1 /* Rewritten by Rusty Russell, on the backs of many others...
2 Copyright (C) 2001 Rusty Russell, 2002 Rusty Russell IBM.
3
4 This program is free software; you can redistribute it and/or modify
5 it under the terms of the GNU General Public License as published by
6 the Free Software Foundation; either version 2 of the License, or
7 (at your option) any later version.
8
9 This program is distributed in the hope that it will be useful,
10 but WITHOUT ANY WARRANTY; without even the implied warranty of
11 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
12 GNU General Public License for more details.
13
14 You should have received a copy of the GNU General Public License
15 along with this program; if not, write to the Free Software
16 Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
17 */
18 #include <linux/module.h>
19 #include <linux/init.h>
20 #include <linux/ftrace.h>
21 #include <asm/uaccess.h>
22 #include <asm/sections.h>
23
24 extern struct exception_table_entry __start___ex_table[];
25 extern struct exception_table_entry __stop___ex_table[];
26
27 /* Sort the kernel's built-in exception table */
sort_main_extable(void)28 void __init sort_main_extable(void)
29 {
30 sort_extable(__start___ex_table, __stop___ex_table);
31 }
32
33 /* Given an address, look for it in the exception tables. */
search_exception_tables(unsigned long addr)34 const struct exception_table_entry *search_exception_tables(unsigned long addr)
35 {
36 const struct exception_table_entry *e;
37
38 e = search_extable(__start___ex_table, __stop___ex_table-1, addr);
39 if (!e)
40 e = search_module_extables(addr);
41 return e;
42 }
43
core_kernel_text(unsigned long addr)44 __notrace_funcgraph int core_kernel_text(unsigned long addr)
45 {
46 if (addr >= (unsigned long)_stext &&
47 addr <= (unsigned long)_etext)
48 return 1;
49
50 if (system_state == SYSTEM_BOOTING &&
51 addr >= (unsigned long)_sinittext &&
52 addr <= (unsigned long)_einittext)
53 return 1;
54 return 0;
55 }
56
__kernel_text_address(unsigned long addr)57 __notrace_funcgraph int __kernel_text_address(unsigned long addr)
58 {
59 if (core_kernel_text(addr))
60 return 1;
61 return __module_text_address(addr) != NULL;
62 }
63
kernel_text_address(unsigned long addr)64 int kernel_text_address(unsigned long addr)
65 {
66 if (core_kernel_text(addr))
67 return 1;
68 return module_text_address(addr) != NULL;
69 }
70
71 /*
72 * On some architectures (PPC64, IA64) function pointers
73 * are actually only tokens to some data that then holds the
74 * real function address. As a result, to find if a function
75 * pointer is part of the kernel text, we need to do some
76 * special dereferencing first.
77 */
func_ptr_is_kernel_text(void * ptr)78 int func_ptr_is_kernel_text(void *ptr)
79 {
80 unsigned long addr;
81 addr = (unsigned long) dereference_function_descriptor(ptr);
82 if (core_kernel_text(addr))
83 return 1;
84 return module_text_address(addr) != NULL;
85 }
86