mybin

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detect_hyperthreading_bug (1836B)

      1 #!/usr/bin/perl
      2 # Copyright 2017 Uwe Kleine-König
      3 #
      4 # This program is free software; you can redistribute it and/or modify it under
      5 # the terms of the GNU General Public License version 2 as published by the
      6 # Free Software Foundation.
      7 #
      8 # https://lists.debian.org/debian-user/2017/06/msg01011.html
      9 
     10 open(my $cpuinfo, "</proc/cpuinfo") or die "failed to open cpuinfo\n";
     11 
     12 my $cpunum, $vendor, $family, $model, $stepping, $microcoderev, $hyperthreading;
     13 
     14 while (<$cpuinfo>) {
     15 	if (/^$/) {
     16 		print "cpu $cpunum: ";
     17 		if ($vendor eq "GenuineIntel" and $family == 6) {
     18 			if ($model == 78 or $model == 94) {
     19 				if ($stepping eq "3") {
     20 					print "Your CPU is affected, ";
     21 					if (hex($microcoderev) >= 0xb9) {
     22 						print "but your microcode is new enough\n";
     23 					} elsif ($hyperthreading ne "on") {
     24 						print "but hyper threading is off, which works around the problem\n";
     25 					} else {
     26 						print "you should install the latest intel-microcode\n";
     27 					}
     28 				} else {
     29 					print "You may need a BIOS/UEFI update (unknown Skylake-Y/H/U/S stepping)\n";
     30 				}
     31 			} elsif ($model == 85 or $model == 142 or $model == 158) {
     32 				print "You may need a BIOS/UEFI update (Kaby Lake, or Skylake-X processor)\n";
     33 			} else {
     34 				print "You're likely not affected\n";
     35 			}
     36 		} else {
     37 			print "You're not affected\n";
     38 		}
     39 
     40 		$cpunum = undef;
     41 		$vendor = undef;
     42 		$family = undef;
     43 		$stepping = undef;
     44 		$microcoderev = undef;
     45 		$hyperthreading = undef;
     46 
     47 		next;
     48 	}
     49 
     50 	$cpunum = $1 if /^processor\s*:\s(.*)/;
     51 	$vendor = $1 if /^vendor_id\s*:\s(.*)/;
     52 	$family = $1 if /^cpu family\s*:\s(.*)/;
     53 	$model = $1 if /^model\s*:\s(.*)/;
     54 	$stepping = $1 if /^stepping\s*:\s(.*)/;
     55 	$microcoderev = $1 if /^microcode\s*:\s(.*)/;
     56 
     57 	if (/^flags\s*:/) {
     58 		if (/^flags\s*:.*\bht\b/) {
     59 			$hyperthreading = "on";
     60 		} else {
     61 			$hyperthreading = "off";
     62 		}
     63 	}
     64 }
     65