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 1.4 2014/08/10 23:35:27 matt Exp $");
33 #endif /* not lint */
34
35 #include "debug.h"
36 #include "rtld.h"
37
38 #if defined(__ARM_EABI__) && !defined(__ARM_DWARF_EH__)
39
40 _Unwind_Ptr
__gnu_Unwind_Find_exidx(_Unwind_Ptr pc,int * pcount)41 __gnu_Unwind_Find_exidx(_Unwind_Ptr pc, int * pcount)
42 {
43 const Obj_Entry *obj;
44 _Unwind_Ptr start = NULL;
45 int count = 0;
46
47 dbg(("__gnu_Unwind_Find_exidx"));
48
49 _rtld_shared_enter();
50
51 vaddr_t va = (vaddr_t)pc;
52 for (obj = _rtld_objlist; obj != NULL; obj = obj->next) {
53 /*
54 * If the address we are looking for is inside this object,
55 * we've found the object to inspect.
56 */
57 if ((vaddr_t)obj->mapbase <= va
58 && va < (vaddr_t)obj->mapbase + obj->mapsize)
59 break;
60 }
61
62 /*
63 * If we found an object and it has some exception data, we
64 * need to see if the address matches a PT_LOAD section.
65 */
66 if (obj != NULL && obj->exidx_start != NULL) {
67 va -= (vaddr_t)obj->relocbase;
68 const Elf_Phdr *ph = obj->phdr;
69 const Elf_Phdr * const phlimit = ph + obj->phsize / sizeof(*ph);
70 for (; ph < phlimit; ph++) {
71 if (ph->p_type == PT_LOAD
72 && ph->p_vaddr <= va
73 && va < ph->p_vaddr + ph->p_memsz) {
74 count = obj->exidx_sz / 8;
75 start = obj->exidx_start;
76 break;
77 }
78 }
79 }
80
81 _rtld_shared_exit();
82
83 /*
84 * deal with the return values.
85 */
86 *pcount = count;
87 return start;
88 }
89
90 #endif
91