github.com/x04/go/src@v0.0.0-20200202162449-3d481ceb3525/runtime/os3_solaris.go (about)

     1  // Copyright 2011 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  	"github.com/x04/go/src/runtime/internal/sys"
     9  	"github.com/x04/go/src/unsafe"
    10  )
    11  
    12  //go:cgo_export_dynamic runtime.end _end
    13  //go:cgo_export_dynamic runtime.etext _etext
    14  //go:cgo_export_dynamic runtime.edata _edata
    15  
    16  //go:cgo_import_dynamic libc____errno ___errno "libc.so"
    17  //go:cgo_import_dynamic libc_clock_gettime clock_gettime "libc.so"
    18  //go:cgo_import_dynamic libc_exit exit "libc.so"
    19  //go:cgo_import_dynamic libc_getcontext getcontext "libc.so"
    20  //go:cgo_import_dynamic libc_kill kill "libc.so"
    21  //go:cgo_import_dynamic libc_madvise madvise "libc.so"
    22  //go:cgo_import_dynamic libc_malloc malloc "libc.so"
    23  //go:cgo_import_dynamic libc_mmap mmap "libc.so"
    24  //go:cgo_import_dynamic libc_munmap munmap "libc.so"
    25  //go:cgo_import_dynamic libc_open open "libc.so"
    26  //go:cgo_import_dynamic libc_pthread_attr_destroy pthread_attr_destroy "libc.so"
    27  //go:cgo_import_dynamic libc_pthread_attr_getstack pthread_attr_getstack "libc.so"
    28  //go:cgo_import_dynamic libc_pthread_attr_init pthread_attr_init "libc.so"
    29  //go:cgo_import_dynamic libc_pthread_attr_setdetachstate pthread_attr_setdetachstate "libc.so"
    30  //go:cgo_import_dynamic libc_pthread_attr_setstack pthread_attr_setstack "libc.so"
    31  //go:cgo_import_dynamic libc_pthread_create pthread_create "libc.so"
    32  //go:cgo_import_dynamic libc_pthread_self pthread_self "libc.so"
    33  //go:cgo_import_dynamic libc_pthread_kill pthread_kill "libc.so"
    34  //go:cgo_import_dynamic libc_raise raise "libc.so"
    35  //go:cgo_import_dynamic libc_read read "libc.so"
    36  //go:cgo_import_dynamic libc_select select "libc.so"
    37  //go:cgo_import_dynamic libc_sched_yield sched_yield "libc.so"
    38  //go:cgo_import_dynamic libc_sem_init sem_init "libc.so"
    39  //go:cgo_import_dynamic libc_sem_post sem_post "libc.so"
    40  //go:cgo_import_dynamic libc_sem_reltimedwait_np sem_reltimedwait_np "libc.so"
    41  //go:cgo_import_dynamic libc_sem_wait sem_wait "libc.so"
    42  //go:cgo_import_dynamic libc_setitimer setitimer "libc.so"
    43  //go:cgo_import_dynamic libc_sigaction sigaction "libc.so"
    44  //go:cgo_import_dynamic libc_sigaltstack sigaltstack "libc.so"
    45  //go:cgo_import_dynamic libc_sigprocmask sigprocmask "libc.so"
    46  //go:cgo_import_dynamic libc_sysconf sysconf "libc.so"
    47  //go:cgo_import_dynamic libc_usleep usleep "libc.so"
    48  //go:cgo_import_dynamic libc_write write "libc.so"
    49  //go:cgo_import_dynamic libc_pipe pipe "libc.so"
    50  //go:cgo_import_dynamic libc_pipe2 pipe2 "libc.so"
    51  
    52  //go:linkname libc____errno libc____errno
    53  //go:linkname libc_clock_gettime libc_clock_gettime
    54  //go:linkname libc_exit libc_exit
    55  //go:linkname libc_getcontext libc_getcontext
    56  //go:linkname libc_kill libc_kill
    57  //go:linkname libc_madvise libc_madvise
    58  //go:linkname libc_malloc libc_malloc
    59  //go:linkname libc_mmap libc_mmap
    60  //go:linkname libc_munmap libc_munmap
    61  //go:linkname libc_open libc_open
    62  //go:linkname libc_pthread_attr_destroy libc_pthread_attr_destroy
    63  //go:linkname libc_pthread_attr_getstack libc_pthread_attr_getstack
    64  //go:linkname libc_pthread_attr_init libc_pthread_attr_init
    65  //go:linkname libc_pthread_attr_setdetachstate libc_pthread_attr_setdetachstate
    66  //go:linkname libc_pthread_attr_setstack libc_pthread_attr_setstack
    67  //go:linkname libc_pthread_create libc_pthread_create
    68  //go:linkname libc_pthread_self libc_pthread_self
    69  //go:linkname libc_pthread_kill libc_pthread_kill
    70  //go:linkname libc_raise libc_raise
    71  //go:linkname libc_read libc_read
    72  //go:linkname libc_select libc_select
    73  //go:linkname libc_sched_yield libc_sched_yield
    74  //go:linkname libc_sem_init libc_sem_init
    75  //go:linkname libc_sem_post libc_sem_post
    76  //go:linkname libc_sem_reltimedwait_np libc_sem_reltimedwait_np
    77  //go:linkname libc_sem_wait libc_sem_wait
    78  //go:linkname libc_setitimer libc_setitimer
    79  //go:linkname libc_sigaction libc_sigaction
    80  //go:linkname libc_sigaltstack libc_sigaltstack
    81  //go:linkname libc_sigprocmask libc_sigprocmask
    82  //go:linkname libc_sysconf libc_sysconf
    83  //go:linkname libc_usleep libc_usleep
    84  //go:linkname libc_write libc_write
    85  //go:linkname libc_pipe libc_pipe
    86  //go:linkname libc_pipe2 libc_pipe2
    87  
    88  var (
    89  	libc____errno,
    90  	libc_clock_gettime,
    91  	libc_exit,
    92  	libc_getcontext,
    93  	libc_kill,
    94  	libc_madvise,
    95  	libc_malloc,
    96  	libc_mmap,
    97  	libc_munmap,
    98  	libc_open,
    99  	libc_pthread_attr_destroy,
   100  	libc_pthread_attr_getstack,
   101  	libc_pthread_attr_init,
   102  	libc_pthread_attr_setdetachstate,
   103  	libc_pthread_attr_setstack,
   104  	libc_pthread_create,
   105  	libc_pthread_self,
   106  	libc_pthread_kill,
   107  	libc_raise,
   108  	libc_read,
   109  	libc_sched_yield,
   110  	libc_select,
   111  	libc_sem_init,
   112  	libc_sem_post,
   113  	libc_sem_reltimedwait_np,
   114  	libc_sem_wait,
   115  	libc_setitimer,
   116  	libc_sigaction,
   117  	libc_sigaltstack,
   118  	libc_sigprocmask,
   119  	libc_sysconf,
   120  	libc_usleep,
   121  	libc_write,
   122  	libc_pipe,
   123  	libc_pipe2 libcFunc
   124  )
   125  
   126  var sigset_all = sigset{[4]uint32{^uint32(0), ^uint32(0), ^uint32(0), ^uint32(0)}}
   127  
   128  func getPageSize() uintptr {
   129  	n := int32(sysconf(__SC_PAGESIZE))
   130  	if n <= 0 {
   131  		return 0
   132  	}
   133  	return uintptr(n)
   134  }
   135  
   136  func osinit() {
   137  	ncpu = getncpu()
   138  	if physPageSize == 0 {
   139  		physPageSize = getPageSize()
   140  	}
   141  }
   142  
   143  func tstart_sysvicall(newm *m) uint32
   144  
   145  // May run with m.p==nil, so write barriers are not allowed.
   146  //go:nowritebarrier
   147  func newosproc(mp *m) {
   148  	var (
   149  		attr	pthreadattr
   150  		oset	sigset
   151  		tid	pthread
   152  		ret	int32
   153  		size	uint64
   154  	)
   155  
   156  	if pthread_attr_init(&attr) != 0 {
   157  		throw("pthread_attr_init")
   158  	}
   159  	// Allocate a new 2MB stack.
   160  	if pthread_attr_setstack(&attr, 0, 0x200000) != 0 {
   161  		throw("pthread_attr_setstack")
   162  	}
   163  	// Read back the allocated stack.
   164  	if pthread_attr_getstack(&attr, unsafe.Pointer(&mp.g0.stack.hi), &size) != 0 {
   165  		throw("pthread_attr_getstack")
   166  	}
   167  	mp.g0.stack.lo = mp.g0.stack.hi - uintptr(size)
   168  	if pthread_attr_setdetachstate(&attr, _PTHREAD_CREATE_DETACHED) != 0 {
   169  		throw("pthread_attr_setdetachstate")
   170  	}
   171  
   172  	// Disable signals during create, so that the new thread starts
   173  	// with signals disabled. It will enable them in minit.
   174  	sigprocmask(_SIG_SETMASK, &sigset_all, &oset)
   175  	ret = pthread_create(&tid, &attr, funcPC(tstart_sysvicall), unsafe.Pointer(mp))
   176  	sigprocmask(_SIG_SETMASK, &oset, nil)
   177  	if ret != 0 {
   178  		print("runtime: failed to create new OS thread (have ", mcount(), " already; errno=", ret, ")\n")
   179  		if ret == -_EAGAIN {
   180  			println("runtime: may need to increase max user processes (ulimit -u)")
   181  		}
   182  		throw("newosproc")
   183  	}
   184  }
   185  
   186  func exitThread(wait *uint32) {
   187  	// We should never reach exitThread on Solaris because we let
   188  	// libc clean up threads.
   189  	throw("exitThread")
   190  }
   191  
   192  var urandom_dev = []byte("/dev/urandom\x00")
   193  
   194  //go:nosplit
   195  func getRandomData(r []byte) {
   196  	fd := open(&urandom_dev[0], 0 /* O_RDONLY */, 0)
   197  	n := read(fd, unsafe.Pointer(&r[0]), int32(len(r)))
   198  	closefd(fd)
   199  	extendRandom(r, int(n))
   200  }
   201  
   202  func goenvs() {
   203  	goenvs_unix()
   204  }
   205  
   206  // Called to initialize a new m (including the bootstrap m).
   207  // Called on the parent thread (main thread in case of bootstrap), can allocate memory.
   208  func mpreinit(mp *m) {
   209  	mp.gsignal = malg(32 * 1024)
   210  	mp.gsignal.m = mp
   211  }
   212  
   213  func miniterrno()
   214  
   215  // Called to initialize a new m (including the bootstrap m).
   216  // Called on the new thread, cannot allocate memory.
   217  func minit() {
   218  	asmcgocall(unsafe.Pointer(funcPC(miniterrno)), unsafe.Pointer(&libc____errno))
   219  
   220  	minitSignals()
   221  
   222  	getg().m.procid = uint64(pthread_self())
   223  }
   224  
   225  // Called from dropm to undo the effect of an minit.
   226  func unminit() {
   227  	unminitSignals()
   228  }
   229  
   230  func sigtramp()
   231  
   232  //go:nosplit
   233  //go:nowritebarrierrec
   234  func setsig(i uint32, fn uintptr) {
   235  	var sa sigactiont
   236  
   237  	sa.sa_flags = _SA_SIGINFO | _SA_ONSTACK | _SA_RESTART
   238  	sa.sa_mask = sigset_all
   239  	if fn == funcPC(sighandler) {
   240  		fn = funcPC(sigtramp)
   241  	}
   242  	*((*uintptr)(unsafe.Pointer(&sa._funcptr))) = fn
   243  	sigaction(i, &sa, nil)
   244  }
   245  
   246  //go:nosplit
   247  //go:nowritebarrierrec
   248  func setsigstack(i uint32) {
   249  	var sa sigactiont
   250  	sigaction(i, nil, &sa)
   251  	if sa.sa_flags&_SA_ONSTACK != 0 {
   252  		return
   253  	}
   254  	sa.sa_flags |= _SA_ONSTACK
   255  	sigaction(i, &sa, nil)
   256  }
   257  
   258  //go:nosplit
   259  //go:nowritebarrierrec
   260  func getsig(i uint32) uintptr {
   261  	var sa sigactiont
   262  	sigaction(i, nil, &sa)
   263  	return *((*uintptr)(unsafe.Pointer(&sa._funcptr)))
   264  }
   265  
   266  // setSignaltstackSP sets the ss_sp field of a stackt.
   267  //go:nosplit
   268  func setSignalstackSP(s *stackt, sp uintptr) {
   269  	*(*uintptr)(unsafe.Pointer(&s.ss_sp)) = sp
   270  }
   271  
   272  //go:nosplit
   273  //go:nowritebarrierrec
   274  func sigaddset(mask *sigset, i int) {
   275  	mask.__sigbits[(i-1)/32] |= 1 << ((uint32(i) - 1) & 31)
   276  }
   277  
   278  func sigdelset(mask *sigset, i int) {
   279  	mask.__sigbits[(i-1)/32] &^= 1 << ((uint32(i) - 1) & 31)
   280  }
   281  
   282  //go:nosplit
   283  func (c *sigctxt) fixsigcode(sig uint32) {
   284  }
   285  
   286  //go:nosplit
   287  func semacreate(mp *m) {
   288  	if mp.waitsema != 0 {
   289  		return
   290  	}
   291  
   292  	var sem *semt
   293  	_g_ := getg()
   294  
   295  	// Call libc's malloc rather than malloc. This will
   296  	// allocate space on the C heap. We can't call malloc
   297  	// here because it could cause a deadlock.
   298  	_g_.m.libcall.fn = uintptr(unsafe.Pointer(&libc_malloc))
   299  	_g_.m.libcall.n = 1
   300  	_g_.m.scratch = mscratch{}
   301  	_g_.m.scratch.v[0] = unsafe.Sizeof(*sem)
   302  	_g_.m.libcall.args = uintptr(unsafe.Pointer(&_g_.m.scratch))
   303  	asmcgocall(unsafe.Pointer(&asmsysvicall6x), unsafe.Pointer(&_g_.m.libcall))
   304  	sem = (*semt)(unsafe.Pointer(_g_.m.libcall.r1))
   305  	if sem_init(sem, 0, 0) != 0 {
   306  		throw("sem_init")
   307  	}
   308  	mp.waitsema = uintptr(unsafe.Pointer(sem))
   309  }
   310  
   311  //go:nosplit
   312  func semasleep(ns int64) int32 {
   313  	_m_ := getg().m
   314  	if ns >= 0 {
   315  		_m_.ts.tv_sec = ns / 1000000000
   316  		_m_.ts.tv_nsec = ns % 1000000000
   317  
   318  		_m_.libcall.fn = uintptr(unsafe.Pointer(&libc_sem_reltimedwait_np))
   319  		_m_.libcall.n = 2
   320  		_m_.scratch = mscratch{}
   321  		_m_.scratch.v[0] = _m_.waitsema
   322  		_m_.scratch.v[1] = uintptr(unsafe.Pointer(&_m_.ts))
   323  		_m_.libcall.args = uintptr(unsafe.Pointer(&_m_.scratch))
   324  		asmcgocall(unsafe.Pointer(&asmsysvicall6x), unsafe.Pointer(&_m_.libcall))
   325  		if *_m_.perrno != 0 {
   326  			if *_m_.perrno == _ETIMEDOUT || *_m_.perrno == _EAGAIN || *_m_.perrno == _EINTR {
   327  				return -1
   328  			}
   329  			throw("sem_reltimedwait_np")
   330  		}
   331  		return 0
   332  	}
   333  	for {
   334  		_m_.libcall.fn = uintptr(unsafe.Pointer(&libc_sem_wait))
   335  		_m_.libcall.n = 1
   336  		_m_.scratch = mscratch{}
   337  		_m_.scratch.v[0] = _m_.waitsema
   338  		_m_.libcall.args = uintptr(unsafe.Pointer(&_m_.scratch))
   339  		asmcgocall(unsafe.Pointer(&asmsysvicall6x), unsafe.Pointer(&_m_.libcall))
   340  		if _m_.libcall.r1 == 0 {
   341  			break
   342  		}
   343  		if *_m_.perrno == _EINTR {
   344  			continue
   345  		}
   346  		throw("sem_wait")
   347  	}
   348  	return 0
   349  }
   350  
   351  //go:nosplit
   352  func semawakeup(mp *m) {
   353  	if sem_post((*semt)(unsafe.Pointer(mp.waitsema))) != 0 {
   354  		throw("sem_post")
   355  	}
   356  }
   357  
   358  //go:nosplit
   359  func closefd(fd int32) int32 {
   360  	return int32(sysvicall1(&libc_close, uintptr(fd)))
   361  }
   362  
   363  //go:nosplit
   364  func exit(r int32) {
   365  	sysvicall1(&libc_exit, uintptr(r))
   366  }
   367  
   368  //go:nosplit
   369  func getcontext(context *ucontext) /* int32 */ {
   370  	sysvicall1(&libc_getcontext, uintptr(unsafe.Pointer(context)))
   371  }
   372  
   373  //go:nosplit
   374  func madvise(addr unsafe.Pointer, n uintptr, flags int32) {
   375  	sysvicall3(&libc_madvise, uintptr(addr), uintptr(n), uintptr(flags))
   376  }
   377  
   378  //go:nosplit
   379  func mmap(addr unsafe.Pointer, n uintptr, prot, flags, fd int32, off uint32) (unsafe.Pointer, int) {
   380  	p, err := doMmap(uintptr(addr), n, uintptr(prot), uintptr(flags), uintptr(fd), uintptr(off))
   381  	if p == ^uintptr(0) {
   382  		return nil, int(err)
   383  	}
   384  	return unsafe.Pointer(p), 0
   385  }
   386  
   387  //go:nosplit
   388  func doMmap(addr, n, prot, flags, fd, off uintptr) (uintptr, uintptr) {
   389  	var libcall libcall
   390  	libcall.fn = uintptr(unsafe.Pointer(&libc_mmap))
   391  	libcall.n = 6
   392  	libcall.args = uintptr(noescape(unsafe.Pointer(&addr)))
   393  	asmcgocall(unsafe.Pointer(&asmsysvicall6x), unsafe.Pointer(&libcall))
   394  	return libcall.r1, libcall.err
   395  }
   396  
   397  //go:nosplit
   398  func munmap(addr unsafe.Pointer, n uintptr) {
   399  	sysvicall2(&libc_munmap, uintptr(addr), uintptr(n))
   400  }
   401  
   402  const (
   403  	_CLOCK_REALTIME		= 3
   404  	_CLOCK_MONOTONIC	= 4
   405  )
   406  
   407  //go:nosplit
   408  func nanotime1() int64 {
   409  	var ts mts
   410  	sysvicall2(&libc_clock_gettime, _CLOCK_MONOTONIC, uintptr(unsafe.Pointer(&ts)))
   411  	return ts.tv_sec*1e9 + ts.tv_nsec
   412  }
   413  
   414  //go:nosplit
   415  func open(path *byte, mode, perm int32) int32 {
   416  	return int32(sysvicall3(&libc_open, uintptr(unsafe.Pointer(path)), uintptr(mode), uintptr(perm)))
   417  }
   418  
   419  func pthread_attr_destroy(attr *pthreadattr) int32 {
   420  	return int32(sysvicall1(&libc_pthread_attr_destroy, uintptr(unsafe.Pointer(attr))))
   421  }
   422  
   423  func pthread_attr_getstack(attr *pthreadattr, addr unsafe.Pointer, size *uint64) int32 {
   424  	return int32(sysvicall3(&libc_pthread_attr_getstack, uintptr(unsafe.Pointer(attr)), uintptr(addr), uintptr(unsafe.Pointer(size))))
   425  }
   426  
   427  func pthread_attr_init(attr *pthreadattr) int32 {
   428  	return int32(sysvicall1(&libc_pthread_attr_init, uintptr(unsafe.Pointer(attr))))
   429  }
   430  
   431  func pthread_attr_setdetachstate(attr *pthreadattr, state int32) int32 {
   432  	return int32(sysvicall2(&libc_pthread_attr_setdetachstate, uintptr(unsafe.Pointer(attr)), uintptr(state)))
   433  }
   434  
   435  func pthread_attr_setstack(attr *pthreadattr, addr uintptr, size uint64) int32 {
   436  	return int32(sysvicall3(&libc_pthread_attr_setstack, uintptr(unsafe.Pointer(attr)), uintptr(addr), uintptr(size)))
   437  }
   438  
   439  func pthread_create(thread *pthread, attr *pthreadattr, fn uintptr, arg unsafe.Pointer) int32 {
   440  	return int32(sysvicall4(&libc_pthread_create, uintptr(unsafe.Pointer(thread)), uintptr(unsafe.Pointer(attr)), uintptr(fn), uintptr(arg)))
   441  }
   442  
   443  func pthread_self() pthread {
   444  	return pthread(sysvicall0(&libc_pthread_self))
   445  }
   446  
   447  func signalM(mp *m, sig int) {
   448  	sysvicall2(&libc_pthread_kill, uintptr(pthread(mp.procid)), uintptr(sig))
   449  }
   450  
   451  //go:nosplit
   452  //go:nowritebarrierrec
   453  func raise(sig uint32) /* int32 */ {
   454  	sysvicall1(&libc_raise, uintptr(sig))
   455  }
   456  
   457  func raiseproc(sig uint32) /* int32 */ {
   458  	pid := sysvicall0(&libc_getpid)
   459  	sysvicall2(&libc_kill, pid, uintptr(sig))
   460  }
   461  
   462  //go:nosplit
   463  func read(fd int32, buf unsafe.Pointer, nbyte int32) int32 {
   464  	r1, err := sysvicall3Err(&libc_read, uintptr(fd), uintptr(buf), uintptr(nbyte))
   465  	if c := int32(r1); c >= 0 {
   466  		return c
   467  	}
   468  	return -int32(err)
   469  }
   470  
   471  //go:nosplit
   472  func sem_init(sem *semt, pshared int32, value uint32) int32 {
   473  	return int32(sysvicall3(&libc_sem_init, uintptr(unsafe.Pointer(sem)), uintptr(pshared), uintptr(value)))
   474  }
   475  
   476  //go:nosplit
   477  func sem_post(sem *semt) int32 {
   478  	return int32(sysvicall1(&libc_sem_post, uintptr(unsafe.Pointer(sem))))
   479  }
   480  
   481  //go:nosplit
   482  func sem_reltimedwait_np(sem *semt, timeout *timespec) int32 {
   483  	return int32(sysvicall2(&libc_sem_reltimedwait_np, uintptr(unsafe.Pointer(sem)), uintptr(unsafe.Pointer(timeout))))
   484  }
   485  
   486  //go:nosplit
   487  func sem_wait(sem *semt) int32 {
   488  	return int32(sysvicall1(&libc_sem_wait, uintptr(unsafe.Pointer(sem))))
   489  }
   490  
   491  func setitimer(which int32, value *itimerval, ovalue *itimerval) /* int32 */ {
   492  	sysvicall3(&libc_setitimer, uintptr(which), uintptr(unsafe.Pointer(value)), uintptr(unsafe.Pointer(ovalue)))
   493  }
   494  
   495  //go:nosplit
   496  //go:nowritebarrierrec
   497  func sigaction(sig uint32, act *sigactiont, oact *sigactiont) /* int32 */ {
   498  	sysvicall3(&libc_sigaction, uintptr(sig), uintptr(unsafe.Pointer(act)), uintptr(unsafe.Pointer(oact)))
   499  }
   500  
   501  //go:nosplit
   502  //go:nowritebarrierrec
   503  func sigaltstack(ss *stackt, oss *stackt) /* int32 */ {
   504  	sysvicall2(&libc_sigaltstack, uintptr(unsafe.Pointer(ss)), uintptr(unsafe.Pointer(oss)))
   505  }
   506  
   507  //go:nosplit
   508  //go:nowritebarrierrec
   509  func sigprocmask(how int32, set *sigset, oset *sigset) /* int32 */ {
   510  	sysvicall3(&libc_sigprocmask, uintptr(how), uintptr(unsafe.Pointer(set)), uintptr(unsafe.Pointer(oset)))
   511  }
   512  
   513  func sysconf(name int32) int64 {
   514  	return int64(sysvicall1(&libc_sysconf, uintptr(name)))
   515  }
   516  
   517  func usleep1(usec uint32)
   518  
   519  //go:nosplit
   520  func usleep(µs uint32) {
   521  	usleep1(µs)
   522  }
   523  
   524  func walltime1() (sec int64, nsec int32) {
   525  	var ts mts
   526  	sysvicall2(&libc_clock_gettime, _CLOCK_REALTIME, uintptr(unsafe.Pointer(&ts)))
   527  	return ts.tv_sec, int32(ts.tv_nsec)
   528  }
   529  
   530  //go:nosplit
   531  func write1(fd uintptr, buf unsafe.Pointer, nbyte int32) int32 {
   532  	r1, err := sysvicall3Err(&libc_write, fd, uintptr(buf), uintptr(nbyte))
   533  	if c := int32(r1); c >= 0 {
   534  		return c
   535  	}
   536  	return -int32(err)
   537  }
   538  
   539  //go:nosplit
   540  func pipe() (r, w int32, errno int32) {
   541  	var p [2]int32
   542  	_, e := sysvicall1Err(&libc_pipe, uintptr(noescape(unsafe.Pointer(&p))))
   543  	return p[0], p[1], int32(e)
   544  }
   545  
   546  //go:nosplit
   547  func pipe2(flags int32) (r, w int32, errno int32) {
   548  	var p [2]int32
   549  	_, e := sysvicall2Err(&libc_pipe2, uintptr(noescape(unsafe.Pointer(&p))), uintptr(flags))
   550  	return p[0], p[1], int32(e)
   551  }
   552  
   553  //go:nosplit
   554  func closeonexec(fd int32) {
   555  	fcntl(fd, _F_SETFD, _FD_CLOEXEC)
   556  }
   557  
   558  //go:nosplit
   559  func setNonblock(fd int32) {
   560  	flags := fcntl(fd, _F_GETFL, 0)
   561  	fcntl(fd, _F_SETFL, flags|_O_NONBLOCK)
   562  }
   563  
   564  func osyield1()
   565  
   566  //go:nosplit
   567  func osyield() {
   568  	_g_ := getg()
   569  
   570  	// Check the validity of m because we might be called in cgo callback
   571  	// path early enough where there isn't a m available yet.
   572  	if _g_ != nil && _g_.m != nil {
   573  		sysvicall0(&libc_sched_yield)
   574  		return
   575  	}
   576  	osyield1()
   577  }
   578  
   579  //go:linkname executablePath os.executablePath
   580  var executablePath string
   581  
   582  func sysargs(argc int32, argv **byte) {
   583  	n := argc + 1
   584  
   585  	// skip over argv, envp to get to auxv
   586  	for argv_index(argv, n) != nil {
   587  		n++
   588  	}
   589  
   590  	// skip NULL separator
   591  	n++
   592  
   593  	// now argv+n is auxv
   594  	auxv := (*[1 << 28]uintptr)(add(unsafe.Pointer(argv), uintptr(n)*sys.PtrSize))
   595  	sysauxv(auxv[:])
   596  }
   597  
   598  const (
   599  	_AT_NULL		= 0	// Terminates the vector
   600  	_AT_PAGESZ		= 6	// Page size in bytes
   601  	_AT_SUN_EXECNAME	= 2014	// exec() path name
   602  )
   603  
   604  func sysauxv(auxv []uintptr) {
   605  	for i := 0; auxv[i] != _AT_NULL; i += 2 {
   606  		tag, val := auxv[i], auxv[i+1]
   607  		switch tag {
   608  		case _AT_PAGESZ:
   609  			physPageSize = val
   610  		case _AT_SUN_EXECNAME:
   611  			executablePath = gostringnocopy((*byte)(unsafe.Pointer(val)))
   612  		}
   613  	}
   614  }