name : decode_stacktrace.sh #!/bin/bash # SPDX-License-Identifier: GPL-2.0 # (c) 2014, Sasha Levin <sasha.levin@oracle.com> #set -x usage() { echo "Usage:" echo " $0 -r <release> | <vmlinux> [<base path>|auto] [<modules path>]" } # Try to find a Rust demangler if type llvm-cxxfilt >/dev/null 2>&1 ; then cppfilt=llvm-cxxfilt elif type c++filt >/dev/null 2>&1 ; then cppfilt=c++filt cppfilt_opts=-i fi UTIL_SUFFIX= if [[ -z ${LLVM:-} ]]; then UTIL_PREFIX=${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} if [[ $1 == "-r" ]] ; then vmlinux="" basepath="auto" modpath="" release=$2 for fn in {,/usr/lib/debug}/boot/vmlinux-$release{,.debug} /lib/modules/$release{,/build}/vmlinux ; do if [ -e "$fn" ] ; then vmlinux=$fn break fi done if [[ $vmlinux == "" ]] ; then echo "ERROR! vmlinux image for release $release is not found" >&2 usage exit 2 fi else vmlinux=$1 basepath=${2-auto} modpath=$3 release="" debuginfod= # Can we use debuginfod-find? if type debuginfod-find >/dev/null 2>&1 ; then debuginfod=${1-only} fi if [[ $vmlinux == "" && -z $debuginfod ]] ; then echo "ERROR! vmlinux image must be specified" >&2 usage exit 1 fi fi declare aarray_support=true declare -A cache 2>/dev/null if [[ $? != 0 ]]; then aarray_support=false else declare -A modcache fi find_module() { if [[ -n $debuginfod ]] ; then if [[ -n $modbuildid ]] ; then debuginfod-find debuginfo $modbuildid && return fi # Only using debuginfod so don't try to find vmlinux module path if [[ $debuginfod == "only" ]] ; then return fi fi if [[ "$modpath" != "" ]] ; then for fn in $(find "$modpath" -name "${module//_/[-_]}.ko*") ; do if ${READELF} -WS "$fn" | grep -qwF .debug_line ; then echo $fn return fi done return 1 fi modpath=$(dirname "$vmlinux") find_module && return if [[ $release == "" ]] ; then release=$(gdb -ex 'print init_uts_ns.name.release' -ex 'quit' -quiet -batch "$vmlinux" 2>/dev/null | sed -n 's/\$1 = "\(.*\)".*/\1/p') fi for dn in {/usr/lib/debug,}/lib/modules/$release ; do if [ -e "$dn" ] ; then modpath="$dn" find_module && return fi done modpath="" return 1 } parse_symbol() { # The structure of symbol at this point is: # ([name]+[offset]/[total length]) # # For example: # do_basic_setup+0x9c/0xbf if [[ $module == "" ]] ; then local objfile=$vmlinux elif [[ $aarray_support == true && "${modcache[$module]+isset}" == "isset" ]]; then local objfile=${modcache[$module]} else local objfile=$(find_module) if [[ $objfile == "" ]] ; then echo "WARNING! Modules path isn't set, but is needed to parse this symbol" >&2 return fi if [[ $aarray_support == true ]]; then modcache[$module]=$objfile fi fi # Remove the englobing parenthesis symbol=${symbol#\(} symbol=${symbol%\)} # Strip segment local segment if [[ $symbol == *:* ]] ; then segment=${symbol%%:*}: symbol=${symbol#*:} fi # Strip the symbol name so that we could look it up local name=${symbol%+*} # Use 'nm vmlinux' to figure out the base address of said symbol. # It's actually faster to call it every time than to load it # all into bash. if [[ $aarray_support == true && "${cache[$module,$name]+isset}" == "isset" ]]; then local base_addr=${cache[$module,$name]} else local base_addr=$(nm "$objfile" 2>/dev/null | awk '$3 == "'$name'" && ($2 == "t" || $2 == "T") {print $1; exit}') if [[ $base_addr == "" ]] ; then # address not found return fi if [[ $aarray_support == true ]]; then cache[$module,$name]="$base_addr" fi fi # Let's start doing the math to get the exact address into the # symbol. First, strip out the symbol total length. local expr=${symbol%/*} # Now, replace the symbol name with the base address we found # before. expr=${expr/$name/0x$base_addr} # Evaluate it to find the actual address expr=$((expr)) local address=$(printf "%x\n" "$expr") # Pass it to addr2line to get filename and line number # Could get more than one result if [[ $aarray_support == true && "${cache[$module,$address]+isset}" == "isset" ]]; then local code=${cache[$module,$address]} else local code=$(${ADDR2LINE} -i -e "$objfile" "$address" 2>/dev/null) if [[ $aarray_support == true ]]; then cache[$module,$address]=$code fi fi # addr2line doesn't return a proper error code if it fails, so # we detect it using the value it prints so that we could preserve # the offset/size into the function and bail out if [[ $code == "??:0" ]]; then return fi # Strip out the base of the path on each line code=$(while read -r line; do echo "${line#$basepath/}"; done <<< "$code") # In the case of inlines, move everything to same line code=${code//$'\n'/' '} # Demangle if the name looks like a Rust symbol and if # we got a Rust demangler if [[ $name =~ ^_R && $cppfilt != "" ]] ; then name=$("$cppfilt" "$cppfilt_opts" "$name") fi # Replace old address with pretty line numbers symbol="$segment$name ($code)" } debuginfod_get_vmlinux() { local vmlinux_buildid=${1##* } if [[ $vmlinux != "" ]]; then return fi if [[ $vmlinux_buildid =~ ^[0-9a-f]+ ]]; then vmlinux=$(debuginfod-find debuginfo $vmlinux_buildid) if [[ $? -ne 0 ]] ; then echo "ERROR! vmlinux image not found via debuginfod-find" >&2 usage exit 2 fi return fi echo "ERROR! Build ID for vmlinux not found. Try passing -r or specifying vmlinux" >&2 usage exit 2 } decode_code() { local scripts=`dirname "${BASH_SOURCE[0]}"` echo "$1" | $scripts/decodecode } handle_line() { if [[ $basepath == "auto" && $vmlinux != "" ]] ; then module="" symbol="kernel_init+0x0/0x0" parse_symbol basepath=${symbol#kernel_init (} basepath=${basepath%/init/main.c:*)} fi local words # Tokenize read -a words <<<"$1" # Remove hex numbers. Do it ourselves until it happens in the # kernel # We need to know the index of the last element before we # remove elements because arrays are sparse local last=$(( ${#words[@]} - 1 )) for i in "${!words[@]}"; do # Remove the address if [[ ${words[$i]} =~ \[\<([^]]+)\>\] ]]; then unset words[$i] fi # Format timestamps with tabs if [[ ${words[$i]} == \[ && ${words[$i+1]} == *\] ]]; then unset words[$i] words[$i+1]=$(printf "[%13s\n" "${words[$i+1]}") fi done if [[ ${words[$last]} =~ ^[0-9a-f]+\] ]]; then words[$last-1]="${words[$last-1]} ${words[$last]}" unset words[$last] last=$(( $last - 1 )) fi if [[ ${words[$last]} =~ \[([^]]+)\] ]]; then module=${words[$last]} module=${module#\[} module=${module%\]} modbuildid=${module#* } module=${module% *} if [[ $modbuildid == $module ]]; then modbuildid= fi symbol=${words[$last-1]} unset words[$last-1] else # The symbol is the last element, process it symbol=${words[$last]} module= modbuildid= fi unset words[$last] parse_symbol # modifies $symbol # Add up the line number to the symbol echo "${words[@]}" "$symbol $module" } while read line; do # Strip unexpected carriage return at end of line line=${line%$'\r'} # Let's see if we have an address in the line if [[ $line =~ \[\<([^]]+)\>\] ]] || [[ $line =~ [^+\ ]+\+0x[0-9a-f]+/0x[0-9a-f]+ ]]; then # Translate address to line numbers handle_line "$line" # Is it a code line? elif [[ $line == *Code:* ]]; then decode_code "$line" # Is it a version line? elif [[ -n $debuginfod && $line =~ PID:\ [0-9]+\ Comm: ]]; then debuginfod_get_vmlinux "$line" else # Nothing special in this line, show it as is echo "$line" fi done