soc: qcom: llcc-slice: Add error checks for API functions

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.

Signed-off-by: Jordan Crouse <jcrouse@codeaurora.org>
Reviewed-by: Vivek Gautam <vivek.gautam@codeaurora.org>
Signed-off-by: Andy Gross <andy.gross@linaro.org>

diff --git a/drivers/soc/qcom/llcc-slice.c b/drivers/soc/qcom/llcc-slice.c
index 7f55203d28d74fe91dd1c199887f22478986b3c6..6a7d0162fe0e52157dffee78c9c94f8996700961 100644 (file)
--- a/drivers/soc/qcom/llcc-slice.c
+++ b/drivers/soc/qcom/llcc-slice.c
@@ -96,7 +96,8 @@ 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);
 }
 EXPORT_SYMBOL_GPL(llcc_slice_putd);
 
@@ -143,6 +144,9 @@ int llcc_slice_activate(struct llcc_slice_desc *desc)
        int ret;
        u32 act_ctrl_val;
 
+       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);
@@ -177,6 +181,9 @@ 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);
@@ -204,6 +211,9 @@ 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);
@@ -214,6 +224,9 @@ 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);