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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 : */
35 : extern char _text[], _stext[], _etext[];
36 : extern char _data[], _sdata[], _edata[];
37 : extern char __bss_start[], __bss_stop[];
38 : extern char __init_begin[], __init_end[];
39 : extern char _sinittext[], _einittext[];
40 : extern char __start_ro_after_init[], __end_ro_after_init[];
41 : extern char _end[];
42 : extern char __per_cpu_load[], __per_cpu_start[], __per_cpu_end[];
43 : extern char __kprobes_text_start[], __kprobes_text_end[];
44 : extern char __entry_text_start[], __entry_text_end[];
45 : extern char __start_rodata[], __end_rodata[];
46 : extern char __irqentry_text_start[], __irqentry_text_end[];
47 : extern char __softirqentry_text_start[], __softirqentry_text_end[];
48 : extern char __start_once[], __end_once[];
49 :
50 : /* Start and end of .ctors section - used for constructor calls. */
51 : extern char __ctors_start[], __ctors_end[];
52 :
53 : /* Start and end of .opd section - used for function descriptors. */
54 : extern char __start_opd[], __end_opd[];
55 :
56 : /* Start and end of instrumentation protected text section */
57 : extern char __noinstr_text_start[], __noinstr_text_end[];
58 :
59 : extern __visible const void __nosave_begin, __nosave_end;
60 :
61 : /* Function descriptor handling (if any). Override in asm/sections.h */
62 : #ifdef CONFIG_HAVE_FUNCTION_DESCRIPTORS
63 : void *dereference_function_descriptor(void *ptr);
64 : void *dereference_kernel_function_descriptor(void *ptr);
65 : #else
66 : #define dereference_function_descriptor(p) ((void *)(p))
67 : #define dereference_kernel_function_descriptor(p) ((void *)(p))
68 :
69 : /* An address is simply the address of the function. */
70 : typedef struct {
71 : unsigned long addr;
72 : } func_desc_t;
73 : #endif
74 :
75 : static inline bool have_function_descriptors(void)
76 : {
77 : return IS_ENABLED(CONFIG_HAVE_FUNCTION_DESCRIPTORS);
78 : }
79 :
80 : /**
81 : * memory_contains - checks if an object is contained within a memory region
82 : * @begin: virtual address of the beginning of the memory region
83 : * @end: virtual address of the end of the memory region
84 : * @virt: virtual address of the memory object
85 : * @size: size of the memory object
86 : *
87 : * Returns: true if the object specified by @virt and @size is entirely
88 : * contained within the memory region defined by @begin and @end, false
89 : * otherwise.
90 : */
91 : static inline bool memory_contains(void *begin, void *end, void *virt,
92 : size_t size)
93 : {
94 0 : return virt >= begin && virt + size <= end;
95 : }
96 :
97 : /**
98 : * memory_intersects - checks if the region occupied by an object intersects
99 : * with another memory region
100 : * @begin: virtual address of the beginning of the memory region
101 : * @end: virtual address of the end of the memory region
102 : * @virt: virtual address of the memory object
103 : * @size: size of the memory object
104 : *
105 : * Returns: true if an object's memory region, specified by @virt and @size,
106 : * intersects with the region specified by @begin and @end, false otherwise.
107 : */
108 : static inline bool memory_intersects(void *begin, void *end, void *virt,
109 : size_t size)
110 : {
111 0 : void *vend = virt + size;
112 :
113 0 : if (virt < end && vend > begin)
114 : return true;
115 :
116 : return false;
117 : }
118 :
119 : /**
120 : * init_section_contains - checks if an object is contained within the init
121 : * section
122 : * @virt: virtual address of the memory object
123 : * @size: size of the memory object
124 : *
125 : * Returns: true if the object specified by @virt and @size is entirely
126 : * contained within the init section, false otherwise.
127 : */
128 : static inline bool init_section_contains(void *virt, size_t size)
129 : {
130 0 : return memory_contains(__init_begin, __init_end, virt, size);
131 : }
132 :
133 : /**
134 : * init_section_intersects - checks if the region occupied by an object
135 : * intersects with the init section
136 : * @virt: virtual address of the memory object
137 : * @size: size of the memory object
138 : *
139 : * Returns: true if an object's memory region, specified by @virt and @size,
140 : * intersects with the init section, false otherwise.
141 : */
142 : static inline bool init_section_intersects(void *virt, size_t size)
143 : {
144 0 : return memory_intersects(__init_begin, __init_end, virt, size);
145 : }
146 :
147 : /**
148 : * is_kernel_core_data - checks if the pointer address is located in the
149 : * .data or .bss section
150 : *
151 : * @addr: address to check
152 : *
153 : * Returns: true if the address is located in .data or .bss, false otherwise.
154 : * Note: On some archs it may return true for core RODATA, and false
155 : * for others. But will always be true for core RW data.
156 : */
157 : static inline bool is_kernel_core_data(unsigned long addr)
158 : {
159 : if (addr >= (unsigned long)_sdata && addr < (unsigned long)_edata)
160 : return true;
161 :
162 : if (addr >= (unsigned long)__bss_start &&
163 : addr < (unsigned long)__bss_stop)
164 : return true;
165 :
166 : return false;
167 : }
168 :
169 : /**
170 : * is_kernel_rodata - checks if the pointer address is located in the
171 : * .rodata section
172 : *
173 : * @addr: address to check
174 : *
175 : * Returns: true if the address is located in .rodata, false otherwise.
176 : */
177 : static inline bool is_kernel_rodata(unsigned long addr)
178 : {
179 20991 : return addr >= (unsigned long)__start_rodata &&
180 10122 : addr < (unsigned long)__end_rodata;
181 : }
182 :
183 : /**
184 : * is_kernel_inittext - checks if the pointer address is located in the
185 : * .init.text section
186 : *
187 : * @addr: address to check
188 : *
189 : * Returns: true if the address is located in .init.text, false otherwise.
190 : */
191 : static inline bool is_kernel_inittext(unsigned long addr)
192 : {
193 1598 : return addr >= (unsigned long)_sinittext &&
194 595 : addr < (unsigned long)_einittext;
195 : }
196 :
197 : /**
198 : * __is_kernel_text - checks if the pointer address is located in the
199 : * .text section
200 : *
201 : * @addr: address to check
202 : *
203 : * Returns: true if the address is located in .text, false otherwise.
204 : * Note: an internal helper, only check the range of _stext to _etext.
205 : */
206 : static inline bool __is_kernel_text(unsigned long addr)
207 : {
208 1469 : return addr >= (unsigned long)_stext &&
209 621 : addr < (unsigned long)_etext;
210 : }
211 :
212 : /**
213 : * __is_kernel - checks if the pointer address is located in the kernel range
214 : *
215 : * @addr: address to check
216 : *
217 : * Returns: true if the address is located in the kernel range, false otherwise.
218 : * Note: an internal helper, check the range of _stext to _end,
219 : * and range from __init_begin to __init_end, which can be outside
220 : * of the _stext to _end range.
221 : */
222 : static inline bool __is_kernel(unsigned long addr)
223 : {
224 : return ((addr >= (unsigned long)_stext &&
225 : addr < (unsigned long)_end) ||
226 : (addr >= (unsigned long)__init_begin &&
227 : addr < (unsigned long)__init_end));
228 : }
229 :
230 : #endif /* _ASM_GENERIC_SECTIONS_H_ */
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