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-rw-r--r--src/runtime/syscall_windows.go546
1 files changed, 546 insertions, 0 deletions
diff --git a/src/runtime/syscall_windows.go b/src/runtime/syscall_windows.go
new file mode 100644
index 0000000..ba88e93
--- /dev/null
+++ b/src/runtime/syscall_windows.go
@@ -0,0 +1,546 @@
+// Copyright 2014 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 (
+ "internal/abi"
+ "internal/goarch"
+ "unsafe"
+)
+
+// cbs stores all registered Go callbacks.
+var cbs struct {
+ lock mutex // use cbsLock / cbsUnlock for race instrumentation.
+ ctxt [cb_max]winCallback
+ index map[winCallbackKey]int
+ n int
+}
+
+func cbsLock() {
+ lock(&cbs.lock)
+ // compileCallback is used by goenvs prior to completion of schedinit.
+ // raceacquire involves a racecallback to get the proc, which is not
+ // safe prior to scheduler initialization. Thus avoid instrumentation
+ // until then.
+ if raceenabled && mainStarted {
+ raceacquire(unsafe.Pointer(&cbs.lock))
+ }
+}
+
+func cbsUnlock() {
+ if raceenabled && mainStarted {
+ racerelease(unsafe.Pointer(&cbs.lock))
+ }
+ unlock(&cbs.lock)
+}
+
+// winCallback records information about a registered Go callback.
+type winCallback struct {
+ fn *funcval // Go function
+ retPop uintptr // For 386 cdecl, how many bytes to pop on return
+ abiMap abiDesc
+}
+
+// abiPartKind is the action an abiPart should take.
+type abiPartKind int
+
+const (
+ abiPartBad abiPartKind = iota
+ abiPartStack // Move a value from memory to the stack.
+ abiPartReg // Move a value from memory to a register.
+)
+
+// abiPart encodes a step in translating between calling ABIs.
+type abiPart struct {
+ kind abiPartKind
+ srcStackOffset uintptr
+ dstStackOffset uintptr // used if kind == abiPartStack
+ dstRegister int // used if kind == abiPartReg
+ len uintptr
+}
+
+func (a *abiPart) tryMerge(b abiPart) bool {
+ if a.kind != abiPartStack || b.kind != abiPartStack {
+ return false
+ }
+ if a.srcStackOffset+a.len == b.srcStackOffset && a.dstStackOffset+a.len == b.dstStackOffset {
+ a.len += b.len
+ return true
+ }
+ return false
+}
+
+// abiDesc specifies how to translate from a C frame to a Go
+// frame. This does not specify how to translate back because
+// the result is always a uintptr. If the C ABI is fastcall,
+// this assumes the four fastcall registers were first spilled
+// to the shadow space.
+type abiDesc struct {
+ parts []abiPart
+
+ srcStackSize uintptr // stdcall/fastcall stack space tracking
+ dstStackSize uintptr // Go stack space used
+ dstSpill uintptr // Extra stack space for argument spill slots
+ dstRegisters int // Go ABI int argument registers used
+
+ // retOffset is the offset of the uintptr-sized result in the Go
+ // frame.
+ retOffset uintptr
+}
+
+func (p *abiDesc) assignArg(t *_type) {
+ if t.Size_ > goarch.PtrSize {
+ // We don't support this right now. In
+ // stdcall/cdecl, 64-bit ints and doubles are
+ // passed as two words (little endian); and
+ // structs are pushed on the stack. In
+ // fastcall, arguments larger than the word
+ // size are passed by reference. On arm,
+ // 8-byte aligned arguments round up to the
+ // next even register and can be split across
+ // registers and the stack.
+ panic("compileCallback: argument size is larger than uintptr")
+ }
+ if k := t.Kind_ & kindMask; GOARCH != "386" && (k == kindFloat32 || k == kindFloat64) {
+ // In fastcall, floating-point arguments in
+ // the first four positions are passed in
+ // floating-point registers, which we don't
+ // currently spill. arm passes floating-point
+ // arguments in VFP registers, which we also
+ // don't support.
+ // So basically we only support 386.
+ panic("compileCallback: float arguments not supported")
+ }
+
+ if t.Size_ == 0 {
+ // The Go ABI aligns for zero-sized types.
+ p.dstStackSize = alignUp(p.dstStackSize, uintptr(t.Align_))
+ return
+ }
+
+ // In the C ABI, we're already on a word boundary.
+ // Also, sub-word-sized fastcall register arguments
+ // are stored to the least-significant bytes of the
+ // argument word and all supported Windows
+ // architectures are little endian, so srcStackOffset
+ // is already pointing to the right place for smaller
+ // arguments. The same is true on arm.
+
+ oldParts := p.parts
+ if p.tryRegAssignArg(t, 0) {
+ // Account for spill space.
+ //
+ // TODO(mknyszek): Remove this when we no longer have
+ // caller reserved spill space.
+ p.dstSpill = alignUp(p.dstSpill, uintptr(t.Align_))
+ p.dstSpill += t.Size_
+ } else {
+ // Register assignment failed.
+ // Undo the work and stack assign.
+ p.parts = oldParts
+
+ // The Go ABI aligns arguments.
+ p.dstStackSize = alignUp(p.dstStackSize, uintptr(t.Align_))
+
+ // Copy just the size of the argument. Note that this
+ // could be a small by-value struct, but C and Go
+ // struct layouts are compatible, so we can copy these
+ // directly, too.
+ part := abiPart{
+ kind: abiPartStack,
+ srcStackOffset: p.srcStackSize,
+ dstStackOffset: p.dstStackSize,
+ len: t.Size_,
+ }
+ // Add this step to the adapter.
+ if len(p.parts) == 0 || !p.parts[len(p.parts)-1].tryMerge(part) {
+ p.parts = append(p.parts, part)
+ }
+ // The Go ABI packs arguments.
+ p.dstStackSize += t.Size_
+ }
+
+ // cdecl, stdcall, fastcall, and arm pad arguments to word size.
+ // TODO(rsc): On arm and arm64 do we need to skip the caller's saved LR?
+ p.srcStackSize += goarch.PtrSize
+}
+
+// tryRegAssignArg tries to register-assign a value of type t.
+// If this type is nested in an aggregate type, then offset is the
+// offset of this type within its parent type.
+// Assumes t.size <= goarch.PtrSize and t.size != 0.
+//
+// Returns whether the assignment succeeded.
+func (p *abiDesc) tryRegAssignArg(t *_type, offset uintptr) bool {
+ switch k := t.Kind_ & kindMask; k {
+ case kindBool, kindInt, kindInt8, kindInt16, kindInt32, kindUint, kindUint8, kindUint16, kindUint32, kindUintptr, kindPtr, kindUnsafePointer:
+ // Assign a register for all these types.
+ return p.assignReg(t.Size_, offset)
+ case kindInt64, kindUint64:
+ // Only register-assign if the registers are big enough.
+ if goarch.PtrSize == 8 {
+ return p.assignReg(t.Size_, offset)
+ }
+ case kindArray:
+ at := (*arraytype)(unsafe.Pointer(t))
+ if at.Len == 1 {
+ return p.tryRegAssignArg(at.Elem, offset) // TODO fix when runtime is fully commoned up w/ abi.Type
+ }
+ case kindStruct:
+ st := (*structtype)(unsafe.Pointer(t))
+ for i := range st.Fields {
+ f := &st.Fields[i]
+ if !p.tryRegAssignArg(f.Typ, offset+f.Offset) {
+ return false
+ }
+ }
+ return true
+ }
+ // Pointer-sized types such as maps and channels are currently
+ // not supported.
+ panic("compileCallback: type " + toRType(t).string() + " is currently not supported for use in system callbacks")
+}
+
+// assignReg attempts to assign a single register for an
+// argument with the given size, at the given offset into the
+// value in the C ABI space.
+//
+// Returns whether the assignment was successful.
+func (p *abiDesc) assignReg(size, offset uintptr) bool {
+ if p.dstRegisters >= intArgRegs {
+ return false
+ }
+ p.parts = append(p.parts, abiPart{
+ kind: abiPartReg,
+ srcStackOffset: p.srcStackSize + offset,
+ dstRegister: p.dstRegisters,
+ len: size,
+ })
+ p.dstRegisters++
+ return true
+}
+
+type winCallbackKey struct {
+ fn *funcval
+ cdecl bool
+}
+
+func callbackasm()
+
+// callbackasmAddr returns address of runtime.callbackasm
+// function adjusted by i.
+// On x86 and amd64, runtime.callbackasm is a series of CALL instructions,
+// and we want callback to arrive at
+// correspondent call instruction instead of start of
+// runtime.callbackasm.
+// On ARM, runtime.callbackasm is a series of mov and branch instructions.
+// R12 is loaded with the callback index. Each entry is two instructions,
+// hence 8 bytes.
+func callbackasmAddr(i int) uintptr {
+ var entrySize int
+ switch GOARCH {
+ default:
+ panic("unsupported architecture")
+ case "386", "amd64":
+ entrySize = 5
+ case "arm", "arm64":
+ // On ARM and ARM64, each entry is a MOV instruction
+ // followed by a branch instruction
+ entrySize = 8
+ }
+ return abi.FuncPCABI0(callbackasm) + uintptr(i*entrySize)
+}
+
+const callbackMaxFrame = 64 * goarch.PtrSize
+
+// compileCallback converts a Go function fn into a C function pointer
+// that can be passed to Windows APIs.
+//
+// On 386, if cdecl is true, the returned C function will use the
+// cdecl calling convention; otherwise, it will use stdcall. On amd64,
+// it always uses fastcall. On arm, it always uses the ARM convention.
+//
+//go:linkname compileCallback syscall.compileCallback
+func compileCallback(fn eface, cdecl bool) (code uintptr) {
+ if GOARCH != "386" {
+ // cdecl is only meaningful on 386.
+ cdecl = false
+ }
+
+ if fn._type == nil || (fn._type.Kind_&kindMask) != kindFunc {
+ panic("compileCallback: expected function with one uintptr-sized result")
+ }
+ ft := (*functype)(unsafe.Pointer(fn._type))
+
+ // Check arguments and construct ABI translation.
+ var abiMap abiDesc
+ for _, t := range ft.InSlice() {
+ abiMap.assignArg(t)
+ }
+ // The Go ABI aligns the result to the word size. src is
+ // already aligned.
+ abiMap.dstStackSize = alignUp(abiMap.dstStackSize, goarch.PtrSize)
+ abiMap.retOffset = abiMap.dstStackSize
+
+ if len(ft.OutSlice()) != 1 {
+ panic("compileCallback: expected function with one uintptr-sized result")
+ }
+ if ft.OutSlice()[0].Size_ != goarch.PtrSize {
+ panic("compileCallback: expected function with one uintptr-sized result")
+ }
+ if k := ft.OutSlice()[0].Kind_ & kindMask; k == kindFloat32 || k == kindFloat64 {
+ // In cdecl and stdcall, float results are returned in
+ // ST(0). In fastcall, they're returned in XMM0.
+ // Either way, it's not AX.
+ panic("compileCallback: float results not supported")
+ }
+ if intArgRegs == 0 {
+ // Make room for the uintptr-sized result.
+ // If there are argument registers, the return value will
+ // be passed in the first register.
+ abiMap.dstStackSize += goarch.PtrSize
+ }
+
+ // TODO(mknyszek): Remove dstSpill from this calculation when we no longer have
+ // caller reserved spill space.
+ frameSize := alignUp(abiMap.dstStackSize, goarch.PtrSize)
+ frameSize += abiMap.dstSpill
+ if frameSize > callbackMaxFrame {
+ panic("compileCallback: function argument frame too large")
+ }
+
+ // For cdecl, the callee is responsible for popping its
+ // arguments from the C stack.
+ var retPop uintptr
+ if cdecl {
+ retPop = abiMap.srcStackSize
+ }
+
+ key := winCallbackKey{(*funcval)(fn.data), cdecl}
+
+ cbsLock()
+
+ // Check if this callback is already registered.
+ if n, ok := cbs.index[key]; ok {
+ cbsUnlock()
+ return callbackasmAddr(n)
+ }
+
+ // Register the callback.
+ if cbs.index == nil {
+ cbs.index = make(map[winCallbackKey]int)
+ }
+ n := cbs.n
+ if n >= len(cbs.ctxt) {
+ cbsUnlock()
+ throw("too many callback functions")
+ }
+ c := winCallback{key.fn, retPop, abiMap}
+ cbs.ctxt[n] = c
+ cbs.index[key] = n
+ cbs.n++
+
+ cbsUnlock()
+ return callbackasmAddr(n)
+}
+
+type callbackArgs struct {
+ index uintptr
+ // args points to the argument block.
+ //
+ // For cdecl and stdcall, all arguments are on the stack.
+ //
+ // For fastcall, the trampoline spills register arguments to
+ // the reserved spill slots below the stack arguments,
+ // resulting in a layout equivalent to stdcall.
+ //
+ // For arm, the trampoline stores the register arguments just
+ // below the stack arguments, so again we can treat it as one
+ // big stack arguments frame.
+ args unsafe.Pointer
+ // Below are out-args from callbackWrap
+ result uintptr
+ retPop uintptr // For 386 cdecl, how many bytes to pop on return
+}
+
+// callbackWrap is called by callbackasm to invoke a registered C callback.
+func callbackWrap(a *callbackArgs) {
+ c := cbs.ctxt[a.index]
+ a.retPop = c.retPop
+
+ // Convert from C to Go ABI.
+ var regs abi.RegArgs
+ var frame [callbackMaxFrame]byte
+ goArgs := unsafe.Pointer(&frame)
+ for _, part := range c.abiMap.parts {
+ switch part.kind {
+ case abiPartStack:
+ memmove(add(goArgs, part.dstStackOffset), add(a.args, part.srcStackOffset), part.len)
+ case abiPartReg:
+ goReg := unsafe.Pointer(&regs.Ints[part.dstRegister])
+ memmove(goReg, add(a.args, part.srcStackOffset), part.len)
+ default:
+ panic("bad ABI description")
+ }
+ }
+
+ // TODO(mknyszek): Remove this when we no longer have
+ // caller reserved spill space.
+ frameSize := alignUp(c.abiMap.dstStackSize, goarch.PtrSize)
+ frameSize += c.abiMap.dstSpill
+
+ // Even though this is copying back results, we can pass a nil
+ // type because those results must not require write barriers.
+ reflectcall(nil, unsafe.Pointer(c.fn), noescape(goArgs), uint32(c.abiMap.dstStackSize), uint32(c.abiMap.retOffset), uint32(frameSize), &regs)
+
+ // Extract the result.
+ //
+ // There's always exactly one return value, one pointer in size.
+ // If it's on the stack, then we will have reserved space for it
+ // at the end of the frame, otherwise it was passed in a register.
+ if c.abiMap.dstStackSize != c.abiMap.retOffset {
+ a.result = *(*uintptr)(unsafe.Pointer(&frame[c.abiMap.retOffset]))
+ } else {
+ var zero int
+ // On architectures with no registers, Ints[0] would be a compile error,
+ // so we use a dynamic index. These architectures will never take this
+ // branch, so this won't cause a runtime panic.
+ a.result = regs.Ints[zero]
+ }
+}
+
+const _LOAD_LIBRARY_SEARCH_SYSTEM32 = 0x00000800
+
+//go:linkname syscall_loadsystemlibrary syscall.loadsystemlibrary
+//go:nosplit
+//go:cgo_unsafe_args
+func syscall_loadsystemlibrary(filename *uint16) (handle, err uintptr) {
+ lockOSThread()
+ c := &getg().m.syscall
+ c.fn = getLoadLibraryEx()
+ c.n = 3
+ args := struct {
+ lpFileName *uint16
+ hFile uintptr // always 0
+ flags uint32
+ }{filename, 0, _LOAD_LIBRARY_SEARCH_SYSTEM32}
+ c.args = uintptr(noescape(unsafe.Pointer(&args)))
+
+ cgocall(asmstdcallAddr, unsafe.Pointer(c))
+ KeepAlive(filename)
+ handle = c.r1
+ if handle == 0 {
+ err = c.err
+ }
+ unlockOSThread() // not defer'd after the lockOSThread above to save stack frame size.
+ return
+}
+
+//go:linkname syscall_loadlibrary syscall.loadlibrary
+//go:nosplit
+//go:cgo_unsafe_args
+func syscall_loadlibrary(filename *uint16) (handle, err uintptr) {
+ lockOSThread()
+ defer unlockOSThread()
+ c := &getg().m.syscall
+ c.fn = getLoadLibrary()
+ c.n = 1
+ c.args = uintptr(noescape(unsafe.Pointer(&filename)))
+ cgocall(asmstdcallAddr, unsafe.Pointer(c))
+ KeepAlive(filename)
+ handle = c.r1
+ if handle == 0 {
+ err = c.err
+ }
+ return
+}
+
+//go:linkname syscall_getprocaddress syscall.getprocaddress
+//go:nosplit
+//go:cgo_unsafe_args
+func syscall_getprocaddress(handle uintptr, procname *byte) (outhandle, err uintptr) {
+ lockOSThread()
+ defer unlockOSThread()
+ c := &getg().m.syscall
+ c.fn = getGetProcAddress()
+ c.n = 2
+ c.args = uintptr(noescape(unsafe.Pointer(&handle)))
+ cgocall(asmstdcallAddr, unsafe.Pointer(c))
+ KeepAlive(procname)
+ outhandle = c.r1
+ if outhandle == 0 {
+ err = c.err
+ }
+ return
+}
+
+//go:linkname syscall_Syscall syscall.Syscall
+//go:nosplit
+func syscall_Syscall(fn, nargs, a1, a2, a3 uintptr) (r1, r2, err uintptr) {
+ return syscall_SyscallN(fn, a1, a2, a3)
+}
+
+//go:linkname syscall_Syscall6 syscall.Syscall6
+//go:nosplit
+func syscall_Syscall6(fn, nargs, a1, a2, a3, a4, a5, a6 uintptr) (r1, r2, err uintptr) {
+ return syscall_SyscallN(fn, a1, a2, a3, a4, a5, a6)
+}
+
+//go:linkname syscall_Syscall9 syscall.Syscall9
+//go:nosplit
+func syscall_Syscall9(fn, nargs, a1, a2, a3, a4, a5, a6, a7, a8, a9 uintptr) (r1, r2, err uintptr) {
+ return syscall_SyscallN(fn, a1, a2, a3, a4, a5, a6, a7, a8, a9)
+}
+
+//go:linkname syscall_Syscall12 syscall.Syscall12
+//go:nosplit
+func syscall_Syscall12(fn, nargs, a1, a2, a3, a4, a5, a6, a7, a8, a9, a10, a11, a12 uintptr) (r1, r2, err uintptr) {
+ return syscall_SyscallN(fn, a1, a2, a3, a4, a5, a6, a7, a8, a9, a10, a11, a12)
+}
+
+//go:linkname syscall_Syscall15 syscall.Syscall15
+//go:nosplit
+func syscall_Syscall15(fn, nargs, a1, a2, a3, a4, a5, a6, a7, a8, a9, a10, a11, a12, a13, a14, a15 uintptr) (r1, r2, err uintptr) {
+ return syscall_SyscallN(fn, a1, a2, a3, a4, a5, a6, a7, a8, a9, a10, a11, a12, a13, a14, a15)
+}
+
+//go:linkname syscall_Syscall18 syscall.Syscall18
+//go:nosplit
+func syscall_Syscall18(fn, nargs, a1, a2, a3, a4, a5, a6, a7, a8, a9, a10, a11, a12, a13, a14, a15, a16, a17, a18 uintptr) (r1, r2, err uintptr) {
+ return syscall_SyscallN(fn, a1, a2, a3, a4, a5, a6, a7, a8, a9, a10, a11, a12, a13, a14, a15, a16, a17, a18)
+}
+
+// maxArgs should be divisible by 2, as Windows stack
+// must be kept 16-byte aligned on syscall entry.
+//
+// Although it only permits maximum 42 parameters, it
+// is arguably large enough.
+const maxArgs = 42
+
+//go:linkname syscall_SyscallN syscall.SyscallN
+//go:nosplit
+func syscall_SyscallN(trap uintptr, args ...uintptr) (r1, r2, err uintptr) {
+ nargs := len(args)
+
+ // asmstdcall expects it can access the first 4 arguments
+ // to load them into registers.
+ var tmp [4]uintptr
+ switch {
+ case nargs < 4:
+ copy(tmp[:], args)
+ args = tmp[:]
+ case nargs > maxArgs:
+ panic("runtime: SyscallN has too many arguments")
+ }
+
+ lockOSThread()
+ defer unlockOSThread()
+ c := &getg().m.syscall
+ c.fn = trap
+ c.n = uintptr(nargs)
+ c.args = uintptr(noescape(unsafe.Pointer(&args[0])))
+ cgocall(asmstdcallAddr, unsafe.Pointer(c))
+ return c.r1, c.r2, c.err
+}