Index: kernel/arch/amd64/src/mm/page.c
===================================================================
--- kernel/arch/amd64/src/mm/page.c	(revision d5a1c73bdb82a0489756953c04a3b37f8167e745)
+++ kernel/arch/amd64/src/mm/page.c	(revision c15b37446cc540323e335d60ebc0166256615461)
@@ -90,5 +90,5 @@
 	if (as_page_fault(page, access, istate) == AS_PF_FAULT) {
 		fault_if_from_uspace(istate, "Page fault: %#x.", page);
-		panic_memtrap(istate, access, page, "Page fault.");
+		panic_memtrap(istate, access, page, NULL);
 	}
 }
Index: kernel/arch/arm32/src/mm/page_fault.c
===================================================================
--- kernel/arch/arm32/src/mm/page_fault.c	(revision d5a1c73bdb82a0489756953c04a3b37f8167e745)
+++ kernel/arch/arm32/src/mm/page_fault.c	(revision c15b37446cc540323e335d60ebc0166256615461)
@@ -183,5 +183,5 @@
 	if (ret == AS_PF_FAULT) {
 		fault_if_from_uspace(istate, "Page fault: %#x.", badvaddr);
-		panic_memtrap(istate, access, badvaddr, "Page fault.");
+		panic_memtrap(istate, access, badvaddr, NULL);
 	}
 }
@@ -200,6 +200,5 @@
 		fault_if_from_uspace(istate,
 		    "Page fault - prefetch_abort: %#x.", istate->pc);
-		panic_memtrap(istate, PF_ACCESS_EXEC, istate->pc,
-		    "Page fault - prefetch_abort.");
+		panic_memtrap(istate, PF_ACCESS_EXEC, istate->pc, NULL);
 	}
 }
Index: kernel/arch/ia32/src/mm/page.c
===================================================================
--- kernel/arch/ia32/src/mm/page.c	(revision d5a1c73bdb82a0489756953c04a3b37f8167e745)
+++ kernel/arch/ia32/src/mm/page.c	(revision c15b37446cc540323e335d60ebc0166256615461)
@@ -115,5 +115,5 @@
 	if (as_page_fault(page, access, istate) == AS_PF_FAULT) {
 		fault_if_from_uspace(istate, "Page fault: %#x.", page);
-		panic_memtrap(istate, access, page, "Page fault.");
+		panic_memtrap(istate, access, page, NULL);
 	}
 }
Index: kernel/arch/ia64/src/mm/tlb.c
===================================================================
--- kernel/arch/ia64/src/mm/tlb.c	(revision d5a1c73bdb82a0489756953c04a3b37f8167e745)
+++ kernel/arch/ia64/src/mm/tlb.c	(revision c15b37446cc540323e335d60ebc0166256615461)
@@ -500,6 +500,5 @@
 		if (as_page_fault(va, PF_ACCESS_EXEC, istate) == AS_PF_FAULT) {
 			fault_if_from_uspace(istate, "Page fault at %p.", va);
-			panic_memtrap(istate, PF_ACCESS_EXEC, va,
-			    "Page fault.");
+			panic_memtrap(istate, PF_ACCESS_EXEC, va, NULL);
 		}
 	}
@@ -622,6 +621,5 @@
 		if (as_page_fault(va, PF_ACCESS_READ, istate) == AS_PF_FAULT) {
 			fault_if_from_uspace(istate, "Page fault at %p.", va);
-			panic_memtrap(istate, PF_ACCESS_READ, va,
-			    "Page fault.");
+			panic_memtrap(istate, PF_ACCESS_UNKNOWN, va, NULL);
 		}
 	}
@@ -671,6 +669,5 @@
 		if (as_page_fault(va, PF_ACCESS_WRITE, istate) == AS_PF_FAULT) {
 			fault_if_from_uspace(istate, "Page fault at %p.", va);
-			panic_memtrap(istate, PF_ACCESS_WRITE, va,
-			    "Page fault.");
+			panic_memtrap(istate, PF_ACCESS_WRITE, va, NULL);
 		}
 	}
@@ -708,6 +705,5 @@
 		if (as_page_fault(va, PF_ACCESS_EXEC, istate) == AS_PF_FAULT) {
 			fault_if_from_uspace(istate, "Page fault at %p.", va);
-			panic_memtrap(istate, PF_ACCESS_EXEC, va,
-			    "Page fault.");
+			panic_memtrap(istate, PF_ACCESS_EXEC, va, NULL);
 		}
 	}
@@ -745,6 +741,5 @@
 		if (as_page_fault(va, PF_ACCESS_READ, istate) == AS_PF_FAULT) {
 			fault_if_from_uspace(istate, "Page fault at %p.", va);
-			panic_memtrap(istate, PF_ACCESS_READ, va,
-			    "Page fault.");
+			panic_memtrap(istate, PF_ACCESS_UNKNOWN, va, NULL);
 		}
 	}
@@ -778,5 +773,5 @@
 	if (as_page_fault(va, PF_ACCESS_WRITE, istate) == AS_PF_FAULT) {
 		fault_if_from_uspace(istate, "Page fault at %p.", va);
-		panic_memtrap(istate, PF_ACCESS_WRITE, va, "Page fault.");
+		panic_memtrap(istate, PF_ACCESS_WRITE, va, NULL);
 	}
 	page_table_unlock(AS, true);
@@ -818,6 +813,5 @@
 		if (as_page_fault(va, PF_ACCESS_READ, istate) == AS_PF_FAULT) {
 			fault_if_from_uspace(istate, "Page fault at %p.", va);
-			panic_memtrap(istate, PF_ACCESS_READ, va,
-			    "Page fault.");
+			panic_memtrap(istate, PF_ACCESS_UNKNOWN, va, NULL);
 		}
 	}
Index: kernel/arch/mips32/src/mm/tlb.c
===================================================================
--- kernel/arch/mips32/src/mm/tlb.c	(revision d5a1c73bdb82a0489756953c04a3b37f8167e745)
+++ kernel/arch/mips32/src/mm/tlb.c	(revision c15b37446cc540323e335d60ebc0166256615461)
@@ -324,5 +324,5 @@
 	
 	fault_if_from_uspace(istate, "TLB Refill Exception on %p.", va);
-	panic_memtrap(istate, PF_ACCESS_READ, va, "TLB Refill Exception.");
+	panic_memtrap(istate, PF_ACCESS_UNKNOWN, va, "TLB Refill Exception.");
 }
 
@@ -333,5 +333,5 @@
 	
 	fault_if_from_uspace(istate, "TLB Invalid Exception on %p.", va);
-	panic_memtrap(istate, PF_ACCESS_READ, va, "TLB Invalid Exception.");
+	panic_memtrap(istate, PF_ACCESS_UNKNOWN, va, "TLB Invalid Exception.");
 }
 
Index: kernel/arch/ppc32/src/mm/tlb.c
===================================================================
--- kernel/arch/ppc32/src/mm/tlb.c	(revision d5a1c73bdb82a0489756953c04a3b37f8167e745)
+++ kernel/arch/ppc32/src/mm/tlb.c	(revision c15b37446cc540323e335d60ebc0166256615461)
@@ -112,5 +112,5 @@
 {
 	fault_if_from_uspace(istate, "PHT Refill Exception on %p.", badvaddr);
-	panic_memtrap(istate, PF_ACCESS_READ, badvaddr,
+	panic_memtrap(istate, PF_ACCESS_UNKNOWN, badvaddr,
 	    "PHT Refill Exception.");
 }
Index: kernel/arch/sparc64/src/mm/sun4u/tlb.c
===================================================================
--- kernel/arch/sparc64/src/mm/sun4u/tlb.c	(revision d5a1c73bdb82a0489756953c04a3b37f8167e745)
+++ kernel/arch/sparc64/src/mm/sun4u/tlb.c	(revision c15b37446cc540323e335d60ebc0166256615461)
@@ -259,5 +259,5 @@
 			/* NULL access in kernel */
 			do_fast_data_access_mmu_miss_fault(istate, tag,
-			    "Dereferencing NULL pointer");
+			    "Dereferencing NULL pointer.");
 		} else if (page_8k >= end_of_identity) {
 			/*
@@ -442,5 +442,5 @@
 {
 	fault_if_from_uspace(istate, "%s, Address=%p.", str, va);
-	panic_memtrap(istate, PF_ACCESS_EXEC, va, "%s.", str);
+	panic_memtrap(istate, PF_ACCESS_EXEC, va, str);
 }
 
@@ -453,5 +453,5 @@
 	fault_if_from_uspace(istate, "%s, Page=%p (ASID=%d).", str, va,
 	    tag.context);
-	panic_memtrap(istate, PF_ACCESS_READ, va, "%s.", str);
+	panic_memtrap(istate, PF_ACCESS_UNKNOWN, va, str);
 }
 
@@ -464,5 +464,5 @@
 	fault_if_from_uspace(istate, "%s, Page=%p (ASID=%d).", str, va,
 	    tag.context);
-	panic_memtrap(istate, PF_ACCESS_WRITE, va, "%s.", str);
+	panic_memtrap(istate, PF_ACCESS_WRITE, va, str);
 }
 
Index: kernel/arch/sparc64/src/mm/sun4v/tlb.c
===================================================================
--- kernel/arch/sparc64/src/mm/sun4v/tlb.c	(revision d5a1c73bdb82a0489756953c04a3b37f8167e745)
+++ kernel/arch/sparc64/src/mm/sun4v/tlb.c	(revision c15b37446cc540323e335d60ebc0166256615461)
@@ -359,5 +359,5 @@
 {
 	fault_if_from_uspace(istate, "%s, Address=%p.", str, va);
-	panic_memtrap(istate, PF_ACCESS_EXEC, va, "%s.", str);
+	panic_memtrap(istate, PF_ACCESS_EXEC, va, str);
 }
 
@@ -367,6 +367,6 @@
 	fault_if_from_uspace(istate, "%s, Page=%p (ASID=%d).", str,
 	    DMISS_ADDRESS(page_and_ctx), DMISS_CONTEXT(page_and_ctx));
-	panic_memtrap(istate, PF_ACCESS_READ, DMISS_ADDRESS(page_and_ctx),
-	    "%s.");
+	panic_memtrap(istate, PF_ACCESS_UNKNOWN, DMISS_ADDRESS(page_and_ctx),
+	    str);
 }
 
@@ -377,5 +377,5 @@
 	    DMISS_ADDRESS(page_and_ctx), DMISS_CONTEXT(page_and_ctx));
 	panic_memtrap(istate, PF_ACCESS_WRITE, DMISS_ADDRESS(page_and_ctx),
-	    "%s.");
+	    str);
 }
 
Index: kernel/generic/include/mm/as.h
===================================================================
--- kernel/generic/include/mm/as.h	(revision d5a1c73bdb82a0489756953c04a3b37f8167e745)
+++ kernel/generic/include/mm/as.h	(revision c15b37446cc540323e335d60ebc0166256615461)
@@ -171,5 +171,6 @@
 	PF_ACCESS_READ,
 	PF_ACCESS_WRITE,
-	PF_ACCESS_EXEC
+	PF_ACCESS_EXEC,
+	PF_ACCESS_UNKNOWN
 } pf_access_t;