Anonymous user
Paging: Difference between revisions
→Handling
| [unchecked revision] | [unchecked revision] |
m (This article is pretty much inaccurate) |
|||
Line 156:
=== Handling ===
The CPU pushes an error code on the stack before firing a page fault exception. The error code must be analyzed by the exception handler to determine how to handle the exception. The
Bit 0 (P) is the Present flag.
Bit 1 (R/W) is the Read/Write flag.
Bit 2 (U/S) is the User/Supervisor flag.
Bit 3 (RSVD) indicates whether a reserved bit was set in some page-structure entry
Bit 4 (I/D) is the Instruction/Data flag (1=instruction fetch, 0=data access)
Bit 5 (PK) indicates a protection-key violation
Bit 6 (SS) indicates a shadow-stack access fault
Bit 15 (SGX) indicates an [https://en.wikipedia.org/wiki/Software_Guard_Extensions SGX violaton]
The combination of these flags specify the details of the page fault and indicate what action to take:
US RW P - Description
| |||