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From:   Souptick Joarder <jrdr.linux@gmail.com>
Date:   Tue, 29 Dec 2020 13:18:55 +0530
Message-ID: <CAFqt6zYC0Or-7KSqoJY0gFT7NEUVy4unUW8a7rpb4XSxf65cOg@mail.gmail.com>
Subject: Re: [PATCH v2] media: atomisp: Fixed error handling path
To:     mchehab@kernel.org, sakari.ailus@linux.intel.com,
        Greg KH <gregkh@linuxfoundation.org>, gustavoars@kernel.org,
        Andrew Morton <akpm@linux-foundation.org>,
        Vlastimil Babka <vbabka@suse.cz>, daniel.m.jordan@oracle.com,
        Michel Lespinasse <walken@google.com>
Cc:     linux-media@vger.kernel.org,
        "open list:ANDROID DRIVERS" <devel@driverdev.osuosl.org>,
        linux-kernel@vger.kernel.org, John Hubbard <jhubbard@nvidia.com>,
        Ira Weiny <ira.weiny@intel.com>,
        Dan Carpenter <dan.carpenter@oracle.com>
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On Wed, Dec 9, 2020 at 1:18 AM Souptick Joarder <jrdr.linux@gmail.com> wrote:
>
> On Thu, Nov 19, 2020 at 1:06 AM Souptick Joarder <jrdr.linux@gmail.com> wrote:
> >
> > On Wed, Nov 4, 2020 at 7:32 AM Souptick Joarder <jrdr.linux@gmail.com> wrote:
> > >
> > > Inside alloc_user_pages() based on flag value either pin_user_pages()
> > > or get_user_pages_fast() will be called. However, these API might fail.
> > >
> > > But free_user_pages() called in error handling path doesn't bother
> > > about return value and will try to unpin bo->pgnr pages, which is
> > > incorrect.
> > >
> > > Fix this by passing the page_nr to free_user_pages(). If page_nr > 0
> > > pages will be unpinned based on bo->mem_type. This will also take care
> > > of non error handling path.
> > >
> > > Fixes: 14a638ab96c5 ("media: atomisp: use pin_user_pages() for memory
> > > allocation")
> > > Signed-off-by: Souptick Joarder <jrdr.linux@gmail.com>
> > > Reviewed-by: Dan Carpenter <dan.carpenter@oracle.com>
> > > Cc: John Hubbard <jhubbard@nvidia.com>
> > > Cc: Ira Weiny <ira.weiny@intel.com>
> > > Cc: Dan Carpenter <dan.carpenter@oracle.com>
> > > ---
> > > v2:
> > >     Added review tag.
> >
> > Any further comment ? If no, can we get this patch in queue for 5.11 ?
>
> Can we get this patch in the queue for 5.11 ?

Any further comment on this patch ?

>
> > >
> > >  drivers/staging/media/atomisp/pci/hmm/hmm_bo.c | 13 ++++++++-----
> > >  1 file changed, 8 insertions(+), 5 deletions(-)
> > >
> > > diff --git a/drivers/staging/media/atomisp/pci/hmm/hmm_bo.c b/drivers/staging/media/atomisp/pci/hmm/hmm_bo.c
> > > index f13af23..0168f98 100644
> > > --- a/drivers/staging/media/atomisp/pci/hmm/hmm_bo.c
> > > +++ b/drivers/staging/media/atomisp/pci/hmm/hmm_bo.c
> > > @@ -857,16 +857,17 @@ static void free_private_pages(struct hmm_buffer_object *bo,
> > >         kfree(bo->page_obj);
> > >  }
> > >
> > > -static void free_user_pages(struct hmm_buffer_object *bo)
> > > +static void free_user_pages(struct hmm_buffer_object *bo,
> > > +                           unsigned int page_nr)
> > >  {
> > >         int i;
> > >
> > >         hmm_mem_stat.usr_size -= bo->pgnr;
> > >
> > >         if (bo->mem_type == HMM_BO_MEM_TYPE_PFN) {
> > > -               unpin_user_pages(bo->pages, bo->pgnr);
> > > +               unpin_user_pages(bo->pages, page_nr);
> > >         } else {
> > > -               for (i = 0; i < bo->pgnr; i++)
> > > +               for (i = 0; i < page_nr; i++)
> > >                         put_page(bo->pages[i]);
> > >         }
> > >         kfree(bo->pages);
> > > @@ -942,6 +943,8 @@ static int alloc_user_pages(struct hmm_buffer_object *bo,
> > >                 dev_err(atomisp_dev,
> > >                         "get_user_pages err: bo->pgnr = %d, pgnr actually pinned = %d.\n",
> > >                         bo->pgnr, page_nr);
> > > +               if (page_nr < 0)
> > > +                       page_nr = 0;
> > >                 goto out_of_mem;
> > >         }
> > >
> > > @@ -954,7 +957,7 @@ static int alloc_user_pages(struct hmm_buffer_object *bo,
> > >
> > >  out_of_mem:
> > >
> > > -       free_user_pages(bo);
> > > +       free_user_pages(bo, page_nr);
> > >
> > >         return -ENOMEM;
> > >  }
> > > @@ -1037,7 +1040,7 @@ void hmm_bo_free_pages(struct hmm_buffer_object *bo)
> > >         if (bo->type == HMM_BO_PRIVATE)
> > >                 free_private_pages(bo, &dynamic_pool, &reserved_pool);
> > >         else if (bo->type == HMM_BO_USER)
> > > -               free_user_pages(bo);
> > > +               free_user_pages(bo, bo->pgnr);
> > >         else
> > >                 dev_err(atomisp_dev, "invalid buffer type.\n");
> > >         mutex_unlock(&bo->mutex);
> > > --
> > > 1.9.1
> > >