41 lines
1.4 KiB
C
41 lines
1.4 KiB
C
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/* SPDX-License-Identifier: GPL-2.0 */
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#ifndef _LINUX_CONTAINER_OF_H
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#define _LINUX_CONTAINER_OF_H
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#include <linux/build_bug.h>
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#include <linux/err.h>
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#define typeof_member(T, m) typeof(((T*)0)->m)
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/**
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* container_of - cast a member of a structure out to the containing structure
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* @ptr: the pointer to the member.
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* @type: the type of the container struct this is embedded in.
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* @member: the name of the member within the struct.
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*
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*/
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#define container_of(ptr, type, member) ({ \
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void *__mptr = (void *)(ptr); \
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BUILD_BUG_ON_MSG(!__same_type(*(ptr), ((type *)0)->member) && \
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!__same_type(*(ptr), void), \
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"pointer type mismatch in container_of()"); \
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((type *)(__mptr - offsetof(type, member))); })
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/**
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* container_of_safe - cast a member of a structure out to the containing structure
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* @ptr: the pointer to the member.
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* @type: the type of the container struct this is embedded in.
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* @member: the name of the member within the struct.
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*
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* If IS_ERR_OR_NULL(ptr), ptr is returned unchanged.
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*/
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#define container_of_safe(ptr, type, member) ({ \
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void *__mptr = (void *)(ptr); \
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BUILD_BUG_ON_MSG(!__same_type(*(ptr), ((type *)0)->member) && \
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!__same_type(*(ptr), void), \
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"pointer type mismatch in container_of()"); \
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IS_ERR_OR_NULL(__mptr) ? ERR_CAST(__mptr) : \
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((type *)(__mptr - offsetof(type, member))); })
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#endif /* _LINUX_CONTAINER_OF_H */
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