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1/* SPDX-License-Identifier: GPL-2.0 */ 2/* Rewritten and vastly simplified by Rusty Russell for in-kernel 3 * module loader: 4 * Copyright 2002 Rusty Russell <rusty@rustcorp.com.au> IBM Corporation 5 */ 6#ifndef _LINUX_KALLSYMS_H 7#define _LINUX_KALLSYMS_H 8 9#include <linux/errno.h> 10#include <linux/kernel.h> 11#include <linux/stddef.h> 12#include <linux/mm.h> 13#include <linux/module.h> 14 15#include <asm/sections.h> 16 17#define KSYM_NAME_LEN 128 18#define KSYM_SYMBOL_LEN (sizeof("%s+%#lx/%#lx [%s]") + (KSYM_NAME_LEN - 1) + \ 19 2*(BITS_PER_LONG*3/10) + (MODULE_NAME_LEN - 1) + 1) 20 21struct module; 22 23static inline int is_kernel_inittext(unsigned long addr) 24{ 25 if (addr >= (unsigned long)_sinittext 26 && addr <= (unsigned long)_einittext) 27 return 1; 28 return 0; 29} 30 31static inline int is_kernel_text(unsigned long addr) 32{ 33 if ((addr >= (unsigned long)_stext && addr <= (unsigned long)_etext) || 34 arch_is_kernel_text(addr)) 35 return 1; 36 return in_gate_area_no_mm(addr); 37} 38 39static inline int is_kernel(unsigned long addr) 40{ 41 if (addr >= (unsigned long)_stext && addr <= (unsigned long)_end) 42 return 1; 43 return in_gate_area_no_mm(addr); 44} 45 46static inline int is_ksym_addr(unsigned long addr) 47{ 48 if (IS_ENABLED(CONFIG_KALLSYMS_ALL)) 49 return is_kernel(addr); 50 51 return is_kernel_text(addr) || is_kernel_inittext(addr); 52} 53 54static inline void *dereference_symbol_descriptor(void *ptr) 55{ 56#ifdef HAVE_DEREFERENCE_FUNCTION_DESCRIPTOR 57 struct module *mod; 58 59 ptr = dereference_kernel_function_descriptor(ptr); 60 if (is_ksym_addr((unsigned long)ptr)) 61 return ptr; 62 63 preempt_disable(); 64 mod = __module_address((unsigned long)ptr); 65 preempt_enable(); 66 67 if (mod) 68 ptr = dereference_module_function_descriptor(mod, ptr); 69#endif 70 return ptr; 71} 72 73#ifdef CONFIG_KALLSYMS 74/* Lookup the address for a symbol. Returns 0 if not found. */ 75unsigned long kallsyms_lookup_name(const char *name); 76 77/* Call a function on each kallsyms symbol in the core kernel */ 78int kallsyms_on_each_symbol(int (*fn)(void *, const char *, struct module *, 79 unsigned long), 80 void *data); 81 82extern int kallsyms_lookup_size_offset(unsigned long addr, 83 unsigned long *symbolsize, 84 unsigned long *offset); 85 86/* Lookup an address. modname is set to NULL if it's in the kernel. */ 87const char *kallsyms_lookup(unsigned long addr, 88 unsigned long *symbolsize, 89 unsigned long *offset, 90 char **modname, char *namebuf); 91 92/* Look up a kernel symbol and return it in a text buffer. */ 93extern int sprint_symbol(char *buffer, unsigned long address); 94extern int sprint_symbol_no_offset(char *buffer, unsigned long address); 95extern int sprint_backtrace(char *buffer, unsigned long address); 96 97int lookup_symbol_name(unsigned long addr, char *symname); 98int lookup_symbol_attrs(unsigned long addr, unsigned long *size, unsigned long *offset, char *modname, char *name); 99 100/* How and when do we show kallsyms values? */ 101extern int kallsyms_show_value(void); 102 103#else /* !CONFIG_KALLSYMS */ 104 105static inline unsigned long kallsyms_lookup_name(const char *name) 106{ 107 return 0; 108} 109 110static inline int kallsyms_on_each_symbol(int (*fn)(void *, const char *, 111 struct module *, 112 unsigned long), 113 void *data) 114{ 115 return 0; 116} 117 118static inline int kallsyms_lookup_size_offset(unsigned long addr, 119 unsigned long *symbolsize, 120 unsigned long *offset) 121{ 122 return 0; 123} 124 125static inline const char *kallsyms_lookup(unsigned long addr, 126 unsigned long *symbolsize, 127 unsigned long *offset, 128 char **modname, char *namebuf) 129{ 130 return NULL; 131} 132 133static inline int sprint_symbol(char *buffer, unsigned long addr) 134{ 135 *buffer = '\0'; 136 return 0; 137} 138 139static inline int sprint_symbol_no_offset(char *buffer, unsigned long addr) 140{ 141 *buffer = '\0'; 142 return 0; 143} 144 145static inline int sprint_backtrace(char *buffer, unsigned long addr) 146{ 147 *buffer = '\0'; 148 return 0; 149} 150 151static inline int lookup_symbol_name(unsigned long addr, char *symname) 152{ 153 return -ERANGE; 154} 155 156static inline int lookup_symbol_attrs(unsigned long addr, unsigned long *size, unsigned long *offset, char *modname, char *name) 157{ 158 return -ERANGE; 159} 160 161static inline int kallsyms_show_value(void) 162{ 163 return false; 164} 165 166#endif /*CONFIG_KALLSYMS*/ 167 168static inline void print_ip_sym(unsigned long ip) 169{ 170 printk("[<%px>] %pS\n", (void *) ip, (void *) ip); 171} 172 173#endif /*_LINUX_KALLSYMS_H*/