scripts/decode_stacktrace.sh

   1 #!/bin/bash
   2 # SPDX-License-Identifier: GPL-2.0
   3 # (c) 2014, Sasha Levin <sasha.levin@oracle.com>
   4 #set -x
   5
   6 usage() {
   7         echo "Usage:"
   8         echo "  $0 -r <release> | <vmlinux> [<base path>|auto] [<modules path>]"
   9 }
  10
  11 # Try to find a Rust demangler
  12 if type llvm-cxxfilt >/dev/null 2>&1 ; then
  13         cppfilt=llvm-cxxfilt
  14 elif type c++filt >/dev/null 2>&1 ; then
  15         cppfilt=c++filt
  16         cppfilt_opts=-i
  17 fi
  18
  19 UTIL_SUFFIX=
  20 if [[ -z ${LLVM:-} ]]; then
  21         UTIL_PREFIX=${CROSS_COMPILE:-}
  22 else
  23         UTIL_PREFIX=llvm-
  24         if [[ ${LLVM} == */ ]]; then
  25                 UTIL_PREFIX=${LLVM}${UTIL_PREFIX}
  26         elif [[ ${LLVM} == -* ]]; then
  27                 UTIL_SUFFIX=${LLVM}
  28         fi
  29 fi
  30
  31 READELF=${UTIL_PREFIX}readelf${UTIL_SUFFIX}
  32 ADDR2LINE=${UTIL_PREFIX}addr2line${UTIL_SUFFIX}
  33
  34 if [[ $1 == "-r" ]] ; then
  35         vmlinux=""
  36         basepath="auto"
  37         modpath=""
  38         release=$2
  39
  40         for fn in {,/usr/lib/debug}/boot/vmlinux-$release{,.debug} /lib/modules/$release{,/build}/vmlinux ; do
  41                 if [ -e "$fn" ] ; then
  42                         vmlinux=$fn
  43                         break
  44                 fi
  45         done
  46
  47         if [[ $vmlinux == "" ]] ; then
  48                 echo "ERROR! vmlinux image for release $release is not found" >&2
  49                 usage
  50                 exit 2
  51         fi
  52 else
  53         vmlinux=$1
  54         basepath=${2-auto}
  55         modpath=$3
  56         release=""
  57         debuginfod=
  58
  59         # Can we use debuginfod-find?
  60         if type debuginfod-find >/dev/null 2>&1 ; then
  61                 debuginfod=${1-only}
  62         fi
  63
  64         if [[ $vmlinux == "" && -z $debuginfod ]] ; then
  65                 echo "ERROR! vmlinux image must be specified" >&2
  66                 usage
  67                 exit 1
  68         fi
  69 fi
  70
  71 declare aarray_support=true
  72 declare -A cache 2>/dev/null
  73 if [[ $? != 0 ]]; then
  74         aarray_support=false
  75 else
  76         declare -A modcache
  77 fi
  78
  79 find_module() {
  80         if [[ -n $debuginfod ]] ; then
  81                 if [[ -n $modbuildid ]] ; then
  82                         debuginfod-find debuginfo $modbuildid && return
  83                 fi
  84
  85                 # Only using debuginfod so don't try to find vmlinux module path
  86                 if [[ $debuginfod == "only" ]] ; then
  87                         return
  88                 fi
  89         fi
  90
  91         if [[ "$modpath" != "" ]] ; then
  92                 for fn in $(find "$modpath" -name "${module//_/[-_]}.ko*") ; do
  93                         if ${READELF} -WS "$fn" | grep -qwF .debug_line ; then
  94                                 echo $fn
  95                                 return
  96                         fi
  97                 done
  98                 return 1
  99         fi
 100
 101         modpath=$(dirname "$vmlinux")
 102         find_module && return
 103
 104         if [[ $release == "" ]] ; then
 105                 release=$(gdb -ex 'print init_uts_ns.name.release' -ex 'quit' -quiet -batch "$vmlinux" 2>/dev/null | sed -n 's/\$1 = "\(.*\)".*/\1/p')
 106         fi
 107
 108         for dn in {/usr/lib/debug,}/lib/modules/$release ; do
 109                 if [ -e "$dn" ] ; then
 110                         modpath="$dn"
 111                         find_module && return
 112                 fi
 113         done
 114
 115         modpath=""
 116         return 1
 117 }
 118
 119 parse_symbol() {
 120         # The structure of symbol at this point is:
 121         #   ([name]+[offset]/[total length])
 122         #
 123         # For example:
 124         #   do_basic_setup+0x9c/0xbf
 125
 126         if [[ $module == "" ]] ; then
 127                 local objfile=$vmlinux
 128         elif [[ $aarray_support == true && "${modcache[$module]+isset}" == "isset" ]]; then
 129                 local objfile=${modcache[$module]}
 130         else
 131                 local objfile=$(find_module)
 132                 if [[ $objfile == "" ]] ; then
 133                         echo "WARNING! Modules path isn't set, but is needed to parse this symbol" >&2
 134                         return
 135                 fi
 136                 if [[ $aarray_support == true ]]; then
 137                         modcache[$module]=$objfile
 138                 fi
 139         fi
 140
 141         # Remove the englobing parenthesis
 142         symbol=${symbol#\(}
 143         symbol=${symbol%\)}
 144
 145         # Strip segment
 146         local segment
 147         if [[ $symbol == *:* ]] ; then
 148                 segment=${symbol%%:*}:
 149                 symbol=${symbol#*:}
 150         fi
 151
 152         # Strip the symbol name so that we could look it up
 153         local name=${symbol%+*}
 154
 155         # Use 'nm vmlinux' to figure out the base address of said symbol.
 156         # It's actually faster to call it every time than to load it
 157         # all into bash.
 158         if [[ $aarray_support == true && "${cache[$module,$name]+isset}" == "isset" ]]; then
 159                 local base_addr=${cache[$module,$name]}
 160         else
 161                 local base_addr=$(nm "$objfile" 2>/dev/null | awk '$3 == "'$name'" && ($2 == "t" || $2 == "T") {print $1; exit}')
 162                 if [[ $base_addr == "" ]] ; then
 163                         # address not found
 164                         return
 165                 fi
 166                 if [[ $aarray_support == true ]]; then
 167                         cache[$module,$name]="$base_addr"
 168                 fi
 169         fi
 170         # Let's start doing the math to get the exact address into the
 171         # symbol. First, strip out the symbol total length.
 172         local expr=${symbol%/*}
 173
 174         # Now, replace the symbol name with the base address we found
 175         # before.
 176         expr=${expr/$name/0x$base_addr}
 177
 178         # Evaluate it to find the actual address
 179         expr=$((expr))
 180         local address=$(printf "%x\n" "$expr")
 181
 182         # Pass it to addr2line to get filename and line number
 183         # Could get more than one result
 184         if [[ $aarray_support == true && "${cache[$module,$address]+isset}" == "isset" ]]; then
 185                 local code=${cache[$module,$address]}
 186         else
 187                 local code=$(${ADDR2LINE} -i -e "$objfile" "$address" 2>/dev/null)
 188                 if [[ $aarray_support == true ]]; then
 189                         cache[$module,$address]=$code
 190                 fi
 191         fi
 192
 193         # addr2line doesn't return a proper error code if it fails, so
 194         # we detect it using the value it prints so that we could preserve
 195         # the offset/size into the function and bail out
 196         if [[ $code == "??:0" ]]; then
 197                 return
 198         fi
 199
 200         # Strip out the base of the path on each line
 201         code=$(while read -r line; do echo "${line#$basepath/}"; done <<< "$code")
 202
 203         # In the case of inlines, move everything to same line
 204         code=${code//$'\n'/' '}
 205
 206         # Demangle if the name looks like a Rust symbol and if
 207         # we got a Rust demangler
 208         if [[ $name =~ ^_R && $cppfilt != "" ]] ; then
 209                 name=$("$cppfilt" "$cppfilt_opts" "$name")
 210         fi
 211
 212         # Replace old address with pretty line numbers
 213         symbol="$segment$name ($code)"
 214 }
 215
 216 debuginfod_get_vmlinux() {
 217         local vmlinux_buildid=${1##* }
 218
 219         if [[ $vmlinux != "" ]]; then
 220                 return
 221         fi
 222
 223         if [[ $vmlinux_buildid =~ ^[0-9a-f]+ ]]; then
 224                 vmlinux=$(debuginfod-find debuginfo $vmlinux_buildid)
 225                 if [[ $? -ne 0 ]] ; then
 226                         echo "ERROR! vmlinux image not found via debuginfod-find" >&2
 227                         usage
 228                         exit 2
 229                 fi
 230                 return
 231         fi
 232         echo "ERROR! Build ID for vmlinux not found. Try passing -r or specifying vmlinux" >&2
 233         usage
 234         exit 2
 235 }
 236
 237 decode_code() {
 238         local scripts=`dirname "${BASH_SOURCE[0]}"`
 239
 240         echo "$1" | $scripts/decodecode
 241 }
 242
 243 handle_line() {
 244         if [[ $basepath == "auto" && $vmlinux != "" ]] ; then
 245                 module=""
 246                 symbol="kernel_init+0x0/0x0"
 247                 parse_symbol
 248                 basepath=${symbol#kernel_init (}
 249                 basepath=${basepath%/init/main.c:*)}
 250         fi
 251
 252         local words
 253
 254         # Tokenize
 255         read -a words <<<"$1"
 256
 257         # Remove hex numbers. Do it ourselves until it happens in the
 258         # kernel
 259
 260         # We need to know the index of the last element before we
 261         # remove elements because arrays are sparse
 262         local last=$(( ${#words[@]} - 1 ))
 263
 264         for i in "${!words[@]}"; do
 265                 # Remove the address
 266                 if [[ ${words[$i]} =~ \[\<([^]]+)\>\] ]]; then
 267                         unset words[$i]
 268                 fi
 269
 270                 # Format timestamps with tabs
 271                 if [[ ${words[$i]} == \[ && ${words[$i+1]} == *\] ]]; then
 272                         unset words[$i]
 273                         words[$i+1]=$(printf "[%13s\n" "${words[$i+1]}")
 274                 fi
 275         done
 276
 277         if [[ ${words[$last]} =~ ^[0-9a-f]+\] ]]; then
 278                 words[$last-1]="${words[$last-1]} ${words[$last]}"
 279                 unset words[$last]
 280                 last=$(( $last - 1 ))
 281         fi
 282
 283         if [[ ${words[$last]} =~ \[([^]]+)\] ]]; then
 284                 module=${words[$last]}
 285                 module=${module#\[}
 286                 module=${module%\]}
 287                 modbuildid=${module#* }
 288                 module=${module% *}
 289                 if [[ $modbuildid == $module ]]; then
 290                         modbuildid=
 291                 fi
 292                 symbol=${words[$last-1]}
 293                 unset words[$last-1]
 294         else
 295                 # The symbol is the last element, process it
 296                 symbol=${words[$last]}
 297                 module=
 298                 modbuildid=
 299         fi
 300
 301         unset words[$last]
 302         parse_symbol # modifies $symbol
 303
 304         # Add up the line number to the symbol
 305         echo "${words[@]}" "$symbol $module"
 306 }
 307
 308 while read line; do
 309         # Let's see if we have an address in the line
 310         if [[ $line =~ \[\<([^]]+)\>\] ]] ||
 311            [[ $line =~ [^+\ ]+\+0x[0-9a-f]+/0x[0-9a-f]+ ]]; then
 312                 # Translate address to line numbers
 313                 handle_line "$line"
 314         # Is it a code line?
 315         elif [[ $line == *Code:* ]]; then
 316                 decode_code "$line"
 317         # Is it a version line?
 318         elif [[ -n $debuginfod && $line =~ PID:\ [0-9]+\ Comm: ]]; then
 319                 debuginfod_get_vmlinux "$line"
 320         else
 321                 # Nothing special in this line, show it as is
 322                 echo "$line"
 323         fi
 324 done