Linux kernel mirror (for testing)
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1/* SPDX-License-Identifier: GPL-2.0 */
2#ifndef _ASM_GENERIC_SECTIONS_H_
3#define _ASM_GENERIC_SECTIONS_H_
4
5/* References to section boundaries */
6
7#include <linux/compiler.h>
8#include <linux/types.h>
9
10/*
11 * Usage guidelines:
12 * _text, _data: architecture specific, don't use them in arch-independent code
13 * [_stext, _etext]: contains .text.* sections, may also contain .rodata.*
14 * and/or .init.* sections
15 * [_sdata, _edata]: contains .data.* sections, may also contain .rodata.*
16 * and/or .init.* sections.
17 * [__start_rodata, __end_rodata]: contains .rodata.* sections
18 * [__start_ro_after_init, __end_ro_after_init]:
19 * contains .data..ro_after_init section
20 * [__init_begin, __init_end]: contains .init.* sections, but .init.text.*
21 * may be out of this range on some architectures.
22 * [_sinittext, _einittext]: contains .init.text.* sections
23 * [__bss_start, __bss_stop]: contains BSS sections
24 *
25 * Following global variables are optional and may be unavailable on some
26 * architectures and/or kernel configurations.
27 * _text, _data
28 * __kprobes_text_start, __kprobes_text_end
29 * __entry_text_start, __entry_text_end
30 * __ctors_start, __ctors_end
31 * __irqentry_text_start, __irqentry_text_end
32 * __softirqentry_text_start, __softirqentry_text_end
33 * __start_opd, __end_opd
34 */
35extern char _text[], _stext[], _etext[];
36extern char _data[], _sdata[], _edata[];
37extern char __bss_start[], __bss_stop[];
38extern char __init_begin[], __init_end[];
39extern char _sinittext[], _einittext[];
40extern char __start_ro_after_init[], __end_ro_after_init[];
41extern char _end[];
42extern char __per_cpu_load[], __per_cpu_start[], __per_cpu_end[];
43extern char __kprobes_text_start[], __kprobes_text_end[];
44extern char __entry_text_start[], __entry_text_end[];
45extern char __start_rodata[], __end_rodata[];
46extern char __irqentry_text_start[], __irqentry_text_end[];
47extern char __softirqentry_text_start[], __softirqentry_text_end[];
48extern char __start_once[], __end_once[];
49
50/* Start and end of .ctors section - used for constructor calls. */
51extern char __ctors_start[], __ctors_end[];
52
53/* Start and end of .opd section - used for function descriptors. */
54extern char __start_opd[], __end_opd[];
55
56/* Start and end of instrumentation protected text section */
57extern char __noinstr_text_start[], __noinstr_text_end[];
58
59extern __visible const void __nosave_begin, __nosave_end;
60
61/* Function descriptor handling (if any). Override in asm/sections.h */
62#ifndef dereference_function_descriptor
63#define dereference_function_descriptor(p) ((void *)(p))
64#define dereference_kernel_function_descriptor(p) ((void *)(p))
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/**
132 * is_kernel_core_data - checks if the pointer address is located in the
133 * .data or .bss section
134 *
135 * @addr: address to check
136 *
137 * Returns: true if the address is located in .data or .bss, false otherwise.
138 * Note: On some archs it may return true for core RODATA, and false
139 * for others. But will always be true for core RW data.
140 */
141static inline bool is_kernel_core_data(unsigned long addr)
142{
143 if (addr >= (unsigned long)_sdata && addr < (unsigned long)_edata)
144 return true;
145
146 if (addr >= (unsigned long)__bss_start &&
147 addr < (unsigned long)__bss_stop)
148 return true;
149
150 return false;
151}
152
153/**
154 * is_kernel_rodata - checks if the pointer address is located in the
155 * .rodata section
156 *
157 * @addr: address to check
158 *
159 * Returns: true if the address is located in .rodata, false otherwise.
160 */
161static inline bool is_kernel_rodata(unsigned long addr)
162{
163 return addr >= (unsigned long)__start_rodata &&
164 addr < (unsigned long)__end_rodata;
165}
166
167/**
168 * is_kernel_inittext - checks if the pointer address is located in the
169 * .init.text section
170 *
171 * @addr: address to check
172 *
173 * Returns: true if the address is located in .init.text, false otherwise.
174 */
175static inline bool is_kernel_inittext(unsigned long addr)
176{
177 return addr >= (unsigned long)_sinittext &&
178 addr < (unsigned long)_einittext;
179}
180
181/**
182 * __is_kernel_text - checks if the pointer address is located in the
183 * .text section
184 *
185 * @addr: address to check
186 *
187 * Returns: true if the address is located in .text, false otherwise.
188 * Note: an internal helper, only check the range of _stext to _etext.
189 */
190static inline bool __is_kernel_text(unsigned long addr)
191{
192 return addr >= (unsigned long)_stext &&
193 addr < (unsigned long)_etext;
194}
195
196/**
197 * __is_kernel - checks if the pointer address is located in the kernel range
198 *
199 * @addr: address to check
200 *
201 * Returns: true if the address is located in the kernel range, false otherwise.
202 * Note: an internal helper, check the range of _stext to _end,
203 * and range from __init_begin to __init_end, which can be outside
204 * of the _stext to _end range.
205 */
206static inline bool __is_kernel(unsigned long addr)
207{
208 return ((addr >= (unsigned long)_stext &&
209 addr < (unsigned long)_end) ||
210 (addr >= (unsigned long)__init_begin &&
211 addr < (unsigned long)__init_end));
212}
213
214#endif /* _ASM_GENERIC_SECTIONS_H_ */