set_restore_sigmask() is never called without SIGPENDING (and never should be)

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

arch/ia64/include/asm/thread_info.h

@@ -141,7 +141,7 @@ static inline void set_restore_sigmask(void)
 {
 	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)
 {

arch/microblaze/include/asm/thread_info.h

@@ -166,7 +166,7 @@ static inline void set_restore_sigmask(void)
 {
 	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)
 {

arch/powerpc/include/asm/thread_info.h

@@ -140,7 +140,7 @@ static inline void set_restore_sigmask(void)
 {
 	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)
 {

arch/sh/include/asm/thread_info.h

@@ -169,7 +169,7 @@ static inline void set_restore_sigmask(void)
 {
 	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

arch/sparc/include/asm/thread_info_64.h

@@ -238,7 +238,7 @@ static inline void set_restore_sigmask(void)
 {
 	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)
 {

arch/tile/include/asm/thread_info.h

@@ -166,7 +166,7 @@ static inline void set_restore_sigmask(void)
 {
 	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)
 {

arch/x86/include/asm/thread_info.h

@@ -248,7 +248,7 @@ static inline void set_restore_sigmask(void)
 {
 	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)
 {

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 int test_ti_thread_flag(struct thread_info *ti, int flag)
 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)
 {