From 9ccc9c75c9117d18a9b1f71a21f0066b1eb9db6f Mon Sep 17 00:00:00 2001
From: Al Viro <viro@zeniv.linux.org.uk>
Date: Sun, 22 Apr 2012 00:59:07 -0400
Subject: [PATCH] xtensa: switch to generic rt_sigsuspend(2)

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
---
 arch/xtensa/include/asm/syscall.h |  2 --
 arch/xtensa/include/asm/unistd.h  |  2 +-
 arch/xtensa/kernel/entry.S        |  1 -
 arch/xtensa/kernel/signal.c       | 54 +++++++++++----------------------------
 4 files changed, 16 insertions(+), 43 deletions(-)

diff --git a/arch/xtensa/include/asm/syscall.h b/arch/xtensa/include/asm/syscall.h
index efcf33b..fc289f7 100644
--- a/arch/xtensa/include/asm/syscall.h
+++ b/arch/xtensa/include/asm/syscall.h
@@ -15,8 +15,6 @@ asmlinkage long xtensa_clone(unsigned long, unsigned long, struct pt_regs*);
 asmlinkage long xtensa_ptrace(long, long, long, long);
 asmlinkage long xtensa_sigreturn(struct pt_regs*);
 asmlinkage long xtensa_rt_sigreturn(struct pt_regs*);
-asmlinkage long xtensa_sigsuspend(struct pt_regs*);
-asmlinkage long xtensa_rt_sigsuspend(struct pt_regs*);
 asmlinkage long xtensa_sigaction(int, const struct old_sigaction*,
 				 struct old_sigaction*);
 asmlinkage long xtensa_sigaltstack(struct pt_regs *regs);
diff --git a/arch/xtensa/include/asm/unistd.h b/arch/xtensa/include/asm/unistd.h
index 798ee6d..bc7e005 100644
--- a/arch/xtensa/include/asm/unistd.h
+++ b/arch/xtensa/include/asm/unistd.h
@@ -507,7 +507,7 @@ __SYSCALL(229, sys_rt_sigtimedwait, 4)
 #define __NR_rt_sigqueueinfo 			230
 __SYSCALL(230, sys_rt_sigqueueinfo, 3)
 #define __NR_rt_sigsuspend 			231
-__SYSCALL(231, xtensa_rt_sigsuspend, 2)
+__SYSCALL(231, sys_rt_sigsuspend, 2)
 
 /* Message */
 
diff --git a/arch/xtensa/kernel/entry.S b/arch/xtensa/kernel/entry.S
index 6223f33..b1bb6d7 100644
--- a/arch/xtensa/kernel/entry.S
+++ b/arch/xtensa/kernel/entry.S
@@ -418,7 +418,6 @@ common_exception_return:
 
 	movi	a4, do_signal	# int do_signal(struct pt_regs*, sigset_t*)
 	mov	a6, a1
-	movi	a7, 0
 	callx4	a4
 	j	1b
 
diff --git a/arch/xtensa/kernel/signal.c b/arch/xtensa/kernel/signal.c
index 44e9329..bb00cc4 100644
--- a/arch/xtensa/kernel/signal.c
+++ b/arch/xtensa/kernel/signal.c
@@ -31,8 +31,6 @@
 
 #define _BLOCKABLE (~(sigmask(SIGKILL) | sigmask(SIGSTOP)))
 
-asmlinkage int do_signal(struct pt_regs *regs, sigset_t *oldset);
-
 extern struct task_struct *coproc_owners[];
 
 struct rt_sigframe
@@ -429,37 +427,6 @@ give_sigsegv:
 	return -EFAULT;
 }
 
-/*
- * Atomically swap in the new signal mask, and wait for a signal.
- */
-
-asmlinkage long xtensa_rt_sigsuspend(sigset_t __user *unewset, 
-    				     size_t sigsetsize,
-    				     long a2, long a3, long a4, long a5, 
-				     struct pt_regs *regs)
-{
-	sigset_t saveset, newset;
-
-	/* XXX: Don't preclude handling different sized sigset_t's.  */
-	if (sigsetsize != sizeof(sigset_t))
-		return -EINVAL;
-
-	if (copy_from_user(&newset, unewset, sizeof(newset)))
-		return -EFAULT;
-
-	sigdelsetmask(&newset, ~_BLOCKABLE);
-	saveset = current->blocked;
-	set_current_blocked(&newset);
-
-	regs->areg[2] = -EINTR;
-	while (1) {
-		current->state = TASK_INTERRUPTIBLE;
-		schedule();
-		if (do_signal(regs, &saveset))
-			return -EINTR;
-	}
-}
-
 asmlinkage long xtensa_sigaltstack(const stack_t __user *uss, 
 				   stack_t __user *uoss,
     				   long a2, long a3, long a4, long a5,
@@ -479,19 +446,22 @@ asmlinkage long xtensa_sigaltstack(const stack_t __user *uss,
  * the kernel can handle, and then we build all the user-level signal handling
  * stack-frames in one go after that.
  */
-int do_signal(struct pt_regs *regs, sigset_t *oldset)
+void do_signal(struct pt_regs *regs)
 {
 	siginfo_t info;
 	int signr;
 	struct k_sigaction ka;
+	sigset_t oldset;
 
 	if (!user_mode(regs))
-		return 0;
+		return;
 
 	if (try_to_freeze())
 		goto no_signal;
 
-	if (!oldset)
+	if (test_thread_flag(TIF_RESTORE_SIGMASK))
+		oldset = &current->saved_sigmask;
+	else
 		oldset = &current->blocked;
 
 	task_pt_regs(current)->icountlevel = 0;
@@ -535,13 +505,14 @@ int do_signal(struct pt_regs *regs, sigset_t *oldset)
 		/* Set up the stack frame */
 		ret = setup_frame(signr, &ka, &info, oldset, regs);
 		if (ret)
-			return ret;
+			return;
 
+		clear_thread_flag(TIF_RESTORE_SIGMASK);
 		block_sigmask(&ka, signr);
 		if (current->ptrace & PT_SINGLESTEP)
 			task_pt_regs(current)->icountlevel = 1;
 
-		return 1;
+		return;
 	}
 
 no_signal:
@@ -561,8 +532,13 @@ no_signal:
 			break;
 		}
 	}
+
+	/* If there's no signal to deliver, we just restore the saved mask.  */
+	if (test_and_clear_thread_flag(TIF_RESTORE_SIGMASK))
+		set_current_blocked(&current->saved_sigmask);
+
 	if (current->ptrace & PT_SINGLESTEP)
 		task_pt_regs(current)->icountlevel = 1;
-	return 0;
+	return;
 }
 
-- 
2.7.4