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