projects/linux·blob v4.13 · refs

134 lines · 4.5 KiB

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_ro_after_init, __end_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_ro_after_init[], __end_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_ */