tracing: use union for multi-usages field
[linux-2.6/libata-dev.git] / kernel / extable.c
blob25d39b0c3a1ba4aeba990e169cfa173d32e4eba3
1 /* Rewritten by Rusty Russell, on the backs of many others...
2 Copyright (C) 2001 Rusty Russell, 2002 Rusty Russell IBM.
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.
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.
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
18 #include <linux/ftrace.h>
19 #include <linux/module.h>
20 #include <linux/mutex.h>
21 #include <linux/init.h>
23 #include <asm/sections.h>
24 #include <asm/uaccess.h>
27 * mutex protecting text section modification (dynamic code patching).
28 * some users need to sleep (allocating memory...) while they hold this lock.
30 * NOT exported to modules - patching kernel text is a really delicate matter.
32 DEFINE_MUTEX(text_mutex);
34 extern struct exception_table_entry __start___ex_table[];
35 extern struct exception_table_entry __stop___ex_table[];
37 /* Sort the kernel's built-in exception table */
38 void __init sort_main_extable(void)
40 sort_extable(__start___ex_table, __stop___ex_table);
43 /* Given an address, look for it in the exception tables. */
44 const struct exception_table_entry *search_exception_tables(unsigned long addr)
46 const struct exception_table_entry *e;
48 e = search_extable(__start___ex_table, __stop___ex_table-1, addr);
49 if (!e)
50 e = search_module_extables(addr);
51 return e;
54 int core_kernel_text(unsigned long addr)
56 if (addr >= (unsigned long)_stext &&
57 addr <= (unsigned long)_etext)
58 return 1;
60 if (system_state == SYSTEM_BOOTING &&
61 addr >= (unsigned long)_sinittext &&
62 addr <= (unsigned long)_einittext)
63 return 1;
64 return 0;
67 int __kernel_text_address(unsigned long addr)
69 if (core_kernel_text(addr))
70 return 1;
71 return __module_text_address(addr) != NULL;
74 int kernel_text_address(unsigned long addr)
76 if (core_kernel_text(addr))
77 return 1;
78 return module_text_address(addr) != NULL;
82 * On some architectures (PPC64, IA64) function pointers
83 * are actually only tokens to some data that then holds the
84 * real function address. As a result, to find if a function
85 * pointer is part of the kernel text, we need to do some
86 * special dereferencing first.
88 int func_ptr_is_kernel_text(void *ptr)
90 unsigned long addr;
91 addr = (unsigned long) dereference_function_descriptor(ptr);
92 if (core_kernel_text(addr))
93 return 1;
94 return module_text_address(addr) != NULL;