include/linux/kallsyms.h

   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/kernel.h>
  11 #include <linux/stddef.h>
  12
  13 #define KSYM_NAME_LEN 128
  14 #define KSYM_SYMBOL_LEN (sizeof("%s+%#lx/%#lx [%s]") + (KSYM_NAME_LEN - 1) + \
  15                          2*(BITS_PER_LONG*3/10) + (MODULE_NAME_LEN - 1) + 1)
  16
  17 struct module;
  18
  19 #ifdef CONFIG_KALLSYMS
  20 /* Lookup the address for a symbol. Returns 0 if not found. */
  21 unsigned long kallsyms_lookup_name(const char *name);
  22
  23 /* Call a function on each kallsyms symbol in the core kernel */
  24 int kallsyms_on_each_symbol(int (*fn)(void *, const char *, struct module *,
  25                                       unsigned long),
  26                             void *data);
  27
  28 extern int kallsyms_lookup_size_offset(unsigned long addr,
  29                                   unsigned long *symbolsize,
  30                                   unsigned long *offset);
  31
  32 /* Lookup an address.  modname is set to NULL if it's in the kernel. */
  33 const char *kallsyms_lookup(unsigned long addr,
  34                             unsigned long *symbolsize,
  35                             unsigned long *offset,
  36                             char **modname, char *namebuf);
  37
  38 /* Look up a kernel symbol and return it in a text buffer. */
  39 extern int sprint_symbol(char *buffer, unsigned long address);
  40 extern int sprint_symbol_no_offset(char *buffer, unsigned long address);
  41 extern int sprint_backtrace(char *buffer, unsigned long address);
  42
  43 /* Look up a kernel symbol and print it to the kernel messages. */
  44 extern void __print_symbol(const char *fmt, unsigned long address);
  45
  46 int lookup_symbol_name(unsigned long addr, char *symname);
  47 int lookup_symbol_attrs(unsigned long addr, unsigned long *size, unsigned long *offset, char *modname, char *name);
  48
  49 /* How and when do we show kallsyms values? */
  50 extern int kallsyms_show_value(void);
  51
  52 #else /* !CONFIG_KALLSYMS */
  53
  54 static inline unsigned long kallsyms_lookup_name(const char *name)
  55 {
  56         return 0;
  57 }
  58
  59 static inline int kallsyms_on_each_symbol(int (*fn)(void *, const char *,
  60                                                     struct module *,
  61                                                     unsigned long),
  62                                           void *data)
  63 {
  64         return 0;
  65 }
  66
  67 static inline int kallsyms_lookup_size_offset(unsigned long addr,
  68                                               unsigned long *symbolsize,
  69                                               unsigned long *offset)
  70 {
  71         return 0;
  72 }
  73
  74 static inline const char *kallsyms_lookup(unsigned long addr,
  75                                           unsigned long *symbolsize,
  76                                           unsigned long *offset,
  77                                           char **modname, char *namebuf)
  78 {
  79         return NULL;
  80 }
  81
  82 static inline int sprint_symbol(char *buffer, unsigned long addr)
  83 {
  84         *buffer = '\0';
  85         return 0;
  86 }
  87
  88 static inline int sprint_symbol_no_offset(char *buffer, unsigned long addr)
  89 {
  90         *buffer = '\0';
  91         return 0;
  92 }
  93
  94 static inline int sprint_backtrace(char *buffer, unsigned long addr)
  95 {
  96         *buffer = '\0';
  97         return 0;
  98 }
  99
 100 static inline int lookup_symbol_name(unsigned long addr, char *symname)
 101 {
 102         return -ERANGE;
 103 }
 104
 105 static inline int lookup_symbol_attrs(unsigned long addr, unsigned long *size, unsigned long *offset, char *modname, char *name)
 106 {
 107         return -ERANGE;
 108 }
 109
 110 static inline int kallsyms_show_value(void)
 111 {
 112         return false;
 113 }
 114
 115 /* Stupid that this does nothing, but I didn't create this mess. */
 116 #define __print_symbol(fmt, addr)
 117 #endif /*CONFIG_KALLSYMS*/
 118
 119 /* This macro allows us to keep printk typechecking */
 120 static __printf(1, 2)
 121 void __check_printsym_format(const char *fmt, ...)
 122 {
 123 }
 124
 125 static inline void print_symbol(const char *fmt, unsigned long addr)
 126 {
 127         __check_printsym_format(fmt, "");
 128         __print_symbol(fmt, (unsigned long)
 129                        __builtin_extract_return_addr((void *)addr));
 130 }
 131
 132 static inline void print_ip_sym(unsigned long ip)
 133 {
 134         printk("[<%p>] %pS\n", (void *) ip, (void *) ip);
 135 }
 136
 137 #endif /*_LINUX_KALLSYMS_H*/