| /* |
| * Copyright (C) 2017-2018 Apple Inc. All rights reserved. |
| * |
| * Redistribution and use in source and binary forms, with or without |
| * modification, are permitted provided that the following conditions |
| * are met: |
| * 1. Redistributions of source code must retain the above copyright |
| * notice, this list of conditions and the following disclaimer. |
| * 2. Redistributions in binary form must reproduce the above copyright |
| * notice, this list of conditions and the following disclaimer in the |
| * documentation and/or other materials provided with the distribution. |
| * |
| * THIS SOFTWARE IS PROVIDED BY APPLE INC. ``AS IS'' AND ANY |
| * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE |
| * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR |
| * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL APPLE INC. OR |
| * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, |
| * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, |
| * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR |
| * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY |
| * OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT |
| * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE |
| * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. |
| */ |
| |
| #include "config.h" |
| #include "SigillCrashAnalyzer.h" |
| |
| #include "CallFrame.h" |
| #include "CodeBlock.h" |
| #include "MachineContext.h" |
| #include "VMInspector.h" |
| #include <mutex> |
| #include <wtf/StdLibExtras.h> |
| |
| #if USE(ARM64_DISASSEMBLER) |
| #include "A64DOpcode.h" |
| #endif |
| |
| #include <wtf/threads/Signals.h> |
| |
| namespace JSC { |
| |
| struct SignalContext; |
| |
| class SigillCrashAnalyzer { |
| public: |
| static SigillCrashAnalyzer& instance(); |
| |
| enum class CrashSource { |
| Unknown, |
| JavaScriptCore, |
| Other, |
| }; |
| CrashSource analyze(SignalContext&); |
| |
| private: |
| SigillCrashAnalyzer() { } |
| void dumpCodeBlock(CodeBlock*, void* machinePC); |
| |
| #if USE(ARM64_DISASSEMBLER) |
| A64DOpcode m_arm64Opcode; |
| #endif |
| }; |
| |
| #if OS(DARWIN) |
| |
| #if USE(OS_LOG) |
| |
| #define log(format, ...) \ |
| os_log_info(OS_LOG_DEFAULT, format, ##__VA_ARGS__) |
| |
| #else // USE(OS_LOG) |
| |
| #define log(format, ...) \ |
| dataLogF(format, ##__VA_ARGS__) |
| |
| #endif // USE(OS_LOG) |
| |
| struct SignalContext { |
| private: |
| SignalContext(PlatformRegisters& registers, MacroAssemblerCodePtr<PlatformRegistersPCPtrTag> machinePC) |
| : registers(registers) |
| , machinePC(machinePC) |
| , stackPointer(MachineContext::stackPointer(registers)) |
| , framePointer(MachineContext::framePointer(registers)) |
| { } |
| |
| public: |
| static Optional<SignalContext> tryCreate(PlatformRegisters& registers) |
| { |
| auto instructionPointer = MachineContext::instructionPointer(registers); |
| if (!instructionPointer) |
| return WTF::nullopt; |
| return SignalContext(registers, *instructionPointer); |
| } |
| |
| void dump() |
| { |
| #if CPU(X86_64) |
| #define FOR_EACH_REGISTER(v) \ |
| v(rax) \ |
| v(rbx) \ |
| v(rcx) \ |
| v(rdx) \ |
| v(rdi) \ |
| v(rsi) \ |
| v(rbp) \ |
| v(rsp) \ |
| v(r8) \ |
| v(r9) \ |
| v(r10) \ |
| v(r11) \ |
| v(r12) \ |
| v(r13) \ |
| v(r14) \ |
| v(r15) \ |
| v(rip) \ |
| v(rflags) \ |
| v(cs) \ |
| v(fs) \ |
| v(gs) |
| |
| #define DUMP_REGISTER(__reg) \ |
| log("Register " #__reg ": %p", reinterpret_cast<void*>(registers.__##__reg)); |
| FOR_EACH_REGISTER(DUMP_REGISTER) |
| #undef FOR_EACH_REGISTER |
| |
| #elif CPU(ARM64) && defined(__LP64__) |
| int i; |
| for (i = 0; i < 28; i += 4) { |
| log("x%d: %016llx x%d: %016llx x%d: %016llx x%d: %016llx", |
| i, registers.__x[i], |
| i+1, registers.__x[i+1], |
| i+2, registers.__x[i+2], |
| i+3, registers.__x[i+3]); |
| } |
| ASSERT(i < 29); |
| log("x%d: %016llx fp: %016llx lr: %016llx", |
| i, registers.__x[i], |
| MachineContext::framePointer<uint64_t>(registers), |
| MachineContext::linkRegister(registers).untaggedExecutableAddress<uint64_t>()); |
| log("sp: %016llx pc: %016llx cpsr: %08x", |
| MachineContext::stackPointer<uint64_t>(registers), |
| machinePC.untaggedExecutableAddress<uint64_t>(), |
| registers.__cpsr); |
| #endif |
| } |
| |
| PlatformRegisters& registers; |
| MacroAssemblerCodePtr<PlatformRegistersPCPtrTag> machinePC; |
| void* stackPointer; |
| void* framePointer; |
| }; |
| |
| static void installCrashHandler() |
| { |
| #if CPU(X86_64) || CPU(ARM64) |
| installSignalHandler(Signal::Ill, [] (Signal, SigInfo&, PlatformRegisters& registers) { |
| auto signalContext = SignalContext::tryCreate(registers); |
| if (!signalContext) |
| return SignalAction::NotHandled; |
| |
| void* machinePC = signalContext->machinePC.untaggedExecutableAddress(); |
| if (!isJITPC(machinePC)) |
| return SignalAction::NotHandled; |
| |
| SigillCrashAnalyzer& analyzer = SigillCrashAnalyzer::instance(); |
| analyzer.analyze(*signalContext); |
| return SignalAction::NotHandled; |
| }); |
| #endif |
| } |
| |
| #else // OS(DARWIN) |
| |
| #define log(format, ...) do { } while (false) |
| |
| struct SignalContext { |
| SignalContext() { } |
| |
| void dump() { } |
| |
| MacroAssemblerCodePtr<PlatformRegistersPCPtrTag> machinePC; |
| void* stackPointer; |
| void* framePointer; |
| }; |
| |
| static void installCrashHandler() |
| { |
| // Do nothing. Not supported for this platform. |
| } |
| |
| #endif // OS(DARWIN) |
| |
| SigillCrashAnalyzer& SigillCrashAnalyzer::instance() |
| { |
| static SigillCrashAnalyzer* analyzer; |
| static std::once_flag once; |
| std::call_once(once, [] { |
| installCrashHandler(); |
| analyzer = new SigillCrashAnalyzer; |
| }); |
| return *analyzer; |
| } |
| |
| void enableSigillCrashAnalyzer() |
| { |
| // Just instantiating the SigillCrashAnalyzer will enable it. |
| SigillCrashAnalyzer::instance(); |
| } |
| |
| auto SigillCrashAnalyzer::analyze(SignalContext& context) -> CrashSource |
| { |
| CrashSource crashSource = CrashSource::Unknown; |
| log("BEGIN SIGILL analysis"); |
| |
| do { |
| // First, dump the signal context info so that we'll at least have the same info |
| // that the default crash handler would given us in case this crash analyzer |
| // itself crashes. |
| context.dump(); |
| |
| VMInspector& inspector = VMInspector::instance(); |
| |
| // Use a timeout period of 2 seconds. The client is about to crash, and we don't |
| // want to turn the crash into a hang by re-trying the lock for too long. |
| auto expectedLocker = inspector.lock(Seconds(2)); |
| if (!expectedLocker) { |
| ASSERT(expectedLocker.error() == VMInspector::Error::TimedOut); |
| log("ERROR: Unable to analyze SIGILL. Timed out while waiting to iterate VMs."); |
| break; |
| } |
| auto& locker = expectedLocker.value(); |
| |
| void* pc = context.machinePC.untaggedExecutableAddress(); |
| auto isInJITMemory = inspector.isValidExecutableMemory(locker, pc); |
| if (!isInJITMemory) { |
| log("ERROR: Timed out: not able to determine if pc %p is in valid JIT executable memory", pc); |
| break; |
| } |
| if (!isInJITMemory.value()) { |
| log("pc %p is NOT in valid JIT executable memory", pc); |
| crashSource = CrashSource::Other; |
| break; |
| } |
| log("pc %p is in valid JIT executable memory", pc); |
| crashSource = CrashSource::JavaScriptCore; |
| |
| #if CPU(ARM64) |
| size_t pcAsSize = reinterpret_cast<size_t>(pc); |
| if (pcAsSize != roundUpToMultipleOf<sizeof(uint32_t)>(pcAsSize)) { |
| log("pc %p is NOT properly aligned", pc); |
| break; |
| } |
| |
| // We know it's safe to read the word at the PC because we're handling a SIGILL. |
| // Otherwise, we would have crashed with a SIGBUS instead. |
| uint32_t wordAtPC = *reinterpret_cast<uint32_t*>(pc); |
| log("instruction bits at pc %p is: 0x%08x", pc, wordAtPC); |
| #endif |
| |
| auto expectedCodeBlock = inspector.codeBlockForMachinePC(locker, pc); |
| if (!expectedCodeBlock) { |
| if (expectedCodeBlock.error() == VMInspector::Error::TimedOut) |
| log("ERROR: Timed out: not able to determine if pc %p is in a valid CodeBlock", pc); |
| else |
| log("The current thread does not own any VM JSLock"); |
| break; |
| } |
| CodeBlock* codeBlock = expectedCodeBlock.value(); |
| if (!codeBlock) { |
| log("machine PC %p does not belong to any CodeBlock in the currently entered VM", pc); |
| break; |
| } |
| |
| log("pc %p belongs to CodeBlock %p of type %s", pc, codeBlock, JITCode::typeName(codeBlock->jitType())); |
| |
| dumpCodeBlock(codeBlock, pc); |
| } while (false); |
| |
| log("END SIGILL analysis"); |
| return crashSource; |
| } |
| |
| void SigillCrashAnalyzer::dumpCodeBlock(CodeBlock* codeBlock, void* machinePC) |
| { |
| #if CPU(ARM64) && ENABLE(JIT) |
| JITCode* jitCode = codeBlock->jitCode().get(); |
| |
| // Dump the raw bits of the code. |
| uint32_t* start = reinterpret_cast<uint32_t*>(jitCode->start()); |
| uint32_t* end = reinterpret_cast<uint32_t*>(jitCode->end()); |
| log("JITCode %p [%p-%p]:", jitCode, start, end); |
| if (start < end) { |
| uint32_t* p = start; |
| while (p + 8 <= end) { |
| log("[%p-%p]: %08x %08x %08x %08x %08x %08x %08x %08x", p, p+7, p[0], p[1], p[2], p[3], p[4], p[5], p[6], p[7]); |
| p += 8; |
| } |
| if (p + 7 <= end) |
| log("[%p-%p]: %08x %08x %08x %08x %08x %08x %08x", p, p+6, p[0], p[1], p[2], p[3], p[4], p[5], p[6]); |
| else if (p + 6 <= end) |
| log("[%p-%p]: %08x %08x %08x %08x %08x %08x", p, p+5, p[0], p[1], p[2], p[3], p[4], p[5]); |
| else if (p + 5 <= end) |
| log("[%p-%p]: %08x %08x %08x %08x %08x", p, p+4, p[0], p[1], p[2], p[3], p[4]); |
| else if (p + 4 <= end) |
| log("[%p-%p]: %08x %08x %08x %08x", p, p+3, p[0], p[1], p[2], p[3]); |
| if (p + 3 <= end) |
| log("[%p-%p]: %08x %08x %08x", p, p+2, p[0], p[1], p[2]); |
| else if (p + 2 <= end) |
| log("[%p-%p]: %08x %08x", p, p+1, p[0], p[1]); |
| else if (p + 1 <= end) |
| log("[%p-%p]: %08x", p, p, p[0]); |
| } |
| |
| // Dump the disassembly of the code. |
| log("Disassembly:"); |
| uint32_t* currentPC = reinterpret_cast<uint32_t*>(jitCode->executableAddress()); |
| size_t byteCount = jitCode->size(); |
| while (byteCount) { |
| char pcString[24]; |
| if (currentPC == machinePC) { |
| snprintf(pcString, sizeof(pcString), "* 0x%lx", reinterpret_cast<uintptr_t>(currentPC)); |
| log("%20s: %s <=========================", pcString, m_arm64Opcode.disassemble(currentPC)); |
| } else { |
| snprintf(pcString, sizeof(pcString), "0x%lx", reinterpret_cast<uintptr_t>(currentPC)); |
| log("%20s: %s", pcString, m_arm64Opcode.disassemble(currentPC)); |
| } |
| currentPC++; |
| byteCount -= sizeof(uint32_t); |
| } |
| #else |
| UNUSED_PARAM(codeBlock); |
| UNUSED_PARAM(machinePC); |
| // Not implemented yet. |
| #endif |
| } |
| |
| } // namespace JSC |
