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