1 // Copyright 2014 The Go Authors. All rights reserved. 2 // Use of this source code is governed by a BSD-style 3 // license that can be found in the LICENSE file. 4 5 package runtime 6 7 import ( 8 "unsafe" 9 ) 10 11 type callbacks struct { 12 lock mutex 13 ctxt [cb_max]*wincallbackcontext 14 n int 15 } 16 17 func (c *wincallbackcontext) isCleanstack() bool { 18 return c.cleanstack 19 } 20 21 func (c *wincallbackcontext) setCleanstack(cleanstack bool) { 22 c.cleanstack = cleanstack 23 } 24 25 var ( 26 cbs callbacks 27 cbctxts **wincallbackcontext = &cbs.ctxt[0] // to simplify access to cbs.ctxt in sys_windows_*.s 28 29 callbackasm byte // type isn't really byte, it's code in runtime 30 ) 31 32 // callbackasmAddr returns address of runtime.callbackasm 33 // function adjusted by i. 34 // runtime.callbackasm is just a series of CALL instructions 35 // (each is 5 bytes long), and we want callback to arrive at 36 // correspondent call instruction instead of start of 37 // runtime.callbackasm. 38 func callbackasmAddr(i int) uintptr { 39 return uintptr(add(unsafe.Pointer(&callbackasm), uintptr(i*5))) 40 } 41 42 //go:linkname compileCallback syscall.compileCallback 43 func compileCallback(fn eface, cleanstack bool) (code uintptr) { 44 if fn._type == nil || (fn._type.kind&kindMask) != kindFunc { 45 panic("compileCallback: not a function") 46 } 47 ft := (*functype)(unsafe.Pointer(fn._type)) 48 if ft.out.len != 1 { 49 panic("compileCallback: function must have one output parameter") 50 } 51 uintptrSize := unsafe.Sizeof(uintptr(0)) 52 if t := (**_type)(unsafe.Pointer(ft.out.array)); (*t).size != uintptrSize { 53 panic("compileCallback: output parameter size is wrong") 54 } 55 argsize := uintptr(0) 56 for _, t := range (*[1024](*_type))(unsafe.Pointer(ft.in.array))[:ft.in.len] { 57 if (*t).size > uintptrSize { 58 panic("compileCallback: input parameter size is wrong") 59 } 60 argsize += uintptrSize 61 } 62 63 lock(&cbs.lock) 64 defer unlock(&cbs.lock) 65 66 n := cbs.n 67 for i := 0; i < n; i++ { 68 if cbs.ctxt[i].gobody == fn.data && cbs.ctxt[i].isCleanstack() == cleanstack { 69 return callbackasmAddr(i) 70 } 71 } 72 if n >= cb_max { 73 throw("too many callback functions") 74 } 75 76 c := new(wincallbackcontext) 77 c.gobody = fn.data 78 c.argsize = argsize 79 c.setCleanstack(cleanstack) 80 if cleanstack && argsize != 0 { 81 c.restorestack = argsize 82 } else { 83 c.restorestack = 0 84 } 85 cbs.ctxt[n] = c 86 cbs.n++ 87 88 return callbackasmAddr(n) 89 } 90 91 //go:linkname syscall_loadlibrary syscall.loadlibrary 92 //go:nosplit 93 func syscall_loadlibrary(filename *uint16) (handle, err uintptr) { 94 c := &getg().m.syscall 95 c.fn = getLoadLibrary() 96 c.n = 1 97 c.args = uintptr(noescape(unsafe.Pointer(&filename))) 98 cgocall(asmstdcallAddr, unsafe.Pointer(c)) 99 handle = c.r1 100 if handle == 0 { 101 err = c.err 102 } 103 return 104 } 105 106 //go:linkname syscall_getprocaddress syscall.getprocaddress 107 //go:nosplit 108 func syscall_getprocaddress(handle uintptr, procname *byte) (outhandle, err uintptr) { 109 c := &getg().m.syscall 110 c.fn = getGetProcAddress() 111 c.n = 2 112 c.args = uintptr(noescape(unsafe.Pointer(&handle))) 113 cgocall(asmstdcallAddr, unsafe.Pointer(c)) 114 outhandle = c.r1 115 if outhandle == 0 { 116 err = c.err 117 } 118 return 119 } 120 121 //go:linkname syscall_Syscall syscall.Syscall 122 //go:nosplit 123 func syscall_Syscall(fn, nargs, a1, a2, a3 uintptr) (r1, r2, err uintptr) { 124 c := &getg().m.syscall 125 c.fn = fn 126 c.n = nargs 127 c.args = uintptr(noescape(unsafe.Pointer(&a1))) 128 cgocall(asmstdcallAddr, unsafe.Pointer(c)) 129 return c.r1, c.r2, c.err 130 } 131 132 //go:linkname syscall_Syscall6 syscall.Syscall6 133 //go:nosplit 134 func syscall_Syscall6(fn, nargs, a1, a2, a3, a4, a5, a6 uintptr) (r1, r2, err uintptr) { 135 c := &getg().m.syscall 136 c.fn = fn 137 c.n = nargs 138 c.args = uintptr(noescape(unsafe.Pointer(&a1))) 139 cgocall(asmstdcallAddr, unsafe.Pointer(c)) 140 return c.r1, c.r2, c.err 141 } 142 143 //go:linkname syscall_Syscall9 syscall.Syscall9 144 //go:nosplit 145 func syscall_Syscall9(fn, nargs, a1, a2, a3, a4, a5, a6, a7, a8, a9 uintptr) (r1, r2, err uintptr) { 146 c := &getg().m.syscall 147 c.fn = fn 148 c.n = nargs 149 c.args = uintptr(noescape(unsafe.Pointer(&a1))) 150 cgocall(asmstdcallAddr, unsafe.Pointer(c)) 151 return c.r1, c.r2, c.err 152 } 153 154 //go:linkname syscall_Syscall12 syscall.Syscall12 155 //go:nosplit 156 func syscall_Syscall12(fn, nargs, a1, a2, a3, a4, a5, a6, a7, a8, a9, a10, a11, a12 uintptr) (r1, r2, err uintptr) { 157 c := &getg().m.syscall 158 c.fn = fn 159 c.n = nargs 160 c.args = uintptr(noescape(unsafe.Pointer(&a1))) 161 cgocall(asmstdcallAddr, unsafe.Pointer(c)) 162 return c.r1, c.r2, c.err 163 } 164 165 //go:linkname syscall_Syscall15 syscall.Syscall15 166 //go:nosplit 167 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) { 168 c := &getg().m.syscall 169 c.fn = fn 170 c.n = nargs 171 c.args = uintptr(noescape(unsafe.Pointer(&a1))) 172 cgocall(asmstdcallAddr, unsafe.Pointer(c)) 173 return c.r1, c.r2, c.err 174 } 175
