Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
io_uring/query: buffer size calculations with a union
Instead of having an array of a calculated size as a buffer, put all
query uapi structures into a union and pass that around. That way
everything is well typed, and the compiler will prevent opcode handling
using a structure not accounted into the buffer size.
Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
authored by
Pavel Begunkov
and committed by
Jens Axboe
21bd7b14
b6c5f945
+11
-9
+11
-9
io_uring/query.c
+11
-9
io_uring/query.c
···
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#include "query.h"
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#include "io_uring.h"
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#define IO_MAX_QUERY_SIZE (sizeof(struct io_uring_query_opcode))
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union io_query_data {
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struct io_uring_query_opcode opcodes;
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};
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#define IO_MAX_QUERY_SIZE sizeof(union io_query_data)
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#define IO_MAX_QUERY_ENTRIES 1000
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static ssize_t io_query_ops(void *data)
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static ssize_t io_query_ops(union io_query_data *data)
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{
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struct io_uring_query_opcode *e = data;
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BUILD_BUG_ON(sizeof(*e) > IO_MAX_QUERY_SIZE);
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struct io_uring_query_opcode *e = &data->opcodes;
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e->nr_request_opcodes = IORING_OP_LAST;
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e->nr_register_opcodes = IORING_REGISTER_LAST;
···
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}
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static int io_handle_query_entry(struct io_ring_ctx *ctx,
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void *data, void __user *uhdr,
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union io_query_data *data, void __user *uhdr,
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u64 *next_entry)
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{
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struct io_uring_query_hdr hdr;
···
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int io_query(struct io_ring_ctx *ctx, void __user *arg, unsigned nr_args)
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{
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char entry_buffer[IO_MAX_QUERY_SIZE];
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union io_query_data entry_buffer;
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void __user *uhdr = arg;
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int ret, nr = 0;
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memset(entry_buffer, 0, sizeof(entry_buffer));
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memset(&entry_buffer, 0, sizeof(entry_buffer));
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if (nr_args)
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return -EINVAL;
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while (uhdr) {
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u64 next_hdr;
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ret = io_handle_query_entry(ctx, entry_buffer, uhdr, &next_hdr);
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ret = io_handle_query_entry(ctx, &entry_buffer, uhdr, &next_hdr);
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if (ret)
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return ret;
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uhdr = u64_to_user_ptr(next_hdr);