1 /*
2 * Copyright (C) 2014 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 <stdint.h>
18
19 #include "context_arm64.h"
20
21 #include "base/bit_utils.h"
22 #include "base/bit_utils_iterator.h"
23 #include "quick/quick_method_frame_info.h"
24 #include "thread-current-inl.h"
25
26 #if __has_feature(hwaddress_sanitizer)
27 #include <sanitizer/hwasan_interface.h>
28 #else
29 #define __hwasan_handle_longjmp(sp)
30 #endif
31
32 namespace art {
33 namespace arm64 {
34
35 static constexpr uint64_t gZero = 0;
36
Reset()37 void Arm64Context::Reset() {
38 std::fill_n(gprs_, arraysize(gprs_), nullptr);
39 std::fill_n(fprs_, arraysize(fprs_), nullptr);
40 gprs_[SP] = &sp_;
41 gprs_[kPC] = &pc_;
42 gprs_[X0] = &arg0_;
43 // Initialize registers with easy to spot debug values.
44 sp_ = Arm64Context::kBadGprBase + SP;
45 pc_ = Arm64Context::kBadGprBase + kPC;
46 arg0_ = 0;
47 }
48
FillCalleeSaves(uint8_t * frame,const QuickMethodFrameInfo & frame_info)49 void Arm64Context::FillCalleeSaves(uint8_t* frame, const QuickMethodFrameInfo& frame_info) {
50 int spill_pos = 0;
51
52 // Core registers come first, from the highest down to the lowest.
53 for (uint32_t core_reg : HighToLowBits(frame_info.CoreSpillMask())) {
54 gprs_[core_reg] = CalleeSaveAddress(frame, spill_pos, frame_info.FrameSizeInBytes());
55 ++spill_pos;
56 }
57 DCHECK_EQ(spill_pos, POPCOUNT(frame_info.CoreSpillMask()));
58
59 // FP registers come second, from the highest down to the lowest.
60 for (uint32_t fp_reg : HighToLowBits(frame_info.FpSpillMask())) {
61 fprs_[fp_reg] = CalleeSaveAddress(frame, spill_pos, frame_info.FrameSizeInBytes());
62 ++spill_pos;
63 }
64 DCHECK_EQ(spill_pos, POPCOUNT(frame_info.CoreSpillMask()) + POPCOUNT(frame_info.FpSpillMask()));
65 }
66
SetGPR(uint32_t reg,uintptr_t value)67 void Arm64Context::SetGPR(uint32_t reg, uintptr_t value) {
68 DCHECK_LT(reg, arraysize(gprs_));
69 // Note: we use kPC == XZR, so do not ensure that reg != XZR.
70 DCHECK(IsAccessibleGPR(reg));
71 DCHECK_NE(gprs_[reg], &gZero); // Can't overwrite this static value since they are never reset.
72 *gprs_[reg] = value;
73 }
74
SetFPR(uint32_t reg,uintptr_t value)75 void Arm64Context::SetFPR(uint32_t reg, uintptr_t value) {
76 DCHECK_LT(reg, static_cast<uint32_t>(kNumberOfDRegisters));
77 DCHECK(IsAccessibleFPR(reg));
78 DCHECK_NE(fprs_[reg], &gZero); // Can't overwrite this static value since they are never reset.
79 *fprs_[reg] = value;
80 }
81
SmashCallerSaves()82 void Arm64Context::SmashCallerSaves() {
83 // This needs to be 0 because we want a null/zero return value.
84 gprs_[X0] = const_cast<uint64_t*>(&gZero);
85 gprs_[X1] = nullptr;
86 gprs_[X2] = nullptr;
87 gprs_[X3] = nullptr;
88 gprs_[X4] = nullptr;
89 gprs_[X5] = nullptr;
90 gprs_[X6] = nullptr;
91 gprs_[X7] = nullptr;
92 gprs_[X8] = nullptr;
93 gprs_[X9] = nullptr;
94 gprs_[X10] = nullptr;
95 gprs_[X11] = nullptr;
96 gprs_[X12] = nullptr;
97 gprs_[X13] = nullptr;
98 gprs_[X14] = nullptr;
99 gprs_[X15] = nullptr;
100 gprs_[X18] = nullptr;
101
102 // d0-d7, d16-d31 are caller-saved; d8-d15 are callee-saved.
103
104 fprs_[D0] = nullptr;
105 fprs_[D1] = nullptr;
106 fprs_[D2] = nullptr;
107 fprs_[D3] = nullptr;
108 fprs_[D4] = nullptr;
109 fprs_[D5] = nullptr;
110 fprs_[D6] = nullptr;
111 fprs_[D7] = nullptr;
112
113 fprs_[D16] = nullptr;
114 fprs_[D17] = nullptr;
115 fprs_[D18] = nullptr;
116 fprs_[D19] = nullptr;
117 fprs_[D20] = nullptr;
118 fprs_[D21] = nullptr;
119 fprs_[D22] = nullptr;
120 fprs_[D23] = nullptr;
121 fprs_[D24] = nullptr;
122 fprs_[D25] = nullptr;
123 fprs_[D26] = nullptr;
124 fprs_[D27] = nullptr;
125 fprs_[D28] = nullptr;
126 fprs_[D29] = nullptr;
127 fprs_[D30] = nullptr;
128 fprs_[D31] = nullptr;
129 }
130
131 extern "C" NO_RETURN void art_quick_do_long_jump(uint64_t*, uint64_t*);
132
DoLongJump()133 void Arm64Context::DoLongJump() {
134 uint64_t gprs[arraysize(gprs_)];
135 uint64_t fprs[kNumberOfDRegisters];
136
137 // The long jump routine called below expects to find the value for SP at index 31.
138 DCHECK_EQ(SP, 31);
139
140 for (size_t i = 0; i < arraysize(gprs_); ++i) {
141 gprs[i] = gprs_[i] != nullptr ? *gprs_[i] : Arm64Context::kBadGprBase + i;
142 }
143 for (size_t i = 0; i < kNumberOfDRegisters; ++i) {
144 fprs[i] = fprs_[i] != nullptr ? *fprs_[i] : Arm64Context::kBadFprBase + i;
145 }
146 // Ensure the Thread Register contains the address of the current thread.
147 DCHECK_EQ(reinterpret_cast<uintptr_t>(Thread::Current()), gprs[TR]);
148 // Tell HWASan about the new stack top.
149 __hwasan_handle_longjmp(reinterpret_cast<void*>(gprs[SP]));
150 // The Marking Register will be updated by art_quick_do_long_jump.
151 art_quick_do_long_jump(gprs, fprs);
152 }
153
154 } // namespace arm64
155 } // namespace art
156