From: Jens Axboe axboe@kernel.dk
mainline inclusion from mainline-5.6-rc1 commit 3e4827b05d2ac2d377ed136a52829ec46787bf4b category: feature bugzilla: https://bugzilla.openeuler.org/show_bug.cgi?id=27 CVE: NA ---------------------------
This adds IORING_OP_EPOLL_CTL, which can perform the same work as the epoll_ctl(2) system call.
Signed-off-by: Jens Axboe axboe@kernel.dk
Conflicts: fs/io_uring.c include/uapi/linux/io_uring.h [commit cebdb98617ae("io_uring: add support for IORING_OP_OPENAT2") is not applied] Signed-off-by: yangerkun yangerkun@huawei.com Reviewed-by: zhangyi (F) yi.zhang@huawei.com Signed-off-by: Cheng Jian cj.chengjian@huawei.com --- fs/io_uring.c | 71 +++++++++++++++++++++++++++++++++++ include/uapi/linux/io_uring.h | 1 + 2 files changed, 72 insertions(+)
diff --git a/fs/io_uring.c b/fs/io_uring.c index f92e1f261dea..d4e5f2ec8151 100644 --- a/fs/io_uring.c +++ b/fs/io_uring.c @@ -74,6 +74,7 @@ #include <linux/namei.h> #include <linux/fsnotify.h> #include <linux/fadvise.h> +#include <linux/eventpoll.h>
#define CREATE_TRACE_POINTS #include <trace/events/io_uring.h> @@ -424,6 +425,14 @@ struct io_madvise { u32 advice; };
+struct io_epoll { + struct file *file; + int epfd; + int op; + int fd; + struct epoll_event event; +}; + struct io_async_connect { struct sockaddr_storage address; }; @@ -537,6 +546,7 @@ struct io_kiocb { struct io_files_update files_update; struct io_fadvise fadvise; struct io_madvise madvise; + struct io_epoll epoll; };
struct io_async_ctx *io; @@ -724,6 +734,10 @@ static const struct io_op_def io_op_defs[] = { .needs_file = 1, .unbound_nonreg_file = 1, }, + [IORING_OP_EPOLL_CTL] = { + .unbound_nonreg_file = 1, + .file_table = 1, + }, };
static void io_wq_submit_work(struct io_wq_work **workptr); @@ -2563,6 +2577,52 @@ static int io_openat(struct io_kiocb *req, struct io_kiocb **nxt, return 0; }
+static int io_epoll_ctl_prep(struct io_kiocb *req, + const struct io_uring_sqe *sqe) +{ +#if defined(CONFIG_EPOLL) + if (sqe->ioprio || sqe->buf_index) + return -EINVAL; + + req->epoll.epfd = READ_ONCE(sqe->fd); + req->epoll.op = READ_ONCE(sqe->len); + req->epoll.fd = READ_ONCE(sqe->off); + + if (ep_op_has_event(req->epoll.op)) { + struct epoll_event __user *ev; + + ev = u64_to_user_ptr(READ_ONCE(sqe->addr)); + if (copy_from_user(&req->epoll.event, ev, sizeof(*ev))) + return -EFAULT; + } + + return 0; +#else + return -EOPNOTSUPP; +#endif +} + +static int io_epoll_ctl(struct io_kiocb *req, struct io_kiocb **nxt, + bool force_nonblock) +{ +#if defined(CONFIG_EPOLL) + struct io_epoll *ie = &req->epoll; + int ret; + + ret = do_epoll_ctl(ie->epfd, ie->op, ie->fd, &ie->event, force_nonblock); + if (force_nonblock && ret == -EAGAIN) + return -EAGAIN; + + if (ret < 0) + req_set_fail_links(req); + io_cqring_add_event(req, ret); + io_put_req_find_next(req, nxt); + return 0; +#else + return -EOPNOTSUPP; +#endif +} + static int io_madvise_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe) { #if defined(CONFIG_ADVISE_SYSCALLS) && defined(CONFIG_MMU) @@ -4024,6 +4084,9 @@ static int io_req_defer_prep(struct io_kiocb *req, case IORING_OP_MADVISE: ret = io_madvise_prep(req, sqe); break; + case IORING_OP_EPOLL_CTL: + ret = io_epoll_ctl_prep(req, sqe); + break; default: printk_once(KERN_WARNING "io_uring: unhandled opcode %d\n", req->opcode); @@ -4244,6 +4307,14 @@ static int io_issue_sqe(struct io_kiocb *req, const struct io_uring_sqe *sqe, } ret = io_madvise(req, nxt, force_nonblock); break; + case IORING_OP_EPOLL_CTL: + if (sqe) { + ret = io_epoll_ctl_prep(req, sqe); + if (ret) + break; + } + ret = io_epoll_ctl(req, nxt, force_nonblock); + break; default: ret = -EINVAL; break; diff --git a/include/uapi/linux/io_uring.h b/include/uapi/linux/io_uring.h index ad96791b34cf..90fed30a38b7 100644 --- a/include/uapi/linux/io_uring.h +++ b/include/uapi/linux/io_uring.h @@ -111,6 +111,7 @@ enum { IORING_OP_MADVISE, IORING_OP_SEND, IORING_OP_RECV, + IORING_OP_EPOLL_CTL,
/* this goes last, obviously */ IORING_OP_LAST,