146 lines
4.5 KiB
C
146 lines
4.5 KiB
C
/*
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* Copyright (C) 2011 The Android Open Source Project
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*
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* Licensed under the Apache License, Version 2.0 (the "License");
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* you may not use this file except in compliance with the License.
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* You may obtain a copy of the License at
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*
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* http://www.apache.org/licenses/LICENSE-2.0
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*
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* Unless required by applicable law or agreed to in writing, software
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* distributed under the License is distributed on an "AS IS" BASIS,
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* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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* See the License for the specific language governing permissions and
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* limitations under the License.
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*/
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#define LOG_TAG "Corkscrew"
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//#define LOG_NDEBUG 0
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#include "ptrace-arch.h"
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#include <corkscrew/ptrace.h>
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#include <errno.h>
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#include <stdlib.h>
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#include <sys/ptrace.h>
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#include <cutils/log.h>
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static const uint32_t ELF_MAGIC = 0x464C457f; // "ELF\0177"
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#ifndef PAGE_SIZE
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#define PAGE_SIZE 4096
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#endif
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#ifndef PAGE_MASK
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#define PAGE_MASK (~(PAGE_SIZE - 1))
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#endif
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void init_memory(memory_t* memory, const map_info_t* map_info_list) {
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memory->tid = -1;
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memory->map_info_list = map_info_list;
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}
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void init_memory_ptrace(memory_t* memory, pid_t tid) {
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memory->tid = tid;
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memory->map_info_list = NULL;
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}
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bool try_get_word(const memory_t* memory, uintptr_t ptr, uint32_t* out_value) {
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ALOGV("try_get_word: reading word at 0x%08x", ptr);
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if (ptr & 3) {
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ALOGV("try_get_word: invalid pointer 0x%08x", ptr);
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*out_value = 0xffffffffL;
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return false;
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}
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if (memory->tid < 0) {
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if (!is_readable_map(memory->map_info_list, ptr)) {
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ALOGV("try_get_word: pointer 0x%08x not in a readable map", ptr);
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*out_value = 0xffffffffL;
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return false;
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}
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*out_value = *(uint32_t*)ptr;
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return true;
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} else {
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// ptrace() returns -1 and sets errno when the operation fails.
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// To disambiguate -1 from a valid result, we clear errno beforehand.
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errno = 0;
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*out_value = ptrace(PTRACE_PEEKTEXT, memory->tid, (void*)ptr, NULL);
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if (*out_value == 0xffffffffL && errno) {
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ALOGV("try_get_word: invalid pointer 0x%08x reading from tid %d, "
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"ptrace() errno=%d", ptr, memory->tid, errno);
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return false;
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}
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return true;
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}
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}
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bool try_get_word_ptrace(pid_t tid, uintptr_t ptr, uint32_t* out_value) {
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memory_t memory;
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init_memory_ptrace(&memory, tid);
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return try_get_word(&memory, ptr, out_value);
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}
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static void load_ptrace_map_info_data(pid_t pid, map_info_t* mi) {
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if (mi->is_executable && mi->is_readable) {
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uint32_t elf_magic;
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if (try_get_word_ptrace(pid, mi->start, &elf_magic) && elf_magic == ELF_MAGIC) {
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map_info_data_t* data = (map_info_data_t*)calloc(1, sizeof(map_info_data_t));
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if (data) {
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mi->data = data;
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if (mi->name[0]) {
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data->symbol_table = load_symbol_table(mi->name);
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}
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#ifdef CORKSCREW_HAVE_ARCH
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load_ptrace_map_info_data_arch(pid, mi, data);
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#endif
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}
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}
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}
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}
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ptrace_context_t* load_ptrace_context(pid_t pid) {
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ptrace_context_t* context =
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(ptrace_context_t*)calloc(1, sizeof(ptrace_context_t));
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if (context) {
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context->map_info_list = load_map_info_list(pid);
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for (map_info_t* mi = context->map_info_list; mi; mi = mi->next) {
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load_ptrace_map_info_data(pid, mi);
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}
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}
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return context;
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}
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static void free_ptrace_map_info_data(map_info_t* mi) {
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map_info_data_t* data = (map_info_data_t*)mi->data;
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if (data) {
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if (data->symbol_table) {
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free_symbol_table(data->symbol_table);
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}
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#ifdef CORKSCREW_HAVE_ARCH
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free_ptrace_map_info_data_arch(mi, data);
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#endif
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free(data);
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mi->data = NULL;
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}
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}
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void free_ptrace_context(ptrace_context_t* context) {
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for (map_info_t* mi = context->map_info_list; mi; mi = mi->next) {
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free_ptrace_map_info_data(mi);
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}
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free_map_info_list(context->map_info_list);
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}
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void find_symbol_ptrace(const ptrace_context_t* context,
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uintptr_t addr, const map_info_t** out_map_info, const symbol_t** out_symbol) {
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const map_info_t* mi = find_map_info(context->map_info_list, addr);
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const symbol_t* symbol = NULL;
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if (mi) {
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const map_info_data_t* data = (const map_info_data_t*)mi->data;
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if (data && data->symbol_table) {
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symbol = find_symbol(data->symbol_table, addr - mi->start);
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}
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}
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*out_map_info = mi;
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*out_symbol = symbol;
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}
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