[PATCH v3] Make instruction dumping work in real mode.

[PATCH v3] Make instruction dumping work in real mode.

[Scott Wood]

On non-book-E-or-4xx, exceptions execute in real mode.  If a fault happens
that leads to a register dump, the kernel currently prints XXXXXXXX because
it doesn't realize that PC is a physical address.

This patch checks the state of the IMMU, and if necessary converts PC into a
virtual address.

Signed-off-by: Scott Wood <scottwood@freescale.com>
---
Resent with 40x->44x.

 arch/powerpc/kernel/process.c |    8 ++++++++
 1 files changed, 8 insertions(+), 0 deletions(-)

diff --git a/arch/powerpc/kernel/process.c b/arch/powerpc/kernel/process.c
index 57c589c..6dbde7f 100644
--- a/arch/powerpc/kernel/process.c
+++ b/arch/powerpc/kernel/process.c
@@ -354,6 +354,14 @@ static void show_instructions(struct pt_regs *regs)
 		if (!(i % 8))
 			printk("\n");
 
+#if !defined(CONFIG_BOOKE) && !defined(CONFIG_44x)
+		/* If executing with the IMMU off, adjust pc rather
+		 * than print XXXXXXXX.
+		 */
+		if (!(regs->msr & MSR_IR))
+			pc = (unsigned long)phys_to_virt(pc);
+#endif
+
 		/* We use __get_user here *only* to avoid an OOPS on a
 		 * bad address because the pc *should* only be a
 		 * kernel address.
-- 
1.5.3.1

Re: [PATCH v3] Make instruction dumping work in real mode.

[Kumar Gala]

On Sep 27, 2007, at 1:00 PM, Scott Wood wrote:

> On non-book-E-or-4xx, exceptions execute in real mode.  If a fault  
> happens
> that leads to a register dump, the kernel currently prints XXXXXXXX  
> because
> it doesn't realize that PC is a physical address.
>
> This patch checks the state of the IMMU, and if necessary converts  
> PC into a
> virtual address.
>
> Signed-off-by: Scott Wood <scottwood@freescale.com>

44x is Book-e :)

all you need is a ifndef CONFIG_BOOKE.

- k

Re: [PATCH v3] Make instruction dumping work in real mode.

[Sergei Shtylyov]

Hello.

Scott Wood wrote:

> On non-book-E-or-4xx, exceptions execute in real mode.  If a fault happens
> that leads to a register dump, the kernel currently prints XXXXXXXX because
> it doesn't realize that PC is a physical address.

> This patch checks the state of the IMMU, and if necessary converts PC into a
> virtual address.
> 
> Signed-off-by: Scott Wood <scottwood@freescale.com>
> ---
> Resent with 40x->44x.
> 
>  arch/powerpc/kernel/process.c |    8 ++++++++
>  1 files changed, 8 insertions(+), 0 deletions(-)
> 
> diff --git a/arch/powerpc/kernel/process.c b/arch/powerpc/kernel/process.c
> index 57c589c..6dbde7f 100644
> --- a/arch/powerpc/kernel/process.c
> +++ b/arch/powerpc/kernel/process.c
> @@ -354,6 +354,14 @@ static void show_instructions(struct pt_regs *regs)
>  		if (!(i % 8))
>  			printk("\n");
>  
> +#if !defined(CONFIG_BOOKE) && !defined(CONFIG_44x)

     Doesn't CONFIG_44x select CONFIG_BOOKE? Maybe you meant CONFIG_40x?

> +		/* If executing with the IMMU off, adjust pc rather
> +		 * than print XXXXXXXX.
> +		 */
> +		if (!(regs->msr & MSR_IR))
> +			pc = (unsigned long)phys_to_virt(pc);
> +#endif
> +
>  		/* We use __get_user here *only* to avoid an OOPS on a
>  		 * bad address because the pc *should* only be a
>  		 * kernel address.

WBR, Sergei

Re: [PATCH v3] Make instruction dumping work in real mode.

[Grant Likely]

On 9/27/07, Sergei Shtylyov <sshtylyov@ru.mvista.com> wrote:
> Hello.
>
> Scott Wood wrote:
>
> > On non-book-E-or-4xx, exceptions execute in real mode.  If a fault happens
> > that leads to a register dump, the kernel currently prints XXXXXXXX because
> > it doesn't realize that PC is a physical address.
>
> > This patch checks the state of the IMMU, and if necessary converts PC into a
> > virtual address.
> >
> > Signed-off-by: Scott Wood <scottwood@freescale.com>
> > ---
> > Resent with 40x->44x.
> >
> >  arch/powerpc/kernel/process.c |    8 ++++++++
> >  1 files changed, 8 insertions(+), 0 deletions(-)
> >
> > diff --git a/arch/powerpc/kernel/process.c b/arch/powerpc/kernel/process.c
> > index 57c589c..6dbde7f 100644
> > --- a/arch/powerpc/kernel/process.c
> > +++ b/arch/powerpc/kernel/process.c
> > @@ -354,6 +354,14 @@ static void show_instructions(struct pt_regs *regs)
> >               if (!(i % 8))
> >                       printk("\n");
> >
> > +#if !defined(CONFIG_BOOKE) && !defined(CONFIG_44x)
>
>      Doesn't CONFIG_44x select CONFIG_BOOKE? Maybe you meant CONFIG_40x?

Heeheehee!  That was the *last* version of the patch.  :-)

40x *does* have real mode, so CONFIG_40x is not appropriate here.  As
Kumar mentioned, only CONFIG_BOOKE is needed.

Cheers,
g.

-- 
Grant Likely, B.Sc., P.Eng.
Secret Lab Technologies Ltd.
grant.likely@secretlab.ca
(403) 399-0195