--- /dev/null
+// SPDX-License-Identifier: GPL-2.0
+#include <linux/kernel.h>
+#include <linux/errno.h>
+#include <linux/fs.h>
+#include <linux/file.h>
+#include <linux/io_uring.h>
+
+#include <uapi/linux/io_uring.h>
+
+#include "../kernel/futex/futex.h"
+#include "io_uring.h"
+#include "rsrc.h"
+#include "futex.h"
+
+struct io_futex {
+ struct file *file;
+ u32 __user *uaddr;
+ unsigned long futex_val;
+ unsigned long futex_mask;
+ u32 futex_flags;
+};
+
+struct io_futex_data {
+ union {
+ struct futex_q q;
+ struct io_cache_entry cache;
+ };
+ struct io_kiocb *req;
+};
+
+void io_futex_cache_init(struct io_ring_ctx *ctx)
+{
+ io_alloc_cache_init(&ctx->futex_cache, IO_NODE_ALLOC_CACHE_MAX,
+ sizeof(struct io_futex_data));
+}
+
+static void io_futex_cache_entry_free(struct io_cache_entry *entry)
+{
+ kfree(container_of(entry, struct io_futex_data, cache));
+}
+
+void io_futex_cache_free(struct io_ring_ctx *ctx)
+{
+ io_alloc_cache_free(&ctx->futex_cache, io_futex_cache_entry_free);
+}
+
+static void io_futex_complete(struct io_kiocb *req, struct io_tw_state *ts)
+{
+ struct io_futex_data *ifd = req->async_data;
+ struct io_ring_ctx *ctx = req->ctx;
+
+ io_tw_lock(ctx, ts);
+ if (!io_alloc_cache_put(&ctx->futex_cache, &ifd->cache))
+ kfree(ifd);
+ req->async_data = NULL;
+ hlist_del_init(&req->hash_node);
+ io_req_task_complete(req, ts);
+}
+
+static bool __io_futex_cancel(struct io_ring_ctx *ctx, struct io_kiocb *req)
+{
+ struct io_futex_data *ifd = req->async_data;
+
+ /* futex wake already done or in progress */
+ if (!futex_unqueue(&ifd->q))
+ return false;
+
+ hlist_del_init(&req->hash_node);
+ io_req_set_res(req, -ECANCELED, 0);
+ req->io_task_work.func = io_futex_complete;
+ io_req_task_work_add(req);
+ return true;
+}
+
+int io_futex_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->futex_list, hash_node) {
+ if (req->cqe.user_data != cd->data &&
+ !(cd->flags & IORING_ASYNC_CANCEL_ANY))
+ continue;
+ if (__io_futex_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;
+}
+
+bool io_futex_remove_all(struct io_ring_ctx *ctx, struct task_struct *task,
+ 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->futex_list, hash_node) {
+ if (!io_match_task_safe(req, task, cancel_all))
+ continue;
+ __io_futex_cancel(ctx, req);
+ found = true;
+ }
+
+ return found;
+}
+
+int io_futex_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe)
+{
+ struct io_futex *iof = io_kiocb_to_cmd(req, struct io_futex);
+ u32 flags;
+
+ if (unlikely(sqe->len || sqe->futex_flags || sqe->buf_index ||
+ sqe->file_index))
+ return -EINVAL;
+
+ iof->uaddr = u64_to_user_ptr(READ_ONCE(sqe->addr));
+ iof->futex_val = READ_ONCE(sqe->addr2);
+ iof->futex_mask = READ_ONCE(sqe->addr3);
+ flags = READ_ONCE(sqe->fd);
+
+ if (flags & ~FUTEX2_VALID_MASK)
+ return -EINVAL;
+
+ iof->futex_flags = futex2_to_flags(flags);
+ if (!futex_flags_valid(iof->futex_flags))
+ return -EINVAL;
+
+ if (!futex_validate_input(iof->futex_flags, iof->futex_val) ||
+ !futex_validate_input(iof->futex_flags, iof->futex_mask))
+ return -EINVAL;
+
+ return 0;
+}
+
+static void io_futex_wake_fn(struct wake_q_head *wake_q, struct futex_q *q)
+{
+ struct io_futex_data *ifd = container_of(q, struct io_futex_data, q);
+ struct io_kiocb *req = ifd->req;
+
+ if (unlikely(!__futex_wake_mark(q)))
+ return;
+
+ io_req_set_res(req, 0, 0);
+ req->io_task_work.func = io_futex_complete;
+ io_req_task_work_add(req);
+}
+
+static struct io_futex_data *io_alloc_ifd(struct io_ring_ctx *ctx)
+{
+ struct io_cache_entry *entry;
+
+ entry = io_alloc_cache_get(&ctx->futex_cache);
+ if (entry)
+ return container_of(entry, struct io_futex_data, cache);
+
+ return kmalloc(sizeof(struct io_futex_data), GFP_NOWAIT);
+}
+
+int io_futex_wait(struct io_kiocb *req, unsigned int issue_flags)
+{
+ struct io_futex *iof = io_kiocb_to_cmd(req, struct io_futex);
+ struct io_ring_ctx *ctx = req->ctx;
+ struct io_futex_data *ifd = NULL;
+ struct futex_hash_bucket *hb;
+ int ret;
+
+ if (!iof->futex_mask) {
+ ret = -EINVAL;
+ goto done;
+ }
+
+ io_ring_submit_lock(ctx, issue_flags);
+ ifd = io_alloc_ifd(ctx);
+ if (!ifd) {
+ ret = -ENOMEM;
+ goto done_unlock;
+ }
+
+ req->async_data = ifd;
+ ifd->q = futex_q_init;
+ ifd->q.bitset = iof->futex_mask;
+ ifd->q.wake = io_futex_wake_fn;
+ ifd->req = req;
+
+ ret = futex_wait_setup(iof->uaddr, iof->futex_val, iof->futex_flags,
+ &ifd->q, &hb);
+ if (!ret) {
+ hlist_add_head(&req->hash_node, &ctx->futex_list);
+ io_ring_submit_unlock(ctx, issue_flags);
+
+ futex_queue(&ifd->q, hb);
+ return IOU_ISSUE_SKIP_COMPLETE;
+ }
+
+done_unlock:
+ io_ring_submit_unlock(ctx, issue_flags);
+done:
+ if (ret < 0)
+ req_set_fail(req);
+ io_req_set_res(req, ret, 0);
+ kfree(ifd);
+ return IOU_OK;
+}
+
+int io_futex_wake(struct io_kiocb *req, unsigned int issue_flags)
+{
+ struct io_futex *iof = io_kiocb_to_cmd(req, struct io_futex);
+ int ret;
+
+ /*
+ * Strict flags - ensure that waking 0 futexes yields a 0 result.
+ * See commit 43adf8449510 ("futex: FLAGS_STRICT") for details.
+ */
+ ret = futex_wake(iof->uaddr, FLAGS_STRICT | iof->futex_flags,
+ iof->futex_val, iof->futex_mask);
+ if (ret < 0)
+ req_set_fail(req);
+ io_req_set_res(req, ret, 0);
+ return IOU_OK;
+}
#include "net.h"
#include "notif.h"
#include "waitid.h"
+#include "futex.h"
#include "timeout.h"
#include "poll.h"
sizeof(struct async_poll));
io_alloc_cache_init(&ctx->netmsg_cache, IO_ALLOC_CACHE_MAX,
sizeof(struct io_async_msghdr));
+ io_futex_cache_init(ctx);
init_completion(&ctx->ref_comp);
xa_init_flags(&ctx->personalities, XA_FLAGS_ALLOC1);
mutex_init(&ctx->uring_lock);
ctx->submit_state.free_list.next = NULL;
INIT_WQ_LIST(&ctx->locked_free_list);
INIT_HLIST_HEAD(&ctx->waitid_list);
+#ifdef CONFIG_FUTEX
+ INIT_HLIST_HEAD(&ctx->futex_list);
+#endif
INIT_DELAYED_WORK(&ctx->fallback_work, io_fallback_req_func);
INIT_WQ_LIST(&ctx->submit_state.compl_reqs);
INIT_HLIST_HEAD(&ctx->cancelable_uring_cmd);
io_eventfd_unregister(ctx);
io_alloc_cache_free(&ctx->apoll_cache, io_apoll_cache_free);
io_alloc_cache_free(&ctx->netmsg_cache, io_netmsg_cache_free);
+ io_futex_cache_free(ctx);
io_destroy_buffers(ctx);
mutex_unlock(&ctx->uring_lock);
if (ctx->sq_creds)
mutex_lock(&ctx->uring_lock);
ret |= io_poll_remove_all(ctx, task, cancel_all);
ret |= io_waitid_remove_all(ctx, task, cancel_all);
+ ret |= io_futex_remove_all(ctx, task, cancel_all);
ret |= io_uring_try_cancel_uring_cmd(ctx, task, cancel_all);
mutex_unlock(&ctx->uring_lock);
ret |= io_kill_timeouts(ctx, task, cancel_all);
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