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 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_inittext(unsigned long addr) 28 { 29 if (addr >= (unsigned long)_sinittext 30 && addr <= (unsigned long)_einittext) 31 return 1; 32 return 0; 33 } 34 35 static inline int is_kernel_text(unsigned long addr) 36 { 37 if ((addr >= (unsigned long)_stext && addr <= (unsigned long)_etext) || 38 arch_is_kernel_text(addr)) 39 return 1; 40 return in_gate_area_no_mm(addr); 41 } 42 43 static inline int is_kernel(unsigned long addr) 44 { 45 if (addr >= (unsigned long)_stext && addr <= (unsigned long)_end) 46 return 1; 47 return in_gate_area_no_mm(addr); 48 } 49 50 static inline int is_ksym_addr(unsigned long addr) 51 { 52 if (IS_ENABLED(CONFIG_KALLSYMS_ALL)) 53 return is_kernel(addr); 54 55 return is_kernel_text(addr) || is_kernel_inittext(addr); 56 } 57 58 static inline void *dereference_symbol_descriptor(void *ptr) 59 { 60 #ifdef HAVE_DEREFERENCE_FUNCTION_DESCRIPTOR 61 struct module *mod; 62 63 ptr = dereference_kernel_function_descriptor(ptr); 64 if (is_ksym_addr((unsigned long)ptr)) 65 return ptr; 66 67 preempt_disable(); 68 mod = __module_address((unsigned long)ptr); 69 preempt_enable(); 70 71 if (mod) 72 ptr = dereference_module_function_descriptor(mod, ptr); 73 #endif 74 return ptr; 75 } 76 77 int kallsyms_on_each_symbol(int (*fn)(void *, const char *, struct module *, 78 unsigned long), 79 void *data); 80 81 #ifdef CONFIG_KALLSYMS 82 /* Lookup the address for a symbol. Returns 0 if not found. */ 83 unsigned long kallsyms_lookup_name(const char *name); 84 85 extern int kallsyms_lookup_size_offset(unsigned long addr, 86 unsigned long *symbolsize, 87 unsigned long *offset); 88 89 /* Lookup an address. modname is set to NULL if it's in the kernel. */ 90 const char *kallsyms_lookup(unsigned long addr, 91 unsigned long *symbolsize, 92 unsigned long *offset, 93 char **modname, char *namebuf); 94 95 /* Look up a kernel symbol and return it in a text buffer. */ 96 extern int sprint_symbol(char *buffer, unsigned long address); 97 extern int sprint_symbol_build_id(char *buffer, unsigned long address); 98 extern int sprint_symbol_no_offset(char *buffer, unsigned long address); 99 extern int sprint_backtrace(char *buffer, unsigned long address); 100 extern int sprint_backtrace_build_id(char *buffer, unsigned long address); 101 102 int lookup_symbol_name(unsigned long addr, char *symname); 103 int lookup_symbol_attrs(unsigned long addr, unsigned long *size, unsigned long *offset, char *modname, char *name); 104 105 /* How and when do we show kallsyms values? */ 106 extern bool kallsyms_show_value(const struct cred *cred); 107 108 #else /* !CONFIG_KALLSYMS */ 109 110 static inline unsigned long kallsyms_lookup_name(const char *name) 111 { 112 return 0; 113 } 114 115 static inline int kallsyms_lookup_size_offset(unsigned long addr, 116 unsigned long *symbolsize, 117 unsigned long *offset) 118 { 119 return 0; 120 } 121 122 static inline const char *kallsyms_lookup(unsigned long addr, 123 unsigned long *symbolsize, 124 unsigned long *offset, 125 char **modname, char *namebuf) 126 { 127 return NULL; 128 } 129 130 static inline int sprint_symbol(char *buffer, unsigned long addr) 131 { 132 *buffer = '\0'; 133 return 0; 134 } 135 136 static inline int sprint_symbol_build_id(char *buffer, unsigned long address) 137 { 138 *buffer = '\0'; 139 return 0; 140 } 141 142 static inline int sprint_symbol_no_offset(char *buffer, unsigned long addr) 143 { 144 *buffer = '\0'; 145 return 0; 146 } 147 148 static inline int sprint_backtrace(char *buffer, unsigned long addr) 149 { 150 *buffer = '\0'; 151 return 0; 152 } 153 154 static inline int sprint_backtrace_build_id(char *buffer, unsigned long addr) 155 { 156 *buffer = '\0'; 157 return 0; 158 } 159 160 static inline int lookup_symbol_name(unsigned long addr, char *symname) 161 { 162 return -ERANGE; 163 } 164 165 static inline int lookup_symbol_attrs(unsigned long addr, unsigned long *size, unsigned long *offset, char *modname, char *name) 166 { 167 return -ERANGE; 168 } 169 170 static inline bool kallsyms_show_value(const struct cred *cred) 171 { 172 return false; 173 } 174 175 #endif /*CONFIG_KALLSYMS*/ 176 177 static inline void print_ip_sym(const char *loglvl, unsigned long ip) 178 { 179 printk("%s[<%px>] %pS\n", loglvl, (void *) ip, (void *) ip); 180 } 181 182 #endif /*_LINUX_KALLSYMS_H*/ 183