diff options
Diffstat (limited to 'src/runtime/cgo/gcc_linux_amd64.c')
-rw-r--r-- | src/runtime/cgo/gcc_linux_amd64.c | 96 |
1 files changed, 96 insertions, 0 deletions
diff --git a/src/runtime/cgo/gcc_linux_amd64.c b/src/runtime/cgo/gcc_linux_amd64.c new file mode 100644 index 0000000..fb164c1 --- /dev/null +++ b/src/runtime/cgo/gcc_linux_amd64.c @@ -0,0 +1,96 @@ +// Copyright 2009 The Go Authors. All rights reserved. +// Use of this source code is governed by a BSD-style +// license that can be found in the LICENSE file. + +#include <pthread.h> +#include <errno.h> +#include <string.h> // strerror +#include <signal.h> +#include <stdlib.h> +#include "libcgo.h" +#include "libcgo_unix.h" + +static void* threadentry(void*); +static void (*setg_gcc)(void*); + +// This will be set in gcc_android.c for android-specific customization. +void (*x_cgo_inittls)(void **tlsg, void **tlsbase) __attribute__((common)); + +void +x_cgo_init(G *g, void (*setg)(void*), void **tlsg, void **tlsbase) +{ + pthread_attr_t *attr; + size_t size; + + /* The memory sanitizer distributed with versions of clang + before 3.8 has a bug: if you call mmap before malloc, mmap + may return an address that is later overwritten by the msan + library. Avoid this problem by forcing a call to malloc + here, before we ever call malloc. + + This is only required for the memory sanitizer, so it's + unfortunate that we always run it. It should be possible + to remove this when we no longer care about versions of + clang before 3.8. The test for this is + misc/cgo/testsanitizers. + + GCC works hard to eliminate a seemingly unnecessary call to + malloc, so we actually use the memory we allocate. */ + + setg_gcc = setg; + attr = (pthread_attr_t*)malloc(sizeof *attr); + if (attr == NULL) { + fatalf("malloc failed: %s", strerror(errno)); + } + pthread_attr_init(attr); + pthread_attr_getstacksize(attr, &size); + g->stacklo = (uintptr)__builtin_frame_address(0) - size + 4096; + if (g->stacklo >= g->stackhi) + fatalf("bad stack bounds: lo=%p hi=%p\n", g->stacklo, g->stackhi); + pthread_attr_destroy(attr); + free(attr); + + if (x_cgo_inittls) { + x_cgo_inittls(tlsg, tlsbase); + } +} + + +void +_cgo_sys_thread_start(ThreadStart *ts) +{ + pthread_attr_t attr; + sigset_t ign, oset; + pthread_t p; + size_t size; + int err; + + sigfillset(&ign); + pthread_sigmask(SIG_SETMASK, &ign, &oset); + + pthread_attr_init(&attr); + pthread_attr_getstacksize(&attr, &size); + // Leave stacklo=0 and set stackhi=size; mstart will do the rest. + ts->g->stackhi = size; + err = _cgo_try_pthread_create(&p, &attr, threadentry, ts); + + pthread_sigmask(SIG_SETMASK, &oset, nil); + + if (err != 0) { + fatalf("pthread_create failed: %s", strerror(err)); + } +} + +static void* +threadentry(void *v) +{ + ThreadStart ts; + + ts = *(ThreadStart*)v; + _cgo_tsan_acquire(); + free(v); + _cgo_tsan_release(); + + crosscall_amd64(ts.fn, setg_gcc, (void*)ts.g); + return nil; +} |