1 #ifndef _ASM_GENERIC_SECTIONS_H_ 2 #define _ASM_GENERIC_SECTIONS_H_ 3 4 /* References to section boundaries */ 5 6 #include <linux/compiler.h> 7 #include <linux/types.h> 8 9 /* 10 * Usage guidelines: 11 * _text, _data: architecture specific, don't use them in arch-independent code 12 * [_stext, _etext]: contains .text.* sections, may also contain .rodata.* 13 * and/or .init.* sections 14 * [_sdata, _edata]: contains .data.* sections, may also contain .rodata.* 15 * and/or .init.* sections. 16 * [__start_rodata, __end_rodata]: contains .rodata.* sections 17 * [__init_begin, __init_end]: contains .init.* sections, but .init.text.* 18 * may be out of this range on some architectures. 19 * [_sinittext, _einittext]: contains .init.text.* sections 20 * [__bss_start, __bss_stop]: contains BSS sections 21 * 22 * Following global variables are optional and may be unavailable on some 23 * architectures and/or kernel configurations. 24 * _text, _data 25 * __kprobes_text_start, __kprobes_text_end 26 * __entry_text_start, __entry_text_end 27 * __ctors_start, __ctors_end 28 */ 29 extern char _text[], _stext[], _etext[]; 30 extern char _data[], _sdata[], _edata[]; 31 extern char __bss_start[], __bss_stop[]; 32 extern char __init_begin[], __init_end[]; 33 extern char _sinittext[], _einittext[]; 34 extern char _end[]; 35 extern char __per_cpu_load[], __per_cpu_start[], __per_cpu_end[]; 36 extern char __kprobes_text_start[], __kprobes_text_end[]; 37 extern char __entry_text_start[], __entry_text_end[]; 38 extern char __start_rodata[], __end_rodata[]; 39 40 /* Start and end of .ctors section - used for constructor calls. */ 41 extern char __ctors_start[], __ctors_end[]; 42 43 extern __visible const void __nosave_begin, __nosave_end; 44 45 /* function descriptor handling (if any). Override 46 * in asm/sections.h */ 47 #ifndef dereference_function_descriptor 48 #define dereference_function_descriptor(p) (p) 49 #endif 50 51 /* random extra sections (if any). Override 52 * in asm/sections.h */ 53 #ifndef arch_is_kernel_text 54 static inline int arch_is_kernel_text(unsigned long addr) 55 { 56 return 0; 57 } 58 #endif 59 60 #ifndef arch_is_kernel_data 61 static inline int arch_is_kernel_data(unsigned long addr) 62 { 63 return 0; 64 } 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 */ 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 */ 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 */ 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 */ 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 #endif /* _ASM_GENERIC_SECTIONS_H_ */ 132