sh64: ppoll/pselect6() and restartable syscalls.

This patch was hanging around for some time while we were waiting
for the compiler situation to improve.. now that all is well again,
finally merge it.

Signed-off-by: Paul Mundt <lethal@linux-sh.org>

3 files changed, 37 insertions, 6 deletions

diff --git a/arch/sh64/kernel/entry.S b/arch/sh64/kernel/entry.S
index 40d45346248d..7013fcb6665c 100644
--- a/arch/sh64/kernel/entry.S
+++ b/arch/sh64/kernel/entry.S
@@ -947,14 +947,14 @@ ret_with_reschedule:
         ! FIXME:!!!
         ! no handling of TIF_SYSCALL_TRACE yet!!
 
-        movi    (1 << TIF_NEED_RESCHED), r8
+        movi    _TIF_NEED_RESCHED, r8
         and     r8, r7, r8
         pta     work_resched, tr0
         bne     r8, ZERO, tr0
 
         pta     restore_all, tr1
 
-        movi    (1 << TIF_SIGPENDING), r8
+        movi    (_TIF_SIGPENDING | _TIF_RESTORE_SIGMASK), r8
         and     r8, r7, r8
         pta     work_notifysig, tr0
         bne     r8, ZERO, tr0
diff --git a/arch/sh64/kernel/signal.c b/arch/sh64/kernel/signal.c
index b76bdfa473d6..c8525ade0564 100644
--- a/arch/sh64/kernel/signal.c
+++ b/arch/sh64/kernel/signal.c
@@ -698,7 +698,9 @@ int do_signal(struct pt_regs *regs, sigset_t *oldset)
         if (try_to_freeze())
                 goto no_signal;
 
-        if (!oldset)
+        if (test_thread_flag(TIF_RESTORE_SIGMASK))
+                oldset = &current->saved_sigmask;
+        else if (!oldset)
                 oldset = &current->blocked;
 
         signr = get_signal_to_deliver(&info, &ka, regs, 0);
@@ -706,6 +708,15 @@ int do_signal(struct pt_regs *regs, sigset_t *oldset)
         if (signr > 0) {
                 /* Whee!  Actually deliver the signal.  */
                 handle_signal(signr, &info, &ka, oldset, regs);
+
+                /*
+                 * If a signal was successfully delivered, the saved sigmask
+                 * is in its frame, and we can clear the TIF_RESTORE_SIGMASK
+                 * flag.
+                 */
+                if (test_thread_flag(TIF_RESTORE_SIGMASK))
+                        clear_thread_flag(TIF_RESTORE_SIGMASK);
+
                 return 1;
         }
 
@@ -713,13 +724,27 @@ no_signal:
         /* Did we come from a system call? */
         if (regs->syscall_nr >= 0) {
                 /* Restart the system call - no handlers present */
-                if (regs->regs[REG_RET] == -ERESTARTNOHAND ||
-                    regs->regs[REG_RET] == -ERESTARTSYS ||
-                    regs->regs[REG_RET] == -ERESTARTNOINTR) {
+                switch (regs->regs[REG_RET]) {
+                case -ERESTARTNOHAND:
+                case -ERESTARTSYS:
+                case -ERESTARTNOINTR:
                         /* Decode Syscall # */
                         regs->regs[REG_RET] = regs->syscall_nr;
                         regs->pc -= 4;
+                        break;
+
+                case -ERESTART_RESTARTBLOCK:
+                        regs->regs[REG_RET] = __NR_restart_syscall;
+                        regs->pc -= 4;
+                        break;
                 }
         }
+
+        /* No signal to deliver -- put the saved sigmask back */
+        if (test_thread_flag(TIF_RESTORE_SIGMASK)) {
+                clear_thread_flag(TIF_RESTORE_SIGMASK);
+                sigprocmask(SIG_SETMASK, &current->saved_sigmask, NULL);
+        }
+
         return 0;
 }
diff --git a/include/asm-sh64/thread_info.h b/include/asm-sh64/thread_info.h
index 1f825cb163c3..f6d5117c53af 100644
--- a/include/asm-sh64/thread_info.h
+++ b/include/asm-sh64/thread_info.h
@@ -78,7 +78,13 @@ static inline struct thread_info *current_thread_info(void)
 #define TIF_SIGPENDING          2       /* signal pending */
 #define TIF_NEED_RESCHED        3       /* rescheduling necessary */
 #define TIF_MEMDIE              4
+#define TIF_RESTORE_SIGMASK     5       /* Restore signal mask in do_signal */
 
+#define _TIF_SYSCALL_TRACE      (1 << TIF_SYSCALL_TRACE)
+#define _TIF_SIGPENDING         (1 << TIF_SIGPENDING)
+#define _TIF_NEED_RESCHED       (1 << TIF_NEED_RESCHED)
+#define _TIF_MEMDIE             (1 << TIF_MEMDIE)
+#define _TIF_RESTORE_SIGMASK    (1 << TIF_RESTORE_SIGMASK)
 
 #endif /* __KERNEL__ */