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 /**
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 */
memory_contains(void * begin,void * end,void * virt,size_t size)78 static 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 */
memory_intersects(void * begin,void * end,void * virt,size_t size)95 static 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 */
init_section_contains(void * virt,size_t size)112 static 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 */
init_section_intersects(void * virt,size_t size)126 static 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 section
134 *
135 * @addr: address to check
136 *
137 * Returns: true if the address is located in .data, 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 */
is_kernel_core_data(unsigned long addr)141 static inline bool is_kernel_core_data(unsigned long addr)
142 {
143 return addr >= (unsigned long)_sdata &&
144 addr < (unsigned long)_edata;
145 }
146
147 /**
148 * is_kernel_rodata - checks if the pointer address is located in the
149 * .rodata section
150 *
151 * @addr: address to check
152 *
153 * Returns: true if the address is located in .rodata, false otherwise.
154 */
is_kernel_rodata(unsigned long addr)155 static inline bool is_kernel_rodata(unsigned long addr)
156 {
157 return addr >= (unsigned long)__start_rodata &&
158 addr < (unsigned long)__end_rodata;
159 }
160
161 /**
162 * is_kernel_inittext - checks if the pointer address is located in the
163 * .init.text section
164 *
165 * @addr: address to check
166 *
167 * Returns: true if the address is located in .init.text, false otherwise.
168 */
is_kernel_inittext(unsigned long addr)169 static inline bool is_kernel_inittext(unsigned long addr)
170 {
171 return addr >= (unsigned long)_sinittext &&
172 addr < (unsigned long)_einittext;
173 }
174
175 /**
176 * __is_kernel_text - checks if the pointer address is located in the
177 * .text section
178 *
179 * @addr: address to check
180 *
181 * Returns: true if the address is located in .text, false otherwise.
182 * Note: an internal helper, only check the range of _stext to _etext.
183 */
__is_kernel_text(unsigned long addr)184 static inline bool __is_kernel_text(unsigned long addr)
185 {
186 return addr >= (unsigned long)_stext &&
187 addr < (unsigned long)_etext;
188 }
189
190 /**
191 * __is_kernel - checks if the pointer address is located in the kernel range
192 *
193 * @addr: address to check
194 *
195 * Returns: true if the address is located in the kernel range, false otherwise.
196 * Note: an internal helper, only check the range of _stext to _end.
197 */
__is_kernel(unsigned long addr)198 static inline bool __is_kernel(unsigned long addr)
199 {
200 return addr >= (unsigned long)_stext &&
201 addr < (unsigned long)_end;
202 }
203
204 #endif /* _ASM_GENERIC_SECTIONS_H_ */
205