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
24 namespace art {
25 namespace x86_64 {
26
27 static constexpr uintptr_t gZero = 0;
28
Reset()29 void 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
FillCalleeSaves(const StackVisitor & fr)42 void 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
SmashCallerSaves()70 void 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
SetGPR(uint32_t reg,uintptr_t value)95 bool 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
SetFPR(uint32_t reg,uintptr_t value)106 bool 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
117 extern "C" void art_quick_do_long_jump(uintptr_t*, uintptr_t*);
118
DoLongJump()119 void 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