With Commit 7917f9cdb503 ("acpi/nfit: rely on mce->misc to determine
poison granularity") that changed nfit_handle_mce() callback to report
badrange according to 1ULL << MCI_MISC_ADDR_LSB(mce->misc), it's been
discovered that the mce->misc LSB field is 0x1000 bytes, hence injecting
2 back-to-back poisons and the driver ends up logging 8 badblocks,
because 0x1000 bytes is 8 512-byte.
Dan Williams noticed that apei_mce_report_mem_error() hardcode
the LSB field to PAGE_SHIFT instead of consulting the input
struct cper_sec_mem_err record. So change to rely on hardware whenever
support is available.
Link: https://lore.kernel.org/r/[email protected]
Reviewed-by: Dan Williams <[email protected]>
Signed-off-by: Jane Chu <[email protected]>
---
arch/x86/kernel/cpu/mce/apei.c | 14 +++++++++++++-
1 file changed, 13 insertions(+), 1 deletion(-)
diff --git a/arch/x86/kernel/cpu/mce/apei.c b/arch/x86/kernel/cpu/mce/apei.c
index 717192915f28..e2439c7872ba 100644
--- a/arch/x86/kernel/cpu/mce/apei.c
+++ b/arch/x86/kernel/cpu/mce/apei.c
@@ -29,15 +29,27 @@
void apei_mce_report_mem_error(int severity, struct cper_sec_mem_err *mem_err)
{
struct mce m;
+ int lsb;
if (!(mem_err->validation_bits & CPER_MEM_VALID_PA))
return;
+ /*
+ * Even if the ->validation_bits are set for address mask,
+ * to be extra safe, check and reject an error radius '0',
+ * and fallback to the default page size.
+ */
+ if (mem_err->validation_bits & CPER_MEM_VALID_PA_MASK)
+ lsb = find_first_bit((const unsigned long *)
+ &mem_err->physical_addr_mask, PAGE_SHIFT);
+ else
+ lsb = PAGE_SHIFT;
+
mce_setup(&m);
m.bank = -1;
/* Fake a memory read error with unknown channel */
m.status = MCI_STATUS_VAL | MCI_STATUS_EN | MCI_STATUS_ADDRV | MCI_STATUS_MISCV | 0x9f;
- m.misc = (MCI_MISC_ADDR_PHYS << 6) | PAGE_SHIFT;
+ m.misc = (MCI_MISC_ADDR_PHYS << 6) | lsb;
if (severity >= GHES_SEV_RECOVERABLE)
m.status |= MCI_STATUS_UC;
--
2.18.4
* Jane Chu <[email protected]> wrote:
> With Commit 7917f9cdb503 ("acpi/nfit: rely on mce->misc to determine
> poison granularity") that changed nfit_handle_mce() callback to report
> badrange according to 1ULL << MCI_MISC_ADDR_LSB(mce->misc), it's been
> discovered that the mce->misc LSB field is 0x1000 bytes, hence injecting
> 2 back-to-back poisons and the driver ends up logging 8 badblocks,
> because 0x1000 bytes is 8 512-byte.
>
> Dan Williams noticed that apei_mce_report_mem_error() hardcode
> the LSB field to PAGE_SHIFT instead of consulting the input
> struct cper_sec_mem_err record. So change to rely on hardware whenever
> support is available.
>
> Link: https://lore.kernel.org/r/[email protected]
>
> Reviewed-by: Dan Williams <[email protected]>
> Signed-off-by: Jane Chu <[email protected]>
> ---
> arch/x86/kernel/cpu/mce/apei.c | 14 +++++++++++++-
> 1 file changed, 13 insertions(+), 1 deletion(-)
>
> diff --git a/arch/x86/kernel/cpu/mce/apei.c b/arch/x86/kernel/cpu/mce/apei.c
> index 717192915f28..e2439c7872ba 100644
> --- a/arch/x86/kernel/cpu/mce/apei.c
> +++ b/arch/x86/kernel/cpu/mce/apei.c
> @@ -29,15 +29,27 @@
> void apei_mce_report_mem_error(int severity, struct cper_sec_mem_err *mem_err)
> {
> struct mce m;
> + int lsb;
>
> if (!(mem_err->validation_bits & CPER_MEM_VALID_PA))
> return;
>
> + /*
> + * Even if the ->validation_bits are set for address mask,
> + * to be extra safe, check and reject an error radius '0',
> + * and fallback to the default page size.
> + */
speling nit:
s/fallback/fall back
> + if (mem_err->validation_bits & CPER_MEM_VALID_PA_MASK)
> + lsb = find_first_bit((const unsigned long *)
> + &mem_err->physical_addr_mask, PAGE_SHIFT);
I think we can write this in a shorter form and in a single line:
lsb = find_first_bit((void *)&mem_err->physical_addr_mask, PAGE_SHIFT);
(Ignore checkpatch if it wants to break the line.)
Untested.
Assuming my suggestion is correct and with those addressed:
Reviewed-by: Ingo Molnar <[email protected]>
Thanks,
Ingo
On 8/2/2022 3:59 AM, Ingo Molnar wrote:
>
> * Jane Chu <[email protected]> wrote:
>
>> With Commit 7917f9cdb503 ("acpi/nfit: rely on mce->misc to determine
>> poison granularity") that changed nfit_handle_mce() callback to report
>> badrange according to 1ULL << MCI_MISC_ADDR_LSB(mce->misc), it's been
>> discovered that the mce->misc LSB field is 0x1000 bytes, hence injecting
>> 2 back-to-back poisons and the driver ends up logging 8 badblocks,
>> because 0x1000 bytes is 8 512-byte.
>>
>> Dan Williams noticed that apei_mce_report_mem_error() hardcode
>> the LSB field to PAGE_SHIFT instead of consulting the input
>> struct cper_sec_mem_err record. So change to rely on hardware whenever
>> support is available.
>>
>> Link: https://lore.kernel.org/r/[email protected]
>>
>> Reviewed-by: Dan Williams <[email protected]>
>> Signed-off-by: Jane Chu <[email protected]>
>> ---
>> arch/x86/kernel/cpu/mce/apei.c | 14 +++++++++++++-
>> 1 file changed, 13 insertions(+), 1 deletion(-)
>>
>> diff --git a/arch/x86/kernel/cpu/mce/apei.c b/arch/x86/kernel/cpu/mce/apei.c
>> index 717192915f28..e2439c7872ba 100644
>> --- a/arch/x86/kernel/cpu/mce/apei.c
>> +++ b/arch/x86/kernel/cpu/mce/apei.c
>> @@ -29,15 +29,27 @@
>> void apei_mce_report_mem_error(int severity, struct cper_sec_mem_err *mem_err)
>> {
>> struct mce m;
>> + int lsb;
>>
>> if (!(mem_err->validation_bits & CPER_MEM_VALID_PA))
>> return;
>>
>> + /*
>> + * Even if the ->validation_bits are set for address mask,
>> + * to be extra safe, check and reject an error radius '0',
>> + * and fallback to the default page size.
>> + */
>
> speling nit:
>
> s/fallback/fall back
>
>> + if (mem_err->validation_bits & CPER_MEM_VALID_PA_MASK)
>> + lsb = find_first_bit((const unsigned long *)
>> + &mem_err->physical_addr_mask, PAGE_SHIFT);
>
> I think we can write this in a shorter form and in a single line:
>
> lsb = find_first_bit((void *)&mem_err->physical_addr_mask, PAGE_SHIFT);
>
> (Ignore checkpatch if it wants to break the line.)
>
> Untested.
>
> Assuming my suggestion is correct and with those addressed:
>
> Reviewed-by: Ingo Molnar <[email protected]>
Thanks! Just tested the change, v7 coming next.
-jane
>
> Thanks,
>
> Ingo