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 */ 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. */ 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 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 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 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 */ 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