diff options
Diffstat (limited to 'sys/kern')
| -rw-r--r-- | sys/kern/kern_descrip.c | 21 | ||||
| -rw-r--r-- | sys/kern/kern_event.c | 21 |
2 files changed, 35 insertions, 7 deletions
diff --git a/sys/kern/kern_descrip.c b/sys/kern/kern_descrip.c index d967d543b38..a9adcb7a83e 100644 --- a/sys/kern/kern_descrip.c +++ b/sys/kern/kern_descrip.c @@ -1,4 +1,4 @@ -/* $OpenBSD: kern_descrip.c,v 1.192 2019/08/05 08:35:59 anton Exp $ */ +/* $OpenBSD: kern_descrip.c,v 1.193 2020/01/03 05:37:00 visa Exp $ */ /* $NetBSD: kern_descrip.c,v 1.42 1996/03/30 22:24:38 christos Exp $ */ /* @@ -262,6 +262,18 @@ fd_getfile_mode(struct filedesc *fdp, int fd, int mode) return (fp); } +int +fd_checkclosed(struct filedesc *fdp, int fd, struct file *fp) +{ + int closed; + + mtx_enter(&fdp->fd_fplock); + KASSERT(fd < fdp->fd_nfiles); + closed = (fdp->fd_ofiles[fd] != fp); + mtx_leave(&fdp->fd_fplock); + return (closed); +} + /* * System calls on descriptors. */ @@ -396,7 +408,7 @@ sys_fcntl(struct proc *p, void *v, register_t *retval) } */ *uap = v; int fd = SCARG(uap, fd); struct filedesc *fdp = p->p_fd; - struct file *fp, *fp2; + struct file *fp; struct vnode *vp; int i, tmp, newmin, flg = F_POSIX; struct flock fl; @@ -570,8 +582,7 @@ restart: goto out; } - fp2 = fd_getfile(fdp, fd); - if (fp != fp2) { + if (fd_checkclosed(fdp, fd, fp)) { /* * We have lost the race with close() or dup2(); * unlock, pretend that we've won the race and that @@ -583,8 +594,6 @@ restart: VOP_ADVLOCK(vp, fdp, F_UNLCK, &fl, F_POSIX); fl.l_type = F_UNLCK; } - if (fp2 != NULL) - FRELE(fp2, p); goto out; diff --git a/sys/kern/kern_event.c b/sys/kern/kern_event.c index c634353caa5..3141af589ce 100644 --- a/sys/kern/kern_event.c +++ b/sys/kern/kern_event.c @@ -1,4 +1,4 @@ -/* $OpenBSD: kern_event.c,v 1.113 2019/12/31 14:09:56 visa Exp $ */ +/* $OpenBSD: kern_event.c,v 1.114 2020/01/03 05:37:00 visa Exp $ */ /*- * Copyright (c) 1999,2000,2001 Jonathan Lemon <jlemon@FreeBSD.org> @@ -724,6 +724,25 @@ again: knote_drop(kn, p); goto done; } + + /* + * If this is a file descriptor filter, check if + * fd was closed while the knote was being added. + * knote_fdclose() has missed kn if the function + * ran before kn appeared in kq_knlist. + */ + if (fops->f_isfd && + fd_checkclosed(fdp, kev->ident, kn->kn_fp)) { + /* + * Drop the knote silently without error + * because another thread might already have + * seen it. This corresponds to the insert + * happening in full before the close. + */ + kn->kn_fop->f_detach(kn); + knote_drop(kn, p); + goto done; + } } else { /* * The user may change some filter values after the |