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
is_kernel_text(unsigned long addr)27 static inline int is_kernel_text(unsigned long addr)
28 {
29 if (__is_kernel_text(addr))
30 return 1;
31 return in_gate_area_no_mm(addr);
32 }
33
is_kernel(unsigned long addr)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
is_ksym_addr(unsigned long addr)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 return is_kernel_text(addr) || is_kernel_inittext(addr);
47 }
48
dereference_symbol_descriptor(void * ptr)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 guard(rcu)();
59 mod = __module_address((unsigned long)ptr);
60
61 if (mod)
62 ptr = dereference_module_function_descriptor(mod, ptr);
63 #endif
64 return ptr;
65 }
66
67 /* How and when do we show kallsyms values? */
68 extern bool kallsyms_show_value(const struct cred *cred);
69
70 #ifdef CONFIG_KALLSYMS
71 unsigned long kallsyms_sym_address(int idx);
72 int kallsyms_on_each_symbol(int (*fn)(void *, const char *, unsigned long),
73 void *data);
74 int kallsyms_on_each_match_symbol(int (*fn)(void *, unsigned long),
75 const char *name, void *data);
76
77 /* Lookup the address for a symbol. Returns 0 if not found. */
78 unsigned long kallsyms_lookup_name(const char *name);
79
80 extern int kallsyms_lookup_size_offset(unsigned long addr,
81 unsigned long *symbolsize,
82 unsigned long *offset);
83
84 /* Lookup an address. modname is set to NULL if it's in the kernel. */
85 const char *kallsyms_lookup(unsigned long addr,
86 unsigned long *symbolsize,
87 unsigned long *offset,
88 char **modname, char *namebuf);
89
90 /* Look up a kernel symbol and return it in a text buffer. */
91 extern int sprint_symbol(char *buffer, unsigned long address);
92 extern int sprint_symbol_build_id(char *buffer, unsigned long address);
93 extern int sprint_symbol_no_offset(char *buffer, unsigned long address);
94 extern int sprint_backtrace(char *buffer, unsigned long address);
95 extern int sprint_backtrace_build_id(char *buffer, unsigned long address);
96
97 int lookup_symbol_name(unsigned long addr, char *symname);
98
99 #else /* !CONFIG_KALLSYMS */
100
kallsyms_lookup_name(const char * name)101 static inline unsigned long kallsyms_lookup_name(const char *name)
102 {
103 return 0;
104 }
105
kallsyms_lookup_size_offset(unsigned long addr,unsigned long * symbolsize,unsigned long * offset)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
kallsyms_lookup(unsigned long addr,unsigned long * symbolsize,unsigned long * offset,char ** modname,char * namebuf)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
sprint_symbol(char * buffer,unsigned long addr)121 static inline int sprint_symbol(char *buffer, unsigned long addr)
122 {
123 *buffer = '\0';
124 return 0;
125 }
126
sprint_symbol_build_id(char * buffer,unsigned long address)127 static inline int sprint_symbol_build_id(char *buffer, unsigned long address)
128 {
129 *buffer = '\0';
130 return 0;
131 }
132
sprint_symbol_no_offset(char * buffer,unsigned long addr)133 static inline int sprint_symbol_no_offset(char *buffer, unsigned long addr)
134 {
135 *buffer = '\0';
136 return 0;
137 }
138
sprint_backtrace(char * buffer,unsigned long addr)139 static inline int sprint_backtrace(char *buffer, unsigned long addr)
140 {
141 *buffer = '\0';
142 return 0;
143 }
144
sprint_backtrace_build_id(char * buffer,unsigned long addr)145 static inline int sprint_backtrace_build_id(char *buffer, unsigned long addr)
146 {
147 *buffer = '\0';
148 return 0;
149 }
150
lookup_symbol_name(unsigned long addr,char * symname)151 static inline int lookup_symbol_name(unsigned long addr, char *symname)
152 {
153 return -ERANGE;
154 }
155
kallsyms_on_each_symbol(int (* fn)(void *,const char *,unsigned long),void * data)156 static inline int kallsyms_on_each_symbol(int (*fn)(void *, const char *, unsigned long),
157 void *data)
158 {
159 return -EOPNOTSUPP;
160 }
161
kallsyms_on_each_match_symbol(int (* fn)(void *,unsigned long),const char * name,void * data)162 static inline int kallsyms_on_each_match_symbol(int (*fn)(void *, unsigned long),
163 const char *name, void *data)
164 {
165 return -EOPNOTSUPP;
166 }
167 #endif /*CONFIG_KALLSYMS*/
168
print_ip_sym(const char * loglvl,unsigned long ip)169 static inline void print_ip_sym(const char *loglvl, unsigned long ip)
170 {
171 printk("%s[<%px>] %pS\n", loglvl, (void *) ip, (void *) ip);
172 }
173
174 #endif /*_LINUX_KALLSYMS_H*/
175