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 * [__start_data_ro_after_init, __end_data_ro_after_init]: 18 * contains data.ro_after_init section 19 * [__init_begin, __init_end]: contains .init.* sections, but .init.text.* 20 * may be out of this range on some architectures. 21 * [_sinittext, _einittext]: contains .init.text.* sections 22 * [__bss_start, __bss_stop]: contains BSS sections 23 * 24 * Following global variables are optional and may be unavailable on some 25 * architectures and/or kernel configurations. 26 * _text, _data 27 * __kprobes_text_start, __kprobes_text_end 28 * __entry_text_start, __entry_text_end 29 * __ctors_start, __ctors_end 30 */ 31 extern char _text[], _stext[], _etext[]; 32 extern char _data[], _sdata[], _edata[]; 33 extern char __bss_start[], __bss_stop[]; 34 extern char __init_begin[], __init_end[]; 35 extern char _sinittext[], _einittext[]; 36 extern char __start_data_ro_after_init[], __end_data_ro_after_init[]; 37 extern char _end[]; 38 extern char __per_cpu_load[], __per_cpu_start[], __per_cpu_end[]; 39 extern char __kprobes_text_start[], __kprobes_text_end[]; 40 extern char __entry_text_start[], __entry_text_end[]; 41 extern char __start_rodata[], __end_rodata[]; 42 43 /* Start and end of .ctors section - used for constructor calls. */ 44 extern char __ctors_start[], __ctors_end[]; 45 46 extern __visible const void __nosave_begin, __nosave_end; 47 48 /* function descriptor handling (if any). Override 49 * in asm/sections.h */ 50 #ifndef dereference_function_descriptor 51 #define dereference_function_descriptor(p) (p) 52 #endif 53 54 /* random extra sections (if any). Override 55 * in asm/sections.h */ 56 #ifndef arch_is_kernel_text 57 static inline int arch_is_kernel_text(unsigned long addr) 58 { 59 return 0; 60 } 61 #endif 62 63 #ifndef arch_is_kernel_data 64 static inline int arch_is_kernel_data(unsigned long addr) 65 { 66 return 0; 67 } 68 #endif 69 70 /** 71 * memory_contains - checks if an object is contained within a memory region 72 * @begin: virtual address of the beginning of the memory region 73 * @end: virtual address of the end of the memory region 74 * @virt: virtual address of the memory object 75 * @size: size of the memory object 76 * 77 * Returns: true if the object specified by @virt and @size is entirely 78 * contained within the memory region defined by @begin and @end, false 79 * otherwise. 80 */ 81 static inline bool memory_contains(void *begin, void *end, void *virt, 82 size_t size) 83 { 84 return virt >= begin && virt + size <= end; 85 } 86 87 /** 88 * memory_intersects - checks if the region occupied by an object intersects 89 * with another memory region 90 * @begin: virtual address of the beginning of the memory regien 91 * @end: virtual address of the end of the memory region 92 * @virt: virtual address of the memory object 93 * @size: size of the memory object 94 * 95 * Returns: true if an object's memory region, specified by @virt and @size, 96 * intersects with the region specified by @begin and @end, false otherwise. 97 */ 98 static inline bool memory_intersects(void *begin, void *end, void *virt, 99 size_t size) 100 { 101 void *vend = virt + size; 102 103 return (virt >= begin && virt < end) || (vend >= begin && vend < end); 104 } 105 106 /** 107 * init_section_contains - checks if an object is contained within the init 108 * section 109 * @virt: virtual address of the memory object 110 * @size: size of the memory object 111 * 112 * Returns: true if the object specified by @virt and @size is entirely 113 * contained within the init section, false otherwise. 114 */ 115 static inline bool init_section_contains(void *virt, size_t size) 116 { 117 return memory_contains(__init_begin, __init_end, virt, size); 118 } 119 120 /** 121 * init_section_intersects - checks if the region occupied by an object 122 * intersects with the init section 123 * @virt: virtual address of the memory object 124 * @size: size of the memory object 125 * 126 * Returns: true if an object's memory region, specified by @virt and @size, 127 * intersects with the init section, false otherwise. 128 */ 129 static inline bool init_section_intersects(void *virt, size_t size) 130 { 131 return memory_intersects(__init_begin, __init_end, virt, size); 132 } 133 134 #endif /* _ASM_GENERIC_SECTIONS_H_ */ 135