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* [PATCHv1 for-4.7] x86: show correct code in CPU state
@ 2016-05-03 16:15 David Vrabel
  2016-05-03 16:19 ` Andrew Cooper
  0 siblings, 1 reply; 3+ messages in thread
From: David Vrabel @ 2016-05-03 16:15 UTC (permalink / raw)
  To: xen-devel; +Cc: Andrew Cooper, David Vrabel, Jan Beulich

When showing the CPU state (e.g., after a crash) the dump of code
around RIP is incorrect.

Incorrect:

    Xen code around <ffff82d0801113cf> (...):
     00 c6 c1 ee 08 48 c1 e0 <04> 03 04 f1 8b ...
     ^^ Uninitialized         ^^ Missing 0x48

Correct:

    Xen code around <ffff82d0801113cf> (...):
     c6 c1 ee 08 48 c1 e0 04 <48> 03 04 f1 8b ...

When coping the bytes before RIP, the destination was off-by-one.

Signed-off-by: David Vrabel <david.vrabel@citrix.com>
---
 xen/arch/x86/traps.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/xen/arch/x86/traps.c b/xen/arch/x86/traps.c
index 8384158..0895441 100644
--- a/xen/arch/x86/traps.c
+++ b/xen/arch/x86/traps.c
@@ -150,7 +150,7 @@ static void show_code(const struct cpu_user_regs *regs)
                   : "=&c" (missing_before),
                     "=&D" (tmp), "=&S" (tmp)
                   : "0" (ARRAY_SIZE(insns_before)),
-                    "1" (insns_before + ARRAY_SIZE(insns_before)),
+                    "1" (insns_before + ARRAY_SIZE(insns_before) - 1),
                     "2" (regs->rip - 1));
     clac();
 
-- 
2.1.4


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^ permalink raw reply related	[flat|nested] 3+ messages in thread

* Re: [PATCHv1 for-4.7] x86: show correct code in CPU state
  2016-05-03 16:15 [PATCHv1 for-4.7] x86: show correct code in CPU state David Vrabel
@ 2016-05-03 16:19 ` Andrew Cooper
  2016-05-03 16:20   ` Wei Liu
  0 siblings, 1 reply; 3+ messages in thread
From: Andrew Cooper @ 2016-05-03 16:19 UTC (permalink / raw)
  To: David Vrabel, xen-devel; +Cc: Wei Liu, Jan Beulich

On 03/05/16 17:15, David Vrabel wrote:
> When showing the CPU state (e.g., after a crash) the dump of code
> around RIP is incorrect.
>
> Incorrect:
>
>     Xen code around <ffff82d0801113cf> (...):
>      00 c6 c1 ee 08 48 c1 e0 <04> 03 04 f1 8b ...
>      ^^ Uninitialized         ^^ Missing 0x48
>
> Correct:
>
>     Xen code around <ffff82d0801113cf> (...):
>      c6 c1 ee 08 48 c1 e0 04 <48> 03 04 f1 8b ...
>
> When coping the bytes before RIP, the destination was off-by-one.
>
> Signed-off-by: David Vrabel <david.vrabel@citrix.com>

Reviewed-by: Andrew Cooper <andrew.cooper3@citrix.com>

CC'ing Wei for release ack.

> ---
>  xen/arch/x86/traps.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/xen/arch/x86/traps.c b/xen/arch/x86/traps.c
> index 8384158..0895441 100644
> --- a/xen/arch/x86/traps.c
> +++ b/xen/arch/x86/traps.c
> @@ -150,7 +150,7 @@ static void show_code(const struct cpu_user_regs *regs)
>                    : "=&c" (missing_before),
>                      "=&D" (tmp), "=&S" (tmp)
>                    : "0" (ARRAY_SIZE(insns_before)),
> -                    "1" (insns_before + ARRAY_SIZE(insns_before)),
> +                    "1" (insns_before + ARRAY_SIZE(insns_before) - 1),
>                      "2" (regs->rip - 1));
>      clac();
>  


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^ permalink raw reply	[flat|nested] 3+ messages in thread

* Re: [PATCHv1 for-4.7] x86: show correct code in CPU state
  2016-05-03 16:19 ` Andrew Cooper
@ 2016-05-03 16:20   ` Wei Liu
  0 siblings, 0 replies; 3+ messages in thread
From: Wei Liu @ 2016-05-03 16:20 UTC (permalink / raw)
  To: Andrew Cooper; +Cc: xen-devel, Wei Liu, David Vrabel, Jan Beulich

On Tue, May 03, 2016 at 05:19:26PM +0100, Andrew Cooper wrote:
> On 03/05/16 17:15, David Vrabel wrote:
> > When showing the CPU state (e.g., after a crash) the dump of code
> > around RIP is incorrect.
> >
> > Incorrect:
> >
> >     Xen code around <ffff82d0801113cf> (...):
> >      00 c6 c1 ee 08 48 c1 e0 <04> 03 04 f1 8b ...
> >      ^^ Uninitialized         ^^ Missing 0x48
> >
> > Correct:
> >
> >     Xen code around <ffff82d0801113cf> (...):
> >      c6 c1 ee 08 48 c1 e0 04 <48> 03 04 f1 8b ...
> >
> > When coping the bytes before RIP, the destination was off-by-one.
> >
> > Signed-off-by: David Vrabel <david.vrabel@citrix.com>
> 
> Reviewed-by: Andrew Cooper <andrew.cooper3@citrix.com>
> 
> CC'ing Wei for release ack.

Release-acked-by: Wei Liu <wei.liu2@citrix.com>

> 
> > ---
> >  xen/arch/x86/traps.c | 2 +-
> >  1 file changed, 1 insertion(+), 1 deletion(-)
> >
> > diff --git a/xen/arch/x86/traps.c b/xen/arch/x86/traps.c
> > index 8384158..0895441 100644
> > --- a/xen/arch/x86/traps.c
> > +++ b/xen/arch/x86/traps.c
> > @@ -150,7 +150,7 @@ static void show_code(const struct cpu_user_regs *regs)
> >                    : "=&c" (missing_before),
> >                      "=&D" (tmp), "=&S" (tmp)
> >                    : "0" (ARRAY_SIZE(insns_before)),
> > -                    "1" (insns_before + ARRAY_SIZE(insns_before)),
> > +                    "1" (insns_before + ARRAY_SIZE(insns_before) - 1),
> >                      "2" (regs->rip - 1));
> >      clac();
> >  
> 

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^ permalink raw reply	[flat|nested] 3+ messages in thread

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2016-05-03 16:19 ` Andrew Cooper
2016-05-03 16:20   ` Wei Liu

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