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Diffstat (limited to 'include/asm-generic/sections.h')
| -rw-r--r-- | include/asm-generic/sections.h | 178 |
1 files changed, 178 insertions, 0 deletions
diff --git a/include/asm-generic/sections.h b/include/asm-generic/sections.h new file mode 100644 index 000000000..72f1e2a8c --- /dev/null +++ b/include/asm-generic/sections.h @@ -0,0 +1,178 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +#ifndef _ASM_GENERIC_SECTIONS_H_ +#define _ASM_GENERIC_SECTIONS_H_ + +/* References to section boundaries */ + +#include <linux/compiler.h> +#include <linux/types.h> + +/* + * Usage guidelines: + * _text, _data: architecture specific, don't use them in arch-independent code + * [_stext, _etext]: contains .text.* sections, may also contain .rodata.* + * and/or .init.* sections + * [_sdata, _edata]: contains .data.* sections, may also contain .rodata.* + * and/or .init.* sections. + * [__start_rodata, __end_rodata]: contains .rodata.* sections + * [__start_ro_after_init, __end_ro_after_init]: + * contains .data..ro_after_init section + * [__init_begin, __init_end]: contains .init.* sections, but .init.text.* + * may be out of this range on some architectures. + * [_sinittext, _einittext]: contains .init.text.* sections + * [__bss_start, __bss_stop]: contains BSS sections + * + * Following global variables are optional and may be unavailable on some + * architectures and/or kernel configurations. + * _text, _data + * __kprobes_text_start, __kprobes_text_end + * __entry_text_start, __entry_text_end + * __ctors_start, __ctors_end + * __irqentry_text_start, __irqentry_text_end + * __softirqentry_text_start, __softirqentry_text_end + * __start_opd, __end_opd + */ +extern char _text[], _stext[], _etext[]; +extern char _data[], _sdata[], _edata[]; +extern char __bss_start[], __bss_stop[]; +extern char __init_begin[], __init_end[]; +extern char _sinittext[], _einittext[]; +extern char __start_ro_after_init[], __end_ro_after_init[]; +extern char _end[]; +extern char __per_cpu_load[], __per_cpu_start[], __per_cpu_end[]; +extern char __kprobes_text_start[], __kprobes_text_end[]; +extern char __entry_text_start[], __entry_text_end[]; +extern char __start_rodata[], __end_rodata[]; +extern char __irqentry_text_start[], __irqentry_text_end[]; +extern char __softirqentry_text_start[], __softirqentry_text_end[]; +extern char __start_once[], __end_once[]; + +/* Start and end of .ctors section - used for constructor calls. */ +extern char __ctors_start[], __ctors_end[]; + +/* Start and end of .opd section - used for function descriptors. */ +extern char __start_opd[], __end_opd[]; + +/* Start and end of instrumentation protected text section */ +extern char __noinstr_text_start[], __noinstr_text_end[]; + +extern __visible const void __nosave_begin, __nosave_end; + +/* Function descriptor handling (if any). Override in asm/sections.h */ +#ifndef dereference_function_descriptor +#define dereference_function_descriptor(p) ((void *)(p)) +#define dereference_kernel_function_descriptor(p) ((void *)(p)) +#endif + +/* random extra sections (if any). Override + * in asm/sections.h */ +#ifndef arch_is_kernel_text +static inline int arch_is_kernel_text(unsigned long addr) +{ + return 0; +} +#endif + +#ifndef arch_is_kernel_data +static inline int arch_is_kernel_data(unsigned long addr) +{ + return 0; +} +#endif + +/* + * Check if an address is part of freed initmem. This is needed on architectures + * with virt == phys kernel mapping, for code that wants to check if an address + * is part of a static object within [_stext, _end]. After initmem is freed, + * memory can be allocated from it, and such allocations would then have + * addresses within the range [_stext, _end]. + */ +#ifndef arch_is_kernel_initmem_freed +static inline int arch_is_kernel_initmem_freed(unsigned long addr) +{ + return 0; +} +#endif + +/** + * memory_contains - checks if an object is contained within a memory region + * @begin: virtual address of the beginning of the memory region + * @end: virtual address of the end of the memory region + * @virt: virtual address of the memory object + * @size: size of the memory object + * + * Returns: true if the object specified by @virt and @size is entirely + * contained within the memory region defined by @begin and @end, false + * otherwise. + */ +static inline bool memory_contains(void *begin, void *end, void *virt, + size_t size) +{ + return virt >= begin && virt + size <= end; +} + +/** + * memory_intersects - checks if the region occupied by an object intersects + * with another memory region + * @begin: virtual address of the beginning of the memory region + * @end: virtual address of the end of the memory region + * @virt: virtual address of the memory object + * @size: size of the memory object + * + * Returns: true if an object's memory region, specified by @virt and @size, + * intersects with the region specified by @begin and @end, false otherwise. + */ +static inline bool memory_intersects(void *begin, void *end, void *virt, + size_t size) +{ + void *vend = virt + size; + + if (virt < end && vend > begin) + return true; + + return false; +} + +/** + * init_section_contains - checks if an object is contained within the init + * section + * @virt: virtual address of the memory object + * @size: size of the memory object + * + * Returns: true if the object specified by @virt and @size is entirely + * contained within the init section, false otherwise. + */ +static inline bool init_section_contains(void *virt, size_t size) +{ + return memory_contains(__init_begin, __init_end, virt, size); +} + +/** + * init_section_intersects - checks if the region occupied by an object + * intersects with the init section + * @virt: virtual address of the memory object + * @size: size of the memory object + * + * Returns: true if an object's memory region, specified by @virt and @size, + * intersects with the init section, false otherwise. + */ +static inline bool init_section_intersects(void *virt, size_t size) +{ + return memory_intersects(__init_begin, __init_end, virt, size); +} + +/** + * is_kernel_rodata - checks if the pointer address is located in the + * .rodata section + * + * @addr: address to check + * + * Returns: true if the address is located in .rodata, false otherwise. + */ +static inline bool is_kernel_rodata(unsigned long addr) +{ + return addr >= (unsigned long)__start_rodata && + addr < (unsigned long)__end_rodata; +} + +#endif /* _ASM_GENERIC_SECTIONS_H_ */ |