3d67d347f5
Currently, moving or copying a Maps object leads to double free of MapInfo.
Even moving a Maps object did not prevent this, as after a move
the object only has to be in an "unspecified but valid state", which can
be the original state for a vector of raw pointers (but not for a vector
of unique_ptrs).
Changing to unique_ptrs is the most failsafe way to make sure we never
accidentally destruct MapInfo.
Test: atest libuwindstack_test
Failed LocalUnwinderTest#unwind_after_dlopen which also fails at master.
Change-Id: Id1c9739b334da5c1ba532fd55366e115940a66d3
104 lines
3.1 KiB
C++
104 lines
3.1 KiB
C++
/*
|
|
* Copyright (C) 2018 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 <stdint.h>
|
|
#include <string.h>
|
|
#include <sys/mman.h>
|
|
|
|
#include <string>
|
|
#include <vector>
|
|
|
|
#include <unwindstack/Global.h>
|
|
#include <unwindstack/MapInfo.h>
|
|
#include <unwindstack/Maps.h>
|
|
#include <unwindstack/Memory.h>
|
|
|
|
namespace unwindstack {
|
|
|
|
Global::Global(std::shared_ptr<Memory>& memory) : memory_(memory) {}
|
|
Global::Global(std::shared_ptr<Memory>& memory, std::vector<std::string>& search_libs)
|
|
: memory_(memory), search_libs_(search_libs) {}
|
|
|
|
void Global::SetArch(ArchEnum arch) {
|
|
if (arch_ == ARCH_UNKNOWN) {
|
|
arch_ = arch;
|
|
ProcessArch();
|
|
}
|
|
}
|
|
|
|
uint64_t Global::GetVariableOffset(MapInfo* info, const std::string& variable) {
|
|
if (!search_libs_.empty()) {
|
|
bool found = false;
|
|
const char* lib = basename(info->name.c_str());
|
|
for (const std::string& name : search_libs_) {
|
|
if (name == lib) {
|
|
found = true;
|
|
break;
|
|
}
|
|
}
|
|
if (!found) {
|
|
return 0;
|
|
}
|
|
}
|
|
|
|
Elf* elf = info->GetElf(memory_, arch());
|
|
uint64_t ptr;
|
|
// Find first non-empty list (libraries might be loaded multiple times).
|
|
if (elf->GetGlobalVariable(variable, &ptr) && ptr != 0) {
|
|
return ptr + info->start;
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
void Global::FindAndReadVariable(Maps* maps, const char* var_str) {
|
|
std::string variable(var_str);
|
|
// When looking for global variables, do not arbitrarily search every
|
|
// readable map. Instead look for a specific pattern that must exist.
|
|
// The pattern should be a readable map, followed by a read-write
|
|
// map with a non-zero offset.
|
|
// For example:
|
|
// f0000-f1000 0 r-- /system/lib/libc.so
|
|
// f1000-f2000 1000 r-x /system/lib/libc.so
|
|
// f2000-f3000 2000 rw- /system/lib/libc.so
|
|
// This also works:
|
|
// f0000-f2000 0 r-- /system/lib/libc.so
|
|
// f2000-f3000 2000 rw- /system/lib/libc.so
|
|
MapInfo* map_start = nullptr;
|
|
for (const auto& info : *maps) {
|
|
if (map_start != nullptr) {
|
|
if (map_start->name == info->name) {
|
|
if (info->offset != 0 &&
|
|
(info->flags & (PROT_READ | PROT_WRITE)) == (PROT_READ | PROT_WRITE)) {
|
|
uint64_t ptr = GetVariableOffset(map_start, variable);
|
|
if (ptr != 0 && ReadVariableData(ptr)) {
|
|
break;
|
|
} else {
|
|
// Failed to find the global variable, do not bother trying again.
|
|
map_start = nullptr;
|
|
}
|
|
}
|
|
} else {
|
|
map_start = nullptr;
|
|
}
|
|
}
|
|
if (map_start == nullptr && (info->flags & PROT_READ) && info->offset == 0 &&
|
|
!info->name.empty()) {
|
|
map_start = info.get();
|
|
}
|
|
}
|
|
}
|
|
|
|
} // namespace unwindstack
|