Several cleanups related to pipe(2).

- Use `fildes[2]' instead of `*fildes' to make more clear that pipe(2)
  fills an array with two descriptors.

- Remove EFAULT from the manual page. Because of the current calling
  convention, pipe(2) raises a segmentation fault when an invalid
  address is passed.

- Introduce kern_pipe() to make it easier for binary emulations to
  implement pipe(2).

- Make Linux binary emulation use kern_pipe(), which means we don't have
  to recover td_retval after calling the FreeBSD system call.

Approved by:	rdivacky
Discussed on:	arch

1 files changed, 5 insertions, 18 deletions

diff --git a/sys/amd64/linux32/linux32_machdep.c b/sys/amd64/linux32/linux32_machdep.c
index aecf869..fcf01c8 100644
--- a/sys/amd64/linux32/linux32_machdep.c
+++ b/sys/amd64/linux32/linux32_machdep.c
@@ -977,33 +977,20 @@ linux_iopl(struct thread *td, struct linux_iopl_args *args)
 int
 linux_pipe(struct thread *td, struct linux_pipe_args *args)
 {
-	int pip[2];
 	int error;
-	register_t reg_rdx;
+	int fildes[2];
 
 #ifdef DEBUG
 	if (ldebug(pipe))
 		printf(ARGS(pipe, "*"));
 #endif
 
-	reg_rdx = td->td_retval[1];
-	error = pipe(td, 0);
-	if (error) {
-		td->td_retval[1] = reg_rdx;
-		return (error);
-	}
-
-	pip[0] = td->td_retval[0];
-	pip[1] = td->td_retval[1];
-	error = copyout(pip, args->pipefds, 2 * sizeof(int));
-	if (error) {
-		td->td_retval[1] = reg_rdx;
+	error = kern_pipe(td, fildes);
+	if (error)
 		return (error);
-	}
 
-	td->td_retval[1] = reg_rdx;
-	td->td_retval[0] = 0;
-	return (0);
+	/* XXX: Close descriptors on error. */
+	return (copyout(fildes, args->pipefds, sizeof fildes));
 }
 
 int