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From:   Souptick Joarder <jrdr.linux@gmail.com>
Date:   Sun, 3 Feb 2019 17:40:51 +0530
Message-ID: <CAFqt6zaN-AJuhVf8_=z3KDCjcuu+zTN_GorxDzcpAUqcM04m2w@mail.gmail.com>
Subject: Re: [PATCHv2 3/9] drivers/firewire/core-iso.c: Convert to use vm_insert_range_buggy
To:     Andrew Morton <akpm@linux-foundation.org>,
        Matthew Wilcox <willy@infradead.org>,
        Michal Hocko <mhocko@suse.com>, stefanr@s5r6.in-berlin.de,
        Russell King - ARM Linux <linux@armlinux.org.uk>,
        robin.murphy@arm.com
Cc:     linux-kernel@vger.kernel.org, Linux-MM <linux-mm@kvack.org>,
        linux-arm-kernel@lists.infradead.org,
        linux1394-devel@lists.sourceforge.net
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Sender: linux-kernel-owner@vger.kernel.org
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Hi Stefanr,

On Thu, Jan 31, 2019 at 8:35 AM Souptick Joarder <jrdr.linux@gmail.com> wrote:
>
> Convert to use vm_insert_range_buggy to map range of kernel memory
> to user vma.
>
> This driver has ignored vm_pgoff and mapped the entire pages. We
> could later "fix" these drivers to behave according to the normal
> vm_pgoff offsetting simply by removing the _buggy suffix on the
> function name and if that causes regressions, it gives us an easy
> way to revert.
>
> Signed-off-by: Souptick Joarder <jrdr.linux@gmail.com>

Can you please help to review this patch ?

> ---
>  drivers/firewire/core-iso.c | 15 ++-------------
>  1 file changed, 2 insertions(+), 13 deletions(-)
>
> diff --git a/drivers/firewire/core-iso.c b/drivers/firewire/core-iso.c
> index 35e784c..99a6582 100644
> --- a/drivers/firewire/core-iso.c
> +++ b/drivers/firewire/core-iso.c
> @@ -107,19 +107,8 @@ int fw_iso_buffer_init(struct fw_iso_buffer *buffer, struct fw_card *card,
>  int fw_iso_buffer_map_vma(struct fw_iso_buffer *buffer,
>                           struct vm_area_struct *vma)
>  {
> -       unsigned long uaddr;
> -       int i, err;
> -
> -       uaddr = vma->vm_start;
> -       for (i = 0; i < buffer->page_count; i++) {
> -               err = vm_insert_page(vma, uaddr, buffer->pages[i]);
> -               if (err)
> -                       return err;
> -
> -               uaddr += PAGE_SIZE;
> -       }
> -
> -       return 0;
> +       return vm_insert_range_buggy(vma, buffer->pages,
> +                                       buffer->page_count);
>  }
>
>  void fw_iso_buffer_destroy(struct fw_iso_buffer *buffer,
> --
> 1.9.1
>