1 files changed, 159 insertions, 0 deletions
diff --git a/src/runtime/cgo/gcc_openbsd_amd64.c b/src/runtime/cgo/gcc_openbsd_amd64.c
new file mode 100644
index 000000000..35b359bba
--- /dev/null
+++ b/src/runtime/cgo/gcc_openbsd_amd64.c
@@ -0,0 +1,159 @@
+// 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 <sys/types.h>
+#include <dlfcn.h>
+#include <errno.h>
+#include <pthread.h>
+#include <signal.h>
+#include <string.h>
+#include "libcgo.h"
+
+static void* threadentry(void*);
+static void (*setg_gcc)(void*);
+
+// TCB_SIZE is sizeof(struct thread_control_block),
+// as defined in /usr/src/lib/librthread/tcb.h
+#define TCB_SIZE (4 * sizeof(void *))
+#define TLS_SIZE (2 * sizeof(void *))
+
+void *__get_tcb(void);
+void __set_tcb(void *);
+
+static int (*sys_pthread_create)(pthread_t *thread, const pthread_attr_t *attr,
+	void *(*start_routine)(void *), void *arg);
+
+struct thread_args {
+	void *(*func)(void *);
+	void *arg;
+};
+
+static void
+tcb_fixup(int mainthread)
+{
+	void *newtcb, *oldtcb;
+
+	// The OpenBSD ld.so(1) does not currently support PT_TLS. As a result,
+	// we need to allocate our own TLS space while preserving the existing
+	// TCB that has been setup via librthread.
+
+	newtcb = malloc(TCB_SIZE + TLS_SIZE);
+	if(newtcb == NULL)
+		abort();
+
+	// The signal trampoline expects the TLS slots to be zeroed.
+	bzero(newtcb, TLS_SIZE);
+
+	oldtcb = __get_tcb();
+	bcopy(oldtcb, newtcb + TLS_SIZE, TCB_SIZE);
+	__set_tcb(newtcb + TLS_SIZE);
+
+	// NOTE(jsing, minux): we can't free oldtcb without causing double-free
+	// problem. so newtcb will be memory leaks. Get rid of this when OpenBSD
+	// has proper support for PT_TLS.
+}
+
+static void *
+thread_start_wrapper(void *arg)
+{
+	struct thread_args args = *(struct thread_args *)arg;
+
+	free(arg);
+	tcb_fixup(0);
+
+	return args.func(args.arg);
+}
+
+int
+pthread_create(pthread_t *thread, const pthread_attr_t *attr,
+	void *(*start_routine)(void *), void *arg)
+{
+	struct thread_args *p;
+
+	p = malloc(sizeof(*p));
+	if(p == NULL) {
+		errno = ENOMEM;
+		return -1;
+	}
+	p->func = start_routine;
+	p->arg = arg;
+
+	return sys_pthread_create(thread, attr, thread_start_wrapper, p);
+}
+
+void
+x_cgo_init(G *g, void (*setg)(void*))
+{
+	pthread_attr_t attr;
+	size_t size;
+	void *handle;
+
+	setg_gcc = setg;
+	pthread_attr_init(&attr);
+	pthread_attr_getstacksize(&attr, &size);
+	g->stacklo = (uintptr)&attr - size + 4096;
+	pthread_attr_destroy(&attr);
+
+	// Locate symbol for the system pthread_create function.
+	handle = dlopen("libpthread.so", RTLD_LAZY);
+	if(handle == NULL) {
+		fprintf(stderr, "dlopen: failed to load libpthread: %s\n", dlerror());
+		abort();
+	}
+	sys_pthread_create = dlsym(handle, "pthread_create");
+	if(sys_pthread_create == NULL) {
+		fprintf(stderr, "dlsym: failed to find pthread_create: %s\n", dlerror());
+		abort();
+	}
+	dlclose(handle);
+
+	tcb_fixup(1);
+}
+
+
+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; mstack will do the rest.
+	ts->g->stackhi = size;
+	err = sys_pthread_create(&p, &attr, threadentry, ts);
+
+	pthread_sigmask(SIG_SETMASK, &oset, nil);
+
+	if (err != 0) {
+		fprintf(stderr, "runtime/cgo: pthread_create failed: %s\n", strerror(err));
+		abort();
+	}
+}
+
+static void*
+threadentry(void *v)
+{
+	ThreadStart ts;
+
+	tcb_fixup(0);
+
+	ts = *(ThreadStart*)v;
+	free(v);
+
+	/*
+	 * Set specific keys.
+	 */
+	setg_gcc((void*)ts.g);
+
+	crosscall_amd64(ts.fn);
+	return nil;
+}