linux-kernel - Re: [PATCHv5 2/3] virtio_console: Add support for remoteproc serial

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <87haqk4a13.fsf@rustcorp.com.au>
Date:	Thu, 27 Sep 2012 09:22:24 +0930
From:	Rusty Russell <rusty@...tcorp.com.au>
To:	sjur.brandeland@...ricsson.com, Amit Shah <amit.shah@...hat.com>
Cc:	linux-kernel@...r.kernel.org,
	virtualization@...ts.linux-foundation.org, sjurbren@...ricsson.com,
	Sjur Brændeland <sjur.brandeland@...ricsson.com>,
	"Michael S. Tsirkin" <mst@...hat.com>,
	Ohad Ben-Cohen <ohad@...ery.com>,
	Linus Walleij <linus.walleij@...aro.org>,
	Arnd Bergmann <arnd@...db.de>
Subject: Re: [PATCHv5 2/3] virtio_console: Add support for remoteproc serial

sjur.brandeland@...ricsson.com writes:
> From: Sjur Brændeland <sjur.brandeland@...ricsson.com>
>
> Add a simple serial connection driver called
> VIRTIO_ID_RPROC_SERIAL (11) for communicating with a
> remote processor in an asymmetric multi-processing
> configuration.
>
...
>  static struct port_buffer *alloc_buf(struct virtqueue *vq, size_t buf_size,
>  				     int nrbufs)
>  {
>  	struct port_buffer *buf;
>  	size_t alloc_size;
>  
> +	if (is_rproc_serial(vq->vdev) && !irqs_disabled())
> +		reclaim_dma_bufs();

Hmm, you need a gfp_t arg into alloc_buf; your last patch simply changed
them all to GFP_ATOMIC, which makes the console far less memory
friendly.

You check !irqs_disabled() in a couple of places; I think the caller
needs to indicate (possibly by checking for gfp == GFP_KERNEL) whether
it's safe to call reclaim_dma_bufs().

> @@ -838,6 +927,10 @@ static ssize_t port_fops_splice_write(struct pipe_inode_info *pipe,
>  		.u.data = &sgl,
>  	};
>  
> +	/* rproc_serial does not support splice */
> +	if (is_rproc_serial(port->out_vq->vdev))
> +		return -EINVAL;

Why not? ;)

Thanks,
Rusty.
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/