FAILED: patch "[PATCH] PM: EM: Address RCU-related sparse warnings" failed to apply to 5.10-stable tree
Subsystems (4)
[email protected]
maintainerThe patch below does not apply to the 5.10-stable tree.
If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <[email protected]>.
To reproduce the conflict and resubmit, you may use the following commands:
git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-5.10.y
git checkout FETCH_HEAD
git cherry-pick -x 3ee7be9e10dd5f79448788b899591d4bd2bf0c19
# <resolve conflicts, build, test, etc.>
git commit -s
git send-email --to '<[email protected]>' --in-reply-to '2025041732-unsigned-random-db34@gregkh' --subject-prefix 'PATCH 5.10.y' HEAD^..
Possible dependencies:
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
From 3ee7be9e10dd5f79448788b899591d4bd2bf0c19 Mon Sep 17 00:00:00 2001
From: "Rafael J. Wysocki" <[email protected]>
Date: Thu, 6 Mar 2025 17:49:20 +0100
Subject: [PATCH] PM: EM: Address RCU-related sparse warnings
The usage of __rcu in the Energy Model code is quite inconsistent which causes the following sparse warnings to trigger:
kernel/power/energy_model.c:169:15: warning: incorrect type in assignment (different address spaces)kernel/power/energy_model.c:169:15: expected struct em_perf_table [noderef] __rcu *tablekernel/power/energy_model.c:169:15: got struct em_perf_table *kernel/power/energy_model.c:171:9: warning: incorrect type in argument 1 (different address spaces)kernel/power/energy_model.c:171:9: expected struct callback_head *headkernel/power/energy_model.c:171:9: got struct callback_head [noderef] __rcu *kernel/power/energy_model.c:171:9: warning: cast removes address space '__rcu' of expression kernel/power/energy_model.c:182:19: warning: incorrect type in argument 1 (different address spaces)kernel/power/energy_model.c:182:19: expected struct kref *krefkernel/power/energy_model.c:182:19: got struct kref [noderef] __rcu *kernel/power/energy_model.c:200:15: warning: incorrect type in assignment (different address spaces)kernel/power/energy_model.c:200:15: expected struct em_perf_table [noderef] __rcu *tablekernel/power/energy_model.c:200:15: got void *[assigned] _reskernel/power/energy_model.c:204:20: warning: incorrect type in argument 1 (different address spaces)kernel/power/energy_model.c:204:20: expected struct kref *krefkernel/power/energy_model.c:204:20: got struct kref [noderef] __rcu *kernel/power/energy_model.c:320:19: warning: incorrect type in argument 1 (different address spaces)kernel/power/energy_model.c:320:19: expected struct kref *krefkernel/power/energy_model.c:320:19: got struct kref [noderef] __rcu *kernel/power/energy_model.c:325:45: warning: incorrect type in argument 2 (different address spaces)kernel/power/energy_model.c:325:45: expected struct em_perf_state *tablekernel/power/energy_model.c:325:45: got struct em_perf_state [noderef] __rcu *kernel/power/energy_model.c:425:45: warning: incorrect type in argument 3 (different address spaces)kernel/power/energy_model.c:425:45: expected struct em_perf_state *tablekernel/power/energy_model.c:425:45: got struct em_perf_state [noderef] __rcu *kernel/power/energy_model.c:442:15: warning: incorrect type in argument 1 (different address spaces)kernel/power/energy_model.c:442:15: expected void const *objpkernel/power/energy_model.c:442:15: got struct em_perf_table [noderef] __rcu *[assigned] em_tablekernel/power/energy_model.c:626:55: warning: incorrect type in argument 2 (different address spaces)kernel/power/energy_model.c:626:55: expected struct em_perf_state *tablekernel/power/energy_model.c:626:55: got struct em_perf_state [noderef] __rcu *kernel/power/energy_model.c:681:16: warning: incorrect type in assignment (different address spaces)kernel/power/energy_model.c:681:16: expected struct em_perf_state *new_pskernel/power/energy_model.c:681:16: got struct em_perf_state [noderef] __rcu *kernel/power/energy_model.c:699:37: warning: incorrect type in argument 2 (different address spaces)kernel/power/energy_model.c:699:37: expected struct em_perf_state *tablekernel/power/energy_model.c:699:37: got struct em_perf_state [noderef] __rcu *kernel/power/energy_model.c:733:38: warning: incorrect type in argument 3 (different address spaces)kernel/power/energy_model.c:733:38: expected struct em_perf_state *tablekernel/power/energy_model.c:733:38: got struct em_perf_state [noderef] __rcu *kernel/power/energy_model.c:855:53: warning: dereference of noderef expression kernel/power/energy_model.c:864:32: warning: dereference of noderef expression
This is because the __rcu annotation for sparse is only applicable to pointers that need rcu_dereference() or equivalent for protection, which basically means pointers assigned with rcu_assign_pointer().
Make all of the above sparse warnings go away by cleaning up the usage of __rcu and using rcu_dereference_protected() where applicable.
include/linux/energy_model.h +6 -6
@@ -167,13 +167,13 @@ struct em_data_callback {struct em_perf_domain *em_cpu_get (int cpu);struct em_perf_domain *em_pd_get (struct device *dev);int em_dev_update_perf_domain (struct device *dev, -struct em_perf_table __rcu *new_table); +struct em_perf_table *new_table);int em_dev_register_perf_domain (struct device *dev,unsigned int nr_states,const struct em_data_callback *cb,const cpumask_t *cpus,bool microwatts);void em_dev_unregister_perf_domain (struct device *dev); -struct em_perf_table __rcu *em_table_alloc (struct em_perf_domain *pd); -void em_table_free (struct em_perf_table __rcu *table); +struct em_perf_table *em_table_alloc (struct em_perf_domain *pd); +void em_table_free (struct em_perf_table *table);int em_dev_compute_costs (struct device *dev,struct em_perf_state *table,int nr_states);int em_dev_update_chip_binning (struct device *dev);
@@ -373,14 +373,14 @@ static inline int em_pd_nr_perf_states(struct em_perf_domain *pd)return 0 ; }static inline -struct em_perf_table __rcu *em_table_alloc (struct em_perf_domain *pd) +struct em_perf_table *em_table_alloc (struct em_perf_domain *pd) {return NULL ; } -static inline void em_table_free (struct em_perf_table __rcu *table) {} +static inline void em_table_free (struct em_perf_table *table) {}static inline int em_dev_update_perf_domain (struct device *dev, -struct em_perf_table __rcu *new_table) +struct em_perf_table *new_table) {return -EINVAL ; }
kernel/power/energy_model.c +20 -19
@@ -163,12 +163,8 @@ static void em_debug_remove_pd(struct device *dev) {}static void em_release_table_kref (struct kref *kref) { -struct em_perf_table __rcu *table; -/* It was the last owner of this table so we can free */ - table = container_of(kref, struct em_perf_table, kref); - -kfree_rcu (table, rcu); + kfree_rcu(container_of(kref, struct em_perf_table, kref), rcu); }/**
@@ -177,7 +173,7 @@ static void em_release_table_kref(struct kref *kref)* * No return values. */ -void em_table_free (struct em_perf_table __rcu *table) +void em_table_free (struct em_perf_table *table) {kref_put (&table->kref, em_release_table_kref); }
@@ -190,9 +186,9 @@ void em_table_free(struct em_perf_table __rcu *table)* has a user. * Returns allocated table or NULL. */ -struct em_perf_table __rcu *em_table_alloc (struct em_perf_domain *pd) +struct em_perf_table *em_table_alloc (struct em_perf_domain *pd) { -struct em_perf_table __rcu *table; +struct em_perf_table *table;int table_size; table_size =sizeof (struct em_perf_state ) * pd->nr_perf_states;
@@ -300,9 +296,9 @@ int em_dev_compute_costs(struct device *dev, struct em_perf_state *table,* Return 0 on success or an error code on failure. */ int em_dev_update_perf_domain (struct device *dev, -struct em_perf_table __rcu *new_table) +struct em_perf_table *new_table) { -struct em_perf_table __rcu *old_table; +struct em_perf_table *old_table;struct em_perf_domain *pd;if (!dev)
@@ -319,7 +315,8 @@ int em_dev_update_perf_domain(struct device *dev,kref_get (&new_table->kref); - old_table = pd->em_table; + old_table =rcu_dereference_protected (pd->em_table, +lockdep_is_held (&em_pd_mutex));rcu_assign_pointer (pd->em_table, new_table);em_cpufreq_update_efficiencies (dev, new_table->state);
@@ -392,7 +389,7 @@ static int em_create_pd(struct device *dev, int nr_states, const cpumask_t *cpus, unsigned long flags) { -struct em_perf_table __rcu *em_table; +struct em_perf_table *em_table;struct em_perf_domain *pd;struct device *cpu_dev;int cpu, ret, num_cpus;
@@ -552,6 +549,7 @@ int em_dev_register_perf_domain(struct device *dev, unsigned int nr_states,const struct em_data_callback *cb, const cpumask_t *cpus, bool microwatts) { + struct em_perf_table *em_table;unsigned long cap, prev_cap =0 ;unsigned long flags =0 ;int cpu, ret;
@@ -624,7 +622,9 @@ int em_dev_register_perf_domain(struct device *dev, unsigned int nr_states, dev->em_pd->min_perf_state =0 ; dev->em_pd->max_perf_state = nr_states -1 ; -em_cpufreq_update_efficiencies (dev, dev->em_pd->em_table->state); + em_table =rcu_dereference_protected (dev->em_pd->em_table, +lockdep_is_held (&em_pd_mutex)); +em_cpufreq_update_efficiencies (dev, em_table->state);em_debug_create_pd (dev);dev_info (dev,"EM: created perf domain\n" );
@@ -661,7 +661,8 @@ void em_dev_unregister_perf_domain(struct device *dev)mutex_lock (&em_pd_mutex);em_debug_remove_pd (dev); -em_table_free (dev->em_pd->em_table); +em_table_free (rcu_dereference_protected (dev->em_pd->em_table, +lockdep_is_held (&em_pd_mutex)));kfree (dev->em_pd); dev->em_pd =NULL ;
@@ -669,9 +670,9 @@ void em_dev_unregister_perf_domain(struct device *dev) }EXPORT_SYMBOL_GPL (em_dev_unregister_perf_domain); -static struct em_perf_table __rcu *em_table_dup (struct em_perf_domain *pd) +static struct em_perf_table *em_table_dup (struct em_perf_domain *pd) { -struct em_perf_table __rcu *em_table; +struct em_perf_table *em_table;struct em_perf_state *ps, *new_ps;int ps_size;
@@ -693,7 +694,7 @@ static struct em_perf_table __rcu *em_table_dup(struct em_perf_domain *pd) }static int em_recalc_and_update (struct device *dev,struct em_perf_domain *pd, -struct em_perf_table __rcu *em_table) +struct em_perf_table *em_table) {int ret;
@@ -723,7 +724,7 @@ static int em_recalc_and_update(struct device *dev, struct em_perf_domain *pd,static void em_adjust_new_capacity (struct device *dev,struct em_perf_domain *pd) { -struct em_perf_table __rcu *em_table; +struct em_perf_table *em_table; em_table =em_table_dup (pd);if (!em_table) {
@@ -814,7 +815,7 @@ static void em_update_workfn(struct work_struct *work)*/ int em_dev_update_chip_binning (struct device *dev) { -struct em_perf_table __rcu *em_table; +struct em_perf_table *em_table;struct em_perf_domain *pd;int i, ret;