April 2025 - Linux-stable-mirror

FAILED: patch "[PATCH] PM: EM: Address RCU-related sparse warnings" failed to apply to 6.12-stable tree

by gregkh＠linuxfoundation.org

The patch below does not apply to the 6.12-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 <stable(a)vger.kernel.org>. 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-6.12.y git checkout FETCH_HEAD git cherry-pick -x 3ee7be9e10dd5f79448788b899591d4bd2bf0c19 # <resolve conflicts, build, test, etc.> git commit -s git send-email --to '<stable(a)vger.kernel.org>' --in-reply-to '2025041718-uncolored-uncurled-4619@gregkh' --subject-prefix 'PATCH 6.12.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" <rafael.j.wysocki(a)intel.com> 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 *table kernel/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 *head kernel/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 *kref kernel/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 *table kernel/power/energy_model.c:200:15: got void *[assigned] _res kernel/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 *kref kernel/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 *kref kernel/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 *table kernel/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 *table kernel/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 *objp kernel/power/energy_model.c:442:15: got struct em_perf_table [noderef] __rcu *[assigned] em_table kernel/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 *table kernel/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_ps kernel/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 *table kernel/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 *table kernel/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. Cc: All applicable <stable(a)vger.kernel.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki(a)intel.com> Reviewed-by: Lukasz Luba <lukasz.luba(a)arm.com> Link: https://patch.msgid.link/5885405.DvuYhMxLoT@rjwysocki.net diff --git a/include/linux/energy_model.h b/include/linux/energy_model.h index b23c8c798dac..ddd09debfc7d 100644 --- a/include/linux/energy_model.h +++ b/include/linux/energy_model.h @@ -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; } diff --git a/kernel/power/energy_model.c b/kernel/power/energy_model.c index 1e3caa96c271..d9b7e2b38c7a 100644 --- a/kernel/power/energy_model.c +++ b/kernel/power/energy_model.c @@ -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;

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FAILED: patch "[PATCH] PM: EM: Address RCU-related sparse warnings" failed to apply to 6.13-stable tree

by gregkh＠linuxfoundation.org

The patch below does not apply to the 6.13-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 <stable(a)vger.kernel.org>. 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-6.13.y git checkout FETCH_HEAD git cherry-pick -x 3ee7be9e10dd5f79448788b899591d4bd2bf0c19 # <resolve conflicts, build, test, etc.> git commit -s git send-email --to '<stable(a)vger.kernel.org>' --in-reply-to '2025041716-stack-slacking-56df@gregkh' --subject-prefix 'PATCH 6.13.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" <rafael.j.wysocki(a)intel.com> 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 *table kernel/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 *head kernel/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 *kref kernel/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 *table kernel/power/energy_model.c:200:15: got void *[assigned] _res kernel/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 *kref kernel/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 *kref kernel/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 *table kernel/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 *table kernel/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 *objp kernel/power/energy_model.c:442:15: got struct em_perf_table [noderef] __rcu *[assigned] em_table kernel/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 *table kernel/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_ps kernel/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 *table kernel/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 *table kernel/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. Cc: All applicable <stable(a)vger.kernel.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki(a)intel.com> Reviewed-by: Lukasz Luba <lukasz.luba(a)arm.com> Link: https://patch.msgid.link/5885405.DvuYhMxLoT@rjwysocki.net diff --git a/include/linux/energy_model.h b/include/linux/energy_model.h index b23c8c798dac..ddd09debfc7d 100644 --- a/include/linux/energy_model.h +++ b/include/linux/energy_model.h @@ -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; } diff --git a/kernel/power/energy_model.c b/kernel/power/energy_model.c index 1e3caa96c271..d9b7e2b38c7a 100644 --- a/kernel/power/energy_model.c +++ b/kernel/power/energy_model.c @@ -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;

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FAILED: patch "[PATCH] PM: EM: Address RCU-related sparse warnings" failed to apply to 6.14-stable tree

by gregkh＠linuxfoundation.org

The patch below does not apply to the 6.14-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 <stable(a)vger.kernel.org>. 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-6.14.y git checkout FETCH_HEAD git cherry-pick -x 3ee7be9e10dd5f79448788b899591d4bd2bf0c19 # <resolve conflicts, build, test, etc.> git commit -s git send-email --to '<stable(a)vger.kernel.org>' --in-reply-to '2025041714-powdering-frill-e0f2@gregkh' --subject-prefix 'PATCH 6.14.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" <rafael.j.wysocki(a)intel.com> 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 *table kernel/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 *head kernel/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 *kref kernel/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 *table kernel/power/energy_model.c:200:15: got void *[assigned] _res kernel/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 *kref kernel/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 *kref kernel/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 *table kernel/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 *table kernel/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 *objp kernel/power/energy_model.c:442:15: got struct em_perf_table [noderef] __rcu *[assigned] em_table kernel/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 *table kernel/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_ps kernel/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 *table kernel/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 *table kernel/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. Cc: All applicable <stable(a)vger.kernel.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki(a)intel.com> Reviewed-by: Lukasz Luba <lukasz.luba(a)arm.com> Link: https://patch.msgid.link/5885405.DvuYhMxLoT@rjwysocki.net diff --git a/include/linux/energy_model.h b/include/linux/energy_model.h index b23c8c798dac..ddd09debfc7d 100644 --- a/include/linux/energy_model.h +++ b/include/linux/energy_model.h @@ -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; } diff --git a/kernel/power/energy_model.c b/kernel/power/energy_model.c index 1e3caa96c271..d9b7e2b38c7a 100644 --- a/kernel/power/energy_model.c +++ b/kernel/power/energy_model.c @@ -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;

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FAILED: patch "[PATCH] spi: cadence-qspi: Fix probe on AM62A LP SK" failed to apply to 5.4-stable tree

by gregkh＠linuxfoundation.org

The patch below does not apply to the 5.4-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 <stable(a)vger.kernel.org>. 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-5.4.y git checkout FETCH_HEAD git cherry-pick -x b8665a1b49f5498edb7b21d730030c06b7348a3c # <resolve conflicts, build, test, etc.> git commit -s git send-email --to '<stable(a)vger.kernel.org>' --in-reply-to '2025041752-harmless-scoring-d983@gregkh' --subject-prefix 'PATCH 5.4.y' HEAD^.. Possible dependencies: thanks, greg k-h ------------------ original commit in Linus's tree ------------------ From b8665a1b49f5498edb7b21d730030c06b7348a3c Mon Sep 17 00:00:00 2001 From: Miquel Raynal <miquel.raynal(a)bootlin.com> Date: Wed, 5 Mar 2025 21:09:32 +0100 Subject: [PATCH] spi: cadence-qspi: Fix probe on AM62A LP SK In 2020, there's been an unnoticed change which rightfully attempted to report probe deferrals upon DMA absence by checking the return value of dma_request_chan_by_mask(). By doing so, it also reported errors which were simply ignored otherwise, likely on purpose. This change actually turned a void return into an error code. Hence, not only the -EPROBE_DEFER error codes but all error codes got reported to the callers, now failing to probe in the absence of Rx DMA channel, despite the fact that DMA seems to not be supported natively by many implementations. Looking at the history, this change probably led to: ad2775dc3fc5 ("spi: cadence-quadspi: Disable the DAC for Intel LGM SoC") f724c296f2f2 ("spi: cadence-quadspi: fix Direct Access Mode disable for SoCFPGA") In my case, the AM62A LP SK core octo-SPI node from TI does not advertise any DMA channel, hinting that there is likely no support for it, but yet when the support for the am654 compatible was added, DMA seemed to be used, so just discarding its use with the CQSPI_DISABLE_DAC_MODE quirk for this compatible does not seem the correct approach. Let's get change the return condition back to: - return a probe deferral error if we get one - ignore the return value otherwise The "error" log level was however likely too high for something that is expected to fail, so let's lower it arbitrarily to the info level. Fixes: 935da5e5100f ("mtd: spi-nor: cadence-quadspi: Handle probe deferral while requesting DMA channel") Cc: stable(a)vger.kernel.org Signed-off-by: Miquel Raynal <miquel.raynal(a)bootlin.com> Link: https://patch.msgid.link/20250305200933.2512925-2-miquel.raynal@bootlin.com Signed-off-by: Mark Brown <broonie(a)kernel.org> diff --git a/drivers/spi/spi-cadence-quadspi.c b/drivers/spi/spi-cadence-quadspi.c index 0cd37a7436d5..c90462783b3f 100644 --- a/drivers/spi/spi-cadence-quadspi.c +++ b/drivers/spi/spi-cadence-quadspi.c @@ -1658,6 +1658,12 @@ static int cqspi_request_mmap_dma(struct cqspi_st *cqspi) int ret = PTR_ERR(cqspi->rx_chan); cqspi->rx_chan = NULL; + if (ret == -ENODEV) { + /* DMA support is not mandatory */ + dev_info(&cqspi->pdev->dev, "No Rx DMA available\n"); + return 0; + } + return dev_err_probe(&cqspi->pdev->dev, ret, "No Rx DMA available\n"); } init_completion(&cqspi->rx_dma_complete);

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FAILED: patch "[PATCH] KVM: arm64: Set HCR_EL2.TID1 unconditionally" failed to apply to 6.1-stable tree

by gregkh＠linuxfoundation.org

The patch below does not apply to the 6.1-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 <stable(a)vger.kernel.org>. 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-6.1.y git checkout FETCH_HEAD git cherry-pick -x 4cd48565b0e5df398e7253c0d2d8c0403d69e7bf # <resolve conflicts, build, test, etc.> git commit -s git send-email --to '<stable(a)vger.kernel.org>' --in-reply-to '2025041727-cozy-manual-7575@gregkh' --subject-prefix 'PATCH 6.1.y' HEAD^.. Possible dependencies: thanks, greg k-h ------------------ original commit in Linus's tree ------------------ From 4cd48565b0e5df398e7253c0d2d8c0403d69e7bf Mon Sep 17 00:00:00 2001 From: Oliver Upton <oliver.upton(a)linux.dev> Date: Mon, 24 Feb 2025 16:53:57 -0800 Subject: [PATCH] KVM: arm64: Set HCR_EL2.TID1 unconditionally commit 90807748ca3a ("KVM: arm64: Hide SME system registers from guests") added trap handling for SMIDR_EL1, treating it as UNDEFINED as KVM does not support SME. This is right for the most part, however KVM needs to set HCR_EL2.TID1 to _actually_ trap the register. Unfortunately, this comes with some collateral damage as TID1 forces REVIDR_EL1 and AIDR_EL1 to trap as well. KVM has long treated these registers as "invariant" which is an awful term for the following: - Userspace sees the boot CPU values on all vCPUs - The guest sees the hardware values of the CPU on which a vCPU is scheduled Keep the plates spinning by adding trap handling for the affected registers and repaint all of the "invariant" crud into terms of identifying an implementation. Yes, at this point we only need to set TID1 on SME hardware, but REVIDR_EL1 and AIDR_EL1 are about to become mutable anyway. Cc: Mark Brown <broonie(a)kernel.org> Cc: stable(a)vger.kernel.org Fixes: 90807748ca3a ("KVM: arm64: Hide SME system registers from guests") [maz: handle traps from 32bit] Co-developed-by: Marc Zyngier <maz(a)kernel.org> Signed-off-by: Marc Zyngier <maz(a)kernel.org> Link: https://lore.kernel.org/r/20250225005401.679536-2-oliver.upton@linux.dev Signed-off-by: Oliver Upton <oliver.upton(a)linux.dev> diff --git a/arch/arm64/include/asm/kvm_arm.h b/arch/arm64/include/asm/kvm_arm.h index 8d94a6c0ed5c..b01c01e55de5 100644 --- a/arch/arm64/include/asm/kvm_arm.h +++ b/arch/arm64/include/asm/kvm_arm.h @@ -92,12 +92,12 @@ * SWIO: Turn set/way invalidates into set/way clean+invalidate * PTW: Take a stage2 fault if a stage1 walk steps in device memory * TID3: Trap EL1 reads of group 3 ID registers - * TID2: Trap CTR_EL0, CCSIDR2_EL1, CLIDR_EL1, and CSSELR_EL1 + * TID1: Trap REVIDR_EL1, AIDR_EL1, and SMIDR_EL1 */ #define HCR_GUEST_FLAGS (HCR_TSC | HCR_TSW | HCR_TWE | HCR_TWI | HCR_VM | \ HCR_BSU_IS | HCR_FB | HCR_TACR | \ HCR_AMO | HCR_SWIO | HCR_TIDCP | HCR_RW | HCR_TLOR | \ - HCR_FMO | HCR_IMO | HCR_PTW | HCR_TID3) + HCR_FMO | HCR_IMO | HCR_PTW | HCR_TID3 | HCR_TID1) #define HCR_HOST_NVHE_FLAGS (HCR_RW | HCR_API | HCR_APK | HCR_ATA) #define HCR_HOST_NVHE_PROTECTED_FLAGS (HCR_HOST_NVHE_FLAGS | HCR_TSC) #define HCR_HOST_VHE_FLAGS (HCR_RW | HCR_TGE | HCR_E2H) diff --git a/arch/arm64/kvm/sys_regs.c b/arch/arm64/kvm/sys_regs.c index 82430c1e1dd0..57e945d6b715 100644 --- a/arch/arm64/kvm/sys_regs.c +++ b/arch/arm64/kvm/sys_regs.c @@ -2493,6 +2493,93 @@ static bool access_mdcr(struct kvm_vcpu *vcpu, return true; } +/* + * For historical (ahem ABI) reasons, KVM treated MIDR_EL1, REVIDR_EL1, and + * AIDR_EL1 as "invariant" registers, meaning userspace cannot change them. + * The values made visible to userspace were the register values of the boot + * CPU. + * + * At the same time, reads from these registers at EL1 previously were not + * trapped, allowing the guest to read the actual hardware value. On big-little + * machines, this means the VM can see different values depending on where a + * given vCPU got scheduled. + * + * These registers are now trapped as collateral damage from SME, and what + * follows attempts to give a user / guest view consistent with the existing + * ABI. + */ +static bool access_imp_id_reg(struct kvm_vcpu *vcpu, + struct sys_reg_params *p, + const struct sys_reg_desc *r) +{ + if (p->is_write) + return write_to_read_only(vcpu, p, r); + + switch (reg_to_encoding(r)) { + case SYS_REVIDR_EL1: + p->regval = read_sysreg(revidr_el1); + break; + case SYS_AIDR_EL1: + p->regval = read_sysreg(aidr_el1); + break; + default: + WARN_ON_ONCE(1); + } + + return true; +} + +static u64 __ro_after_init boot_cpu_midr_val; +static u64 __ro_after_init boot_cpu_revidr_val; +static u64 __ro_after_init boot_cpu_aidr_val; + +static void init_imp_id_regs(void) +{ + boot_cpu_midr_val = read_sysreg(midr_el1); + boot_cpu_revidr_val = read_sysreg(revidr_el1); + boot_cpu_aidr_val = read_sysreg(aidr_el1); +} + +static int get_imp_id_reg(struct kvm_vcpu *vcpu, const struct sys_reg_desc *r, + u64 *val) +{ + switch (reg_to_encoding(r)) { + case SYS_MIDR_EL1: + *val = boot_cpu_midr_val; + break; + case SYS_REVIDR_EL1: + *val = boot_cpu_revidr_val; + break; + case SYS_AIDR_EL1: + *val = boot_cpu_aidr_val; + break; + default: + WARN_ON_ONCE(1); + return -EINVAL; + } + + return 0; +} + +static int set_imp_id_reg(struct kvm_vcpu *vcpu, const struct sys_reg_desc *r, + u64 val) +{ + u64 expected; + int ret; + + ret = get_imp_id_reg(vcpu, r, &expected); + if (ret) + return ret; + + return (expected == val) ? 0 : -EINVAL; +} + +#define IMPLEMENTATION_ID(reg) { \ + SYS_DESC(SYS_##reg), \ + .access = access_imp_id_reg, \ + .get_user = get_imp_id_reg, \ + .set_user = set_imp_id_reg, \ +} /* * Architected system registers. @@ -2542,7 +2629,9 @@ static const struct sys_reg_desc sys_reg_descs[] = { { SYS_DESC(SYS_DBGVCR32_EL2), undef_access, reset_val, DBGVCR32_EL2, 0 }, + IMPLEMENTATION_ID(MIDR_EL1), { SYS_DESC(SYS_MPIDR_EL1), NULL, reset_mpidr, MPIDR_EL1 }, + IMPLEMENTATION_ID(REVIDR_EL1), /* * ID regs: all ID_SANITISED() entries here must have corresponding @@ -2814,6 +2903,7 @@ static const struct sys_reg_desc sys_reg_descs[] = { .set_user = set_clidr, .val = ~CLIDR_EL1_RES0 }, { SYS_DESC(SYS_CCSIDR2_EL1), undef_access }, { SYS_DESC(SYS_SMIDR_EL1), undef_access }, + IMPLEMENTATION_ID(AIDR_EL1), { SYS_DESC(SYS_CSSELR_EL1), access_csselr, reset_unknown, CSSELR_EL1 }, ID_FILTERED(CTR_EL0, ctr_el0, CTR_EL0_DIC_MASK | @@ -4272,9 +4362,13 @@ int kvm_handle_cp15_32(struct kvm_vcpu *vcpu) * Certain AArch32 ID registers are handled by rerouting to the AArch64 * system register table. Registers in the ID range where CRm=0 are * excluded from this scheme as they do not trivially map into AArch64 - * system register encodings. + * system register encodings, except for AIDR/REVIDR. */ - if (params.Op1 == 0 && params.CRn == 0 && params.CRm) + if (params.Op1 == 0 && params.CRn == 0 && + (params.CRm || params.Op2 == 6 /* REVIDR */)) + return kvm_emulate_cp15_id_reg(vcpu, &params); + if (params.Op1 == 1 && params.CRn == 0 && + params.CRm == 0 && params.Op2 == 7 /* AIDR */) return kvm_emulate_cp15_id_reg(vcpu, &params); return kvm_handle_cp_32(vcpu, &params, cp15_regs, ARRAY_SIZE(cp15_regs)); @@ -4578,65 +4672,6 @@ id_to_sys_reg_desc(struct kvm_vcpu *vcpu, u64 id, return r; } -/* - * These are the invariant sys_reg registers: we let the guest see the - * host versions of these, so they're part of the guest state. - * - * A future CPU may provide a mechanism to present different values to - * the guest, or a future kvm may trap them. - */ - -#define FUNCTION_INVARIANT(reg) \ - static u64 reset_##reg(struct kvm_vcpu *v, \ - const struct sys_reg_desc *r) \ - { \ - ((struct sys_reg_desc *)r)->val = read_sysreg(reg); \ - return ((struct sys_reg_desc *)r)->val; \ - } - -FUNCTION_INVARIANT(midr_el1) -FUNCTION_INVARIANT(revidr_el1) -FUNCTION_INVARIANT(aidr_el1) - -/* ->val is filled in by kvm_sys_reg_table_init() */ -static struct sys_reg_desc invariant_sys_regs[] __ro_after_init = { - { SYS_DESC(SYS_MIDR_EL1), NULL, reset_midr_el1 }, - { SYS_DESC(SYS_REVIDR_EL1), NULL, reset_revidr_el1 }, - { SYS_DESC(SYS_AIDR_EL1), NULL, reset_aidr_el1 }, -}; - -static int get_invariant_sys_reg(u64 id, u64 __user *uaddr) -{ - const struct sys_reg_desc *r; - - r = get_reg_by_id(id, invariant_sys_regs, - ARRAY_SIZE(invariant_sys_regs)); - if (!r) - return -ENOENT; - - return put_user(r->val, uaddr); -} - -static int set_invariant_sys_reg(u64 id, u64 __user *uaddr) -{ - const struct sys_reg_desc *r; - u64 val; - - r = get_reg_by_id(id, invariant_sys_regs, - ARRAY_SIZE(invariant_sys_regs)); - if (!r) - return -ENOENT; - - if (get_user(val, uaddr)) - return -EFAULT; - - /* This is what we mean by invariant: you can't change it. */ - if (r->val != val) - return -EINVAL; - - return 0; -} - static int demux_c15_get(struct kvm_vcpu *vcpu, u64 id, void __user *uaddr) { u32 val; @@ -4718,15 +4753,10 @@ int kvm_sys_reg_get_user(struct kvm_vcpu *vcpu, const struct kvm_one_reg *reg, int kvm_arm_sys_reg_get_reg(struct kvm_vcpu *vcpu, const struct kvm_one_reg *reg) { void __user *uaddr = (void __user *)(unsigned long)reg->addr; - int err; if ((reg->id & KVM_REG_ARM_COPROC_MASK) == KVM_REG_ARM_DEMUX) return demux_c15_get(vcpu, reg->id, uaddr); - err = get_invariant_sys_reg(reg->id, uaddr); - if (err != -ENOENT) - return err; - return kvm_sys_reg_get_user(vcpu, reg, sys_reg_descs, ARRAY_SIZE(sys_reg_descs)); } @@ -4762,15 +4792,10 @@ int kvm_sys_reg_set_user(struct kvm_vcpu *vcpu, const struct kvm_one_reg *reg, int kvm_arm_sys_reg_set_reg(struct kvm_vcpu *vcpu, const struct kvm_one_reg *reg) { void __user *uaddr = (void __user *)(unsigned long)reg->addr; - int err; if ((reg->id & KVM_REG_ARM_COPROC_MASK) == KVM_REG_ARM_DEMUX) return demux_c15_set(vcpu, reg->id, uaddr); - err = set_invariant_sys_reg(reg->id, uaddr); - if (err != -ENOENT) - return err; - return kvm_sys_reg_set_user(vcpu, reg, sys_reg_descs, ARRAY_SIZE(sys_reg_descs)); } @@ -4859,23 +4884,14 @@ static int walk_sys_regs(struct kvm_vcpu *vcpu, u64 __user *uind) unsigned long kvm_arm_num_sys_reg_descs(struct kvm_vcpu *vcpu) { - return ARRAY_SIZE(invariant_sys_regs) - + num_demux_regs() + return num_demux_regs() + walk_sys_regs(vcpu, (u64 __user *)NULL); } int kvm_arm_copy_sys_reg_indices(struct kvm_vcpu *vcpu, u64 __user *uindices) { - unsigned int i; int err; - /* Then give them all the invariant registers' indices. */ - for (i = 0; i < ARRAY_SIZE(invariant_sys_regs); i++) { - if (put_user(sys_reg_to_index(&invariant_sys_regs[i]), uindices)) - return -EFAULT; - uindices++; - } - err = walk_sys_regs(vcpu, uindices); if (err < 0) return err; @@ -5101,15 +5117,12 @@ int __init kvm_sys_reg_table_init(void) valid &= check_sysreg_table(cp14_64_regs, ARRAY_SIZE(cp14_64_regs), true); valid &= check_sysreg_table(cp15_regs, ARRAY_SIZE(cp15_regs), true); valid &= check_sysreg_table(cp15_64_regs, ARRAY_SIZE(cp15_64_regs), true); - valid &= check_sysreg_table(invariant_sys_regs, ARRAY_SIZE(invariant_sys_regs), false); valid &= check_sysreg_table(sys_insn_descs, ARRAY_SIZE(sys_insn_descs), false); if (!valid) return -EINVAL; - /* We abuse the reset function to overwrite the table itself. */ - for (i = 0; i < ARRAY_SIZE(invariant_sys_regs); i++) - invariant_sys_regs[i].reset(NULL, &invariant_sys_regs[i]); + init_imp_id_regs(); ret = populate_nv_trap_config();

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FAILED: patch "[PATCH] KVM: arm64: Set HCR_EL2.TID1 unconditionally" failed to apply to 6.6-stable tree

by gregkh＠linuxfoundation.org

The patch below does not apply to the 6.6-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 <stable(a)vger.kernel.org>. 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-6.6.y git checkout FETCH_HEAD git cherry-pick -x 4cd48565b0e5df398e7253c0d2d8c0403d69e7bf # <resolve conflicts, build, test, etc.> git commit -s git send-email --to '<stable(a)vger.kernel.org>' --in-reply-to '2025041726-radar-catcher-d061@gregkh' --subject-prefix 'PATCH 6.6.y' HEAD^.. Possible dependencies: thanks, greg k-h ------------------ original commit in Linus's tree ------------------ From 4cd48565b0e5df398e7253c0d2d8c0403d69e7bf Mon Sep 17 00:00:00 2001 From: Oliver Upton <oliver.upton(a)linux.dev> Date: Mon, 24 Feb 2025 16:53:57 -0800 Subject: [PATCH] KVM: arm64: Set HCR_EL2.TID1 unconditionally commit 90807748ca3a ("KVM: arm64: Hide SME system registers from guests") added trap handling for SMIDR_EL1, treating it as UNDEFINED as KVM does not support SME. This is right for the most part, however KVM needs to set HCR_EL2.TID1 to _actually_ trap the register. Unfortunately, this comes with some collateral damage as TID1 forces REVIDR_EL1 and AIDR_EL1 to trap as well. KVM has long treated these registers as "invariant" which is an awful term for the following: - Userspace sees the boot CPU values on all vCPUs - The guest sees the hardware values of the CPU on which a vCPU is scheduled Keep the plates spinning by adding trap handling for the affected registers and repaint all of the "invariant" crud into terms of identifying an implementation. Yes, at this point we only need to set TID1 on SME hardware, but REVIDR_EL1 and AIDR_EL1 are about to become mutable anyway. Cc: Mark Brown <broonie(a)kernel.org> Cc: stable(a)vger.kernel.org Fixes: 90807748ca3a ("KVM: arm64: Hide SME system registers from guests") [maz: handle traps from 32bit] Co-developed-by: Marc Zyngier <maz(a)kernel.org> Signed-off-by: Marc Zyngier <maz(a)kernel.org> Link: https://lore.kernel.org/r/20250225005401.679536-2-oliver.upton@linux.dev Signed-off-by: Oliver Upton <oliver.upton(a)linux.dev> diff --git a/arch/arm64/include/asm/kvm_arm.h b/arch/arm64/include/asm/kvm_arm.h index 8d94a6c0ed5c..b01c01e55de5 100644 --- a/arch/arm64/include/asm/kvm_arm.h +++ b/arch/arm64/include/asm/kvm_arm.h @@ -92,12 +92,12 @@ * SWIO: Turn set/way invalidates into set/way clean+invalidate * PTW: Take a stage2 fault if a stage1 walk steps in device memory * TID3: Trap EL1 reads of group 3 ID registers - * TID2: Trap CTR_EL0, CCSIDR2_EL1, CLIDR_EL1, and CSSELR_EL1 + * TID1: Trap REVIDR_EL1, AIDR_EL1, and SMIDR_EL1 */ #define HCR_GUEST_FLAGS (HCR_TSC | HCR_TSW | HCR_TWE | HCR_TWI | HCR_VM | \ HCR_BSU_IS | HCR_FB | HCR_TACR | \ HCR_AMO | HCR_SWIO | HCR_TIDCP | HCR_RW | HCR_TLOR | \ - HCR_FMO | HCR_IMO | HCR_PTW | HCR_TID3) + HCR_FMO | HCR_IMO | HCR_PTW | HCR_TID3 | HCR_TID1) #define HCR_HOST_NVHE_FLAGS (HCR_RW | HCR_API | HCR_APK | HCR_ATA) #define HCR_HOST_NVHE_PROTECTED_FLAGS (HCR_HOST_NVHE_FLAGS | HCR_TSC) #define HCR_HOST_VHE_FLAGS (HCR_RW | HCR_TGE | HCR_E2H) diff --git a/arch/arm64/kvm/sys_regs.c b/arch/arm64/kvm/sys_regs.c index 82430c1e1dd0..57e945d6b715 100644 --- a/arch/arm64/kvm/sys_regs.c +++ b/arch/arm64/kvm/sys_regs.c @@ -2493,6 +2493,93 @@ static bool access_mdcr(struct kvm_vcpu *vcpu, return true; } +/* + * For historical (ahem ABI) reasons, KVM treated MIDR_EL1, REVIDR_EL1, and + * AIDR_EL1 as "invariant" registers, meaning userspace cannot change them. + * The values made visible to userspace were the register values of the boot + * CPU. + * + * At the same time, reads from these registers at EL1 previously were not + * trapped, allowing the guest to read the actual hardware value. On big-little + * machines, this means the VM can see different values depending on where a + * given vCPU got scheduled. + * + * These registers are now trapped as collateral damage from SME, and what + * follows attempts to give a user / guest view consistent with the existing + * ABI. + */ +static bool access_imp_id_reg(struct kvm_vcpu *vcpu, + struct sys_reg_params *p, + const struct sys_reg_desc *r) +{ + if (p->is_write) + return write_to_read_only(vcpu, p, r); + + switch (reg_to_encoding(r)) { + case SYS_REVIDR_EL1: + p->regval = read_sysreg(revidr_el1); + break; + case SYS_AIDR_EL1: + p->regval = read_sysreg(aidr_el1); + break; + default: + WARN_ON_ONCE(1); + } + + return true; +} + +static u64 __ro_after_init boot_cpu_midr_val; +static u64 __ro_after_init boot_cpu_revidr_val; +static u64 __ro_after_init boot_cpu_aidr_val; + +static void init_imp_id_regs(void) +{ + boot_cpu_midr_val = read_sysreg(midr_el1); + boot_cpu_revidr_val = read_sysreg(revidr_el1); + boot_cpu_aidr_val = read_sysreg(aidr_el1); +} + +static int get_imp_id_reg(struct kvm_vcpu *vcpu, const struct sys_reg_desc *r, + u64 *val) +{ + switch (reg_to_encoding(r)) { + case SYS_MIDR_EL1: + *val = boot_cpu_midr_val; + break; + case SYS_REVIDR_EL1: + *val = boot_cpu_revidr_val; + break; + case SYS_AIDR_EL1: + *val = boot_cpu_aidr_val; + break; + default: + WARN_ON_ONCE(1); + return -EINVAL; + } + + return 0; +} + +static int set_imp_id_reg(struct kvm_vcpu *vcpu, const struct sys_reg_desc *r, + u64 val) +{ + u64 expected; + int ret; + + ret = get_imp_id_reg(vcpu, r, &expected); + if (ret) + return ret; + + return (expected == val) ? 0 : -EINVAL; +} + +#define IMPLEMENTATION_ID(reg) { \ + SYS_DESC(SYS_##reg), \ + .access = access_imp_id_reg, \ + .get_user = get_imp_id_reg, \ + .set_user = set_imp_id_reg, \ +} /* * Architected system registers. @@ -2542,7 +2629,9 @@ static const struct sys_reg_desc sys_reg_descs[] = { { SYS_DESC(SYS_DBGVCR32_EL2), undef_access, reset_val, DBGVCR32_EL2, 0 }, + IMPLEMENTATION_ID(MIDR_EL1), { SYS_DESC(SYS_MPIDR_EL1), NULL, reset_mpidr, MPIDR_EL1 }, + IMPLEMENTATION_ID(REVIDR_EL1), /* * ID regs: all ID_SANITISED() entries here must have corresponding @@ -2814,6 +2903,7 @@ static const struct sys_reg_desc sys_reg_descs[] = { .set_user = set_clidr, .val = ~CLIDR_EL1_RES0 }, { SYS_DESC(SYS_CCSIDR2_EL1), undef_access }, { SYS_DESC(SYS_SMIDR_EL1), undef_access }, + IMPLEMENTATION_ID(AIDR_EL1), { SYS_DESC(SYS_CSSELR_EL1), access_csselr, reset_unknown, CSSELR_EL1 }, ID_FILTERED(CTR_EL0, ctr_el0, CTR_EL0_DIC_MASK | @@ -4272,9 +4362,13 @@ int kvm_handle_cp15_32(struct kvm_vcpu *vcpu) * Certain AArch32 ID registers are handled by rerouting to the AArch64 * system register table. Registers in the ID range where CRm=0 are * excluded from this scheme as they do not trivially map into AArch64 - * system register encodings. + * system register encodings, except for AIDR/REVIDR. */ - if (params.Op1 == 0 && params.CRn == 0 && params.CRm) + if (params.Op1 == 0 && params.CRn == 0 && + (params.CRm || params.Op2 == 6 /* REVIDR */)) + return kvm_emulate_cp15_id_reg(vcpu, &params); + if (params.Op1 == 1 && params.CRn == 0 && + params.CRm == 0 && params.Op2 == 7 /* AIDR */) return kvm_emulate_cp15_id_reg(vcpu, &params); return kvm_handle_cp_32(vcpu, &params, cp15_regs, ARRAY_SIZE(cp15_regs)); @@ -4578,65 +4672,6 @@ id_to_sys_reg_desc(struct kvm_vcpu *vcpu, u64 id, return r; } -/* - * These are the invariant sys_reg registers: we let the guest see the - * host versions of these, so they're part of the guest state. - * - * A future CPU may provide a mechanism to present different values to - * the guest, or a future kvm may trap them. - */ - -#define FUNCTION_INVARIANT(reg) \ - static u64 reset_##reg(struct kvm_vcpu *v, \ - const struct sys_reg_desc *r) \ - { \ - ((struct sys_reg_desc *)r)->val = read_sysreg(reg); \ - return ((struct sys_reg_desc *)r)->val; \ - } - -FUNCTION_INVARIANT(midr_el1) -FUNCTION_INVARIANT(revidr_el1) -FUNCTION_INVARIANT(aidr_el1) - -/* ->val is filled in by kvm_sys_reg_table_init() */ -static struct sys_reg_desc invariant_sys_regs[] __ro_after_init = { - { SYS_DESC(SYS_MIDR_EL1), NULL, reset_midr_el1 }, - { SYS_DESC(SYS_REVIDR_EL1), NULL, reset_revidr_el1 }, - { SYS_DESC(SYS_AIDR_EL1), NULL, reset_aidr_el1 }, -}; - -static int get_invariant_sys_reg(u64 id, u64 __user *uaddr) -{ - const struct sys_reg_desc *r; - - r = get_reg_by_id(id, invariant_sys_regs, - ARRAY_SIZE(invariant_sys_regs)); - if (!r) - return -ENOENT; - - return put_user(r->val, uaddr); -} - -static int set_invariant_sys_reg(u64 id, u64 __user *uaddr) -{ - const struct sys_reg_desc *r; - u64 val; - - r = get_reg_by_id(id, invariant_sys_regs, - ARRAY_SIZE(invariant_sys_regs)); - if (!r) - return -ENOENT; - - if (get_user(val, uaddr)) - return -EFAULT; - - /* This is what we mean by invariant: you can't change it. */ - if (r->val != val) - return -EINVAL; - - return 0; -} - static int demux_c15_get(struct kvm_vcpu *vcpu, u64 id, void __user *uaddr) { u32 val; @@ -4718,15 +4753,10 @@ int kvm_sys_reg_get_user(struct kvm_vcpu *vcpu, const struct kvm_one_reg *reg, int kvm_arm_sys_reg_get_reg(struct kvm_vcpu *vcpu, const struct kvm_one_reg *reg) { void __user *uaddr = (void __user *)(unsigned long)reg->addr; - int err; if ((reg->id & KVM_REG_ARM_COPROC_MASK) == KVM_REG_ARM_DEMUX) return demux_c15_get(vcpu, reg->id, uaddr); - err = get_invariant_sys_reg(reg->id, uaddr); - if (err != -ENOENT) - return err; - return kvm_sys_reg_get_user(vcpu, reg, sys_reg_descs, ARRAY_SIZE(sys_reg_descs)); } @@ -4762,15 +4792,10 @@ int kvm_sys_reg_set_user(struct kvm_vcpu *vcpu, const struct kvm_one_reg *reg, int kvm_arm_sys_reg_set_reg(struct kvm_vcpu *vcpu, const struct kvm_one_reg *reg) { void __user *uaddr = (void __user *)(unsigned long)reg->addr; - int err; if ((reg->id & KVM_REG_ARM_COPROC_MASK) == KVM_REG_ARM_DEMUX) return demux_c15_set(vcpu, reg->id, uaddr); - err = set_invariant_sys_reg(reg->id, uaddr); - if (err != -ENOENT) - return err; - return kvm_sys_reg_set_user(vcpu, reg, sys_reg_descs, ARRAY_SIZE(sys_reg_descs)); } @@ -4859,23 +4884,14 @@ static int walk_sys_regs(struct kvm_vcpu *vcpu, u64 __user *uind) unsigned long kvm_arm_num_sys_reg_descs(struct kvm_vcpu *vcpu) { - return ARRAY_SIZE(invariant_sys_regs) - + num_demux_regs() + return num_demux_regs() + walk_sys_regs(vcpu, (u64 __user *)NULL); } int kvm_arm_copy_sys_reg_indices(struct kvm_vcpu *vcpu, u64 __user *uindices) { - unsigned int i; int err; - /* Then give them all the invariant registers' indices. */ - for (i = 0; i < ARRAY_SIZE(invariant_sys_regs); i++) { - if (put_user(sys_reg_to_index(&invariant_sys_regs[i]), uindices)) - return -EFAULT; - uindices++; - } - err = walk_sys_regs(vcpu, uindices); if (err < 0) return err; @@ -5101,15 +5117,12 @@ int __init kvm_sys_reg_table_init(void) valid &= check_sysreg_table(cp14_64_regs, ARRAY_SIZE(cp14_64_regs), true); valid &= check_sysreg_table(cp15_regs, ARRAY_SIZE(cp15_regs), true); valid &= check_sysreg_table(cp15_64_regs, ARRAY_SIZE(cp15_64_regs), true); - valid &= check_sysreg_table(invariant_sys_regs, ARRAY_SIZE(invariant_sys_regs), false); valid &= check_sysreg_table(sys_insn_descs, ARRAY_SIZE(sys_insn_descs), false); if (!valid) return -EINVAL; - /* We abuse the reset function to overwrite the table itself. */ - for (i = 0; i < ARRAY_SIZE(invariant_sys_regs); i++) - invariant_sys_regs[i].reset(NULL, &invariant_sys_regs[i]); + init_imp_id_regs(); ret = populate_nv_trap_config();

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FAILED: patch "[PATCH] KVM: arm64: Set HCR_EL2.TID1 unconditionally" failed to apply to 6.12-stable tree

by gregkh＠linuxfoundation.org

The patch below does not apply to the 6.12-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 <stable(a)vger.kernel.org>. 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-6.12.y git checkout FETCH_HEAD git cherry-pick -x 4cd48565b0e5df398e7253c0d2d8c0403d69e7bf # <resolve conflicts, build, test, etc.> git commit -s git send-email --to '<stable(a)vger.kernel.org>' --in-reply-to '2025041726-condiment-numeral-db82@gregkh' --subject-prefix 'PATCH 6.12.y' HEAD^.. Possible dependencies: thanks, greg k-h ------------------ original commit in Linus's tree ------------------ From 4cd48565b0e5df398e7253c0d2d8c0403d69e7bf Mon Sep 17 00:00:00 2001 From: Oliver Upton <oliver.upton(a)linux.dev> Date: Mon, 24 Feb 2025 16:53:57 -0800 Subject: [PATCH] KVM: arm64: Set HCR_EL2.TID1 unconditionally commit 90807748ca3a ("KVM: arm64: Hide SME system registers from guests") added trap handling for SMIDR_EL1, treating it as UNDEFINED as KVM does not support SME. This is right for the most part, however KVM needs to set HCR_EL2.TID1 to _actually_ trap the register. Unfortunately, this comes with some collateral damage as TID1 forces REVIDR_EL1 and AIDR_EL1 to trap as well. KVM has long treated these registers as "invariant" which is an awful term for the following: - Userspace sees the boot CPU values on all vCPUs - The guest sees the hardware values of the CPU on which a vCPU is scheduled Keep the plates spinning by adding trap handling for the affected registers and repaint all of the "invariant" crud into terms of identifying an implementation. Yes, at this point we only need to set TID1 on SME hardware, but REVIDR_EL1 and AIDR_EL1 are about to become mutable anyway. Cc: Mark Brown <broonie(a)kernel.org> Cc: stable(a)vger.kernel.org Fixes: 90807748ca3a ("KVM: arm64: Hide SME system registers from guests") [maz: handle traps from 32bit] Co-developed-by: Marc Zyngier <maz(a)kernel.org> Signed-off-by: Marc Zyngier <maz(a)kernel.org> Link: https://lore.kernel.org/r/20250225005401.679536-2-oliver.upton@linux.dev Signed-off-by: Oliver Upton <oliver.upton(a)linux.dev> diff --git a/arch/arm64/include/asm/kvm_arm.h b/arch/arm64/include/asm/kvm_arm.h index 8d94a6c0ed5c..b01c01e55de5 100644 --- a/arch/arm64/include/asm/kvm_arm.h +++ b/arch/arm64/include/asm/kvm_arm.h @@ -92,12 +92,12 @@ * SWIO: Turn set/way invalidates into set/way clean+invalidate * PTW: Take a stage2 fault if a stage1 walk steps in device memory * TID3: Trap EL1 reads of group 3 ID registers - * TID2: Trap CTR_EL0, CCSIDR2_EL1, CLIDR_EL1, and CSSELR_EL1 + * TID1: Trap REVIDR_EL1, AIDR_EL1, and SMIDR_EL1 */ #define HCR_GUEST_FLAGS (HCR_TSC | HCR_TSW | HCR_TWE | HCR_TWI | HCR_VM | \ HCR_BSU_IS | HCR_FB | HCR_TACR | \ HCR_AMO | HCR_SWIO | HCR_TIDCP | HCR_RW | HCR_TLOR | \ - HCR_FMO | HCR_IMO | HCR_PTW | HCR_TID3) + HCR_FMO | HCR_IMO | HCR_PTW | HCR_TID3 | HCR_TID1) #define HCR_HOST_NVHE_FLAGS (HCR_RW | HCR_API | HCR_APK | HCR_ATA) #define HCR_HOST_NVHE_PROTECTED_FLAGS (HCR_HOST_NVHE_FLAGS | HCR_TSC) #define HCR_HOST_VHE_FLAGS (HCR_RW | HCR_TGE | HCR_E2H) diff --git a/arch/arm64/kvm/sys_regs.c b/arch/arm64/kvm/sys_regs.c index 82430c1e1dd0..57e945d6b715 100644 --- a/arch/arm64/kvm/sys_regs.c +++ b/arch/arm64/kvm/sys_regs.c @@ -2493,6 +2493,93 @@ static bool access_mdcr(struct kvm_vcpu *vcpu, return true; } +/* + * For historical (ahem ABI) reasons, KVM treated MIDR_EL1, REVIDR_EL1, and + * AIDR_EL1 as "invariant" registers, meaning userspace cannot change them. + * The values made visible to userspace were the register values of the boot + * CPU. + * + * At the same time, reads from these registers at EL1 previously were not + * trapped, allowing the guest to read the actual hardware value. On big-little + * machines, this means the VM can see different values depending on where a + * given vCPU got scheduled. + * + * These registers are now trapped as collateral damage from SME, and what + * follows attempts to give a user / guest view consistent with the existing + * ABI. + */ +static bool access_imp_id_reg(struct kvm_vcpu *vcpu, + struct sys_reg_params *p, + const struct sys_reg_desc *r) +{ + if (p->is_write) + return write_to_read_only(vcpu, p, r); + + switch (reg_to_encoding(r)) { + case SYS_REVIDR_EL1: + p->regval = read_sysreg(revidr_el1); + break; + case SYS_AIDR_EL1: + p->regval = read_sysreg(aidr_el1); + break; + default: + WARN_ON_ONCE(1); + } + + return true; +} + +static u64 __ro_after_init boot_cpu_midr_val; +static u64 __ro_after_init boot_cpu_revidr_val; +static u64 __ro_after_init boot_cpu_aidr_val; + +static void init_imp_id_regs(void) +{ + boot_cpu_midr_val = read_sysreg(midr_el1); + boot_cpu_revidr_val = read_sysreg(revidr_el1); + boot_cpu_aidr_val = read_sysreg(aidr_el1); +} + +static int get_imp_id_reg(struct kvm_vcpu *vcpu, const struct sys_reg_desc *r, + u64 *val) +{ + switch (reg_to_encoding(r)) { + case SYS_MIDR_EL1: + *val = boot_cpu_midr_val; + break; + case SYS_REVIDR_EL1: + *val = boot_cpu_revidr_val; + break; + case SYS_AIDR_EL1: + *val = boot_cpu_aidr_val; + break; + default: + WARN_ON_ONCE(1); + return -EINVAL; + } + + return 0; +} + +static int set_imp_id_reg(struct kvm_vcpu *vcpu, const struct sys_reg_desc *r, + u64 val) +{ + u64 expected; + int ret; + + ret = get_imp_id_reg(vcpu, r, &expected); + if (ret) + return ret; + + return (expected == val) ? 0 : -EINVAL; +} + +#define IMPLEMENTATION_ID(reg) { \ + SYS_DESC(SYS_##reg), \ + .access = access_imp_id_reg, \ + .get_user = get_imp_id_reg, \ + .set_user = set_imp_id_reg, \ +} /* * Architected system registers. @@ -2542,7 +2629,9 @@ static const struct sys_reg_desc sys_reg_descs[] = { { SYS_DESC(SYS_DBGVCR32_EL2), undef_access, reset_val, DBGVCR32_EL2, 0 }, + IMPLEMENTATION_ID(MIDR_EL1), { SYS_DESC(SYS_MPIDR_EL1), NULL, reset_mpidr, MPIDR_EL1 }, + IMPLEMENTATION_ID(REVIDR_EL1), /* * ID regs: all ID_SANITISED() entries here must have corresponding @@ -2814,6 +2903,7 @@ static const struct sys_reg_desc sys_reg_descs[] = { .set_user = set_clidr, .val = ~CLIDR_EL1_RES0 }, { SYS_DESC(SYS_CCSIDR2_EL1), undef_access }, { SYS_DESC(SYS_SMIDR_EL1), undef_access }, + IMPLEMENTATION_ID(AIDR_EL1), { SYS_DESC(SYS_CSSELR_EL1), access_csselr, reset_unknown, CSSELR_EL1 }, ID_FILTERED(CTR_EL0, ctr_el0, CTR_EL0_DIC_MASK | @@ -4272,9 +4362,13 @@ int kvm_handle_cp15_32(struct kvm_vcpu *vcpu) * Certain AArch32 ID registers are handled by rerouting to the AArch64 * system register table. Registers in the ID range where CRm=0 are * excluded from this scheme as they do not trivially map into AArch64 - * system register encodings. + * system register encodings, except for AIDR/REVIDR. */ - if (params.Op1 == 0 && params.CRn == 0 && params.CRm) + if (params.Op1 == 0 && params.CRn == 0 && + (params.CRm || params.Op2 == 6 /* REVIDR */)) + return kvm_emulate_cp15_id_reg(vcpu, &params); + if (params.Op1 == 1 && params.CRn == 0 && + params.CRm == 0 && params.Op2 == 7 /* AIDR */) return kvm_emulate_cp15_id_reg(vcpu, &params); return kvm_handle_cp_32(vcpu, &params, cp15_regs, ARRAY_SIZE(cp15_regs)); @@ -4578,65 +4672,6 @@ id_to_sys_reg_desc(struct kvm_vcpu *vcpu, u64 id, return r; } -/* - * These are the invariant sys_reg registers: we let the guest see the - * host versions of these, so they're part of the guest state. - * - * A future CPU may provide a mechanism to present different values to - * the guest, or a future kvm may trap them. - */ - -#define FUNCTION_INVARIANT(reg) \ - static u64 reset_##reg(struct kvm_vcpu *v, \ - const struct sys_reg_desc *r) \ - { \ - ((struct sys_reg_desc *)r)->val = read_sysreg(reg); \ - return ((struct sys_reg_desc *)r)->val; \ - } - -FUNCTION_INVARIANT(midr_el1) -FUNCTION_INVARIANT(revidr_el1) -FUNCTION_INVARIANT(aidr_el1) - -/* ->val is filled in by kvm_sys_reg_table_init() */ -static struct sys_reg_desc invariant_sys_regs[] __ro_after_init = { - { SYS_DESC(SYS_MIDR_EL1), NULL, reset_midr_el1 }, - { SYS_DESC(SYS_REVIDR_EL1), NULL, reset_revidr_el1 }, - { SYS_DESC(SYS_AIDR_EL1), NULL, reset_aidr_el1 }, -}; - -static int get_invariant_sys_reg(u64 id, u64 __user *uaddr) -{ - const struct sys_reg_desc *r; - - r = get_reg_by_id(id, invariant_sys_regs, - ARRAY_SIZE(invariant_sys_regs)); - if (!r) - return -ENOENT; - - return put_user(r->val, uaddr); -} - -static int set_invariant_sys_reg(u64 id, u64 __user *uaddr) -{ - const struct sys_reg_desc *r; - u64 val; - - r = get_reg_by_id(id, invariant_sys_regs, - ARRAY_SIZE(invariant_sys_regs)); - if (!r) - return -ENOENT; - - if (get_user(val, uaddr)) - return -EFAULT; - - /* This is what we mean by invariant: you can't change it. */ - if (r->val != val) - return -EINVAL; - - return 0; -} - static int demux_c15_get(struct kvm_vcpu *vcpu, u64 id, void __user *uaddr) { u32 val; @@ -4718,15 +4753,10 @@ int kvm_sys_reg_get_user(struct kvm_vcpu *vcpu, const struct kvm_one_reg *reg, int kvm_arm_sys_reg_get_reg(struct kvm_vcpu *vcpu, const struct kvm_one_reg *reg) { void __user *uaddr = (void __user *)(unsigned long)reg->addr; - int err; if ((reg->id & KVM_REG_ARM_COPROC_MASK) == KVM_REG_ARM_DEMUX) return demux_c15_get(vcpu, reg->id, uaddr); - err = get_invariant_sys_reg(reg->id, uaddr); - if (err != -ENOENT) - return err; - return kvm_sys_reg_get_user(vcpu, reg, sys_reg_descs, ARRAY_SIZE(sys_reg_descs)); } @@ -4762,15 +4792,10 @@ int kvm_sys_reg_set_user(struct kvm_vcpu *vcpu, const struct kvm_one_reg *reg, int kvm_arm_sys_reg_set_reg(struct kvm_vcpu *vcpu, const struct kvm_one_reg *reg) { void __user *uaddr = (void __user *)(unsigned long)reg->addr; - int err; if ((reg->id & KVM_REG_ARM_COPROC_MASK) == KVM_REG_ARM_DEMUX) return demux_c15_set(vcpu, reg->id, uaddr); - err = set_invariant_sys_reg(reg->id, uaddr); - if (err != -ENOENT) - return err; - return kvm_sys_reg_set_user(vcpu, reg, sys_reg_descs, ARRAY_SIZE(sys_reg_descs)); } @@ -4859,23 +4884,14 @@ static int walk_sys_regs(struct kvm_vcpu *vcpu, u64 __user *uind) unsigned long kvm_arm_num_sys_reg_descs(struct kvm_vcpu *vcpu) { - return ARRAY_SIZE(invariant_sys_regs) - + num_demux_regs() + return num_demux_regs() + walk_sys_regs(vcpu, (u64 __user *)NULL); } int kvm_arm_copy_sys_reg_indices(struct kvm_vcpu *vcpu, u64 __user *uindices) { - unsigned int i; int err; - /* Then give them all the invariant registers' indices. */ - for (i = 0; i < ARRAY_SIZE(invariant_sys_regs); i++) { - if (put_user(sys_reg_to_index(&invariant_sys_regs[i]), uindices)) - return -EFAULT; - uindices++; - } - err = walk_sys_regs(vcpu, uindices); if (err < 0) return err; @@ -5101,15 +5117,12 @@ int __init kvm_sys_reg_table_init(void) valid &= check_sysreg_table(cp14_64_regs, ARRAY_SIZE(cp14_64_regs), true); valid &= check_sysreg_table(cp15_regs, ARRAY_SIZE(cp15_regs), true); valid &= check_sysreg_table(cp15_64_regs, ARRAY_SIZE(cp15_64_regs), true); - valid &= check_sysreg_table(invariant_sys_regs, ARRAY_SIZE(invariant_sys_regs), false); valid &= check_sysreg_table(sys_insn_descs, ARRAY_SIZE(sys_insn_descs), false); if (!valid) return -EINVAL; - /* We abuse the reset function to overwrite the table itself. */ - for (i = 0; i < ARRAY_SIZE(invariant_sys_regs); i++) - invariant_sys_regs[i].reset(NULL, &invariant_sys_regs[i]); + init_imp_id_regs(); ret = populate_nv_trap_config();

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FAILED: patch "[PATCH] arm64: errata: Assume that unknown CPUs _are_ vulnerable to" failed to apply to 5.4-stable tree

by gregkh＠linuxfoundation.org

The patch below does not apply to the 5.4-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 <stable(a)vger.kernel.org>. 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-5.4.y git checkout FETCH_HEAD git cherry-pick -x e403e8538359d8580cbee1976ff71813e947101e # <resolve conflicts, build, test, etc.> git commit -s git send-email --to '<stable(a)vger.kernel.org>' --in-reply-to '2025041725-shrapnel-dimmed-5c5e@gregkh' --subject-prefix 'PATCH 5.4.y' HEAD^.. Possible dependencies: thanks, greg k-h ------------------ original commit in Linus's tree ------------------ From e403e8538359d8580cbee1976ff71813e947101e Mon Sep 17 00:00:00 2001 From: Douglas Anderson <dianders(a)chromium.org> Date: Tue, 7 Jan 2025 12:05:59 -0800 Subject: [PATCH] arm64: errata: Assume that unknown CPUs _are_ vulnerable to Spectre BHB The code for detecting CPUs that are vulnerable to Spectre BHB was based on a hardcoded list of CPU IDs that were known to be affected. Unfortunately, the list mostly only contained the IDs of standard ARM cores. The IDs for many cores that are minor variants of the standard ARM cores (like many Qualcomm Kyro CPUs) weren't listed. This led the code to assume that those variants were not affected. Flip the code on its head and instead assume that a core is vulnerable if it doesn't have CSV2_3 but is unrecognized as being safe. This involves creating a "Spectre BHB safe" list. As of right now, the only CPU IDs added to the "Spectre BHB safe" list are ARM Cortex A35, A53, A55, A510, and A520. This list was created by looking for cores that weren't listed in ARM's list [1] as per review feedback on v2 of this patch [2]. Additionally Brahma A53 is added as per mailing list feedback [3]. NOTE: this patch will not actually _mitigate_ anyone, it will simply cause them to report themselves as vulnerable. If any cores in the system are reported as vulnerable but not mitigated then the whole system will be reported as vulnerable though the system will attempt to mitigate with the information it has about the known cores. [1] https://developer.arm.com/Arm%20Security%20Center/Spectre-BHB [2] https://lore.kernel.org/r/20241219175128.GA25477@willie-the-truck [3] https://lore.kernel.org/r/18dbd7d1-a46c-4112-a425-320c99f67a8d@broadcom.com Fixes: 558c303c9734 ("arm64: Mitigate spectre style branch history side channels") Cc: stable(a)vger.kernel.org Reviewed-by: Julius Werner <jwerner(a)chromium.org> Signed-off-by: Douglas Anderson <dianders(a)chromium.org> Link: https://lore.kernel.org/r/20250107120555.v4.2.I2040fa004dafe196243f67ebcc64… Signed-off-by: Catalin Marinas <catalin.marinas(a)arm.com> diff --git a/arch/arm64/include/asm/spectre.h b/arch/arm64/include/asm/spectre.h index 0c4d9045c31f..f1524cdeacf1 100644 --- a/arch/arm64/include/asm/spectre.h +++ b/arch/arm64/include/asm/spectre.h @@ -97,7 +97,6 @@ enum mitigation_state arm64_get_meltdown_state(void); enum mitigation_state arm64_get_spectre_bhb_state(void); bool is_spectre_bhb_affected(const struct arm64_cpu_capabilities *entry, int scope); -u8 spectre_bhb_loop_affected(int scope); void spectre_bhb_enable_mitigation(const struct arm64_cpu_capabilities *__unused); bool try_emulate_el1_ssbs(struct pt_regs *regs, u32 instr); diff --git a/arch/arm64/kernel/proton-pack.c b/arch/arm64/kernel/proton-pack.c index e149efadff20..17aa836fe46d 100644 --- a/arch/arm64/kernel/proton-pack.c +++ b/arch/arm64/kernel/proton-pack.c @@ -845,53 +845,70 @@ static unsigned long system_bhb_mitigations; * This must be called with SCOPE_LOCAL_CPU for each type of CPU, before any * SCOPE_SYSTEM call will give the right answer. */ -u8 spectre_bhb_loop_affected(int scope) +static bool is_spectre_bhb_safe(int scope) +{ + static const struct midr_range spectre_bhb_safe_list[] = { + MIDR_ALL_VERSIONS(MIDR_CORTEX_A35), + MIDR_ALL_VERSIONS(MIDR_CORTEX_A53), + MIDR_ALL_VERSIONS(MIDR_CORTEX_A55), + MIDR_ALL_VERSIONS(MIDR_CORTEX_A510), + MIDR_ALL_VERSIONS(MIDR_CORTEX_A520), + MIDR_ALL_VERSIONS(MIDR_BRAHMA_B53), + {}, + }; + static bool all_safe = true; + + if (scope != SCOPE_LOCAL_CPU) + return all_safe; + + if (is_midr_in_range_list(read_cpuid_id(), spectre_bhb_safe_list)) + return true; + + all_safe = false; + + return false; +} + +static u8 spectre_bhb_loop_affected(void) { u8 k = 0; - static u8 max_bhb_k; - if (scope == SCOPE_LOCAL_CPU) { - static const struct midr_range spectre_bhb_k32_list[] = { - MIDR_ALL_VERSIONS(MIDR_CORTEX_A78), - MIDR_ALL_VERSIONS(MIDR_CORTEX_A78AE), - MIDR_ALL_VERSIONS(MIDR_CORTEX_A78C), - MIDR_ALL_VERSIONS(MIDR_CORTEX_X1), - MIDR_ALL_VERSIONS(MIDR_CORTEX_A710), - MIDR_ALL_VERSIONS(MIDR_CORTEX_X2), - MIDR_ALL_VERSIONS(MIDR_NEOVERSE_N2), - MIDR_ALL_VERSIONS(MIDR_NEOVERSE_V1), - {}, - }; - static const struct midr_range spectre_bhb_k24_list[] = { - MIDR_ALL_VERSIONS(MIDR_CORTEX_A76), - MIDR_ALL_VERSIONS(MIDR_CORTEX_A77), - MIDR_ALL_VERSIONS(MIDR_NEOVERSE_N1), - MIDR_ALL_VERSIONS(MIDR_QCOM_KRYO_4XX_GOLD), - {}, - }; - static const struct midr_range spectre_bhb_k11_list[] = { - MIDR_ALL_VERSIONS(MIDR_AMPERE1), - {}, - }; - static const struct midr_range spectre_bhb_k8_list[] = { - MIDR_ALL_VERSIONS(MIDR_CORTEX_A72), - MIDR_ALL_VERSIONS(MIDR_CORTEX_A57), - {}, - }; + static const struct midr_range spectre_bhb_k32_list[] = { + MIDR_ALL_VERSIONS(MIDR_CORTEX_A78), + MIDR_ALL_VERSIONS(MIDR_CORTEX_A78AE), + MIDR_ALL_VERSIONS(MIDR_CORTEX_A78C), + MIDR_ALL_VERSIONS(MIDR_CORTEX_X1), + MIDR_ALL_VERSIONS(MIDR_CORTEX_A710), + MIDR_ALL_VERSIONS(MIDR_CORTEX_X2), + MIDR_ALL_VERSIONS(MIDR_NEOVERSE_N2), + MIDR_ALL_VERSIONS(MIDR_NEOVERSE_V1), + {}, + }; + static const struct midr_range spectre_bhb_k24_list[] = { + MIDR_ALL_VERSIONS(MIDR_CORTEX_A76), + MIDR_ALL_VERSIONS(MIDR_CORTEX_A77), + MIDR_ALL_VERSIONS(MIDR_NEOVERSE_N1), + MIDR_ALL_VERSIONS(MIDR_QCOM_KRYO_4XX_GOLD), + {}, + }; + static const struct midr_range spectre_bhb_k11_list[] = { + MIDR_ALL_VERSIONS(MIDR_AMPERE1), + {}, + }; + static const struct midr_range spectre_bhb_k8_list[] = { + MIDR_ALL_VERSIONS(MIDR_CORTEX_A72), + MIDR_ALL_VERSIONS(MIDR_CORTEX_A57), + {}, + }; - if (is_midr_in_range_list(read_cpuid_id(), spectre_bhb_k32_list)) - k = 32; - else if (is_midr_in_range_list(read_cpuid_id(), spectre_bhb_k24_list)) - k = 24; - else if (is_midr_in_range_list(read_cpuid_id(), spectre_bhb_k11_list)) - k = 11; - else if (is_midr_in_range_list(read_cpuid_id(), spectre_bhb_k8_list)) - k = 8; - - max_bhb_k = max(max_bhb_k, k); - } else { - k = max_bhb_k; - } + if (is_midr_in_range_list(read_cpuid_id(), spectre_bhb_k32_list)) + k = 32; + else if (is_midr_in_range_list(read_cpuid_id(), spectre_bhb_k24_list)) + k = 24; + else if (is_midr_in_range_list(read_cpuid_id(), spectre_bhb_k11_list)) + k = 11; + else if (is_midr_in_range_list(read_cpuid_id(), spectre_bhb_k8_list)) + k = 8; return k; } @@ -917,29 +934,13 @@ static enum mitigation_state spectre_bhb_get_cpu_fw_mitigation_state(void) } } -static bool is_spectre_bhb_fw_affected(int scope) +static bool has_spectre_bhb_fw_mitigation(void) { - static bool system_affected; enum mitigation_state fw_state; bool has_smccc = arm_smccc_1_1_get_conduit() != SMCCC_CONDUIT_NONE; - static const struct midr_range spectre_bhb_firmware_mitigated_list[] = { - MIDR_ALL_VERSIONS(MIDR_CORTEX_A73), - MIDR_ALL_VERSIONS(MIDR_CORTEX_A75), - {}, - }; - bool cpu_in_list = is_midr_in_range_list(read_cpuid_id(), - spectre_bhb_firmware_mitigated_list); - - if (scope != SCOPE_LOCAL_CPU) - return system_affected; fw_state = spectre_bhb_get_cpu_fw_mitigation_state(); - if (cpu_in_list || (has_smccc && fw_state == SPECTRE_MITIGATED)) { - system_affected = true; - return true; - } - - return false; + return has_smccc && fw_state == SPECTRE_MITIGATED; } static bool supports_ecbhb(int scope) @@ -955,6 +956,8 @@ static bool supports_ecbhb(int scope) ID_AA64MMFR1_EL1_ECBHB_SHIFT); } +static u8 max_bhb_k; + bool is_spectre_bhb_affected(const struct arm64_cpu_capabilities *entry, int scope) { @@ -963,16 +966,18 @@ bool is_spectre_bhb_affected(const struct arm64_cpu_capabilities *entry, if (supports_csv2p3(scope)) return false; - if (supports_clearbhb(scope)) - return true; + if (is_spectre_bhb_safe(scope)) + return false; - if (spectre_bhb_loop_affected(scope)) - return true; + /* + * At this point the core isn't known to be "safe" so we're going to + * assume it's vulnerable. We still need to update `max_bhb_k` though, + * but only if we aren't mitigating with clearbhb though. + */ + if (scope == SCOPE_LOCAL_CPU && !supports_clearbhb(SCOPE_LOCAL_CPU)) + max_bhb_k = max(max_bhb_k, spectre_bhb_loop_affected()); - if (is_spectre_bhb_fw_affected(scope)) - return true; - - return false; + return true; } static void this_cpu_set_vectors(enum arm64_bp_harden_el1_vectors slot) @@ -1003,7 +1008,7 @@ early_param("nospectre_bhb", parse_spectre_bhb_param); void spectre_bhb_enable_mitigation(const struct arm64_cpu_capabilities *entry) { bp_hardening_cb_t cpu_cb; - enum mitigation_state fw_state, state = SPECTRE_VULNERABLE; + enum mitigation_state state = SPECTRE_VULNERABLE; struct bp_hardening_data *data = this_cpu_ptr(&bp_hardening_data); if (!is_spectre_bhb_affected(entry, SCOPE_LOCAL_CPU)) @@ -1029,7 +1034,7 @@ void spectre_bhb_enable_mitigation(const struct arm64_cpu_capabilities *entry) this_cpu_set_vectors(EL1_VECTOR_BHB_CLEAR_INSN); state = SPECTRE_MITIGATED; set_bit(BHB_INSN, &system_bhb_mitigations); - } else if (spectre_bhb_loop_affected(SCOPE_LOCAL_CPU)) { + } else if (spectre_bhb_loop_affected()) { /* * Ensure KVM uses the indirect vector which will have the * branchy-loop added. A57/A72-r0 will already have selected @@ -1042,32 +1047,29 @@ void spectre_bhb_enable_mitigation(const struct arm64_cpu_capabilities *entry) this_cpu_set_vectors(EL1_VECTOR_BHB_LOOP); state = SPECTRE_MITIGATED; set_bit(BHB_LOOP, &system_bhb_mitigations); - } else if (is_spectre_bhb_fw_affected(SCOPE_LOCAL_CPU)) { - fw_state = spectre_bhb_get_cpu_fw_mitigation_state(); - if (fw_state == SPECTRE_MITIGATED) { - /* - * Ensure KVM uses one of the spectre bp_hardening - * vectors. The indirect vector doesn't include the EL3 - * call, so needs upgrading to - * HYP_VECTOR_SPECTRE_INDIRECT. - */ - if (!data->slot || data->slot == HYP_VECTOR_INDIRECT) - data->slot += 1; + } else if (has_spectre_bhb_fw_mitigation()) { + /* + * Ensure KVM uses one of the spectre bp_hardening + * vectors. The indirect vector doesn't include the EL3 + * call, so needs upgrading to + * HYP_VECTOR_SPECTRE_INDIRECT. + */ + if (!data->slot || data->slot == HYP_VECTOR_INDIRECT) + data->slot += 1; - this_cpu_set_vectors(EL1_VECTOR_BHB_FW); + this_cpu_set_vectors(EL1_VECTOR_BHB_FW); - /* - * The WA3 call in the vectors supersedes the WA1 call - * made during context-switch. Uninstall any firmware - * bp_hardening callback. - */ - cpu_cb = spectre_v2_get_sw_mitigation_cb(); - if (__this_cpu_read(bp_hardening_data.fn) != cpu_cb) - __this_cpu_write(bp_hardening_data.fn, NULL); + /* + * The WA3 call in the vectors supersedes the WA1 call + * made during context-switch. Uninstall any firmware + * bp_hardening callback. + */ + cpu_cb = spectre_v2_get_sw_mitigation_cb(); + if (__this_cpu_read(bp_hardening_data.fn) != cpu_cb) + __this_cpu_write(bp_hardening_data.fn, NULL); - state = SPECTRE_MITIGATED; - set_bit(BHB_FW, &system_bhb_mitigations); - } + state = SPECTRE_MITIGATED; + set_bit(BHB_FW, &system_bhb_mitigations); } update_mitigation_state(&spectre_bhb_state, state); @@ -1101,7 +1103,6 @@ void noinstr spectre_bhb_patch_loop_iter(struct alt_instr *alt, { u8 rd; u32 insn; - u16 loop_count = spectre_bhb_loop_affected(SCOPE_SYSTEM); BUG_ON(nr_inst != 1); /* MOV -> MOV */ @@ -1110,7 +1111,7 @@ void noinstr spectre_bhb_patch_loop_iter(struct alt_instr *alt, insn = le32_to_cpu(*origptr); rd = aarch64_insn_decode_register(AARCH64_INSN_REGTYPE_RD, insn); - insn = aarch64_insn_gen_movewide(rd, loop_count, 0, + insn = aarch64_insn_gen_movewide(rd, max_bhb_k, 0, AARCH64_INSN_VARIANT_64BIT, AARCH64_INSN_MOVEWIDE_ZERO); *updptr++ = cpu_to_le32(insn);

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FAILED: patch "[PATCH] arm64: errata: Assume that unknown CPUs _are_ vulnerable to" failed to apply to 5.10-stable tree

by gregkh＠linuxfoundation.org

The 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 <stable(a)vger.kernel.org>. 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 e403e8538359d8580cbee1976ff71813e947101e # <resolve conflicts, build, test, etc.> git commit -s git send-email --to '<stable(a)vger.kernel.org>' --in-reply-to '2025041724-roundup-salary-6623@gregkh' --subject-prefix 'PATCH 5.10.y' HEAD^.. Possible dependencies: thanks, greg k-h ------------------ original commit in Linus's tree ------------------ From e403e8538359d8580cbee1976ff71813e947101e Mon Sep 17 00:00:00 2001 From: Douglas Anderson <dianders(a)chromium.org> Date: Tue, 7 Jan 2025 12:05:59 -0800 Subject: [PATCH] arm64: errata: Assume that unknown CPUs _are_ vulnerable to Spectre BHB The code for detecting CPUs that are vulnerable to Spectre BHB was based on a hardcoded list of CPU IDs that were known to be affected. Unfortunately, the list mostly only contained the IDs of standard ARM cores. The IDs for many cores that are minor variants of the standard ARM cores (like many Qualcomm Kyro CPUs) weren't listed. This led the code to assume that those variants were not affected. Flip the code on its head and instead assume that a core is vulnerable if it doesn't have CSV2_3 but is unrecognized as being safe. This involves creating a "Spectre BHB safe" list. As of right now, the only CPU IDs added to the "Spectre BHB safe" list are ARM Cortex A35, A53, A55, A510, and A520. This list was created by looking for cores that weren't listed in ARM's list [1] as per review feedback on v2 of this patch [2]. Additionally Brahma A53 is added as per mailing list feedback [3]. NOTE: this patch will not actually _mitigate_ anyone, it will simply cause them to report themselves as vulnerable. If any cores in the system are reported as vulnerable but not mitigated then the whole system will be reported as vulnerable though the system will attempt to mitigate with the information it has about the known cores. [1] https://developer.arm.com/Arm%20Security%20Center/Spectre-BHB [2] https://lore.kernel.org/r/20241219175128.GA25477@willie-the-truck [3] https://lore.kernel.org/r/18dbd7d1-a46c-4112-a425-320c99f67a8d@broadcom.com Fixes: 558c303c9734 ("arm64: Mitigate spectre style branch history side channels") Cc: stable(a)vger.kernel.org Reviewed-by: Julius Werner <jwerner(a)chromium.org> Signed-off-by: Douglas Anderson <dianders(a)chromium.org> Link: https://lore.kernel.org/r/20250107120555.v4.2.I2040fa004dafe196243f67ebcc64… Signed-off-by: Catalin Marinas <catalin.marinas(a)arm.com> diff --git a/arch/arm64/include/asm/spectre.h b/arch/arm64/include/asm/spectre.h index 0c4d9045c31f..f1524cdeacf1 100644 --- a/arch/arm64/include/asm/spectre.h +++ b/arch/arm64/include/asm/spectre.h @@ -97,7 +97,6 @@ enum mitigation_state arm64_get_meltdown_state(void); enum mitigation_state arm64_get_spectre_bhb_state(void); bool is_spectre_bhb_affected(const struct arm64_cpu_capabilities *entry, int scope); -u8 spectre_bhb_loop_affected(int scope); void spectre_bhb_enable_mitigation(const struct arm64_cpu_capabilities *__unused); bool try_emulate_el1_ssbs(struct pt_regs *regs, u32 instr); diff --git a/arch/arm64/kernel/proton-pack.c b/arch/arm64/kernel/proton-pack.c index e149efadff20..17aa836fe46d 100644 --- a/arch/arm64/kernel/proton-pack.c +++ b/arch/arm64/kernel/proton-pack.c @@ -845,53 +845,70 @@ static unsigned long system_bhb_mitigations; * This must be called with SCOPE_LOCAL_CPU for each type of CPU, before any * SCOPE_SYSTEM call will give the right answer. */ -u8 spectre_bhb_loop_affected(int scope) +static bool is_spectre_bhb_safe(int scope) +{ + static const struct midr_range spectre_bhb_safe_list[] = { + MIDR_ALL_VERSIONS(MIDR_CORTEX_A35), + MIDR_ALL_VERSIONS(MIDR_CORTEX_A53), + MIDR_ALL_VERSIONS(MIDR_CORTEX_A55), + MIDR_ALL_VERSIONS(MIDR_CORTEX_A510), + MIDR_ALL_VERSIONS(MIDR_CORTEX_A520), + MIDR_ALL_VERSIONS(MIDR_BRAHMA_B53), + {}, + }; + static bool all_safe = true; + + if (scope != SCOPE_LOCAL_CPU) + return all_safe; + + if (is_midr_in_range_list(read_cpuid_id(), spectre_bhb_safe_list)) + return true; + + all_safe = false; + + return false; +} + +static u8 spectre_bhb_loop_affected(void) { u8 k = 0; - static u8 max_bhb_k; - if (scope == SCOPE_LOCAL_CPU) { - static const struct midr_range spectre_bhb_k32_list[] = { - MIDR_ALL_VERSIONS(MIDR_CORTEX_A78), - MIDR_ALL_VERSIONS(MIDR_CORTEX_A78AE), - MIDR_ALL_VERSIONS(MIDR_CORTEX_A78C), - MIDR_ALL_VERSIONS(MIDR_CORTEX_X1), - MIDR_ALL_VERSIONS(MIDR_CORTEX_A710), - MIDR_ALL_VERSIONS(MIDR_CORTEX_X2), - MIDR_ALL_VERSIONS(MIDR_NEOVERSE_N2), - MIDR_ALL_VERSIONS(MIDR_NEOVERSE_V1), - {}, - }; - static const struct midr_range spectre_bhb_k24_list[] = { - MIDR_ALL_VERSIONS(MIDR_CORTEX_A76), - MIDR_ALL_VERSIONS(MIDR_CORTEX_A77), - MIDR_ALL_VERSIONS(MIDR_NEOVERSE_N1), - MIDR_ALL_VERSIONS(MIDR_QCOM_KRYO_4XX_GOLD), - {}, - }; - static const struct midr_range spectre_bhb_k11_list[] = { - MIDR_ALL_VERSIONS(MIDR_AMPERE1), - {}, - }; - static const struct midr_range spectre_bhb_k8_list[] = { - MIDR_ALL_VERSIONS(MIDR_CORTEX_A72), - MIDR_ALL_VERSIONS(MIDR_CORTEX_A57), - {}, - }; + static const struct midr_range spectre_bhb_k32_list[] = { + MIDR_ALL_VERSIONS(MIDR_CORTEX_A78), + MIDR_ALL_VERSIONS(MIDR_CORTEX_A78AE), + MIDR_ALL_VERSIONS(MIDR_CORTEX_A78C), + MIDR_ALL_VERSIONS(MIDR_CORTEX_X1), + MIDR_ALL_VERSIONS(MIDR_CORTEX_A710), + MIDR_ALL_VERSIONS(MIDR_CORTEX_X2), + MIDR_ALL_VERSIONS(MIDR_NEOVERSE_N2), + MIDR_ALL_VERSIONS(MIDR_NEOVERSE_V1), + {}, + }; + static const struct midr_range spectre_bhb_k24_list[] = { + MIDR_ALL_VERSIONS(MIDR_CORTEX_A76), + MIDR_ALL_VERSIONS(MIDR_CORTEX_A77), + MIDR_ALL_VERSIONS(MIDR_NEOVERSE_N1), + MIDR_ALL_VERSIONS(MIDR_QCOM_KRYO_4XX_GOLD), + {}, + }; + static const struct midr_range spectre_bhb_k11_list[] = { + MIDR_ALL_VERSIONS(MIDR_AMPERE1), + {}, + }; + static const struct midr_range spectre_bhb_k8_list[] = { + MIDR_ALL_VERSIONS(MIDR_CORTEX_A72), + MIDR_ALL_VERSIONS(MIDR_CORTEX_A57), + {}, + }; - if (is_midr_in_range_list(read_cpuid_id(), spectre_bhb_k32_list)) - k = 32; - else if (is_midr_in_range_list(read_cpuid_id(), spectre_bhb_k24_list)) - k = 24; - else if (is_midr_in_range_list(read_cpuid_id(), spectre_bhb_k11_list)) - k = 11; - else if (is_midr_in_range_list(read_cpuid_id(), spectre_bhb_k8_list)) - k = 8; - - max_bhb_k = max(max_bhb_k, k); - } else { - k = max_bhb_k; - } + if (is_midr_in_range_list(read_cpuid_id(), spectre_bhb_k32_list)) + k = 32; + else if (is_midr_in_range_list(read_cpuid_id(), spectre_bhb_k24_list)) + k = 24; + else if (is_midr_in_range_list(read_cpuid_id(), spectre_bhb_k11_list)) + k = 11; + else if (is_midr_in_range_list(read_cpuid_id(), spectre_bhb_k8_list)) + k = 8; return k; } @@ -917,29 +934,13 @@ static enum mitigation_state spectre_bhb_get_cpu_fw_mitigation_state(void) } } -static bool is_spectre_bhb_fw_affected(int scope) +static bool has_spectre_bhb_fw_mitigation(void) { - static bool system_affected; enum mitigation_state fw_state; bool has_smccc = arm_smccc_1_1_get_conduit() != SMCCC_CONDUIT_NONE; - static const struct midr_range spectre_bhb_firmware_mitigated_list[] = { - MIDR_ALL_VERSIONS(MIDR_CORTEX_A73), - MIDR_ALL_VERSIONS(MIDR_CORTEX_A75), - {}, - }; - bool cpu_in_list = is_midr_in_range_list(read_cpuid_id(), - spectre_bhb_firmware_mitigated_list); - - if (scope != SCOPE_LOCAL_CPU) - return system_affected; fw_state = spectre_bhb_get_cpu_fw_mitigation_state(); - if (cpu_in_list || (has_smccc && fw_state == SPECTRE_MITIGATED)) { - system_affected = true; - return true; - } - - return false; + return has_smccc && fw_state == SPECTRE_MITIGATED; } static bool supports_ecbhb(int scope) @@ -955,6 +956,8 @@ static bool supports_ecbhb(int scope) ID_AA64MMFR1_EL1_ECBHB_SHIFT); } +static u8 max_bhb_k; + bool is_spectre_bhb_affected(const struct arm64_cpu_capabilities *entry, int scope) { @@ -963,16 +966,18 @@ bool is_spectre_bhb_affected(const struct arm64_cpu_capabilities *entry, if (supports_csv2p3(scope)) return false; - if (supports_clearbhb(scope)) - return true; + if (is_spectre_bhb_safe(scope)) + return false; - if (spectre_bhb_loop_affected(scope)) - return true; + /* + * At this point the core isn't known to be "safe" so we're going to + * assume it's vulnerable. We still need to update `max_bhb_k` though, + * but only if we aren't mitigating with clearbhb though. + */ + if (scope == SCOPE_LOCAL_CPU && !supports_clearbhb(SCOPE_LOCAL_CPU)) + max_bhb_k = max(max_bhb_k, spectre_bhb_loop_affected()); - if (is_spectre_bhb_fw_affected(scope)) - return true; - - return false; + return true; } static void this_cpu_set_vectors(enum arm64_bp_harden_el1_vectors slot) @@ -1003,7 +1008,7 @@ early_param("nospectre_bhb", parse_spectre_bhb_param); void spectre_bhb_enable_mitigation(const struct arm64_cpu_capabilities *entry) { bp_hardening_cb_t cpu_cb; - enum mitigation_state fw_state, state = SPECTRE_VULNERABLE; + enum mitigation_state state = SPECTRE_VULNERABLE; struct bp_hardening_data *data = this_cpu_ptr(&bp_hardening_data); if (!is_spectre_bhb_affected(entry, SCOPE_LOCAL_CPU)) @@ -1029,7 +1034,7 @@ void spectre_bhb_enable_mitigation(const struct arm64_cpu_capabilities *entry) this_cpu_set_vectors(EL1_VECTOR_BHB_CLEAR_INSN); state = SPECTRE_MITIGATED; set_bit(BHB_INSN, &system_bhb_mitigations); - } else if (spectre_bhb_loop_affected(SCOPE_LOCAL_CPU)) { + } else if (spectre_bhb_loop_affected()) { /* * Ensure KVM uses the indirect vector which will have the * branchy-loop added. A57/A72-r0 will already have selected @@ -1042,32 +1047,29 @@ void spectre_bhb_enable_mitigation(const struct arm64_cpu_capabilities *entry) this_cpu_set_vectors(EL1_VECTOR_BHB_LOOP); state = SPECTRE_MITIGATED; set_bit(BHB_LOOP, &system_bhb_mitigations); - } else if (is_spectre_bhb_fw_affected(SCOPE_LOCAL_CPU)) { - fw_state = spectre_bhb_get_cpu_fw_mitigation_state(); - if (fw_state == SPECTRE_MITIGATED) { - /* - * Ensure KVM uses one of the spectre bp_hardening - * vectors. The indirect vector doesn't include the EL3 - * call, so needs upgrading to - * HYP_VECTOR_SPECTRE_INDIRECT. - */ - if (!data->slot || data->slot == HYP_VECTOR_INDIRECT) - data->slot += 1; + } else if (has_spectre_bhb_fw_mitigation()) { + /* + * Ensure KVM uses one of the spectre bp_hardening + * vectors. The indirect vector doesn't include the EL3 + * call, so needs upgrading to + * HYP_VECTOR_SPECTRE_INDIRECT. + */ + if (!data->slot || data->slot == HYP_VECTOR_INDIRECT) + data->slot += 1; - this_cpu_set_vectors(EL1_VECTOR_BHB_FW); + this_cpu_set_vectors(EL1_VECTOR_BHB_FW); - /* - * The WA3 call in the vectors supersedes the WA1 call - * made during context-switch. Uninstall any firmware - * bp_hardening callback. - */ - cpu_cb = spectre_v2_get_sw_mitigation_cb(); - if (__this_cpu_read(bp_hardening_data.fn) != cpu_cb) - __this_cpu_write(bp_hardening_data.fn, NULL); + /* + * The WA3 call in the vectors supersedes the WA1 call + * made during context-switch. Uninstall any firmware + * bp_hardening callback. + */ + cpu_cb = spectre_v2_get_sw_mitigation_cb(); + if (__this_cpu_read(bp_hardening_data.fn) != cpu_cb) + __this_cpu_write(bp_hardening_data.fn, NULL); - state = SPECTRE_MITIGATED; - set_bit(BHB_FW, &system_bhb_mitigations); - } + state = SPECTRE_MITIGATED; + set_bit(BHB_FW, &system_bhb_mitigations); } update_mitigation_state(&spectre_bhb_state, state); @@ -1101,7 +1103,6 @@ void noinstr spectre_bhb_patch_loop_iter(struct alt_instr *alt, { u8 rd; u32 insn; - u16 loop_count = spectre_bhb_loop_affected(SCOPE_SYSTEM); BUG_ON(nr_inst != 1); /* MOV -> MOV */ @@ -1110,7 +1111,7 @@ void noinstr spectre_bhb_patch_loop_iter(struct alt_instr *alt, insn = le32_to_cpu(*origptr); rd = aarch64_insn_decode_register(AARCH64_INSN_REGTYPE_RD, insn); - insn = aarch64_insn_gen_movewide(rd, loop_count, 0, + insn = aarch64_insn_gen_movewide(rd, max_bhb_k, 0, AARCH64_INSN_VARIANT_64BIT, AARCH64_INSN_MOVEWIDE_ZERO); *updptr++ = cpu_to_le32(insn);

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FAILED: patch "[PATCH] arm64: errata: Add KRYO 2XX/3XX/4XX silver cores to Spectre" failed to apply to 5.4-stable tree

by gregkh＠linuxfoundation.org

The patch below does not apply to the 5.4-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 <stable(a)vger.kernel.org>. 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-5.4.y git checkout FETCH_HEAD git cherry-pick -x 0c9fc6e652cd5aed48c5f700c32b7642bea7f453 # <resolve conflicts, build, test, etc.> git commit -s git send-email --to '<stable(a)vger.kernel.org>' --in-reply-to '2025041759-disarray-snowplow-d290@gregkh' --subject-prefix 'PATCH 5.4.y' HEAD^.. Possible dependencies: thanks, greg k-h ------------------ original commit in Linus's tree ------------------ From 0c9fc6e652cd5aed48c5f700c32b7642bea7f453 Mon Sep 17 00:00:00 2001 From: Douglas Anderson <dianders(a)chromium.org> Date: Tue, 7 Jan 2025 12:06:00 -0800 Subject: [PATCH] arm64: errata: Add KRYO 2XX/3XX/4XX silver cores to Spectre BHB safe list Qualcomm has confirmed that, much like Cortex A53 and A55, KRYO 2XX/3XX/4XX silver cores are unaffected by Spectre BHB. Add them to the safe list. Fixes: 558c303c9734 ("arm64: Mitigate spectre style branch history side channels") Cc: stable(a)vger.kernel.org Cc: Scott Bauer <sbauer(a)quicinc.com> Signed-off-by: Douglas Anderson <dianders(a)chromium.org> Acked-by: Trilok Soni <quic_tsoni(a)quicinc.com> Link: https://lore.kernel.org/r/20250107120555.v4.3.Iab8dbfb5c9b1e143e7a29f410bce… Signed-off-by: Catalin Marinas <catalin.marinas(a)arm.com> diff --git a/arch/arm64/kernel/proton-pack.c b/arch/arm64/kernel/proton-pack.c index 17aa836fe46d..89405be53d8f 100644 --- a/arch/arm64/kernel/proton-pack.c +++ b/arch/arm64/kernel/proton-pack.c @@ -854,6 +854,9 @@ static bool is_spectre_bhb_safe(int scope) MIDR_ALL_VERSIONS(MIDR_CORTEX_A510), MIDR_ALL_VERSIONS(MIDR_CORTEX_A520), MIDR_ALL_VERSIONS(MIDR_BRAHMA_B53), + MIDR_ALL_VERSIONS(MIDR_QCOM_KRYO_2XX_SILVER), + MIDR_ALL_VERSIONS(MIDR_QCOM_KRYO_3XX_SILVER), + MIDR_ALL_VERSIONS(MIDR_QCOM_KRYO_4XX_SILVER), {}, }; static bool all_safe = true;

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