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/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 21 struct cred; 22 struct module; 23 24 static 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 32 static 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 40 static 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 47 static 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 55 static 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. */ 76 unsigned long kallsyms_lookup_name(const char *name); 77 78 /* Call a function on each kallsyms symbol in the core kernel */ 79 int kallsyms_on_each_symbol(int (*fn)(void *, const char *, struct module *, 80 unsigned long), 81 void *data); 82 83 extern 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. */ 88 const 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. */ 94 extern int sprint_symbol(char *buffer, unsigned long address); 95 extern int sprint_symbol_no_offset(char *buffer, unsigned long address); 96 extern int sprint_backtrace(char *buffer, unsigned long address); 97 98 int lookup_symbol_name(unsigned long addr, char *symname); 99 int 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? */ 102 extern bool kallsyms_show_value(const struct cred *cred); 103 104 #else /* !CONFIG_KALLSYMS */ 105 106 static inline unsigned long kallsyms_lookup_name(const char *name) 107 { 108 return 0; 109 } 110 111 static 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 } 118 119 static inline int kallsyms_lookup_size_offset(unsigned long addr, 120 unsigned long *symbolsize, 121 unsigned long *offset) 122 { 123 return 0; 124 } 125 126 static 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 } 133 134 static inline int sprint_symbol(char *buffer, unsigned long addr) 135 { 136 *buffer = '\0'; 137 return 0; 138 } 139 140 static inline int sprint_symbol_no_offset(char *buffer, unsigned long addr) 141 { 142 *buffer = '\0'; 143 return 0; 144 } 145 146 static inline int sprint_backtrace(char *buffer, unsigned long addr) 147 { 148 *buffer = '\0'; 149 return 0; 150 } 151 152 static inline int lookup_symbol_name(unsigned long addr, char *symname) 153 { 154 return -ERANGE; 155 } 156 157 static inline int lookup_symbol_attrs(unsigned long addr, unsigned long *size, unsigned long *offset, char *modname, char *name) 158 { 159 return -ERANGE; 160 } 161 162 static inline bool kallsyms_show_value(const struct cred *cred) 163 { 164 return false; 165 } 166 167 #endif /*CONFIG_KALLSYMS*/ 168 169 static 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*/ 175