[SPARC]: Add support for *at(), ppoll, and pselect syscalls.

This also includes by necessity _TIF_RESTORE_SIGMASK support,
which actually resulted in a lot of cleanups.

The sparc signal handling code is quite a mess and I should
clean it up some day.

Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 31 insertions, 86 deletions

diff --git a/arch/sparc/kernel/signal.c b/arch/sparc/kernel/signal.c
index 5f34d7dc2b8..0748d8147bb 100644
--- a/arch/sparc/kernel/signal.c
+++ b/arch/sparc/kernel/signal.c
@@ -35,9 +35,6 @@ extern void fpsave(unsigned long *fpregs, unsigned long *fsr,
 		   void *fpqueue, unsigned long *fpqdepth);
 extern void fpload(unsigned long *fpregs, unsigned long *fsr);
 
-asmlinkage int do_signal(sigset_t *oldset, struct pt_regs * regs,
-			 unsigned long orig_o0, int restart_syscall);
-
 /* Signal frames: the original one (compatible with SunOS):
  *
  * Set up a signal frame... Make the stack look the way SunOS
@@ -95,98 +92,30 @@ struct rt_signal_frame {
 #define NF_ALIGNEDSZ  (((sizeof(struct new_signal_frame) + 7) & (~7)))
 #define RT_ALIGNEDSZ  (((sizeof(struct rt_signal_frame) + 7) & (~7)))
 
-/*
- * atomically swap in the new signal mask, and wait for a signal.
- * This is really tricky on the Sparc, watch out...
- */
-asmlinkage void _sigpause_common(old_sigset_t set, struct pt_regs *regs)
+static int _sigpause_common(old_sigset_t set)
 {
-	sigset_t saveset;
-
 	set &= _BLOCKABLE;
 	spin_lock_irq(&current->sighand->siglock);
-	saveset = current->blocked;
+	current->saved_sigmask = current->blocked;
 	siginitset(&current->blocked, set);
 	recalc_sigpending();
 	spin_unlock_irq(&current->sighand->siglock);
 
-	regs->pc = regs->npc;
-	regs->npc += 4;
-
-	/* Condition codes and return value where set here for sigpause,
-	 * and so got used by setup_frame, which again causes sigreturn()
-	 * to return -EINTR.
-	 */
-	while (1) {
-		current->state = TASK_INTERRUPTIBLE;
-		schedule();
-		/*
-		 * Return -EINTR and set condition code here,
-		 * so the interrupted system call actually returns
-		 * these.
-		 */
-		regs->psr |= PSR_C;
-		regs->u_regs[UREG_I0] = EINTR;
-		if (do_signal(&saveset, regs, 0, 0))
-			return;
-	}
-}
+	current->state = TASK_INTERRUPTIBLE;
+	schedule();
+	set_thread_flag(TIF_RESTORE_SIGMASK);
 
-asmlinkage void do_sigpause(unsigned int set, struct pt_regs *regs)
-{
-	_sigpause_common(set, regs);
+	return -ERESTARTNOHAND;
 }
 
-asmlinkage void do_sigsuspend (struct pt_regs *regs)
+asmlinkage int sys_sigpause(unsigned int set)
 {
-	_sigpause_common(regs->u_regs[UREG_I0], regs);
+	return _sigpause_common(set);
 }
 
-asmlinkage void do_rt_sigsuspend(sigset_t __user *uset, size_t sigsetsize,
-				 struct pt_regs *regs)
+asmlinkage int sys_sigsuspend(old_sigset_t set)
 {
-	sigset_t oldset, set;
-
-	/* XXX: Don't preclude handling different sized sigset_t's.  */
-	if (sigsetsize != sizeof(sigset_t)) {
-		regs->psr |= PSR_C;
-		regs->u_regs[UREG_I0] = EINVAL;
-		return;
-	}
-
-	if (copy_from_user(&set, uset, sizeof(set))) {
-		regs->psr |= PSR_C;
-		regs->u_regs[UREG_I0] = EFAULT;
-		return;
-	}
-
-	sigdelsetmask(&set, ~_BLOCKABLE);
-	spin_lock_irq(&current->sighand->siglock);
-	oldset = current->blocked;
-	current->blocked = set;
-	recalc_sigpending();
-	spin_unlock_irq(&current->sighand->siglock);
-
-	regs->pc = regs->npc;
-	regs->npc += 4;
-
-	/* Condition codes and return value where set here for sigpause,
-	 * and so got used by setup_frame, which again causes sigreturn()
-	 * to return -EINTR.
-	 */
-	while (1) {
-		current->state = TASK_INTERRUPTIBLE;
-		schedule();
-		/*
-		 * Return -EINTR and set condition code here,
-		 * so the interrupted system call actually returns
-		 * these.
-		 */
-		regs->psr |= PSR_C;
-		regs->u_regs[UREG_I0] = EINTR;
-		if (do_signal(&oldset, regs, 0, 0))
-			return;
-	}
+	return _sigpause_common(set);
 }
 
 static inline int
@@ -1067,13 +996,13 @@ static inline void syscall_restart(unsigned long orig_i0, struct pt_regs *regs,
  * want to handle. Thus you cannot kill init even with a SIGKILL even by
  * mistake.
  */
-asmlinkage int do_signal(sigset_t *oldset, struct pt_regs * regs,
-			 unsigned long orig_i0, int restart_syscall)
+asmlinkage void do_signal(struct pt_regs * regs, unsigned long orig_i0, int restart_syscall)
 {
 	siginfo_t info;
 	struct sparc_deliver_cookie cookie;
 	struct k_sigaction ka;
 	int signr;
+	sigset_t *oldset;
 
 	/*
 	 * XXX Disable svr4 signal handling until solaris emulation works.
@@ -1089,7 +1018,9 @@ asmlinkage int do_signal(sigset_t *oldset, struct pt_regs * regs,
 	cookie.restart_syscall = restart_syscall;
 	cookie.orig_i0 = orig_i0;
 
-	if (!oldset)
+	if (test_thread_flag(TIF_RESTORE_SIGMASK))
+		oldset = &current->saved_sigmask;
+	else
 		oldset = &current->blocked;
 
 	signr = get_signal_to_deliver(&info, &ka, regs, &cookie);
@@ -1098,7 +1029,14 @@ asmlinkage int do_signal(sigset_t *oldset, struct pt_regs * regs,
 			syscall_restart(cookie.orig_i0, regs, &ka.sa);
 		handle_signal(signr, &ka, &info, oldset,
 			      regs, svr4_signal);
-		return 1;
+		/* a signal was successfully delivered; the saved
+		 * sigmask will have been stored in the signal frame,
+		 * and will be restored by sigreturn, so we can simply
+		 * clear the TIF_RESTORE_SIGMASK flag.
+		 */
+		if (test_thread_flag(TIF_RESTORE_SIGMASK))
+			clear_thread_flag(TIF_RESTORE_SIGMASK);
+		return;
 	}
 	if (cookie.restart_syscall &&
 	    (regs->u_regs[UREG_I0] == ERESTARTNOHAND ||
@@ -1115,7 +1053,14 @@ asmlinkage int do_signal(sigset_t *oldset, struct pt_regs * regs,
 		regs->pc -= 4;
 		regs->npc -= 4;
 	}
-	return 0;
+
+	/* if there's no signal to deliver, we just 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);
+	}
 }
 
 asmlinkage int