summaryrefslogtreecommitdiff
path: root/include/linux/kallsyms.h
blob: 98338dc6b5d275acdc80b2026ee6ac7111cb9f7d (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
/* SPDX-License-Identifier: GPL-2.0 */
/* Rewritten and vastly simplified by Rusty Russell for in-kernel
 * module loader:
 *   Copyright 2002 Rusty Russell <rusty@rustcorp.com.au> IBM Corporation
 */
#ifndef _LINUX_KALLSYMS_H
#define _LINUX_KALLSYMS_H

#include <linux/errno.h>
#include <linux/kernel.h>
#include <linux/stddef.h>
#include <linux/mm.h>
#include <linux/module.h>

#include <asm/sections.h>

#define KSYM_NAME_LEN 128
#define KSYM_SYMBOL_LEN (sizeof("%s+%#lx/%#lx [%s]") + (KSYM_NAME_LEN - 1) + \
			 2*(BITS_PER_LONG*3/10) + (MODULE_NAME_LEN - 1) + 1)

struct module;

static inline int is_kernel_inittext(unsigned long addr)
{
	if (addr >= (unsigned long)_sinittext
	    && addr <= (unsigned long)_einittext)
		return 1;
	return 0;
}

static inline int is_kernel_text(unsigned long addr)
{
	if ((addr >= (unsigned long)_stext && addr <= (unsigned long)_etext) ||
	    arch_is_kernel_text(addr))
		return 1;
	return in_gate_area_no_mm(addr);
}

static inline int is_kernel(unsigned long addr)
{
	if (addr >= (unsigned long)_stext && addr <= (unsigned long)_end)
		return 1;
	return in_gate_area_no_mm(addr);
}

static inline int is_ksym_addr(unsigned long addr)
{
	if (IS_ENABLED(CONFIG_KALLSYMS_ALL))
		return is_kernel(addr);

	return is_kernel_text(addr) || is_kernel_inittext(addr);
}

static inline void *dereference_symbol_descriptor(void *ptr)
{
#ifdef HAVE_DEREFERENCE_FUNCTION_DESCRIPTOR
	struct module *mod;

	ptr = dereference_kernel_function_descriptor(ptr);
	if (is_ksym_addr((unsigned long)ptr))
		return ptr;

	preempt_disable();
	mod = __module_address((unsigned long)ptr);
	preempt_enable();

	if (mod)
		ptr = dereference_module_function_descriptor(mod, ptr);
#endif
	return ptr;
}

#ifdef CONFIG_KALLSYMS
/* Lookup the address for a symbol. Returns 0 if not found. */
unsigned long kallsyms_lookup_name(const char *name);

/* Call a function on each kallsyms symbol in the core kernel */
int kallsyms_on_each_symbol(int (*fn)(void *, const char *, struct module *,
				      unsigned long),
			    void *data);

extern int kallsyms_lookup_size_offset(unsigned long addr,
				  unsigned long *symbolsize,
				  unsigned long *offset);

/* Lookup an address.  modname is set to NULL if it's in the kernel. */
const char *kallsyms_lookup(unsigned long addr,
			    unsigned long *symbolsize,
			    unsigned long *offset,
			    char **modname, char *namebuf);

/* Look up a kernel symbol and return it in a text buffer. */
extern int sprint_symbol(char *buffer, unsigned long address);
extern int sprint_symbol_no_offset(char *buffer, unsigned long address);
extern int sprint_backtrace(char *buffer, unsigned long address);

int lookup_symbol_name(unsigned long addr, char *symname);
int lookup_symbol_attrs(unsigned long addr, unsigned long *size, unsigned long *offset, char *modname, char *name);

/* How and when do we show kallsyms values? */
extern int kallsyms_show_value(void);

#else /* !CONFIG_KALLSYMS */

static inline unsigned long kallsyms_lookup_name(const char *name)
{
	return 0;
}

static inline int kallsyms_on_each_symbol(int (*fn)(void *, const char *,
						    struct module *,
						    unsigned long),
					  void *data)
{
	return 0;
}

static inline int kallsyms_lookup_size_offset(unsigned long addr,
					      unsigned long *symbolsize,
					      unsigned long *offset)
{
	return 0;
}

static inline const char *kallsyms_lookup(unsigned long addr,
					  unsigned long *symbolsize,
					  unsigned long *offset,
					  char **modname, char *namebuf)
{
	return NULL;
}

static inline int sprint_symbol(char *buffer, unsigned long addr)
{
	*buffer = '\0';
	return 0;
}

static inline int sprint_symbol_no_offset(char *buffer, unsigned long addr)
{
	*buffer = '\0';
	return 0;
}

static inline int sprint_backtrace(char *buffer, unsigned long addr)
{
	*buffer = '\0';
	return 0;
}

static inline int lookup_symbol_name(unsigned long addr, char *symname)
{
	return -ERANGE;
}

static inline int lookup_symbol_attrs(unsigned long addr, unsigned long *size, unsigned long *offset, char *modname, char *name)
{
	return -ERANGE;
}

static inline int kallsyms_show_value(void)
{
	return false;
}

#endif /*CONFIG_KALLSYMS*/

static inline void print_ip_sym(const char *loglvl, unsigned long ip)
{
	printk("%s[<%px>] %pS\n", loglvl, (void *) ip, (void *) ip);
}

#endif /*_LINUX_KALLSYMS_H*/