- /* Reserved-bit violation or user access to kernel space? */
- if (error_code & (PF_USER | PF_RSVD))
+ /*
+ * Only writes to RO or instruction fetches from NX may cause
+ * spurious faults.
+ *
+ * These could be from user or supervisor accesses but the TLB
+ * is only lazily flushed after a kernel mapping protection
+ * change, so user accesses are not expected to cause spurious
+ * faults.
+ */
+ if (error_code != (PF_WRITE | PF_PROT)
+ && error_code != (PF_INSTR | PF_PROT))