1 files changed, 65 insertions, 2 deletions

diff --git a/include/linux/compiler.h b/include/linux/compiler.h
index dd852b73b28..d5ad7b1118f 100644
--- a/include/linux/compiler.h
+++ b/include/linux/compiler.h
@@ -63,6 +63,13 @@ extern void __chk_io_ptr(const volatile void __iomem *);
 # include <linux/compiler-intel.h>
 #endif
 
+/* Clang compiler defines __GNUC__. So we will overwrite implementations
+ * coming from above header files here
+ */
+#ifdef __clang__
+#include <linux/compiler-clang.h>
+#endif
+
 /*
  * Generic compiler-dependent macros required for kernel
  * build go below this comment. Actual compiler/compiler version
@@ -170,6 +177,10 @@ void ftrace_likely_update(struct ftrace_branch_data *f, int val, int expect);
     (typeof(ptr)) (__ptr + (off)); })
 #endif
 
+#ifndef OPTIMIZER_HIDE_VAR
+#define OPTIMIZER_HIDE_VAR(var) barrier()
+#endif
+
 /* Not-quite-unique ID. */
 #ifndef __UNIQUE_ID
 # define __UNIQUE_ID(prefix) __PASTE(__PASTE(__UNIQUE_ID_, prefix), __LINE__)
@@ -298,6 +309,11 @@ void ftrace_likely_update(struct ftrace_branch_data *f, int val, int expect);
 # define __same_type(a, b) __builtin_types_compatible_p(typeof(a), typeof(b))
 #endif
 
+/* Is this type a native word size -- useful for atomic operations */
+#ifndef __native_word
+# define __native_word(t) (sizeof(t) == sizeof(int) || sizeof(t) == sizeof(long))
+#endif
+
 /* Compile time object size, -1 for unknown */
 #ifndef __compiletime_object_size
 # define __compiletime_object_size(obj) -1
@@ -307,10 +323,49 @@ void ftrace_likely_update(struct ftrace_branch_data *f, int val, int expect);
 #endif
 #ifndef __compiletime_error
 # define __compiletime_error(message)
+/*
+ * Sparse complains of variable sized arrays due to the temporary variable in
+ * __compiletime_assert. Unfortunately we can't just expand it out to make
+ * sparse see a constant array size without breaking compiletime_assert on old
+ * versions of GCC (e.g. 4.2.4), so hide the array from sparse altogether.
+ */
+# ifndef __CHECKER__
+#  define __compiletime_error_fallback(condition) \
+	do { ((void)sizeof(char[1 - 2 * condition])); } while (0)
+# endif
 #endif
-#ifndef __linktime_error
-# define __linktime_error(message)
+#ifndef __compiletime_error_fallback
+# define __compiletime_error_fallback(condition) do { } while (0)
 #endif
+
+#define __compiletime_assert(condition, msg, prefix, suffix)		\
+	do {								\
+		bool __cond = !(condition);				\
+		extern void prefix ## suffix(void) __compiletime_error(msg); \
+		if (__cond)						\
+			prefix ## suffix();				\
+		__compiletime_error_fallback(__cond);			\
+	} while (0)
+
+#define _compiletime_assert(condition, msg, prefix, suffix) \
+	__compiletime_assert(condition, msg, prefix, suffix)
+
+/**
+ * compiletime_assert - break build and emit msg if condition is false
+ * @condition: a compile-time constant condition to check
+ * @msg:       a message to emit if condition is false
+ *
+ * In tradition of POSIX assert, this macro will break the build if the
+ * supplied condition is *false*, emitting the supplied error message if the
+ * compiler has support to do so.
+ */
+#define compiletime_assert(condition, msg) \
+	_compiletime_assert(condition, msg, __compiletime_assert_, __LINE__)
+
+#define compiletime_assert_atomic_type(t)				\
+	compiletime_assert(__native_word(t),				\
+		"Need native word sized stores/loads for atomicity.")
+
 /*
  * Prevent the compiler from merging or refetching accesses.  The compiler
  * is also forbidden from reordering successive instances of ACCESS_ONCE(),
@@ -325,4 +380,12 @@ void ftrace_likely_update(struct ftrace_branch_data *f, int val, int expect);
  */
 #define ACCESS_ONCE(x) (*(volatile typeof(x) *)&(x))
 
+/* Ignore/forbid kprobes attach on very low level functions marked by this attribute: */
+#ifdef CONFIG_KPROBES
+# define __kprobes	__attribute__((__section__(".kprobes.text")))
+# define nokprobe_inline	__always_inline
+#else
+# define __kprobes
+# define nokprobe_inline	inline
+#endif
 #endif /* __LINUX_COMPILER_H */