1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
|
// SPDX-License-Identifier: GPL-2.0
#include "linux/io_uring/query.h"
#include "query.h"
#include "io_uring.h"
#define IO_MAX_QUERY_SIZE (sizeof(struct io_uring_query_opcode))
#define IO_MAX_QUERY_ENTRIES 1000
static ssize_t io_query_ops(void *data)
{
struct io_uring_query_opcode *e = data;
BUILD_BUG_ON(sizeof(*e) > IO_MAX_QUERY_SIZE);
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;
return sizeof(*e);
}
static int io_handle_query_entry(struct io_ring_ctx *ctx,
void *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;
}
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(struct io_ring_ctx *ctx, void __user *arg, unsigned nr_args)
{
char entry_buffer[IO_MAX_QUERY_SIZE];
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(ctx, 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;
}
|
