diff options
Diffstat (limited to 'usr/src/uts/common/io/signalfd.c')
-rw-r--r-- | usr/src/uts/common/io/signalfd.c | 774 |
1 files changed, 774 insertions, 0 deletions
diff --git a/usr/src/uts/common/io/signalfd.c b/usr/src/uts/common/io/signalfd.c new file mode 100644 index 0000000000..32f8f85f7a --- /dev/null +++ b/usr/src/uts/common/io/signalfd.c @@ -0,0 +1,774 @@ +/* + * This file and its contents are supplied under the terms of the + * Common Development and Distribution License ("CDDL"), version 1.0. + * You may only use this file in accordance with the terms of version + * 1.0 of the CDDL. + * + * A full copy of the text of the CDDL should have accompanied this + * source. A copy of the CDDL is also available via the Internet at + * http://www.illumos.org/license/CDDL. + */ + +/* + * Copyright 2015 Joyent, Inc. + */ + +/* + * Support for the signalfd facility, a Linux-borne facility for + * file descriptor-based synchronous signal consumption. + * + * As described on the signalfd(3C) man page, the general idea behind these + * file descriptors is that they can be used to synchronously consume signals + * via the read(2) syscall. That capability already exists with the + * sigwaitinfo(3C) function but the key advantage of signalfd is that, because + * it is file descriptor based, poll(2) can be used to determine when signals + * are available to be consumed. + * + * The general implementation uses signalfd_state to hold both the signal set + * and poll head for an open file descriptor. Because a process can be using + * different sigfds with different signal sets, each signalfd_state poll head + * can be thought of as an independent signal stream and the thread(s) waiting + * on that stream will get poll notification when any signal in the + * corresponding set is received. + * + * The sigfd_proc_state_t struct lives on the proc_t and maintains per-proc + * state for function callbacks and data when the proc needs to do work during + * signal delivery for pollwakeup. + * + * The read side of the implementation is straightforward and mimics the + * kernel behavior for sigtimedwait(). Signals continue to live on either + * the proc's p_sig, or thread's t_sig, member. Read consumes the signal so + * that it is no longer pending. + * + * The poll side is more complex since all of the sigfds on the process need + * to be examined every time a signal is delivered to the process in order to + * pollwake any thread waiting in poll for that signal. + * + * Because it is likely that a process will only be using one, or a few, sigfds, + * but many total file descriptors, we maintain a list of sigfds which need + * pollwakeup. The list lives on the proc's p_sigfd struct. In this way only + * zero, or a few, of the state structs will need to be examined every time a + * signal is delivered to the process, instead of having to examine all of the + * file descriptors to find the state structs. When a state struct with a + * matching signal set is found then pollwakeup is called. + * + * The sigfd_list is self-cleaning; as signalfd_pollwake_cb is called, the list + * will clear out on its own. There is an exit helper (signalfd_exit_helper) + * which cleans up any remaining per-proc state when the process exits. + * + * The main complexity with signalfd is the interaction of forking and polling. + * This interaction is complex because now two processes have a fd that + * references the same dev_t (and its associated signalfd_state), but signals + * go to only one of those processes. Also, we don't know when one of the + * processes closes its fd because our 'close' entry point is only called when + * the last fd is closed (which could be by either process). + * + * Because the state struct is referenced by both file descriptors, and the + * state struct represents a signal stream needing a pollwakeup, if both + * processes were polling then both processes would get a pollwakeup when a + * signal arrives for either process (that is, the pollhead is associated with + * our dev_t so when a signal arrives the pollwakeup wakes up all waiters). + * + * Fortunately this is not a common problem in practice, but the implementation + * attempts to mitigate unexpected behavior. The typical behavior is that the + * parent has been polling the signalfd (which is why it was open in the first + * place) and the parent might have a pending signalfd_state (with the + * pollhead) on its per-process sigfd_list. After the fork the child will + * simply close that fd (among others) as part of the typical fork/close/exec + * pattern. Because the child will never poll that fd, it will never get any + * state onto its own sigfd_list (the child starts with a null list). The + * intention is that the child sees no pollwakeup activity for signals unless + * it explicitly reinvokes poll on the sigfd. + * + * As background, there are two primary polling cases to consider when the + * parent process forks: + * 1) If any thread is blocked in poll(2) then both the parent and child will + * return from the poll syscall with EINTR. This means that if either + * process wants to re-poll on a sigfd then it needs to re-run poll and + * would come back in to the signalfd_poll entry point. The parent would + * already have the dev_t's state on its sigfd_list and the child would not + * have anything there unless it called poll again on its fd. + * 2) If the process is using /dev/poll(7D) then the polling info is being + * cached by the poll device and the process might not currently be blocked + * on anything polling related. A subsequent DP_POLL ioctl will not invoke + * our signalfd_poll entry point again. Because the parent still has its + * sigfd_list setup, an incoming signal will hit our signalfd_pollwake_cb + * entry point, which in turn calls pollwake, and /dev/poll will do the + * right thing on DP_POLL. The child will not have a sigfd_list yet so the + * signal will not cause a pollwakeup. The dp code does its own handling for + * cleaning up its cache. + * + * This leaves only one odd corner case. If the parent and child both use + * the dup-ed sigfd to poll then when a signal is delivered to either process + * there is no way to determine which one should get the pollwakeup (since + * both processes will be queued on the same signal stream poll head). What + * happens in this case is that both processes will return from poll, but only + * one of them will actually have a signal to read. The other will return + * from read with EAGAIN, or block. This case is actually similar to the + * situation within a single process which got two different sigfd's with the + * same mask (or poll on two fd's that are dup-ed). Both would return from poll + * when a signal arrives but only one read would consume the signal and the + * other read would fail or block. Applications which poll on shared fd's + * cannot assume that a subsequent read will actually obtain data. + */ + +#include <sys/ddi.h> +#include <sys/sunddi.h> +#include <sys/signalfd.h> +#include <sys/conf.h> +#include <sys/sysmacros.h> +#include <sys/filio.h> +#include <sys/stat.h> +#include <sys/file.h> +#include <sys/schedctl.h> +#include <sys/id_space.h> +#include <sys/sdt.h> + +typedef struct signalfd_state signalfd_state_t; + +struct signalfd_state { + kmutex_t sfd_lock; /* lock protecting state */ + pollhead_t sfd_pollhd; /* poll head */ + k_sigset_t sfd_set; /* signals for this fd */ + signalfd_state_t *sfd_next; /* next state on global list */ +}; + +/* + * Internal global variables. + */ +static kmutex_t signalfd_lock; /* lock protecting state */ +static dev_info_t *signalfd_devi; /* device info */ +static id_space_t *signalfd_minor; /* minor number arena */ +static void *signalfd_softstate; /* softstate pointer */ +static signalfd_state_t *signalfd_state; /* global list of state */ + +/* + * If we don't already have an entry in the proc's list for this state, add one. + */ +static void +signalfd_wake_list_add(signalfd_state_t *state) +{ + proc_t *p = curproc; + list_t *lst; + sigfd_wake_list_t *wlp; + + ASSERT(MUTEX_HELD(&p->p_lock)); + ASSERT(p->p_sigfd != NULL); + + lst = &((sigfd_proc_state_t *)p->p_sigfd)->sigfd_list; + for (wlp = list_head(lst); wlp != NULL; wlp = list_next(lst, wlp)) { + if (wlp->sigfd_wl_state == state) + break; + } + + if (wlp == NULL) { + wlp = kmem_zalloc(sizeof (sigfd_wake_list_t), KM_SLEEP); + wlp->sigfd_wl_state = state; + list_insert_head(lst, wlp); + } +} + +static void +signalfd_wake_rm(list_t *lst, sigfd_wake_list_t *wlp) +{ + list_remove(lst, wlp); + kmem_free(wlp, sizeof (sigfd_wake_list_t)); +} + +static void +signalfd_wake_list_rm(proc_t *p, signalfd_state_t *state) +{ + sigfd_wake_list_t *wlp; + list_t *lst; + + ASSERT(MUTEX_HELD(&p->p_lock)); + + if (p->p_sigfd == NULL) + return; + + lst = &((sigfd_proc_state_t *)p->p_sigfd)->sigfd_list; + for (wlp = list_head(lst); wlp != NULL; wlp = list_next(lst, wlp)) { + if (wlp->sigfd_wl_state == state) { + signalfd_wake_rm(lst, wlp); + break; + } + } + + if (list_is_empty(lst)) { + ((sigfd_proc_state_t *)p->p_sigfd)->sigfd_pollwake_cb = NULL; + list_destroy(lst); + kmem_free(p->p_sigfd, sizeof (sigfd_proc_state_t)); + p->p_sigfd = NULL; + } +} + +static void +signalfd_wake_list_cleanup(proc_t *p) +{ + sigfd_wake_list_t *wlp; + list_t *lst; + + ASSERT(MUTEX_HELD(&p->p_lock)); + + ((sigfd_proc_state_t *)p->p_sigfd)->sigfd_pollwake_cb = NULL; + + lst = &((sigfd_proc_state_t *)p->p_sigfd)->sigfd_list; + while (!list_is_empty(lst)) { + wlp = (sigfd_wake_list_t *)list_remove_head(lst); + kmem_free(wlp, sizeof (sigfd_wake_list_t)); + } +} + +static void +signalfd_exit_helper(void) +{ + proc_t *p = curproc; + list_t *lst; + + /* This being non-null is the only way we can get here */ + ASSERT(p->p_sigfd != NULL); + + mutex_enter(&p->p_lock); + lst = &((sigfd_proc_state_t *)p->p_sigfd)->sigfd_list; + + signalfd_wake_list_cleanup(p); + list_destroy(lst); + kmem_free(p->p_sigfd, sizeof (sigfd_proc_state_t)); + p->p_sigfd = NULL; + mutex_exit(&p->p_lock); +} + +/* + * Called every time a signal is delivered to the process so that we can + * see if any signal stream needs a pollwakeup. We maintain a list of + * signal state elements so that we don't have to look at every file descriptor + * on the process. If necessary, a further optimization would be to maintain a + * signal set mask that is a union of all of the sets in the list so that + * we don't even traverse the list if the signal is not in one of the elements. + * However, since the list is likely to be very short, this is not currently + * being done. A more complex data structure might also be used, but it is + * unclear what that would be since each signal set needs to be checked for a + * match. + */ +static void +signalfd_pollwake_cb(void *arg0, int sig) +{ + proc_t *p = (proc_t *)arg0; + list_t *lst; + sigfd_wake_list_t *wlp; + + ASSERT(MUTEX_HELD(&p->p_lock)); + + if (p->p_sigfd == NULL) + return; + + lst = &((sigfd_proc_state_t *)p->p_sigfd)->sigfd_list; + wlp = list_head(lst); + while (wlp != NULL) { + signalfd_state_t *state = wlp->sigfd_wl_state; + + mutex_enter(&state->sfd_lock); + + if (sigismember(&state->sfd_set, sig) && + state->sfd_pollhd.ph_list != NULL) { + sigfd_wake_list_t *tmp = wlp; + + /* remove it from the list */ + wlp = list_next(lst, wlp); + signalfd_wake_rm(lst, tmp); + + mutex_exit(&state->sfd_lock); + pollwakeup(&state->sfd_pollhd, POLLRDNORM | POLLIN); + } else { + mutex_exit(&state->sfd_lock); + wlp = list_next(lst, wlp); + } + } +} + +_NOTE(ARGSUSED(1)) +static int +signalfd_open(dev_t *devp, int flag, int otyp, cred_t *cred_p) +{ + signalfd_state_t *state; + major_t major = getemajor(*devp); + minor_t minor = getminor(*devp); + + if (minor != SIGNALFDMNRN_SIGNALFD) + return (ENXIO); + + mutex_enter(&signalfd_lock); + + minor = (minor_t)id_allocff(signalfd_minor); + + if (ddi_soft_state_zalloc(signalfd_softstate, minor) != DDI_SUCCESS) { + id_free(signalfd_minor, minor); + mutex_exit(&signalfd_lock); + return (ENODEV); + } + + state = ddi_get_soft_state(signalfd_softstate, minor); + *devp = makedevice(major, minor); + + state->sfd_next = signalfd_state; + signalfd_state = state; + + mutex_exit(&signalfd_lock); + + return (0); +} + +/* + * Consume one signal from our set in a manner similar to sigtimedwait(). + * The block parameter is used to control whether we wait for a signal or + * return immediately if no signal is pending. We use the thread's t_sigwait + * member in the same way that it is used by sigtimedwait. + * + * Return 0 if we successfully consumed a signal or an errno if not. + */ +static int +consume_signal(k_sigset_t set, uio_t *uio, boolean_t block) +{ + k_sigset_t oldmask; + kthread_t *t = curthread; + klwp_t *lwp = ttolwp(t); + proc_t *p = ttoproc(t); + timespec_t now; + timespec_t *rqtp = NULL; /* null means blocking */ + int timecheck = 0; + int ret = 0; + k_siginfo_t info, *infop; + signalfd_siginfo_t ssi, *ssp = &ssi; + + if (block == B_FALSE) { + timecheck = timechanged; + gethrestime(&now); + rqtp = &now; /* non-blocking check for pending signals */ + } + + t->t_sigwait = set; + + mutex_enter(&p->p_lock); + /* + * set the thread's signal mask to unmask those signals in the + * specified set. + */ + schedctl_finish_sigblock(t); + oldmask = t->t_hold; + sigdiffset(&t->t_hold, &t->t_sigwait); + + /* + * Based on rqtp, wait indefinitely until we take a signal in our set + * or return immediately if there are no signals pending from our set. + */ + while ((ret = cv_waituntil_sig(&t->t_delay_cv, &p->p_lock, rqtp, + timecheck)) > 0) + continue; + + /* Restore thread's signal mask to its previous value. */ + t->t_hold = oldmask; + t->t_sig_check = 1; /* so post_syscall sees new t_hold mask */ + + if (ret == -1) { + /* no signals pending */ + mutex_exit(&p->p_lock); + sigemptyset(&t->t_sigwait); + return (EAGAIN); /* no signals pending */ + } + + /* Don't bother with signal if it is not in request set. */ + if (lwp->lwp_cursig == 0 || + !sigismember(&t->t_sigwait, lwp->lwp_cursig)) { + mutex_exit(&p->p_lock); + /* + * lwp_cursig is zero if pokelwps() awakened cv_wait_sig(). + * This happens if some other thread in this process called + * forkall() or exit(). + */ + sigemptyset(&t->t_sigwait); + return (EINTR); + } + + if (lwp->lwp_curinfo) { + infop = &lwp->lwp_curinfo->sq_info; + } else { + infop = &info; + bzero(infop, sizeof (info)); + infop->si_signo = lwp->lwp_cursig; + infop->si_code = SI_NOINFO; + } + + lwp->lwp_ru.nsignals++; + + DTRACE_PROC2(signal__clear, int, ret, ksiginfo_t *, infop); + lwp->lwp_cursig = 0; + lwp->lwp_extsig = 0; + mutex_exit(&p->p_lock); + + /* Convert k_siginfo into external, datamodel independent, struct. */ + bzero(ssp, sizeof (*ssp)); + ssp->ssi_signo = infop->si_signo; + ssp->ssi_errno = infop->si_errno; + ssp->ssi_code = infop->si_code; + ssp->ssi_pid = infop->si_pid; + ssp->ssi_uid = infop->si_uid; + ssp->ssi_fd = infop->si_fd; + ssp->ssi_band = infop->si_band; + ssp->ssi_trapno = infop->si_trapno; + ssp->ssi_status = infop->si_status; + ssp->ssi_utime = infop->si_utime; + ssp->ssi_stime = infop->si_stime; + ssp->ssi_addr = (uint64_t)(intptr_t)infop->si_addr; + + ret = uiomove(ssp, sizeof (*ssp), UIO_READ, uio); + + if (lwp->lwp_curinfo) { + siginfofree(lwp->lwp_curinfo); + lwp->lwp_curinfo = NULL; + } + sigemptyset(&t->t_sigwait); + return (ret); +} + +/* + * This is similar to sigtimedwait. Based on the fd mode we may wait until a + * signal within our specified set is posted. We consume as many available + * signals within our set as we can. + */ +_NOTE(ARGSUSED(2)) +static int +signalfd_read(dev_t dev, uio_t *uio, cred_t *cr) +{ + signalfd_state_t *state; + minor_t minor = getminor(dev); + boolean_t block = B_TRUE; + k_sigset_t set; + boolean_t got_one = B_FALSE; + int res; + + if (uio->uio_resid < sizeof (signalfd_siginfo_t)) + return (EINVAL); + + state = ddi_get_soft_state(signalfd_softstate, minor); + + if (uio->uio_fmode & (FNDELAY|FNONBLOCK)) + block = B_FALSE; + + mutex_enter(&state->sfd_lock); + set = state->sfd_set; + mutex_exit(&state->sfd_lock); + + if (sigisempty(&set)) + return (set_errno(EINVAL)); + + do { + res = consume_signal(state->sfd_set, uio, block); + if (res == 0) + got_one = B_TRUE; + + /* + * After consuming one signal we won't block trying to consume + * further signals. + */ + block = B_FALSE; + } while (res == 0 && uio->uio_resid >= sizeof (signalfd_siginfo_t)); + + if (got_one) + res = 0; + + return (res); +} + +/* + * If ksigset_t's were a single word, we would do: + * return (((p->p_sig | t->t_sig) & set) & fillset); + */ +static int +signalfd_sig_pending(proc_t *p, kthread_t *t, k_sigset_t set) +{ + return (((p->p_sig.__sigbits[0] | t->t_sig.__sigbits[0]) & + set.__sigbits[0]) | + ((p->p_sig.__sigbits[1] | t->t_sig.__sigbits[1]) & + set.__sigbits[1]) | + (((p->p_sig.__sigbits[2] | t->t_sig.__sigbits[2]) & + set.__sigbits[2]) & FILLSET2)); +} + +_NOTE(ARGSUSED(4)) +static int +signalfd_poll(dev_t dev, short events, int anyyet, short *reventsp, + struct pollhead **phpp) +{ + signalfd_state_t *state; + minor_t minor = getminor(dev); + kthread_t *t = curthread; + proc_t *p = ttoproc(t); + short revents = 0; + + state = ddi_get_soft_state(signalfd_softstate, minor); + + mutex_enter(&state->sfd_lock); + + if (signalfd_sig_pending(p, t, state->sfd_set) != 0) + revents |= POLLRDNORM | POLLIN; + + mutex_exit(&state->sfd_lock); + + if (!(*reventsp = revents & events) && !anyyet) { + *phpp = &state->sfd_pollhd; + + /* + * Enable pollwakeup handling. + */ + if (p->p_sigfd == NULL) { + sigfd_proc_state_t *pstate; + + pstate = kmem_zalloc(sizeof (sigfd_proc_state_t), + KM_SLEEP); + list_create(&pstate->sigfd_list, + sizeof (sigfd_wake_list_t), + offsetof(sigfd_wake_list_t, sigfd_wl_lst)); + + mutex_enter(&p->p_lock); + /* check again now that we're locked */ + if (p->p_sigfd == NULL) { + p->p_sigfd = pstate; + } else { + /* someone beat us to it */ + list_destroy(&pstate->sigfd_list); + kmem_free(pstate, sizeof (sigfd_proc_state_t)); + } + mutex_exit(&p->p_lock); + } + + mutex_enter(&p->p_lock); + if (((sigfd_proc_state_t *)p->p_sigfd)->sigfd_pollwake_cb == + NULL) { + ((sigfd_proc_state_t *)p->p_sigfd)->sigfd_pollwake_cb = + signalfd_pollwake_cb; + } + signalfd_wake_list_add(state); + mutex_exit(&p->p_lock); + } + + return (0); +} + +_NOTE(ARGSUSED(4)) +static int +signalfd_ioctl(dev_t dev, int cmd, intptr_t arg, int md, cred_t *cr, int *rv) +{ + signalfd_state_t *state; + minor_t minor = getminor(dev); + sigset_t mask; + + state = ddi_get_soft_state(signalfd_softstate, minor); + + switch (cmd) { + case SIGNALFDIOC_MASK: + if (ddi_copyin((caddr_t)arg, (caddr_t)&mask, sizeof (sigset_t), + md) != 0) + return (set_errno(EFAULT)); + + mutex_enter(&state->sfd_lock); + sigutok(&mask, &state->sfd_set); + mutex_exit(&state->sfd_lock); + + return (0); + + default: + break; + } + + return (ENOTTY); +} + +_NOTE(ARGSUSED(1)) +static int +signalfd_close(dev_t dev, int flag, int otyp, cred_t *cred_p) +{ + signalfd_state_t *state, **sp; + minor_t minor = getminor(dev); + proc_t *p = curproc; + + state = ddi_get_soft_state(signalfd_softstate, minor); + + if (state->sfd_pollhd.ph_list != NULL) { + pollwakeup(&state->sfd_pollhd, POLLERR); + pollhead_clean(&state->sfd_pollhd); + } + + /* Make sure our state is removed from our proc's pollwake list. */ + mutex_enter(&p->p_lock); + signalfd_wake_list_rm(p, state); + mutex_exit(&p->p_lock); + + mutex_enter(&signalfd_lock); + + /* Remove our state from our global list. */ + for (sp = &signalfd_state; *sp != state; sp = &((*sp)->sfd_next)) + VERIFY(*sp != NULL); + + *sp = (*sp)->sfd_next; + + ddi_soft_state_free(signalfd_softstate, minor); + id_free(signalfd_minor, minor); + + mutex_exit(&signalfd_lock); + + return (0); +} + +static int +signalfd_attach(dev_info_t *devi, ddi_attach_cmd_t cmd) +{ + if (cmd != DDI_ATTACH || signalfd_devi != NULL) + return (DDI_FAILURE); + + mutex_enter(&signalfd_lock); + + signalfd_minor = id_space_create("signalfd_minor", 1, L_MAXMIN32 + 1); + if (signalfd_minor == NULL) { + cmn_err(CE_WARN, "signalfd couldn't create id space"); + mutex_exit(&signalfd_lock); + return (DDI_FAILURE); + } + + if (ddi_soft_state_init(&signalfd_softstate, + sizeof (signalfd_state_t), 0) != 0) { + cmn_err(CE_WARN, "signalfd failed to create soft state"); + id_space_destroy(signalfd_minor); + mutex_exit(&signalfd_lock); + return (DDI_FAILURE); + } + + if (ddi_create_minor_node(devi, "signalfd", S_IFCHR, + SIGNALFDMNRN_SIGNALFD, DDI_PSEUDO, NULL) == DDI_FAILURE) { + cmn_err(CE_NOTE, "/dev/signalfd couldn't create minor node"); + ddi_soft_state_fini(&signalfd_softstate); + id_space_destroy(signalfd_minor); + mutex_exit(&signalfd_lock); + return (DDI_FAILURE); + } + + ddi_report_dev(devi); + signalfd_devi = devi; + + sigfd_exit_helper = signalfd_exit_helper; + + mutex_exit(&signalfd_lock); + + return (DDI_SUCCESS); +} + +_NOTE(ARGSUSED(0)) +static int +signalfd_detach(dev_info_t *dip, ddi_detach_cmd_t cmd) +{ + switch (cmd) { + case DDI_DETACH: + break; + + default: + return (DDI_FAILURE); + } + + /* list should be empty */ + VERIFY(signalfd_state == NULL); + + mutex_enter(&signalfd_lock); + id_space_destroy(signalfd_minor); + + ddi_remove_minor_node(signalfd_devi, NULL); + signalfd_devi = NULL; + sigfd_exit_helper = NULL; + + ddi_soft_state_fini(&signalfd_softstate); + mutex_exit(&signalfd_lock); + + return (DDI_SUCCESS); +} + +_NOTE(ARGSUSED(0)) +static int +signalfd_info(dev_info_t *dip, ddi_info_cmd_t infocmd, void *arg, void **result) +{ + int error; + + switch (infocmd) { + case DDI_INFO_DEVT2DEVINFO: + *result = (void *)signalfd_devi; + error = DDI_SUCCESS; + break; + case DDI_INFO_DEVT2INSTANCE: + *result = (void *)0; + error = DDI_SUCCESS; + break; + default: + error = DDI_FAILURE; + } + return (error); +} + +static struct cb_ops signalfd_cb_ops = { + signalfd_open, /* open */ + signalfd_close, /* close */ + nulldev, /* strategy */ + nulldev, /* print */ + nodev, /* dump */ + signalfd_read, /* read */ + nodev, /* write */ + signalfd_ioctl, /* ioctl */ + nodev, /* devmap */ + nodev, /* mmap */ + nodev, /* segmap */ + signalfd_poll, /* poll */ + ddi_prop_op, /* cb_prop_op */ + 0, /* streamtab */ + D_NEW | D_MP /* Driver compatibility flag */ +}; + +static struct dev_ops signalfd_ops = { + DEVO_REV, /* devo_rev */ + 0, /* refcnt */ + signalfd_info, /* get_dev_info */ + nulldev, /* identify */ + nulldev, /* probe */ + signalfd_attach, /* attach */ + signalfd_detach, /* detach */ + nodev, /* reset */ + &signalfd_cb_ops, /* driver operations */ + NULL, /* bus operations */ + nodev, /* dev power */ + ddi_quiesce_not_needed, /* quiesce */ +}; + +static struct modldrv modldrv = { + &mod_driverops, /* module type (this is a pseudo driver) */ + "signalfd support", /* name of module */ + &signalfd_ops, /* driver ops */ +}; + +static struct modlinkage modlinkage = { + MODREV_1, + (void *)&modldrv, + NULL +}; + +int +_init(void) +{ + return (mod_install(&modlinkage)); +} + +int +_info(struct modinfo *modinfop) +{ + return (mod_info(&modlinkage, modinfop)); +} + +int +_fini(void) +{ + return (mod_remove(&modlinkage)); +} |