lkdtm: add "SPINLOCKUP" trigger

For additional lockup testing, add "SPINLOCKUP" to trigger a spinlock
deadlock when triggered twice.

Signed-off-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

1 files changed, 7 insertions, 0 deletions

diff --git a/drivers/misc/lkdtm.c b/drivers/misc/lkdtm.c
index b1323fc881b1..8bc7f0bcd945 100644
--- a/drivers/misc/lkdtm.c
+++ b/drivers/misc/lkdtm.c
@@ -78,6 +78,7 @@ enum ctype {
         CT_WRITE_AFTER_FREE,
         CT_SOFTLOCKUP,
         CT_HARDLOCKUP,
+        CT_SPINLOCKUP,
         CT_HUNG_TASK,
 };
 
@@ -106,6 +107,7 @@ static char* cp_type[] = {
         "WRITE_AFTER_FREE",
         "SOFTLOCKUP",
         "HARDLOCKUP",
+        "SPINLOCKUP",
         "HUNG_TASK",
 };
 
@@ -123,6 +125,7 @@ static enum cname cpoint = CN_INVALID;
 static enum ctype cptype = CT_NONE;
 static int count = DEFAULT_COUNT;
 static DEFINE_SPINLOCK(count_lock);
+static DEFINE_SPINLOCK(lock_me_up);
 
 module_param(recur_count, int, 0644);
 MODULE_PARM_DESC(recur_count, " Recursion level for the stack overflow test, "\
@@ -345,6 +348,10 @@ static void lkdtm_do_action(enum ctype which)
                 for (;;)
                         cpu_relax();
                 break;
+        case CT_SPINLOCKUP:
+                /* Must be called twice to trigger. */
+                spin_lock(&lock_me_up);
+                break;
         case CT_HUNG_TASK:
                 set_current_state(TASK_UNINTERRUPTIBLE);
                 schedule();