1 // SPDX-License-Identifier: GPL-2.0 2 3 #include "linux/io_uring/query.h" 4 5 #include "query.h" 6 #include "io_uring.h" 7 8 #define IO_MAX_QUERY_SIZE (sizeof(struct io_uring_query_opcode)) 9 10 static ssize_t io_query_ops(void *data) 11 { 12 struct io_uring_query_opcode *e = data; 13 14 BUILD_BUG_ON(sizeof(*e) > IO_MAX_QUERY_SIZE); 15 16 e->nr_request_opcodes = IORING_OP_LAST; 17 e->nr_register_opcodes = IORING_REGISTER_LAST; 18 e->feature_flags = IORING_FEAT_FLAGS; 19 e->ring_setup_flags = IORING_SETUP_FLAGS; 20 e->enter_flags = IORING_ENTER_FLAGS; 21 e->sqe_flags = SQE_VALID_FLAGS; 22 return sizeof(*e); 23 } 24 25 static int io_handle_query_entry(struct io_ring_ctx *ctx, 26 void *data, void __user *uhdr, 27 u64 *next_entry) 28 { 29 struct io_uring_query_hdr hdr; 30 size_t usize, res_size = 0; 31 ssize_t ret = -EINVAL; 32 void __user *udata; 33 34 if (copy_from_user(&hdr, uhdr, sizeof(hdr))) 35 return -EFAULT; 36 usize = hdr.size; 37 hdr.size = min(hdr.size, IO_MAX_QUERY_SIZE); 38 udata = u64_to_user_ptr(hdr.query_data); 39 40 if (hdr.query_op >= __IO_URING_QUERY_MAX) { 41 ret = -EOPNOTSUPP; 42 goto out; 43 } 44 if (!mem_is_zero(hdr.__resv, sizeof(hdr.__resv)) || hdr.result || !hdr.size) 45 goto out; 46 if (copy_from_user(data, udata, hdr.size)) 47 return -EFAULT; 48 49 switch (hdr.query_op) { 50 case IO_URING_QUERY_OPCODES: 51 ret = io_query_ops(data); 52 break; 53 } 54 55 if (ret >= 0) { 56 if (WARN_ON_ONCE(ret > IO_MAX_QUERY_SIZE)) 57 return -EFAULT; 58 res_size = ret; 59 ret = 0; 60 } 61 out: 62 hdr.result = ret; 63 hdr.size = min_t(size_t, usize, res_size); 64 65 if (copy_struct_to_user(udata, usize, data, hdr.size, NULL)) 66 return -EFAULT; 67 if (copy_to_user(uhdr, &hdr, sizeof(hdr))) 68 return -EFAULT; 69 *next_entry = hdr.next_entry; 70 return 0; 71 } 72 73 int io_query(struct io_ring_ctx *ctx, void __user *arg, unsigned nr_args) 74 { 75 char entry_buffer[IO_MAX_QUERY_SIZE]; 76 void __user *uhdr = arg; 77 int ret; 78 79 memset(entry_buffer, 0, sizeof(entry_buffer)); 80 81 if (nr_args) 82 return -EINVAL; 83 84 while (uhdr) { 85 u64 next_hdr; 86 87 ret = io_handle_query_entry(ctx, entry_buffer, uhdr, &next_hdr); 88 if (ret) 89 return ret; 90 uhdr = u64_to_user_ptr(next_hdr); 91 } 92 return 0; 93 } 94