figure out the source directory prefix so we can remove it from the
+# addr2line output.  HACK ALERT: This assumes that start_kernel() is in
+# init/main.c!  This only works for vmlinux.  Otherwise it falls back to
+# printing the absolute path.
+find_dir_prefix() {
+	local objfile=$1
+
+	local start_kernel_addr=$(${READELF} --symbols --wide $objfile | sed 's/\[.*\]//' |
+		${AWK} '$8 == "start_kernel" {printf "0x%s", $2}')
+	[[ -z $start_kernel_addr ]] && return
+
+	local file_line=$(${ADDR2LINE} -e $objfile $start_kernel_addr)
+	[[ -z $file_line ]] && return
+
+	local prefix=${file_line%init/main.c:*}
+	if [[ -z $prefix ]] || [[ $prefix = $file_line ]]; then
+		return
+	fi
+
+	DIR_PREFIX=$prefix
+	return 0
+}
+
+__faddr2line() {
+	local objfile=$1
+	local func_addr=$2
+	local dir_prefix=$3
+	local print_warnings=$4
+
+	local sym_name=${func_addr%+*}
+	local func_offset=${func_addr#*+}
+	func_offset=${func_offset%/*}
+	local user_size=
+	local file_type
+	local is_vmlinux=0
+	[[ $func_addr =~ "/" ]] && user_size=${func_addr#*/}
+
+	if [[ -z $sym_name ]] || [[ -z $func_offset ]] || [[ $sym_name = $func_addr ]]; then
+		warn "bad func+offset $func_addr"
+		DONE=1
+		return
+	fi
+
+	# vmlinux uses absolute addresses in the section table rather than
+	# section offsets.
+	local file_type=$(${READELF} --file-header $objfile |
+		${AWK} '$1 == "Type:" { print $2; exit }')
+	if [[ $file_type = "EXEC" ]] || [[ $file_type == "DYN" ]]; then
+		is_vmlinux=1
+	fi
+
+	# Go through each of the object's symbols which match the func name.
+	# In rare cases there might be duplicates, in which case we print all
+	# matches.
+	while read line; do
+		local fields=($line)
+		local sym_addr=0x${fields[1]}
+		local sym_elf_size=${fields[2]}
+		local sym_sec=${fields[6]}
+		local sec_size
+		local sec_name
+
+		# Get the section size:
+		sec_size=$(${READELF} --section-headers --wide $objfile |
+			sed 's/\[ /\[/' |
+			${AWK} -v sec=$sym_sec '$1 == "[" sec "]" { print "0x" $6; exit }')
+
+		if [[ -z $sec_size ]]; then
+			warn "bad section size: section: $sym_sec"
+			DONE=1
+			return
+		fi
+
+		# Get the section name:
+		sec_name=$(${READELF} --section-headers --wide $objfile |
+			sed 's/\[ /\[/' |
+			${AWK} -v sec=$sym_sec '$1 == "[" sec "]" { print $2; exit }')
+
+		if [[ -z $sec_name ]]; then
+			warn "bad section name: section: $sym_sec"
+			DONE=1
+			return
+		fi
+
+		# Calculate the symbol size.
+		#
+		# Unfortunately we can't use the ELF size, because kallsyms
+		# also includes the padding bytes in its size calculation.  For
+		# kallsyms, the size calculation is the distance between the
+		# symbol and the next symbol in a sorted list.
+		local sym_size
+		local cur_sym_addr
+		local found=0
+		while read line; do
+			local fields=($line)
+			cur_sym_addr=0x${fields[1]}
+			local cur_sym_elf_size=${fields[2]}
+			local cur_sym_name=${fields[7]:-}
+
+			if [[ $cur_sym_addr = $sym_addr ]] &&
+			   [[ $cur_sym_elf_size = $sym_elf_size ]] &&
+			   [[ $cur_sym_name = $sym_name ]]; then
+				found=1
+				continue
+			fi
+
+			if [[ $found = 1 ]]; then
+				sym_size=$(($cur_sym_addr - $sym_addr))
+				[[ $sym_size -lt $sym_elf_size ]] && continue;
+				found=2
+				break
+			fi
+		done < <(${READELF} --symbols --wide $objfile | sed 's/\[.*\]//' | ${AWK} -v sec=$sym_sec '$7 == sec' | sort --key=2)
+
+		if [[ $found = 0 ]]; then
+			warn "can't find symbol: sym_name: $sym_name sym_sec: $sym_sec sym_addr: $sym_addr sym_elf_size: $sym_elf_size"
+			DONE=1
+			return
+		fi
+
+		# If nothing was found after the symbol, assume it's the last
+		# symbol in the section.
+		[[ $found = 1 ]] && sym_size=$(($sec_size - $sym_addr))
+
+		if [[ -z $sym_size ]] || [[ $sym_size -le 0 ]]; then
+			warn "bad symbol size: sym_addr: $sym_addr cur_sym_addr: $cur_sym_addr"
+			DONE=1
+			return
+		fi
+
+		sym_size=0x$(printf %x $sym_size)
+
+		# Calculate the address from user-supplied offset:
+		local addr=$(($sym_addr + $func_offset))
+		if [[ -z $addr ]] || [[ $addr = 0 ]]; then
+			warn "bad address: $sym_addr + $func_offset"
+			DONE=1
+			return
+		fi
+		addr=0x$(printf %x $addr)
+
+		# If the user provided a size, make sure it matches the symbol's size:
+		if [[ -n $user_size ]] && [[ $user_size -ne $sym_size ]]; then
+			[[ $print_warnings = 1 ]] &&
+				echo "skipping $sym_name address at $addr due to size mismatch ($user_size != $sym_size)"
+			continue;
+		fi
+
+		# Make sure the provided offset is within the symbol's range:
+		if [[ $func_offset -gt $sym_size ]]; then
+			[[ $print_warnings = 1 ]] &&
+				echo "skipping $sym_name address at $addr due to size mismatch ($func_offset > $sym_size)"
+			continue
+		fi
+
+		# In case of duplicates or multiple addresses specified on the
+		# cmdline, separate multiple entries with a blank line:
+		[[ $FIRST = 0 ]] && echo
+		FIRST=0
+
+		echo "$sym_name+$func_offset/$sym_size:"
+
+		# Pass section address to addr2line and strip absolute paths
+		# from the output:
+		local args="--functions --pretty-print --inlines --exe=$objfile"
+		[[ $is_vmlinux = 0 ]] && args="$args --section=$sec_name"
+		local output=$(${ADDR2LINE} $args $addr | sed "s; $dir_prefix\(\./\)*; ;")
+		[[ -z $output ]] && continue
+
+		# Default output (non --list):
+		if [[ $LIST = 0 ]]; then
+			echo "$output" | while read -r line
+			do
+				echo $line
+			done
+			DONE=1;
+			continue
+		fi
+
+		# For --list, show each line with its corresponding source code:
+		echo "$output" | while read -r line
+		do
+			echo
+			echo $line
+			n=$(echo $line | sed 's/.*:\([0-9]\+\).*/\1/g')
+			n1=$[$n-5]
+			n2=$[$n+5]
+			f=$(echo $line | sed 's/.*at \(.\+\):.*/\1/g')
+			${AWK} 'NR>=strtonum("'$n1'") && NR<=strtonum("'$n2'") { if (NR=='$n') printf(">%d<", NR); else printf(" %d ", NR); printf("\t%s\n", $0)}' $f
+		done
+
+		DONE=1
+
+	done < <(${READELF} --symbols --wide $objfile | sed 's/\[.*\]//' | ${AWK} -v fn=$sym_name '$4 == "FUNC" && $8 == fn')
+}
+
+[[ $# -lt 2 ]] && usage
+
+objfile=$1
+
+LIST=0
+[[ "$objfile" == "--list" ]] && LIST=1 && shift && objfile=$1
+
+[[ ! -f $objfile ]] && die "can't find objfile $objfile"
+shift
+
+${READELF} --section-headers --wide $objfile | ${GREP} -q '\.debug_info' || die "CONFIG_DEBUG_INFO not enabled"
+
+DIR_PREFIX=supercalifragilisticexpialidocious
+find_dir_prefix $objfile
+
+FIRST=1
+while [[ $# -gt 0 ]]; do
+	func_addr=$1
+	shift
+
+	# print any matches found
+	DONE=0
+	__faddr2line $objfile $func_addr $DIR_PREFIX 0
+
+	# if no match was found, print warnings
+	if [[ $DONE = 0 ]]; then
+		__faddr2line $objfile $func_addr $DIR_PREFIX 1
+		warn "no match for $func_addr"
+	fi
+done