1/*
2 * Copyright (C) 2011 The Android Open Source Project
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
7 *
8 *      http://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
15 */
16
17#define LOG_TAG "Corkscrew"
18//#define LOG_NDEBUG 0
19
20#include "../ptrace-arch.h"
21
22#include <stddef.h>
23#include <elf.h>
24#include <cutils/log.h>
25
26static void load_eh_frame_hdr(pid_t pid, map_info_t* mi, uintptr_t *eh_frame_hdr) {
27    uint32_t elf_phoff;
28    uint32_t elf_phentsize_ehsize;
29    uint32_t elf_shentsize_phnum;
30    if (try_get_word_ptrace(pid, mi->start + offsetof(Elf32_Ehdr, e_phoff), &elf_phoff)
31            && try_get_word_ptrace(pid, mi->start + offsetof(Elf32_Ehdr, e_ehsize),
32                    &elf_phentsize_ehsize)
33            && try_get_word_ptrace(pid, mi->start + offsetof(Elf32_Ehdr, e_phnum),
34                    &elf_shentsize_phnum)) {
35        uint32_t elf_phentsize = elf_phentsize_ehsize >> 16;
36        uint32_t elf_phnum = elf_shentsize_phnum & 0xffff;
37        for (uint32_t i = 0; i < elf_phnum; i++) {
38            uintptr_t elf_phdr = mi->start + elf_phoff + i * elf_phentsize;
39            uint32_t elf_phdr_type;
40            if (!try_get_word_ptrace(pid, elf_phdr + offsetof(Elf32_Phdr, p_type), &elf_phdr_type)) {
41                break;
42            }
43            if (elf_phdr_type == PT_GNU_EH_FRAME) {
44                uint32_t elf_phdr_offset;
45                if (!try_get_word_ptrace(pid, elf_phdr + offsetof(Elf32_Phdr, p_offset),
46                        &elf_phdr_offset)) {
47                    break;
48                }
49                *eh_frame_hdr = mi->start + elf_phdr_offset;
50                ALOGV("Parsed .eh_frame_hdr info for %s: start=0x%08x", mi->name, *eh_frame_hdr);
51                return;
52            }
53        }
54    }
55    *eh_frame_hdr = 0;
56}
57
58void load_ptrace_map_info_data_arch(pid_t pid, map_info_t* mi, map_info_data_t* data) {
59    load_eh_frame_hdr(pid, mi, &data->eh_frame_hdr);
60}
61
62void free_ptrace_map_info_data_arch(map_info_t* mi __attribute__((unused)),
63                                    map_info_data_t* data __attribute__((unused))) {
64}
65