The branch main has been updated by dchagin: URL: https://cgit.FreeBSD.org/src/commit/?id=e884512ad143952f0dbacad631487ce28363fd08
commit e884512ad143952f0dbacad631487ce28363fd08 Author: Dmitry Chagin <[email protected]> AuthorDate: 2021-06-10 12:11:25 +0000 Commit: Dmitry Chagin <[email protected]> CommitDate: 2021-06-10 12:11:25 +0000 Split kern_poll() on two counterparts. The kern_poll_kfds() operates on clear kernel data, kfds points to an array in the kernel, while kern_poll() operates on user supplied pollfd. Move nfds check to kern_poll_maxfds(). No functional changes, it's for future use in the Linux emulation layer. Reviewd by: kib Differential Revision: https://reviews.freebsd.org/D30690 MFC after: 2 weeks --- sys/kern/sys_generic.c | 83 +++++++++++++++++++++++++++++--------------------- sys/sys/syscallsubr.h | 3 ++ 2 files changed, 52 insertions(+), 34 deletions(-) diff --git a/sys/kern/sys_generic.c b/sys/kern/sys_generic.c index 6fcdee7a088f..c89a643cfcf9 100644 --- a/sys/kern/sys_generic.c +++ b/sys/kern/sys_generic.c @@ -1417,12 +1417,13 @@ sys_poll(struct thread *td, struct poll_args *uap) return (kern_poll(td, uap->fds, uap->nfds, tsp, NULL)); } +/* + * kfds points to an array in the kernel. + */ int -kern_poll(struct thread *td, struct pollfd *ufds, u_int nfds, +kern_poll_kfds(struct thread *td, struct pollfd *kfds, 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; @@ -1453,28 +1454,11 @@ kern_poll(struct thread *td, struct pollfd *ufds, u_int nfds, } 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; + return (error); td->td_pflags |= TDP_OLDMASK; /* * Make sure that ast() is called on return to @@ -1501,20 +1485,11 @@ kern_poll(struct thread *td, struct pollfd *ufds, u_int nfds, } 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); } @@ -1539,12 +1514,52 @@ sys_ppoll(struct thread *td, struct ppoll_args *uap) ssp = &set; } else ssp = NULL; + return (kern_poll(td, uap->fds, uap->nfds, tsp, ssp)); +} + +/* + * ufds points to an array in user space. + */ +int +kern_poll(struct thread *td, struct pollfd *ufds, u_int nfds, + struct timespec *tsp, sigset_t *set) +{ + struct pollfd *kfds; + struct pollfd stackfds[32]; + int error; + + if (kern_poll_maxfds(nfds)) + 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 != 0) + goto out; + + error = kern_poll_kfds(td, kfds, nfds, tsp, set); + if (error == 0) + error = pollout(td, kfds, ufds, nfds); + +out: + if (nfds > nitems(stackfds)) + free(kfds, M_TEMP); + return (error); +} + +bool +kern_poll_maxfds(u_int nfds) +{ + /* - * fds is still a pointer to user space. kern_poll() will - * take care of copyin that array to the kernel space. + * 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. */ - - return (kern_poll(td, uap->fds, uap->nfds, tsp, ssp)); + return (nfds > maxfilesperproc && nfds > FD_SETSIZE); } static int diff --git a/sys/sys/syscallsubr.h b/sys/sys/syscallsubr.h index 471c38ab0e12..eb7b82946988 100644 --- a/sys/sys/syscallsubr.h +++ b/sys/sys/syscallsubr.h @@ -225,6 +225,9 @@ int kern_pipe(struct thread *td, int fildes[2], int flags, struct filecaps *fcaps1, struct filecaps *fcaps2); int kern_poll(struct thread *td, struct pollfd *fds, u_int nfds, struct timespec *tsp, sigset_t *uset); +int kern_poll_kfds(struct thread *td, struct pollfd *fds, u_int nfds, + struct timespec *tsp, sigset_t *uset); +bool kern_poll_maxfds(u_int nfds); int kern_posix_error(struct thread *td, int error); int kern_posix_fadvise(struct thread *td, int fd, off_t offset, off_t len, int advice); _______________________________________________ [email protected] mailing list https://lists.freebsd.org/mailman/listinfo/dev-commits-src-all To unsubscribe, send any mail to "[email protected]"
