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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 cred; 22struct module; 23 24static inline int is_kernel_inittext(unsigned long addr) 25{ 26 if (addr >= (unsigned long)_sinittext 27 && addr <= (unsigned long)_einittext) 28 return 1; 29 return 0; 30} 31 32static inline int is_kernel_text(unsigned long addr) 33{ 34 if ((addr >= (unsigned long)_stext && addr <= (unsigned long)_etext) || 35 arch_is_kernel_text(addr)) 36 return 1; 37 return in_gate_area_no_mm(addr); 38} 39 40static inline int is_kernel(unsigned long addr) 41{ 42 if (addr >= (unsigned long)_stext && addr <= (unsigned long)_end) 43 return 1; 44 return in_gate_area_no_mm(addr); 45} 46 47static inline int is_ksym_addr(unsigned long addr) 48{ 49 if (IS_ENABLED(CONFIG_KALLSYMS_ALL)) 50 return is_kernel(addr); 51 52 return is_kernel_text(addr) || is_kernel_inittext(addr); 53} 54 55static inline void *dereference_symbol_descriptor(void *ptr) 56{ 57#ifdef HAVE_DEREFERENCE_FUNCTION_DESCRIPTOR 58 struct module *mod; 59 60 ptr = dereference_kernel_function_descriptor(ptr); 61 if (is_ksym_addr((unsigned long)ptr)) 62 return ptr; 63 64 preempt_disable(); 65 mod = __module_address((unsigned long)ptr); 66 preempt_enable(); 67 68 if (mod) 69 ptr = dereference_module_function_descriptor(mod, ptr); 70#endif 71 return ptr; 72} 73 74#ifdef CONFIG_KALLSYMS 75/* Lookup the address for a symbol. Returns 0 if not found. */ 76unsigned long kallsyms_lookup_name(const char *name); 77 78/* Call a function on each kallsyms symbol in the core kernel */ 79int kallsyms_on_each_symbol(int (*fn)(void *, const char *, struct module *, 80 unsigned long), 81 void *data); 82 83extern int kallsyms_lookup_size_offset(unsigned long addr, 84 unsigned long *symbolsize, 85 unsigned long *offset); 86 87/* Lookup an address. modname is set to NULL if it's in the kernel. */ 88const char *kallsyms_lookup(unsigned long addr, 89 unsigned long *symbolsize, 90 unsigned long *offset, 91 char **modname, char *namebuf); 92 93/* Look up a kernel symbol and return it in a text buffer. */ 94extern int sprint_symbol(char *buffer, unsigned long address); 95extern int sprint_symbol_no_offset(char *buffer, unsigned long address); 96extern int sprint_backtrace(char *buffer, unsigned long address); 97 98int lookup_symbol_name(unsigned long addr, char *symname); 99int lookup_symbol_attrs(unsigned long addr, unsigned long *size, unsigned long *offset, char *modname, char *name); 100 101/* How and when do we show kallsyms values? */ 102extern bool kallsyms_show_value(const struct cred *cred); 103 104#else /* !CONFIG_KALLSYMS */ 105 106static inline unsigned long kallsyms_lookup_name(const char *name) 107{ 108 return 0; 109} 110 111static inline int kallsyms_on_each_symbol(int (*fn)(void *, const char *, 112 struct module *, 113 unsigned long), 114 void *data) 115{ 116 return 0; 117} 118 119static inline int kallsyms_lookup_size_offset(unsigned long addr, 120 unsigned long *symbolsize, 121 unsigned long *offset) 122{ 123 return 0; 124} 125 126static inline const char *kallsyms_lookup(unsigned long addr, 127 unsigned long *symbolsize, 128 unsigned long *offset, 129 char **modname, char *namebuf) 130{ 131 return NULL; 132} 133 134static inline int sprint_symbol(char *buffer, unsigned long addr) 135{ 136 *buffer = '\0'; 137 return 0; 138} 139 140static inline int sprint_symbol_no_offset(char *buffer, unsigned long addr) 141{ 142 *buffer = '\0'; 143 return 0; 144} 145 146static inline int sprint_backtrace(char *buffer, unsigned long addr) 147{ 148 *buffer = '\0'; 149 return 0; 150} 151 152static inline int lookup_symbol_name(unsigned long addr, char *symname) 153{ 154 return -ERANGE; 155} 156 157static inline int lookup_symbol_attrs(unsigned long addr, unsigned long *size, unsigned long *offset, char *modname, char *name) 158{ 159 return -ERANGE; 160} 161 162static inline bool kallsyms_show_value(const struct cred *cred) 163{ 164 return false; 165} 166 167#endif /*CONFIG_KALLSYMS*/ 168 169static inline void print_ip_sym(const char *loglvl, unsigned long ip) 170{ 171 printk("%s[<%px>] %pS\n", loglvl, (void *) ip, (void *) ip); 172} 173 174#endif /*_LINUX_KALLSYMS_H*/