This change prints the hexadecimal EC value in mem_abort_decode(),
which makes it easier to lookup the corresponding EC in
the ARM Architecture Reference Manual.
The commit 1f9b8936f36f ("arm64: Decode information from ESR upon mem
faults") prints useful information when memory abort occurs. It would
be easier to lookup "0x25" instead of "DABT" in the document. Then we
can check the corresponding ISS.
For example:
Current info Document
EC Exception class
"CP15 MCR/MRC" 0x3 "MCR or MRC access to CP15a..."
"ASIMD" 0x7 "Access to SIMD or floating-point..."
"DABT (current EL)" 0x25 "Data Abort taken without..."
...
Before:
Unable to handle kernel paging request at virtual address 000000000000c000
Mem abort info:
ESR = 0x96000046
Exception class = DABT (current EL), IL = 32 bits
SET = 0, FnV = 0
EA = 0, S1PTW = 0
Data abort info:
ISV = 0, ISS = 0x00000046
CM = 0, WnR = 1
After:
Unable to handle kernel paging request at virtual address 000000000000c000
Mem abort info:
ESR = 0x96000046
EC = 0x25, Exception class = DABT (current EL), IL = 32 bits
SET = 0, FnV = 0
EA = 0, S1PTW = 0
Data abort info:
ISV = 0, ISS = 0x00000046
CM = 0, WnR = 1
Cc: Mark Rutland <[email protected]>
Cc: Anshuman Khandual <[email protected]>
Cc: James Morse <[email protected]>
Signed-off-by: Miles Chen <[email protected]>
---
arch/arm64/mm/fault.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/arch/arm64/mm/fault.c b/arch/arm64/mm/fault.c
index cfd65b63f36f..afb6041e25e6 100644
--- a/arch/arm64/mm/fault.c
+++ b/arch/arm64/mm/fault.c
@@ -86,8 +86,8 @@ static void mem_abort_decode(unsigned int esr)
pr_alert("Mem abort info:\n");
pr_alert(" ESR = 0x%08x\n", esr);
- pr_alert(" Exception class = %s, IL = %u bits\n",
- esr_get_class_string(esr),
+ pr_alert(" EC = 0x%lx, Exception class = %s, IL = %u bits\n",
+ ESR_ELx_EC(esr), esr_get_class_string(esr),
(esr & ESR_ELx_IL) ? 32 : 16);
pr_alert(" SET = %lu, FnV = %lu\n",
(esr & ESR_ELx_SET_MASK) >> ESR_ELx_SET_SHIFT,
--
2.18.0
On Tue, Aug 06, 2019 at 07:29:48PM +0800, Miles Chen wrote:
> This change prints the hexadecimal EC value in mem_abort_decode(),
> which makes it easier to lookup the corresponding EC in
> the ARM Architecture Reference Manual.
>
> The commit 1f9b8936f36f ("arm64: Decode information from ESR upon mem
> faults") prints useful information when memory abort occurs. It would
> be easier to lookup "0x25" instead of "DABT" in the document. Then we
> can check the corresponding ISS.
>
> For example:
> Current info Document
> EC Exception class
> "CP15 MCR/MRC" 0x3 "MCR or MRC access to CP15a..."
> "ASIMD" 0x7 "Access to SIMD or floating-point..."
> "DABT (current EL)" 0x25 "Data Abort taken without..."
> ...
>
> Before:
> Unable to handle kernel paging request at virtual address 000000000000c000
> Mem abort info:
> ESR = 0x96000046
> Exception class = DABT (current EL), IL = 32 bits
> SET = 0, FnV = 0
> EA = 0, S1PTW = 0
> Data abort info:
> ISV = 0, ISS = 0x00000046
> CM = 0, WnR = 1
>
> After:
> Unable to handle kernel paging request at virtual address 000000000000c000
> Mem abort info:
> ESR = 0x96000046
> EC = 0x25, Exception class = DABT (current EL), IL = 32 bits
> SET = 0, FnV = 0
> EA = 0, S1PTW = 0
> Data abort info:
> ISV = 0, ISS = 0x00000046
> CM = 0, WnR = 1
>
> Cc: Mark Rutland <[email protected]>
> Cc: Anshuman Khandual <[email protected]>
> Cc: James Morse <[email protected]>
> Signed-off-by: Miles Chen <[email protected]>
> ---
> arch/arm64/mm/fault.c | 4 ++--
> 1 file changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/arch/arm64/mm/fault.c b/arch/arm64/mm/fault.c
> index cfd65b63f36f..afb6041e25e6 100644
> --- a/arch/arm64/mm/fault.c
> +++ b/arch/arm64/mm/fault.c
> @@ -86,8 +86,8 @@ static void mem_abort_decode(unsigned int esr)
> pr_alert("Mem abort info:\n");
>
> pr_alert(" ESR = 0x%08x\n", esr);
> - pr_alert(" Exception class = %s, IL = %u bits\n",
> - esr_get_class_string(esr),
> + pr_alert(" EC = 0x%lx, Exception class = %s, IL = %u bits\n",
> + ESR_ELx_EC(esr), esr_get_class_string(esr),
Could we make this:
pr_alert(" EC = 0x%02lx: %s, IL = %u bits\n",
ESR_ELx_EC(esr), esr_get_class_string(esr));
We don't need to spell out "Exception Class" if we say "EC", and we
should print the EC hex value with a consistent width as we do for the
ISS.
With that:
Acked-by: Mark Rutland <[email protected]>
Thanks,
Mark.
On Tue, 2019-08-06 at 13:34 +0100, Mark Rutland wrote:
> On Tue, Aug 06, 2019 at 07:29:48PM +0800, Miles Chen wrote:
> > This change prints the hexadecimal EC value in mem_abort_decode(),
> > which makes it easier to lookup the corresponding EC in
> > the ARM Architecture Reference Manual.
> >
> > The commit 1f9b8936f36f ("arm64: Decode information from ESR upon mem
> > faults") prints useful information when memory abort occurs. It would
> > be easier to lookup "0x25" instead of "DABT" in the document. Then we
> > can check the corresponding ISS.
> >
> > For example:
> > Current info Document
> > EC Exception class
> > "CP15 MCR/MRC" 0x3 "MCR or MRC access to CP15a..."
> > "ASIMD" 0x7 "Access to SIMD or floating-point..."
> > "DABT (current EL)" 0x25 "Data Abort taken without..."
> > ...
> >
> > Before:
> > Unable to handle kernel paging request at virtual address 000000000000c000
> > Mem abort info:
> > ESR = 0x96000046
> > Exception class = DABT (current EL), IL = 32 bits
> > SET = 0, FnV = 0
> > EA = 0, S1PTW = 0
> > Data abort info:
> > ISV = 0, ISS = 0x00000046
> > CM = 0, WnR = 1
> >
> > After:
> > Unable to handle kernel paging request at virtual address 000000000000c000
> > Mem abort info:
> > ESR = 0x96000046
> > EC = 0x25, Exception class = DABT (current EL), IL = 32 bits
> > SET = 0, FnV = 0
> > EA = 0, S1PTW = 0
> > Data abort info:
> > ISV = 0, ISS = 0x00000046
> > CM = 0, WnR = 1
> >
> > Cc: Mark Rutland <[email protected]>
> > Cc: Anshuman Khandual <[email protected]>
> > Cc: James Morse <[email protected]>
> > Signed-off-by: Miles Chen <[email protected]>
> > ---
> > arch/arm64/mm/fault.c | 4 ++--
> > 1 file changed, 2 insertions(+), 2 deletions(-)
> >
> > diff --git a/arch/arm64/mm/fault.c b/arch/arm64/mm/fault.c
> > index cfd65b63f36f..afb6041e25e6 100644
> > --- a/arch/arm64/mm/fault.c
> > +++ b/arch/arm64/mm/fault.c
> > @@ -86,8 +86,8 @@ static void mem_abort_decode(unsigned int esr)
> > pr_alert("Mem abort info:\n");
> >
> > pr_alert(" ESR = 0x%08x\n", esr);
> > - pr_alert(" Exception class = %s, IL = %u bits\n",
> > - esr_get_class_string(esr),
> > + pr_alert(" EC = 0x%lx, Exception class = %s, IL = %u bits\n",
> > + ESR_ELx_EC(esr), esr_get_class_string(esr),
>
> Could we make this:
>
> pr_alert(" EC = 0x%02lx: %s, IL = %u bits\n",
> ESR_ELx_EC(esr), esr_get_class_string(esr));
>
> We don't need to spell out "Exception Class" if we say "EC", and we
> should print the EC hex value with a consistent width as we do for the
> ISS.
Thanks for the advise.
It looks better this way. I'll send patch v2.
Miles
>
> With that:
>
> Acked-by: Mark Rutland <[email protected]>
>
> Thanks,
> Mark.