os_aix.go

     1  // Copyright 2018 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  //go:build aix
     6  
     7  package runtime
     8  
     9  import (
    10  	"internal/abi"
    11  	"runtime/internal/atomic"
    12  	"unsafe"
    13  )
    14  
    15  const (
    16  	threadStackSize = 0x100000 // size of a thread stack allocated by OS
    17  )
    18  
    19  // funcDescriptor is a structure representing a function descriptor
    20  // A variable with this type is always created in assembler
    21  type funcDescriptor struct {
    22  	fn         uintptr
    23  	toc        uintptr
    24  	envPointer uintptr // unused in Golang
    25  }
    26  
    27  type mOS struct {
    28  	waitsema uintptr // semaphore for parking on locks
    29  	perrno   uintptr // pointer to tls errno
    30  }
    31  
    32  //go:nosplit
    33  func semacreate(mp *m) {
    34  	if mp.waitsema != 0 {
    35  		return
    36  	}
    37  
    38  	var sem *semt
    39  
    40  	// Call libc's malloc rather than malloc. This will
    41  	// allocate space on the C heap. We can't call mallocgc
    42  	// here because it could cause a deadlock.
    43  	sem = (*semt)(malloc(unsafe.Sizeof(*sem)))
    44  	if sem_init(sem, 0, 0) != 0 {
    45  		throw("sem_init")
    46  	}
    47  	mp.waitsema = uintptr(unsafe.Pointer(sem))
    48  }
    49  
    50  //go:nosplit
    51  func semasleep(ns int64) int32 {
    52  	mp := getg().m
    53  	if ns >= 0 {
    54  		var ts timespec
    55  
    56  		if clock_gettime(_CLOCK_REALTIME, &ts) != 0 {
    57  			throw("clock_gettime")
    58  		}
    59  		ts.tv_sec += ns / 1e9
    60  		ts.tv_nsec += ns % 1e9
    61  		if ts.tv_nsec >= 1e9 {
    62  			ts.tv_sec++
    63  			ts.tv_nsec -= 1e9
    64  		}
    65  
    66  		if r, err := sem_timedwait((*semt)(unsafe.Pointer(mp.waitsema)), &ts); r != 0 {
    67  			if err == _ETIMEDOUT || err == _EAGAIN || err == _EINTR {
    68  				return -1
    69  			}
    70  			println("sem_timedwait err ", err, " ts.tv_sec ", ts.tv_sec, " ts.tv_nsec ", ts.tv_nsec, " ns ", ns, " id ", mp.id)
    71  			throw("sem_timedwait")
    72  		}
    73  		return 0
    74  	}
    75  	for {
    76  		r1, err := sem_wait((*semt)(unsafe.Pointer(mp.waitsema)))
    77  		if r1 == 0 {
    78  			break
    79  		}
    80  		if err == _EINTR {
    81  			continue
    82  		}
    83  		throw("sem_wait")
    84  	}
    85  	return 0
    86  }
    87  
    88  //go:nosplit
    89  func semawakeup(mp *m) {
    90  	if sem_post((*semt)(unsafe.Pointer(mp.waitsema))) != 0 {
    91  		throw("sem_post")
    92  	}
    93  }
    94  
    95  func osinit() {
    96  	ncpu = int32(sysconf(__SC_NPROCESSORS_ONLN))
    97  	physPageSize = sysconf(__SC_PAGE_SIZE)
    98  }
    99  
   100  // newosproc0 is a version of newosproc that can be called before the runtime
   101  // is initialized.
   102  //
   103  // This function is not safe to use after initialization as it does not pass an M as fnarg.
   104  //
   105  //go:nosplit
   106  func newosproc0(stacksize uintptr, fn *funcDescriptor) {
   107  	var (
   108  		attr pthread_attr
   109  		oset sigset
   110  		tid  pthread
   111  	)
   112  
   113  	if pthread_attr_init(&attr) != 0 {
   114  		write(2, unsafe.Pointer(&failthreadcreate[0]), int32(len(failthreadcreate)))
   115  		exit(1)
   116  	}
   117  
   118  	if pthread_attr_setstacksize(&attr, threadStackSize) != 0 {
   119  		write(2, unsafe.Pointer(&failthreadcreate[0]), int32(len(failthreadcreate)))
   120  		exit(1)
   121  	}
   122  
   123  	if pthread_attr_setdetachstate(&attr, _PTHREAD_CREATE_DETACHED) != 0 {
   124  		write(2, unsafe.Pointer(&failthreadcreate[0]), int32(len(failthreadcreate)))
   125  		exit(1)
   126  	}
   127  
   128  	// Disable signals during create, so that the new thread starts
   129  	// with signals disabled. It will enable them in minit.
   130  	sigprocmask(_SIG_SETMASK, &sigset_all, &oset)
   131  	var ret int32
   132  	for tries := 0; tries < 20; tries++ {
   133  		// pthread_create can fail with EAGAIN for no reasons
   134  		// but it will be ok if it retries.
   135  		ret = pthread_create(&tid, &attr, fn, nil)
   136  		if ret != _EAGAIN {
   137  			break
   138  		}
   139  		usleep(uint32(tries+1) * 1000) // Milliseconds.
   140  	}
   141  	sigprocmask(_SIG_SETMASK, &oset, nil)
   142  	if ret != 0 {
   143  		write(2, unsafe.Pointer(&failthreadcreate[0]), int32(len(failthreadcreate)))
   144  		exit(1)
   145  	}
   146  
   147  }
   148  
   149  var failthreadcreate = []byte("runtime: failed to create new OS thread\n")
   150  
   151  // Called to do synchronous initialization of Go code built with
   152  // -buildmode=c-archive or -buildmode=c-shared.
   153  // None of the Go runtime is initialized.
   154  //
   155  //go:nosplit
   156  //go:nowritebarrierrec
   157  func libpreinit() {
   158  	initsig(true)
   159  }
   160  
   161  // Ms related functions
   162  func mpreinit(mp *m) {
   163  	mp.gsignal = malg(32 * 1024) // AIX wants >= 8K
   164  	mp.gsignal.m = mp
   165  }
   166  
   167  // errno address must be retrieved by calling _Errno libc function.
   168  // This will return a pointer to errno
   169  func miniterrno() {
   170  	mp := getg().m
   171  	r, _ := syscall0(&libc__Errno)
   172  	mp.perrno = r
   173  
   174  }
   175  
   176  func minit() {
   177  	miniterrno()
   178  	minitSignals()
   179  	getg().m.procid = uint64(pthread_self())
   180  }
   181  
   182  func unminit() {
   183  	unminitSignals()
   184  }
   185  
   186  // Called from exitm, but not from drop, to undo the effect of thread-owned
   187  // resources in minit, semacreate, or elsewhere. Do not take locks after calling this.
   188  func mdestroy(mp *m) {
   189  }
   190  
   191  // tstart is a function descriptor to _tstart defined in assembly.
   192  var tstart funcDescriptor
   193  
   194  func newosproc(mp *m) {
   195  	var (
   196  		attr pthread_attr
   197  		oset sigset
   198  		tid  pthread
   199  	)
   200  
   201  	if pthread_attr_init(&attr) != 0 {
   202  		throw("pthread_attr_init")
   203  	}
   204  
   205  	if pthread_attr_setstacksize(&attr, threadStackSize) != 0 {
   206  		throw("pthread_attr_getstacksize")
   207  	}
   208  
   209  	if pthread_attr_setdetachstate(&attr, _PTHREAD_CREATE_DETACHED) != 0 {
   210  		throw("pthread_attr_setdetachstate")
   211  	}
   212  
   213  	// Disable signals during create, so that the new thread starts
   214  	// with signals disabled. It will enable them in minit.
   215  	sigprocmask(_SIG_SETMASK, &sigset_all, &oset)
   216  	var ret int32
   217  	for tries := 0; tries < 20; tries++ {
   218  		// pthread_create can fail with EAGAIN for no reasons
   219  		// but it will be ok if it retries.
   220  		ret = pthread_create(&tid, &attr, &tstart, unsafe.Pointer(mp))
   221  		if ret != _EAGAIN {
   222  			break
   223  		}
   224  		usleep(uint32(tries+1) * 1000) // Milliseconds.
   225  	}
   226  	sigprocmask(_SIG_SETMASK, &oset, nil)
   227  	if ret != 0 {
   228  		print("runtime: failed to create new OS thread (have ", mcount(), " already; errno=", ret, ")\n")
   229  		if ret == _EAGAIN {
   230  			println("runtime: may need to increase max user processes (ulimit -u)")
   231  		}
   232  		throw("newosproc")
   233  	}
   234  
   235  }
   236  
   237  func exitThread(wait *atomic.Uint32) {
   238  	// We should never reach exitThread on AIX because we let
   239  	// libc clean up threads.
   240  	throw("exitThread")
   241  }
   242  
   243  var urandom_dev = []byte("/dev/urandom\x00")
   244  
   245  //go:nosplit
   246  func getRandomData(r []byte) {
   247  	fd := open(&urandom_dev[0], 0 /* O_RDONLY */, 0)
   248  	n := read(fd, unsafe.Pointer(&r[0]), int32(len(r)))
   249  	closefd(fd)
   250  	extendRandom(r, int(n))
   251  }
   252  
   253  func goenvs() {
   254  	goenvs_unix()
   255  }
   256  
   257  /* SIGNAL */
   258  
   259  const (
   260  	_NSIG = 256
   261  )
   262  
   263  // sigtramp is a function descriptor to _sigtramp defined in assembly
   264  var sigtramp funcDescriptor
   265  
   266  //go:nosplit
   267  //go:nowritebarrierrec
   268  func setsig(i uint32, fn uintptr) {
   269  	var sa sigactiont
   270  	sa.sa_flags = _SA_SIGINFO | _SA_ONSTACK | _SA_RESTART
   271  	sa.sa_mask = sigset_all
   272  	if fn == abi.FuncPCABIInternal(sighandler) { // abi.FuncPCABIInternal(sighandler) matches the callers in signal_unix.go
   273  		fn = uintptr(unsafe.Pointer(&sigtramp))
   274  	}
   275  	sa.sa_handler = fn
   276  	sigaction(uintptr(i), &sa, nil)
   277  
   278  }
   279  
   280  //go:nosplit
   281  //go:nowritebarrierrec
   282  func setsigstack(i uint32) {
   283  	var sa sigactiont
   284  	sigaction(uintptr(i), nil, &sa)
   285  	if sa.sa_flags&_SA_ONSTACK != 0 {
   286  		return
   287  	}
   288  	sa.sa_flags |= _SA_ONSTACK
   289  	sigaction(uintptr(i), &sa, nil)
   290  }
   291  
   292  //go:nosplit
   293  //go:nowritebarrierrec
   294  func getsig(i uint32) uintptr {
   295  	var sa sigactiont
   296  	sigaction(uintptr(i), nil, &sa)
   297  	return sa.sa_handler
   298  }
   299  
   300  // setSignaltstackSP sets the ss_sp field of a stackt.
   301  //
   302  //go:nosplit
   303  func setSignalstackSP(s *stackt, sp uintptr) {
   304  	*(*uintptr)(unsafe.Pointer(&s.ss_sp)) = sp
   305  }
   306  
   307  //go:nosplit
   308  func (c *sigctxt) fixsigcode(sig uint32) {
   309  	switch sig {
   310  	case _SIGPIPE:
   311  		// For SIGPIPE, c.sigcode() isn't set to _SI_USER as on Linux.
   312  		// Therefore, raisebadsignal won't raise SIGPIPE again if
   313  		// it was deliver in a non-Go thread.
   314  		c.set_sigcode(_SI_USER)
   315  	}
   316  }
   317  
   318  //go:nosplit
   319  //go:nowritebarrierrec
   320  func sigaddset(mask *sigset, i int) {
   321  	(*mask)[(i-1)/64] |= 1 << ((uint32(i) - 1) & 63)
   322  }
   323  
   324  func sigdelset(mask *sigset, i int) {
   325  	(*mask)[(i-1)/64] &^= 1 << ((uint32(i) - 1) & 63)
   326  }
   327  
   328  func setProcessCPUProfiler(hz int32) {
   329  	setProcessCPUProfilerTimer(hz)
   330  }
   331  
   332  func setThreadCPUProfiler(hz int32) {
   333  	setThreadCPUProfilerHz(hz)
   334  }
   335  
   336  //go:nosplit
   337  func validSIGPROF(mp *m, c *sigctxt) bool {
   338  	return true
   339  }
   340  
   341  const (
   342  	_CLOCK_REALTIME  = 9
   343  	_CLOCK_MONOTONIC = 10
   344  )
   345  
   346  //go:nosplit
   347  func nanotime1() int64 {
   348  	tp := &timespec{}
   349  	if clock_gettime(_CLOCK_REALTIME, tp) != 0 {
   350  		throw("syscall clock_gettime failed")
   351  	}
   352  	return tp.tv_sec*1000000000 + tp.tv_nsec
   353  }
   354  
   355  func walltime() (sec int64, nsec int32) {
   356  	ts := &timespec{}
   357  	if clock_gettime(_CLOCK_REALTIME, ts) != 0 {
   358  		throw("syscall clock_gettime failed")
   359  	}
   360  	return ts.tv_sec, int32(ts.tv_nsec)
   361  }
   362  
   363  //go:nosplit
   364  func fcntl(fd, cmd, arg int32) int32 {
   365  	r, _ := syscall3(&libc_fcntl, uintptr(fd), uintptr(cmd), uintptr(arg))
   366  	return int32(r)
   367  }
   368  
   369  //go:nosplit
   370  func closeonexec(fd int32) {
   371  	fcntl(fd, _F_SETFD, _FD_CLOEXEC)
   372  }
   373  
   374  //go:nosplit
   375  func setNonblock(fd int32) {
   376  	flags := fcntl(fd, _F_GETFL, 0)
   377  	fcntl(fd, _F_SETFL, flags|_O_NONBLOCK)
   378  }
   379  
   380  // sigPerThreadSyscall is only used on linux, so we assign a bogus signal
   381  // number.
   382  const sigPerThreadSyscall = 1 << 31
   383  
   384  //go:nosplit
   385  func runPerThreadSyscall() {
   386  	throw("runPerThreadSyscall only valid on linux")
   387  }
   388
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