kmsan: expose KMSAN_WARN_ON()

KMSAN_WARN_ON() is required for implementing s390-specific KMSAN
functions, but right now it's available only to the KMSAN internal
functions.  Expose it to subsystems through <linux/kmsan.h>.

Link: https://lkml.kernel.org/r/[email protected]
Signed-off-by: Ilya Leoshkevich <[email protected]>
Reviewed-by: Alexander Potapenko <[email protected]>
Cc: Alexander Gordeev <[email protected]>
Cc: Christian Borntraeger <[email protected]>
Cc: Christoph Lameter <[email protected]>
Cc: David Rientjes <[email protected]>
Cc: Dmitry Vyukov <[email protected]>
Cc: Heiko Carstens <[email protected]>
Cc: Hyeonggon Yoo <[email protected]>
Cc: Joonsoo Kim <[email protected]>
Cc: <[email protected]>
Cc: Marco Elver <[email protected]>
Cc: Mark Rutland <[email protected]>
Cc: Masami Hiramatsu (Google) <[email protected]>
Cc: Pekka Enberg <[email protected]>
Cc: Roman Gushchin <[email protected]>
Cc: Steven Rostedt (Google) <[email protected]>
Cc: Sven Schnelle <[email protected]>
Cc: Vasily Gorbik <[email protected]>
Cc: Vlastimil Babka <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>

2 files changed, 26 insertions, 23 deletions

diff --git a/include/linux/kmsan.h b/include/linux/kmsan.h
index 7109644f4c19..2b1432cc16d5 100644
--- a/include/linux/kmsan.h
+++ b/include/linux/kmsan.h
@@ -268,6 +268,29 @@ static inline void *memset_no_sanitize_memory(void *s, int c, size_t n)
 	return __memset(s, c, n);
 }
 
+extern bool kmsan_enabled;
+extern int panic_on_kmsan;
+
+/*
+ * KMSAN performs a lot of consistency checks that are currently enabled by
+ * default. BUG_ON is normally discouraged in the kernel, unless used for
+ * debugging, but KMSAN itself is a debugging tool, so it makes little sense to
+ * recover if something goes wrong.
+ */
+#define KMSAN_WARN_ON(cond)                                           \
+	({                                                            \
+		const bool __cond = WARN_ON(cond);                    \
+		if (unlikely(__cond)) {                               \
+			WRITE_ONCE(kmsan_enabled, false);             \
+			if (panic_on_kmsan) {                         \
+				/* Can't call panic() here because */ \
+				/* of uaccess checks. */              \
+				BUG();                                \
+			}                                             \
+		}                                                     \
+		__cond;                                               \
+	})
+
 #else
 
 static inline void kmsan_init_shadow(void)
@@ -380,6 +403,8 @@ static inline void *memset_no_sanitize_memory(void *s, int c, size_t n)
 	return memset(s, c, n);
 }
 
+#define KMSAN_WARN_ON WARN_ON
+
 #endif
 
 #endif /* _LINUX_KMSAN_H */
diff --git a/mm/kmsan/kmsan.h b/mm/kmsan/kmsan.h
index 34b83c301d57..91a360a31e85 100644
--- a/mm/kmsan/kmsan.h
+++ b/mm/kmsan/kmsan.h
@@ -11,6 +11,7 @@
 #define __MM_KMSAN_KMSAN_H
 
 #include <linux/irqflags.h>
+#include <linux/kmsan.h>
 #include <linux/mm.h>
 #include <linux/nmi.h>
 #include <linux/pgtable.h>
@@ -34,29 +35,6 @@
 #define KMSAN_META_SHADOW (false)
 #define KMSAN_META_ORIGIN (true)
 
-extern bool kmsan_enabled;
-extern int panic_on_kmsan;
-
-/*
- * KMSAN performs a lot of consistency checks that are currently enabled by
- * default. BUG_ON is normally discouraged in the kernel, unless used for
- * debugging, but KMSAN itself is a debugging tool, so it makes little sense to
- * recover if something goes wrong.
- */
-#define KMSAN_WARN_ON(cond)                                           \
-	({                                                            \
-		const bool __cond = WARN_ON(cond);                    \
-		if (unlikely(__cond)) {                               \
-			WRITE_ONCE(kmsan_enabled, false);             \
-			if (panic_on_kmsan) {                         \
-				/* Can't call panic() here because */ \
-				/* of uaccess checks. */              \
-				BUG();                                \
-			}                                             \
-		}                                                     \
-		__cond;                                               \
-	})
-
 /*
  * A pair of metadata pointers to be returned by the instrumentation functions.
  */