1/*
2 * Copyright (C) 2011 The Android Open Source Project
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
7 *
8 *      http://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
15 */
16
17#include "context_x86_64.h"
18
19#include "mirror/art_method-inl.h"
20#include "mirror/object-inl.h"
21#include "quick/quick_method_frame_info.h"
22#include "stack.h"
23
24namespace art {
25namespace x86_64 {
26
27static constexpr uintptr_t gZero = 0;
28
29void X86_64Context::Reset() {
30  for (size_t i = 0; i < kNumberOfCpuRegisters; ++i) {
31    gprs_[i] = nullptr;
32  }
33  for (size_t i = 0; i < kNumberOfFloatRegisters; ++i) {
34    fprs_[i] = nullptr;
35  }
36  gprs_[RSP] = &rsp_;
37  // Initialize registers with easy to spot debug values.
38  rsp_ = X86_64Context::kBadGprBase + RSP;
39  rip_ = X86_64Context::kBadGprBase + kNumberOfCpuRegisters;
40}
41
42void X86_64Context::FillCalleeSaves(const StackVisitor& fr) {
43  mirror::ArtMethod* method = fr.GetMethod();
44  const QuickMethodFrameInfo frame_info = method->GetQuickFrameInfo();
45  size_t spill_count = POPCOUNT(frame_info.CoreSpillMask());
46  size_t fp_spill_count = POPCOUNT(frame_info.FpSpillMask());
47  if (spill_count > 0) {
48    // Lowest number spill is farthest away, walk registers and fill into context.
49    size_t j = 2;  // Offset j to skip return address spill.
50    for (size_t i = 0; i < kNumberOfCpuRegisters; ++i) {
51      if (((frame_info.CoreSpillMask() >> i) & 1) != 0) {
52        gprs_[i] = fr.CalleeSaveAddress(spill_count - j, frame_info.FrameSizeInBytes());
53        j++;
54      }
55    }
56  }
57  if (fp_spill_count > 0) {
58    // Lowest number spill is farthest away, walk registers and fill into context.
59    size_t j = 2;  // Offset j to skip return address spill.
60    for (size_t i = 0; i < kNumberOfFloatRegisters; ++i) {
61      if (((frame_info.FpSpillMask() >> i) & 1) != 0) {
62        fprs_[i] = reinterpret_cast<uint64_t*>(
63            fr.CalleeSaveAddress(spill_count + fp_spill_count - j, frame_info.FrameSizeInBytes()));
64        j++;
65      }
66    }
67  }
68}
69
70void X86_64Context::SmashCallerSaves() {
71  // This needs to be 0 because we want a null/zero return value.
72  gprs_[RAX] = const_cast<uintptr_t*>(&gZero);
73  gprs_[RDX] = const_cast<uintptr_t*>(&gZero);
74  gprs_[RCX] = nullptr;
75  gprs_[RSI] = nullptr;
76  gprs_[RDI] = nullptr;
77  gprs_[R8] = nullptr;
78  gprs_[R9] = nullptr;
79  gprs_[R10] = nullptr;
80  gprs_[R11] = nullptr;
81  fprs_[XMM0] = nullptr;
82  fprs_[XMM1] = nullptr;
83  fprs_[XMM2] = nullptr;
84  fprs_[XMM3] = nullptr;
85  fprs_[XMM4] = nullptr;
86  fprs_[XMM5] = nullptr;
87  fprs_[XMM6] = nullptr;
88  fprs_[XMM7] = nullptr;
89  fprs_[XMM8] = nullptr;
90  fprs_[XMM9] = nullptr;
91  fprs_[XMM10] = nullptr;
92  fprs_[XMM11] = nullptr;
93}
94
95bool X86_64Context::SetGPR(uint32_t reg, uintptr_t value) {
96  CHECK_LT(reg, static_cast<uint32_t>(kNumberOfCpuRegisters));
97  CHECK_NE(gprs_[reg], &gZero);
98  if (gprs_[reg] != nullptr) {
99    *gprs_[reg] = value;
100    return true;
101  } else {
102    return false;
103  }
104}
105
106bool X86_64Context::SetFPR(uint32_t reg, uintptr_t value) {
107  CHECK_LT(reg, static_cast<uint32_t>(kNumberOfFloatRegisters));
108  CHECK_NE(fprs_[reg], reinterpret_cast<const uint64_t*>(&gZero));
109  if (fprs_[reg] != nullptr) {
110    *fprs_[reg] = value;
111    return true;
112  } else {
113    return false;
114  }
115}
116
117extern "C" void art_quick_do_long_jump(uintptr_t*, uintptr_t*);
118
119void X86_64Context::DoLongJump() {
120#if defined(__x86_64__)
121  uintptr_t gprs[kNumberOfCpuRegisters + 1];
122  uintptr_t fprs[kNumberOfFloatRegisters];
123
124  for (size_t i = 0; i < kNumberOfCpuRegisters; ++i) {
125    gprs[kNumberOfCpuRegisters - i - 1] = gprs_[i] != nullptr ? *gprs_[i] : X86_64Context::kBadGprBase + i;
126  }
127  for (size_t i = 0; i < kNumberOfFloatRegisters; ++i) {
128    fprs[i] = fprs_[i] != nullptr ? *fprs_[i] : X86_64Context::kBadFprBase + i;
129  }
130
131  // We want to load the stack pointer one slot below so that the ret will pop eip.
132  uintptr_t rsp = gprs[kNumberOfCpuRegisters - RSP - 1] - kWordSize;
133  gprs[kNumberOfCpuRegisters] = rsp;
134  *(reinterpret_cast<uintptr_t*>(rsp)) = rip_;
135
136  art_quick_do_long_jump(gprs, fprs);
137#else
138  UNIMPLEMENTED(FATAL);
139#endif
140}
141
142}  // namespace x86_64
143}  // namespace art
144