// SPDX-License-Identifier: GPL-2.0#include <linux/kernel.h>#include <linux/errno.h>#include <linux/file.h>#include <linux/mm.h>#include <linux/slab.h>#include <linux/nospec.h>#include <linux/io_uring.h> #include <uapi/linux/io_uring.h> #include "io_uring.h"#include "rsrc.h"#include "filetable.h" static int io_file_bitmap_get(struct io_ring_ctx *ctx){	struct io_file_table *table = &ctx->file_table;	unsigned long nr = ctx->file_alloc_end;	int ret; 	if (!table->bitmap)		return -ENFILE; 	do {		ret = find_next_zero_bit(table->bitmap, nr, table->alloc_hint);		if (ret != nr)			return ret; 		if (table->alloc_hint == ctx->file_alloc_start)			break;		nr = table->alloc_hint;		table->alloc_hint = ctx->file_alloc_start;	} while (1); 	return -ENFILE;} bool io_alloc_file_tables(struct io_ring_ctx *ctx, struct io_file_table *table,			  unsigned nr_files){	if (io_rsrc_data_alloc(&table->data, nr_files))		return false;	table->bitmap = bitmap_zalloc(nr_files, GFP_KERNEL_ACCOUNT);	if (table->bitmap)		return true;	io_rsrc_data_free(ctx, &table->data);	return false;} void io_free_file_tables(struct io_ring_ctx *ctx, struct io_file_table *table){	io_rsrc_data_free(ctx, &table->data);	bitmap_free(table->bitmap);	table->bitmap = NULL;} static int io_install_fixed_file(struct io_ring_ctx *ctx, struct file *file,				 u32 slot_index)	__must_hold(&req->ctx->uring_lock){	struct io_rsrc_node *node; 	if (io_is_uring_fops(file))		return -EBADF;	if (!ctx->file_table.data.nr)		return -ENXIO;	if (slot_index >= ctx->file_table.data.nr)		return -EINVAL; 	node = io_rsrc_node_alloc(ctx, IORING_RSRC_FILE);	if (!node)		return -ENOMEM; 	if (!io_reset_rsrc_node(ctx, &ctx->file_table.data, slot_index))		io_file_bitmap_set(&ctx->file_table, slot_index); 	ctx->file_table.data.nodes[slot_index] = node;	io_fixed_file_set(node, file);	return 0;} int __io_fixed_fd_install(struct io_ring_ctx *ctx, struct file *file,			  unsigned int file_slot){	bool alloc_slot = file_slot == IORING_FILE_INDEX_ALLOC;	int ret; 	if (alloc_slot) {		ret = io_file_bitmap_get(ctx);		if (unlikely(ret < 0))			return ret;		file_slot = ret;	} else {		file_slot--;	} 	ret = io_install_fixed_file(ctx, file, file_slot);	if (!ret && alloc_slot)		ret = file_slot;	return ret;}/* * Note when io_fixed_fd_install() returns error value, it will ensure * fput() is called correspondingly. */int io_fixed_fd_install(struct io_kiocb *req, unsigned int issue_flags,			struct file *file, unsigned int file_slot){	struct io_ring_ctx *ctx = req->ctx;	int ret; 	io_ring_submit_lock(ctx, issue_flags);	ret = __io_fixed_fd_install(ctx, file, file_slot);	io_ring_submit_unlock(ctx, issue_flags); 	if (unlikely(ret < 0))		fput(file);	return ret;} int io_fixed_fd_remove(struct io_ring_ctx *ctx, unsigned int offset){	struct io_rsrc_node *node; 	if (unlikely(!ctx->file_table.data.nr))		return -ENXIO;	if (offset >= ctx->file_table.data.nr)		return -EINVAL; 	node = io_rsrc_node_lookup(&ctx->file_table.data, offset);	if (!node)		return -EBADF;	io_reset_rsrc_node(ctx, &ctx->file_table.data, offset);	io_file_bitmap_clear(&ctx->file_table, offset);	return 0;} int io_register_file_alloc_range(struct io_ring_ctx *ctx,				 struct io_uring_file_index_range __user *arg){	struct io_uring_file_index_range range;	u32 end; 	if (copy_from_user(&range, arg, sizeof(range)))		return -EFAULT;	if (check_add_overflow(range.off, range.len, &end))		return -EOVERFLOW;	if (range.resv || end > ctx->file_table.data.nr)		return -EINVAL; 	io_file_table_set_alloc_range(ctx, range.off, range.len);	return 0;}