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 128
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 : {
29 170 : if (__is_kernel_text(addr))
30 : return 1;
31 96 : 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 66 : 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 : int kallsyms_on_each_symbol(int (*fn)(void *, const char *, struct module *,
69 : unsigned long),
70 : void *data);
71 :
72 : #ifdef CONFIG_KALLSYMS
73 : /* Lookup the address for a symbol. Returns 0 if not found. */
74 : unsigned long kallsyms_lookup_name(const char *name);
75 :
76 : extern int kallsyms_lookup_size_offset(unsigned long addr,
77 : unsigned long *symbolsize,
78 : unsigned long *offset);
79 :
80 : /* Lookup an address. modname is set to NULL if it's in the kernel. */
81 : const char *kallsyms_lookup(unsigned long addr,
82 : unsigned long *symbolsize,
83 : unsigned long *offset,
84 : char **modname, char *namebuf);
85 :
86 : /* Look up a kernel symbol and return it in a text buffer. */
87 : extern int sprint_symbol(char *buffer, unsigned long address);
88 : extern int sprint_symbol_build_id(char *buffer, unsigned long address);
89 : extern int sprint_symbol_no_offset(char *buffer, unsigned long address);
90 : extern int sprint_backtrace(char *buffer, unsigned long address);
91 : extern int sprint_backtrace_build_id(char *buffer, unsigned long address);
92 :
93 : int lookup_symbol_name(unsigned long addr, char *symname);
94 : int lookup_symbol_attrs(unsigned long addr, unsigned long *size, unsigned long *offset, char *modname, char *name);
95 :
96 : /* How and when do we show kallsyms values? */
97 : extern bool kallsyms_show_value(const struct cred *cred);
98 :
99 : #else /* !CONFIG_KALLSYMS */
100 :
101 : static inline unsigned long kallsyms_lookup_name(const char *name)
102 : {
103 : return 0;
104 : }
105 :
106 : static inline int kallsyms_lookup_size_offset(unsigned long addr,
107 : unsigned long *symbolsize,
108 : unsigned long *offset)
109 : {
110 : return 0;
111 : }
112 :
113 : static inline const char *kallsyms_lookup(unsigned long addr,
114 : unsigned long *symbolsize,
115 : unsigned long *offset,
116 : char **modname, char *namebuf)
117 : {
118 : return NULL;
119 : }
120 :
121 : static inline int sprint_symbol(char *buffer, unsigned long addr)
122 : {
123 : *buffer = '\0';
124 : return 0;
125 : }
126 :
127 : static inline int sprint_symbol_build_id(char *buffer, unsigned long address)
128 : {
129 : *buffer = '\0';
130 : return 0;
131 : }
132 :
133 : static inline int sprint_symbol_no_offset(char *buffer, unsigned long addr)
134 : {
135 : *buffer = '\0';
136 : return 0;
137 : }
138 :
139 : static inline int sprint_backtrace(char *buffer, unsigned long addr)
140 : {
141 : *buffer = '\0';
142 : return 0;
143 : }
144 :
145 : static inline int sprint_backtrace_build_id(char *buffer, unsigned long addr)
146 : {
147 : *buffer = '\0';
148 : return 0;
149 : }
150 :
151 : static inline int lookup_symbol_name(unsigned long addr, char *symname)
152 : {
153 : return -ERANGE;
154 : }
155 :
156 : static inline int lookup_symbol_attrs(unsigned long addr, unsigned long *size, unsigned long *offset, char *modname, char *name)
157 : {
158 : return -ERANGE;
159 : }
160 :
161 : static inline bool kallsyms_show_value(const struct cred *cred)
162 : {
163 : return false;
164 : }
165 :
166 : #endif /*CONFIG_KALLSYMS*/
167 :
168 : static inline void print_ip_sym(const char *loglvl, unsigned long ip)
169 : {
170 : printk("%s[<%px>] %pS\n", loglvl, (void *) ip, (void *) ip);
171 : }
172 :
173 : #endif /*_LINUX_KALLSYMS_H*/
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