Errata
40
Specification Update
AZ46.
Self/Cross Modifying Code May Not be Detected or May Cause a Machine
Check Exception
Problem:
If instructions from at least three different ways in the same instruction cache set exist in
the pipeline combined with some rare internal state, self-modifying code (SMC) or cross-
modifying code may not be detected and/or handled.
Implication:
An instruction that should be overwritten by another instruction while in the processor
pipeline may not be detected/modified, and could retire without detection. Alternatively
the instruction may cause a Machine Check Exception. Intel has not observed this
erratum with any commercially available software.
Workaround:
It is possible for the BIOS to contain a workaround for this erratum.
Status:
For the steppings affected, see the Summary Tables of Changes.
AZ47.
Data TLB Eviction Condition in the Middle of a Cacheline Split Load
Operation May Cause the Processor to Hang
Problem:
If the TLB translation gets evicted while completing a cacheline split load operation,
under rare scenarios the processor may hang.
Implication:
The cacheline split load operation may not be able to complete normally, and the
machine may hang and generate Machine Check Exception. Intel has not observed this
erratum with any commercially available software.
Workaround:
It is possible for the BIOS to contain a workaround for this erratum.
Status:
For the steppings affected, see the Summary Tables of Changes.
AZ48.
Update of Read/Write (R/W) or User/Supervisor (U/S) or Present (P)
Bits without TLB Shootdown May Cause Unexpected Processor Behavior
Problem:
Updating a page table entry by changing R/W, U/S or P bits, even when transitioning
these bits from 0 to 1, without keeping the affected linear address range coherent with
all TLB (Translation Lookaside Buffers) and paging-structures caches in the processor, in
conjunction with a complex sequence of internal processor micro-architectural events
and store operations, may lead to unexpected processor behavior.
Implication:
This erratum may lead to livelock, shutdown or other unexpected processor behavior.
Intel has not observed this erratum with any commercially available software.
Workaround:
None identified.
Status:
For the steppings affected, see the Summary Tables of Changes.