Current File : //usr/local/go/src/runtime/signal_windows.go
// Copyright 2011 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
package runtime
import (
"runtime/internal/sys"
"unsafe"
)
func disableWER() {
// do not display Windows Error Reporting dialogue
const (
SEM_FAILCRITICALERRORS = 0x0001
SEM_NOGPFAULTERRORBOX = 0x0002
SEM_NOALIGNMENTFAULTEXCEPT = 0x0004
SEM_NOOPENFILEERRORBOX = 0x8000
)
errormode := uint32(stdcall1(_SetErrorMode, SEM_NOGPFAULTERRORBOX))
stdcall1(_SetErrorMode, uintptr(errormode)|SEM_FAILCRITICALERRORS|SEM_NOGPFAULTERRORBOX|SEM_NOOPENFILEERRORBOX)
}
// in sys_windows_386.s and sys_windows_amd64.s
func exceptiontramp()
func firstcontinuetramp()
func lastcontinuetramp()
func initExceptionHandler() {
stdcall2(_AddVectoredExceptionHandler, 1, funcPC(exceptiontramp))
if _AddVectoredContinueHandler == nil || GOARCH == "386" {
// use SetUnhandledExceptionFilter for windows-386 or
// if VectoredContinueHandler is unavailable.
// note: SetUnhandledExceptionFilter handler won't be called, if debugging.
stdcall1(_SetUnhandledExceptionFilter, funcPC(lastcontinuetramp))
} else {
stdcall2(_AddVectoredContinueHandler, 1, funcPC(firstcontinuetramp))
stdcall2(_AddVectoredContinueHandler, 0, funcPC(lastcontinuetramp))
}
}
// isAbort returns true, if context r describes exception raised
// by calling runtime.abort function.
//
//go:nosplit
func isAbort(r *context) bool {
pc := r.ip()
if GOARCH == "386" || GOARCH == "amd64" || GOARCH == "arm" {
// In the case of an abort, the exception IP is one byte after
// the INT3 (this differs from UNIX OSes). Note that on ARM,
// this means that the exception IP is no longer aligned.
pc--
}
return isAbortPC(pc)
}
// isgoexception reports whether this exception should be translated
// into a Go panic or throw.
//
// It is nosplit to avoid growing the stack in case we're aborting
// because of a stack overflow.
//
//go:nosplit
func isgoexception(info *exceptionrecord, r *context) bool {
// Only handle exception if executing instructions in Go binary
// (not Windows library code).
// TODO(mwhudson): needs to loop to support shared libs
if r.ip() < firstmoduledata.text || firstmoduledata.etext < r.ip() {
return false
}
// Go will only handle some exceptions.
switch info.exceptioncode {
default:
return false
case _EXCEPTION_ACCESS_VIOLATION:
case _EXCEPTION_INT_DIVIDE_BY_ZERO:
case _EXCEPTION_INT_OVERFLOW:
case _EXCEPTION_FLT_DENORMAL_OPERAND:
case _EXCEPTION_FLT_DIVIDE_BY_ZERO:
case _EXCEPTION_FLT_INEXACT_RESULT:
case _EXCEPTION_FLT_OVERFLOW:
case _EXCEPTION_FLT_UNDERFLOW:
case _EXCEPTION_BREAKPOINT:
case _EXCEPTION_ILLEGAL_INSTRUCTION: // breakpoint arrives this way on arm64
}
return true
}
// Called by sigtramp from Windows VEH handler.
// Return value signals whether the exception has been handled (EXCEPTION_CONTINUE_EXECUTION)
// or should be made available to other handlers in the chain (EXCEPTION_CONTINUE_SEARCH).
//
// This is the first entry into Go code for exception handling. This
// is nosplit to avoid growing the stack until we've checked for
// _EXCEPTION_BREAKPOINT, which is raised if we overflow the g0 stack,
//
//go:nosplit
func exceptionhandler(info *exceptionrecord, r *context, gp *g) int32 {
if !isgoexception(info, r) {
return _EXCEPTION_CONTINUE_SEARCH
}
if gp.throwsplit || isAbort(r) {
// We can't safely sigpanic because it may grow the stack.
// Or this is a call to abort.
// Don't go through any more of the Windows handler chain.
// Crash now.
winthrow(info, r, gp)
}
// After this point, it is safe to grow the stack.
// Make it look like a call to the signal func.
// Have to pass arguments out of band since
// augmenting the stack frame would break
// the unwinding code.
gp.sig = info.exceptioncode
gp.sigcode0 = info.exceptioninformation[0]
gp.sigcode1 = info.exceptioninformation[1]
gp.sigpc = r.ip()
// Only push runtime·sigpanic if r.ip() != 0.
// If r.ip() == 0, probably panicked because of a
// call to a nil func. Not pushing that onto sp will
// make the trace look like a call to runtime·sigpanic instead.
// (Otherwise the trace will end at runtime·sigpanic and we
// won't get to see who faulted.)
// Also don't push a sigpanic frame if the faulting PC
// is the entry of asyncPreempt. In this case, we suspended
// the thread right between the fault and the exception handler
// starting to run, and we have pushed an asyncPreempt call.
// The exception is not from asyncPreempt, so not to push a
// sigpanic call to make it look like that. Instead, just
// overwrite the PC. (See issue #35773)
if r.ip() != 0 && r.ip() != funcPC(asyncPreempt) {
sp := unsafe.Pointer(r.sp())
delta := uintptr(sys.StackAlign)
sp = add(sp, -delta)
r.set_sp(uintptr(sp))
if usesLR {
*((*uintptr)(sp)) = r.lr()
r.set_lr(r.ip())
} else {
*((*uintptr)(sp)) = r.ip()
}
}
r.set_ip(funcPC(sigpanic0))
return _EXCEPTION_CONTINUE_EXECUTION
}
// It seems Windows searches ContinueHandler's list even
// if ExceptionHandler returns EXCEPTION_CONTINUE_EXECUTION.
// firstcontinuehandler will stop that search,
// if exceptionhandler did the same earlier.
//
// It is nosplit for the same reason as exceptionhandler.
//
//go:nosplit
func firstcontinuehandler(info *exceptionrecord, r *context, gp *g) int32 {
if !isgoexception(info, r) {
return _EXCEPTION_CONTINUE_SEARCH
}
return _EXCEPTION_CONTINUE_EXECUTION
}
var testingWER bool
// lastcontinuehandler is reached, because runtime cannot handle
// current exception. lastcontinuehandler will print crash info and exit.
//
// It is nosplit for the same reason as exceptionhandler.
//
//go:nosplit
func lastcontinuehandler(info *exceptionrecord, r *context, gp *g) int32 {
if islibrary || isarchive {
// Go DLL/archive has been loaded in a non-go program.
// If the exception does not originate from go, the go runtime
// should not take responsibility of crashing the process.
return _EXCEPTION_CONTINUE_SEARCH
}
if testingWER {
return _EXCEPTION_CONTINUE_SEARCH
}
// VEH is called before SEH, but arm64 MSVC DLLs use SEH to trap
// illegal instructions during runtime initialization to determine
// CPU features, so if we make it to the last handler and we're
// arm64 and it's an illegal instruction and this is coming from
// non-Go code, then assume it's this runtime probing happen, and
// pass that onward to SEH.
if GOARCH == "arm64" && info.exceptioncode == _EXCEPTION_ILLEGAL_INSTRUCTION &&
(r.ip() < firstmoduledata.text || firstmoduledata.etext < r.ip()) {
return _EXCEPTION_CONTINUE_SEARCH
}
winthrow(info, r, gp)
return 0 // not reached
}
//go:nosplit
func winthrow(info *exceptionrecord, r *context, gp *g) {
_g_ := getg()
if panicking != 0 { // traceback already printed
exit(2)
}
panicking = 1
// In case we're handling a g0 stack overflow, blow away the
// g0 stack bounds so we have room to print the traceback. If
// this somehow overflows the stack, the OS will trap it.
_g_.stack.lo = 0
_g_.stackguard0 = _g_.stack.lo + _StackGuard
_g_.stackguard1 = _g_.stackguard0
print("Exception ", hex(info.exceptioncode), " ", hex(info.exceptioninformation[0]), " ", hex(info.exceptioninformation[1]), " ", hex(r.ip()), "\n")
print("PC=", hex(r.ip()), "\n")
if _g_.m.lockedg != 0 && _g_.m.ncgo > 0 && gp == _g_.m.g0 {
if iscgo {
print("signal arrived during external code execution\n")
}
gp = _g_.m.lockedg.ptr()
}
print("\n")
_g_.m.throwing = 1
_g_.m.caughtsig.set(gp)
level, _, docrash := gotraceback()
if level > 0 {
tracebacktrap(r.ip(), r.sp(), r.lr(), gp)
tracebackothers(gp)
dumpregs(r)
}
if docrash {
crash()
}
exit(2)
}
func sigpanic() {
g := getg()
if !canpanic(g) {
throw("unexpected signal during runtime execution")
}
switch g.sig {
case _EXCEPTION_ACCESS_VIOLATION:
if g.sigcode1 < 0x1000 {
panicmem()
}
if g.paniconfault {
panicmemAddr(g.sigcode1)
}
print("unexpected fault address ", hex(g.sigcode1), "\n")
throw("fault")
case _EXCEPTION_INT_DIVIDE_BY_ZERO:
panicdivide()
case _EXCEPTION_INT_OVERFLOW:
panicoverflow()
case _EXCEPTION_FLT_DENORMAL_OPERAND,
_EXCEPTION_FLT_DIVIDE_BY_ZERO,
_EXCEPTION_FLT_INEXACT_RESULT,
_EXCEPTION_FLT_OVERFLOW,
_EXCEPTION_FLT_UNDERFLOW:
panicfloat()
}
throw("fault")
}
var (
badsignalmsg [100]byte
badsignallen int32
)
func setBadSignalMsg() {
const msg = "runtime: signal received on thread not created by Go.\n"
for i, c := range msg {
badsignalmsg[i] = byte(c)
badsignallen++
}
}
// Following are not implemented.
func initsig(preinit bool) {
}
func sigenable(sig uint32) {
}
func sigdisable(sig uint32) {
}
func sigignore(sig uint32) {
}
func badsignal2()
func raisebadsignal(sig uint32) {
badsignal2()
}
func signame(sig uint32) string {
return ""
}
//go:nosplit
func crash() {
// TODO: This routine should do whatever is needed
// to make the Windows program abort/crash as it
// would if Go was not intercepting signals.
// On Unix the routine would remove the custom signal
// handler and then raise a signal (like SIGABRT).
// Something like that should happen here.
// It's okay to leave this empty for now: if crash returns
// the ordinary exit-after-panic happens.
}
// gsignalStack is unused on Windows.
type gsignalStack struct{}
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