linux-kernel - Re: linux 4.2-rc1 broken Nokia N900

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: <20150722133318.GA17442@earth>
Date:	Wed, 22 Jul 2015 15:33:18 +0200
From:	Sebastian Reichel <sre@...nel.org>
To:	Pali Rohár <pali.rohar@...il.com>
Cc:	Michael Welling <mwelling@...e.org>, Pavel Machek <pavel@....cz>,
	Tony Lindgren <tony@...mide.com>,
	Ivaylo Dimitrov <ivo.g.dimitrov.75@...il.com>,
	Aaro Koskinen <aaro.koskinen@....fi>,
	Nishanth Menon <nm@...com>, linux-omap@...r.kernel.org,
	linux-kernel@...r.kernel.org
Subject: Re: linux 4.2-rc1 broken Nokia N900

Hi,

On Wed, Jul 22, 2015 at 09:27:32AM +0200, Pali Rohár wrote:
> > > diff --git a/drivers/spi/spi-omap2-mcspi.c b/drivers/spi/spi-omap2-mcspi.c
> > > index 5867384..f7d9ffd 100644
> > > --- a/drivers/spi/spi-omap2-mcspi.c
> > > +++ b/drivers/spi/spi-omap2-mcspi.c
> > > @@ -245,6 +245,7 @@ static void omap2_mcspi_set_enable(const struct spi_device *spi, int enable)
> > >  
> > >  static void omap2_mcspi_set_cs(struct spi_device *spi, bool enable)
> > >  {
> > > +       struct omap2_mcspi *mcspi = spi_master_get_devdata(spi->master);
> > >         u32 l;
> > >  
> > >         /* The controller handles the inverted chip selects
> > > @@ -255,6 +256,8 @@ static void omap2_mcspi_set_cs(struct spi_device *spi, bool enable)
> > >                 enable = !enable;
> > >  
> > >         if (spi->controller_state) {
> > > +               pm_runtime_get_sync(mcspi->dev);
> > > +
> > 
> > Should the return code should be checked here as with the other
> > instances of pm_runtime_get_sync?

Yes. If it fails, the line fetch error would be triggered again.

Probably the set_cs callback should also be changed, so that it can
return an error code. This is not something for 4.2-rc, though.

> Anyway, what do you think about adding gcc macro for pm_runtime_get_sync
> function which report compiler warning when return value is not checked?

Adding __must_check to pm_runtime_get_sync() should be discussed
separately with the relevant people in Cc. A quick grep in drivers/
reveals a huge amount of code not handling pm_runtime_get_sync's return
code.

-- Sebastian

Download attachment "signature.asc" of type "application/pgp-signature" (820 bytes)