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-rw-r--r--usr/src/uts/common/io/signalfd.c774
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
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+++ b/usr/src/uts/common/io/signalfd.c
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+/*
+ * 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));
+}
generated by cgit v1.2.3 (git 2.39.1) at 2025-05-31 08:59:53 +0000