From 3b920b4596c85d1de6ee0daf7e82dfe3e329ef0c Mon Sep 17 00:00:00 2001
From: Peter Collingbourne <pcc@google.com>
Date: Fri, 18 Feb 2022 17:29:44 -0800
Subject: [PATCH] BACKPORT: kasan: split kasan_*enabled() functions into a
 separate header

In an upcoming commit we are going to need to call
kasan_hw_tags_enabled() from arch/arm64/include/asm/mte.h. This
would create a circular dependency between headers if KASAN_GENERIC
or KASAN_SW_TAGS is enabled: linux/kasan.h -> linux/pgtable.h ->
asm/pgtable.h -> asm/mte.h -> linux/kasan.h. Break the cycle
by introducing a new header linux/kasan-enabled.h with the
kasan_*enabled() functions that can be included from asm/mte.h.

Link: https://linux-review.googlesource.com/id/I5b0d96c6ed0026fc790899e14d42b2fac6ab568e
Signed-off-by: Peter Collingbourne <pcc@google.com>
Reviewed-by: Andrey Konovalov <andreyknvl@gmail.com>
Link: https://lore.kernel.org/r/20220219012945.894950-1-pcc@google.com
Signed-off-by: Will Deacon <will@kernel.org>

Bug: 238956478
(cherry picked from commit f9b5e46f4097eb298f68e5b02f70697a90a44739)
Change-Id: I631ae7d32ed560dd22917a4691c498e234b4f51d
Signed-off-by: Jaewon Kim <jaewon31.kim@samsung.com>
Bug: 254721825
Signed-off-by: Andrey Konovalov <andreyknvl@google.com>
---
 include/linux/kasan-enabled.h | 33 +++++++++++++++++++++++++++++++++
 include/linux/kasan.h         | 29 +----------------------------
 2 files changed, 34 insertions(+), 28 deletions(-)
 create mode 100644 include/linux/kasan-enabled.h

diff --git a/include/linux/kasan-enabled.h b/include/linux/kasan-enabled.h
new file mode 100644
index 000000000000..4b6615375022
--- /dev/null
+++ b/include/linux/kasan-enabled.h
@@ -0,0 +1,33 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef _LINUX_KASAN_ENABLED_H
+#define _LINUX_KASAN_ENABLED_H
+
+#ifdef CONFIG_KASAN_HW_TAGS
+
+DECLARE_STATIC_KEY_FALSE(kasan_flag_enabled);
+
+static __always_inline bool kasan_enabled(void)
+{
+	return static_branch_likely(&kasan_flag_enabled);
+}
+
+static inline bool kasan_hw_tags_enabled(void)
+{
+	return kasan_enabled();
+}
+
+#else /* CONFIG_KASAN_HW_TAGS */
+
+static inline bool kasan_enabled(void)
+{
+	return IS_ENABLED(CONFIG_KASAN);
+}
+
+static inline bool kasan_hw_tags_enabled(void)
+{
+	return false;
+}
+
+#endif /* CONFIG_KASAN_HW_TAGS */
+
+#endif /* LINUX_KASAN_ENABLED_H */
diff --git a/include/linux/kasan.h b/include/linux/kasan.h
index b9ba719eddeb..0ab2dfa914ff 100644
--- a/include/linux/kasan.h
+++ b/include/linux/kasan.h
@@ -3,6 +3,7 @@
 #define _LINUX_KASAN_H
 
 #include <linux/bug.h>
+#include <linux/kasan-enabled.h>
 #include <linux/kernel.h>
 #include <linux/static_key.h>
 #include <linux/types.h>
@@ -82,34 +83,6 @@ static inline void kasan_disable_current(void) {}
 
 #endif /* CONFIG_KASAN_GENERIC || CONFIG_KASAN_SW_TAGS */
 
-#ifdef CONFIG_KASAN_HW_TAGS
-
-DECLARE_STATIC_KEY_FALSE(kasan_flag_enabled);
-
-static __always_inline bool kasan_enabled(void)
-{
-	return static_branch_likely(&kasan_flag_enabled);
-}
-
-static inline bool kasan_hw_tags_enabled(void)
-{
-	return kasan_enabled();
-}
-
-#else /* CONFIG_KASAN_HW_TAGS */
-
-static inline bool kasan_enabled(void)
-{
-	return IS_ENABLED(CONFIG_KASAN);
-}
-
-static inline bool kasan_hw_tags_enabled(void)
-{
-	return false;
-}
-
-#endif /* CONFIG_KASAN_HW_TAGS */
-
 static inline bool kasan_has_integrated_init(void)
 {
 	return kasan_hw_tags_enabled();