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 [[ $# < 1 ]]; then
   7         echo "Usage:"
   8         echo "  $0 -r <release> | <vmlinux> [base path] [modules path]"
   9         exit 1
  10 fi
  11
  12 # Try to find a Rust demangler
  13 if type llvm-cxxfilt >/dev/null 2>&1 ; then
  14         cppfilt=llvm-cxxfilt
  15 elif type c++filt >/dev/null 2>&1 ; then
  16         cppfilt=c++filt
  17         cppfilt_opts=-i
  18 fi
  19
  20 UTIL_SUFFIX=
  21 if [[ -z ${LLVM:-} ]]; then
  22         UTIL_PREFIX=${CROSS_COMPILE:-}
  23 else
  24         UTIL_PREFIX=llvm-
  25         if [[ ${LLVM} == */ ]]; then
  26                 UTIL_PREFIX=${LLVM}${UTIL_PREFIX}
  27         elif [[ ${LLVM} == -* ]]; then
  28                 UTIL_SUFFIX=${LLVM}
  29         fi
  30 fi
  31
  32 READELF=${UTIL_PREFIX}readelf${UTIL_SUFFIX}
  33 ADDR2LINE=${UTIL_PREFIX}addr2line${UTIL_SUFFIX}
  34
  35 if [[ $1 == "-r" ]] ; then
  36         vmlinux=""
  37         basepath="auto"
  38         modpath=""
  39         release=$2
  40
  41         for fn in {,/usr/lib/debug}/boot/vmlinux-$release{,.debug} /lib/modules/$release{,/build}/vmlinux ; do
  42                 if [ -e "$fn" ] ; then
  43                         vmlinux=$fn
  44                         break
  45                 fi
  46         done
  47
  48         if [[ $vmlinux == "" ]] ; then
  49                 echo "ERROR! vmlinux image for release $release is not found" >&2
  50                 exit 2
  51         fi
  52 else
  53         vmlinux=$1
  54         basepath=${2-auto}
  55         modpath=$3
  56         release=""
  57 fi
  58
  59 declare aarray_support=true
  60 declare -A cache 2>/dev/null
  61 if [[ $? != 0 ]]; then
  62         aarray_support=false
  63 else
  64         declare -A modcache
  65 fi
  66
  67 find_module() {
  68         if [[ "$modpath" != "" ]] ; then
  69                 for fn in $(find "$modpath" -name "${module//_/[-_]}.ko*") ; do
  70                         if ${READELF} -WS "$fn" | grep -qwF .debug_line ; then
  71                                 echo $fn
  72                                 return
  73                         fi
  74                 done
  75                 return 1
  76         fi
  77
  78         modpath=$(dirname "$vmlinux")
  79         find_module && return
  80
  81         if [[ $release == "" ]] ; then
  82                 release=$(gdb -ex 'print init_uts_ns.name.release' -ex 'quit' -quiet -batch "$vmlinux" 2>/dev/null | sed -n 's/\$1 = "\(.*\)".*/\1/p')
  83         fi
  84
  85         for dn in {/usr/lib/debug,}/lib/modules/$release ; do
  86                 if [ -e "$dn" ] ; then
  87                         modpath="$dn"
  88                         find_module && return
  89                 fi
  90         done
  91
  92         modpath=""
  93         return 1
  94 }
  95
  96 parse_symbol() {
  97         # The structure of symbol at this point is:
  98         #   ([name]+[offset]/[total length])
  99         #
 100         # For example:
 101         #   do_basic_setup+0x9c/0xbf
 102
 103         if [[ $module == "" ]] ; then
 104                 local objfile=$vmlinux
 105         elif [[ $aarray_support == true && "${modcache[$module]+isset}" == "isset" ]]; then
 106                 local objfile=${modcache[$module]}
 107         else
 108                 local objfile=$(find_module)
 109                 if [[ $objfile == "" ]] ; then
 110                         echo "WARNING! Modules path isn't set, but is needed to parse this symbol" >&2
 111                         return
 112                 fi
 113                 if [[ $aarray_support == true ]]; then
 114                         modcache[$module]=$objfile
 115                 fi
 116         fi
 117
 118         # Remove the englobing parenthesis
 119         symbol=${symbol#\(}
 120         symbol=${symbol%\)}
 121
 122         # Strip segment
 123         local segment
 124         if [[ $symbol == *:* ]] ; then
 125                 segment=${symbol%%:*}:
 126                 symbol=${symbol#*:}
 127         fi
 128
 129         # Strip the symbol name so that we could look it up
 130         local name=${symbol%+*}
 131
 132         # Use 'nm vmlinux' to figure out the base address of said symbol.
 133         # It's actually faster to call it every time than to load it
 134         # all into bash.
 135         if [[ $aarray_support == true && "${cache[$module,$name]+isset}" == "isset" ]]; then
 136                 local base_addr=${cache[$module,$name]}
 137         else
 138                 local base_addr=$(nm "$objfile" 2>/dev/null | awk '$3 == "'$name'" && ($2 == "t" || $2 == "T") {print $1; exit}')
 139                 if [[ $base_addr == "" ]] ; then
 140                         # address not found
 141                         return
 142                 fi
 143                 if [[ $aarray_support == true ]]; then
 144                         cache[$module,$name]="$base_addr"
 145                 fi
 146         fi
 147         # Let's start doing the math to get the exact address into the
 148         # symbol. First, strip out the symbol total length.
 149         local expr=${symbol%/*}
 150
 151         # Now, replace the symbol name with the base address we found
 152         # before.
 153         expr=${expr/$name/0x$base_addr}
 154
 155         # Evaluate it to find the actual address
 156         expr=$((expr))
 157         local address=$(printf "%x\n" "$expr")
 158
 159         # Pass it to addr2line to get filename and line number
 160         # Could get more than one result
 161         if [[ $aarray_support == true && "${cache[$module,$address]+isset}" == "isset" ]]; then
 162                 local code=${cache[$module,$address]}
 163         else
 164                 local code=$(${ADDR2LINE} -i -e "$objfile" "$address" 2>/dev/null)
 165                 if [[ $aarray_support == true ]]; then
 166                         cache[$module,$address]=$code
 167                 fi
 168         fi
 169
 170         # addr2line doesn't return a proper error code if it fails, so
 171         # we detect it using the value it prints so that we could preserve
 172         # the offset/size into the function and bail out
 173         if [[ $code == "??:0" ]]; then
 174                 return
 175         fi
 176
 177         # Strip out the base of the path on each line
 178         code=$(while read -r line; do echo "${line#$basepath/}"; done <<< "$code")
 179
 180         # In the case of inlines, move everything to same line
 181         code=${code//$'\n'/' '}
 182
 183         # Demangle if the name looks like a Rust symbol and if
 184         # we got a Rust demangler
 185         if [[ $name =~ ^_R && $cppfilt != "" ]] ; then
 186                 name=$("$cppfilt" "$cppfilt_opts" "$name")
 187         fi
 188
 189         # Replace old address with pretty line numbers
 190         symbol="$segment$name ($code)"
 191 }
 192
 193 decode_code() {
 194         local scripts=`dirname "${BASH_SOURCE[0]}"`
 195
 196         echo "$1" | $scripts/decodecode
 197 }
 198
 199 handle_line() {
 200         local words
 201
 202         # Tokenize
 203         read -a words <<<"$1"
 204
 205         # Remove hex numbers. Do it ourselves until it happens in the
 206         # kernel
 207
 208         # We need to know the index of the last element before we
 209         # remove elements because arrays are sparse
 210         local last=$(( ${#words[@]} - 1 ))
 211
 212         for i in "${!words[@]}"; do
 213                 # Remove the address
 214                 if [[ ${words[$i]} =~ \[\<([^]]+)\>\] ]]; then
 215                         unset words[$i]
 216                 fi
 217
 218                 # Format timestamps with tabs
 219                 if [[ ${words[$i]} == \[ && ${words[$i+1]} == *\] ]]; then
 220                         unset words[$i]
 221                         words[$i+1]=$(printf "[%13s\n" "${words[$i+1]}")
 222                 fi
 223         done
 224
 225         if [[ ${words[$last]} =~ \[([^]]+)\] ]]; then
 226                 module=${words[$last]}
 227                 module=${module#\[}
 228                 module=${module%\]}
 229                 symbol=${words[$last-1]}
 230                 unset words[$last-1]
 231         else
 232                 # The symbol is the last element, process it
 233                 symbol=${words[$last]}
 234                 module=
 235         fi
 236
 237         unset words[$last]
 238         parse_symbol # modifies $symbol
 239
 240         # Add up the line number to the symbol
 241         echo "${words[@]}" "$symbol $module"
 242 }
 243
 244 if [[ $basepath == "auto" ]] ; then
 245         module=""
 246         symbol="kernel_init+0x0/0x0"
 247         parse_symbol
 248         basepath=${symbol#kernel_init (}
 249         basepath=${basepath%/init/main.c:*)}
 250 fi
 251
 252 while read line; do
 253         # Let's see if we have an address in the line
 254         if [[ $line =~ \[\<([^]]+)\>\] ]] ||
 255            [[ $line =~ [^+\ ]+\+0x[0-9a-f]+/0x[0-9a-f]+ ]]; then
 256                 # Translate address to line numbers
 257                 handle_line "$line"
 258         # Is it a code line?
 259         elif [[ $line == *Code:* ]]; then
 260                 decode_code "$line"
 261         else
 262                 # Nothing special in this line, show it as is
 263                 echo "$line"
 264         fi
 265 done