Line data Source code
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 512
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 :
24 : struct cred;
25 : struct module;
26 :
27 : static inline int is_kernel_text(unsigned long addr)
28 : {
29 826 : if (__is_kernel_text(addr))
30 : return 1;
31 500 : return in_gate_area_no_mm(addr);
32 : }
33 :
34 : static 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 :
41 : static inline int is_ksym_addr(unsigned long addr)
42 : {
43 : if (IS_ENABLED(CONFIG_KALLSYMS_ALL))
44 : return is_kernel(addr);
45 :
46 252 : return is_kernel_text(addr) || is_kernel_inittext(addr);
47 : }
48 :
49 : static 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
69 : unsigned long kallsyms_sym_address(int idx);
70 : int kallsyms_on_each_symbol(int (*fn)(void *, const char *, struct module *,
71 : unsigned long),
72 : void *data);
73 : int kallsyms_on_each_match_symbol(int (*fn)(void *, unsigned long),
74 : const char *name, void *data);
75 :
76 : /* Lookup the address for a symbol. Returns 0 if not found. */
77 : unsigned long kallsyms_lookup_name(const char *name);
78 :
79 : extern int kallsyms_lookup_size_offset(unsigned long addr,
80 : unsigned long *symbolsize,
81 : unsigned long *offset);
82 :
83 : /* Lookup an address. modname is set to NULL if it's in the kernel. */
84 : const char *kallsyms_lookup(unsigned long addr,
85 : unsigned long *symbolsize,
86 : unsigned long *offset,
87 : char **modname, char *namebuf);
88 :
89 : /* Look up a kernel symbol and return it in a text buffer. */
90 : extern int sprint_symbol(char *buffer, unsigned long address);
91 : extern int sprint_symbol_build_id(char *buffer, unsigned long address);
92 : extern int sprint_symbol_no_offset(char *buffer, unsigned long address);
93 : extern int sprint_backtrace(char *buffer, unsigned long address);
94 : extern int sprint_backtrace_build_id(char *buffer, unsigned long address);
95 :
96 : int lookup_symbol_name(unsigned long addr, char *symname);
97 : int lookup_symbol_attrs(unsigned long addr, unsigned long *size, unsigned long *offset, char *modname, char *name);
98 :
99 : /* How and when do we show kallsyms values? */
100 : extern bool kallsyms_show_value(const struct cred *cred);
101 :
102 : #else /* !CONFIG_KALLSYMS */
103 :
104 : static inline unsigned long kallsyms_lookup_name(const char *name)
105 : {
106 : return 0;
107 : }
108 :
109 : static inline int kallsyms_lookup_size_offset(unsigned long addr,
110 : unsigned long *symbolsize,
111 : unsigned long *offset)
112 : {
113 : return 0;
114 : }
115 :
116 : static inline const char *kallsyms_lookup(unsigned long addr,
117 : unsigned long *symbolsize,
118 : unsigned long *offset,
119 : char **modname, char *namebuf)
120 : {
121 : return NULL;
122 : }
123 :
124 : static inline int sprint_symbol(char *buffer, unsigned long addr)
125 : {
126 : *buffer = '\0';
127 : return 0;
128 : }
129 :
130 : static inline int sprint_symbol_build_id(char *buffer, unsigned long address)
131 : {
132 : *buffer = '\0';
133 : return 0;
134 : }
135 :
136 : static inline int sprint_symbol_no_offset(char *buffer, unsigned long addr)
137 : {
138 : *buffer = '\0';
139 : return 0;
140 : }
141 :
142 : static inline int sprint_backtrace(char *buffer, unsigned long addr)
143 : {
144 : *buffer = '\0';
145 : return 0;
146 : }
147 :
148 : static inline int sprint_backtrace_build_id(char *buffer, unsigned long addr)
149 : {
150 : *buffer = '\0';
151 : return 0;
152 : }
153 :
154 : static inline int lookup_symbol_name(unsigned long addr, char *symname)
155 : {
156 : return -ERANGE;
157 : }
158 :
159 : static inline int lookup_symbol_attrs(unsigned long addr, unsigned long *size, unsigned long *offset, char *modname, char *name)
160 : {
161 : return -ERANGE;
162 : }
163 :
164 : static inline bool kallsyms_show_value(const struct cred *cred)
165 : {
166 : return false;
167 : }
168 :
169 : static inline int kallsyms_on_each_symbol(int (*fn)(void *, const char *, struct module *,
170 : unsigned long), void *data)
171 : {
172 : return -EOPNOTSUPP;
173 : }
174 :
175 : static inline int kallsyms_on_each_match_symbol(int (*fn)(void *, unsigned long),
176 : const char *name, void *data)
177 : {
178 : return -EOPNOTSUPP;
179 : }
180 : #endif /*CONFIG_KALLSYMS*/
181 :
182 : static inline void print_ip_sym(const char *loglvl, unsigned long ip)
183 : {
184 : printk("%s[<%px>] %pS\n", loglvl, (void *) ip, (void *) ip);
185 : }
186 :
187 : #endif /*_LINUX_KALLSYMS_H*/
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