1 files changed, 52 insertions, 71 deletions

diff --git a/io_uring/waitid.c b/io_uring/waitid.c
index daef5dd644f0..2d4cbd47c67c 100644
--- a/io_uring/waitid.c
+++ b/io_uring/waitid.c
@@ -16,7 +16,7 @@
 #include "waitid.h"
 #include "../kernel/exit.h"
 
-static void io_waitid_cb(struct io_kiocb *req, struct io_tw_state *ts);
+static void io_waitid_cb(struct io_tw_req tw_req, io_tw_token_t tw);
 
 #define IO_WAITID_CANCEL_FLAG	BIT(31)
 #define IO_WAITID_REF_MASK	GENMASK(30, 0)
@@ -37,12 +37,9 @@ static void io_waitid_free(struct io_kiocb *req)
 	struct io_waitid_async *iwa = req->async_data;
 
 	put_pid(iwa->wo.wo_pid);
-	kfree(req->async_data);
-	req->async_data = NULL;
-	req->flags &= ~REQ_F_ASYNC_DATA;
+	io_req_async_data_free(req);
 }
 
-#ifdef CONFIG_COMPAT
 static bool io_waitid_compat_copy_si(struct io_waitid *iw, int signo)
 {
 	struct compat_siginfo __user *infop;
@@ -67,7 +64,6 @@ Efault:
 	ret = false;
 	goto done;
 }
-#endif
 
 static bool io_waitid_copy_si(struct io_kiocb *req, int signo)
 {
@@ -77,10 +73,8 @@ static bool io_waitid_copy_si(struct io_kiocb *req, int signo)
 	if (!iw->infop)
 		return true;
 
-#ifdef CONFIG_COMPAT
-	if (req->ctx->compat)
+	if (io_is_compat(req->ctx))
 		return io_waitid_compat_copy_si(iw, signo);
-#endif
 
 	if (!user_write_access_begin(iw->infop, sizeof(*iw->infop)))
 		return false;
@@ -115,10 +109,25 @@ static int io_waitid_finish(struct io_kiocb *req, int ret)
 	return ret;
 }
 
+static void io_waitid_remove_wq(struct io_kiocb *req)
+{
+	struct io_waitid *iw = io_kiocb_to_cmd(req, struct io_waitid);
+	struct wait_queue_head *head;
+
+	head = READ_ONCE(iw->head);
+	if (head) {
+		struct io_waitid_async *iwa = req->async_data;
+
+		iw->head = NULL;
+		spin_lock_irq(&head->lock);
+		list_del_init(&iwa->wo.child_wait.entry);
+		spin_unlock_irq(&head->lock);
+	}
+}
+
 static void io_waitid_complete(struct io_kiocb *req, int ret)
 {
 	struct io_waitid *iw = io_kiocb_to_cmd(req, struct io_waitid);
-	struct io_tw_state ts = {};
 
 	/* anyone completing better be holding a reference */
 	WARN_ON_ONCE(!(atomic_read(&iw->refs) & IO_WAITID_REF_MASK));
@@ -126,18 +135,19 @@ static void io_waitid_complete(struct io_kiocb *req, int ret)
 	lockdep_assert_held(&req->ctx->uring_lock);
 
 	hlist_del_init(&req->hash_node);
+	io_waitid_remove_wq(req);
 
 	ret = io_waitid_finish(req, ret);
 	if (ret < 0)
 		req_set_fail(req);
 	io_req_set_res(req, ret, 0);
-	io_req_task_complete(req, &ts);
 }
 
-static bool __io_waitid_cancel(struct io_ring_ctx *ctx, struct io_kiocb *req)
+static bool __io_waitid_cancel(struct io_kiocb *req)
 {
 	struct io_waitid *iw = io_kiocb_to_cmd(req, struct io_waitid);
-	struct io_waitid_async *iwa = req->async_data;
+
+	lockdep_assert_held(&req->ctx->uring_lock);
 
 	/*
 	 * Mark us canceled regardless of ownership. This will prevent a
@@ -149,86 +159,49 @@ static bool __io_waitid_cancel(struct io_ring_ctx *ctx, struct io_kiocb *req)
 	if (atomic_fetch_inc(&iw->refs) & IO_WAITID_REF_MASK)
 		return false;
 
-	spin_lock_irq(&iw->head->lock);
-	list_del_init(&iwa->wo.child_wait.entry);
-	spin_unlock_irq(&iw->head->lock);
 	io_waitid_complete(req, -ECANCELED);
+	io_req_queue_tw_complete(req, -ECANCELED);
 	return true;
 }
 
 int io_waitid_cancel(struct io_ring_ctx *ctx, struct io_cancel_data *cd,
 		     unsigned int issue_flags)
 {
-	struct hlist_node *tmp;
-	struct io_kiocb *req;
-	int nr = 0;
-
-	if (cd->flags & (IORING_ASYNC_CANCEL_FD|IORING_ASYNC_CANCEL_FD_FIXED))
-		return -ENOENT;
-
-	io_ring_submit_lock(ctx, issue_flags);
-	hlist_for_each_entry_safe(req, tmp, &ctx->waitid_list, hash_node) {
-		if (req->cqe.user_data != cd->data &&
-		    !(cd->flags & IORING_ASYNC_CANCEL_ANY))
-			continue;
-		if (__io_waitid_cancel(ctx, req))
-			nr++;
-		if (!(cd->flags & IORING_ASYNC_CANCEL_ALL))
-			break;
-	}
-	io_ring_submit_unlock(ctx, issue_flags);
-
-	if (nr)
-		return nr;
-
-	return -ENOENT;
+	return io_cancel_remove(ctx, cd, issue_flags, &ctx->waitid_list, __io_waitid_cancel);
 }
 
 bool io_waitid_remove_all(struct io_ring_ctx *ctx, struct io_uring_task *tctx,
 			  bool cancel_all)
 {
-	struct hlist_node *tmp;
-	struct io_kiocb *req;
-	bool found = false;
-
-	lockdep_assert_held(&ctx->uring_lock);
-
-	hlist_for_each_entry_safe(req, tmp, &ctx->waitid_list, hash_node) {
-		if (!io_match_task_safe(req, tctx, cancel_all))
-			continue;
-		hlist_del_init(&req->hash_node);
-		__io_waitid_cancel(ctx, req);
-		found = true;
-	}
-
-	return found;
+	return io_cancel_remove_all(ctx, tctx, &ctx->waitid_list, cancel_all, __io_waitid_cancel);
 }
 
 static inline bool io_waitid_drop_issue_ref(struct io_kiocb *req)
 {
 	struct io_waitid *iw = io_kiocb_to_cmd(req, struct io_waitid);
-	struct io_waitid_async *iwa = req->async_data;
 
 	if (!atomic_sub_return(1, &iw->refs))
 		return false;
 
+	io_waitid_remove_wq(req);
+
 	/*
 	 * Wakeup triggered, racing with us. It was prevented from
 	 * completing because of that, queue up the tw to do that.
 	 */
 	req->io_task_work.func = io_waitid_cb;
 	io_req_task_work_add(req);
-	remove_wait_queue(iw->head, &iwa->wo.child_wait);
 	return true;
 }
 
-static void io_waitid_cb(struct io_kiocb *req, struct io_tw_state *ts)
+static void io_waitid_cb(struct io_tw_req tw_req, io_tw_token_t tw)
 {
+	struct io_kiocb *req = tw_req.req;
 	struct io_waitid_async *iwa = req->async_data;
 	struct io_ring_ctx *ctx = req->ctx;
 	int ret;
 
-	io_tw_lock(ctx, ts);
+	io_tw_lock(ctx, tw);
 
 	ret = __do_wait(&iwa->wo);
 
@@ -252,12 +225,12 @@ static void io_waitid_cb(struct io_kiocb *req, struct io_tw_state *ts)
 				io_waitid_drop_issue_ref(req);
 				return;
 			}
-
-			remove_wait_queue(iw->head, &iwa->wo.child_wait);
+			/* fall through to complete, will kill waitqueue */
 		}
 	}
 
 	io_waitid_complete(req, ret);
+	io_req_task_complete(tw_req, tw);
 }
 
 static int io_waitid_wait(struct wait_queue_entry *wait, unsigned mode,
@@ -272,26 +245,35 @@ static int io_waitid_wait(struct wait_queue_entry *wait, unsigned mode,
 	if (!pid_child_should_wake(wo, p))
 		return 0;
 
+	list_del_init(&wait->entry);
+	iw->head = NULL;
+
 	/* cancel is in progress */
 	if (atomic_fetch_inc(&iw->refs) & IO_WAITID_REF_MASK)
 		return 1;
 
 	req->io_task_work.func = io_waitid_cb;
 	io_req_task_work_add(req);
-	list_del_init(&wait->entry);
 	return 1;
 }
 
 int io_waitid_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe)
 {
 	struct io_waitid *iw = io_kiocb_to_cmd(req, struct io_waitid);
+	struct io_waitid_async *iwa;
 
 	if (sqe->addr || sqe->buf_index || sqe->addr3 || sqe->waitid_flags)
 		return -EINVAL;
 
+	iwa = io_uring_alloc_async_data(NULL, req);
+	if (unlikely(!iwa))
+		return -ENOMEM;
+	iwa->req = req;
+
 	iw->which = READ_ONCE(sqe->len);
 	iw->upid = READ_ONCE(sqe->fd);
 	iw->options = READ_ONCE(sqe->file_index);
+	iw->head = NULL;
 	iw->infop = u64_to_user_ptr(READ_ONCE(sqe->addr2));
 	return 0;
 }
@@ -299,16 +281,10 @@ int io_waitid_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe)
 int io_waitid(struct io_kiocb *req, unsigned int issue_flags)
 {
 	struct io_waitid *iw = io_kiocb_to_cmd(req, struct io_waitid);
+	struct io_waitid_async *iwa = req->async_data;
 	struct io_ring_ctx *ctx = req->ctx;
-	struct io_waitid_async *iwa;
 	int ret;
 
-	if (io_alloc_async_data(req))
-		return -ENOMEM;
-
-	iwa = req->async_data;
-	iwa->req = req;
-
 	ret = kernel_waitid_prepare(&iwa->wo, iw->which, iw->upid, &iw->info,
 					iw->options, NULL);
 	if (ret)
@@ -328,11 +304,16 @@ int io_waitid(struct io_kiocb *req, unsigned int issue_flags)
 	 * callback.
 	 */
 	io_ring_submit_lock(ctx, issue_flags);
+
+	/*
+	 * iw->head is valid under the ring lock, and as long as the request
+	 * is on the waitid_list where cancelations may find it.
+	 */
+	iw->head = &current->signal->wait_chldexit;
 	hlist_add_head(&req->hash_node, &ctx->waitid_list);
 
 	init_waitqueue_func_entry(&iwa->wo.child_wait, io_waitid_wait);
 	iwa->wo.child_wait.private = req->tctx->task;
-	iw->head = &current->signal->wait_chldexit;
 	add_wait_queue(iw->head, &iwa->wo.child_wait);
 
 	ret = __do_wait(&iwa->wo);
@@ -355,7 +336,7 @@ int io_waitid(struct io_kiocb *req, unsigned int issue_flags)
 	}
 
 	hlist_del_init(&req->hash_node);
-	remove_wait_queue(iw->head, &iwa->wo.child_wait);
+	io_waitid_remove_wq(req);
 	ret = io_waitid_finish(req, ret);
 
 	io_ring_submit_unlock(ctx, issue_flags);
@@ -363,5 +344,5 @@ done:
 	if (ret < 0)
 		req_set_fail(req);
 	io_req_set_res(req, ret, 0);
-	return IOU_OK;
+	return IOU_COMPLETE;
 }