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-rw-r--r--io_uring/rsrc.c1371
1 files changed, 1371 insertions, 0 deletions
diff --git a/io_uring/rsrc.c b/io_uring/rsrc.c
new file mode 100644
index 000000000..7ada0339b
--- /dev/null
+++ b/io_uring/rsrc.c
@@ -0,0 +1,1371 @@
+// SPDX-License-Identifier: GPL-2.0
+#include <linux/kernel.h>
+#include <linux/errno.h>
+#include <linux/fs.h>
+#include <linux/file.h>
+#include <linux/mm.h>
+#include <linux/slab.h>
+#include <linux/nospec.h>
+#include <linux/hugetlb.h>
+#include <linux/compat.h>
+#include <linux/io_uring.h>
+
+#include <uapi/linux/io_uring.h>
+
+#include "io_uring.h"
+#include "openclose.h"
+#include "rsrc.h"
+
+struct io_rsrc_update {
+ struct file *file;
+ u64 arg;
+ u32 nr_args;
+ u32 offset;
+};
+
+static int io_sqe_buffer_register(struct io_ring_ctx *ctx, struct iovec *iov,
+ struct io_mapped_ubuf **pimu,
+ struct page **last_hpage);
+
+#define IO_RSRC_REF_BATCH 100
+
+/* only define max */
+#define IORING_MAX_FIXED_FILES (1U << 20)
+#define IORING_MAX_REG_BUFFERS (1U << 14)
+
+void io_rsrc_refs_drop(struct io_ring_ctx *ctx)
+ __must_hold(&ctx->uring_lock)
+{
+ if (ctx->rsrc_cached_refs) {
+ io_rsrc_put_node(ctx->rsrc_node, ctx->rsrc_cached_refs);
+ ctx->rsrc_cached_refs = 0;
+ }
+}
+
+int __io_account_mem(struct user_struct *user, unsigned long nr_pages)
+{
+ unsigned long page_limit, cur_pages, new_pages;
+
+ if (!nr_pages)
+ return 0;
+
+ /* Don't allow more pages than we can safely lock */
+ page_limit = rlimit(RLIMIT_MEMLOCK) >> PAGE_SHIFT;
+
+ cur_pages = atomic_long_read(&user->locked_vm);
+ do {
+ new_pages = cur_pages + nr_pages;
+ if (new_pages > page_limit)
+ return -ENOMEM;
+ } while (!atomic_long_try_cmpxchg(&user->locked_vm,
+ &cur_pages, new_pages));
+ return 0;
+}
+
+static void io_unaccount_mem(struct io_ring_ctx *ctx, unsigned long nr_pages)
+{
+ if (ctx->user)
+ __io_unaccount_mem(ctx->user, nr_pages);
+
+ if (ctx->mm_account)
+ atomic64_sub(nr_pages, &ctx->mm_account->pinned_vm);
+}
+
+static int io_account_mem(struct io_ring_ctx *ctx, unsigned long nr_pages)
+{
+ int ret;
+
+ if (ctx->user) {
+ ret = __io_account_mem(ctx->user, nr_pages);
+ if (ret)
+ return ret;
+ }
+
+ if (ctx->mm_account)
+ atomic64_add(nr_pages, &ctx->mm_account->pinned_vm);
+
+ return 0;
+}
+
+static int io_copy_iov(struct io_ring_ctx *ctx, struct iovec *dst,
+ void __user *arg, unsigned index)
+{
+ struct iovec __user *src;
+
+#ifdef CONFIG_COMPAT
+ if (ctx->compat) {
+ struct compat_iovec __user *ciovs;
+ struct compat_iovec ciov;
+
+ ciovs = (struct compat_iovec __user *) arg;
+ if (copy_from_user(&ciov, &ciovs[index], sizeof(ciov)))
+ return -EFAULT;
+
+ dst->iov_base = u64_to_user_ptr((u64)ciov.iov_base);
+ dst->iov_len = ciov.iov_len;
+ return 0;
+ }
+#endif
+ src = (struct iovec __user *) arg;
+ if (copy_from_user(dst, &src[index], sizeof(*dst)))
+ return -EFAULT;
+ return 0;
+}
+
+static int io_buffer_validate(struct iovec *iov)
+{
+ unsigned long tmp, acct_len = iov->iov_len + (PAGE_SIZE - 1);
+
+ /*
+ * Don't impose further limits on the size and buffer
+ * constraints here, we'll -EINVAL later when IO is
+ * submitted if they are wrong.
+ */
+ if (!iov->iov_base)
+ return iov->iov_len ? -EFAULT : 0;
+ if (!iov->iov_len)
+ return -EFAULT;
+
+ /* arbitrary limit, but we need something */
+ if (iov->iov_len > SZ_1G)
+ return -EFAULT;
+
+ if (check_add_overflow((unsigned long)iov->iov_base, acct_len, &tmp))
+ return -EOVERFLOW;
+
+ return 0;
+}
+
+static void io_buffer_unmap(struct io_ring_ctx *ctx, struct io_mapped_ubuf **slot)
+{
+ struct io_mapped_ubuf *imu = *slot;
+ unsigned int i;
+
+ if (imu != ctx->dummy_ubuf) {
+ for (i = 0; i < imu->nr_bvecs; i++)
+ unpin_user_page(imu->bvec[i].bv_page);
+ if (imu->acct_pages)
+ io_unaccount_mem(ctx, imu->acct_pages);
+ kvfree(imu);
+ }
+ *slot = NULL;
+}
+
+void io_rsrc_refs_refill(struct io_ring_ctx *ctx)
+ __must_hold(&ctx->uring_lock)
+{
+ ctx->rsrc_cached_refs += IO_RSRC_REF_BATCH;
+ percpu_ref_get_many(&ctx->rsrc_node->refs, IO_RSRC_REF_BATCH);
+}
+
+static void __io_rsrc_put_work(struct io_rsrc_node *ref_node)
+{
+ struct io_rsrc_data *rsrc_data = ref_node->rsrc_data;
+ struct io_ring_ctx *ctx = rsrc_data->ctx;
+ struct io_rsrc_put *prsrc, *tmp;
+
+ list_for_each_entry_safe(prsrc, tmp, &ref_node->rsrc_list, list) {
+ list_del(&prsrc->list);
+
+ if (prsrc->tag) {
+ if (ctx->flags & IORING_SETUP_IOPOLL) {
+ mutex_lock(&ctx->uring_lock);
+ io_post_aux_cqe(ctx, prsrc->tag, 0, 0, true);
+ mutex_unlock(&ctx->uring_lock);
+ } else {
+ io_post_aux_cqe(ctx, prsrc->tag, 0, 0, true);
+ }
+ }
+
+ rsrc_data->do_put(ctx, prsrc);
+ kfree(prsrc);
+ }
+
+ io_rsrc_node_destroy(ref_node);
+ if (atomic_dec_and_test(&rsrc_data->refs))
+ complete(&rsrc_data->done);
+}
+
+void io_rsrc_put_work(struct work_struct *work)
+{
+ struct io_ring_ctx *ctx;
+ struct llist_node *node;
+
+ ctx = container_of(work, struct io_ring_ctx, rsrc_put_work.work);
+ node = llist_del_all(&ctx->rsrc_put_llist);
+
+ while (node) {
+ struct io_rsrc_node *ref_node;
+ struct llist_node *next = node->next;
+
+ ref_node = llist_entry(node, struct io_rsrc_node, llist);
+ __io_rsrc_put_work(ref_node);
+ node = next;
+ }
+}
+
+void io_wait_rsrc_data(struct io_rsrc_data *data)
+{
+ if (data && !atomic_dec_and_test(&data->refs))
+ wait_for_completion(&data->done);
+}
+
+void io_rsrc_node_destroy(struct io_rsrc_node *ref_node)
+{
+ percpu_ref_exit(&ref_node->refs);
+ kfree(ref_node);
+}
+
+static __cold void io_rsrc_node_ref_zero(struct percpu_ref *ref)
+{
+ struct io_rsrc_node *node = container_of(ref, struct io_rsrc_node, refs);
+ struct io_ring_ctx *ctx = node->rsrc_data->ctx;
+ unsigned long flags;
+ bool first_add = false;
+ unsigned long delay = HZ;
+
+ spin_lock_irqsave(&ctx->rsrc_ref_lock, flags);
+ node->done = true;
+
+ /* if we are mid-quiesce then do not delay */
+ if (node->rsrc_data->quiesce)
+ delay = 0;
+
+ while (!list_empty(&ctx->rsrc_ref_list)) {
+ node = list_first_entry(&ctx->rsrc_ref_list,
+ struct io_rsrc_node, node);
+ /* recycle ref nodes in order */
+ if (!node->done)
+ break;
+ list_del(&node->node);
+ first_add |= llist_add(&node->llist, &ctx->rsrc_put_llist);
+ }
+ spin_unlock_irqrestore(&ctx->rsrc_ref_lock, flags);
+
+ if (first_add)
+ mod_delayed_work(system_wq, &ctx->rsrc_put_work, delay);
+}
+
+static struct io_rsrc_node *io_rsrc_node_alloc(void)
+{
+ struct io_rsrc_node *ref_node;
+
+ ref_node = kzalloc(sizeof(*ref_node), GFP_KERNEL);
+ if (!ref_node)
+ return NULL;
+
+ if (percpu_ref_init(&ref_node->refs, io_rsrc_node_ref_zero,
+ 0, GFP_KERNEL)) {
+ kfree(ref_node);
+ return NULL;
+ }
+ INIT_LIST_HEAD(&ref_node->node);
+ INIT_LIST_HEAD(&ref_node->rsrc_list);
+ ref_node->done = false;
+ return ref_node;
+}
+
+void io_rsrc_node_switch(struct io_ring_ctx *ctx,
+ struct io_rsrc_data *data_to_kill)
+ __must_hold(&ctx->uring_lock)
+{
+ WARN_ON_ONCE(!ctx->rsrc_backup_node);
+ WARN_ON_ONCE(data_to_kill && !ctx->rsrc_node);
+
+ io_rsrc_refs_drop(ctx);
+
+ if (data_to_kill) {
+ struct io_rsrc_node *rsrc_node = ctx->rsrc_node;
+
+ rsrc_node->rsrc_data = data_to_kill;
+ spin_lock_irq(&ctx->rsrc_ref_lock);
+ list_add_tail(&rsrc_node->node, &ctx->rsrc_ref_list);
+ spin_unlock_irq(&ctx->rsrc_ref_lock);
+
+ atomic_inc(&data_to_kill->refs);
+ percpu_ref_kill(&rsrc_node->refs);
+ ctx->rsrc_node = NULL;
+ }
+
+ if (!ctx->rsrc_node) {
+ ctx->rsrc_node = ctx->rsrc_backup_node;
+ ctx->rsrc_backup_node = NULL;
+ }
+}
+
+int io_rsrc_node_switch_start(struct io_ring_ctx *ctx)
+{
+ if (ctx->rsrc_backup_node)
+ return 0;
+ ctx->rsrc_backup_node = io_rsrc_node_alloc();
+ return ctx->rsrc_backup_node ? 0 : -ENOMEM;
+}
+
+__cold static int io_rsrc_ref_quiesce(struct io_rsrc_data *data,
+ struct io_ring_ctx *ctx)
+{
+ int ret;
+
+ /* As we may drop ->uring_lock, other task may have started quiesce */
+ if (data->quiesce)
+ return -ENXIO;
+
+ data->quiesce = true;
+ do {
+ ret = io_rsrc_node_switch_start(ctx);
+ if (ret)
+ break;
+ io_rsrc_node_switch(ctx, data);
+
+ /* kill initial ref, already quiesced if zero */
+ if (atomic_dec_and_test(&data->refs))
+ break;
+ mutex_unlock(&ctx->uring_lock);
+ flush_delayed_work(&ctx->rsrc_put_work);
+ ret = wait_for_completion_interruptible(&data->done);
+ if (!ret) {
+ mutex_lock(&ctx->uring_lock);
+ if (atomic_read(&data->refs) > 0) {
+ /*
+ * it has been revived by another thread while
+ * we were unlocked
+ */
+ mutex_unlock(&ctx->uring_lock);
+ } else {
+ break;
+ }
+ }
+
+ atomic_inc(&data->refs);
+ /* wait for all works potentially completing data->done */
+ flush_delayed_work(&ctx->rsrc_put_work);
+ reinit_completion(&data->done);
+
+ ret = io_run_task_work_sig(ctx);
+ mutex_lock(&ctx->uring_lock);
+ } while (ret >= 0);
+ data->quiesce = false;
+
+ return ret;
+}
+
+static void io_free_page_table(void **table, size_t size)
+{
+ unsigned i, nr_tables = DIV_ROUND_UP(size, PAGE_SIZE);
+
+ for (i = 0; i < nr_tables; i++)
+ kfree(table[i]);
+ kfree(table);
+}
+
+static void io_rsrc_data_free(struct io_rsrc_data *data)
+{
+ size_t size = data->nr * sizeof(data->tags[0][0]);
+
+ if (data->tags)
+ io_free_page_table((void **)data->tags, size);
+ kfree(data);
+}
+
+static __cold void **io_alloc_page_table(size_t size)
+{
+ unsigned i, nr_tables = DIV_ROUND_UP(size, PAGE_SIZE);
+ size_t init_size = size;
+ void **table;
+
+ table = kcalloc(nr_tables, sizeof(*table), GFP_KERNEL_ACCOUNT);
+ if (!table)
+ return NULL;
+
+ for (i = 0; i < nr_tables; i++) {
+ unsigned int this_size = min_t(size_t, size, PAGE_SIZE);
+
+ table[i] = kzalloc(this_size, GFP_KERNEL_ACCOUNT);
+ if (!table[i]) {
+ io_free_page_table(table, init_size);
+ return NULL;
+ }
+ size -= this_size;
+ }
+ return table;
+}
+
+__cold static int io_rsrc_data_alloc(struct io_ring_ctx *ctx,
+ rsrc_put_fn *do_put, u64 __user *utags,
+ unsigned nr, struct io_rsrc_data **pdata)
+{
+ struct io_rsrc_data *data;
+ int ret = -ENOMEM;
+ unsigned i;
+
+ data = kzalloc(sizeof(*data), GFP_KERNEL);
+ if (!data)
+ return -ENOMEM;
+ data->tags = (u64 **)io_alloc_page_table(nr * sizeof(data->tags[0][0]));
+ if (!data->tags) {
+ kfree(data);
+ return -ENOMEM;
+ }
+
+ data->nr = nr;
+ data->ctx = ctx;
+ data->do_put = do_put;
+ if (utags) {
+ ret = -EFAULT;
+ for (i = 0; i < nr; i++) {
+ u64 *tag_slot = io_get_tag_slot(data, i);
+
+ if (copy_from_user(tag_slot, &utags[i],
+ sizeof(*tag_slot)))
+ goto fail;
+ }
+ }
+
+ atomic_set(&data->refs, 1);
+ init_completion(&data->done);
+ *pdata = data;
+ return 0;
+fail:
+ io_rsrc_data_free(data);
+ return ret;
+}
+
+static int __io_sqe_files_update(struct io_ring_ctx *ctx,
+ struct io_uring_rsrc_update2 *up,
+ unsigned nr_args)
+{
+ u64 __user *tags = u64_to_user_ptr(up->tags);
+ __s32 __user *fds = u64_to_user_ptr(up->data);
+ struct io_rsrc_data *data = ctx->file_data;
+ struct io_fixed_file *file_slot;
+ struct file *file;
+ int fd, i, err = 0;
+ unsigned int done;
+ bool needs_switch = false;
+
+ if (!ctx->file_data)
+ return -ENXIO;
+ if (up->offset + nr_args > ctx->nr_user_files)
+ return -EINVAL;
+
+ for (done = 0; done < nr_args; done++) {
+ u64 tag = 0;
+
+ if ((tags && copy_from_user(&tag, &tags[done], sizeof(tag))) ||
+ copy_from_user(&fd, &fds[done], sizeof(fd))) {
+ err = -EFAULT;
+ break;
+ }
+ if ((fd == IORING_REGISTER_FILES_SKIP || fd == -1) && tag) {
+ err = -EINVAL;
+ break;
+ }
+ if (fd == IORING_REGISTER_FILES_SKIP)
+ continue;
+
+ i = array_index_nospec(up->offset + done, ctx->nr_user_files);
+ file_slot = io_fixed_file_slot(&ctx->file_table, i);
+
+ if (file_slot->file_ptr) {
+ file = (struct file *)(file_slot->file_ptr & FFS_MASK);
+ err = io_queue_rsrc_removal(data, i, ctx->rsrc_node, file);
+ if (err)
+ break;
+ file_slot->file_ptr = 0;
+ io_file_bitmap_clear(&ctx->file_table, i);
+ needs_switch = true;
+ }
+ if (fd != -1) {
+ file = fget(fd);
+ if (!file) {
+ err = -EBADF;
+ break;
+ }
+ /*
+ * Don't allow io_uring instances to be registered. If
+ * UNIX isn't enabled, then this causes a reference
+ * cycle and this instance can never get freed. If UNIX
+ * is enabled we'll handle it just fine, but there's
+ * still no point in allowing a ring fd as it doesn't
+ * support regular read/write anyway.
+ */
+ if (io_is_uring_fops(file)) {
+ fput(file);
+ err = -EBADF;
+ break;
+ }
+ err = io_scm_file_account(ctx, file);
+ if (err) {
+ fput(file);
+ break;
+ }
+ *io_get_tag_slot(data, i) = tag;
+ io_fixed_file_set(file_slot, file);
+ io_file_bitmap_set(&ctx->file_table, i);
+ }
+ }
+
+ if (needs_switch)
+ io_rsrc_node_switch(ctx, data);
+ return done ? done : err;
+}
+
+static int __io_sqe_buffers_update(struct io_ring_ctx *ctx,
+ struct io_uring_rsrc_update2 *up,
+ unsigned int nr_args)
+{
+ u64 __user *tags = u64_to_user_ptr(up->tags);
+ struct iovec iov, __user *iovs = u64_to_user_ptr(up->data);
+ struct page *last_hpage = NULL;
+ bool needs_switch = false;
+ __u32 done;
+ int i, err;
+
+ if (!ctx->buf_data)
+ return -ENXIO;
+ if (up->offset + nr_args > ctx->nr_user_bufs)
+ return -EINVAL;
+
+ for (done = 0; done < nr_args; done++) {
+ struct io_mapped_ubuf *imu;
+ int offset = up->offset + done;
+ u64 tag = 0;
+
+ err = io_copy_iov(ctx, &iov, iovs, done);
+ if (err)
+ break;
+ if (tags && copy_from_user(&tag, &tags[done], sizeof(tag))) {
+ err = -EFAULT;
+ break;
+ }
+ err = io_buffer_validate(&iov);
+ if (err)
+ break;
+ if (!iov.iov_base && tag) {
+ err = -EINVAL;
+ break;
+ }
+ err = io_sqe_buffer_register(ctx, &iov, &imu, &last_hpage);
+ if (err)
+ break;
+
+ i = array_index_nospec(offset, ctx->nr_user_bufs);
+ if (ctx->user_bufs[i] != ctx->dummy_ubuf) {
+ err = io_queue_rsrc_removal(ctx->buf_data, i,
+ ctx->rsrc_node, ctx->user_bufs[i]);
+ if (unlikely(err)) {
+ io_buffer_unmap(ctx, &imu);
+ break;
+ }
+ ctx->user_bufs[i] = ctx->dummy_ubuf;
+ needs_switch = true;
+ }
+
+ ctx->user_bufs[i] = imu;
+ *io_get_tag_slot(ctx->buf_data, i) = tag;
+ }
+
+ if (needs_switch)
+ io_rsrc_node_switch(ctx, ctx->buf_data);
+ return done ? done : err;
+}
+
+static int __io_register_rsrc_update(struct io_ring_ctx *ctx, unsigned type,
+ struct io_uring_rsrc_update2 *up,
+ unsigned nr_args)
+{
+ __u32 tmp;
+ int err;
+
+ if (check_add_overflow(up->offset, nr_args, &tmp))
+ return -EOVERFLOW;
+ err = io_rsrc_node_switch_start(ctx);
+ if (err)
+ return err;
+
+ switch (type) {
+ case IORING_RSRC_FILE:
+ return __io_sqe_files_update(ctx, up, nr_args);
+ case IORING_RSRC_BUFFER:
+ return __io_sqe_buffers_update(ctx, up, nr_args);
+ }
+ return -EINVAL;
+}
+
+int io_register_files_update(struct io_ring_ctx *ctx, void __user *arg,
+ unsigned nr_args)
+{
+ struct io_uring_rsrc_update2 up;
+
+ if (!nr_args)
+ return -EINVAL;
+ memset(&up, 0, sizeof(up));
+ if (copy_from_user(&up, arg, sizeof(struct io_uring_rsrc_update)))
+ return -EFAULT;
+ if (up.resv || up.resv2)
+ return -EINVAL;
+ return __io_register_rsrc_update(ctx, IORING_RSRC_FILE, &up, nr_args);
+}
+
+int io_register_rsrc_update(struct io_ring_ctx *ctx, void __user *arg,
+ unsigned size, unsigned type)
+{
+ struct io_uring_rsrc_update2 up;
+
+ if (size != sizeof(up))
+ return -EINVAL;
+ if (copy_from_user(&up, arg, sizeof(up)))
+ return -EFAULT;
+ if (!up.nr || up.resv || up.resv2)
+ return -EINVAL;
+ return __io_register_rsrc_update(ctx, type, &up, up.nr);
+}
+
+__cold int io_register_rsrc(struct io_ring_ctx *ctx, void __user *arg,
+ unsigned int size, unsigned int type)
+{
+ struct io_uring_rsrc_register rr;
+
+ /* keep it extendible */
+ if (size != sizeof(rr))
+ return -EINVAL;
+
+ memset(&rr, 0, sizeof(rr));
+ if (copy_from_user(&rr, arg, size))
+ return -EFAULT;
+ if (!rr.nr || rr.resv2)
+ return -EINVAL;
+ if (rr.flags & ~IORING_RSRC_REGISTER_SPARSE)
+ return -EINVAL;
+
+ switch (type) {
+ case IORING_RSRC_FILE:
+ if (rr.flags & IORING_RSRC_REGISTER_SPARSE && rr.data)
+ break;
+ return io_sqe_files_register(ctx, u64_to_user_ptr(rr.data),
+ rr.nr, u64_to_user_ptr(rr.tags));
+ case IORING_RSRC_BUFFER:
+ if (rr.flags & IORING_RSRC_REGISTER_SPARSE && rr.data)
+ break;
+ return io_sqe_buffers_register(ctx, u64_to_user_ptr(rr.data),
+ rr.nr, u64_to_user_ptr(rr.tags));
+ }
+ return -EINVAL;
+}
+
+int io_files_update_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe)
+{
+ struct io_rsrc_update *up = io_kiocb_to_cmd(req, struct io_rsrc_update);
+
+ if (unlikely(req->flags & (REQ_F_FIXED_FILE | REQ_F_BUFFER_SELECT)))
+ return -EINVAL;
+ if (sqe->rw_flags || sqe->splice_fd_in)
+ return -EINVAL;
+
+ up->offset = READ_ONCE(sqe->off);
+ up->nr_args = READ_ONCE(sqe->len);
+ if (!up->nr_args)
+ return -EINVAL;
+ up->arg = READ_ONCE(sqe->addr);
+ return 0;
+}
+
+static int io_files_update_with_index_alloc(struct io_kiocb *req,
+ unsigned int issue_flags)
+{
+ struct io_rsrc_update *up = io_kiocb_to_cmd(req, struct io_rsrc_update);
+ __s32 __user *fds = u64_to_user_ptr(up->arg);
+ unsigned int done;
+ struct file *file;
+ int ret, fd;
+
+ if (!req->ctx->file_data)
+ return -ENXIO;
+
+ for (done = 0; done < up->nr_args; done++) {
+ if (copy_from_user(&fd, &fds[done], sizeof(fd))) {
+ ret = -EFAULT;
+ break;
+ }
+
+ file = fget(fd);
+ if (!file) {
+ ret = -EBADF;
+ break;
+ }
+ ret = io_fixed_fd_install(req, issue_flags, file,
+ IORING_FILE_INDEX_ALLOC);
+ if (ret < 0)
+ break;
+ if (copy_to_user(&fds[done], &ret, sizeof(ret))) {
+ __io_close_fixed(req->ctx, issue_flags, ret);
+ ret = -EFAULT;
+ break;
+ }
+ }
+
+ if (done)
+ return done;
+ return ret;
+}
+
+int io_files_update(struct io_kiocb *req, unsigned int issue_flags)
+{
+ struct io_rsrc_update *up = io_kiocb_to_cmd(req, struct io_rsrc_update);
+ struct io_ring_ctx *ctx = req->ctx;
+ struct io_uring_rsrc_update2 up2;
+ int ret;
+
+ up2.offset = up->offset;
+ up2.data = up->arg;
+ up2.nr = 0;
+ up2.tags = 0;
+ up2.resv = 0;
+ up2.resv2 = 0;
+
+ if (up->offset == IORING_FILE_INDEX_ALLOC) {
+ ret = io_files_update_with_index_alloc(req, issue_flags);
+ } else {
+ io_ring_submit_lock(ctx, issue_flags);
+ ret = __io_register_rsrc_update(ctx, IORING_RSRC_FILE,
+ &up2, up->nr_args);
+ io_ring_submit_unlock(ctx, issue_flags);
+ }
+
+ if (ret < 0)
+ req_set_fail(req);
+ io_req_set_res(req, ret, 0);
+ return IOU_OK;
+}
+
+int io_queue_rsrc_removal(struct io_rsrc_data *data, unsigned idx,
+ struct io_rsrc_node *node, void *rsrc)
+{
+ u64 *tag_slot = io_get_tag_slot(data, idx);
+ struct io_rsrc_put *prsrc;
+
+ prsrc = kzalloc(sizeof(*prsrc), GFP_KERNEL);
+ if (!prsrc)
+ return -ENOMEM;
+
+ prsrc->tag = *tag_slot;
+ *tag_slot = 0;
+ prsrc->rsrc = rsrc;
+ list_add(&prsrc->list, &node->rsrc_list);
+ return 0;
+}
+
+void __io_sqe_files_unregister(struct io_ring_ctx *ctx)
+{
+ int i;
+
+ for (i = 0; i < ctx->nr_user_files; i++) {
+ struct file *file = io_file_from_index(&ctx->file_table, i);
+
+ /* skip scm accounted files, they'll be freed by ->ring_sock */
+ if (!file || io_file_need_scm(file))
+ continue;
+ io_file_bitmap_clear(&ctx->file_table, i);
+ fput(file);
+ }
+
+#if defined(CONFIG_UNIX)
+ if (ctx->ring_sock) {
+ struct sock *sock = ctx->ring_sock->sk;
+ struct sk_buff *skb;
+
+ while ((skb = skb_dequeue(&sock->sk_receive_queue)) != NULL)
+ kfree_skb(skb);
+ }
+#endif
+ io_free_file_tables(&ctx->file_table);
+ io_file_table_set_alloc_range(ctx, 0, 0);
+ io_rsrc_data_free(ctx->file_data);
+ ctx->file_data = NULL;
+ ctx->nr_user_files = 0;
+}
+
+int io_sqe_files_unregister(struct io_ring_ctx *ctx)
+{
+ unsigned nr = ctx->nr_user_files;
+ int ret;
+
+ if (!ctx->file_data)
+ return -ENXIO;
+
+ /*
+ * Quiesce may unlock ->uring_lock, and while it's not held
+ * prevent new requests using the table.
+ */
+ ctx->nr_user_files = 0;
+ ret = io_rsrc_ref_quiesce(ctx->file_data, ctx);
+ ctx->nr_user_files = nr;
+ if (!ret)
+ __io_sqe_files_unregister(ctx);
+ return ret;
+}
+
+/*
+ * Ensure the UNIX gc is aware of our file set, so we are certain that
+ * the io_uring can be safely unregistered on process exit, even if we have
+ * loops in the file referencing. We account only files that can hold other
+ * files because otherwise they can't form a loop and so are not interesting
+ * for GC.
+ */
+int __io_scm_file_account(struct io_ring_ctx *ctx, struct file *file)
+{
+#if defined(CONFIG_UNIX)
+ struct sock *sk = ctx->ring_sock->sk;
+ struct sk_buff_head *head = &sk->sk_receive_queue;
+ struct scm_fp_list *fpl;
+ struct sk_buff *skb;
+
+ if (likely(!io_file_need_scm(file)))
+ return 0;
+
+ /*
+ * See if we can merge this file into an existing skb SCM_RIGHTS
+ * file set. If there's no room, fall back to allocating a new skb
+ * and filling it in.
+ */
+ spin_lock_irq(&head->lock);
+ skb = skb_peek(head);
+ if (skb && UNIXCB(skb).fp->count < SCM_MAX_FD)
+ __skb_unlink(skb, head);
+ else
+ skb = NULL;
+ spin_unlock_irq(&head->lock);
+
+ if (!skb) {
+ fpl = kzalloc(sizeof(*fpl), GFP_KERNEL);
+ if (!fpl)
+ return -ENOMEM;
+
+ skb = alloc_skb(0, GFP_KERNEL);
+ if (!skb) {
+ kfree(fpl);
+ return -ENOMEM;
+ }
+
+ fpl->user = get_uid(current_user());
+ fpl->max = SCM_MAX_FD;
+ fpl->count = 0;
+
+ UNIXCB(skb).fp = fpl;
+ skb->sk = sk;
+ skb->scm_io_uring = 1;
+ skb->destructor = unix_destruct_scm;
+ refcount_add(skb->truesize, &sk->sk_wmem_alloc);
+ }
+
+ fpl = UNIXCB(skb).fp;
+ fpl->fp[fpl->count++] = get_file(file);
+ unix_inflight(fpl->user, file);
+ skb_queue_head(head, skb);
+ fput(file);
+#endif
+ return 0;
+}
+
+static void io_rsrc_file_put(struct io_ring_ctx *ctx, struct io_rsrc_put *prsrc)
+{
+ struct file *file = prsrc->file;
+#if defined(CONFIG_UNIX)
+ struct sock *sock = ctx->ring_sock->sk;
+ struct sk_buff_head list, *head = &sock->sk_receive_queue;
+ struct sk_buff *skb;
+ int i;
+
+ if (!io_file_need_scm(file)) {
+ fput(file);
+ return;
+ }
+
+ __skb_queue_head_init(&list);
+
+ /*
+ * Find the skb that holds this file in its SCM_RIGHTS. When found,
+ * remove this entry and rearrange the file array.
+ */
+ skb = skb_dequeue(head);
+ while (skb) {
+ struct scm_fp_list *fp;
+
+ fp = UNIXCB(skb).fp;
+ for (i = 0; i < fp->count; i++) {
+ int left;
+
+ if (fp->fp[i] != file)
+ continue;
+
+ unix_notinflight(fp->user, fp->fp[i]);
+ left = fp->count - 1 - i;
+ if (left) {
+ memmove(&fp->fp[i], &fp->fp[i + 1],
+ left * sizeof(struct file *));
+ }
+ fp->count--;
+ if (!fp->count) {
+ kfree_skb(skb);
+ skb = NULL;
+ } else {
+ __skb_queue_tail(&list, skb);
+ }
+ fput(file);
+ file = NULL;
+ break;
+ }
+
+ if (!file)
+ break;
+
+ __skb_queue_tail(&list, skb);
+
+ skb = skb_dequeue(head);
+ }
+
+ if (skb_peek(&list)) {
+ spin_lock_irq(&head->lock);
+ while ((skb = __skb_dequeue(&list)) != NULL)
+ __skb_queue_tail(head, skb);
+ spin_unlock_irq(&head->lock);
+ }
+#else
+ fput(file);
+#endif
+}
+
+int io_sqe_files_register(struct io_ring_ctx *ctx, void __user *arg,
+ unsigned nr_args, u64 __user *tags)
+{
+ __s32 __user *fds = (__s32 __user *) arg;
+ struct file *file;
+ int fd, ret;
+ unsigned i;
+
+ if (ctx->file_data)
+ return -EBUSY;
+ if (!nr_args)
+ return -EINVAL;
+ if (nr_args > IORING_MAX_FIXED_FILES)
+ return -EMFILE;
+ if (nr_args > rlimit(RLIMIT_NOFILE))
+ return -EMFILE;
+ ret = io_rsrc_node_switch_start(ctx);
+ if (ret)
+ return ret;
+ ret = io_rsrc_data_alloc(ctx, io_rsrc_file_put, tags, nr_args,
+ &ctx->file_data);
+ if (ret)
+ return ret;
+
+ if (!io_alloc_file_tables(&ctx->file_table, nr_args)) {
+ io_rsrc_data_free(ctx->file_data);
+ ctx->file_data = NULL;
+ return -ENOMEM;
+ }
+
+ for (i = 0; i < nr_args; i++, ctx->nr_user_files++) {
+ struct io_fixed_file *file_slot;
+
+ if (fds && copy_from_user(&fd, &fds[i], sizeof(fd))) {
+ ret = -EFAULT;
+ goto fail;
+ }
+ /* allow sparse sets */
+ if (!fds || fd == -1) {
+ ret = -EINVAL;
+ if (unlikely(*io_get_tag_slot(ctx->file_data, i)))
+ goto fail;
+ continue;
+ }
+
+ file = fget(fd);
+ ret = -EBADF;
+ if (unlikely(!file))
+ goto fail;
+
+ /*
+ * Don't allow io_uring instances to be registered. If UNIX
+ * isn't enabled, then this causes a reference cycle and this
+ * instance can never get freed. If UNIX is enabled we'll
+ * handle it just fine, but there's still no point in allowing
+ * a ring fd as it doesn't support regular read/write anyway.
+ */
+ if (io_is_uring_fops(file)) {
+ fput(file);
+ goto fail;
+ }
+ ret = io_scm_file_account(ctx, file);
+ if (ret) {
+ fput(file);
+ goto fail;
+ }
+ file_slot = io_fixed_file_slot(&ctx->file_table, i);
+ io_fixed_file_set(file_slot, file);
+ io_file_bitmap_set(&ctx->file_table, i);
+ }
+
+ /* default it to the whole table */
+ io_file_table_set_alloc_range(ctx, 0, ctx->nr_user_files);
+ io_rsrc_node_switch(ctx, NULL);
+ return 0;
+fail:
+ __io_sqe_files_unregister(ctx);
+ return ret;
+}
+
+static void io_rsrc_buf_put(struct io_ring_ctx *ctx, struct io_rsrc_put *prsrc)
+{
+ io_buffer_unmap(ctx, &prsrc->buf);
+ prsrc->buf = NULL;
+}
+
+void __io_sqe_buffers_unregister(struct io_ring_ctx *ctx)
+{
+ unsigned int i;
+
+ for (i = 0; i < ctx->nr_user_bufs; i++)
+ io_buffer_unmap(ctx, &ctx->user_bufs[i]);
+ kfree(ctx->user_bufs);
+ io_rsrc_data_free(ctx->buf_data);
+ ctx->user_bufs = NULL;
+ ctx->buf_data = NULL;
+ ctx->nr_user_bufs = 0;
+}
+
+int io_sqe_buffers_unregister(struct io_ring_ctx *ctx)
+{
+ unsigned nr = ctx->nr_user_bufs;
+ int ret;
+
+ if (!ctx->buf_data)
+ return -ENXIO;
+
+ /*
+ * Quiesce may unlock ->uring_lock, and while it's not held
+ * prevent new requests using the table.
+ */
+ ctx->nr_user_bufs = 0;
+ ret = io_rsrc_ref_quiesce(ctx->buf_data, ctx);
+ ctx->nr_user_bufs = nr;
+ if (!ret)
+ __io_sqe_buffers_unregister(ctx);
+ return ret;
+}
+
+/*
+ * Not super efficient, but this is just a registration time. And we do cache
+ * the last compound head, so generally we'll only do a full search if we don't
+ * match that one.
+ *
+ * We check if the given compound head page has already been accounted, to
+ * avoid double accounting it. This allows us to account the full size of the
+ * page, not just the constituent pages of a huge page.
+ */
+static bool headpage_already_acct(struct io_ring_ctx *ctx, struct page **pages,
+ int nr_pages, struct page *hpage)
+{
+ int i, j;
+
+ /* check current page array */
+ for (i = 0; i < nr_pages; i++) {
+ if (!PageCompound(pages[i]))
+ continue;
+ if (compound_head(pages[i]) == hpage)
+ return true;
+ }
+
+ /* check previously registered pages */
+ for (i = 0; i < ctx->nr_user_bufs; i++) {
+ struct io_mapped_ubuf *imu = ctx->user_bufs[i];
+
+ for (j = 0; j < imu->nr_bvecs; j++) {
+ if (!PageCompound(imu->bvec[j].bv_page))
+ continue;
+ if (compound_head(imu->bvec[j].bv_page) == hpage)
+ return true;
+ }
+ }
+
+ return false;
+}
+
+static int io_buffer_account_pin(struct io_ring_ctx *ctx, struct page **pages,
+ int nr_pages, struct io_mapped_ubuf *imu,
+ struct page **last_hpage)
+{
+ int i, ret;
+
+ imu->acct_pages = 0;
+ for (i = 0; i < nr_pages; i++) {
+ if (!PageCompound(pages[i])) {
+ imu->acct_pages++;
+ } else {
+ struct page *hpage;
+
+ hpage = compound_head(pages[i]);
+ if (hpage == *last_hpage)
+ continue;
+ *last_hpage = hpage;
+ if (headpage_already_acct(ctx, pages, i, hpage))
+ continue;
+ imu->acct_pages += page_size(hpage) >> PAGE_SHIFT;
+ }
+ }
+
+ if (!imu->acct_pages)
+ return 0;
+
+ ret = io_account_mem(ctx, imu->acct_pages);
+ if (ret)
+ imu->acct_pages = 0;
+ return ret;
+}
+
+struct page **io_pin_pages(unsigned long ubuf, unsigned long len, int *npages)
+{
+ unsigned long start, end, nr_pages;
+ struct vm_area_struct **vmas = NULL;
+ struct page **pages = NULL;
+ int i, pret, ret = -ENOMEM;
+
+ end = (ubuf + len + PAGE_SIZE - 1) >> PAGE_SHIFT;
+ start = ubuf >> PAGE_SHIFT;
+ nr_pages = end - start;
+
+ pages = kvmalloc_array(nr_pages, sizeof(struct page *), GFP_KERNEL);
+ if (!pages)
+ goto done;
+
+ vmas = kvmalloc_array(nr_pages, sizeof(struct vm_area_struct *),
+ GFP_KERNEL);
+ if (!vmas)
+ goto done;
+
+ ret = 0;
+ mmap_read_lock(current->mm);
+ pret = pin_user_pages(ubuf, nr_pages, FOLL_WRITE | FOLL_LONGTERM,
+ pages, vmas);
+ if (pret == nr_pages) {
+ struct file *file = vmas[0]->vm_file;
+
+ /* don't support file backed memory */
+ for (i = 0; i < nr_pages; i++) {
+ if (vmas[i]->vm_file != file) {
+ ret = -EINVAL;
+ break;
+ }
+ if (!file)
+ continue;
+ if (!vma_is_shmem(vmas[i]) && !is_file_hugepages(file)) {
+ ret = -EOPNOTSUPP;
+ break;
+ }
+ }
+ *npages = nr_pages;
+ } else {
+ ret = pret < 0 ? pret : -EFAULT;
+ }
+ mmap_read_unlock(current->mm);
+ if (ret) {
+ /*
+ * if we did partial map, or found file backed vmas,
+ * release any pages we did get
+ */
+ if (pret > 0)
+ unpin_user_pages(pages, pret);
+ goto done;
+ }
+ ret = 0;
+done:
+ kvfree(vmas);
+ if (ret < 0) {
+ kvfree(pages);
+ pages = ERR_PTR(ret);
+ }
+ return pages;
+}
+
+static int io_sqe_buffer_register(struct io_ring_ctx *ctx, struct iovec *iov,
+ struct io_mapped_ubuf **pimu,
+ struct page **last_hpage)
+{
+ struct io_mapped_ubuf *imu = NULL;
+ struct page **pages = NULL;
+ unsigned long off;
+ size_t size;
+ int ret, nr_pages, i;
+
+ *pimu = ctx->dummy_ubuf;
+ if (!iov->iov_base)
+ return 0;
+
+ ret = -ENOMEM;
+ pages = io_pin_pages((unsigned long) iov->iov_base, iov->iov_len,
+ &nr_pages);
+ if (IS_ERR(pages)) {
+ ret = PTR_ERR(pages);
+ pages = NULL;
+ goto done;
+ }
+
+ imu = kvmalloc(struct_size(imu, bvec, nr_pages), GFP_KERNEL);
+ if (!imu)
+ goto done;
+
+ ret = io_buffer_account_pin(ctx, pages, nr_pages, imu, last_hpage);
+ if (ret) {
+ unpin_user_pages(pages, nr_pages);
+ goto done;
+ }
+
+ off = (unsigned long) iov->iov_base & ~PAGE_MASK;
+ size = iov->iov_len;
+ for (i = 0; i < nr_pages; i++) {
+ size_t vec_len;
+
+ vec_len = min_t(size_t, size, PAGE_SIZE - off);
+ imu->bvec[i].bv_page = pages[i];
+ imu->bvec[i].bv_len = vec_len;
+ imu->bvec[i].bv_offset = off;
+ off = 0;
+ size -= vec_len;
+ }
+ /* store original address for later verification */
+ imu->ubuf = (unsigned long) iov->iov_base;
+ imu->ubuf_end = imu->ubuf + iov->iov_len;
+ imu->nr_bvecs = nr_pages;
+ *pimu = imu;
+ ret = 0;
+done:
+ if (ret)
+ kvfree(imu);
+ kvfree(pages);
+ return ret;
+}
+
+static int io_buffers_map_alloc(struct io_ring_ctx *ctx, unsigned int nr_args)
+{
+ ctx->user_bufs = kcalloc(nr_args, sizeof(*ctx->user_bufs), GFP_KERNEL);
+ return ctx->user_bufs ? 0 : -ENOMEM;
+}
+
+int io_sqe_buffers_register(struct io_ring_ctx *ctx, void __user *arg,
+ unsigned int nr_args, u64 __user *tags)
+{
+ struct page *last_hpage = NULL;
+ struct io_rsrc_data *data;
+ int i, ret;
+ struct iovec iov;
+
+ BUILD_BUG_ON(IORING_MAX_REG_BUFFERS >= (1u << 16));
+
+ if (ctx->user_bufs)
+ return -EBUSY;
+ if (!nr_args || nr_args > IORING_MAX_REG_BUFFERS)
+ return -EINVAL;
+ ret = io_rsrc_node_switch_start(ctx);
+ if (ret)
+ return ret;
+ ret = io_rsrc_data_alloc(ctx, io_rsrc_buf_put, tags, nr_args, &data);
+ if (ret)
+ return ret;
+ ret = io_buffers_map_alloc(ctx, nr_args);
+ if (ret) {
+ io_rsrc_data_free(data);
+ return ret;
+ }
+
+ for (i = 0; i < nr_args; i++, ctx->nr_user_bufs++) {
+ if (arg) {
+ ret = io_copy_iov(ctx, &iov, arg, i);
+ if (ret)
+ break;
+ ret = io_buffer_validate(&iov);
+ if (ret)
+ break;
+ } else {
+ memset(&iov, 0, sizeof(iov));
+ }
+
+ if (!iov.iov_base && *io_get_tag_slot(data, i)) {
+ ret = -EINVAL;
+ break;
+ }
+
+ ret = io_sqe_buffer_register(ctx, &iov, &ctx->user_bufs[i],
+ &last_hpage);
+ if (ret)
+ break;
+ }
+
+ WARN_ON_ONCE(ctx->buf_data);
+
+ ctx->buf_data = data;
+ if (ret)
+ __io_sqe_buffers_unregister(ctx);
+ else
+ io_rsrc_node_switch(ctx, NULL);
+ return ret;
+}
+
+int io_import_fixed(int ddir, struct iov_iter *iter,
+ struct io_mapped_ubuf *imu,
+ u64 buf_addr, size_t len)
+{
+ u64 buf_end;
+ size_t offset;
+
+ if (WARN_ON_ONCE(!imu))
+ return -EFAULT;
+ if (unlikely(check_add_overflow(buf_addr, (u64)len, &buf_end)))
+ return -EFAULT;
+ /* not inside the mapped region */
+ if (unlikely(buf_addr < imu->ubuf || buf_end > imu->ubuf_end))
+ return -EFAULT;
+
+ /*
+ * May not be a start of buffer, set size appropriately
+ * and advance us to the beginning.
+ */
+ offset = buf_addr - imu->ubuf;
+ iov_iter_bvec(iter, ddir, imu->bvec, imu->nr_bvecs, offset + len);
+
+ if (offset) {
+ /*
+ * Don't use iov_iter_advance() here, as it's really slow for
+ * using the latter parts of a big fixed buffer - it iterates
+ * over each segment manually. We can cheat a bit here, because
+ * we know that:
+ *
+ * 1) it's a BVEC iter, we set it up
+ * 2) all bvecs are PAGE_SIZE in size, except potentially the
+ * first and last bvec
+ *
+ * So just find our index, and adjust the iterator afterwards.
+ * If the offset is within the first bvec (or the whole first
+ * bvec, just use iov_iter_advance(). This makes it easier
+ * since we can just skip the first segment, which may not
+ * be PAGE_SIZE aligned.
+ */
+ const struct bio_vec *bvec = imu->bvec;
+
+ if (offset < bvec->bv_len) {
+ iov_iter_advance(iter, offset);
+ } else {
+ unsigned long seg_skip;
+
+ /* skip first vec */
+ offset -= bvec->bv_len;
+ seg_skip = 1 + (offset >> PAGE_SHIFT);
+
+ iter->bvec = bvec + seg_skip;
+ iter->nr_segs -= seg_skip;
+ iter->count -= bvec->bv_len + offset;
+ iter->iov_offset = offset & ~PAGE_MASK;
+ }
+ }
+
+ return 0;
+}