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container_of() casts the original type to another which leads to the loss of the const qualifier if it is not specified in the caller-provided type. This easily leads to container_of() returning a non-const pointer to a const struct which the C compiler does not warn about. Acked-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com> Link: https://lore.kernel.org/r/20221024111627.75183-1-sakari.ailus@linux.intel.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
26 lines
818 B
C
26 lines
818 B
C
/* 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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* WARNING: any const qualifier of @ptr is lost.
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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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static_assert(__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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#endif /* _LINUX_CONTAINER_OF_H */
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