Fix ETW package to work on 386

The ETW registration handle is defined to be 64-bits on all platforms. The Go
type previously used a uintptr which created problems on 32-bit systems. This
change adds a new wrapper file which receives a 64-bit handle for the functions
defined in it, and correctly passes it to the native ETW functions either as-is
(on 64-bit) or as two 32-bit values (on 32-bit).

This required a minor change in mksyscall_windows.go, to allow multiple syscalls
that map to the same underlying function without causing a duplicate definition
error in the generated file.

pkg/etw/etw.go

@@ -7,9 +7,14 @@
 // set of C macros.
 package etw
 
-//go:generate go run $GOROOT/src/syscall/mksyscall_windows.go -output zsyscall_windows.go etw.go
+//go:generate go run mksyscall_windows.go -output zsyscall_windows.go etw.go
 
 //sys eventRegister(providerId *windows.GUID, callback uintptr, callbackContext uintptr, providerHandle *providerHandle) (win32err error) = advapi32.EventRegister
-//sys eventUnregister(providerHandle providerHandle) (win32err error) = advapi32.EventUnregister
-//sys eventWriteTransfer(providerHandle providerHandle, descriptor *eventDescriptor, activityID *windows.GUID, relatedActivityID *windows.GUID, dataDescriptorCount uint32, dataDescriptors *eventDataDescriptor) (win32err error) = advapi32.EventWriteTransfer
-//sys eventSetInformation(providerHandle providerHandle, class eventInfoClass, information uintptr, length uint32) (win32err error) = advapi32.EventSetInformation
+
+//sys eventUnregister_64(providerHandle providerHandle) (win32err error) = advapi32.EventUnregister
+//sys eventWriteTransfer_64(providerHandle providerHandle, descriptor *eventDescriptor, activityID *windows.GUID, relatedActivityID *windows.GUID, dataDescriptorCount uint32, dataDescriptors *eventDataDescriptor) (win32err error) = advapi32.EventWriteTransfer
+//sys eventSetInformation_64(providerHandle providerHandle, class eventInfoClass, information uintptr, length uint32) (win32err error) = advapi32.EventSetInformation
+
+//sys eventUnregister_32(providerHandle_low uint32, providerHandle_high uint32) (win32err error) = advapi32.EventUnregister
+//sys eventWriteTransfer_32(providerHandle_low uint32, providerHandle_high uint32, descriptor *eventDescriptor, activityID *windows.GUID, relatedActivityID *windows.GUID, dataDescriptorCount uint32, dataDescriptors *eventDataDescriptor) (win32err error) = advapi32.EventWriteTransfer
+//sys eventSetInformation_32(providerHandle_low uint32, providerHandle_high uint32, class eventInfoClass, information uintptr, length uint32) (win32err error) = advapi32.EventSetInformation

pkg/etw/mksyscall_windows.go

@@ -603,6 +603,19 @@ type Source struct {
 	ExternalImports []string
 }
 
+func (src *Source) FuncImports() []*Fn {
+	uniq := make(map[string]bool)
+	r := make([]*Fn, 0)
+	for _, f := range src.Funcs {
+		name := f.DLLFuncName()
+		if _, found := uniq[name]; !found {
+			uniq[name] = true
+			r = append(r, f)
+		}
+	}
+	return r
+}
+
 func (src *Source) Import(pkg string) {
 	src.StdLibImports = append(src.StdLibImports, pkg)
 	sort.Strings(src.StdLibImports)
@@ -865,7 +878,7 @@ var (
 {{define "dlls"}}{{range .DLLs}}	mod{{.}} = {{newlazydll .}}
 {{end}}{{end}}
 
-{{define "funcnames"}}{{range .Funcs}}	proc{{.DLLFuncName}} = mod{{.DLLName}}.NewProc("{{.DLLFuncName}}")
+{{define "funcnames"}}{{range .FuncImports}}	proc{{.DLLFuncName}} = mod{{.DLLName}}.NewProc("{{.DLLFuncName}}")
 {{end}}{{end}}
 
 {{define "helperbody"}}

pkg/etw/newprovider.go

@@ -1,4 +1,4 @@
-// +build amd64 arm64
+// +build amd64 arm64 386
 
 package etw
 

pkg/etw/newprovider_unsupported.go

@@ -1,4 +1,4 @@
-// +build arm 386
+// +build arm
 
 package etw
 

pkg/etw/provider.go

@@ -34,7 +34,7 @@ func (provider *Provider) String() string {
 	return provider.ID.String()
 }
 
-type providerHandle windows.Handle
+type providerHandle uint64
 
 // ProviderState informs the provider EnableCallback what action is being
 // performed.

pkg/etw/wrapper_32.go

@@ -0,0 +1,51 @@
+// +build 386 arm
+
+package etw
+
+import (
+	"golang.org/x/sys/windows"
+)
+
+func low(v providerHandle) uint32 {
+	return uint32(v & 0xffffffff)
+}
+
+func high(v providerHandle) uint32 {
+	return low(v >> 32)
+}
+
+func eventUnregister(providerHandle providerHandle) (win32err error) {
+	return eventUnregister_32(low(providerHandle), high(providerHandle))
+}
+
+func eventWriteTransfer(
+	providerHandle providerHandle,
+	descriptor *eventDescriptor,
+	activityID *windows.GUID,
+	relatedActivityID *windows.GUID,
+	dataDescriptorCount uint32,
+	dataDescriptors *eventDataDescriptor) (win32err error) {
+
+	return eventWriteTransfer_32(
+		low(providerHandle),
+		high(providerHandle),
+		descriptor,
+		activityID,
+		relatedActivityID,
+		dataDescriptorCount,
+		dataDescriptors)
+}
+
+func eventSetInformation(
+	providerHandle providerHandle,
+	class eventInfoClass,
+	information uintptr,
+	length uint32) (win32err error) {
+
+	return eventSetInformation_32(
+		low(providerHandle),
+		high(providerHandle),
+		class,
+		information,
+		length)
+}

pkg/etw/wrapper_64.go

@@ -0,0 +1,41 @@
+// +build amd64 arm64
+
+package etw
+
+import (
+	"golang.org/x/sys/windows"
+)
+
+func eventUnregister(providerHandle providerHandle) (win32err error) {
+	return eventUnregister_64(providerHandle)
+}
+
+func eventWriteTransfer(
+	providerHandle providerHandle,
+	descriptor *eventDescriptor,
+	activityID *windows.GUID,
+	relatedActivityID *windows.GUID,
+	dataDescriptorCount uint32,
+	dataDescriptors *eventDataDescriptor) (win32err error) {
+
+	return eventWriteTransfer_64(
+		providerHandle,
+		descriptor,
+		activityID,
+		relatedActivityID,
+		dataDescriptorCount,
+		dataDescriptors)
+}
+
+func eventSetInformation(
+	providerHandle providerHandle,
+	class eventInfoClass,
+	information uintptr,
+	length uint32) (win32err error) {
+
+	return eventSetInformation_64(
+		providerHandle,
+		class,
+		information,
+		length)
+}

pkg/etw/zsyscall_windows.go

@@ -53,7 +53,7 @@ func eventRegister(providerId *windows.GUID, callback uintptr, callbackContext u
 	return
 }
 
-func eventUnregister(providerHandle providerHandle) (win32err error) {
+func eventUnregister_64(providerHandle providerHandle) (win32err error) {
 	r0, _, _ := syscall.Syscall(procEventUnregister.Addr(), 1, uintptr(providerHandle), 0, 0)
 	if r0 != 0 {
 		win32err = syscall.Errno(r0)
@@ -61,7 +61,7 @@ func eventUnregister(providerHandle providerHandle) (win32err error) {
 	return
 }
 
-func eventWriteTransfer(providerHandle providerHandle, descriptor *eventDescriptor, activityID *windows.GUID, relatedActivityID *windows.GUID, dataDescriptorCount uint32, dataDescriptors *eventDataDescriptor) (win32err error) {
+func eventWriteTransfer_64(providerHandle providerHandle, descriptor *eventDescriptor, activityID *windows.GUID, relatedActivityID *windows.GUID, dataDescriptorCount uint32, dataDescriptors *eventDataDescriptor) (win32err error) {
 	r0, _, _ := syscall.Syscall6(procEventWriteTransfer.Addr(), 6, uintptr(providerHandle), uintptr(unsafe.Pointer(descriptor)), uintptr(unsafe.Pointer(activityID)), uintptr(unsafe.Pointer(relatedActivityID)), uintptr(dataDescriptorCount), uintptr(unsafe.Pointer(dataDescriptors)))
 	if r0 != 0 {
 		win32err = syscall.Errno(r0)
@@ -69,10 +69,34 @@ func eventWriteTransfer(providerHandle providerHandle, descriptor *eventDescript
 	return
 }
 
-func eventSetInformation(providerHandle providerHandle, class eventInfoClass, information uintptr, length uint32) (win32err error) {
+func eventSetInformation_64(providerHandle providerHandle, class eventInfoClass, information uintptr, length uint32) (win32err error) {
 	r0, _, _ := syscall.Syscall6(procEventSetInformation.Addr(), 4, uintptr(providerHandle), uintptr(class), uintptr(information), uintptr(length), 0, 0)
 	if r0 != 0 {
 		win32err = syscall.Errno(r0)
 	}
 	return
 }
+
+func eventUnregister_32(providerHandle_low uint32, providerHandle_high uint32) (win32err error) {
+	r0, _, _ := syscall.Syscall(procEventUnregister.Addr(), 2, uintptr(providerHandle_low), uintptr(providerHandle_high), 0)
+	if r0 != 0 {
+		win32err = syscall.Errno(r0)
+	}
+	return
+}
+
+func eventWriteTransfer_32(providerHandle_low uint32, providerHandle_high uint32, descriptor *eventDescriptor, activityID *windows.GUID, relatedActivityID *windows.GUID, dataDescriptorCount uint32, dataDescriptors *eventDataDescriptor) (win32err error) {
+	r0, _, _ := syscall.Syscall9(procEventWriteTransfer.Addr(), 7, uintptr(providerHandle_low), uintptr(providerHandle_high), uintptr(unsafe.Pointer(descriptor)), uintptr(unsafe.Pointer(activityID)), uintptr(unsafe.Pointer(relatedActivityID)), uintptr(dataDescriptorCount), uintptr(unsafe.Pointer(dataDescriptors)), 0, 0)
+	if r0 != 0 {
+		win32err = syscall.Errno(r0)
+	}
+	return
+}
+
+func eventSetInformation_32(providerHandle_low uint32, providerHandle_high uint32, class eventInfoClass, information uintptr, length uint32) (win32err error) {
+	r0, _, _ := syscall.Syscall6(procEventSetInformation.Addr(), 5, uintptr(providerHandle_low), uintptr(providerHandle_high), uintptr(class), uintptr(information), uintptr(length), 0)
+	if r0 != 0 {
+		win32err = syscall.Errno(r0)
+	}
+	return
+}