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 | 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 | void *vend = virt + size; |
112 | |
113 | 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 | return memory_contains(begin: __init_begin, end: __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 | return memory_intersects(begin: __init_begin, end: __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 | return addr >= (unsigned long)__start_rodata && |
180 | 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 | return addr >= (unsigned long)_sinittext && |
194 | 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 | return addr >= (unsigned long)_stext && |
209 | 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_ */ |
231 | |