signals: x86 TS_RESTORE_SIGMASK

Replace TIF_RESTORE_SIGMASK with TS_RESTORE_SIGMASK and define our own
set_restore_sigmask() function.  This saves the costly SMP-safe set_bit
operation, which we do not need for the sigmask flag since TIF_SIGPENDING
always has to be set too.

Signed-off-by: Roland McGrath <roland@redhat.com>
Cc: Oleg Nesterov <oleg@tv-sign.ru>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: "Luck, Tony" <tony.luck@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

2 files changed, 22 insertions, 4 deletions

diff --git a/include/asm-x86/thread_info_32.h b/include/asm-x86/thread_info_32.h
index 531859962096..b6338829d1a8 100644
--- a/include/asm-x86/thread_info_32.h
+++ b/include/asm-x86/thread_info_32.h
@@ -131,7 +131,6 @@ static inline struct thread_info *current_thread_info(void)
 #define TIF_SYSCALL_EMU         5       /* syscall emulation active */
 #define TIF_SYSCALL_AUDIT       6       /* syscall auditing active */
 #define TIF_SECCOMP             7       /* secure computing */
-#define TIF_RESTORE_SIGMASK     8       /* restore signal mask in do_signal() */
 #define TIF_HRTICK_RESCHED      9       /* reprogram hrtick timer */
 #define TIF_MEMDIE              16
 #define TIF_DEBUG               17      /* uses debug registers */
@@ -151,7 +150,6 @@ static inline struct thread_info *current_thread_info(void)
 #define _TIF_SYSCALL_EMU        (1 << TIF_SYSCALL_EMU)
 #define _TIF_SYSCALL_AUDIT      (1 << TIF_SYSCALL_AUDIT)
 #define _TIF_SECCOMP            (1 << TIF_SECCOMP)
-#define _TIF_RESTORE_SIGMASK    (1 << TIF_RESTORE_SIGMASK)
 #define _TIF_HRTICK_RESCHED     (1 << TIF_HRTICK_RESCHED)
 #define _TIF_DEBUG              (1 << TIF_DEBUG)
 #define _TIF_IO_BITMAP          (1 << TIF_IO_BITMAP)
@@ -188,9 +186,20 @@ static inline struct thread_info *current_thread_info(void)
                                            this quantum (SMP) */
 #define TS_POLLING              0x0002  /* True if in idle loop
                                            and not sleeping */
+#define TS_RESTORE_SIGMASK      0x0004  /* restore signal mask in do_signal() */
 
 #define tsk_is_polling(t) (task_thread_info(t)->status & TS_POLLING)
 
+#ifndef __ASSEMBLY__
+#define HAVE_SET_RESTORE_SIGMASK        1
+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);
+}
+#endif  /* !__ASSEMBLY__ */
+
 #endif /* __KERNEL__ */
 
 #endif /* _ASM_THREAD_INFO_H */
diff --git a/include/asm-x86/thread_info_64.h b/include/asm-x86/thread_info_64.h
index ed664e874dec..cb69f70abba1 100644
--- a/include/asm-x86/thread_info_64.h
+++ b/include/asm-x86/thread_info_64.h
@@ -109,7 +109,6 @@ static inline struct thread_info *stack_thread_info(void)
 #define TIF_IRET                5       /* force IRET */
 #define TIF_SYSCALL_AUDIT       7       /* syscall auditing active */
 #define TIF_SECCOMP             8       /* secure computing */
-#define TIF_RESTORE_SIGMASK     9       /* restore signal mask in do_signal */
 #define TIF_MCE_NOTIFY          10      /* notify userspace of an MCE */
 #define TIF_HRTICK_RESCHED      11      /* reprogram hrtick timer */
 /* 16 free */
@@ -133,7 +132,6 @@ static inline struct thread_info *stack_thread_info(void)
 #define _TIF_IRET               (1 << TIF_IRET)
 #define _TIF_SYSCALL_AUDIT      (1 << TIF_SYSCALL_AUDIT)
 #define _TIF_SECCOMP            (1 << TIF_SECCOMP)
-#define _TIF_RESTORE_SIGMASK    (1 << TIF_RESTORE_SIGMASK)
 #define _TIF_MCE_NOTIFY         (1 << TIF_MCE_NOTIFY)
 #define _TIF_HRTICK_RESCHED     (1 << TIF_HRTICK_RESCHED)
 #define _TIF_IA32               (1 << TIF_IA32)
@@ -178,9 +176,20 @@ static inline struct thread_info *stack_thread_info(void)
 #define TS_COMPAT               0x0002  /* 32bit syscall active */
 #define TS_POLLING              0x0004  /* true if in idle loop
                                            and not sleeping */
+#define TS_RESTORE_SIGMASK      0x0008  /* restore signal mask in do_signal() */
 
 #define tsk_is_polling(t) (task_thread_info(t)->status & TS_POLLING)
 
+#ifndef __ASSEMBLY__
+#define HAVE_SET_RESTORE_SIGMASK        1
+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);
+}
+#endif  /* !__ASSEMBLY__ */
+
 #endif /* __KERNEL__ */
 
 #endif /* _ASM_THREAD_INFO_H */