linux-kernel - Re: [PATCH v5 17/20] ACPI: platform_profile: Check all profile handler to calculate next

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

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <79626508-d9da-45ae-947b-22fb8a62522d@gmx.de>
Date: Fri, 8 Nov 2024 19:10:03 +0100
From: Armin Wolf <W_Armin@....de>
To: Mario Limonciello <mario.limonciello@....com>,
 Hans de Goede <hdegoede@...hat.com>,
 Ilpo Järvinen <ilpo.jarvinen@...ux.intel.com>
Cc: "Rafael J . Wysocki" <rafael@...nel.org>, Len Brown <lenb@...nel.org>,
 Maximilian Luz <luzmaximilian@...il.com>, Lee Chun-Yi <jlee@...e.com>,
 Shyam Sundar S K <Shyam-sundar.S-k@....com>,
 Corentin Chary <corentin.chary@...il.com>, "Luke D . Jones"
 <luke@...nes.dev>, Ike Panhc <ike.pan@...onical.com>,
 Henrique de Moraes Holschuh <hmh@....eng.br>,
 Alexis Belmonte <alexbelm48@...il.com>,
 Uwe Kleine-König <u.kleine-koenig@...gutronix.de>,
 Ai Chao <aichao@...inos.cn>, Gergo Koteles <soyer@....hu>,
 open list <linux-kernel@...r.kernel.org>,
 "open list:ACPI" <linux-acpi@...r.kernel.org>,
 "open list:MICROSOFT SURFACE PLATFORM PROFILE DRIVER"
 <platform-driver-x86@...r.kernel.org>,
 "open list:THINKPAD ACPI EXTRAS DRIVER"
 <ibm-acpi-devel@...ts.sourceforge.net>,
 Mark Pearson <mpearson-lenovo@...ebb.ca>,
 Matthew Schwartz <matthew.schwartz@...ux.dev>
Subject: Re: [PATCH v5 17/20] ACPI: platform_profile: Check all profile
 handler to calculate next

Am 07.11.24 um 23:05 schrieb Mario Limonciello:

> On 11/7/2024 02:58, Armin Wolf wrote:
>> Am 07.11.24 um 07:02 schrieb Mario Limonciello:
>>
>>> As multiple platform profile handlers might not all support the same
>>> profile, cycling to the next profile could have a different result
>>> depending on what handler are registered.
>>>
>>> Check what is active and supported by all handlers to decide what
>>> to do.
>>>
>>> Tested-by: Mark Pearson <mpearson-lenovo@...ebb.ca>
>>> Signed-off-by: Mario Limonciello <mario.limonciello@....com>
>>> ---
>>> v5:
>>>   * Adjust mutex use
>>> ---
>>>   drivers/acpi/platform_profile.c | 23 ++++++++++++++---------
>>>   1 file changed, 14 insertions(+), 9 deletions(-)
>>>
>>> diff --git a/drivers/acpi/platform_profile.c b/drivers/acpi/ 
>>> platform_profile.c
>>> index 7f302ac4d3779..2c466f2d16b42 100644
>>> --- a/drivers/acpi/platform_profile.c
>>> +++ b/drivers/acpi/platform_profile.c
>>> @@ -411,34 +411,39 @@ EXPORT_SYMBOL_GPL(platform_profile_notify);
>>>
>>>   int platform_profile_cycle(void)
>>>   {
>>> +    enum platform_profile_option next = PLATFORM_PROFILE_LAST;
>>>       enum platform_profile_option profile;
>>> -    enum platform_profile_option next;
>>> +    unsigned long choices;
>>>       int err;
>>>
>>>       if (!class_is_registered(&platform_profile_class))
>>>           return -ENODEV;
>>>
>>>       scoped_cond_guard(mutex_intr, return -ERESTARTSYS, 
>>> &profile_lock) {
>>> -        if (!cur_profile)
>>> -            return -ENODEV;
>>> +        err = class_for_each_device(&platform_profile_class, NULL,
>>> +                        &profile, _aggregate_profiles);
>>> +        if (err)
>>> +            return err;
>>>
>>> -        err = cur_profile->profile_get(cur_profile, &profile);
>>> +        err = class_for_each_device(&platform_profile_class, NULL,
>>> +                        &choices, _aggregate_choices);
>>>           if (err)
>>>               return err;
>>>
>>> -        next = find_next_bit_wrap(cur_profile->choices, 
>>> PLATFORM_PROFILE_LAST,
>>> +        next = find_next_bit_wrap(&choices,
>>> +                      PLATFORM_PROFILE_LAST,
>>>                         profile + 1);
>>
>> Could it be that this would lead to be "custom" profile being 
>> selected under some conditions?
>
> Yeah, you're right.  If all drivers supported custom then this could 
> happen.  I'll clear custom like this:
>
>         choices &= ~BIT(PLATFORM_PROFILE_CUSTOM);
>
Sound good to me.

>> Also _aggregate_profiles() expects profile to be initialized with 
>> PLATFORM_PROFILE_LAST.
>
> Will correct initialization in platform_profile_cycle() to this.
>
>     enum platform_profile_option profile = PLATFORM_PROFILE_LAST;
>
> But this also raises a good point.  If _aggregate_profiles() returns
> custom then this should be an error because next profile is undefined.
> So I'll catch that like this.
>         err = class_for_each_device()
>         if (err)
>             return err;
>         if (profile == PLATFORM_PROFILE_CUSTOM)
>             return -EINVAL;

Good point, please also check if profile == PLATFORM_PROFILE_LAST in case no platform profile handlers are currently installed.

Thanks,
Armin Wol

>>
>> Thanks,
>> Armin Wolf
>>
>>>
>>> -        if (WARN_ON(next == PLATFORM_PROFILE_LAST))
>>> -            return -EINVAL;
>>> +        err = class_for_each_device(&platform_profile_class, NULL, 
>>> &next,
>>> +                        _store_class_profile);
>>>
>>> -        err = cur_profile->profile_set(cur_profile, next);
>>>           if (err)
>>>               return err;
>>>       }
>>>
>>>       sysfs_notify(acpi_kobj, NULL, "platform_profile");
>>> -    return 0;
>>> +
>>> +    return err;
>>>   }
>>>   EXPORT_SYMBOL_GPL(platform_profile_cycle);
>>>
>
>