When memory poison consumption machine checks fire,
mce-notifier-handlers like nfit_handle_mce() record the impacted
physical address range which is reported by the hardware in the
MCi_MISC MSR. The error information includes data about blast radius,
i.e. how many cachelines did the hardware determine are impacted.
A recent change, commit 7917f9cdb503 ("acpi/nfit: rely on mce->misc to
determine poison granularity"), updated nfit_handle_mce() to stop hard
coding the blast radius value of 1 cacheline, and instead rely on the
blast radius reported in 'struct mce' which can be up to 4K (64 cachelines).
It turns out that apei_mce_report_mem_error() had a similar problem in
that it hard coded a blast radius of 4K rather than reading the blast
radius from the error information. Fix apei_mce_report_mem_error() to
convey the proper poison granularity.
Link: https://lore.kernel.org/r/[email protected]
Reviewed-by: Dan Williams <[email protected]>
Reviewed-by: Ingo Molnar <[email protected]>
Signed-off-by: Jane Chu <[email protected]>
---
arch/x86/kernel/cpu/mce/apei.c | 13 ++++++++++++-
1 file changed, 12 insertions(+), 1 deletion(-)
diff --git a/arch/x86/kernel/cpu/mce/apei.c b/arch/x86/kernel/cpu/mce/apei.c
index 717192915f28..8ed341714686 100644
--- a/arch/x86/kernel/cpu/mce/apei.c
+++ b/arch/x86/kernel/cpu/mce/apei.c
@@ -29,15 +29,26 @@
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 fall back to the default page size.
+ */
+ if (mem_err->validation_bits & CPER_MEM_VALID_PA_MASK)
+ lsb = find_first_bit((void *)&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