os_aix.go

Documentation: runtime

     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  	"internal/runtime/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  	// Call miniterrno so that we can safely make system calls
    97  	// before calling minit on m0.
    98  	miniterrno()
    99  
   100  	ncpu = int32(sysconf(__SC_NPROCESSORS_ONLN))
   101  	physPageSize = sysconf(__SC_PAGE_SIZE)
   102  }
   103  
   104  // newosproc0 is a version of newosproc that can be called before the runtime
   105  // is initialized.
   106  //
   107  // This function is not safe to use after initialization as it does not pass an M as fnarg.
   108  //
   109  //go:nosplit
   110  func newosproc0(stacksize uintptr, fn *funcDescriptor) {
   111  	var (
   112  		attr pthread_attr
   113  		oset sigset
   114  		tid  pthread
   115  	)
   116  
   117  	if pthread_attr_init(&attr) != 0 {
   118  		writeErrStr(failthreadcreate)
   119  		exit(1)
   120  	}
   121  
   122  	if pthread_attr_setstacksize(&attr, threadStackSize) != 0 {
   123  		writeErrStr(failthreadcreate)
   124  		exit(1)
   125  	}
   126  
   127  	if pthread_attr_setdetachstate(&attr, _PTHREAD_CREATE_DETACHED) != 0 {
   128  		writeErrStr(failthreadcreate)
   129  		exit(1)
   130  	}
   131  
   132  	// Disable signals during create, so that the new thread starts
   133  	// with signals disabled. It will enable them in minit.
   134  	sigprocmask(_SIG_SETMASK, &sigset_all, &oset)
   135  	var ret int32
   136  	for tries := 0; tries < 20; tries++ {
   137  		// pthread_create can fail with EAGAIN for no reasons
   138  		// but it will be ok if it retries.
   139  		ret = pthread_create(&tid, &attr, fn, nil)
   140  		if ret != _EAGAIN {
   141  			break
   142  		}
   143  		usleep(uint32(tries+1) * 1000) // Milliseconds.
   144  	}
   145  	sigprocmask(_SIG_SETMASK, &oset, nil)
   146  	if ret != 0 {
   147  		writeErrStr(failthreadcreate)
   148  		exit(1)
   149  	}
   150  
   151  }
   152  
   153  // Called to do synchronous initialization of Go code built with
   154  // -buildmode=c-archive or -buildmode=c-shared.
   155  // None of the Go runtime is initialized.
   156  //
   157  //go:nosplit
   158  //go:nowritebarrierrec
   159  func libpreinit() {
   160  	initsig(true)
   161  }
   162  
   163  // Ms related functions
   164  func mpreinit(mp *m) {
   165  	mp.gsignal = malg(32 * 1024) // AIX wants >= 8K
   166  	mp.gsignal.m = mp
   167  }
   168  
   169  // errno address must be retrieved by calling _Errno libc function.
   170  // This will return a pointer to errno.
   171  func miniterrno() {
   172  	mp := getg().m
   173  	r, _ := syscall0(&libc__Errno)
   174  	mp.perrno = r
   175  
   176  }
   177  
   178  func minit() {
   179  	miniterrno()
   180  	minitSignals()
   181  	getg().m.procid = uint64(pthread_self())
   182  }
   183  
   184  func unminit() {
   185  	unminitSignals()
   186  	getg().m.procid = 0
   187  }
   188  
   189  // Called from exitm, but not from drop, to undo the effect of thread-owned
   190  // resources in minit, semacreate, or elsewhere. Do not take locks after calling this.
   191  func mdestroy(mp *m) {
   192  }
   193  
   194  // tstart is a function descriptor to _tstart defined in assembly.
   195  var tstart funcDescriptor
   196  
   197  func newosproc(mp *m) {
   198  	var (
   199  		attr pthread_attr
   200  		oset sigset
   201  		tid  pthread
   202  	)
   203  
   204  	if pthread_attr_init(&attr) != 0 {
   205  		throw("pthread_attr_init")
   206  	}
   207  
   208  	if pthread_attr_setstacksize(&attr, threadStackSize) != 0 {
   209  		throw("pthread_attr_getstacksize")
   210  	}
   211  
   212  	if pthread_attr_setdetachstate(&attr, _PTHREAD_CREATE_DETACHED) != 0 {
   213  		throw("pthread_attr_setdetachstate")
   214  	}
   215  
   216  	// Disable signals during create, so that the new thread starts
   217  	// with signals disabled. It will enable them in minit.
   218  	sigprocmask(_SIG_SETMASK, &sigset_all, &oset)
   219  	ret := retryOnEAGAIN(func() int32 {
   220  		return pthread_create(&tid, &attr, &tstart, unsafe.Pointer(mp))
   221  	})
   222  	sigprocmask(_SIG_SETMASK, &oset, nil)
   223  	if ret != 0 {
   224  		print("runtime: failed to create new OS thread (have ", mcount(), " already; errno=", ret, ")\n")
   225  		if ret == _EAGAIN {
   226  			println("runtime: may need to increase max user processes (ulimit -u)")
   227  		}
   228  		throw("newosproc")
   229  	}
   230  
   231  }
   232  
   233  func exitThread(wait *atomic.Uint32) {
   234  	// We should never reach exitThread on AIX because we let
   235  	// libc clean up threads.
   236  	throw("exitThread")
   237  }
   238  
   239  var urandom_dev = []byte("/dev/urandom\x00")
   240  
   241  //go:nosplit
   242  func readRandom(r []byte) int {
   243  	fd := open(&urandom_dev[0], 0 /* O_RDONLY */, 0)
   244  	n := read(fd, unsafe.Pointer(&r[0]), int32(len(r)))
   245  	closefd(fd)
   246  	return int(n)
   247  }
   248  
   249  func goenvs() {
   250  	goenvs_unix()
   251  }
   252  
   253  /* SIGNAL */
   254  
   255  const (
   256  	_NSIG = 256
   257  )
   258  
   259  // sigtramp is a function descriptor to _sigtramp defined in assembly
   260  var sigtramp funcDescriptor
   261  
   262  //go:nosplit
   263  //go:nowritebarrierrec
   264  func setsig(i uint32, fn uintptr) {
   265  	var sa sigactiont
   266  	sa.sa_flags = _SA_SIGINFO | _SA_ONSTACK | _SA_RESTART
   267  	sa.sa_mask = sigset_all
   268  	if fn == abi.FuncPCABIInternal(sighandler) { // abi.FuncPCABIInternal(sighandler) matches the callers in signal_unix.go
   269  		fn = uintptr(unsafe.Pointer(&sigtramp))
   270  	}
   271  	sa.sa_handler = fn
   272  	sigaction(uintptr(i), &sa, nil)
   273  
   274  }
   275  
   276  //go:nosplit
   277  //go:nowritebarrierrec
   278  func setsigstack(i uint32) {
   279  	var sa sigactiont
   280  	sigaction(uintptr(i), nil, &sa)
   281  	if sa.sa_flags&_SA_ONSTACK != 0 {
   282  		return
   283  	}
   284  	sa.sa_flags |= _SA_ONSTACK
   285  	sigaction(uintptr(i), &sa, nil)
   286  }
   287  
   288  //go:nosplit
   289  //go:nowritebarrierrec
   290  func getsig(i uint32) uintptr {
   291  	var sa sigactiont
   292  	sigaction(uintptr(i), nil, &sa)
   293  	return sa.sa_handler
   294  }
   295  
   296  // setSignalstackSP sets the ss_sp field of a stackt.
   297  //
   298  //go:nosplit
   299  func setSignalstackSP(s *stackt, sp uintptr) {
   300  	*(*uintptr)(unsafe.Pointer(&s.ss_sp)) = sp
   301  }
   302  
   303  //go:nosplit
   304  func (c *sigctxt) fixsigcode(sig uint32) {
   305  	switch sig {
   306  	case _SIGPIPE:
   307  		// For SIGPIPE, c.sigcode() isn't set to _SI_USER as on Linux.
   308  		// Therefore, raisebadsignal won't raise SIGPIPE again if
   309  		// it was deliver in a non-Go thread.
   310  		c.set_sigcode(_SI_USER)
   311  	}
   312  }
   313  
   314  //go:nosplit
   315  //go:nowritebarrierrec
   316  func sigaddset(mask *sigset, i int) {
   317  	(*mask)[(i-1)/64] |= 1 << ((uint32(i) - 1) & 63)
   318  }
   319  
   320  func sigdelset(mask *sigset, i int) {
   321  	(*mask)[(i-1)/64] &^= 1 << ((uint32(i) - 1) & 63)
   322  }
   323  
   324  func setProcessCPUProfiler(hz int32) {
   325  	setProcessCPUProfilerTimer(hz)
   326  }
   327  
   328  func setThreadCPUProfiler(hz int32) {
   329  	setThreadCPUProfilerHz(hz)
   330  }
   331  
   332  //go:nosplit
   333  func validSIGPROF(mp *m, c *sigctxt) bool {
   334  	return true
   335  }
   336  
   337  const (
   338  	_CLOCK_REALTIME  = 9
   339  	_CLOCK_MONOTONIC = 10
   340  )
   341  
   342  //go:nosplit
   343  func nanotime1() int64 {
   344  	tp := &timespec{}
   345  	if clock_gettime(_CLOCK_REALTIME, tp) != 0 {
   346  		throw("syscall clock_gettime failed")
   347  	}
   348  	return tp.tv_sec*1000000000 + tp.tv_nsec
   349  }
   350  
   351  func walltime() (sec int64, nsec int32) {
   352  	ts := &timespec{}
   353  	if clock_gettime(_CLOCK_REALTIME, ts) != 0 {
   354  		throw("syscall clock_gettime failed")
   355  	}
   356  	return ts.tv_sec, int32(ts.tv_nsec)
   357  }
   358  
   359  //go:nosplit
   360  func fcntl(fd, cmd, arg int32) (int32, int32) {
   361  	r, errno := syscall3(&libc_fcntl, uintptr(fd), uintptr(cmd), uintptr(arg))
   362  	return int32(r), int32(errno)
   363  }
   364  
   365  //go:nosplit
   366  func setNonblock(fd int32) {
   367  	flags, _ := fcntl(fd, _F_GETFL, 0)
   368  	if flags != -1 {
   369  		fcntl(fd, _F_SETFL, flags|_O_NONBLOCK)
   370  	}
   371  }
   372  
   373  // sigPerThreadSyscall is only used on linux, so we assign a bogus signal
   374  // number.
   375  const sigPerThreadSyscall = 1 << 31
   376  
   377  //go:nosplit
   378  func runPerThreadSyscall() {
   379  	throw("runPerThreadSyscall only valid on linux")
   380  }
   381  
   382  //go:nosplit
   383  func getuid() int32 {
   384  	r, errno := syscall0(&libc_getuid)
   385  	if errno != 0 {
   386  		print("getuid failed ", errno)
   387  		throw("getuid")
   388  	}
   389  	return int32(r)
   390  }
   391  
   392  //go:nosplit
   393  func geteuid() int32 {
   394  	r, errno := syscall0(&libc_geteuid)
   395  	if errno != 0 {
   396  		print("geteuid failed ", errno)
   397  		throw("geteuid")
   398  	}
   399  	return int32(r)
   400  }
   401  
   402  //go:nosplit
   403  func getgid() int32 {
   404  	r, errno := syscall0(&libc_getgid)
   405  	if errno != 0 {
   406  		print("getgid failed ", errno)
   407  		throw("getgid")
   408  	}
   409  	return int32(r)
   410  }
   411  
   412  //go:nosplit
   413  func getegid() int32 {
   414  	r, errno := syscall0(&libc_getegid)
   415  	if errno != 0 {
   416  		print("getegid failed ", errno)
   417  		throw("getegid")
   418  	}
   419  	return int32(r)
   420  }
   421
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