!773 轻内核支持clone接口

Merge pull request !773 from zhushengle/pid_container

porting/liteos_a/user/src/linux/clone.c

@@ -2,22 +2,79 @@
 #include <stdarg.h>
 #include <unistd.h>
 #include <sched.h>
+#include <signal.h>
 #include "pthread_impl.h"
 #include "syscall.h"
-#include <unsupported_api.h>
+#include "libc.h"
+
+struct __clone_args {
+	int (*func)(void *);
+	void *arg;
+};
+
+static int __start_child(void *clone_args)
+{
+	int status;
+	sigset_t set;
+	int (*func)(void *) = ((struct __clone_args *)clone_args)->func;
+	void *arg = ((struct __clone_args *)clone_args)->arg;
+
+	__block_all_sigs(&set);
+	pthread_t self = __pthread_self();
+	self->tid = __syscall(SYS_gettid);
+	self->robust_list.off = 0;
+	self->robust_list.pending = 0;
+	self->next = self->prev = self;
+	__thread_list_lock = 0;
+	libc.threads_minus_1 = 0;
+	libc.exit = 0;
+	signal(SIGSYS, arm_do_signal);
+	__restore_sigs(&set);
+
+	status = func(arg);
+	exit(status);
+}
 
 int clone(int (*func)(void *), void *stack, int flags, void *arg, ...)
 {
+	int ret;
 	va_list ap;
 	pid_t *ptid, *ctid;
 	void  *tls;
+	void *mmap_stack = NULL;
+	void *clone_stack = stack;
+	int (*clone_func)(void *) = func;
+	struct __clone_args *clone_args = (struct __clone_args *)arg;
 
-	unsupported_api(__FUNCTION__);
 	va_start(ap, arg);
 	ptid = va_arg(ap, pid_t *);
 	tls  = va_arg(ap, void *);
 	ctid = va_arg(ap, pid_t *);
 	va_end(ap);
 
-	return __syscall_ret(__clone(func, stack, flags, arg, ptid, tls, ctid));
+	if (!(flags & (CLONE_VM | CLONE_VFORK))) {
+		if (func) {
+			if (!stack) {
+				mmap_stack = __mmap(0, __default_stacksize, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANON, -1, 0);
+				if (mmap_stack == MAP_FAILED) {
+					errno = ENOMEM;
+					return -1;
+				}
+				clone_args = (struct __clone_args *)((char *)mmap_stack + __default_stacksize);
+			} else {
+				clone_args = (struct __clone_args *)stack;
+ 			}
+			clone_args = (struct __clone_args *)((uintptr_t)clone_args - ((uintptr_t)clone_args % sizeof(uintptr_t)));
+			clone_args = (struct __clone_args *)((char *)clone_args - sizeof(struct __clone_args));
+			clone_args->func = clone_func;
+			clone_args->arg = arg;
+			clone_func = __start_child;
+			clone_stack = (void *)clone_args;
+		}
+	}
+	ret = __syscall_ret(__clone(clone_func, clone_stack, flags, (void *)clone_args, ptid, tls, ctid));
+	if (mmap_stack) {
+		__munmap(mmap_stack, __default_stacksize);
+	}
+	return ret;
 }