compiler*.h: sync include/linux/compiler*.h with Linux 5.7-rc5

Copy these from Linux v5.7-rc5 tag.

This brings in some handy new attributes and is otherwise important to
keep in sync.

We drop the reference to smp_read_barrier_depends() as it is not
relevant on the architectures we support at this time, based on where
it's implemented in Linux today.  We drop the call to kasan_check_read()
as that is not relevant to U-Boot as well.

Cc: Masahiro Yamada <yamada.masahiro@socionext.com>
Signed-off-by: Tom Rini <trini@konsulko.com>

1 files changed, 38 insertions, 6 deletions

diff --git a/include/linux/compiler-clang.h b/include/linux/compiler-clang.h
index d1e49d52b6..333a6695a9 100644
--- a/include/linux/compiler-clang.h
+++ b/include/linux/compiler-clang.h
@@ -1,12 +1,44 @@
-#ifndef __LINUX_COMPILER_H
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef __LINUX_COMPILER_TYPES_H
 #error "Please don't include <linux/compiler-clang.h> directly, include <linux/compiler.h> instead."
 #endif
 
-/* Some compiler specific definitions are overwritten here
- * for Clang compiler
- */
+/* Compiler specific definitions for Clang compiler */
 
-#ifdef uninitialized_var
-#undef uninitialized_var
 #define uninitialized_var(x) x = *(&(x))
+
+/* same as gcc, this was present in clang-2.6 so we can assume it works
+ * with any version that can compile the kernel
+ */
+#define __UNIQUE_ID(prefix) __PASTE(__PASTE(__UNIQUE_ID_, prefix), __COUNTER__)
+
+/* all clang versions usable with the kernel support KASAN ABI version 5 */
+#define KASAN_ABI_VERSION 5
+
+#if __has_feature(address_sanitizer) || __has_feature(hwaddress_sanitizer)
+/* emulate gcc's __SANITIZE_ADDRESS__ flag */
+#define __SANITIZE_ADDRESS__
+#define __no_sanitize_address \
+		__attribute__((no_sanitize("address", "hwaddress")))
+#else
+#define __no_sanitize_address
 #endif
+
+/*
+ * Not all versions of clang implement the the type-generic versions
+ * of the builtin overflow checkers. Fortunately, clang implements
+ * __has_builtin allowing us to avoid awkward version
+ * checks. Unfortunately, we don't know which version of gcc clang
+ * pretends to be, so the macro may or may not be defined.
+ */
+#if __has_builtin(__builtin_mul_overflow) && \
+    __has_builtin(__builtin_add_overflow) && \
+    __has_builtin(__builtin_sub_overflow)
+#define COMPILER_HAS_GENERIC_BUILTIN_OVERFLOW 1
+#endif
+
+/* The following are for compatibility with GCC, from compiler-gcc.h,
+ * and may be redefined here because they should not be shared with other
+ * compilers, like ICC.
+ */
+#define barrier() __asm__ __volatile__("" : : : "memory")