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_ro_after_init, __end_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 * __irqentry_text_start, __irqentry_text_end 31 * __softirqentry_text_start, __softirqentry_text_end 32 */ 33 extern char _text[], _stext[], _etext[]; 34 extern char _data[], _sdata[], _edata[]; 35 extern char __bss_start[], __bss_stop[]; 36 extern char __init_begin[], __init_end[]; 37 extern char _sinittext[], _einittext[]; 38 extern char __start_ro_after_init[], __end_ro_after_init[]; 39 extern char _end[]; 40 extern char __per_cpu_load[], __per_cpu_start[], __per_cpu_end[]; 41 extern char __kprobes_text_start[], __kprobes_text_end[]; 42 extern char __entry_text_start[], __entry_text_end[]; 43 extern char __start_rodata[], __end_rodata[]; 44 extern char __irqentry_text_start[], __irqentry_text_end[]; 45 extern char __softirqentry_text_start[], __softirqentry_text_end[]; 46 47 /* Start and end of .ctors section - used for constructor calls. */ 48 extern char __ctors_start[], __ctors_end[]; 49 50 extern __visible const void __nosave_begin, __nosave_end; 51 52 /* function descriptor handling (if any). Override 53 * in asm/sections.h */ 54 #ifndef dereference_function_descriptor 55 #define dereference_function_descriptor(p) (p) 56 #endif 57 58 /* random extra sections (if any). Override 59 * in asm/sections.h */ 60 #ifndef arch_is_kernel_text 61 static inline int arch_is_kernel_text(unsigned long addr) 62 { 63 return 0; 64 } 65 #endif 66 67 #ifndef arch_is_kernel_data 68 static inline int arch_is_kernel_data(unsigned long addr) 69 { 70 return 0; 71 } 72 #endif 73 74 /** 75 * memory_contains - checks if an object is contained within a memory region 76 * @begin: virtual address of the beginning of the memory region 77 * @end: virtual address of the end of the memory region 78 * @virt: virtual address of the memory object 79 * @size: size of the memory object 80 * 81 * Returns: true if the object specified by @virt and @size is entirely 82 * contained within the memory region defined by @begin and @end, false 83 * otherwise. 84 */ 85 static inline bool memory_contains(void *begin, void *end, void *virt, 86 size_t size) 87 { 88 return virt >= begin && virt + size <= end; 89 } 90 91 /** 92 * memory_intersects - checks if the region occupied by an object intersects 93 * with another memory region 94 * @begin: virtual address of the beginning of the memory regien 95 * @end: virtual address of the end of the memory region 96 * @virt: virtual address of the memory object 97 * @size: size of the memory object 98 * 99 * Returns: true if an object's memory region, specified by @virt and @size, 100 * intersects with the region specified by @begin and @end, false otherwise. 101 */ 102 static inline bool memory_intersects(void *begin, void *end, void *virt, 103 size_t size) 104 { 105 void *vend = virt + size; 106 107 return (virt >= begin && virt < end) || (vend >= begin && vend < end); 108 } 109 110 /** 111 * init_section_contains - checks if an object is contained within the init 112 * section 113 * @virt: virtual address of the memory object 114 * @size: size of the memory object 115 * 116 * Returns: true if the object specified by @virt and @size is entirely 117 * contained within the init section, false otherwise. 118 */ 119 static inline bool init_section_contains(void *virt, size_t size) 120 { 121 return memory_contains(__init_begin, __init_end, virt, size); 122 } 123 124 /** 125 * init_section_intersects - checks if the region occupied by an object 126 * intersects with the init section 127 * @virt: virtual address of the memory object 128 * @size: size of the memory object 129 * 130 * Returns: true if an object's memory region, specified by @virt and @size, 131 * intersects with the init section, false otherwise. 132 */ 133 static inline bool init_section_intersects(void *virt, size_t size) 134 { 135 return memory_intersects(__init_begin, __init_end, virt, size); 136 } 137 138 #endif /* _ASM_GENERIC_SECTIONS_H_ */ 139