1 files changed, 57 insertions, 0 deletions

diff --git a/include/linux/kcsan-checks.h b/include/linux/kcsan-checks.h
index 3cd8bb03eb41..b24253d3a442 100644
--- a/include/linux/kcsan-checks.h
+++ b/include/linux/kcsan-checks.h
@@ -3,6 +3,8 @@
 #ifndef _LINUX_KCSAN_CHECKS_H
 #define _LINUX_KCSAN_CHECKS_H
 
+/* Note: Only include what is already included by compiler.h. */
+#include <linux/compiler_attributes.h>
 #include <linux/types.h>
 
 /*
@@ -12,10 +14,12 @@
  *   WRITE : write access;
  *   ATOMIC: access is atomic;
  *   ASSERT: access is not a regular access, but an assertion;
+ *   SCOPED: access is a scoped access;
  */
 #define KCSAN_ACCESS_WRITE  0x1
 #define KCSAN_ACCESS_ATOMIC 0x2
 #define KCSAN_ACCESS_ASSERT 0x4
+#define KCSAN_ACCESS_SCOPED 0x8
 
 /*
  * __kcsan_*: Always calls into the runtime when KCSAN is enabled. This may be used
@@ -78,6 +82,52 @@ void kcsan_atomic_next(int n);
  */
 void kcsan_set_access_mask(unsigned long mask);
 
+/* Scoped access information. */
+struct kcsan_scoped_access {
+	struct list_head list;
+	const volatile void *ptr;
+	size_t size;
+	int type;
+};
+/*
+ * Automatically call kcsan_end_scoped_access() when kcsan_scoped_access goes
+ * out of scope; relies on attribute "cleanup", which is supported by all
+ * compilers that support KCSAN.
+ */
+#define __kcsan_cleanup_scoped                                                 \
+	__maybe_unused __attribute__((__cleanup__(kcsan_end_scoped_access)))
+
+/**
+ * kcsan_begin_scoped_access - begin scoped access
+ *
+ * Begin scoped access and initialize @sa, which will cause KCSAN to
+ * continuously check the memory range in the current thread until
+ * kcsan_end_scoped_access() is called for @sa.
+ *
+ * Scoped accesses are implemented by appending @sa to an internal list for the
+ * current execution context, and then checked on every call into the KCSAN
+ * runtime.
+ *
+ * @ptr: address of access
+ * @size: size of access
+ * @type: access type modifier
+ * @sa: struct kcsan_scoped_access to use for the scope of the access
+ */
+struct kcsan_scoped_access *
+kcsan_begin_scoped_access(const volatile void *ptr, size_t size, int type,
+			  struct kcsan_scoped_access *sa);
+
+/**
+ * kcsan_end_scoped_access - end scoped access
+ *
+ * End a scoped access, which will stop KCSAN checking the memory range.
+ * Requires that kcsan_begin_scoped_access() was previously called once for @sa.
+ *
+ * @sa: a previously initialized struct kcsan_scoped_access
+ */
+void kcsan_end_scoped_access(struct kcsan_scoped_access *sa);
+
+
 #else /* CONFIG_KCSAN */
 
 static inline void __kcsan_check_access(const volatile void *ptr, size_t size,
@@ -90,6 +140,13 @@ static inline void kcsan_flat_atomic_end(void)		{ }
 static inline void kcsan_atomic_next(int n)		{ }
 static inline void kcsan_set_access_mask(unsigned long mask) { }
 
+struct kcsan_scoped_access { };
+#define __kcsan_cleanup_scoped __maybe_unused
+static inline struct kcsan_scoped_access *
+kcsan_begin_scoped_access(const volatile void *ptr, size_t size, int type,
+			  struct kcsan_scoped_access *sa) { return sa; }
+static inline void kcsan_end_scoped_access(struct kcsan_scoped_access *sa) { }
+
 #endif /* CONFIG_KCSAN */
 
 /*