LXR linux/scripts/decode

   1#!/bin/bash
   2# SPDX-License-Identifier: GPL-2.0
   3# (c) 2014, Sasha Levin <sasha.levin@oracle.com>
   4#set -x
   5
   6if [[ $# < 2 ]]; then
   7        echo "Usage:"
   8        echo "  $0 [vmlinux] [base path] [modules path]"
   9        exit 1
  10fi
  11
  12vmlinux=$1
  13basepath=$2
  14modpath=$3
  15declare -A cache
  16declare -A modcache
  17
  18parse_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,$address]}
  75        else
  76                local code=$(${CROSS_COMPILE}addr2line -i -e "$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
  97decode_code() {
  98        local scripts=`dirname "${BASH_SOURCE[0]}"`
  99
 100        echo "$1" | $scripts/decodecode
 101}
 102
 103handle_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
 148while 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
 161done
 162