diff --git a/sys/amd64/amd64/support.S b/sys/amd64/amd64/support.S
--- a/sys/amd64/amd64/support.S
+++ b/sys/amd64/amd64/support.S
@@ -1577,6 +1577,26 @@
 	POP_FRAME_POINTER
 	ret
 
+ENTRY(safe_read)
+/* int safe_read(vm_offset_t address %rdi, char *valp %rsi) */
+	PUSH_FRAME_POINTER
+	movq	PCPU(CURPCB),%r8
+	movq	PCB_ONFAULT(%r8),%r9
+	movq	$safe_read_onfault,PCB_ONFAULT(%r8)
+	.globl	safe_read_read
+safe_read_read:
+	movb	(%rdi),%al
+	movq	%r9,PCB_ONFAULT(%r8)
+	movb	%al,(%rsi)
+	xorl	%eax,%eax
+	POP_FRAME_POINTER
+	ret
+safe_read_onfault:
+	movq	%r9,PCB_ONFAULT(%r8)
+	movl	$EFAULT,%eax
+	POP_FRAME_POINTER
+	ret
+
 /*
  * void pmap_pti_pcid_invalidate(uint64_t ucr3, uint64_t kcr3);
  * Invalidates address space addressed by ucr3, then returns to kcr3.
diff --git a/sys/amd64/amd64/trap.c b/sys/amd64/amd64/trap.c
--- a/sys/amd64/amd64/trap.c
+++ b/sys/amd64/amd64/trap.c
@@ -210,6 +210,8 @@
 	},
 };
 
+extern const char safe_read_read[];
+
 /*
  * Exception, fault, and trap interface to the FreeBSD kernel.
  * This common code is called from assembly language IDT gate entry
@@ -716,6 +718,13 @@
 	p = td->td_proc;
 	eva = frame->tf_addr;
 
+	if (__predict_false(frame->tf_rip == (uintptr_t)safe_read_read &&
+	    curpcb->pcb_onfault != NULL && !usermode &&
+	    eva >= VM_MIN_KERNEL_ADDRESS)) {
+		frame->tf_rip = (long)curpcb->pcb_onfault;
+		return (0);
+	}
+		
 	if (__predict_false((td->td_pflags & TDP_NOFAULTING) != 0)) {
 		/*
 		 * Due to both processor errata and lazy TLB invalidation when
diff --git a/sys/sys/systm.h b/sys/sys/systm.h
--- a/sys/sys/systm.h
+++ b/sys/sys/systm.h
@@ -563,6 +563,14 @@
 
 void counted_warning(unsigned *counter, const char *msg);
 
+/*
+ * Safely read the kernel memory at address addr, places the value
+ * into *valp.  Returns 0 on success, EFAULT if read was impossible,
+ * e.g. due to the address not mapped or not having neccessary
+ * permissions.
+ */
+int safe_read(vm_offset_t addr, char *valp);
+
 /*
  * APIs to manage deprecation and obsolescence.
  */