f572b91c4f
The kernel can hold references to binder objects that have no userspace references. Allow libmemunreachable to call into libbinder and libhwbinder to get lists of kernel references. Use undefined weak symbols so that libmemunreachable will continue to work in processes that do not have libbinder. Test: memunreachable_binder_test Bug: 28275695 Change-Id: I9eae73f2a51a49a7025ffe6309ccdc2693a2391b
80 lines
2.2 KiB
C++
80 lines
2.2 KiB
C++
/*
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* Copyright (C) 2017 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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#include <sys/cdefs.h>
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#include <unistd.h>
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#include <functional>
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#include "Binder.h"
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#include "log.h"
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__BEGIN_DECLS
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// Weak undefined references to the symbols in libbinder and libhwbinder
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// so that libmemunreachable can call them in processes that have them
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// loaded without requiring libmemunreachable to have dependencies on them.
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ssize_t __attribute__((weak)) getBinderKernelReferences(size_t, uintptr_t*);
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ssize_t __attribute__((weak)) getHWBinderKernelReferences(size_t, uintptr_t*);
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__END_DECLS
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namespace android {
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static bool BinderReferencesToVector(allocator::vector<uintptr_t>& refs,
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std::function<ssize_t(size_t, uintptr_t*)> fn) {
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if (fn == nullptr) {
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return true;
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}
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size_t size = refs.size();
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do {
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refs.resize(size);
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ssize_t ret = fn(refs.size(), refs.data());
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if (ret < 0) {
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return false;
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}
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size = ret;
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} while (size > refs.size());
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refs.resize(size);
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return true;
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}
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bool BinderReferences(allocator::vector<uintptr_t>& refs) {
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refs.clear();
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allocator::vector<uintptr_t> binder_refs{refs.get_allocator()};
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if (BinderReferencesToVector(refs, getBinderKernelReferences)) {
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refs.insert(refs.end(), binder_refs.begin(), binder_refs.end());
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} else {
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MEM_ALOGE("getBinderKernelReferences failed");
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}
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allocator::vector<uintptr_t> hwbinder_refs{refs.get_allocator()};
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if (BinderReferencesToVector(hwbinder_refs, getHWBinderKernelReferences)) {
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refs.insert(refs.end(), hwbinder_refs.begin(), hwbinder_refs.end());
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} else {
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MEM_ALOGE("getHWBinderKernelReferences failed");
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}
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return true;
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}
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} // namespace android
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