On Sun, Aug 13, 2023 at 05:58:01PM -0700, Philip Guenther wrote:
> I think that changing the behavior of the existing API in a way that
> gratuitously increases the differences between BSDs is unwise. IMHO, we
> should follow NetBSD on this and add kqueue1(), that being obviously
> consistent with the previous 'add flags argument' extensions: pipe2(),
> dup3(), and accept4().
I agree that changing the behavior is not good.
Below is an implementation of the kqueue1() syscall and the libc stub.
NetBSD's kqueue1() accepts flags that do not really affect kqueue
behavior, namely O_NONBLOCK and O_NOSIGPIPE (this is specific to
NetBSD). For compatibility, the new syscall code passes O_NONBLOCK to
file flags but otherwise ignores it. I have omitted this flag from the
syscall manual page because it does not make sense with kqueue.
However, I can add a note about the flag if it is deemed necessary.
Index: sys/kern/kern_event.c
===
RCS file: src/sys/kern/kern_event.c,v
retrieving revision 1.197
diff -u -p -r1.197 kern_event.c
--- sys/kern/kern_event.c 13 Aug 2023 08:29:28 - 1.197
+++ sys/kern/kern_event.c 14 Aug 2023 14:52:44 -
@@ -60,6 +60,7 @@
#define KLIST_ASSERT_LOCKED(kl)((void)(kl))
#endif
+intdokqueue(struct proc *, int, register_t *);
struct kqueue *kqueue_alloc(struct filedesc *);
void kqueue_terminate(struct proc *p, struct kqueue *);
void KQREF(struct kqueue *);
@@ -912,12 +913,14 @@ kqueue_alloc(struct filedesc *fdp)
}
int
-sys_kqueue(struct proc *p, void *v, register_t *retval)
+dokqueue(struct proc *p, int flags, register_t *retval)
{
struct filedesc *fdp = p->p_fd;
struct kqueue *kq;
struct file *fp;
- int fd, error;
+ int cloexec, error, fd;
+
+ cloexec = (flags & O_CLOEXEC) ? UF_EXCLOSE : 0;
kq = kqueue_alloc(fdp);
@@ -925,14 +928,14 @@ sys_kqueue(struct proc *p, void *v, regi
error = falloc(p, , );
if (error)
goto out;
- fp->f_flag = FREAD | FWRITE;
+ fp->f_flag = FREAD | FWRITE | (flags & FNONBLOCK);
fp->f_type = DTYPE_KQUEUE;
fp->f_ops =
fp->f_data = kq;
*retval = fd;
LIST_INSERT_HEAD(>fd_kqlist, kq, kq_next);
kq = NULL;
- fdinsert(fdp, fd, 0, fp);
+ fdinsert(fdp, fd, cloexec, fp);
FRELE(fp, p);
out:
fdpunlock(fdp);
@@ -942,6 +945,24 @@ out:
}
int
+sys_kqueue(struct proc *p, void *v, register_t *retval)
+{
+ return (dokqueue(p, 0, retval));
+}
+
+int
+sys_kqueue1(struct proc *p, void *v, register_t *retval)
+{
+ struct sys_kqueue1_args /* {
+ syscallarg(int) flags;
+ } */ *uap = v;
+
+ if (SCARG(uap, flags) & ~(O_CLOEXEC | O_NONBLOCK))
+ return (EINVAL);
+ return (dokqueue(p, SCARG(uap, flags), retval));
+}
+
+int
sys_kevent(struct proc *p, void *v, register_t *retval)
{
struct kqueue_scan_state scan;
Index: sys/kern/syscalls.master
===
RCS file: src/sys/kern/syscalls.master,v
retrieving revision 1.249
diff -u -p -r1.249 syscalls.master
--- sys/kern/syscalls.master24 Jul 2023 19:32:23 - 1.249
+++ sys/kern/syscalls.master14 Aug 2023 14:52:44 -
@@ -462,7 +462,7 @@
267OBSOL pad_preadv
268OBSOL pad_pwritev
269STD NOLOCK { int sys_kqueue(void); }
-270OBSOL t32_kevent
+270STD NOLOCK { int sys_kqueue1(int flags); }
271STD { int sys_mlockall(int flags); }
272STD { int sys_munlockall(void); }
273UNIMPL sys_getpeereid
Index: sys/sys/event.h
===
RCS file: src/sys/sys/event.h,v
retrieving revision 1.70
diff -u -p -r1.70 event.h
--- sys/sys/event.h 13 Aug 2023 08:29:28 - 1.70
+++ sys/sys/event.h 14 Aug 2023 14:52:44 -
@@ -369,6 +369,7 @@ struct timespec;
__BEGIN_DECLS
intkqueue(void);
+intkqueue1(int flags);
intkevent(int kq, const struct kevent *changelist, int nchanges,
struct kevent *eventlist, int nevents,
const struct timespec *timeout);
Index: lib/libc/Symbols.list
===
RCS file: src/lib/libc/Symbols.list,v
retrieving revision 1.81
diff -u -p -r1.81 Symbols.list
--- lib/libc/Symbols.list 11 Feb 2023 23:07:28 - 1.81
+++ lib/libc/Symbols.list 14 Aug 2023 14:52:42 -
@@ -121,6 +121,7 @@ _thread_sys_issetugid
_thread_sys_kevent
_thread_sys_kill
_thread_sys_kqueue
+_thread_sys_kqueue1
_thread_sys_ktrace
_thread_sys_lchown
_thread_sys_link
@@ -322,6 +323,7 @@ issetugid
kevent
kill
kqueue
+kqueue1
ktrace
lchown
link
Index: lib/libc/shlib_version
===
RCS
