* [PATCH] powercap: intel_rapl: Fix rapl_packages list corruption
@ 2026-08-29 16:43 Sumeet Pawnikar
2026-08-29 18:01 ` Sumeet Pawnikar
2026-09-04 13:42 ` Rafael J. Wysocki (Intel)
0 siblings, 2 replies; 4+ messages in thread
From: Sumeet Pawnikar @ 2026-08-29 16:43 UTC (permalink / raw)
To: rafael, linux-acpi; +Cc: linux-kernel, sumeet4linux
The rapl_packages list was previously documented as being guarded by the
CPU hotplug lock (cpus_read_lock()). However, cpus_read_lock() is a
reader-writer semaphore taken for shared read access. This provides zero
mutual exclusion between multiple concurrent callers.
Because auxiliary device probes (such as intel_rapl_tpmi_probe) can
execute concurrently on different CPUs, multiple packages can race on
list operations (list_add and list_del) inside
rapl_add_package_cpuslocked() and rapl_remove_package_cpuslocked(),
leading to list corruption.
Introduce a dedicated rapl_packages_lock mutex to protect all additions,
removals and iterations of the rapl_packages list.
Signed-off-by: Sumeet Pawnikar <sumeet4linux@gmail.com>
---
drivers/powercap/intel_rapl_common.c | 29 ++++++++++++++++++++++++----
1 file changed, 25 insertions(+), 4 deletions(-)
diff --git a/drivers/powercap/intel_rapl_common.c b/drivers/powercap/intel_rapl_common.c
index 70cab5f08bc6..e544629dbe30 100644
--- a/drivers/powercap/intel_rapl_common.c
+++ b/drivers/powercap/intel_rapl_common.c
@@ -175,7 +175,8 @@ static u64 rapl_unit_xlate(struct rapl_domain *rd,
enum unit_type type, u64 value, int to_raw);
static void package_power_limit_irq_save(struct rapl_package *rp);
-static LIST_HEAD(rapl_packages); /* guarded by CPU hotplug lock */
+static DEFINE_MUTEX(rapl_packages_lock);
+static LIST_HEAD(rapl_packages); /* guarded by rapl_packages_lock */
static const char *const rapl_domain_names[] = {
"package",
@@ -1360,12 +1361,14 @@ static int rapl_pmu_event_init(struct perf_event *event)
return -EINVAL;
/* Find out which Package the event belongs to */
+ mutex_lock(&rapl_packages_lock);
list_for_each_entry(pos, &rapl_packages, plist) {
if (is_rp_pmu_cpu(pos, event->cpu)) {
rp = pos;
break;
}
}
+ mutex_unlock(&rapl_packages_lock);
if (!rp)
return -ENODEV;
@@ -1445,9 +1448,11 @@ static ssize_t cpumask_show(struct device *dev,
cpumask_clear(cpu_mask);
/* Choose a cpu for each RAPL Package */
+ mutex_lock(&rapl_packages_lock);
list_for_each_entry(rp, &rapl_packages, plist) {
set_pmu_cpumask(rp, cpu_mask);
}
+ mutex_unlock(&rapl_packages_lock);
cpus_read_unlock();
ret = sysfs_emit(buf, "%*pbl\n", cpumask_pr_args(cpu_mask));
@@ -1655,11 +1660,15 @@ void rapl_package_remove_pmu_locked(struct rapl_package *rp)
if (!rp->has_pmu)
return;
+ mutex_lock(&rapl_packages_lock);
list_for_each_entry(pos, &rapl_packages, plist) {
/* PMU is still needed */
- if (pos->has_pmu && pos != rp)
+ if (pos->has_pmu && pos != rp) {
+ mutex_unlock(&rapl_packages_lock);
return;
+ }
}
+ mutex_unlock(&rapl_packages_lock);
if (rapl_pmu.registered)
perf_pmu_unregister(&rapl_pmu.pmu);
@@ -1704,7 +1713,9 @@ void rapl_remove_package_cpuslocked(struct rapl_package *rp)
/* do parent zone last */
powercap_unregister_zone(rp->priv->control_type,
&rd_package->power_zone);
+ mutex_lock(&rapl_packages_lock);
list_del(&rp->plist);
+ mutex_unlock(&rapl_packages_lock);
kfree(rp);
}
EXPORT_SYMBOL_NS_GPL(rapl_remove_package_cpuslocked, "INTEL_RAPL");
@@ -1749,11 +1760,15 @@ struct rapl_package *rapl_find_package_domain_cpuslocked(int id, struct rapl_if_
else
uid = id;
+ mutex_lock(&rapl_packages_lock);
list_for_each_entry(rp, &rapl_packages, plist) {
- if (rp->id == uid
- && rp->priv->control_type == priv->control_type)
+ if (rp->id == uid &&
+ rp->priv->control_type == priv->control_type) {
+ mutex_unlock(&rapl_packages_lock);
return rp;
+ }
}
+ mutex_unlock(&rapl_packages_lock);
return NULL;
}
@@ -1810,7 +1825,9 @@ struct rapl_package *rapl_add_package_cpuslocked(int id, struct rapl_if_priv *pr
ret = rapl_package_register_powercap(rp);
if (!ret) {
INIT_LIST_HEAD(&rp->plist);
+ mutex_lock(&rapl_packages_lock);
list_add(&rp->plist, &rapl_packages);
+ mutex_unlock(&rapl_packages_lock);
return rp;
}
@@ -1835,6 +1852,7 @@ static void power_limit_state_save(void)
int ret, i;
cpus_read_lock();
+ mutex_lock(&rapl_packages_lock);
list_for_each_entry(rp, &rapl_packages, plist) {
if (!rp->power_zone)
continue;
@@ -1846,6 +1864,7 @@ static void power_limit_state_save(void)
rd->rpl[i].last_power_limit = 0;
}
}
+ mutex_unlock(&rapl_packages_lock);
cpus_read_unlock();
}
@@ -1856,6 +1875,7 @@ static void power_limit_state_restore(void)
int i;
cpus_read_lock();
+ mutex_lock(&rapl_packages_lock);
list_for_each_entry(rp, &rapl_packages, plist) {
if (!rp->power_zone)
continue;
@@ -1865,6 +1885,7 @@ static void power_limit_state_restore(void)
rapl_write_pl_data(rd, i, PL_LIMIT,
rd->rpl[i].last_power_limit);
}
+ mutex_unlock(&rapl_packages_lock);
cpus_read_unlock();
}
--
2.43.0
^ permalink raw reply [flat|nested] 4+ messages in thread* Re: [PATCH] powercap: intel_rapl: Fix rapl_packages list corruption
2026-08-29 16:43 [PATCH] powercap: intel_rapl: Fix rapl_packages list corruption Sumeet Pawnikar
@ 2026-08-29 18:01 ` Sumeet Pawnikar
2026-09-04 13:42 ` Rafael J. Wysocki (Intel)
1 sibling, 0 replies; 4+ messages in thread
From: Sumeet Pawnikar @ 2026-08-29 18:01 UTC (permalink / raw)
To: rafael, linux-acpi, linux-pm; +Cc: linux-kernel
Added linux-pm mailing list now. Earlier by mistake I sent it to acpi
mailing list.
On Sat, Aug 29, 2026 at 10:13 PM Sumeet Pawnikar <sumeet4linux@gmail.com> wrote:
>
> The rapl_packages list was previously documented as being guarded by the
> CPU hotplug lock (cpus_read_lock()). However, cpus_read_lock() is a
> reader-writer semaphore taken for shared read access. This provides zero
> mutual exclusion between multiple concurrent callers.
>
> Because auxiliary device probes (such as intel_rapl_tpmi_probe) can
> execute concurrently on different CPUs, multiple packages can race on
> list operations (list_add and list_del) inside
> rapl_add_package_cpuslocked() and rapl_remove_package_cpuslocked(),
> leading to list corruption.
>
> Introduce a dedicated rapl_packages_lock mutex to protect all additions,
> removals and iterations of the rapl_packages list.
>
> Signed-off-by: Sumeet Pawnikar <sumeet4linux@gmail.com>
> ---
> drivers/powercap/intel_rapl_common.c | 29 ++++++++++++++++++++++++----
> 1 file changed, 25 insertions(+), 4 deletions(-)
>
> diff --git a/drivers/powercap/intel_rapl_common.c b/drivers/powercap/intel_rapl_common.c
> index 70cab5f08bc6..e544629dbe30 100644
> --- a/drivers/powercap/intel_rapl_common.c
> +++ b/drivers/powercap/intel_rapl_common.c
> @@ -175,7 +175,8 @@ static u64 rapl_unit_xlate(struct rapl_domain *rd,
> enum unit_type type, u64 value, int to_raw);
> static void package_power_limit_irq_save(struct rapl_package *rp);
>
> -static LIST_HEAD(rapl_packages); /* guarded by CPU hotplug lock */
> +static DEFINE_MUTEX(rapl_packages_lock);
> +static LIST_HEAD(rapl_packages); /* guarded by rapl_packages_lock */
>
> static const char *const rapl_domain_names[] = {
> "package",
> @@ -1360,12 +1361,14 @@ static int rapl_pmu_event_init(struct perf_event *event)
> return -EINVAL;
>
> /* Find out which Package the event belongs to */
> + mutex_lock(&rapl_packages_lock);
> list_for_each_entry(pos, &rapl_packages, plist) {
> if (is_rp_pmu_cpu(pos, event->cpu)) {
> rp = pos;
> break;
> }
> }
> + mutex_unlock(&rapl_packages_lock);
> if (!rp)
> return -ENODEV;
>
> @@ -1445,9 +1448,11 @@ static ssize_t cpumask_show(struct device *dev,
> cpumask_clear(cpu_mask);
>
> /* Choose a cpu for each RAPL Package */
> + mutex_lock(&rapl_packages_lock);
> list_for_each_entry(rp, &rapl_packages, plist) {
> set_pmu_cpumask(rp, cpu_mask);
> }
> + mutex_unlock(&rapl_packages_lock);
> cpus_read_unlock();
>
> ret = sysfs_emit(buf, "%*pbl\n", cpumask_pr_args(cpu_mask));
> @@ -1655,11 +1660,15 @@ void rapl_package_remove_pmu_locked(struct rapl_package *rp)
> if (!rp->has_pmu)
> return;
>
> + mutex_lock(&rapl_packages_lock);
> list_for_each_entry(pos, &rapl_packages, plist) {
> /* PMU is still needed */
> - if (pos->has_pmu && pos != rp)
> + if (pos->has_pmu && pos != rp) {
> + mutex_unlock(&rapl_packages_lock);
> return;
> + }
> }
> + mutex_unlock(&rapl_packages_lock);
>
> if (rapl_pmu.registered)
> perf_pmu_unregister(&rapl_pmu.pmu);
> @@ -1704,7 +1713,9 @@ void rapl_remove_package_cpuslocked(struct rapl_package *rp)
> /* do parent zone last */
> powercap_unregister_zone(rp->priv->control_type,
> &rd_package->power_zone);
> + mutex_lock(&rapl_packages_lock);
> list_del(&rp->plist);
> + mutex_unlock(&rapl_packages_lock);
> kfree(rp);
> }
> EXPORT_SYMBOL_NS_GPL(rapl_remove_package_cpuslocked, "INTEL_RAPL");
> @@ -1749,11 +1760,15 @@ struct rapl_package *rapl_find_package_domain_cpuslocked(int id, struct rapl_if_
> else
> uid = id;
>
> + mutex_lock(&rapl_packages_lock);
> list_for_each_entry(rp, &rapl_packages, plist) {
> - if (rp->id == uid
> - && rp->priv->control_type == priv->control_type)
> + if (rp->id == uid &&
> + rp->priv->control_type == priv->control_type) {
> + mutex_unlock(&rapl_packages_lock);
> return rp;
> + }
> }
> + mutex_unlock(&rapl_packages_lock);
>
> return NULL;
> }
> @@ -1810,7 +1825,9 @@ struct rapl_package *rapl_add_package_cpuslocked(int id, struct rapl_if_priv *pr
> ret = rapl_package_register_powercap(rp);
> if (!ret) {
> INIT_LIST_HEAD(&rp->plist);
> + mutex_lock(&rapl_packages_lock);
> list_add(&rp->plist, &rapl_packages);
> + mutex_unlock(&rapl_packages_lock);
> return rp;
> }
>
> @@ -1835,6 +1852,7 @@ static void power_limit_state_save(void)
> int ret, i;
>
> cpus_read_lock();
> + mutex_lock(&rapl_packages_lock);
> list_for_each_entry(rp, &rapl_packages, plist) {
> if (!rp->power_zone)
> continue;
> @@ -1846,6 +1864,7 @@ static void power_limit_state_save(void)
> rd->rpl[i].last_power_limit = 0;
> }
> }
> + mutex_unlock(&rapl_packages_lock);
> cpus_read_unlock();
> }
>
> @@ -1856,6 +1875,7 @@ static void power_limit_state_restore(void)
> int i;
>
> cpus_read_lock();
> + mutex_lock(&rapl_packages_lock);
> list_for_each_entry(rp, &rapl_packages, plist) {
> if (!rp->power_zone)
> continue;
> @@ -1865,6 +1885,7 @@ static void power_limit_state_restore(void)
> rapl_write_pl_data(rd, i, PL_LIMIT,
> rd->rpl[i].last_power_limit);
> }
> + mutex_unlock(&rapl_packages_lock);
> cpus_read_unlock();
> }
>
> --
> 2.43.0
>
^ permalink raw reply [flat|nested] 4+ messages in thread* Re: [PATCH] powercap: intel_rapl: Fix rapl_packages list corruption
2026-08-29 16:43 [PATCH] powercap: intel_rapl: Fix rapl_packages list corruption Sumeet Pawnikar
2026-08-29 18:01 ` Sumeet Pawnikar
@ 2026-09-04 13:42 ` Rafael J. Wysocki (Intel)
2026-09-04 21:41 ` srinivas pandruvada
1 sibling, 1 reply; 4+ messages in thread
From: Rafael J. Wysocki (Intel) @ 2026-09-04 13:42 UTC (permalink / raw)
To: Sumeet Pawnikar, Srinivas Pandruvada; +Cc: linux-acpi, linux-kernel, Linux PM
Hi Srinivas,
Can you please have a look at the patch below and let me know what you think?
On Sat, Aug 29, 2026 at 6:43 PM Sumeet Pawnikar <sumeet4linux@gmail.com> wrote:
>
> The rapl_packages list was previously documented as being guarded by the
> CPU hotplug lock (cpus_read_lock()). However, cpus_read_lock() is a
> reader-writer semaphore taken for shared read access. This provides zero
> mutual exclusion between multiple concurrent callers.
>
> Because auxiliary device probes (such as intel_rapl_tpmi_probe) can
> execute concurrently on different CPUs, multiple packages can race on
> list operations (list_add and list_del) inside
> rapl_add_package_cpuslocked() and rapl_remove_package_cpuslocked(),
> leading to list corruption.
>
> Introduce a dedicated rapl_packages_lock mutex to protect all additions,
> removals and iterations of the rapl_packages list.
>
> Signed-off-by: Sumeet Pawnikar <sumeet4linux@gmail.com>
> ---
> drivers/powercap/intel_rapl_common.c | 29 ++++++++++++++++++++++++----
> 1 file changed, 25 insertions(+), 4 deletions(-)
>
> diff --git a/drivers/powercap/intel_rapl_common.c b/drivers/powercap/intel_rapl_common.c
> index 70cab5f08bc6..e544629dbe30 100644
> --- a/drivers/powercap/intel_rapl_common.c
> +++ b/drivers/powercap/intel_rapl_common.c
> @@ -175,7 +175,8 @@ static u64 rapl_unit_xlate(struct rapl_domain *rd,
> enum unit_type type, u64 value, int to_raw);
> static void package_power_limit_irq_save(struct rapl_package *rp);
>
> -static LIST_HEAD(rapl_packages); /* guarded by CPU hotplug lock */
> +static DEFINE_MUTEX(rapl_packages_lock);
> +static LIST_HEAD(rapl_packages); /* guarded by rapl_packages_lock */
>
> static const char *const rapl_domain_names[] = {
> "package",
> @@ -1360,12 +1361,14 @@ static int rapl_pmu_event_init(struct perf_event *event)
> return -EINVAL;
>
> /* Find out which Package the event belongs to */
> + mutex_lock(&rapl_packages_lock);
> list_for_each_entry(pos, &rapl_packages, plist) {
> if (is_rp_pmu_cpu(pos, event->cpu)) {
> rp = pos;
> break;
> }
> }
> + mutex_unlock(&rapl_packages_lock);
> if (!rp)
> return -ENODEV;
>
> @@ -1445,9 +1448,11 @@ static ssize_t cpumask_show(struct device *dev,
> cpumask_clear(cpu_mask);
>
> /* Choose a cpu for each RAPL Package */
> + mutex_lock(&rapl_packages_lock);
> list_for_each_entry(rp, &rapl_packages, plist) {
> set_pmu_cpumask(rp, cpu_mask);
> }
> + mutex_unlock(&rapl_packages_lock);
> cpus_read_unlock();
>
> ret = sysfs_emit(buf, "%*pbl\n", cpumask_pr_args(cpu_mask));
> @@ -1655,11 +1660,15 @@ void rapl_package_remove_pmu_locked(struct rapl_package *rp)
> if (!rp->has_pmu)
> return;
>
> + mutex_lock(&rapl_packages_lock);
> list_for_each_entry(pos, &rapl_packages, plist) {
> /* PMU is still needed */
> - if (pos->has_pmu && pos != rp)
> + if (pos->has_pmu && pos != rp) {
> + mutex_unlock(&rapl_packages_lock);
> return;
> + }
> }
> + mutex_unlock(&rapl_packages_lock);
>
> if (rapl_pmu.registered)
> perf_pmu_unregister(&rapl_pmu.pmu);
> @@ -1704,7 +1713,9 @@ void rapl_remove_package_cpuslocked(struct rapl_package *rp)
> /* do parent zone last */
> powercap_unregister_zone(rp->priv->control_type,
> &rd_package->power_zone);
> + mutex_lock(&rapl_packages_lock);
> list_del(&rp->plist);
> + mutex_unlock(&rapl_packages_lock);
> kfree(rp);
> }
> EXPORT_SYMBOL_NS_GPL(rapl_remove_package_cpuslocked, "INTEL_RAPL");
> @@ -1749,11 +1760,15 @@ struct rapl_package *rapl_find_package_domain_cpuslocked(int id, struct rapl_if_
> else
> uid = id;
>
> + mutex_lock(&rapl_packages_lock);
> list_for_each_entry(rp, &rapl_packages, plist) {
> - if (rp->id == uid
> - && rp->priv->control_type == priv->control_type)
> + if (rp->id == uid &&
> + rp->priv->control_type == priv->control_type) {
> + mutex_unlock(&rapl_packages_lock);
> return rp;
> + }
> }
> + mutex_unlock(&rapl_packages_lock);
>
> return NULL;
> }
> @@ -1810,7 +1825,9 @@ struct rapl_package *rapl_add_package_cpuslocked(int id, struct rapl_if_priv *pr
> ret = rapl_package_register_powercap(rp);
> if (!ret) {
> INIT_LIST_HEAD(&rp->plist);
> + mutex_lock(&rapl_packages_lock);
> list_add(&rp->plist, &rapl_packages);
> + mutex_unlock(&rapl_packages_lock);
> return rp;
> }
>
> @@ -1835,6 +1852,7 @@ static void power_limit_state_save(void)
> int ret, i;
>
> cpus_read_lock();
> + mutex_lock(&rapl_packages_lock);
> list_for_each_entry(rp, &rapl_packages, plist) {
> if (!rp->power_zone)
> continue;
> @@ -1846,6 +1864,7 @@ static void power_limit_state_save(void)
> rd->rpl[i].last_power_limit = 0;
> }
> }
> + mutex_unlock(&rapl_packages_lock);
> cpus_read_unlock();
> }
>
> @@ -1856,6 +1875,7 @@ static void power_limit_state_restore(void)
> int i;
>
> cpus_read_lock();
> + mutex_lock(&rapl_packages_lock);
> list_for_each_entry(rp, &rapl_packages, plist) {
> if (!rp->power_zone)
> continue;
> @@ -1865,6 +1885,7 @@ static void power_limit_state_restore(void)
> rapl_write_pl_data(rd, i, PL_LIMIT,
> rd->rpl[i].last_power_limit);
> }
> + mutex_unlock(&rapl_packages_lock);
> cpus_read_unlock();
> }
>
> --
> 2.43.0
>
^ permalink raw reply [flat|nested] 4+ messages in thread* Re: [PATCH] powercap: intel_rapl: Fix rapl_packages list corruption
2026-09-04 13:42 ` Rafael J. Wysocki (Intel)
@ 2026-09-04 21:41 ` srinivas pandruvada
0 siblings, 0 replies; 4+ messages in thread
From: srinivas pandruvada @ 2026-09-04 21:41 UTC (permalink / raw)
To: Rafael J. Wysocki (Intel), Sumeet Pawnikar, sathyanarayanan.kuppuswamy
Cc: linux-acpi, linux-kernel, Linux PM
On Fri, 2026-09-04 at 15:42 +0200, Rafael J. Wysocki (Intel) wrote:
> Hi Srinivas,
>
> Can you please have a look at the patch below and let me know what
> you think?
>
> On Sat, Aug 29, 2026 at 6:43 PM Sumeet Pawnikar
> <sumeet4linux@gmail.com> wrote:
> >
> > The rapl_packages list was previously documented as being guarded
> > by the
> > CPU hotplug lock (cpus_read_lock()). However, cpus_read_lock() is a
> > reader-writer semaphore taken for shared read access. This provides
> > zero
> > mutual exclusion between multiple concurrent callers.
> >
Using these locks together need to be careful as it will be lock
inversion risk.
> > Because auxiliary device probes (such as intel_rapl_tpmi_probe) can
> > execute concurrently on different CPUs, multiple packages can race
> > on
> > list operations (list_add and list_del) inside
> > rapl_add_package_cpuslocked() and rapl_remove_package_cpuslocked(),
> > leading to list corruption.
> >
> > Introduce a dedicated rapl_packages_lock mutex to protect all
> > additions,
> > removals and iterations of the rapl_packages list.
> >
> > Signed-off-by: Sumeet Pawnikar <sumeet4linux@gmail.com>
> > ---
> > drivers/powercap/intel_rapl_common.c | 29
> > ++++++++++++++++++++++++----
> > 1 file changed, 25 insertions(+), 4 deletions(-)
> >
> > diff --git a/drivers/powercap/intel_rapl_common.c
> > b/drivers/powercap/intel_rapl_common.c
> > index 70cab5f08bc6..e544629dbe30 100644
> > --- a/drivers/powercap/intel_rapl_common.c
> > +++ b/drivers/powercap/intel_rapl_common.c
> > @@ -175,7 +175,8 @@ static u64 rapl_unit_xlate(struct rapl_domain
> > *rd,
> > enum unit_type type, u64 value, int
> > to_raw);
> > static void package_power_limit_irq_save(struct rapl_package *rp);
> >
> > -static LIST_HEAD(rapl_packages); /* guarded by CPU hotplug
> > lock */
> > +static DEFINE_MUTEX(rapl_packages_lock);
> > +static LIST_HEAD(rapl_packages); /* guarded by
> > rapl_packages_lock */
> >
> > static const char *const rapl_domain_names[] = {
> > "package",
> > @@ -1360,12 +1361,14 @@ static int rapl_pmu_event_init(struct
> > perf_event *event)
> > return -EINVAL;
> >
> > /* Find out which Package the event belongs to */
> > + mutex_lock(&rapl_packages_lock);
Have you tried to exercise this path from perf ?
> > list_for_each_entry(pos, &rapl_packages, plist) {
> > if (is_rp_pmu_cpu(pos, event->cpu)) {
> > rp = pos;
> > break;
> > }
> > }
> > + mutex_unlock(&rapl_packages_lock);
Mutex is released while event->pmu_private = rp is assigned while
perf_event_open does not hold hotplug or package reference locks.
So rapl_remove_package_cpuslocked() can free this rp, but events->rp
still holds that pointer.
You may need
cpus_read_lock()
before
mutex_lock(&rapl_packages_lock);
above
and
and cpus_read_unlock() at the end of function
Please run LOCKDEP, perf RAPL and online offline tests before.
Thanks,
Srinivas
> > if (!rp)
> > return -ENODEV;
> >
> > @@ -1445,9 +1448,11 @@ static ssize_t cpumask_show(struct device
> > *dev,
> > cpumask_clear(cpu_mask);
> >
> > /* Choose a cpu for each RAPL Package */
> > + mutex_lock(&rapl_packages_lock);
> > list_for_each_entry(rp, &rapl_packages, plist) {
> > set_pmu_cpumask(rp, cpu_mask);
> > }
> > + mutex_unlock(&rapl_packages_lock);
> > cpus_read_unlock();
> >
> > ret = sysfs_emit(buf, "%*pbl\n",
> > cpumask_pr_args(cpu_mask));
> > @@ -1655,11 +1660,15 @@ void rapl_package_remove_pmu_locked(struct
> > rapl_package *rp)
> > if (!rp->has_pmu)
> > return;
> >
> > + mutex_lock(&rapl_packages_lock);
> > list_for_each_entry(pos, &rapl_packages, plist) {
> > /* PMU is still needed */
> > - if (pos->has_pmu && pos != rp)
> > + if (pos->has_pmu && pos != rp) {
> > + mutex_unlock(&rapl_packages_lock);
> > return;
> > + }
> > }
> > + mutex_unlock(&rapl_packages_lock);
> >
> > if (rapl_pmu.registered)
> > perf_pmu_unregister(&rapl_pmu.pmu);
> > @@ -1704,7 +1713,9 @@ void rapl_remove_package_cpuslocked(struct
> > rapl_package *rp)
> > /* do parent zone last */
> > powercap_unregister_zone(rp->priv->control_type,
> > &rd_package->power_zone);
> > + mutex_lock(&rapl_packages_lock);
> > list_del(&rp->plist);
> > + mutex_unlock(&rapl_packages_lock);
> > kfree(rp);
> > }
> > EXPORT_SYMBOL_NS_GPL(rapl_remove_package_cpuslocked,
> > "INTEL_RAPL");
> > @@ -1749,11 +1760,15 @@ struct rapl_package
> > *rapl_find_package_domain_cpuslocked(int id, struct rapl_if_
> > else
> > uid = id;
> >
> > + mutex_lock(&rapl_packages_lock);
> > list_for_each_entry(rp, &rapl_packages, plist) {
> > - if (rp->id == uid
> > - && rp->priv->control_type == priv-
> > >control_type)
> > + if (rp->id == uid &&
> > + rp->priv->control_type == priv->control_type) {
> > + mutex_unlock(&rapl_packages_lock);
> > return rp;
> > + }
> > }
> > + mutex_unlock(&rapl_packages_lock);
> >
> > return NULL;
> > }
> > @@ -1810,7 +1825,9 @@ struct rapl_package
> > *rapl_add_package_cpuslocked(int id, struct rapl_if_priv *pr
> > ret = rapl_package_register_powercap(rp);
> > if (!ret) {
> > INIT_LIST_HEAD(&rp->plist);
> > + mutex_lock(&rapl_packages_lock);
> > list_add(&rp->plist, &rapl_packages);
> > + mutex_unlock(&rapl_packages_lock);
> > return rp;
> > }
> >
> > @@ -1835,6 +1852,7 @@ static void power_limit_state_save(void)
> > int ret, i;
> >
> > cpus_read_lock();
> > + mutex_lock(&rapl_packages_lock);
> > list_for_each_entry(rp, &rapl_packages, plist) {
> > if (!rp->power_zone)
> > continue;
> > @@ -1846,6 +1864,7 @@ static void power_limit_state_save(void)
> > rd->rpl[i].last_power_limit = 0;
> > }
> > }
> > + mutex_unlock(&rapl_packages_lock);
> > cpus_read_unlock();
> > }
> >
> > @@ -1856,6 +1875,7 @@ static void power_limit_state_restore(void)
> > int i;
> >
> > cpus_read_lock();
> > + mutex_lock(&rapl_packages_lock);
> > list_for_each_entry(rp, &rapl_packages, plist) {
> > if (!rp->power_zone)
> > continue;
> > @@ -1865,6 +1885,7 @@ static void power_limit_state_restore(void)
> > rapl_write_pl_data(rd, i, PL_LIMIT,
> > rd-
> > >rpl[i].last_power_limit);
> > }
> > + mutex_unlock(&rapl_packages_lock);
> > cpus_read_unlock();
> > }
> >
> > --
> > 2.43.0
> >
^ permalink raw reply [flat|nested] 4+ messages in thread
end of thread, other threads:[~2026-09-04 21:41 UTC | newest]
Thread overview: 4+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2026-08-29 16:43 [PATCH] powercap: intel_rapl: Fix rapl_packages list corruption Sumeet Pawnikar
2026-08-29 18:01 ` Sumeet Pawnikar
2026-09-04 13:42 ` Rafael J. Wysocki (Intel)
2026-09-04 21:41 ` srinivas pandruvada
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