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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 : #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 : /* random extra sections (if any). Override
68 : * in asm/sections.h */
69 : #ifndef arch_is_kernel_text
70 : static inline int arch_is_kernel_text(unsigned long addr)
71 : {
72 : return 0;
73 : }
74 : #endif
75 :
76 : #ifndef arch_is_kernel_data
77 85 : static inline int arch_is_kernel_data(unsigned long addr)
78 : {
79 85 : return 0;
80 : }
81 : #endif
82 :
83 : /*
84 : * Check if an address is part of freed initmem. This is needed on architectures
85 : * with virt == phys kernel mapping, for code that wants to check if an address
86 : * is part of a static object within [_stext, _end]. After initmem is freed,
87 : * memory can be allocated from it, and such allocations would then have
88 : * addresses within the range [_stext, _end].
89 : */
90 : #ifndef arch_is_kernel_initmem_freed
91 : static inline int arch_is_kernel_initmem_freed(unsigned long addr)
92 : {
93 : return 0;
94 : }
95 : #endif
96 :
97 : /**
98 : * memory_contains - checks if an object is contained within a memory region
99 : * @begin: virtual address of the beginning of the memory region
100 : * @end: virtual address of the end of the memory region
101 : * @virt: virtual address of the memory object
102 : * @size: size of the memory object
103 : *
104 : * Returns: true if the object specified by @virt and @size is entirely
105 : * contained within the memory region defined by @begin and @end, false
106 : * otherwise.
107 : */
108 531 : static inline bool memory_contains(void *begin, void *end, void *virt,
109 : size_t size)
110 : {
111 5 : return virt >= begin && virt + size <= end;
112 : }
113 :
114 : /**
115 : * memory_intersects - checks if the region occupied by an object intersects
116 : * with another memory region
117 : * @begin: virtual address of the beginning of the memory regien
118 : * @end: virtual address of the end of the memory region
119 : * @virt: virtual address of the memory object
120 : * @size: size of the memory object
121 : *
122 : * Returns: true if an object's memory region, specified by @virt and @size,
123 : * intersects with the region specified by @begin and @end, false otherwise.
124 : */
125 0 : static inline bool memory_intersects(void *begin, void *end, void *virt,
126 : size_t size)
127 : {
128 0 : void *vend = virt + size;
129 :
130 0 : return (virt >= begin && virt < end) || (vend >= begin && vend < end);
131 : }
132 :
133 : /**
134 : * init_section_contains - checks if an object is contained within the init
135 : * section
136 : * @virt: virtual address of the memory object
137 : * @size: size of the memory object
138 : *
139 : * Returns: true if the object specified by @virt and @size is entirely
140 : * contained within the init section, false otherwise.
141 : */
142 531 : static inline bool init_section_contains(void *virt, size_t size)
143 : {
144 1062 : return memory_contains(__init_begin, __init_end, virt, size);
145 : }
146 :
147 : /**
148 : * init_section_intersects - checks if the region occupied by an object
149 : * intersects with the init section
150 : * @virt: virtual address of the memory object
151 : * @size: size of the memory object
152 : *
153 : * Returns: true if an object's memory region, specified by @virt and @size,
154 : * intersects with the init section, false otherwise.
155 : */
156 0 : static inline bool init_section_intersects(void *virt, size_t size)
157 : {
158 0 : return memory_intersects(__init_begin, __init_end, virt, size);
159 : }
160 :
161 : /**
162 : * is_kernel_rodata - checks if the pointer address is located in the
163 : * .rodata section
164 : *
165 : * @addr: address to check
166 : *
167 : * Returns: true if the address is located in .rodata, false otherwise.
168 : */
169 12828 : static inline bool is_kernel_rodata(unsigned long addr)
170 : {
171 25656 : return addr >= (unsigned long)__start_rodata &&
172 8241 : addr < (unsigned long)__end_rodata;
173 : }
174 :
175 : #endif /* _ASM_GENERIC_SECTIONS_H_ */
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