linux/drivers/clk/clk-devres.c
Uwe Kleine-König 8b3d743fc9 clk: Fix pointer casting to prevent oops in devm_clk_release()
The release function is called with a pointer to the memory returned by
devres_alloc(). I was confused about that by the code before the
generalization that used a struct clk **ptr.

Reported-by: Marek Szyprowski <m.szyprowski@samsung.com>
Fixes: abae8e57e4 ("clk: generalize devm_clk_get() a bit")
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Link: https://lore.kernel.org/r/20220620171815.114212-1-u.kleine-koenig@pengutronix.de
Tested-by: Marek Szyprowski <m.szyprowski@samsung.com>
Tested-by: Linux Kernel Functional Testing <lkft@linaro.org>
Signed-off-by: Stephen Boyd <sboyd@kernel.org>
2022-06-22 16:10:23 -07:00

225 lines
4.8 KiB
C

// SPDX-License-Identifier: GPL-2.0
#include <linux/clk.h>
#include <linux/device.h>
#include <linux/export.h>
#include <linux/gfp.h>
struct devm_clk_state {
struct clk *clk;
void (*exit)(struct clk *clk);
};
static void devm_clk_release(struct device *dev, void *res)
{
struct devm_clk_state *state = res;
if (state->exit)
state->exit(state->clk);
clk_put(state->clk);
}
static struct clk *__devm_clk_get(struct device *dev, const char *id,
struct clk *(*get)(struct device *dev, const char *id),
int (*init)(struct clk *clk),
void (*exit)(struct clk *clk))
{
struct devm_clk_state *state;
struct clk *clk;
int ret;
state = devres_alloc(devm_clk_release, sizeof(*state), GFP_KERNEL);
if (!state)
return ERR_PTR(-ENOMEM);
clk = get(dev, id);
if (IS_ERR(clk)) {
ret = PTR_ERR(clk);
goto err_clk_get;
}
if (init) {
ret = init(clk);
if (ret)
goto err_clk_init;
}
state->clk = clk;
state->exit = exit;
devres_add(dev, state);
return clk;
err_clk_init:
clk_put(clk);
err_clk_get:
devres_free(state);
return ERR_PTR(ret);
}
struct clk *devm_clk_get(struct device *dev, const char *id)
{
return __devm_clk_get(dev, id, clk_get, NULL, NULL);
}
EXPORT_SYMBOL(devm_clk_get);
struct clk *devm_clk_get_prepared(struct device *dev, const char *id)
{
return __devm_clk_get(dev, id, clk_get, clk_prepare, clk_unprepare);
}
EXPORT_SYMBOL_GPL(devm_clk_get_prepared);
struct clk *devm_clk_get_enabled(struct device *dev, const char *id)
{
return __devm_clk_get(dev, id, clk_get,
clk_prepare_enable, clk_disable_unprepare);
}
EXPORT_SYMBOL_GPL(devm_clk_get_enabled);
struct clk *devm_clk_get_optional(struct device *dev, const char *id)
{
return __devm_clk_get(dev, id, clk_get_optional, NULL, NULL);
}
EXPORT_SYMBOL(devm_clk_get_optional);
struct clk *devm_clk_get_optional_prepared(struct device *dev, const char *id)
{
return __devm_clk_get(dev, id, clk_get_optional,
clk_prepare, clk_unprepare);
}
EXPORT_SYMBOL_GPL(devm_clk_get_optional_prepared);
struct clk *devm_clk_get_optional_enabled(struct device *dev, const char *id)
{
return __devm_clk_get(dev, id, clk_get_optional,
clk_prepare_enable, clk_disable_unprepare);
}
EXPORT_SYMBOL_GPL(devm_clk_get_optional_enabled);
struct clk_bulk_devres {
struct clk_bulk_data *clks;
int num_clks;
};
static void devm_clk_bulk_release(struct device *dev, void *res)
{
struct clk_bulk_devres *devres = res;
clk_bulk_put(devres->num_clks, devres->clks);
}
static int __devm_clk_bulk_get(struct device *dev, int num_clks,
struct clk_bulk_data *clks, bool optional)
{
struct clk_bulk_devres *devres;
int ret;
devres = devres_alloc(devm_clk_bulk_release,
sizeof(*devres), GFP_KERNEL);
if (!devres)
return -ENOMEM;
if (optional)
ret = clk_bulk_get_optional(dev, num_clks, clks);
else
ret = clk_bulk_get(dev, num_clks, clks);
if (!ret) {
devres->clks = clks;
devres->num_clks = num_clks;
devres_add(dev, devres);
} else {
devres_free(devres);
}
return ret;
}
int __must_check devm_clk_bulk_get(struct device *dev, int num_clks,
struct clk_bulk_data *clks)
{
return __devm_clk_bulk_get(dev, num_clks, clks, false);
}
EXPORT_SYMBOL_GPL(devm_clk_bulk_get);
int __must_check devm_clk_bulk_get_optional(struct device *dev, int num_clks,
struct clk_bulk_data *clks)
{
return __devm_clk_bulk_get(dev, num_clks, clks, true);
}
EXPORT_SYMBOL_GPL(devm_clk_bulk_get_optional);
static void devm_clk_bulk_release_all(struct device *dev, void *res)
{
struct clk_bulk_devres *devres = res;
clk_bulk_put_all(devres->num_clks, devres->clks);
}
int __must_check devm_clk_bulk_get_all(struct device *dev,
struct clk_bulk_data **clks)
{
struct clk_bulk_devres *devres;
int ret;
devres = devres_alloc(devm_clk_bulk_release_all,
sizeof(*devres), GFP_KERNEL);
if (!devres)
return -ENOMEM;
ret = clk_bulk_get_all(dev, &devres->clks);
if (ret > 0) {
*clks = devres->clks;
devres->num_clks = ret;
devres_add(dev, devres);
} else {
devres_free(devres);
}
return ret;
}
EXPORT_SYMBOL_GPL(devm_clk_bulk_get_all);
static int devm_clk_match(struct device *dev, void *res, void *data)
{
struct clk **c = res;
if (!c || !*c) {
WARN_ON(!c || !*c);
return 0;
}
return *c == data;
}
void devm_clk_put(struct device *dev, struct clk *clk)
{
int ret;
ret = devres_release(dev, devm_clk_release, devm_clk_match, clk);
WARN_ON(ret);
}
EXPORT_SYMBOL(devm_clk_put);
struct clk *devm_get_clk_from_child(struct device *dev,
struct device_node *np, const char *con_id)
{
struct clk **ptr, *clk;
ptr = devres_alloc(devm_clk_release, sizeof(*ptr), GFP_KERNEL);
if (!ptr)
return ERR_PTR(-ENOMEM);
clk = of_clk_get_by_name(np, con_id);
if (!IS_ERR(clk)) {
*ptr = clk;
devres_add(dev, ptr);
} else {
devres_free(ptr);
}
return clk;
}
EXPORT_SYMBOL(devm_get_clk_from_child);