freebsd-dev/sys/compat/linux/linux_event.c
Mark Johnston 792843c38f Pass malloc flags directly through kevent(2) subroutines.
Some kevent functions have a boolean "waitok" parameter for use when
calling malloc(9).  Replace them with the corresponding malloc() flags:
the desired behaviour is known at compile-time, so this eliminates a
couple of conditional branches, and makes the code easier to read.

No functional change intended.

Reviewed by:	kib
MFC after:	1 week
Sponsored by:	The FreeBSD Foundation
Differential Revision:	https://reviews.freebsd.org/D18318
2018-11-24 17:06:01 +00:00

1329 lines
30 KiB
C

/*-
* 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/callout.h>
#include <sys/capsicum.h>
#include <sys/types.h>
#include <sys/user.h>
#include <sys/file.h>
#include <sys/filedesc.h>
#include <sys/filio.h>
#include <sys/errno.h>
#include <sys/event.h>
#include <sys/poll.h>
#include <sys/proc.h>
#include <sys/selinfo.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_timer.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;
};
/* eventfd */
typedef uint64_t eventfd_t;
static fo_rdwr_t eventfd_read;
static fo_rdwr_t eventfd_write;
static fo_ioctl_t eventfd_ioctl;
static fo_poll_t eventfd_poll;
static fo_kqfilter_t eventfd_kqfilter;
static fo_stat_t eventfd_stat;
static fo_close_t eventfd_close;
static fo_fill_kinfo_t eventfd_fill_kinfo;
static struct fileops eventfdops = {
.fo_read = eventfd_read,
.fo_write = eventfd_write,
.fo_truncate = invfo_truncate,
.fo_ioctl = eventfd_ioctl,
.fo_poll = eventfd_poll,
.fo_kqfilter = eventfd_kqfilter,
.fo_stat = eventfd_stat,
.fo_close = eventfd_close,
.fo_chmod = invfo_chmod,
.fo_chown = invfo_chown,
.fo_sendfile = invfo_sendfile,
.fo_fill_kinfo = eventfd_fill_kinfo,
.fo_flags = DFLAG_PASSABLE
};
static void filt_eventfddetach(struct knote *kn);
static int filt_eventfdread(struct knote *kn, long hint);
static int filt_eventfdwrite(struct knote *kn, long hint);
static struct filterops eventfd_rfiltops = {
.f_isfd = 1,
.f_detach = filt_eventfddetach,
.f_event = filt_eventfdread
};
static struct filterops eventfd_wfiltops = {
.f_isfd = 1,
.f_detach = filt_eventfddetach,
.f_event = filt_eventfdwrite
};
/* timerfd */
typedef uint64_t timerfd_t;
static fo_rdwr_t timerfd_read;
static fo_poll_t timerfd_poll;
static fo_kqfilter_t timerfd_kqfilter;
static fo_stat_t timerfd_stat;
static fo_close_t timerfd_close;
static fo_fill_kinfo_t timerfd_fill_kinfo;
static struct fileops timerfdops = {
.fo_read = timerfd_read,
.fo_write = invfo_rdwr,
.fo_truncate = invfo_truncate,
.fo_ioctl = eventfd_ioctl,
.fo_poll = timerfd_poll,
.fo_kqfilter = timerfd_kqfilter,
.fo_stat = timerfd_stat,
.fo_close = timerfd_close,
.fo_chmod = invfo_chmod,
.fo_chown = invfo_chown,
.fo_sendfile = invfo_sendfile,
.fo_fill_kinfo = timerfd_fill_kinfo,
.fo_flags = DFLAG_PASSABLE
};
static void filt_timerfddetach(struct knote *kn);
static int filt_timerfdread(struct knote *kn, long hint);
static struct filterops timerfd_rfiltops = {
.f_isfd = 1,
.f_detach = filt_timerfddetach,
.f_event = filt_timerfdread
};
struct eventfd {
eventfd_t efd_count;
uint32_t efd_flags;
struct selinfo efd_sel;
struct mtx efd_lock;
};
struct timerfd {
clockid_t tfd_clockid;
struct itimerspec tfd_time;
struct callout tfd_callout;
timerfd_t tfd_count;
bool tfd_canceled;
struct selinfo tfd_sel;
struct mtx tfd_lock;
};
static int eventfd_create(struct thread *td, uint32_t initval, int flags);
static void linux_timerfd_expire(void *);
static void linux_timerfd_curval(struct timerfd *, struct itimerspec *);
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, NULL);
if (error != 0)
return (error);
epoll_fd_install(td, EPOLL_DEF_SZ, 0);
return (0);
}
#ifdef LINUX_LEGACY_SYSCALLS
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));
}
#endif
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;
if ((levents & LINUX_EPOLLERR) != 0)
*kev_flags |= EV_ERROR;
if ((levents & LINUX_EPOLLRDHUP) != 0)
*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);
++(*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) {
l_event->events = LINUX_EPOLLERR;
return;
}
/* XXX EPOLLPRI, EPOLLHUP */
switch (kevent->filter) {
case EVFILT_READ:
l_event->events = LINUX_EPOLLIN;
if ((kevent->flags & EV_EOF) != 0)
l_event->events |= LINUX_EPOLLRDHUP;
break;
case EVFILT_WRITE:
l_event->events = LINUX_EPOLLOUT;
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) {
error = EINVAL;
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;
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);
if (error != 0)
goto leave0;
}
switch (args->op) {
case LINUX_EPOLL_CTL_MOD:
error = epoll_delete_all_events(td, epfp, args->fd);
if (error != 0)
goto leave0;
break;
case LINUX_EPOLL_CTL_ADD:
/*
* kqueue_register() return ENOENT if event does not exists
* and the EV_ADD flag is not set.
*/
kev[0].flags &= ~EV_ADD;
error = kqfd_register(args->epfd, &kev[0], td, M_WAITOK);
if (error != ENOENT) {
error = EEXIST;
goto leave0;
}
error = 0;
kev[0].flags |= EV_ADD;
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;
}
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.
*/
static int
linux_epoll_wait_common(struct thread *td, int epfd, struct epoll_event *events,
int maxevents, int timeout, sigset_t *uset)
{
struct epoll_copyout_args coargs;
struct kevent_copyops k_ops = { &coargs,
epoll_kev_copyout,
NULL};
struct timespec ts, *tsp;
cap_rights_t rights;
struct file *epfp;
sigset_t omask;
int error;
if (maxevents <= 0 || maxevents > LINUX_MAX_EVENTS)
return (EINVAL);
error = fget(td, epfd,
cap_rights_init(&rights, CAP_KQUEUE_EVENT), &epfp);
if (error != 0)
return (error);
if (epfp->f_type != DTYPE_KQUEUE) {
error = EINVAL;
goto leave1;
}
if (uset != NULL) {
error = kern_sigprocmask(td, SIG_SETMASK, uset,
&omask, 0);
if (error != 0)
goto leave1;
td->td_pflags |= TDP_OLDMASK;
/*
* Make sure that ast() is called on return to
* usermode and TDP_OLDMASK is cleared, restoring old
* sigmask.
*/
thread_lock(td);
td->td_flags |= TDF_ASTPENDING;
thread_unlock(td);
}
coargs.leventlist = events;
coargs.p = td->td_proc;
coargs.count = 0;
coargs.error = 0;
if (timeout != -1) {
if (timeout < 0) {
error = EINVAL;
goto leave0;
}
/* Convert from milliseconds to timespec. */
ts.tv_sec = timeout / 1000;
ts.tv_nsec = (timeout % 1000) * 1000000;
tsp = &ts;
} else {
tsp = NULL;
}
error = kern_kevent_fp(td, epfp, 0, 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;
leave0:
if (uset != NULL)
error = kern_sigprocmask(td, SIG_SETMASK, &omask,
NULL, 0);
leave1:
fdrop(epfp, td);
return (error);
}
#ifdef LINUX_LEGACY_SYSCALLS
int
linux_epoll_wait(struct thread *td, struct linux_epoll_wait_args *args)
{
return (linux_epoll_wait_common(td, args->epfd, args->events,
args->maxevents, args->timeout, NULL));
}
#endif
int
linux_epoll_pwait(struct thread *td, struct linux_epoll_pwait_args *args)
{
sigset_t mask, *pmask;
l_sigset_t lmask;
int error;
if (args->mask != NULL) {
if (args->sigsetsize != sizeof(l_sigset_t))
return (EINVAL);
error = copyin(args->mask, &lmask, sizeof(l_sigset_t));
if (error != 0)
return (error);
linux_to_bsd_sigset(&lmask, &mask);
pmask = &mask;
} else
pmask = NULL;
return (linux_epoll_wait_common(td, args->epfd, args->events,
args->maxevents, args->timeout, pmask));
}
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};
ciargs.changelist = &kev;
EV_SET(&kev, fd, filter, EV_DELETE | EV_DISABLE, 0, 0, 0);
return (kern_kevent_fp(td, epfp, 1, 0, &k_ops, NULL));
}
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);
/* return 0 if at least one result positive */
return (error1 == 0 ? 0 : error2);
}
static int
eventfd_create(struct thread *td, uint32_t initval, int flags)
{
struct filedesc *fdp;
struct eventfd *efd;
struct file *fp;
int fflags, fd, error;
fflags = 0;
if ((flags & LINUX_O_CLOEXEC) != 0)
fflags |= O_CLOEXEC;
fdp = td->td_proc->p_fd;
error = falloc(td, &fp, &fd, fflags);
if (error != 0)
return (error);
efd = malloc(sizeof(*efd), M_EPOLL, M_WAITOK | M_ZERO);
efd->efd_flags = flags;
efd->efd_count = initval;
mtx_init(&efd->efd_lock, "eventfd", NULL, MTX_DEF);
knlist_init_mtx(&efd->efd_sel.si_note, &efd->efd_lock);
fflags = FREAD | FWRITE;
if ((flags & LINUX_O_NONBLOCK) != 0)
fflags |= FNONBLOCK;
finit(fp, fflags, DTYPE_LINUXEFD, efd, &eventfdops);
fdrop(fp, td);
td->td_retval[0] = fd;
return (error);
}
#ifdef LINUX_LEGACY_SYSCALLS
int
linux_eventfd(struct thread *td, struct linux_eventfd_args *args)
{
return (eventfd_create(td, args->initval, 0));
}
#endif
int
linux_eventfd2(struct thread *td, struct linux_eventfd2_args *args)
{
if ((args->flags & ~(LINUX_O_CLOEXEC|LINUX_O_NONBLOCK|LINUX_EFD_SEMAPHORE)) != 0)
return (EINVAL);
return (eventfd_create(td, args->initval, args->flags));
}
static int
eventfd_close(struct file *fp, struct thread *td)
{
struct eventfd *efd;
efd = fp->f_data;
if (fp->f_type != DTYPE_LINUXEFD || efd == NULL)
return (EINVAL);
seldrain(&efd->efd_sel);
knlist_destroy(&efd->efd_sel.si_note);
fp->f_ops = &badfileops;
mtx_destroy(&efd->efd_lock);
free(efd, M_EPOLL);
return (0);
}
static int
eventfd_read(struct file *fp, struct uio *uio, struct ucred *active_cred,
int flags, struct thread *td)
{
struct eventfd *efd;
eventfd_t count;
int error;
efd = fp->f_data;
if (fp->f_type != DTYPE_LINUXEFD || efd == NULL)
return (EINVAL);
if (uio->uio_resid < sizeof(eventfd_t))
return (EINVAL);
error = 0;
mtx_lock(&efd->efd_lock);
retry:
if (efd->efd_count == 0) {
if ((fp->f_flag & FNONBLOCK) != 0) {
mtx_unlock(&efd->efd_lock);
return (EAGAIN);
}
error = mtx_sleep(&efd->efd_count, &efd->efd_lock, PCATCH, "lefdrd", 0);
if (error == 0)
goto retry;
}
if (error == 0) {
if ((efd->efd_flags & LINUX_EFD_SEMAPHORE) != 0) {
count = 1;
--efd->efd_count;
} else {
count = efd->efd_count;
efd->efd_count = 0;
}
KNOTE_LOCKED(&efd->efd_sel.si_note, 0);
selwakeup(&efd->efd_sel);
wakeup(&efd->efd_count);
mtx_unlock(&efd->efd_lock);
error = uiomove(&count, sizeof(eventfd_t), uio);
} else
mtx_unlock(&efd->efd_lock);
return (error);
}
static int
eventfd_write(struct file *fp, struct uio *uio, struct ucred *active_cred,
int flags, struct thread *td)
{
struct eventfd *efd;
eventfd_t count;
int error;
efd = fp->f_data;
if (fp->f_type != DTYPE_LINUXEFD || efd == NULL)
return (EINVAL);
if (uio->uio_resid < sizeof(eventfd_t))
return (EINVAL);
error = uiomove(&count, sizeof(eventfd_t), uio);
if (error != 0)
return (error);
if (count == UINT64_MAX)
return (EINVAL);
mtx_lock(&efd->efd_lock);
retry:
if (UINT64_MAX - efd->efd_count <= count) {
if ((fp->f_flag & FNONBLOCK) != 0) {
mtx_unlock(&efd->efd_lock);
/* Do not not return the number of bytes written */
uio->uio_resid += sizeof(eventfd_t);
return (EAGAIN);
}
error = mtx_sleep(&efd->efd_count, &efd->efd_lock,
PCATCH, "lefdwr", 0);
if (error == 0)
goto retry;
}
if (error == 0) {
efd->efd_count += count;
KNOTE_LOCKED(&efd->efd_sel.si_note, 0);
selwakeup(&efd->efd_sel);
wakeup(&efd->efd_count);
}
mtx_unlock(&efd->efd_lock);
return (error);
}
static int
eventfd_poll(struct file *fp, int events, struct ucred *active_cred,
struct thread *td)
{
struct eventfd *efd;
int revents = 0;
efd = fp->f_data;
if (fp->f_type != DTYPE_LINUXEFD || efd == NULL)
return (POLLERR);
mtx_lock(&efd->efd_lock);
if ((events & (POLLIN|POLLRDNORM)) && efd->efd_count > 0)
revents |= events & (POLLIN|POLLRDNORM);
if ((events & (POLLOUT|POLLWRNORM)) && UINT64_MAX - 1 > efd->efd_count)
revents |= events & (POLLOUT|POLLWRNORM);
if (revents == 0)
selrecord(td, &efd->efd_sel);
mtx_unlock(&efd->efd_lock);
return (revents);
}
/*ARGSUSED*/
static int
eventfd_kqfilter(struct file *fp, struct knote *kn)
{
struct eventfd *efd;
efd = fp->f_data;
if (fp->f_type != DTYPE_LINUXEFD || efd == NULL)
return (EINVAL);
mtx_lock(&efd->efd_lock);
switch (kn->kn_filter) {
case EVFILT_READ:
kn->kn_fop = &eventfd_rfiltops;
break;
case EVFILT_WRITE:
kn->kn_fop = &eventfd_wfiltops;
break;
default:
mtx_unlock(&efd->efd_lock);
return (EINVAL);
}
kn->kn_hook = efd;
knlist_add(&efd->efd_sel.si_note, kn, 1);
mtx_unlock(&efd->efd_lock);
return (0);
}
static void
filt_eventfddetach(struct knote *kn)
{
struct eventfd *efd = kn->kn_hook;
mtx_lock(&efd->efd_lock);
knlist_remove(&efd->efd_sel.si_note, kn, 1);
mtx_unlock(&efd->efd_lock);
}
/*ARGSUSED*/
static int
filt_eventfdread(struct knote *kn, long hint)
{
struct eventfd *efd = kn->kn_hook;
int ret;
mtx_assert(&efd->efd_lock, MA_OWNED);
ret = (efd->efd_count > 0);
return (ret);
}
/*ARGSUSED*/
static int
filt_eventfdwrite(struct knote *kn, long hint)
{
struct eventfd *efd = kn->kn_hook;
int ret;
mtx_assert(&efd->efd_lock, MA_OWNED);
ret = (UINT64_MAX - 1 > efd->efd_count);
return (ret);
}
/*ARGSUSED*/
static int
eventfd_ioctl(struct file *fp, u_long cmd, void *data,
struct ucred *active_cred, struct thread *td)
{
if (fp->f_data == NULL || (fp->f_type != DTYPE_LINUXEFD &&
fp->f_type != DTYPE_LINUXTFD))
return (EINVAL);
switch (cmd)
{
case FIONBIO:
if ((*(int *)data))
atomic_set_int(&fp->f_flag, FNONBLOCK);
else
atomic_clear_int(&fp->f_flag, FNONBLOCK);
case FIOASYNC:
return (0);
default:
return (ENXIO);
}
}
/*ARGSUSED*/
static int
eventfd_stat(struct file *fp, struct stat *st, struct ucred *active_cred,
struct thread *td)
{
return (ENXIO);
}
/*ARGSUSED*/
static int
eventfd_fill_kinfo(struct file *fp, struct kinfo_file *kif, struct filedesc *fdp)
{
kif->kf_type = KF_TYPE_UNKNOWN;
return (0);
}
int
linux_timerfd_create(struct thread *td, struct linux_timerfd_create_args *args)
{
struct filedesc *fdp;
struct timerfd *tfd;
struct file *fp;
clockid_t clockid;
int fflags, fd, error;
if ((args->flags & ~LINUX_TFD_CREATE_FLAGS) != 0)
return (EINVAL);
error = linux_to_native_clockid(&clockid, args->clockid);
if (error != 0)
return (error);
if (clockid != CLOCK_REALTIME && clockid != CLOCK_MONOTONIC)
return (EINVAL);
fflags = 0;
if ((args->flags & LINUX_TFD_CLOEXEC) != 0)
fflags |= O_CLOEXEC;
fdp = td->td_proc->p_fd;
error = falloc(td, &fp, &fd, fflags);
if (error != 0)
return (error);
tfd = malloc(sizeof(*tfd), M_EPOLL, M_WAITOK | M_ZERO);
tfd->tfd_clockid = clockid;
mtx_init(&tfd->tfd_lock, "timerfd", NULL, MTX_DEF);
callout_init_mtx(&tfd->tfd_callout, &tfd->tfd_lock, 0);
knlist_init_mtx(&tfd->tfd_sel.si_note, &tfd->tfd_lock);
fflags = FREAD;
if ((args->flags & LINUX_O_NONBLOCK) != 0)
fflags |= FNONBLOCK;
finit(fp, fflags, DTYPE_LINUXTFD, tfd, &timerfdops);
fdrop(fp, td);
td->td_retval[0] = fd;
return (error);
}
static int
timerfd_close(struct file *fp, struct thread *td)
{
struct timerfd *tfd;
tfd = fp->f_data;
if (fp->f_type != DTYPE_LINUXTFD || tfd == NULL)
return (EINVAL);
timespecclear(&tfd->tfd_time.it_value);
timespecclear(&tfd->tfd_time.it_interval);
mtx_lock(&tfd->tfd_lock);
callout_drain(&tfd->tfd_callout);
mtx_unlock(&tfd->tfd_lock);
seldrain(&tfd->tfd_sel);
knlist_destroy(&tfd->tfd_sel.si_note);
fp->f_ops = &badfileops;
mtx_destroy(&tfd->tfd_lock);
free(tfd, M_EPOLL);
return (0);
}
static int
timerfd_read(struct file *fp, struct uio *uio, struct ucred *active_cred,
int flags, struct thread *td)
{
struct timerfd *tfd;
timerfd_t count;
int error;
tfd = fp->f_data;
if (fp->f_type != DTYPE_LINUXTFD || tfd == NULL)
return (EINVAL);
if (uio->uio_resid < sizeof(timerfd_t))
return (EINVAL);
error = 0;
mtx_lock(&tfd->tfd_lock);
retry:
if (tfd->tfd_canceled) {
tfd->tfd_count = 0;
mtx_unlock(&tfd->tfd_lock);
return (ECANCELED);
}
if (tfd->tfd_count == 0) {
if ((fp->f_flag & FNONBLOCK) != 0) {
mtx_unlock(&tfd->tfd_lock);
return (EAGAIN);
}
error = mtx_sleep(&tfd->tfd_count, &tfd->tfd_lock, PCATCH, "ltfdrd", 0);
if (error == 0)
goto retry;
}
if (error == 0) {
count = tfd->tfd_count;
tfd->tfd_count = 0;
mtx_unlock(&tfd->tfd_lock);
error = uiomove(&count, sizeof(timerfd_t), uio);
} else
mtx_unlock(&tfd->tfd_lock);
return (error);
}
static int
timerfd_poll(struct file *fp, int events, struct ucred *active_cred,
struct thread *td)
{
struct timerfd *tfd;
int revents = 0;
tfd = fp->f_data;
if (fp->f_type != DTYPE_LINUXTFD || tfd == NULL)
return (POLLERR);
mtx_lock(&tfd->tfd_lock);
if ((events & (POLLIN|POLLRDNORM)) && tfd->tfd_count > 0)
revents |= events & (POLLIN|POLLRDNORM);
if (revents == 0)
selrecord(td, &tfd->tfd_sel);
mtx_unlock(&tfd->tfd_lock);
return (revents);
}
/*ARGSUSED*/
static int
timerfd_kqfilter(struct file *fp, struct knote *kn)
{
struct timerfd *tfd;
tfd = fp->f_data;
if (fp->f_type != DTYPE_LINUXTFD || tfd == NULL)
return (EINVAL);
if (kn->kn_filter == EVFILT_READ)
kn->kn_fop = &timerfd_rfiltops;
else
return (EINVAL);
kn->kn_hook = tfd;
knlist_add(&tfd->tfd_sel.si_note, kn, 0);
return (0);
}
static void
filt_timerfddetach(struct knote *kn)
{
struct timerfd *tfd = kn->kn_hook;
mtx_lock(&tfd->tfd_lock);
knlist_remove(&tfd->tfd_sel.si_note, kn, 1);
mtx_unlock(&tfd->tfd_lock);
}
/*ARGSUSED*/
static int
filt_timerfdread(struct knote *kn, long hint)
{
struct timerfd *tfd = kn->kn_hook;
return (tfd->tfd_count > 0);
}
/*ARGSUSED*/
static int
timerfd_stat(struct file *fp, struct stat *st, struct ucred *active_cred,
struct thread *td)
{
return (ENXIO);
}
/*ARGSUSED*/
static int
timerfd_fill_kinfo(struct file *fp, struct kinfo_file *kif, struct filedesc *fdp)
{
kif->kf_type = KF_TYPE_UNKNOWN;
return (0);
}
static void
linux_timerfd_clocktime(struct timerfd *tfd, struct timespec *ts)
{
if (tfd->tfd_clockid == CLOCK_REALTIME)
getnanotime(ts);
else /* CLOCK_MONOTONIC */
getnanouptime(ts);
}
static void
linux_timerfd_curval(struct timerfd *tfd, struct itimerspec *ots)
{
struct timespec cts;
linux_timerfd_clocktime(tfd, &cts);
*ots = tfd->tfd_time;
if (ots->it_value.tv_sec != 0 || ots->it_value.tv_nsec != 0) {
timespecsub(&ots->it_value, &cts, &ots->it_value);
if (ots->it_value.tv_sec < 0 ||
(ots->it_value.tv_sec == 0 &&
ots->it_value.tv_nsec == 0)) {
ots->it_value.tv_sec = 0;
ots->it_value.tv_nsec = 1;
}
}
}
int
linux_timerfd_gettime(struct thread *td, struct linux_timerfd_gettime_args *args)
{
struct l_itimerspec lots;
struct itimerspec ots;
struct timerfd *tfd;
struct file *fp;
int error;
error = fget(td, args->fd, &cap_read_rights, &fp);
if (error != 0)
return (error);
tfd = fp->f_data;
if (fp->f_type != DTYPE_LINUXTFD || tfd == NULL) {
error = EINVAL;
goto out;
}
mtx_lock(&tfd->tfd_lock);
linux_timerfd_curval(tfd, &ots);
mtx_unlock(&tfd->tfd_lock);
error = native_to_linux_itimerspec(&lots, &ots);
if (error == 0)
error = copyout(&lots, args->old_value, sizeof(lots));
out:
fdrop(fp, td);
return (error);
}
int
linux_timerfd_settime(struct thread *td, struct linux_timerfd_settime_args *args)
{
struct l_itimerspec lots;
struct itimerspec nts, ots;
struct timespec cts, ts;
struct timerfd *tfd;
struct timeval tv;
struct file *fp;
int error;
if ((args->flags & ~LINUX_TFD_SETTIME_FLAGS) != 0)
return (EINVAL);
error = copyin(args->new_value, &lots, sizeof(lots));
if (error != 0)
return (error);
error = linux_to_native_itimerspec(&nts, &lots);
if (error != 0)
return (error);
error = fget(td, args->fd, &cap_write_rights, &fp);
if (error != 0)
return (error);
tfd = fp->f_data;
if (fp->f_type != DTYPE_LINUXTFD || tfd == NULL) {
error = EINVAL;
goto out;
}
mtx_lock(&tfd->tfd_lock);
if (!timespecisset(&nts.it_value))
timespecclear(&nts.it_interval);
if (args->old_value != NULL)
linux_timerfd_curval(tfd, &ots);
tfd->tfd_time = nts;
if (timespecisset(&nts.it_value)) {
linux_timerfd_clocktime(tfd, &cts);
ts = nts.it_value;
if ((args->flags & LINUX_TFD_TIMER_ABSTIME) == 0) {
timespecadd(&tfd->tfd_time.it_value, &cts,
&tfd->tfd_time.it_value);
} else {
timespecsub(&ts, &cts, &ts);
}
TIMESPEC_TO_TIMEVAL(&tv, &ts);
callout_reset(&tfd->tfd_callout, tvtohz(&tv),
linux_timerfd_expire, tfd);
tfd->tfd_canceled = false;
} else {
tfd->tfd_canceled = true;
callout_stop(&tfd->tfd_callout);
}
mtx_unlock(&tfd->tfd_lock);
if (args->old_value != NULL) {
error = native_to_linux_itimerspec(&lots, &ots);
if (error == 0)
error = copyout(&lots, args->old_value, sizeof(lots));
}
out:
fdrop(fp, td);
return (error);
}
static void
linux_timerfd_expire(void *arg)
{
struct timespec cts, ts;
struct timeval tv;
struct timerfd *tfd;
tfd = (struct timerfd *)arg;
linux_timerfd_clocktime(tfd, &cts);
if (timespeccmp(&cts, &tfd->tfd_time.it_value, >=)) {
if (timespecisset(&tfd->tfd_time.it_interval))
timespecadd(&tfd->tfd_time.it_value,
&tfd->tfd_time.it_interval,
&tfd->tfd_time.it_value);
else
/* single shot timer */
timespecclear(&tfd->tfd_time.it_value);
if (timespecisset(&tfd->tfd_time.it_value)) {
timespecsub(&tfd->tfd_time.it_value, &cts, &ts);
TIMESPEC_TO_TIMEVAL(&tv, &ts);
callout_reset(&tfd->tfd_callout, tvtohz(&tv),
linux_timerfd_expire, tfd);
}
tfd->tfd_count++;
KNOTE_LOCKED(&tfd->tfd_sel.si_note, 0);
selwakeup(&tfd->tfd_sel);
wakeup(&tfd->tfd_count);
} else if (timespecisset(&tfd->tfd_time.it_value)) {
timespecsub(&tfd->tfd_time.it_value, &cts, &ts);
TIMESPEC_TO_TIMEVAL(&tv, &ts);
callout_reset(&tfd->tfd_callout, tvtohz(&tv),
linux_timerfd_expire, tfd);
}
}