[PATCH] powerpc/fsl-rio: Fix fsl_rio_setup error paths and use-after-unmap

Scott Wood scottwood at freescale.com
Wed Apr 30 03:12:32 EST 2014

On Mon, 2014-04-28 at 23:04 -0500, Liu Gang-B34182 wrote:
> > -----Original Message-----
> > From: Wood Scott-B07421
> > Sent: Tuesday, April 29, 2014 9:32 AM
> > To: linuxppc-dev at lists.ozlabs.org
> > Cc: Wood Scott-B07421; Liu Gang-B34182
> > Subject: [PATCH] powerpc/fsl-rio: Fix fsl_rio_setup error paths and use-
> > after-unmap
> > 
> > Several of the error paths from fsl_rio_setup are missing error messages.
> > 
> > Worse, fsl_rio_setup initializes several global pointers and does not
> > NULL them out after freeing/unmapping on error.  This caused
> > fsl_rio_mcheck_exception() to crash when accessing rio_regs_win which was
> > non-NULL but had been unmapped.
> > 
> > Signed-off-by: Scott Wood <scottwood at freescale.com>
> > Cc: Liu Gang <Gang.Liu at freescale.com>
> > ---
> > Liu Gang, are you sure all of these error conditions are fatal?  Why does
> > the rio driver fail if rmu is not present (e.g.  on t4240)?
> Hi Scott, I think the errors you modified in the patch are serious and should
> be fixed. Thanks very much!
> And in fact, the rio driver can be used just for the submodule of the SRIO: RMU.
> It should be used with arch/powerpc/sysdev/fsl_rmu.c and there should have the
> RMU module.
> The fsl_rio.c implements some basic and needed works to support the RMU running well.

I don't quite follow -- is it expected that rio can work without rmu, or
not?  As is, fsl_rio_setup() will error out if it doesn't find an
fsl,srio-rmu-handle property.

> In addition, could you please help to apply the following patch:
> http://patchwork.ozlabs.org/patch/337810/

Yes, I'll apply it when I do my next batch of patch applications.


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