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 module; 22 23 static 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 31 static 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 39 static 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 46 static 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 54 static 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. */ 75 unsigned long kallsyms_lookup_name(const char *name); 76 77 /* Call a function on each kallsyms symbol in the core kernel */ 78 int kallsyms_on_each_symbol(int (*fn)(void *, const char *, struct module *, 79 unsigned long), 80 void *data); 81 82 extern 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. */ 87 const 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. */ 93 extern int sprint_symbol(char *buffer, unsigned long address); 94 extern int sprint_symbol_no_offset(char *buffer, unsigned long address); 95 extern int sprint_backtrace(char *buffer, unsigned long address); 96 97 int lookup_symbol_name(unsigned long addr, char *symname); 98 int 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? */ 101 extern int kallsyms_show_value(void); 102 103 #else /* !CONFIG_KALLSYMS */ 104 105 static inline unsigned long kallsyms_lookup_name(const char *name) 106 { 107 return 0; 108 } 109 110 static 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 } 117 118 static inline int kallsyms_lookup_size_offset(unsigned long addr, 119 unsigned long *symbolsize, 120 unsigned long *offset) 121 { 122 return 0; 123 } 124 125 static 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 } 132 133 static inline int sprint_symbol(char *buffer, unsigned long addr) 134 { 135 *buffer = '\0'; 136 return 0; 137 } 138 139 static inline int sprint_symbol_no_offset(char *buffer, unsigned long addr) 140 { 141 *buffer = '\0'; 142 return 0; 143 } 144 145 static inline int sprint_backtrace(char *buffer, unsigned long addr) 146 { 147 *buffer = '\0'; 148 return 0; 149 } 150 151 static inline int lookup_symbol_name(unsigned long addr, char *symname) 152 { 153 return -ERANGE; 154 } 155 156 static inline int lookup_symbol_attrs(unsigned long addr, unsigned long *size, unsigned long *offset, char *modname, char *name) 157 { 158 return -ERANGE; 159 } 160 161 static inline int kallsyms_show_value(void) 162 { 163 return false; 164 } 165 166 #endif /*CONFIG_KALLSYMS*/ 167 168 static 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*/ 174