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