From 9559aca8252373cc30d4ea396ff724209d0a807f Mon Sep 17 00:00:00 2001 From: Joel Dice Date: Tue, 15 Jun 2010 19:10:48 -0600 Subject: [PATCH] fix Thread.getStackTrace race conditions Implementing Thread.getStackTrace is tricky. A thread may interrupt another thread at any time to grab a stack trace, including while the latter is executing Java code, JNI code, helper thunks, VM code, or while transitioning between any of these. To create a stack trace we use several context fields associated with the target thread, including snapshots of the instruction pointer, stack pointer, and frame pointer. These fields must be current, accurate, and consistent with each other in order to get a reliable trace. Otherwise, we risk crashing the VM by trying to walk garbage stack frames or by misinterpreting the size and/or content of legitimate frames. This commit addresses sensitive transition points such as entering the helper thunks which bridge the transitions from Java to native code (where we must save the stack and frame registers for use from native code) and stack unwinding (where we must atomically update the thread context fields to indicate which frame we are unwinding to). When grabbing a trace for another thread, we determine what kind of code we caught the thread executing in and use that information to choose the thread context values with which to begin the trace. See MyProcessor::getStackTrace::Visitor::visit for details. In order to atomically update the thread context fields, we do the following: 1. Create a temporary "transition" object to serve as a staging area and populate it with the new field values. 2. Update a transition pointer in the thread object to point to the object created above. As long as this pointer is non-null, interrupting threads will use the context values in the staging object instead of those in the thread object. 3. Update the fields in the thread object. 4. Clear the transition pointer in the thread object. We use a memory barrier between each of these steps to ensure they are made visible to other threads in program order. See MyThread::doTransition for details. --- src/bootimage.h | 32 ++- src/compile-powerpc.S | 12 + src/compile-x86.S | 34 +++ src/compile.cpp | 561 ++++++++++++++++++++++++++++++------------ 4 files changed, 481 insertions(+), 158 deletions(-) diff --git a/src/bootimage.h b/src/bootimage.h index 4472ac28ae..b76a77b7fa 100644 --- a/src/bootimage.h +++ b/src/bootimage.h @@ -24,6 +24,30 @@ const unsigned BootHeapOffset = 1 << (BootShift + 1); class BootImage { public: + class Thunk { + public: + Thunk(): + start(0), frameSavedOffset(0), length(0) + { } + + Thunk(unsigned start, unsigned frameSavedOffset, unsigned length): + start(start), frameSavedOffset(frameSavedOffset), length(length) + { } + + unsigned start; + unsigned frameSavedOffset; + unsigned length; + }; + + class ThunkCollection { + public: + Thunk default_; + Thunk defaultVirtual; + Thunk native; + Thunk aioob; + Thunk table; + }; + static const unsigned Magic = 0x22377322; unsigned magic; @@ -43,13 +67,7 @@ class BootImage { uintptr_t codeBase; - unsigned defaultThunk; - unsigned defaultVirtualThunk; - unsigned nativeThunk; - unsigned aioobThunk; - - unsigned thunkTable; - unsigned thunkSize; + ThunkCollection thunks; unsigned compileMethodCall; unsigned compileVirtualMethodCall; diff --git a/src/compile-powerpc.S b/src/compile-powerpc.S index 8936899b53..e967a3dfd7 100644 --- a/src/compile-powerpc.S +++ b/src/compile-powerpc.S @@ -24,6 +24,7 @@ # define GLOBAL(x) x #endif +#define THREAD_STACK 108 #define THREAD_CONTINUATION 112 #define THREAD_EXCEPTION 44 #define THREAD_EXCEPTION_STACK_ADJUSTMENT 116 @@ -106,6 +107,17 @@ LOCAL(vmInvoke_argumentTest): LOCAL(vmInvoke_returnAddress): // restore stack pointer lwz r1,0(r1) + + // clear MyThread::stack to avoid confusing another thread calling + // java.lang.Thread.getStackTrace on this one. See + // MyProcess::getStackTrace in compile.cpp for details on how we get + // a reliable stack trace from a thread that might be interrupted at + // any point in its execution. + li r5,0 + stw r5,THREAD_STACK(r13) + +.globl GLOBAL(vmInvoke_safeStack) +GLOBAL(vmInvoke_safeStack): #ifdef AVIAN_CONTINUATIONS // call the next continuation, if any diff --git a/src/compile-x86.S b/src/compile-x86.S index e680190bbb..c78a89dd6b 100644 --- a/src/compile-x86.S +++ b/src/compile-x86.S @@ -22,6 +22,8 @@ #ifdef __x86_64__ +#define THREAD_STACK 184 + #if defined __MINGW32__ || defined __CYGWIN32__ #define CALLEE_SAVED_REGISTER_FOOTPRINT 64 @@ -79,6 +81,16 @@ GLOBAL(vmInvoke_returnAddress): // restore stack pointer movq %rbp,%rsp + // clear MyThread::stack to avoid confusing another thread calling + // java.lang.Thread.getStackTrace on this one. See + // MyProcess::getStackTrace in compile.cpp for details on how we get + // a reliable stack trace from a thread that might be interrupted at + // any point in its execution. + movq $0,THREAD_STACK(%rbx) + +.globl GLOBAL(vmInvoke_safeStack) +GLOBAL(vmInvoke_safeStack): + #ifdef AVIAN_CONTINUATIONS # include "continuations-x86.S" #endif // AVIAN_CONTINUATIONS @@ -207,6 +219,16 @@ LOCAL(vmInvoke_argumentTest): GLOBAL(vmInvoke_returnAddress): // restore stack pointer movq %rbp,%rsp + + // clear MyThread::stack to avoid confusing another thread calling + // java.lang.Thread.getStackTrace on this one. See + // MyProcess::getStackTrace in compile.cpp for details on how we get + // a reliable stack trace from a thread that might be interrupted at + // any point in its execution. + movq $0,THREAD_STACK(%rbx) + +.globl GLOBAL(vmInvoke_safeStack) +GLOBAL(vmInvoke_safeStack): #ifdef AVIAN_CONTINUATIONS # include "continuations-x86.S" @@ -283,6 +305,8 @@ LOCAL(vmJumpAndInvoke_argumentTest): #elif defined __i386__ +#define THREAD_STACK 104 + #define CALLEE_SAVED_REGISTER_FOOTPRINT 16 .globl GLOBAL(vmInvoke) @@ -336,6 +360,16 @@ vmInvoke_returnAddress: movl %ebp,%ecx subl $CALLEE_SAVED_REGISTER_FOOTPRINT,%ecx movl %ecx,%esp + + // clear MyThread::stack to avoid confusing another thread calling + // java.lang.Thread.getStackTrace on this one. See + // MyProcess::getStackTrace in compile.cpp for details on how we get + // a reliable stack trace from a thread that might be interrupted at + // any point in its execution. + movq $0,THREAD_STACK(%ebx) + +.globl GLOBAL(vmInvoke_safeStack) +GLOBAL(vmInvoke_safeStack): #ifdef AVIAN_CONTINUATIONS # include "continuations-x86.S" diff --git a/src/compile.cpp b/src/compile.cpp index 89cac7125d..5a56dc0ffb 100644 --- a/src/compile.cpp +++ b/src/compile.cpp @@ -22,6 +22,12 @@ extern "C" uint64_t vmInvoke(void* thread, void* function, void* arguments, unsigned argumentFootprint, unsigned frameSize, unsigned returnType); +extern "C" void +vmInvoke_returnAddress(); + +extern "C" void +vmInvoke_safeStack(); + extern "C" void vmJumpAndInvoke(void* thread, void* function, void* base, void* stack, unsigned argumentFootprint, uintptr_t* arguments, @@ -55,6 +61,15 @@ const unsigned InitialZoneCapacityInBytes = 64 * 1024; const unsigned ExecutableAreaSizeInBytes = 16 * 1024 * 1024; +inline bool +isVmInvokeUnsafeStack(void* ip) +{ + return reinterpret_cast(ip) + >= reinterpret_cast(voidPointer(vmInvoke_returnAddress)) + and reinterpret_cast(ip) + < reinterpret_cast (voidPointer(vmInvoke_safeStack)); +} + class MyThread: public Thread { public: class CallTrace { @@ -69,17 +84,13 @@ class MyThread: public Thread { originalMethod(method), next(t->trace) { - t->trace = this; - t->base = 0; - t->stack = 0; - t->continuation = 0; + doTransition(t, 0, 0, 0, 0, this); } ~CallTrace() { - t->stack = stack; - t->base = base; - t->continuation = continuation; - t->trace = next; + assert(t, t->stack == 0); + + doTransition(t, 0, stack, base, continuation, next); } MyThread* t; @@ -92,6 +103,95 @@ class MyThread: public Thread { CallTrace* next; }; + class Context { + public: + class MyProtector: public Thread::Protector { + public: + MyProtector(MyThread* t, Context* context): + Protector(t), context(context) + { } + + virtual void visit(Heap::Visitor* v) { + v->visit(&(context->continuation)); + } + + Context* context; + }; + + Context(MyThread* t, void* ip, void* stack, void* base, + object continuation, CallTrace* trace): + ip(ip), + stack(stack), + base(base), + continuation(continuation), + trace(trace), + protector(t, this) + { } + + void* ip; + void* stack; + void* base; + object continuation; + CallTrace* trace; + MyProtector protector; + }; + + class TraceContext: public Context { + public: + TraceContext(MyThread* t, void* ip, void* stack, void* base, + object continuation, CallTrace* trace): + Context(t, ip, stack, base, continuation, trace), + t(t), + next(t->traceContext) + { + t->traceContext = this; + } + + TraceContext(MyThread* t): + Context(t, t->ip, t->stack, t->base, t->continuation, t->trace), + t(t), + next(t->traceContext) + { + t->traceContext = this; + } + + ~TraceContext() { + t->traceContext = next; + } + + MyThread* t; + TraceContext* next; + }; + + static void doTransition(MyThread* t, void* ip, void* stack, void* base, + object continuation, MyThread::CallTrace* trace) + { + // in this function, we "atomically" update the thread context + // fields in such a way to ensure that another thread may + // interrupt us at any time and still get a consistent, accurate + // stack trace. See MyProcess::getStackTrace for details. + + assert(t, t->transition == 0); + + Context c(t, ip, stack, base, continuation, trace); + + compileTimeMemoryBarrier(); + + t->transition = &c; + + compileTimeMemoryBarrier(); + + t->ip = ip; + t->base = base; + t->stack = stack; + t->continuation = continuation; + t->trace = trace; + + compileTimeMemoryBarrier(); + + t->transition = 0; + } + MyThread(Machine* m, object javaThread, MyThread* parent, bool useNativeFeatures): Thread(m, javaThread, parent), @@ -109,7 +209,9 @@ class MyThread: public Thread { reference(0), arch(parent ? parent->arch - : makeArchitecture(m->system, useNativeFeatures)) + : makeArchitecture(m->system, useNativeFeatures)), + transition(0), + traceContext(0) { arch->acquire(); } @@ -127,8 +229,17 @@ class MyThread: public Thread { CallTrace* trace; Reference* reference; Assembler::Architecture* arch; + Context* transition; + TraceContext* traceContext; }; +void +transition(MyThread* t, void* ip, void* stack, void* base, object continuation, + MyThread::CallTrace* trace) +{ + MyThread::doTransition(t, ip, stack, base, continuation, trace); +} + unsigned parameterOffset(MyThread* t, object method) { @@ -246,6 +357,7 @@ class MyStackWalker: public Processor::StackWalker { enum State { Start, Next, + Trace, Continuation, Method, NativeMethod, @@ -269,14 +381,23 @@ class MyStackWalker: public Processor::StackWalker { MyStackWalker(MyThread* t): t(t), state(Start), - ip_(t->ip), - base(t->base), - stack(t->stack), - trace(t->trace), method_(0), - continuation(t->continuation), protector(this) - { } + { + if (t->traceContext) { + ip_ = t->traceContext->ip; + base = t->traceContext->base; + stack = t->traceContext->stack; + trace = t->traceContext->trace; + continuation = t->traceContext->continuation; + } else { + ip_ = 0; + base = t->base; + stack = t->stack; + trace = t->trace; + continuation = t->continuation; + } + } MyStackWalker(MyStackWalker* w): t(w->t), @@ -325,24 +446,27 @@ class MyStackWalker: public Processor::StackWalker { } else if (continuation) { method_ = continuationMethod(t, continuation); state = Continuation; - } else if (trace) { - continuation = trace->continuation; - stack = trace->stack; - base = trace->base; - ip_ = t->arch->frameIp(stack); - trace = trace->next; - - if (trace and trace->nativeMethod) { - method_ = trace->nativeMethod; - state = NativeMethod; - } } else { - state = Finish; + state = Trace; } + } else { + state = Trace; + } + break; + + case Trace: { + if (trace) { + continuation = trace->continuation; + stack = trace->stack; + base = trace->base; + ip_ = t->arch->frameIp(stack); + trace = trace->next; + + state = Start; } else { state = Finish; } - break; + } break; case Continuation: case Method: @@ -1746,11 +1870,25 @@ releaseLock(MyThread* t, object method, void* stack) void findUnwindTarget(MyThread* t, void** targetIp, void** targetBase, - void** targetStack) + void** targetStack, object* targetContinuation) { - void* ip = t->ip; - void* base = t->base; - void* stack = t->stack; + void* ip; + void* base; + void* stack; + object continuation; + + if (t->traceContext) { + ip = t->traceContext->ip; + base = t->traceContext->base; + stack = t->traceContext->stack; + continuation = t->traceContext->continuation; + } else { + ip = 0; + base = t->base; + stack = t->stack; + continuation = t->continuation; + } + if (ip == 0) { ip = t->arch->frameIp(stack); } @@ -1773,6 +1911,7 @@ findUnwindTarget(MyThread* t, void** targetIp, void** targetBase, + t->arch->frameReturnAddressSize(); *targetStack = sp; + *targetContinuation = continuation; sp[localOffset(t, localSize(t, method), method)] = t->exception; @@ -1792,9 +1931,10 @@ findUnwindTarget(MyThread* t, void** targetIp, void** targetBase, *targetBase = base; *targetStack = static_cast(stack) + t->arch->frameReturnAddressSize(); + *targetContinuation = continuation; - while (Continuations and t->continuation) { - object c = t->continuation; + while (Continuations and *targetContinuation) { + object c = *targetContinuation; object method = continuationMethod(t, c); @@ -1812,6 +1952,7 @@ findUnwindTarget(MyThread* t, void** targetIp, void** targetBase, t->exceptionOffset = localOffset(t, localSize(t, method), method) * BytesPerWord; + break; } else if (t->exception) { releaseLock(t, method, @@ -1821,7 +1962,7 @@ findUnwindTarget(MyThread* t, void** targetIp, void** targetBase, - t->arch->returnAddressOffset()); } - t->continuation = continuationNext(t, c); + *targetContinuation = continuationNext(t, c); } } } @@ -1831,12 +1972,9 @@ object makeCurrentContinuation(MyThread* t, void** targetIp, void** targetBase, void** targetStack) { - void* ip = t->ip; + void* ip = t->arch->frameIp(t->stack); void* base = t->base; void* stack = t->stack; - if (ip == 0) { - ip = t->arch->frameIp(stack); - } object context = t->continuation ? continuationContext(t, t->continuation) @@ -1921,7 +2059,11 @@ unwind(MyThread* t) void* ip; void* base; void* stack; - findUnwindTarget(t, &ip, &base, &stack); + object continuation; + findUnwindTarget(t, &ip, &base, &stack, &continuation); + + transition(t, ip, stack, base, continuation, t->trace); + vmJump(ip, base, stack, t, 0, 0); } @@ -5535,11 +5677,11 @@ finish(MyThread* t, Allocator* allocator, Context* context) ::strcmp (reinterpret_cast (&byteArrayBody(t, className(t, methodClass(t, context->method)), 0)), - "org/eclipse/swt/widgets/Control") == 0 and + "java/lang/System") == 0 and ::strcmp (reinterpret_cast (&byteArrayBody(t, methodName(t, context->method), 0)), - "gtk_motion_notify_event") == 0) + "") == 0) { trap(); } @@ -5669,11 +5811,11 @@ finish(MyThread* t, Allocator* allocator, Context* context) ::strcmp (reinterpret_cast (&byteArrayBody(t, className(t, methodClass(t, context->method)), 0)), - "AllFloats") == 0 and + "java/lang/System") == 0 and ::strcmp (reinterpret_cast (&byteArrayBody(t, methodName(t, context->method), 0)), - "multiplyByFive") == 0) + "") == 0) { trap(); } @@ -6222,17 +6364,20 @@ invokeNative(MyThread* t) if (UNLIKELY(t->exception)) { unwind(t); } else { + uintptr_t* stack = static_cast(t->stack); + if (TailCalls and t->arch->argumentFootprint(parameterFootprint) > t->arch->stackAlignmentInWords()) { - t->stack = static_cast(t->stack) - + (t->arch->argumentFootprint(parameterFootprint) - - t->arch->stackAlignmentInWords()); + stack += t->arch->argumentFootprint(parameterFootprint) + - t->arch->stackAlignmentInWords(); } - t->stack = static_cast(t->stack) - + t->arch->frameReturnAddressSize(); + stack += t->arch->frameReturnAddressSize(); + + transition(t, t->arch->frameIp(t->stack), stack, t->base, t->continuation, + t->trace); return result; } @@ -6405,12 +6550,9 @@ visitArguments(MyThread* t, Heap::Visitor* v, void* stack, object method) void visitStack(MyThread* t, Heap::Visitor* v) { - void* ip = t->ip; + void* ip = t->arch->frameIp(t->stack); void* base = t->base; void* stack = t->stack; - if (ip == 0) { - ip = t->arch->frameIp(stack); - } MyThread::CallTrace* trace = t->trace; object targetMethod = (trace ? trace->targetMethod : 0); @@ -6489,23 +6631,17 @@ callContinuation(MyThread* t, object continuation, object result, { assert(t, t->exception == 0); - t->continuation = continuation; - if (exception) { t->exception = exception; - t->ip = ip; - t->base = base; - t->stack = stack; - - findUnwindTarget(t, &ip, &base, &stack); - - t->ip = 0; + findUnwindTarget(t, &ip, &base, &stack, &continuation); } t->trace->nativeMethod = 0; t->trace->targetMethod = 0; + transition(t, ip, stack, base, continuation, t->trace); + vmJump(ip, base, stack, t, reinterpret_cast(result), 0); } @@ -6688,7 +6824,8 @@ callContinuation(MyThread* t, object continuation, object result, void* ip; void* base; void* stack; - findUnwindTarget(t, &ip, &base, &stack); + object threadContinuation; + findUnwindTarget(t, &ip, &base, &stack, &threadContinuation); switch (action) { case Call: { @@ -6700,7 +6837,7 @@ callContinuation(MyThread* t, object continuation, object result, } break; case Rewind: { - t->continuation = nextContinuation; + transition(t, 0, 0, 0, nextContinuation, t->trace); jumpAndInvoke (t, rewindMethod(t), base, stack, @@ -6709,6 +6846,8 @@ callContinuation(MyThread* t, object continuation, object result, } break; case Throw: { + transition(t, ip, stack, base, threadContinuation, t->trace); + vmJump(ip, base, stack, t, 0, 0); } break; @@ -7002,16 +7141,12 @@ class SegFaultHandler: public System::SignalHandler { if (t and t->state == Thread::ActiveState) { object node = methodForIp(t, *ip); if (node) { - void* oldIp = t->ip; - void* oldBase = t->base; - void* oldStack = t->stack; - // add one to the IP since findLineNumber will subtract one // when we make the trace: - t->ip = static_cast(*ip) + 1; - t->base = *base; - t->stack = static_cast(*stack) - - t->arch->frameReturnAddressSize(); + MyThread::TraceContext context + (t, static_cast(*ip) + 1, + static_cast(*stack) - t->arch->frameReturnAddressSize(), + *base, t->continuation, t->trace); ensure(t, FixedSizeOfNullPointerException + traceSize(t)); @@ -7021,13 +7156,13 @@ class SegFaultHandler: public System::SignalHandler { // printTrace(t, t->exception); - findUnwindTarget(t, ip, base, stack); + object continuation; + findUnwindTarget(t, ip, base, stack, &continuation); - t->ip = oldIp; - t->base = oldBase; - t->stack = oldStack; + transition(t, ip, stack, base, continuation, t->trace); *thread = t; + return true; } } @@ -7042,6 +7177,12 @@ class SegFaultHandler: public System::SignalHandler { Machine* m; }; +bool +isThunk(MyThread* t, void* ip); + +bool +isThunkUnsafeStack(MyThread* t, void* ip); + void boot(MyThread* t, BootImage* image); @@ -7055,17 +7196,33 @@ processor(MyThread* t); class MyProcessor: public Processor { public: + class Thunk { + public: + Thunk(): + start(0), frameSavedOffset(0), length(0) + { } + + Thunk(uint8_t* start, unsigned frameSavedOffset, unsigned length): + start(start), frameSavedOffset(frameSavedOffset), length(length) + { } + + uint8_t* start; + unsigned frameSavedOffset; + unsigned length; + }; + + class ThunkCollection { + public: + Thunk default_; + Thunk defaultVirtual; + Thunk native; + Thunk aioob; + Thunk table; + }; + MyProcessor(System* s, Allocator* allocator, bool useNativeFeatures): s(s), allocator(allocator), - defaultThunk(0), - bootDefaultThunk(0), - defaultVirtualThunk(0), - nativeThunk(0), - bootNativeThunk(0), - aioobThunk(0), - thunkTable(0), - bootThunkTable(0), callTable(0), methodTree(0), methodTreeSentinal(0), @@ -7077,9 +7234,6 @@ class MyProcessor: public Processor { rewindMethod(0), bootImage(0), codeAllocator(s, 0, 0), - thunkSize(0), - bootThunkSize(0), - callTableSize(0), useNativeFeatures(useNativeFeatures) { } @@ -7389,31 +7543,48 @@ class MyProcessor: public Processor { { } virtual void visit(void* ip, void* base, void* stack) { - void* oldIp = target->ip; - void* oldBase = target->base; - void* oldStack = target->stack; + MyThread::TraceContext c(target); if (methodForIp(t, ip)) { - target->ip = ip; - target->base = base; - target->stack = stack; + // we caught the thread in Java code - use the register values + c.ip = ip; + c.base = base; + c.stack = stack; + } else if (target->transition) { + // we caught the thread in native code while in the middle + // of updating the context fields (MyThread::stack, + // MyThread::base, etc.) + static_cast(c) = *(target->transition); + } else if (isVmInvokeUnsafeStack(ip)) { + // we caught the thread in native code just after returning + // from java code, but before clearing MyThread::stack + // (which now contains a garbage value), and the most recent + // Java frame, if any, can be found in + // MyThread::continuation or MyThread::trace + c.ip = 0; + c.base = 0; + c.stack = 0; + } else if (target->stack and (not isThunkUnsafeStack(t, ip))) { + // we caught the thread in a thunk or native code, and the + // saved stack and base pointers indicate the most recent + // Java frame on the stack + c.ip = t->arch->frameIp(target->stack); + c.base = target->base; + c.stack = target->stack; + } else if (isThunk(t, ip)) { + // we caught the thread in a thunk where the stack and base + // registers indicate the most recent Java frame on the + // stack + c.ip = t->arch->frameIp(stack); + c.base = base; + c.stack = stack; } else { - uint8_t* thunkStart = p->thunkTable; - uint8_t* thunkEnd = thunkStart + (p->thunkSize * ThunkCount); - - uint8_t* bootThunkStart = p->bootThunkTable; - uint8_t* bootThunkEnd = bootThunkStart - + (p->bootThunkSize * ThunkCount); - - if ((static_cast(ip) >= thunkStart - and static_cast(ip) < thunkEnd) - or (static_cast(ip) >= bootThunkStart - and static_cast(ip) < bootThunkEnd)) - { - target->ip = t->arch->frameIp(stack); - target->base = base; - target->stack = stack; - } + // we caught the thread in native code, and the most recent + // Java frame, if any, can be found in + // MyThread::continuation or MyThread::trace + c.ip = 0; + c.base = 0; + c.stack = 0; } ensure(t, traceSize(target)); @@ -7421,10 +7592,6 @@ class MyProcessor: public Processor { t->tracing = true; trace = makeTrace(t, target); t->tracing = false; - - target->ip = oldIp; - target->base = oldBase; - target->stack = oldStack; } MyThread* t; @@ -7564,14 +7731,6 @@ class MyProcessor: public Processor { System* s; Allocator* allocator; - uint8_t* defaultThunk; - uint8_t* bootDefaultThunk; - uint8_t* defaultVirtualThunk; - uint8_t* nativeThunk; - uint8_t* bootNativeThunk; - uint8_t* aioobThunk; - uint8_t* thunkTable; - uint8_t* bootThunkTable; object callTable; object methodTree; object methodTreeSentinal; @@ -7584,12 +7743,76 @@ class MyProcessor: public Processor { BootImage* bootImage; SegFaultHandler segFaultHandler; FixedAllocator codeAllocator; - unsigned thunkSize; - unsigned bootThunkSize; + ThunkCollection thunks; + ThunkCollection bootThunks; unsigned callTableSize; bool useNativeFeatures; }; +bool +isThunk(MyThread* t, void* ip) +{ + MyProcessor* p = processor(t); + + uint8_t* thunkStart = p->thunks.default_.start; + uint8_t* thunkEnd = p->thunks.table.start + + (p->thunks.table.length * ThunkCount); + + uint8_t* bootThunkStart = p->bootThunks.default_.start; + uint8_t* bootThunkEnd = p->bootThunks.table.start + + (p->bootThunks.table.length * ThunkCount); + + return (reinterpret_cast(ip) + >= reinterpret_cast(thunkStart) + and reinterpret_cast(ip) + < reinterpret_cast(thunkEnd)) + or (reinterpret_cast(ip) + >= reinterpret_cast(bootThunkStart) + and reinterpret_cast(ip) + < reinterpret_cast(bootThunkEnd)); +} + +bool +isThunkUnsafeStack(MyProcessor::Thunk* thunk, void* ip) +{ + return reinterpret_cast(ip) + >= reinterpret_cast(thunk->start) + and reinterpret_cast(ip) + < reinterpret_cast(thunk->start + thunk->frameSavedOffset); +} + +bool +isThunkUnsafeStack(MyThread* t, void* ip) +{ + if (isThunk(t, ip)) { + MyProcessor* p = processor(t); + + const unsigned NamedThunkCount = 4; + + MyProcessor::Thunk thunks[NamedThunkCount + ThunkCount]; + + thunks[0] = p->thunks.default_; + thunks[1] = p->thunks.defaultVirtual; + thunks[2] = p->thunks.native; + thunks[3] = p->thunks.aioob; + + for (unsigned i = 0; i < ThunkCount; ++i) { + new (thunks + NamedThunkCount + i) MyProcessor::Thunk + (p->thunks.table.start + (i * p->bootThunks.table.length), + p->thunks.table.frameSavedOffset, + p->bootThunks.table.length); + } + + for (unsigned i = 0; i < NamedThunkCount + ThunkCount; ++i) { + if (isThunkUnsafeStack(thunks + i, ip)) { + return true; + } + } + } + + return false; +} + object findCallNode(MyThread* t, void* address) { @@ -7852,15 +8075,24 @@ fixupMethods(Thread* t, BootImage* image, uint8_t* code) } } +MyProcessor::Thunk +thunkToThunk(const BootImage::Thunk& thunk, uint8_t* base) +{ + return MyProcessor::Thunk + (base + thunk.start, thunk.frameSavedOffset, thunk.length); +} + void fixupThunks(MyThread* t, BootImage* image, uint8_t* code) { MyProcessor* p = processor(t); - p->bootDefaultThunk = code + image->defaultThunk; - p->bootNativeThunk = code + image->nativeThunk; - p->bootThunkTable = code + image->thunkTable; - p->bootThunkSize = image->thunkSize; + p->bootThunks.default_ = thunkToThunk(image->thunks.default_, code); + p->bootThunks.defaultVirtual + = thunkToThunk(image->thunks.defaultVirtual, code); + p->bootThunks.native = thunkToThunk(image->thunks.native, code); + p->bootThunks.aioob = thunkToThunk(image->thunks.aioob, code); + p->bootThunks.table = thunkToThunk(image->thunks.table, code); updateCall(t, LongCall, code + image->compileMethodCall, voidPointer(local::compileMethod)); @@ -7967,7 +8199,14 @@ getThunk(MyThread* t, Thunk thunk) MyProcessor* p = processor(t); return reinterpret_cast - (p->thunkTable + (thunk * p->thunkSize)); + (p->thunks.table.start + (thunk * p->thunks.table.length)); +} + +BootImage::Thunk +thunkToThunk(const MyProcessor::Thunk& thunk, uint8_t* base) +{ + return BootImage::Thunk + (thunk.start - base, thunk.frameSavedOffset, thunk.length); } void @@ -7991,6 +8230,8 @@ compileThunks(MyThread* t, Allocator* allocator, MyProcessor* p) a->saveFrame(difference(&(t->stack), t), difference(&(t->base), t)); + p->thunks.default_.frameSavedOffset = a->length(); + Assembler::Register thread(t->arch->thread()); a->pushFrame(1, BytesPerWord, RegisterOperand, &thread); @@ -8003,6 +8244,8 @@ compileThunks(MyThread* t, Allocator* allocator, MyProcessor* p) a->apply(Jump, BytesPerWord, RegisterOperand, &result); a->endBlock(false)->resolve(0, 0); + + p->thunks.default_.length = a->length(); } ThunkContext defaultVirtualContext(t, &zone); @@ -8033,6 +8276,8 @@ compileThunks(MyThread* t, Allocator* allocator, MyProcessor* p) a->saveFrame(difference(&(t->stack), t), difference(&(t->base), t)); + p->thunks.defaultVirtual.frameSavedOffset = a->length(); + Assembler::Register thread(t->arch->thread()); a->pushFrame(1, BytesPerWord, RegisterOperand, &thread); @@ -8045,6 +8290,8 @@ compileThunks(MyThread* t, Allocator* allocator, MyProcessor* p) a->apply(Jump, BytesPerWord, RegisterOperand, &result); a->endBlock(false)->resolve(0, 0); + + p->thunks.defaultVirtual.length = a->length(); } ThunkContext nativeContext(t, &zone); @@ -8053,6 +8300,8 @@ compileThunks(MyThread* t, Allocator* allocator, MyProcessor* p) a->saveFrame(difference(&(t->stack), t), difference(&(t->base), t)); + p->thunks.native.frameSavedOffset = a->length(); + Assembler::Register thread(t->arch->thread()); a->pushFrame(1, BytesPerWord, RegisterOperand, &thread); @@ -8062,6 +8311,8 @@ compileThunks(MyThread* t, Allocator* allocator, MyProcessor* p) a->popFrameAndUpdateStackAndReturn(difference(&(t->stack), t)); a->endBlock(false)->resolve(0, 0); + + p->thunks.native.length = a->length(); } ThunkContext aioobContext(t, &zone); @@ -8070,6 +8321,8 @@ compileThunks(MyThread* t, Allocator* allocator, MyProcessor* p) a->saveFrame(difference(&(t->stack), t), difference(&(t->base), t)); + p->thunks.aioob.frameSavedOffset = a->length(); + Assembler::Register thread(t->arch->thread()); a->pushFrame(1, BytesPerWord, RegisterOperand, &thread); @@ -8077,6 +8330,8 @@ compileThunks(MyThread* t, Allocator* allocator, MyProcessor* p) a->apply(LongCall, BytesPerWord, ConstantOperand, &proc); a->endBlock(false)->resolve(0, 0); + + p->thunks.aioob.length = a->length(); } ThunkContext tableContext(t, &zone); @@ -8085,15 +8340,17 @@ compileThunks(MyThread* t, Allocator* allocator, MyProcessor* p) a->saveFrame(difference(&(t->stack), t), difference(&(t->base), t)); + p->thunks.table.frameSavedOffset = a->length(); + Assembler::Constant proc(&(tableContext.promise)); a->apply(LongJump, BytesPerWord, ConstantOperand, &proc); a->endBlock(false)->resolve(0, 0); - } - p->thunkSize = pad(tableContext.context.assembler->length()); + p->thunks.table.length = a->length(); + } - p->defaultThunk = finish + p->thunks.default_.start = finish (t, allocator, defaultContext.context.assembler, "default"); BootImage* image = p->bootImage; @@ -8104,12 +8361,11 @@ compileThunks(MyThread* t, Allocator* allocator, MyProcessor* p) (reinterpret_cast(voidPointer(compileMethod)), &call); if (image) { - image->defaultThunk = p->defaultThunk - imageBase; image->compileMethodCall = static_cast(call) - imageBase; } } - p->defaultVirtualThunk = finish + p->thunks.defaultVirtual.start = finish (t, allocator, defaultVirtualContext.context.assembler, "defaultVirtual"); { void* call; @@ -8117,13 +8373,12 @@ compileThunks(MyThread* t, Allocator* allocator, MyProcessor* p) (reinterpret_cast(voidPointer(compileVirtualMethod)), &call); if (image) { - image->defaultVirtualThunk = p->defaultVirtualThunk - imageBase; image->compileVirtualMethodCall = static_cast(call) - imageBase; } } - p->nativeThunk = finish + p->thunks.native.start = finish (t, allocator, nativeContext.context.assembler, "native"); { void* call; @@ -8131,12 +8386,11 @@ compileThunks(MyThread* t, Allocator* allocator, MyProcessor* p) (reinterpret_cast(voidPointer(invokeNative)), &call); if (image) { - image->nativeThunk = p->nativeThunk - imageBase; image->invokeNativeCall = static_cast(call) - imageBase; } } - p->aioobThunk = finish + p->thunks.aioob.start = finish (t, allocator, aioobContext.context.assembler, "aioob"); { void* call; @@ -8145,27 +8399,31 @@ compileThunks(MyThread* t, Allocator* allocator, MyProcessor* p) &call); if (image) { - image->aioobThunk = p->aioobThunk - imageBase; image->throwArrayIndexOutOfBoundsCall = static_cast(call) - imageBase; } } - p->thunkTable = static_cast - (allocator->allocate(p->thunkSize * ThunkCount)); + p->thunks.table.start = static_cast + (allocator->allocate(p->thunks.table.length * ThunkCount)); if (image) { - image->thunkTable = p->thunkTable - imageBase; - image->thunkSize = p->thunkSize; + image->thunks.default_ = thunkToThunk(p->thunks.default_, imageBase); + image->thunks.defaultVirtual + = thunkToThunk(p->thunks.defaultVirtual, imageBase); + image->thunks.native = thunkToThunk(p->thunks.native, imageBase); + image->thunks.aioob = thunkToThunk(p->thunks.aioob, imageBase); + image->thunks.table = thunkToThunk(p->thunks.table, imageBase); } - logCompile(t, p->thunkTable, p->thunkSize * ThunkCount, 0, "thunkTable", 0); + logCompile(t, p->thunks.table.start, p->thunks.table.length * ThunkCount, 0, + "thunkTable", 0); - uint8_t* start = p->thunkTable; + uint8_t* start = p->thunks.table.start; #define THUNK(s) \ tableContext.context.assembler->writeTo(start); \ - start += p->thunkSize; \ + start += p->thunks.table.length; \ { void* call; \ tableContext.promise.listener->resolve \ (reinterpret_cast(voidPointer(s)), &call); \ @@ -8212,37 +8470,38 @@ receiveMethod(MyThread* t) uintptr_t defaultThunk(MyThread* t) { - return reinterpret_cast(processor(t)->defaultThunk); + return reinterpret_cast(processor(t)->thunks.default_.start); } uintptr_t bootDefaultThunk(MyThread* t) { - return reinterpret_cast(processor(t)->bootDefaultThunk); + return reinterpret_cast(processor(t)->bootThunks.default_.start); } uintptr_t defaultVirtualThunk(MyThread* t) { - return reinterpret_cast(processor(t)->defaultVirtualThunk); + return reinterpret_cast + (processor(t)->thunks.defaultVirtual.start); } uintptr_t nativeThunk(MyThread* t) { - return reinterpret_cast(processor(t)->nativeThunk); + return reinterpret_cast(processor(t)->thunks.native.start); } uintptr_t bootNativeThunk(MyThread* t) { - return reinterpret_cast(processor(t)->bootNativeThunk); + return reinterpret_cast(processor(t)->bootThunks.native.start); } uintptr_t aioobThunk(MyThread* t) { - return reinterpret_cast(processor(t)->aioobThunk); + return reinterpret_cast(processor(t)->thunks.aioob.start); } bool