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 int kallsyms_on_each_symbol(int (*fn)(void *, const char *, struct module *, 75 unsigned long), 76 void *data); 77 78 #ifdef CONFIG_KALLSYMS 79 /* Lookup the address for a symbol. Returns 0 if not found. */ 80 unsigned long kallsyms_lookup_name(const char *name); 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 bool kallsyms_show_value(const struct cred *cred); 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_lookup_size_offset(unsigned long addr, 111 unsigned long *symbolsize, 112 unsigned long *offset) 113 { 114 return 0; 115 } 116 117 static inline const char *kallsyms_lookup(unsigned long addr, 118 unsigned long *symbolsize, 119 unsigned long *offset, 120 char **modname, char *namebuf) 121 { 122 return NULL; 123 } 124 125 static inline int sprint_symbol(char *buffer, unsigned long addr) 126 { 127 *buffer = '\0'; 128 return 0; 129 } 130 131 static inline int sprint_symbol_no_offset(char *buffer, unsigned long addr) 132 { 133 *buffer = '\0'; 134 return 0; 135 } 136 137 static inline int sprint_backtrace(char *buffer, unsigned long addr) 138 { 139 *buffer = '\0'; 140 return 0; 141 } 142 143 static inline int lookup_symbol_name(unsigned long addr, char *symname) 144 { 145 return -ERANGE; 146 } 147 148 static inline int lookup_symbol_attrs(unsigned long addr, unsigned long *size, unsigned long *offset, char *modname, char *name) 149 { 150 return -ERANGE; 151 } 152 153 static inline bool kallsyms_show_value(const struct cred *cred) 154 { 155 return false; 156 } 157 158 #endif /*CONFIG_KALLSYMS*/ 159 160 static inline void print_ip_sym(const char *loglvl, unsigned long ip) 161 { 162 printk("%s[<%px>] %pS\n", loglvl, (void *) ip, (void *) ip); 163 } 164 165 #endif /*_LINUX_KALLSYMS_H*/ 166