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 */ 34 extern char _text[], _stext[], _etext[]; 35 extern char _data[], _sdata[], _edata[]; 36 extern char __bss_start[], __bss_stop[]; 37 extern char __init_begin[], __init_end[]; 38 extern char _sinittext[], _einittext[]; 39 extern char __start_ro_after_init[], __end_ro_after_init[]; 40 extern char _end[]; 41 extern char __per_cpu_load[], __per_cpu_start[], __per_cpu_end[]; 42 extern char __kprobes_text_start[], __kprobes_text_end[]; 43 extern char __entry_text_start[], __entry_text_end[]; 44 extern char __start_rodata[], __end_rodata[]; 45 extern char __irqentry_text_start[], __irqentry_text_end[]; 46 extern char __softirqentry_text_start[], __softirqentry_text_end[]; 47 48 /* Start and end of .ctors section - used for constructor calls. */ 49 extern char __ctors_start[], __ctors_end[]; 50 51 extern __visible const void __nosave_begin, __nosave_end; 52 53 /* function descriptor handling (if any). Override 54 * in asm/sections.h */ 55 #ifndef dereference_function_descriptor 56 #define dereference_function_descriptor(p) (p) 57 #endif 58 59 /* random extra sections (if any). Override 60 * in asm/sections.h */ 61 #ifndef arch_is_kernel_text 62 static inline int arch_is_kernel_text(unsigned long addr) 63 { 64 return 0; 65 } 66 #endif 67 68 #ifndef arch_is_kernel_data 69 static inline int arch_is_kernel_data(unsigned long addr) 70 { 71 return 0; 72 } 73 #endif 74 75 /** 76 * memory_contains - checks if an object is contained within a memory region 77 * @begin: virtual address of the beginning of the memory region 78 * @end: virtual address of the end of the memory region 79 * @virt: virtual address of the memory object 80 * @size: size of the memory object 81 * 82 * Returns: true if the object specified by @virt and @size is entirely 83 * contained within the memory region defined by @begin and @end, false 84 * otherwise. 85 */ 86 static inline bool memory_contains(void *begin, void *end, void *virt, 87 size_t size) 88 { 89 return virt >= begin && virt + size <= end; 90 } 91 92 /** 93 * memory_intersects - checks if the region occupied by an object intersects 94 * with another memory region 95 * @begin: virtual address of the beginning of the memory regien 96 * @end: virtual address of the end of the memory region 97 * @virt: virtual address of the memory object 98 * @size: size of the memory object 99 * 100 * Returns: true if an object's memory region, specified by @virt and @size, 101 * intersects with the region specified by @begin and @end, false otherwise. 102 */ 103 static inline bool memory_intersects(void *begin, void *end, void *virt, 104 size_t size) 105 { 106 void *vend = virt + size; 107 108 return (virt >= begin && virt < end) || (vend >= begin && vend < end); 109 } 110 111 /** 112 * init_section_contains - checks if an object is contained within the init 113 * section 114 * @virt: virtual address of the memory object 115 * @size: size of the memory object 116 * 117 * Returns: true if the object specified by @virt and @size is entirely 118 * contained within the init section, false otherwise. 119 */ 120 static inline bool init_section_contains(void *virt, size_t size) 121 { 122 return memory_contains(__init_begin, __init_end, virt, size); 123 } 124 125 /** 126 * init_section_intersects - checks if the region occupied by an object 127 * intersects with the init section 128 * @virt: virtual address of the memory object 129 * @size: size of the memory object 130 * 131 * Returns: true if an object's memory region, specified by @virt and @size, 132 * intersects with the init section, false otherwise. 133 */ 134 static inline bool init_section_intersects(void *virt, size_t size) 135 { 136 return memory_intersects(__init_begin, __init_end, virt, size); 137 } 138 139 #endif /* _ASM_GENERIC_SECTIONS_H_ */ 140