#!/bin/bash # SPDX-License-Identifier: GPL-2.0
java.lang.NullPointerException # Translate stack dump function offsets.
java.lang.NullPointerException # addr2line doesn't work with KASLR addresses. This works similarly to # addr2line, but instead takes the 'func+0x123' format as input:
java.lang.NullPointerException # $ ./scripts/faddr2line ~/k/vmlinux meminfo_proc_show+0x5/0x568 # meminfo_proc_show+0x5/0x568: # meminfo_proc_show at fs/proc/meminfo.c:27
java.lang.NullPointerException # If the address is part of an inlined function, the full inline call chain is # printed:
java.lang.NullPointerException # $ ./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
java.lang.NullPointerException # 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:
java.lang.NullPointerException # $ ./scripts/faddr2line ~/k/vmlinux raw_ioctl+0x5 # raw_ioctl+0x5/0x20: # raw_ioctl at drivers/char/raw.c:122
java.lang.NullPointerException # raw_ioctl+0x5/0xb1: # raw_ioctl at net/ipv4/raw.c:876
java.lang.NullPointerException # Multiple addresses can be specified on a single command line:
java.lang.NullPointerException # $ ./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
java.lang.NullPointerException # free_reserved_area+0x90/0x123: # free_reserved_area at mm/page_alloc.c:6429 (discriminator 2)
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 $start_kernel_addr ]] && return
local file_line=${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 return0
}
run_readelf() {
local objfile=$1
local out=$(${READELF} --file-header --section-headers --symbols --wide $objfile)
# This assumes that readelf first prints the file header, then the section headers, then the symbols. # Note: It seems that GNU readelf does not prefix section headers with the "There are X section headers" # line when multiple options are given, so let's also match with the "Section Headers:" line.
ELF_FILEHEADER=$(echo "${out}" | sed -n '/There are [0-9]* section headers, starting at offset\|Section Headers:/q;p')
ELF_SECHEADERS=$(echo "${out}" | sed -n '/There are [0-9]* section headers, starting at offset\|Section Headers:/,$p' | sed -n '/Symbol table .* contains [0-9]* entries:/q;p')
ELF_SYMS=$(echo "${out}" | sed -n '/Symbol table .* contains [0-9]* entries:/,$p')
}
check_vmlinux() { # vmlinux uses absolute addresses in the section table rather than # section offsets.
IS_VMLINUX=0
local file_type=$(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: $sym_sec"
DONE=1 return
fi
# Calculate the symbol size.
java.lang.NullPointerException # Unfortunately we can't use the ELF size, because kallsyms # also includes the padding bytes in its size calculation. For # kallsyms, the size calculation is the distance between the # symbol and the next symbol in a sorted list.
local sym_size
local cur_sym_addr
local found=0 while read line; do
local fields=($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
