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  	libcall  libcall
    31  }
    32  
    33  //go:nosplit
    34  func semacreate(mp *m) {
    35  	if mp.waitsema != 0 {
    36  		return
    37  	}
    38  
    39  	var sem *semt
    40  
    41  	// Call libc's malloc rather than malloc. This will
    42  	// allocate space on the C heap. We can't call mallocgc
    43  	// here because it could cause a deadlock.
    44  	sem = (*semt)(malloc(unsafe.Sizeof(*sem)))
    45  	if sem_init(sem, 0, 0) != 0 {
    46  		throw("sem_init")
    47  	}
    48  	mp.waitsema = uintptr(unsafe.Pointer(sem))
    49  }
    50  
    51  //go:nosplit
    52  func semasleep(ns int64) int32 {
    53  	mp := getg().m
    54  	if ns >= 0 {
    55  		var ts timespec
    56  
    57  		if clock_gettime(_CLOCK_REALTIME, &ts) != 0 {
    58  			throw("clock_gettime")
    59  		}
    60  		ts.tv_sec += ns / 1e9
    61  		ts.tv_nsec += ns % 1e9
    62  		if ts.tv_nsec >= 1e9 {
    63  			ts.tv_sec++
    64  			ts.tv_nsec -= 1e9
    65  		}
    66  
    67  		if r, err := sem_timedwait((*semt)(unsafe.Pointer(mp.waitsema)), &ts); r != 0 {
    68  			if err == _ETIMEDOUT || err == _EAGAIN || err == _EINTR {
    69  				return -1
    70  			}
    71  			println("sem_timedwait err ", err, " ts.tv_sec ", ts.tv_sec, " ts.tv_nsec ", ts.tv_nsec, " ns ", ns, " id ", mp.id)
    72  			throw("sem_timedwait")
    73  		}
    74  		return 0
    75  	}
    76  	for {
    77  		r1, err := sem_wait((*semt)(unsafe.Pointer(mp.waitsema)))
    78  		if r1 == 0 {
    79  			break
    80  		}
    81  		if err == _EINTR {
    82  			continue
    83  		}
    84  		throw("sem_wait")
    85  	}
    86  	return 0
    87  }
    88  
    89  //go:nosplit
    90  func semawakeup(mp *m) {
    91  	if sem_post((*semt)(unsafe.Pointer(mp.waitsema))) != 0 {
    92  		throw("sem_post")
    93  	}
    94  }
    95  
    96  func osinit() {
    97  	// Call miniterrno so that we can safely make system calls
    98  	// before calling minit on m0.
    99  	miniterrno()
   100  
   101  	numCPUStartup = getCPUCount()
   102  	physPageSize = sysconf(__SC_PAGE_SIZE)
   103  }
   104  
   105  func getCPUCount() int32 {
   106  	return int32(sysconf(__SC_NPROCESSORS_ONLN))
   107  }
   108  
   109  // newosproc0 is a version of newosproc that can be called before the runtime
   110  // is initialized.
   111  //
   112  // This function is not safe to use after initialization as it does not pass an M as fnarg.
   113  //
   114  //go:nosplit
   115  func newosproc0(stacksize uintptr, fn *funcDescriptor) {
   116  	var (
   117  		attr pthread_attr
   118  		oset sigset
   119  		tid  pthread
   120  	)
   121  
   122  	if pthread_attr_init(&attr) != 0 {
   123  		writeErrStr(failthreadcreate)
   124  		exit(1)
   125  	}
   126  
   127  	if pthread_attr_setstacksize(&attr, threadStackSize) != 0 {
   128  		writeErrStr(failthreadcreate)
   129  		exit(1)
   130  	}
   131  
   132  	if pthread_attr_setdetachstate(&attr, _PTHREAD_CREATE_DETACHED) != 0 {
   133  		writeErrStr(failthreadcreate)
   134  		exit(1)
   135  	}
   136  
   137  	// Disable signals during create, so that the new thread starts
   138  	// with signals disabled. It will enable them in minit.
   139  	sigprocmask(_SIG_SETMASK, &sigset_all, &oset)
   140  	var ret int32
   141  	for tries := 0; tries < 20; tries++ {
   142  		// pthread_create can fail with EAGAIN for no reasons
   143  		// but it will be ok if it retries.
   144  		ret = pthread_create(&tid, &attr, fn, nil)
   145  		if ret != _EAGAIN {
   146  			break
   147  		}
   148  		usleep(uint32(tries+1) * 1000) // Milliseconds.
   149  	}
   150  	sigprocmask(_SIG_SETMASK, &oset, nil)
   151  	if ret != 0 {
   152  		writeErrStr(failthreadcreate)
   153  		exit(1)
   154  	}
   155  
   156  }
   157  
   158  // Called to do synchronous initialization of Go code built with
   159  // -buildmode=c-archive or -buildmode=c-shared.
   160  // None of the Go runtime is initialized.
   161  //
   162  //go:nosplit
   163  //go:nowritebarrierrec
   164  func libpreinit() {
   165  	initsig(true)
   166  }
   167  
   168  // Ms related functions
   169  func mpreinit(mp *m) {
   170  	mp.gsignal = malg(32 * 1024) // AIX wants >= 8K
   171  	mp.gsignal.m = mp
   172  }
   173  
   174  // errno address must be retrieved by calling _Errno libc function.
   175  // This will return a pointer to errno.
   176  func miniterrno() {
   177  	mp := getg().m
   178  	r, _ := syscall0(&libc__Errno)
   179  	mp.perrno = r
   180  
   181  }
   182  
   183  func minit() {
   184  	miniterrno()
   185  	minitSignals()
   186  	getg().m.procid = uint64(pthread_self())
   187  }
   188  
   189  func unminit() {
   190  	unminitSignals()
   191  	getg().m.procid = 0
   192  }
   193  
   194  // Called from mexit, but not from dropm, to undo the effect of thread-owned
   195  // resources in minit, semacreate, or elsewhere. Do not take locks after calling this.
   196  //
   197  // This always runs without a P, so //go:nowritebarrierrec is required.
   198  //
   199  //go:nowritebarrierrec
   200  func mdestroy(mp *m) {
   201  }
   202  
   203  // tstart is a function descriptor to _tstart defined in assembly.
   204  var tstart funcDescriptor
   205  
   206  func newosproc(mp *m) {
   207  	var (
   208  		attr pthread_attr
   209  		oset sigset
   210  		tid  pthread
   211  	)
   212  
   213  	if pthread_attr_init(&attr) != 0 {
   214  		throw("pthread_attr_init")
   215  	}
   216  
   217  	if pthread_attr_setstacksize(&attr, threadStackSize) != 0 {
   218  		throw("pthread_attr_getstacksize")
   219  	}
   220  
   221  	if pthread_attr_setdetachstate(&attr, _PTHREAD_CREATE_DETACHED) != 0 {
   222  		throw("pthread_attr_setdetachstate")
   223  	}
   224  
   225  	// Disable signals during create, so that the new thread starts
   226  	// with signals disabled. It will enable them in minit.
   227  	sigprocmask(_SIG_SETMASK, &sigset_all, &oset)
   228  	ret := retryOnEAGAIN(func() int32 {
   229  		return pthread_create(&tid, &attr, &tstart, unsafe.Pointer(mp))
   230  	})
   231  	sigprocmask(_SIG_SETMASK, &oset, nil)
   232  	if ret != 0 {
   233  		print("runtime: failed to create new OS thread (have ", mcount(), " already; errno=", ret, ")\n")
   234  		if ret == _EAGAIN {
   235  			println("runtime: may need to increase max user processes (ulimit -u)")
   236  		}
   237  		throw("newosproc")
   238  	}
   239  
   240  }
   241  
   242  func exitThread(wait *atomic.Uint32) {
   243  	// We should never reach exitThread on AIX because we let
   244  	// libc clean up threads.
   245  	throw("exitThread")
   246  }
   247  
   248  var urandom_dev = []byte("/dev/urandom\x00")
   249  
   250  //go:nosplit
   251  func readRandom(r []byte) int {
   252  	fd := open(&urandom_dev[0], 0 /* O_RDONLY */, 0)
   253  	n := read(fd, unsafe.Pointer(&r[0]), int32(len(r)))
   254  	closefd(fd)
   255  	return int(n)
   256  }
   257  
   258  func goenvs() {
   259  	goenvs_unix()
   260  }
   261  
   262  /* SIGNAL */
   263  
   264  const (
   265  	_NSIG = 256
   266  )
   267  
   268  // sigtramp is a function descriptor to _sigtramp defined in assembly
   269  var sigtramp funcDescriptor
   270  
   271  //go:nosplit
   272  //go:nowritebarrierrec
   273  func setsig(i uint32, fn uintptr) {
   274  	var sa sigactiont
   275  	sa.sa_flags = _SA_SIGINFO | _SA_ONSTACK | _SA_RESTART
   276  	sa.sa_mask = sigset_all
   277  	if fn == abi.FuncPCABIInternal(sighandler) { // abi.FuncPCABIInternal(sighandler) matches the callers in signal_unix.go
   278  		fn = uintptr(unsafe.Pointer(&sigtramp))
   279  	}
   280  	sa.sa_handler = fn
   281  	sigaction(uintptr(i), &sa, nil)
   282  
   283  }
   284  
   285  //go:nosplit
   286  //go:nowritebarrierrec
   287  func setsigstack(i uint32) {
   288  	var sa sigactiont
   289  	sigaction(uintptr(i), nil, &sa)
   290  	if sa.sa_flags&_SA_ONSTACK != 0 {
   291  		return
   292  	}
   293  	sa.sa_flags |= _SA_ONSTACK
   294  	sigaction(uintptr(i), &sa, nil)
   295  }
   296  
   297  //go:nosplit
   298  //go:nowritebarrierrec
   299  func getsig(i uint32) uintptr {
   300  	var sa sigactiont
   301  	sigaction(uintptr(i), nil, &sa)
   302  	return sa.sa_handler
   303  }
   304  
   305  // setSignalstackSP sets the ss_sp field of a stackt.
   306  //
   307  //go:nosplit
   308  func setSignalstackSP(s *stackt, sp uintptr) {
   309  	*(*uintptr)(unsafe.Pointer(&s.ss_sp)) = sp
   310  }
   311  
   312  //go:nosplit
   313  func (c *sigctxt) fixsigcode(sig uint32) {
   314  	switch sig {
   315  	case _SIGPIPE:
   316  		// For SIGPIPE, c.sigcode() isn't set to _SI_USER as on Linux.
   317  		// Therefore, raisebadsignal won't raise SIGPIPE again if
   318  		// it was deliver in a non-Go thread.
   319  		c.set_sigcode(_SI_USER)
   320  	}
   321  }
   322  
   323  //go:nosplit
   324  //go:nowritebarrierrec
   325  func sigaddset(mask *sigset, i int) {
   326  	(*mask)[(i-1)/64] |= 1 << ((uint32(i) - 1) & 63)
   327  }
   328  
   329  func sigdelset(mask *sigset, i int) {
   330  	(*mask)[(i-1)/64] &^= 1 << ((uint32(i) - 1) & 63)
   331  }
   332  
   333  func setProcessCPUProfiler(hz int32) {
   334  	setProcessCPUProfilerTimer(hz)
   335  }
   336  
   337  func setThreadCPUProfiler(hz int32) {
   338  	setThreadCPUProfilerHz(hz)
   339  }
   340  
   341  //go:nosplit
   342  func validSIGPROF(mp *m, c *sigctxt) bool {
   343  	return true
   344  }
   345  
   346  const (
   347  	_CLOCK_REALTIME  = 9
   348  	_CLOCK_MONOTONIC = 10
   349  )
   350  
   351  //go:nosplit
   352  func nanotime1() int64 {
   353  	tp := &timespec{}
   354  	if clock_gettime(_CLOCK_REALTIME, tp) != 0 {
   355  		throw("syscall clock_gettime failed")
   356  	}
   357  	return tp.tv_sec*1000000000 + tp.tv_nsec
   358  }
   359  
   360  func walltime() (sec int64, nsec int32) {
   361  	ts := &timespec{}
   362  	if clock_gettime(_CLOCK_REALTIME, ts) != 0 {
   363  		throw("syscall clock_gettime failed")
   364  	}
   365  	return ts.tv_sec, int32(ts.tv_nsec)
   366  }
   367  
   368  //go:nosplit
   369  func fcntl(fd, cmd, arg int32) (int32, int32) {
   370  	r, errno := syscall3(&libc_fcntl, uintptr(fd), uintptr(cmd), uintptr(arg))
   371  	return int32(r), int32(errno)
   372  }
   373  
   374  //go:nosplit
   375  func setNonblock(fd int32) {
   376  	flags, _ := fcntl(fd, _F_GETFL, 0)
   377  	if flags != -1 {
   378  		fcntl(fd, _F_SETFL, flags|_O_NONBLOCK)
   379  	}
   380  }
   381  
   382  // sigPerThreadSyscall is only used on linux, so we assign a bogus signal
   383  // number.
   384  const sigPerThreadSyscall = 1 << 31
   385  
   386  //go:nosplit
   387  func runPerThreadSyscall() {
   388  	throw("runPerThreadSyscall only valid on linux")
   389  }
   390  
   391  //go:nosplit
   392  func getuid() int32 {
   393  	r, errno := syscall0(&libc_getuid)
   394  	if errno != 0 {
   395  		print("getuid failed ", errno)
   396  		throw("getuid")
   397  	}
   398  	return int32(r)
   399  }
   400  
   401  //go:nosplit
   402  func geteuid() int32 {
   403  	r, errno := syscall0(&libc_geteuid)
   404  	if errno != 0 {
   405  		print("geteuid failed ", errno)
   406  		throw("geteuid")
   407  	}
   408  	return int32(r)
   409  }
   410  
   411  //go:nosplit
   412  func getgid() int32 {
   413  	r, errno := syscall0(&libc_getgid)
   414  	if errno != 0 {
   415  		print("getgid failed ", errno)
   416  		throw("getgid")
   417  	}
   418  	return int32(r)
   419  }
   420  
   421  //go:nosplit
   422  func getegid() int32 {
   423  	r, errno := syscall0(&libc_getegid)
   424  	if errno != 0 {
   425  		print("getegid failed ", errno)
   426  		throw("getegid")
   427  	}
   428  	return int32(r)
   429  }
   430
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