io_uring/query.c

Source file repositories/reference/linux-study-clean/io_uring/query.c

File Facts

System
Linux kernel
Corpus path
io_uring/query.c
Extension
.c
Size
3650 bytes
Lines
153
Domain
Kernel Services
Bucket
io_uring
Inferred role
Kernel Services: implementation source
Status
source implementation candidate

Why This File Exists

Shared kernel service surface used by multiple subsystems, including helpers, cryptography, virtualization support, and async I/O infrastructure.

Dependency Surface

Detected Declarations

Annotated Snippet

// SPDX-License-Identifier: GPL-2.0

#include "linux/io_uring/query.h"

#include "query.h"
#include "io_uring.h"
#include "zcrx.h"

union io_query_data {
	struct io_uring_query_opcode opcodes;
	struct io_uring_query_zcrx zcrx;
	struct io_uring_query_zcrx_notif zcrx_notif;
	struct io_uring_query_scq scq;
};

#define IO_MAX_QUERY_SIZE		sizeof(union io_query_data)
#define IO_MAX_QUERY_ENTRIES		1000

static ssize_t io_query_ops(union io_query_data *data)
{
	struct io_uring_query_opcode *e = &data->opcodes;

	e->nr_request_opcodes = IORING_OP_LAST;
	e->nr_register_opcodes = IORING_REGISTER_LAST;
	e->feature_flags = IORING_FEAT_FLAGS;
	e->ring_setup_flags = IORING_SETUP_FLAGS;
	e->enter_flags = IORING_ENTER_FLAGS;
	e->sqe_flags = SQE_VALID_FLAGS;
	e->nr_query_opcodes = __IO_URING_QUERY_MAX;
	e->__pad = 0;
	return sizeof(*e);
}

static ssize_t io_query_zcrx(union io_query_data *data)
{
	struct io_uring_query_zcrx *e = &data->zcrx;

	e->register_flags = ZCRX_SUPPORTED_REG_FLAGS;
	e->area_flags = IORING_ZCRX_AREA_DMABUF;
	e->nr_ctrl_opcodes = __ZCRX_CTRL_LAST;
	e->rq_hdr_size = sizeof(struct io_uring);
	e->rq_hdr_alignment = L1_CACHE_BYTES;
	e->features = ZCRX_FEATURES;
	e->__resv2 = 0;
	return sizeof(*e);
}

static ssize_t io_query_zcrx_notif(union io_query_data *data)
{
	struct io_uring_query_zcrx_notif *e = &data->zcrx_notif;

	e->notif_flags = ZCRX_NOTIF_TYPE_MASK;
	e->notif_stats_size = sizeof(struct zcrx_notif_stats);
	e->notif_stats_off_alignment = __alignof__(struct zcrx_notif_stats);
	e->__resv1 = 0;
	memset(&e->__resv2, 0, sizeof(e->__resv2));
	return sizeof(*e);
}

static ssize_t io_query_scq(union io_query_data *data)
{
	struct io_uring_query_scq *e = &data->scq;

	e->hdr_size = sizeof(struct io_rings);
	e->hdr_alignment = SMP_CACHE_BYTES;
	return sizeof(*e);
}

static int io_handle_query_entry(union io_query_data *data, void __user *uhdr,
				 u64 *next_entry)
{
	struct io_uring_query_hdr hdr;
	size_t usize, res_size = 0;
	ssize_t ret = -EINVAL;
	void __user *udata;

	if (copy_from_user(&hdr, uhdr, sizeof(hdr)))
		return -EFAULT;
	usize = hdr.size;
	hdr.size = min(hdr.size, IO_MAX_QUERY_SIZE);
	udata = u64_to_user_ptr(hdr.query_data);

	if (hdr.query_op >= __IO_URING_QUERY_MAX) {
		ret = -EOPNOTSUPP;
		goto out;
	}
	if (!mem_is_zero(hdr.__resv, sizeof(hdr.__resv)) || hdr.result || !hdr.size)
		goto out;
	if (copy_from_user(data, udata, hdr.size))
		return -EFAULT;

Annotation

Implementation Notes