Intel 80287, 80286 manual Protection, Inter-Level Return Checks

PROTECTION

Table 7-4. Inter-Level Return Checks

	Type of Check	Exception·	Error Code
SP is not within Segment Limit		SF	0
SP + N + 7 is not in Segment Limit·		SF	0
RPL of Return CS is Greater than CPL		GP	Return CS id
Return CS Selector is not null		GP	Return CS id
Return CS segment is within Descriptor Table Limit		GP	Return CS id
Return CS Descriptor is a Code Segment		GP	Return CS id
Return CS Segment is Present		NP	Return CS id
DPL of Return Non-Conforming Code Segment ~ RPL of CS		GP	Return CS id
55	Selector at SP + N + 6 is not Null	SF	Return 55 id
55	Selector at SP + N + 6 is within Descriptor Table Limit	SF	Return 55 id
55 Descriptor is Writable Data Segment		SF	Return 55 id
55	Segment is Present	SF	Return 55 id
55	Segment DPL = RPL of CS	SF	Return 55 id

'SF= Stack Fault, GP = General Protection Exception, NP = Not-Present Exception

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