From: Ambresh K <ambr...@ti.com>
clk_mux_get_parent should return an error if the value read
from the register is erroneous.
Currently if the value read is greater than the number of
available parents clk_mux_get_parent return's signed error
which will result in NULL pointer dereferencing in the
calling functions.
Signed-off-by: Ambresh K <ambr...@ti.com>
---
drivers/clk/clk-mux.c | 2 +-
drivers/clk/clk.c | 12 +++++++++++-
include/linux/clk-provider.h | 6 +++---
3 files changed, 15 insertions(+), 5 deletions(-)
diff --git a/drivers/clk/clk-mux.c b/drivers/clk/clk-mux.c
index 614444c..001b4df 100644
--- a/drivers/clk/clk-mux.c
+++ b/drivers/clk/clk-mux.c
@@ -29,7 +29,7 @@
#define to_clk_mux(_hw) container_of(_hw, struct clk_mux, hw)
-static u8 clk_mux_get_parent(struct clk_hw *hw)
+static int clk_mux_get_parent(struct clk_hw *hw)
{
struct clk_mux *mux = to_clk_mux(hw);
int num_parents = __clk_get_num_parents(hw->clk);
diff --git a/drivers/clk/clk.c b/drivers/clk/clk.c
index edf3fe1..2842450 100644
--- a/drivers/clk/clk.c
+++ b/drivers/clk/clk.c
@@ -1281,7 +1281,7 @@ EXPORT_SYMBOL_GPL(clk_get_parent);
static struct clk *__clk_init_parent(struct clk *clk)
{
struct clk *ret = NULL;
- u8 index;
+ int index;
/* handle the trivial cases */
@@ -1309,6 +1309,11 @@ static struct clk *__clk_init_parent(struct clk *clk)
*/
index = clk->ops->get_parent(clk->hw);
+ if (index < 0) {
+ pr_err("%s: clk(%s) invalid parent index(%d)\n",
+ __func__, clk->name, index);
+ goto out;
+ }
if (!clk->parents)
clk->parents =
@@ -1630,6 +1635,11 @@ int __clk_init(struct device *dev, struct clk *clk)
hlist_for_each_entry_safe(orphan, tmp2, &clk_orphan_list, child_node) {
if (orphan->ops->get_parent) {
i = orphan->ops->get_parent(orphan->hw);
+ if (i < 0) {
+ pr_err_once("%s: clk(%s) has invalid parent\n",
+ __func__, orphan->name);
+ continue;
+ }
if (!strcmp(clk->name, orphan->parent_names[i]))
__clk_reparent(orphan, clk);
continue;
diff --git a/include/linux/clk-provider.h b/include/linux/clk-provider.h
index 1ec14a7..b01cbdb 100644
--- a/include/linux/clk-provider.h
+++ b/include/linux/clk-provider.h
@@ -79,8 +79,8 @@ struct clk_hw;
* @round_rate: Given a target rate as input, returns the closest rate
actually
* supported by the clock.
*
- * @get_parent: Queries the hardware to determine the parent of a
clock. The
- * return value is a u8 which specifies the index corresponding to
+ * @get_parent: Queries the hardware to determine the parent of a
clock. The
+ * return value which specifies the index corresponding to
* the parent clock. This index can be applied to either the
* .parent_names or .parents arrays. In short, this function
* translates the parent value read from hardware into an array
@@ -127,7 +127,7 @@ struct clk_ops {
long (*round_rate)(struct clk_hw *hw, unsigned long,
unsigned long *);
int (*set_parent)(struct clk_hw *hw, u8 index);
- u8 (*get_parent)(struct clk_hw *hw);
+ int (*get_parent)(struct clk_hw *hw);
int (*set_rate)(struct clk_hw *hw, unsigned long,
unsigned long);
void (*init)(struct clk_hw *hw);
--
1.7.4.1
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