Initial commit: Go 1.23 release state

src/runtime/os_netbsd.go

@@ -0,0 +1,452 @@
+// 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"
+	"internal/runtime/atomic"
+	"unsafe"
+)
+
+const (
+	_SS_DISABLE  = 4
+	_SIG_BLOCK   = 1
+	_SIG_UNBLOCK = 2
+	_SIG_SETMASK = 3
+	_NSIG        = 33
+	_SI_USER     = 0
+
+	// From NetBSD's <sys/ucontext.h>
+	_UC_SIGMASK = 0x01
+	_UC_CPU     = 0x04
+
+	// From <sys/lwp.h>
+	_LWP_DETACHED = 0x00000040
+)
+
+type mOS struct {
+	waitsemacount uint32
+}
+
+//go:noescape
+func setitimer(mode int32, new, old *itimerval)
+
+//go:noescape
+func sigaction(sig uint32, new, old *sigactiont)
+
+//go:noescape
+func sigaltstack(new, old *stackt)
+
+//go:noescape
+func sigprocmask(how int32, new, old *sigset)
+
+//go:noescape
+func sysctl(mib *uint32, miblen uint32, out *byte, size *uintptr, dst *byte, ndst uintptr) int32
+
+func lwp_tramp()
+
+func raiseproc(sig uint32)
+
+func lwp_kill(tid int32, sig int)
+
+//go:noescape
+func getcontext(ctxt unsafe.Pointer)
+
+//go:noescape
+func lwp_create(ctxt unsafe.Pointer, flags uintptr, lwpid unsafe.Pointer) int32
+
+//go:noescape
+func lwp_park(clockid, flags int32, ts *timespec, unpark int32, hint, unparkhint unsafe.Pointer) int32
+
+//go:noescape
+func lwp_unpark(lwp int32, hint unsafe.Pointer) int32
+
+func lwp_self() int32
+
+func osyield()
+
+//go:nosplit
+func osyield_no_g() {
+	osyield()
+}
+
+func kqueue() int32
+
+//go:noescape
+func kevent(kq int32, ch *keventt, nch int32, ev *keventt, nev int32, ts *timespec) int32
+
+func pipe2(flags int32) (r, w int32, errno int32)
+func fcntl(fd, cmd, arg int32) (ret int32, errno int32)
+
+func issetugid() int32
+
+const (
+	_ESRCH     = 3
+	_ETIMEDOUT = 60
+
+	// From NetBSD's <sys/time.h>
+	_CLOCK_REALTIME  = 0
+	_CLOCK_VIRTUAL   = 1
+	_CLOCK_PROF      = 2
+	_CLOCK_MONOTONIC = 3
+
+	_TIMER_RELTIME = 0
+	_TIMER_ABSTIME = 1
+)
+
+var sigset_all = sigset{[4]uint32{^uint32(0), ^uint32(0), ^uint32(0), ^uint32(0)}}
+
+// From NetBSD's <sys/sysctl.h>
+const (
+	_CTL_KERN   = 1
+	_KERN_OSREV = 3
+
+	_CTL_HW        = 6
+	_HW_NCPU       = 3
+	_HW_PAGESIZE   = 7
+	_HW_NCPUONLINE = 16
+)
+
+func sysctlInt(mib []uint32) (int32, bool) {
+	var out int32
+	nout := unsafe.Sizeof(out)
+	ret := sysctl(&mib[0], uint32(len(mib)), (*byte)(unsafe.Pointer(&out)), &nout, nil, 0)
+	if ret < 0 {
+		return 0, false
+	}
+	return out, true
+}
+
+func getncpu() int32 {
+	if n, ok := sysctlInt([]uint32{_CTL_HW, _HW_NCPUONLINE}); ok {
+		return int32(n)
+	}
+	if n, ok := sysctlInt([]uint32{_CTL_HW, _HW_NCPU}); ok {
+		return int32(n)
+	}
+	return 1
+}
+
+func getPageSize() uintptr {
+	mib := [2]uint32{_CTL_HW, _HW_PAGESIZE}
+	out := uint32(0)
+	nout := unsafe.Sizeof(out)
+	ret := sysctl(&mib[0], 2, (*byte)(unsafe.Pointer(&out)), &nout, nil, 0)
+	if ret >= 0 {
+		return uintptr(out)
+	}
+	return 0
+}
+
+func getOSRev() int {
+	if osrev, ok := sysctlInt([]uint32{_CTL_KERN, _KERN_OSREV}); ok {
+		return int(osrev)
+	}
+	return 0
+}
+
+//go:nosplit
+func semacreate(mp *m) {
+}
+
+//go:nosplit
+func semasleep(ns int64) int32 {
+	gp := getg()
+	var deadline int64
+	if ns >= 0 {
+		deadline = nanotime() + ns
+	}
+
+	for {
+		v := atomic.Load(&gp.m.waitsemacount)
+		if v > 0 {
+			if atomic.Cas(&gp.m.waitsemacount, v, v-1) {
+				return 0 // semaphore acquired
+			}
+			continue
+		}
+
+		// Sleep until unparked by semawakeup or timeout.
+		var tsp *timespec
+		var ts timespec
+		if ns >= 0 {
+			wait := deadline - nanotime()
+			if wait <= 0 {
+				return -1
+			}
+			ts.setNsec(wait)
+			tsp = &ts
+		}
+		ret := lwp_park(_CLOCK_MONOTONIC, _TIMER_RELTIME, tsp, 0, unsafe.Pointer(&gp.m.waitsemacount), nil)
+		if ret == _ETIMEDOUT {
+			return -1
+		}
+	}
+}
+
+//go:nosplit
+func semawakeup(mp *m) {
+	atomic.Xadd(&mp.waitsemacount, 1)
+	// From NetBSD's _lwp_unpark(2) manual:
+	// "If the target LWP is not currently waiting, it will return
+	// immediately upon the next call to _lwp_park()."
+	ret := lwp_unpark(int32(mp.procid), unsafe.Pointer(&mp.waitsemacount))
+	if ret != 0 && ret != _ESRCH {
+		// semawakeup can be called on signal stack.
+		systemstack(func() {
+			print("thrwakeup addr=", &mp.waitsemacount, " sem=", mp.waitsemacount, " ret=", ret, "\n")
+		})
+	}
+}
+
+// May run with m.p==nil, so write barriers are not allowed.
+//
+//go:nowritebarrier
+func newosproc(mp *m) {
+	stk := unsafe.Pointer(mp.g0.stack.hi)
+	if false {
+		print("newosproc stk=", stk, " m=", mp, " g=", mp.g0, " id=", mp.id, " ostk=", &mp, "\n")
+	}
+
+	var uc ucontextt
+	getcontext(unsafe.Pointer(&uc))
+
+	// _UC_SIGMASK does not seem to work here.
+	// It would be nice if _UC_SIGMASK and _UC_STACK
+	// worked so that we could do all the work setting
+	// the sigmask and the stack here, instead of setting
+	// the mask here and the stack in netbsdMstart.
+	// For now do the blocking manually.
+	uc.uc_flags = _UC_SIGMASK | _UC_CPU
+	uc.uc_link = nil
+	uc.uc_sigmask = sigset_all
+
+	var oset sigset
+	sigprocmask(_SIG_SETMASK, &sigset_all, &oset)
+
+	lwp_mcontext_init(&uc.uc_mcontext, stk, mp, mp.g0, abi.FuncPCABI0(netbsdMstart))
+
+	ret := retryOnEAGAIN(func() int32 {
+		errno := lwp_create(unsafe.Pointer(&uc), _LWP_DETACHED, unsafe.Pointer(&mp.procid))
+		// lwp_create returns negative errno
+		return -errno
+	})
+	sigprocmask(_SIG_SETMASK, &oset, nil)
+	if ret != 0 {
+		print("runtime: failed to create new OS thread (have ", mcount()-1, " already; errno=", ret, ")\n")
+		if ret == _EAGAIN {
+			println("runtime: may need to increase max user processes (ulimit -p)")
+		}
+		throw("runtime.newosproc")
+	}
+}
+
+// mstart is the entry-point for new Ms.
+// It is written in assembly, uses ABI0, is marked TOPFRAME, and calls netbsdMstart0.
+func netbsdMstart()
+
+// netbsdMstart0 is the function call that starts executing a newly
+// created thread. On NetBSD, a new thread inherits the signal stack
+// of the creating thread. That confuses minit, so we remove that
+// signal stack here before calling the regular mstart. It's a bit
+// baroque to remove a signal stack here only to add one in minit, but
+// it's a simple change that keeps NetBSD working like other OS's.
+// At this point all signals are blocked, so there is no race.
+//
+//go:nosplit
+func netbsdMstart0() {
+	st := stackt{ss_flags: _SS_DISABLE}
+	sigaltstack(&st, nil)
+	mstart0()
+}
+
+func osinit() {
+	ncpu = getncpu()
+	if physPageSize == 0 {
+		physPageSize = getPageSize()
+	}
+	needSysmonWorkaround = getOSRev() < 902000000 // NetBSD 9.2
+}
+
+var urandom_dev = []byte("/dev/urandom\x00")
+
+//go:nosplit
+func readRandom(r []byte) int {
+	fd := open(&urandom_dev[0], 0 /* O_RDONLY */, 0)
+	n := read(fd, unsafe.Pointer(&r[0]), int32(len(r)))
+	closefd(fd)
+	return int(n)
+}
+
+func goenvs() {
+	goenvs_unix()
+}
+
+// Called to initialize a new m (including the bootstrap m).
+// Called on the parent thread (main thread in case of bootstrap), can allocate memory.
+func mpreinit(mp *m) {
+	mp.gsignal = malg(32 * 1024)
+	mp.gsignal.m = mp
+}
+
+// Called to initialize a new m (including the bootstrap m).
+// Called on the new thread, cannot allocate memory.
+func minit() {
+	gp := getg()
+	gp.m.procid = uint64(lwp_self())
+
+	// On NetBSD a thread created by pthread_create inherits the
+	// signal stack of the creating thread. We always create a
+	// new signal stack here, to avoid having two Go threads using
+	// the same signal stack. This breaks the case of a thread
+	// created in C that calls sigaltstack and then calls a Go
+	// function, because we will lose track of the C code's
+	// sigaltstack, but it's the best we can do.
+	signalstack(&gp.m.gsignal.stack)
+	gp.m.newSigstack = true
+
+	minitSignalMask()
+}
+
+// Called from dropm to undo the effect of an minit.
+//
+//go:nosplit
+func unminit() {
+	unminitSignals()
+	// Don't clear procid, it is used by locking (semawake), and locking
+	// must continue working after unminit.
+}
+
+// Called from exitm, but not from drop, to undo the effect of thread-owned
+// resources in minit, semacreate, or elsewhere. Do not take locks after calling this.
+func mdestroy(mp *m) {
+}
+
+func sigtramp()
+
+type sigactiont struct {
+	sa_sigaction uintptr
+	sa_mask      sigset
+	sa_flags     int32
+}
+
+//go:nosplit
+//go:nowritebarrierrec
+func setsig(i uint32, fn uintptr) {
+	var sa sigactiont
+	sa.sa_flags = _SA_SIGINFO | _SA_ONSTACK | _SA_RESTART
+	sa.sa_mask = sigset_all
+	if fn == abi.FuncPCABIInternal(sighandler) { // abi.FuncPCABIInternal(sighandler) matches the callers in signal_unix.go
+		fn = abi.FuncPCABI0(sigtramp)
+	}
+	sa.sa_sigaction = fn
+	sigaction(i, &sa, nil)
+}
+
+//go:nosplit
+//go:nowritebarrierrec
+func setsigstack(i uint32) {
+	throw("setsigstack")
+}
+
+//go:nosplit
+//go:nowritebarrierrec
+func getsig(i uint32) uintptr {
+	var sa sigactiont
+	sigaction(i, nil, &sa)
+	return sa.sa_sigaction
+}
+
+// setSignalstackSP sets the ss_sp field of a stackt.
+//
+//go:nosplit
+func setSignalstackSP(s *stackt, sp uintptr) {
+	s.ss_sp = sp
+}
+
+//go:nosplit
+//go:nowritebarrierrec
+func sigaddset(mask *sigset, i int) {
+	mask.__bits[(i-1)/32] |= 1 << ((uint32(i) - 1) & 31)
+}
+
+func sigdelset(mask *sigset, i int) {
+	mask.__bits[(i-1)/32] &^= 1 << ((uint32(i) - 1) & 31)
+}
+
+//go:nosplit
+func (c *sigctxt) fixsigcode(sig uint32) {
+}
+
+func setProcessCPUProfiler(hz int32) {
+	setProcessCPUProfilerTimer(hz)
+}
+
+func setThreadCPUProfiler(hz int32) {
+	setThreadCPUProfilerHz(hz)
+}
+
+//go:nosplit
+func validSIGPROF(mp *m, c *sigctxt) bool {
+	return true
+}
+
+func sysargs(argc int32, argv **byte) {
+	n := argc + 1
+
+	// skip over argv, envp to get to auxv
+	for argv_index(argv, n) != nil {
+		n++
+	}
+
+	// skip NULL separator
+	n++
+
+	// now argv+n is auxv
+	auxvp := (*[1 << 28]uintptr)(add(unsafe.Pointer(argv), uintptr(n)*goarch.PtrSize))
+	pairs := sysauxv(auxvp[:])
+	auxv = auxvp[: pairs*2 : pairs*2]
+}
+
+const (
+	_AT_NULL   = 0 // Terminates the vector
+	_AT_PAGESZ = 6 // Page size in bytes
+)
+
+func sysauxv(auxv []uintptr) (pairs int) {
+	var i int
+	for i = 0; auxv[i] != _AT_NULL; i += 2 {
+		tag, val := auxv[i], auxv[i+1]
+		switch tag {
+		case _AT_PAGESZ:
+			physPageSize = val
+		}
+	}
+	return i / 2
+}
+
+// raise sends signal to the calling thread.
+//
+// It must be nosplit because it is used by the signal handler before
+// it definitely has a Go stack.
+//
+//go:nosplit
+func raise(sig uint32) {
+	lwp_kill(lwp_self(), int(sig))
+}
+
+func signalM(mp *m, sig int) {
+	lwp_kill(int32(mp.procid), sig)
+}
+
+// sigPerThreadSyscall is only used on linux, so we assign a bogus signal
+// number.
+const sigPerThreadSyscall = 1 << 31
+
+//go:nosplit
+func runPerThreadSyscall() {
+	throw("runPerThreadSyscall only valid on linux")
+}