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* [PATCH] media: atomisp: Fixed error handling path
@ 2020-09-27 15:08 Souptick Joarder
  2020-09-28  8:37 ` Dan Carpenter
  0 siblings, 1 reply; 4+ messages in thread
From: Souptick Joarder @ 2020-09-27 15:08 UTC (permalink / raw)
  To: mchehab, sakari.ailus, gregkh, daniel.m.jordan, akpm, walken, gustavoars
  Cc: linux-media, devel, linux-kernel, Souptick Joarder, John Hubbard,
	Ira Weiny, Dan Carpenter

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>
Cc: John Hubbard <jhubbard@nvidia.com>
Cc: Ira Weiny <ira.weiny@intel.com>
Cc: Dan Carpenter <dan.carpenter@oracle.com>
---
 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


^ permalink raw reply related	[flat|nested] 4+ messages in thread

* Re: [PATCH] media: atomisp: Fixed error handling path
  2020-09-27 15:08 [PATCH] media: atomisp: Fixed error handling path Souptick Joarder
@ 2020-09-28  8:37 ` Dan Carpenter
  2020-09-29  2:04   ` Souptick Joarder
  0 siblings, 1 reply; 4+ messages in thread
From: Dan Carpenter @ 2020-09-28  8:37 UTC (permalink / raw)
  To: Souptick Joarder
  Cc: mchehab, sakari.ailus, gregkh, daniel.m.jordan, akpm, walken,
	gustavoars, linux-media, devel, linux-kernel, John Hubbard,
	Ira Weiny

On Sun, Sep 27, 2020 at 08:38:04PM +0530, Souptick Joarder 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>
> Cc: John Hubbard <jhubbard@nvidia.com>
> Cc: Ira Weiny <ira.weiny@intel.com>
> Cc: Dan Carpenter <dan.carpenter@oracle.com>
> ---
>  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;
                              ^^^^^^^^^^^
This is still a problem.  It needs to be hmm_mem_stat.usr_size -= page_nr.

regards,
dan carpenter

>  
>  	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);


^ permalink raw reply	[flat|nested] 4+ messages in thread

* Re: [PATCH] media: atomisp: Fixed error handling path
  2020-09-28  8:37 ` Dan Carpenter
@ 2020-09-29  2:04   ` Souptick Joarder
  2020-09-29  6:14     ` Dan Carpenter
  0 siblings, 1 reply; 4+ messages in thread
From: Souptick Joarder @ 2020-09-29  2:04 UTC (permalink / raw)
  To: Dan Carpenter
  Cc: mchehab, sakari.ailus, Greg KH, daniel.m.jordan, Andrew Morton,
	Michel Lespinasse, gustavoars, linux-media,
	open list:ANDROID DRIVERS, linux-kernel, John Hubbard, Ira Weiny

Hi Dan,


On Mon, Sep 28, 2020 at 2:08 PM Dan Carpenter <dan.carpenter@oracle.com> wrote:
>
> On Sun, Sep 27, 2020 at 08:38:04PM +0530, Souptick Joarder 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>
> > Cc: John Hubbard <jhubbard@nvidia.com>
> > Cc: Ira Weiny <ira.weiny@intel.com>
> > Cc: Dan Carpenter <dan.carpenter@oracle.com>
> > ---
> >  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;
>                               ^^^^^^^^^^^
> This is still a problem.  It needs to be hmm_mem_stat.usr_size -= page_nr.

In failure path, it is hmm_mem_stat.usr_size += bo->pgnr.
I think, hmm_mem_stat.usr_size -= bo->pgnr is correct as per existing code.
Do you think that needs to be changed ?

>
> regards,
> dan carpenter
>
> >
> >       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);
>

^ permalink raw reply	[flat|nested] 4+ messages in thread

* Re: [PATCH] media: atomisp: Fixed error handling path
  2020-09-29  2:04   ` Souptick Joarder
@ 2020-09-29  6:14     ` Dan Carpenter
  0 siblings, 0 replies; 4+ messages in thread
From: Dan Carpenter @ 2020-09-29  6:14 UTC (permalink / raw)
  To: Souptick Joarder
  Cc: open list:ANDROID DRIVERS, Michel Lespinasse, Greg KH,
	gustavoars, daniel.m.jordan, sakari.ailus, John Hubbard,
	Andrew Morton, mchehab, linux-kernel, linux-media

On Tue, Sep 29, 2020 at 07:34:39AM +0530, Souptick Joarder wrote:
> Hi Dan,
> 
> 
> On Mon, Sep 28, 2020 at 2:08 PM Dan Carpenter <dan.carpenter@oracle.com> wrote:
> >
> > On Sun, Sep 27, 2020 at 08:38:04PM +0530, Souptick Joarder 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>
> > > Cc: John Hubbard <jhubbard@nvidia.com>
> > > Cc: Ira Weiny <ira.weiny@intel.com>
> > > Cc: Dan Carpenter <dan.carpenter@oracle.com>
> > > ---
> > >  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;
> >                               ^^^^^^^^^^^
> > This is still a problem.  It needs to be hmm_mem_stat.usr_size -= page_nr.
> 
> In failure path, it is hmm_mem_stat.usr_size += bo->pgnr.
> I think, hmm_mem_stat.usr_size -= bo->pgnr is correct as per existing code.
> Do you think that needs to be changed ?
> 

Yeah.  Crud.  I'm sorry.  You had it right.

Reviewed-by: Dan Carpenter <dan.carpenter@oracle.com>

regards,
dan carpenter


^ permalink raw reply	[flat|nested] 4+ messages in thread

end of thread, other threads:[~2020-09-29  6:14 UTC | newest]

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2020-09-27 15:08 [PATCH] media: atomisp: Fixed error handling path Souptick Joarder
2020-09-28  8:37 ` Dan Carpenter
2020-09-29  2:04   ` Souptick Joarder
2020-09-29  6:14     ` Dan Carpenter

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