From 4617721c502b2ddaa4e324e86da4997edf738fa5 Mon Sep 17 00:00:00 2001 From: Steven Rostedt Date: Wed, 2 Sep 2026 09:55:01 -0400 Subject: ftrace: Synchronize the initialization of ftrace_ops There's some internal state that ftrace_ops needs to have set, but since it can be declared outside of the ftrace.c code, it calls ftrace_ops_init() on the ops in every global function. The issue is that if two tasks call it on the same ops at the same time it is possible to have the initialization of one corrupt the initialization of the other call. Create a ops_mutex to use to synchronize every initialization of the ftrace_ops. The mutex is taken within checking the ftrace_ops flag that states it was initializied but the flag is checked again after the mutex has been taken. Checking first outside the mutex allows it to shortcut having to take the mutex. But then the check needs to be done again after the mute is taken in case of races. Cc: stable@vger.kernel.org Link: https://patch.msgid.link/20260902095501.6b59af20@gandalf.local.home Fixes: f04f24fb7e48d ("ftrace, kprobes: Fix a deadlock on ftrace_regex_lock") Reported-by: sashiko-bot@kernel.org Close: https://lore.kernel.org/all/20260829025528.49A831F000E9@smtp.kernel.org/ Signed-off-by: Steven Rostedt --- drivers/clk/clk-devres.c | 359 +++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 359 insertions(+) create mode 100644 drivers/clk/clk-devres.c (limited to 'drivers/clk/clk-devres.c') diff --git a/drivers/clk/clk-devres.c b/drivers/clk/clk-devres.c new file mode 100644 index 000000000..4cc3863bd --- /dev/null +++ b/drivers/clk/clk-devres.c @@ -0,0 +1,359 @@ +// SPDX-License-Identifier: GPL-2.0 +#include +#include +#include +#include + +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); + +static void devm_clk_disable_unprepare(void *data) +{ + clk_disable_unprepare(data); +} + +struct clk *devm_clk_get_optional_enabled_with_rate(struct device *dev, + const char *id, + unsigned long rate) +{ + struct clk *clk; + int ret; + + clk = devm_clk_get_optional(dev, id); + if (IS_ERR(clk)) + return ERR_CAST(clk); + + ret = clk_set_rate(clk, rate); + if (ret) + goto out_put_clk; + + ret = clk_prepare_enable(clk); + if (ret) + goto out_put_clk; + + ret = devm_add_action_or_reset(dev, devm_clk_disable_unprepare, clk); + if (ret) + goto out_put_clk; + + return clk; + +out_put_clk: + devm_clk_put(dev, clk); + return ERR_PTR(ret); +} +EXPORT_SYMBOL_GPL(devm_clk_get_optional_enabled_with_rate); + +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_enable(struct device *dev, void *res) +{ + struct clk_bulk_devres *devres = res; + + clk_bulk_disable_unprepare(devres->num_clks, devres->clks); + clk_bulk_put(devres->num_clks, devres->clks); +} + +static int __devm_clk_bulk_get_enable(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_enable, + 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) + goto err_clk_get; + + ret = clk_bulk_prepare_enable(num_clks, clks); + if (ret) + goto err_clk_prepare; + + devres->clks = clks; + devres->num_clks = num_clks; + devres_add(dev, devres); + + return 0; + +err_clk_prepare: + clk_bulk_put(num_clks, clks); +err_clk_get: + devres_free(devres); + return ret; +} + +int __must_check devm_clk_bulk_get_enable(struct device *dev, int num_clks, + struct clk_bulk_data *clks) +{ + return __devm_clk_bulk_get_enable(dev, num_clks, clks, false); +} +EXPORT_SYMBOL_GPL(devm_clk_bulk_get_enable); + +int __must_check devm_clk_bulk_get_optional_enable(struct device *dev, int num_clks, + struct clk_bulk_data *clks) +{ + return __devm_clk_bulk_get_enable(dev, num_clks, clks, true); +} +EXPORT_SYMBOL_GPL(devm_clk_bulk_get_optional_enable); + +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 void devm_clk_bulk_release_all_enable(struct device *dev, void *res) +{ + struct clk_bulk_devres *devres = res; + + clk_bulk_disable_unprepare(devres->num_clks, devres->clks); + clk_bulk_put_all(devres->num_clks, devres->clks); +} + +int __must_check devm_clk_bulk_get_all_enabled(struct device *dev, + struct clk_bulk_data **clks) +{ + struct clk_bulk_devres *devres; + int ret; + + devres = devres_alloc(devm_clk_bulk_release_all_enable, + 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; + } else { + devres_free(devres); + return ret; + } + + ret = clk_bulk_prepare_enable(devres->num_clks, *clks); + if (!ret) { + devres_add(dev, devres); + } else { + clk_bulk_put_all(devres->num_clks, devres->clks); + devres_free(devres); + return ret; + } + + return devres->num_clks; +} +EXPORT_SYMBOL_GPL(devm_clk_bulk_get_all_enabled); + +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 devm_clk_state *state; + struct clk *clk; + + state = devres_alloc(devm_clk_release, sizeof(*state), GFP_KERNEL); + if (!state) + return ERR_PTR(-ENOMEM); + + clk = of_clk_get_by_name(np, con_id); + if (!IS_ERR(clk)) { + state->clk = clk; + devres_add(dev, state); + } else { + devres_free(state); + } + + return clk; +} +EXPORT_SYMBOL(devm_get_clk_from_child); -- cgit v1.3.1