/* * Copyright (c) 1982, 1986, 1989, 1993 * The Regents of the University of California. All rights reserved. * (c) UNIX System Laboratories, Inc. * All or some portions of this file are derived from material licensed * to the University of California by American Telephone and Telegraph * Co. or Unix System Laboratories, Inc. and are reproduced herein with * the permission of UNIX System Laboratories, Inc. * * 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. * 3. All advertising materials mentioning features or use of this software * must display the following acknowledgement: * This product includes software developed by the University of * California, Berkeley and its contributors. * 4. Neither the name of the University nor the names of its contributors * may be used to endorse or promote products derived from this software * without specific prior written permission. * * THIS SOFTWARE IS PROVIDED BY THE REGENTS 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 REGENTS 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. * * @(#)sys_generic.c 8.5 (Berkeley) 1/21/94 * $FreeBSD: src/sys/kern/sys_generic.c,v 1.55.2.10 2001/03/17 10:39:32 peter Exp $ * $DragonFly: src/sys/kern/sys_generic.c,v 1.49 2008/05/05 22:09:44 dillon Exp $ */ #include "opt_ktrace.h" #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #ifdef KTRACE #include #endif #include #include #include #include #include static MALLOC_DEFINE(M_IOCTLOPS, "ioctlops", "ioctl data buffer"); static MALLOC_DEFINE(M_IOCTLMAP, "ioctlmap", "mapped ioctl handler buffer"); static MALLOC_DEFINE(M_SELECT, "select", "select() buffer"); MALLOC_DEFINE(M_IOV, "iov", "large iov's"); typedef struct kfd_set { fd_mask fds_bits[0]; } kfd_set; enum select_copyin_states { COPYIN_READ, COPYIN_WRITE, COPYIN_EXCEPT, COPYIN_DONE }; struct select_kevent_copyin_args { kfd_set *read_set; kfd_set *write_set; kfd_set *except_set; int active_set; /* One of select_copyin_states */ struct lwp *lwp; /* Pointer to our lwp */ int num_fds; /* Number of file descriptors (syscall arg) */ int proc_fds; /* Processed fd's (wraps) */ int error; /* Returned to userland */ }; static int doselect(int nd, fd_set *in, fd_set *ou, fd_set *ex, struct timespec *ts, int *res); static int pollscan (struct proc *, struct pollfd *, u_int, int *); static int dofileread(int, struct file *, struct uio *, int, size_t *); static int dofilewrite(int, struct file *, struct uio *, int, size_t *); /* * Read system call. * * MPSAFE */ int sys_read(struct read_args *uap) { struct thread *td = curthread; struct uio auio; struct iovec aiov; int error; if ((ssize_t)uap->nbyte < 0) error = EINVAL; aiov.iov_base = uap->buf; aiov.iov_len = uap->nbyte; auio.uio_iov = &aiov; auio.uio_iovcnt = 1; auio.uio_offset = -1; auio.uio_resid = uap->nbyte; auio.uio_rw = UIO_READ; auio.uio_segflg = UIO_USERSPACE; auio.uio_td = td; error = kern_preadv(uap->fd, &auio, 0, &uap->sysmsg_szresult); return(error); } /* * Positioned (Pread) read system call * * MPSAFE */ int sys_extpread(struct extpread_args *uap) { struct thread *td = curthread; struct uio auio; struct iovec aiov; int error; int flags; if ((ssize_t)uap->nbyte < 0) return(EINVAL); aiov.iov_base = uap->buf; aiov.iov_len = uap->nbyte; auio.uio_iov = &aiov; auio.uio_iovcnt = 1; auio.uio_offset = uap->offset; auio.uio_resid = uap->nbyte; auio.uio_rw = UIO_READ; auio.uio_segflg = UIO_USERSPACE; auio.uio_td = td; flags = uap->flags & O_FMASK; if (uap->offset != (off_t)-1) flags |= O_FOFFSET; error = kern_preadv(uap->fd, &auio, flags, &uap->sysmsg_szresult); return(error); } /* * Scatter read system call. * * MPSAFE */ int sys_readv(struct readv_args *uap) { struct thread *td = curthread; struct uio auio; struct iovec aiov[UIO_SMALLIOV], *iov = NULL; int error; error = iovec_copyin(uap->iovp, &iov, aiov, uap->iovcnt, &auio.uio_resid); if (error) return (error); auio.uio_iov = iov; auio.uio_iovcnt = uap->iovcnt; auio.uio_offset = -1; auio.uio_rw = UIO_READ; auio.uio_segflg = UIO_USERSPACE; auio.uio_td = td; error = kern_preadv(uap->fd, &auio, 0, &uap->sysmsg_szresult); iovec_free(&iov, aiov); return (error); } /* * Scatter positioned read system call. * * MPSAFE */ int sys_extpreadv(struct extpreadv_args *uap) { struct thread *td = curthread; struct uio auio; struct iovec aiov[UIO_SMALLIOV], *iov = NULL; int error; int flags; error = iovec_copyin(uap->iovp, &iov, aiov, uap->iovcnt, &auio.uio_resid); if (error) return (error); auio.uio_iov = iov; auio.uio_iovcnt = uap->iovcnt; auio.uio_offset = uap->offset; auio.uio_rw = UIO_READ; auio.uio_segflg = UIO_USERSPACE; auio.uio_td = td; flags = uap->flags & O_FMASK; if (uap->offset != (off_t)-1) flags |= O_FOFFSET; error = kern_preadv(uap->fd, &auio, flags, &uap->sysmsg_szresult); iovec_free(&iov, aiov); return(error); } /* * MPSAFE */ int kern_preadv(int fd, struct uio *auio, int flags, size_t *res) { struct thread *td = curthread; struct proc *p = td->td_proc; struct file *fp; int error; KKASSERT(p); fp = holdfp(p->p_fd, fd, FREAD); if (fp == NULL) return (EBADF); if (flags & O_FOFFSET && fp->f_type != DTYPE_VNODE) { error = ESPIPE; } else { error = dofileread(fd, fp, auio, flags, res); } fdrop(fp); return(error); } /* * Common code for readv and preadv that reads data in * from a file using the passed in uio, offset, and flags. * * MPALMOSTSAFE - ktrace needs help */ static int dofileread(int fd, struct file *fp, struct uio *auio, int flags, size_t *res) { int error; size_t len; #ifdef KTRACE struct thread *td = curthread; struct iovec *ktriov = NULL; struct uio ktruio; #endif #ifdef KTRACE /* * if tracing, save a copy of iovec */ if (KTRPOINT(td, KTR_GENIO)) { int iovlen = auio->uio_iovcnt * sizeof(struct iovec); MALLOC(ktriov, struct iovec *, iovlen, M_TEMP, M_WAITOK); bcopy((caddr_t)auio->uio_iov, (caddr_t)ktriov, iovlen); ktruio = *auio; } #endif len = auio->uio_resid; error = fo_read(fp, auio, fp->f_cred, flags); if (error) { if (auio->uio_resid != len && (error == ERESTART || error == EINTR || error == EWOULDBLOCK)) error = 0; } #ifdef KTRACE if (ktriov != NULL) { if (error == 0) { ktruio.uio_iov = ktriov; ktruio.uio_resid = len - auio->uio_resid; get_mplock(); ktrgenio(td->td_lwp, fd, UIO_READ, &ktruio, error); rel_mplock(); } FREE(ktriov, M_TEMP); } #endif if (error == 0) *res = len - auio->uio_resid; return(error); } /* * Write system call * * MPSAFE */ int sys_write(struct write_args *uap) { struct thread *td = curthread; struct uio auio; struct iovec aiov; int error; if ((ssize_t)uap->nbyte < 0) error = EINVAL; aiov.iov_base = (void *)(uintptr_t)uap->buf; aiov.iov_len = uap->nbyte; auio.uio_iov = &aiov; auio.uio_iovcnt = 1; auio.uio_offset = -1; auio.uio_resid = uap->nbyte; auio.uio_rw = UIO_WRITE; auio.uio_segflg = UIO_USERSPACE; auio.uio_td = td; error = kern_pwritev(uap->fd, &auio, 0, &uap->sysmsg_szresult); return(error); } /* * Pwrite system call * * MPSAFE */ int sys_extpwrite(struct extpwrite_args *uap) { struct thread *td = curthread; struct uio auio; struct iovec aiov; int error; int flags; if ((ssize_t)uap->nbyte < 0) error = EINVAL; aiov.iov_base = (void *)(uintptr_t)uap->buf; aiov.iov_len = uap->nbyte; auio.uio_iov = &aiov; auio.uio_iovcnt = 1; auio.uio_offset = uap->offset; auio.uio_resid = uap->nbyte; auio.uio_rw = UIO_WRITE; auio.uio_segflg = UIO_USERSPACE; auio.uio_td = td; flags = uap->flags & O_FMASK; if (uap->offset != (off_t)-1) flags |= O_FOFFSET; error = kern_pwritev(uap->fd, &auio, flags, &uap->sysmsg_szresult); return(error); } /* * MPSAFE */ int sys_writev(struct writev_args *uap) { struct thread *td = curthread; struct uio auio; struct iovec aiov[UIO_SMALLIOV], *iov = NULL; int error; error = iovec_copyin(uap->iovp, &iov, aiov, uap->iovcnt, &auio.uio_resid); if (error) return (error); auio.uio_iov = iov; auio.uio_iovcnt = uap->iovcnt; auio.uio_offset = -1; auio.uio_rw = UIO_WRITE; auio.uio_segflg = UIO_USERSPACE; auio.uio_td = td; error = kern_pwritev(uap->fd, &auio, 0, &uap->sysmsg_szresult); iovec_free(&iov, aiov); return (error); } /* * Gather positioned write system call * * MPSAFE */ int sys_extpwritev(struct extpwritev_args *uap) { struct thread *td = curthread; struct uio auio; struct iovec aiov[UIO_SMALLIOV], *iov = NULL; int error; int flags; error = iovec_copyin(uap->iovp, &iov, aiov, uap->iovcnt, &auio.uio_resid); if (error) return (error); auio.uio_iov = iov; auio.uio_iovcnt = uap->iovcnt; auio.uio_offset = uap->offset; auio.uio_rw = UIO_WRITE; auio.uio_segflg = UIO_USERSPACE; auio.uio_td = td; flags = uap->flags & O_FMASK; if (uap->offset != (off_t)-1) flags |= O_FOFFSET; error = kern_pwritev(uap->fd, &auio, flags, &uap->sysmsg_szresult); iovec_free(&iov, aiov); return(error); } /* * MPSAFE */ int kern_pwritev(int fd, struct uio *auio, int flags, size_t *res) { struct thread *td = curthread; struct proc *p = td->td_proc; struct file *fp; int error; KKASSERT(p); fp = holdfp(p->p_fd, fd, FWRITE); if (fp == NULL) return (EBADF); else if ((flags & O_FOFFSET) && fp->f_type != DTYPE_VNODE) { error = ESPIPE; } else { error = dofilewrite(fd, fp, auio, flags, res); } fdrop(fp); return (error); } /* * Common code for writev and pwritev that writes data to * a file using the passed in uio, offset, and flags. * * MPALMOSTSAFE - ktrace needs help */ static int dofilewrite(int fd, struct file *fp, struct uio *auio, int flags, size_t *res) { struct thread *td = curthread; struct lwp *lp = td->td_lwp; int error; size_t len; #ifdef KTRACE struct iovec *ktriov = NULL; struct uio ktruio; #endif #ifdef KTRACE /* * if tracing, save a copy of iovec and uio */ if (KTRPOINT(td, KTR_GENIO)) { int iovlen = auio->uio_iovcnt * sizeof(struct iovec); MALLOC(ktriov, struct iovec *, iovlen, M_TEMP, M_WAITOK); bcopy((caddr_t)auio->uio_iov, (caddr_t)ktriov, iovlen); ktruio = *auio; } #endif len = auio->uio_resid; error = fo_write(fp, auio, fp->f_cred, flags); if (error) { if (auio->uio_resid != len && (error == ERESTART || error == EINTR || error == EWOULDBLOCK)) error = 0; /* Socket layer is responsible for issuing SIGPIPE. */ if (error == EPIPE) { get_mplock(); lwpsignal(lp->lwp_proc, lp, SIGPIPE); rel_mplock(); } } #ifdef KTRACE if (ktriov != NULL) { if (error == 0) { ktruio.uio_iov = ktriov; ktruio.uio_resid = len - auio->uio_resid; get_mplock(); ktrgenio(lp, fd, UIO_WRITE, &ktruio, error); rel_mplock(); } FREE(ktriov, M_TEMP); } #endif if (error == 0) *res = len - auio->uio_resid; return(error); } /* * Ioctl system call * * MPALMOSTSAFE */ int sys_ioctl(struct ioctl_args *uap) { int error; get_mplock(); error = mapped_ioctl(uap->fd, uap->com, uap->data, NULL, &uap->sysmsg); rel_mplock(); return (error); } struct ioctl_map_entry { const char *subsys; struct ioctl_map_range *cmd_ranges; LIST_ENTRY(ioctl_map_entry) entries; }; /* * The true heart of all ioctl syscall handlers (native, emulation). * If map != NULL, it will be searched for a matching entry for com, * and appropriate conversions/conversion functions will be utilized. */ int mapped_ioctl(int fd, u_long com, caddr_t uspc_data, struct ioctl_map *map, struct sysmsg *msg) { struct thread *td = curthread; struct proc *p = td->td_proc; struct ucred *cred; struct file *fp; struct ioctl_map_range *iomc = NULL; int error; u_int size; u_long ocom = com; caddr_t data, memp; int tmp; #define STK_PARAMS 128 union { char stkbuf[STK_PARAMS]; long align; } ubuf; KKASSERT(p); cred = td->td_ucred; fp = holdfp(p->p_fd, fd, FREAD|FWRITE); if (fp == NULL) return(EBADF); if (map != NULL) { /* obey translation map */ u_long maskcmd; struct ioctl_map_entry *e; maskcmd = com & map->mask; LIST_FOREACH(e, &map->mapping, entries) { for (iomc = e->cmd_ranges; iomc->start != 0 || iomc->maptocmd != 0 || iomc->wrapfunc != NULL || iomc->mapfunc != NULL; iomc++) { if (maskcmd >= iomc->start && maskcmd <= iomc->end) break; } /* Did we find a match? */ if (iomc->start != 0 || iomc->maptocmd != 0 || iomc->wrapfunc != NULL || iomc->mapfunc != NULL) break; } if (iomc == NULL || (iomc->start == 0 && iomc->maptocmd == 0 && iomc->wrapfunc == NULL && iomc->mapfunc == NULL)) { kprintf("%s: 'ioctl' fd=%d, cmd=0x%lx ('%c',%d) not implemented\n", map->sys, fd, maskcmd, (int)((maskcmd >> 8) & 0xff), (int)(maskcmd & 0xff)); error = EINVAL; goto done; } /* * If it's a non-range one to one mapping, maptocmd should be * correct. If it's a ranged one to one mapping, we pass the * original value of com, and for a range mapped to a different * range, we always need a mapping function to translate the * ioctl to our native ioctl. Ex. 6500-65ff <-> 9500-95ff */ if (iomc->start == iomc->end && iomc->maptocmd == iomc->maptoend) { com = iomc->maptocmd; } else if (iomc->start == iomc->maptocmd && iomc->end == iomc->maptoend) { if (iomc->mapfunc != NULL) com = iomc->mapfunc(iomc->start, iomc->end, iomc->start, iomc->end, com, com); } else { if (iomc->mapfunc != NULL) { com = iomc->mapfunc(iomc->start, iomc->end, iomc->maptocmd, iomc->maptoend, com, ocom); } else { kprintf("%s: Invalid mapping for fd=%d, cmd=%#lx ('%c',%d)\n", map->sys, fd, maskcmd, (int)((maskcmd >> 8) & 0xff), (int)(maskcmd & 0xff)); error = EINVAL; goto done; } } } switch (com) { case FIONCLEX: error = fclrfdflags(p->p_fd, fd, UF_EXCLOSE); goto done; case FIOCLEX: error = fsetfdflags(p->p_fd, fd, UF_EXCLOSE); goto done; } /* * Interpret high order word to find amount of data to be * copied to/from the user's address space. */ size = IOCPARM_LEN(com); if (size > IOCPARM_MAX) { error = ENOTTY; goto done; } memp = NULL; if (size > sizeof (ubuf.stkbuf)) { memp = kmalloc(size, M_IOCTLOPS, M_WAITOK); data = memp; } else { data = ubuf.stkbuf; } if ((com & IOC_IN) != 0) { if (size != 0) { error = copyin(uspc_data, data, (size_t)size); if (error) { if (memp != NULL) kfree(memp, M_IOCTLOPS); goto done; } } else { *(caddr_t *)data = uspc_data; } } else if ((com & IOC_OUT) != 0 && size) { /* * Zero the buffer so the user always * gets back something deterministic. */ bzero(data, (size_t)size); } else if ((com & IOC_VOID) != 0) { *(caddr_t *)data = uspc_data; } switch (com) { case FIONBIO: if ((tmp = *(int *)data)) fp->f_flag |= FNONBLOCK; else fp->f_flag &= ~FNONBLOCK; error = 0; break; case FIOASYNC: if ((tmp = *(int *)data)) fp->f_flag |= FASYNC; else fp->f_flag &= ~FASYNC; error = fo_ioctl(fp, FIOASYNC, (caddr_t)&tmp, cred, msg); break; default: /* * If there is a override function, * call it instead of directly routing the call */ if (map != NULL && iomc->wrapfunc != NULL) error = iomc->wrapfunc(fp, com, ocom, data, cred); else error = fo_ioctl(fp, com, data, cred, msg); /* * Copy any data to user, size was * already set and checked above. */ if (error == 0 && (com & IOC_OUT) != 0 && size != 0) error = copyout(data, uspc_data, (size_t)size); break; } if (memp != NULL) kfree(memp, M_IOCTLOPS); done: fdrop(fp); return(error); } int mapped_ioctl_register_handler(struct ioctl_map_handler *he) { struct ioctl_map_entry *ne; KKASSERT(he != NULL && he->map != NULL && he->cmd_ranges != NULL && he->subsys != NULL && *he->subsys != '\0'); ne = kmalloc(sizeof(struct ioctl_map_entry), M_IOCTLMAP, M_WAITOK); ne->subsys = he->subsys; ne->cmd_ranges = he->cmd_ranges; LIST_INSERT_HEAD(&he->map->mapping, ne, entries); return(0); } int mapped_ioctl_unregister_handler(struct ioctl_map_handler *he) { struct ioctl_map_entry *ne; KKASSERT(he != NULL && he->map != NULL && he->cmd_ranges != NULL); LIST_FOREACH(ne, &he->map->mapping, entries) { if (ne->cmd_ranges != he->cmd_ranges) continue; LIST_REMOVE(ne, entries); kfree(ne, M_IOCTLMAP); return(0); } return(EINVAL); } static int nselcoll; /* Select collisions since boot */ int selwait; SYSCTL_INT(_kern, OID_AUTO, nselcoll, CTLFLAG_RD, &nselcoll, 0, ""); /* * Select system call. * * MPSAFE */ int sys_select(struct select_args *uap) { struct timeval ktv; struct timespec *ktsp, kts; int error; /* * Get timeout if any. */ if (uap->tv != NULL) { error = copyin(uap->tv, &ktv, sizeof (ktv)); if (error) return (error); TIMEVAL_TO_TIMESPEC(&ktv, &kts); ktsp = &kts; } else { ktsp = NULL; } /* * Do real work. */ error = doselect(uap->nd, uap->in, uap->ou, uap->ex, ktsp, &uap->sysmsg_result); return (error); } /* * Pselect system call. * * MPALMOSTSAFE */ int sys_pselect(struct pselect_args *uap) { struct thread *td = curthread; struct lwp *lp = td->td_lwp; struct timespec *ktsp, kts; sigset_t sigmask; int error; /* * Get timeout if any. */ if (uap->ts != NULL) { error = copyin(uap->ts, &kts, sizeof (kts)); if (error) return (error); ktsp = &kts; } else { ktsp = NULL; } /* * Install temporary signal mask if any provided. */ if (uap->sigmask != NULL) { error = copyin(uap->sigmask, &sigmask, sizeof(sigmask)); if (error) return (error); get_mplock(); lp->lwp_oldsigmask = lp->lwp_sigmask; SIG_CANTMASK(sigmask); lp->lwp_sigmask = sigmask; } else { get_mplock(); } /* * Do real job. */ error = doselect(uap->nd, uap->in, uap->ou, uap->ex, ktsp, &uap->sysmsg_result); if (uap->sigmask != NULL) { /* doselect() responsible for turning ERESTART into EINTR */ KKASSERT(error != ERESTART); if (error == EINTR) { /* * We can't restore the previous signal mask now * because it could block the signal that interrupted * us. So make a note to restore it after executing * the handler. */ lp->lwp_flag |= LWP_OLDMASK; } else { /* * No handler to run. Restore previous mask immediately. */ lp->lwp_sigmask = lp->lwp_oldsigmask; } } rel_mplock(); return (error); } static int select_copyin(void *arg, struct kevent *kevp, int max, int *events) { struct select_kevent_copyin_args *skap = NULL; struct kevent kev; int fd; kfd_set *fdp = NULL; short filter = 0; u_int fflags = 0; skap = (struct select_kevent_copyin_args *)arg; while (skap->active_set < COPYIN_DONE) { switch (skap->active_set) { case COPYIN_READ: fdp = skap->read_set; filter = EVFILT_READ; fflags = 0; break; case COPYIN_WRITE: fdp = skap->write_set; filter = EVFILT_WRITE; fflags = 0; break; case COPYIN_EXCEPT: fdp = skap->except_set; filter = EVFILT_READ; fflags = NOTE_OOB; break; } if (fdp == NULL) { skap->active_set++; continue; } for (fd = skap->proc_fds; fd < skap->num_fds; ++fd) { if (FD_ISSET(fd, fdp)) { EV_SET(&kev, fd, filter, EV_ADD|EV_ENABLE|EV_CLEAR, fflags, 0, (void *)((skap->active_set << 28) | skap->lwp->lwp_kqueue_serial)); FD_CLR(fd, fdp); memcpy(kevp + *events, &kev, sizeof(*kevp)); (*events)++; } skap->proc_fds++; if (skap->proc_fds == skap->num_fds) break; if (*events == max) return (0); } skap->active_set++; skap->proc_fds = 0; } return (0); } static int select_copyout(void *arg, struct kevent *kevp, int count, int *res) { struct select_kevent_copyin_args *skap; struct kevent kev; int serial, i = 0; skap = (struct select_kevent_copyin_args *)arg; if (kevp[0].flags & EV_ERROR) { skap->error = kevp[0].data; return (0); } for (i = 0; i < count; ++i) { serial = (u_int)kevp[i].udata & ~(0xF << 28); if (serial != skap->lwp->lwp_kqueue_serial) { kprintf("select serial mismatch\n"); memcpy(&kev, &kevp[i], sizeof(kev)); kev.flags = EV_DISABLE|EV_DELETE; (void)kqueue_register(&skap->lwp->lwp_kqueue, &kev); continue; } switch (((u_int)kevp[i].udata >> 28) & ~(0x0FFFFFFF)) { case COPYIN_READ: FD_SET(kevp[i].ident, skap->read_set); break; case COPYIN_WRITE: FD_SET(kevp[i].ident, skap->write_set); break; case COPYIN_EXCEPT: FD_SET(kevp[i].ident, skap->except_set); break; } (*res)++; } return (0); } /* * Common code for sys_select() and sys_pselect(). * * in, out and ex are userland pointers. ts must point to validated * kernel-side timeout value or NULL for infinite timeout. res must * point to syscall return value. */ static int doselect(int nd, fd_set *read, fd_set *write, fd_set *except, struct timespec *ts, int *res) { struct proc *p = curproc; struct select_kevent_copyin_args *kap, ka; int bytes, error; if (nd < 0) return (EINVAL); if (nd > p->p_fd->fd_nfiles) nd = p->p_fd->fd_nfiles; /* forgiving; slightly wrong */ kap = &ka; kap->lwp = curthread->td_lwp; kap->num_fds = nd; kap->proc_fds = 0; kap->error = 0; bytes = howmany(nd, NFDBITS); #define getbits(name) \ do { \ if (name != NULL) { \ kap->name##_set = kmalloc(bytes, M_SELECT, M_WAITOK); \ error = copyin(name, kap->name##_set, bytes); \ if (error != 0) \ goto done; \ } else { \ kap->name##_set = NULL; \ } \ } while (0) getbits(read); getbits(write); getbits(except); #undef getbits if (kap->read_set != NULL) kap->active_set = COPYIN_READ; else if (kap->write_set != NULL) kap->active_set = COPYIN_WRITE; else if (kap->except_set != NULL) kap->active_set = COPYIN_EXCEPT; else nd = 0; /* copyin/out functions will never be called */ //restart: error = kern_kevent(&kap->lwp->lwp_kqueue, nd, res, kap, select_copyin, select_copyout, ts); if (error == 0) { #define putbits(name) \ do { \ if (kap->name##_set != NULL) { \ error = copyout(kap->name##_set, name, bytes); \ if (error != 0) \ goto done; \ } \ } while (0) putbits(read); putbits(write); putbits(except); #undef putbits } if (kap->error) error = kap->error; done: if (nd) { if (kap->read_set != NULL) kfree(kap->read_set, M_SELECT); if (kap->write_set != NULL) kfree(kap->write_set, M_SELECT); if (kap->except_set != NULL) kfree(kap->except_set, M_SELECT); } if (error) *res = -1; /* No results but nothing to return, spurious wakeup? */ // if (!error && *res == 0) { // nd = 0; // goto restart; // } kap->lwp->lwp_kqueue_serial++; return (error); } /* * Poll system call. * * MPALMOSTSAFE */ int sys_poll(struct poll_args *uap) { struct pollfd *bits; struct pollfd smallbits[32]; struct timeval atv, rtv, ttv; int ncoll, error = 0, timo; u_int nfds; size_t ni; struct lwp *lp = curthread->td_lwp; struct proc *p = curproc; nfds = uap->nfds; /* * This is kinda bogus. We have fd limits, but that is not * really related to the size of the pollfd array. Make sure * we let the process use at least FD_SETSIZE entries and at * least enough for the current limits. We want to be reasonably * safe, but not overly restrictive. */ if (nfds > p->p_rlimit[RLIMIT_NOFILE].rlim_cur && nfds > FD_SETSIZE) return (EINVAL); ni = nfds * sizeof(struct pollfd); if (ni > sizeof(smallbits)) bits = kmalloc(ni, M_TEMP, M_WAITOK); else bits = smallbits; error = copyin(uap->fds, bits, ni); if (error) goto done2; if (uap->timeout != INFTIM) { atv.tv_sec = uap->timeout / 1000; atv.tv_usec = (uap->timeout % 1000) * 1000; if (itimerfix(&atv)) { error = EINVAL; goto done2; } getmicrouptime(&rtv); timevaladd(&atv, &rtv); } else { atv.tv_sec = 0; atv.tv_usec = 0; } timo = 0; get_mplock(); retry: ncoll = nselcoll; lp->lwp_flag |= LWP_SELECT; error = pollscan(p, bits, nfds, &uap->sysmsg_result); if (error || uap->sysmsg_result) goto done1; if (atv.tv_sec || atv.tv_usec) { getmicrouptime(&rtv); if (timevalcmp(&rtv, &atv, >=)) goto done1; ttv = atv; timevalsub(&ttv, &rtv); timo = ttv.tv_sec > 24 * 60 * 60 ? 24 * 60 * 60 * hz : tvtohz_high(&ttv); } crit_enter(); tsleep_interlock(&selwait, PCATCH); if ((lp->lwp_flag & LWP_SELECT) == 0 || nselcoll != ncoll) { crit_exit(); goto retry; } lp->lwp_flag &= ~LWP_SELECT; error = tsleep(&selwait, PCATCH | PINTERLOCKED, "poll", timo); crit_exit(); if (error == 0) goto retry; done1: rel_mplock(); done2: lp->lwp_flag &= ~LWP_SELECT; /* poll is not restarted after signals... */ if (error == ERESTART) error = EINTR; if (error == EWOULDBLOCK) error = 0; if (error == 0) { error = copyout(bits, uap->fds, ni); if (error) goto out; } out: if (ni > sizeof(smallbits)) kfree(bits, M_TEMP); return (error); } static int pollscan(struct proc *p, struct pollfd *fds, u_int nfd, int *res) { int i; struct file *fp; int n = 0; for (i = 0; i < nfd; i++, fds++) { if (fds->fd >= p->p_fd->fd_nfiles) { fds->revents = POLLNVAL; n++; } else if (fds->fd < 0) { fds->revents = 0; } else { fp = holdfp(p->p_fd, fds->fd, -1); if (fp == NULL) { fds->revents = POLLNVAL; n++; } else { /* * Note: backend also returns POLLHUP and * POLLERR if appropriate. */ fds->revents = fo_poll(fp, fds->events, fp->f_cred); if (fds->revents != 0) n++; fdrop(fp); } } } *res = n; return (0); } /* * OpenBSD poll system call. * XXX this isn't quite a true representation.. OpenBSD uses select ops. * * MPSAFE */ int sys_openbsd_poll(struct openbsd_poll_args *uap) { return (sys_poll((struct poll_args *)uap)); } /*ARGSUSED*/ int seltrue(cdev_t dev, int events) { return (events & (POLLIN | POLLOUT | POLLRDNORM | POLLWRNORM)); } /* * Record a select request. A global wait must be used since a process/thread * might go away after recording its request. */ void selrecord(struct thread *selector, struct selinfo *sip) { struct proc *p; struct lwp *lp = NULL; if (selector->td_lwp == NULL) panic("selrecord: thread needs a process"); if (sip->si_pid == selector->td_proc->p_pid && sip->si_tid == selector->td_lwp->lwp_tid) return; if (sip->si_pid && (p = pfind(sip->si_pid))) lp = lwp_rb_tree_RB_LOOKUP(&p->p_lwp_tree, sip->si_tid); if (lp != NULL && lp->lwp_wchan == (caddr_t)&selwait) { sip->si_flags |= SI_COLL; } else { sip->si_pid = selector->td_proc->p_pid; sip->si_tid = selector->td_lwp->lwp_tid; } } /* * Do a wakeup when a selectable event occurs. */ void selwakeup(struct selinfo *sip) { struct proc *p; struct lwp *lp = NULL; if (sip->si_pid == 0) return; if (sip->si_flags & SI_COLL) { nselcoll++; sip->si_flags &= ~SI_COLL; wakeup((caddr_t)&selwait); /* YYY fixable */ } p = pfind(sip->si_pid); sip->si_pid = 0; if (p == NULL) return; lp = lwp_rb_tree_RB_LOOKUP(&p->p_lwp_tree, sip->si_tid); if (lp == NULL) return; /* * This is a temporary hack until the code can be rewritten. * Check LWP_SELECT before assuming we can setrunnable(). * Otherwise we might catch the lwp before it actually goes to * sleep. */ crit_enter(); if (lp->lwp_flag & LWP_SELECT) { lp->lwp_flag &= ~LWP_SELECT; } else if (lp->lwp_wchan == (caddr_t)&selwait) { /* * Flag the process to break the tsleep when * setrunnable is called, but only call setrunnable * here if the process is not in a stopped state. */ lp->lwp_flag |= LWP_BREAKTSLEEP; if (p->p_stat != SSTOP) setrunnable(lp); } crit_exit(); kqueue_wakeup(&lp->lwp_kqueue); }