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/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 128 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 int kallsyms_on_each_symbol(int (*fn)(void *, const char *, struct module *, 69 unsigned long), 70 void *data); 71 72 #ifdef CONFIG_KALLSYMS 73 /* Lookup the address for a symbol. Returns 0 if not found. */ 74 unsigned long kallsyms_lookup_name(const char *name); 75 76 extern int kallsyms_lookup_size_offset(unsigned long addr, 77 unsigned long *symbolsize, 78 unsigned long *offset); 79 80 /* Lookup an address. modname is set to NULL if it's in the kernel. */ 81 const char *kallsyms_lookup(unsigned long addr, 82 unsigned long *symbolsize, 83 unsigned long *offset, 84 char **modname, char *namebuf); 85 86 /* Look up a kernel symbol and return it in a text buffer. */ 87 extern int sprint_symbol(char *buffer, unsigned long address); 88 extern int sprint_symbol_build_id(char *buffer, unsigned long address); 89 extern int sprint_symbol_no_offset(char *buffer, unsigned long address); 90 extern int sprint_backtrace(char *buffer, unsigned long address); 91 extern int sprint_backtrace_build_id(char *buffer, unsigned long address); 92 93 int lookup_symbol_name(unsigned long addr, char *symname); 94 int lookup_symbol_attrs(unsigned long addr, unsigned long *size, unsigned long *offset, char *modname, char *name); 95 96 /* How and when do we show kallsyms values? */ 97 extern bool kallsyms_show_value(const struct cred *cred); 98 99 #else /* !CONFIG_KALLSYMS */ 100 101 static inline unsigned long kallsyms_lookup_name(const char *name) 102 { 103 return 0; 104 } 105 106 static inline int kallsyms_lookup_size_offset(unsigned long addr, 107 unsigned long *symbolsize, 108 unsigned long *offset) 109 { 110 return 0; 111 } 112 113 static inline const char *kallsyms_lookup(unsigned long addr, 114 unsigned long *symbolsize, 115 unsigned long *offset, 116 char **modname, char *namebuf) 117 { 118 return NULL; 119 } 120 121 static inline int sprint_symbol(char *buffer, unsigned long addr) 122 { 123 *buffer = '\0'; 124 return 0; 125 } 126 127 static inline int sprint_symbol_build_id(char *buffer, unsigned long address) 128 { 129 *buffer = '\0'; 130 return 0; 131 } 132 133 static inline int sprint_symbol_no_offset(char *buffer, unsigned long addr) 134 { 135 *buffer = '\0'; 136 return 0; 137 } 138 139 static inline int sprint_backtrace(char *buffer, unsigned long addr) 140 { 141 *buffer = '\0'; 142 return 0; 143 } 144 145 static inline int sprint_backtrace_build_id(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 bool kallsyms_show_value(const struct cred *cred) 162 { 163 return false; 164 } 165 166 #endif /*CONFIG_KALLSYMS*/ 167 168 static inline void print_ip_sym(const char *loglvl, unsigned long ip) 169 { 170 printk("%s[<%px>] %pS\n", loglvl, (void *) ip, (void *) ip); 171 } 172 173 #endif /*_LINUX_KALLSYMS_H*/ 174