On Tue, Jun 14, 2022 at 5:14 PM Dongliang Mu <dzm91@xxxxxxxxxxx> wrote:
>
> From: mudongliang <mudongliangabcd@xxxxxxxxx>
>
> kfree can handle NULL pointer as its argument.
> According to coccinelle isnullfree check, remove NULL check
> before kfree operation.
>
> Signed-off-by: mudongliang <mudongliangabcd@xxxxxxxxx>
> ---
> fs/io_uring.c | 15 +++++----------
> 1 file changed, 5 insertions(+), 10 deletions(-)
>
> diff --git a/fs/io_uring.c b/fs/io_uring.c
> index 3aab4182fd89..bec47eae2a9b 100644
> --- a/fs/io_uring.c
> +++ b/fs/io_uring.c
> @@ -3159,8 +3159,7 @@ static void io_free_batch_list(struct io_ring_ctx *ctx,
> if ((req->flags & REQ_F_POLLED) && req->apoll) {
> struct async_poll *apoll = req->apoll;
>
> - if (apoll->double_poll)
> - kfree(apoll->double_poll);
> + kfree(apoll->double_poll);
> list_add(&apoll->poll.wait.entry,
> &ctx->apoll_cache);
> req->flags &= ~REQ_F_POLLED;
> @@ -4499,8 +4498,7 @@ static int io_read(struct io_kiocb *req, unsigned int issue_flags)
> kiocb_done(req, ret, issue_flags);
> out_free:
> /* it's faster to check here then delegate to kfree */
I am feeling you are not on the right way. See the comment
here.
Thanks.
> - if (iovec)
> - kfree(iovec);
> + kfree(iovec);
> return 0;
> }
>
> @@ -4602,8 +4600,7 @@ static int io_write(struct io_kiocb *req, unsigned int issue_flags)
> }
> out_free:
> /* it's reportedly faster than delegating the null check to kfree() */
See here.
> - if (iovec)
> - kfree(iovec);
> + kfree(iovec);
> return ret;
> }
>
> @@ -6227,8 +6224,7 @@ static int io_sendmsg(struct io_kiocb *req, unsigned int issue_flags)
> req_set_fail(req);
> }
> /* fast path, check for non-NULL to avoid function call */
here.
> - if (kmsg->free_iov)
> - kfree(kmsg->free_iov);
> + kfree(kmsg->free_iov);
> req->flags &= ~REQ_F_NEED_CLEANUP;
> if (ret >= 0)
> ret += sr->done_io;
> @@ -6481,8 +6477,7 @@ static int io_recvmsg(struct io_kiocb *req, unsigned int issue_flags)
> }
>
> /* fast path, check for non-NULL to avoid function call */
And here.
> - if (kmsg->free_iov)
> - kfree(kmsg->free_iov);
> + kfree(kmsg->free_iov);
> req->flags &= ~REQ_F_NEED_CLEANUP;
> if (ret >= 0)
> ret += sr->done_io;
> --
> 2.35.1
>
