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 | extern __visible const void __nosave_begin, __nosave_end; |
57 | |
58 | /* Function descriptor handling (if any). Override in asm/sections.h */ |
59 | #ifndef dereference_function_descriptor |
60 | #define dereference_function_descriptor(p) (p) |
61 | #define dereference_kernel_function_descriptor(p) (p) |
62 | #endif |
63 | |
64 | /* random extra sections (if any). Override |
65 | * in asm/sections.h */ |
66 | #ifndef arch_is_kernel_text |
67 | static inline int arch_is_kernel_text(unsigned long addr) |
68 | { |
69 | return 0; |
70 | } |
71 | #endif |
72 | |
73 | #ifndef arch_is_kernel_data |
74 | static inline int arch_is_kernel_data(unsigned long addr) |
75 | { |
76 | return 0; |
77 | } |
78 | #endif |
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 | 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 regien |
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 | void *vend = virt + size; |
112 | |
113 | return (virt >= begin && virt < end) || (vend >= begin && vend < end); |
114 | } |
115 | |
116 | /** |
117 | * init_section_contains - checks if an object is contained within the init |
118 | * section |
119 | * @virt: virtual address of the memory object |
120 | * @size: size of the memory object |
121 | * |
122 | * Returns: true if the object specified by @virt and @size is entirely |
123 | * contained within the init section, false otherwise. |
124 | */ |
125 | static inline bool init_section_contains(void *virt, size_t size) |
126 | { |
127 | return memory_contains(__init_begin, __init_end, virt, size); |
128 | } |
129 | |
130 | /** |
131 | * init_section_intersects - checks if the region occupied by an object |
132 | * intersects with the init section |
133 | * @virt: virtual address of the memory object |
134 | * @size: size of the memory object |
135 | * |
136 | * Returns: true if an object's memory region, specified by @virt and @size, |
137 | * intersects with the init section, false otherwise. |
138 | */ |
139 | static inline bool init_section_intersects(void *virt, size_t size) |
140 | { |
141 | return memory_intersects(__init_begin, __init_end, virt, size); |
142 | } |
143 | |
144 | /** |
145 | * is_kernel_rodata - checks if the pointer address is located in the |
146 | * .rodata section |
147 | * |
148 | * @addr: address to check |
149 | * |
150 | * Returns: true if the address is located in .rodata, false otherwise. |
151 | */ |
152 | static inline bool is_kernel_rodata(unsigned long addr) |
153 | { |
154 | return addr >= (unsigned long)__start_rodata && |
155 | addr < (unsigned long)__end_rodata; |
156 | } |
157 | |
158 | #endif /* _ASM_GENERIC_SECTIONS_H_ */ |
159 | |