[MIPS] Add support for TIF_RESTORE_SIGMASK.

Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

---

arch/mips/kernel/process.c

@@ -58,8 +58,8 @@ ATTRIB_NORET void cpu_idle(void)
 	}
 }
 
-extern int do_signal(sigset_t *oldset, struct pt_regs *regs);
-extern int do_signal32(sigset_t *oldset, struct pt_regs *regs);
+extern int do_signal(struct pt_regs *regs);
+extern int do_signal32(struct pt_regs *regs);
 
 /*
  * Native o32 and N64 ABI without DSP ASE

arch/mips/kernel/signal.c

@@ -39,8 +39,6 @@
 
 #define _BLOCKABLE (~(sigmask(SIGKILL) | sigmask(SIGSTOP)))
 
-int do_signal(sigset_t *oldset, struct pt_regs *regs);
-
 /*
  * Atomically swap in the new signal mask, and wait for a signal.
  */
@@ -50,7 +48,7 @@ save_static_function(sys_sigsuspend);
 __attribute_used__ noinline static int
 _sys_sigsuspend(nabi_no_regargs struct pt_regs regs)
 {
-	sigset_t saveset, newset;
+	sigset_t newset;
 	sigset_t __user *uset;
 
 	uset = (sigset_t __user *) regs.regs[4];
@@ -59,19 +57,15 @@ _sys_sigsuspend(nabi_no_regargs struct pt_regs regs)
 	sigdelsetmask(&newset, ~_BLOCKABLE);
 
 	spin_lock_irq(&current->sighand->siglock);
-	saveset = current->blocked;
+	current->saved_sigmask = current->blocked;
 	current->blocked = newset;
 	recalc_sigpending();
 	spin_unlock_irq(&current->sighand->siglock);
 
-	regs.regs[2] = EINTR;
-	regs.regs[7] = 1;
-	while (1) {
-		current->state = TASK_INTERRUPTIBLE;
-		schedule();
-		if (do_signal(&saveset, &regs))
-			return -EINTR;
-	}
+	current->state = TASK_INTERRUPTIBLE;
+	schedule();
+	set_thread_flag(TIF_RESTORE_SIGMASK);
+	return -ERESTARTNOHAND;
 }
 #endif
 
@@ -79,7 +73,7 @@ save_static_function(sys_rt_sigsuspend);
 __attribute_used__ noinline static int
 _sys_rt_sigsuspend(nabi_no_regargs struct pt_regs regs)
 {
-	sigset_t saveset, newset;
+	sigset_t newset;
 	sigset_t __user *unewset;
 	size_t sigsetsize;
 
@@ -94,19 +88,15 @@ _sys_rt_sigsuspend(nabi_no_regargs struct pt_regs regs)
 	sigdelsetmask(&newset, ~_BLOCKABLE);
 
 	spin_lock_irq(&current->sighand->siglock);
-	saveset = current->blocked;
+	current->saved_sigmask = current->blocked;
 	current->blocked = newset;
         recalc_sigpending();
 	spin_unlock_irq(&current->sighand->siglock);
 
-	regs.regs[2] = EINTR;
-	regs.regs[7] = 1;
-	while (1) {
-		current->state = TASK_INTERRUPTIBLE;
-		schedule();
-		if (do_signal(&saveset, &regs))
-			return -EINTR;
-	}
+	current->state = TASK_INTERRUPTIBLE;
+	schedule();
+	set_thread_flag(TIF_RESTORE_SIGMASK);
+	return -ERESTARTNOHAND;
 }
 
 #ifdef CONFIG_TRAD_SIGNALS
@@ -315,11 +305,11 @@ int setup_frame(struct k_sigaction * ka, struct pt_regs *regs,
 	       current->comm, current->pid,
 	       frame, regs->cp0_epc, frame->regs[31]);
 #endif
-        return 1;
+        return 0;
 
 give_sigsegv:
 	force_sigsegv(signr, current);
-	return 0;
+	return -EFAULT;
 }
 #endif
 
@@ -375,11 +365,11 @@ int setup_rt_frame(struct k_sigaction * ka, struct pt_regs *regs,
 	       current->comm, current->pid,
 	       frame, regs->cp0_epc, regs->regs[31]);
 #endif
-	return 1;
+	return 0;
 
 give_sigsegv:
 	force_sigsegv(signr, current);
-	return 0;
+	return -EFAULT;
 }
 
 static inline int handle_signal(unsigned long sig, siginfo_t *info,
@@ -393,7 +383,7 @@ static inline int handle_signal(unsigned long sig, siginfo_t *info,
 		regs->regs[2] = EINTR;
 		break;
 	case ERESTARTSYS:
-		if(!(ka->sa.sa_flags & SA_RESTART)) {
+		if (!(ka->sa.sa_flags & SA_RESTART)) {
 			regs->regs[2] = EINTR;
 			break;
 		}
@@ -420,9 +410,10 @@ static inline int handle_signal(unsigned long sig, siginfo_t *info,
 	return ret;
 }
 
-int do_signal(sigset_t *oldset, struct pt_regs *regs)
+int do_signal(struct pt_regs *regs)
 {
 	struct k_sigaction ka;
+	sigset_t *oldset;
 	siginfo_t info;
 	int signr;
 
@@ -437,12 +428,26 @@ int do_signal(sigset_t *oldset, struct pt_regs *regs)
 	if (try_to_freeze())
 		goto no_signal;
 
-	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, NULL);
-	if (signr > 0)
-		return handle_signal(signr, &info, &ka, oldset, regs);
+	if (signr > 0) {
+		/* Whee!  Actually deliver the signal.  */
+		if (handle_signal(signr, &info, &ka, oldset, regs) == 0) {
+			/*
+			 * 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);
+		}
+	}
 
 no_signal:
 	/*
@@ -463,18 +468,27 @@ int do_signal(sigset_t *oldset, struct pt_regs *regs)
 			regs->cp0_epc -= 4;
 		}
 	}
+
+	/*
+	 * 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);
+	}
+
 	return 0;
 }
 
 /*
  * notification of userspace execution resumption
- * - triggered by current->work.notify_resume
+ * - triggered by the TIF_WORK_MASK flags
  */
-asmlinkage void do_notify_resume(struct pt_regs *regs, sigset_t *oldset,
+asmlinkage void do_notify_resume(struct pt_regs *regs, void *unused,
 	__u32 thread_info_flags)
 {
 	/* deal with pending signal delivery */
-	if (thread_info_flags & _TIF_SIGPENDING) {
-		current->thread.abi->do_signal(oldset, regs);
-	}
+	if (thread_info_flags & (_TIF_SIGPENDING | _TIF_RESTORE_SIGMASK))
+		current->thread.abi->do_signal(regs);
 }

arch/mips/kernel/signal32.c

@@ -694,11 +694,11 @@ int setup_frame_32(struct k_sigaction * ka, struct pt_regs *regs,
 	       current->comm, current->pid,
 	       frame, regs->cp0_epc, frame->sf_code);
 #endif
-	return 1;
+	return 0;
 
 give_sigsegv:
 	force_sigsegv(signr, current);
-	return 0;
+	return -EFAULT;
 }
 
 int setup_rt_frame_32(struct k_sigaction * ka, struct pt_regs *regs,
@@ -765,11 +765,11 @@ int setup_rt_frame_32(struct k_sigaction * ka, struct pt_regs *regs,
 	       current->comm, current->pid,
 	       frame, regs->cp0_epc, frame->rs_code);
 #endif
-	return 1;
+	return 0;
 
 give_sigsegv:
 	force_sigsegv(signr, current);
-	return 0;
+	return -EFAULT;
 }
 
 static inline int handle_signal(unsigned long sig, siginfo_t *info,

arch/mips/kernel/signal_n32.c

@@ -186,9 +186,9 @@ int setup_rt_frame_n32(struct k_sigaction * ka,
 	       current->comm, current->pid,
 	       frame, regs->cp0_epc, regs->regs[31]);
 #endif
-	return 1;
+	return 0;
 
 give_sigsegv:
 	force_sigsegv(signr, current);
-	return 0;
+	return -EFAULT;
 }

include/asm-mips/abi.h

@@ -3,7 +3,7 @@
  * License.  See the file "COPYING" in the main directory of this archive
  * for more details.
  *
- * Copyright (C) 2005 by Ralf Baechle
+ * Copyright (C) 2005, 06 by Ralf Baechle (ralf@linux-mips.org)
  * Copyright (C) 2005 MIPS Technologies, Inc.
  */
 #ifndef _ASM_ABI_H
@@ -13,7 +13,7 @@
 #include <asm/siginfo.h>
 
 struct mips_abi {
-	int (* const do_signal)(sigset_t *oldset, struct pt_regs *regs);
+	int (* const do_signal)(struct pt_regs *regs);
 	int (* const setup_frame)(struct k_sigaction * ka,
 	                          struct pt_regs *regs, int signr,
 	                          sigset_t *set);

include/asm-mips/thread_info.h

@@ -114,6 +114,7 @@ register struct thread_info *__current_thread_info __asm__("$28");
 #define TIF_NEED_RESCHED	3	/* rescheduling necessary */
 #define TIF_SYSCALL_AUDIT	4	/* syscall auditing active */
 #define TIF_SECCOMP		5	/* secure computing */
+#define TIF_RESTORE_SIGMASK	9	/* restore signal mask in do_signal() */
 #define TIF_USEDFPU		16	/* FPU was used by this task this quantum (SMP) */
 #define TIF_POLLING_NRFLAG	17	/* true if poll_idle() is polling TIF_NEED_RESCHED */
 #define TIF_MEMDIE		18
@@ -125,6 +126,7 @@ register struct thread_info *__current_thread_info __asm__("$28");
 #define _TIF_NEED_RESCHED	(1<<TIF_NEED_RESCHED)
 #define _TIF_SYSCALL_AUDIT	(1<<TIF_SYSCALL_AUDIT)
 #define _TIF_SECCOMP		(1<<TIF_SECCOMP)
+#define _TIF_RESTORE_SIGMASK	(1<<TIF_RESTORE_SIGMASK)
 #define _TIF_USEDFPU		(1<<TIF_USEDFPU)
 #define _TIF_POLLING_NRFLAG	(1<<TIF_POLLING_NRFLAG)