Add a "fork" of musl as //fusl.
This is musl verbatim at d5f8394f6ea9549607567bd92de12a2446c15614.
See http://www.musl-libc.org/.
R=kulakowski@chromium.org
Review URL: https://codereview.chromium.org/1573973002 .
diff --git a/fusl/src/process/fork.c b/fusl/src/process/fork.c
new file mode 100644
index 0000000..b96f002
--- /dev/null
+++ b/fusl/src/process/fork.c
@@ -0,0 +1,35 @@
+#include <unistd.h>
+#include <string.h>
+#include <signal.h>
+#include "syscall.h"
+#include "libc.h"
+#include "pthread_impl.h"
+
+static void dummy(int x)
+{
+}
+
+weak_alias(dummy, __fork_handler);
+
+pid_t fork(void)
+{
+ pid_t ret;
+ sigset_t set;
+ __fork_handler(-1);
+ __block_all_sigs(&set);
+#ifdef SYS_fork
+ ret = syscall(SYS_fork);
+#else
+ ret = syscall(SYS_clone, SIGCHLD, 0);
+#endif
+ if (!ret) {
+ pthread_t self = __pthread_self();
+ self->tid = __syscall(SYS_gettid);
+ self->robust_list.off = 0;
+ self->robust_list.pending = 0;
+ libc.threads_minus_1 = 0;
+ }
+ __restore_sigs(&set);
+ __fork_handler(!ret);
+ return ret;
+}
