github.com/c12o16h1/go/src@v0.0.0-20200114212001-5a151c0f00ed/runtime/cgo/gcc_netbsd_arm64.c (about) 1 // Copyright 2019 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; mstart 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 static void* 57 threadentry(void *v) 58 { 59 ThreadStart ts; 60 stack_t ss; 61 62 ts = *(ThreadStart*)v; 63 free(v); 64 65 // On NetBSD, a new thread inherits the signal stack of the 66 // creating thread. That confuses minit, so we remove that 67 // signal stack here before calling the regular mstart. It's 68 // a bit baroque to remove a signal stack here only to add one 69 // in minit, but it's a simple change that keeps NetBSD 70 // working like other OS's. At this point all signals are 71 // blocked, so there is no race. 72 memset(&ss, 0, sizeof ss); 73 ss.ss_flags = SS_DISABLE; 74 sigaltstack(&ss, nil); 75 76 crosscall1(ts.fn, setg_gcc, (void*)ts.g); 77 return nil; 78 }