1/* 2 * Copyright (C) 2009 Internet Systems Consortium, Inc. ("ISC") 3 * 4 * Permission to use, copy, modify, and/or distribute this software for any 5 * purpose with or without fee is hereby granted, provided that the above 6 * copyright notice and this permission notice appear in all copies. 7 * 8 * THE SOFTWARE IS PROVIDED "AS IS" AND ISC DISCLAIMS ALL WARRANTIES WITH 9 * REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY 10 * AND FITNESS. IN NO EVENT SHALL ISC BE LIABLE FOR ANY SPECIAL, DIRECT, 11 * INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM 12 * LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE 13 * OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR 14 * PERFORMANCE OF THIS SOFTWARE. 15 */ 16 17/* $Id: backtrace.h,v 1.2 2009/09/01 18:40:25 jinmei Exp $ */ 18 19/*! \file isc/backtrace.h 20 * \brief provide a back trace of the running process to help debug problems. 21 * 22 * This module tries to get a back trace of the process using some platform 23 * dependent way when available. It also manages an internal symbol table 24 * that maps function addresses used in the process to their textual symbols. 25 * This module is expected to be used to help debug when some fatal error 26 * happens. 27 * 28 * IMPORTANT NOTE: since the (major) intended use case of this module is 29 * dumping a back trace on a fatal error, normally followed by self termination, 30 * functions defined in this module generally doesn't employ assertion checks 31 * (if it did, a program bug could cause infinite recursive calls to a 32 * backtrace function). These functions still perform minimal checks and return 33 * ISC_R_FAILURE if they detect an error, but the caller should therefore be 34 * very careful about the use of these functions, and generally discouraged to 35 * use them except in an exit path. The exception is 36 * isc_backtrace_getsymbolfromindex(), which is expected to be used in a 37 * non-error-handling context and validates arguments with assertion checks. 38 */ 39 40#ifndef ISC_BACKTRACE_H 41#define ISC_BACKTRACE_H 1 42 43/*** 44 *** Imports 45 ***/ 46 47#include <isc/types.h> 48 49/*** 50 *** Types 51 ***/ 52struct isc_backtrace_symmap { 53 void *addr; 54 const char *symbol; 55}; 56 57extern const int isc__backtrace_nsymbols; 58extern const isc_backtrace_symmap_t isc__backtrace_symtable[]; 59 60/*** 61 *** Functions 62 ***/ 63 64ISC_LANG_BEGINDECLS 65isc_result_t 66isc_backtrace_gettrace(void **addrs, int maxaddrs, int *nframes); 67/*%< 68 * Get a back trace of the running process above this function itself. On 69 * success, addrs[i] will store the address of the call point of the i-th 70 * stack frame (addrs[0] is the caller of this function). *nframes will store 71 * the total number of frames. 72 * 73 * Requires (note that these are not ensured by assertion checks, see above): 74 * 75 *\li 'addrs' is a valid array containing at least 'maxaddrs' void * entries. 76 * 77 *\li 'nframes' must be non NULL. 78 * 79 * Returns: 80 * 81 *\li #ISC_R_SUCCESS 82 *\li #ISC_R_FAILURE 83 *\li #ISC_R_NOTFOUND 84 *\li #ISC_R_NOTIMPLEMENTED 85 */ 86 87isc_result_t 88isc_backtrace_getsymbolfromindex(int idx, const void **addrp, 89 const char **symbolp); 90/*%< 91 * Returns the content of the internal symbol table of the given index. 92 * On success, *addrsp and *symbolp point to the address and the symbol of 93 * the 'index'th entry of the table, respectively. If 'idx' is not in the 94 * range of the symbol table, ISC_R_RANGE will be returned. 95 * 96 * Requires 97 * 98 *\li 'addrp' must be non NULL && '*addrp' == NULL. 99 * 100 *\li 'symbolp' must be non NULL && '*symbolp' == NULL. 101 * 102 * Returns: 103 * 104 *\li #ISC_R_SUCCESS 105 *\li #ISC_R_RANGE 106 */ 107 108isc_result_t 109isc_backtrace_getsymbol(const void *addr, const char **symbolp, 110 unsigned long *offsetp); 111/*%< 112 * Searches the internal symbol table for the symbol that most matches the 113 * given 'addr'. On success, '*symbolp' will point to the name of function 114 * to which the address 'addr' belong, and '*offsetp' will store the offset 115 * from the function's entry address to 'addr'. 116 * 117 * Requires (note that these are not ensured by assertion checks, see above): 118 * 119 *\li 'symbolp' must be non NULL && '*symbolp' == NULL. 120 * 121 *\li 'offsetp' must be non NULL. 122 * 123 * Returns: 124 * 125 *\li #ISC_R_SUCCESS 126 *\li #ISC_R_FAILURE 127 *\li #ISC_R_NOTFOUND 128 */ 129ISC_LANG_ENDDECLS 130 131#endif /* ISC_BACKTRACE_H */ 132