kallsyms.h (4467B)
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 24struct cred; 25struct module; 26 27static 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 34static 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 41static 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 49static 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#ifdef CONFIG_KALLSYMS 69int kallsyms_on_each_symbol(int (*fn)(void *, const char *, struct module *, 70 unsigned long), 71 void *data); 72 73/* Lookup the address for a symbol. Returns 0 if not found. */ 74unsigned long kallsyms_lookup_name(const char *name); 75 76extern 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. */ 81const 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. */ 87extern int sprint_symbol(char *buffer, unsigned long address); 88extern int sprint_symbol_build_id(char *buffer, unsigned long address); 89extern int sprint_symbol_no_offset(char *buffer, unsigned long address); 90extern int sprint_backtrace(char *buffer, unsigned long address); 91extern int sprint_backtrace_build_id(char *buffer, unsigned long address); 92 93int lookup_symbol_name(unsigned long addr, char *symname); 94int 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? */ 97extern bool kallsyms_show_value(const struct cred *cred); 98 99#else /* !CONFIG_KALLSYMS */ 100 101static inline unsigned long kallsyms_lookup_name(const char *name) 102{ 103 return 0; 104} 105 106static inline int kallsyms_lookup_size_offset(unsigned long addr, 107 unsigned long *symbolsize, 108 unsigned long *offset) 109{ 110 return 0; 111} 112 113static 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 121static inline int sprint_symbol(char *buffer, unsigned long addr) 122{ 123 *buffer = '\0'; 124 return 0; 125} 126 127static inline int sprint_symbol_build_id(char *buffer, unsigned long address) 128{ 129 *buffer = '\0'; 130 return 0; 131} 132 133static inline int sprint_symbol_no_offset(char *buffer, unsigned long addr) 134{ 135 *buffer = '\0'; 136 return 0; 137} 138 139static inline int sprint_backtrace(char *buffer, unsigned long addr) 140{ 141 *buffer = '\0'; 142 return 0; 143} 144 145static inline int sprint_backtrace_build_id(char *buffer, unsigned long addr) 146{ 147 *buffer = '\0'; 148 return 0; 149} 150 151static inline int lookup_symbol_name(unsigned long addr, char *symname) 152{ 153 return -ERANGE; 154} 155 156static inline int lookup_symbol_attrs(unsigned long addr, unsigned long *size, unsigned long *offset, char *modname, char *name) 157{ 158 return -ERANGE; 159} 160 161static inline bool kallsyms_show_value(const struct cred *cred) 162{ 163 return false; 164} 165 166static inline int kallsyms_on_each_symbol(int (*fn)(void *, const char *, struct module *, 167 unsigned long), void *data) 168{ 169 return -EOPNOTSUPP; 170} 171#endif /*CONFIG_KALLSYMS*/ 172 173static inline void print_ip_sym(const char *loglvl, unsigned long ip) 174{ 175 printk("%s[<%px>] %pS\n", loglvl, (void *) ip, (void *) ip); 176} 177 178#endif /*_LINUX_KALLSYMS_H*/