stacksize argument is gone and replaced with tidptr argument

Document new FORK_TFORK bit and that stack argument is used by compat_linux

ok jmc@

1 files changed, 25 insertions, 15 deletions

diff --git a/share/man/man9/fork1.9 b/share/man/man9/fork1.9
index f82b02d94c8..77ad71ca573 100644
--- a/share/man/man9/fork1.9
+++ b/share/man/man9/fork1.9
@@ -1,4 +1,4 @@
-.\"	$OpenBSD: fork1.9,v 1.14 2010/06/29 17:54:12 tedu Exp $
+.\"	$OpenBSD: fork1.9,v 1.15 2011/10/16 06:48:38 guenther Exp $
 .\"	$NetBSD: fork1.9,v 1.3 1999/03/16 00:40:47 garbled Exp $
 .\"
 .\" Copyright (c) 1998 The NetBSD Foundation, Inc.
@@ -29,7 +29,7 @@
 .\" ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
 .\" POSSIBILITY OF SUCH DAMAGE.
 .\"
-.Dd $Mdocdate: June 29 2010 $
+.Dd $Mdocdate: October 16 2011 $
 .Dt FORK1 9
 .Os
 .Sh NAME
@@ -44,7 +44,7 @@
 .Fa "int exitsig"
 .Fa "int flags"
 .Fa "void *stack"
-.Fa "size_t stacksize"
+.Fa "pid_t *tidptr"
 .Fa "void (*func)(void *)"
 .Fa "void *arg"
 .Fa "register_t *retval"
@@ -83,6 +83,11 @@ The call is done by the
 .Xr rfork 2
 system call.
 Used only for statistics.
+.It Dv FORK_TFORK
+The call is done by the
+.Xr __tfork 2
+system call.
+Used only for statistics.
 .It Dv FORK_PPWAIT
 Suspend the parent process until the child is terminated (by calling
 .Xr _exit 2
@@ -129,12 +134,17 @@ If
 .Fa stack
 is not
 .Dv NULL ,
-the area starting at
-.Fa stack
-of extent
-.Fa stacksize
-will be used for the child's stack, instead of cloning the parent's
-stack.
+it will be used as the initial value of the child's stack pointer,
+instead of using the child's copy of the parent's stack.
+.Pp
+If
+.Fa tidptr
+is not
+.Dv NULL ,
+the PID of the child process will be written there in the parent
+on success.
+This is guaranteed to be done before
+the child process is started.
 .Pp
 If
 .Fa retval
@@ -144,7 +154,7 @@ it will hold the following values after successful completion
 of the fork operation:
 .Bl -tag -width retval[0]
 .It Fa retval[0]
-This will contain the pid of the child process.
+This will contain the PID of the child process.
 .It Fa retval[1]
 In the parent process, this will contain the value 0.
 In the child process, this will contain 1.
@@ -202,8 +212,8 @@ function semantics are specific to
 .Ox .
 Other BSD systems have different semantics.
 .Pp
-The system never uses
-.Fn fork1
-with a non-null
-.Fa stack ,
-so that feature is not even tested.
+The only use of a non-null
+.Fa stack
+is for
+.Xr compat_linux 8
+on i386, so that feature is mostly untested.