1/*
2 * Copyright (C) 2013, 2014 Apple Inc. All rights reserved.
3 *
4 * Redistribution and use in source and binary forms, with or without
5 * modification, are permitted provided that the following conditions
6 * are met:
7 * 1. Redistributions of source code must retain the above copyright
8 *    notice, this list of conditions and the following disclaimer.
9 * 2. Redistributions in binary form must reproduce the above copyright
10 *    notice, this list of conditions and the following disclaimer in the
11 *    documentation and/or other materials provided with the distribution.
12 *
13 * THIS SOFTWARE IS PROVIDED BY APPLE INC. ``AS IS'' AND ANY
14 * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
15 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
16 * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL APPLE INC. OR
17 * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
18 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
19 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
20 * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
21 * OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
22 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
23 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
24 */
25
26#include "config.h"
27#include "FTLUnwindInfo.h"
28
29#if ENABLE(FTL_JIT)
30
31#include <mach-o/compact_unwind_encoding.h>
32#include <wtf/ListDump.h>
33
34namespace JSC { namespace FTL {
35
36UnwindInfo::UnwindInfo() { }
37UnwindInfo::~UnwindInfo() { }
38
39namespace {
40
41struct CompactUnwind {
42    void* function;
43    uint32_t size;
44    compact_unwind_encoding_t encoding;
45    void* personality;
46    void* lsda;
47};
48
49} // anonymous namespace
50
51bool UnwindInfo::parse(void* section, size_t size, GeneratedFunction generatedFunction)
52{
53    m_registers.clear();
54
55    RELEASE_ASSERT(!!section == !!size);
56    if (!section)
57        return false;
58
59    RELEASE_ASSERT(size >= sizeof(CompactUnwind));
60
61    CompactUnwind* data = bitwise_cast<CompactUnwind*>(section);
62
63    RELEASE_ASSERT(!data->personality); // We don't know how to handle this.
64    RELEASE_ASSERT(!data->lsda); // We don't know how to handle this.
65    RELEASE_ASSERT(data->function == generatedFunction); // The unwind data better be for our function.
66
67    compact_unwind_encoding_t encoding = data->encoding;
68    RELEASE_ASSERT(!(encoding & UNWIND_IS_NOT_FUNCTION_START));
69    RELEASE_ASSERT(!(encoding & UNWIND_HAS_LSDA));
70    RELEASE_ASSERT(!(encoding & UNWIND_PERSONALITY_MASK));
71
72#if CPU(X86_64)
73    RELEASE_ASSERT((encoding & UNWIND_X86_64_MODE_MASK) == UNWIND_X86_64_MODE_RBP_FRAME);
74
75    int32_t offset = -((encoding & UNWIND_X86_64_RBP_FRAME_OFFSET) >> 16) * 8;
76    uint32_t nextRegisters = encoding;
77    for (unsigned i = 5; i--;) {
78        uint32_t currentRegister = nextRegisters & 7;
79        nextRegisters >>= 3;
80
81        switch (currentRegister) {
82        case UNWIND_X86_64_REG_NONE:
83            break;
84
85        case UNWIND_X86_64_REG_RBX:
86            m_registers.append(RegisterAtOffset(X86Registers::ebx, offset));
87            break;
88
89        case UNWIND_X86_64_REG_R12:
90            m_registers.append(RegisterAtOffset(X86Registers::r12, offset));
91            break;
92
93        case UNWIND_X86_64_REG_R13:
94            m_registers.append(RegisterAtOffset(X86Registers::r13, offset));
95            break;
96
97        case UNWIND_X86_64_REG_R14:
98            m_registers.append(RegisterAtOffset(X86Registers::r14, offset));
99            break;
100
101        case UNWIND_X86_64_REG_R15:
102            m_registers.append(RegisterAtOffset(X86Registers::r15, offset));
103            break;
104
105        case UNWIND_X86_64_REG_RBP:
106            m_registers.append(RegisterAtOffset(X86Registers::ebp, offset));
107            break;
108
109        default:
110            RELEASE_ASSERT_NOT_REACHED();
111        }
112
113        offset += 8;
114    }
115#elif CPU(ARM64)
116    RELEASE_ASSERT((encoding & UNWIND_ARM64_MODE_MASK) == UNWIND_ARM64_MODE_FRAME);
117
118    m_registers.append(RegisterAtOffset(ARM64Registers::fp, 0));
119
120    int32_t offset = 0;
121    if (encoding & UNWIND_ARM64_FRAME_X19_X20_PAIR) {
122        m_registers.append(RegisterAtOffset(ARM64Registers::x19, offset -= 8));
123        m_registers.append(RegisterAtOffset(ARM64Registers::x20, offset -= 8));
124    }
125    if (encoding & UNWIND_ARM64_FRAME_X21_X22_PAIR) {
126        m_registers.append(RegisterAtOffset(ARM64Registers::x21, offset -= 8));
127        m_registers.append(RegisterAtOffset(ARM64Registers::x22, offset -= 8));
128    }
129    if (encoding & UNWIND_ARM64_FRAME_X23_X24_PAIR) {
130        m_registers.append(RegisterAtOffset(ARM64Registers::x23, offset -= 8));
131        m_registers.append(RegisterAtOffset(ARM64Registers::x24, offset -= 8));
132    }
133    if (encoding & UNWIND_ARM64_FRAME_X25_X26_PAIR) {
134        m_registers.append(RegisterAtOffset(ARM64Registers::x25, offset -= 8));
135        m_registers.append(RegisterAtOffset(ARM64Registers::x26, offset -= 8));
136    }
137    if (encoding & UNWIND_ARM64_FRAME_X27_X28_PAIR) {
138        m_registers.append(RegisterAtOffset(ARM64Registers::x27, offset -= 8));
139        m_registers.append(RegisterAtOffset(ARM64Registers::x28, offset -= 8));
140    }
141    if (encoding & UNWIND_ARM64_FRAME_D8_D9_PAIR) {
142        m_registers.append(RegisterAtOffset(ARM64Registers::q8, offset -= 8));
143        m_registers.append(RegisterAtOffset(ARM64Registers::q9, offset -= 8));
144    }
145    if (encoding & UNWIND_ARM64_FRAME_D10_D11_PAIR) {
146        m_registers.append(RegisterAtOffset(ARM64Registers::q10, offset -= 8));
147        m_registers.append(RegisterAtOffset(ARM64Registers::q11, offset -= 8));
148    }
149    if (encoding & UNWIND_ARM64_FRAME_D12_D13_PAIR) {
150        m_registers.append(RegisterAtOffset(ARM64Registers::q12, offset -= 8));
151        m_registers.append(RegisterAtOffset(ARM64Registers::q13, offset -= 8));
152    }
153    if (encoding & UNWIND_ARM64_FRAME_D14_D15_PAIR) {
154        m_registers.append(RegisterAtOffset(ARM64Registers::q14, offset -= 8));
155        m_registers.append(RegisterAtOffset(ARM64Registers::q15, offset -= 8));
156    }
157#else
158#error "Unrecognized architecture"
159#endif
160
161    std::sort(m_registers.begin(), m_registers.end());
162    return true;
163}
164
165void UnwindInfo::dump(PrintStream& out) const
166{
167    out.print(listDump(m_registers));
168}
169
170RegisterAtOffset* UnwindInfo::find(Reg reg) const
171{
172    return tryBinarySearch<RegisterAtOffset, Reg>(m_registers, m_registers.size(), reg, RegisterAtOffset::getReg);
173}
174
175unsigned UnwindInfo::indexOf(Reg reg) const
176{
177    if (RegisterAtOffset* pointer = find(reg))
178        return pointer - m_registers.begin();
179    return UINT_MAX;
180}
181
182} } // namespace JSC::FTL
183
184#endif // ENABLE(FTL_JIT)
185
186