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 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 ($code)"
  88}
  89
  90decode_code() {
  91        local scripts=`dirname "${BASH_SOURCE[0]}"`
  92
  93        echo "$1" | $scripts/decodecode
  94}
  95
  96handle_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
 141while 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
 154done
 155