MFC r283441:

Implement epoll family system calls. This is a tiny wrapper
around kqueue() to implement epoll subset of functionality.
The kqueue user data are 32bit on i386 which is not enough for
epoll user data, so we keep user data in the proc emuldata.

Initial patch developed by rdivacky@ in 2007, then extended
by Yuri Victorovich @ r255672 and finished by me
in collaboration with mjg@ and jillies@.

17 files changed, 625 insertions, 31 deletions

diff --git a/sys/amd64/linux/linux_dummy.c b/sys/amd64/linux/linux_dummy.c
index 4e85bec..b2c175b 100644
--- a/sys/amd64/linux/linux_dummy.c
+++ b/sys/amd64/linux/linux_dummy.c
@@ -69,13 +69,10 @@ DUMMY(tuxcall);
 DUMMY(security);
 DUMMY(set_thread_area);
 DUMMY(lookup_dcookie);
-DUMMY(epoll_create);
 DUMMY(epoll_ctl_old);
 DUMMY(epoll_wait_old);
 DUMMY(remap_file_pages);
 DUMMY(semtimedop);
-DUMMY(epoll_ctl);
-DUMMY(epoll_wait);
 DUMMY(mbind);
 DUMMY(get_mempolicy);
 DUMMY(set_mempolicy);
@@ -112,7 +109,6 @@ DUMMY(timerfd_settime);
 DUMMY(timerfd_gettime);
 DUMMY(signalfd4);
 DUMMY(eventfd2);
-DUMMY(epoll_create1);
 DUMMY(inotify_init1);
 DUMMY(preadv);
 DUMMY(pwritev);
diff --git a/sys/amd64/linux/syscalls.master b/sys/amd64/linux/syscalls.master
index 4bdf287..b5d0bdc 100644
--- a/sys/amd64/linux/syscalls.master
+++ b/sys/amd64/linux/syscalls.master
@@ -373,7 +373,7 @@
 210	AUE_NULL	UNIMPL	linux_io_cancel
 211	AUE_NULL	UNIMPL	linux_get_thread_area
 212	AUE_NULL	STD	{ int linux_lookup_dcookie(void); }
-213	AUE_NULL	STD	{ int linux_epoll_create(void); }
+213	AUE_NULL	STD	{ int linux_epoll_create(l_int size); }
 214	AUE_NULL	STD	{ int linux_epoll_ctl_old(void); }
 215	AUE_NULL	STD	{ int linux_epoll_wait_old(void); }
 216	AUE_NULL	STD	{ int linux_remap_file_pages(void); }
@@ -397,8 +397,10 @@
 230	AUE_NULL	STD	{ int linux_clock_nanosleep(clockid_t which, int flags, \
 				    struct l_timespec *rqtp, struct l_timespec *rmtp); }
 231	AUE_EXIT	STD	{ int linux_exit_group(int error_code); }
-232	AUE_NULL	STD	{ int linux_epoll_wait(void); }
-233	AUE_NULL	STD	{ int linux_epoll_ctl(void); }
+232	AUE_NULL	STD	{ int linux_epoll_wait(l_int epfd, struct epoll_event *events, \
+					l_int maxevents, l_int timeout); }
+233	AUE_NULL	STD	{ int linux_epoll_ctl(l_int epfd, l_int op, l_int fd, \
+					struct epoll_event *event); }
 234	AUE_NULL	STD	{ int linux_tgkill(int tgid, int pid, int sig); }
 235	AUE_UTIMES	STD	{ int linux_utimes(char *fname, \
 				    struct l_timeval *tptr); }
@@ -466,7 +468,8 @@
 278	AUE_NULL	STD	{ int linux_vmsplice(void); }
 279	AUE_NULL	STD	{ int linux_move_pages(void); }
 280	AUE_NULL	STD	{ int linux_utimensat(void); }
-281	AUE_NULL	STD	{ int linux_epoll_pwait(void); }
+281     AUE_NULL        STD     { int linux_epoll_pwait(l_int epfd, struct epoll_event *events, \
+                                        l_int maxevents, l_int timeout, l_sigset_t *mask); }
 282	AUE_NULL	STD	{ int linux_signalfd(void); }
 283	AUE_NULL	STD	{ int linux_timerfd(void); }
 284	AUE_NULL	STD	{ int linux_eventfd(void); }
@@ -477,7 +480,7 @@
 				    l_uintptr_t namelen, int flags); }
 289	AUE_NULL	STD	{ int linux_signalfd4(void); }
 290	AUE_NULL	STD	{ int linux_eventfd2(void); }
-291	AUE_NULL	STD	{ int linux_epoll_create1(void); }
+291	AUE_NULL	STD	{ int linux_epoll_create1(l_int flags); }
 292	AUE_NULL	STD	{ int linux_dup3(l_int oldfd,		\
 				    l_int newfd, l_int flags); }
 293	AUE_NULL	STD	{ int linux_pipe2(l_int *pipefds, l_int flags); }
diff --git a/sys/amd64/linux32/linux32_dummy.c b/sys/amd64/linux32/linux32_dummy.c
index b02e113..27f6480 100644
--- a/sys/amd64/linux32/linux32_dummy.c
+++ b/sys/amd64/linux32/linux32_dummy.c
@@ -69,9 +69,6 @@ DUMMY(pivot_root);
 DUMMY(mincore);
 DUMMY(ptrace);
 DUMMY(lookup_dcookie);
-DUMMY(epoll_create);
-DUMMY(epoll_ctl);
-DUMMY(epoll_wait);
 DUMMY(remap_file_pages);
 DUMMY(fstatfs64);
 DUMMY(mbind);
@@ -121,7 +118,6 @@ DUMMY(timerfd_gettime);
 /* linux 2.6.27: */
 DUMMY(signalfd4);
 DUMMY(eventfd2);
-DUMMY(epoll_create1);
 DUMMY(inotify_init1);
 /* linux 2.6.30: */
 DUMMY(preadv);
diff --git a/sys/amd64/linux32/syscalls.master b/sys/amd64/linux32/syscalls.master
index f286c69..0c66beb 100644
--- a/sys/amd64/linux32/syscalls.master
+++ b/sys/amd64/linux32/syscalls.master
@@ -430,9 +430,11 @@
 251	AUE_NULL	UNIMPL
 252	AUE_EXIT	STD	{ int linux_exit_group(int error_code); }
 253	AUE_NULL	STD	{ int linux_lookup_dcookie(void); }
-254	AUE_NULL	STD	{ int linux_epoll_create(void); }
-255	AUE_NULL	STD	{ int linux_epoll_ctl(void); }
-256	AUE_NULL	STD	{ int linux_epoll_wait(void); }
+254	AUE_NULL	STD	{ int linux_epoll_create(l_int size); }
+255	AUE_NULL	STD	{ int linux_epoll_ctl(l_int epfd, l_int op, l_int fd, \
+					struct epoll_event *event); }
+256	AUE_NULL	STD	{ int linux_epoll_wait(l_int epfd, struct epoll_event *events, \
+					l_int maxevents, l_int timeout); }
 257	AUE_NULL	STD	{ int linux_remap_file_pages(void); }
 258	AUE_NULL	STD	{ int linux_set_tid_address(int *tidptr); }
 259	AUE_NULL	STD	{ int linux_timer_create(clockid_t clock_id, \
@@ -527,7 +529,8 @@
 317	AUE_NULL	STD	{ int linux_move_pages(void); }
 ; linux 2.6.19:
 318	AUE_NULL	STD	{ int linux_getcpu(void); }
-319	AUE_NULL	STD	{ int linux_epoll_pwait(void); }
+319     AUE_NULL        STD     { int linux_epoll_pwait(l_int epfd, struct epoll_event *events, \
+                                        l_int maxevents, l_int timeout, l_osigset_t *mask); }
 ; linux 2.6.22:
 320	AUE_NULL	STD	{ int linux_utimensat(void); }
 321	AUE_NULL	STD	{ int linux_signalfd(void); }
@@ -541,7 +544,7 @@
 ; linux 2.6.27:
 327	AUE_NULL	STD	{ int linux_signalfd4(void); }
 328	AUE_NULL	STD	{ int linux_eventfd2(void); }
-329	AUE_NULL	STD	{ int linux_epoll_create1(void); }
+329	AUE_NULL	STD	{ int linux_epoll_create1(l_int flags); }
 330	AUE_NULL	STD	{ int linux_dup3(l_int oldfd,		\
 					l_int newfd, l_int flags); }
 331	AUE_NULL	STD	{ int linux_pipe2(l_int *pipefds, l_int flags); }
diff --git a/sys/compat/linux/linux_emul.c b/sys/compat/linux/linux_emul.c
index 20eb8d1..78a1176 100644
--- a/sys/compat/linux/linux_emul.c
+++ b/sys/compat/linux/linux_emul.c
@@ -42,8 +42,6 @@ __FBSDID("$FreeBSD$");
 #include <sys/proc.h>
 #include <sys/syscallsubr.h>
 #include <sys/sysent.h>
-#include <sys/sysproto.h>
-#include <sys/unistd.h>
 
 #include <compat/linux/linux_emul.h>
 #include <compat/linux/linux_misc.h>
@@ -86,6 +84,7 @@ linux_proc_init(struct thread *td, struct thread *newtd, int flags)
 {
 	struct linux_emuldata *em;
 	struct linux_pemuldata *pem;
+	struct epoll_emuldata *emd;
 
 	if (newtd != NULL) {
 		/* non-exec call */
@@ -93,8 +92,13 @@ linux_proc_init(struct thread *td, struct thread *newtd, int flags)
 		em->pdeath_signal = 0;
 		em->robust_futexes = NULL;
 		if (flags & LINUX_CLONE_THREAD) {
+			LINUX_CTR1(proc_init, "thread newtd(%d)",
+			    newtd->td_tid);
+
 			em->em_tid = newtd->td_tid;
 		} else {
+			LINUX_CTR1(proc_init, "fork newtd(%d)",
+			    newtd->td_proc->p_pid);
 
 			em->em_tid = newtd->td_proc->p_pid;
 
@@ -105,12 +109,24 @@ linux_proc_init(struct thread *td, struct thread *newtd, int flags)
 		newtd->td_emuldata = em;
 	} else {
 		/* exec */
+		LINUX_CTR1(proc_init, "exec newtd(%d)",
+		    td->td_proc->p_pid);
 
 		/* lookup the old one */
 		em = em_find(td);
 		KASSERT(em != NULL, ("proc_init: emuldata not found in exec case.\n"));
 
 		em->em_tid = td->td_proc->p_pid;
+
+		 /* epoll should be destroyed in a case of exec. */
+		pem = pem_find(td->td_proc);
+		KASSERT(pem != NULL, ("proc_exit: proc emuldata not found.\n"));
+
+		if (pem->epoll != NULL) {
+			emd = pem->epoll;
+			pem->epoll = NULL;
+			free(emd, M_EPOLL);
+		}
 	}
 
 	em->child_clear_tid = NULL;
@@ -121,6 +137,7 @@ void
 linux_proc_exit(void *arg __unused, struct proc *p)
 {
 	struct linux_pemuldata *pem;
+	struct epoll_emuldata *emd;
 	struct thread *td = curthread;
 
 	if (__predict_false(SV_CURPROC_ABI() != SV_ABI_LINUX))
@@ -133,6 +150,12 @@ linux_proc_exit(void *arg __unused, struct proc *p)
 
 	p->p_emuldata = NULL;
 
+	if (pem->epoll != NULL) {
+		emd = pem->epoll;
+		pem->epoll = NULL;
+		free(emd, M_EPOLL);
+	}
+
 	sx_destroy(&pem->pem_sx);
 	free(pem, M_LINUX);
 }
@@ -141,6 +164,7 @@ int
 linux_common_execve(struct thread *td, struct image_args *eargs)
 {
 	struct linux_pemuldata *pem;
+	struct epoll_emuldata *emd;
 	struct linux_emuldata *em;
 	struct proc *p;
 	int error;
@@ -180,6 +204,12 @@ linux_common_execve(struct thread *td, struct image_args *eargs)
 		p->p_emuldata = NULL;
 		PROC_UNLOCK(p);
 
+		if (pem->epoll != NULL) {
+			emd = pem->epoll;
+			pem->epoll = NULL;
+			free(emd, M_EPOLL);
+		}
+
 		free(em, M_TEMP);
 		free(pem, M_LINUX);
 	}
@@ -197,6 +227,7 @@ linux_proc_exec(void *arg __unused, struct proc *p, struct image_params *imgp)
 	 */
 	if (__predict_false((imgp->sysent->sv_flags & SV_ABI_MASK) ==
 	    SV_ABI_LINUX)) {
+
 		if (SV_PROC_ABI(p) == SV_ABI_LINUX)
 			linux_proc_init(td, NULL, 0);
 		else
diff --git a/sys/compat/linux/linux_emul.h b/sys/compat/linux/linux_emul.h
index 2178701..3558b0a 100644
--- a/sys/compat/linux/linux_emul.h
+++ b/sys/compat/linux/linux_emul.h
@@ -60,9 +60,12 @@ int	linux_common_execve(struct thread *, struct image_args *);
 /* process emuldata flags */
 #define	LINUX_XDEPR_REQUEUEOP	0x00000001	/* uses deprecated
 						   futex REQUEUE op*/
+#define	LINUX_XUNSUP_EPOLL	0x00000002	/* unsupported epoll events */
+
 struct linux_pemuldata {
 	uint32_t	flags;		/* process emuldata flags */
 	struct sx	pem_sx;		/* lock for this struct */
+	void		*epoll;		/* epoll data */
 };
 
 #define	LINUX_PEM_XLOCK(p)	sx_xlock(&(p)->pem_sx)
diff --git a/sys/compat/linux/linux_event.c b/sys/compat/linux/linux_event.c
new file mode 100644
index 0000000..2456c41
--- /dev/null
+++ b/sys/compat/linux/linux_event.c
@@ -0,0 +1,500 @@
+/*-
+ * Copyright (c) 2007 Roman Divacky
+ * Copyright (c) 2014 Dmitry Chagin
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ */
+
+#include <sys/cdefs.h>
+__FBSDID("$FreeBSD$");
+
+#include "opt_compat.h"
+
+#include <sys/param.h>
+#include <sys/systm.h>
+#include <sys/imgact.h>
+#include <sys/kernel.h>
+#include <sys/limits.h>
+#include <sys/lock.h>
+#include <sys/mutex.h>
+#include <sys/capability.h>
+#include <sys/types.h>
+#include <sys/file.h>
+#include <sys/filedesc.h>
+#include <sys/errno.h>
+#include <sys/event.h>
+#include <sys/proc.h>
+#include <sys/sx.h>
+#include <sys/syscallsubr.h>
+#include <sys/timespec.h>
+
+#ifdef COMPAT_LINUX32
+#include <machine/../linux32/linux.h>
+#include <machine/../linux32/linux32_proto.h>
+#else
+#include <machine/../linux/linux.h>
+#include <machine/../linux/linux_proto.h>
+#endif
+
+#include <compat/linux/linux_emul.h>
+#include <compat/linux/linux_event.h>
+#include <compat/linux/linux_file.h>
+#include <compat/linux/linux_util.h>
+
+/*
+ * epoll defines 'struct epoll_event' with the field 'data' as 64 bits
+ * on all architectures. But on 32 bit architectures BSD 'struct kevent' only
+ * has 32 bit opaque pointer as 'udata' field. So we can't pass epoll supplied
+ * data verbatuim. Therefore we allocate 64-bit memory block to pass
+ * user supplied data for every file descriptor.
+ */
+
+typedef uint64_t	epoll_udata_t;
+
+struct epoll_emuldata {
+	uint32_t	fdc;		/* epoll udata max index */
+	epoll_udata_t	udata[1];	/* epoll user data vector */
+};
+
+#define	EPOLL_DEF_SZ		16
+#define	EPOLL_SIZE(fdn)			\
+	(sizeof(struct epoll_emuldata)+(fdn) * sizeof(epoll_udata_t))
+
+struct epoll_event {
+	uint32_t	events;
+	epoll_udata_t	data;
+}
+#if defined(__amd64__)
+__attribute__((packed))
+#endif
+;
+
+#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 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_delete_all_events(struct thread *td, struct file *epfp,
+		    int fd);
+
+struct epoll_copyin_args {
+	struct kevent	*changelist;
+};
+
+struct epoll_copyout_args {
+	struct epoll_event	*leventlist;
+	struct proc		*p;
+	uint32_t		count;
+	int			error;
+};
+
+
+static void
+epoll_fd_install(struct thread *td, int fd, epoll_udata_t udata)
+{
+	struct linux_pemuldata *pem;
+	struct epoll_emuldata *emd;
+	struct proc *p;
+
+	p = td->td_proc;
+
+	pem = pem_find(p);
+	KASSERT(pem != NULL, ("epoll proc emuldata not found.\n"));
+
+	LINUX_PEM_XLOCK(pem);
+	if (pem->epoll == NULL) {
+		emd = malloc(EPOLL_SIZE(fd), M_EPOLL, M_WAITOK);
+		emd->fdc = fd;
+		pem->epoll = emd;
+	} else {
+		emd = pem->epoll;
+		if (fd > emd->fdc) {
+			emd = realloc(emd, EPOLL_SIZE(fd), M_EPOLL, M_WAITOK);
+			emd->fdc = fd;
+			pem->epoll = emd;
+		}
+	}
+	emd->udata[fd] = udata;
+	LINUX_PEM_XUNLOCK(pem);
+}
+
+static int
+epoll_create_common(struct thread *td, int flags)
+{
+	int error;
+
+	error = kern_kqueue(td, flags);
+	if (error)
+		return (error);
+
+	epoll_fd_install(td, EPOLL_DEF_SZ, 0);
+
+	return (0);
+}
+
+int
+linux_epoll_create(struct thread *td, struct linux_epoll_create_args *args)
+{
+
+	/*
+	 * args->size is unused. Linux just tests it
+	 * and then forgets it as well.
+	 */
+	if (args->size <= 0)
+		return (EINVAL);
+
+	return (epoll_create_common(td, 0));
+}
+
+int
+linux_epoll_create1(struct thread *td, struct linux_epoll_create1_args *args)
+{
+	int flags;
+
+	if ((args->flags & ~(LINUX_O_CLOEXEC)) != 0)
+		return (EINVAL);
+
+	flags = 0;
+	if ((args->flags & LINUX_O_CLOEXEC) != 0)
+		flags |= O_CLOEXEC;
+
+	return (epoll_create_common(td, flags));
+}
+
+/* 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,
+    struct kevent *kevent, int *nkevents)
+{
+	uint32_t levents = l_event->events;
+	struct linux_pemuldata *pem;
+	struct proc *p;
+
+	/* flags related to how event is registered */
+	if ((levents & LINUX_EPOLLONESHOT) != 0)
+		*kev_flags |= EV_ONESHOT;
+	if ((levents & LINUX_EPOLLET) != 0)
+		*kev_flags |= EV_CLEAR;
+
+	/* flags related to what event is registered */
+	if ((levents & LINUX_EPOLL_EVRD) != 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);
+		++(*nkevents);
+	}
+
+	if ((levents & ~(LINUX_EPOLL_EVSUP)) != 0) {
+		p = td->td_proc;
+
+		pem = pem_find(p);
+		KASSERT(pem != NULL, ("epoll proc emuldata not found.\n"));
+		KASSERT(pem->epoll != NULL, ("epoll proc epolldata not found.\n"));
+
+		LINUX_PEM_XLOCK(pem);
+		if ((pem->flags & LINUX_XUNSUP_EPOLL) == 0) {
+			pem->flags |= LINUX_XUNSUP_EPOLL;
+			LINUX_PEM_XUNLOCK(pem);
+			linux_msg(td, "epoll_ctl unsupported flags: 0x%x\n",
+			    levents);
+		} else
+			LINUX_PEM_XUNLOCK(pem);
+		return (EINVAL);
+	}
+
+	return (0);
+}
+
+/* 
+ * Structure converting function from kevent to epoll. In a case
+ * this is called on error in registration we store the error in
+ * event->data and pick it up later in linux_epoll_ctl().
+ */
+static void
+kevent_to_epoll(struct kevent *kevent, struct epoll_event *l_event)
+{
+
+	if ((kevent->flags & EV_ERROR) != 0)
+		return;
+
+	switch (kevent->filter) {
+	case EVFILT_READ:
+		l_event->events = LINUX_EPOLLIN|LINUX_EPOLLRDNORM|LINUX_EPOLLPRI;
+	break;
+	case EVFILT_WRITE:
+		l_event->events = LINUX_EPOLLOUT|LINUX_EPOLLWRNORM;
+	break;
+	}
+}
+
+/* 
+ * Copyout callback used by kevent. This converts kevent
+ * events to epoll events and copies them back to the
+ * userspace. This is also called on error on registering
+ * of the filter.
+ */
+static int
+epoll_kev_copyout(void *arg, struct kevent *kevp, int count)
+{
+	struct epoll_copyout_args *args;
+	struct linux_pemuldata *pem;
+	struct epoll_emuldata *emd;
+	struct epoll_event *eep;
+	int error, fd, i;
+
+	args = (struct epoll_copyout_args*) arg;
+	eep = malloc(sizeof(*eep) * count, M_EPOLL, M_WAITOK | M_ZERO);
+
+	pem = pem_find(args->p);
+	KASSERT(pem != NULL, ("epoll proc emuldata not found.\n"));
+	LINUX_PEM_SLOCK(pem);
+	emd = pem->epoll;
+	KASSERT(emd != NULL, ("epoll proc epolldata not found.\n"));
+
+	for (i = 0; i < count; i++) {
+		kevent_to_epoll(&kevp[i], &eep[i]);
+
+		fd = kevp[i].ident;
+		KASSERT(fd <= emd->fdc, ("epoll user data vector"
+						    " is too small.\n"));
+		eep[i].data = emd->udata[fd];
+	}
+	LINUX_PEM_SUNLOCK(pem);
+
+	error = copyout(eep, args->leventlist, count * sizeof(*eep));
+	if (error == 0) {
+		args->leventlist += count;
+		args->count += count;
+	} else if (args->error == 0)
+		args->error = error;
+
+	free(eep, M_EPOLL);
+	return (error);
+}
+
+/*
+ * Copyin callback used by kevent. This copies already
+ * converted filters from kernel memory to the kevent 
+ * internal kernel memory. Hence the memcpy instead of
+ * copyin.
+ */
+static int
+epoll_kev_copyin(void *arg, struct kevent *kevp, int count)
+{
+	struct epoll_copyin_args *args;
+
+	args = (struct epoll_copyin_args*) arg;
+	
+	memcpy(kevp, args->changelist, count * sizeof(*kevp));
+	args->changelist += count;
+
+	return (0);
+}
+
+/*
+ * Load epoll filter, convert it to kevent filter
+ * and load it into kevent subsystem.
+ */
+int
+linux_epoll_ctl(struct thread *td, struct linux_epoll_ctl_args *args)
+{
+	struct file *epfp, *fp;
+	struct epoll_copyin_args ciargs;
+	struct kevent kev[2];
+	struct kevent_copyops k_ops = { &ciargs,
+					NULL,
+					epoll_kev_copyin};
+	struct epoll_event le;
+	cap_rights_t rights;
+	int kev_flags;
+	int nchanges = 0;
+	int error;
+
+	if (args->op != LINUX_EPOLL_CTL_DEL) {
+		error = copyin(args->event, &le, sizeof(le));
+		if (error != 0)
+			return (error);
+	}
+
+	error = fget(td, args->epfd,
+	    cap_rights_init(&rights, CAP_KQUEUE_CHANGE), &epfp);
+	if (error != 0)
+		return (error);
+	if (epfp->f_type != DTYPE_KQUEUE)
+		goto leave1;
+
+	 /* Protect user data vector from incorrectly supplied fd. */
+	error = fget(td, args->fd, cap_rights_init(&rights, CAP_POLL_EVENT), &fp);
+	if (error != 0)
+		goto leave1;
+
+	/* Linux disallows spying on himself */
+	if (epfp == fp) {
+		error = EINVAL;
+		goto leave0;
+	}
+
+	ciargs.changelist = kev;
+
+	switch (args->op) {
+	case LINUX_EPOLL_CTL_MOD:
+		/*
+		 * We don't memorize which events were set for this FD
+		 * on this level, so just delete all we could have set:
+		 * EVFILT_READ and EVFILT_WRITE, ignoring any errors
+		 */
+		error = epoll_delete_all_events(td, epfp, args->fd);
+		if (error)
+			goto leave0;
+		/* FALLTHROUGH */
+
+	case LINUX_EPOLL_CTL_ADD:
+			kev_flags = EV_ADD | EV_ENABLE;
+		break;
+
+	case LINUX_EPOLL_CTL_DEL:
+		/* CTL_DEL means unregister this fd with this epoll */
+		error = epoll_delete_all_events(td, epfp, args->fd);
+		goto leave0;
+
+	default:
+		error = EINVAL;
+		goto leave0;
+	}
+
+	error = epoll_to_kevent(td, epfp, args->fd, &le, &kev_flags,
+	    kev, &nchanges);
+	if (error)
+		goto leave0;
+
+	epoll_fd_install(td, args->fd, le.data);
+
+	error = kern_kevent_fp(td, epfp, nchanges, 0, &k_ops, NULL);
+
+leave0:
+	fdrop(fp, td);
+
+leave1:
+	fdrop(epfp, td);
+	return (error);
+}
+
+/*
+ * Wait for a filter to be triggered on the epoll file descriptor.
+ */
+int
+linux_epoll_wait(struct thread *td, struct linux_epoll_wait_args *args)
+{
+	struct file *epfp;
+	struct timespec ts, *tsp;
+	cap_rights_t rights;
+	struct epoll_copyout_args coargs;
+	struct kevent_copyops k_ops = { &coargs,
+					epoll_kev_copyout,
+					NULL};
+	int error;
+
+	if (args->maxevents <= 0 || args->maxevents > LINUX_MAX_EVENTS)
+		return (EINVAL);
+
+	error = fget(td, args->epfd,
+	    cap_rights_init(&rights, CAP_KQUEUE_EVENT), &epfp);
+	if (error != 0)
+		return (error);
+
+	coargs.leventlist = args->events;
+	coargs.p = td->td_proc;
+	coargs.count = 0;
+	coargs.error = 0;
+
+	if (args->timeout != -1) {
+		if (args->timeout < 0) {
+			error = EINVAL;
+			goto leave;
+		}
+		/* Convert from milliseconds to timespec. */
+		ts.tv_sec = args->timeout / 1000;
+		ts.tv_nsec = (args->timeout % 1000) * 1000000;
+		tsp = &ts;
+	} else {
+		tsp = NULL;
+	}
+
+	error = kern_kevent_fp(td, epfp, 0, args->maxevents, &k_ops, tsp);
+	if (error == 0 && coargs.error != 0)
+		error = coargs.error;
+
+	/* 
+	 * kern_kevent might return ENOMEM which is not expected from epoll_wait.
+	 * Maybe we should translate that but I don't think it matters at all.
+	 */
+	if (error == 0)
+		td->td_retval[0] = coargs.count;
+leave:
+	fdrop(epfp, td);
+	return (error);
+}
+
+static int
+epoll_delete_event(struct thread *td, struct file *epfp, int fd, int filter)
+{
+	struct epoll_copyin_args ciargs;
+	struct kevent kev;
+	struct kevent_copyops k_ops = { &ciargs,
+					NULL,
+					epoll_kev_copyin};
+	int error;
+
+	ciargs.changelist = &kev;
+	EV_SET(&kev, fd, filter, EV_DELETE | EV_DISABLE, 0, 0, 0);
+
+	error = kern_kevent_fp(td, epfp, 1, 0, &k_ops, NULL);
+
+	/*
+	 * here we ignore ENONT, because we don't keep track of events here
+	 */
+	if (error == ENOENT)
+		error = 0;
+	return (error);
+}
+
+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);
+
+	/* report any errors we got */
+	return (error1 == 0 ? error2 : error1);
+}
diff --git a/sys/compat/linux/linux_event.h b/sys/compat/linux/linux_event.h
new file mode 100644
index 0000000..f4bb803
--- /dev/null
+++ b/sys/compat/linux/linux_event.h
@@ -0,0 +1,58 @@
+/*-
+ * Copyright (c) 2007 Roman Divacky
+ * Copyright (c) 2014 Dmitry Chagin
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ *
+ * $FreeBSD$
+ */
+
+#ifndef _LINUX_EVENT_H_
+#define	_LINUX_EVENT_H_
+
+#define	LINUX_EPOLLIN		0x001
+#define	LINUX_EPOLLPRI		0x002
+#define	LINUX_EPOLLOUT		0x004
+#define	LINUX_EPOLLRDNORM	0x040
+#define	LINUX_EPOLLRDBAND	0x080
+#define	LINUX_EPOLLWRNORM	0x100
+#define	LINUX_EPOLLWRBAND	0x200
+#define	LINUX_EPOLLMSG		0x400
+#define	LINUX_EPOLLERR		0x008
+#define	LINUX_EPOLLHUP		0x010
+#define	LINUX_EPOLLRDHUP	0x2000
+#define	LINUX_EPOLLWAKEUP	1u<<29
+#define	LINUX_EPOLLONESHOT	1u<<30
+#define	LINUX_EPOLLET		1u<<31
+
+#define	LINUX_EPOLL_EVRD	(LINUX_EPOLLIN|LINUX_EPOLLRDNORM	\
+		|LINUX_EPOLLHUP|LINUX_EPOLLPRI)
+#define	LINUX_EPOLL_EVWR	(LINUX_EPOLLOUT|LINUX_EPOLLWRNORM)
+#define	LINUX_EPOLL_EVSUP	(LINUX_EPOLLET|LINUX_EPOLLONESHOT	\
+		|LINUX_EPOLL_EVRD|LINUX_EPOLL_EVWR)
+
+#define	LINUX_EPOLL_CTL_ADD	1
+#define	LINUX_EPOLL_CTL_DEL	2
+#define	LINUX_EPOLL_CTL_MOD	3
+
+#endif	/* !_LINUX_EVENT_H_ */
diff --git a/sys/compat/linux/linux_util.c b/sys/compat/linux/linux_util.c
index c4c26ac..fe49120 100644
--- a/sys/compat/linux/linux_util.c
+++ b/sys/compat/linux/linux_util.c
@@ -55,6 +55,7 @@ __FBSDID("$FreeBSD$");
 #include <compat/linux/linux_util.h>
 
 MALLOC_DEFINE(M_LINUX, "linux", "Linux mode structures");
+MALLOC_DEFINE(M_EPOLL, "lepoll", "Linux events structures");
 MALLOC_DEFINE(M_FUTEX, "futex", "Linux futexes");
 MALLOC_DEFINE(M_FUTEX_WP, "futex wp", "Linux futex waiting proc");
 
diff --git a/sys/compat/linux/linux_util.h b/sys/compat/linux/linux_util.h
index 0683099..a52a7b9 100644
--- a/sys/compat/linux/linux_util.h
+++ b/sys/compat/linux/linux_util.h
@@ -45,6 +45,7 @@
 #include <sys/uio.h>
 
 MALLOC_DECLARE(M_LINUX);
+MALLOC_DECLARE(M_EPOLL);
 MALLOC_DECLARE(M_FUTEX);
 MALLOC_DECLARE(M_FUTEX_WP);
 
diff --git a/sys/conf/files.amd64 b/sys/conf/files.amd64
index faf4b64..dd01c1a 100644
--- a/sys/conf/files.amd64
+++ b/sys/conf/files.amd64
@@ -541,6 +541,7 @@ compat/linux/linux_uid16.c	optional	compat_linux32
 compat/linux/linux_util.c	optional	compat_linux32
 compat/linux/linux_vdso.c	optional	compat_linux32
 compat/linux/linux_common.c	optional	compat_linux32
+compat/linux/linux_event.c	optional	compat_linux32
 dev/amr/amr_linux.c		optional	compat_linux32 amr
 dev/mfi/mfi_linux.c		optional	compat_linux32 mfi
 #
diff --git a/sys/conf/files.i386 b/sys/conf/files.i386
index e34169b..a705060 100644
--- a/sys/conf/files.i386
+++ b/sys/conf/files.i386
@@ -92,6 +92,7 @@ hptrr_lib.o			optional	hptrr			\
 cddl/contrib/opensolaris/common/atomic/i386/opensolaris_atomic.S	optional zfs compile-with "${ZFS_S}"
 compat/linprocfs/linprocfs.c	optional linprocfs
 compat/linsysfs/linsysfs.c	optional linsysfs
+compat/linux/linux_event.c	optional compat_linux
 compat/linux/linux_emul.c	optional compat_linux
 compat/linux/linux_file.c	optional compat_linux
 compat/linux/linux_fork.c	optional compat_linux
diff --git a/sys/conf/files.pc98 b/sys/conf/files.pc98
index a1a9663..584d1dd 100644
--- a/sys/conf/files.pc98
+++ b/sys/conf/files.pc98
@@ -41,6 +41,7 @@ ukbdmap.h			optional	ukbd_dflt_keymap	\
 cddl/contrib/opensolaris/common/atomic/i386/opensolaris_atomic.S	optional zfs compile-with "${ZFS_S}"
 compat/linprocfs/linprocfs.c	optional linprocfs
 compat/linsysfs/linsysfs.c	optional linsysfs
+compat/linux/linux_event.c	optional compat_linux
 compat/linux/linux_emul.c	optional compat_linux
 compat/linux/linux_file.c	optional compat_linux
 compat/linux/linux_fork.c	optional compat_linux
diff --git a/sys/i386/linux/linux_dummy.c b/sys/i386/linux/linux_dummy.c
index 5e64a1f..de1f061 100644
--- a/sys/i386/linux/linux_dummy.c
+++ b/sys/i386/linux/linux_dummy.c
@@ -71,9 +71,6 @@ DUMMY(setfsgid);
 DUMMY(pivot_root);
 DUMMY(mincore);
 DUMMY(lookup_dcookie);
-DUMMY(epoll_create);
-DUMMY(epoll_ctl);
-DUMMY(epoll_wait);
 DUMMY(remap_file_pages);
 DUMMY(fstatfs64);
 DUMMY(mbind);
@@ -117,7 +114,6 @@ DUMMY(timerfd_gettime);
 /* linux 2.6.27: */
 DUMMY(signalfd4);
 DUMMY(eventfd2);
-DUMMY(epoll_create1);
 DUMMY(inotify_init1);
 /* linux 2.6.30: */
 DUMMY(preadv);
diff --git a/sys/i386/linux/syscalls.master b/sys/i386/linux/syscalls.master
index 9477910..ff72a48 100644
--- a/sys/i386/linux/syscalls.master
+++ b/sys/i386/linux/syscalls.master
@@ -432,9 +432,11 @@
 251	AUE_NULL	UNIMPL
 252	AUE_EXIT	STD	{ int linux_exit_group(int error_code); }
 253	AUE_NULL	STD	{ int linux_lookup_dcookie(void); }
-254	AUE_NULL	STD	{ int linux_epoll_create(void); }
-255	AUE_NULL	STD	{ int linux_epoll_ctl(void); }
-256	AUE_NULL	STD	{ int linux_epoll_wait(void); }
+254	AUE_NULL	STD	{ int linux_epoll_create(l_int size); }
+255	AUE_NULL	STD	{ int linux_epoll_ctl(l_int epfd, l_int op, l_int fd, \
+					struct epoll_event *event); }
+256	AUE_NULL	STD	{ int linux_epoll_wait(l_int epfd, struct epoll_event *events, \
+					l_int maxevents, l_int timeout); }
 257	AUE_NULL	STD	{ int linux_remap_file_pages(void); }
 258	AUE_NULL	STD	{ int linux_set_tid_address(int *tidptr); }
 259	AUE_NULL	STD	{ int linux_timer_create(clockid_t clock_id, \
@@ -535,7 +537,8 @@
 317	AUE_NULL	STD	{ int linux_move_pages(void); }
 ; linux 2.6.19:
 318	AUE_NULL	STD	{ int linux_getcpu(void); }
-319	AUE_NULL	STD	{ int linux_epoll_pwait(void); }
+319	AUE_NULL	STD	{ int linux_epoll_pwait(l_int epfd, struct epoll_event *events, \
+					l_int maxevents, l_int timeout, l_osigset_t *mask); }
 ; linux 2.6.22:
 320	AUE_NULL	STD	{ int linux_utimensat(void); }
 321	AUE_NULL	STD	{ int linux_signalfd(void); }
@@ -549,7 +552,7 @@
 ; linux 2.6.27:
 327	AUE_NULL	STD	{ int linux_signalfd4(void); }
 328	AUE_NULL	STD	{ int linux_eventfd2(void); }
-329	AUE_NULL	STD	{ int linux_epoll_create1(void); }
+329	AUE_NULL	STD	{ int linux_epoll_create1(l_int flags); }
 330	AUE_NULL	STD	{ int linux_dup3(l_int oldfd,		\
 					l_int newfd, l_int flags); }
 331	AUE_NULL	STD	{ int linux_pipe2(l_int *pipefds, l_int flags); }
diff --git a/sys/modules/linux/Makefile b/sys/modules/linux/Makefile
index 5817aab..57e2688 100644
--- a/sys/modules/linux/Makefile
+++ b/sys/modules/linux/Makefile
@@ -10,7 +10,7 @@ CFLAGS+=-DCOMPAT_FREEBSD32 -DCOMPAT_LINUX32
 VDSO=	linux${SFX}_vdso
 
 KMOD=	linux
-SRCS=	linux_fork.c linux${SFX}_dummy.c linux_file.c \
+SRCS=	linux_fork.c linux${SFX}_dummy.c linux_file.c linux_event.c \
 	linux_futex.c linux_getcwd.c linux_ioctl.c linux_ipc.c \
 	linux${SFX}_machdep.c linux_misc.c linux_signal.c \
 	linux_socket.c linux_stats.c linux_sysctl.c linux${SFX}_sysent.c \
diff --git a/sys/modules/linux64/Makefile b/sys/modules/linux64/Makefile
index 40ae873..fe86d53 100644
--- a/sys/modules/linux64/Makefile
+++ b/sys/modules/linux64/Makefile
@@ -5,7 +5,7 @@
 VDSO=	linux_vdso
 
 KMOD=	linux64
-SRCS=	linux_fork.c linux_dummy.c linux_file.c \
+SRCS=	linux_fork.c linux_dummy.c linux_file.c linux_event.c \
 	linux_futex.c linux_getcwd.c linux_ioctl.c linux_ipc.c \
 	linux_machdep.c linux_misc.c linux_signal.c \
 	linux_socket.c linux_stats.c linux_sysctl.c linux_sysent.c \