Re: [PATCHv7 2/4] virtio_console: Use kmalloc instead of kzalloc

From: Rusty Russell
Date: Mon Oct 22 2012 - 22:01:07 EST


sjur.brandeland@xxxxxxxxxxxxxx writes:

> From: Sjur BrÃndeland <sjur.brandeland@xxxxxxxxxxxxxx>
>
> Avoid the more cpu expensive kzalloc when allocating buffers.
> Originally kzalloc was intended for isolating the guest from
> the host by not sending random guest data to the host. But device
> isolation is not yet in place so kzalloc is not really needed.
>
> Signed-off-by: Sjur BrÃndeland <sjur.brandeland@xxxxxxxxxxxxxx>

This looks fine to me. This is *why* the device gives us the length
which was written; we can trust that, even if we can't trust the
writer of data.

(In theory: noone has implemented such a system, yet).

Applied.
Rusty.

> diff --git a/drivers/char/virtio_console.c b/drivers/char/virtio_console.c
> index c36b2f6..301d17e 100644
> --- a/drivers/char/virtio_console.c
> +++ b/drivers/char/virtio_console.c
> @@ -349,7 +349,7 @@ static struct port_buffer *alloc_buf(size_t buf_size)
> buf = kmalloc(sizeof(*buf), GFP_KERNEL);
> if (!buf)
> goto fail;
> - buf->buf = kzalloc(buf_size, GFP_KERNEL);
> + buf->buf = kmalloc(buf_size, GFP_KERNEL);
> if (!buf->buf)
> goto free_buf;
> buf->len = 0;
> --
> 1.7.5.4
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