Initial commit: Go 1.23 release state

src/runtime/os_freebsd.go

@@ -0,0 +1,484 @@
+// 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 (
+	"internal/abi"
+	"internal/goarch"
+	"unsafe"
+)
+
+type mOS struct{}
+
+//go:noescape
+func thr_new(param *thrparam, size int32) int32
+
+//go:noescape
+func sigaltstack(new, old *stackt)
+
+//go:noescape
+func sigprocmask(how int32, new, old *sigset)
+
+//go:noescape
+func setitimer(mode int32, new, old *itimerval)
+
+//go:noescape
+func sysctl(mib *uint32, miblen uint32, out *byte, size *uintptr, dst *byte, ndst uintptr) int32
+
+func raiseproc(sig uint32)
+
+func thr_self() thread
+func thr_kill(tid thread, sig int)
+
+//go:noescape
+func sys_umtx_op(addr *uint32, mode int32, val uint32, uaddr1 uintptr, ut *umtx_time) 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
+
+// From FreeBSD's <sys/sysctl.h>
+const (
+	_CTL_HW      = 6
+	_HW_PAGESIZE = 7
+)
+
+var sigset_all = sigset{[4]uint32{^uint32(0), ^uint32(0), ^uint32(0), ^uint32(0)}}
+
+// Undocumented numbers from FreeBSD's lib/libc/gen/sysctlnametomib.c.
+const (
+	_CTL_QUERY     = 0
+	_CTL_QUERY_MIB = 3
+)
+
+// sysctlnametomib fill mib with dynamically assigned sysctl entries of name,
+// return count of effected mib slots, return 0 on error.
+func sysctlnametomib(name []byte, mib *[_CTL_MAXNAME]uint32) uint32 {
+	oid := [2]uint32{_CTL_QUERY, _CTL_QUERY_MIB}
+	miblen := uintptr(_CTL_MAXNAME)
+	if sysctl(&oid[0], 2, (*byte)(unsafe.Pointer(mib)), &miblen, (*byte)(unsafe.Pointer(&name[0])), (uintptr)(len(name))) < 0 {
+		return 0
+	}
+	miblen /= unsafe.Sizeof(uint32(0))
+	if miblen <= 0 {
+		return 0
+	}
+	return uint32(miblen)
+}
+
+const (
+	_CPU_CURRENT_PID = -1 // Current process ID.
+)
+
+//go:noescape
+func cpuset_getaffinity(level int, which int, id int64, size int, mask *byte) int32
+
+//go:systemstack
+func getncpu() int32 {
+	// Use a large buffer for the CPU mask. We're on the system
+	// stack, so this is fine, and we can't allocate memory for a
+	// dynamically-sized buffer at this point.
+	const maxCPUs = 64 * 1024
+	var mask [maxCPUs / 8]byte
+	var mib [_CTL_MAXNAME]uint32
+
+	// According to FreeBSD's /usr/src/sys/kern/kern_cpuset.c,
+	// cpuset_getaffinity return ERANGE when provided buffer size exceed the limits in kernel.
+	// Querying kern.smp.maxcpus to calculate maximum buffer size.
+	// See https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=200802
+
+	// Variable kern.smp.maxcpus introduced at Dec 23 2003, revision 123766,
+	// with dynamically assigned sysctl entries.
+	miblen := sysctlnametomib([]byte("kern.smp.maxcpus"), &mib)
+	if miblen == 0 {
+		return 1
+	}
+
+	// Query kern.smp.maxcpus.
+	dstsize := uintptr(4)
+	maxcpus := uint32(0)
+	if sysctl(&mib[0], miblen, (*byte)(unsafe.Pointer(&maxcpus)), &dstsize, nil, 0) != 0 {
+		return 1
+	}
+
+	maskSize := int(maxcpus+7) / 8
+	if maskSize < goarch.PtrSize {
+		maskSize = goarch.PtrSize
+	}
+	if maskSize > len(mask) {
+		maskSize = len(mask)
+	}
+
+	if cpuset_getaffinity(_CPU_LEVEL_WHICH, _CPU_WHICH_PID, _CPU_CURRENT_PID,
+		maskSize, (*byte)(unsafe.Pointer(&mask[0]))) != 0 {
+		return 1
+	}
+	n := int32(0)
+	for _, v := range mask[:maskSize] {
+		for v != 0 {
+			n += int32(v & 1)
+			v >>= 1
+		}
+	}
+	if n == 0 {
+		return 1
+	}
+	return n
+}
+
+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
+}
+
+// FreeBSD's umtx_op syscall is effectively the same as Linux's futex, and
+// thus the code is largely similar. See Linux implementation
+// and lock_futex.go for comments.
+
+//go:nosplit
+func futexsleep(addr *uint32, val uint32, ns int64) {
+	systemstack(func() {
+		futexsleep1(addr, val, ns)
+	})
+}
+
+func futexsleep1(addr *uint32, val uint32, ns int64) {
+	var utp *umtx_time
+	if ns >= 0 {
+		var ut umtx_time
+		ut._clockid = _CLOCK_MONOTONIC
+		ut._timeout.setNsec(ns)
+		utp = &ut
+	}
+	ret := sys_umtx_op(addr, _UMTX_OP_WAIT_UINT_PRIVATE, val, unsafe.Sizeof(*utp), utp)
+	if ret >= 0 || ret == -_EINTR || ret == -_ETIMEDOUT {
+		return
+	}
+	print("umtx_wait addr=", addr, " val=", val, " ret=", ret, "\n")
+	*(*int32)(unsafe.Pointer(uintptr(0x1005))) = 0x1005
+}
+
+//go:nosplit
+func futexwakeup(addr *uint32, cnt uint32) {
+	ret := sys_umtx_op(addr, _UMTX_OP_WAKE_PRIVATE, cnt, 0, nil)
+	if ret >= 0 {
+		return
+	}
+
+	systemstack(func() {
+		print("umtx_wake_addr=", addr, " ret=", ret, "\n")
+	})
+}
+
+func thr_start()
+
+// 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, " thr_start=", abi.FuncPCABI0(thr_start), " id=", mp.id, " ostk=", &mp, "\n")
+	}
+
+	param := thrparam{
+		start_func: abi.FuncPCABI0(thr_start),
+		arg:        unsafe.Pointer(mp),
+		stack_base: mp.g0.stack.lo,
+		stack_size: uintptr(stk) - mp.g0.stack.lo,
+		child_tid:  nil, // minit will record tid
+		parent_tid: nil,
+		tls_base:   unsafe.Pointer(&mp.tls[0]),
+		tls_size:   unsafe.Sizeof(mp.tls),
+	}
+
+	var oset sigset
+	sigprocmask(_SIG_SETMASK, &sigset_all, &oset)
+	ret := retryOnEAGAIN(func() int32 {
+		errno := thr_new(&param, int32(unsafe.Sizeof(param)))
+		// thr_new returns negative errno
+		return -errno
+	})
+	sigprocmask(_SIG_SETMASK, &oset, nil)
+	if ret != 0 {
+		print("runtime: failed to create new OS thread (have ", mcount(), " already; errno=", ret, ")\n")
+		throw("newosproc")
+	}
+}
+
+// Version of newosproc that doesn't require a valid G.
+//
+//go:nosplit
+func newosproc0(stacksize uintptr, fn unsafe.Pointer) {
+	stack := sysAlloc(stacksize, &memstats.stacks_sys)
+	if stack == nil {
+		writeErrStr(failallocatestack)
+		exit(1)
+	}
+	// This code "knows" it's being called once from the library
+	// initialization code, and so it's using the static m0 for the
+	// tls and procid (thread) pointers. thr_new() requires the tls
+	// pointers, though the tid pointers can be nil.
+	// However, newosproc0 is currently unreachable because builds
+	// utilizing c-shared/c-archive force external linking.
+	param := thrparam{
+		start_func: uintptr(fn),
+		arg:        nil,
+		stack_base: uintptr(stack), //+stacksize?
+		stack_size: stacksize,
+		child_tid:  nil, // minit will record tid
+		parent_tid: nil,
+		tls_base:   unsafe.Pointer(&m0.tls[0]),
+		tls_size:   unsafe.Sizeof(m0.tls),
+	}
+
+	var oset sigset
+	sigprocmask(_SIG_SETMASK, &sigset_all, &oset)
+	ret := thr_new(&param, int32(unsafe.Sizeof(param)))
+	sigprocmask(_SIG_SETMASK, &oset, nil)
+	if ret < 0 {
+		writeErrStr(failthreadcreate)
+		exit(1)
+	}
+}
+
+// Called to do synchronous initialization of Go code built with
+// -buildmode=c-archive or -buildmode=c-shared.
+// None of the Go runtime is initialized.
+//
+//go:nosplit
+//go:nowritebarrierrec
+func libpreinit() {
+	initsig(true)
+}
+
+func osinit() {
+	ncpu = getncpu()
+	if physPageSize == 0 {
+		physPageSize = getPageSize()
+	}
+}
+
+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() {
+	getg().m.procid = uint64(thr_self())
+
+	// On FreeBSD before about April 2017 there was a bug such
+	// that calling execve from a thread other than the main
+	// thread did not reset the signal stack. That would confuse
+	// minitSignals, which calls minitSignalStack, which checks
+	// whether there is currently a signal stack and uses it if
+	// present. To avoid this confusion, explicitly disable the
+	// signal stack on the main thread when not running in a
+	// library. This can be removed when we are confident that all
+	// FreeBSD users are running a patched kernel. See issue #15658.
+	if gp := getg(); !isarchive && !islibrary && gp.m == &m0 && gp == gp.m.g0 {
+		st := stackt{ss_flags: _SS_DISABLE}
+		sigaltstack(&st, nil)
+	}
+
+	minitSignals()
+}
+
+// Called from dropm to undo the effect of an minit.
+//
+//go:nosplit
+func unminit() {
+	unminitSignals()
+	getg().m.procid = 0
+}
+
+// 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_handler uintptr
+	sa_flags   int32
+	sa_mask    sigset
+}
+
+// See os_freebsd2.go, os_freebsd_amd64.go for setsig function
+
+//go:nosplit
+//go:nowritebarrierrec
+func setsigstack(i uint32) {
+	var sa sigactiont
+	sigaction(i, nil, &sa)
+	if sa.sa_flags&_SA_ONSTACK != 0 {
+		return
+	}
+	sa.sa_flags |= _SA_ONSTACK
+	sigaction(i, &sa, nil)
+}
+
+//go:nosplit
+//go:nowritebarrierrec
+func getsig(i uint32) uintptr {
+	var sa sigactiont
+	sigaction(i, nil, &sa)
+	return sa.sa_handler
+}
+
+// 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
+	_AT_PLATFORM = 15 // string identifying platform
+	_AT_TIMEKEEP = 22 // Pointer to timehands.
+	_AT_HWCAP    = 25 // CPU feature flags
+	_AT_HWCAP2   = 26 // CPU feature flags 2
+)
+
+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 {
+		// _AT_NCPUS from auxv shouldn't be used due to golang.org/issue/15206
+		case _AT_PAGESZ:
+			physPageSize = val
+		case _AT_TIMEKEEP:
+			timekeepSharedPage = (*vdsoTimekeep)(unsafe.Pointer(val))
+		}
+
+		archauxv(tag, val)
+	}
+	return i / 2
+}
+
+// sysSigaction calls the sigaction system call.
+//
+//go:nosplit
+func sysSigaction(sig uint32, new, old *sigactiont) {
+	// Use system stack to avoid split stack overflow on amd64
+	if asmSigaction(uintptr(sig), new, old) != 0 {
+		systemstack(func() {
+			throw("sigaction failed")
+		})
+	}
+}
+
+// asmSigaction is implemented in assembly.
+//
+//go:noescape
+func asmSigaction(sig uintptr, new, old *sigactiont) int32
+
+// raise sends a 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) {
+	thr_kill(thr_self(), int(sig))
+}
+
+func signalM(mp *m, sig int) {
+	thr_kill(thread(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")
+}