Re: [PATCH v2] [RESEND] Handle instruction cache maintenance faultproperly

[Kirill A. Shutemov]

On Thu, Dec 15, 2011 at 10:56:49PM +0100, Uwe Kleine-König wrote:
> Hello,
> 
> On Tue, May 11, 2010 at 01:33:14PM +0300, Kirill A. Shutemov wrote:
> > Between "clean D line..." and "invalidate I line" operations in
> > v7_coherent_user_range(), the memory page may get swapped out.
> > And the fault on "invalidate I line" could not be properly handled
> > causing the oops.
> > 
> > In ARMv6 "external abort on linefetch" replaced by "instruction cache
> > maintenance fault". Let's handle it as translation fault. It fixes the
> > issue.
> > 
> > I'm not sure if it's reasonable to check arch version in run-time.
> > Let's do it in compile time for now.
> > 
> > Signed-off-by: Siarhei Siamashka <siarhei.siamashka@xxxxxxxxx>
> > Signed-off-by: Kirill A. Shutemov <kirill@xxxxxxxxxxxxx>
> I found this patch in Catalin's stack that I picked up to get support
> for Cortex-M3. Is this still relevant?

It's in upstream. See 8c0b742.

> 
> Best regards
> Uwe
> 
> > Sorry for resend. I've made mistake in maillist address.
> > 
> > ---
> >  arch/arm/mm/fault.c |    5 +++++
> >  1 files changed, 5 insertions(+), 0 deletions(-)
> > 
> > diff --git a/arch/arm/mm/fault.c b/arch/arm/mm/fault.c
> > index 9d40c34..7f193ea 100644
> > --- a/arch/arm/mm/fault.c
> > +++ b/arch/arm/mm/fault.c
> > @@ -463,7 +463,12 @@ static struct fsr_info {
> >  	{ do_bad,		SIGILL,	 BUS_ADRALN,	"alignment exception"		   },
> >  	{ do_bad,		SIGKILL, 0,		"terminal exception"		   },
> >  	{ do_bad,		SIGILL,	 BUS_ADRALN,	"alignment exception"		   },
> > +/* Do we need runtime check ? */
> > +#if __LINUX_ARM_ARCH__ < 6
> >  	{ do_bad,		SIGBUS,	 0,		"external abort on linefetch"	   },
> > +#else
> > +	{ do_translation_fault,	SIGSEGV, SEGV_MAPPER,	"I-cache maintenance
> > fault"	   },
> > +#endif
> >  	{ do_translation_fault,	SIGSEGV, SEGV_MAPERR,	"section translation
> > fault"	   },
> >  	{ do_bad,		SIGBUS,	 0,		"external abort on linefetch"	   },
> >  	{ do_page_fault,	SIGSEGV, SEGV_MAPERR,	"page translation fault"	   },
> > -- 
> > 1.7.0.4
> > 
> > _______________________________________________
> > linux-arm-kernel mailing list
> > linux-arm-kernel@xxxxxxxxxxxxxxxxxxx
> > http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
> > 
> 
> -- 
> Pengutronix e.K.                           | Uwe Kleine-König            |
> Industrial Linux Solutions                 | http://www.pengutronix.de/  |

-- 
 Kirill A. Shutemov
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