1#!/usr/bin/env perl 2 3use File::Basename; 4use Math::BigInt; 5use Getopt::Long; 6 7# Copyright 2008, Intel Corporation 8# 9# This file is part of the Linux kernel 10# 11# This program file is free software; you can redistribute it and/or modify it 12# under the terms of the GNU General Public License as published by the 13# Free Software Foundation; version 2 of the License. 14# 15# Authors: 16# Arjan van de Ven <arjan@linux.intel.com> 17 18 19my $cross_compile = ""; 20my $vmlinux_name = ""; 21my $modulefile = ""; 22 23# Get options 24Getopt::Long::GetOptions( 25 'cross-compile|c=s' => \$cross_compile, 26 'module|m=s' => \$modulefile, 27 'help|h' => \&usage, 28) || usage (); 29my $vmlinux_name = $ARGV[0]; 30if (!defined($vmlinux_name)) { 31 my $kerver = `uname -r`; 32 chomp($kerver); 33 $vmlinux_name = "/lib/modules/$kerver/build/vmlinux"; 34 print "No vmlinux specified, assuming $vmlinux_name\n"; 35} 36my $filename = $vmlinux_name; 37 38# Parse the oops to find the EIP value 39 40my $target = "0"; 41my $function; 42my $module = ""; 43my $func_offset = 0; 44my $vmaoffset = 0; 45 46my %regs; 47 48 49sub parse_x86_regs 50{ 51 my ($line) = @_; 52 if ($line =~ /EAX: ([0-9a-f]+) EBX: ([0-9a-f]+) ECX: ([0-9a-f]+) EDX: ([0-9a-f]+)/) { 53 $regs{"%eax"} = $1; 54 $regs{"%ebx"} = $2; 55 $regs{"%ecx"} = $3; 56 $regs{"%edx"} = $4; 57 } 58 if ($line =~ /ESI: ([0-9a-f]+) EDI: ([0-9a-f]+) EBP: ([0-9a-f]+) ESP: ([0-9a-f]+)/) { 59 $regs{"%esi"} = $1; 60 $regs{"%edi"} = $2; 61 $regs{"%esp"} = $4; 62 } 63 if ($line =~ /RAX: ([0-9a-f]+) RBX: ([0-9a-f]+) RCX: ([0-9a-f]+)/) { 64 $regs{"%eax"} = $1; 65 $regs{"%ebx"} = $2; 66 $regs{"%ecx"} = $3; 67 } 68 if ($line =~ /RDX: ([0-9a-f]+) RSI: ([0-9a-f]+) RDI: ([0-9a-f]+)/) { 69 $regs{"%edx"} = $1; 70 $regs{"%esi"} = $2; 71 $regs{"%edi"} = $3; 72 } 73 if ($line =~ /RBP: ([0-9a-f]+) R08: ([0-9a-f]+) R09: ([0-9a-f]+)/) { 74 $regs{"%r08"} = $2; 75 $regs{"%r09"} = $3; 76 } 77 if ($line =~ /R10: ([0-9a-f]+) R11: ([0-9a-f]+) R12: ([0-9a-f]+)/) { 78 $regs{"%r10"} = $1; 79 $regs{"%r11"} = $2; 80 $regs{"%r12"} = $3; 81 } 82 if ($line =~ /R13: ([0-9a-f]+) R14: ([0-9a-f]+) R15: ([0-9a-f]+)/) { 83 $regs{"%r13"} = $1; 84 $regs{"%r14"} = $2; 85 $regs{"%r15"} = $3; 86 } 87} 88 89sub reg_name 90{ 91 my ($reg) = @_; 92 $reg =~ s/r(.)x/e\1x/; 93 $reg =~ s/r(.)i/e\1i/; 94 $reg =~ s/r(.)p/e\1p/; 95 return $reg; 96} 97 98sub process_x86_regs 99{ 100 my ($line, $cntr) = @_; 101 my $str = ""; 102 if (length($line) < 40) { 103 return ""; # not an asm istruction 104 } 105 106 # find the arguments to the instruction 107 if ($line =~ /([0-9a-zA-Z\,\%\(\)\-\+]+)$/) { 108 $lastword = $1; 109 } else { 110 return ""; 111 } 112 113 # we need to find the registers that get clobbered, 114 # since their value is no longer relevant for previous 115 # instructions in the stream. 116 117 $clobber = $lastword; 118 # first, remove all memory operands, they're read only 119 $clobber =~ s/\([a-z0-9\%\,]+\)//g; 120 # then, remove everything before the comma, thats the read part 121 $clobber =~ s/.*\,//g; 122 123 # if this is the instruction that faulted, we haven't actually done 124 # the write yet... nothing is clobbered. 125 if ($cntr == 0) { 126 $clobber = ""; 127 } 128 129 foreach $reg (keys(%regs)) { 130 my $clobberprime = reg_name($clobber); 131 my $lastwordprime = reg_name($lastword); 132 my $val = $regs{$reg}; 133 if ($val =~ /^[0]+$/) { 134 $val = "0"; 135 } else { 136 $val =~ s/^0*//; 137 } 138 139 # first check if we're clobbering this register; if we do 140 # we print it with a =>, and then delete its value 141 if ($clobber =~ /$reg/ || $clobberprime =~ /$reg/) { 142 if (length($val) > 0) { 143 $str = $str . " $reg => $val "; 144 } 145 $regs{$reg} = ""; 146 $val = ""; 147 } 148 # now check if we're reading this register 149 if ($lastword =~ /$reg/ || $lastwordprime =~ /$reg/) { 150 if (length($val) > 0) { 151 $str = $str . " $reg = $val "; 152 } 153 } 154 } 155 return $str; 156} 157 158# parse the oops 159while (<STDIN>) { 160 my $line = $_; 161 if ($line =~ /EIP: 0060:\[\<([a-z0-9]+)\>\]/) { 162 $target = $1; 163 } 164 if ($line =~ /RIP: 0010:\[\<([a-z0-9]+)\>\]/) { 165 $target = $1; 166 } 167 if ($line =~ /EIP is at ([a-zA-Z0-9\_]+)\+0x([0-9a-f]+)\/0x[a-f0-9]/) { 168 $function = $1; 169 $func_offset = $2; 170 } 171 if ($line =~ /RIP: 0010:\[\<[0-9a-f]+\>\] \[\<[0-9a-f]+\>\] ([a-zA-Z0-9\_]+)\+0x([0-9a-f]+)\/0x[a-f0-9]/) { 172 $function = $1; 173 $func_offset = $2; 174 } 175 176 # check if it's a module 177 if ($line =~ /EIP is at ([a-zA-Z0-9\_]+)\+(0x[0-9a-f]+)\/0x[a-f0-9]+\W\[([a-zA-Z0-9\_\-]+)\]/) { 178 $module = $3; 179 } 180 if ($line =~ /RIP: 0010:\[\<[0-9a-f]+\>\] \[\<[0-9a-f]+\>\] ([a-zA-Z0-9\_]+)\+(0x[0-9a-f]+)\/0x[a-f0-9]+\W\[([a-zA-Z0-9\_\-]+)\]/) { 181 $module = $3; 182 } 183 parse_x86_regs($line); 184} 185 186my $decodestart = Math::BigInt->from_hex("0x$target") - Math::BigInt->from_hex("0x$func_offset"); 187my $decodestop = Math::BigInt->from_hex("0x$target") + 8192; 188if ($target eq "0") { 189 print "No oops found!\n"; 190 usage(); 191} 192 193# if it's a module, we need to find the .ko file and calculate a load offset 194if ($module ne "") { 195 if ($modulefile eq "") { 196 $modulefile = `modinfo -F filename $module`; 197 chomp($modulefile); 198 } 199 $filename = $modulefile; 200 if ($filename eq "") { 201 print "Module .ko file for $module not found. Aborting\n"; 202 exit; 203 } 204 # ok so we found the module, now we need to calculate the vma offset 205 open(FILE, $cross_compile."objdump -dS $filename |") || die "Cannot start objdump"; 206 while (<FILE>) { 207 if ($_ =~ /^([0-9a-f]+) \<$function\>\:/) { 208 my $fu = $1; 209 $vmaoffset = Math::BigInt->from_hex("0x$target") - Math::BigInt->from_hex("0x$fu") - Math::BigInt->from_hex("0x$func_offset"); 210 } 211 } 212 close(FILE); 213} 214 215my $counter = 0; 216my $state = 0; 217my $center = -1; 218my @lines; 219my @reglines; 220 221sub InRange { 222 my ($address, $target) = @_; 223 my $ad = "0x".$address; 224 my $ta = "0x".$target; 225 my $delta = Math::BigInt->from_hex($ad) - Math::BigInt->from_hex($ta); 226 227 if (($delta > -4096) && ($delta < 4096)) { 228 return 1; 229 } 230 return 0; 231} 232 233 234 235# first, parse the input into the lines array, but to keep size down, 236# we only do this for 4Kb around the sweet spot 237 238open(FILE, $cross_compile."objdump -dS --adjust-vma=$vmaoffset --start-address=$decodestart --stop-address=$decodestop $filename |") || die "Cannot start objdump"; 239 240while (<FILE>) { 241 my $line = $_; 242 chomp($line); 243 if ($state == 0) { 244 if ($line =~ /^([a-f0-9]+)\:/) { 245 if (InRange($1, $target)) { 246 $state = 1; 247 } 248 } 249 } 250 if ($state == 1) { 251 if ($line =~ /^([a-f0-9][a-f0-9][a-f0-9][a-f0-9][a-f0-9][a-f0-9]+)\:/) { 252 my $val = $1; 253 if (!InRange($val, $target)) { 254 last; 255 } 256 if ($val eq $target) { 257 $center = $counter; 258 } 259 } 260 $lines[$counter] = $line; 261 262 $counter = $counter + 1; 263 } 264} 265 266close(FILE); 267 268if ($counter == 0) { 269 print "No matching code found \n"; 270 exit; 271} 272 273if ($center == -1) { 274 print "No matching code found \n"; 275 exit; 276} 277 278my $start; 279my $finish; 280my $codelines = 0; 281my $binarylines = 0; 282# now we go up and down in the array to find how much we want to print 283 284$start = $center; 285 286while ($start > 1) { 287 $start = $start - 1; 288 my $line = $lines[$start]; 289 if ($line =~ /^([a-f0-9]+)\:/) { 290 $binarylines = $binarylines + 1; 291 } else { 292 $codelines = $codelines + 1; 293 } 294 if ($codelines > 10) { 295 last; 296 } 297 if ($binarylines > 20) { 298 last; 299 } 300} 301 302 303$finish = $center; 304$codelines = 0; 305$binarylines = 0; 306while ($finish < $counter) { 307 $finish = $finish + 1; 308 my $line = $lines[$finish]; 309 if ($line =~ /^([a-f0-9]+)\:/) { 310 $binarylines = $binarylines + 1; 311 } else { 312 $codelines = $codelines + 1; 313 } 314 if ($codelines > 10) { 315 last; 316 } 317 if ($binarylines > 20) { 318 last; 319 } 320} 321 322 323my $i; 324 325 326# start annotating the registers in the asm. 327# this goes from the oopsing point back, so that the annotator 328# can track (opportunistically) which registers got written and 329# whos value no longer is relevant. 330 331$i = $center; 332while ($i >= $start) { 333 $reglines[$i] = process_x86_regs($lines[$i], $center - $i); 334 $i = $i - 1; 335} 336 337$i = $start; 338while ($i < $finish) { 339 my $line; 340 if ($i == $center) { 341 $line = "*$lines[$i] "; 342 } else { 343 $line = " $lines[$i] "; 344 } 345 print $line; 346 if (defined($reglines[$i]) && length($reglines[$i]) > 0) { 347 my $c = 60 - length($line); 348 while ($c > 0) { print " "; $c = $c - 1; }; 349 print "| $reglines[$i]"; 350 } 351 if ($i == $center) { 352 print "<--- faulting instruction"; 353 } 354 print "\n"; 355 $i = $i +1; 356} 357 358sub usage { 359 print <<EOT; 360Usage: 361 dmesg | perl $0 [OPTION] [VMLINUX] 362 363OPTION: 364 -c, --cross-compile CROSS_COMPILE Specify the prefix used for toolchain. 365 -m, --module MODULE_DIRNAME Specify the module filename. 366 -h, --help Help. 367EOT 368 exit; 369} 370