Re: [PATCH] Fix vq_memory_access_ok error checking

From: Michael S. Tsirkin
Date: Wed Apr 07 2010 - 03:53:20 EST

On Tue, Apr 06, 2010 at 04:14:14PM -0400, Jeff Dike wrote:
> Here's another small patch fixing an error path...
> Jeff
> --
> Work email - jdike at linux dot intel dot com
> commit 7938779d9f357ede8bc3c122fd0dc9d5ec4fcf1d
> Author: Jeff Dike <jdike@xxxxxxxxxxx>
> Date: Wed Mar 31 15:05:08 2010 -0400
> vq_memory_access_ok needs to check whether mem == NULL

Can you add a Signed-off-by line?

The sign-off is a simple line at the end of the explanation for the
patch, which certifies that you wrote it or otherwise have the right to
pass it on as a open-source patch. The rules are pretty simple: if you
can certify the below:

Developer's Certificate of Origin 1.1

By making a contribution to this project, I certify that:

(a) The contribution was created in whole or in part by me and I
have the right to submit it under the open source license
indicated in the file; or

(b) The contribution is based upon previous work that, to the best
of my knowledge, is covered under an appropriate open source
license and I have the right under that license to submit that
work with modifications, whether created in whole or in part
by me, under the same open source license (unless I am
permitted to submit under a different license), as indicated
in the file; or

(c) The contribution was provided directly to me by some other
person who certified (a), (b) or (c) and I have not modified

(d) I understand and agree that this project and the contribution
are public and that a record of the contribution (including all
personal information I submit with it, including my sign-off) is
maintained indefinitely and may be redistributed consistent with
this project or the open source license(s) involved.

then you just add a line saying

Signed-off-by: Random J Developer <random@xxxxxxxxxxxxxxxxxxxxx>

> diff --git a/drivers/vhost/vhost.c b/drivers/vhost/vhost.c
> index 7bd7a1e..b8e1127 100644
> --- a/drivers/vhost/vhost.c
> +++ b/drivers/vhost/vhost.c
> @@ -235,6 +235,10 @@ static int vq_memory_access_ok(void __user *log_base, struct vhost_memory *mem,
> int log_all)
> {
> int i;
> +
> + if (!mem)
> + return 0;
> +
> for (i = 0; i < mem->nregions; ++i) {
> struct vhost_memory_region *m = mem->regions + i;
> unsigned long a = m->userspace_addr;
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