diff options
Diffstat (limited to 'tools/mkimage/patches/200-compiler-support.patch')
| -rw-r--r-- | tools/mkimage/patches/200-compiler-support.patch | 702 |
1 files changed, 0 insertions, 702 deletions
diff --git a/tools/mkimage/patches/200-compiler-support.patch b/tools/mkimage/patches/200-compiler-support.patch deleted file mode 100644 index ca9c5b5a30..0000000000 --- a/tools/mkimage/patches/200-compiler-support.patch +++ /dev/null @@ -1,702 +0,0 @@ -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 |