signals: add set_restore_sigmask

This adds the set_restore_sigmask() inline in <linux/thread_info.h> and
replaces every set_thread_flag(TIF_RESTORE_SIGMASK) with a call to it.  No
change, but abstracts the details of the flag protocol from all the calls.

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>

6 files changed, 22 insertions, 11 deletions

diff --git a/fs/compat.c b/fs/compat.c
index 2ce4456aad30..9964d542ae9e 100644
--- a/fs/compat.c
+++ b/fs/compat.c
@@ -1720,7 +1720,7 @@ sticky:
                 if (sigmask) {
                         memcpy(&current->saved_sigmask, &sigsaved,
                                         sizeof(sigsaved));
-                        set_thread_flag(TIF_RESTORE_SIGMASK);
+                        set_restore_sigmask();
                 }
         } else if (sigmask)
                 sigprocmask(SIG_SETMASK, &sigsaved, NULL);
@@ -1791,7 +1791,7 @@ asmlinkage long compat_sys_ppoll(struct pollfd __user *ufds,
                 if (sigmask) {
                         memcpy(&current->saved_sigmask, &sigsaved,
                                 sizeof(sigsaved));
-                        set_thread_flag(TIF_RESTORE_SIGMASK);
+                        set_restore_sigmask();
                 }
                 ret = -ERESTARTNOHAND;
         } else if (sigmask)
@@ -2117,7 +2117,7 @@ asmlinkage long compat_sys_epoll_pwait(int epfd,
                 if (err == -EINTR) {
                         memcpy(&current->saved_sigmask, &sigsaved,
                                sizeof(sigsaved));
-                        set_thread_flag(TIF_RESTORE_SIGMASK);
+                        set_restore_sigmask();
                 } else
                         sigprocmask(SIG_SETMASK, &sigsaved, NULL);
         }
diff --git a/fs/eventpoll.c b/fs/eventpoll.c
index 0d237182d721..71af2fc0041e 100644
--- a/fs/eventpoll.c
+++ b/fs/eventpoll.c
@@ -1279,7 +1279,7 @@ asmlinkage long sys_epoll_pwait(int epfd, struct epoll_event __user *events,
                 if (error == -EINTR) {
                         memcpy(&current->saved_sigmask, &sigsaved,
                                sizeof(sigsaved));
-                        set_thread_flag(TIF_RESTORE_SIGMASK);
+                        set_restore_sigmask();
                 } else
                         sigprocmask(SIG_SETMASK, &sigsaved, NULL);
         }
@@ -1309,4 +1309,3 @@ static int __init eventpoll_init(void)
         return 0;
 }
 fs_initcall(eventpoll_init);
-
diff --git a/fs/select.c b/fs/select.c
index 00f58c5c7e05..32ce2b32fad1 100644
--- a/fs/select.c
+++ b/fs/select.c
@@ -498,7 +498,7 @@ sticky:
                 if (sigmask) {
                         memcpy(&current->saved_sigmask, &sigsaved,
                                         sizeof(sigsaved));
-                        set_thread_flag(TIF_RESTORE_SIGMASK);
+                        set_restore_sigmask();
                 }
         } else if (sigmask)
                 sigprocmask(SIG_SETMASK, &sigsaved, NULL);
@@ -805,7 +805,7 @@ asmlinkage long sys_ppoll(struct pollfd __user *ufds, unsigned int nfds,
                 if (sigmask) {
                         memcpy(&current->saved_sigmask, &sigsaved,
                                         sizeof(sigsaved));
-                        set_thread_flag(TIF_RESTORE_SIGMASK);
+                        set_restore_sigmask();
                 }
                 ret = -ERESTARTNOHAND;
         } else if (sigmask)
diff --git a/include/linux/thread_info.h b/include/linux/thread_info.h
index accd7bad35b0..43d8162c696e 100644
--- a/include/linux/thread_info.h
+++ b/include/linux/thread_info.h
@@ -92,6 +92,19 @@ static inline int test_ti_thread_flag(struct thread_info *ti, int flag)
 #define set_need_resched()      set_thread_flag(TIF_NEED_RESCHED)
 #define clear_need_resched()    clear_thread_flag(TIF_NEED_RESCHED)
 
-#endif
+#ifdef TIF_RESTORE_SIGMASK
+/**
+ * set_restore_sigmask() - make sure saved_sigmask processing gets done
+ *
+ * This sets TIF_RESTORE_SIGMASK and ensures that the arch signal code
+ * will run before returning to user mode, to process the flag.
+ */
+static inline void set_restore_sigmask(void)
+{
+        set_thread_flag(TIF_RESTORE_SIGMASK);
+}
+#endif  /* TIF_RESTORE_SIGMASK */
+
+#endif  /* __KERNEL__ */
 
 #endif /* _LINUX_THREAD_INFO_H */
diff --git a/kernel/compat.c b/kernel/compat.c
index e1ef04870c2a..4a856a3643bb 100644
--- a/kernel/compat.c
+++ b/kernel/compat.c
@@ -898,7 +898,7 @@ asmlinkage long compat_sys_rt_sigsuspend(compat_sigset_t __user *unewset, compat
 
         current->state = TASK_INTERRUPTIBLE;
         schedule();
-        set_thread_flag(TIF_RESTORE_SIGMASK);
+        set_restore_sigmask();
         return -ERESTARTNOHAND;
 }
 #endif /* __ARCH_WANT_COMPAT_SYS_RT_SIGSUSPEND */
@@ -1080,4 +1080,3 @@ compat_sys_sysinfo(struct compat_sysinfo __user *info)
 
         return 0;
 }
-
diff --git a/kernel/signal.c b/kernel/signal.c
index 9ac737e53df1..72bb4f51f963 100644
--- a/kernel/signal.c
+++ b/kernel/signal.c
@@ -2541,7 +2541,7 @@ asmlinkage long sys_rt_sigsuspend(sigset_t __user *unewset, size_t sigsetsize)
 
         current->state = TASK_INTERRUPTIBLE;
         schedule();
-        set_thread_flag(TIF_RESTORE_SIGMASK);
+        set_restore_sigmask();
         return -ERESTARTNOHAND;
 }
 #endif /* __ARCH_WANT_SYS_RT_SIGSUSPEND */