efbe9a5eef
Introduce a new flag ANDROID_DLEXT_RESERVED_ADDRESS_RECURSIVE which instructs the linker to use the reserved address space to load all of the newly-loaded libraries required by a dlopen() call instead of only the main library. They will be loaded consecutively into that region if they fit. The RELRO sections of all the loaded libraries will also be considered for reading/writing shared RELRO data. This will allow the WebView implementation to potentially consist of more than one .so file while still benefiting from the RELRO sharing optimisation, which would otherwise only apply to the "root" .so file. Test: bionic-unit-tests (existing and newly added) Bug: 110790153 Change-Id: I61da775c29fd5017d9a1e2b6b3757c3d20a355b3
45 lines
1.4 KiB
C++
45 lines
1.4 KiB
C++
/*
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* Copyright (C) 2018 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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extern "C" int getRandomNumber();
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class B {
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public:
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virtual int getBiggerRandomNumber() {
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// Call to the other library.
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return getRandomNumber() * 2;
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}
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virtual ~B() {}
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};
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B b;
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// nested macros to make it easy to define a large amount of read-only data
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// which will require relocation.
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#define B_16 &b, &b, &b, &b, &b, &b, &b, &b, &b, &b, &b, &b, &b, &b, &b, &b,
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#define B_128 B_16 B_16 B_16 B_16 B_16 B_16 B_16 B_16
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#define B_1024 B_128 B_128 B_128 B_128 B_128 B_128 B_128 B_128
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extern "C" B* const lots_more_relro[] = {
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B_1024 B_1024 B_1024 B_1024 B_1024 B_1024 B_1024 B_1024
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};
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extern "C" int getBiggerRandomNumber() {
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// access the relro section (twice, in fact, once for the pointer, and once
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// for the vtable of B) to check it's actually there.
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return lots_more_relro[0]->getBiggerRandomNumber();
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}
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