syscall: change Dup,Dup2,Dup3 to use Syscall, not RawSyscall
This avoids hanging when a Go program uses a FUSE filesystem and the
dup system call has to close a file descriptor. When dup uses
RawSyscall then the goroutine calling dup will occupy a scheduler slot
(a p structure) during the call, and may block waiting for some other
goroutine to respond to the close call on the FUSE filesystem.
Changing to Syscall avoids the problem. This makes Dup a tiny bit
slower but is quite unlikely to make a difference for any real
programs.
Fixes #10202.
Change-Id: If6490a8f9b3c9cfed6acbfb4bfd1eaeac62ced17
Reviewed-on: https://go-review.googlesource.com/8095
Reviewed-by: Rob Pike <r@golang.org>
diff --git a/src/syscall/syscall_freebsd.go b/src/syscall/syscall_freebsd.go
index 3d834f5..257d419 100644
--- a/src/syscall/syscall_freebsd.go
+++ b/src/syscall/syscall_freebsd.go
@@ -147,8 +147,8 @@
//sys Chown(path string, uid int, gid int) (err error)
//sys Chroot(path string) (err error)
//sys Close(fd int) (err error)
-//sysnb Dup(fd int) (nfd int, err error)
-//sysnb Dup2(from int, to int) (err error)
+//sys Dup(fd int) (nfd int, err error)
+//sys Dup2(from int, to int) (err error)
//sys Exit(code int)
//sys Fchdir(fd int) (err error)
//sys Fchflags(fd int, flags int) (err error)
