syscall: use fcntl with F_DUP2FD_CLOEXEC in forkAndExecInChild on FreeBSD
Use fcntl(oldfd, F_DUP2FD_CLOEXEC, newfd) to duplicate the file
descriptor and mark is as close-on-exec instead of dup2 & fcntl.
FreeBSD implements dup3 like this in libc.
Change-Id: I36e37bc61c2e31561adb49001f287764125a74de
Reviewed-on: https://go-review.googlesource.com/c/go/+/355571
Trust: Tobias Klauser <tobias.klauser@gmail.com>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
diff --git a/src/syscall/exec_freebsd.go b/src/syscall/exec_freebsd.go
index a7410db..90793fe 100644
--- a/src/syscall/exec_freebsd.go
+++ b/src/syscall/exec_freebsd.go
@@ -214,11 +214,10 @@
// Pass 1: look for fd[i] < i and move those up above len(fd)
// so that pass 2 won't stomp on an fd it needs later.
if pipe < nextfd {
- _, _, err1 = RawSyscall(SYS_DUP2, uintptr(pipe), uintptr(nextfd), 0)
+ _, _, err1 = RawSyscall(SYS_FCNTL, uintptr(pipe), F_DUP2FD_CLOEXEC, uintptr(nextfd))
if err1 != 0 {
goto childerror
}
- RawSyscall(SYS_FCNTL, uintptr(nextfd), F_SETFD, FD_CLOEXEC)
pipe = nextfd
nextfd++
}
@@ -227,11 +226,10 @@
if nextfd == pipe { // don't stomp on pipe
nextfd++
}
- _, _, err1 = RawSyscall(SYS_DUP2, uintptr(fd[i]), uintptr(nextfd), 0)
+ _, _, err1 = RawSyscall(SYS_FCNTL, uintptr(fd[i]), F_DUP2FD_CLOEXEC, uintptr(nextfd))
if err1 != 0 {
goto childerror
}
- RawSyscall(SYS_FCNTL, uintptr(nextfd), F_SETFD, FD_CLOEXEC)
fd[i] = nextfd
nextfd++
}
