[PATCH v2] media: atomisp: Fixed error handling path

[Souptick Joarder]

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.li...@gmail.com>
Reviewed-by: Dan Carpenter <dan.carpen...@oracle.com>
Cc: John Hubbard <jhubb...@nvidia.com>
Cc: Ira Weiny <ira.we...@intel.com>
Cc: Dan Carpenter <dan.carpen...@oracle.com>
---
v2:
    Added review tag.

 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