xref: /linux-6.15/include/linux/kallsyms.h (revision 12bb14aa)
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 
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 #ifndef CONFIG_64BIT
18 # define KALLSYM_FMT "%08lx"
19 #else
20 # define KALLSYM_FMT "%016lx"
21 #endif
22 
23 struct module;
24 
25 #ifdef CONFIG_KALLSYMS
26 /* Lookup the address for a symbol. Returns 0 if not found. */
27 unsigned long kallsyms_lookup_name(const char *name);
28 
29 /* Call a function on each kallsyms symbol in the core kernel */
30 int kallsyms_on_each_symbol(int (*fn)(void *, const char *, struct module *,
31 				      unsigned long),
32 			    void *data);
33 
34 extern int kallsyms_lookup_size_offset(unsigned long addr,
35 				  unsigned long *symbolsize,
36 				  unsigned long *offset);
37 
38 /* Lookup an address.  modname is set to NULL if it's in the kernel. */
39 const char *kallsyms_lookup(unsigned long addr,
40 			    unsigned long *symbolsize,
41 			    unsigned long *offset,
42 			    char **modname, char *namebuf);
43 
44 /* Look up a kernel symbol and return it in a text buffer. */
45 extern int sprint_symbol(char *buffer, unsigned long address);
46 extern int sprint_symbol_no_offset(char *buffer, unsigned long address);
47 extern int sprint_backtrace(char *buffer, unsigned long address);
48 
49 /* Look up a kernel symbol and print it to the kernel messages. */
50 extern void __print_symbol(const char *fmt, unsigned long address);
51 
52 int lookup_symbol_name(unsigned long addr, char *symname);
53 int lookup_symbol_attrs(unsigned long addr, unsigned long *size, unsigned long *offset, char *modname, char *name);
54 
55 /* How and when do we show kallsyms values? */
56 extern int kallsyms_show_value(void);
57 
58 #else /* !CONFIG_KALLSYMS */
59 
60 static inline unsigned long kallsyms_lookup_name(const char *name)
61 {
62 	return 0;
63 }
64 
65 static inline int kallsyms_on_each_symbol(int (*fn)(void *, const char *,
66 						    struct module *,
67 						    unsigned long),
68 					  void *data)
69 {
70 	return 0;
71 }
72 
73 static inline int kallsyms_lookup_size_offset(unsigned long addr,
74 					      unsigned long *symbolsize,
75 					      unsigned long *offset)
76 {
77 	return 0;
78 }
79 
80 static inline const char *kallsyms_lookup(unsigned long addr,
81 					  unsigned long *symbolsize,
82 					  unsigned long *offset,
83 					  char **modname, char *namebuf)
84 {
85 	return NULL;
86 }
87 
88 static inline int sprint_symbol(char *buffer, unsigned long addr)
89 {
90 	*buffer = '\0';
91 	return 0;
92 }
93 
94 static inline int sprint_symbol_no_offset(char *buffer, unsigned long addr)
95 {
96 	*buffer = '\0';
97 	return 0;
98 }
99 
100 static inline int sprint_backtrace(char *buffer, unsigned long addr)
101 {
102 	*buffer = '\0';
103 	return 0;
104 }
105 
106 static inline int lookup_symbol_name(unsigned long addr, char *symname)
107 {
108 	return -ERANGE;
109 }
110 
111 static inline int lookup_symbol_attrs(unsigned long addr, unsigned long *size, unsigned long *offset, char *modname, char *name)
112 {
113 	return -ERANGE;
114 }
115 
116 static inline int kallsyms_show_value(void)
117 {
118 	return false;
119 }
120 
121 /* Stupid that this does nothing, but I didn't create this mess. */
122 #define __print_symbol(fmt, addr)
123 #endif /*CONFIG_KALLSYMS*/
124 
125 /* This macro allows us to keep printk typechecking */
126 static __printf(1, 2)
127 void __check_printsym_format(const char *fmt, ...)
128 {
129 }
130 
131 static inline void print_symbol(const char *fmt, unsigned long addr)
132 {
133 	__check_printsym_format(fmt, "");
134 	__print_symbol(fmt, (unsigned long)
135 		       __builtin_extract_return_addr((void *)addr));
136 }
137 
138 static inline void print_ip_sym(unsigned long ip)
139 {
140 	printk("[<%p>] %pS\n", (void *) ip, (void *) ip);
141 }
142 
143 #endif /*_LINUX_KALLSYMS_H*/
144