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 if [[ $# < 2 ]]; then
   7         echo "Usage:"
   8         echo "  $0 [vmlinux] [base path] [modules path]"
   9         exit 1
  10 fi
  11
  12 vmlinux=$1
  13 basepath=$2
  14 modpath=$3
  15 declare -A cache
  16 declare -A modcache
  17
  18 parse_symbol() {
  19         # The structure of symbol at this point is:
  20         #   ([name]+[offset]/[total length])
  21         #
  22         # For example:
  23         #   do_basic_setup+0x9c/0xbf
  24
  25         if [[ $module == "" ]] ; then
  26                 local objfile=$vmlinux
  27         elif [[ "${modcache[$module]+isset}" == "isset" ]]; then
  28                 local objfile=${modcache[$module]}
  29         else
  30                 [[ $modpath == "" ]] && return
  31                 local objfile=$(find "$modpath" -name $module.ko -print -quit)
  32                 [[ $objfile == "" ]] && return
  33                 modcache[$module]=$objfile
  34         fi
  35
  36         # Remove the englobing parenthesis
  37         symbol=${symbol#\(}
  38         symbol=${symbol%\)}
  39
  40         # Strip segment
  41         local segment
  42         if [[ $symbol == *:* ]] ; then
  43                 segment=${symbol%%:*}:
  44                 symbol=${symbol#*:}
  45         fi
  46
  47         # Strip the symbol name so that we could look it up
  48         local name=${symbol%+*}
  49
  50         # Use 'nm vmlinux' to figure out the base address of said symbol.
  51         # It's actually faster to call it every time than to load it
  52         # all into bash.
  53         if [[ "${cache[$module,$name]+isset}" == "isset" ]]; then
  54                 local base_addr=${cache[$module,$name]}
  55         else
  56                 local base_addr=$(nm "$objfile" | grep -i ' t ' | awk "/ $name\$/ {print \$1}" | head -n1)
  57                 cache[$module,$name]="$base_addr"
  58         fi
  59         # Let's start doing the math to get the exact address into the
  60         # symbol. First, strip out the symbol total length.
  61         local expr=${symbol%/*}
  62
  63         # Now, replace the symbol name with the base address we found
  64         # before.
  65         expr=${expr/$name/0x$base_addr}
  66
  67         # Evaluate it to find the actual address
  68         expr=$((expr))
  69         local address=$(printf "%x\n" "$expr")
  70
  71         # Pass it to addr2line to get filename and line number
  72         # Could get more than one result
  73         if [[ "${cache[$module,$address]+isset}" == "isset" ]]; then
  74                 local code=${cache[$module,$address]}
  75         else
  76                 local code=$(addr2line -i -e "$objfile" "$address")
  77                 cache[$module,$address]=$code
  78         fi
  79
  80         # addr2line doesn't return a proper error code if it fails, so
  81         # we detect it using the value it prints so that we could preserve
  82         # the offset/size into the function and bail out
  83         if [[ $code == "??:0" ]]; then
  84                 return
  85         fi
  86
  87         # Strip out the base of the path
  88         code=${code//^$basepath/""}
  89
  90         # In the case of inlines, move everything to same line
  91         code=${code//$'\n'/' '}
  92
  93         # Replace old address with pretty line numbers
  94         symbol="$segment$name ($code)"
  95 }
  96
  97 decode_code() {
  98         local scripts=`dirname "${BASH_SOURCE[0]}"`
  99
 100         echo "$1" | $scripts/decodecode
 101 }
 102
 103 handle_line() {
 104         local words
 105
 106         # Tokenize
 107         read -a words <<<"$1"
 108
 109         # Remove hex numbers. Do it ourselves until it happens in the
 110         # kernel
 111
 112         # We need to know the index of the last element before we
 113         # remove elements because arrays are sparse
 114         local last=$(( ${#words[@]} - 1 ))
 115
 116         for i in "${!words[@]}"; do
 117                 # Remove the address
 118                 if [[ ${words[$i]} =~ \[\<([^]]+)\>\] ]]; then
 119                         unset words[$i]
 120                 fi
 121
 122                 # Format timestamps with tabs
 123                 if [[ ${words[$i]} == \[ && ${words[$i+1]} == *\] ]]; then
 124                         unset words[$i]
 125                         words[$i+1]=$(printf "[%13s\n" "${words[$i+1]}")
 126                 fi
 127         done
 128
 129         if [[ ${words[$last]} =~ \[([^]]+)\] ]]; then
 130                 module=${words[$last]}
 131                 module=${module#\[}
 132                 module=${module%\]}
 133                 symbol=${words[$last-1]}
 134                 unset words[$last-1]
 135         else
 136                 # The symbol is the last element, process it
 137                 symbol=${words[$last]}
 138                 module=
 139         fi
 140
 141         unset words[$last]
 142         parse_symbol # modifies $symbol
 143
 144         # Add up the line number to the symbol
 145         echo "${words[@]}" "$symbol $module"
 146 }
 147
 148 while read line; do
 149         # Let's see if we have an address in the line
 150         if [[ $line =~ \[\<([^]]+)\>\] ]] ||
 151            [[ $line =~ [^+\ ]+\+0x[0-9a-f]+/0x[0-9a-f]+ ]]; then
 152                 # Translate address to line numbers
 153                 handle_line "$line"
 154         # Is it a code line?
 155         elif [[ $line == *Code:* ]]; then
 156                 decode_code "$line"
 157         else
 158                 # Nothing special in this line, show it as is
 159                 echo "$line"
 160         fi
 161 done