MFC 308820,308821: Fixes for fatal page faults on x86.

308820:
Report page faults due to reserved bits in PTEs as a separate fault type.

Rather than reporting a page fault due to a bad PTE as a protection
violation with the "rsv" flag, treat these faults as a separate type of
fault altogether.

308821:
MFamd64: Various fatal page fault fixes.

- If a page fault is triggered due to reserved bits in a PTE, treat it
  as a fatal fault and panic.
- If PG_NX is in use, report whether a fatal page fault is due to an
  instruction fetch or a data access.
- If a fatal page fault is due to reserved bits in a PTE, report that as
  the page fault type rather than a protection violation.

1 files changed, 15 insertions, 1 deletions

diff --git a/sys/i386/i386/trap.c b/sys/i386/i386/trap.c
index 3cf0c5a..2ab8d1b 100644
--- a/sys/i386/i386/trap.c
+++ b/sys/i386/i386/trap.c
@@ -857,6 +857,14 @@ trap_pfault(frame, usermode, eva)
 	}
 
 	/*
+	 * If the trap was caused by errant bits in the PTE then panic.
+	 */
+	if (frame->tf_err & PGEX_RSV) {
+		trap_fatal(frame, eva);
+		return (-1);
+	}
+
+	/*
 	 * PGEX_I is defined only if the execute disable bit capability is
 	 * supported and enabled.
 	 */
@@ -926,9 +934,15 @@ trap_fatal(frame, eva)
 #endif
 	if (type == T_PAGEFLT) {
 		printf("fault virtual address	= 0x%x\n", eva);
-		printf("fault code		= %s %s, %s\n",
+		printf("fault code		= %s %s%s, %s\n",
 			code & PGEX_U ? "user" : "supervisor",
 			code & PGEX_W ? "write" : "read",
+#if defined(PAE) || defined(PAE_TABLES)
+			pg_nx != 0 ?
+			(code & PGEX_I ? " instruction" : " data") :
+#endif
+			"",
+			code & PGEX_RSV ? "reserved bits in PTE" :
 			code & PGEX_P ? "protection violation" : "page not present");
 	}
 	printf("instruction pointer	= 0x%x:0x%x\n",