blob: 88686775ebd4a3917db4d230e70ac4f439cbf50a [file] [log] [blame]
/*
* 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 {
WTF_MAKE_FAST_ALLOCATED;
WTF_MAKE_NONCOPYABLE(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