github.com/lovishpuri/go-40569/src@v0.0.0-20230519171745-f8623e7c56cf/runtime/cgo/gcc_linux_arm64.c (about) 1 // Copyright 2015 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 <pthread.h> 6 #include <errno.h> 7 #include <string.h> 8 #include <signal.h> 9 #include <stdlib.h> 10 #include "libcgo.h" 11 #include "libcgo_unix.h" 12 13 static void *threadentry(void*); 14 15 void (*x_cgo_inittls)(void **tlsg, void **tlsbase) __attribute__((common)); 16 static void (*setg_gcc)(void*); 17 18 void 19 _cgo_sys_thread_start(ThreadStart *ts) 20 { 21 pthread_attr_t attr; 22 sigset_t ign, oset; 23 pthread_t p; 24 size_t size; 25 int err; 26 27 sigfillset(&ign); 28 pthread_sigmask(SIG_SETMASK, &ign, &oset); 29 30 pthread_attr_init(&attr); 31 pthread_attr_getstacksize(&attr, &size); 32 // Leave stacklo=0 and set stackhi=size; mstart will do the rest. 33 ts->g->stackhi = size; 34 err = _cgo_try_pthread_create(&p, &attr, threadentry, ts); 35 36 pthread_sigmask(SIG_SETMASK, &oset, nil); 37 38 if (err != 0) { 39 fatalf("pthread_create failed: %s", strerror(err)); 40 } 41 } 42 43 extern void crosscall1(void (*fn)(void), void (*setg_gcc)(void*), void *g); 44 static void* 45 threadentry(void *v) 46 { 47 ThreadStart ts; 48 49 ts = *(ThreadStart*)v; 50 free(v); 51 52 crosscall1(ts.fn, setg_gcc, (void*)ts.g); 53 return nil; 54 } 55 56 void 57 x_cgo_init(G *g, void (*setg)(void*), void **tlsg, void **tlsbase) 58 { 59 pthread_attr_t *attr; 60 size_t size; 61 62 /* The memory sanitizer distributed with versions of clang 63 before 3.8 has a bug: if you call mmap before malloc, mmap 64 may return an address that is later overwritten by the msan 65 library. Avoid this problem by forcing a call to malloc 66 here, before we ever call malloc. 67 68 This is only required for the memory sanitizer, so it's 69 unfortunate that we always run it. It should be possible 70 to remove this when we no longer care about versions of 71 clang before 3.8. The test for this is 72 misc/cgo/testsanitizers. 73 74 GCC works hard to eliminate a seemingly unnecessary call to 75 malloc, so we actually use the memory we allocate. */ 76 77 setg_gcc = setg; 78 attr = (pthread_attr_t*)malloc(sizeof *attr); 79 if (attr == NULL) { 80 fatalf("malloc failed: %s", strerror(errno)); 81 } 82 pthread_attr_init(attr); 83 pthread_attr_getstacksize(attr, &size); 84 g->stacklo = (uintptr)&size - size + 4096; 85 pthread_attr_destroy(attr); 86 free(attr); 87 88 if (x_cgo_inittls) { 89 x_cgo_inittls(tlsg, tlsbase); 90 } 91 }