diff --git a/ChangeLog b/ChangeLog
index 9074c2895b..10201d7a1d 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -4342,6 +4342,18 @@
 	* tools/mkconfig.c:  Logic that attempts to suppressed buffered I/O
 	  within the kernel is wrong.  sizeof(struct file_struct) must be
 	  the same in both kernel- and user-spaces (2013-03-16).
-	* arch/arm/src/common/up_pthread_start.c, nuttx/libc/pthread/pthread_startup.c,
+	* arch/arm/src/common/up_pthread_start.c, libc/pthread/pthread_startup.c,
 	  and related files:  Implement switch to user-space and user-space
-	  pthread start-up function  (2013-03-16).
+	  pthread start-up function (2013-03-16).
+	* arch/arm/src/common/up_signal_handler.c, libc/pthread/pthread_startup.c,
+	  and related files:  Implement switch to user-space and user-space
+	  pthread start-up function (2013-03-16).
+	* arch/arm/src/common/up_signal_handler.c, libc/signal/signal_handler.c,
+	  arch/arm/src/armv[6|7]-m/up_svcall.c, arch/arm/include/armv[6|7]-m/svcall.h,
+	  include/nuttx/userspace.h, and sched/sig_deliver.c:  Implement switch
+	  to user-space from kernel signal delivery trampoline before calling user-
+	  space signal handler.  Return from user-space signal handler using a
+	  system call (2013-03-16).
+	* arch/arm/src/armv[6|7]-m/up_schedulesigaction.c: Need make sure we are
+	  in kernel mode before switching to kernel-mode signal handler
+	  trampoline.
diff --git a/arch/arm/src/armv6-m/up_schedulesigaction.c b/arch/arm/src/armv6-m/up_schedulesigaction.c
index aa85d56f08..fa12327043 100644
--- a/arch/arm/src/armv6-m/up_schedulesigaction.c
+++ b/arch/arm/src/armv6-m/up_schedulesigaction.c
@@ -46,6 +46,7 @@
 #include <nuttx/arch.h>
 
 #include "psr.h"
+#include "exc_return.h"
 #include "os_internal.h"
 #include "up_internal.h"
 #include "up_arch.h"
@@ -159,12 +160,16 @@ void up_schedule_sigaction(struct tcb_s *tcb, sig_deliver_t sigdeliver)
               tcb->xcp.saved_xpsr       = current_regs[REG_XPSR];
 
               /* Then set up to vector to the trampoline with interrupts
-               * disabled
+               * disabled.  The kernel-space trampoline must run in
+               * privileged thread mode.
                */
 
               current_regs[REG_PC]      = (uint32_t)up_sigdeliver;
               current_regs[REG_BASEPRI] = NVIC_SYSH_DISABLE_PRIORITY;
               current_regs[REG_XPSR]    = ARMV6M_XPSR_T;
+#ifdef CONFIG_NUTTX_KERNEL
+              current_regs[REG_XPSR]    = EXC_RETURN_PRIVTHR;
+#endif
 
               /* And make sure that the saved context in the TCB
                * is the same as the interrupt return context.
@@ -193,7 +198,8 @@ void up_schedule_sigaction(struct tcb_s *tcb, sig_deliver_t sigdeliver)
           tcb->xcp.saved_xpsr       = tcb->xcp.regs[REG_XPSR];
 
           /* Then set up to vector to the trampoline with interrupts
-           * disabled
+           * disabled.  We must already be in privileged thread mode
+           * to be here.
            */
 
           tcb->xcp.regs[REG_PC]      = (uint32_t)up_sigdeliver;
diff --git a/arch/arm/src/armv7-m/up_schedulesigaction.c b/arch/arm/src/armv7-m/up_schedulesigaction.c
index 32f7082b3c..f4cde206a3 100644
--- a/arch/arm/src/armv7-m/up_schedulesigaction.c
+++ b/arch/arm/src/armv7-m/up_schedulesigaction.c
@@ -46,6 +46,7 @@
 #include <nuttx/arch.h>
 
 #include "psr.h"
+#include "exc_return.h"
 #include "os_internal.h"
 #include "up_internal.h"
 #include "up_arch.h"
@@ -163,7 +164,8 @@ void up_schedule_sigaction(struct tcb_s *tcb, sig_deliver_t sigdeliver)
               tcb->xcp.saved_xpsr       = current_regs[REG_XPSR];
 
               /* Then set up to vector to the trampoline with interrupts
-               * disabled
+               * disabled.  The kernel-space trampoline must run in
+               * privileged thread mode.
                */
 
               current_regs[REG_PC]      = (uint32_t)up_sigdeliver;
@@ -173,6 +175,9 @@ void up_schedule_sigaction(struct tcb_s *tcb, sig_deliver_t sigdeliver)
               current_regs[REG_PRIMASK] = 1;
 #endif
               current_regs[REG_XPSR]    = ARMV7M_XPSR_T;
+#ifdef CONFIG_NUTTX_KERNEL
+              current_regs[REG_XPSR]    = EXC_RETURN_PRIVTHR;
+#endif
 
               /* And make sure that the saved context in the TCB
                * is the same as the interrupt return context.
@@ -205,7 +210,8 @@ void up_schedule_sigaction(struct tcb_s *tcb, sig_deliver_t sigdeliver)
           tcb->xcp.saved_xpsr       = tcb->xcp.regs[REG_XPSR];
 
           /* Then set up to vector to the trampoline with interrupts
-           * disabled
+           * disabled.  We must already be in privileged thread mode
+           * to be here.
            */
 
           tcb->xcp.regs[REG_PC]      = (uint32_t)up_sigdeliver;