xref: /linux-6.15/include/linux/kallsyms.h (revision e00a844a)
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 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*/
138