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