platform_system_core/libunwindstack/MapInfo.cpp

87 lines
2.3 KiB
C++

/*
* Copyright (C) 2017 The Android Open Source Project
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
#include <sys/types.h>
#include <unistd.h>
#include <memory>
#include <string>
#include "Elf.h"
#include "MapInfo.h"
#include "Maps.h"
#include "Memory.h"
Memory* MapInfo::CreateMemory(pid_t pid) {
if (end <= start) {
return nullptr;
}
elf_offset = 0;
// First try and use the file associated with the info.
if (!name.empty()) {
// Fail on device maps.
if (flags & MAPS_FLAGS_DEVICE_MAP) {
return nullptr;
}
std::unique_ptr<MemoryFileAtOffset> file_memory(new MemoryFileAtOffset);
uint64_t map_size;
if (offset != 0) {
// Only map in a piece of the file.
map_size = end - start;
} else {
map_size = UINT64_MAX;
}
if (file_memory->Init(name, offset, map_size)) {
// It's possible that a non-zero offset might not be pointing to
// valid elf data. Check if this is a valid elf, and if not assume
// that this was meant to incorporate the entire file.
if (offset != 0 && !Elf::IsValidElf(file_memory.get())) {
// Don't bother checking the validity that will happen on the elf init.
if (file_memory->Init(name, 0)) {
elf_offset = offset;
return file_memory.release();
}
// Fall through if the init fails.
} else {
return file_memory.release();
}
}
}
Memory* memory = nullptr;
if (pid == getpid()) {
memory = new MemoryLocal();
} else {
memory = new MemoryRemote(pid);
}
return new MemoryRange(memory, start, end);
}
Elf* MapInfo::GetElf(pid_t pid, bool) {
if (elf) {
return elf;
}
elf = new Elf(CreateMemory(pid));
elf->Init();
// If the init fails, keep the elf around as an invalid object so we
// don't try to reinit the object.
return elf;
}