An oops dump also contains the register values. This patch parses these for (32 bit) x86, and then annotates the disassembly with these values; this helps in analysis of the oops by the developer, for example, NULL pointer or other pointer bugs show up clearly this way.
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| @@ -32,6 +32,78 @@ my $module = ""; · 31 unmodified lines | ||
| 32 | 32 | my $func_offset; |
| 33 | 33 | my $vmaoffset = 0; |
| 34 | 34 | |
| 35 | +my %regs; | |
| 36 | + | |
| 37 | + | |
| 38 | +sub parse_x86_regs | |
| 39 | +{ | |
| 40 | + my ($line) = @_; | |
| 41 | + if ($line =~ /EAX: ([0-9a-f]+) EBX: ([0-9a-f]+) ECX: ([0-9a-f]+) EDX: ([0-9a-f]+)/) { | |
| 42 | + $regs{"%eax"} = $1; | |
| 43 | + $regs{"%ebx"} = $2; | |
| 44 | + $regs{"%ecx"} = $3; | |
| 45 | + $regs{"%edx"} = $4; | |
| 46 | + } | |
| 47 | + if ($line =~ /ESI: ([0-9a-f]+) EDI: ([0-9a-f]+) EBP: ([0-9a-f]+) ESP: ([0-9a-f]+)/) { | |
| 48 | + $regs{"%esi"} = $1; | |
| 49 | + $regs{"%edi"} = $2; | |
| 50 | + $regs{"%esp"} = $4; | |
| 51 | + } | |
| 52 | +} | |
| 53 | + | |
| 54 | +sub process_x86_regs | |
| 55 | +{ | |
| 56 | + my ($line, $cntr) = @_; | |
| 57 | + my $str = ""; | |
| 58 | + if (length($line) < 40) { | |
| 59 | + return ""; # not an asm istruction | |
| 60 | + } | |
| 61 | + | |
| 62 | + # find the arguments to the instruction | |
| 63 | + if ($line =~ /([0-9a-zA-Z\,\%\(\)\-\+]+)$/) { | |
| 64 | + $lastword = $1; | |
| 65 | + } else { | |
| 66 | + return ""; | |
| 67 | + } | |
| 68 | + | |
| 69 | + # we need to find the registers that get clobbered, | |
| 70 | + # since their value is no longer relevant for previous | |
| 71 | + # instructions in the stream. | |
| 72 | + | |
| 73 | + $clobber = $lastword; | |
| 74 | + # first, remove all memory operands, they're read only | |
| 75 | + $clobber =~ s/\([a-z0-9\%\,]+\)//g; | |
| 76 | + # then, remove everything before the comma, thats the read part | |
| 77 | + $clobber =~ s/.*\,//g; | |
| 78 | + | |
| 79 | + # if this is the instruction that faulted, we haven't actually done | |
| 80 | + # the write yet... nothing is clobbered. | |
| 81 | + if ($cntr == 0) { | |
| 82 | + $clobber = ""; | |
| 83 | + } | |
| 84 | + | |
| 85 | + foreach $reg (keys(%regs)) { | |
| 86 | + my $val = $regs{$reg}; | |
| 87 | + # first check if we're clobbering this register; if we do | |
| 88 | + # we print it with a =>, and then delete its value | |
| 89 | + if ($clobber =~ /$reg/) { | |
| 90 | + if (length($val) > 0) { | |
| 91 | + $str = $str . " $reg => $val "; | |
| 92 | + } | |
| 93 | + $regs{$reg} = ""; | |
| 94 | + $val = ""; | |
| 95 | + } | |
| 96 | + # now check if we're reading this register | |
| 97 | + if ($lastword =~ /$reg/) { | |
| 98 | + if (length($val) > 0) { | |
| 99 | + $str = $str . " $reg = $val "; | |
| 100 | + } | |
| 101 | + } | |
| 102 | + } | |
| 103 | + return $str; | |
| 104 | +} | |
| 105 | + | |
| 106 | +# parse the oops | |
| 35 | 107 | while (<STDIN>) { |
| 36 | 108 | my $line = $_; |
| 37 | 109 | if ($line =~ /EIP: 0060:\[\<([a-z0-9]+)\>\]/) { |
| @@ -46,10 +118,11 @@ while (<STDIN>) { · 8 unmodified lines | ||
| 46 | 118 | if ($line =~ /EIP is at ([a-zA-Z0-9\_]+)\+(0x[0-9a-f]+)\/0x[a-f0-9]+\W\[([a-zA-Z0-9\_\-]+)\]/) { |
| 47 | 119 | $module = $3; |
| 48 | 120 | } |
| 121 | + parse_x86_regs($line); | |
| 49 | 122 | } |
| 50 | 123 | |
| 51 | 124 | my $decodestart = hex($target) - hex($func_offset); |
| 52 | −my $decodestop = $decodestart + 8192; | |
| 125 | +my $decodestop = hex($target) + 8192; | |
| 53 | 126 | if ($target eq "0") { |
| 54 | 127 | print "No oops found!\n"; |
| 55 | 128 | print "Usage: \n"; |
| @@ -84,6 +157,7 @@ my $counter = 0; · 28 unmodified lines | ||
| 84 | 157 | my $state = 0; |
| 85 | 158 | my $center = 0; |
| 86 | 159 | my @lines; |
| 160 | +my @reglines; | |
| 87 | 161 | |
| 88 | 162 | sub InRange { |
| 89 | 163 | my ($address, $target) = @_; |
| @@ -188,16 +262,36 @@ while ($finish < $counter) { · 98 unmodified lines | ||
| 188 | 262 | |
| 189 | 263 | my $i; |
| 190 | 264 | |
| 191 | −my $fulltext = ""; | |
| 265 | + | |
| 266 | +# start annotating the registers in the asm. | |
| 267 | +# this goes from the oopsing point back, so that the annotator | |
| 268 | +# can track (opportunistically) which registers got written and | |
| 269 | +# whos value no longer is relevant. | |
| 270 | + | |
| 271 | +$i = $center; | |
| 272 | +while ($i >= $start) { | |
| 273 | + $reglines[$i] = process_x86_regs($lines[$i], $center - $i); | |
| 274 | + $i = $i - 1; | |
| 275 | +} | |
| 276 | + | |
| 192 | 277 | $i = $start; |
| 193 | 278 | while ($i < $finish) { |
| 279 | + my $line; | |
| 194 | 280 | if ($i == $center) { |
| 195 | − $fulltext = $fulltext . "*$lines[$i] <----- faulting instruction\n"; | |
| 281 | + $line = "*$lines[$i] "; | |
| 196 | 282 | } else { |
| 197 | − $fulltext = $fulltext . " $lines[$i]\n"; | |
| 283 | + $line = " $lines[$i] "; | |
| 284 | + } | |
| 285 | + print $line; | |
| 286 | + if (defined($reglines[$i]) && length($reglines[$i]) > 0) { | |
| 287 | + my $c = 60 - length($line); | |
| 288 | + while ($c > 0) { print " "; $c = $c - 1; }; | |
| 289 | + print "| $reglines[$i]"; | |
| 198 | 290 | } |
| 291 | + if ($i == $center) { | |
| 292 | + print "<--- faulting instruction"; | |
| 293 | + } | |
| 294 | + print "\n"; | |
| 199 | 295 | $i = $i +1; |
| 200 | 296 | } |
| 201 | 297 | |
| 202 | −print $fulltext; | |
| 203 | − | |