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Diffstat (limited to 'lib/isc/include/isc/backtrace.h')
| -rw-r--r-- | lib/isc/include/isc/backtrace.h | 127 |
1 files changed, 127 insertions, 0 deletions
diff --git a/lib/isc/include/isc/backtrace.h b/lib/isc/include/isc/backtrace.h new file mode 100644 index 0000000..d32748a --- /dev/null +++ b/lib/isc/include/isc/backtrace.h @@ -0,0 +1,127 @@ +/* + * Copyright (C) Internet Systems Consortium, Inc. ("ISC") + * + * SPDX-License-Identifier: MPL-2.0 + * + * This Source Code Form is subject to the terms of the Mozilla Public + * License, v. 2.0. If a copy of the MPL was not distributed with this + * file, you can obtain one at https://mozilla.org/MPL/2.0/. + * + * See the COPYRIGHT file distributed with this work for additional + * information regarding copyright ownership. + */ + +/*! \file isc/backtrace.h + * \brief provide a back trace of the running process to help debug problems. + * + * This module tries to get a back trace of the process using some platform + * dependent way when available. It also manages an internal symbol table + * that maps function addresses used in the process to their textual symbols. + * This module is expected to be used to help debug when some fatal error + * happens. + * + * IMPORTANT NOTE: since the (major) intended use case of this module is + * dumping a back trace on a fatal error, normally followed by self termination, + * functions defined in this module generally doesn't employ assertion checks + * (if it did, a program bug could cause infinite recursive calls to a + * backtrace function). These functions still perform minimal checks and return + * ISC_R_FAILURE if they detect an error, but the caller should therefore be + * very careful about the use of these functions, and generally discouraged to + * use them except in an exit path. The exception is + * isc_backtrace_getsymbolfromindex(), which is expected to be used in a + * non-error-handling context and validates arguments with assertion checks. + */ + +#ifndef ISC_BACKTRACE_H +#define ISC_BACKTRACE_H 1 + +/*** + *** Imports + ***/ + +#include <isc/types.h> + +/*** + *** Types + ***/ +struct isc_backtrace_symmap { + void *addr; + const char *symbol; +}; + +LIBISC_EXTERNAL_DATA extern const int isc__backtrace_nsymbols; +LIBISC_EXTERNAL_DATA extern const isc_backtrace_symmap_t + isc__backtrace_symtable[]; + +/*** + *** Functions + ***/ + +ISC_LANG_BEGINDECLS +isc_result_t +isc_backtrace_gettrace(void **addrs, int maxaddrs, int *nframes); +/*%< + * Get a back trace of the running process above this function itself. On + * success, addrs[i] will store the address of the call point of the i-th + * stack frame (addrs[0] is the caller of this function). *nframes will store + * the total number of frames. + * + * Requires (note that these are not ensured by assertion checks, see above): + * + *\li 'addrs' is a valid array containing at least 'maxaddrs' void * entries. + * + *\li 'nframes' must be non NULL. + * + * Returns: + * + *\li #ISC_R_SUCCESS + *\li #ISC_R_FAILURE + *\li #ISC_R_NOTFOUND + *\li #ISC_R_NOTIMPLEMENTED + */ + +isc_result_t +isc_backtrace_getsymbolfromindex(int index, const void **addrp, + const char **symbolp); +/*%< + * Returns the content of the internal symbol table of the given index. + * On success, *addrsp and *symbolp point to the address and the symbol of + * the 'index'th entry of the table, respectively. If 'index' is not in the + * range of the symbol table, ISC_R_RANGE will be returned. + * + * Requires + * + *\li 'addrp' must be non NULL && '*addrp' == NULL. + * + *\li 'symbolp' must be non NULL && '*symbolp' == NULL. + * + * Returns: + * + *\li #ISC_R_SUCCESS + *\li #ISC_R_RANGE + */ + +isc_result_t +isc_backtrace_getsymbol(const void *addr, const char **symbolp, + unsigned long *offsetp); +/*%< + * Searches the internal symbol table for the symbol that most matches the + * given 'addr'. On success, '*symbolp' will point to the name of function + * to which the address 'addr' belong, and '*offsetp' will store the offset + * from the function's entry address to 'addr'. + * + * Requires (note that these are not ensured by assertion checks, see above): + * + *\li 'symbolp' must be non NULL && '*symbolp' == NULL. + * + *\li 'offsetp' must be non NULL. + * + * Returns: + * + *\li #ISC_R_SUCCESS + *\li #ISC_R_FAILURE + *\li #ISC_R_NOTFOUND + */ +ISC_LANG_ENDDECLS + +#endif /* ISC_BACKTRACE_H */ |