linux-kernel - Re: [PATCH v1 1/1] serial: 8250

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]

Date:   Thu, 30 Jun 2022 09:44:07 +0100
From:   Paul Cercueil <paul@...pouillou.net>
To:     Ilpo Järvinen <ilpo.jarvinen@...ux.intel.com>
Cc:     Andy Shevchenko <andriy.shevchenko@...ux.intel.com>,
        Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
        linux-serial <linux-serial@...r.kernel.org>,
        LKML <linux-kernel@...r.kernel.org>,
        Jiri Slaby <jirislaby@...nel.org>
Subject: Re: [PATCH v1 1/1] serial: 8250_dw: Drop PM ifdeffery

Hi Ilpo,

Le jeu., juin 30 2022 at 10:41:40 +0300, Ilpo Järvinen 
<ilpo.jarvinen@...ux.intel.com> a écrit :
> On Wed, 29 Jun 2022, Andy Shevchenko wrote:
> 
>>  Drop CONFIG_PM and CONFIG_PM_SLEEP ifdeffery while converting 
>> dw8250_pm_ops
>>  to use new PM macros.
>> 
>>  Signed-off-by: Andy Shevchenko <andriy.shevchenko@...ux.intel.com>
> 
> Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@...ux.intel.com>
> 
> Not directily related to the patch itself but do you have any idea why
> 1a3c7bb08826 ("PM: core: Add new *_PM_OPS macros, deprecate old ones")
> didn't wrap RUNTIME_PM_OPS() pointers with pm_ptr()? I'm asking this
> because in SET_RUNTIME_PM_OPS() the callbacks are only created with
> #ifdef CONFIG_PM so I'd have expected RUNTIME_PM_OPS() to maintain 
> that
> behavior but it didn't? Was it just an oversight that should be fixed?

The RUNTIME_PM_OPS() does not wrap pointers with pm_ptr(), because the 
pointer to the dev_pm_ops should only ever be used wrapped with 
pm_ptr() or pm_sleep_ptr().

Which is not done here.

Andy:
The deference of dw8250_pm_ops should be pm_ptr(&dw8250_pm_ops). If you 
only had system suspend/resume functions, you'd use pm_sleep_ptr() 
there.

Cheers,
-Paul

> --
>  i.
> 
>>  ---
>>   drivers/tty/serial/8250/8250_dw.c | 8 ++------
>>   1 file changed, 2 insertions(+), 6 deletions(-)
>> 
>>  diff --git a/drivers/tty/serial/8250/8250_dw.c 
>> b/drivers/tty/serial/8250/8250_dw.c
>>  index f71428c85562..adcc869352b1 100644
>>  --- a/drivers/tty/serial/8250/8250_dw.c
>>  +++ b/drivers/tty/serial/8250/8250_dw.c
>>  @@ -691,7 +691,6 @@ static int dw8250_remove(struct platform_device 
>> *pdev)
>>   	return 0;
>>   }
>> 
>>  -#ifdef CONFIG_PM_SLEEP
>>   static int dw8250_suspend(struct device *dev)
>>   {
>>   	struct dw8250_data *data = dev_get_drvdata(dev);
>>  @@ -709,9 +708,7 @@ static int dw8250_resume(struct device *dev)
>> 
>>   	return 0;
>>   }
>>  -#endif /* CONFIG_PM_SLEEP */
>> 
>>  -#ifdef CONFIG_PM
>>   static int dw8250_runtime_suspend(struct device *dev)
>>   {
>>   	struct dw8250_data *data = dev_get_drvdata(dev);
>>  @@ -733,11 +730,10 @@ static int dw8250_runtime_resume(struct 
>> device *dev)
>> 
>>   	return 0;
>>   }
>>  -#endif
>> 
>>   static const struct dev_pm_ops dw8250_pm_ops = {
>>  -	SET_SYSTEM_SLEEP_PM_OPS(dw8250_suspend, dw8250_resume)
>>  -	SET_RUNTIME_PM_OPS(dw8250_runtime_suspend, dw8250_runtime_resume, 
>> NULL)
>>  +	SYSTEM_SLEEP_PM_OPS(dw8250_suspend, dw8250_resume)
>>  +	RUNTIME_PM_OPS(dw8250_runtime_suspend, dw8250_runtime_resume, 
>> NULL)
>>   };
>> 
>>   static const struct dw8250_platform_data dw8250_dw_apb = {
>>