[linux-block.git] / scripts / faddr2line

#!/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"

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 | ${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 | ${AWK} -v sec=$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 | ${AWK} -v fn=$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

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
Commit	Line	Data
67326666	1	#!/bin/bash
b2441318	2	# SPDX-License-Identifier: GPL-2.0
67326666 JP	3	#
	4	# Translate stack dump function offsets.
	5	#
	6	# addr2line doesn't work with KASLR addresses. This works similarly to
	7	# addr2line, but instead takes the 'func+0x123' format as input:
	8	#
	9	# $ ./scripts/faddr2line ~/k/vmlinux meminfo_proc_show+0x5/0x568
	10	# meminfo_proc_show+0x5/0x568:
	11	# meminfo_proc_show at fs/proc/meminfo.c:27
	12	#
	13	# If the address is part of an inlined function, the full inline call chain is
	14	# printed:
	15	#
	16	# $ ./scripts/faddr2line ~/k/vmlinux native_write_msr+0x6/0x27
	17	# native_write_msr+0x6/0x27:
	18	# arch_static_branch at arch/x86/include/asm/msr.h:121
	19	# (inlined by) static_key_false at include/linux/jump_label.h:125
	20	# (inlined by) native_write_msr at arch/x86/include/asm/msr.h:125
	21	#
	22	# The function size after the '/' in the input is optional, but recommended.
	23	# It's used to help disambiguate any duplicate symbol names, which can occur
	24	# rarely. If the size is omitted for a duplicate symbol then it's possible for
	25	# multiple code sites to be printed:
	26	#
	27	# $ ./scripts/faddr2line ~/k/vmlinux raw_ioctl+0x5
	28	# raw_ioctl+0x5/0x20:
	29	# raw_ioctl at drivers/char/raw.c:122
	30	#
	31	# raw_ioctl+0x5/0xb1:
	32	# raw_ioctl at net/ipv4/raw.c:876
	33	#
	34	# Multiple addresses can be specified on a single command line:
	35	#
	36	# $ ./scripts/faddr2line ~/k/vmlinux type_show+0x10/45 free_reserved_area+0x90
	37	# type_show+0x10/0x2d:
	38	# type_show at drivers/video/backlight/backlight.c:213
	39	#
	40	# free_reserved_area+0x90/0x123:
	41	# free_reserved_area at mm/page_alloc.c:6429 (discriminator 2)
	42
	43
	44	set -o errexit
	45	set -o nounset
	46
67326666	47	usage() {
689135f0	48	echo "usage: faddr2line [--list] <object file> <func+offset> <func+offset>..." >&2
67326666 JP	49	exit 1
	50	}
	51
	52	warn() {
	53	echo "$1" >&2
	54	}
	55
	56	die() {
	57	echo "ERROR: $1" >&2
	58	exit 1
	59	}
	60
1d1a0e7c JP	61	READELF="${CROSS_COMPILE:-}readelf"
	62	ADDR2LINE="${CROSS_COMPILE:-}addr2line"
	63	AWK="awk"
	64
	65	command -v ${AWK} >/dev/null 2>&1 \|\| die "${AWK} isn't installed"
	66	command -v ${READELF} >/dev/null 2>&1 \|\| die "${READELF} isn't installed"
	67	command -v ${ADDR2LINE} >/dev/null 2>&1 \|\| die "${ADDR2LINE} isn't installed"
	68
67326666 JP	69	# Try to figure out the source directory prefix so we can remove it from the
67326666 JP	70	# addr2line output. HACK ALERT: This assumes that start_kernel() is in
f5f67cc0	71	# init/main.c! This only works for vmlinux. Otherwise it falls back to
67326666 JP	72	# printing the absolute path.
	73	find_dir_prefix() {
	74	local objfile=$1
	75
1d1a0e7c	76	local start_kernel_addr=$(${READELF} --symbols --wide $objfile \| ${AWK} '$8 == "start_kernel" {printf "0x%s", $2}')
67326666 JP	77	[[ -z $start_kernel_addr ]] && return
67326666 JP	78
95a87982	79	local file_line=$(${ADDR2LINE} -e $objfile $start_kernel_addr)
67326666 JP	80	[[ -z $file_line ]] && return
	81
	82	local prefix=${file_line%init/main.c:*}
	83	if [[ -z $prefix ]] \|\| [[ $prefix = $file_line ]]; then
	84	return
	85	fi
	86
	87	DIR_PREFIX=$prefix
	88	return 0
	89	}
	90
	91	__faddr2line() {
	92	local objfile=$1
	93	local func_addr=$2
	94	local dir_prefix=$3
	95	local print_warnings=$4
	96
1d1a0e7c	97	local sym_name=${func_addr%+*}
dcea997b JP	98	local func_offset=${func_addr#*+}
dcea997b JP	99	func_offset=${func_offset%/*}
1d1a0e7c	100	local user_size=
dcea997b JP	101	local file_type
dcea997b JP	102	local is_vmlinux=0
1d1a0e7c	103	[[ $func_addr =~ "/" ]] && user_size=${func_addr#*/}
67326666	104
dcea997b	105	if [[ -z $sym_name ]] \|\| [[ -z $func_offset ]] \|\| [[ $sym_name = $func_addr ]]; then
67326666 JP	106	warn "bad func+offset $func_addr"
	107	DONE=1
	108	return
	109	fi
	110
dcea997b JP	111	# vmlinux uses absolute addresses in the section table rather than
	112	# section offsets.
	113	local file_type=$(${READELF} --file-header $objfile \|
	114	${AWK} '$1 == "Type:" { print $2; exit }')
b6a50688 JP	115	if [[ $file_type = "EXEC" ]] \|\| [[ $file_type == "DYN" ]]; then
	116	is_vmlinux=1
	117	fi
dcea997b	118
67326666	119	# Go through each of the object's symbols which match the func name.
1d1a0e7c JP	120	# In rare cases there might be duplicates, in which case we print all
	121	# matches.
	122	while read line; do
	123	local fields=($line)
	124	local sym_addr=0x${fields[1]}
	125	local sym_elf_size=${fields[2]}
	126	local sym_sec=${fields[6]}
dcea997b JP	127	local sec_size
dcea997b JP	128	local sec_name
1d1a0e7c JP	129
1d1a0e7c JP	130	# Get the section size:
dcea997b	131	sec_size=$(${READELF} --section-headers --wide $objfile \|
1d1a0e7c JP	132	sed 's/\[ /\[/' \|
	133	${AWK} -v sec=$sym_sec '$1 == "[" sec "]" { print "0x" $6; exit }')
	134
	135	if [[ -z $sec_size ]]; then
	136	warn "bad section size: section: $sym_sec"
	137	DONE=1
	138	return
	139	fi
	140
dcea997b JP	141	# Get the section name:
	142	sec_name=$(${READELF} --section-headers --wide $objfile \|
	143	sed 's/\[ /\[/' \|
	144	${AWK} -v sec=$sym_sec '$1 == "[" sec "]" { print $2; exit }')
	145
	146	if [[ -z $sec_name ]]; then
	147	warn "bad section name: section: $sym_sec"
	148	DONE=1
	149	return
	150	fi
	151
1d1a0e7c JP	152	# Calculate the symbol size.
	153	#
	154	# Unfortunately we can't use the ELF size, because kallsyms
	155	# also includes the padding bytes in its size calculation. For
	156	# kallsyms, the size calculation is the distance between the
	157	# symbol and the next symbol in a sorted list.
	158	local sym_size
	159	local cur_sym_addr
	160	local found=0
	161	while read line; do
	162	local fields=($line)
	163	cur_sym_addr=0x${fields[1]}
	164	local cur_sym_elf_size=${fields[2]}
	165	local cur_sym_name=${fields[7]:-}
	166
	167	if [[ $cur_sym_addr = $sym_addr ]] &&
	168	[[ $cur_sym_elf_size = $sym_elf_size ]] &&
	169	[[ $cur_sym_name = $sym_name ]]; then
	170	found=1
	171	continue
	172	fi
	173
	174	if [[ $found = 1 ]]; then
	175	sym_size=$(($cur_sym_addr - $sym_addr))
	176	[[ $sym_size -lt $sym_elf_size ]] && continue;
	177	found=2
	178	break
	179	fi
	180	done < <(${READELF} --symbols --wide $objfile \| ${AWK} -v sec=$sym_sec '$7 == sec' \| sort --key=2)
	181
	182	if [[ $found = 0 ]]; then
	183	warn "can't find symbol: sym_name: $sym_name sym_sec: $sym_sec sym_addr: $sym_addr sym_elf_size: $sym_elf_size"
	184	DONE=1
	185	return
	186	fi
	187
	188	# If nothing was found after the symbol, assume it's the last
	189	# symbol in the section.
	190	[[ $found = 1 ]] && sym_size=$(($sec_size - $sym_addr))
	191
efdb4167	192	if [[ -z $sym_size ]] \|\| [[ $sym_size -le 0 ]]; then
1d1a0e7c	193	warn "bad symbol size: sym_addr: $sym_addr cur_sym_addr: $cur_sym_addr"
efdb4167 JP	194	DONE=1
	195	return
	196	fi
1d1a0e7c	197
efdb4167	198	sym_size=0x$(printf %x $sym_size)
67326666	199
dcea997b JP	200	# Calculate the address from user-supplied offset:
dcea997b JP	201	local addr=$(($sym_addr + $func_offset))
67326666	202	if [[ -z $addr ]] \|\| [[ $addr = 0 ]]; then
dcea997b	203	warn "bad address: $sym_addr + $func_offset"
67326666 JP	204	DONE=1
	205	return
	206	fi
efdb4167	207	addr=0x$(printf %x $addr)
67326666	208
1d1a0e7c JP	209	# If the user provided a size, make sure it matches the symbol's size:
1d1a0e7c JP	210	if [[ -n $user_size ]] && [[ $user_size -ne $sym_size ]]; then
67326666	211	[[ $print_warnings = 1 ]] &&
1d1a0e7c	212	echo "skipping $sym_name address at $addr due to size mismatch ($user_size != $sym_size)"
67326666 JP	213	continue;
	214	fi
	215
1d1a0e7c	216	# Make sure the provided offset is within the symbol's range:
dcea997b	217	if [[ $func_offset -gt $sym_size ]]; then
67326666	218	[[ $print_warnings = 1 ]] &&
dcea997b	219	echo "skipping $sym_name address at $addr due to size mismatch ($func_offset > $sym_size)"
67326666 JP	220	continue
	221	fi
	222
1d1a0e7c JP	223	# In case of duplicates or multiple addresses specified on the
1d1a0e7c JP	224	# cmdline, separate multiple entries with a blank line:
67326666 JP	225	[[ $FIRST = 0 ]] && echo
	226	FIRST=0
	227
dcea997b	228	echo "$sym_name+$func_offset/$sym_size:"
6870c016	229
1d1a0e7c JP	230	# Pass section address to addr2line and strip absolute paths
1d1a0e7c JP	231	# from the output:
dcea997b JP	232	local args="--functions --pretty-print --inlines --exe=$objfile"
	233	[[ $is_vmlinux = 0 ]] && args="$args --section=$sec_name"
	234	local output=$(${ADDR2LINE} $args $addr \| sed "s; $dir_prefix\(\./\)*; ;")
1d1a0e7c JP	235	[[ -z $output ]] && continue
	236
	237	# Default output (non --list):
689135f0	238	if [[ $LIST = 0 ]]; then
1d1a0e7c	239	echo "$output" \| while read -r line
689135f0 PZI	240	do
	241	echo $line
	242	done
	243	DONE=1;
1d1a0e7c	244	continue
689135f0 PZI	245	fi
689135f0 PZI	246
1d1a0e7c JP	247	# For --list, show each line with its corresponding source code:
1d1a0e7c JP	248	echo "$output" \| while read -r line
6870c016	249	do
689135f0	250	echo
6870c016	251	echo $line
78eb0c63 CD	252	n=$(echo $line \| sed 's/.:\([0-9]\+\)./\1/g')
	253	n1=$[$n-5]
	254	n2=$[$n+5]
	255	f=$(echo $line \| sed 's/.at \(.\+\):./\1/g')
1d1a0e7c	256	${AWK} 'NR>=strtonum("'$n1'") && NR<=strtonum("'$n2'") { if (NR=='$n') printf(">%d<", NR); else printf(" %d ", NR); printf("\t%s\n", $0)}' $f
6870c016 CD	257	done
6870c016 CD	258
67326666 JP	259	DONE=1
67326666 JP	260
1d1a0e7c	261	done < <(${READELF} --symbols --wide $objfile \| ${AWK} -v fn=$sym_name '$4 == "FUNC" && $8 == fn')
67326666 JP	262	}
	263
	264	[[ $# -lt 2 ]] && usage
	265
	266	objfile=$1
689135f0 PZI	267
	268	LIST=0
	269	[[ "$objfile" == "--list" ]] && LIST=1 && shift && objfile=$1
	270
67326666 JP	271	[[ ! -f $objfile ]] && die "can't find objfile $objfile"
	272	shift
	273
	274	DIR_PREFIX=supercalifragilisticexpialidocious
	275	find_dir_prefix $objfile
	276
	277	FIRST=1
	278	while [[ $# -gt 0 ]]; do
	279	func_addr=$1
	280	shift
	281
	282	# print any matches found
	283	DONE=0
	284	__faddr2line $objfile $func_addr $DIR_PREFIX 0
	285
	286	# if no match was found, print warnings
	287	if [[ $DONE = 0 ]]; then
	288	__faddr2line $objfile $func_addr $DIR_PREFIX 1
	289	warn "no match for $func_addr"
	290	fi
	291	done