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 * [__start_data_ro_after_init, __end_data_ro_after_init]:
  18 *                   contains data.ro_after_init section
  19 * [__init_begin, __init_end]: contains .init.* sections, but .init.text.*
  20 *                   may be out of this range on some architectures.
  21 * [_sinittext, _einittext]: contains .init.text.* sections
  22 * [__bss_start, __bss_stop]: contains BSS sections
  23 *
  24 * Following global variables are optional and may be unavailable on some
  25 * architectures and/or kernel configurations.
  26 *      _text, _data
  27 *      __kprobes_text_start, __kprobes_text_end
  28 *      __entry_text_start, __entry_text_end
  29 *      __ctors_start, __ctors_end
  30 */
  31extern char _text[], _stext[], _etext[];
  32extern char _data[], _sdata[], _edata[];
  33extern char __bss_start[], __bss_stop[];
  34extern char __init_begin[], __init_end[];
  35extern char _sinittext[], _einittext[];
  36extern char __start_data_ro_after_init[], __end_data_ro_after_init[];
  37extern char _end[];
  38extern char __per_cpu_load[], __per_cpu_start[], __per_cpu_end[];
  39extern char __kprobes_text_start[], __kprobes_text_end[];
  40extern char __entry_text_start[], __entry_text_end[];
  41extern char __start_rodata[], __end_rodata[];
  42
  43/* Start and end of .ctors section - used for constructor calls. */
  44extern char __ctors_start[], __ctors_end[];
  45
  46extern __visible const void __nosave_begin, __nosave_end;
  47
  48/* function descriptor handling (if any).  Override
  49 * in asm/sections.h */
  50#ifndef dereference_function_descriptor
  51#define dereference_function_descriptor(p) (p)
  52#endif
  53
  54/* random extra sections (if any).  Override
  55 * in asm/sections.h */
  56#ifndef arch_is_kernel_text
  57static inline int arch_is_kernel_text(unsigned long addr)
  58{
  59        return 0;
  60}
  61#endif
  62
  63#ifndef arch_is_kernel_data
  64static inline int arch_is_kernel_data(unsigned long addr)
  65{
  66        return 0;
  67}
  68#endif
  69
  70/**
  71 * memory_contains - checks if an object is contained within a memory region
  72 * @begin: virtual address of the beginning of the memory region
  73 * @end: virtual address of the end of the memory region
  74 * @virt: virtual address of the memory object
  75 * @size: size of the memory object
  76 *
  77 * Returns: true if the object specified by @virt and @size is entirely
  78 * contained within the memory region defined by @begin and @end, false
  79 * otherwise.
  80 */
  81static inline bool memory_contains(void *begin, void *end, void *virt,
  82                                   size_t size)
  83{
  84        return virt >= begin && virt + size <= end;
  85}
  86
  87/**
  88 * memory_intersects - checks if the region occupied by an object intersects
  89 *                     with another memory region
  90 * @begin: virtual address of the beginning of the memory regien
  91 * @end: virtual address of the end of the memory region
  92 * @virt: virtual address of the memory object
  93 * @size: size of the memory object
  94 *
  95 * Returns: true if an object's memory region, specified by @virt and @size,
  96 * intersects with the region specified by @begin and @end, false otherwise.
  97 */
  98static inline bool memory_intersects(void *begin, void *end, void *virt,
  99                                     size_t size)
 100{
 101        void *vend = virt + size;
 102
 103        return (virt >= begin && virt < end) || (vend >= begin && vend < end);
 104}
 105
 106/**
 107 * init_section_contains - checks if an object is contained within the init
 108 *                         section
 109 * @virt: virtual address of the memory object
 110 * @size: size of the memory object
 111 *
 112 * Returns: true if the object specified by @virt and @size is entirely
 113 * contained within the init section, false otherwise.
 114 */
 115static inline bool init_section_contains(void *virt, size_t size)
 116{
 117        return memory_contains(__init_begin, __init_end, virt, size);
 118}
 119
 120/**
 121 * init_section_intersects - checks if the region occupied by an object
 122 *                           intersects with the init section
 123 * @virt: virtual address of the memory object
 124 * @size: size of the memory object
 125 *
 126 * Returns: true if an object's memory region, specified by @virt and @size,
 127 * intersects with the init section, false otherwise.
 128 */
 129static inline bool init_section_intersects(void *virt, size_t size)
 130{
 131        return memory_intersects(__init_begin, __init_end, virt, size);
 132}
 133
 134#endif /* _ASM_GENERIC_SECTIONS_H_ */
 135