diff options
Diffstat (limited to 'include/linux/cleanup.h')
-rw-r--r-- | include/linux/cleanup.h | 57 |
1 files changed, 34 insertions, 23 deletions
diff --git a/include/linux/cleanup.h b/include/linux/cleanup.h index 966fcc5ff8ef..7093e1d08af0 100644 --- a/include/linux/cleanup.h +++ b/include/linux/cleanup.h @@ -212,10 +212,29 @@ const volatile void * __must_check_fn(const volatile void *val) { return val; } #define no_free_ptr(p) \ - ((typeof(p)) __must_check_fn(__get_and_null(p, NULL))) + ((typeof(p)) __must_check_fn((__force const volatile void *)__get_and_null(p, NULL))) #define return_ptr(p) return no_free_ptr(p) +/* + * Only for situations where an allocation is handed in to another function + * and consumed by that function on success. + * + * struct foo *f __free(kfree) = kzalloc(sizeof(*f), GFP_KERNEL); + * + * setup(f); + * if (some_condition) + * return -EINVAL; + * .... + * ret = bar(f); + * if (!ret) + * retain_and_null_ptr(f); + * return ret; + * + * After retain_and_null_ptr(f) the variable f is NULL and cannot be + * dereferenced anymore. + */ +#define retain_and_null_ptr(p) ((void)__get_and_null(p, NULL)) /* * DEFINE_CLASS(name, type, exit, init, init_args...): @@ -273,12 +292,6 @@ static inline class_##_name##_t class_##_name##ext##_constructor(_init_args) \ * an anonymous instance of the (guard) class, not recommended for * conditional locks. * - * if_not_guard(name, args...) { <error handling> }: - * convenience macro for conditional guards that calls the statement that - * follows only if the lock was not acquired (typically an error return). - * - * Only for conditional locks. - * * scoped_guard (name, args...) { }: * similar to CLASS(name, scope)(args), except the variable (with the * explicit name 'scope') is declard in a for-loop such that its scope is @@ -297,11 +310,21 @@ static inline class_##_name##_t class_##_name##ext##_constructor(_init_args) \ #define __DEFINE_CLASS_IS_CONDITIONAL(_name, _is_cond) \ static __maybe_unused const bool class_##_name##_is_conditional = _is_cond -#define DEFINE_GUARD(_name, _type, _lock, _unlock) \ +#define __DEFINE_GUARD_LOCK_PTR(_name, _exp) \ + static inline void * class_##_name##_lock_ptr(class_##_name##_t *_T) \ + { return (void *)(__force unsigned long)*(_exp); } + +#define DEFINE_CLASS_IS_GUARD(_name) \ __DEFINE_CLASS_IS_CONDITIONAL(_name, false); \ + __DEFINE_GUARD_LOCK_PTR(_name, _T) + +#define DEFINE_CLASS_IS_COND_GUARD(_name) \ + __DEFINE_CLASS_IS_CONDITIONAL(_name, true); \ + __DEFINE_GUARD_LOCK_PTR(_name, _T) + +#define DEFINE_GUARD(_name, _type, _lock, _unlock) \ DEFINE_CLASS(_name, _type, if (_T) { _unlock; }, ({ _lock; _T; }), _type _T); \ - static inline void * class_##_name##_lock_ptr(class_##_name##_t *_T) \ - { return (void *)(__force unsigned long)*_T; } + DEFINE_CLASS_IS_GUARD(_name) #define DEFINE_GUARD_COND(_name, _ext, _condlock) \ __DEFINE_CLASS_IS_CONDITIONAL(_name##_ext, true); \ @@ -350,14 +373,6 @@ _label: \ #define scoped_cond_guard(_name, _fail, args...) \ __scoped_cond_guard(_name, _fail, __UNIQUE_ID(label), args) -#define __if_not_guard(_name, _id, args...) \ - BUILD_BUG_ON(!__is_cond_ptr(_name)); \ - CLASS(_name, _id)(args); \ - if (!__guard_ptr(_name)(&_id)) - -#define if_not_guard(_name, args...) \ - __if_not_guard(_name, __UNIQUE_ID(guard), args) - /* * Additional helper macros for generating lock guards with types, either for * locks that don't have a native type (eg. RCU, preempt) or those that need a @@ -389,11 +404,7 @@ static inline void class_##_name##_destructor(class_##_name##_t *_T) \ if (_T->lock) { _unlock; } \ } \ \ -static inline void *class_##_name##_lock_ptr(class_##_name##_t *_T) \ -{ \ - return (void *)(__force unsigned long)_T->lock; \ -} - +__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) \ |