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  	"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  	numCPUStartup = getCPUCount()
   101  	physPageSize = sysconf(__SC_PAGE_SIZE)
   102  }
   103  
   104  func getCPUCount() int32 {
   105  	return int32(sysconf(__SC_NPROCESSORS_ONLN))
   106  }
   107  
   108  // newosproc0 is a version of newosproc that can be called before the runtime
   109  // is initialized.
   110  //
   111  // This function is not safe to use after initialization as it does not pass an M as fnarg.
   112  //
   113  //go:nosplit
   114  func newosproc0(stacksize uintptr, fn *funcDescriptor) {
   115  	var (
   116  		attr pthread_attr
   117  		oset sigset
   118  		tid  pthread
   119  	)
   120  
   121  	if pthread_attr_init(&attr) != 0 {
   122  		writeErrStr(failthreadcreate)
   123  		exit(1)
   124  	}
   125  
   126  	if pthread_attr_setstacksize(&attr, threadStackSize) != 0 {
   127  		writeErrStr(failthreadcreate)
   128  		exit(1)
   129  	}
   130  
   131  	if pthread_attr_setdetachstate(&attr, _PTHREAD_CREATE_DETACHED) != 0 {
   132  		writeErrStr(failthreadcreate)
   133  		exit(1)
   134  	}
   135  
   136  	// Disable signals during create, so that the new thread starts
   137  	// with signals disabled. It will enable them in minit.
   138  	sigprocmask(_SIG_SETMASK, &sigset_all, &oset)
   139  	var ret int32
   140  	for tries := 0; tries < 20; tries++ {
   141  		// pthread_create can fail with EAGAIN for no reasons
   142  		// but it will be ok if it retries.
   143  		ret = pthread_create(&tid, &attr, fn, nil)
   144  		if ret != _EAGAIN {
   145  			break
   146  		}
   147  		usleep(uint32(tries+1) * 1000) // Milliseconds.
   148  	}
   149  	sigprocmask(_SIG_SETMASK, &oset, nil)
   150  	if ret != 0 {
   151  		writeErrStr(failthreadcreate)
   152  		exit(1)
   153  	}
   154  
   155  }
   156  
   157  // Called to do synchronous initialization of Go code built with
   158  // -buildmode=c-archive or -buildmode=c-shared.
   159  // None of the Go runtime is initialized.
   160  //
   161  //go:nosplit
   162  //go:nowritebarrierrec
   163  func libpreinit() {
   164  	initsig(true)
   165  }
   166  
   167  // Ms related functions
   168  func mpreinit(mp *m) {
   169  	mp.gsignal = malg(32 * 1024) // AIX wants >= 8K
   170  	mp.gsignal.m = mp
   171  }
   172  
   173  // errno address must be retrieved by calling _Errno libc function.
   174  // This will return a pointer to errno.
   175  func miniterrno() {
   176  	mp := getg().m
   177  	r, _ := syscall0(&libc__Errno)
   178  	mp.perrno = r
   179  
   180  }
   181  
   182  func minit() {
   183  	miniterrno()
   184  	minitSignals()
   185  	getg().m.procid = uint64(pthread_self())
   186  }
   187  
   188  func unminit() {
   189  	unminitSignals()
   190  	getg().m.procid = 0
   191  }
   192  
   193  // Called from mexit, but not from dropm, to undo the effect of thread-owned
   194  // resources in minit, semacreate, or elsewhere. Do not take locks after calling this.
   195  //
   196  // This always runs without a P, so //go:nowritebarrierrec is required.
   197  //
   198  //go:nowritebarrierrec
   199  func mdestroy(mp *m) {
   200  }
   201  
   202  // tstart is a function descriptor to _tstart defined in assembly.
   203  var tstart funcDescriptor
   204  
   205  func newosproc(mp *m) {
   206  	var (
   207  		attr pthread_attr
   208  		oset sigset
   209  		tid  pthread
   210  	)
   211  
   212  	if pthread_attr_init(&attr) != 0 {
   213  		throw("pthread_attr_init")
   214  	}
   215  
   216  	if pthread_attr_setstacksize(&attr, threadStackSize) != 0 {
   217  		throw("pthread_attr_getstacksize")
   218  	}
   219  
   220  	if pthread_attr_setdetachstate(&attr, _PTHREAD_CREATE_DETACHED) != 0 {
   221  		throw("pthread_attr_setdetachstate")
   222  	}
   223  
   224  	// Disable signals during create, so that the new thread starts
   225  	// with signals disabled. It will enable them in minit.
   226  	sigprocmask(_SIG_SETMASK, &sigset_all, &oset)
   227  	ret := retryOnEAGAIN(func() int32 {
   228  		return pthread_create(&tid, &attr, &tstart, unsafe.Pointer(mp))
   229  	})
   230  	sigprocmask(_SIG_SETMASK, &oset, nil)
   231  	if ret != 0 {
   232  		print("runtime: failed to create new OS thread (have ", mcount(), " already; errno=", ret, ")\n")
   233  		if ret == _EAGAIN {
   234  			println("runtime: may need to increase max user processes (ulimit -u)")
   235  		}
   236  		throw("newosproc")
   237  	}
   238  
   239  }
   240  
   241  func exitThread(wait *atomic.Uint32) {
   242  	// We should never reach exitThread on AIX because we let
   243  	// libc clean up threads.
   244  	throw("exitThread")
   245  }
   246  
   247  var urandom_dev = []byte("/dev/urandom\x00")
   248  
   249  //go:nosplit
   250  func readRandom(r []byte) int {
   251  	fd := open(&urandom_dev[0], 0 /* O_RDONLY */, 0)
   252  	n := read(fd, unsafe.Pointer(&r[0]), int32(len(r)))
   253  	closefd(fd)
   254  	return int(n)
   255  }
   256  
   257  func goenvs() {
   258  	goenvs_unix()
   259  }
   260  
   261  /* SIGNAL */
   262  
   263  const (
   264  	_NSIG = 256
   265  )
   266  
   267  // sigtramp is a function descriptor to _sigtramp defined in assembly
   268  var sigtramp funcDescriptor
   269  
   270  //go:nosplit
   271  //go:nowritebarrierrec
   272  func setsig(i uint32, fn uintptr) {
   273  	var sa sigactiont
   274  	sa.sa_flags = _SA_SIGINFO | _SA_ONSTACK | _SA_RESTART
   275  	sa.sa_mask = sigset_all
   276  	if fn == abi.FuncPCABIInternal(sighandler) { // abi.FuncPCABIInternal(sighandler) matches the callers in signal_unix.go
   277  		fn = uintptr(unsafe.Pointer(&sigtramp))
   278  	}
   279  	sa.sa_handler = fn
   280  	sigaction(uintptr(i), &sa, nil)
   281  
   282  }
   283  
   284  //go:nosplit
   285  //go:nowritebarrierrec
   286  func setsigstack(i uint32) {
   287  	var sa sigactiont
   288  	sigaction(uintptr(i), nil, &sa)
   289  	if sa.sa_flags&_SA_ONSTACK != 0 {
   290  		return
   291  	}
   292  	sa.sa_flags |= _SA_ONSTACK
   293  	sigaction(uintptr(i), &sa, nil)
   294  }
   295  
   296  //go:nosplit
   297  //go:nowritebarrierrec
   298  func getsig(i uint32) uintptr {
   299  	var sa sigactiont
   300  	sigaction(uintptr(i), nil, &sa)
   301  	return sa.sa_handler
   302  }
   303  
   304  // setSignalstackSP sets the ss_sp field of a stackt.
   305  //
   306  //go:nosplit
   307  func setSignalstackSP(s *stackt, sp uintptr) {
   308  	*(*uintptr)(unsafe.Pointer(&s.ss_sp)) = sp
   309  }
   310  
   311  //go:nosplit
   312  func (c *sigctxt) fixsigcode(sig uint32) {
   313  	switch sig {
   314  	case _SIGPIPE:
   315  		// For SIGPIPE, c.sigcode() isn't set to _SI_USER as on Linux.
   316  		// Therefore, raisebadsignal won't raise SIGPIPE again if
   317  		// it was deliver in a non-Go thread.
   318  		c.set_sigcode(_SI_USER)
   319  	}
   320  }
   321  
   322  //go:nosplit
   323  //go:nowritebarrierrec
   324  func sigaddset(mask *sigset, i int) {
   325  	(*mask)[(i-1)/64] |= 1 << ((uint32(i) - 1) & 63)
   326  }
   327  
   328  func sigdelset(mask *sigset, i int) {
   329  	(*mask)[(i-1)/64] &^= 1 << ((uint32(i) - 1) & 63)
   330  }
   331  
   332  func setProcessCPUProfiler(hz int32) {
   333  	setProcessCPUProfilerTimer(hz)
   334  }
   335  
   336  func setThreadCPUProfiler(hz int32) {
   337  	setThreadCPUProfilerHz(hz)
   338  }
   339  
   340  //go:nosplit
   341  func validSIGPROF(mp *m, c *sigctxt) bool {
   342  	return true
   343  }
   344  
   345  const (
   346  	_CLOCK_REALTIME  = 9
   347  	_CLOCK_MONOTONIC = 10
   348  )
   349  
   350  //go:nosplit
   351  func nanotime1() int64 {
   352  	tp := &timespec{}
   353  	if clock_gettime(_CLOCK_REALTIME, tp) != 0 {
   354  		throw("syscall clock_gettime failed")
   355  	}
   356  	return tp.tv_sec*1000000000 + tp.tv_nsec
   357  }
   358  
   359  func walltime() (sec int64, nsec int32) {
   360  	ts := &timespec{}
   361  	if clock_gettime(_CLOCK_REALTIME, ts) != 0 {
   362  		throw("syscall clock_gettime failed")
   363  	}
   364  	return ts.tv_sec, int32(ts.tv_nsec)
   365  }
   366  
   367  //go:nosplit
   368  func fcntl(fd, cmd, arg int32) (int32, int32) {
   369  	r, errno := syscall3(&libc_fcntl, uintptr(fd), uintptr(cmd), uintptr(arg))
   370  	return int32(r), int32(errno)
   371  }
   372  
   373  //go:nosplit
   374  func setNonblock(fd int32) {
   375  	flags, _ := fcntl(fd, _F_GETFL, 0)
   376  	if flags != -1 {
   377  		fcntl(fd, _F_SETFL, flags|_O_NONBLOCK)
   378  	}
   379  }
   380  
   381  // sigPerThreadSyscall is only used on linux, so we assign a bogus signal
   382  // number.
   383  const sigPerThreadSyscall = 1 << 31
   384  
   385  //go:nosplit
   386  func runPerThreadSyscall() {
   387  	throw("runPerThreadSyscall only valid on linux")
   388  }
   389  
   390  //go:nosplit
   391  func getuid() int32 {
   392  	r, errno := syscall0(&libc_getuid)
   393  	if errno != 0 {
   394  		print("getuid failed ", errno)
   395  		throw("getuid")
   396  	}
   397  	return int32(r)
   398  }
   399  
   400  //go:nosplit
   401  func geteuid() int32 {
   402  	r, errno := syscall0(&libc_geteuid)
   403  	if errno != 0 {
   404  		print("geteuid failed ", errno)
   405  		throw("geteuid")
   406  	}
   407  	return int32(r)
   408  }
   409  
   410  //go:nosplit
   411  func getgid() int32 {
   412  	r, errno := syscall0(&libc_getgid)
   413  	if errno != 0 {
   414  		print("getgid failed ", errno)
   415  		throw("getgid")
   416  	}
   417  	return int32(r)
   418  }
   419  
   420  //go:nosplit
   421  func getegid() int32 {
   422  	r, errno := syscall0(&libc_getegid)
   423  	if errno != 0 {
   424  		print("getegid failed ", errno)
   425  		throw("getegid")
   426  	}
   427  	return int32(r)
   428  }
   429
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