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#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
21struct module;
22
23static inline int is_kernel_inittext(unsigned long addr)
24{
25 if (addr >= (unsigned long)_sinittext
26 && addr <= (unsigned long)_einittext)
27 return 1;
28 return 0;
29}
30
31static inline int is_kernel_text(unsigned long addr)
32{
33 if ((addr >= (unsigned long)_stext && addr <= (unsigned long)_etext) ||
34 arch_is_kernel_text(addr))
35 return 1;
36 return in_gate_area_no_mm(addr);
37}
38
39static inline int is_kernel(unsigned long addr)
40{
41 if (addr >= (unsigned long)_stext && addr <= (unsigned long)_end)
42 return 1;
43 return in_gate_area_no_mm(addr);
44}
45
46static inline int is_ksym_addr(unsigned long addr)
47{
48 if (IS_ENABLED(CONFIG_KALLSYMS_ALL))
49 return is_kernel(addr);
50
51 return is_kernel_text(addr) || is_kernel_inittext(addr);
52}
53
54static inline void *dereference_symbol_descriptor(void *ptr)
55{
56#ifdef HAVE_DEREFERENCE_FUNCTION_DESCRIPTOR
57 struct module *mod;
58
59 ptr = dereference_kernel_function_descriptor(ptr);
60 if (is_ksym_addr((unsigned long)ptr))
61 return ptr;
62
63 preempt_disable();
64 mod = __module_address((unsigned long)ptr);
65 preempt_enable();
66
67 if (mod)
68 ptr = dereference_module_function_descriptor(mod, ptr);
69#endif
70 return ptr;
71}
72
73#ifdef CONFIG_KALLSYMS
74/* Lookup the address for a symbol. Returns 0 if not found. */
75unsigned long kallsyms_lookup_name(const char *name);
76
77/* Call a function on each kallsyms symbol in the core kernel */
78int kallsyms_on_each_symbol(int (*fn)(void *, const char *, struct module *,
79 unsigned long),
80 void *data);
81
82extern 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. */
87const 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. */
93extern int sprint_symbol(char *buffer, unsigned long address);
94extern int sprint_symbol_no_offset(char *buffer, unsigned long address);
95extern int sprint_backtrace(char *buffer, unsigned long address);
96
97int lookup_symbol_name(unsigned long addr, char *symname);
98int 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? */
101extern int kallsyms_show_value(void);
102
103#else /* !CONFIG_KALLSYMS */
104
105static inline unsigned long kallsyms_lookup_name(const char *name)
106{
107 return 0;
108}
109
110static inline int kallsyms_on_each_symbol(int (*fn)(void *, const char *,
111 struct module *,
112 unsigned long),
113 void *data)
114{
115 return 0;
116}
117
118static inline int kallsyms_lookup_size_offset(unsigned long addr,
119 unsigned long *symbolsize,
120 unsigned long *offset)
121{
122 return 0;
123}
124
125static inline const char *kallsyms_lookup(unsigned long addr,
126 unsigned long *symbolsize,
127 unsigned long *offset,
128 char **modname, char *namebuf)
129{
130 return NULL;
131}
132
133static inline int sprint_symbol(char *buffer, unsigned long addr)
134{
135 *buffer = '\0';
136 return 0;
137}
138
139static inline int sprint_symbol_no_offset(char *buffer, unsigned long addr)
140{
141 *buffer = '\0';
142 return 0;
143}
144
145static inline int sprint_backtrace(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 int kallsyms_show_value(void)
162{
163 return false;
164}
165
166#endif /*CONFIG_KALLSYMS*/
167
168static inline void print_ip_sym(unsigned long ip)
169{
170 printk("[<%px>] %pS\n", (void *) ip, (void *) ip);
171}
172
173#endif /*_LINUX_KALLSYMS_H*/
174