1 // Copyright 2013 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 <sys/types.h> 6 #include <pthread.h> 7 #include <signal.h> 8 #include <string.h> 9 #include "libcgo.h" 10 #include "libcgo_unix.h" 11 12 static void *threadentry(void*); 13 14 static void (*setg_gcc)(void*); 15 16 void 17 x_cgo_init(G *g, void (*setg)(void*)) 18 { 19 pthread_attr_t attr; 20 size_t size; 21 22 setg_gcc = setg; 23 pthread_attr_init(&attr); 24 pthread_attr_getstacksize(&attr, &size); 25 g->stacklo = (uintptr)&attr - size + 4096; 26 pthread_attr_destroy(&attr); 27 } 28 29 30 void 31 _cgo_sys_thread_start(ThreadStart *ts) 32 { 33 pthread_attr_t attr; 34 sigset_t ign, oset; 35 pthread_t p; 36 size_t size; 37 int err; 38 39 sigfillset(&ign); 40 pthread_sigmask(SIG_SETMASK, &ign, &oset); 41 42 pthread_attr_init(&attr); 43 pthread_attr_getstacksize(&attr, &size); 44 // Leave stacklo=0 and set stackhi=size; mstack will do the rest. 45 ts->g->stackhi = size; 46 err = _cgo_try_pthread_create(&p, &attr, threadentry, ts); 47 48 pthread_sigmask(SIG_SETMASK, &oset, nil); 49 50 if (err != 0) { 51 fprintf(stderr, "runtime/cgo: pthread_create failed: %s\n", strerror(err)); 52 abort(); 53 } 54 } 55 56 extern void crosscall_arm1(void (*fn)(void), void (*setg_gcc)(void*), void *g); 57 static void* 58 threadentry(void *v) 59 { 60 ThreadStart ts; 61 stack_t ss; 62 63 ts = *(ThreadStart*)v; 64 free(v); 65 66 // On NetBSD, a new thread inherits the signal stack of the 67 // creating thread. That confuses minit, so we remove that 68 // signal stack here before calling the regular mstart. It's 69 // a bit baroque to remove a signal stack here only to add one 70 // in minit, but it's a simple change that keeps NetBSD 71 // working like other OS's. At this point all signals are 72 // blocked, so there is no race. 73 memset(&ss, 0, sizeof ss); 74 ss.ss_flags = SS_DISABLE; 75 sigaltstack(&ss, nil); 76 77 crosscall_arm1(ts.fn, setg_gcc, (void*)ts.g); 78 return nil; 79 } 80
