1 // Copyright 2009 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> // strerror 8 #include <signal.h> 9 #include <stdlib.h> 10 #include "libcgo.h" 11 #include "libcgo_unix.h" 12 13 static void* threadentry(void*); 14 static void (*setg_gcc)(void*); 15 16 // These will be set in gcc_android_amd64.c for android-specific customization. 17 void (*x_cgo_inittls)(void); 18 void* (*x_cgo_threadentry)(void*); 19 20 void 21 x_cgo_init(G* g, void (*setg)(void*)) 22 { 23 pthread_attr_t *attr; 24 size_t size; 25 26 /* The memory sanitizer distributed with versions of clang 27 before 3.8 has a bug: if you call mmap before malloc, mmap 28 may return an address that is later overwritten by the msan 29 library. Avoid this problem by forcing a call to malloc 30 here, before we ever call malloc. 31 32 This is only required for the memory sanitizer, so it's 33 unfortunate that we always run it. It should be possible 34 to remove this when we no longer care about versions of 35 clang before 3.8. The test for this is 36 misc/cgo/testsanitizers. 37 38 GCC works hard to eliminate a seemingly unnecessary call to 39 malloc, so we actually use the memory we allocate. */ 40 41 setg_gcc = setg; 42 attr = (pthread_attr_t*)malloc(sizeof *attr); 43 if (attr == NULL) { 44 fatalf("malloc failed: %s", strerror(errno)); 45 } 46 pthread_attr_init(attr); 47 pthread_attr_getstacksize(attr, &size); 48 g->stacklo = (uintptr)&size - size + 4096; 49 pthread_attr_destroy(attr); 50 free(attr); 51 52 if (x_cgo_inittls) { 53 x_cgo_inittls(); 54 } 55 } 56 57 58 void 59 _cgo_sys_thread_start(ThreadStart *ts) 60 { 61 pthread_attr_t attr; 62 sigset_t ign, oset; 63 pthread_t p; 64 size_t size; 65 int err; 66 67 sigfillset(&ign); 68 pthread_sigmask(SIG_SETMASK, &ign, &oset); 69 70 pthread_attr_init(&attr); 71 pthread_attr_getstacksize(&attr, &size); 72 // Leave stacklo=0 and set stackhi=size; mstart will do the rest. 73 ts->g->stackhi = size; 74 err = _cgo_try_pthread_create(&p, &attr, threadentry, ts); 75 76 pthread_sigmask(SIG_SETMASK, &oset, nil); 77 78 if (err != 0) { 79 fatalf("pthread_create failed: %s", strerror(err)); 80 } 81 } 82 83 static void* 84 threadentry(void *v) 85 { 86 if (x_cgo_threadentry) { 87 return x_cgo_threadentry(v); 88 } 89 90 ThreadStart ts; 91 92 ts = *(ThreadStart*)v; 93 _cgo_tsan_acquire(); 94 free(v); 95 _cgo_tsan_release(); 96 97 /* 98 * Set specific keys. 99 */ 100 setg_gcc((void*)ts.g); 101 102 crosscall_amd64(ts.fn); 103 return nil; 104 } 105
