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>

diff --git a/drivers/misc/lkdtm.c b/drivers/misc/lkdtm.c
index b1323fc..8bc7f0b 100644 (file)
--- 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();