Re: [PATCH] misc: genwqe: should return proper error value.

[haver]

On 2018-09-20 04:29, zhong jiang wrote:

The function should return -EFAULT when copy_from_user fails. Even

though the caller does not distinguish them. but we should keep backward

compatibility.

Signed-off-by: zhong jiang <zhongji...@huawei.com>
---
 drivers/misc/genwqe/card_utils.c | 13 +++++++------
 1 file changed, 7 insertions(+), 6 deletions(-)

diff --git a/drivers/misc/genwqe/card_utils.c b/drivers/misc/genwqe/card_utils.c

index 8679e0b..f0961ec 100644
--- a/drivers/misc/genwqe/card_utils.c
+++ b/drivers/misc/genwqe/card_utils.c
@@ -298,7 +298,7 @@ static int genwqe_sgl_size(int num_pages)

int genwqe_alloc_sync_sgl(struct genwqe_dev *cd, struct genwqe_sgl *sgl,

                          void __user *user_addr, size_t user_size, int write)
 {
-       int rc;
+       int ret = -ENOMEM;
        struct pci_dev *pci_dev = cd->pci_dev;

        sgl->fpage_offs = offset_in_page((unsigned long)user_addr);
@@ -318,7 +318,7 @@ int genwqe_alloc_sync_sgl(struct genwqe_dev *cd,
struct genwqe_sgl *sgl,
        if (get_order(sgl->sgl_size) > MAX_ORDER) {
                dev_err(&pci_dev->dev,
                        "[%s] err: too much memory requested!\n", __func__);
-               return -ENOMEM;
+               return ret;
        }

        sgl->sgl = __genwqe_alloc_consistent(cd, sgl->sgl_size,
@@ -326,7 +326,7 @@ int genwqe_alloc_sync_sgl(struct genwqe_dev *cd,
struct genwqe_sgl *sgl,
        if (sgl->sgl == NULL) {
                dev_err(&pci_dev->dev,
                        "[%s] err: no memory available!\n", __func__);
-               return -ENOMEM;
+               return ret;
        }

        /* Only use buffering on incomplete pages */
@@ -339,7 +339,7 @@ int genwqe_alloc_sync_sgl(struct genwqe_dev *cd,
struct genwqe_sgl *sgl,
                /* Sync with user memory */
                if (copy_from_user(sgl->fpage + sgl->fpage_offs,
                                   user_addr, sgl->fpage_size)) {
-                       rc = -EFAULT;
+                       ret = -EFAULT;
                        goto err_out;
                }
        }
@@ -352,7 +352,7 @@ int genwqe_alloc_sync_sgl(struct genwqe_dev *cd,
struct genwqe_sgl *sgl,
                /* Sync with user memory */
                if (copy_from_user(sgl->lpage, user_addr + user_size -
                                   sgl->lpage_size, sgl->lpage_size)) {
-                       rc = -EFAULT;
+                       ret = -EFAULT;
                        goto err_out2;
                }
        }
@@ -374,7 +374,8 @@ int genwqe_alloc_sync_sgl(struct genwqe_dev *cd,
struct genwqe_sgl *sgl,
        sgl->sgl = NULL;
        sgl->sgl_dma_addr = 0;
        sgl->sgl_size = 0;
-       return -ENOMEM;
+
+       return ret;
 }

 int genwqe_setup_sgl(struct genwqe_dev *cd, struct genwqe_sgl *sgl,

Thanks for the contribution. Should be fine to change that and have
a more precise failure information.

Signed-off-by: Frank Haverkamp <ha...@linux.vnet.ibm.com>