| lists.openwall.net | lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC | |
|
Open Source and information security mailing list archives
| ||
|
Message-ID: <4e28458b-baba-456a-bae6-08c2818aedf8@gmx.de>
Date: Sat, 28 Jun 2025 23:34:32 +0200
From: Armin Wolf <W_Armin@....de>
To: Hans de Goede <hansg@...nel.org>, sre@...nel.org, hdegoede@...hat.com,
ilpo.jarvinen@...ux.intel.com
Cc: linux-pm@...r.kernel.org, platform-driver-x86@...r.kernel.org,
linux-kernel@...r.kernel.org
Subject: Re: [PATCH 1/3] power: supply: core: Add
power_supply_get/set_property_direct()
Am 28.06.25 um 11:25 schrieb Hans de Goede:
> Hi Armin,
>
> On 27-Jun-25 10:51 PM, Armin Wolf wrote:
>> Power supply extensions might want to interact with the underlying
>> power supply to retrieve data like serial numbers, charging status
>> and more. However doing so causes psy->extensions_sem to be locked
>> twice, possibly causing a deadlock.
>>
>> Provide special variants of power_supply_get/set_property() that
>> ignore any power supply extensions and thus do not touch the
>> associated psy->extensions_sem lock.
>>
>> Suggested-by: Hans de Goede <hansg@...nel.org>
>> Signed-off-by: Armin Wolf <W_Armin@....de>
> Thank you for your work on this.
>
> The entire series looks good to me:
>
> Reviewed-by: Hans de Goede <hansg@...nel.org>
>
> for the series.
>
> There is the question of how to merge this. I think it might
> be best for the entire series to go through the power-supply
> tree.
>
> Ilpo would that work for you and if yes can we have your ack ?
>
> Sebastian, IMHO this should be merged as fixed not as for-next
> material.
>
> Regards,
>
> Hans
Personally i would prefer to merge this through the pdx86 tree as the
uniwill-laptop driver currently under review will also require this functionality.
Thanks,
Armin Wolf
>> ---
>> drivers/power/supply/power_supply_core.c | 82 ++++++++++++++++++++----
>> include/linux/power_supply.h | 8 +++
>> 2 files changed, 78 insertions(+), 12 deletions(-)
>>
>> diff --git a/drivers/power/supply/power_supply_core.c b/drivers/power/supply/power_supply_core.c
>> index aedb20c1d276..e70ffedf1a80 100644
>> --- a/drivers/power/supply/power_supply_core.c
>> +++ b/drivers/power/supply/power_supply_core.c
>> @@ -1241,9 +1241,8 @@ bool power_supply_has_property(struct power_supply *psy,
>> return false;
>> }
>>
>> -int power_supply_get_property(struct power_supply *psy,
>> - enum power_supply_property psp,
>> - union power_supply_propval *val)
>> +static int __power_supply_get_property(struct power_supply *psy, enum power_supply_property psp,
>> + union power_supply_propval *val, bool use_extensions)
>> {
>> struct power_supply_ext_registration *reg;
>>
>> @@ -1253,10 +1252,14 @@ int power_supply_get_property(struct power_supply *psy,
>> return -ENODEV;
>> }
>>
>> - scoped_guard(rwsem_read, &psy->extensions_sem) {
>> - power_supply_for_each_extension(reg, psy) {
>> - if (power_supply_ext_has_property(reg->ext, psp))
>> + if (use_extensions) {
>> + scoped_guard(rwsem_read, &psy->extensions_sem) {
>> + power_supply_for_each_extension(reg, psy) {
>> + if (!power_supply_ext_has_property(reg->ext, psp))
>> + continue;
>> +
>> return reg->ext->get_property(psy, reg->ext, reg->data, psp, val);
>> + }
>> }
>> }
>>
>> @@ -1267,20 +1270,49 @@ int power_supply_get_property(struct power_supply *psy,
>> else
>> return -EINVAL;
>> }
>> +
>> +int power_supply_get_property(struct power_supply *psy, enum power_supply_property psp,
>> + union power_supply_propval *val)
>> +{
>> + return __power_supply_get_property(psy, psp, val, true);
>> +}
>> EXPORT_SYMBOL_GPL(power_supply_get_property);
>>
>> -int power_supply_set_property(struct power_supply *psy,
>> - enum power_supply_property psp,
>> - const union power_supply_propval *val)
>> +/**
>> + * power_supply_get_property_direct - Read a power supply property without checking for extensions
>> + * @psy: The power supply
>> + * @psp: The power supply property to read
>> + * @val: The resulting value of the power supply property
>> + *
>> + * Read a power supply property without taking into account any power supply extensions registered
>> + * on the given power supply. This is mostly useful for power supply extensions that want to access
>> + * their own power supply as using power_supply_get_property() directly will result in a potential
>> + * deadlock.
>> + *
>> + * Return: 0 on success or negative error code on failure.
>> + */
>> +int power_supply_get_property_direct(struct power_supply *psy, enum power_supply_property psp,
>> + union power_supply_propval *val)
>> +{
>> + return __power_supply_get_property(psy, psp, val, false);
>> +}
>> +EXPORT_SYMBOL_GPL(power_supply_get_property_direct);
>> +
>> +
>> +static int __power_supply_set_property(struct power_supply *psy, enum power_supply_property psp,
>> + const union power_supply_propval *val, bool use_extensions)
>> {
>> struct power_supply_ext_registration *reg;
>>
>> if (atomic_read(&psy->use_cnt) <= 0)
>> return -ENODEV;
>>
>> - scoped_guard(rwsem_read, &psy->extensions_sem) {
>> - power_supply_for_each_extension(reg, psy) {
>> - if (power_supply_ext_has_property(reg->ext, psp)) {
>> + if (use_extensions) {
>> + scoped_guard(rwsem_read, &psy->extensions_sem) {
>> + power_supply_for_each_extension(reg, psy) {
>> + if (!power_supply_ext_has_property(reg->ext, psp))
>> + continue;
>> +
>> if (reg->ext->set_property)
>> return reg->ext->set_property(psy, reg->ext, reg->data,
>> psp, val);
>> @@ -1295,8 +1327,34 @@ int power_supply_set_property(struct power_supply *psy,
>>
>> return psy->desc->set_property(psy, psp, val);
>> }
>> +
>> +int power_supply_set_property(struct power_supply *psy, enum power_supply_property psp,
>> + const union power_supply_propval *val)
>> +{
>> + return __power_supply_set_property(psy, psp, val, true);
>> +}
>> EXPORT_SYMBOL_GPL(power_supply_set_property);
>>
>> +/**
>> + * power_supply_set_property_direct - Write a power supply property without checking for extensions
>> + * @psy: The power supply
>> + * @psp: The power supply property to write
>> + * @val: The value to write to the power supply property
>> + *
>> + * Write a power supply property without taking into account any power supply extensions registered
>> + * on the given power supply. This is mostly useful for power supply extensions that want to access
>> + * their own power supply as using power_supply_set_property() directly will result in a potential
>> + * deadlock.
>> + *
>> + * Return: 0 on success or negative error code on failure.
>> + */
>> +int power_supply_set_property_direct(struct power_supply *psy, enum power_supply_property psp,
>> + const union power_supply_propval *val)
>> +{
>> + return __power_supply_set_property(psy, psp, val, false);
>> +}
>> +EXPORT_SYMBOL_GPL(power_supply_set_property_direct);
>> +
>> int power_supply_property_is_writeable(struct power_supply *psy,
>> enum power_supply_property psp)
>> {
>> diff --git a/include/linux/power_supply.h b/include/linux/power_supply.h
>> index 45468959dd98..f21f806bfb38 100644
>> --- a/include/linux/power_supply.h
>> +++ b/include/linux/power_supply.h
>> @@ -878,15 +878,23 @@ static inline int power_supply_is_system_supplied(void) { return -ENOSYS; }
>> extern int power_supply_get_property(struct power_supply *psy,
>> enum power_supply_property psp,
>> union power_supply_propval *val);
>> +int power_supply_get_property_direct(struct power_supply *psy, enum power_supply_property psp,
>> + union power_supply_propval *val);
>> #if IS_ENABLED(CONFIG_POWER_SUPPLY)
>> extern int power_supply_set_property(struct power_supply *psy,
>> enum power_supply_property psp,
>> const union power_supply_propval *val);
>> +int power_supply_set_property_direct(struct power_supply *psy, enum power_supply_property psp,
>> + const union power_supply_propval *val);
>> #else
>> static inline int power_supply_set_property(struct power_supply *psy,
>> enum power_supply_property psp,
>> const union power_supply_propval *val)
>> { return 0; }
>> +static inline int power_supply_set_property_direct(struct power_supply *psy,
>> + enum power_supply_property psp,
>> + const union power_supply_propval *val)
>> +{ return 0; }
>> #endif
>> extern void power_supply_external_power_changed(struct power_supply *psy);
>>
>
Powered by blists - more mailing lists