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