1 /*- 2 * Copyright (c) 2013 The NetBSD Foundation, Inc. 3 * All rights reserved. 4 * 5 * This code is derived from software contributed to The NetBSD Foundation 6 * by Matt Thomas of 3am Software Foundry. 7 * 8 * Redistribution and use in source and binary forms, with or without 9 * modification, are permitted provided that the following conditions 10 * are met: 11 * 1. Redistributions of source code must retain the above copyright 12 * notice, this list of conditions and the following disclaimer. 13 * 2. Redistributions in binary form must reproduce the above copyright 14 * notice, this list of conditions and the following disclaimer in the 15 * documentation and/or other materials provided with the distribution. 16 * 17 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS 18 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED 19 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 20 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS 21 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 22 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 23 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 24 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 25 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 26 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 27 * POSSIBILITY OF SUCH DAMAGE. 28 */ 29 30 #include <sys/cdefs.h> 31 #ifndef lint 32 __RCSID("$NetBSD: find_exidx.c,v 1.3 2013/05/03 10:27:06 skrll Exp $"); 33 #endif /* not lint */ 34 35 #include "debug.h" 36 #include "rtld.h" 37 38 _Unwind_Ptr 39 __gnu_Unwind_Find_exidx(_Unwind_Ptr pc, int * pcount) 40 { 41 const Obj_Entry *obj; 42 _Unwind_Ptr start = NULL; 43 int count = 0; 44 45 dbg(("__gnu_Unwind_Find_exidx")); 46 47 _rtld_shared_enter(); 48 49 vaddr_t va = (vaddr_t)pc; 50 for (obj = _rtld_objlist; obj != NULL; obj = obj->next) { 51 /* 52 * If the address we are looking for is inside this object, 53 * we've found the object to inspect. 54 */ 55 if ((vaddr_t)obj->mapbase <= va 56 && va < (vaddr_t)obj->mapbase + obj->mapsize) 57 break; 58 } 59 60 /* 61 * If we found an object and it has some exception data, we 62 * need to see if the address matches a PT_LOAD section. 63 */ 64 if (obj != NULL && obj->exidx_start != NULL) { 65 va -= (vaddr_t)obj->relocbase; 66 const Elf_Phdr *ph = obj->phdr; 67 const Elf_Phdr * const phlimit = ph + obj->phsize / sizeof(*ph); 68 for (; ph < phlimit; ph++) { 69 if (ph->p_type == PT_LOAD 70 && ph->p_vaddr <= va 71 && va < ph->p_vaddr + ph->p_memsz) { 72 count = obj->exidx_sz / 8; 73 start = obj->exidx_start; 74 break; 75 } 76 } 77 } 78 79 _rtld_shared_exit(); 80 81 /* 82 * deal with the return values. 83 */ 84 *pcount = count; 85 return start; 86 } 87