github.com/rohankumardubey/syslog-redirector-golang@v0.0.0-20140320174030-4859f03d829a/src/pkg/runtime/os_openbsd.c (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  #include "runtime.h"
     6  #include "defs_GOOS_GOARCH.h"
     7  #include "os_GOOS.h"
     8  #include "signal_unix.h"
     9  #include "stack.h"
    10  #include "../../cmd/ld/textflag.h"
    11  
    12  enum
    13  {
    14  	ESRCH = 3,
    15  	ENOTSUP = 91,
    16  
    17  	// From OpenBSD's sys/time.h
    18  	CLOCK_REALTIME = 0,
    19  	CLOCK_VIRTUAL = 1,
    20  	CLOCK_PROF = 2,
    21  	CLOCK_MONOTONIC = 3
    22  };
    23  
    24  extern SigTab runtime·sigtab[];
    25  
    26  static Sigset sigset_none;
    27  static Sigset sigset_all = ~(Sigset)0;
    28  
    29  extern int64 runtime·tfork(void *param, uintptr psize, M *mp, G *gp, void (*fn)(void));
    30  extern int32 runtime·thrsleep(void *ident, int32 clock_id, void *tsp, void *lock, const int32 *abort);
    31  extern int32 runtime·thrwakeup(void *ident, int32 n);
    32  
    33  // From OpenBSD's <sys/sysctl.h>
    34  #define	CTL_HW	6
    35  #define	HW_NCPU	3
    36  
    37  static int32
    38  getncpu(void)
    39  {
    40  	uint32 mib[2];
    41  	uint32 out;
    42  	int32 ret;
    43  	uintptr nout;
    44  
    45  	// Fetch hw.ncpu via sysctl.
    46  	mib[0] = CTL_HW;
    47  	mib[1] = HW_NCPU;
    48  	nout = sizeof out;
    49  	out = 0;
    50  	ret = runtime·sysctl(mib, 2, (byte*)&out, &nout, nil, 0);
    51  	if(ret >= 0)
    52  		return out;
    53  	else
    54  		return 1;
    55  }
    56  
    57  uintptr
    58  runtime·semacreate(void)
    59  {
    60  	return 1;
    61  }
    62  
    63  #pragma textflag NOSPLIT
    64  int32
    65  runtime·semasleep(int64 ns)
    66  {
    67  	Timespec ts;
    68  
    69  	// spin-mutex lock
    70  	while(runtime·xchg(&m->waitsemalock, 1))
    71  		runtime·osyield();
    72  
    73  	for(;;) {
    74  		// lock held
    75  		if(m->waitsemacount == 0) {
    76  			// sleep until semaphore != 0 or timeout.
    77  			// thrsleep unlocks m->waitsemalock.
    78  			if(ns < 0)
    79  				runtime·thrsleep(&m->waitsemacount, 0, nil, &m->waitsemalock, nil);
    80  			else {
    81  				ns += runtime·nanotime();
    82  				// NOTE: tv_nsec is int64 on amd64, so this assumes a little-endian system.
    83  				ts.tv_nsec = 0;
    84  				ts.tv_sec = runtime·timediv(ns, 1000000000, (int32*)&ts.tv_nsec);
    85  				runtime·thrsleep(&m->waitsemacount, CLOCK_REALTIME, &ts, &m->waitsemalock, nil);
    86  			}
    87  			// reacquire lock
    88  			while(runtime·xchg(&m->waitsemalock, 1))
    89  				runtime·osyield();
    90  		}
    91  
    92  		// lock held (again)
    93  		if(m->waitsemacount != 0) {
    94  			// semaphore is available.
    95  			m->waitsemacount--;
    96  			// spin-mutex unlock
    97  			runtime·atomicstore(&m->waitsemalock, 0);
    98  			return 0;  // semaphore acquired
    99  		}
   100  
   101  		// semaphore not available.
   102  		// if there is a timeout, stop now.
   103  		// otherwise keep trying.
   104  		if(ns >= 0)
   105  			break;
   106  	}
   107  
   108  	// lock held but giving up
   109  	// spin-mutex unlock
   110  	runtime·atomicstore(&m->waitsemalock, 0);
   111  	return -1;
   112  }
   113  
   114  void
   115  runtime·semawakeup(M *mp)
   116  {
   117  	uint32 ret;
   118  
   119  	// spin-mutex lock
   120  	while(runtime·xchg(&mp->waitsemalock, 1))
   121  		runtime·osyield();
   122  	mp->waitsemacount++;
   123  	ret = runtime·thrwakeup(&mp->waitsemacount, 1);
   124  	if(ret != 0 && ret != ESRCH)
   125  		runtime·printf("thrwakeup addr=%p sem=%d ret=%d\n", &mp->waitsemacount, mp->waitsemacount, ret);
   126  	// spin-mutex unlock
   127  	runtime·atomicstore(&mp->waitsemalock, 0);
   128  }
   129  
   130  void
   131  runtime·newosproc(M *mp, void *stk)
   132  {
   133  	Tfork param;
   134  	Sigset oset;
   135  	int32 ret;
   136  
   137  	if(0) {
   138  		runtime·printf(
   139  			"newosproc stk=%p m=%p g=%p id=%d/%d ostk=%p\n",
   140  			stk, mp, mp->g0, mp->id, (int32)mp->tls[0], &mp);
   141  	}
   142  
   143  	mp->tls[0] = mp->id;	// so 386 asm can find it
   144  
   145  	param.tf_tcb = (byte*)&mp->tls[0];
   146  	param.tf_tid = (int32*)&mp->procid;
   147  	param.tf_stack = stk;
   148  
   149  	oset = runtime·sigprocmask(SIG_SETMASK, sigset_all);
   150  	ret = runtime·tfork((byte*)&param, sizeof(param), mp, mp->g0, runtime·mstart);
   151  	runtime·sigprocmask(SIG_SETMASK, oset);
   152  
   153  	if(ret < 0) {
   154  		runtime·printf("runtime: failed to create new OS thread (have %d already; errno=%d)\n", runtime·mcount() - 1, -ret);
   155  		if (ret == -ENOTSUP)
   156  			runtime·printf("runtime: is kern.rthreads disabled?\n");
   157  		runtime·throw("runtime.newosproc");
   158  	}
   159  }
   160  
   161  void
   162  runtime·osinit(void)
   163  {
   164  	runtime·ncpu = getncpu();
   165  }
   166  
   167  void
   168  runtime·get_random_data(byte **rnd, int32 *rnd_len)
   169  {
   170  	static byte urandom_data[HashRandomBytes];
   171  	int32 fd;
   172  	fd = runtime·open("/dev/urandom", 0 /* O_RDONLY */, 0);
   173  	if(runtime·read(fd, urandom_data, HashRandomBytes) == HashRandomBytes) {
   174  		*rnd = urandom_data;
   175  		*rnd_len = HashRandomBytes;
   176  	} else {
   177  		*rnd = nil;
   178  		*rnd_len = 0;
   179  	}
   180  	runtime·close(fd);
   181  }
   182  
   183  void
   184  runtime·goenvs(void)
   185  {
   186  	runtime·goenvs_unix();
   187  }
   188  
   189  // Called to initialize a new m (including the bootstrap m).
   190  // Called on the parent thread (main thread in case of bootstrap), can allocate memory.
   191  void
   192  runtime·mpreinit(M *mp)
   193  {
   194  	mp->gsignal = runtime·malg(32*1024);
   195  }
   196  
   197  // Called to initialize a new m (including the bootstrap m).
   198  // Called on the new thread, can not allocate memory.
   199  void
   200  runtime·minit(void)
   201  {
   202  	// Initialize signal handling
   203  	runtime·signalstack((byte*)m->gsignal->stackguard - StackGuard, 32*1024);
   204  	runtime·sigprocmask(SIG_SETMASK, sigset_none);
   205  }
   206  
   207  // Called from dropm to undo the effect of an minit.
   208  void
   209  runtime·unminit(void)
   210  {
   211  	runtime·signalstack(nil, 0);
   212  }
   213  
   214  void
   215  runtime·sigpanic(void)
   216  {
   217  	switch(g->sig) {
   218  	case SIGBUS:
   219  		if(g->sigcode0 == BUS_ADRERR && g->sigcode1 < 0x1000) {
   220  			if(g->sigpc == 0)
   221  				runtime·panicstring("call of nil func value");
   222  			runtime·panicstring("invalid memory address or nil pointer dereference");
   223  		}
   224  		runtime·printf("unexpected fault address %p\n", g->sigcode1);
   225  		runtime·throw("fault");
   226  	case SIGSEGV:
   227  		if((g->sigcode0 == 0 || g->sigcode0 == SEGV_MAPERR || g->sigcode0 == SEGV_ACCERR) && g->sigcode1 < 0x1000) {
   228  			if(g->sigpc == 0)
   229  				runtime·panicstring("call of nil func value");
   230  			runtime·panicstring("invalid memory address or nil pointer dereference");
   231  		}
   232  		runtime·printf("unexpected fault address %p\n", g->sigcode1);
   233  		runtime·throw("fault");
   234  	case SIGFPE:
   235  		switch(g->sigcode0) {
   236  		case FPE_INTDIV:
   237  			runtime·panicstring("integer divide by zero");
   238  		case FPE_INTOVF:
   239  			runtime·panicstring("integer overflow");
   240  		}
   241  		runtime·panicstring("floating point error");
   242  	}
   243  	runtime·panicstring(runtime·sigtab[g->sig].name);
   244  }
   245  
   246  uintptr
   247  runtime·memlimit(void)
   248  {
   249  	return 0;
   250  }
   251  
   252  extern void runtime·sigtramp(void);
   253  
   254  typedef struct sigaction {
   255  	union {
   256  		void    (*__sa_handler)(int32);
   257  		void    (*__sa_sigaction)(int32, Siginfo*, void *);
   258  	} __sigaction_u;		/* signal handler */
   259  	uint32	sa_mask;		/* signal mask to apply */
   260  	int32	sa_flags;		/* see signal options below */
   261  } Sigaction;
   262  
   263  void
   264  runtime·setsig(int32 i, GoSighandler *fn, bool restart)
   265  {
   266  	Sigaction sa;
   267  
   268  	runtime·memclr((byte*)&sa, sizeof sa);
   269  	sa.sa_flags = SA_SIGINFO|SA_ONSTACK;
   270  	if(restart)
   271  		sa.sa_flags |= SA_RESTART;
   272  	sa.sa_mask = ~0U;
   273  	if(fn == runtime·sighandler)
   274  		fn = (void*)runtime·sigtramp;
   275  	sa.__sigaction_u.__sa_sigaction = (void*)fn;
   276  	runtime·sigaction(i, &sa, nil);
   277  }
   278  
   279  GoSighandler*
   280  runtime·getsig(int32 i)
   281  {
   282  	Sigaction sa;
   283  
   284  	runtime·memclr((byte*)&sa, sizeof sa);
   285  	runtime·sigaction(i, nil, &sa);
   286  	if((void*)sa.__sigaction_u.__sa_sigaction == runtime·sigtramp)
   287  		return runtime·sighandler;
   288  	return (void*)sa.__sigaction_u.__sa_sigaction;
   289  }
   290  
   291  void
   292  runtime·signalstack(byte *p, int32 n)
   293  {
   294  	StackT st;
   295  
   296  	st.ss_sp = (void*)p;
   297  	st.ss_size = n;
   298  	st.ss_flags = 0;
   299  	if(p == nil)
   300  		st.ss_flags = SS_DISABLE;
   301  	runtime·sigaltstack(&st, nil);
   302  }