| // 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; |
| } |