Commit 21bd7b14 authored by Pavel Begunkov's avatar Pavel Begunkov Committed by Jens Axboe
Browse files

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: default avatarPavel Begunkov <asml.silence@gmail.com>
Signed-off-by: default avatarJens Axboe <axboe@kernel.dk>
parent b6c5f945

io_uring/query.c

+11 −9
Original line number Diff line number Diff line
@@ -5,14 +5,16 @@ 
#include "query.h"

#include "io_uring.h"



#define IO_MAX_QUERY_SIZE		(sizeof(struct io_uring_query_opcode))

union io_query_data {

	struct io_uring_query_opcode opcodes;

};



#define IO_MAX_QUERY_SIZE		sizeof(union io_query_data)

#define IO_MAX_QUERY_ENTRIES		1000



static ssize_t io_query_ops(void *data)

static ssize_t io_query_ops(union io_query_data *data)

{

	struct io_uring_query_opcode *e = data;



	BUILD_BUG_ON(sizeof(*e) > IO_MAX_QUERY_SIZE);

	struct io_uring_query_opcode *e = &data->opcodes;



	e->nr_request_opcodes = IORING_OP_LAST;

	e->nr_register_opcodes = IORING_REGISTER_LAST;
@@ -24,7 +26,7 @@ static ssize_t io_query_ops(void *data) 
}



static int io_handle_query_entry(struct io_ring_ctx *ctx,

				 void *data, void __user *uhdr,

				 union io_query_data *data, void __user *uhdr,

				 u64 *next_entry)

{

	struct io_uring_query_hdr hdr;
@@ -73,11 +75,11 @@ static int io_handle_query_entry(struct io_ring_ctx *ctx, 


int io_query(struct io_ring_ctx *ctx, void __user *arg, unsigned nr_args)

{

	char entry_buffer[IO_MAX_QUERY_SIZE];

	union io_query_data entry_buffer;

	void __user *uhdr = arg;

	int ret, nr = 0;



	memset(entry_buffer, 0, sizeof(entry_buffer));

	memset(&entry_buffer, 0, sizeof(entry_buffer));



	if (nr_args)

		return -EINVAL;
@@ -85,7 +87,7 @@ int io_query(struct io_ring_ctx *ctx, void __user *arg, unsigned nr_args) 
	while (uhdr) {

		u64 next_hdr;



		ret = io_handle_query_entry(ctx, entry_buffer, uhdr, &next_hdr);

		ret = io_handle_query_entry(ctx, &entry_buffer, uhdr, &next_hdr);

		if (ret)

			return ret;

		uhdr = u64_to_user_ptr(next_hdr);