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
21 struct cred;
22 struct module;
23
is_kernel_inittext(unsigned long addr)24 static inline int is_kernel_inittext(unsigned long addr)
25 {
26 if (addr >= (unsigned long)_sinittext
27 && addr <= (unsigned long)_einittext)
28 return 1;
29 return 0;
30 }
31
is_kernel_text(unsigned long addr)32 static inline int is_kernel_text(unsigned long addr)
33 {
34 if ((addr >= (unsigned long)_stext && addr <= (unsigned long)_etext) ||
35 arch_is_kernel_text(addr))
36 return 1;
37 return in_gate_area_no_mm(addr);
38 }
39
is_kernel(unsigned long addr)40 static inline int is_kernel(unsigned long addr)
41 {
42 if (addr >= (unsigned long)_stext && addr <= (unsigned long)_end)
43 return 1;
44 return in_gate_area_no_mm(addr);
45 }
46
is_ksym_addr(unsigned long addr)47 static inline int is_ksym_addr(unsigned long addr)
48 {
49 if (IS_ENABLED(CONFIG_KALLSYMS_ALL))
50 return is_kernel(addr);
51
52 return is_kernel_text(addr) || is_kernel_inittext(addr);
53 }
54
dereference_symbol_descriptor(void * ptr)55 static inline void *dereference_symbol_descriptor(void *ptr)
56 {
57 #ifdef HAVE_DEREFERENCE_FUNCTION_DESCRIPTOR
58 struct module *mod;
59
60 ptr = dereference_kernel_function_descriptor(ptr);
61 if (is_ksym_addr((unsigned long)ptr))
62 return ptr;
63
64 preempt_disable();
65 mod = __module_address((unsigned long)ptr);
66 preempt_enable();
67
68 if (mod)
69 ptr = dereference_module_function_descriptor(mod, ptr);
70 #endif
71 return ptr;
72 }
73
74 #ifdef CONFIG_KALLSYMS
75 /* Lookup the address for a symbol. Returns 0 if not found. */
76 unsigned long kallsyms_lookup_name(const char *name);
77
78 /* Call a function on each kallsyms symbol in the core kernel */
79 int kallsyms_on_each_symbol(int (*fn)(void *, const char *, struct module *,
80 unsigned long),
81 void *data);
82
83 extern int kallsyms_lookup_size_offset(unsigned long addr,
84 unsigned long *symbolsize,
85 unsigned long *offset);
86
87 /* Lookup an address. modname is set to NULL if it's in the kernel. */
88 const char *kallsyms_lookup(unsigned long addr,
89 unsigned long *symbolsize,
90 unsigned long *offset,
91 char **modname, char *namebuf);
92
93 /* Look up a kernel symbol and return it in a text buffer. */
94 extern int sprint_symbol(char *buffer, unsigned long address);
95 extern int sprint_symbol_no_offset(char *buffer, unsigned long address);
96 extern int sprint_backtrace(char *buffer, unsigned long address);
97
98 int lookup_symbol_name(unsigned long addr, char *symname);
99 int lookup_symbol_attrs(unsigned long addr, unsigned long *size, unsigned long *offset, char *modname, char *name);
100
101 /* How and when do we show kallsyms values? */
102 extern bool kallsyms_show_value(const struct cred *cred);
103
104 #else /* !CONFIG_KALLSYMS */
105
kallsyms_lookup_name(const char * name)106 static inline unsigned long kallsyms_lookup_name(const char *name)
107 {
108 return 0;
109 }
110
kallsyms_on_each_symbol(int (* fn)(void *,const char *,struct module *,unsigned long),void * data)111 static inline int kallsyms_on_each_symbol(int (*fn)(void *, const char *,
112 struct module *,
113 unsigned long),
114 void *data)
115 {
116 return 0;
117 }
118
kallsyms_lookup_size_offset(unsigned long addr,unsigned long * symbolsize,unsigned long * offset)119 static inline int kallsyms_lookup_size_offset(unsigned long addr,
120 unsigned long *symbolsize,
121 unsigned long *offset)
122 {
123 return 0;
124 }
125
kallsyms_lookup(unsigned long addr,unsigned long * symbolsize,unsigned long * offset,char ** modname,char * namebuf)126 static inline const char *kallsyms_lookup(unsigned long addr,
127 unsigned long *symbolsize,
128 unsigned long *offset,
129 char **modname, char *namebuf)
130 {
131 return NULL;
132 }
133
sprint_symbol(char * buffer,unsigned long addr)134 static inline int sprint_symbol(char *buffer, unsigned long addr)
135 {
136 *buffer = '\0';
137 return 0;
138 }
139
sprint_symbol_no_offset(char * buffer,unsigned long addr)140 static inline int sprint_symbol_no_offset(char *buffer, unsigned long addr)
141 {
142 *buffer = '\0';
143 return 0;
144 }
145
sprint_backtrace(char * buffer,unsigned long addr)146 static inline int sprint_backtrace(char *buffer, unsigned long addr)
147 {
148 *buffer = '\0';
149 return 0;
150 }
151
lookup_symbol_name(unsigned long addr,char * symname)152 static inline int lookup_symbol_name(unsigned long addr, char *symname)
153 {
154 return -ERANGE;
155 }
156
lookup_symbol_attrs(unsigned long addr,unsigned long * size,unsigned long * offset,char * modname,char * name)157 static inline int lookup_symbol_attrs(unsigned long addr, unsigned long *size, unsigned long *offset, char *modname, char *name)
158 {
159 return -ERANGE;
160 }
161
kallsyms_show_value(const struct cred * cred)162 static inline bool kallsyms_show_value(const struct cred *cred)
163 {
164 return false;
165 }
166
167 #endif /*CONFIG_KALLSYMS*/
168
print_ip_sym(unsigned long ip)169 static inline void print_ip_sym(unsigned long ip)
170 {
171 printk("[<%px>] %pS\n", (void *) ip, (void *) ip);
172 }
173
174 #endif /*_LINUX_KALLSYMS_H*/
175