summaryrefslogtreecommitdiffstats
path: root/include/asm-generic/sections.h
blob: 849cd8eb5ca0650c46e51f1848302ced07533757 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
/* SPDX-License-Identifier: GPL-2.0 */
#ifndef _ASM_GENERIC_SECTIONS_H_
#define _ASM_GENERIC_SECTIONS_H_

/* References to section boundaries */

#include <linux/compiler.h>
#include <linux/types.h>

/*
 * Usage guidelines:
 * _text, _data: architecture specific, don't use them in arch-independent code
 * [_stext, _etext]: contains .text.* sections, may also contain .rodata.*
 *                   and/or .init.* sections
 * [_sdata, _edata]: contains .data.* sections, may also contain .rodata.*
 *                   and/or .init.* sections.
 * [__start_rodata, __end_rodata]: contains .rodata.* sections
 * [__start_ro_after_init, __end_ro_after_init]:
 *		     contains .data..ro_after_init section
 * [__init_begin, __init_end]: contains .init.* sections, but .init.text.*
 *                   may be out of this range on some architectures.
 * [_sinittext, _einittext]: contains .init.text.* sections
 * [__bss_start, __bss_stop]: contains BSS sections
 *
 * Following global variables are optional and may be unavailable on some
 * architectures and/or kernel configurations.
 *	_text, _data
 *	__kprobes_text_start, __kprobes_text_end
 *	__entry_text_start, __entry_text_end
 *	__ctors_start, __ctors_end
 *	__irqentry_text_start, __irqentry_text_end
 *	__softirqentry_text_start, __softirqentry_text_end
 *	__start_opd, __end_opd
 */
extern char _text[], _stext[], _etext[];
extern char _data[], _sdata[], _edata[];
extern char __bss_start[], __bss_stop[];
extern char __init_begin[], __init_end[];
extern char _sinittext[], _einittext[];
extern char __start_ro_after_init[], __end_ro_after_init[];
extern char _end[];
extern char __per_cpu_load[], __per_cpu_start[], __per_cpu_end[];
extern char __kprobes_text_start[], __kprobes_text_end[];
extern char __entry_text_start[], __entry_text_end[];
extern char __start_rodata[], __end_rodata[];
extern char __irqentry_text_start[], __irqentry_text_end[];
extern char __softirqentry_text_start[], __softirqentry_text_end[];
extern char __start_once[], __end_once[];

/* Start and end of .ctors section - used for constructor calls. */
extern char __ctors_start[], __ctors_end[];

/* Start and end of .opd section - used for function descriptors. */
extern char __start_opd[], __end_opd[];

extern __visible const void __nosave_begin, __nosave_end;

/* Function descriptor handling (if any).  Override in asm/sections.h */
#ifndef dereference_function_descriptor
#define dereference_function_descriptor(p) (p)
#define dereference_kernel_function_descriptor(p) (p)
#endif

/* random extra sections (if any).  Override
 * in asm/sections.h */
#ifndef arch_is_kernel_text
static inline int arch_is_kernel_text(unsigned long addr)
{
	return 0;
}
#endif

#ifndef arch_is_kernel_data
static inline int arch_is_kernel_data(unsigned long addr)
{
	return 0;
}
#endif

/**
 * memory_contains - checks if an object is contained within a memory region
 * @begin: virtual address of the beginning of the memory region
 * @end: virtual address of the end of the memory region
 * @virt: virtual address of the memory object
 * @size: size of the memory object
 *
 * Returns: true if the object specified by @virt and @size is entirely
 * contained within the memory region defined by @begin and @end, false
 * otherwise.
 */
static inline bool memory_contains(void *begin, void *end, void *virt,
				   size_t size)
{
	return virt >= begin && virt + size <= end;
}

/**
 * memory_intersects - checks if the region occupied by an object intersects
 *                     with another memory region
 * @begin: virtual address of the beginning of the memory regien
 * @end: virtual address of the end of the memory region
 * @virt: virtual address of the memory object
 * @size: size of the memory object
 *
 * Returns: true if an object's memory region, specified by @virt and @size,
 * intersects with the region specified by @begin and @end, false otherwise.
 */
static inline bool memory_intersects(void *begin, void *end, void *virt,
				     size_t size)
{
	void *vend = virt + size;

	return (virt >= begin && virt < end) || (vend >= begin && vend < end);
}

/**
 * init_section_contains - checks if an object is contained within the init
 *                         section
 * @virt: virtual address of the memory object
 * @size: size of the memory object
 *
 * Returns: true if the object specified by @virt and @size is entirely
 * contained within the init section, false otherwise.
 */
static inline bool init_section_contains(void *virt, size_t size)
{
	return memory_contains(__init_begin, __init_end, virt, size);
}

/**
 * init_section_intersects - checks if the region occupied by an object
 *                           intersects with the init section
 * @virt: virtual address of the memory object
 * @size: size of the memory object
 *
 * Returns: true if an object's memory region, specified by @virt and @size,
 * intersects with the init section, false otherwise.
 */
static inline bool init_section_intersects(void *virt, size_t size)
{
	return memory_intersects(__init_begin, __init_end, virt, size);
}

#endif /* _ASM_GENERIC_SECTIONS_H_ */