Index: head/lib/libc/sys/poll.2 =================================================================== --- head/lib/libc/sys/poll.2 (revision 340037) +++ head/lib/libc/sys/poll.2 (revision 340038) @@ -1,273 +1,281 @@ .\" $NetBSD: poll.2,v 1.3 1996/09/07 21:53:08 mycroft Exp $ .\" $FreeBSD$ .\" .\" Copyright (c) 1996 Charles M. Hannum. 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. .\" 3. All advertising materials mentioning features or use of this software .\" must display the following acknowledgement: .\" This product includes software developed by Charles M. Hannum. .\" 4. The name of the author may not be used to endorse or promote products .\" derived from this software without specific prior written permission. .\" .\" THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``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 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. .\" -.Dd November 13, 2014 +.Dd November 1, 2018 .Dt POLL 2 .Os .Sh NAME .Nm poll .Nd synchronous I/O multiplexing .Sh LIBRARY .Lb libc .Sh SYNOPSIS .In poll.h .Ft int .Fn poll "struct pollfd fds[]" "nfds_t nfds" "int timeout" .Ft int .Fo ppoll .Fa "struct pollfd fds[]" .Fa "nfds_t nfds" .Fa "const struct timespec * restrict timeout" .Fa "const sigset_t * restrict newsigmask" .Fc .Sh DESCRIPTION The .Fn poll system call examines a set of file descriptors to see if some of them are ready for I/O. The .Fa fds argument is a pointer to an array of pollfd structures as defined in .In poll.h (shown below). The .Fa nfds argument determines the size of the .Fa fds array. .Bd -literal struct pollfd { int fd; /* file descriptor */ short events; /* events to look for */ short revents; /* events returned */ }; .Ed .Pp The fields of .Fa struct pollfd are as follows: .Bl -tag -width XXXrevents .It fd File descriptor to poll. If fd is equal to -1 then .Fa revents is cleared (set to zero), and that pollfd is not checked. .It events Events to poll for. (See below.) .It revents Events which may occur. (See below.) .El .Pp The event bitmasks in .Fa events and .Fa revents have the following bits: .Bl -tag -width XXXPOLLWRNORM .It POLLIN Data other than high priority data may be read without blocking. .It POLLRDNORM Normal data may be read without blocking. .It POLLRDBAND Data with a non-zero priority may be read without blocking. .It POLLPRI High priority data may be read without blocking. .It POLLOUT .It POLLWRNORM Normal data may be written without blocking. .It POLLWRBAND Data with a non-zero priority may be written without blocking. .It POLLERR An exceptional condition has occurred on the device or socket. This flag is always checked, even if not present in the .Fa events bitmask. .It POLLHUP The device or socket has been disconnected. This flag is always checked, even if not present in the .Fa events bitmask. Note that POLLHUP and POLLOUT should never be present in the .Fa revents bitmask at the same time. .It POLLNVAL The file descriptor is not open. This flag is always checked, even if not present in the .Fa events bitmask. .El .Pp If .Fa timeout is neither zero nor INFTIM (-1), it specifies a maximum interval to wait for any file descriptor to become ready, in milliseconds. If .Fa timeout is INFTIM (-1), the poll blocks indefinitely. If .Fa timeout is zero, then .Fn poll will return without blocking. .Pp The .Fn ppoll system call, unlike .Fn poll , is used to safely wait until either a set of file descriptors becomes ready or until a signal is caught. The .Fa fds and .Fa nfds arguments are identical to the analogous arguments of .Fn poll . The .Fa timeout argument in .Fn ppoll points to a .Vt "const struct timespec" which is defined in .In sys/timespec.h (shown below) rather than the .Vt "int timeout" used by .Fn poll . A null pointer may be passed to indicate that .Fn ppoll should wait indefinitely. Finally, .Fa newsigmask specifies a signal mask which is set while waiting for input. When .Fn ppoll returns, the original signal mask is restored. .Bd -literal struct timespec { time_t tv_sec; /* seconds */ long tv_nsec; /* and nanoseconds */ }; .Ed .Sh RETURN VALUES The .Fn poll system call returns the number of descriptors that are ready for I/O, or -1 if an error occurred. If the time limit expires, .Fn poll returns 0. If .Fn poll returns with an error, including one due to an interrupted system call, the .Fa fds array will be unmodified. .Sh COMPATIBILITY This implementation differs from the historical one in that a given file descriptor may not cause .Fn poll to return with an error. In cases where this would have happened in the historical implementation (e.g.\& trying to poll a .Xr revoke 2 Ns ed descriptor), this implementation instead copies the .Fa events bitmask to the .Fa revents bitmask. Attempting to perform I/O on this descriptor will then return an error. This behaviour is believed to be more useful. .Sh ERRORS An error return from .Fn poll indicates: .Bl -tag -width Er .It Bq Er EFAULT The .Fa fds argument points outside the process's allocated address space. .It Bq Er EINTR A signal was delivered before the time limit expired and before any of the selected events occurred. .It Bq Er EINVAL -The specified time limit is invalid. One of its components is negative or too large. +The specified time limit is invalid. +One of its components is negative or too large. +.It Bq Er EINVAL +The number of pollfd structures specified by +.Fa nfds +exceeds the system tunable +.Va kern.maxfilesperproc +and +.Dv FD_SETSIZE . .El .Sh SEE ALSO .Xr accept 2 , .Xr connect 2 , .Xr kqueue 2 , .Xr pselect 2 , .Xr read 2 , .Xr recv 2 , .Xr select 2 , .Xr send 2 , .Xr write 2 .Sh STANDARDS The .Fn poll function conforms to .St -p1003.1-2001 . The .Fn ppoll is not specified by POSIX. .Sh HISTORY The .Fn poll function appeared in .At V . This manual page and the core of the implementation was taken from .Nx . The .Fn ppoll function first appeared in .Fx 11.0 .Sh BUGS The distinction between some of the fields in the .Fa events and .Fa revents bitmasks is really not useful without STREAMS. The fields are defined for compatibility with existing software. Index: head/sys/kern/sys_generic.c =================================================================== --- head/sys/kern/sys_generic.c (revision 340037) +++ head/sys/kern/sys_generic.c (revision 340038) @@ -1,1866 +1,1873 @@ /*- * SPDX-License-Identifier: BSD-3-Clause * * 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. 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 */ #include __FBSDID("$FreeBSD$"); #include "opt_capsicum.h" #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 #include #include #include #include #include #include #ifdef KTRACE #include #endif #include /* * The following macro defines how many bytes will be allocated from * the stack instead of memory allocated when passing the IOCTL data * structures from userspace and to the kernel. Some IOCTLs having * small data structures are used very frequently and this small * buffer on the stack gives a significant speedup improvement for * those requests. The value of this define should be greater or equal * to 64 bytes and should also be power of two. The data structure is * currently hard-aligned to a 8-byte boundary on the stack. This * should currently be sufficient for all supported platforms. */ #define SYS_IOCTL_SMALL_SIZE 128 /* bytes */ #define SYS_IOCTL_SMALL_ALIGN 8 /* bytes */ #ifdef __LP64__ static int iosize_max_clamp = 0; SYSCTL_INT(_debug, OID_AUTO, iosize_max_clamp, CTLFLAG_RW, &iosize_max_clamp, 0, "Clamp max i/o size to INT_MAX"); static int devfs_iosize_max_clamp = 1; SYSCTL_INT(_debug, OID_AUTO, devfs_iosize_max_clamp, CTLFLAG_RW, &devfs_iosize_max_clamp, 0, "Clamp max i/o size to INT_MAX for devices"); #endif /* * Assert that the return value of read(2) and write(2) syscalls fits * into a register. If not, an architecture will need to provide the * usermode wrappers to reconstruct the result. */ CTASSERT(sizeof(register_t) >= sizeof(size_t)); static MALLOC_DEFINE(M_IOCTLOPS, "ioctlops", "ioctl data buffer"); static MALLOC_DEFINE(M_SELECT, "select", "select() buffer"); MALLOC_DEFINE(M_IOV, "iov", "large iov's"); static int pollout(struct thread *, struct pollfd *, struct pollfd *, u_int); static int pollscan(struct thread *, struct pollfd *, u_int); static int pollrescan(struct thread *); static int selscan(struct thread *, fd_mask **, fd_mask **, int); static int selrescan(struct thread *, fd_mask **, fd_mask **); static void selfdalloc(struct thread *, void *); static void selfdfree(struct seltd *, struct selfd *); static int dofileread(struct thread *, int, struct file *, struct uio *, off_t, int); static int dofilewrite(struct thread *, int, struct file *, struct uio *, off_t, int); static void doselwakeup(struct selinfo *, int); static void seltdinit(struct thread *); static int seltdwait(struct thread *, sbintime_t, sbintime_t); static void seltdclear(struct thread *); /* * One seltd per-thread allocated on demand as needed. * * t - protected by st_mtx * k - Only accessed by curthread or read-only */ struct seltd { STAILQ_HEAD(, selfd) st_selq; /* (k) List of selfds. */ struct selfd *st_free1; /* (k) free fd for read set. */ struct selfd *st_free2; /* (k) free fd for write set. */ struct mtx st_mtx; /* Protects struct seltd */ struct cv st_wait; /* (t) Wait channel. */ int st_flags; /* (t) SELTD_ flags. */ }; #define SELTD_PENDING 0x0001 /* We have pending events. */ #define SELTD_RESCAN 0x0002 /* Doing a rescan. */ /* * One selfd allocated per-thread per-file-descriptor. * f - protected by sf_mtx */ struct selfd { STAILQ_ENTRY(selfd) sf_link; /* (k) fds owned by this td. */ TAILQ_ENTRY(selfd) sf_threads; /* (f) fds on this selinfo. */ struct selinfo *sf_si; /* (f) selinfo when linked. */ struct mtx *sf_mtx; /* Pointer to selinfo mtx. */ struct seltd *sf_td; /* (k) owning seltd. */ void *sf_cookie; /* (k) fd or pollfd. */ u_int sf_refs; }; static uma_zone_t selfd_zone; static struct mtx_pool *mtxpool_select; #ifdef __LP64__ size_t devfs_iosize_max(void) { return (devfs_iosize_max_clamp || SV_CURPROC_FLAG(SV_ILP32) ? INT_MAX : SSIZE_MAX); } size_t iosize_max(void) { return (iosize_max_clamp || SV_CURPROC_FLAG(SV_ILP32) ? INT_MAX : SSIZE_MAX); } #endif #ifndef _SYS_SYSPROTO_H_ struct read_args { int fd; void *buf; size_t nbyte; }; #endif int sys_read(struct thread *td, struct read_args *uap) { struct uio auio; struct iovec aiov; int error; if (uap->nbyte > IOSIZE_MAX) return (EINVAL); aiov.iov_base = uap->buf; aiov.iov_len = uap->nbyte; auio.uio_iov = &aiov; auio.uio_iovcnt = 1; auio.uio_resid = uap->nbyte; auio.uio_segflg = UIO_USERSPACE; error = kern_readv(td, uap->fd, &auio); return (error); } /* * Positioned read system call */ #ifndef _SYS_SYSPROTO_H_ struct pread_args { int fd; void *buf; size_t nbyte; int pad; off_t offset; }; #endif int sys_pread(struct thread *td, struct pread_args *uap) { return (kern_pread(td, uap->fd, uap->buf, uap->nbyte, uap->offset)); } int kern_pread(struct thread *td, int fd, void *buf, size_t nbyte, off_t offset) { struct uio auio; struct iovec aiov; int error; if (nbyte > IOSIZE_MAX) return (EINVAL); aiov.iov_base = buf; aiov.iov_len = nbyte; auio.uio_iov = &aiov; auio.uio_iovcnt = 1; auio.uio_resid = nbyte; auio.uio_segflg = UIO_USERSPACE; error = kern_preadv(td, fd, &auio, offset); return (error); } #if defined(COMPAT_FREEBSD6) int freebsd6_pread(struct thread *td, struct freebsd6_pread_args *uap) { return (kern_pread(td, uap->fd, uap->buf, uap->nbyte, uap->offset)); } #endif /* * Scatter read system call. */ #ifndef _SYS_SYSPROTO_H_ struct readv_args { int fd; struct iovec *iovp; u_int iovcnt; }; #endif int sys_readv(struct thread *td, struct readv_args *uap) { struct uio *auio; int error; error = copyinuio(uap->iovp, uap->iovcnt, &auio); if (error) return (error); error = kern_readv(td, uap->fd, auio); free(auio, M_IOV); return (error); } int kern_readv(struct thread *td, int fd, struct uio *auio) { struct file *fp; int error; error = fget_read(td, fd, &cap_read_rights, &fp); if (error) return (error); error = dofileread(td, fd, fp, auio, (off_t)-1, 0); fdrop(fp, td); return (error); } /* * Scatter positioned read system call. */ #ifndef _SYS_SYSPROTO_H_ struct preadv_args { int fd; struct iovec *iovp; u_int iovcnt; off_t offset; }; #endif int sys_preadv(struct thread *td, struct preadv_args *uap) { struct uio *auio; int error; error = copyinuio(uap->iovp, uap->iovcnt, &auio); if (error) return (error); error = kern_preadv(td, uap->fd, auio, uap->offset); free(auio, M_IOV); return (error); } int kern_preadv(struct thread *td, int fd, struct uio *auio, off_t offset) { struct file *fp; int error; error = fget_read(td, fd, &cap_pread_rights, &fp); if (error) return (error); if (!(fp->f_ops->fo_flags & DFLAG_SEEKABLE)) error = ESPIPE; else if (offset < 0 && (fp->f_vnode == NULL || fp->f_vnode->v_type != VCHR)) error = EINVAL; else error = dofileread(td, fd, fp, auio, offset, FOF_OFFSET); fdrop(fp, td); return (error); } /* * Common code for readv and preadv that reads data in * from a file using the passed in uio, offset, and flags. */ static int dofileread(struct thread *td, int fd, struct file *fp, struct uio *auio, off_t offset, int flags) { ssize_t cnt; int error; #ifdef KTRACE struct uio *ktruio = NULL; #endif AUDIT_ARG_FD(fd); /* Finish zero length reads right here */ if (auio->uio_resid == 0) { td->td_retval[0] = 0; return (0); } auio->uio_rw = UIO_READ; auio->uio_offset = offset; auio->uio_td = td; #ifdef KTRACE if (KTRPOINT(td, KTR_GENIO)) ktruio = cloneuio(auio); #endif cnt = auio->uio_resid; if ((error = fo_read(fp, auio, td->td_ucred, flags, td))) { if (auio->uio_resid != cnt && (error == ERESTART || error == EINTR || error == EWOULDBLOCK)) error = 0; } cnt -= auio->uio_resid; #ifdef KTRACE if (ktruio != NULL) { ktruio->uio_resid = cnt; ktrgenio(fd, UIO_READ, ktruio, error); } #endif td->td_retval[0] = cnt; return (error); } #ifndef _SYS_SYSPROTO_H_ struct write_args { int fd; const void *buf; size_t nbyte; }; #endif int sys_write(struct thread *td, struct write_args *uap) { struct uio auio; struct iovec aiov; int error; if (uap->nbyte > IOSIZE_MAX) return (EINVAL); aiov.iov_base = (void *)(uintptr_t)uap->buf; aiov.iov_len = uap->nbyte; auio.uio_iov = &aiov; auio.uio_iovcnt = 1; auio.uio_resid = uap->nbyte; auio.uio_segflg = UIO_USERSPACE; error = kern_writev(td, uap->fd, &auio); return (error); } /* * Positioned write system call. */ #ifndef _SYS_SYSPROTO_H_ struct pwrite_args { int fd; const void *buf; size_t nbyte; int pad; off_t offset; }; #endif int sys_pwrite(struct thread *td, struct pwrite_args *uap) { return (kern_pwrite(td, uap->fd, uap->buf, uap->nbyte, uap->offset)); } int kern_pwrite(struct thread *td, int fd, const void *buf, size_t nbyte, off_t offset) { struct uio auio; struct iovec aiov; int error; if (nbyte > IOSIZE_MAX) return (EINVAL); aiov.iov_base = (void *)(uintptr_t)buf; aiov.iov_len = nbyte; auio.uio_iov = &aiov; auio.uio_iovcnt = 1; auio.uio_resid = nbyte; auio.uio_segflg = UIO_USERSPACE; error = kern_pwritev(td, fd, &auio, offset); return (error); } #if defined(COMPAT_FREEBSD6) int freebsd6_pwrite(struct thread *td, struct freebsd6_pwrite_args *uap) { return (kern_pwrite(td, uap->fd, uap->buf, uap->nbyte, uap->offset)); } #endif /* * Gather write system call. */ #ifndef _SYS_SYSPROTO_H_ struct writev_args { int fd; struct iovec *iovp; u_int iovcnt; }; #endif int sys_writev(struct thread *td, struct writev_args *uap) { struct uio *auio; int error; error = copyinuio(uap->iovp, uap->iovcnt, &auio); if (error) return (error); error = kern_writev(td, uap->fd, auio); free(auio, M_IOV); return (error); } int kern_writev(struct thread *td, int fd, struct uio *auio) { struct file *fp; int error; error = fget_write(td, fd, &cap_write_rights, &fp); if (error) return (error); error = dofilewrite(td, fd, fp, auio, (off_t)-1, 0); fdrop(fp, td); return (error); } /* * Gather positioned write system call. */ #ifndef _SYS_SYSPROTO_H_ struct pwritev_args { int fd; struct iovec *iovp; u_int iovcnt; off_t offset; }; #endif int sys_pwritev(struct thread *td, struct pwritev_args *uap) { struct uio *auio; int error; error = copyinuio(uap->iovp, uap->iovcnt, &auio); if (error) return (error); error = kern_pwritev(td, uap->fd, auio, uap->offset); free(auio, M_IOV); return (error); } int kern_pwritev(struct thread *td, int fd, struct uio *auio, off_t offset) { struct file *fp; int error; error = fget_write(td, fd, &cap_pwrite_rights, &fp); if (error) return (error); if (!(fp->f_ops->fo_flags & DFLAG_SEEKABLE)) error = ESPIPE; else if (offset < 0 && (fp->f_vnode == NULL || fp->f_vnode->v_type != VCHR)) error = EINVAL; else error = dofilewrite(td, fd, fp, auio, offset, FOF_OFFSET); fdrop(fp, td); return (error); } /* * Common code for writev and pwritev that writes data to * a file using the passed in uio, offset, and flags. */ static int dofilewrite(struct thread *td, int fd, struct file *fp, struct uio *auio, off_t offset, int flags) { ssize_t cnt; int error; #ifdef KTRACE struct uio *ktruio = NULL; #endif AUDIT_ARG_FD(fd); auio->uio_rw = UIO_WRITE; auio->uio_td = td; auio->uio_offset = offset; #ifdef KTRACE if (KTRPOINT(td, KTR_GENIO)) ktruio = cloneuio(auio); #endif cnt = auio->uio_resid; if (fp->f_type == DTYPE_VNODE && (fp->f_vnread_flags & FDEVFS_VNODE) == 0) bwillwrite(); if ((error = fo_write(fp, auio, td->td_ucred, flags, td))) { if (auio->uio_resid != cnt && (error == ERESTART || error == EINTR || error == EWOULDBLOCK)) error = 0; /* Socket layer is responsible for issuing SIGPIPE. */ if (fp->f_type != DTYPE_SOCKET && error == EPIPE) { PROC_LOCK(td->td_proc); tdsignal(td, SIGPIPE); PROC_UNLOCK(td->td_proc); } } cnt -= auio->uio_resid; #ifdef KTRACE if (ktruio != NULL) { ktruio->uio_resid = cnt; ktrgenio(fd, UIO_WRITE, ktruio, error); } #endif td->td_retval[0] = cnt; return (error); } /* * Truncate a file given a file descriptor. * * Can't use fget_write() here, since must return EINVAL and not EBADF if the * descriptor isn't writable. */ int kern_ftruncate(struct thread *td, int fd, off_t length) { struct file *fp; int error; AUDIT_ARG_FD(fd); if (length < 0) return (EINVAL); error = fget(td, fd, &cap_ftruncate_rights, &fp); if (error) return (error); AUDIT_ARG_FILE(td->td_proc, fp); if (!(fp->f_flag & FWRITE)) { fdrop(fp, td); return (EINVAL); } error = fo_truncate(fp, length, td->td_ucred, td); fdrop(fp, td); return (error); } #ifndef _SYS_SYSPROTO_H_ struct ftruncate_args { int fd; int pad; off_t length; }; #endif int sys_ftruncate(struct thread *td, struct ftruncate_args *uap) { return (kern_ftruncate(td, uap->fd, uap->length)); } #if defined(COMPAT_43) #ifndef _SYS_SYSPROTO_H_ struct oftruncate_args { int fd; long length; }; #endif int oftruncate(struct thread *td, struct oftruncate_args *uap) { return (kern_ftruncate(td, uap->fd, uap->length)); } #endif /* COMPAT_43 */ #ifndef _SYS_SYSPROTO_H_ struct ioctl_args { int fd; u_long com; caddr_t data; }; #endif /* ARGSUSED */ int sys_ioctl(struct thread *td, struct ioctl_args *uap) { u_char smalldata[SYS_IOCTL_SMALL_SIZE] __aligned(SYS_IOCTL_SMALL_ALIGN); u_long com; int arg, error; u_int size; caddr_t data; if (uap->com > 0xffffffff) { printf( "WARNING pid %d (%s): ioctl sign-extension ioctl %lx\n", td->td_proc->p_pid, td->td_name, uap->com); uap->com &= 0xffffffff; } com = uap->com; /* * 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) || ((com & (IOC_VOID | IOC_IN | IOC_OUT)) == 0) || #if defined(COMPAT_FREEBSD5) || defined(COMPAT_FREEBSD4) || defined(COMPAT_43) ((com & IOC_OUT) && size == 0) || #else ((com & (IOC_IN | IOC_OUT)) && size == 0) || #endif ((com & IOC_VOID) && size > 0 && size != sizeof(int))) return (ENOTTY); if (size > 0) { if (com & IOC_VOID) { /* Integer argument. */ arg = (intptr_t)uap->data; data = (void *)&arg; size = 0; } else { if (size > SYS_IOCTL_SMALL_SIZE) data = malloc((u_long)size, M_IOCTLOPS, M_WAITOK); else data = smalldata; } } else data = (void *)&uap->data; if (com & IOC_IN) { error = copyin(uap->data, data, (u_int)size); if (error != 0) goto out; } else if (com & IOC_OUT) { /* * Zero the buffer so the user always * gets back something deterministic. */ bzero(data, size); } error = kern_ioctl(td, uap->fd, com, data); if (error == 0 && (com & IOC_OUT)) error = copyout(data, uap->data, (u_int)size); out: if (size > SYS_IOCTL_SMALL_SIZE) free(data, M_IOCTLOPS); return (error); } int kern_ioctl(struct thread *td, int fd, u_long com, caddr_t data) { struct file *fp; struct filedesc *fdp; int error, tmp, locked; AUDIT_ARG_FD(fd); AUDIT_ARG_CMD(com); fdp = td->td_proc->p_fd; switch (com) { case FIONCLEX: case FIOCLEX: FILEDESC_XLOCK(fdp); locked = LA_XLOCKED; break; default: #ifdef CAPABILITIES FILEDESC_SLOCK(fdp); locked = LA_SLOCKED; #else locked = LA_UNLOCKED; #endif break; } #ifdef CAPABILITIES if ((fp = fget_locked(fdp, fd)) == NULL) { error = EBADF; goto out; } if ((error = cap_ioctl_check(fdp, fd, com)) != 0) { fp = NULL; /* fhold() was not called yet */ goto out; } fhold(fp); if (locked == LA_SLOCKED) { FILEDESC_SUNLOCK(fdp); locked = LA_UNLOCKED; } #else error = fget(td, fd, &cap_ioctl_rights, &fp); if (error != 0) { fp = NULL; goto out; } #endif if ((fp->f_flag & (FREAD | FWRITE)) == 0) { error = EBADF; goto out; } switch (com) { case FIONCLEX: fdp->fd_ofiles[fd].fde_flags &= ~UF_EXCLOSE; goto out; case FIOCLEX: fdp->fd_ofiles[fd].fde_flags |= UF_EXCLOSE; goto out; case FIONBIO: if ((tmp = *(int *)data)) atomic_set_int(&fp->f_flag, FNONBLOCK); else atomic_clear_int(&fp->f_flag, FNONBLOCK); data = (void *)&tmp; break; case FIOASYNC: if ((tmp = *(int *)data)) atomic_set_int(&fp->f_flag, FASYNC); else atomic_clear_int(&fp->f_flag, FASYNC); data = (void *)&tmp; break; } error = fo_ioctl(fp, com, data, td->td_ucred, td); out: switch (locked) { case LA_XLOCKED: FILEDESC_XUNLOCK(fdp); break; #ifdef CAPABILITIES case LA_SLOCKED: FILEDESC_SUNLOCK(fdp); break; #endif default: FILEDESC_UNLOCK_ASSERT(fdp); break; } if (fp != NULL) fdrop(fp, td); return (error); } int poll_no_poll(int events) { /* * Return true for read/write. If the user asked for something * special, return POLLNVAL, so that clients have a way of * determining reliably whether or not the extended * functionality is present without hard-coding knowledge * of specific filesystem implementations. */ if (events & ~POLLSTANDARD) return (POLLNVAL); return (events & (POLLIN | POLLOUT | POLLRDNORM | POLLWRNORM)); } int sys_pselect(struct thread *td, struct pselect_args *uap) { struct timespec ts; struct timeval tv, *tvp; sigset_t set, *uset; int error; if (uap->ts != NULL) { error = copyin(uap->ts, &ts, sizeof(ts)); if (error != 0) return (error); TIMESPEC_TO_TIMEVAL(&tv, &ts); tvp = &tv; } else tvp = NULL; if (uap->sm != NULL) { error = copyin(uap->sm, &set, sizeof(set)); if (error != 0) return (error); uset = &set; } else uset = NULL; return (kern_pselect(td, uap->nd, uap->in, uap->ou, uap->ex, tvp, uset, NFDBITS)); } int kern_pselect(struct thread *td, int nd, fd_set *in, fd_set *ou, fd_set *ex, struct timeval *tvp, sigset_t *uset, int abi_nfdbits) { int error; if (uset != NULL) { error = kern_sigprocmask(td, SIG_SETMASK, uset, &td->td_oldsigmask, 0); if (error != 0) return (error); 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); } error = kern_select(td, nd, in, ou, ex, tvp, abi_nfdbits); return (error); } #ifndef _SYS_SYSPROTO_H_ struct select_args { int nd; fd_set *in, *ou, *ex; struct timeval *tv; }; #endif int sys_select(struct thread *td, struct select_args *uap) { struct timeval tv, *tvp; int error; if (uap->tv != NULL) { error = copyin(uap->tv, &tv, sizeof(tv)); if (error) return (error); tvp = &tv; } else tvp = NULL; return (kern_select(td, uap->nd, uap->in, uap->ou, uap->ex, tvp, NFDBITS)); } /* * In the unlikely case when user specified n greater then the last * open file descriptor, check that no bits are set after the last * valid fd. We must return EBADF if any is set. * * There are applications that rely on the behaviour. * * nd is fd_lastfile + 1. */ static int select_check_badfd(fd_set *fd_in, int nd, int ndu, int abi_nfdbits) { char *addr, *oaddr; int b, i, res; uint8_t bits; if (nd >= ndu || fd_in == NULL) return (0); oaddr = NULL; bits = 0; /* silence gcc */ for (i = nd; i < ndu; i++) { b = i / NBBY; #if BYTE_ORDER == LITTLE_ENDIAN addr = (char *)fd_in + b; #else addr = (char *)fd_in; if (abi_nfdbits == NFDBITS) { addr += rounddown(b, sizeof(fd_mask)) + sizeof(fd_mask) - 1 - b % sizeof(fd_mask); } else { addr += rounddown(b, sizeof(uint32_t)) + sizeof(uint32_t) - 1 - b % sizeof(uint32_t); } #endif if (addr != oaddr) { res = fubyte(addr); if (res == -1) return (EFAULT); oaddr = addr; bits = res; } if ((bits & (1 << (i % NBBY))) != 0) return (EBADF); } return (0); } int kern_select(struct thread *td, int nd, fd_set *fd_in, fd_set *fd_ou, fd_set *fd_ex, struct timeval *tvp, int abi_nfdbits) { struct filedesc *fdp; /* * The magic 2048 here is chosen to be just enough for FD_SETSIZE * infds with the new FD_SETSIZE of 1024, and more than enough for * FD_SETSIZE infds, outfds and exceptfds with the old FD_SETSIZE * of 256. */ fd_mask s_selbits[howmany(2048, NFDBITS)]; fd_mask *ibits[3], *obits[3], *selbits, *sbp; struct timeval rtv; sbintime_t asbt, precision, rsbt; u_int nbufbytes, ncpbytes, ncpubytes, nfdbits; int error, lf, ndu; if (nd < 0) return (EINVAL); fdp = td->td_proc->p_fd; ndu = nd; lf = fdp->fd_lastfile; if (nd > lf + 1) nd = lf + 1; error = select_check_badfd(fd_in, nd, ndu, abi_nfdbits); if (error != 0) return (error); error = select_check_badfd(fd_ou, nd, ndu, abi_nfdbits); if (error != 0) return (error); error = select_check_badfd(fd_ex, nd, ndu, abi_nfdbits); if (error != 0) return (error); /* * Allocate just enough bits for the non-null fd_sets. Use the * preallocated auto buffer if possible. */ nfdbits = roundup(nd, NFDBITS); ncpbytes = nfdbits / NBBY; ncpubytes = roundup(nd, abi_nfdbits) / NBBY; nbufbytes = 0; if (fd_in != NULL) nbufbytes += 2 * ncpbytes; if (fd_ou != NULL) nbufbytes += 2 * ncpbytes; if (fd_ex != NULL) nbufbytes += 2 * ncpbytes; if (nbufbytes <= sizeof s_selbits) selbits = &s_selbits[0]; else selbits = malloc(nbufbytes, M_SELECT, M_WAITOK); /* * Assign pointers into the bit buffers and fetch the input bits. * Put the output buffers together so that they can be bzeroed * together. */ sbp = selbits; #define getbits(name, x) \ do { \ if (name == NULL) { \ ibits[x] = NULL; \ obits[x] = NULL; \ } else { \ ibits[x] = sbp + nbufbytes / 2 / sizeof *sbp; \ obits[x] = sbp; \ sbp += ncpbytes / sizeof *sbp; \ error = copyin(name, ibits[x], ncpubytes); \ if (error != 0) \ goto done; \ if (ncpbytes != ncpubytes) \ bzero((char *)ibits[x] + ncpubytes, \ ncpbytes - ncpubytes); \ } \ } while (0) getbits(fd_in, 0); getbits(fd_ou, 1); getbits(fd_ex, 2); #undef getbits #if BYTE_ORDER == BIG_ENDIAN && defined(__LP64__) /* * XXX: swizzle_fdset assumes that if abi_nfdbits != NFDBITS, * we are running under 32-bit emulation. This should be more * generic. */ #define swizzle_fdset(bits) \ if (abi_nfdbits != NFDBITS && bits != NULL) { \ int i; \ for (i = 0; i < ncpbytes / sizeof *sbp; i++) \ bits[i] = (bits[i] >> 32) | (bits[i] << 32); \ } #else #define swizzle_fdset(bits) #endif /* Make sure the bit order makes it through an ABI transition */ swizzle_fdset(ibits[0]); swizzle_fdset(ibits[1]); swizzle_fdset(ibits[2]); if (nbufbytes != 0) bzero(selbits, nbufbytes / 2); precision = 0; if (tvp != NULL) { rtv = *tvp; if (rtv.tv_sec < 0 || rtv.tv_usec < 0 || rtv.tv_usec >= 1000000) { error = EINVAL; goto done; } if (!timevalisset(&rtv)) asbt = 0; else if (rtv.tv_sec <= INT32_MAX) { rsbt = tvtosbt(rtv); precision = rsbt; precision >>= tc_precexp; if (TIMESEL(&asbt, rsbt)) asbt += tc_tick_sbt; if (asbt <= SBT_MAX - rsbt) asbt += rsbt; else asbt = -1; } else asbt = -1; } else asbt = -1; seltdinit(td); /* Iterate until the timeout expires or descriptors become ready. */ for (;;) { error = selscan(td, ibits, obits, nd); if (error || td->td_retval[0] != 0) break; error = seltdwait(td, asbt, precision); if (error) break; error = selrescan(td, ibits, obits); if (error || td->td_retval[0] != 0) break; } seltdclear(td); done: /* select is not restarted after signals... */ if (error == ERESTART) error = EINTR; if (error == EWOULDBLOCK) error = 0; /* swizzle bit order back, if necessary */ swizzle_fdset(obits[0]); swizzle_fdset(obits[1]); swizzle_fdset(obits[2]); #undef swizzle_fdset #define putbits(name, x) \ if (name && (error2 = copyout(obits[x], name, ncpubytes))) \ error = error2; if (error == 0) { int error2; putbits(fd_in, 0); putbits(fd_ou, 1); putbits(fd_ex, 2); #undef putbits } if (selbits != &s_selbits[0]) free(selbits, M_SELECT); return (error); } /* * Convert a select bit set to poll flags. * * The backend always returns POLLHUP/POLLERR if appropriate and we * return this as a set bit in any set. */ static int select_flags[3] = { POLLRDNORM | POLLHUP | POLLERR, POLLWRNORM | POLLHUP | POLLERR, POLLRDBAND | POLLERR }; /* * Compute the fo_poll flags required for a fd given by the index and * bit position in the fd_mask array. */ static __inline int selflags(fd_mask **ibits, int idx, fd_mask bit) { int flags; int msk; flags = 0; for (msk = 0; msk < 3; msk++) { if (ibits[msk] == NULL) continue; if ((ibits[msk][idx] & bit) == 0) continue; flags |= select_flags[msk]; } return (flags); } /* * Set the appropriate output bits given a mask of fired events and the * input bits originally requested. */ static __inline int selsetbits(fd_mask **ibits, fd_mask **obits, int idx, fd_mask bit, int events) { int msk; int n; n = 0; for (msk = 0; msk < 3; msk++) { if ((events & select_flags[msk]) == 0) continue; if (ibits[msk] == NULL) continue; if ((ibits[msk][idx] & bit) == 0) continue; /* * XXX Check for a duplicate set. This can occur because a * socket calls selrecord() twice for each poll() call * resulting in two selfds per real fd. selrescan() will * call selsetbits twice as a result. */ if ((obits[msk][idx] & bit) != 0) continue; obits[msk][idx] |= bit; n++; } return (n); } static __inline int getselfd_cap(struct filedesc *fdp, int fd, struct file **fpp) { return (fget_unlocked(fdp, fd, &cap_event_rights, fpp, NULL)); } /* * Traverse the list of fds attached to this thread's seltd and check for * completion. */ static int selrescan(struct thread *td, fd_mask **ibits, fd_mask **obits) { struct filedesc *fdp; struct selinfo *si; struct seltd *stp; struct selfd *sfp; struct selfd *sfn; struct file *fp; fd_mask bit; int fd, ev, n, idx; int error; fdp = td->td_proc->p_fd; stp = td->td_sel; n = 0; STAILQ_FOREACH_SAFE(sfp, &stp->st_selq, sf_link, sfn) { fd = (int)(uintptr_t)sfp->sf_cookie; si = sfp->sf_si; selfdfree(stp, sfp); /* If the selinfo wasn't cleared the event didn't fire. */ if (si != NULL) continue; error = getselfd_cap(fdp, fd, &fp); if (error) return (error); idx = fd / NFDBITS; bit = (fd_mask)1 << (fd % NFDBITS); ev = fo_poll(fp, selflags(ibits, idx, bit), td->td_ucred, td); fdrop(fp, td); if (ev != 0) n += selsetbits(ibits, obits, idx, bit, ev); } stp->st_flags = 0; td->td_retval[0] = n; return (0); } /* * Perform the initial filedescriptor scan and register ourselves with * each selinfo. */ static int selscan(struct thread *td, fd_mask **ibits, fd_mask **obits, int nfd) { struct filedesc *fdp; struct file *fp; fd_mask bit; int ev, flags, end, fd; int n, idx; int error; fdp = td->td_proc->p_fd; n = 0; for (idx = 0, fd = 0; fd < nfd; idx++) { end = imin(fd + NFDBITS, nfd); for (bit = 1; fd < end; bit <<= 1, fd++) { /* Compute the list of events we're interested in. */ flags = selflags(ibits, idx, bit); if (flags == 0) continue; error = getselfd_cap(fdp, fd, &fp); if (error) return (error); selfdalloc(td, (void *)(uintptr_t)fd); ev = fo_poll(fp, flags, td->td_ucred, td); fdrop(fp, td); if (ev != 0) n += selsetbits(ibits, obits, idx, bit, ev); } } td->td_retval[0] = n; return (0); } int sys_poll(struct thread *td, struct poll_args *uap) { struct timespec ts, *tsp; if (uap->timeout != INFTIM) { if (uap->timeout < 0) return (EINVAL); ts.tv_sec = uap->timeout / 1000; ts.tv_nsec = (uap->timeout % 1000) * 1000000; tsp = &ts; } else tsp = NULL; return (kern_poll(td, uap->fds, uap->nfds, tsp, NULL)); } int kern_poll(struct thread *td, struct pollfd *ufds, u_int nfds, struct timespec *tsp, sigset_t *uset) { struct pollfd *kfds; struct pollfd stackfds[32]; sbintime_t sbt, precision, tmp; time_t over; struct timespec ts; int error; precision = 0; if (tsp != NULL) { if (tsp->tv_sec < 0) return (EINVAL); if (tsp->tv_nsec < 0 || tsp->tv_nsec >= 1000000000) return (EINVAL); if (tsp->tv_sec == 0 && tsp->tv_nsec == 0) sbt = 0; else { ts = *tsp; if (ts.tv_sec > INT32_MAX / 2) { over = ts.tv_sec - INT32_MAX / 2; ts.tv_sec -= over; } else over = 0; tmp = tstosbt(ts); precision = tmp; precision >>= tc_precexp; if (TIMESEL(&sbt, tmp)) sbt += tc_tick_sbt; sbt += tmp; } } else sbt = -1; + /* + * 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 system-wide limits. We want to be reasonably + * safe, but not overly restrictive. + */ if (nfds > maxfilesperproc && nfds > FD_SETSIZE) return (EINVAL); if (nfds > nitems(stackfds)) kfds = mallocarray(nfds, sizeof(*kfds), M_TEMP, M_WAITOK); else kfds = stackfds; error = copyin(ufds, kfds, nfds * sizeof(*kfds)); if (error) goto done; if (uset != NULL) { error = kern_sigprocmask(td, SIG_SETMASK, uset, &td->td_oldsigmask, 0); if (error) goto done; 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); } seltdinit(td); /* Iterate until the timeout expires or descriptors become ready. */ for (;;) { error = pollscan(td, kfds, nfds); if (error || td->td_retval[0] != 0) break; error = seltdwait(td, sbt, precision); if (error) break; error = pollrescan(td); if (error || td->td_retval[0] != 0) break; } seltdclear(td); done: /* poll is not restarted after signals... */ if (error == ERESTART) error = EINTR; if (error == EWOULDBLOCK) error = 0; if (error == 0) { error = pollout(td, kfds, ufds, nfds); if (error) goto out; } out: if (nfds > nitems(stackfds)) free(kfds, M_TEMP); return (error); } int sys_ppoll(struct thread *td, struct ppoll_args *uap) { struct timespec ts, *tsp; sigset_t set, *ssp; int error; if (uap->ts != NULL) { error = copyin(uap->ts, &ts, sizeof(ts)); if (error) return (error); tsp = &ts; } else tsp = NULL; if (uap->set != NULL) { error = copyin(uap->set, &set, sizeof(set)); if (error) return (error); ssp = &set; } else ssp = NULL; /* * fds is still a pointer to user space. kern_poll() will * take care of copyin that array to the kernel space. */ return (kern_poll(td, uap->fds, uap->nfds, tsp, ssp)); } static int pollrescan(struct thread *td) { struct seltd *stp; struct selfd *sfp; struct selfd *sfn; struct selinfo *si; struct filedesc *fdp; struct file *fp; struct pollfd *fd; int n; n = 0; fdp = td->td_proc->p_fd; stp = td->td_sel; FILEDESC_SLOCK(fdp); STAILQ_FOREACH_SAFE(sfp, &stp->st_selq, sf_link, sfn) { fd = (struct pollfd *)sfp->sf_cookie; si = sfp->sf_si; selfdfree(stp, sfp); /* If the selinfo wasn't cleared the event didn't fire. */ if (si != NULL) continue; fp = fdp->fd_ofiles[fd->fd].fde_file; #ifdef CAPABILITIES if (fp == NULL || cap_check(cap_rights(fdp, fd->fd), &cap_event_rights) != 0) #else if (fp == NULL) #endif { fd->revents = POLLNVAL; n++; continue; } /* * Note: backend also returns POLLHUP and * POLLERR if appropriate. */ fd->revents = fo_poll(fp, fd->events, td->td_ucred, td); if (fd->revents != 0) n++; } FILEDESC_SUNLOCK(fdp); stp->st_flags = 0; td->td_retval[0] = n; return (0); } static int pollout(struct thread *td, struct pollfd *fds, struct pollfd *ufds, u_int nfd) { int error = 0; u_int i = 0; u_int n = 0; for (i = 0; i < nfd; i++) { error = copyout(&fds->revents, &ufds->revents, sizeof(ufds->revents)); if (error) return (error); if (fds->revents != 0) n++; fds++; ufds++; } td->td_retval[0] = n; return (0); } static int pollscan(struct thread *td, struct pollfd *fds, u_int nfd) { struct filedesc *fdp = td->td_proc->p_fd; struct file *fp; int i, n = 0; FILEDESC_SLOCK(fdp); for (i = 0; i < nfd; i++, fds++) { if (fds->fd > fdp->fd_lastfile) { fds->revents = POLLNVAL; n++; } else if (fds->fd < 0) { fds->revents = 0; } else { fp = fdp->fd_ofiles[fds->fd].fde_file; #ifdef CAPABILITIES if (fp == NULL || cap_check(cap_rights(fdp, fds->fd), &cap_event_rights) != 0) #else if (fp == NULL) #endif { fds->revents = POLLNVAL; n++; } else { /* * Note: backend also returns POLLHUP and * POLLERR if appropriate. */ selfdalloc(td, fds); fds->revents = fo_poll(fp, fds->events, td->td_ucred, td); /* * POSIX requires POLLOUT to be never * set simultaneously with POLLHUP. */ if ((fds->revents & POLLHUP) != 0) fds->revents &= ~POLLOUT; if (fds->revents != 0) n++; } } } FILEDESC_SUNLOCK(fdp); td->td_retval[0] = n; return (0); } /* * XXX This was created specifically to support netncp and netsmb. This * allows the caller to specify a socket to wait for events on. It returns * 0 if any events matched and an error otherwise. There is no way to * determine which events fired. */ int selsocket(struct socket *so, int events, struct timeval *tvp, struct thread *td) { struct timeval rtv; sbintime_t asbt, precision, rsbt; int error; precision = 0; /* stupid gcc! */ if (tvp != NULL) { rtv = *tvp; if (rtv.tv_sec < 0 || rtv.tv_usec < 0 || rtv.tv_usec >= 1000000) return (EINVAL); if (!timevalisset(&rtv)) asbt = 0; else if (rtv.tv_sec <= INT32_MAX) { rsbt = tvtosbt(rtv); precision = rsbt; precision >>= tc_precexp; if (TIMESEL(&asbt, rsbt)) asbt += tc_tick_sbt; if (asbt <= SBT_MAX - rsbt) asbt += rsbt; else asbt = -1; } else asbt = -1; } else asbt = -1; seltdinit(td); /* * Iterate until the timeout expires or the socket becomes ready. */ for (;;) { selfdalloc(td, NULL); error = sopoll(so, events, NULL, td); /* error here is actually the ready events. */ if (error) return (0); error = seltdwait(td, asbt, precision); if (error) break; } seltdclear(td); /* XXX Duplicates ncp/smb behavior. */ if (error == ERESTART) error = 0; return (error); } /* * Preallocate two selfds associated with 'cookie'. Some fo_poll routines * have two select sets, one for read and another for write. */ static void selfdalloc(struct thread *td, void *cookie) { struct seltd *stp; stp = td->td_sel; if (stp->st_free1 == NULL) stp->st_free1 = uma_zalloc(selfd_zone, M_WAITOK|M_ZERO); stp->st_free1->sf_td = stp; stp->st_free1->sf_cookie = cookie; if (stp->st_free2 == NULL) stp->st_free2 = uma_zalloc(selfd_zone, M_WAITOK|M_ZERO); stp->st_free2->sf_td = stp; stp->st_free2->sf_cookie = cookie; } static void selfdfree(struct seltd *stp, struct selfd *sfp) { STAILQ_REMOVE(&stp->st_selq, sfp, selfd, sf_link); if (sfp->sf_si != NULL) { mtx_lock(sfp->sf_mtx); if (sfp->sf_si != NULL) { TAILQ_REMOVE(&sfp->sf_si->si_tdlist, sfp, sf_threads); refcount_release(&sfp->sf_refs); } mtx_unlock(sfp->sf_mtx); } if (refcount_release(&sfp->sf_refs)) uma_zfree(selfd_zone, sfp); } /* Drain the waiters tied to all the selfd belonging the specified selinfo. */ void seldrain(struct selinfo *sip) { /* * This feature is already provided by doselwakeup(), thus it is * enough to go for it. * Eventually, the context, should take care to avoid races * between thread calling select()/poll() and file descriptor * detaching, but, again, the races are just the same as * selwakeup(). */ doselwakeup(sip, -1); } /* * Record a select request. */ void selrecord(struct thread *selector, struct selinfo *sip) { struct selfd *sfp; struct seltd *stp; struct mtx *mtxp; stp = selector->td_sel; /* * Don't record when doing a rescan. */ if (stp->st_flags & SELTD_RESCAN) return; /* * Grab one of the preallocated descriptors. */ sfp = NULL; if ((sfp = stp->st_free1) != NULL) stp->st_free1 = NULL; else if ((sfp = stp->st_free2) != NULL) stp->st_free2 = NULL; else panic("selrecord: No free selfd on selq"); mtxp = sip->si_mtx; if (mtxp == NULL) mtxp = mtx_pool_find(mtxpool_select, sip); /* * Initialize the sfp and queue it in the thread. */ sfp->sf_si = sip; sfp->sf_mtx = mtxp; refcount_init(&sfp->sf_refs, 2); STAILQ_INSERT_TAIL(&stp->st_selq, sfp, sf_link); /* * Now that we've locked the sip, check for initialization. */ mtx_lock(mtxp); if (sip->si_mtx == NULL) { sip->si_mtx = mtxp; TAILQ_INIT(&sip->si_tdlist); } /* * Add this thread to the list of selfds listening on this selinfo. */ TAILQ_INSERT_TAIL(&sip->si_tdlist, sfp, sf_threads); mtx_unlock(sip->si_mtx); } /* Wake up a selecting thread. */ void selwakeup(struct selinfo *sip) { doselwakeup(sip, -1); } /* Wake up a selecting thread, and set its priority. */ void selwakeuppri(struct selinfo *sip, int pri) { doselwakeup(sip, pri); } /* * Do a wakeup when a selectable event occurs. */ static void doselwakeup(struct selinfo *sip, int pri) { struct selfd *sfp; struct selfd *sfn; struct seltd *stp; /* If it's not initialized there can't be any waiters. */ if (sip->si_mtx == NULL) return; /* * Locking the selinfo locks all selfds associated with it. */ mtx_lock(sip->si_mtx); TAILQ_FOREACH_SAFE(sfp, &sip->si_tdlist, sf_threads, sfn) { /* * Once we remove this sfp from the list and clear the * sf_si seltdclear will know to ignore this si. */ TAILQ_REMOVE(&sip->si_tdlist, sfp, sf_threads); sfp->sf_si = NULL; stp = sfp->sf_td; mtx_lock(&stp->st_mtx); stp->st_flags |= SELTD_PENDING; cv_broadcastpri(&stp->st_wait, pri); mtx_unlock(&stp->st_mtx); if (refcount_release(&sfp->sf_refs)) uma_zfree(selfd_zone, sfp); } mtx_unlock(sip->si_mtx); } static void seltdinit(struct thread *td) { struct seltd *stp; if ((stp = td->td_sel) != NULL) goto out; td->td_sel = stp = malloc(sizeof(*stp), M_SELECT, M_WAITOK|M_ZERO); mtx_init(&stp->st_mtx, "sellck", NULL, MTX_DEF); cv_init(&stp->st_wait, "select"); out: stp->st_flags = 0; STAILQ_INIT(&stp->st_selq); } static int seltdwait(struct thread *td, sbintime_t sbt, sbintime_t precision) { struct seltd *stp; int error; stp = td->td_sel; /* * An event of interest may occur while we do not hold the seltd * locked so check the pending flag before we sleep. */ mtx_lock(&stp->st_mtx); /* * Any further calls to selrecord will be a rescan. */ stp->st_flags |= SELTD_RESCAN; if (stp->st_flags & SELTD_PENDING) { mtx_unlock(&stp->st_mtx); return (0); } if (sbt == 0) error = EWOULDBLOCK; else if (sbt != -1) error = cv_timedwait_sig_sbt(&stp->st_wait, &stp->st_mtx, sbt, precision, C_ABSOLUTE); else error = cv_wait_sig(&stp->st_wait, &stp->st_mtx); mtx_unlock(&stp->st_mtx); return (error); } void seltdfini(struct thread *td) { struct seltd *stp; stp = td->td_sel; if (stp == NULL) return; if (stp->st_free1) uma_zfree(selfd_zone, stp->st_free1); if (stp->st_free2) uma_zfree(selfd_zone, stp->st_free2); td->td_sel = NULL; cv_destroy(&stp->st_wait); mtx_destroy(&stp->st_mtx); free(stp, M_SELECT); } /* * Remove the references to the thread from all of the objects we were * polling. */ static void seltdclear(struct thread *td) { struct seltd *stp; struct selfd *sfp; struct selfd *sfn; stp = td->td_sel; STAILQ_FOREACH_SAFE(sfp, &stp->st_selq, sf_link, sfn) selfdfree(stp, sfp); stp->st_flags = 0; } static void selectinit(void *); SYSINIT(select, SI_SUB_SYSCALLS, SI_ORDER_ANY, selectinit, NULL); static void selectinit(void *dummy __unused) { selfd_zone = uma_zcreate("selfd", sizeof(struct selfd), NULL, NULL, NULL, NULL, UMA_ALIGN_PTR, 0); mtxpool_select = mtx_pool_create("select mtxpool", 128, MTX_DEF); } /* * Set up a syscall return value that follows the convention specified for * posix_* functions. */ int kern_posix_error(struct thread *td, int error) { if (error <= 0) return (error); td->td_errno = error; td->td_pflags |= TDP_NERRNO; td->td_retval[0] = error; return (0); }