[PATCH v2] Make instruction dumping work in real mode.

[PATCH v2] 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>
---
This version uses MSR_IR rather than address heuristics, and fixes breakage
that somehow crept into the address adjustment in the previous patch.

 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_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.
-- 
1.5.3.1

Re: [PATCH v2] Make instruction dumping work in real mode.

[Kumar Gala]

On Sep 25, 2007, at 3:19 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>
> ---
> This version uses MSR_IR rather than address heuristics, and fixes  
> breakage
> that somehow crept into the address adjustment in the previous patch.
>
>  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_40x)

40x has a real mode and can have the IMMU off.

> +		/* 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
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