scripts/markup_oops.pl

   1 #!/usr/bin/env perl
   2 # SPDX-License-Identifier: GPL-2.0-only
   3
   4 use File::Basename;
   5 use Math::BigInt;
   6 use Getopt::Long;
   7
   8 # Copyright 2008, Intel Corporation
   9 #
  10 # This file is part of the Linux kernel
  11 #
  12 # Authors:
  13 #       Arjan van de Ven <arjan@linux.intel.com>
  14
  15
  16 my $cross_compile = "";
  17 my $vmlinux_name = "";
  18 my $modulefile = "";
  19
  20 # Get options
  21 Getopt::Long::GetOptions(
  22         'cross-compile|c=s'     => \$cross_compile,
  23         'module|m=s'            => \$modulefile,
  24         'help|h'                => \&usage,
  25 ) || usage ();
  26 my $vmlinux_name = $ARGV[0];
  27 if (!defined($vmlinux_name)) {
  28         my $kerver = `uname -r`;
  29         chomp($kerver);
  30         $vmlinux_name = "/lib/modules/$kerver/build/vmlinux";
  31         print "No vmlinux specified, assuming $vmlinux_name\n";
  32 }
  33 my $filename = $vmlinux_name;
  34
  35 # Parse the oops to find the EIP value
  36
  37 my $target = "0";
  38 my $function;
  39 my $module = "";
  40 my $func_offset = 0;
  41 my $vmaoffset = 0;
  42
  43 my %regs;
  44
  45
  46 sub parse_x86_regs
  47 {
  48         my ($line) = @_;
  49         if ($line =~ /EAX: ([0-9a-f]+) EBX: ([0-9a-f]+) ECX: ([0-9a-f]+) EDX: ([0-9a-f]+)/) {
  50                 $regs{"%eax"} = $1;
  51                 $regs{"%ebx"} = $2;
  52                 $regs{"%ecx"} = $3;
  53                 $regs{"%edx"} = $4;
  54         }
  55         if ($line =~ /ESI: ([0-9a-f]+) EDI: ([0-9a-f]+) EBP: ([0-9a-f]+) ESP: ([0-9a-f]+)/) {
  56                 $regs{"%esi"} = $1;
  57                 $regs{"%edi"} = $2;
  58                 $regs{"%esp"} = $4;
  59         }
  60         if ($line =~ /RAX: ([0-9a-f]+) RBX: ([0-9a-f]+) RCX: ([0-9a-f]+)/) {
  61                 $regs{"%eax"} = $1;
  62                 $regs{"%ebx"} = $2;
  63                 $regs{"%ecx"} = $3;
  64         }
  65         if ($line =~ /RDX: ([0-9a-f]+) RSI: ([0-9a-f]+) RDI: ([0-9a-f]+)/) {
  66                 $regs{"%edx"} = $1;
  67                 $regs{"%esi"} = $2;
  68                 $regs{"%edi"} = $3;
  69         }
  70         if ($line =~ /RBP: ([0-9a-f]+) R08: ([0-9a-f]+) R09: ([0-9a-f]+)/) {
  71                 $regs{"%r08"} = $2;
  72                 $regs{"%r09"} = $3;
  73         }
  74         if ($line =~ /R10: ([0-9a-f]+) R11: ([0-9a-f]+) R12: ([0-9a-f]+)/) {
  75                 $regs{"%r10"} = $1;
  76                 $regs{"%r11"} = $2;
  77                 $regs{"%r12"} = $3;
  78         }
  79         if ($line =~ /R13: ([0-9a-f]+) R14: ([0-9a-f]+) R15: ([0-9a-f]+)/) {
  80                 $regs{"%r13"} = $1;
  81                 $regs{"%r14"} = $2;
  82                 $regs{"%r15"} = $3;
  83         }
  84 }
  85
  86 sub reg_name
  87 {
  88         my ($reg) = @_;
  89         $reg =~ s/r(.)x/e\1x/;
  90         $reg =~ s/r(.)i/e\1i/;
  91         $reg =~ s/r(.)p/e\1p/;
  92         return $reg;
  93 }
  94
  95 sub process_x86_regs
  96 {
  97         my ($line, $cntr) = @_;
  98         my $str = "";
  99         if (length($line) < 40) {
 100                 return ""; # not an asm istruction
 101         }
 102
 103         # find the arguments to the instruction
 104         if ($line =~ /([0-9a-zA-Z\,\%\(\)\-\+]+)$/) {
 105                 $lastword = $1;
 106         } else {
 107                 return "";
 108         }
 109
 110         # we need to find the registers that get clobbered,
 111         # since their value is no longer relevant for previous
 112         # instructions in the stream.
 113
 114         $clobber = $lastword;
 115         # first, remove all memory operands, they're read only
 116         $clobber =~ s/\([a-z0-9\%\,]+\)//g;
 117         # then, remove everything before the comma, thats the read part
 118         $clobber =~ s/.*\,//g;
 119
 120         # if this is the instruction that faulted, we haven't actually done
 121         # the write yet... nothing is clobbered.
 122         if ($cntr == 0) {
 123                 $clobber = "";
 124         }
 125
 126         foreach $reg (keys(%regs)) {
 127                 my $clobberprime = reg_name($clobber);
 128                 my $lastwordprime = reg_name($lastword);
 129                 my $val = $regs{$reg};
 130                 if ($val =~ /^[0]+$/) {
 131                         $val = "0";
 132                 } else {
 133                         $val =~ s/^0*//;
 134                 }
 135
 136                 # first check if we're clobbering this register; if we do
 137                 # we print it with a =>, and then delete its value
 138                 if ($clobber =~ /$reg/ || $clobberprime =~ /$reg/) {
 139                         if (length($val) > 0) {
 140                                 $str = $str . " $reg => $val ";
 141                         }
 142                         $regs{$reg} = "";
 143                         $val = "";
 144                 }
 145                 # now check if we're reading this register
 146                 if ($lastword =~ /$reg/ || $lastwordprime =~ /$reg/) {
 147                         if (length($val) > 0) {
 148                                 $str = $str . " $reg = $val ";
 149                         }
 150                 }
 151         }
 152         return $str;
 153 }
 154
 155 # parse the oops
 156 while (<STDIN>) {
 157         my $line = $_;
 158         if ($line =~ /EIP: 0060:\[\<([a-z0-9]+)\>\]/) {
 159                 $target = $1;
 160         }
 161         if ($line =~ /RIP: 0010:\[\<([a-z0-9]+)\>\]/) {
 162                 $target = $1;
 163         }
 164         if ($line =~ /EIP is at ([a-zA-Z0-9\_]+)\+0x([0-9a-f]+)\/0x[a-f0-9]/) {
 165                 $function = $1;
 166                 $func_offset = $2;
 167         }
 168         if ($line =~ /RIP: 0010:\[\<[0-9a-f]+\>\]  \[\<[0-9a-f]+\>\] ([a-zA-Z0-9\_]+)\+0x([0-9a-f]+)\/0x[a-f0-9]/) {
 169                 $function = $1;
 170                 $func_offset = $2;
 171         }
 172
 173         # check if it's a module
 174         if ($line =~ /EIP is at ([a-zA-Z0-9\_]+)\+(0x[0-9a-f]+)\/0x[a-f0-9]+\W\[([a-zA-Z0-9\_\-]+)\]/) {
 175                 $module = $3;
 176         }
 177         if ($line =~ /RIP: 0010:\[\<[0-9a-f]+\>\]  \[\<[0-9a-f]+\>\] ([a-zA-Z0-9\_]+)\+(0x[0-9a-f]+)\/0x[a-f0-9]+\W\[([a-zA-Z0-9\_\-]+)\]/) {
 178                 $module = $3;
 179         }
 180         parse_x86_regs($line);
 181 }
 182
 183 my $decodestart = Math::BigInt->from_hex("0x$target") - Math::BigInt->from_hex("0x$func_offset");
 184 my $decodestop = Math::BigInt->from_hex("0x$target") + 8192;
 185 if ($target eq "0") {
 186         print "No oops found!\n";
 187         usage();
 188 }
 189
 190 # if it's a module, we need to find the .ko file and calculate a load offset
 191 if ($module ne "") {
 192         if ($modulefile eq "") {
 193                 $modulefile = `modinfo -F filename $module`;
 194                 chomp($modulefile);
 195         }
 196         $filename = $modulefile;
 197         if ($filename eq "") {
 198                 print "Module .ko file for $module not found. Aborting\n";
 199                 exit;
 200         }
 201         # ok so we found the module, now we need to calculate the vma offset
 202         open(FILE, $cross_compile."objdump -dS $filename |") || die "Cannot start objdump";
 203         while (<FILE>) {
 204                 if ($_ =~ /^([0-9a-f]+) \<$function\>\:/) {
 205                         my $fu = $1;
 206                         $vmaoffset = Math::BigInt->from_hex("0x$target") - Math::BigInt->from_hex("0x$fu") - Math::BigInt->from_hex("0x$func_offset");
 207                 }
 208         }
 209         close(FILE);
 210 }
 211
 212 my $counter = 0;
 213 my $state   = 0;
 214 my $center  = -1;
 215 my @lines;
 216 my @reglines;
 217
 218 sub InRange {
 219         my ($address, $target) = @_;
 220         my $ad = "0x".$address;
 221         my $ta = "0x".$target;
 222         my $delta = Math::BigInt->from_hex($ad) - Math::BigInt->from_hex($ta);
 223
 224         if (($delta > -4096) && ($delta < 4096)) {
 225                 return 1;
 226         }
 227         return 0;
 228 }
 229
 230
 231
 232 # first, parse the input into the lines array, but to keep size down,
 233 # we only do this for 4Kb around the sweet spot
 234
 235 open(FILE, $cross_compile."objdump -dS --adjust-vma=$vmaoffset --start-address=$decodestart --stop-address=$decodestop $filename |") || die "Cannot start objdump";
 236
 237 while (<FILE>) {
 238         my $line = $_;
 239         chomp($line);
 240         if ($state == 0) {
 241                 if ($line =~ /^([a-f0-9]+)\:/) {
 242                         if (InRange($1, $target)) {
 243                                 $state = 1;
 244                         }
 245                 }
 246         }
 247         if ($state == 1) {
 248                 if ($line =~ /^([a-f0-9][a-f0-9][a-f0-9][a-f0-9][a-f0-9][a-f0-9]+)\:/) {
 249                         my $val = $1;
 250                         if (!InRange($val, $target)) {
 251                                 last;
 252                         }
 253                         if ($val eq $target) {
 254                                 $center = $counter;
 255                         }
 256                 }
 257                 $lines[$counter] = $line;
 258
 259                 $counter = $counter + 1;
 260         }
 261 }
 262
 263 close(FILE);
 264
 265 if ($counter == 0) {
 266         print "No matching code found \n";
 267         exit;
 268 }
 269
 270 if ($center == -1) {
 271         print "No matching code found \n";
 272         exit;
 273 }
 274
 275 my $start;
 276 my $finish;
 277 my $codelines = 0;
 278 my $binarylines = 0;
 279 # now we go up and down in the array to find how much we want to print
 280
 281 $start = $center;
 282
 283 while ($start > 1) {
 284         $start = $start - 1;
 285         my $line = $lines[$start];
 286         if ($line =~ /^([a-f0-9]+)\:/) {
 287                 $binarylines = $binarylines + 1;
 288         } else {
 289                 $codelines = $codelines + 1;
 290         }
 291         if ($codelines > 10) {
 292                 last;
 293         }
 294         if ($binarylines > 20) {
 295                 last;
 296         }
 297 }
 298
 299
 300 $finish = $center;
 301 $codelines = 0;
 302 $binarylines = 0;
 303 while ($finish < $counter) {
 304         $finish = $finish + 1;
 305         my $line = $lines[$finish];
 306         if ($line =~ /^([a-f0-9]+)\:/) {
 307                 $binarylines = $binarylines + 1;
 308         } else {
 309                 $codelines = $codelines + 1;
 310         }
 311         if ($codelines > 10) {
 312                 last;
 313         }
 314         if ($binarylines > 20) {
 315                 last;
 316         }
 317 }
 318
 319
 320 my $i;
 321
 322
 323 # start annotating the registers in the asm.
 324 # this goes from the oopsing point back, so that the annotator
 325 # can track (opportunistically) which registers got written and
 326 # whos value no longer is relevant.
 327
 328 $i = $center;
 329 while ($i >= $start) {
 330         $reglines[$i] = process_x86_regs($lines[$i], $center - $i);
 331         $i = $i - 1;
 332 }
 333
 334 $i = $start;
 335 while ($i < $finish) {
 336         my $line;
 337         if ($i == $center) {
 338                 $line =  "*$lines[$i] ";
 339         } else {
 340                 $line =  " $lines[$i] ";
 341         }
 342         print $line;
 343         if (defined($reglines[$i]) && length($reglines[$i]) > 0) {
 344                 my $c = 60 - length($line);
 345                 while ($c > 0) { print " "; $c = $c - 1; };
 346                 print "| $reglines[$i]";
 347         }
 348         if ($i == $center) {
 349                 print "<--- faulting instruction";
 350         }
 351         print "\n";
 352         $i = $i +1;
 353 }
 354
 355 sub usage {
 356         print <<EOT;
 357 Usage:
 358   dmesg | perl $0 [OPTION] [VMLINUX]
 359
 360 OPTION:
 361   -c, --cross-compile CROSS_COMPILE     Specify the prefix used for toolchain.
 362   -m, --module MODULE_DIRNAME           Specify the module filename.
 363   -h, --help                            Help.
 364 EOT
 365         exit;
 366 }