HAVE_RESTORE_SIGMASK is defined on all architectures now

Everyone either defines it in arch thread_info.h or has TIF_RESTORE_SIGMASK
and picks default set_restore_sigmask() in linux/thread_info.h.  Kill the
ifdefs, slap #error in linux/thread_info.h to catch breakage when new ones
get merged.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

fs/compat.c

@@ -1547,7 +1547,6 @@ asmlinkage long compat_sys_old_select(struct compat_sel_arg_struct __user *arg)
 				 compat_ptr(a.exp), compat_ptr(a.tvp));
 }
 
-#ifdef HAVE_SET_RESTORE_SIGMASK
 static long do_compat_pselect(int n, compat_ulong_t __user *inp,
 	compat_ulong_t __user *outp, compat_ulong_t __user *exp,
 	struct compat_timespec __user *tsp, compat_sigset_t __user *sigmask,
@@ -1670,11 +1669,9 @@ asmlinkage long compat_sys_ppoll(struct pollfd __user *ufds,
 
 	return ret;
 }
-#endif /* HAVE_SET_RESTORE_SIGMASK */
 
 #ifdef CONFIG_EPOLL
 
-#ifdef HAVE_SET_RESTORE_SIGMASK
 asmlinkage long compat_sys_epoll_pwait(int epfd,
 			struct compat_epoll_event __user *events,
 			int maxevents, int timeout,
@@ -1718,7 +1715,6 @@ asmlinkage long compat_sys_epoll_pwait(int epfd,
 
 	return err;
 }
-#endif /* HAVE_SET_RESTORE_SIGMASK */
 
 #endif /* CONFIG_EPOLL */
 

fs/eventpoll.c

@@ -1853,8 +1853,6 @@ SYSCALL_DEFINE4(epoll_wait, int, epfd, struct epoll_event __user *, events,
 	return error;
 }
 
-#ifdef HAVE_SET_RESTORE_SIGMASK
-
 /*
  * Implement the event wait interface for the eventpoll file. It is the kernel
  * part of the user space epoll_pwait(2).
@@ -1899,8 +1897,6 @@ SYSCALL_DEFINE6(epoll_pwait, int, epfd, struct epoll_event __user *, events,
 	return error;
 }
 
-#endif /* HAVE_SET_RESTORE_SIGMASK */
-
 static int __init eventpoll_init(void)
 {
 	struct sysinfo si;

fs/select.c

@@ -614,7 +614,6 @@ SYSCALL_DEFINE5(select, int, n, fd_set __user *, inp, fd_set __user *, outp,
 	return ret;
 }
 
-#ifdef HAVE_SET_RESTORE_SIGMASK
 static long do_pselect(int n, fd_set __user *inp, fd_set __user *outp,
 		       fd_set __user *exp, struct timespec __user *tsp,
 		       const sigset_t __user *sigmask, size_t sigsetsize)
@@ -686,7 +685,6 @@ SYSCALL_DEFINE6(pselect6, int, n, fd_set __user *, inp, fd_set __user *, outp,
 
 	return do_pselect(n, inp, outp, exp, tsp, up, sigsetsize);
 }
-#endif /* HAVE_SET_RESTORE_SIGMASK */
 
 #ifdef __ARCH_WANT_SYS_OLD_SELECT
 struct sel_arg_struct {
@@ -941,7 +939,6 @@ SYSCALL_DEFINE3(poll, struct pollfd __user *, ufds, unsigned int, nfds,
 	return ret;
 }
 
-#ifdef HAVE_SET_RESTORE_SIGMASK
 SYSCALL_DEFINE5(ppoll, struct pollfd __user *, ufds, unsigned int, nfds,
 		struct timespec __user *, tsp, const sigset_t __user *, sigmask,
 		size_t, sigsetsize)
@@ -992,4 +989,3 @@ SYSCALL_DEFINE5(ppoll, struct pollfd __user *, ufds, unsigned int, nfds,
 
 	return ret;
 }
-#endif /* HAVE_SET_RESTORE_SIGMASK */

include/linux/thread_info.h

@@ -129,6 +129,10 @@ static inline void set_restore_sigmask(void)
 }
 #endif	/* TIF_RESTORE_SIGMASK && !HAVE_SET_RESTORE_SIGMASK */
 
+#ifndef HAVE_SET_RESTORE_SIGMASK
+#error "no set_restore_sigmask() provided and default one won't work"
+#endif
+
 #endif	/* __KERNEL__ */
 
 #endif /* _LINUX_THREAD_INFO_H */

kernel/signal.c

@@ -3235,7 +3235,6 @@ SYSCALL_DEFINE0(pause)
 
 #endif
 
-#ifdef HAVE_SET_RESTORE_SIGMASK
 int sigsuspend(sigset_t *set)
 {
 	sigdelsetmask(set, sigmask(SIGKILL)|sigmask(SIGSTOP));
@@ -3248,7 +3247,6 @@ int sigsuspend(sigset_t *set)
 	set_restore_sigmask();
 	return -ERESTARTNOHAND;
 }
-#endif
 
 #ifdef __ARCH_WANT_SYS_RT_SIGSUSPEND
 /**