+++ /dev/null
-diff --git b/include/linux/compiler-gcc.h a/include/linux/compiler-gcc.h
-index e057bd2..22ab246 100644
---- b/include/linux/compiler-gcc.h
-+++ a/include/linux/compiler-gcc.h
-@@ -5,14 +5,28 @@
- /*
- * Common definitions for all gcc versions go here.
- */
--#define GCC_VERSION (__GNUC__ * 10000 \
-- + __GNUC_MINOR__ * 100 \
-- + __GNUC_PATCHLEVEL__)
--
-+#define GCC_VERSION (__GNUC__ * 10000 \
-+ + __GNUC_MINOR__ * 100 \
-+ + __GNUC_PATCHLEVEL__)
-
- /* Optimization barrier */
-+
- /* The "volatile" is due to gcc bugs */
- #define barrier() __asm__ __volatile__("": : :"memory")
-+/*
-+ * This version is i.e. to prevent dead stores elimination on @ptr
-+ * where gcc and llvm may behave differently when otherwise using
-+ * normal barrier(): while gcc behavior gets along with a normal
-+ * barrier(), llvm needs an explicit input variable to be assumed
-+ * clobbered. The issue is as follows: while the inline asm might
-+ * access any memory it wants, the compiler could have fit all of
-+ * @ptr into memory registers instead, and since @ptr never escaped
-+ * from that, it proofed that the inline asm wasn't touching any of
-+ * it. This version works well with both compilers, i.e. we're telling
-+ * the compiler that the inline asm absolutely may see the contents
-+ * of @ptr. See also: https://llvm.org/bugs/show_bug.cgi?id=15495
-+ */
-+#define barrier_data(ptr) __asm__ __volatile__("": :"r"(ptr) :"memory")
-
- /*
- * This macro obfuscates arithmetic on a variable address so that gcc
-@@ -32,58 +46,63 @@
- * the inline assembly constraint from =g to =r, in this particular
- * case either is valid.
- */
--#define RELOC_HIDE(ptr, off) \
-- ({ unsigned long __ptr; \
-- __asm__ ("" : "=r"(__ptr) : "0"(ptr)); \
-- (typeof(ptr)) (__ptr + (off)); })
-+#define RELOC_HIDE(ptr, off) \
-+({ \
-+ unsigned long __ptr; \
-+ __asm__ ("" : "=r"(__ptr) : "0"(ptr)); \
-+ (typeof(ptr)) (__ptr + (off)); \
-+})
-
- /* Make the optimizer believe the variable can be manipulated arbitrarily. */
--#define OPTIMIZER_HIDE_VAR(var) __asm__ ("" : "=r" (var) : "0" (var))
-+#define OPTIMIZER_HIDE_VAR(var) \
-+ __asm__ ("" : "=r" (var) : "0" (var))
-
- #ifdef __CHECKER__
--#define __must_be_array(arr) 0
-+#define __must_be_array(a) 0
- #else
- /* &a[0] degrades to a pointer: a different type from an array */
--#define __must_be_array(a) BUILD_BUG_ON_ZERO(__same_type((a), &(a)[0]))
-+#define __must_be_array(a) BUILD_BUG_ON_ZERO(__same_type((a), &(a)[0]))
- #endif
-
- /*
- * Force always-inline if the user requests it so via the .config,
- * or if gcc is too old:
- */
--#if !defined(CONFIG_ARCH_SUPPORTS_OPTIMIZED_INLINING) || \
-+#if !defined(CONFIG_ARCH_SUPPORTS_OPTIMIZED_INLINING) || \
- !defined(CONFIG_OPTIMIZE_INLINING) || (__GNUC__ < 4)
--# define inline inline __attribute__((always_inline)) notrace
--# define __inline__ __inline__ __attribute__((always_inline)) notrace
--# define __inline __inline __attribute__((always_inline)) notrace
-+#define inline inline __attribute__((always_inline)) notrace
-+#define __inline__ __inline__ __attribute__((always_inline)) notrace
-+#define __inline __inline __attribute__((always_inline)) notrace
- #else
- /* A lot of inline functions can cause havoc with function tracing */
--# define inline inline notrace
--# define __inline__ __inline__ notrace
--# define __inline __inline notrace
-+#define inline inline notrace
-+#define __inline__ __inline__ notrace
-+#define __inline __inline notrace
- #endif
-
--#define __deprecated __attribute__((deprecated))
--#ifndef __packed
--#define __packed __attribute__((packed))
--#endif
--#ifndef __weak
--#define __weak __attribute__((weak))
--#endif
-+#define __always_inline inline __attribute__((always_inline))
-+#define noinline __attribute__((noinline))
-+
-+#define __deprecated __attribute__((deprecated))
-+#define __packed __attribute__((packed))
-+#define __weak __attribute__((weak))
-+#define __alias(symbol) __attribute__((alias(#symbol)))
-
- /*
-- * it doesn't make sense on ARM (currently the only user of __naked) to trace
-- * naked functions because then mcount is called without stack and frame pointer
-- * being set up and there is no chance to restore the lr register to the value
-- * before mcount was called.
-+ * it doesn't make sense on ARM (currently the only user of __naked)
-+ * to trace naked functions because then mcount is called without
-+ * stack and frame pointer being set up and there is no chance to
-+ * restore the lr register to the value before mcount was called.
-+ *
-+ * The asm() bodies of naked functions often depend on standard calling
-+ * conventions, therefore they must be noinline and noclone.
- *
-- * The asm() bodies of naked functions often depend on standard calling conventions,
-- * therefore they must be noinline and noclone. GCC 4.[56] currently fail to enforce
-- * this, so we must do so ourselves. See GCC PR44290.
-+ * GCC 4.[56] currently fail to enforce this, so we must do so ourselves.
-+ * See GCC PR44290.
- */
--#define __naked __attribute__((naked)) noinline __noclone notrace
-+#define __naked __attribute__((naked)) noinline __noclone notrace
-
--#define __noreturn __attribute__((noreturn))
-+#define __noreturn __attribute__((noreturn))
-
- /*
- * From the GCC manual:
-@@ -95,34 +114,170 @@
- * would be.
- * [...]
- */
--#ifndef __pure
--#define __pure __attribute__((pure))
-+#define __pure __attribute__((pure))
-+#define __aligned(x) __attribute__((aligned(x)))
-+#define __printf(a, b) __attribute__((format(printf, a, b)))
-+#define __scanf(a, b) __attribute__((format(scanf, a, b)))
-+#define __attribute_const__ __attribute__((__const__))
-+#define __maybe_unused __attribute__((unused))
-+#define __always_unused __attribute__((unused))
-+
-+/* gcc version specific checks */
-+
-+#if GCC_VERSION < 30200
-+# error Sorry, your compiler is too old - please upgrade it.
-+#endif
-+
-+#if GCC_VERSION < 30300
-+# define __used __attribute__((__unused__))
-+#else
-+# define __used __attribute__((__used__))
-+#endif
-+
-+#ifdef CONFIG_GCOV_KERNEL
-+# if GCC_VERSION < 30400
-+# error "GCOV profiling support for gcc versions below 3.4 not included"
-+# endif /* __GNUC_MINOR__ */
-+#endif /* CONFIG_GCOV_KERNEL */
-+
-+#if GCC_VERSION >= 30400
-+#define __must_check __attribute__((warn_unused_result))
-+#endif
-+
-+#if GCC_VERSION >= 40000
-+
-+/* GCC 4.1.[01] miscompiles __weak */
-+#ifdef __KERNEL__
-+# if GCC_VERSION >= 40100 && GCC_VERSION <= 40101
-+# error Your version of gcc miscompiles the __weak directive
-+# endif
-+#endif
-+
-+#define __used __attribute__((__used__))
-+#define __compiler_offsetof(a, b) \
-+ __builtin_offsetof(a, b)
-+
-+#if GCC_VERSION >= 40100 && GCC_VERSION < 40600
-+# define __compiletime_object_size(obj) __builtin_object_size(obj, 0)
-+#endif
-+
-+#if GCC_VERSION >= 40300
-+/* Mark functions as cold. gcc will assume any path leading to a call
-+ * to them will be unlikely. This means a lot of manual unlikely()s
-+ * are unnecessary now for any paths leading to the usual suspects
-+ * like BUG(), printk(), panic() etc. [but let's keep them for now for
-+ * older compilers]
-+ *
-+ * Early snapshots of gcc 4.3 don't support this and we can't detect this
-+ * in the preprocessor, but we can live with this because they're unreleased.
-+ * Maketime probing would be overkill here.
-+ *
-+ * gcc also has a __attribute__((__hot__)) to move hot functions into
-+ * a special section, but I don't see any sense in this right now in
-+ * the kernel context
-+ */
-+#define __cold __attribute__((__cold__))
-+
-+#define __UNIQUE_ID(prefix) __PASTE(__PASTE(__UNIQUE_ID_, prefix), __COUNTER__)
-+
-+#ifndef __CHECKER__
-+# define __compiletime_warning(message) __attribute__((warning(message)))
-+# define __compiletime_error(message) __attribute__((error(message)))
-+#endif /* __CHECKER__ */
-+#endif /* GCC_VERSION >= 40300 */
-+
-+#if GCC_VERSION >= 40500
-+/*
-+ * Mark a position in code as unreachable. This can be used to
-+ * suppress control flow warnings after asm blocks that transfer
-+ * control elsewhere.
-+ *
-+ * Early snapshots of gcc 4.5 don't support this and we can't detect
-+ * this in the preprocessor, but we can live with this because they're
-+ * unreleased. Really, we need to have autoconf for the kernel.
-+ */
-+#define unreachable() __builtin_unreachable()
-+
-+/* Mark a function definition as prohibited from being cloned. */
-+#define __noclone __attribute__((__noclone__))
-+
-+#endif /* GCC_VERSION >= 40500 */
-+
-+#if GCC_VERSION >= 40600
-+/*
-+ * When used with Link Time Optimization, gcc can optimize away C functions or
-+ * variables which are referenced only from assembly code. __visible tells the
-+ * optimizer that something else uses this function or variable, thus preventing
-+ * this.
-+ */
-+#define __visible __attribute__((externally_visible))
- #endif
--#ifndef __aligned
--#define __aligned(x) __attribute__((aligned(x)))
-+
-+
-+#if GCC_VERSION >= 40900 && !defined(__CHECKER__)
-+/*
-+ * __assume_aligned(n, k): Tell the optimizer that the returned
-+ * pointer can be assumed to be k modulo n. The second argument is
-+ * optional (default 0), so we use a variadic macro to make the
-+ * shorthand.
-+ *
-+ * Beware: Do not apply this to functions which may return
-+ * ERR_PTRs. Also, it is probably unwise to apply it to functions
-+ * returning extra information in the low bits (but in that case the
-+ * compiler should see some alignment anyway, when the return value is
-+ * massaged by 'flags = ptr & 3; ptr &= ~3;').
-+ */
-+#define __assume_aligned(a, ...) __attribute__((__assume_aligned__(a, ## __VA_ARGS__)))
- #endif
--#define __printf(a, b) __attribute__((format(printf, a, b)))
--#define __scanf(a, b) __attribute__((format(scanf, a, b)))
--#define noinline __attribute__((noinline))
--#define __attribute_const__ __attribute__((__const__))
--#define __maybe_unused __attribute__((unused))
--#define __always_unused __attribute__((unused))
-
--#define __gcc_header(x) #x
--#define _gcc_header(x) __gcc_header(linux/compiler-gcc##x.h)
--#define gcc_header(x) _gcc_header(x)
--#include gcc_header(__GNUC__)
-+/*
-+ * GCC 'asm goto' miscompiles certain code sequences:
-+ *
-+ * http://gcc.gnu.org/bugzilla/show_bug.cgi?id=58670
-+ *
-+ * Work it around via a compiler barrier quirk suggested by Jakub Jelinek.
-+ *
-+ * (asm goto is automatically volatile - the naming reflects this.)
-+ */
-+#define asm_volatile_goto(x...) do { asm goto(x); asm (""); } while (0)
-+
-+#ifdef CONFIG_ARCH_USE_BUILTIN_BSWAP
-+#if GCC_VERSION >= 40400
-+#define __HAVE_BUILTIN_BSWAP32__
-+#define __HAVE_BUILTIN_BSWAP64__
-+#endif
-+#if GCC_VERSION >= 40800 || (defined(__powerpc__) && GCC_VERSION >= 40600)
-+#define __HAVE_BUILTIN_BSWAP16__
-+#endif
-+#endif /* CONFIG_ARCH_USE_BUILTIN_BSWAP */
-+
-+#if GCC_VERSION >= 50000
-+#define KASAN_ABI_VERSION 4
-+#elif GCC_VERSION >= 40902
-+#define KASAN_ABI_VERSION 3
-+#endif
-+
-+#if GCC_VERSION >= 40902
-+/*
-+ * Tell the compiler that address safety instrumentation (KASAN)
-+ * should not be applied to that function.
-+ * Conflicts with inlining: https://gcc.gnu.org/bugzilla/show_bug.cgi?id=67368
-+ */
-+#define __no_sanitize_address __attribute__((no_sanitize_address))
-+#endif
-+
-+#endif /* gcc version >= 40000 specific checks */
-
- #if !defined(__noclone)
- #define __noclone /* not needed */
- #endif
-
-+#if !defined(__no_sanitize_address)
-+#define __no_sanitize_address
-+#endif
-+
- /*
- * A trick to suppress uninitialized variable warning without generating any
- * code
- */
- #define uninitialized_var(x) x = x
--
--#ifndef __always_inline
--#define __always_inline inline __attribute__((always_inline))
--#endif
-diff --git b/include/linux/compiler-gcc3.h a/include/linux/compiler-gcc3.h
-deleted file mode 100644
-index 7d89feb..0000000
---- b/include/linux/compiler-gcc3.h
-+++ /dev/null
-@@ -1,23 +0,0 @@
--#ifndef __LINUX_COMPILER_H
--#error "Please don't include <linux/compiler-gcc3.h> directly, include <linux/compiler.h> instead."
--#endif
--
--#if GCC_VERSION < 30200
--# error Sorry, your compiler is too old - please upgrade it.
--#endif
--
--#if GCC_VERSION >= 30300
--# define __used __attribute__((__used__))
--#else
--# define __used __attribute__((__unused__))
--#endif
--
--#if GCC_VERSION >= 30400
--#define __must_check __attribute__((warn_unused_result))
--#endif
--
--#ifdef CONFIG_GCOV_KERNEL
--# if GCC_VERSION < 30400
--# error "GCOV profiling support for gcc versions below 3.4 not included"
--# endif /* __GNUC_MINOR__ */
--#endif /* CONFIG_GCOV_KERNEL */
-diff --git b/include/linux/compiler-gcc4.h a/include/linux/compiler-gcc4.h
-deleted file mode 100644
-index c982a09..0000000
---- b/include/linux/compiler-gcc4.h
-+++ /dev/null
-@@ -1,81 +0,0 @@
--#ifndef __LINUX_COMPILER_H
--#error "Please don't include <linux/compiler-gcc4.h> directly, include <linux/compiler.h> instead."
--#endif
--
--#define __used __attribute__((__used__))
--#define __must_check __attribute__((warn_unused_result))
--#define __compiler_offsetof(a,b) __builtin_offsetof(a,b)
--
--#if GCC_VERSION >= 40100 && GCC_VERSION < 40600
--# define __compiletime_object_size(obj) __builtin_object_size(obj, 0)
--#endif
--
--#if GCC_VERSION >= 40300
--/* Mark functions as cold. gcc will assume any path leading to a call
-- to them will be unlikely. This means a lot of manual unlikely()s
-- are unnecessary now for any paths leading to the usual suspects
-- like BUG(), printk(), panic() etc. [but let's keep them for now for
-- older compilers]
--
-- Early snapshots of gcc 4.3 don't support this and we can't detect this
-- in the preprocessor, but we can live with this because they're unreleased.
-- Maketime probing would be overkill here.
--
-- gcc also has a __attribute__((__hot__)) to move hot functions into
-- a special section, but I don't see any sense in this right now in
-- the kernel context */
--#define __cold __attribute__((__cold__))
--
--#define __UNIQUE_ID(prefix) __PASTE(__PASTE(__UNIQUE_ID_, prefix), __COUNTER__)
--
--#ifndef __CHECKER__
--# define __compiletime_warning(message) __attribute__((warning(message)))
--# define __compiletime_error(message) __attribute__((error(message)))
--#endif /* __CHECKER__ */
--#endif /* GCC_VERSION >= 40300 */
--
--#if GCC_VERSION >= 40500
--/*
-- * Mark a position in code as unreachable. This can be used to
-- * suppress control flow warnings after asm blocks that transfer
-- * control elsewhere.
-- *
-- * Early snapshots of gcc 4.5 don't support this and we can't detect
-- * this in the preprocessor, but we can live with this because they're
-- * unreleased. Really, we need to have autoconf for the kernel.
-- */
--#define unreachable() __builtin_unreachable()
--
--/* Mark a function definition as prohibited from being cloned. */
--#define __noclone __attribute__((__noclone__))
--
--#endif /* GCC_VERSION >= 40500 */
--
--#if GCC_VERSION >= 40600
--/*
-- * Tell the optimizer that something else uses this function or variable.
-- */
--#define __visible __attribute__((externally_visible))
--#endif
--
--/*
-- * GCC 'asm goto' miscompiles certain code sequences:
-- *
-- * http://gcc.gnu.org/bugzilla/show_bug.cgi?id=58670
-- *
-- * Work it around via a compiler barrier quirk suggested by Jakub Jelinek.
-- * Fixed in GCC 4.8.2 and later versions.
-- *
-- * (asm goto is automatically volatile - the naming reflects this.)
-- */
--#define asm_volatile_goto(x...) do { asm goto(x); asm (""); } while (0)
--
--#ifdef CONFIG_ARCH_USE_BUILTIN_BSWAP
--#if GCC_VERSION >= 40400
--#define __HAVE_BUILTIN_BSWAP32__
--#define __HAVE_BUILTIN_BSWAP64__
--#endif
--#if GCC_VERSION >= 40800 || (defined(__powerpc__) && GCC_VERSION >= 40600)
--#define __HAVE_BUILTIN_BSWAP16__
--#endif
--#endif /* CONFIG_ARCH_USE_BUILTIN_BSWAP */
-diff --git b/include/linux/compiler-intel.h a/include/linux/compiler-intel.h
-index ba147a1..d4c7113 100644
---- b/include/linux/compiler-intel.h
-+++ a/include/linux/compiler-intel.h
-@@ -13,9 +13,14 @@
- /* Intel ECC compiler doesn't support gcc specific asm stmts.
- * It uses intrinsics to do the equivalent things.
- */
-+#undef barrier
-+#undef barrier_data
- #undef RELOC_HIDE
- #undef OPTIMIZER_HIDE_VAR
-
-+#define barrier() __memory_barrier()
-+#define barrier_data(ptr) barrier()
-+
- #define RELOC_HIDE(ptr, off) \
- ({ unsigned long __ptr; \
- __ptr = (unsigned long) (ptr); \
-diff --git b/include/linux/compiler.h a/include/linux/compiler.h
-index d5ad7b1..020ad16 100644
---- b/include/linux/compiler.h
-+++ a/include/linux/compiler.h
-@@ -17,6 +17,7 @@
- # define __release(x) __context__(x,-1)
- # define __cond_lock(x,c) ((c) ? ({ __acquire(x); 1; }) : 0)
- # define __percpu __attribute__((noderef, address_space(3)))
-+# define __pmem __attribute__((noderef, address_space(5)))
- #ifdef CONFIG_SPARSE_RCU_POINTER
- # define __rcu __attribute__((noderef, address_space(4)))
- #else
-@@ -42,6 +43,7 @@ extern void __chk_io_ptr(const volatile void __iomem *);
- # define __cond_lock(x,c) (c)
- # define __percpu
- # define __rcu
-+# define __pmem
- #endif
-
- /* Indirect macros required for expanded argument pasting, eg. __LINE__. */
-@@ -54,7 +56,11 @@ extern void __chk_io_ptr(const volatile void __iomem *);
- #include <linux/compiler-gcc.h>
- #endif
-
-+#if defined(CC_USING_HOTPATCH) && !defined(__CHECKER__)
-+#define notrace __attribute__((hotpatch(0,0)))
-+#else
- #define notrace __attribute__((no_instrument_function))
-+#endif
-
- /* Intel compiler defines __GNUC__. So we will overwrite implementations
- * coming from above header files here
-@@ -138,7 +144,7 @@ void ftrace_likely_update(struct ftrace_branch_data *f, int val, int expect);
- */
- #define if(cond, ...) __trace_if( (cond , ## __VA_ARGS__) )
- #define __trace_if(cond) \
-- if (__builtin_constant_p((cond)) ? !!(cond) : \
-+ if (__builtin_constant_p(!!(cond)) ? !!(cond) : \
- ({ \
- int ______r; \
- static struct ftrace_branch_data \
-@@ -165,6 +171,10 @@ void ftrace_likely_update(struct ftrace_branch_data *f, int val, int expect);
- # define barrier() __memory_barrier()
- #endif
-
-+#ifndef barrier_data
-+# define barrier_data(ptr) barrier()
-+#endif
-+
- /* Unreachable code */
- #ifndef unreachable
- # define unreachable() do { } while (1)
-@@ -186,6 +196,126 @@ void ftrace_likely_update(struct ftrace_branch_data *f, int val, int expect);
- # define __UNIQUE_ID(prefix) __PASTE(__PASTE(__UNIQUE_ID_, prefix), __LINE__)
- #endif
-
-+#include <linux/types.h>
-+
-+#define __READ_ONCE_SIZE \
-+({ \
-+ switch (size) { \
-+ case 1: *(__u8 *)res = *(volatile __u8 *)p; break; \
-+ case 2: *(__u16 *)res = *(volatile __u16 *)p; break; \
-+ case 4: *(__u32 *)res = *(volatile __u32 *)p; break; \
-+ case 8: *(__u64 *)res = *(volatile __u64 *)p; break; \
-+ default: \
-+ barrier(); \
-+ __builtin_memcpy((void *)res, (const void *)p, size); \
-+ barrier(); \
-+ } \
-+})
-+
-+static __always_inline
-+void __read_once_size(const volatile void *p, void *res, int size)
-+{
-+ __READ_ONCE_SIZE;
-+}
-+
-+#ifdef CONFIG_KASAN
-+/*
-+ * This function is not 'inline' because __no_sanitize_address confilcts
-+ * with inlining. Attempt to inline it may cause a build failure.
-+ * https://gcc.gnu.org/bugzilla/show_bug.cgi?id=67368
-+ * '__maybe_unused' allows us to avoid defined-but-not-used warnings.
-+ */
-+static __no_sanitize_address __maybe_unused
-+void __read_once_size_nocheck(const volatile void *p, void *res, int size)
-+{
-+ __READ_ONCE_SIZE;
-+}
-+#else
-+static __always_inline
-+void __read_once_size_nocheck(const volatile void *p, void *res, int size)
-+{
-+ __READ_ONCE_SIZE;
-+}
-+#endif
-+
-+static __always_inline void __write_once_size(volatile void *p, void *res, int size)
-+{
-+ switch (size) {
-+ case 1: *(volatile __u8 *)p = *(__u8 *)res; break;
-+ case 2: *(volatile __u16 *)p = *(__u16 *)res; break;
-+ case 4: *(volatile __u32 *)p = *(__u32 *)res; break;
-+ case 8: *(volatile __u64 *)p = *(__u64 *)res; break;
-+ default:
-+ barrier();
-+ __builtin_memcpy((void *)p, (const void *)res, size);
-+ barrier();
-+ }
-+}
-+
-+/*
-+ * Prevent the compiler from merging or refetching reads or writes. The
-+ * compiler is also forbidden from reordering successive instances of
-+ * READ_ONCE, WRITE_ONCE and ACCESS_ONCE (see below), but only when the
-+ * compiler is aware of some particular ordering. One way to make the
-+ * compiler aware of ordering is to put the two invocations of READ_ONCE,
-+ * WRITE_ONCE or ACCESS_ONCE() in different C statements.
-+ *
-+ * In contrast to ACCESS_ONCE these two macros will also work on aggregate
-+ * data types like structs or unions. If the size of the accessed data
-+ * type exceeds the word size of the machine (e.g., 32 bits or 64 bits)
-+ * READ_ONCE() and WRITE_ONCE() will fall back to memcpy and print a
-+ * compile-time warning.
-+ *
-+ * Their two major use cases are: (1) Mediating communication between
-+ * process-level code and irq/NMI handlers, all running on the same CPU,
-+ * and (2) Ensuring that the compiler does not fold, spindle, or otherwise
-+ * mutilate accesses that either do not require ordering or that interact
-+ * with an explicit memory barrier or atomic instruction that provides the
-+ * required ordering.
-+ */
-+
-+#define __READ_ONCE(x, check) \
-+({ \
-+ union { typeof(x) __val; char __c[1]; } __u; \
-+ if (check) \
-+ __read_once_size(&(x), __u.__c, sizeof(x)); \
-+ else \
-+ __read_once_size_nocheck(&(x), __u.__c, sizeof(x)); \
-+ __u.__val; \
-+})
-+#define READ_ONCE(x) __READ_ONCE(x, 1)
-+
-+/*
-+ * Use READ_ONCE_NOCHECK() instead of READ_ONCE() if you need
-+ * to hide memory access from KASAN.
-+ */
-+#define READ_ONCE_NOCHECK(x) __READ_ONCE(x, 0)
-+
-+#define WRITE_ONCE(x, val) \
-+({ \
-+ union { typeof(x) __val; char __c[1]; } __u = \
-+ { .__val = (__force typeof(x)) (val) }; \
-+ __write_once_size(&(x), __u.__c, sizeof(x)); \
-+ __u.__val; \
-+})
-+
-+/**
-+ * smp_cond_acquire() - Spin wait for cond with ACQUIRE ordering
-+ * @cond: boolean expression to wait for
-+ *
-+ * Equivalent to using smp_load_acquire() on the condition variable but employs
-+ * the control dependency of the wait to reduce the barrier on many platforms.
-+ *
-+ * The control dependency provides a LOAD->STORE order, the additional RMB
-+ * provides LOAD->LOAD order, together they provide LOAD->{LOAD,STORE} order,
-+ * aka. ACQUIRE.
-+ */
-+#define smp_cond_acquire(cond) do { \
-+ while (!(cond)) \
-+ cpu_relax(); \
-+ smp_rmb(); /* ctrl + rmb := acquire */ \
-+} while (0)
-+
- #endif /* __KERNEL__ */
-
- #endif /* __ASSEMBLY__ */
-@@ -304,6 +434,14 @@ void ftrace_likely_update(struct ftrace_branch_data *f, int val, int expect);
- #define __visible
- #endif
-
-+/*
-+ * Assume alignment of return value.
-+ */
-+#ifndef __assume_aligned
-+#define __assume_aligned(a, ...)
-+#endif
-+
-+
- /* Are two types/vars the same type (ignoring qualifiers)? */
- #ifndef __same_type
- # define __same_type(a, b) __builtin_types_compatible_p(typeof(a), typeof(b))
-@@ -311,7 +449,7 @@ void ftrace_likely_update(struct ftrace_branch_data *f, int val, int expect);
-
- /* 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))
-+# define __native_word(t) (sizeof(t) == sizeof(char) || sizeof(t) == sizeof(short) || sizeof(t) == sizeof(int) || sizeof(t) == sizeof(long))
- #endif
-
- /* Compile time object size, -1 for unknown */
-@@ -373,12 +511,38 @@ void ftrace_likely_update(struct ftrace_branch_data *f, int val, int expect);
- * to make the compiler aware of ordering is to put the two invocations of
- * ACCESS_ONCE() in different C statements.
- *
-- * This macro does absolutely -nothing- to prevent the CPU from reordering,
-- * merging, or refetching absolutely anything at any time. Its main intended
-- * use is to mediate communication between process-level code and irq/NMI
-- * handlers, all running on the same CPU.
-+ * ACCESS_ONCE will only work on scalar types. For union types, ACCESS_ONCE
-+ * on a union member will work as long as the size of the member matches the
-+ * size of the union and the size is smaller than word size.
-+ *
-+ * The major use cases of ACCESS_ONCE used to be (1) Mediating communication
-+ * between process-level code and irq/NMI handlers, all running on the same CPU,
-+ * and (2) Ensuring that the compiler does not fold, spindle, or otherwise
-+ * mutilate accesses that either do not require ordering or that interact
-+ * with an explicit memory barrier or atomic instruction that provides the
-+ * required ordering.
-+ *
-+ * If possible use READ_ONCE()/WRITE_ONCE() instead.
-+ */
-+#define __ACCESS_ONCE(x) ({ \
-+ __maybe_unused typeof(x) __var = (__force typeof(x)) 0; \
-+ (volatile typeof(x) *)&(x); })
-+#define ACCESS_ONCE(x) (*__ACCESS_ONCE(x))
-+
-+/**
-+ * lockless_dereference() - safely load a pointer for later dereference
-+ * @p: The pointer to load
-+ *
-+ * Similar to rcu_dereference(), but for situations where the pointed-to
-+ * object's lifetime is managed by something other than RCU. That
-+ * "something other" might be reference counting or simple immortality.
- */
--#define ACCESS_ONCE(x) (*(volatile typeof(x) *)&(x))
-+#define lockless_dereference(p) \
-+({ \
-+ typeof(p) _________p1 = READ_ONCE(p); \
-+ smp_read_barrier_depends(); /* Dependency order vs. p above. */ \
-+ (_________p1); \
-+})
-
- /* Ignore/forbid kprobes attach on very low level functions marked by this attribute: */
- #ifdef CONFIG_KPROBES
projects / openwrt / openwrt.git / commitdiff