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