scripts/decode_stacktrace.sh

   1 #!/usr/bin/env bash
   2 # SPDX-License-Identifier: GPL-2.0
   3 # (c) 2014, Sasha Levin <[email protected]>
   4 #set -x
   5
   6 usage() {
   7         echo "Usage:"
   8         echo "  $0 -r <release>"
   9         echo "  $0 [<vmlinux> [<base_path>|auto [<modules_path>]]]"
  10         echo "  $0 -h"
  11 }
  12
  13 # Try to find a Rust demangler
  14 if type llvm-cxxfilt >/dev/null 2>&1 ; then
  15         cppfilt=llvm-cxxfilt
  16 elif type c++filt >/dev/null 2>&1 ; then
  17         cppfilt=c++filt
  18         cppfilt_opts=-i
  19 fi
  20
  21 UTIL_SUFFIX=
  22 if [[ -z ${LLVM:-} ]]; then
  23         UTIL_PREFIX=${CROSS_COMPILE:-}
  24 else
  25         UTIL_PREFIX=llvm-
  26         if [[ ${LLVM} == */ ]]; then
  27                 UTIL_PREFIX=${LLVM}${UTIL_PREFIX}
  28         elif [[ ${LLVM} == -* ]]; then
  29                 UTIL_SUFFIX=${LLVM}
  30         fi
  31 fi
  32
  33 READELF=${UTIL_PREFIX}readelf${UTIL_SUFFIX}
  34 ADDR2LINE=${UTIL_PREFIX}addr2line${UTIL_SUFFIX}
  35 NM=${UTIL_PREFIX}nm${UTIL_SUFFIX}
  36
  37 if [[ $1 == "-h" ]] ; then
  38         usage
  39         exit 0
  40 elif [[ $1 == "-r" ]] ; then
  41         vmlinux=""
  42         basepath="auto"
  43         modpath=""
  44         release=$2
  45
  46         for fn in {,/usr/lib/debug}/boot/vmlinux-$release{,.debug} /lib/modules/$release{,/build}/vmlinux ; do
  47                 if [ -e "$fn" ] ; then
  48                         vmlinux=$fn
  49                         break
  50                 fi
  51         done
  52
  53         if [[ $vmlinux == "" ]] ; then
  54                 echo "ERROR! vmlinux image for release $release is not found" >&2
  55                 usage
  56                 exit 2
  57         fi
  58 else
  59         vmlinux=$1
  60         basepath=${2-auto}
  61         modpath=$3
  62         release=""
  63         debuginfod=
  64
  65         # Can we use debuginfod-find?
  66         if type debuginfod-find >/dev/null 2>&1 ; then
  67                 debuginfod=${1-only}
  68         fi
  69
  70         if [[ $vmlinux == "" && -z $debuginfod ]] ; then
  71                 echo "ERROR! vmlinux image must be specified" >&2
  72                 usage
  73                 exit 1
  74         fi
  75 fi
  76
  77 declare aarray_support=true
  78 declare -A cache 2>/dev/null
  79 if [[ $? != 0 ]]; then
  80         aarray_support=false
  81 else
  82         declare -A modcache
  83 fi
  84
  85 find_module() {
  86         if [[ -n $debuginfod ]] ; then
  87                 if [[ -n $modbuildid ]] ; then
  88                         debuginfod-find debuginfo $modbuildid && return
  89                 fi
  90
  91                 # Only using debuginfod so don't try to find vmlinux module path
  92                 if [[ $debuginfod == "only" ]] ; then
  93                         return
  94                 fi
  95         fi
  96
  97         if [ -z $release ] ; then
  98                 release=$(gdb -ex 'print init_uts_ns.name.release' -ex 'quit' -quiet -batch "$vmlinux" 2>/dev/null | sed -n 's/\$1 = "\(.*\)".*/\1/p')
  99         fi
 100         if [ -n "${release}" ] ; then
 101                 release_dirs="/usr/lib/debug/lib/modules/$release /lib/modules/$release"
 102         fi
 103
 104         found_without_debug_info=false
 105         for dir in "$modpath" "$(dirname "$vmlinux")" ${release_dirs}; do
 106                 if [ -n "${dir}" ] && [ -e "${dir}" ]; then
 107                         for fn in $(find "$dir" -name "${module//_/[-_]}.ko*") ; do
 108                                 if ${READELF} -WS "$fn" | grep -qwF .debug_line ; then
 109                                         echo $fn
 110                                         return
 111                                 fi
 112                                 found_without_debug_info=true
 113                         done
 114                 fi
 115         done
 116
 117         if [[ ${found_without_debug_info} == true ]]; then
 118                 echo "WARNING! No debugging info in module ${module}, rebuild with DEBUG_KERNEL and DEBUG_INFO" >&2
 119         else
 120                 echo "WARNING! Cannot find .ko for module ${module}, please pass a valid module path" >&2
 121         fi
 122
 123         return 1
 124 }
 125
 126 parse_symbol() {
 127         # The structure of symbol at this point is:
 128         #   ([name]+[offset]/[total length])
 129         #
 130         # For example:
 131         #   do_basic_setup+0x9c/0xbf
 132
 133         if [[ $module == "" ]] ; then
 134                 local objfile=$vmlinux
 135         elif [[ $aarray_support == true && "${modcache[$module]+isset}" == "isset" ]]; then
 136                 local objfile=${modcache[$module]}
 137         else
 138                 local objfile=$(find_module)
 139                 if [[ $objfile == "" ]] ; then
 140                         return
 141                 fi
 142                 if [[ $aarray_support == true ]]; then
 143                         modcache[$module]=$objfile
 144                 fi
 145         fi
 146
 147         # Remove the englobing parenthesis
 148         symbol=${symbol#\(}
 149         symbol=${symbol%\)}
 150
 151         # Strip segment
 152         local segment
 153         if [[ $symbol == *:* ]] ; then
 154                 segment=${symbol%%:*}:
 155                 symbol=${symbol#*:}
 156         fi
 157
 158         # Strip the symbol name so that we could look it up
 159         local name=${symbol%+*}
 160
 161         # Use 'nm vmlinux' to figure out the base address of said symbol.
 162         # It's actually faster to call it every time than to load it
 163         # all into bash.
 164         if [[ $aarray_support == true && "${cache[$module,$name]+isset}" == "isset" ]]; then
 165                 local base_addr=${cache[$module,$name]}
 166         else
 167                 local base_addr=$(${NM} "$objfile" 2>/dev/null | awk '$3 == "'$name'" && ($2 == "t" || $2 == "T") {print $1; exit}')
 168                 if [[ $base_addr == "" ]] ; then
 169                         # address not found
 170                         return
 171                 fi
 172                 if [[ $aarray_support == true ]]; then
 173                         cache[$module,$name]="$base_addr"
 174                 fi
 175         fi
 176         # Let's start doing the math to get the exact address into the
 177         # symbol. First, strip out the symbol total length.
 178         local expr=${symbol%/*}
 179
 180         # Now, replace the symbol name with the base address we found
 181         # before.
 182         expr=${expr/$name/0x$base_addr}
 183
 184         # Evaluate it to find the actual address
 185         expr=$((expr))
 186         local address=$(printf "%x\n" "$expr")
 187
 188         # Pass it to addr2line to get filename and line number
 189         # Could get more than one result
 190         if [[ $aarray_support == true && "${cache[$module,$address]+isset}" == "isset" ]]; then
 191                 local code=${cache[$module,$address]}
 192         else
 193                 local code=$(${ADDR2LINE} -i -e "$objfile" "$address" 2>/dev/null)
 194                 if [[ $aarray_support == true ]]; then
 195                         cache[$module,$address]=$code
 196                 fi
 197         fi
 198
 199         # addr2line doesn't return a proper error code if it fails, so
 200         # we detect it using the value it prints so that we could preserve
 201         # the offset/size into the function and bail out
 202         if [[ $code == "??:0" ]]; then
 203                 return
 204         fi
 205
 206         # Strip out the base of the path on each line
 207         code=$(while read -r line; do echo "${line#$basepath/}"; done <<< "$code")
 208
 209         # In the case of inlines, move everything to same line
 210         code=${code//$'\n'/' '}
 211
 212         # Demangle if the name looks like a Rust symbol and if
 213         # we got a Rust demangler
 214         if [[ $name =~ ^_R && $cppfilt != "" ]] ; then
 215                 name=$("$cppfilt" "$cppfilt_opts" "$name")
 216         fi
 217
 218         # Replace old address with pretty line numbers
 219         symbol="$segment$name ($code)"
 220 }
 221
 222 debuginfod_get_vmlinux() {
 223         local vmlinux_buildid=${1##* }
 224
 225         if [[ $vmlinux != "" ]]; then
 226                 return
 227         fi
 228
 229         if [[ $vmlinux_buildid =~ ^[0-9a-f]+ ]]; then
 230                 vmlinux=$(debuginfod-find debuginfo $vmlinux_buildid)
 231                 if [[ $? -ne 0 ]] ; then
 232                         echo "ERROR! vmlinux image not found via debuginfod-find" >&2
 233                         usage
 234                         exit 2
 235                 fi
 236                 return
 237         fi
 238         echo "ERROR! Build ID for vmlinux not found. Try passing -r or specifying vmlinux" >&2
 239         usage
 240         exit 2
 241 }
 242
 243 decode_code() {
 244         local scripts=`dirname "${BASH_SOURCE[0]}"`
 245
 246         echo "$1" | $scripts/decodecode
 247 }
 248
 249 handle_line() {
 250         if [[ $basepath == "auto" && $vmlinux != "" ]] ; then
 251                 module=""
 252                 symbol="kernel_init+0x0/0x0"
 253                 parse_symbol
 254                 basepath=${symbol#kernel_init (}
 255                 basepath=${basepath%/init/main.c:*)}
 256         fi
 257
 258         local words
 259
 260         # Tokenize
 261         read -a words <<<"$1"
 262
 263         # Remove hex numbers. Do it ourselves until it happens in the
 264         # kernel
 265
 266         # We need to know the index of the last element before we
 267         # remove elements because arrays are sparse
 268         local last=$(( ${#words[@]} - 1 ))
 269
 270         for i in "${!words[@]}"; do
 271                 # Remove the address
 272                 if [[ ${words[$i]} =~ \[\<([^]]+)\>\] ]]; then
 273                         unset words[$i]
 274                 fi
 275
 276                 # Format timestamps with tabs
 277                 if [[ ${words[$i]} == \[ && ${words[$i+1]} == *\] ]]; then
 278                         unset words[$i]
 279                         words[$i+1]=$(printf "[%13s\n" "${words[$i+1]}")
 280                 fi
 281         done
 282
 283         if [[ ${words[$last]} =~ ^[0-9a-f]+\] ]]; then
 284                 words[$last-1]="${words[$last-1]} ${words[$last]}"
 285                 unset words[$last]
 286                 last=$(( $last - 1 ))
 287         fi
 288
 289         if [[ ${words[$last]} =~ \[([^]]+)\] ]]; then
 290                 module=${words[$last]}
 291                 # some traces format is "(%pS)", which like "(foo+0x0/0x1 [bar])"
 292                 # so $module may like "[bar])". Strip the right parenthesis firstly
 293                 module=${module%\)}
 294                 module=${module#\[}
 295                 module=${module%\]}
 296                 modbuildid=${module#* }
 297                 module=${module% *}
 298                 if [[ $modbuildid == $module ]]; then
 299                         modbuildid=
 300                 fi
 301                 symbol=${words[$last-1]}
 302                 unset words[$last-1]
 303         else
 304                 # The symbol is the last element, process it
 305                 symbol=${words[$last]}
 306                 module=
 307                 modbuildid=
 308         fi
 309
 310         unset words[$last]
 311         parse_symbol # modifies $symbol
 312
 313         # Add up the line number to the symbol
 314         echo "${words[@]}" "$symbol $module"
 315 }
 316
 317 while read line; do
 318         # Strip unexpected carriage return at end of line
 319         line=${line%$'\r'}
 320
 321         # Let's see if we have an address in the line
 322         if [[ $line =~ \[\<([^]]+)\>\] ]] ||
 323            [[ $line =~ [^+\ ]+\+0x[0-9a-f]+/0x[0-9a-f]+ ]]; then
 324                 # Translate address to line numbers
 325                 handle_line "$line"
 326         # Is it a code line?
 327         elif [[ $line == *Code:* ]]; then
 328                 decode_code "$line"
 329         # Is it a version line?
 330         elif [[ -n $debuginfod && $line =~ PID:\ [0-9]+\ Comm: ]]; then
 331                 debuginfod_get_vmlinux "$line"
 332         else
 333                 # Nothing special in this line, show it as is
 334                 echo "$line"
 335         fi
 336 done