1
0
mirror of https://github.com/golang/go synced 2024-11-07 18:06:27 -07:00
go/src/runtime/sys_openbsd2.go

258 lines
7.3 KiB
Go
Raw Normal View History

// Copyright 2020 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.
//go:build (openbsd && amd64) || (openbsd && arm64)
// +build openbsd,amd64 openbsd,arm64
package runtime
import "unsafe"
// This is exported via linkname to assembly in runtime/cgo.
//go:linkname exit
//go:nosplit
//go:cgo_unsafe_args
func exit(code int32) {
libcCall(unsafe.Pointer(funcPC(exit_trampoline)), unsafe.Pointer(&code))
}
func exit_trampoline()
//go:nosplit
//go:cgo_unsafe_args
func getthrid() (tid int32) {
libcCall(unsafe.Pointer(funcPC(getthrid_trampoline)), unsafe.Pointer(&tid))
return
}
func getthrid_trampoline()
//go:nosplit
//go:cgo_unsafe_args
func raiseproc(sig uint32) {
libcCall(unsafe.Pointer(funcPC(raiseproc_trampoline)), unsafe.Pointer(&sig))
}
func raiseproc_trampoline()
//go:nosplit
//go:cgo_unsafe_args
func thrkill(tid int32, sig int) {
libcCall(unsafe.Pointer(funcPC(thrkill_trampoline)), unsafe.Pointer(&tid))
}
func thrkill_trampoline()
// mmap is used to do low-level memory allocation via mmap. Don't allow stack
// splits, since this function (used by sysAlloc) is called in a lot of low-level
// parts of the runtime and callers often assume it won't acquire any locks.
// go:nosplit
func mmap(addr unsafe.Pointer, n uintptr, prot, flags, fd int32, off uint32) (unsafe.Pointer, int) {
args := struct {
addr unsafe.Pointer
n uintptr
prot, flags, fd int32
off uint32
ret1 unsafe.Pointer
ret2 int
}{addr, n, prot, flags, fd, off, nil, 0}
libcCall(unsafe.Pointer(funcPC(mmap_trampoline)), unsafe.Pointer(&args))
return args.ret1, args.ret2
}
func mmap_trampoline()
//go:nosplit
//go:cgo_unsafe_args
func munmap(addr unsafe.Pointer, n uintptr) {
libcCall(unsafe.Pointer(funcPC(munmap_trampoline)), unsafe.Pointer(&addr))
}
func munmap_trampoline()
//go:nosplit
//go:cgo_unsafe_args
func madvise(addr unsafe.Pointer, n uintptr, flags int32) {
libcCall(unsafe.Pointer(funcPC(madvise_trampoline)), unsafe.Pointer(&addr))
}
func madvise_trampoline()
//go:nosplit
//go:cgo_unsafe_args
func open(name *byte, mode, perm int32) (ret int32) {
return libcCall(unsafe.Pointer(funcPC(open_trampoline)), unsafe.Pointer(&name))
}
func open_trampoline()
//go:nosplit
//go:cgo_unsafe_args
func closefd(fd int32) int32 {
return libcCall(unsafe.Pointer(funcPC(close_trampoline)), unsafe.Pointer(&fd))
}
func close_trampoline()
//go:nosplit
//go:cgo_unsafe_args
func read(fd int32, p unsafe.Pointer, n int32) int32 {
return libcCall(unsafe.Pointer(funcPC(read_trampoline)), unsafe.Pointer(&fd))
}
func read_trampoline()
//go:nosplit
//go:cgo_unsafe_args
func write1(fd uintptr, p unsafe.Pointer, n int32) int32 {
return libcCall(unsafe.Pointer(funcPC(write_trampoline)), unsafe.Pointer(&fd))
}
func write_trampoline()
func pipe() (r, w int32, errno int32) {
return pipe2(0)
}
func pipe2(flags int32) (r, w int32, errno int32) {
var p [2]int32
args := struct {
p unsafe.Pointer
flags int32
}{noescape(unsafe.Pointer(&p)), flags}
errno = libcCall(unsafe.Pointer(funcPC(pipe2_trampoline)), unsafe.Pointer(&args))
return p[0], p[1], errno
}
func pipe2_trampoline()
//go:nosplit
//go:cgo_unsafe_args
func setitimer(mode int32, new, old *itimerval) {
libcCall(unsafe.Pointer(funcPC(setitimer_trampoline)), unsafe.Pointer(&mode))
}
func setitimer_trampoline()
//go:nosplit
//go:cgo_unsafe_args
func usleep(usec uint32) {
libcCall(unsafe.Pointer(funcPC(usleep_trampoline)), unsafe.Pointer(&usec))
}
func usleep_trampoline()
runtime: clean up system calls during cgo callback init During a cgocallback, the runtime calls needm to get an m. The calls made during needm cannot themselves assume that there is an m or a g (which is attached to the m). In the old days of making direct system calls, the only thing you had to do for such functions was mark them //go:nosplit, to avoid the use of g in the stack split prologue. But now, on operating systems that make system calls through shared libraries and use code that saves state in the g or m before doing so, it's not safe to assume g exists. In fact, it is not even safe to call getg(), because it might fault deferencing the TLS storage to find the g pointer (that storage may not be initialized yet, at least on Windows, and perhaps on other systems in the future). The specific routines that are problematic are usleep and osyield, which are called during lock contention in lockextra, called from needm. All this is rather subtle and hidden, so in addition to fixing the problem on Windows, this CL makes the fact of not running on a g much clearer by introducing variants usleep_no_g and osyield_no_g whose names should make clear that there is no g. And then we can remove the various sketchy getg() == nil checks in the existing routines. As part of this cleanup, this CL also deletes onosstack on Windows. onosstack is from back when the runtime was implemented in C. It predates systemstack but does essentially the same thing. Instead of having two different copies of this code, we can use systemstack consistently. This way we need not port onosstack to each architecture. This CL is part of a stack adding windows/arm64 support (#36439), intended to land in the Go 1.17 cycle. This CL is, however, not windows/arm64-specific. It is cleanup meant to make the port (and future ports) easier. Change-Id: I3352de1fd0a3c26267c6e209063e6e86abd26187 Reviewed-on: https://go-review.googlesource.com/c/go/+/288793 Trust: Russ Cox <rsc@golang.org> Trust: Jason A. Donenfeld <Jason@zx2c4.com> Reviewed-by: Cherry Zhang <cherryyz@google.com> Reviewed-by: Jason A. Donenfeld <Jason@zx2c4.com>
2021-01-30 05:07:42 -07:00
//go:nosplit
//go:cgo_unsafe_args
func usleep_no_g(usec uint32) {
asmcgocall_no_g(unsafe.Pointer(funcPC(usleep_trampoline)), unsafe.Pointer(&usec))
}
//go:nosplit
//go:cgo_unsafe_args
func sysctl(mib *uint32, miblen uint32, out *byte, size *uintptr, dst *byte, ndst uintptr) int32 {
return libcCall(unsafe.Pointer(funcPC(sysctl_trampoline)), unsafe.Pointer(&mib))
}
func sysctl_trampoline()
//go:nosplit
//go:cgo_unsafe_args
func fcntl(fd, cmd, arg int32) int32 {
return libcCall(unsafe.Pointer(funcPC(fcntl_trampoline)), unsafe.Pointer(&fd))
}
func fcntl_trampoline()
//go:nosplit
func nanotime1() int64 {
var ts timespec
args := struct {
clock_id int32
tp unsafe.Pointer
}{_CLOCK_MONOTONIC, unsafe.Pointer(&ts)}
libcCall(unsafe.Pointer(funcPC(clock_gettime_trampoline)), unsafe.Pointer(&args))
return ts.tv_sec*1e9 + int64(ts.tv_nsec)
}
func clock_gettime_trampoline()
//go:nosplit
func walltime1() (int64, int32) {
var ts timespec
args := struct {
clock_id int32
tp unsafe.Pointer
}{_CLOCK_REALTIME, unsafe.Pointer(&ts)}
libcCall(unsafe.Pointer(funcPC(clock_gettime_trampoline)), unsafe.Pointer(&args))
return ts.tv_sec, int32(ts.tv_nsec)
}
//go:nosplit
//go:cgo_unsafe_args
func kqueue() int32 {
return libcCall(unsafe.Pointer(funcPC(kqueue_trampoline)), nil)
}
func kqueue_trampoline()
//go:nosplit
//go:cgo_unsafe_args
func kevent(kq int32, ch *keventt, nch int32, ev *keventt, nev int32, ts *timespec) int32 {
return libcCall(unsafe.Pointer(funcPC(kevent_trampoline)), unsafe.Pointer(&kq))
}
func kevent_trampoline()
//go:nosplit
//go:cgo_unsafe_args
func sigaction(sig uint32, new *sigactiont, old *sigactiont) {
libcCall(unsafe.Pointer(funcPC(sigaction_trampoline)), unsafe.Pointer(&sig))
}
func sigaction_trampoline()
//go:nosplit
//go:cgo_unsafe_args
func sigprocmask(how uint32, new *sigset, old *sigset) {
libcCall(unsafe.Pointer(funcPC(sigprocmask_trampoline)), unsafe.Pointer(&how))
}
func sigprocmask_trampoline()
//go:nosplit
//go:cgo_unsafe_args
func sigaltstack(new *stackt, old *stackt) {
libcCall(unsafe.Pointer(funcPC(sigaltstack_trampoline)), unsafe.Pointer(&new))
}
func sigaltstack_trampoline()
// Not used on OpenBSD, but must be defined.
func exitThread(wait *uint32) {
}
//go:nosplit
func closeonexec(fd int32) {
fcntl(fd, _F_SETFD, _FD_CLOEXEC)
}
//go:nosplit
func setNonblock(fd int32) {
flags := fcntl(fd, _F_GETFL, 0)
fcntl(fd, _F_SETFL, flags|_O_NONBLOCK)
}
// Tell the linker that the libc_* functions are to be found
// in a system library, with the libc_ prefix missing.
//go:cgo_import_dynamic libc_errno __errno "libc.so"
//go:cgo_import_dynamic libc_exit exit "libc.so"
//go:cgo_import_dynamic libc_getthrid getthrid "libc.so"
//go:cgo_import_dynamic libc_sched_yield sched_yield "libc.so"
//go:cgo_import_dynamic libc_thrkill thrkill "libc.so"
//go:cgo_import_dynamic libc_mmap mmap "libc.so"
//go:cgo_import_dynamic libc_munmap munmap "libc.so"
//go:cgo_import_dynamic libc_madvise madvise "libc.so"
//go:cgo_import_dynamic libc_open open "libc.so"
//go:cgo_import_dynamic libc_close close "libc.so"
//go:cgo_import_dynamic libc_read read "libc.so"
//go:cgo_import_dynamic libc_write write "libc.so"
//go:cgo_import_dynamic libc_pipe2 pipe2 "libc.so"
//go:cgo_import_dynamic libc_clock_gettime clock_gettime "libc.so"
//go:cgo_import_dynamic libc_setitimer setitimer "libc.so"
//go:cgo_import_dynamic libc_usleep usleep "libc.so"
//go:cgo_import_dynamic libc_sysctl sysctl "libc.so"
//go:cgo_import_dynamic libc_fcntl fcntl "libc.so"
//go:cgo_import_dynamic libc_getpid getpid "libc.so"
//go:cgo_import_dynamic libc_kill kill "libc.so"
//go:cgo_import_dynamic libc_kqueue kqueue "libc.so"
//go:cgo_import_dynamic libc_kevent kevent "libc.so"
//go:cgo_import_dynamic libc_sigaction sigaction "libc.so"
//go:cgo_import_dynamic libc_sigaltstack sigaltstack "libc.so"
//go:cgo_import_dynamic _ _ "libc.so"