1 files changed, 380 insertions, 0 deletions
diff --git a/scripts/faddr2line b/scripts/faddr2line
new file mode 100755
index 000000000000..622875396bcf
--- /dev/null
+++ b/scripts/faddr2line
@@ -0,0 +1,380 @@
+#!/usr/bin/env 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: $1" >&2
+	exit 1
+}
+
+UTIL_SUFFIX=""
+if [[ "${LLVM:-}" == "" ]]; then
+	UTIL_PREFIX=${CROSS_COMPILE:-}
+else
+	UTIL_PREFIX=llvm-
+
+	if [[ "${LLVM}" == *"/" ]]; then
+		UTIL_PREFIX=${LLVM}${UTIL_PREFIX}
+	elif [[ "${LLVM}" == "-"* ]]; then
+		UTIL_SUFFIX=${LLVM}
+	fi
+fi
+
+READELF="${UTIL_PREFIX}readelf${UTIL_SUFFIX}"
+ADDR2LINE="${UTIL_PREFIX}addr2line${UTIL_SUFFIX}"
+AWK="awk"
+GREP="grep"
+
+# Enforce ASCII-only output from tools like readelf
+# ensuring sed processes strings correctly.
+export LANG=C
+
+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 start_kernel_addr=$(echo "${ELF_SYMS}" | sed 's/\[.*\]//' |
+		${AWK} '$8 == "start_kernel" {printf "0x%s", $2}')
+	[[ -z $start_kernel_addr ]] && return
+
+	run_addr2line ${start_kernel_addr} ""
+	[[ -z $ADDR2LINE_OUT ]] && return
+
+	local file_line=${ADDR2LINE_OUT#* at }
+	if [[ -z $file_line ]] || [[ $file_line = $ADDR2LINE_OUT ]]; then
+		return
+	fi
+	local prefix=${file_line%init/main.c:*}
+	if [[ -z $prefix ]] || [[ $prefix = $file_line ]]; then
+		return
+	fi
+
+	DIR_PREFIX=$prefix
+	return 0
+}
+
+run_readelf() {
+	local objfile=$1
+	local tmpfile
+	tmpfile=$(mktemp)
+
+	${READELF} --file-header --section-headers --symbols --wide "$objfile" > "$tmpfile"
+
+	# This assumes that readelf first prints the file header, then the section headers, then the symbols.
+	# Note: It seems that GNU readelf does not prefix section headers with the "There are X section headers"
+	# line when multiple options are given, so let's also match with the "Section Headers:" line.
+	ELF_FILEHEADER=$(sed -n '/There are [0-9]* section headers, starting at offset\|Section Headers:/q;p' "$tmpfile")
+	ELF_SECHEADERS=$(sed -n '/There are [0-9]* section headers, starting at offset\|Section Headers:/,$p' "$tmpfile" | sed -n '/Symbol table .* contains [0-9]* entries:/q;p')
+	ELF_SYMS=$(sed -n '/Symbol table .* contains [0-9]* entries:/,$p' "$tmpfile")
+
+	rm -f -- "$tmpfile"
+}
+
+check_vmlinux() {
+	# vmlinux uses absolute addresses in the section table rather than
+	# section offsets.
+	IS_VMLINUX=0
+	local file_type=$(echo "${ELF_FILEHEADER}" |
+		${AWK} '$1 == "Type:" { print $2; exit }')
+	if [[ $file_type = "EXEC" ]] || [[ $file_type == "DYN" ]]; then
+		IS_VMLINUX=1
+	fi
+}
+
+init_addr2line() {
+	local objfile=$1
+
+	check_vmlinux
+
+	ADDR2LINE_ARGS="--functions --pretty-print --inlines --addresses --exe=$objfile"
+	if [[ $IS_VMLINUX = 1 ]]; then
+		# If the executable file is vmlinux, we don't pass section names to
+		# addr2line, so we can launch it now as a single long-running process.
+		coproc ADDR2LINE_PROC (${ADDR2LINE} ${ADDR2LINE_ARGS})
+	fi
+}
+
+run_addr2line() {
+	local addr=$1
+	local sec_name=$2
+
+	if [[ $IS_VMLINUX = 1 ]]; then
+		# We send to the addr2line process: (1) the address, then (2) a sentinel
+		# value, i.e., something that can't be interpreted as a valid address
+		# (i.e., ","). This causes addr2line to write out: (1) the answer for
+		# our address, then (2) either "?? ??:0" or "0x0...0: ..." (if
+		# using binutils' addr2line), or "," (if using LLVM's addr2line).
+		echo ${addr} >& "${ADDR2LINE_PROC[1]}"
+		echo "," >& "${ADDR2LINE_PROC[1]}"
+		local first_line
+		read -r first_line <& "${ADDR2LINE_PROC[0]}"
+		ADDR2LINE_OUT=$(echo "${first_line}" | sed 's/^0x[0-9a-fA-F]*: //')
+		while read -r line <& "${ADDR2LINE_PROC[0]}"; do
+			if [[ "$line" == "?? ??:0" ]] || [[ "$line" == "," ]] || [[ $(echo "$line" | ${GREP} "^0x00*: ") ]]; then
+				break
+			fi
+			ADDR2LINE_OUT+=$'\n'$(echo "$line" | sed 's/^0x[0-9a-fA-F]*: //')
+		done
+	else
+		# Run addr2line as a single invocation.
+		local sec_arg
+		[[ -z $sec_name ]] && sec_arg="" || sec_arg="--section=${sec_name}"
+		ADDR2LINE_OUT=$(${ADDR2LINE} ${ADDR2LINE_ARGS} ${sec_arg} ${addr} | sed 's/^0x[0-9a-fA-F]*: //')
+	fi
+}
+
+__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=
+	[[ $func_addr =~ "/" ]] && user_size=${func_addr#*/}
+
+	if [[ -z $sym_name ]] || [[ -z $func_offset ]] || [[ $sym_name = $func_addr ]]; then
+		warn "bad func+offset $func_addr"
+		DONE=1
+		return
+	fi
+
+	# Go through each of the object's symbols which match the func name.
+	# In rare cases there might be duplicates, in which case we print all
+	# matches.
+	while read line; do
+		local fields=($line)
+		local sym_addr=0x${fields[1]}
+		local sym_elf_size=${fields[2]}
+		local sym_sec=${fields[6]}
+		local sec_size
+		local sec_name
+
+		# Get the section size:
+		sec_size=$(echo "${ELF_SECHEADERS}" | sed 's/\[ /\[/' |
+			${AWK} -v sec=$sym_sec '$1 == "[" sec "]" { print "0x" $6; exit }')
+
+		if [[ -z $sec_size ]]; then
+			warn "bad section size: section: $sym_sec"
+			DONE=1
+			return
+		fi
+
+		# Get the section name:
+		sec_name=$(echo "${ELF_SECHEADERS}" | 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]:-}
+
+			# is_mapping_symbol(cur_sym_name)
+			if [[ ${cur_sym_name} =~ ^(\.L|L0|\$) ]]; then
+				continue
+			fi
+
+			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 $sym_elf_size ]] && continue;
+				found=2
+				break
+			fi
+		done < <(echo "${ELF_SYMS}" | 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:
+		run_addr2line $addr $sec_name
+		local output=$(echo "${ADDR2LINE_OUT}" | 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)}' $f
+		done
+
+		DONE=1
+
+	done < <(echo "${ELF_SYMS}" | sed 's/\[.*\]//' | ${AWK} -v fn=$sym_name '$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
+
+run_readelf $objfile
+
+echo "${ELF_SECHEADERS}" | ${GREP} -q '\.debug_info' || die "CONFIG_DEBUG_INFO not enabled"
+
+init_addr2line $objfile
+
+DIR_PREFIX=supercalifragilisticexpialidocious
+find_dir_prefix
+
+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