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 *, unsigned long), 71 void *data); 72 int kallsyms_on_each_match_symbol(int (*fn)(void *, unsigned long), 73 const char *name, void *data); 74 75 /* Lookup the address for a symbol. Returns 0 if not found. */ 76 unsigned long kallsyms_lookup_name(const char *name); 77 78 extern int kallsyms_lookup_size_offset(unsigned long addr, 79 unsigned long *symbolsize, 80 unsigned long *offset); 81 82 /* Lookup an address. modname is set to NULL if it's in the kernel. */ 83 const char *kallsyms_lookup(unsigned long addr, 84 unsigned long *symbolsize, 85 unsigned long *offset, 86 char **modname, char *namebuf); 87 88 /* Look up a kernel symbol and return it in a text buffer. */ 89 extern int sprint_symbol(char *buffer, unsigned long address); 90 extern int sprint_symbol_build_id(char *buffer, unsigned long address); 91 extern int sprint_symbol_no_offset(char *buffer, unsigned long address); 92 extern int sprint_backtrace(char *buffer, unsigned long address); 93 extern int sprint_backtrace_build_id(char *buffer, unsigned long address); 94 95 int lookup_symbol_name(unsigned long addr, char *symname); 96 int lookup_symbol_attrs(unsigned long addr, unsigned long *size, unsigned long *offset, char *modname, char *name); 97 98 /* How and when do we show kallsyms values? */ 99 extern bool kallsyms_show_value(const struct cred *cred); 100 101 #else /* !CONFIG_KALLSYMS */ 102 103 static inline unsigned long kallsyms_lookup_name(const char *name) 104 { 105 return 0; 106 } 107 108 static inline int kallsyms_lookup_size_offset(unsigned long addr, 109 unsigned long *symbolsize, 110 unsigned long *offset) 111 { 112 return 0; 113 } 114 115 static inline const char *kallsyms_lookup(unsigned long addr, 116 unsigned long *symbolsize, 117 unsigned long *offset, 118 char **modname, char *namebuf) 119 { 120 return NULL; 121 } 122 123 static inline int sprint_symbol(char *buffer, unsigned long addr) 124 { 125 *buffer = '\0'; 126 return 0; 127 } 128 129 static inline int sprint_symbol_build_id(char *buffer, unsigned long address) 130 { 131 *buffer = '\0'; 132 return 0; 133 } 134 135 static inline int sprint_symbol_no_offset(char *buffer, unsigned long addr) 136 { 137 *buffer = '\0'; 138 return 0; 139 } 140 141 static inline int sprint_backtrace(char *buffer, unsigned long addr) 142 { 143 *buffer = '\0'; 144 return 0; 145 } 146 147 static inline int sprint_backtrace_build_id(char *buffer, unsigned long addr) 148 { 149 *buffer = '\0'; 150 return 0; 151 } 152 153 static inline int lookup_symbol_name(unsigned long addr, char *symname) 154 { 155 return -ERANGE; 156 } 157 158 static inline int lookup_symbol_attrs(unsigned long addr, unsigned long *size, unsigned long *offset, char *modname, char *name) 159 { 160 return -ERANGE; 161 } 162 163 static inline bool kallsyms_show_value(const struct cred *cred) 164 { 165 return false; 166 } 167 168 static inline int kallsyms_on_each_symbol(int (*fn)(void *, const char *, unsigned long), 169 void *data) 170 { 171 return -EOPNOTSUPP; 172 } 173 174 static inline int kallsyms_on_each_match_symbol(int (*fn)(void *, unsigned long), 175 const char *name, void *data) 176 { 177 return -EOPNOTSUPP; 178 } 179 #endif /*CONFIG_KALLSYMS*/ 180 181 static inline void print_ip_sym(const char *loglvl, unsigned long ip) 182 { 183 printk("%s[<%px>] %pS\n", loglvl, (void *) ip, (void *) ip); 184 } 185 186 #endif /*_LINUX_KALLSYMS_H*/ 187