commit b927b3e2c9bc39b7eeeaca91e4cd6c3ed59f165a
author Richard Henderson <rth@twiddle.net> Tue May 29 16:03:28 2007 -0700
committer Linus Torvalds <torvalds@woody.linux-foundation.org> Wed May 30 10:07:54 2007 -0700
tree abdb72c2f2b8ab6cfaa954b558e8c078d04d1a85
parent 74fd1b687fbeba566ceb59cc1fdbc7a64c5e0c0b

alpha: support new syscalls

Some of the new syscalls require supporting TIF_RESTORE_SIGMASK.

Signed-off-by: Richard Henderson <rth@twiddle.net>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

arch/alpha/kernel/signal.c

diff --git a/arch/alpha/kernel/signal.c b/arch/alpha/kernel/signal.c
index 7f64aa7..410af4f 100644
--- a/arch/alpha/kernel/signal.c
+++ b/arch/alpha/kernel/signal.c
@@ -32,8 +32,8 @@
 #define _BLOCKABLE (~(sigmask(SIGKILL) | sigmask(SIGSTOP)))
 
 asmlinkage void ret_from_sys_call(void);
-static int do_signal(sigset_t *, struct pt_regs *, struct switch_stack *,
-		     unsigned long, unsigned long);
+static void do_signal(struct pt_regs *, struct switch_stack *,
+		      unsigned long, unsigned long);
 
 
 /*
@@ -146,11 +146,9 @@
 asmlinkage int
 do_sigsuspend(old_sigset_t mask, struct pt_regs *regs, struct switch_stack *sw)
 {
-	sigset_t oldset;
-
 	mask &= _BLOCKABLE;
 	spin_lock_irq(&current->sighand->siglock);
-	oldset = current->blocked;
+	current->saved_sigmask = current->blocked;
 	siginitset(&current->blocked, mask);
 	recalc_sigpending();
 	spin_unlock_irq(&current->sighand->siglock);
@@ -160,19 +158,17 @@
 	regs->r0 = EINTR;
 	regs->r19 = 1;
 
-	while (1) {
-		current->state = TASK_INTERRUPTIBLE;
-		schedule();
-		if (do_signal(&oldset, regs, sw, 0, 0))
-			return -EINTR;
-	}
+	current->state = TASK_INTERRUPTIBLE;
+	schedule();
+	set_thread_flag(TIF_RESTORE_SIGMASK);
+	return -ERESTARTNOHAND;
 }
 
 asmlinkage int
 do_rt_sigsuspend(sigset_t __user *uset, size_t sigsetsize,
 		 struct pt_regs *regs, struct switch_stack *sw)
 {
-	sigset_t oldset, set;
+	sigset_t set;
 
 	/* XXX: Don't preclude handling different sized sigset_t's.  */
 	if (sigsetsize != sizeof(sigset_t))
@@ -182,7 +178,7 @@
 
 	sigdelsetmask(&set, ~_BLOCKABLE);
 	spin_lock_irq(&current->sighand->siglock);
-	oldset = current->blocked;
+	current->saved_sigmask = current->blocked;
 	current->blocked = set;
 	recalc_sigpending();
 	spin_unlock_irq(&current->sighand->siglock);
@@ -192,12 +188,10 @@
 	regs->r0 = EINTR;
 	regs->r19 = 1;
 
-	while (1) {
-		current->state = TASK_INTERRUPTIBLE;
-		schedule();
-		if (do_signal(&oldset, regs, sw, 0, 0))
-			return -EINTR;
-	}
+	current->state = TASK_INTERRUPTIBLE;
+	schedule();
+	set_thread_flag(TIF_RESTORE_SIGMASK);
+	return -ERESTARTNOHAND;
 }
 
 asmlinkage int
@@ -436,7 +430,7 @@
 	return err;
 }
 
-static void
+static int
 setup_frame(int sig, struct k_sigaction *ka, sigset_t *set,
 	    struct pt_regs *regs, struct switch_stack * sw)
 {
@@ -481,13 +475,14 @@
 		current->comm, current->pid, frame, regs->pc, regs->r26);
 #endif
 
-	return;
+	return 0;
 
 give_sigsegv:
 	force_sigsegv(sig, current);
+	return -EFAULT;
 }
 
-static void
+static int
 setup_rt_frame(int sig, struct k_sigaction *ka, siginfo_t *info,
 	       sigset_t *set, struct pt_regs *regs, struct switch_stack * sw)
 {
@@ -543,34 +538,38 @@
 		current->comm, current->pid, frame, regs->pc, regs->r26);
 #endif
 
-	return;
+	return 0;
 
 give_sigsegv:
 	force_sigsegv(sig, current);
+	return -EFAULT;
 }
 
 
 /*
  * OK, we're invoking a handler.
  */
-static inline void
+static inline int
 handle_signal(int sig, struct k_sigaction *ka, siginfo_t *info,
 	      sigset_t *oldset, struct pt_regs * regs, struct switch_stack *sw)
 {
+	int ret;
+
 	if (ka->sa.sa_flags & SA_SIGINFO)
-		setup_rt_frame(sig, ka, info, oldset, regs, sw);
+		ret = setup_rt_frame(sig, ka, info, oldset, regs, sw);
 	else
-		setup_frame(sig, ka, oldset, regs, sw);
+		ret = setup_frame(sig, ka, oldset, regs, sw);
 
-	if (ka->sa.sa_flags & SA_RESETHAND)
-		ka->sa.sa_handler = SIG_DFL;
+	if (ret == 0) {
+		spin_lock_irq(&current->sighand->siglock);
+		sigorsets(&current->blocked,&current->blocked,&ka->sa.sa_mask);
+		if (!(ka->sa.sa_flags & SA_NODEFER)) 
+			sigaddset(&current->blocked,sig);
+		recalc_sigpending();
+		spin_unlock_irq(&current->sighand->siglock);
+	}
 
-	spin_lock_irq(&current->sighand->siglock);
-	sigorsets(&current->blocked,&current->blocked,&ka->sa.sa_mask);
-	if (!(ka->sa.sa_flags & SA_NODEFER)) 
-		sigaddset(&current->blocked,sig);
-	recalc_sigpending();
-	spin_unlock_irq(&current->sighand->siglock);
+	return ret;
 }
 
 static inline void
@@ -611,30 +610,42 @@
  * restart. "r0" is also used as an indicator whether we can restart at
  * all (if we get here from anything but a syscall return, it will be 0)
  */
-static int
-do_signal(sigset_t *oldset, struct pt_regs * regs, struct switch_stack * sw,
+static void
+do_signal(struct pt_regs * regs, struct switch_stack * sw,
 	  unsigned long r0, unsigned long r19)
 {
 	siginfo_t info;
 	int signr;
 	unsigned long single_stepping = ptrace_cancel_bpt(current);
 	struct k_sigaction ka;
+	sigset_t *oldset;
 
-	if (!oldset)
+	if (test_thread_flag(TIF_RESTORE_SIGMASK))
+		oldset = &current->saved_sigmask;
+	else
 		oldset = &current->blocked;
 
 	/* This lets the debugger run, ... */
 	signr = get_signal_to_deliver(&info, &ka, regs, NULL);
+
 	/* ... so re-check the single stepping. */
 	single_stepping |= ptrace_cancel_bpt(current);
 
 	if (signr > 0) {
 		/* Whee!  Actually deliver the signal.  */
-		if (r0) syscall_restart(r0, r19, regs, &ka);
-		handle_signal(signr, &ka, &info, oldset, regs, sw);
+		if (r0)
+			syscall_restart(r0, r19, regs, &ka);
+		if (handle_signal(signr, &ka, &info, oldset, regs, sw) == 0) {
+			/* A signal was successfully delivered, and the
+			   saved sigmask was stored on the signal frame,
+			   and will be restored by sigreturn.  So we can
+			   simply clear the restore sigmask flag.  */
+			if (test_thread_flag(TIF_RESTORE_SIGMASK))
+				clear_thread_flag(TIF_RESTORE_SIGMASK);
+		}
 		if (single_stepping) 
 			ptrace_set_bpt(current); /* re-set bpt */
-		return 1;
+		return;
 	}
 
 	if (r0) {
@@ -654,17 +665,22 @@
 			break;
 		}
 	}
+
+	/* If there's no signal to deliver, we just restore the saved mask.  */
+	if (test_thread_flag(TIF_RESTORE_SIGMASK)) {
+		clear_thread_flag(TIF_RESTORE_SIGMASK);
+		sigprocmask(SIG_SETMASK, &current->saved_sigmask, NULL);
+	}
+
 	if (single_stepping)
 		ptrace_set_bpt(current);	/* re-set breakpoint */
-
-	return 0;
 }
 
 void
-do_notify_resume(sigset_t *oldset, struct pt_regs *regs,
-		 struct switch_stack *sw, unsigned long r0,
-		 unsigned long r19, unsigned long thread_info_flags)
+do_notify_resume(struct pt_regs *regs, struct switch_stack *sw,
+		 unsigned long thread_info_flags,
+		 unsigned long r0, unsigned long r19)
 {
-	if (thread_info_flags & _TIF_SIGPENDING)
-		do_signal(oldset, regs, sw, r0, r19);
+	if (thread_info_flags & (_TIF_SIGPENDING | _TIF_RESTORE_SIGMASK))
+		do_signal(regs, sw, r0, r19);
 }