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From:   Souptick Joarder <jrdr.linux@gmail.com>
Date:   Wed, 24 Jun 2020 07:11:54 +0530
Message-ID: <CAFqt6zYiiDpZE9poaEXShmWfqwjYYKa4tRqBhiaLMBPdvynWZg@mail.gmail.com>
Subject: Re: [PATCH] VMCI: Avoid extra check for access_ok()
To:     Arnd Bergmann <arnd@arndb.de>,
        Greg KH <gregkh@linuxfoundation.org>,
        Jason Gunthorpe <jgg@ziepe.ca>,
        Mike Marshall <hubcap@omnibond.com>,
        Daniel Vetter <daniel.vetter@ffwll.ch>, dvhart@infradead.org,
        sgarzare@redhat.com, Thomas Gleixner <tglx@linutronix.de>,
        Ira Weiny <ira.weiny@intel.com>
Cc:     linux-kernel@vger.kernel.org
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Sender: linux-kernel-owner@vger.kernel.org
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Hi Greg,

On Wed, May 6, 2020 at 1:40 AM Souptick Joarder <jrdr.linux@gmail.com> wrote:
>
> get_user_pages_fast() is already having a check for the same. This
> double check can be removed.
>
> Signed-off-by: Souptick Joarder <jrdr.linux@gmail.com>

Does this need to be marked as stable ?

> ---
>  drivers/misc/vmw_vmci/vmci_host.c | 2 --
>  1 file changed, 2 deletions(-)
>
> diff --git a/drivers/misc/vmw_vmci/vmci_host.c b/drivers/misc/vmw_vmci/vmci_host.c
> index ce16d6b..2d8328d9 100644
> --- a/drivers/misc/vmw_vmci/vmci_host.c
> +++ b/drivers/misc/vmw_vmci/vmci_host.c
> @@ -233,8 +233,6 @@ static int vmci_host_setup_notify(struct vmci_ctx *context,
>          * about the size.
>          */
>         BUILD_BUG_ON(sizeof(bool) != sizeof(u8));
> -       if (!access_ok((void __user *)uva, sizeof(u8)))
> -               return VMCI_ERROR_GENERIC;
>
>         /*
>          * Lock physical page backing a given user VA.
> --
> 1.9.1
>