Index: sys/arm/arm/locore-v6.S
===================================================================
--- sys/arm/arm/locore-v6.S
+++ sys/arm/arm/locore-v6.S
@@ -171,6 +171,7 @@
 	ldr	r5, [r4, #4]
 	str	r5, [r0, #24]		/* store the pagetable address */
 	mov	fp, #0			/* trace back starts here */
+	mcr	p15, 0, fp, c13, c0, 3	/* Zero the thread pointer */
 	bl	_C_LABEL(initarm)	/* Off we go */
 
 	/* init	arm will return	the new	stack pointer. */
@@ -437,6 +438,7 @@
 	ldr	pc, =1f
 1:
 	mov	fp, #0			/* trace back starts here */
+	mcr	p15, 0, fp, c13, c0, 3	/* Zero the thread pointer */
 	bl	_C_LABEL(init_secondary)/* Off we go, cpu id in r0. */
 
 	adr	r0, .Lmpreturned
Index: sys/arm/arm/sys_machdep.c
===================================================================
--- sys/arm/arm/sys_machdep.c
+++ sys/arm/arm/sys_machdep.c
@@ -84,9 +84,8 @@
 arm32_set_tp(struct thread *td, void *args)
 {
 
-	if (td != curthread)
-		td->td_md.md_tp = (register_t)args;
-	else 
+	td->td_md.md_tp = (register_t)args;
+	if (td == curthread)
 #ifndef ARM_TP_ADDRESS
 		set_tls(args);
 #else
@@ -101,12 +100,16 @@
 
 	if (td != curthread)
 		td->td_retval[0] = td->td_md.md_tp;
-	else
+	else {
 #ifndef ARM_TP_ADDRESS
+		KASSERT((register_t)get_tls() == td->td_md.md_tp,
+		    ("arm32_get_tp: Invalid TLS pointer (%x != %x)",
+		    (register_t)get_tls(), td->td_md.md_tp));
 		td->td_retval[0] = (register_t)get_tls();
 #else
 		td->td_retval[0] = *(register_t *)ARM_TP_ADDRESS;
 #endif
+	}
 	return (0);
 }
 
Index: sys/arm/arm/syscall.c
===================================================================
--- sys/arm/arm/syscall.c
+++ sys/arm/arm/syscall.c
@@ -168,6 +168,11 @@
 {
 	struct thread *td = curthread;
 
+#ifndef ARM_TP_ADDRESS
+	KASSERT((register_t)get_tls() == td->td_md.md_tp,
+	    ("swi_handler: Invalid TLS pointer on entrance (%x != %x)",
+	    (register_t)get_tls(), td->td_md.md_tp));
+#endif
 	td->td_frame = frame;
 
 	td->td_pticks = 0;
@@ -194,4 +199,10 @@
 	}
 
 	syscall(td, frame);
+
+#ifndef ARM_TP_ADDRESS
+	KASSERT((register_t)get_tls() == td->td_md.md_tp,
+	    ("swi_handler: Invalid TLS pointer on exit (%x != %x)",
+	    (register_t)get_tls(), td->td_md.md_tp));
+#endif
 }
Index: sys/arm/arm/vm_machdep.c
===================================================================
--- sys/arm/arm/vm_machdep.c
+++ sys/arm/arm/vm_machdep.c
@@ -145,6 +145,9 @@
 #ifdef ARM_TP_ADDRESS
 	td2->td_md.md_tp = *(register_t *)ARM_TP_ADDRESS;
 #else
+	KASSERT((register_t)get_tls() == td1->td_md.md_tp,
+	    ("cpu_fork: Invalid TLS pointer (%x != %x)",
+	    (register_t)get_tls(), td1->td_md.md_tp));
 	td2->td_md.md_tp = (register_t) get_tls();
 #endif
 }