diff --git a/arch/ia64/include/asm/thread_info.h b/arch/ia64/include/asm/thread_info.h
index 8d60036..f7ee853 100644
--- a/arch/ia64/include/asm/thread_info.h
+++ b/arch/ia64/include/asm/thread_info.h
@@ -141,7 +141,7 @@
 {
 	struct thread_info *ti = current_thread_info();
 	ti->status |= TS_RESTORE_SIGMASK;
-	set_bit(TIF_SIGPENDING, &ti->flags);
+	WARN_ON(!test_bit(TIF_SIGPENDING, &ti->flags));
 }
 static inline void clear_restore_sigmask(void)
 {
diff --git a/arch/microblaze/include/asm/thread_info.h b/arch/microblaze/include/asm/thread_info.h
index 12e3920..6c610234 100644
--- a/arch/microblaze/include/asm/thread_info.h
+++ b/arch/microblaze/include/asm/thread_info.h
@@ -166,7 +166,7 @@
 {
 	struct thread_info *ti = current_thread_info();
 	ti->status |= TS_RESTORE_SIGMASK;
-	set_bit(TIF_SIGPENDING, (unsigned long *)&ti->flags);
+	WARN_ON(!test_bit(TIF_SIGPENDING, (unsigned long *)&ti->flags));
 }
 static inline void clear_restore_sigmask(void)
 {
diff --git a/arch/powerpc/include/asm/thread_info.h b/arch/powerpc/include/asm/thread_info.h
index 85d50a9..68831e9 100644
--- a/arch/powerpc/include/asm/thread_info.h
+++ b/arch/powerpc/include/asm/thread_info.h
@@ -140,7 +140,7 @@
 {
 	struct thread_info *ti = current_thread_info();
 	ti->local_flags |= _TLF_RESTORE_SIGMASK;
-	set_bit(TIF_SIGPENDING, &ti->flags);
+	WARN_ON(!test_bit(TIF_SIGPENDING, &ti->flags));
 }
 static inline void clear_restore_sigmask(void)
 {
diff --git a/arch/sh/include/asm/thread_info.h b/arch/sh/include/asm/thread_info.h
index a109157..bc13b57 100644
--- a/arch/sh/include/asm/thread_info.h
+++ b/arch/sh/include/asm/thread_info.h
@@ -169,7 +169,7 @@
 {
 	struct thread_info *ti = current_thread_info();
 	ti->status |= TS_RESTORE_SIGMASK;
-	set_bit(TIF_SIGPENDING, (unsigned long *)&ti->flags);
+	WARN_ON(!test_bit(TIF_SIGPENDING, (unsigned long *)&ti->flags));
 }
 
 #define TI_FLAG_FAULT_CODE_SHIFT	24
diff --git a/arch/sparc/include/asm/thread_info_64.h b/arch/sparc/include/asm/thread_info_64.h
index cb9b7a9..cfa8c38 100644
--- a/arch/sparc/include/asm/thread_info_64.h
+++ b/arch/sparc/include/asm/thread_info_64.h
@@ -238,7 +238,7 @@
 {
 	struct thread_info *ti = current_thread_info();
 	ti->status |= TS_RESTORE_SIGMASK;
-	set_bit(TIF_SIGPENDING, &ti->flags);
+	WARN_ON(!test_bit(TIF_SIGPENDING, &ti->flags));
 }
 static inline void clear_restore_sigmask(void)
 {
diff --git a/arch/tile/include/asm/thread_info.h b/arch/tile/include/asm/thread_info.h
index 5aef371..7e1fef3 100644
--- a/arch/tile/include/asm/thread_info.h
+++ b/arch/tile/include/asm/thread_info.h
@@ -166,7 +166,7 @@
 {
 	struct thread_info *ti = current_thread_info();
 	ti->status |= TS_RESTORE_SIGMASK;
-	set_bit(TIF_SIGPENDING, &ti->flags);
+	WARN_ON(!test_bit(TIF_SIGPENDING, &ti->flags));
 }
 static inline void clear_restore_sigmask(void)
 {
diff --git a/arch/x86/include/asm/thread_info.h b/arch/x86/include/asm/thread_info.h
index 8f3f1ff..89f794f 100644
--- a/arch/x86/include/asm/thread_info.h
+++ b/arch/x86/include/asm/thread_info.h
@@ -248,7 +248,7 @@
 {
 	struct thread_info *ti = current_thread_info();
 	ti->status |= TS_RESTORE_SIGMASK;
-	set_bit(TIF_SIGPENDING, (unsigned long *)&ti->flags);
+	WARN_ON(!test_bit(TIF_SIGPENDING, (unsigned long *)&ti->flags));
 }
 static inline void clear_restore_sigmask(void)
 {
diff --git a/include/linux/thread_info.h b/include/linux/thread_info.h
index ed27970..ccc1899 100644
--- a/include/linux/thread_info.h
+++ b/include/linux/thread_info.h
@@ -8,6 +8,7 @@
 #define _LINUX_THREAD_INFO_H
 
 #include <linux/types.h>
+#include <linux/bug.h>
 
 struct timespec;
 struct compat_timespec;
@@ -125,7 +126,7 @@
 static inline void set_restore_sigmask(void)
 {
 	set_thread_flag(TIF_RESTORE_SIGMASK);
-	set_thread_flag(TIF_SIGPENDING);
+	WARN_ON(!test_thread_flag(TIF_SIGPENDING));
 }
 static inline void clear_restore_sigmask(void)
 {