Attachment 207926 Details for Bug 240590 – EPOLLNUL.patch

[patch] EPOLLNUL.patch

LINUX_EPOLLNUL.patch (text/plain), 6.50 KB, created by Vladimir Kondratyev on 2019-09-28 23:56:44 UTC

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Creator: Vladimir Kondratyev

Created: 2019-09-28 23:56:44 UTC

Size: 6.50 KB

patch

obsolete

>diff --git a/sys/compat/linux/linux_event.c b/sys/compat/linux/linux_event.c
>index 7d26ee3e5051..15b3f6aca5b1 100644
>--- a/sys/compat/linux/linux_event.c
>+++ b/sys/compat/linux/linux_event.c
>@@ -98,14 +98,16 @@ __attribute__((packed))
> #define	LINUX_MAX_EVENTS	(INT_MAX / sizeof(struct epoll_event))
> 
> static void	epoll_fd_install(struct thread *td, int fd, epoll_udata_t udata);
>-static int	epoll_to_kevent(struct thread *td, struct file *epfp,
>-		    int fd, struct epoll_event *l_event, int *kev_flags,
>-		    struct kevent *kevent, int *nkevents);
>+static int	epoll_to_kevent(struct thread *td, int fd,
>+		    struct epoll_event *l_event, struct kevent *kevent,
>+		    int *nkevents);
> static void	kevent_to_epoll(struct kevent *kevent, struct epoll_event *l_event);
> static int	epoll_kev_copyout(void *arg, struct kevent *kevp, int count);
> static int	epoll_kev_copyin(void *arg, struct kevent *kevp, int count);
>-static int	epoll_delete_event(struct thread *td, struct file *epfp,
>-		    int fd, int filter);
>+static int	epoll_register_kevent(struct thread *td, struct file *epfp,
>+		    int fd, int filter, unsigned int flags);
>+static int	epoll_fd_registered(struct thread *td, struct file *epfp,
>+		    int fd);
> static int	epoll_delete_all_events(struct thread *td, struct file *epfp,
> 		    int fd);
> 
>@@ -296,31 +298,36 @@ linux_epoll_create1(struct thread *td, struct linux_epoll_create1_args *args)
> 
> /* Structure converting function from epoll to kevent. */
> static int
>-epoll_to_kevent(struct thread *td, struct file *epfp,
>-    int fd, struct epoll_event *l_event, int *kev_flags,
>+epoll_to_kevent(struct thread *td, int fd, struct epoll_event *l_event,
>     struct kevent *kevent, int *nkevents)
> {
> 	uint32_t levents = l_event->events;
> 	struct linux_pemuldata *pem;
> 	struct proc *p;
>+	unsigned short kev_flags = EV_ADD | EV_ENABLE;
> 
> 	/* flags related to how event is registered */
> 	if ((levents & LINUX_EPOLLONESHOT) != 0)
>-		*kev_flags |= EV_DISPATCH;
>+		kev_flags |= EV_DISPATCH;
> 	if ((levents & LINUX_EPOLLET) != 0)
>-		*kev_flags |= EV_CLEAR;
>+		kev_flags |= EV_CLEAR;
> 	if ((levents & LINUX_EPOLLERR) != 0)
>-		*kev_flags |= EV_ERROR;
>+		kev_flags |= EV_ERROR;
> 	if ((levents & LINUX_EPOLLRDHUP) != 0)
>-		*kev_flags |= EV_EOF;
>+		kev_flags |= EV_EOF;
> 
> 	/* flags related to what event is registered */
> 	if ((levents & LINUX_EPOLL_EVRD) != 0) {
>-		EV_SET(kevent++, fd, EVFILT_READ, *kev_flags, 0, 0, 0);
>+		EV_SET(kevent++, fd, EVFILT_READ, kev_flags, 0, 0, 0);
> 		++(*nkevents);
> 	}
> 	if ((levents & LINUX_EPOLL_EVWR) != 0) {
>-		EV_SET(kevent++, fd, EVFILT_WRITE, *kev_flags, 0, 0, 0);
>+		EV_SET(kevent++, fd, EVFILT_WRITE, kev_flags, 0, 0, 0);
>+		++(*nkevents);
>+	}
>+	/* zero event mask is legal */
>+	if ((levents & (LINUX_EPOLL_EVRD | LINUX_EPOLL_EVWR)) == 0) {
>+		EV_SET(kevent++, fd, EVFILT_READ, EV_ADD|EV_DISABLE, 0, 0, 0);
> 		++(*nkevents);
> 	}
> 
>@@ -451,7 +458,6 @@ linux_epoll_ctl(struct thread *td, struct linux_epoll_ctl_args *args)
> 					epoll_kev_copyin};
> 	struct epoll_event le;
> 	cap_rights_t rights;
>-	int kev_flags;
> 	int nchanges = 0;
> 	int error;
> 
>@@ -484,9 +490,7 @@ linux_epoll_ctl(struct thread *td, struct linux_epoll_ctl_args *args)
> 	ciargs.changelist = kev;
> 
> 	if (args->op != LINUX_EPOLL_CTL_DEL) {
>-		kev_flags = EV_ADD | EV_ENABLE;
>-		error = epoll_to_kevent(td, epfp, args->fd, &le,
>-		    &kev_flags, kev, &nchanges);
>+		error = epoll_to_kevent(td, args->fd, &le, kev, &nchanges);
> 		if (error != 0)
> 			goto leave0;
> 	}
>@@ -499,19 +503,10 @@ linux_epoll_ctl(struct thread *td, struct linux_epoll_ctl_args *args)
> 		break;
> 
> 	case LINUX_EPOLL_CTL_ADD:
>-		/*
>-		 * kqueue_register() return ENOENT if event does not exists
>-		 * and the EV_ADD flag is not set. Reset EV_ENABLE flag to
>-		 * avoid accidental activation of fired oneshot events.
>-		 */
>-		kev[0].flags &= ~(EV_ADD | EV_ENABLE);
>-		error = kqfd_register(args->epfd, &kev[0], td, M_WAITOK);
>-		if (error != ENOENT) {
>+		if (epoll_fd_registered(td, epfp, args->fd)) {
> 			error = EEXIST;
> 			goto leave0;
> 		}
>-		error = 0;
>-		kev[0].flags |= (EV_ADD | EV_ENABLE);
> 		break;
> 
> 	case LINUX_EPOLL_CTL_DEL:
>@@ -651,7 +646,8 @@ linux_epoll_pwait(struct thread *td, struct linux_epoll_pwait_args *args)
> }
> 
> static int
>-epoll_delete_event(struct thread *td, struct file *epfp, int fd, int filter)
>+epoll_register_kevent(struct thread *td, struct file *epfp, int fd, int filter,
>+    unsigned int flags)
> {
> 	struct epoll_copyin_args ciargs;
> 	struct kevent kev;
>@@ -660,18 +656,36 @@ epoll_delete_event(struct thread *td, struct file *epfp, int fd, int filter)
> 					epoll_kev_copyin};
> 
> 	ciargs.changelist = &kev;
>-	EV_SET(&kev, fd, filter, EV_DELETE | EV_DISABLE, 0, 0, 0);
>+	EV_SET(&kev, fd, filter, flags, 0, 0, 0);
> 
> 	return (kern_kevent_fp(td, epfp, 1, 0, &k_ops, NULL));
> }
> 
>+static int
>+epoll_fd_registered(struct thread *td, struct file *epfp, int fd)
>+{
>+	/*
>+	 * Set empty filter flags to avoid accidental modification of already
>+	 * registered events. In the case of re-registration:
>+	 * 1. If event does not exists kevent() does nothing and returns ENOENT
>+	 * 2. If event does exists, it's enabled/disabled state is preserved
>+	 *    but fflags, data and udata fields are overwritten.
>+	 * p.2 means that we can not store user's context pointer in udata.
>+	 */
>+	if (epoll_register_kevent(td, epfp, fd, EVFILT_READ, 0) != ENOENT ||
>+	    epoll_register_kevent(td, epfp, fd, EVFILT_WRITE, 0) != ENOENT)
>+		return (1);
>+
>+	return (0);
>+}
>+
> static int
> epoll_delete_all_events(struct thread *td, struct file *epfp, int fd)
> {
> 	int error1, error2;
> 
>-	error1 = epoll_delete_event(td, epfp, fd, EVFILT_READ);
>-	error2 = epoll_delete_event(td, epfp, fd, EVFILT_WRITE);
>+	error1 = epoll_register_kevent(td, epfp, fd, EVFILT_READ, EV_DELETE);
>+	error2 = epoll_register_kevent(td, epfp, fd, EVFILT_WRITE, EV_DELETE);
> 
> 	/* return 0 if at least one result positive */
> 	return (error1 == 0 ? 0 : error2);
>diff --git a/sys/compat/linux/linux_event.h b/sys/compat/linux/linux_event.h
>index c483df58736b..d6a0c2d42d0c 100644
>--- a/sys/compat/linux/linux_event.h
>+++ b/sys/compat/linux/linux_event.h
>@@ -45,10 +45,10 @@
> #define	LINUX_EPOLLONESHOT	1u<<30
> #define	LINUX_EPOLLET		1u<<31
> 
>-#define	LINUX_EPOLL_EVRD	(LINUX_EPOLLIN|LINUX_EPOLLRDNORM	\
>-		|LINUX_EPOLLHUP|LINUX_EPOLLERR|LINUX_EPOLLPRI)
>+#define	LINUX_EPOLL_EVRD	(LINUX_EPOLLIN|LINUX_EPOLLRDNORM)
> #define	LINUX_EPOLL_EVWR	(LINUX_EPOLLOUT|LINUX_EPOLLWRNORM)
> #define	LINUX_EPOLL_EVSUP	(LINUX_EPOLLET|LINUX_EPOLLONESHOT	\
>+		|LINUX_EPOLLHUP|LINUX_EPOLLERR|LINUX_EPOLLPRI		\
> 		|LINUX_EPOLL_EVRD|LINUX_EPOLL_EVWR|LINUX_EPOLLRDHUP)
> 
> #define	LINUX_EPOLL_CTL_ADD	1

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Attachments on bug 240590: 207708 | 207916 | 207926