#ifndef __LINUX_COMPILER_H#error "Please don't include <linux/compiler-gcc.h> directly, include <linux/compiler.h> instead."#endif/* * Common definitions for all gcc versions go here. */#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 proved 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 * shouldn't recognize the original var, and make assumptions about it. * * This is needed because the C standard makes it undefined to do * pointer arithmetic on "objects" outside their boundaries and the * gcc optimizers assume this is the case. In particular they * assume such arithmetic does not wrap. * * A miscompilation has been observed because of this on PPC. * To work around it we hide the relationship of the pointer and the object * using this macro. * * Versions of the ppc64 compiler before 4.1 had a bug where use of * RELOC_HIDE could trash r30. The bug can be worked around by changing * 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)); \})/* Make the optimizer believe the variable can be manipulated arbitrarily. */#define OPTIMIZER_HIDE_VAR(var) \ __asm__ ("" : "=r" (var) : "0" (var))#ifdef __CHECKER__#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]))#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) || \ !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#else/* A lot of inline functions can cause havoc with function tracing */#define inline inline notrace#define __inline__ __inline__ notrace#define __inline __inline notrace#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. * * 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. */#define __naked __attribute__((naked)) noinline __noclone notrace#define __noreturn __attribute__((noreturn))/* * From the GCC manual: * * Many functions have no effects except the return value and their * return value depends only on the parameters and/or global * variables. Such a function can be subject to common subexpression * elimination and loop optimization just as an arithmetic operator * would be. * [...] */#define __pure __attribute__((pure))#define __aligned(x) __attribute__((aligned(x)))#define __aligned_largest __attribute__((aligned))#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))#define __mode(x) __attribute__((mode(x)))/* 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))#define __malloc __attribute__((__malloc__))#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# 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#ifndef __CHECKER__#ifdef LATENT_ENTROPY_PLUGIN#define __latent_entropy __attribute__((latent_entropy))#endif#endif#ifdef CONFIG_STACK_VALIDATION#define annotate_unreachable() ({ \ asm("%c0:\t\n" \ ".pushsection .discard.unreachable\t\n" \ ".long %c0b - .\t\n" \ ".popsection\t\n" : : "i" (__LINE__)); \})#else#define annotate_unreachable()#endif/* * 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() \ do { annotate_unreachable(); __builtin_unreachable(); } while (0)/* Mark a function definition as prohibited from being cloned. */#define __noclone __attribute__((__noclone__, __optimize__("no-tracer")))#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#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/* * 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)/* * sparse (__CHECKER__) pretends to be gcc, but can't do constant * folding in __builtin_bswap*() (yet), so don't set these for it. */#if defined(CONFIG_ARCH_USE_BUILTIN_BSWAP) && !defined(__CHECKER__)#if GCC_VERSION >= 40400#define __HAVE_BUILTIN_BSWAP32__#define __HAVE_BUILTIN_BSWAP64__#endif#if GCC_VERSION >= 40800#define __HAVE_BUILTIN_BSWAP16__#endif#endif /* CONFIG_ARCH_USE_BUILTIN_BSWAP && !__CHECKER__ */#if GCC_VERSION >= 70000#define KASAN_ABI_VERSION 5#elif 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 __LINUX_COMPILER_H
#error "Please don't include <linux/compiler-gcc.h> directly, include <linux/compiler.h> instead."
#endif
/*
* Common definitions for all gcc versions go here.
*/
#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 proved 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
* shouldn't recognize the original var, and make assumptions about it.
*
* This is needed because the C standard makes it undefined to do
* pointer arithmetic on "objects" outside their boundaries and the
* gcc optimizers assume this is the case. In particular they
* assume such arithmetic does not wrap.
*
* A miscompilation has been observed because of this on PPC.
* To work around it we hide the relationship of the pointer and the object
* using this macro.
*
* Versions of the ppc64 compiler before 4.1 had a bug where use of
* RELOC_HIDE could trash r30. The bug can be worked around by changing
* 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)); \
})
/* Make the optimizer believe the variable can be manipulated arbitrarily. */
#define OPTIMIZER_HIDE_VAR(var) \
__asm__ ("" : "=r" (var) : "0" (var))
#ifdef __CHECKER__
#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]))
#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) || \
!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
#else
/* A lot of inline functions can cause havoc with function tracing */
#define inline inline notrace
#define __inline__ __inline__ notrace
#define __inline __inline notrace
#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.
*
* 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.
*/
#define __naked __attribute__((naked)) noinline __noclone notrace
#define __noreturn __attribute__((noreturn))
/*
* From the GCC manual:
*
* Many functions have no effects except the return value and their
* return value depends only on the parameters and/or global
* variables. Such a function can be subject to common subexpression
* elimination and loop optimization just as an arithmetic operator
* would be.
* [...]
*/
#define __pure __attribute__((pure))
#define __aligned(x) __attribute__((aligned(x)))
#define __aligned_largest __attribute__((aligned))
#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))
#define __mode(x) __attribute__((mode(x)))
/* 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))
#define __malloc __attribute__((__malloc__))
#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
# 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
#ifndef __CHECKER__
#ifdef LATENT_ENTROPY_PLUGIN
#define __latent_entropy __attribute__((latent_entropy))
#endif
#endif
#ifdef CONFIG_STACK_VALIDATION
#define annotate_unreachable() ({ \
asm("%c0:\t\n" \
".pushsection .discard.unreachable\t\n" \
".long %c0b - .\t\n" \
".popsection\t\n" : : "i" (__LINE__)); \
})
#else
#define annotate_unreachable()
#endif
/*
* 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() \
do { annotate_unreachable(); __builtin_unreachable(); } while (0)
/* Mark a function definition as prohibited from being cloned. */
#define __noclone __attribute__((__noclone__, __optimize__("no-tracer")))
#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
#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
/*
* 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)
/*
* sparse (__CHECKER__) pretends to be gcc, but can't do constant
* folding in __builtin_bswap*() (yet), so don't set these for it.
*/
#if defined(CONFIG_ARCH_USE_BUILTIN_BSWAP) && !defined(__CHECKER__)
#if GCC_VERSION >= 40400
#define __HAVE_BUILTIN_BSWAP32__
#define __HAVE_BUILTIN_BSWAP64__
#endif
#if GCC_VERSION >= 40800
#define __HAVE_BUILTIN_BSWAP16__
#endif
#endif /* CONFIG_ARCH_USE_BUILTIN_BSWAP && !__CHECKER__ */
#if GCC_VERSION >= 70000
#define KASAN_ABI_VERSION 5
#elif 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