1b163bb742a099c1808907b513ae39068b63b1692Vladimir Marko/* 2b163bb742a099c1808907b513ae39068b63b1692Vladimir Marko * Copyright (C) 2015 The Android Open Source Project 3b163bb742a099c1808907b513ae39068b63b1692Vladimir Marko * 4b163bb742a099c1808907b513ae39068b63b1692Vladimir Marko * Licensed under the Apache License, Version 2.0 (the "License"); 5b163bb742a099c1808907b513ae39068b63b1692Vladimir Marko * you may not use this file except in compliance with the License. 6b163bb742a099c1808907b513ae39068b63b1692Vladimir Marko * You may obtain a copy of the License at 7b163bb742a099c1808907b513ae39068b63b1692Vladimir Marko * 8b163bb742a099c1808907b513ae39068b63b1692Vladimir Marko * http://www.apache.org/licenses/LICENSE-2.0 9b163bb742a099c1808907b513ae39068b63b1692Vladimir Marko * 10b163bb742a099c1808907b513ae39068b63b1692Vladimir Marko * Unless required by applicable law or agreed to in writing, software 11b163bb742a099c1808907b513ae39068b63b1692Vladimir Marko * distributed under the License is distributed on an "AS IS" BASIS, 12b163bb742a099c1808907b513ae39068b63b1692Vladimir Marko * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 13b163bb742a099c1808907b513ae39068b63b1692Vladimir Marko * See the License for the specific language governing permissions and 14b163bb742a099c1808907b513ae39068b63b1692Vladimir Marko * limitations under the License. 15b163bb742a099c1808907b513ae39068b63b1692Vladimir Marko */ 16b163bb742a099c1808907b513ae39068b63b1692Vladimir Marko 17b163bb742a099c1808907b513ae39068b63b1692Vladimir Marko#include "linker/x86/relative_patcher_x86.h" 18b163bb742a099c1808907b513ae39068b63b1692Vladimir Marko 191961b609bfefaedb71cee3651c4f931cc3e7393dVladimir Marko#include "compiled_method.h" 201961b609bfefaedb71cee3651c4f931cc3e7393dVladimir Marko 21b163bb742a099c1808907b513ae39068b63b1692Vladimir Markonamespace art { 22b163bb742a099c1808907b513ae39068b63b1692Vladimir Markonamespace linker { 23b163bb742a099c1808907b513ae39068b63b1692Vladimir Marko 241961b609bfefaedb71cee3651c4f931cc3e7393dVladimir Markovoid X86RelativePatcher::PatchDexCacheReference(std::vector<uint8_t>* code, 251961b609bfefaedb71cee3651c4f931cc3e7393dVladimir Marko const LinkerPatch& patch, 261961b609bfefaedb71cee3651c4f931cc3e7393dVladimir Marko uint32_t patch_offset, 271961b609bfefaedb71cee3651c4f931cc3e7393dVladimir Marko uint32_t target_offset) { 281961b609bfefaedb71cee3651c4f931cc3e7393dVladimir Marko uint32_t anchor_literal_offset = patch.PcInsnOffset(); 291961b609bfefaedb71cee3651c4f931cc3e7393dVladimir Marko uint32_t literal_offset = patch.LiteralOffset(); 301961b609bfefaedb71cee3651c4f931cc3e7393dVladimir Marko 311961b609bfefaedb71cee3651c4f931cc3e7393dVladimir Marko // Check that the anchor points to pop in a "call +0; pop <reg>" sequence. 321961b609bfefaedb71cee3651c4f931cc3e7393dVladimir Marko DCHECK_GE(anchor_literal_offset, 5u); 331961b609bfefaedb71cee3651c4f931cc3e7393dVladimir Marko DCHECK_LT(anchor_literal_offset, code->size()); 341961b609bfefaedb71cee3651c4f931cc3e7393dVladimir Marko DCHECK_EQ((*code)[anchor_literal_offset - 5u], 0xe8u); 351961b609bfefaedb71cee3651c4f931cc3e7393dVladimir Marko DCHECK_EQ((*code)[anchor_literal_offset - 4u], 0x00u); 361961b609bfefaedb71cee3651c4f931cc3e7393dVladimir Marko DCHECK_EQ((*code)[anchor_literal_offset - 3u], 0x00u); 371961b609bfefaedb71cee3651c4f931cc3e7393dVladimir Marko DCHECK_EQ((*code)[anchor_literal_offset - 2u], 0x00u); 381961b609bfefaedb71cee3651c4f931cc3e7393dVladimir Marko DCHECK_EQ((*code)[anchor_literal_offset - 1u], 0x00u); 391961b609bfefaedb71cee3651c4f931cc3e7393dVladimir Marko DCHECK_EQ((*code)[anchor_literal_offset] & 0xf8u, 0x58u); 401961b609bfefaedb71cee3651c4f931cc3e7393dVladimir Marko 411961b609bfefaedb71cee3651c4f931cc3e7393dVladimir Marko // Check that the patched data contains kDummy32BitOffset. 421961b609bfefaedb71cee3651c4f931cc3e7393dVladimir Marko constexpr int kDummy32BitOffset = 256; // Must match X86Mir2Lir::kDummy32BitOffset. 431961b609bfefaedb71cee3651c4f931cc3e7393dVladimir Marko DCHECK_LE(literal_offset, code->size()); 441961b609bfefaedb71cee3651c4f931cc3e7393dVladimir Marko DCHECK_EQ((*code)[literal_offset + 0u], static_cast<uint8_t>(kDummy32BitOffset >> 0)); 451961b609bfefaedb71cee3651c4f931cc3e7393dVladimir Marko DCHECK_EQ((*code)[literal_offset + 1u], static_cast<uint8_t>(kDummy32BitOffset >> 8)); 461961b609bfefaedb71cee3651c4f931cc3e7393dVladimir Marko DCHECK_EQ((*code)[literal_offset + 2u], static_cast<uint8_t>(kDummy32BitOffset >> 16)); 471961b609bfefaedb71cee3651c4f931cc3e7393dVladimir Marko DCHECK_EQ((*code)[literal_offset + 3u], static_cast<uint8_t>(kDummy32BitOffset >> 24)); 481961b609bfefaedb71cee3651c4f931cc3e7393dVladimir Marko 491961b609bfefaedb71cee3651c4f931cc3e7393dVladimir Marko // Apply patch. 501961b609bfefaedb71cee3651c4f931cc3e7393dVladimir Marko uint32_t anchor_offset = patch_offset - literal_offset + anchor_literal_offset; 511961b609bfefaedb71cee3651c4f931cc3e7393dVladimir Marko uint32_t diff = target_offset - anchor_offset; 521961b609bfefaedb71cee3651c4f931cc3e7393dVladimir Marko (*code)[literal_offset + 0u] = static_cast<uint8_t>(diff >> 0); 531961b609bfefaedb71cee3651c4f931cc3e7393dVladimir Marko (*code)[literal_offset + 1u] = static_cast<uint8_t>(diff >> 8); 541961b609bfefaedb71cee3651c4f931cc3e7393dVladimir Marko (*code)[literal_offset + 2u] = static_cast<uint8_t>(diff >> 16); 551961b609bfefaedb71cee3651c4f931cc3e7393dVladimir Marko (*code)[literal_offset + 3u] = static_cast<uint8_t>(diff >> 24); 56b163bb742a099c1808907b513ae39068b63b1692Vladimir Marko} 57b163bb742a099c1808907b513ae39068b63b1692Vladimir Marko 58b163bb742a099c1808907b513ae39068b63b1692Vladimir Marko} // namespace linker 59b163bb742a099c1808907b513ae39068b63b1692Vladimir Marko} // namespace art 60