2 files changed, 30 insertions, 0 deletions

diff --git a/tools/testing/ktest/ktest.pl b/tools/testing/ktest/ktest.pl
index b96d3819c42e..a8e1826e0cba 100755
--- a/tools/testing/ktest/ktest.pl
+++ b/tools/testing/ktest/ktest.pl
@@ -41,6 +41,7 @@ $default{"CLEAR_LOG"}		= 0;
 $default{"BISECT_MANUAL"}       = 0;
 $default{"BISECT_SKIP"}         = 1;
 $default{"SUCCESS_LINE"}        = "login:";
+$default{"DETECT_TRIPLE_FAULT"} = 1;
 $default{"BOOTED_TIMEOUT"}      = 1;
 $default{"DIE_ON_FAILURE"}      = 1;
 $default{"SSH_EXEC"}            = "ssh \$SSH_USER\@\$MACHINE \$SSH_COMMAND";
@@ -101,6 +102,7 @@ my $patchcheck_sleep_time;
 my $store_failures;
 my $timeout;
 my $booted_timeout;
+my $detect_triplefault;
 my $console;
 my $success_line;
 my $stop_after_success;
@@ -836,6 +838,7 @@ sub monitor {
     my $failure_start;
     my $monitor_start = time;
     my $done = 0;
+    my $version_found = 0;
 
     while (!$done) {
 
@@ -904,6 +907,22 @@ sub monitor {
             $bug = 1;
         }
 
+        # Detect triple faults by testing the banner
+        if ($full_line =~ /\bLinux version (\S+).*\n/) {
+            if ($1 eq $version) {
+                $version_found = 1;
+            } elsif ($version_found && $detect_triplefault) {
+                # We already booted into the kernel we are testing,
+                # but now we booted into another kernel?
+                # Consider this a triple fault.
+                doprint "Aleady booted in Linux kernel $version, but now\n";
+                doprint "we booted into Linux kernel $1.\n";
+                doprint "Assuming that this is a triple fault.\n";
+                doprint "To disable this: set DETECT_TRIPLE_FAULT to 0\n";
+                last;
+            }
+        }
+
         if ($line =~ /\n/) {
             $full_line = "";
         }
@@ -2159,6 +2178,7 @@ for (my $i = 1; $i <= $opt{"NUM_TESTS"}; $i++) {
     $timeout = set_test_option("TIMEOUT", $i);
     $booted_timeout = set_test_option("BOOTED_TIMEOUT", $i);
     $console = set_test_option("CONSOLE", $i);
+    $detect_triplefault = set_test_option("DETECT_TRIPLE_FAULT", $i);
     $success_line = set_test_option("SUCCESS_LINE", $i);
     $stop_after_success = set_test_option("STOP_AFTER_SUCCESS", $i);
     $stop_after_failure = set_test_option("STOP_AFTER_FAILURE", $i);
diff --git a/tools/testing/ktest/sample.conf b/tools/testing/ktest/sample.conf
index 48cbcc80602a..c2c072e96032 100644
--- a/tools/testing/ktest/sample.conf
+++ b/tools/testing/ktest/sample.conf
@@ -518,6 +518,16 @@
 # The variables SSH_USER and MACHINE are defined.
 #REBOOT = ssh $SSH_USER@$MACHINE reboot
 
+# The way triple faults are detected is by testing the kernel
+# banner. If the kernel banner for the kernel we are testing is
+# found, and then later a kernel banner for another kernel version
+# is found, it is considered that we encountered a triple fault,
+# and there is no panic or callback, but simply a reboot.
+# To disable this (because it did a false positive) set the following
+# to 0.
+# (default 1)
+#DETECT_TRIPLE_FAULT = 0
+
 #### Per test run options ####
 # The following options are only allowed in TEST_START sections.
 # They are ignored in the DEFAULTS sections.