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@xxxxxxxxxx> 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@xxxxxxxxx> > > > Cc: John Hubbard <jhubbard@xxxxxxxxxx> > > > Cc: Ira Weiny <ira.weiny@xxxxxxxxx> > > > Cc: Dan Carpenter <dan.carpenter@xxxxxxxxxx> > > > --- > > > 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@xxxxxxxxxx> regards, dan carpenter