lkdtm: Split WARNING into separate tests

There are three paths through the kernel code exception logging:

- BUG (no configurable printk message)
- WARN_ON (no configurable printk message)
- WARN (configurable printk message)

LKDTM was not testing WARN_ON(). This is needed to evaluate the placement
of the "cut here" line, which needs special handling in each of the
three exceptions (and between architectures that implement instruction
exceptions to implement the code exceptions).

Signed-off-by: Kees Cook <keescook@chromium.org>

3 files changed, 8 insertions, 1 deletions

diff --git a/drivers/misc/lkdtm/bugs.c b/drivers/misc/lkdtm/bugs.c
index 1606658b9b7e..98fad7909592 100644
--- a/drivers/misc/lkdtm/bugs.c
+++ b/drivers/misc/lkdtm/bugs.c
@@ -75,7 +75,12 @@ static int warn_counter;
 
 void lkdtm_WARNING(void)
 {
-	WARN(1, "Warning message trigger count: %d\n", warn_counter++);
+	WARN_ON(++warn_counter);
+}
+
+void lkdtm_WARNING_MESSAGE(void)
+{
+	WARN(1, "Warning message trigger count: %d\n", ++warn_counter);
 }
 
 void lkdtm_EXCEPTION(void)
diff --git a/drivers/misc/lkdtm/core.c b/drivers/misc/lkdtm/core.c
index 42136196681e..cbc4c9045a99 100644
--- a/drivers/misc/lkdtm/core.c
+++ b/drivers/misc/lkdtm/core.c
@@ -104,6 +104,7 @@ static const struct crashtype crashtypes[] = {
 	CRASHTYPE(PANIC),
 	CRASHTYPE(BUG),
 	CRASHTYPE(WARNING),
+	CRASHTYPE(WARNING_MESSAGE),
 	CRASHTYPE(EXCEPTION),
 	CRASHTYPE(LOOP),
 	CRASHTYPE(EXHAUST_STACK),
diff --git a/drivers/misc/lkdtm/lkdtm.h b/drivers/misc/lkdtm/lkdtm.h
index 8a25afbdf954..ab446e0bde97 100644
--- a/drivers/misc/lkdtm/lkdtm.h
+++ b/drivers/misc/lkdtm/lkdtm.h
@@ -11,6 +11,7 @@ void __init lkdtm_bugs_init(int *recur_param);
 void lkdtm_PANIC(void);
 void lkdtm_BUG(void);
 void lkdtm_WARNING(void);
+void lkdtm_WARNING_MESSAGE(void);
 void lkdtm_EXCEPTION(void);
 void lkdtm_LOOP(void);
 void lkdtm_EXHAUST_STACK(void);