| /* |
| * Copyright (C) 2011 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 "context_x86.h" |
| |
| #include "mirror/art_method-inl.h" |
| #include "quick/quick_method_frame_info.h" |
| #include "utils.h" |
| |
| |
| namespace art { |
| namespace x86 { |
| |
| static constexpr uintptr_t gZero = 0; |
| |
| void X86Context::Reset() { |
| for (size_t i = 0; i < kNumberOfCpuRegisters; i++) { |
| gprs_[i] = nullptr; |
| } |
| gprs_[ESP] = &esp_; |
| // Initialize registers with easy to spot debug values. |
| esp_ = X86Context::kBadGprBase + ESP; |
| eip_ = X86Context::kBadGprBase + kNumberOfCpuRegisters; |
| } |
| |
| void X86Context::FillCalleeSaves(const StackVisitor& fr) { |
| mirror::ArtMethod* method = fr.GetMethod(); |
| const QuickMethodFrameInfo frame_info = method->GetQuickFrameInfo(); |
| size_t spill_count = POPCOUNT(frame_info.CoreSpillMask()); |
| DCHECK_EQ(frame_info.FpSpillMask(), 0u); |
| if (spill_count > 0) { |
| // Lowest number spill is farthest away, walk registers and fill into context. |
| int j = 2; // Offset j to skip return address spill. |
| for (int i = 0; i < kNumberOfCpuRegisters; i++) { |
| if (((frame_info.CoreSpillMask() >> i) & 1) != 0) { |
| gprs_[i] = fr.CalleeSaveAddress(spill_count - j, frame_info.FrameSizeInBytes()); |
| j++; |
| } |
| } |
| } |
| } |
| |
| void X86Context::SmashCallerSaves() { |
| // This needs to be 0 because we want a null/zero return value. |
| gprs_[EAX] = const_cast<uintptr_t*>(&gZero); |
| gprs_[EDX] = const_cast<uintptr_t*>(&gZero); |
| gprs_[ECX] = nullptr; |
| gprs_[EBX] = nullptr; |
| } |
| |
| bool X86Context::SetGPR(uint32_t reg, uintptr_t value) { |
| CHECK_LT(reg, static_cast<uint32_t>(kNumberOfCpuRegisters)); |
| CHECK_NE(gprs_[reg], &gZero); |
| if (gprs_[reg] != nullptr) { |
| *gprs_[reg] = value; |
| return true; |
| } else { |
| return false; |
| } |
| } |
| |
| void X86Context::DoLongJump() { |
| #if defined(__i386__) |
| // Array of GPR values, filled from the context backward for the long jump pop. We add a slot at |
| // the top for the stack pointer that doesn't get popped in a pop-all. |
| volatile uintptr_t gprs[kNumberOfCpuRegisters + 1]; |
| for (size_t i = 0; i < kNumberOfCpuRegisters; ++i) { |
| gprs[kNumberOfCpuRegisters - i - 1] = gprs_[i] != nullptr ? *gprs_[i] : X86Context::kBadGprBase + i; |
| } |
| // We want to load the stack pointer one slot below so that the ret will pop eip. |
| uintptr_t esp = gprs[kNumberOfCpuRegisters - ESP - 1] - sizeof(intptr_t); |
| gprs[kNumberOfCpuRegisters] = esp; |
| *(reinterpret_cast<uintptr_t*>(esp)) = eip_; |
| __asm__ __volatile__( |
| "movl %0, %%esp\n\t" // ESP points to gprs. |
| "popal\n\t" // Load all registers except ESP and EIP with values in gprs. |
| "popl %%esp\n\t" // Load stack pointer. |
| "ret\n\t" // From higher in the stack pop eip. |
| : // output. |
| : "g"(&gprs[0]) // input. |
| :); // clobber. |
| #else |
| UNIMPLEMENTED(FATAL); |
| #endif |
| } |
| |
| } // namespace x86 |
| } // namespace art |