diff options
Diffstat (limited to 'include/linux/cleanup.h')
| -rw-r--r-- | include/linux/cleanup.h | 121 |
1 files changed, 92 insertions, 29 deletions
diff --git a/include/linux/cleanup.h b/include/linux/cleanup.h index 2573585b7f06..dbc4162921e9 100644 --- a/include/linux/cleanup.h +++ b/include/linux/cleanup.h @@ -208,19 +208,19 @@ */ #define DEFINE_FREE(_name, _type, _free) \ - static inline void __free_##_name(void *p) { _type _T = *(_type *)p; _free; } + static __always_inline void __free_##_name(void *p) { _type _T = *(_type *)p; _free; } #define __free(_name) __cleanup(__free_##_name) -#define __get_and_null(p, nullvalue) \ +#define __get_and_null(p, nullvalue) \ ({ \ - __auto_type __ptr = &(p); \ - __auto_type __val = *__ptr; \ + auto __ptr = &(p); \ + auto __val = *__ptr; \ *__ptr = nullvalue; \ __val; \ }) -static inline __must_check +static __always_inline __must_check const volatile void * __must_check_fn(const volatile void *val) { return val; } @@ -261,6 +261,10 @@ const volatile void * __must_check_fn(const volatile void *val) * CLASS(name, var)(args...): * declare the variable @var as an instance of the named class * + * CLASS_INIT(name, var, init_expr): + * declare the variable @var as an instance of the named class with + * custom initialization expression. + * * Ex. * * DEFINE_CLASS(fdget, struct fd, fdput(_T), fdget(fd), int fd) @@ -274,31 +278,40 @@ const volatile void * __must_check_fn(const volatile void *val) #define DEFINE_CLASS(_name, _type, _exit, _init, _init_args...) \ typedef _type class_##_name##_t; \ -static inline void class_##_name##_destructor(_type *p) \ +typedef _type lock_##_name##_t; \ +static __always_inline void class_##_name##_destructor(_type *p) \ + __no_context_analysis \ { _type _T = *p; _exit; } \ -static inline _type class_##_name##_constructor(_init_args) \ +static __always_inline _type class_##_name##_constructor(_init_args) \ + __no_context_analysis \ { _type t = _init; return t; } #define EXTEND_CLASS(_name, ext, _init, _init_args...) \ +typedef lock_##_name##_t lock_##_name##ext##_t; \ typedef class_##_name##_t class_##_name##ext##_t; \ -static inline void class_##_name##ext##_destructor(class_##_name##_t *p)\ +static __always_inline void class_##_name##ext##_destructor(class_##_name##_t *p) \ { class_##_name##_destructor(p); } \ -static inline class_##_name##_t class_##_name##ext##_constructor(_init_args) \ +static __always_inline class_##_name##_t class_##_name##ext##_constructor(_init_args) \ + __no_context_analysis \ { class_##_name##_t t = _init; return t; } #define CLASS(_name, var) \ class_##_name##_t var __cleanup(class_##_name##_destructor) = \ class_##_name##_constructor -#define scoped_class(_name, var, args) \ - for (CLASS(_name, var)(args); \ - __guard_ptr(_name)(&var) || !__is_cond_ptr(_name); \ - ({ goto _label; })) \ - if (0) { \ -_label: \ - break; \ +#define CLASS_INIT(_name, _var, _init_expr) \ + class_##_name##_t _var __cleanup(class_##_name##_destructor) = (_init_expr) + +#define __scoped_class(_name, var, _label, args...) \ + for (CLASS(_name, var)(args); ; ({ goto _label; })) \ + if (0) { \ +_label: \ + break; \ } else +#define scoped_class(_name, var, args...) \ + __scoped_class(_name, var, __UNIQUE_ID(label), args) + /* * DEFINE_GUARD(name, type, lock, unlock): * trivial wrapper around DEFINE_CLASS() above specifically @@ -340,6 +353,11 @@ _label: \ #define __DEFINE_CLASS_IS_CONDITIONAL(_name, _is_cond) \ static __maybe_unused const bool class_##_name##_is_conditional = _is_cond +#define DEFINE_CLASS_IS_UNCONDITIONAL(_name) \ + __DEFINE_CLASS_IS_CONDITIONAL(_name, false); \ + static inline void * class_##_name##_lock_ptr(class_##_name##_t *_T) \ + { return (void *)1; } + #define __GUARD_IS_ERR(_ptr) \ ({ \ unsigned long _rc = (__force unsigned long)(_ptr); \ @@ -347,7 +365,7 @@ static __maybe_unused const bool class_##_name##_is_conditional = _is_cond }) #define __DEFINE_GUARD_LOCK_PTR(_name, _exp) \ - static inline void *class_##_name##_lock_ptr(class_##_name##_t *_T) \ + static __always_inline void *class_##_name##_lock_ptr(class_##_name##_t *_T) \ { \ void *_ptr = (void *)(__force unsigned long)*(_exp); \ if (IS_ERR(_ptr)) { \ @@ -355,7 +373,7 @@ static __maybe_unused const bool class_##_name##_is_conditional = _is_cond } \ return _ptr; \ } \ - static inline int class_##_name##_lock_err(class_##_name##_t *_T) \ + static __always_inline int class_##_name##_lock_err(class_##_name##_t *_T) \ { \ long _rc = (__force unsigned long)*(_exp); \ if (!_rc) { \ @@ -384,9 +402,9 @@ static __maybe_unused const bool class_##_name##_is_conditional = _is_cond EXTEND_CLASS(_name, _ext, \ ({ void *_t = _T; int _RET = (_lock); if (_T && !(_cond)) _t = ERR_PTR(_RET); _t; }), \ class_##_name##_t _T) \ - static inline void * class_##_name##_ext##_lock_ptr(class_##_name##_t *_T) \ + static __always_inline void * class_##_name##_ext##_lock_ptr(class_##_name##_t *_T) \ { return class_##_name##_lock_ptr(_T); } \ - static inline int class_##_name##_ext##_lock_err(class_##_name##_t *_T) \ + static __always_inline int class_##_name##_ext##_lock_err(class_##_name##_t *_T) \ { return class_##_name##_lock_err(_T); } /* @@ -461,35 +479,80 @@ _label: \ */ #define __DEFINE_UNLOCK_GUARD(_name, _type, _unlock, ...) \ +typedef _type lock_##_name##_t; \ typedef struct { \ _type *lock; \ __VA_ARGS__; \ } class_##_name##_t; \ \ -static inline void class_##_name##_destructor(class_##_name##_t *_T) \ +static __always_inline void class_##_name##_destructor(class_##_name##_t *_T) \ + __no_context_analysis \ { \ if (!__GUARD_IS_ERR(_T->lock)) { _unlock; } \ } \ \ __DEFINE_GUARD_LOCK_PTR(_name, &_T->lock) -#define __DEFINE_LOCK_GUARD_1(_name, _type, _lock) \ -static inline class_##_name##_t class_##_name##_constructor(_type *l) \ +#define __DEFINE_LOCK_GUARD_1(_name, _type, ...) \ +static __always_inline class_##_name##_t class_##_name##_constructor(_type *l) \ + __no_context_analysis \ { \ class_##_name##_t _t = { .lock = l }, *_T = &_t; \ - _lock; \ + __VA_ARGS__; \ return _t; \ } -#define __DEFINE_LOCK_GUARD_0(_name, _lock) \ -static inline class_##_name##_t class_##_name##_constructor(void) \ +#define __DEFINE_LOCK_GUARD_0(_name, ...) \ +static __always_inline class_##_name##_t class_##_name##_constructor(void) \ + __no_context_analysis \ { \ class_##_name##_t _t = { .lock = (void*)1 }, \ *_T __maybe_unused = &_t; \ - _lock; \ + __VA_ARGS__; \ return _t; \ } +#define DECLARE_LOCK_GUARD_0_ATTRS(_name, _lock, _unlock) \ +static inline class_##_name##_t class_##_name##_constructor(void) _lock;\ +static inline void class_##_name##_destructor(class_##_name##_t *_T) _unlock; + +/* + * To support Context Analysis, we need to allow the compiler to see the + * acquisition and release of the context lock. However, the "cleanup" helpers + * wrap the lock in a struct passed through separate helper functions, which + * hides the lock alias from the compiler (no inter-procedural analysis). + * + * To make it work, we introduce an explicit alias to the context lock instance + * that is "cleaned" up with a separate cleanup helper. This helper is a dummy + * function that does nothing at runtime, but has the "_unlock" attribute to + * tell the compiler what happens at the end of the scope. + * + * To generalize the pattern, the WITH_LOCK_GUARD_1_ATTRS() macro should be used + * to redefine the constructor, which then also creates the alias variable with + * the right "cleanup" attribute, *after* DECLARE_LOCK_GUARD_1_ATTRS() has been + * used. + * + * Example usage: + * + * DECLARE_LOCK_GUARD_1_ATTRS(mutex, __acquires(_T), __releases(*(struct mutex **)_T)) + * #define class_mutex_constructor(_T) WITH_LOCK_GUARD_1_ATTRS(mutex, _T) + * + * Note: To support the for-loop based scoped helpers, the auxiliary variable + * must be a pointer to the "class" type because it is defined in the same + * statement as the guard variable. However, we initialize it with the lock + * pointer (despite the type mismatch, the compiler's alias analysis still works + * as expected). The "_unlock" attribute receives a pointer to the auxiliary + * variable (a double pointer to the class type), and must be cast and + * dereferenced appropriately. + */ +#define DECLARE_LOCK_GUARD_1_ATTRS(_name, _lock, _unlock) \ +static inline class_##_name##_t class_##_name##_constructor(lock_##_name##_t *_T) _lock;\ +static __always_inline void __class_##_name##_cleanup_ctx(class_##_name##_t **_T) \ + __no_context_analysis _unlock { } +#define WITH_LOCK_GUARD_1_ATTRS(_name, _T) \ + class_##_name##_constructor(_T), \ + *__UNIQUE_ID(unlock) __cleanup(__class_##_name##_cleanup_ctx) = (void *)(unsigned long)(_T) + #define DEFINE_LOCK_GUARD_1(_name, _type, _lock, _unlock, ...) \ __DEFINE_CLASS_IS_CONDITIONAL(_name, false); \ __DEFINE_UNLOCK_GUARD(_name, _type, _unlock, __VA_ARGS__) \ @@ -508,9 +571,9 @@ __DEFINE_LOCK_GUARD_0(_name, _lock) if (_T->lock && !(_cond)) _T->lock = ERR_PTR(_RET);\ _t; }), \ typeof_member(class_##_name##_t, lock) l) \ - static inline void * class_##_name##_ext##_lock_ptr(class_##_name##_t *_T) \ + static __always_inline void * class_##_name##_ext##_lock_ptr(class_##_name##_t *_T) \ { return class_##_name##_lock_ptr(_T); } \ - static inline int class_##_name##_ext##_lock_err(class_##_name##_t *_T) \ + static __always_inline int class_##_name##_ext##_lock_err(class_##_name##_t *_T) \ { return class_##_name##_lock_err(_T); } #define DEFINE_LOCK_GUARD_1_COND_3(_name, _ext, _lock) \ |