[PATCHv2] clk: kirkwood: use kzalloc_flex

[PATCHv2] clk: kirkwood: use kzalloc_flex

[Rosen Penev]

Simplify allocation by using a flexible array member and kzalloc_flex to
combine allocations.

Add __counted_by for extra runtime analysis. Move counting variable
assignment to right after allocation as required by __counted_by.

Signed-off-by: Rosen Penev <rosenp@gmail.com>
---
 v2: remove unused goto.
 drivers/clk/mvebu/kirkwood.c | 21 ++++++++-------------
 1 file changed, 8 insertions(+), 13 deletions(-)

diff --git a/drivers/clk/mvebu/kirkwood.c b/drivers/clk/mvebu/kirkwood.c
index ed061d82fb65..f4f62b241193 100644
--- a/drivers/clk/mvebu/kirkwood.c
+++ b/drivers/clk/mvebu/kirkwood.c
@@ -253,8 +253,8 @@ struct clk_muxing_soc_desc {

 struct clk_muxing_ctrl {
 	spinlock_t *lock;
-	struct clk **muxes;
 	int num_muxes;
+	struct clk *muxes[] __counted_by(num_muxes);
 };

 static const char *powersave_parents[] = {
@@ -297,21 +297,18 @@ static void __init kirkwood_clk_muxing_setup(struct device_node *np,
 	if (WARN_ON(!base))
 		return;

-	ctrl = kzalloc_obj(*ctrl);
-	if (WARN_ON(!ctrl))
-		goto ctrl_out;
-
-	/* lock must already be initialized */
-	ctrl->lock = &ctrl_gating_lock;
-
 	/* Count, allocate, and register clock muxes */
 	for (n = 0; desc[n].name;)
 		n++;

+	ctrl = kzalloc_flex(*ctrl, muxes, n);
+	if (WARN_ON(!ctrl))
+		goto ctrl_out;
+
 	ctrl->num_muxes = n;
-	ctrl->muxes = kzalloc_objs(struct clk *, ctrl->num_muxes);
-	if (WARN_ON(!ctrl->muxes))
-		goto muxes_out;
+
+	/* lock must already be initialized */
+	ctrl->lock = &ctrl_gating_lock;

 	for (n = 0; n < ctrl->num_muxes; n++) {
 		ctrl->muxes[n] = clk_register_mux(NULL, desc[n].name,
@@ -324,8 +321,6 @@ static void __init kirkwood_clk_muxing_setup(struct device_node *np,
 	of_clk_add_provider(np, clk_muxing_get_src, ctrl);

 	return;
-muxes_out:
-	kfree(ctrl);
 ctrl_out:
 	iounmap(base);
 }
--
2.53.0

Re: [PATCHv2] clk: kirkwood: use kzalloc_flex

[Brian Masney]

On Mon, Mar 30, 2026 at 01:55:04PM -0700, Rosen Penev wrote:
> Simplify allocation by using a flexible array member and kzalloc_flex to
> combine allocations.
> 
> Add __counted_by for extra runtime analysis. Move counting variable
> assignment to right after allocation as required by __counted_by.
> 
> Signed-off-by: Rosen Penev <rosenp@gmail.com>
> ---
>  v2: remove unused goto.

Reviewed-by: Brian Masney <bmasney@redhat.com>

For the future, if someone asks for changes in a previous version, then
be sure to CC them on the next revision.

Re: [PATCHv2] clk: kirkwood: use kzalloc_flex

[Gustavo A. R. Silva]

On 3/31/26 08:05, Brian Masney wrote:
> On Mon, Mar 30, 2026 at 01:55:04PM -0700, Rosen Penev wrote:
>> Simplify allocation by using a flexible array member and kzalloc_flex to
>> combine allocations.
>>
>> Add __counted_by for extra runtime analysis. Move counting variable
>> assignment to right after allocation as required by __counted_by.

This is misinformation and should be phrased differently[1]

-Gustavo

[1] https://lore.kernel.org/linux-hardening/37378f49-437f-438b-ad6c-d60480feb306@embeddedor.com/

>>
>> Signed-off-by: Rosen Penev <rosenp@gmail.com>
>> ---
>>   v2: remove unused goto.
> 
> Reviewed-by: Brian Masney <bmasney@redhat.com>
> 
> For the future, if someone asks for changes in a previous version, then
> be sure to CC them on the next revision.
>