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// 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_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_REG_IMPORT;
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->__resv1 = 0;
e->__resv2 = 0;
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;
switch (hdr.query_op) {
case IO_URING_QUERY_OPCODES:
ret = io_query_ops(data);
break;
case IO_URING_QUERY_ZCRX:
ret = io_query_zcrx(data);
break;
case IO_URING_QUERY_SCQ:
ret = io_query_scq(data);
break;
}
if (ret >= 0) {
if (WARN_ON_ONCE(ret > IO_MAX_QUERY_SIZE))
return -EFAULT;
res_size = ret;
ret = 0;
}
out:
hdr.result = ret;
hdr.size = min_t(size_t, usize, res_size);
if (copy_struct_to_user(udata, usize, data, hdr.size, NULL))
return -EFAULT;
if (copy_to_user(uhdr, &hdr, sizeof(hdr)))
return -EFAULT;
*next_entry = hdr.next_entry;
return 0;
}
int io_query(void __user *arg, unsigned nr_args)
{
union io_query_data entry_buffer;
void __user *uhdr = arg;
int ret, nr = 0;
memset(&entry_buffer, 0, sizeof(entry_buffer));
if (nr_args)
return -EINVAL;
while (uhdr) {
u64 next_hdr;
ret = io_handle_query_entry(&entry_buffer, uhdr, &next_hdr);
if (ret)
return ret;
uhdr = u64_to_user_ptr(next_hdr);
/* Have some limit to avoid a potential cycle */
if (++nr >= IO_MAX_QUERY_ENTRIES)
return -ERANGE;
if (fatal_signal_pending(current))
return -EINTR;
cond_resched();
}
return 0;
}
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