Hi Jordan
On Tue, Sep 25, 2018 at 2:56 AM Jordan Crouse <jcrouse@xxxxxxxxxxxxxx> wrote:
>
> llcc_slice_getd can return a ERR_PTR code on failure. Add a IS_ERR_OR_NULL
> check to subsequent API calls that use struct llcc_slice_desc to guard
> against faults and to let the leaf drivers get away with safely using a
> ERR_PTR() encoded "pointer" in the aftermath of a llcc_slice_getd error.
To me calling llcc_slice_putd(), llcc_slice_{de}activate(), and others
with a error pointer sounds like we are on the wrong path anyways.
The users can check for the error pointer return value and assign
llcc_slice_desc to NULL, e.g., something that GPU is trying to do [1].
So we can simply check for NULL value of desc in these APIs.
[1] https://patchwork.freedesktop.org/patch/212400/
>
> Signed-off-by: Jordan Crouse <jcrouse@xxxxxxxxxxxxxx>
> ---
> drivers/soc/qcom/llcc-slice.c | 15 ++++++++++++++-
> 1 file changed, 14 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/soc/qcom/llcc-slice.c b/drivers/soc/qcom/llcc-slice.c
> index 192ca761b2cb..de1a35cd20ed 100644
> --- a/drivers/soc/qcom/llcc-slice.c
> +++ b/drivers/soc/qcom/llcc-slice.c
> @@ -95,7 +95,8 @@ EXPORT_SYMBOL_GPL(llcc_slice_getd);
> */
> void llcc_slice_putd(struct llcc_slice_desc *desc)
> {
> - kfree(desc);
> + if (!IS_ERR_OR_NULL(desc))
> + kfree(desc);
you will not need this check at all when desc = NULL.
> }
> EXPORT_SYMBOL_GPL(llcc_slice_putd);
>
> @@ -142,6 +143,9 @@ int llcc_slice_activate(struct llcc_slice_desc *desc)
> int ret;
> u32 act_ctrl_val;
>
> + if (IS_ERR_OR_NULL(desc))
This can be simply replaced with NULL check.
if (!desc)
and same in the below hunks.
Best regards
Vivek
> + return -EINVAL;
> +
> mutex_lock(&drv_data->lock);
> if (test_bit(desc->slice_id, drv_data->bitmap)) {
> mutex_unlock(&drv_data->lock);
> @@ -176,6 +180,9 @@ int llcc_slice_deactivate(struct llcc_slice_desc *desc)
> u32 act_ctrl_val;
> int ret;
>
> + if (IS_ERR_OR_NULL(desc))
> + return -EINVAL;
> +
> mutex_lock(&drv_data->lock);
> if (!test_bit(desc->slice_id, drv_data->bitmap)) {
> mutex_unlock(&drv_data->lock);
> @@ -203,6 +210,9 @@ EXPORT_SYMBOL_GPL(llcc_slice_deactivate);
> */
> int llcc_get_slice_id(struct llcc_slice_desc *desc)
> {
> + if (IS_ERR_OR_NULL(desc))
> + return -EINVAL;
> +
> return desc->slice_id;
> }
> EXPORT_SYMBOL_GPL(llcc_get_slice_id);
> @@ -213,6 +223,9 @@ EXPORT_SYMBOL_GPL(llcc_get_slice_id);
> */
> size_t llcc_get_slice_size(struct llcc_slice_desc *desc)
> {
> + if (IS_ERR_OR_NULL(desc))
> + return 0;
> +
> return desc->slice_size;
> }
> EXPORT_SYMBOL_GPL(llcc_get_slice_size);
> --
> 2.18.0
>
--
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