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 <[email protected]> IBM Corporation 5 */ 6 #ifndef _LINUX_KALLSYMS_H 7 #define _LINUX_KALLSYMS_H 8 9 #include <linux/errno.h> 10 #include <linux/buildid.h> 11 #include <linux/kernel.h> 12 #include <linux/stddef.h> 13 #include <linux/mm.h> 14 #include <linux/module.h> 15 16 #include <asm/sections.h> 17 18 #define KSYM_NAME_LEN 512 19 #define KSYM_SYMBOL_LEN (sizeof("%s+%#lx/%#lx [%s %s]") + \ 20 (KSYM_NAME_LEN - 1) + \ 21 2*(BITS_PER_LONG*3/10) + (MODULE_NAME_LEN - 1) + \ 22 (BUILD_ID_SIZE_MAX * 2) + 1) 23 24 struct cred; 25 struct module; 26 27 static inline int is_kernel_text(unsigned long addr) 28 { 29 if (__is_kernel_text(addr)) 30 return 1; 31 return in_gate_area_no_mm(addr); 32 } 33 34 static inline int is_kernel(unsigned long addr) 35 { 36 if (__is_kernel(addr)) 37 return 1; 38 return in_gate_area_no_mm(addr); 39 } 40 41 static inline int is_ksym_addr(unsigned long addr) 42 { 43 if (IS_ENABLED(CONFIG_KALLSYMS_ALL)) 44 return is_kernel(addr); 45 46 return is_kernel_text(addr) || is_kernel_inittext(addr); 47 } 48 49 static inline void *dereference_symbol_descriptor(void *ptr) 50 { 51 #ifdef CONFIG_HAVE_FUNCTION_DESCRIPTORS 52 struct module *mod; 53 54 ptr = dereference_kernel_function_descriptor(ptr); 55 if (is_ksym_addr((unsigned long)ptr)) 56 return ptr; 57 58 preempt_disable(); 59 mod = __module_address((unsigned long)ptr); 60 preempt_enable(); 61 62 if (mod) 63 ptr = dereference_module_function_descriptor(mod, ptr); 64 #endif 65 return ptr; 66 } 67 68 #ifdef CONFIG_KALLSYMS 69 unsigned long kallsyms_sym_address(int idx); 70 int kallsyms_on_each_symbol(int (*fn)(void *, const char *, struct module *, 71 unsigned long), 72 void *data); 73 int kallsyms_on_each_match_symbol(int (*fn)(void *, unsigned long), 74 const char *name, void *data); 75 76 /* Lookup the address for a symbol. Returns 0 if not found. */ 77 unsigned long kallsyms_lookup_name(const char *name); 78 79 extern int kallsyms_lookup_size_offset(unsigned long addr, 80 unsigned long *symbolsize, 81 unsigned long *offset); 82 83 /* Lookup an address. modname is set to NULL if it's in the kernel. */ 84 const char *kallsyms_lookup(unsigned long addr, 85 unsigned long *symbolsize, 86 unsigned long *offset, 87 char **modname, char *namebuf); 88 89 /* Look up a kernel symbol and return it in a text buffer. */ 90 extern int sprint_symbol(char *buffer, unsigned long address); 91 extern int sprint_symbol_build_id(char *buffer, unsigned long address); 92 extern int sprint_symbol_no_offset(char *buffer, unsigned long address); 93 extern int sprint_backtrace(char *buffer, unsigned long address); 94 extern int sprint_backtrace_build_id(char *buffer, unsigned long address); 95 96 int lookup_symbol_name(unsigned long addr, char *symname); 97 int lookup_symbol_attrs(unsigned long addr, unsigned long *size, unsigned long *offset, char *modname, char *name); 98 99 /* How and when do we show kallsyms values? */ 100 extern bool kallsyms_show_value(const struct cred *cred); 101 102 #else /* !CONFIG_KALLSYMS */ 103 104 static inline unsigned long kallsyms_lookup_name(const char *name) 105 { 106 return 0; 107 } 108 109 static inline int kallsyms_lookup_size_offset(unsigned long addr, 110 unsigned long *symbolsize, 111 unsigned long *offset) 112 { 113 return 0; 114 } 115 116 static inline const char *kallsyms_lookup(unsigned long addr, 117 unsigned long *symbolsize, 118 unsigned long *offset, 119 char **modname, char *namebuf) 120 { 121 return NULL; 122 } 123 124 static inline int sprint_symbol(char *buffer, unsigned long addr) 125 { 126 *buffer = '\0'; 127 return 0; 128 } 129 130 static inline int sprint_symbol_build_id(char *buffer, unsigned long address) 131 { 132 *buffer = '\0'; 133 return 0; 134 } 135 136 static inline int sprint_symbol_no_offset(char *buffer, unsigned long addr) 137 { 138 *buffer = '\0'; 139 return 0; 140 } 141 142 static inline int sprint_backtrace(char *buffer, unsigned long addr) 143 { 144 *buffer = '\0'; 145 return 0; 146 } 147 148 static inline int sprint_backtrace_build_id(char *buffer, unsigned long addr) 149 { 150 *buffer = '\0'; 151 return 0; 152 } 153 154 static inline int lookup_symbol_name(unsigned long addr, char *symname) 155 { 156 return -ERANGE; 157 } 158 159 static inline int lookup_symbol_attrs(unsigned long addr, unsigned long *size, unsigned long *offset, char *modname, char *name) 160 { 161 return -ERANGE; 162 } 163 164 static inline bool kallsyms_show_value(const struct cred *cred) 165 { 166 return false; 167 } 168 169 static inline int kallsyms_on_each_symbol(int (*fn)(void *, const char *, struct module *, 170 unsigned long), void *data) 171 { 172 return -EOPNOTSUPP; 173 } 174 175 static inline int kallsyms_on_each_match_symbol(int (*fn)(void *, unsigned long), 176 const char *name, void *data) 177 { 178 return -EOPNOTSUPP; 179 } 180 #endif /*CONFIG_KALLSYMS*/ 181 182 static inline void print_ip_sym(const char *loglvl, unsigned long ip) 183 { 184 printk("%s[<%px>] %pS\n", loglvl, (void *) ip, (void *) ip); 185 } 186 187 #endif /*_LINUX_KALLSYMS_H*/ 188