18 Specification Update
HSD4. LER MSRs May Be Unreliable
Problem: Due to certain internal processor events, updates to the LER (Last Exception Record)
MSRs, MSR_LER_FROM_LIP (1DDH) and MSR_LER_TO_LIP (1DEH), may happen when
no update was expected.
Implication: The values of the LER MSRs may be unreliable.
Workaround: None identified.
Status: For the steppings affected, see the Summary Table of Changes.
HSD5. MONITOR or CLFLUSH on the Local XAPIC's Address Space Results in
Hang
Problem: If the target linear address range for a MONITOR or CLFLUSH is mapped to the local
xAPIC's address space, the processor will hang.
Implication: When this erratum occurs, the processor will hang. The local xAPIC's address space
must be uncached. The MONITOR instruction only functions correctly if the specified
linear address range is of the type write-back. CLFLUSH flushes data from the cache.
Intel has not observed this erratum with any commercially available software.
Workaround: Do not execute MONITOR or CLFLUSH instructions on the local xAPIC address space.
Status: For the steppings affected, see the Summary Table of Changes.
HSD6. An Uncorrectable Error Logged in IA32_CR_MC2_STATUS May also
Result in a System Hang
Problem: Uncorrectable errors logged in IA32_CR_MC2_STATUS MSR (409H) may also result in a
system hang causing an Internal Timer Error (MCACOD = 0x0400h) to be logged in
another machine check bank (IA32_MCi_STATUS).
Implication: Uncorrectable errors logged in IA32_CR_MC2_STATUS can further cause a system hang
and an Internal Timer Error to be logged.
Workaround: None identified.
Status: For the steppings affected, see the Summary Table of Changes.
HSD7. #GP on Segment Selector Descriptor that Straddles Canonical
Boundary May Not Provide Correct Exception Error Code
Problem: During a #GP (General Protection Exception), the processor pushes an error code on to
the exception handler’s stack. If the segment selector descriptor straddles the
canonical boundary, the error code pushed onto the stack may be incorrect.
Implication: An incorrect error code may be pushed onto the stack. Intel has not observed this
erratum with any commercially available software.
Workaround: None identified.
Status: For the steppings affected, see the Summary Table of Changes.