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 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
kallsyms_lookup_name(const char * name)104 static inline unsigned long kallsyms_lookup_name(const char *name)
105 {
106 return 0;
107 }
108
kallsyms_lookup_size_offset(unsigned long addr,unsigned long * symbolsize,unsigned long * offset)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
kallsyms_lookup(unsigned long addr,unsigned long * symbolsize,unsigned long * offset,char ** modname,char * namebuf)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
sprint_symbol(char * buffer,unsigned long addr)124 static inline int sprint_symbol(char *buffer, unsigned long addr)
125 {
126 *buffer = '\0';
127 return 0;
128 }
129
sprint_symbol_build_id(char * buffer,unsigned long address)130 static inline int sprint_symbol_build_id(char *buffer, unsigned long address)
131 {
132 *buffer = '\0';
133 return 0;
134 }
135
sprint_symbol_no_offset(char * buffer,unsigned long addr)136 static inline int sprint_symbol_no_offset(char *buffer, unsigned long addr)
137 {
138 *buffer = '\0';
139 return 0;
140 }
141
sprint_backtrace(char * buffer,unsigned long addr)142 static inline int sprint_backtrace(char *buffer, unsigned long addr)
143 {
144 *buffer = '\0';
145 return 0;
146 }
147
sprint_backtrace_build_id(char * buffer,unsigned long addr)148 static inline int sprint_backtrace_build_id(char *buffer, unsigned long addr)
149 {
150 *buffer = '\0';
151 return 0;
152 }
153
lookup_symbol_name(unsigned long addr,char * symname)154 static inline int lookup_symbol_name(unsigned long addr, char *symname)
155 {
156 return -ERANGE;
157 }
158
lookup_symbol_attrs(unsigned long addr,unsigned long * size,unsigned long * offset,char * modname,char * name)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
kallsyms_show_value(const struct cred * cred)164 static inline bool kallsyms_show_value(const struct cred *cred)
165 {
166 return false;
167 }
168
kallsyms_on_each_symbol(int (* fn)(void *,const char *,struct module *,unsigned long),void * data)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
kallsyms_on_each_match_symbol(int (* fn)(void *,unsigned long),const char * name,void * data)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
print_ip_sym(const char * loglvl,unsigned long ip)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*/
188