Commit 0214f33c authored by Stephen Boyd's avatar Stephen Boyd
Browse files

clk: Overwrite clk_hw::init with NULL during clk_register() 



We don't want clk provider drivers to use the init structure after clk
registration time, but we leave a dangling reference to it by means of
clk_hw::init. Let's overwrite the member with NULL during clk_register()
so that this can't be used anymore after registration time.

Cc: Bjorn Andersson <bjorn.andersson@linaro.org>
Cc: Doug Anderson <dianders@chromium.org>
Signed-off-by: default avatarStephen Boyd <sboyd@kernel.org>
Link: https://lkml.kernel.org/r/20190731193517.237136-10-sboyd@kernel.org


Reviewed-by: default avatarSylwester Nawrocki <s.nawrocki@samsung.com>
parent a7b85ad2

drivers/clk/clk.c

+16 −8
Original line number Diff line number Diff line
@@ -3484,9 +3484,9 @@ static int clk_cpy_name(const char **dst_p, const char *src, bool must_exist) 
	return 0;

}



static int clk_core_populate_parent_map(struct clk_core *core)

static int clk_core_populate_parent_map(struct clk_core *core,

					const struct clk_init_data *init)

{

	const struct clk_init_data *init = core->hw->init;

	u8 num_parents = init->num_parents;

	const char * const *parent_names = init->parent_names;

	const struct clk_hw **parent_hws = init->parent_hws;
@@ -3566,6 +3566,14 @@ __clk_register(struct device *dev, struct device_node *np, struct clk_hw *hw) 
{

	int ret;

	struct clk_core *core;

	const struct clk_init_data *init = hw->init;



	/*

	 * The init data is not supposed to be used outside of registration path.

	 * Set it to NULL so that provider drivers can't use it either and so that

	 * we catch use of hw->init early on in the core.

	 */

	hw->init = NULL;



	core = kzalloc(sizeof(*core), GFP_KERNEL);

	if (!core) {
@@ -3573,17 +3581,17 @@ __clk_register(struct device *dev, struct device_node *np, struct clk_hw *hw) 
		goto fail_out;

	}



	core->name = kstrdup_const(hw->init->name, GFP_KERNEL);

	core->name = kstrdup_const(init->name, GFP_KERNEL);

	if (!core->name) {

		ret = -ENOMEM;

		goto fail_name;

	}



	if (WARN_ON(!hw->init->ops)) {

	if (WARN_ON(!init->ops)) {

		ret = -EINVAL;

		goto fail_ops;

	}

	core->ops = hw->init->ops;

	core->ops = init->ops;



	if (dev && pm_runtime_enabled(dev))

		core->rpm_enabled = true;
@@ -3592,13 +3600,13 @@ __clk_register(struct device *dev, struct device_node *np, struct clk_hw *hw) 
	if (dev && dev->driver)

		core->owner = dev->driver->owner;

	core->hw = hw;

	core->flags = hw->init->flags;

	core->num_parents = hw->init->num_parents;

	core->flags = init->flags;

	core->num_parents = init->num_parents;

	core->min_rate = 0;

	core->max_rate = ULONG_MAX;

	hw->core = core;



	ret = clk_core_populate_parent_map(core);

	ret = clk_core_populate_parent_map(core, init);

	if (ret)

		goto fail_parents;

include/linux/clk-provider.h

+2 −1
Original line number Diff line number Diff line
@@ -299,7 +299,8 @@ struct clk_init_data { 
 * into the clk API

 *

 * @init: pointer to struct clk_init_data that contains the init data shared

 * with the common clock framework.

 * with the common clock framework. This pointer will be set to NULL once

 * a clk_register() variant is called on this clk_hw pointer.

 */

struct clk_hw {

	struct clk_core *core;

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