LXR linux/include/asm-generic/sections.h

   1#ifndef _ASM_GENERIC_SECTIONS_H_
   2#define _ASM_GENERIC_SECTIONS_H_
   3
   4/* References to section boundaries */
   5
   6#include <linux/compiler.h>
   7#include <linux/types.h>
   8
   9/*
  10 * Usage guidelines:
  11 * _text, _data: architecture specific, don't use them in arch-independent code
  12 * [_stext, _etext]: contains .text.* sections, may also contain .rodata.*
  13 *                   and/or .init.* sections
  14 * [_sdata, _edata]: contains .data.* sections, may also contain .rodata.*
  15 *                   and/or .init.* sections.
  16 * [__start_rodata, __end_rodata]: contains .rodata.* sections
  17 * [__init_begin, __init_end]: contains .init.* sections, but .init.text.*
  18 *                   may be out of this range on some architectures.
  19 * [_sinittext, _einittext]: contains .init.text.* sections
  20 * [__bss_start, __bss_stop]: contains BSS sections
  21 *
  22 * Following global variables are optional and may be unavailable on some
  23 * architectures and/or kernel configurations.
  24 *      _text, _data
  25 *      __kprobes_text_start, __kprobes_text_end
  26 *      __entry_text_start, __entry_text_end
  27 *      __ctors_start, __ctors_end
  28 */
  29extern char _text[], _stext[], _etext[];
  30extern char _data[], _sdata[], _edata[];
  31extern char __bss_start[], __bss_stop[];
  32extern char __init_begin[], __init_end[];
  33extern char _sinittext[], _einittext[];
  34extern char _end[];
  35extern char __per_cpu_load[], __per_cpu_start[], __per_cpu_end[];
  36extern char __kprobes_text_start[], __kprobes_text_end[];
  37extern char __entry_text_start[], __entry_text_end[];
  38extern char __start_rodata[], __end_rodata[];
  39
  40/* Start and end of .ctors section - used for constructor calls. */
  41extern char __ctors_start[], __ctors_end[];
  42
  43extern __visible const void __nosave_begin, __nosave_end;
  44
  45/* function descriptor handling (if any).  Override
  46 * in asm/sections.h */
  47#ifndef dereference_function_descriptor
  48#define dereference_function_descriptor(p) (p)
  49#endif
  50
  51/* random extra sections (if any).  Override
  52 * in asm/sections.h */
  53#ifndef arch_is_kernel_text
  54static inline int arch_is_kernel_text(unsigned long addr)
  55{
  56        return 0;
  57}
  58#endif
  59
  60#ifndef arch_is_kernel_data
  61static inline int arch_is_kernel_data(unsigned long addr)
  62{
  63        return 0;
  64}
  65#endif
  66
  67/**
  68 * memory_contains - checks if an object is contained within a memory region
  69 * @begin: virtual address of the beginning of the memory region
  70 * @end: virtual address of the end of the memory region
  71 * @virt: virtual address of the memory object
  72 * @size: size of the memory object
  73 *
  74 * Returns: true if the object specified by @virt and @size is entirely
  75 * contained within the memory region defined by @begin and @end, false
  76 * otherwise.
  77 */
  78static inline bool memory_contains(void *begin, void *end, void *virt,
  79                                   size_t size)
  80{
  81        return virt >= begin && virt + size <= end;
  82}
  83
  84/**
  85 * memory_intersects - checks if the region occupied by an object intersects
  86 *                     with another memory region
  87 * @begin: virtual address of the beginning of the memory regien
  88 * @end: virtual address of the end of the memory region
  89 * @virt: virtual address of the memory object
  90 * @size: size of the memory object
  91 *
  92 * Returns: true if an object's memory region, specified by @virt and @size,
  93 * intersects with the region specified by @begin and @end, false otherwise.
  94 */
  95static inline bool memory_intersects(void *begin, void *end, void *virt,
  96                                     size_t size)
  97{
  98        void *vend = virt + size;
  99
 100        return (virt >= begin && virt < end) || (vend >= begin && vend < end);
 101}
 102
 103/**
 104 * init_section_contains - checks if an object is contained within the init
 105 *                         section
 106 * @virt: virtual address of the memory object
 107 * @size: size of the memory object
 108 *
 109 * Returns: true if the object specified by @virt and @size is entirely
 110 * contained within the init section, false otherwise.
 111 */
 112static inline bool init_section_contains(void *virt, size_t size)
 113{
 114        return memory_contains(__init_begin, __init_end, virt, size);
 115}
 116
 117/**
 118 * init_section_intersects - checks if the region occupied by an object
 119 *                           intersects with the init section
 120 * @virt: virtual address of the memory object
 121 * @size: size of the memory object
 122 *
 123 * Returns: true if an object's memory region, specified by @virt and @size,
 124 * intersects with the init section, false otherwise.
 125 */
 126static inline bool init_section_intersects(void *virt, size_t size)
 127{
 128        return memory_intersects(__init_begin, __init_end, virt, size);
 129}
 130
 131#endif /* _ASM_GENERIC_SECTIONS_H_ */
 132